16cbd5570SChris Mason /* 2d352ac68SChris Mason * Copyright (C) 2007,2008 Oracle. All rights reserved. 36cbd5570SChris Mason * 46cbd5570SChris Mason * This program is free software; you can redistribute it and/or 56cbd5570SChris Mason * modify it under the terms of the GNU General Public 66cbd5570SChris Mason * License v2 as published by the Free Software Foundation. 76cbd5570SChris Mason * 86cbd5570SChris Mason * This program is distributed in the hope that it will be useful, 96cbd5570SChris Mason * but WITHOUT ANY WARRANTY; without even the implied warranty of 106cbd5570SChris Mason * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 116cbd5570SChris Mason * General Public License for more details. 126cbd5570SChris Mason * 136cbd5570SChris Mason * You should have received a copy of the GNU General Public 146cbd5570SChris Mason * License along with this program; if not, write to the 156cbd5570SChris Mason * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 166cbd5570SChris Mason * Boston, MA 021110-1307, USA. 176cbd5570SChris Mason */ 186cbd5570SChris Mason 19a6b6e75eSChris Mason #include <linux/sched.h> 205a0e3ad6STejun Heo #include <linux/slab.h> 21bd989ba3SJan Schmidt #include <linux/rbtree.h> 22eb60ceacSChris Mason #include "ctree.h" 23eb60ceacSChris Mason #include "disk-io.h" 247f5c1516SChris Mason #include "transaction.h" 255f39d397SChris Mason #include "print-tree.h" 26925baeddSChris Mason #include "locking.h" 279a8dd150SChris Mason 28e089f05cSChris Mason static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root 29e089f05cSChris Mason *root, struct btrfs_path *path, int level); 30e089f05cSChris Mason static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root 31d4dbff95SChris Mason *root, struct btrfs_key *ins_key, 32cc0c5538SChris Mason struct btrfs_path *path, int data_size, int extend); 335f39d397SChris Mason static int push_node_left(struct btrfs_trans_handle *trans, 345f39d397SChris Mason struct btrfs_root *root, struct extent_buffer *dst, 35971a1f66SChris Mason struct extent_buffer *src, int empty); 365f39d397SChris Mason static int balance_node_right(struct btrfs_trans_handle *trans, 375f39d397SChris Mason struct btrfs_root *root, 385f39d397SChris Mason struct extent_buffer *dst_buf, 395f39d397SChris Mason struct extent_buffer *src_buf); 40afe5fea7STsutomu Itoh static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, 41afe5fea7STsutomu Itoh int level, int slot); 425de865eeSFilipe David Borba Manana static int tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, 43f230475eSJan Schmidt struct extent_buffer *eb); 44d97e63b6SChris Mason 452c90e5d6SChris Mason struct btrfs_path *btrfs_alloc_path(void) 462c90e5d6SChris Mason { 47df24a2b9SChris Mason struct btrfs_path *path; 48e00f7308SJeff Mahoney path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); 49df24a2b9SChris Mason return path; 502c90e5d6SChris Mason } 512c90e5d6SChris Mason 52b4ce94deSChris Mason /* 53b4ce94deSChris Mason * set all locked nodes in the path to blocking locks. This should 54b4ce94deSChris Mason * be done before scheduling 55b4ce94deSChris Mason */ 56b4ce94deSChris Mason noinline void btrfs_set_path_blocking(struct btrfs_path *p) 57b4ce94deSChris Mason { 58b4ce94deSChris Mason int i; 59b4ce94deSChris Mason for (i = 0; i < BTRFS_MAX_LEVEL; i++) { 60bd681513SChris Mason if (!p->nodes[i] || !p->locks[i]) 61bd681513SChris Mason continue; 62bd681513SChris Mason btrfs_set_lock_blocking_rw(p->nodes[i], p->locks[i]); 63bd681513SChris Mason if (p->locks[i] == BTRFS_READ_LOCK) 64bd681513SChris Mason p->locks[i] = BTRFS_READ_LOCK_BLOCKING; 65bd681513SChris Mason else if (p->locks[i] == BTRFS_WRITE_LOCK) 66bd681513SChris Mason p->locks[i] = BTRFS_WRITE_LOCK_BLOCKING; 67b4ce94deSChris Mason } 68b4ce94deSChris Mason } 69b4ce94deSChris Mason 70b4ce94deSChris Mason /* 71b4ce94deSChris Mason * reset all the locked nodes in the patch to spinning locks. 724008c04aSChris Mason * 734008c04aSChris Mason * held is used to keep lockdep happy, when lockdep is enabled 744008c04aSChris Mason * we set held to a blocking lock before we go around and 754008c04aSChris Mason * retake all the spinlocks in the path. You can safely use NULL 764008c04aSChris Mason * for held 77b4ce94deSChris Mason */ 784008c04aSChris Mason noinline void btrfs_clear_path_blocking(struct btrfs_path *p, 79bd681513SChris Mason struct extent_buffer *held, int held_rw) 80b4ce94deSChris Mason { 81b4ce94deSChris Mason int i; 824008c04aSChris Mason 83bd681513SChris Mason if (held) { 84bd681513SChris Mason btrfs_set_lock_blocking_rw(held, held_rw); 85bd681513SChris Mason if (held_rw == BTRFS_WRITE_LOCK) 86bd681513SChris Mason held_rw = BTRFS_WRITE_LOCK_BLOCKING; 87bd681513SChris Mason else if (held_rw == BTRFS_READ_LOCK) 88bd681513SChris Mason held_rw = BTRFS_READ_LOCK_BLOCKING; 89bd681513SChris Mason } 904008c04aSChris Mason btrfs_set_path_blocking(p); 914008c04aSChris Mason 924008c04aSChris Mason for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) { 93bd681513SChris Mason if (p->nodes[i] && p->locks[i]) { 94bd681513SChris Mason btrfs_clear_lock_blocking_rw(p->nodes[i], p->locks[i]); 95bd681513SChris Mason if (p->locks[i] == BTRFS_WRITE_LOCK_BLOCKING) 96bd681513SChris Mason p->locks[i] = BTRFS_WRITE_LOCK; 97bd681513SChris Mason else if (p->locks[i] == BTRFS_READ_LOCK_BLOCKING) 98bd681513SChris Mason p->locks[i] = BTRFS_READ_LOCK; 99bd681513SChris Mason } 100b4ce94deSChris Mason } 1014008c04aSChris Mason 1024008c04aSChris Mason if (held) 103bd681513SChris Mason btrfs_clear_lock_blocking_rw(held, held_rw); 104b4ce94deSChris Mason } 105b4ce94deSChris Mason 106d352ac68SChris Mason /* this also releases the path */ 1072c90e5d6SChris Mason void btrfs_free_path(struct btrfs_path *p) 1082c90e5d6SChris Mason { 109ff175d57SJesper Juhl if (!p) 110ff175d57SJesper Juhl return; 111b3b4aa74SDavid Sterba btrfs_release_path(p); 1122c90e5d6SChris Mason kmem_cache_free(btrfs_path_cachep, p); 1132c90e5d6SChris Mason } 1142c90e5d6SChris Mason 115d352ac68SChris Mason /* 116d352ac68SChris Mason * path release drops references on the extent buffers in the path 117d352ac68SChris Mason * and it drops any locks held by this path 118d352ac68SChris Mason * 119d352ac68SChris Mason * It is safe to call this on paths that no locks or extent buffers held. 120d352ac68SChris Mason */ 121b3b4aa74SDavid Sterba noinline void btrfs_release_path(struct btrfs_path *p) 122eb60ceacSChris Mason { 123eb60ceacSChris Mason int i; 124a2135011SChris Mason 125234b63a0SChris Mason for (i = 0; i < BTRFS_MAX_LEVEL; i++) { 1263f157a2fSChris Mason p->slots[i] = 0; 127eb60ceacSChris Mason if (!p->nodes[i]) 128925baeddSChris Mason continue; 129925baeddSChris Mason if (p->locks[i]) { 130bd681513SChris Mason btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); 131925baeddSChris Mason p->locks[i] = 0; 132925baeddSChris Mason } 1335f39d397SChris Mason free_extent_buffer(p->nodes[i]); 1343f157a2fSChris Mason p->nodes[i] = NULL; 135eb60ceacSChris Mason } 136eb60ceacSChris Mason } 137eb60ceacSChris Mason 138d352ac68SChris Mason /* 139d352ac68SChris Mason * safely gets a reference on the root node of a tree. A lock 140d352ac68SChris Mason * is not taken, so a concurrent writer may put a different node 141d352ac68SChris Mason * at the root of the tree. See btrfs_lock_root_node for the 142d352ac68SChris Mason * looping required. 143d352ac68SChris Mason * 144d352ac68SChris Mason * The extent buffer returned by this has a reference taken, so 145d352ac68SChris Mason * it won't disappear. It may stop being the root of the tree 146d352ac68SChris Mason * at any time because there are no locks held. 147d352ac68SChris Mason */ 148925baeddSChris Mason struct extent_buffer *btrfs_root_node(struct btrfs_root *root) 149925baeddSChris Mason { 150925baeddSChris Mason struct extent_buffer *eb; 151240f62c8SChris Mason 1523083ee2eSJosef Bacik while (1) { 153240f62c8SChris Mason rcu_read_lock(); 154240f62c8SChris Mason eb = rcu_dereference(root->node); 1553083ee2eSJosef Bacik 1563083ee2eSJosef Bacik /* 1573083ee2eSJosef Bacik * RCU really hurts here, we could free up the root node because 1583083ee2eSJosef Bacik * it was cow'ed but we may not get the new root node yet so do 1593083ee2eSJosef Bacik * the inc_not_zero dance and if it doesn't work then 1603083ee2eSJosef Bacik * synchronize_rcu and try again. 1613083ee2eSJosef Bacik */ 1623083ee2eSJosef Bacik if (atomic_inc_not_zero(&eb->refs)) { 163240f62c8SChris Mason rcu_read_unlock(); 1643083ee2eSJosef Bacik break; 1653083ee2eSJosef Bacik } 1663083ee2eSJosef Bacik rcu_read_unlock(); 1673083ee2eSJosef Bacik synchronize_rcu(); 1683083ee2eSJosef Bacik } 169925baeddSChris Mason return eb; 170925baeddSChris Mason } 171925baeddSChris Mason 172d352ac68SChris Mason /* loop around taking references on and locking the root node of the 173d352ac68SChris Mason * tree until you end up with a lock on the root. A locked buffer 174d352ac68SChris Mason * is returned, with a reference held. 175d352ac68SChris Mason */ 176925baeddSChris Mason struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) 177925baeddSChris Mason { 178925baeddSChris Mason struct extent_buffer *eb; 179925baeddSChris Mason 180925baeddSChris Mason while (1) { 181925baeddSChris Mason eb = btrfs_root_node(root); 182925baeddSChris Mason btrfs_tree_lock(eb); 183240f62c8SChris Mason if (eb == root->node) 184925baeddSChris Mason break; 185925baeddSChris Mason btrfs_tree_unlock(eb); 186925baeddSChris Mason free_extent_buffer(eb); 187925baeddSChris Mason } 188925baeddSChris Mason return eb; 189925baeddSChris Mason } 190925baeddSChris Mason 191bd681513SChris Mason /* loop around taking references on and locking the root node of the 192bd681513SChris Mason * tree until you end up with a lock on the root. A locked buffer 193bd681513SChris Mason * is returned, with a reference held. 194bd681513SChris Mason */ 19548a3b636SEric Sandeen static struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root) 196bd681513SChris Mason { 197bd681513SChris Mason struct extent_buffer *eb; 198bd681513SChris Mason 199bd681513SChris Mason while (1) { 200bd681513SChris Mason eb = btrfs_root_node(root); 201bd681513SChris Mason btrfs_tree_read_lock(eb); 202bd681513SChris Mason if (eb == root->node) 203bd681513SChris Mason break; 204bd681513SChris Mason btrfs_tree_read_unlock(eb); 205bd681513SChris Mason free_extent_buffer(eb); 206bd681513SChris Mason } 207bd681513SChris Mason return eb; 208bd681513SChris Mason } 209bd681513SChris Mason 210d352ac68SChris Mason /* cowonly root (everything not a reference counted cow subvolume), just get 211d352ac68SChris Mason * put onto a simple dirty list. transaction.c walks this to make sure they 212d352ac68SChris Mason * get properly updated on disk. 213d352ac68SChris Mason */ 2140b86a832SChris Mason static void add_root_to_dirty_list(struct btrfs_root *root) 2150b86a832SChris Mason { 216e7070be1SJosef Bacik if (test_bit(BTRFS_ROOT_DIRTY, &root->state) || 217e7070be1SJosef Bacik !test_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state)) 218e7070be1SJosef Bacik return; 219e7070be1SJosef Bacik 220e5846fc6SChris Mason spin_lock(&root->fs_info->trans_lock); 221e7070be1SJosef Bacik if (!test_and_set_bit(BTRFS_ROOT_DIRTY, &root->state)) { 222e7070be1SJosef Bacik /* Want the extent tree to be the last on the list */ 223e7070be1SJosef Bacik if (root->objectid == BTRFS_EXTENT_TREE_OBJECTID) 224e7070be1SJosef Bacik list_move_tail(&root->dirty_list, 225e7070be1SJosef Bacik &root->fs_info->dirty_cowonly_roots); 226e7070be1SJosef Bacik else 227e7070be1SJosef Bacik list_move(&root->dirty_list, 2280b86a832SChris Mason &root->fs_info->dirty_cowonly_roots); 2290b86a832SChris Mason } 230e5846fc6SChris Mason spin_unlock(&root->fs_info->trans_lock); 2310b86a832SChris Mason } 2320b86a832SChris Mason 233d352ac68SChris Mason /* 234d352ac68SChris Mason * used by snapshot creation to make a copy of a root for a tree with 235d352ac68SChris Mason * a given objectid. The buffer with the new root node is returned in 236d352ac68SChris Mason * cow_ret, and this func returns zero on success or a negative error code. 237d352ac68SChris Mason */ 238be20aa9dSChris Mason int btrfs_copy_root(struct btrfs_trans_handle *trans, 239be20aa9dSChris Mason struct btrfs_root *root, 240be20aa9dSChris Mason struct extent_buffer *buf, 241be20aa9dSChris Mason struct extent_buffer **cow_ret, u64 new_root_objectid) 242be20aa9dSChris Mason { 243be20aa9dSChris Mason struct extent_buffer *cow; 244be20aa9dSChris Mason int ret = 0; 245be20aa9dSChris Mason int level; 2465d4f98a2SYan Zheng struct btrfs_disk_key disk_key; 247be20aa9dSChris Mason 24827cdeb70SMiao Xie WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && 24927cdeb70SMiao Xie trans->transid != root->fs_info->running_transaction->transid); 25027cdeb70SMiao Xie WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && 25127cdeb70SMiao Xie trans->transid != root->last_trans); 252be20aa9dSChris Mason 253be20aa9dSChris Mason level = btrfs_header_level(buf); 2545d4f98a2SYan Zheng if (level == 0) 2555d4f98a2SYan Zheng btrfs_item_key(buf, &disk_key, 0); 2565d4f98a2SYan Zheng else 2575d4f98a2SYan Zheng btrfs_node_key(buf, &disk_key, 0); 25831840ae1SZheng Yan 2594d75f8a9SDavid Sterba cow = btrfs_alloc_tree_block(trans, root, 0, new_root_objectid, 2604d75f8a9SDavid Sterba &disk_key, level, buf->start, 0); 2615d4f98a2SYan Zheng if (IS_ERR(cow)) 262be20aa9dSChris Mason return PTR_ERR(cow); 263be20aa9dSChris Mason 264be20aa9dSChris Mason copy_extent_buffer(cow, buf, 0, 0, cow->len); 265be20aa9dSChris Mason btrfs_set_header_bytenr(cow, cow->start); 266be20aa9dSChris Mason btrfs_set_header_generation(cow, trans->transid); 2675d4f98a2SYan Zheng btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); 2685d4f98a2SYan Zheng btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | 2695d4f98a2SYan Zheng BTRFS_HEADER_FLAG_RELOC); 2705d4f98a2SYan Zheng if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) 2715d4f98a2SYan Zheng btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); 2725d4f98a2SYan Zheng else 273be20aa9dSChris Mason btrfs_set_header_owner(cow, new_root_objectid); 274be20aa9dSChris Mason 2750a4e5586SRoss Kirk write_extent_buffer(cow, root->fs_info->fsid, btrfs_header_fsid(), 2762b82032cSYan Zheng BTRFS_FSID_SIZE); 2772b82032cSYan Zheng 278be20aa9dSChris Mason WARN_ON(btrfs_header_generation(buf) > trans->transid); 2795d4f98a2SYan Zheng if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) 280e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 1); 2815d4f98a2SYan Zheng else 282e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 0); 2834aec2b52SChris Mason 284be20aa9dSChris Mason if (ret) 285be20aa9dSChris Mason return ret; 286be20aa9dSChris Mason 287be20aa9dSChris Mason btrfs_mark_buffer_dirty(cow); 288be20aa9dSChris Mason *cow_ret = cow; 289be20aa9dSChris Mason return 0; 290be20aa9dSChris Mason } 291be20aa9dSChris Mason 292bd989ba3SJan Schmidt enum mod_log_op { 293bd989ba3SJan Schmidt MOD_LOG_KEY_REPLACE, 294bd989ba3SJan Schmidt MOD_LOG_KEY_ADD, 295bd989ba3SJan Schmidt MOD_LOG_KEY_REMOVE, 296bd989ba3SJan Schmidt MOD_LOG_KEY_REMOVE_WHILE_FREEING, 297bd989ba3SJan Schmidt MOD_LOG_KEY_REMOVE_WHILE_MOVING, 298bd989ba3SJan Schmidt MOD_LOG_MOVE_KEYS, 299bd989ba3SJan Schmidt MOD_LOG_ROOT_REPLACE, 300bd989ba3SJan Schmidt }; 301bd989ba3SJan Schmidt 302bd989ba3SJan Schmidt struct tree_mod_move { 303bd989ba3SJan Schmidt int dst_slot; 304bd989ba3SJan Schmidt int nr_items; 305bd989ba3SJan Schmidt }; 306bd989ba3SJan Schmidt 307bd989ba3SJan Schmidt struct tree_mod_root { 308bd989ba3SJan Schmidt u64 logical; 309bd989ba3SJan Schmidt u8 level; 310bd989ba3SJan Schmidt }; 311bd989ba3SJan Schmidt 312bd989ba3SJan Schmidt struct tree_mod_elem { 313bd989ba3SJan Schmidt struct rb_node node; 314bd989ba3SJan Schmidt u64 index; /* shifted logical */ 315097b8a7cSJan Schmidt u64 seq; 316bd989ba3SJan Schmidt enum mod_log_op op; 317bd989ba3SJan Schmidt 318bd989ba3SJan Schmidt /* this is used for MOD_LOG_KEY_* and MOD_LOG_MOVE_KEYS operations */ 319bd989ba3SJan Schmidt int slot; 320bd989ba3SJan Schmidt 321bd989ba3SJan Schmidt /* this is used for MOD_LOG_KEY* and MOD_LOG_ROOT_REPLACE */ 322bd989ba3SJan Schmidt u64 generation; 323bd989ba3SJan Schmidt 324bd989ba3SJan Schmidt /* those are used for op == MOD_LOG_KEY_{REPLACE,REMOVE} */ 325bd989ba3SJan Schmidt struct btrfs_disk_key key; 326bd989ba3SJan Schmidt u64 blockptr; 327bd989ba3SJan Schmidt 328bd989ba3SJan Schmidt /* this is used for op == MOD_LOG_MOVE_KEYS */ 329bd989ba3SJan Schmidt struct tree_mod_move move; 330bd989ba3SJan Schmidt 331bd989ba3SJan Schmidt /* this is used for op == MOD_LOG_ROOT_REPLACE */ 332bd989ba3SJan Schmidt struct tree_mod_root old_root; 333bd989ba3SJan Schmidt }; 334bd989ba3SJan Schmidt 335097b8a7cSJan Schmidt static inline void tree_mod_log_read_lock(struct btrfs_fs_info *fs_info) 336bd989ba3SJan Schmidt { 337097b8a7cSJan Schmidt read_lock(&fs_info->tree_mod_log_lock); 338bd989ba3SJan Schmidt } 339bd989ba3SJan Schmidt 340097b8a7cSJan Schmidt static inline void tree_mod_log_read_unlock(struct btrfs_fs_info *fs_info) 341097b8a7cSJan Schmidt { 342097b8a7cSJan Schmidt read_unlock(&fs_info->tree_mod_log_lock); 343097b8a7cSJan Schmidt } 344097b8a7cSJan Schmidt 345097b8a7cSJan Schmidt static inline void tree_mod_log_write_lock(struct btrfs_fs_info *fs_info) 346097b8a7cSJan Schmidt { 347097b8a7cSJan Schmidt write_lock(&fs_info->tree_mod_log_lock); 348097b8a7cSJan Schmidt } 349097b8a7cSJan Schmidt 350097b8a7cSJan Schmidt static inline void tree_mod_log_write_unlock(struct btrfs_fs_info *fs_info) 351097b8a7cSJan Schmidt { 352097b8a7cSJan Schmidt write_unlock(&fs_info->tree_mod_log_lock); 353097b8a7cSJan Schmidt } 354097b8a7cSJan Schmidt 355097b8a7cSJan Schmidt /* 356fcebe456SJosef Bacik * Pull a new tree mod seq number for our operation. 357fc36ed7eSJan Schmidt */ 358fcebe456SJosef Bacik static inline u64 btrfs_inc_tree_mod_seq(struct btrfs_fs_info *fs_info) 359fc36ed7eSJan Schmidt { 360fc36ed7eSJan Schmidt return atomic64_inc_return(&fs_info->tree_mod_seq); 361fc36ed7eSJan Schmidt } 362fc36ed7eSJan Schmidt 363fc36ed7eSJan Schmidt /* 364097b8a7cSJan Schmidt * This adds a new blocker to the tree mod log's blocker list if the @elem 365097b8a7cSJan Schmidt * passed does not already have a sequence number set. So when a caller expects 366097b8a7cSJan Schmidt * to record tree modifications, it should ensure to set elem->seq to zero 367097b8a7cSJan Schmidt * before calling btrfs_get_tree_mod_seq. 368097b8a7cSJan Schmidt * Returns a fresh, unused tree log modification sequence number, even if no new 369097b8a7cSJan Schmidt * blocker was added. 370097b8a7cSJan Schmidt */ 371097b8a7cSJan Schmidt u64 btrfs_get_tree_mod_seq(struct btrfs_fs_info *fs_info, 372bd989ba3SJan Schmidt struct seq_list *elem) 373bd989ba3SJan Schmidt { 374097b8a7cSJan Schmidt tree_mod_log_write_lock(fs_info); 375bd989ba3SJan Schmidt spin_lock(&fs_info->tree_mod_seq_lock); 376097b8a7cSJan Schmidt if (!elem->seq) { 377fcebe456SJosef Bacik elem->seq = btrfs_inc_tree_mod_seq(fs_info); 378097b8a7cSJan Schmidt list_add_tail(&elem->list, &fs_info->tree_mod_seq_list); 379097b8a7cSJan Schmidt } 380bd989ba3SJan Schmidt spin_unlock(&fs_info->tree_mod_seq_lock); 381097b8a7cSJan Schmidt tree_mod_log_write_unlock(fs_info); 382097b8a7cSJan Schmidt 383fcebe456SJosef Bacik return elem->seq; 384bd989ba3SJan Schmidt } 385bd989ba3SJan Schmidt 386bd989ba3SJan Schmidt void btrfs_put_tree_mod_seq(struct btrfs_fs_info *fs_info, 387bd989ba3SJan Schmidt struct seq_list *elem) 388bd989ba3SJan Schmidt { 389bd989ba3SJan Schmidt struct rb_root *tm_root; 390bd989ba3SJan Schmidt struct rb_node *node; 391bd989ba3SJan Schmidt struct rb_node *next; 392bd989ba3SJan Schmidt struct seq_list *cur_elem; 393bd989ba3SJan Schmidt struct tree_mod_elem *tm; 394bd989ba3SJan Schmidt u64 min_seq = (u64)-1; 395bd989ba3SJan Schmidt u64 seq_putting = elem->seq; 396bd989ba3SJan Schmidt 397bd989ba3SJan Schmidt if (!seq_putting) 398bd989ba3SJan Schmidt return; 399bd989ba3SJan Schmidt 400bd989ba3SJan Schmidt spin_lock(&fs_info->tree_mod_seq_lock); 401bd989ba3SJan Schmidt list_del(&elem->list); 402097b8a7cSJan Schmidt elem->seq = 0; 403bd989ba3SJan Schmidt 404bd989ba3SJan Schmidt list_for_each_entry(cur_elem, &fs_info->tree_mod_seq_list, list) { 405097b8a7cSJan Schmidt if (cur_elem->seq < min_seq) { 406bd989ba3SJan Schmidt if (seq_putting > cur_elem->seq) { 407bd989ba3SJan Schmidt /* 408bd989ba3SJan Schmidt * blocker with lower sequence number exists, we 409bd989ba3SJan Schmidt * cannot remove anything from the log 410bd989ba3SJan Schmidt */ 411097b8a7cSJan Schmidt spin_unlock(&fs_info->tree_mod_seq_lock); 412097b8a7cSJan Schmidt return; 413bd989ba3SJan Schmidt } 414bd989ba3SJan Schmidt min_seq = cur_elem->seq; 415bd989ba3SJan Schmidt } 416bd989ba3SJan Schmidt } 417097b8a7cSJan Schmidt spin_unlock(&fs_info->tree_mod_seq_lock); 418097b8a7cSJan Schmidt 419097b8a7cSJan Schmidt /* 420bd989ba3SJan Schmidt * anything that's lower than the lowest existing (read: blocked) 421bd989ba3SJan Schmidt * sequence number can be removed from the tree. 422bd989ba3SJan Schmidt */ 423097b8a7cSJan Schmidt tree_mod_log_write_lock(fs_info); 424bd989ba3SJan Schmidt tm_root = &fs_info->tree_mod_log; 425bd989ba3SJan Schmidt for (node = rb_first(tm_root); node; node = next) { 426bd989ba3SJan Schmidt next = rb_next(node); 427bd989ba3SJan Schmidt tm = container_of(node, struct tree_mod_elem, node); 428097b8a7cSJan Schmidt if (tm->seq > min_seq) 429bd989ba3SJan Schmidt continue; 430bd989ba3SJan Schmidt rb_erase(node, tm_root); 431bd989ba3SJan Schmidt kfree(tm); 432bd989ba3SJan Schmidt } 433097b8a7cSJan Schmidt tree_mod_log_write_unlock(fs_info); 434bd989ba3SJan Schmidt } 435bd989ba3SJan Schmidt 436bd989ba3SJan Schmidt /* 437bd989ba3SJan Schmidt * key order of the log: 438bd989ba3SJan Schmidt * index -> sequence 439bd989ba3SJan Schmidt * 440bd989ba3SJan Schmidt * the index is the shifted logical of the *new* root node for root replace 441bd989ba3SJan Schmidt * operations, or the shifted logical of the affected block for all other 442bd989ba3SJan Schmidt * operations. 4435de865eeSFilipe David Borba Manana * 4445de865eeSFilipe David Borba Manana * Note: must be called with write lock (tree_mod_log_write_lock). 445bd989ba3SJan Schmidt */ 446bd989ba3SJan Schmidt static noinline int 447bd989ba3SJan Schmidt __tree_mod_log_insert(struct btrfs_fs_info *fs_info, struct tree_mod_elem *tm) 448bd989ba3SJan Schmidt { 449bd989ba3SJan Schmidt struct rb_root *tm_root; 450bd989ba3SJan Schmidt struct rb_node **new; 451bd989ba3SJan Schmidt struct rb_node *parent = NULL; 452bd989ba3SJan Schmidt struct tree_mod_elem *cur; 453bd989ba3SJan Schmidt 454c8cc6341SJosef Bacik BUG_ON(!tm); 455c8cc6341SJosef Bacik 456fcebe456SJosef Bacik tm->seq = btrfs_inc_tree_mod_seq(fs_info); 457bd989ba3SJan Schmidt 458bd989ba3SJan Schmidt tm_root = &fs_info->tree_mod_log; 459bd989ba3SJan Schmidt new = &tm_root->rb_node; 460bd989ba3SJan Schmidt while (*new) { 461bd989ba3SJan Schmidt cur = container_of(*new, struct tree_mod_elem, node); 462bd989ba3SJan Schmidt parent = *new; 463bd989ba3SJan Schmidt if (cur->index < tm->index) 464bd989ba3SJan Schmidt new = &((*new)->rb_left); 465bd989ba3SJan Schmidt else if (cur->index > tm->index) 466bd989ba3SJan Schmidt new = &((*new)->rb_right); 467097b8a7cSJan Schmidt else if (cur->seq < tm->seq) 468bd989ba3SJan Schmidt new = &((*new)->rb_left); 469097b8a7cSJan Schmidt else if (cur->seq > tm->seq) 470bd989ba3SJan Schmidt new = &((*new)->rb_right); 4715de865eeSFilipe David Borba Manana else 4725de865eeSFilipe David Borba Manana return -EEXIST; 473bd989ba3SJan Schmidt } 474bd989ba3SJan Schmidt 475bd989ba3SJan Schmidt rb_link_node(&tm->node, parent, new); 476bd989ba3SJan Schmidt rb_insert_color(&tm->node, tm_root); 4775de865eeSFilipe David Borba Manana return 0; 478bd989ba3SJan Schmidt } 479bd989ba3SJan Schmidt 480097b8a7cSJan Schmidt /* 481097b8a7cSJan Schmidt * Determines if logging can be omitted. Returns 1 if it can. Otherwise, it 482097b8a7cSJan Schmidt * returns zero with the tree_mod_log_lock acquired. The caller must hold 483097b8a7cSJan Schmidt * this until all tree mod log insertions are recorded in the rb tree and then 484097b8a7cSJan Schmidt * call tree_mod_log_write_unlock() to release. 485097b8a7cSJan Schmidt */ 486e9b7fd4dSJan Schmidt static inline int tree_mod_dont_log(struct btrfs_fs_info *fs_info, 487e9b7fd4dSJan Schmidt struct extent_buffer *eb) { 488e9b7fd4dSJan Schmidt smp_mb(); 489e9b7fd4dSJan Schmidt if (list_empty(&(fs_info)->tree_mod_seq_list)) 490e9b7fd4dSJan Schmidt return 1; 491097b8a7cSJan Schmidt if (eb && btrfs_header_level(eb) == 0) 492e9b7fd4dSJan Schmidt return 1; 4935de865eeSFilipe David Borba Manana 4945de865eeSFilipe David Borba Manana tree_mod_log_write_lock(fs_info); 4955de865eeSFilipe David Borba Manana if (list_empty(&(fs_info)->tree_mod_seq_list)) { 4965de865eeSFilipe David Borba Manana tree_mod_log_write_unlock(fs_info); 4975de865eeSFilipe David Borba Manana return 1; 4985de865eeSFilipe David Borba Manana } 4995de865eeSFilipe David Borba Manana 500e9b7fd4dSJan Schmidt return 0; 501e9b7fd4dSJan Schmidt } 502e9b7fd4dSJan Schmidt 5035de865eeSFilipe David Borba Manana /* Similar to tree_mod_dont_log, but doesn't acquire any locks. */ 5045de865eeSFilipe David Borba Manana static inline int tree_mod_need_log(const struct btrfs_fs_info *fs_info, 5055de865eeSFilipe David Borba Manana struct extent_buffer *eb) 5065de865eeSFilipe David Borba Manana { 5075de865eeSFilipe David Borba Manana smp_mb(); 5085de865eeSFilipe David Borba Manana if (list_empty(&(fs_info)->tree_mod_seq_list)) 5095de865eeSFilipe David Borba Manana return 0; 5105de865eeSFilipe David Borba Manana if (eb && btrfs_header_level(eb) == 0) 5115de865eeSFilipe David Borba Manana return 0; 5125de865eeSFilipe David Borba Manana 5135de865eeSFilipe David Borba Manana return 1; 5145de865eeSFilipe David Borba Manana } 5155de865eeSFilipe David Borba Manana 5165de865eeSFilipe David Borba Manana static struct tree_mod_elem * 5175de865eeSFilipe David Borba Manana alloc_tree_mod_elem(struct extent_buffer *eb, int slot, 518bd989ba3SJan Schmidt enum mod_log_op op, gfp_t flags) 519bd989ba3SJan Schmidt { 520097b8a7cSJan Schmidt struct tree_mod_elem *tm; 521bd989ba3SJan Schmidt 522c8cc6341SJosef Bacik tm = kzalloc(sizeof(*tm), flags); 523c8cc6341SJosef Bacik if (!tm) 5245de865eeSFilipe David Borba Manana return NULL; 525bd989ba3SJan Schmidt 526bd989ba3SJan Schmidt tm->index = eb->start >> PAGE_CACHE_SHIFT; 527bd989ba3SJan Schmidt if (op != MOD_LOG_KEY_ADD) { 528bd989ba3SJan Schmidt btrfs_node_key(eb, &tm->key, slot); 529bd989ba3SJan Schmidt tm->blockptr = btrfs_node_blockptr(eb, slot); 530bd989ba3SJan Schmidt } 531bd989ba3SJan Schmidt tm->op = op; 532bd989ba3SJan Schmidt tm->slot = slot; 533bd989ba3SJan Schmidt tm->generation = btrfs_node_ptr_generation(eb, slot); 5345de865eeSFilipe David Borba Manana RB_CLEAR_NODE(&tm->node); 535bd989ba3SJan Schmidt 5365de865eeSFilipe David Borba Manana return tm; 537097b8a7cSJan Schmidt } 538097b8a7cSJan Schmidt 539097b8a7cSJan Schmidt static noinline int 540c8cc6341SJosef Bacik tree_mod_log_insert_key(struct btrfs_fs_info *fs_info, 541097b8a7cSJan Schmidt struct extent_buffer *eb, int slot, 542097b8a7cSJan Schmidt enum mod_log_op op, gfp_t flags) 543097b8a7cSJan Schmidt { 5445de865eeSFilipe David Borba Manana struct tree_mod_elem *tm; 5455de865eeSFilipe David Borba Manana int ret; 5465de865eeSFilipe David Borba Manana 5475de865eeSFilipe David Borba Manana if (!tree_mod_need_log(fs_info, eb)) 548097b8a7cSJan Schmidt return 0; 549097b8a7cSJan Schmidt 5505de865eeSFilipe David Borba Manana tm = alloc_tree_mod_elem(eb, slot, op, flags); 5515de865eeSFilipe David Borba Manana if (!tm) 5525de865eeSFilipe David Borba Manana return -ENOMEM; 5535de865eeSFilipe David Borba Manana 5545de865eeSFilipe David Borba Manana if (tree_mod_dont_log(fs_info, eb)) { 5555de865eeSFilipe David Borba Manana kfree(tm); 5565de865eeSFilipe David Borba Manana return 0; 5575de865eeSFilipe David Borba Manana } 5585de865eeSFilipe David Borba Manana 5595de865eeSFilipe David Borba Manana ret = __tree_mod_log_insert(fs_info, tm); 5605de865eeSFilipe David Borba Manana tree_mod_log_write_unlock(fs_info); 5615de865eeSFilipe David Borba Manana if (ret) 5625de865eeSFilipe David Borba Manana kfree(tm); 5635de865eeSFilipe David Borba Manana 5645de865eeSFilipe David Borba Manana return ret; 565097b8a7cSJan Schmidt } 566097b8a7cSJan Schmidt 567097b8a7cSJan Schmidt static noinline int 568bd989ba3SJan Schmidt tree_mod_log_insert_move(struct btrfs_fs_info *fs_info, 569bd989ba3SJan Schmidt struct extent_buffer *eb, int dst_slot, int src_slot, 570bd989ba3SJan Schmidt int nr_items, gfp_t flags) 571bd989ba3SJan Schmidt { 5725de865eeSFilipe David Borba Manana struct tree_mod_elem *tm = NULL; 5735de865eeSFilipe David Borba Manana struct tree_mod_elem **tm_list = NULL; 5745de865eeSFilipe David Borba Manana int ret = 0; 575bd989ba3SJan Schmidt int i; 5765de865eeSFilipe David Borba Manana int locked = 0; 577bd989ba3SJan Schmidt 5785de865eeSFilipe David Borba Manana if (!tree_mod_need_log(fs_info, eb)) 579f395694cSJan Schmidt return 0; 580bd989ba3SJan Schmidt 5815de865eeSFilipe David Borba Manana tm_list = kzalloc(nr_items * sizeof(struct tree_mod_elem *), flags); 5825de865eeSFilipe David Borba Manana if (!tm_list) 5835de865eeSFilipe David Borba Manana return -ENOMEM; 584bd989ba3SJan Schmidt 585c8cc6341SJosef Bacik tm = kzalloc(sizeof(*tm), flags); 5865de865eeSFilipe David Borba Manana if (!tm) { 5875de865eeSFilipe David Borba Manana ret = -ENOMEM; 5885de865eeSFilipe David Borba Manana goto free_tms; 5895de865eeSFilipe David Borba Manana } 590f395694cSJan Schmidt 591bd989ba3SJan Schmidt tm->index = eb->start >> PAGE_CACHE_SHIFT; 592bd989ba3SJan Schmidt tm->slot = src_slot; 593bd989ba3SJan Schmidt tm->move.dst_slot = dst_slot; 594bd989ba3SJan Schmidt tm->move.nr_items = nr_items; 595bd989ba3SJan Schmidt tm->op = MOD_LOG_MOVE_KEYS; 596bd989ba3SJan Schmidt 5975de865eeSFilipe David Borba Manana for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { 5985de865eeSFilipe David Borba Manana tm_list[i] = alloc_tree_mod_elem(eb, i + dst_slot, 5995de865eeSFilipe David Borba Manana MOD_LOG_KEY_REMOVE_WHILE_MOVING, flags); 6005de865eeSFilipe David Borba Manana if (!tm_list[i]) { 6015de865eeSFilipe David Borba Manana ret = -ENOMEM; 6025de865eeSFilipe David Borba Manana goto free_tms; 6035de865eeSFilipe David Borba Manana } 604bd989ba3SJan Schmidt } 605bd989ba3SJan Schmidt 6065de865eeSFilipe David Borba Manana if (tree_mod_dont_log(fs_info, eb)) 6075de865eeSFilipe David Borba Manana goto free_tms; 6085de865eeSFilipe David Borba Manana locked = 1; 6095de865eeSFilipe David Borba Manana 6105de865eeSFilipe David Borba Manana /* 6115de865eeSFilipe David Borba Manana * When we override something during the move, we log these removals. 6125de865eeSFilipe David Borba Manana * This can only happen when we move towards the beginning of the 6135de865eeSFilipe David Borba Manana * buffer, i.e. dst_slot < src_slot. 6145de865eeSFilipe David Borba Manana */ 6155de865eeSFilipe David Borba Manana for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { 6165de865eeSFilipe David Borba Manana ret = __tree_mod_log_insert(fs_info, tm_list[i]); 6175de865eeSFilipe David Borba Manana if (ret) 6185de865eeSFilipe David Borba Manana goto free_tms; 6195de865eeSFilipe David Borba Manana } 6205de865eeSFilipe David Borba Manana 6215de865eeSFilipe David Borba Manana ret = __tree_mod_log_insert(fs_info, tm); 6225de865eeSFilipe David Borba Manana if (ret) 6235de865eeSFilipe David Borba Manana goto free_tms; 6245de865eeSFilipe David Borba Manana tree_mod_log_write_unlock(fs_info); 6255de865eeSFilipe David Borba Manana kfree(tm_list); 6265de865eeSFilipe David Borba Manana 6275de865eeSFilipe David Borba Manana return 0; 6285de865eeSFilipe David Borba Manana free_tms: 6295de865eeSFilipe David Borba Manana for (i = 0; i < nr_items; i++) { 6305de865eeSFilipe David Borba Manana if (tm_list[i] && !RB_EMPTY_NODE(&tm_list[i]->node)) 6315de865eeSFilipe David Borba Manana rb_erase(&tm_list[i]->node, &fs_info->tree_mod_log); 6325de865eeSFilipe David Borba Manana kfree(tm_list[i]); 6335de865eeSFilipe David Borba Manana } 6345de865eeSFilipe David Borba Manana if (locked) 6355de865eeSFilipe David Borba Manana tree_mod_log_write_unlock(fs_info); 6365de865eeSFilipe David Borba Manana kfree(tm_list); 6375de865eeSFilipe David Borba Manana kfree(tm); 6385de865eeSFilipe David Borba Manana 6395de865eeSFilipe David Borba Manana return ret; 6405de865eeSFilipe David Borba Manana } 6415de865eeSFilipe David Borba Manana 6425de865eeSFilipe David Borba Manana static inline int 6435de865eeSFilipe David Borba Manana __tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, 6445de865eeSFilipe David Borba Manana struct tree_mod_elem **tm_list, 6455de865eeSFilipe David Borba Manana int nritems) 646097b8a7cSJan Schmidt { 6475de865eeSFilipe David Borba Manana int i, j; 648097b8a7cSJan Schmidt int ret; 649097b8a7cSJan Schmidt 650097b8a7cSJan Schmidt for (i = nritems - 1; i >= 0; i--) { 6515de865eeSFilipe David Borba Manana ret = __tree_mod_log_insert(fs_info, tm_list[i]); 6525de865eeSFilipe David Borba Manana if (ret) { 6535de865eeSFilipe David Borba Manana for (j = nritems - 1; j > i; j--) 6545de865eeSFilipe David Borba Manana rb_erase(&tm_list[j]->node, 6555de865eeSFilipe David Borba Manana &fs_info->tree_mod_log); 6565de865eeSFilipe David Borba Manana return ret; 657097b8a7cSJan Schmidt } 658097b8a7cSJan Schmidt } 659097b8a7cSJan Schmidt 6605de865eeSFilipe David Borba Manana return 0; 6615de865eeSFilipe David Borba Manana } 6625de865eeSFilipe David Borba Manana 663bd989ba3SJan Schmidt static noinline int 664bd989ba3SJan Schmidt tree_mod_log_insert_root(struct btrfs_fs_info *fs_info, 665bd989ba3SJan Schmidt struct extent_buffer *old_root, 66690f8d62eSJan Schmidt struct extent_buffer *new_root, gfp_t flags, 66790f8d62eSJan Schmidt int log_removal) 668bd989ba3SJan Schmidt { 6695de865eeSFilipe David Borba Manana struct tree_mod_elem *tm = NULL; 6705de865eeSFilipe David Borba Manana struct tree_mod_elem **tm_list = NULL; 6715de865eeSFilipe David Borba Manana int nritems = 0; 6725de865eeSFilipe David Borba Manana int ret = 0; 6735de865eeSFilipe David Borba Manana int i; 674bd989ba3SJan Schmidt 6755de865eeSFilipe David Borba Manana if (!tree_mod_need_log(fs_info, NULL)) 676097b8a7cSJan Schmidt return 0; 677097b8a7cSJan Schmidt 6785de865eeSFilipe David Borba Manana if (log_removal && btrfs_header_level(old_root) > 0) { 6795de865eeSFilipe David Borba Manana nritems = btrfs_header_nritems(old_root); 6805de865eeSFilipe David Borba Manana tm_list = kzalloc(nritems * sizeof(struct tree_mod_elem *), 6815de865eeSFilipe David Borba Manana flags); 6825de865eeSFilipe David Borba Manana if (!tm_list) { 6835de865eeSFilipe David Borba Manana ret = -ENOMEM; 6845de865eeSFilipe David Borba Manana goto free_tms; 6855de865eeSFilipe David Borba Manana } 6865de865eeSFilipe David Borba Manana for (i = 0; i < nritems; i++) { 6875de865eeSFilipe David Borba Manana tm_list[i] = alloc_tree_mod_elem(old_root, i, 6885de865eeSFilipe David Borba Manana MOD_LOG_KEY_REMOVE_WHILE_FREEING, flags); 6895de865eeSFilipe David Borba Manana if (!tm_list[i]) { 6905de865eeSFilipe David Borba Manana ret = -ENOMEM; 6915de865eeSFilipe David Borba Manana goto free_tms; 6925de865eeSFilipe David Borba Manana } 6935de865eeSFilipe David Borba Manana } 6945de865eeSFilipe David Borba Manana } 695d9abbf1cSJan Schmidt 696c8cc6341SJosef Bacik tm = kzalloc(sizeof(*tm), flags); 6975de865eeSFilipe David Borba Manana if (!tm) { 6985de865eeSFilipe David Borba Manana ret = -ENOMEM; 6995de865eeSFilipe David Borba Manana goto free_tms; 7005de865eeSFilipe David Borba Manana } 701bd989ba3SJan Schmidt 702bd989ba3SJan Schmidt tm->index = new_root->start >> PAGE_CACHE_SHIFT; 703bd989ba3SJan Schmidt tm->old_root.logical = old_root->start; 704bd989ba3SJan Schmidt tm->old_root.level = btrfs_header_level(old_root); 705bd989ba3SJan Schmidt tm->generation = btrfs_header_generation(old_root); 706bd989ba3SJan Schmidt tm->op = MOD_LOG_ROOT_REPLACE; 707bd989ba3SJan Schmidt 7085de865eeSFilipe David Borba Manana if (tree_mod_dont_log(fs_info, NULL)) 7095de865eeSFilipe David Borba Manana goto free_tms; 7105de865eeSFilipe David Borba Manana 7115de865eeSFilipe David Borba Manana if (tm_list) 7125de865eeSFilipe David Borba Manana ret = __tree_mod_log_free_eb(fs_info, tm_list, nritems); 7135de865eeSFilipe David Borba Manana if (!ret) 7145de865eeSFilipe David Borba Manana ret = __tree_mod_log_insert(fs_info, tm); 7155de865eeSFilipe David Borba Manana 7165de865eeSFilipe David Borba Manana tree_mod_log_write_unlock(fs_info); 7175de865eeSFilipe David Borba Manana if (ret) 7185de865eeSFilipe David Borba Manana goto free_tms; 7195de865eeSFilipe David Borba Manana kfree(tm_list); 7205de865eeSFilipe David Borba Manana 7215de865eeSFilipe David Borba Manana return ret; 7225de865eeSFilipe David Borba Manana 7235de865eeSFilipe David Borba Manana free_tms: 7245de865eeSFilipe David Borba Manana if (tm_list) { 7255de865eeSFilipe David Borba Manana for (i = 0; i < nritems; i++) 7265de865eeSFilipe David Borba Manana kfree(tm_list[i]); 7275de865eeSFilipe David Borba Manana kfree(tm_list); 7285de865eeSFilipe David Borba Manana } 7295de865eeSFilipe David Borba Manana kfree(tm); 7305de865eeSFilipe David Borba Manana 7315de865eeSFilipe David Borba Manana return ret; 732bd989ba3SJan Schmidt } 733bd989ba3SJan Schmidt 734bd989ba3SJan Schmidt static struct tree_mod_elem * 735bd989ba3SJan Schmidt __tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq, 736bd989ba3SJan Schmidt int smallest) 737bd989ba3SJan Schmidt { 738bd989ba3SJan Schmidt struct rb_root *tm_root; 739bd989ba3SJan Schmidt struct rb_node *node; 740bd989ba3SJan Schmidt struct tree_mod_elem *cur = NULL; 741bd989ba3SJan Schmidt struct tree_mod_elem *found = NULL; 742bd989ba3SJan Schmidt u64 index = start >> PAGE_CACHE_SHIFT; 743bd989ba3SJan Schmidt 744097b8a7cSJan Schmidt tree_mod_log_read_lock(fs_info); 745bd989ba3SJan Schmidt tm_root = &fs_info->tree_mod_log; 746bd989ba3SJan Schmidt node = tm_root->rb_node; 747bd989ba3SJan Schmidt while (node) { 748bd989ba3SJan Schmidt cur = container_of(node, struct tree_mod_elem, node); 749bd989ba3SJan Schmidt if (cur->index < index) { 750bd989ba3SJan Schmidt node = node->rb_left; 751bd989ba3SJan Schmidt } else if (cur->index > index) { 752bd989ba3SJan Schmidt node = node->rb_right; 753097b8a7cSJan Schmidt } else if (cur->seq < min_seq) { 754bd989ba3SJan Schmidt node = node->rb_left; 755bd989ba3SJan Schmidt } else if (!smallest) { 756bd989ba3SJan Schmidt /* we want the node with the highest seq */ 757bd989ba3SJan Schmidt if (found) 758097b8a7cSJan Schmidt BUG_ON(found->seq > cur->seq); 759bd989ba3SJan Schmidt found = cur; 760bd989ba3SJan Schmidt node = node->rb_left; 761097b8a7cSJan Schmidt } else if (cur->seq > min_seq) { 762bd989ba3SJan Schmidt /* we want the node with the smallest seq */ 763bd989ba3SJan Schmidt if (found) 764097b8a7cSJan Schmidt BUG_ON(found->seq < cur->seq); 765bd989ba3SJan Schmidt found = cur; 766bd989ba3SJan Schmidt node = node->rb_right; 767bd989ba3SJan Schmidt } else { 768bd989ba3SJan Schmidt found = cur; 769bd989ba3SJan Schmidt break; 770bd989ba3SJan Schmidt } 771bd989ba3SJan Schmidt } 772097b8a7cSJan Schmidt tree_mod_log_read_unlock(fs_info); 773bd989ba3SJan Schmidt 774bd989ba3SJan Schmidt return found; 775bd989ba3SJan Schmidt } 776bd989ba3SJan Schmidt 777bd989ba3SJan Schmidt /* 778bd989ba3SJan Schmidt * this returns the element from the log with the smallest time sequence 779bd989ba3SJan Schmidt * value that's in the log (the oldest log item). any element with a time 780bd989ba3SJan Schmidt * sequence lower than min_seq will be ignored. 781bd989ba3SJan Schmidt */ 782bd989ba3SJan Schmidt static struct tree_mod_elem * 783bd989ba3SJan Schmidt tree_mod_log_search_oldest(struct btrfs_fs_info *fs_info, u64 start, 784bd989ba3SJan Schmidt u64 min_seq) 785bd989ba3SJan Schmidt { 786bd989ba3SJan Schmidt return __tree_mod_log_search(fs_info, start, min_seq, 1); 787bd989ba3SJan Schmidt } 788bd989ba3SJan Schmidt 789bd989ba3SJan Schmidt /* 790bd989ba3SJan Schmidt * this returns the element from the log with the largest time sequence 791bd989ba3SJan Schmidt * value that's in the log (the most recent log item). any element with 792bd989ba3SJan Schmidt * a time sequence lower than min_seq will be ignored. 793bd989ba3SJan Schmidt */ 794bd989ba3SJan Schmidt static struct tree_mod_elem * 795bd989ba3SJan Schmidt tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq) 796bd989ba3SJan Schmidt { 797bd989ba3SJan Schmidt return __tree_mod_log_search(fs_info, start, min_seq, 0); 798bd989ba3SJan Schmidt } 799bd989ba3SJan Schmidt 8005de865eeSFilipe David Borba Manana static noinline int 801bd989ba3SJan Schmidt tree_mod_log_eb_copy(struct btrfs_fs_info *fs_info, struct extent_buffer *dst, 802bd989ba3SJan Schmidt struct extent_buffer *src, unsigned long dst_offset, 80390f8d62eSJan Schmidt unsigned long src_offset, int nr_items) 804bd989ba3SJan Schmidt { 8055de865eeSFilipe David Borba Manana int ret = 0; 8065de865eeSFilipe David Borba Manana struct tree_mod_elem **tm_list = NULL; 8075de865eeSFilipe David Borba Manana struct tree_mod_elem **tm_list_add, **tm_list_rem; 808bd989ba3SJan Schmidt int i; 8095de865eeSFilipe David Borba Manana int locked = 0; 810bd989ba3SJan Schmidt 8115de865eeSFilipe David Borba Manana if (!tree_mod_need_log(fs_info, NULL)) 8125de865eeSFilipe David Borba Manana return 0; 813bd989ba3SJan Schmidt 814c8cc6341SJosef Bacik if (btrfs_header_level(dst) == 0 && btrfs_header_level(src) == 0) 8155de865eeSFilipe David Borba Manana return 0; 8165de865eeSFilipe David Borba Manana 8175de865eeSFilipe David Borba Manana tm_list = kzalloc(nr_items * 2 * sizeof(struct tree_mod_elem *), 8185de865eeSFilipe David Borba Manana GFP_NOFS); 8195de865eeSFilipe David Borba Manana if (!tm_list) 8205de865eeSFilipe David Borba Manana return -ENOMEM; 8215de865eeSFilipe David Borba Manana 8225de865eeSFilipe David Borba Manana tm_list_add = tm_list; 8235de865eeSFilipe David Borba Manana tm_list_rem = tm_list + nr_items; 8245de865eeSFilipe David Borba Manana for (i = 0; i < nr_items; i++) { 8255de865eeSFilipe David Borba Manana tm_list_rem[i] = alloc_tree_mod_elem(src, i + src_offset, 8265de865eeSFilipe David Borba Manana MOD_LOG_KEY_REMOVE, GFP_NOFS); 8275de865eeSFilipe David Borba Manana if (!tm_list_rem[i]) { 8285de865eeSFilipe David Borba Manana ret = -ENOMEM; 8295de865eeSFilipe David Borba Manana goto free_tms; 8305de865eeSFilipe David Borba Manana } 8315de865eeSFilipe David Borba Manana 8325de865eeSFilipe David Borba Manana tm_list_add[i] = alloc_tree_mod_elem(dst, i + dst_offset, 8335de865eeSFilipe David Borba Manana MOD_LOG_KEY_ADD, GFP_NOFS); 8345de865eeSFilipe David Borba Manana if (!tm_list_add[i]) { 8355de865eeSFilipe David Borba Manana ret = -ENOMEM; 8365de865eeSFilipe David Borba Manana goto free_tms; 8375de865eeSFilipe David Borba Manana } 8385de865eeSFilipe David Borba Manana } 8395de865eeSFilipe David Borba Manana 8405de865eeSFilipe David Borba Manana if (tree_mod_dont_log(fs_info, NULL)) 8415de865eeSFilipe David Borba Manana goto free_tms; 8425de865eeSFilipe David Borba Manana locked = 1; 843bd989ba3SJan Schmidt 844bd989ba3SJan Schmidt for (i = 0; i < nr_items; i++) { 8455de865eeSFilipe David Borba Manana ret = __tree_mod_log_insert(fs_info, tm_list_rem[i]); 8465de865eeSFilipe David Borba Manana if (ret) 8475de865eeSFilipe David Borba Manana goto free_tms; 8485de865eeSFilipe David Borba Manana ret = __tree_mod_log_insert(fs_info, tm_list_add[i]); 8495de865eeSFilipe David Borba Manana if (ret) 8505de865eeSFilipe David Borba Manana goto free_tms; 851bd989ba3SJan Schmidt } 8525de865eeSFilipe David Borba Manana 8535de865eeSFilipe David Borba Manana tree_mod_log_write_unlock(fs_info); 8545de865eeSFilipe David Borba Manana kfree(tm_list); 8555de865eeSFilipe David Borba Manana 8565de865eeSFilipe David Borba Manana return 0; 8575de865eeSFilipe David Borba Manana 8585de865eeSFilipe David Borba Manana free_tms: 8595de865eeSFilipe David Borba Manana for (i = 0; i < nr_items * 2; i++) { 8605de865eeSFilipe David Borba Manana if (tm_list[i] && !RB_EMPTY_NODE(&tm_list[i]->node)) 8615de865eeSFilipe David Borba Manana rb_erase(&tm_list[i]->node, &fs_info->tree_mod_log); 8625de865eeSFilipe David Borba Manana kfree(tm_list[i]); 8635de865eeSFilipe David Borba Manana } 8645de865eeSFilipe David Borba Manana if (locked) 8655de865eeSFilipe David Borba Manana tree_mod_log_write_unlock(fs_info); 8665de865eeSFilipe David Borba Manana kfree(tm_list); 8675de865eeSFilipe David Borba Manana 8685de865eeSFilipe David Borba Manana return ret; 869bd989ba3SJan Schmidt } 870bd989ba3SJan Schmidt 871bd989ba3SJan Schmidt static inline void 872bd989ba3SJan Schmidt tree_mod_log_eb_move(struct btrfs_fs_info *fs_info, struct extent_buffer *dst, 873bd989ba3SJan Schmidt int dst_offset, int src_offset, int nr_items) 874bd989ba3SJan Schmidt { 875bd989ba3SJan Schmidt int ret; 876bd989ba3SJan Schmidt ret = tree_mod_log_insert_move(fs_info, dst, dst_offset, src_offset, 877bd989ba3SJan Schmidt nr_items, GFP_NOFS); 878bd989ba3SJan Schmidt BUG_ON(ret < 0); 879bd989ba3SJan Schmidt } 880bd989ba3SJan Schmidt 881097b8a7cSJan Schmidt static noinline void 882bd989ba3SJan Schmidt tree_mod_log_set_node_key(struct btrfs_fs_info *fs_info, 88332adf090SLiu Bo struct extent_buffer *eb, int slot, int atomic) 884bd989ba3SJan Schmidt { 885bd989ba3SJan Schmidt int ret; 886bd989ba3SJan Schmidt 88778357766SFilipe David Borba Manana ret = tree_mod_log_insert_key(fs_info, eb, slot, 888bd989ba3SJan Schmidt MOD_LOG_KEY_REPLACE, 889bd989ba3SJan Schmidt atomic ? GFP_ATOMIC : GFP_NOFS); 890bd989ba3SJan Schmidt BUG_ON(ret < 0); 891bd989ba3SJan Schmidt } 892bd989ba3SJan Schmidt 8935de865eeSFilipe David Borba Manana static noinline int 894097b8a7cSJan Schmidt tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, struct extent_buffer *eb) 895bd989ba3SJan Schmidt { 8965de865eeSFilipe David Borba Manana struct tree_mod_elem **tm_list = NULL; 8975de865eeSFilipe David Borba Manana int nritems = 0; 8985de865eeSFilipe David Borba Manana int i; 8995de865eeSFilipe David Borba Manana int ret = 0; 9005de865eeSFilipe David Borba Manana 9015de865eeSFilipe David Borba Manana if (btrfs_header_level(eb) == 0) 9025de865eeSFilipe David Borba Manana return 0; 9035de865eeSFilipe David Borba Manana 9045de865eeSFilipe David Borba Manana if (!tree_mod_need_log(fs_info, NULL)) 9055de865eeSFilipe David Borba Manana return 0; 9065de865eeSFilipe David Borba Manana 9075de865eeSFilipe David Borba Manana nritems = btrfs_header_nritems(eb); 9085de865eeSFilipe David Borba Manana tm_list = kzalloc(nritems * sizeof(struct tree_mod_elem *), 9095de865eeSFilipe David Borba Manana GFP_NOFS); 9105de865eeSFilipe David Borba Manana if (!tm_list) 9115de865eeSFilipe David Borba Manana return -ENOMEM; 9125de865eeSFilipe David Borba Manana 9135de865eeSFilipe David Borba Manana for (i = 0; i < nritems; i++) { 9145de865eeSFilipe David Borba Manana tm_list[i] = alloc_tree_mod_elem(eb, i, 9155de865eeSFilipe David Borba Manana MOD_LOG_KEY_REMOVE_WHILE_FREEING, GFP_NOFS); 9165de865eeSFilipe David Borba Manana if (!tm_list[i]) { 9175de865eeSFilipe David Borba Manana ret = -ENOMEM; 9185de865eeSFilipe David Borba Manana goto free_tms; 9195de865eeSFilipe David Borba Manana } 9205de865eeSFilipe David Borba Manana } 9215de865eeSFilipe David Borba Manana 922e9b7fd4dSJan Schmidt if (tree_mod_dont_log(fs_info, eb)) 9235de865eeSFilipe David Borba Manana goto free_tms; 9245de865eeSFilipe David Borba Manana 9255de865eeSFilipe David Borba Manana ret = __tree_mod_log_free_eb(fs_info, tm_list, nritems); 9265de865eeSFilipe David Borba Manana tree_mod_log_write_unlock(fs_info); 9275de865eeSFilipe David Borba Manana if (ret) 9285de865eeSFilipe David Borba Manana goto free_tms; 9295de865eeSFilipe David Borba Manana kfree(tm_list); 9305de865eeSFilipe David Borba Manana 9315de865eeSFilipe David Borba Manana return 0; 9325de865eeSFilipe David Borba Manana 9335de865eeSFilipe David Borba Manana free_tms: 9345de865eeSFilipe David Borba Manana for (i = 0; i < nritems; i++) 9355de865eeSFilipe David Borba Manana kfree(tm_list[i]); 9365de865eeSFilipe David Borba Manana kfree(tm_list); 9375de865eeSFilipe David Borba Manana 9385de865eeSFilipe David Borba Manana return ret; 939bd989ba3SJan Schmidt } 940bd989ba3SJan Schmidt 941097b8a7cSJan Schmidt static noinline void 942bd989ba3SJan Schmidt tree_mod_log_set_root_pointer(struct btrfs_root *root, 94390f8d62eSJan Schmidt struct extent_buffer *new_root_node, 94490f8d62eSJan Schmidt int log_removal) 945bd989ba3SJan Schmidt { 946bd989ba3SJan Schmidt int ret; 947bd989ba3SJan Schmidt ret = tree_mod_log_insert_root(root->fs_info, root->node, 94890f8d62eSJan Schmidt new_root_node, GFP_NOFS, log_removal); 949bd989ba3SJan Schmidt BUG_ON(ret < 0); 950bd989ba3SJan Schmidt } 951bd989ba3SJan Schmidt 952d352ac68SChris Mason /* 9535d4f98a2SYan Zheng * check if the tree block can be shared by multiple trees 9545d4f98a2SYan Zheng */ 9555d4f98a2SYan Zheng int btrfs_block_can_be_shared(struct btrfs_root *root, 9565d4f98a2SYan Zheng struct extent_buffer *buf) 9575d4f98a2SYan Zheng { 9585d4f98a2SYan Zheng /* 9595d4f98a2SYan Zheng * Tree blocks not in refernece counted trees and tree roots 9605d4f98a2SYan Zheng * are never shared. If a block was allocated after the last 9615d4f98a2SYan Zheng * snapshot and the block was not allocated by tree relocation, 9625d4f98a2SYan Zheng * we know the block is not shared. 9635d4f98a2SYan Zheng */ 96427cdeb70SMiao Xie if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) && 9655d4f98a2SYan Zheng buf != root->node && buf != root->commit_root && 9665d4f98a2SYan Zheng (btrfs_header_generation(buf) <= 9675d4f98a2SYan Zheng btrfs_root_last_snapshot(&root->root_item) || 9685d4f98a2SYan Zheng btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) 9695d4f98a2SYan Zheng return 1; 9705d4f98a2SYan Zheng #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 97127cdeb70SMiao Xie if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) && 9725d4f98a2SYan Zheng btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) 9735d4f98a2SYan Zheng return 1; 9745d4f98a2SYan Zheng #endif 9755d4f98a2SYan Zheng return 0; 9765d4f98a2SYan Zheng } 9775d4f98a2SYan Zheng 9785d4f98a2SYan Zheng static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, 9795d4f98a2SYan Zheng struct btrfs_root *root, 9805d4f98a2SYan Zheng struct extent_buffer *buf, 981f0486c68SYan, Zheng struct extent_buffer *cow, 982f0486c68SYan, Zheng int *last_ref) 9835d4f98a2SYan Zheng { 9845d4f98a2SYan Zheng u64 refs; 9855d4f98a2SYan Zheng u64 owner; 9865d4f98a2SYan Zheng u64 flags; 9875d4f98a2SYan Zheng u64 new_flags = 0; 9885d4f98a2SYan Zheng int ret; 9895d4f98a2SYan Zheng 9905d4f98a2SYan Zheng /* 9915d4f98a2SYan Zheng * Backrefs update rules: 9925d4f98a2SYan Zheng * 9935d4f98a2SYan Zheng * Always use full backrefs for extent pointers in tree block 9945d4f98a2SYan Zheng * allocated by tree relocation. 9955d4f98a2SYan Zheng * 9965d4f98a2SYan Zheng * If a shared tree block is no longer referenced by its owner 9975d4f98a2SYan Zheng * tree (btrfs_header_owner(buf) == root->root_key.objectid), 9985d4f98a2SYan Zheng * use full backrefs for extent pointers in tree block. 9995d4f98a2SYan Zheng * 10005d4f98a2SYan Zheng * If a tree block is been relocating 10015d4f98a2SYan Zheng * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), 10025d4f98a2SYan Zheng * use full backrefs for extent pointers in tree block. 10035d4f98a2SYan Zheng * The reason for this is some operations (such as drop tree) 10045d4f98a2SYan Zheng * are only allowed for blocks use full backrefs. 10055d4f98a2SYan Zheng */ 10065d4f98a2SYan Zheng 10075d4f98a2SYan Zheng if (btrfs_block_can_be_shared(root, buf)) { 10085d4f98a2SYan Zheng ret = btrfs_lookup_extent_info(trans, root, buf->start, 10093173a18fSJosef Bacik btrfs_header_level(buf), 1, 10103173a18fSJosef Bacik &refs, &flags); 1011be1a5564SMark Fasheh if (ret) 1012be1a5564SMark Fasheh return ret; 1013e5df9573SMark Fasheh if (refs == 0) { 1014e5df9573SMark Fasheh ret = -EROFS; 1015e5df9573SMark Fasheh btrfs_std_error(root->fs_info, ret); 1016e5df9573SMark Fasheh return ret; 1017e5df9573SMark Fasheh } 10185d4f98a2SYan Zheng } else { 10195d4f98a2SYan Zheng refs = 1; 10205d4f98a2SYan Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || 10215d4f98a2SYan Zheng btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) 10225d4f98a2SYan Zheng flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; 10235d4f98a2SYan Zheng else 10245d4f98a2SYan Zheng flags = 0; 10255d4f98a2SYan Zheng } 10265d4f98a2SYan Zheng 10275d4f98a2SYan Zheng owner = btrfs_header_owner(buf); 10285d4f98a2SYan Zheng BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && 10295d4f98a2SYan Zheng !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); 10305d4f98a2SYan Zheng 10315d4f98a2SYan Zheng if (refs > 1) { 10325d4f98a2SYan Zheng if ((owner == root->root_key.objectid || 10335d4f98a2SYan Zheng root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && 10345d4f98a2SYan Zheng !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { 1035e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, buf, 1); 103679787eaaSJeff Mahoney BUG_ON(ret); /* -ENOMEM */ 10375d4f98a2SYan Zheng 10385d4f98a2SYan Zheng if (root->root_key.objectid == 10395d4f98a2SYan Zheng BTRFS_TREE_RELOC_OBJECTID) { 1040e339a6b0SJosef Bacik ret = btrfs_dec_ref(trans, root, buf, 0); 104179787eaaSJeff Mahoney BUG_ON(ret); /* -ENOMEM */ 1042e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 1); 104379787eaaSJeff Mahoney BUG_ON(ret); /* -ENOMEM */ 10445d4f98a2SYan Zheng } 10455d4f98a2SYan Zheng new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; 10465d4f98a2SYan Zheng } else { 10475d4f98a2SYan Zheng 10485d4f98a2SYan Zheng if (root->root_key.objectid == 10495d4f98a2SYan Zheng BTRFS_TREE_RELOC_OBJECTID) 1050e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 1); 10515d4f98a2SYan Zheng else 1052e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 0); 105379787eaaSJeff Mahoney BUG_ON(ret); /* -ENOMEM */ 10545d4f98a2SYan Zheng } 10555d4f98a2SYan Zheng if (new_flags != 0) { 1056b1c79e09SJosef Bacik int level = btrfs_header_level(buf); 1057b1c79e09SJosef Bacik 10585d4f98a2SYan Zheng ret = btrfs_set_disk_extent_flags(trans, root, 10595d4f98a2SYan Zheng buf->start, 10605d4f98a2SYan Zheng buf->len, 1061b1c79e09SJosef Bacik new_flags, level, 0); 1062be1a5564SMark Fasheh if (ret) 1063be1a5564SMark Fasheh return ret; 10645d4f98a2SYan Zheng } 10655d4f98a2SYan Zheng } else { 10665d4f98a2SYan Zheng if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { 10675d4f98a2SYan Zheng if (root->root_key.objectid == 10685d4f98a2SYan Zheng BTRFS_TREE_RELOC_OBJECTID) 1069e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 1); 10705d4f98a2SYan Zheng else 1071e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 0); 107279787eaaSJeff Mahoney BUG_ON(ret); /* -ENOMEM */ 1073e339a6b0SJosef Bacik ret = btrfs_dec_ref(trans, root, buf, 1); 107479787eaaSJeff Mahoney BUG_ON(ret); /* -ENOMEM */ 10755d4f98a2SYan Zheng } 10765d4f98a2SYan Zheng clean_tree_block(trans, root, buf); 1077f0486c68SYan, Zheng *last_ref = 1; 10785d4f98a2SYan Zheng } 10795d4f98a2SYan Zheng return 0; 10805d4f98a2SYan Zheng } 10815d4f98a2SYan Zheng 10825d4f98a2SYan Zheng /* 1083d397712bSChris Mason * does the dirty work in cow of a single block. The parent block (if 1084d397712bSChris Mason * supplied) is updated to point to the new cow copy. The new buffer is marked 1085d397712bSChris Mason * dirty and returned locked. If you modify the block it needs to be marked 1086d397712bSChris Mason * dirty again. 1087d352ac68SChris Mason * 1088d352ac68SChris Mason * search_start -- an allocation hint for the new block 1089d352ac68SChris Mason * 1090d397712bSChris Mason * empty_size -- a hint that you plan on doing more cow. This is the size in 1091d397712bSChris Mason * bytes the allocator should try to find free next to the block it returns. 1092d397712bSChris Mason * This is just a hint and may be ignored by the allocator. 1093d352ac68SChris Mason */ 1094d397712bSChris Mason static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, 10955f39d397SChris Mason struct btrfs_root *root, 10965f39d397SChris Mason struct extent_buffer *buf, 10975f39d397SChris Mason struct extent_buffer *parent, int parent_slot, 10985f39d397SChris Mason struct extent_buffer **cow_ret, 10999fa8cfe7SChris Mason u64 search_start, u64 empty_size) 11006702ed49SChris Mason { 11015d4f98a2SYan Zheng struct btrfs_disk_key disk_key; 11025f39d397SChris Mason struct extent_buffer *cow; 1103be1a5564SMark Fasheh int level, ret; 1104f0486c68SYan, Zheng int last_ref = 0; 1105925baeddSChris Mason int unlock_orig = 0; 11065d4f98a2SYan Zheng u64 parent_start; 11076702ed49SChris Mason 1108925baeddSChris Mason if (*cow_ret == buf) 1109925baeddSChris Mason unlock_orig = 1; 1110925baeddSChris Mason 1111b9447ef8SChris Mason btrfs_assert_tree_locked(buf); 1112925baeddSChris Mason 111327cdeb70SMiao Xie WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && 111427cdeb70SMiao Xie trans->transid != root->fs_info->running_transaction->transid); 111527cdeb70SMiao Xie WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && 111627cdeb70SMiao Xie trans->transid != root->last_trans); 11175f39d397SChris Mason 11187bb86316SChris Mason level = btrfs_header_level(buf); 111931840ae1SZheng Yan 11205d4f98a2SYan Zheng if (level == 0) 11215d4f98a2SYan Zheng btrfs_item_key(buf, &disk_key, 0); 11225d4f98a2SYan Zheng else 11235d4f98a2SYan Zheng btrfs_node_key(buf, &disk_key, 0); 11245d4f98a2SYan Zheng 11255d4f98a2SYan Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { 11265d4f98a2SYan Zheng if (parent) 11275d4f98a2SYan Zheng parent_start = parent->start; 11285d4f98a2SYan Zheng else 11295d4f98a2SYan Zheng parent_start = 0; 11305d4f98a2SYan Zheng } else 11315d4f98a2SYan Zheng parent_start = 0; 11325d4f98a2SYan Zheng 11334d75f8a9SDavid Sterba cow = btrfs_alloc_tree_block(trans, root, parent_start, 11344d75f8a9SDavid Sterba root->root_key.objectid, &disk_key, level, 11354d75f8a9SDavid Sterba search_start, empty_size); 11366702ed49SChris Mason if (IS_ERR(cow)) 11376702ed49SChris Mason return PTR_ERR(cow); 11386702ed49SChris Mason 1139b4ce94deSChris Mason /* cow is set to blocking by btrfs_init_new_buffer */ 1140b4ce94deSChris Mason 11415f39d397SChris Mason copy_extent_buffer(cow, buf, 0, 0, cow->len); 1142db94535dSChris Mason btrfs_set_header_bytenr(cow, cow->start); 11435f39d397SChris Mason btrfs_set_header_generation(cow, trans->transid); 11445d4f98a2SYan Zheng btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); 11455d4f98a2SYan Zheng btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | 11465d4f98a2SYan Zheng BTRFS_HEADER_FLAG_RELOC); 11475d4f98a2SYan Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) 11485d4f98a2SYan Zheng btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); 11495d4f98a2SYan Zheng else 11505f39d397SChris Mason btrfs_set_header_owner(cow, root->root_key.objectid); 11516702ed49SChris Mason 11520a4e5586SRoss Kirk write_extent_buffer(cow, root->fs_info->fsid, btrfs_header_fsid(), 11532b82032cSYan Zheng BTRFS_FSID_SIZE); 11542b82032cSYan Zheng 1155be1a5564SMark Fasheh ret = update_ref_for_cow(trans, root, buf, cow, &last_ref); 1156b68dc2a9SMark Fasheh if (ret) { 115779787eaaSJeff Mahoney btrfs_abort_transaction(trans, root, ret); 1158b68dc2a9SMark Fasheh return ret; 1159b68dc2a9SMark Fasheh } 11601a40e23bSZheng Yan 116127cdeb70SMiao Xie if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) { 116283d4cfd4SJosef Bacik ret = btrfs_reloc_cow_block(trans, root, buf, cow); 116383d4cfd4SJosef Bacik if (ret) 116483d4cfd4SJosef Bacik return ret; 116583d4cfd4SJosef Bacik } 11663fd0a558SYan, Zheng 11676702ed49SChris Mason if (buf == root->node) { 1168925baeddSChris Mason WARN_ON(parent && parent != buf); 11695d4f98a2SYan Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || 11705d4f98a2SYan Zheng btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) 11715d4f98a2SYan Zheng parent_start = buf->start; 11725d4f98a2SYan Zheng else 11735d4f98a2SYan Zheng parent_start = 0; 1174925baeddSChris Mason 11755f39d397SChris Mason extent_buffer_get(cow); 117690f8d62eSJan Schmidt tree_mod_log_set_root_pointer(root, cow, 1); 1177240f62c8SChris Mason rcu_assign_pointer(root->node, cow); 1178925baeddSChris Mason 1179f0486c68SYan, Zheng btrfs_free_tree_block(trans, root, buf, parent_start, 11805581a51aSJan Schmidt last_ref); 11815f39d397SChris Mason free_extent_buffer(buf); 11820b86a832SChris Mason add_root_to_dirty_list(root); 11836702ed49SChris Mason } else { 11845d4f98a2SYan Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) 11855d4f98a2SYan Zheng parent_start = parent->start; 11865d4f98a2SYan Zheng else 11875d4f98a2SYan Zheng parent_start = 0; 11885d4f98a2SYan Zheng 11895d4f98a2SYan Zheng WARN_ON(trans->transid != btrfs_header_generation(parent)); 1190f230475eSJan Schmidt tree_mod_log_insert_key(root->fs_info, parent, parent_slot, 1191c8cc6341SJosef Bacik MOD_LOG_KEY_REPLACE, GFP_NOFS); 11925f39d397SChris Mason btrfs_set_node_blockptr(parent, parent_slot, 1193db94535dSChris Mason cow->start); 119474493f7aSChris Mason btrfs_set_node_ptr_generation(parent, parent_slot, 119574493f7aSChris Mason trans->transid); 11966702ed49SChris Mason btrfs_mark_buffer_dirty(parent); 11975de865eeSFilipe David Borba Manana if (last_ref) { 11985de865eeSFilipe David Borba Manana ret = tree_mod_log_free_eb(root->fs_info, buf); 11995de865eeSFilipe David Borba Manana if (ret) { 12005de865eeSFilipe David Borba Manana btrfs_abort_transaction(trans, root, ret); 12015de865eeSFilipe David Borba Manana return ret; 12025de865eeSFilipe David Borba Manana } 12035de865eeSFilipe David Borba Manana } 1204f0486c68SYan, Zheng btrfs_free_tree_block(trans, root, buf, parent_start, 12055581a51aSJan Schmidt last_ref); 12066702ed49SChris Mason } 1207925baeddSChris Mason if (unlock_orig) 1208925baeddSChris Mason btrfs_tree_unlock(buf); 12093083ee2eSJosef Bacik free_extent_buffer_stale(buf); 12106702ed49SChris Mason btrfs_mark_buffer_dirty(cow); 12116702ed49SChris Mason *cow_ret = cow; 12126702ed49SChris Mason return 0; 12136702ed49SChris Mason } 12146702ed49SChris Mason 12155d9e75c4SJan Schmidt /* 12165d9e75c4SJan Schmidt * returns the logical address of the oldest predecessor of the given root. 12175d9e75c4SJan Schmidt * entries older than time_seq are ignored. 12185d9e75c4SJan Schmidt */ 12195d9e75c4SJan Schmidt static struct tree_mod_elem * 12205d9e75c4SJan Schmidt __tree_mod_log_oldest_root(struct btrfs_fs_info *fs_info, 122130b0463aSJan Schmidt struct extent_buffer *eb_root, u64 time_seq) 12225d9e75c4SJan Schmidt { 12235d9e75c4SJan Schmidt struct tree_mod_elem *tm; 12245d9e75c4SJan Schmidt struct tree_mod_elem *found = NULL; 122530b0463aSJan Schmidt u64 root_logical = eb_root->start; 12265d9e75c4SJan Schmidt int looped = 0; 12275d9e75c4SJan Schmidt 12285d9e75c4SJan Schmidt if (!time_seq) 122935a3621bSStefan Behrens return NULL; 12305d9e75c4SJan Schmidt 12315d9e75c4SJan Schmidt /* 12325d9e75c4SJan Schmidt * the very last operation that's logged for a root is the replacement 12335d9e75c4SJan Schmidt * operation (if it is replaced at all). this has the index of the *new* 12345d9e75c4SJan Schmidt * root, making it the very first operation that's logged for this root. 12355d9e75c4SJan Schmidt */ 12365d9e75c4SJan Schmidt while (1) { 12375d9e75c4SJan Schmidt tm = tree_mod_log_search_oldest(fs_info, root_logical, 12385d9e75c4SJan Schmidt time_seq); 12395d9e75c4SJan Schmidt if (!looped && !tm) 124035a3621bSStefan Behrens return NULL; 12415d9e75c4SJan Schmidt /* 124228da9fb4SJan Schmidt * if there are no tree operation for the oldest root, we simply 124328da9fb4SJan Schmidt * return it. this should only happen if that (old) root is at 124428da9fb4SJan Schmidt * level 0. 12455d9e75c4SJan Schmidt */ 124628da9fb4SJan Schmidt if (!tm) 124728da9fb4SJan Schmidt break; 12485d9e75c4SJan Schmidt 124928da9fb4SJan Schmidt /* 125028da9fb4SJan Schmidt * if there's an operation that's not a root replacement, we 125128da9fb4SJan Schmidt * found the oldest version of our root. normally, we'll find a 125228da9fb4SJan Schmidt * MOD_LOG_KEY_REMOVE_WHILE_FREEING operation here. 125328da9fb4SJan Schmidt */ 12545d9e75c4SJan Schmidt if (tm->op != MOD_LOG_ROOT_REPLACE) 12555d9e75c4SJan Schmidt break; 12565d9e75c4SJan Schmidt 12575d9e75c4SJan Schmidt found = tm; 12585d9e75c4SJan Schmidt root_logical = tm->old_root.logical; 12595d9e75c4SJan Schmidt looped = 1; 12605d9e75c4SJan Schmidt } 12615d9e75c4SJan Schmidt 1262a95236d9SJan Schmidt /* if there's no old root to return, return what we found instead */ 1263a95236d9SJan Schmidt if (!found) 1264a95236d9SJan Schmidt found = tm; 1265a95236d9SJan Schmidt 12665d9e75c4SJan Schmidt return found; 12675d9e75c4SJan Schmidt } 12685d9e75c4SJan Schmidt 12695d9e75c4SJan Schmidt /* 12705d9e75c4SJan Schmidt * tm is a pointer to the first operation to rewind within eb. then, all 12715d9e75c4SJan Schmidt * previous operations will be rewinded (until we reach something older than 12725d9e75c4SJan Schmidt * time_seq). 12735d9e75c4SJan Schmidt */ 12745d9e75c4SJan Schmidt static void 1275f1ca7e98SJosef Bacik __tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, 1276f1ca7e98SJosef Bacik u64 time_seq, struct tree_mod_elem *first_tm) 12775d9e75c4SJan Schmidt { 12785d9e75c4SJan Schmidt u32 n; 12795d9e75c4SJan Schmidt struct rb_node *next; 12805d9e75c4SJan Schmidt struct tree_mod_elem *tm = first_tm; 12815d9e75c4SJan Schmidt unsigned long o_dst; 12825d9e75c4SJan Schmidt unsigned long o_src; 12835d9e75c4SJan Schmidt unsigned long p_size = sizeof(struct btrfs_key_ptr); 12845d9e75c4SJan Schmidt 12855d9e75c4SJan Schmidt n = btrfs_header_nritems(eb); 1286f1ca7e98SJosef Bacik tree_mod_log_read_lock(fs_info); 1287097b8a7cSJan Schmidt while (tm && tm->seq >= time_seq) { 12885d9e75c4SJan Schmidt /* 12895d9e75c4SJan Schmidt * all the operations are recorded with the operator used for 12905d9e75c4SJan Schmidt * the modification. as we're going backwards, we do the 12915d9e75c4SJan Schmidt * opposite of each operation here. 12925d9e75c4SJan Schmidt */ 12935d9e75c4SJan Schmidt switch (tm->op) { 12945d9e75c4SJan Schmidt case MOD_LOG_KEY_REMOVE_WHILE_FREEING: 12955d9e75c4SJan Schmidt BUG_ON(tm->slot < n); 12961c697d4aSEric Sandeen /* Fallthrough */ 129795c80bb1SLiu Bo case MOD_LOG_KEY_REMOVE_WHILE_MOVING: 12984c3e6969SChris Mason case MOD_LOG_KEY_REMOVE: 12995d9e75c4SJan Schmidt btrfs_set_node_key(eb, &tm->key, tm->slot); 13005d9e75c4SJan Schmidt btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr); 13015d9e75c4SJan Schmidt btrfs_set_node_ptr_generation(eb, tm->slot, 13025d9e75c4SJan Schmidt tm->generation); 13034c3e6969SChris Mason n++; 13045d9e75c4SJan Schmidt break; 13055d9e75c4SJan Schmidt case MOD_LOG_KEY_REPLACE: 13065d9e75c4SJan Schmidt BUG_ON(tm->slot >= n); 13075d9e75c4SJan Schmidt btrfs_set_node_key(eb, &tm->key, tm->slot); 13085d9e75c4SJan Schmidt btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr); 13095d9e75c4SJan Schmidt btrfs_set_node_ptr_generation(eb, tm->slot, 13105d9e75c4SJan Schmidt tm->generation); 13115d9e75c4SJan Schmidt break; 13125d9e75c4SJan Schmidt case MOD_LOG_KEY_ADD: 131319956c7eSJan Schmidt /* if a move operation is needed it's in the log */ 13145d9e75c4SJan Schmidt n--; 13155d9e75c4SJan Schmidt break; 13165d9e75c4SJan Schmidt case MOD_LOG_MOVE_KEYS: 1317c3193108SJan Schmidt o_dst = btrfs_node_key_ptr_offset(tm->slot); 1318c3193108SJan Schmidt o_src = btrfs_node_key_ptr_offset(tm->move.dst_slot); 1319c3193108SJan Schmidt memmove_extent_buffer(eb, o_dst, o_src, 13205d9e75c4SJan Schmidt tm->move.nr_items * p_size); 13215d9e75c4SJan Schmidt break; 13225d9e75c4SJan Schmidt case MOD_LOG_ROOT_REPLACE: 13235d9e75c4SJan Schmidt /* 13245d9e75c4SJan Schmidt * this operation is special. for roots, this must be 13255d9e75c4SJan Schmidt * handled explicitly before rewinding. 13265d9e75c4SJan Schmidt * for non-roots, this operation may exist if the node 13275d9e75c4SJan Schmidt * was a root: root A -> child B; then A gets empty and 13285d9e75c4SJan Schmidt * B is promoted to the new root. in the mod log, we'll 13295d9e75c4SJan Schmidt * have a root-replace operation for B, a tree block 13305d9e75c4SJan Schmidt * that is no root. we simply ignore that operation. 13315d9e75c4SJan Schmidt */ 13325d9e75c4SJan Schmidt break; 13335d9e75c4SJan Schmidt } 13345d9e75c4SJan Schmidt next = rb_next(&tm->node); 13355d9e75c4SJan Schmidt if (!next) 13365d9e75c4SJan Schmidt break; 13375d9e75c4SJan Schmidt tm = container_of(next, struct tree_mod_elem, node); 13385d9e75c4SJan Schmidt if (tm->index != first_tm->index) 13395d9e75c4SJan Schmidt break; 13405d9e75c4SJan Schmidt } 1341f1ca7e98SJosef Bacik tree_mod_log_read_unlock(fs_info); 13425d9e75c4SJan Schmidt btrfs_set_header_nritems(eb, n); 13435d9e75c4SJan Schmidt } 13445d9e75c4SJan Schmidt 134547fb091fSJan Schmidt /* 134647fb091fSJan Schmidt * Called with eb read locked. If the buffer cannot be rewinded, the same buffer 134747fb091fSJan Schmidt * is returned. If rewind operations happen, a fresh buffer is returned. The 134847fb091fSJan Schmidt * returned buffer is always read-locked. If the returned buffer is not the 134947fb091fSJan Schmidt * input buffer, the lock on the input buffer is released and the input buffer 135047fb091fSJan Schmidt * is freed (its refcount is decremented). 135147fb091fSJan Schmidt */ 13525d9e75c4SJan Schmidt static struct extent_buffer * 13539ec72677SJosef Bacik tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct btrfs_path *path, 13549ec72677SJosef Bacik struct extent_buffer *eb, u64 time_seq) 13555d9e75c4SJan Schmidt { 13565d9e75c4SJan Schmidt struct extent_buffer *eb_rewin; 13575d9e75c4SJan Schmidt struct tree_mod_elem *tm; 13585d9e75c4SJan Schmidt 13595d9e75c4SJan Schmidt if (!time_seq) 13605d9e75c4SJan Schmidt return eb; 13615d9e75c4SJan Schmidt 13625d9e75c4SJan Schmidt if (btrfs_header_level(eb) == 0) 13635d9e75c4SJan Schmidt return eb; 13645d9e75c4SJan Schmidt 13655d9e75c4SJan Schmidt tm = tree_mod_log_search(fs_info, eb->start, time_seq); 13665d9e75c4SJan Schmidt if (!tm) 13675d9e75c4SJan Schmidt return eb; 13685d9e75c4SJan Schmidt 13699ec72677SJosef Bacik btrfs_set_path_blocking(path); 13709ec72677SJosef Bacik btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); 13719ec72677SJosef Bacik 13725d9e75c4SJan Schmidt if (tm->op == MOD_LOG_KEY_REMOVE_WHILE_FREEING) { 13735d9e75c4SJan Schmidt BUG_ON(tm->slot != 0); 13745d9e75c4SJan Schmidt eb_rewin = alloc_dummy_extent_buffer(eb->start, 13755d9e75c4SJan Schmidt fs_info->tree_root->nodesize); 1376db7f3436SJosef Bacik if (!eb_rewin) { 13779ec72677SJosef Bacik btrfs_tree_read_unlock_blocking(eb); 1378db7f3436SJosef Bacik free_extent_buffer(eb); 1379db7f3436SJosef Bacik return NULL; 1380db7f3436SJosef Bacik } 13815d9e75c4SJan Schmidt btrfs_set_header_bytenr(eb_rewin, eb->start); 13825d9e75c4SJan Schmidt btrfs_set_header_backref_rev(eb_rewin, 13835d9e75c4SJan Schmidt btrfs_header_backref_rev(eb)); 13845d9e75c4SJan Schmidt btrfs_set_header_owner(eb_rewin, btrfs_header_owner(eb)); 1385c3193108SJan Schmidt btrfs_set_header_level(eb_rewin, btrfs_header_level(eb)); 13865d9e75c4SJan Schmidt } else { 13875d9e75c4SJan Schmidt eb_rewin = btrfs_clone_extent_buffer(eb); 1388db7f3436SJosef Bacik if (!eb_rewin) { 13899ec72677SJosef Bacik btrfs_tree_read_unlock_blocking(eb); 1390db7f3436SJosef Bacik free_extent_buffer(eb); 1391db7f3436SJosef Bacik return NULL; 1392db7f3436SJosef Bacik } 13935d9e75c4SJan Schmidt } 13945d9e75c4SJan Schmidt 13959ec72677SJosef Bacik btrfs_clear_path_blocking(path, NULL, BTRFS_READ_LOCK); 13969ec72677SJosef Bacik btrfs_tree_read_unlock_blocking(eb); 13975d9e75c4SJan Schmidt free_extent_buffer(eb); 13985d9e75c4SJan Schmidt 139947fb091fSJan Schmidt extent_buffer_get(eb_rewin); 140047fb091fSJan Schmidt btrfs_tree_read_lock(eb_rewin); 1401f1ca7e98SJosef Bacik __tree_mod_log_rewind(fs_info, eb_rewin, time_seq, tm); 140257911b8bSJan Schmidt WARN_ON(btrfs_header_nritems(eb_rewin) > 14032a745b14SArne Jansen BTRFS_NODEPTRS_PER_BLOCK(fs_info->tree_root)); 14045d9e75c4SJan Schmidt 14055d9e75c4SJan Schmidt return eb_rewin; 14065d9e75c4SJan Schmidt } 14075d9e75c4SJan Schmidt 14088ba97a15SJan Schmidt /* 14098ba97a15SJan Schmidt * get_old_root() rewinds the state of @root's root node to the given @time_seq 14108ba97a15SJan Schmidt * value. If there are no changes, the current root->root_node is returned. If 14118ba97a15SJan Schmidt * anything changed in between, there's a fresh buffer allocated on which the 14128ba97a15SJan Schmidt * rewind operations are done. In any case, the returned buffer is read locked. 14138ba97a15SJan Schmidt * Returns NULL on error (with no locks held). 14148ba97a15SJan Schmidt */ 14155d9e75c4SJan Schmidt static inline struct extent_buffer * 14165d9e75c4SJan Schmidt get_old_root(struct btrfs_root *root, u64 time_seq) 14175d9e75c4SJan Schmidt { 14185d9e75c4SJan Schmidt struct tree_mod_elem *tm; 141930b0463aSJan Schmidt struct extent_buffer *eb = NULL; 142030b0463aSJan Schmidt struct extent_buffer *eb_root; 14217bfdcf7fSLiu Bo struct extent_buffer *old; 1422a95236d9SJan Schmidt struct tree_mod_root *old_root = NULL; 14234325edd0SChris Mason u64 old_generation = 0; 1424a95236d9SJan Schmidt u64 logical; 14255d9e75c4SJan Schmidt 142630b0463aSJan Schmidt eb_root = btrfs_read_lock_root_node(root); 142730b0463aSJan Schmidt tm = __tree_mod_log_oldest_root(root->fs_info, eb_root, time_seq); 14285d9e75c4SJan Schmidt if (!tm) 142930b0463aSJan Schmidt return eb_root; 14305d9e75c4SJan Schmidt 1431a95236d9SJan Schmidt if (tm->op == MOD_LOG_ROOT_REPLACE) { 14325d9e75c4SJan Schmidt old_root = &tm->old_root; 14335d9e75c4SJan Schmidt old_generation = tm->generation; 1434a95236d9SJan Schmidt logical = old_root->logical; 1435a95236d9SJan Schmidt } else { 143630b0463aSJan Schmidt logical = eb_root->start; 1437a95236d9SJan Schmidt } 14385d9e75c4SJan Schmidt 1439a95236d9SJan Schmidt tm = tree_mod_log_search(root->fs_info, logical, time_seq); 1440834328a8SJan Schmidt if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) { 144130b0463aSJan Schmidt btrfs_tree_read_unlock(eb_root); 144230b0463aSJan Schmidt free_extent_buffer(eb_root); 1443ce86cd59SDavid Sterba old = read_tree_block(root, logical, 0); 1444fae7f21cSDulshani Gunawardhana if (WARN_ON(!old || !extent_buffer_uptodate(old))) { 1445416bc658SJosef Bacik free_extent_buffer(old); 1446efe120a0SFrank Holton btrfs_warn(root->fs_info, 1447efe120a0SFrank Holton "failed to read tree block %llu from get_old_root", logical); 1448834328a8SJan Schmidt } else { 14497bfdcf7fSLiu Bo eb = btrfs_clone_extent_buffer(old); 14507bfdcf7fSLiu Bo free_extent_buffer(old); 1451834328a8SJan Schmidt } 1452834328a8SJan Schmidt } else if (old_root) { 145330b0463aSJan Schmidt btrfs_tree_read_unlock(eb_root); 145430b0463aSJan Schmidt free_extent_buffer(eb_root); 145528da9fb4SJan Schmidt eb = alloc_dummy_extent_buffer(logical, root->nodesize); 1456834328a8SJan Schmidt } else { 14579ec72677SJosef Bacik btrfs_set_lock_blocking_rw(eb_root, BTRFS_READ_LOCK); 145830b0463aSJan Schmidt eb = btrfs_clone_extent_buffer(eb_root); 14599ec72677SJosef Bacik btrfs_tree_read_unlock_blocking(eb_root); 146030b0463aSJan Schmidt free_extent_buffer(eb_root); 1461834328a8SJan Schmidt } 1462834328a8SJan Schmidt 14638ba97a15SJan Schmidt if (!eb) 14648ba97a15SJan Schmidt return NULL; 1465d6381084SJan Schmidt extent_buffer_get(eb); 14668ba97a15SJan Schmidt btrfs_tree_read_lock(eb); 1467a95236d9SJan Schmidt if (old_root) { 14685d9e75c4SJan Schmidt btrfs_set_header_bytenr(eb, eb->start); 14695d9e75c4SJan Schmidt btrfs_set_header_backref_rev(eb, BTRFS_MIXED_BACKREF_REV); 147030b0463aSJan Schmidt btrfs_set_header_owner(eb, btrfs_header_owner(eb_root)); 14715d9e75c4SJan Schmidt btrfs_set_header_level(eb, old_root->level); 14725d9e75c4SJan Schmidt btrfs_set_header_generation(eb, old_generation); 1473a95236d9SJan Schmidt } 147428da9fb4SJan Schmidt if (tm) 1475f1ca7e98SJosef Bacik __tree_mod_log_rewind(root->fs_info, eb, time_seq, tm); 147628da9fb4SJan Schmidt else 147728da9fb4SJan Schmidt WARN_ON(btrfs_header_level(eb) != 0); 147857911b8bSJan Schmidt WARN_ON(btrfs_header_nritems(eb) > BTRFS_NODEPTRS_PER_BLOCK(root)); 14795d9e75c4SJan Schmidt 14805d9e75c4SJan Schmidt return eb; 14815d9e75c4SJan Schmidt } 14825d9e75c4SJan Schmidt 14835b6602e7SJan Schmidt int btrfs_old_root_level(struct btrfs_root *root, u64 time_seq) 14845b6602e7SJan Schmidt { 14855b6602e7SJan Schmidt struct tree_mod_elem *tm; 14865b6602e7SJan Schmidt int level; 148730b0463aSJan Schmidt struct extent_buffer *eb_root = btrfs_root_node(root); 14885b6602e7SJan Schmidt 148930b0463aSJan Schmidt tm = __tree_mod_log_oldest_root(root->fs_info, eb_root, time_seq); 14905b6602e7SJan Schmidt if (tm && tm->op == MOD_LOG_ROOT_REPLACE) { 14915b6602e7SJan Schmidt level = tm->old_root.level; 14925b6602e7SJan Schmidt } else { 149330b0463aSJan Schmidt level = btrfs_header_level(eb_root); 14945b6602e7SJan Schmidt } 149530b0463aSJan Schmidt free_extent_buffer(eb_root); 14965b6602e7SJan Schmidt 14975b6602e7SJan Schmidt return level; 14985b6602e7SJan Schmidt } 14995b6602e7SJan Schmidt 15005d4f98a2SYan Zheng static inline int should_cow_block(struct btrfs_trans_handle *trans, 15015d4f98a2SYan Zheng struct btrfs_root *root, 15025d4f98a2SYan Zheng struct extent_buffer *buf) 15035d4f98a2SYan Zheng { 1504fccb84c9SDavid Sterba if (btrfs_test_is_dummy_root(root)) 1505faa2dbf0SJosef Bacik return 0; 1506fccb84c9SDavid Sterba 1507f1ebcc74SLiu Bo /* ensure we can see the force_cow */ 1508f1ebcc74SLiu Bo smp_rmb(); 1509f1ebcc74SLiu Bo 1510f1ebcc74SLiu Bo /* 1511f1ebcc74SLiu Bo * We do not need to cow a block if 1512f1ebcc74SLiu Bo * 1) this block is not created or changed in this transaction; 1513f1ebcc74SLiu Bo * 2) this block does not belong to TREE_RELOC tree; 1514f1ebcc74SLiu Bo * 3) the root is not forced COW. 1515f1ebcc74SLiu Bo * 1516f1ebcc74SLiu Bo * What is forced COW: 1517f1ebcc74SLiu Bo * when we create snapshot during commiting the transaction, 1518f1ebcc74SLiu Bo * after we've finished coping src root, we must COW the shared 1519f1ebcc74SLiu Bo * block to ensure the metadata consistency. 1520f1ebcc74SLiu Bo */ 15215d4f98a2SYan Zheng if (btrfs_header_generation(buf) == trans->transid && 15225d4f98a2SYan Zheng !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && 15235d4f98a2SYan Zheng !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && 1524f1ebcc74SLiu Bo btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && 152527cdeb70SMiao Xie !test_bit(BTRFS_ROOT_FORCE_COW, &root->state)) 15265d4f98a2SYan Zheng return 0; 15275d4f98a2SYan Zheng return 1; 15285d4f98a2SYan Zheng } 15295d4f98a2SYan Zheng 1530d352ac68SChris Mason /* 1531d352ac68SChris Mason * cows a single block, see __btrfs_cow_block for the real work. 1532d352ac68SChris Mason * This version of it has extra checks so that a block isn't cow'd more than 1533d352ac68SChris Mason * once per transaction, as long as it hasn't been written yet 1534d352ac68SChris Mason */ 1535d397712bSChris Mason noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, 15365f39d397SChris Mason struct btrfs_root *root, struct extent_buffer *buf, 15375f39d397SChris Mason struct extent_buffer *parent, int parent_slot, 15389fa8cfe7SChris Mason struct extent_buffer **cow_ret) 153902217ed2SChris Mason { 15406702ed49SChris Mason u64 search_start; 1541f510cfecSChris Mason int ret; 1542dc17ff8fSChris Mason 154331b1a2bdSJulia Lawall if (trans->transaction != root->fs_info->running_transaction) 154431b1a2bdSJulia Lawall WARN(1, KERN_CRIT "trans %llu running %llu\n", 1545c1c9ff7cSGeert Uytterhoeven trans->transid, 1546ccd467d6SChris Mason root->fs_info->running_transaction->transid); 154731b1a2bdSJulia Lawall 154831b1a2bdSJulia Lawall if (trans->transid != root->fs_info->generation) 154931b1a2bdSJulia Lawall WARN(1, KERN_CRIT "trans %llu running %llu\n", 1550c1c9ff7cSGeert Uytterhoeven trans->transid, root->fs_info->generation); 1551dc17ff8fSChris Mason 15525d4f98a2SYan Zheng if (!should_cow_block(trans, root, buf)) { 155302217ed2SChris Mason *cow_ret = buf; 155402217ed2SChris Mason return 0; 155502217ed2SChris Mason } 1556c487685dSChris Mason 15570b86a832SChris Mason search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1); 1558b4ce94deSChris Mason 1559b4ce94deSChris Mason if (parent) 1560b4ce94deSChris Mason btrfs_set_lock_blocking(parent); 1561b4ce94deSChris Mason btrfs_set_lock_blocking(buf); 1562b4ce94deSChris Mason 1563f510cfecSChris Mason ret = __btrfs_cow_block(trans, root, buf, parent, 15649fa8cfe7SChris Mason parent_slot, cow_ret, search_start, 0); 15651abe9b8aSliubo 15661abe9b8aSliubo trace_btrfs_cow_block(root, buf, *cow_ret); 15671abe9b8aSliubo 1568f510cfecSChris Mason return ret; 15692c90e5d6SChris Mason } 15706702ed49SChris Mason 1571d352ac68SChris Mason /* 1572d352ac68SChris Mason * helper function for defrag to decide if two blocks pointed to by a 1573d352ac68SChris Mason * node are actually close by 1574d352ac68SChris Mason */ 15756b80053dSChris Mason static int close_blocks(u64 blocknr, u64 other, u32 blocksize) 15766702ed49SChris Mason { 15776b80053dSChris Mason if (blocknr < other && other - (blocknr + blocksize) < 32768) 15786702ed49SChris Mason return 1; 15796b80053dSChris Mason if (blocknr > other && blocknr - (other + blocksize) < 32768) 15806702ed49SChris Mason return 1; 158102217ed2SChris Mason return 0; 158202217ed2SChris Mason } 158302217ed2SChris Mason 1584081e9573SChris Mason /* 1585081e9573SChris Mason * compare two keys in a memcmp fashion 1586081e9573SChris Mason */ 1587081e9573SChris Mason static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) 1588081e9573SChris Mason { 1589081e9573SChris Mason struct btrfs_key k1; 1590081e9573SChris Mason 1591081e9573SChris Mason btrfs_disk_key_to_cpu(&k1, disk); 1592081e9573SChris Mason 159320736abaSDiego Calleja return btrfs_comp_cpu_keys(&k1, k2); 1594081e9573SChris Mason } 1595081e9573SChris Mason 1596f3465ca4SJosef Bacik /* 1597f3465ca4SJosef Bacik * same as comp_keys only with two btrfs_key's 1598f3465ca4SJosef Bacik */ 15995d4f98a2SYan Zheng int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2) 1600f3465ca4SJosef Bacik { 1601f3465ca4SJosef Bacik if (k1->objectid > k2->objectid) 1602f3465ca4SJosef Bacik return 1; 1603f3465ca4SJosef Bacik if (k1->objectid < k2->objectid) 1604f3465ca4SJosef Bacik return -1; 1605f3465ca4SJosef Bacik if (k1->type > k2->type) 1606f3465ca4SJosef Bacik return 1; 1607f3465ca4SJosef Bacik if (k1->type < k2->type) 1608f3465ca4SJosef Bacik return -1; 1609f3465ca4SJosef Bacik if (k1->offset > k2->offset) 1610f3465ca4SJosef Bacik return 1; 1611f3465ca4SJosef Bacik if (k1->offset < k2->offset) 1612f3465ca4SJosef Bacik return -1; 1613f3465ca4SJosef Bacik return 0; 1614f3465ca4SJosef Bacik } 1615081e9573SChris Mason 1616d352ac68SChris Mason /* 1617d352ac68SChris Mason * this is used by the defrag code to go through all the 1618d352ac68SChris Mason * leaves pointed to by a node and reallocate them so that 1619d352ac68SChris Mason * disk order is close to key order 1620d352ac68SChris Mason */ 16216702ed49SChris Mason int btrfs_realloc_node(struct btrfs_trans_handle *trans, 16225f39d397SChris Mason struct btrfs_root *root, struct extent_buffer *parent, 1623de78b51aSEric Sandeen int start_slot, u64 *last_ret, 1624a6b6e75eSChris Mason struct btrfs_key *progress) 16256702ed49SChris Mason { 16266b80053dSChris Mason struct extent_buffer *cur; 16276702ed49SChris Mason u64 blocknr; 1628ca7a79adSChris Mason u64 gen; 1629e9d0b13bSChris Mason u64 search_start = *last_ret; 1630e9d0b13bSChris Mason u64 last_block = 0; 16316702ed49SChris Mason u64 other; 16326702ed49SChris Mason u32 parent_nritems; 16336702ed49SChris Mason int end_slot; 16346702ed49SChris Mason int i; 16356702ed49SChris Mason int err = 0; 1636f2183bdeSChris Mason int parent_level; 16376b80053dSChris Mason int uptodate; 16386b80053dSChris Mason u32 blocksize; 1639081e9573SChris Mason int progress_passed = 0; 1640081e9573SChris Mason struct btrfs_disk_key disk_key; 16416702ed49SChris Mason 16425708b959SChris Mason parent_level = btrfs_header_level(parent); 16435708b959SChris Mason 16446c1500f2SJulia Lawall WARN_ON(trans->transaction != root->fs_info->running_transaction); 16456c1500f2SJulia Lawall WARN_ON(trans->transid != root->fs_info->generation); 164686479a04SChris Mason 16476b80053dSChris Mason parent_nritems = btrfs_header_nritems(parent); 1648707e8a07SDavid Sterba blocksize = root->nodesize; 16496702ed49SChris Mason end_slot = parent_nritems; 16506702ed49SChris Mason 16516702ed49SChris Mason if (parent_nritems == 1) 16526702ed49SChris Mason return 0; 16536702ed49SChris Mason 1654b4ce94deSChris Mason btrfs_set_lock_blocking(parent); 1655b4ce94deSChris Mason 16566702ed49SChris Mason for (i = start_slot; i < end_slot; i++) { 16576702ed49SChris Mason int close = 1; 1658a6b6e75eSChris Mason 1659081e9573SChris Mason btrfs_node_key(parent, &disk_key, i); 1660081e9573SChris Mason if (!progress_passed && comp_keys(&disk_key, progress) < 0) 1661081e9573SChris Mason continue; 1662081e9573SChris Mason 1663081e9573SChris Mason progress_passed = 1; 16646b80053dSChris Mason blocknr = btrfs_node_blockptr(parent, i); 1665ca7a79adSChris Mason gen = btrfs_node_ptr_generation(parent, i); 1666e9d0b13bSChris Mason if (last_block == 0) 1667e9d0b13bSChris Mason last_block = blocknr; 16685708b959SChris Mason 16696702ed49SChris Mason if (i > 0) { 16706b80053dSChris Mason other = btrfs_node_blockptr(parent, i - 1); 16716b80053dSChris Mason close = close_blocks(blocknr, other, blocksize); 16726702ed49SChris Mason } 16730ef3e66bSChris Mason if (!close && i < end_slot - 2) { 16746b80053dSChris Mason other = btrfs_node_blockptr(parent, i + 1); 16756b80053dSChris Mason close = close_blocks(blocknr, other, blocksize); 16766702ed49SChris Mason } 1677e9d0b13bSChris Mason if (close) { 1678e9d0b13bSChris Mason last_block = blocknr; 16796702ed49SChris Mason continue; 1680e9d0b13bSChris Mason } 16816702ed49SChris Mason 16820308af44SDavid Sterba cur = btrfs_find_tree_block(root, blocknr); 16836b80053dSChris Mason if (cur) 1684b9fab919SChris Mason uptodate = btrfs_buffer_uptodate(cur, gen, 0); 16856b80053dSChris Mason else 16866b80053dSChris Mason uptodate = 0; 16875708b959SChris Mason if (!cur || !uptodate) { 16886b80053dSChris Mason if (!cur) { 1689ce86cd59SDavid Sterba cur = read_tree_block(root, blocknr, gen); 1690416bc658SJosef Bacik if (!cur || !extent_buffer_uptodate(cur)) { 1691416bc658SJosef Bacik free_extent_buffer(cur); 169297d9a8a4STsutomu Itoh return -EIO; 1693416bc658SJosef Bacik } 16946b80053dSChris Mason } else if (!uptodate) { 1695018642a1STsutomu Itoh err = btrfs_read_buffer(cur, gen); 1696018642a1STsutomu Itoh if (err) { 1697018642a1STsutomu Itoh free_extent_buffer(cur); 1698018642a1STsutomu Itoh return err; 1699018642a1STsutomu Itoh } 17006702ed49SChris Mason } 1701f2183bdeSChris Mason } 1702e9d0b13bSChris Mason if (search_start == 0) 17036b80053dSChris Mason search_start = last_block; 1704e9d0b13bSChris Mason 1705e7a84565SChris Mason btrfs_tree_lock(cur); 1706b4ce94deSChris Mason btrfs_set_lock_blocking(cur); 17076b80053dSChris Mason err = __btrfs_cow_block(trans, root, cur, parent, i, 1708e7a84565SChris Mason &cur, search_start, 17096b80053dSChris Mason min(16 * blocksize, 17109fa8cfe7SChris Mason (end_slot - i) * blocksize)); 1711252c38f0SYan if (err) { 1712e7a84565SChris Mason btrfs_tree_unlock(cur); 17136b80053dSChris Mason free_extent_buffer(cur); 17146702ed49SChris Mason break; 1715252c38f0SYan } 1716e7a84565SChris Mason search_start = cur->start; 1717e7a84565SChris Mason last_block = cur->start; 1718f2183bdeSChris Mason *last_ret = search_start; 1719e7a84565SChris Mason btrfs_tree_unlock(cur); 1720e7a84565SChris Mason free_extent_buffer(cur); 17216702ed49SChris Mason } 17226702ed49SChris Mason return err; 17236702ed49SChris Mason } 17246702ed49SChris Mason 172574123bd7SChris Mason /* 172674123bd7SChris Mason * The leaf data grows from end-to-front in the node. 172774123bd7SChris Mason * this returns the address of the start of the last item, 172874123bd7SChris Mason * which is the stop of the leaf data stack 172974123bd7SChris Mason */ 1730123abc88SChris Mason static inline unsigned int leaf_data_end(struct btrfs_root *root, 17315f39d397SChris Mason struct extent_buffer *leaf) 1732be0e5c09SChris Mason { 17335f39d397SChris Mason u32 nr = btrfs_header_nritems(leaf); 1734be0e5c09SChris Mason if (nr == 0) 1735123abc88SChris Mason return BTRFS_LEAF_DATA_SIZE(root); 17365f39d397SChris Mason return btrfs_item_offset_nr(leaf, nr - 1); 1737be0e5c09SChris Mason } 1738be0e5c09SChris Mason 1739aa5d6bedSChris Mason 174074123bd7SChris Mason /* 17415f39d397SChris Mason * search for key in the extent_buffer. The items start at offset p, 17425f39d397SChris Mason * and they are item_size apart. There are 'max' items in p. 17435f39d397SChris Mason * 174474123bd7SChris Mason * the slot in the array is returned via slot, and it points to 174574123bd7SChris Mason * the place where you would insert key if it is not found in 174674123bd7SChris Mason * the array. 174774123bd7SChris Mason * 174874123bd7SChris Mason * slot may point to max if the key is bigger than all of the keys 174974123bd7SChris Mason */ 1750e02119d5SChris Mason static noinline int generic_bin_search(struct extent_buffer *eb, 1751e02119d5SChris Mason unsigned long p, 17525f39d397SChris Mason int item_size, struct btrfs_key *key, 1753be0e5c09SChris Mason int max, int *slot) 1754be0e5c09SChris Mason { 1755be0e5c09SChris Mason int low = 0; 1756be0e5c09SChris Mason int high = max; 1757be0e5c09SChris Mason int mid; 1758be0e5c09SChris Mason int ret; 1759479965d6SChris Mason struct btrfs_disk_key *tmp = NULL; 17605f39d397SChris Mason struct btrfs_disk_key unaligned; 17615f39d397SChris Mason unsigned long offset; 17625f39d397SChris Mason char *kaddr = NULL; 17635f39d397SChris Mason unsigned long map_start = 0; 17645f39d397SChris Mason unsigned long map_len = 0; 1765479965d6SChris Mason int err; 1766be0e5c09SChris Mason 1767be0e5c09SChris Mason while (low < high) { 1768be0e5c09SChris Mason mid = (low + high) / 2; 17695f39d397SChris Mason offset = p + mid * item_size; 17705f39d397SChris Mason 1771a6591715SChris Mason if (!kaddr || offset < map_start || 17725f39d397SChris Mason (offset + sizeof(struct btrfs_disk_key)) > 17735f39d397SChris Mason map_start + map_len) { 1774934d375bSChris Mason 1775934d375bSChris Mason err = map_private_extent_buffer(eb, offset, 1776479965d6SChris Mason sizeof(struct btrfs_disk_key), 1777a6591715SChris Mason &kaddr, &map_start, &map_len); 17785f39d397SChris Mason 1779479965d6SChris Mason if (!err) { 1780479965d6SChris Mason tmp = (struct btrfs_disk_key *)(kaddr + offset - 1781479965d6SChris Mason map_start); 1782479965d6SChris Mason } else { 17835f39d397SChris Mason read_extent_buffer(eb, &unaligned, 17845f39d397SChris Mason offset, sizeof(unaligned)); 17855f39d397SChris Mason tmp = &unaligned; 1786479965d6SChris Mason } 1787479965d6SChris Mason 17885f39d397SChris Mason } else { 17895f39d397SChris Mason tmp = (struct btrfs_disk_key *)(kaddr + offset - 17905f39d397SChris Mason map_start); 17915f39d397SChris Mason } 1792be0e5c09SChris Mason ret = comp_keys(tmp, key); 1793be0e5c09SChris Mason 1794be0e5c09SChris Mason if (ret < 0) 1795be0e5c09SChris Mason low = mid + 1; 1796be0e5c09SChris Mason else if (ret > 0) 1797be0e5c09SChris Mason high = mid; 1798be0e5c09SChris Mason else { 1799be0e5c09SChris Mason *slot = mid; 1800be0e5c09SChris Mason return 0; 1801be0e5c09SChris Mason } 1802be0e5c09SChris Mason } 1803be0e5c09SChris Mason *slot = low; 1804be0e5c09SChris Mason return 1; 1805be0e5c09SChris Mason } 1806be0e5c09SChris Mason 180797571fd0SChris Mason /* 180897571fd0SChris Mason * simple bin_search frontend that does the right thing for 180997571fd0SChris Mason * leaves vs nodes 181097571fd0SChris Mason */ 18115f39d397SChris Mason static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, 18125f39d397SChris Mason int level, int *slot) 1813be0e5c09SChris Mason { 1814f775738fSWang Sheng-Hui if (level == 0) 18155f39d397SChris Mason return generic_bin_search(eb, 18165f39d397SChris Mason offsetof(struct btrfs_leaf, items), 18170783fcfcSChris Mason sizeof(struct btrfs_item), 18185f39d397SChris Mason key, btrfs_header_nritems(eb), 18197518a238SChris Mason slot); 1820f775738fSWang Sheng-Hui else 18215f39d397SChris Mason return generic_bin_search(eb, 18225f39d397SChris Mason offsetof(struct btrfs_node, ptrs), 1823123abc88SChris Mason sizeof(struct btrfs_key_ptr), 18245f39d397SChris Mason key, btrfs_header_nritems(eb), 18257518a238SChris Mason slot); 1826be0e5c09SChris Mason } 1827be0e5c09SChris Mason 18285d4f98a2SYan Zheng int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key, 18295d4f98a2SYan Zheng int level, int *slot) 18305d4f98a2SYan Zheng { 18315d4f98a2SYan Zheng return bin_search(eb, key, level, slot); 18325d4f98a2SYan Zheng } 18335d4f98a2SYan Zheng 1834f0486c68SYan, Zheng static void root_add_used(struct btrfs_root *root, u32 size) 1835f0486c68SYan, Zheng { 1836f0486c68SYan, Zheng spin_lock(&root->accounting_lock); 1837f0486c68SYan, Zheng btrfs_set_root_used(&root->root_item, 1838f0486c68SYan, Zheng btrfs_root_used(&root->root_item) + size); 1839f0486c68SYan, Zheng spin_unlock(&root->accounting_lock); 1840f0486c68SYan, Zheng } 1841f0486c68SYan, Zheng 1842f0486c68SYan, Zheng static void root_sub_used(struct btrfs_root *root, u32 size) 1843f0486c68SYan, Zheng { 1844f0486c68SYan, Zheng spin_lock(&root->accounting_lock); 1845f0486c68SYan, Zheng btrfs_set_root_used(&root->root_item, 1846f0486c68SYan, Zheng btrfs_root_used(&root->root_item) - size); 1847f0486c68SYan, Zheng spin_unlock(&root->accounting_lock); 1848f0486c68SYan, Zheng } 1849f0486c68SYan, Zheng 1850d352ac68SChris Mason /* given a node and slot number, this reads the blocks it points to. The 1851d352ac68SChris Mason * extent buffer is returned with a reference taken (but unlocked). 1852d352ac68SChris Mason * NULL is returned on error. 1853d352ac68SChris Mason */ 1854e02119d5SChris Mason static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root, 18555f39d397SChris Mason struct extent_buffer *parent, int slot) 1856bb803951SChris Mason { 1857ca7a79adSChris Mason int level = btrfs_header_level(parent); 1858416bc658SJosef Bacik struct extent_buffer *eb; 1859416bc658SJosef Bacik 1860bb803951SChris Mason if (slot < 0) 1861bb803951SChris Mason return NULL; 18625f39d397SChris Mason if (slot >= btrfs_header_nritems(parent)) 1863bb803951SChris Mason return NULL; 1864ca7a79adSChris Mason 1865ca7a79adSChris Mason BUG_ON(level == 0); 1866ca7a79adSChris Mason 1867416bc658SJosef Bacik eb = read_tree_block(root, btrfs_node_blockptr(parent, slot), 1868ca7a79adSChris Mason btrfs_node_ptr_generation(parent, slot)); 1869416bc658SJosef Bacik if (eb && !extent_buffer_uptodate(eb)) { 1870416bc658SJosef Bacik free_extent_buffer(eb); 1871416bc658SJosef Bacik eb = NULL; 1872416bc658SJosef Bacik } 1873416bc658SJosef Bacik 1874416bc658SJosef Bacik return eb; 1875bb803951SChris Mason } 1876bb803951SChris Mason 1877d352ac68SChris Mason /* 1878d352ac68SChris Mason * node level balancing, used to make sure nodes are in proper order for 1879d352ac68SChris Mason * item deletion. We balance from the top down, so we have to make sure 1880d352ac68SChris Mason * that a deletion won't leave an node completely empty later on. 1881d352ac68SChris Mason */ 1882e02119d5SChris Mason static noinline int balance_level(struct btrfs_trans_handle *trans, 188398ed5174SChris Mason struct btrfs_root *root, 188498ed5174SChris Mason struct btrfs_path *path, int level) 1885bb803951SChris Mason { 18865f39d397SChris Mason struct extent_buffer *right = NULL; 18875f39d397SChris Mason struct extent_buffer *mid; 18885f39d397SChris Mason struct extent_buffer *left = NULL; 18895f39d397SChris Mason struct extent_buffer *parent = NULL; 1890bb803951SChris Mason int ret = 0; 1891bb803951SChris Mason int wret; 1892bb803951SChris Mason int pslot; 1893bb803951SChris Mason int orig_slot = path->slots[level]; 189479f95c82SChris Mason u64 orig_ptr; 1895bb803951SChris Mason 1896bb803951SChris Mason if (level == 0) 1897bb803951SChris Mason return 0; 1898bb803951SChris Mason 18995f39d397SChris Mason mid = path->nodes[level]; 1900b4ce94deSChris Mason 1901bd681513SChris Mason WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK && 1902bd681513SChris Mason path->locks[level] != BTRFS_WRITE_LOCK_BLOCKING); 19037bb86316SChris Mason WARN_ON(btrfs_header_generation(mid) != trans->transid); 19047bb86316SChris Mason 19051d4f8a0cSChris Mason orig_ptr = btrfs_node_blockptr(mid, orig_slot); 190679f95c82SChris Mason 1907a05a9bb1SLi Zefan if (level < BTRFS_MAX_LEVEL - 1) { 19085f39d397SChris Mason parent = path->nodes[level + 1]; 1909bb803951SChris Mason pslot = path->slots[level + 1]; 1910a05a9bb1SLi Zefan } 1911bb803951SChris Mason 191240689478SChris Mason /* 191340689478SChris Mason * deal with the case where there is only one pointer in the root 191440689478SChris Mason * by promoting the node below to a root 191540689478SChris Mason */ 19165f39d397SChris Mason if (!parent) { 19175f39d397SChris Mason struct extent_buffer *child; 1918bb803951SChris Mason 19195f39d397SChris Mason if (btrfs_header_nritems(mid) != 1) 1920bb803951SChris Mason return 0; 1921bb803951SChris Mason 1922bb803951SChris Mason /* promote the child to a root */ 19235f39d397SChris Mason child = read_node_slot(root, mid, 0); 1924305a26afSMark Fasheh if (!child) { 1925305a26afSMark Fasheh ret = -EROFS; 1926305a26afSMark Fasheh btrfs_std_error(root->fs_info, ret); 1927305a26afSMark Fasheh goto enospc; 1928305a26afSMark Fasheh } 1929305a26afSMark Fasheh 1930925baeddSChris Mason btrfs_tree_lock(child); 1931b4ce94deSChris Mason btrfs_set_lock_blocking(child); 19329fa8cfe7SChris Mason ret = btrfs_cow_block(trans, root, child, mid, 0, &child); 1933f0486c68SYan, Zheng if (ret) { 1934f0486c68SYan, Zheng btrfs_tree_unlock(child); 1935f0486c68SYan, Zheng free_extent_buffer(child); 1936f0486c68SYan, Zheng goto enospc; 1937f0486c68SYan, Zheng } 19382f375ab9SYan 193990f8d62eSJan Schmidt tree_mod_log_set_root_pointer(root, child, 1); 1940240f62c8SChris Mason rcu_assign_pointer(root->node, child); 1941925baeddSChris Mason 19420b86a832SChris Mason add_root_to_dirty_list(root); 1943925baeddSChris Mason btrfs_tree_unlock(child); 1944b4ce94deSChris Mason 1945925baeddSChris Mason path->locks[level] = 0; 1946bb803951SChris Mason path->nodes[level] = NULL; 19475f39d397SChris Mason clean_tree_block(trans, root, mid); 1948925baeddSChris Mason btrfs_tree_unlock(mid); 1949bb803951SChris Mason /* once for the path */ 19505f39d397SChris Mason free_extent_buffer(mid); 1951f0486c68SYan, Zheng 1952f0486c68SYan, Zheng root_sub_used(root, mid->len); 19535581a51aSJan Schmidt btrfs_free_tree_block(trans, root, mid, 0, 1); 1954bb803951SChris Mason /* once for the root ptr */ 19553083ee2eSJosef Bacik free_extent_buffer_stale(mid); 1956f0486c68SYan, Zheng return 0; 1957bb803951SChris Mason } 19585f39d397SChris Mason if (btrfs_header_nritems(mid) > 1959123abc88SChris Mason BTRFS_NODEPTRS_PER_BLOCK(root) / 4) 1960bb803951SChris Mason return 0; 1961bb803951SChris Mason 19625f39d397SChris Mason left = read_node_slot(root, parent, pslot - 1); 19635f39d397SChris Mason if (left) { 1964925baeddSChris Mason btrfs_tree_lock(left); 1965b4ce94deSChris Mason btrfs_set_lock_blocking(left); 19665f39d397SChris Mason wret = btrfs_cow_block(trans, root, left, 19679fa8cfe7SChris Mason parent, pslot - 1, &left); 196854aa1f4dSChris Mason if (wret) { 196954aa1f4dSChris Mason ret = wret; 197054aa1f4dSChris Mason goto enospc; 197154aa1f4dSChris Mason } 19722cc58cf2SChris Mason } 19735f39d397SChris Mason right = read_node_slot(root, parent, pslot + 1); 19745f39d397SChris Mason if (right) { 1975925baeddSChris Mason btrfs_tree_lock(right); 1976b4ce94deSChris Mason btrfs_set_lock_blocking(right); 19775f39d397SChris Mason wret = btrfs_cow_block(trans, root, right, 19789fa8cfe7SChris Mason parent, pslot + 1, &right); 19792cc58cf2SChris Mason if (wret) { 19802cc58cf2SChris Mason ret = wret; 19812cc58cf2SChris Mason goto enospc; 19822cc58cf2SChris Mason } 19832cc58cf2SChris Mason } 19842cc58cf2SChris Mason 19852cc58cf2SChris Mason /* first, try to make some room in the middle buffer */ 19865f39d397SChris Mason if (left) { 19875f39d397SChris Mason orig_slot += btrfs_header_nritems(left); 1988bce4eae9SChris Mason wret = push_node_left(trans, root, left, mid, 1); 198979f95c82SChris Mason if (wret < 0) 199079f95c82SChris Mason ret = wret; 1991bb803951SChris Mason } 199279f95c82SChris Mason 199379f95c82SChris Mason /* 199479f95c82SChris Mason * then try to empty the right most buffer into the middle 199579f95c82SChris Mason */ 19965f39d397SChris Mason if (right) { 1997971a1f66SChris Mason wret = push_node_left(trans, root, mid, right, 1); 199854aa1f4dSChris Mason if (wret < 0 && wret != -ENOSPC) 199979f95c82SChris Mason ret = wret; 20005f39d397SChris Mason if (btrfs_header_nritems(right) == 0) { 20015f39d397SChris Mason clean_tree_block(trans, root, right); 2002925baeddSChris Mason btrfs_tree_unlock(right); 2003afe5fea7STsutomu Itoh del_ptr(root, path, level + 1, pslot + 1); 2004f0486c68SYan, Zheng root_sub_used(root, right->len); 20055581a51aSJan Schmidt btrfs_free_tree_block(trans, root, right, 0, 1); 20063083ee2eSJosef Bacik free_extent_buffer_stale(right); 2007f0486c68SYan, Zheng right = NULL; 2008bb803951SChris Mason } else { 20095f39d397SChris Mason struct btrfs_disk_key right_key; 20105f39d397SChris Mason btrfs_node_key(right, &right_key, 0); 2011f230475eSJan Schmidt tree_mod_log_set_node_key(root->fs_info, parent, 201232adf090SLiu Bo pslot + 1, 0); 20135f39d397SChris Mason btrfs_set_node_key(parent, &right_key, pslot + 1); 20145f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 2015bb803951SChris Mason } 2016bb803951SChris Mason } 20175f39d397SChris Mason if (btrfs_header_nritems(mid) == 1) { 201879f95c82SChris Mason /* 201979f95c82SChris Mason * we're not allowed to leave a node with one item in the 202079f95c82SChris Mason * tree during a delete. A deletion from lower in the tree 202179f95c82SChris Mason * could try to delete the only pointer in this node. 202279f95c82SChris Mason * So, pull some keys from the left. 202379f95c82SChris Mason * There has to be a left pointer at this point because 202479f95c82SChris Mason * otherwise we would have pulled some pointers from the 202579f95c82SChris Mason * right 202679f95c82SChris Mason */ 2027305a26afSMark Fasheh if (!left) { 2028305a26afSMark Fasheh ret = -EROFS; 2029305a26afSMark Fasheh btrfs_std_error(root->fs_info, ret); 2030305a26afSMark Fasheh goto enospc; 2031305a26afSMark Fasheh } 20325f39d397SChris Mason wret = balance_node_right(trans, root, mid, left); 203354aa1f4dSChris Mason if (wret < 0) { 203479f95c82SChris Mason ret = wret; 203554aa1f4dSChris Mason goto enospc; 203654aa1f4dSChris Mason } 2037bce4eae9SChris Mason if (wret == 1) { 2038bce4eae9SChris Mason wret = push_node_left(trans, root, left, mid, 1); 2039bce4eae9SChris Mason if (wret < 0) 2040bce4eae9SChris Mason ret = wret; 2041bce4eae9SChris Mason } 204279f95c82SChris Mason BUG_ON(wret == 1); 204379f95c82SChris Mason } 20445f39d397SChris Mason if (btrfs_header_nritems(mid) == 0) { 20455f39d397SChris Mason clean_tree_block(trans, root, mid); 2046925baeddSChris Mason btrfs_tree_unlock(mid); 2047afe5fea7STsutomu Itoh del_ptr(root, path, level + 1, pslot); 2048f0486c68SYan, Zheng root_sub_used(root, mid->len); 20495581a51aSJan Schmidt btrfs_free_tree_block(trans, root, mid, 0, 1); 20503083ee2eSJosef Bacik free_extent_buffer_stale(mid); 2051f0486c68SYan, Zheng mid = NULL; 205279f95c82SChris Mason } else { 205379f95c82SChris Mason /* update the parent key to reflect our changes */ 20545f39d397SChris Mason struct btrfs_disk_key mid_key; 20555f39d397SChris Mason btrfs_node_key(mid, &mid_key, 0); 205632adf090SLiu Bo tree_mod_log_set_node_key(root->fs_info, parent, 2057f230475eSJan Schmidt pslot, 0); 20585f39d397SChris Mason btrfs_set_node_key(parent, &mid_key, pslot); 20595f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 206079f95c82SChris Mason } 2061bb803951SChris Mason 206279f95c82SChris Mason /* update the path */ 20635f39d397SChris Mason if (left) { 20645f39d397SChris Mason if (btrfs_header_nritems(left) > orig_slot) { 20655f39d397SChris Mason extent_buffer_get(left); 2066925baeddSChris Mason /* left was locked after cow */ 20675f39d397SChris Mason path->nodes[level] = left; 2068bb803951SChris Mason path->slots[level + 1] -= 1; 2069bb803951SChris Mason path->slots[level] = orig_slot; 2070925baeddSChris Mason if (mid) { 2071925baeddSChris Mason btrfs_tree_unlock(mid); 20725f39d397SChris Mason free_extent_buffer(mid); 2073925baeddSChris Mason } 2074bb803951SChris Mason } else { 20755f39d397SChris Mason orig_slot -= btrfs_header_nritems(left); 2076bb803951SChris Mason path->slots[level] = orig_slot; 2077bb803951SChris Mason } 2078bb803951SChris Mason } 207979f95c82SChris Mason /* double check we haven't messed things up */ 2080e20d96d6SChris Mason if (orig_ptr != 20815f39d397SChris Mason btrfs_node_blockptr(path->nodes[level], path->slots[level])) 208279f95c82SChris Mason BUG(); 208354aa1f4dSChris Mason enospc: 2084925baeddSChris Mason if (right) { 2085925baeddSChris Mason btrfs_tree_unlock(right); 20865f39d397SChris Mason free_extent_buffer(right); 2087925baeddSChris Mason } 2088925baeddSChris Mason if (left) { 2089925baeddSChris Mason if (path->nodes[level] != left) 2090925baeddSChris Mason btrfs_tree_unlock(left); 20915f39d397SChris Mason free_extent_buffer(left); 2092925baeddSChris Mason } 2093bb803951SChris Mason return ret; 2094bb803951SChris Mason } 2095bb803951SChris Mason 2096d352ac68SChris Mason /* Node balancing for insertion. Here we only split or push nodes around 2097d352ac68SChris Mason * when they are completely full. This is also done top down, so we 2098d352ac68SChris Mason * have to be pessimistic. 2099d352ac68SChris Mason */ 2100d397712bSChris Mason static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, 2101e66f709bSChris Mason struct btrfs_root *root, 2102e66f709bSChris Mason struct btrfs_path *path, int level) 2103e66f709bSChris Mason { 21045f39d397SChris Mason struct extent_buffer *right = NULL; 21055f39d397SChris Mason struct extent_buffer *mid; 21065f39d397SChris Mason struct extent_buffer *left = NULL; 21075f39d397SChris Mason struct extent_buffer *parent = NULL; 2108e66f709bSChris Mason int ret = 0; 2109e66f709bSChris Mason int wret; 2110e66f709bSChris Mason int pslot; 2111e66f709bSChris Mason int orig_slot = path->slots[level]; 2112e66f709bSChris Mason 2113e66f709bSChris Mason if (level == 0) 2114e66f709bSChris Mason return 1; 2115e66f709bSChris Mason 21165f39d397SChris Mason mid = path->nodes[level]; 21177bb86316SChris Mason WARN_ON(btrfs_header_generation(mid) != trans->transid); 2118e66f709bSChris Mason 2119a05a9bb1SLi Zefan if (level < BTRFS_MAX_LEVEL - 1) { 21205f39d397SChris Mason parent = path->nodes[level + 1]; 2121e66f709bSChris Mason pslot = path->slots[level + 1]; 2122a05a9bb1SLi Zefan } 2123e66f709bSChris Mason 21245f39d397SChris Mason if (!parent) 2125e66f709bSChris Mason return 1; 2126e66f709bSChris Mason 21275f39d397SChris Mason left = read_node_slot(root, parent, pslot - 1); 2128e66f709bSChris Mason 2129e66f709bSChris Mason /* first, try to make some room in the middle buffer */ 21305f39d397SChris Mason if (left) { 2131e66f709bSChris Mason u32 left_nr; 2132925baeddSChris Mason 2133925baeddSChris Mason btrfs_tree_lock(left); 2134b4ce94deSChris Mason btrfs_set_lock_blocking(left); 2135b4ce94deSChris Mason 21365f39d397SChris Mason left_nr = btrfs_header_nritems(left); 213733ade1f8SChris Mason if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { 213833ade1f8SChris Mason wret = 1; 213933ade1f8SChris Mason } else { 21405f39d397SChris Mason ret = btrfs_cow_block(trans, root, left, parent, 21419fa8cfe7SChris Mason pslot - 1, &left); 214254aa1f4dSChris Mason if (ret) 214354aa1f4dSChris Mason wret = 1; 214454aa1f4dSChris Mason else { 214554aa1f4dSChris Mason wret = push_node_left(trans, root, 2146971a1f66SChris Mason left, mid, 0); 214754aa1f4dSChris Mason } 214833ade1f8SChris Mason } 2149e66f709bSChris Mason if (wret < 0) 2150e66f709bSChris Mason ret = wret; 2151e66f709bSChris Mason if (wret == 0) { 21525f39d397SChris Mason struct btrfs_disk_key disk_key; 2153e66f709bSChris Mason orig_slot += left_nr; 21545f39d397SChris Mason btrfs_node_key(mid, &disk_key, 0); 2155f230475eSJan Schmidt tree_mod_log_set_node_key(root->fs_info, parent, 215632adf090SLiu Bo pslot, 0); 21575f39d397SChris Mason btrfs_set_node_key(parent, &disk_key, pslot); 21585f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 21595f39d397SChris Mason if (btrfs_header_nritems(left) > orig_slot) { 21605f39d397SChris Mason path->nodes[level] = left; 2161e66f709bSChris Mason path->slots[level + 1] -= 1; 2162e66f709bSChris Mason path->slots[level] = orig_slot; 2163925baeddSChris Mason btrfs_tree_unlock(mid); 21645f39d397SChris Mason free_extent_buffer(mid); 2165e66f709bSChris Mason } else { 2166e66f709bSChris Mason orig_slot -= 21675f39d397SChris Mason btrfs_header_nritems(left); 2168e66f709bSChris Mason path->slots[level] = orig_slot; 2169925baeddSChris Mason btrfs_tree_unlock(left); 21705f39d397SChris Mason free_extent_buffer(left); 2171e66f709bSChris Mason } 2172e66f709bSChris Mason return 0; 2173e66f709bSChris Mason } 2174925baeddSChris Mason btrfs_tree_unlock(left); 21755f39d397SChris Mason free_extent_buffer(left); 2176e66f709bSChris Mason } 21775f39d397SChris Mason right = read_node_slot(root, parent, pslot + 1); 2178e66f709bSChris Mason 2179e66f709bSChris Mason /* 2180e66f709bSChris Mason * then try to empty the right most buffer into the middle 2181e66f709bSChris Mason */ 21825f39d397SChris Mason if (right) { 218333ade1f8SChris Mason u32 right_nr; 2184b4ce94deSChris Mason 2185925baeddSChris Mason btrfs_tree_lock(right); 2186b4ce94deSChris Mason btrfs_set_lock_blocking(right); 2187b4ce94deSChris Mason 21885f39d397SChris Mason right_nr = btrfs_header_nritems(right); 218933ade1f8SChris Mason if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { 219033ade1f8SChris Mason wret = 1; 219133ade1f8SChris Mason } else { 21925f39d397SChris Mason ret = btrfs_cow_block(trans, root, right, 21935f39d397SChris Mason parent, pslot + 1, 21949fa8cfe7SChris Mason &right); 219554aa1f4dSChris Mason if (ret) 219654aa1f4dSChris Mason wret = 1; 219754aa1f4dSChris Mason else { 219833ade1f8SChris Mason wret = balance_node_right(trans, root, 21995f39d397SChris Mason right, mid); 220033ade1f8SChris Mason } 220154aa1f4dSChris Mason } 2202e66f709bSChris Mason if (wret < 0) 2203e66f709bSChris Mason ret = wret; 2204e66f709bSChris Mason if (wret == 0) { 22055f39d397SChris Mason struct btrfs_disk_key disk_key; 22065f39d397SChris Mason 22075f39d397SChris Mason btrfs_node_key(right, &disk_key, 0); 2208f230475eSJan Schmidt tree_mod_log_set_node_key(root->fs_info, parent, 220932adf090SLiu Bo pslot + 1, 0); 22105f39d397SChris Mason btrfs_set_node_key(parent, &disk_key, pslot + 1); 22115f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 22125f39d397SChris Mason 22135f39d397SChris Mason if (btrfs_header_nritems(mid) <= orig_slot) { 22145f39d397SChris Mason path->nodes[level] = right; 2215e66f709bSChris Mason path->slots[level + 1] += 1; 2216e66f709bSChris Mason path->slots[level] = orig_slot - 22175f39d397SChris Mason btrfs_header_nritems(mid); 2218925baeddSChris Mason btrfs_tree_unlock(mid); 22195f39d397SChris Mason free_extent_buffer(mid); 2220e66f709bSChris Mason } else { 2221925baeddSChris Mason btrfs_tree_unlock(right); 22225f39d397SChris Mason free_extent_buffer(right); 2223e66f709bSChris Mason } 2224e66f709bSChris Mason return 0; 2225e66f709bSChris Mason } 2226925baeddSChris Mason btrfs_tree_unlock(right); 22275f39d397SChris Mason free_extent_buffer(right); 2228e66f709bSChris Mason } 2229e66f709bSChris Mason return 1; 2230e66f709bSChris Mason } 2231e66f709bSChris Mason 223274123bd7SChris Mason /* 2233d352ac68SChris Mason * readahead one full node of leaves, finding things that are close 2234d352ac68SChris Mason * to the block in 'slot', and triggering ra on them. 22353c69faecSChris Mason */ 2236c8c42864SChris Mason static void reada_for_search(struct btrfs_root *root, 2237e02119d5SChris Mason struct btrfs_path *path, 223801f46658SChris Mason int level, int slot, u64 objectid) 22393c69faecSChris Mason { 22405f39d397SChris Mason struct extent_buffer *node; 224101f46658SChris Mason struct btrfs_disk_key disk_key; 22423c69faecSChris Mason u32 nritems; 22433c69faecSChris Mason u64 search; 2244a7175319SChris Mason u64 target; 22456b80053dSChris Mason u64 nread = 0; 2246cb25c2eaSJosef Bacik u64 gen; 22473c69faecSChris Mason int direction = path->reada; 22485f39d397SChris Mason struct extent_buffer *eb; 22496b80053dSChris Mason u32 nr; 22506b80053dSChris Mason u32 blocksize; 22516b80053dSChris Mason u32 nscan = 0; 2252db94535dSChris Mason 2253a6b6e75eSChris Mason if (level != 1) 22543c69faecSChris Mason return; 22553c69faecSChris Mason 22566702ed49SChris Mason if (!path->nodes[level]) 22576702ed49SChris Mason return; 22586702ed49SChris Mason 22595f39d397SChris Mason node = path->nodes[level]; 2260925baeddSChris Mason 22613c69faecSChris Mason search = btrfs_node_blockptr(node, slot); 2262707e8a07SDavid Sterba blocksize = root->nodesize; 22630308af44SDavid Sterba eb = btrfs_find_tree_block(root, search); 22645f39d397SChris Mason if (eb) { 22655f39d397SChris Mason free_extent_buffer(eb); 22663c69faecSChris Mason return; 22673c69faecSChris Mason } 22683c69faecSChris Mason 2269a7175319SChris Mason target = search; 22706b80053dSChris Mason 22715f39d397SChris Mason nritems = btrfs_header_nritems(node); 22726b80053dSChris Mason nr = slot; 227325b8b936SJosef Bacik 22743c69faecSChris Mason while (1) { 22756b80053dSChris Mason if (direction < 0) { 22766b80053dSChris Mason if (nr == 0) 22773c69faecSChris Mason break; 22786b80053dSChris Mason nr--; 22796b80053dSChris Mason } else if (direction > 0) { 22806b80053dSChris Mason nr++; 22816b80053dSChris Mason if (nr >= nritems) 22826b80053dSChris Mason break; 22833c69faecSChris Mason } 228401f46658SChris Mason if (path->reada < 0 && objectid) { 228501f46658SChris Mason btrfs_node_key(node, &disk_key, nr); 228601f46658SChris Mason if (btrfs_disk_key_objectid(&disk_key) != objectid) 228701f46658SChris Mason break; 228801f46658SChris Mason } 22896b80053dSChris Mason search = btrfs_node_blockptr(node, nr); 2290a7175319SChris Mason if ((search <= target && target - search <= 65536) || 2291a7175319SChris Mason (search > target && search - target <= 65536)) { 2292cb25c2eaSJosef Bacik gen = btrfs_node_ptr_generation(node, nr); 229358dc4ce4SDavid Sterba readahead_tree_block(root, search, blocksize); 22946b80053dSChris Mason nread += blocksize; 22953c69faecSChris Mason } 22966b80053dSChris Mason nscan++; 2297a7175319SChris Mason if ((nread > 65536 || nscan > 32)) 22986b80053dSChris Mason break; 22993c69faecSChris Mason } 23003c69faecSChris Mason } 2301925baeddSChris Mason 23020b08851fSJosef Bacik static noinline void reada_for_balance(struct btrfs_root *root, 2303b4ce94deSChris Mason struct btrfs_path *path, int level) 2304b4ce94deSChris Mason { 2305b4ce94deSChris Mason int slot; 2306b4ce94deSChris Mason int nritems; 2307b4ce94deSChris Mason struct extent_buffer *parent; 2308b4ce94deSChris Mason struct extent_buffer *eb; 2309b4ce94deSChris Mason u64 gen; 2310b4ce94deSChris Mason u64 block1 = 0; 2311b4ce94deSChris Mason u64 block2 = 0; 2312b4ce94deSChris Mason int blocksize; 2313b4ce94deSChris Mason 23148c594ea8SChris Mason parent = path->nodes[level + 1]; 2315b4ce94deSChris Mason if (!parent) 23160b08851fSJosef Bacik return; 2317b4ce94deSChris Mason 2318b4ce94deSChris Mason nritems = btrfs_header_nritems(parent); 23198c594ea8SChris Mason slot = path->slots[level + 1]; 2320707e8a07SDavid Sterba blocksize = root->nodesize; 2321b4ce94deSChris Mason 2322b4ce94deSChris Mason if (slot > 0) { 2323b4ce94deSChris Mason block1 = btrfs_node_blockptr(parent, slot - 1); 2324b4ce94deSChris Mason gen = btrfs_node_ptr_generation(parent, slot - 1); 23250308af44SDavid Sterba eb = btrfs_find_tree_block(root, block1); 2326b9fab919SChris Mason /* 2327b9fab919SChris Mason * if we get -eagain from btrfs_buffer_uptodate, we 2328b9fab919SChris Mason * don't want to return eagain here. That will loop 2329b9fab919SChris Mason * forever 2330b9fab919SChris Mason */ 2331b9fab919SChris Mason if (eb && btrfs_buffer_uptodate(eb, gen, 1) != 0) 2332b4ce94deSChris Mason block1 = 0; 2333b4ce94deSChris Mason free_extent_buffer(eb); 2334b4ce94deSChris Mason } 23358c594ea8SChris Mason if (slot + 1 < nritems) { 2336b4ce94deSChris Mason block2 = btrfs_node_blockptr(parent, slot + 1); 2337b4ce94deSChris Mason gen = btrfs_node_ptr_generation(parent, slot + 1); 23380308af44SDavid Sterba eb = btrfs_find_tree_block(root, block2); 2339b9fab919SChris Mason if (eb && btrfs_buffer_uptodate(eb, gen, 1) != 0) 2340b4ce94deSChris Mason block2 = 0; 2341b4ce94deSChris Mason free_extent_buffer(eb); 2342b4ce94deSChris Mason } 23438c594ea8SChris Mason 2344b4ce94deSChris Mason if (block1) 234558dc4ce4SDavid Sterba readahead_tree_block(root, block1, blocksize); 2346b4ce94deSChris Mason if (block2) 234758dc4ce4SDavid Sterba readahead_tree_block(root, block2, blocksize); 2348b4ce94deSChris Mason } 2349b4ce94deSChris Mason 2350b4ce94deSChris Mason 2351b4ce94deSChris Mason /* 2352d397712bSChris Mason * when we walk down the tree, it is usually safe to unlock the higher layers 2353d397712bSChris Mason * in the tree. The exceptions are when our path goes through slot 0, because 2354d397712bSChris Mason * operations on the tree might require changing key pointers higher up in the 2355d397712bSChris Mason * tree. 2356d352ac68SChris Mason * 2357d397712bSChris Mason * callers might also have set path->keep_locks, which tells this code to keep 2358d397712bSChris Mason * the lock if the path points to the last slot in the block. This is part of 2359d397712bSChris Mason * walking through the tree, and selecting the next slot in the higher block. 2360d352ac68SChris Mason * 2361d397712bSChris Mason * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so 2362d397712bSChris Mason * if lowest_unlock is 1, level 0 won't be unlocked 2363d352ac68SChris Mason */ 2364e02119d5SChris Mason static noinline void unlock_up(struct btrfs_path *path, int level, 2365f7c79f30SChris Mason int lowest_unlock, int min_write_lock_level, 2366f7c79f30SChris Mason int *write_lock_level) 2367925baeddSChris Mason { 2368925baeddSChris Mason int i; 2369925baeddSChris Mason int skip_level = level; 2370051e1b9fSChris Mason int no_skips = 0; 2371925baeddSChris Mason struct extent_buffer *t; 2372925baeddSChris Mason 2373925baeddSChris Mason for (i = level; i < BTRFS_MAX_LEVEL; i++) { 2374925baeddSChris Mason if (!path->nodes[i]) 2375925baeddSChris Mason break; 2376925baeddSChris Mason if (!path->locks[i]) 2377925baeddSChris Mason break; 2378051e1b9fSChris Mason if (!no_skips && path->slots[i] == 0) { 2379925baeddSChris Mason skip_level = i + 1; 2380925baeddSChris Mason continue; 2381925baeddSChris Mason } 2382051e1b9fSChris Mason if (!no_skips && path->keep_locks) { 2383925baeddSChris Mason u32 nritems; 2384925baeddSChris Mason t = path->nodes[i]; 2385925baeddSChris Mason nritems = btrfs_header_nritems(t); 2386051e1b9fSChris Mason if (nritems < 1 || path->slots[i] >= nritems - 1) { 2387925baeddSChris Mason skip_level = i + 1; 2388925baeddSChris Mason continue; 2389925baeddSChris Mason } 2390925baeddSChris Mason } 2391051e1b9fSChris Mason if (skip_level < i && i >= lowest_unlock) 2392051e1b9fSChris Mason no_skips = 1; 2393051e1b9fSChris Mason 2394925baeddSChris Mason t = path->nodes[i]; 2395925baeddSChris Mason if (i >= lowest_unlock && i > skip_level && path->locks[i]) { 2396bd681513SChris Mason btrfs_tree_unlock_rw(t, path->locks[i]); 2397925baeddSChris Mason path->locks[i] = 0; 2398f7c79f30SChris Mason if (write_lock_level && 2399f7c79f30SChris Mason i > min_write_lock_level && 2400f7c79f30SChris Mason i <= *write_lock_level) { 2401f7c79f30SChris Mason *write_lock_level = i - 1; 2402f7c79f30SChris Mason } 2403925baeddSChris Mason } 2404925baeddSChris Mason } 2405925baeddSChris Mason } 2406925baeddSChris Mason 24073c69faecSChris Mason /* 2408b4ce94deSChris Mason * This releases any locks held in the path starting at level and 2409b4ce94deSChris Mason * going all the way up to the root. 2410b4ce94deSChris Mason * 2411b4ce94deSChris Mason * btrfs_search_slot will keep the lock held on higher nodes in a few 2412b4ce94deSChris Mason * corner cases, such as COW of the block at slot zero in the node. This 2413b4ce94deSChris Mason * ignores those rules, and it should only be called when there are no 2414b4ce94deSChris Mason * more updates to be done higher up in the tree. 2415b4ce94deSChris Mason */ 2416b4ce94deSChris Mason noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) 2417b4ce94deSChris Mason { 2418b4ce94deSChris Mason int i; 2419b4ce94deSChris Mason 242009a2a8f9SJosef Bacik if (path->keep_locks) 2421b4ce94deSChris Mason return; 2422b4ce94deSChris Mason 2423b4ce94deSChris Mason for (i = level; i < BTRFS_MAX_LEVEL; i++) { 2424b4ce94deSChris Mason if (!path->nodes[i]) 242512f4daccSChris Mason continue; 2426b4ce94deSChris Mason if (!path->locks[i]) 242712f4daccSChris Mason continue; 2428bd681513SChris Mason btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); 2429b4ce94deSChris Mason path->locks[i] = 0; 2430b4ce94deSChris Mason } 2431b4ce94deSChris Mason } 2432b4ce94deSChris Mason 2433b4ce94deSChris Mason /* 2434c8c42864SChris Mason * helper function for btrfs_search_slot. The goal is to find a block 2435c8c42864SChris Mason * in cache without setting the path to blocking. If we find the block 2436c8c42864SChris Mason * we return zero and the path is unchanged. 2437c8c42864SChris Mason * 2438c8c42864SChris Mason * If we can't find the block, we set the path blocking and do some 2439c8c42864SChris Mason * reada. -EAGAIN is returned and the search must be repeated. 2440c8c42864SChris Mason */ 2441c8c42864SChris Mason static int 2442c8c42864SChris Mason read_block_for_search(struct btrfs_trans_handle *trans, 2443c8c42864SChris Mason struct btrfs_root *root, struct btrfs_path *p, 2444c8c42864SChris Mason struct extent_buffer **eb_ret, int level, int slot, 24455d9e75c4SJan Schmidt struct btrfs_key *key, u64 time_seq) 2446c8c42864SChris Mason { 2447c8c42864SChris Mason u64 blocknr; 2448c8c42864SChris Mason u64 gen; 2449c8c42864SChris Mason struct extent_buffer *b = *eb_ret; 2450c8c42864SChris Mason struct extent_buffer *tmp; 245176a05b35SChris Mason int ret; 2452c8c42864SChris Mason 2453c8c42864SChris Mason blocknr = btrfs_node_blockptr(b, slot); 2454c8c42864SChris Mason gen = btrfs_node_ptr_generation(b, slot); 2455c8c42864SChris Mason 24560308af44SDavid Sterba tmp = btrfs_find_tree_block(root, blocknr); 2457cb44921aSChris Mason if (tmp) { 2458b9fab919SChris Mason /* first we do an atomic uptodate check */ 2459b9fab919SChris Mason if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { 2460c8c42864SChris Mason *eb_ret = tmp; 2461c8c42864SChris Mason return 0; 2462c8c42864SChris Mason } 2463bdf7c00eSJosef Bacik 2464cb44921aSChris Mason /* the pages were up to date, but we failed 2465cb44921aSChris Mason * the generation number check. Do a full 2466cb44921aSChris Mason * read for the generation number that is correct. 2467cb44921aSChris Mason * We must do this without dropping locks so 2468cb44921aSChris Mason * we can trust our generation number 2469cb44921aSChris Mason */ 2470bd681513SChris Mason btrfs_set_path_blocking(p); 2471bd681513SChris Mason 2472b9fab919SChris Mason /* now we're allowed to do a blocking uptodate check */ 2473bdf7c00eSJosef Bacik ret = btrfs_read_buffer(tmp, gen); 2474bdf7c00eSJosef Bacik if (!ret) { 2475cb44921aSChris Mason *eb_ret = tmp; 2476cb44921aSChris Mason return 0; 2477cb44921aSChris Mason } 2478cb44921aSChris Mason free_extent_buffer(tmp); 2479b3b4aa74SDavid Sterba btrfs_release_path(p); 2480cb44921aSChris Mason return -EIO; 2481cb44921aSChris Mason } 2482c8c42864SChris Mason 2483c8c42864SChris Mason /* 2484c8c42864SChris Mason * reduce lock contention at high levels 2485c8c42864SChris Mason * of the btree by dropping locks before 248676a05b35SChris Mason * we read. Don't release the lock on the current 248776a05b35SChris Mason * level because we need to walk this node to figure 248876a05b35SChris Mason * out which blocks to read. 2489c8c42864SChris Mason */ 24908c594ea8SChris Mason btrfs_unlock_up_safe(p, level + 1); 24918c594ea8SChris Mason btrfs_set_path_blocking(p); 24928c594ea8SChris Mason 2493c8c42864SChris Mason free_extent_buffer(tmp); 2494c8c42864SChris Mason if (p->reada) 2495c8c42864SChris Mason reada_for_search(root, p, level, slot, key->objectid); 2496c8c42864SChris Mason 2497b3b4aa74SDavid Sterba btrfs_release_path(p); 249876a05b35SChris Mason 249976a05b35SChris Mason ret = -EAGAIN; 2500ce86cd59SDavid Sterba tmp = read_tree_block(root, blocknr, 0); 250176a05b35SChris Mason if (tmp) { 250276a05b35SChris Mason /* 250376a05b35SChris Mason * If the read above didn't mark this buffer up to date, 250476a05b35SChris Mason * it will never end up being up to date. Set ret to EIO now 250576a05b35SChris Mason * and give up so that our caller doesn't loop forever 250676a05b35SChris Mason * on our EAGAINs. 250776a05b35SChris Mason */ 2508b9fab919SChris Mason if (!btrfs_buffer_uptodate(tmp, 0, 0)) 250976a05b35SChris Mason ret = -EIO; 2510c8c42864SChris Mason free_extent_buffer(tmp); 251176a05b35SChris Mason } 251276a05b35SChris Mason return ret; 2513c8c42864SChris Mason } 2514c8c42864SChris Mason 2515c8c42864SChris Mason /* 2516c8c42864SChris Mason * helper function for btrfs_search_slot. This does all of the checks 2517c8c42864SChris Mason * for node-level blocks and does any balancing required based on 2518c8c42864SChris Mason * the ins_len. 2519c8c42864SChris Mason * 2520c8c42864SChris Mason * If no extra work was required, zero is returned. If we had to 2521c8c42864SChris Mason * drop the path, -EAGAIN is returned and btrfs_search_slot must 2522c8c42864SChris Mason * start over 2523c8c42864SChris Mason */ 2524c8c42864SChris Mason static int 2525c8c42864SChris Mason setup_nodes_for_search(struct btrfs_trans_handle *trans, 2526c8c42864SChris Mason struct btrfs_root *root, struct btrfs_path *p, 2527bd681513SChris Mason struct extent_buffer *b, int level, int ins_len, 2528bd681513SChris Mason int *write_lock_level) 2529c8c42864SChris Mason { 2530c8c42864SChris Mason int ret; 2531c8c42864SChris Mason if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= 2532c8c42864SChris Mason BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { 2533c8c42864SChris Mason int sret; 2534c8c42864SChris Mason 2535bd681513SChris Mason if (*write_lock_level < level + 1) { 2536bd681513SChris Mason *write_lock_level = level + 1; 2537bd681513SChris Mason btrfs_release_path(p); 2538bd681513SChris Mason goto again; 2539bd681513SChris Mason } 2540bd681513SChris Mason 2541c8c42864SChris Mason btrfs_set_path_blocking(p); 25420b08851fSJosef Bacik reada_for_balance(root, p, level); 2543c8c42864SChris Mason sret = split_node(trans, root, p, level); 2544bd681513SChris Mason btrfs_clear_path_blocking(p, NULL, 0); 2545c8c42864SChris Mason 2546c8c42864SChris Mason BUG_ON(sret > 0); 2547c8c42864SChris Mason if (sret) { 2548c8c42864SChris Mason ret = sret; 2549c8c42864SChris Mason goto done; 2550c8c42864SChris Mason } 2551c8c42864SChris Mason b = p->nodes[level]; 2552c8c42864SChris Mason } else if (ins_len < 0 && btrfs_header_nritems(b) < 2553cfbb9308SChris Mason BTRFS_NODEPTRS_PER_BLOCK(root) / 2) { 2554c8c42864SChris Mason int sret; 2555c8c42864SChris Mason 2556bd681513SChris Mason if (*write_lock_level < level + 1) { 2557bd681513SChris Mason *write_lock_level = level + 1; 2558bd681513SChris Mason btrfs_release_path(p); 2559bd681513SChris Mason goto again; 2560bd681513SChris Mason } 2561bd681513SChris Mason 2562c8c42864SChris Mason btrfs_set_path_blocking(p); 25630b08851fSJosef Bacik reada_for_balance(root, p, level); 2564c8c42864SChris Mason sret = balance_level(trans, root, p, level); 2565bd681513SChris Mason btrfs_clear_path_blocking(p, NULL, 0); 2566c8c42864SChris Mason 2567c8c42864SChris Mason if (sret) { 2568c8c42864SChris Mason ret = sret; 2569c8c42864SChris Mason goto done; 2570c8c42864SChris Mason } 2571c8c42864SChris Mason b = p->nodes[level]; 2572c8c42864SChris Mason if (!b) { 2573b3b4aa74SDavid Sterba btrfs_release_path(p); 2574c8c42864SChris Mason goto again; 2575c8c42864SChris Mason } 2576c8c42864SChris Mason BUG_ON(btrfs_header_nritems(b) == 1); 2577c8c42864SChris Mason } 2578c8c42864SChris Mason return 0; 2579c8c42864SChris Mason 2580c8c42864SChris Mason again: 2581c8c42864SChris Mason ret = -EAGAIN; 2582c8c42864SChris Mason done: 2583c8c42864SChris Mason return ret; 2584c8c42864SChris Mason } 2585c8c42864SChris Mason 2586d7396f07SFilipe David Borba Manana static void key_search_validate(struct extent_buffer *b, 2587d7396f07SFilipe David Borba Manana struct btrfs_key *key, 2588d7396f07SFilipe David Borba Manana int level) 2589d7396f07SFilipe David Borba Manana { 2590d7396f07SFilipe David Borba Manana #ifdef CONFIG_BTRFS_ASSERT 2591d7396f07SFilipe David Borba Manana struct btrfs_disk_key disk_key; 2592d7396f07SFilipe David Borba Manana 2593d7396f07SFilipe David Borba Manana btrfs_cpu_key_to_disk(&disk_key, key); 2594d7396f07SFilipe David Borba Manana 2595d7396f07SFilipe David Borba Manana if (level == 0) 2596d7396f07SFilipe David Borba Manana ASSERT(!memcmp_extent_buffer(b, &disk_key, 2597d7396f07SFilipe David Borba Manana offsetof(struct btrfs_leaf, items[0].key), 2598d7396f07SFilipe David Borba Manana sizeof(disk_key))); 2599d7396f07SFilipe David Borba Manana else 2600d7396f07SFilipe David Borba Manana ASSERT(!memcmp_extent_buffer(b, &disk_key, 2601d7396f07SFilipe David Borba Manana offsetof(struct btrfs_node, ptrs[0].key), 2602d7396f07SFilipe David Borba Manana sizeof(disk_key))); 2603d7396f07SFilipe David Borba Manana #endif 2604d7396f07SFilipe David Borba Manana } 2605d7396f07SFilipe David Borba Manana 2606d7396f07SFilipe David Borba Manana static int key_search(struct extent_buffer *b, struct btrfs_key *key, 2607d7396f07SFilipe David Borba Manana int level, int *prev_cmp, int *slot) 2608d7396f07SFilipe David Borba Manana { 2609d7396f07SFilipe David Borba Manana if (*prev_cmp != 0) { 2610d7396f07SFilipe David Borba Manana *prev_cmp = bin_search(b, key, level, slot); 2611d7396f07SFilipe David Borba Manana return *prev_cmp; 2612d7396f07SFilipe David Borba Manana } 2613d7396f07SFilipe David Borba Manana 2614d7396f07SFilipe David Borba Manana key_search_validate(b, key, level); 2615d7396f07SFilipe David Borba Manana *slot = 0; 2616d7396f07SFilipe David Borba Manana 2617d7396f07SFilipe David Borba Manana return 0; 2618d7396f07SFilipe David Borba Manana } 2619d7396f07SFilipe David Borba Manana 26203f870c28SKelley Nielsen int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *found_path, 2621e33d5c3dSKelley Nielsen u64 iobjectid, u64 ioff, u8 key_type, 2622e33d5c3dSKelley Nielsen struct btrfs_key *found_key) 2623e33d5c3dSKelley Nielsen { 2624e33d5c3dSKelley Nielsen int ret; 2625e33d5c3dSKelley Nielsen struct btrfs_key key; 2626e33d5c3dSKelley Nielsen struct extent_buffer *eb; 26273f870c28SKelley Nielsen struct btrfs_path *path; 2628e33d5c3dSKelley Nielsen 2629e33d5c3dSKelley Nielsen key.type = key_type; 2630e33d5c3dSKelley Nielsen key.objectid = iobjectid; 2631e33d5c3dSKelley Nielsen key.offset = ioff; 2632e33d5c3dSKelley Nielsen 26333f870c28SKelley Nielsen if (found_path == NULL) { 26343f870c28SKelley Nielsen path = btrfs_alloc_path(); 26353f870c28SKelley Nielsen if (!path) 26363f870c28SKelley Nielsen return -ENOMEM; 26373f870c28SKelley Nielsen } else 26383f870c28SKelley Nielsen path = found_path; 26393f870c28SKelley Nielsen 2640e33d5c3dSKelley Nielsen ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); 26413f870c28SKelley Nielsen if ((ret < 0) || (found_key == NULL)) { 26423f870c28SKelley Nielsen if (path != found_path) 26433f870c28SKelley Nielsen btrfs_free_path(path); 2644e33d5c3dSKelley Nielsen return ret; 26453f870c28SKelley Nielsen } 2646e33d5c3dSKelley Nielsen 2647e33d5c3dSKelley Nielsen eb = path->nodes[0]; 2648e33d5c3dSKelley Nielsen if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { 2649e33d5c3dSKelley Nielsen ret = btrfs_next_leaf(fs_root, path); 2650e33d5c3dSKelley Nielsen if (ret) 2651e33d5c3dSKelley Nielsen return ret; 2652e33d5c3dSKelley Nielsen eb = path->nodes[0]; 2653e33d5c3dSKelley Nielsen } 2654e33d5c3dSKelley Nielsen 2655e33d5c3dSKelley Nielsen btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); 2656e33d5c3dSKelley Nielsen if (found_key->type != key.type || 2657e33d5c3dSKelley Nielsen found_key->objectid != key.objectid) 2658e33d5c3dSKelley Nielsen return 1; 2659e33d5c3dSKelley Nielsen 2660e33d5c3dSKelley Nielsen return 0; 2661e33d5c3dSKelley Nielsen } 2662e33d5c3dSKelley Nielsen 2663c8c42864SChris Mason /* 266474123bd7SChris Mason * look for key in the tree. path is filled in with nodes along the way 266574123bd7SChris Mason * if key is found, we return zero and you can find the item in the leaf 266674123bd7SChris Mason * level of the path (level 0) 266774123bd7SChris Mason * 266874123bd7SChris Mason * If the key isn't found, the path points to the slot where it should 2669aa5d6bedSChris Mason * be inserted, and 1 is returned. If there are other errors during the 2670aa5d6bedSChris Mason * search a negative error number is returned. 267197571fd0SChris Mason * 267297571fd0SChris Mason * if ins_len > 0, nodes and leaves will be split as we walk down the 267397571fd0SChris Mason * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if 267497571fd0SChris Mason * possible) 267574123bd7SChris Mason */ 2676e089f05cSChris Mason int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root 2677e089f05cSChris Mason *root, struct btrfs_key *key, struct btrfs_path *p, int 2678e089f05cSChris Mason ins_len, int cow) 2679be0e5c09SChris Mason { 26805f39d397SChris Mason struct extent_buffer *b; 2681be0e5c09SChris Mason int slot; 2682be0e5c09SChris Mason int ret; 268333c66f43SYan Zheng int err; 2684be0e5c09SChris Mason int level; 2685925baeddSChris Mason int lowest_unlock = 1; 2686bd681513SChris Mason int root_lock; 2687bd681513SChris Mason /* everything at write_lock_level or lower must be write locked */ 2688bd681513SChris Mason int write_lock_level = 0; 26899f3a7427SChris Mason u8 lowest_level = 0; 2690f7c79f30SChris Mason int min_write_lock_level; 2691d7396f07SFilipe David Borba Manana int prev_cmp; 26929f3a7427SChris Mason 26936702ed49SChris Mason lowest_level = p->lowest_level; 2694323ac95bSChris Mason WARN_ON(lowest_level && ins_len > 0); 269522b0ebdaSChris Mason WARN_ON(p->nodes[0] != NULL); 2696eb653de1SFilipe David Borba Manana BUG_ON(!cow && ins_len); 269725179201SJosef Bacik 2698bd681513SChris Mason if (ins_len < 0) { 2699925baeddSChris Mason lowest_unlock = 2; 270065b51a00SChris Mason 2701bd681513SChris Mason /* when we are removing items, we might have to go up to level 2702bd681513SChris Mason * two as we update tree pointers Make sure we keep write 2703bd681513SChris Mason * for those levels as well 2704bd681513SChris Mason */ 2705bd681513SChris Mason write_lock_level = 2; 2706bd681513SChris Mason } else if (ins_len > 0) { 2707bd681513SChris Mason /* 2708bd681513SChris Mason * for inserting items, make sure we have a write lock on 2709bd681513SChris Mason * level 1 so we can update keys 2710bd681513SChris Mason */ 2711bd681513SChris Mason write_lock_level = 1; 2712bd681513SChris Mason } 2713bd681513SChris Mason 2714bd681513SChris Mason if (!cow) 2715bd681513SChris Mason write_lock_level = -1; 2716bd681513SChris Mason 271709a2a8f9SJosef Bacik if (cow && (p->keep_locks || p->lowest_level)) 2718bd681513SChris Mason write_lock_level = BTRFS_MAX_LEVEL; 2719bd681513SChris Mason 2720f7c79f30SChris Mason min_write_lock_level = write_lock_level; 2721f7c79f30SChris Mason 2722bb803951SChris Mason again: 2723d7396f07SFilipe David Borba Manana prev_cmp = -1; 2724bd681513SChris Mason /* 2725bd681513SChris Mason * we try very hard to do read locks on the root 2726bd681513SChris Mason */ 2727bd681513SChris Mason root_lock = BTRFS_READ_LOCK; 2728bd681513SChris Mason level = 0; 27295d4f98a2SYan Zheng if (p->search_commit_root) { 2730bd681513SChris Mason /* 2731bd681513SChris Mason * the commit roots are read only 2732bd681513SChris Mason * so we always do read locks 2733bd681513SChris Mason */ 27343f8a18ccSJosef Bacik if (p->need_commit_sem) 27353f8a18ccSJosef Bacik down_read(&root->fs_info->commit_root_sem); 27365d4f98a2SYan Zheng b = root->commit_root; 27375d4f98a2SYan Zheng extent_buffer_get(b); 2738bd681513SChris Mason level = btrfs_header_level(b); 27393f8a18ccSJosef Bacik if (p->need_commit_sem) 27403f8a18ccSJosef Bacik up_read(&root->fs_info->commit_root_sem); 27415d4f98a2SYan Zheng if (!p->skip_locking) 2742bd681513SChris Mason btrfs_tree_read_lock(b); 27435d4f98a2SYan Zheng } else { 2744bd681513SChris Mason if (p->skip_locking) { 27455cd57b2cSChris Mason b = btrfs_root_node(root); 2746bd681513SChris Mason level = btrfs_header_level(b); 2747bd681513SChris Mason } else { 2748bd681513SChris Mason /* we don't know the level of the root node 2749bd681513SChris Mason * until we actually have it read locked 2750bd681513SChris Mason */ 2751bd681513SChris Mason b = btrfs_read_lock_root_node(root); 2752bd681513SChris Mason level = btrfs_header_level(b); 2753bd681513SChris Mason if (level <= write_lock_level) { 2754bd681513SChris Mason /* whoops, must trade for write lock */ 2755bd681513SChris Mason btrfs_tree_read_unlock(b); 2756bd681513SChris Mason free_extent_buffer(b); 2757925baeddSChris Mason b = btrfs_lock_root_node(root); 2758bd681513SChris Mason root_lock = BTRFS_WRITE_LOCK; 2759bd681513SChris Mason 2760bd681513SChris Mason /* the level might have changed, check again */ 2761bd681513SChris Mason level = btrfs_header_level(b); 27625d4f98a2SYan Zheng } 2763bd681513SChris Mason } 2764bd681513SChris Mason } 2765bd681513SChris Mason p->nodes[level] = b; 2766bd681513SChris Mason if (!p->skip_locking) 2767bd681513SChris Mason p->locks[level] = root_lock; 2768925baeddSChris Mason 2769eb60ceacSChris Mason while (b) { 27705f39d397SChris Mason level = btrfs_header_level(b); 277165b51a00SChris Mason 277265b51a00SChris Mason /* 277365b51a00SChris Mason * setup the path here so we can release it under lock 277465b51a00SChris Mason * contention with the cow code 277565b51a00SChris Mason */ 277602217ed2SChris Mason if (cow) { 2777c8c42864SChris Mason /* 2778c8c42864SChris Mason * if we don't really need to cow this block 2779c8c42864SChris Mason * then we don't want to set the path blocking, 2780c8c42864SChris Mason * so we test it here 2781c8c42864SChris Mason */ 27825d4f98a2SYan Zheng if (!should_cow_block(trans, root, b)) 278365b51a00SChris Mason goto cow_done; 27845d4f98a2SYan Zheng 2785bd681513SChris Mason /* 2786bd681513SChris Mason * must have write locks on this node and the 2787bd681513SChris Mason * parent 2788bd681513SChris Mason */ 27895124e00eSJosef Bacik if (level > write_lock_level || 27905124e00eSJosef Bacik (level + 1 > write_lock_level && 27915124e00eSJosef Bacik level + 1 < BTRFS_MAX_LEVEL && 27925124e00eSJosef Bacik p->nodes[level + 1])) { 2793bd681513SChris Mason write_lock_level = level + 1; 2794bd681513SChris Mason btrfs_release_path(p); 2795bd681513SChris Mason goto again; 2796bd681513SChris Mason } 2797bd681513SChris Mason 2798160f4089SFilipe Manana btrfs_set_path_blocking(p); 279933c66f43SYan Zheng err = btrfs_cow_block(trans, root, b, 2800e20d96d6SChris Mason p->nodes[level + 1], 28019fa8cfe7SChris Mason p->slots[level + 1], &b); 280233c66f43SYan Zheng if (err) { 280333c66f43SYan Zheng ret = err; 280465b51a00SChris Mason goto done; 280554aa1f4dSChris Mason } 280602217ed2SChris Mason } 280765b51a00SChris Mason cow_done: 2808eb60ceacSChris Mason p->nodes[level] = b; 2809bd681513SChris Mason btrfs_clear_path_blocking(p, NULL, 0); 2810b4ce94deSChris Mason 2811b4ce94deSChris Mason /* 2812b4ce94deSChris Mason * we have a lock on b and as long as we aren't changing 2813b4ce94deSChris Mason * the tree, there is no way to for the items in b to change. 2814b4ce94deSChris Mason * It is safe to drop the lock on our parent before we 2815b4ce94deSChris Mason * go through the expensive btree search on b. 2816b4ce94deSChris Mason * 2817eb653de1SFilipe David Borba Manana * If we're inserting or deleting (ins_len != 0), then we might 2818eb653de1SFilipe David Borba Manana * be changing slot zero, which may require changing the parent. 2819eb653de1SFilipe David Borba Manana * So, we can't drop the lock until after we know which slot 2820eb653de1SFilipe David Borba Manana * we're operating on. 2821b4ce94deSChris Mason */ 2822eb653de1SFilipe David Borba Manana if (!ins_len && !p->keep_locks) { 2823eb653de1SFilipe David Borba Manana int u = level + 1; 2824eb653de1SFilipe David Borba Manana 2825eb653de1SFilipe David Borba Manana if (u < BTRFS_MAX_LEVEL && p->locks[u]) { 2826eb653de1SFilipe David Borba Manana btrfs_tree_unlock_rw(p->nodes[u], p->locks[u]); 2827eb653de1SFilipe David Borba Manana p->locks[u] = 0; 2828eb653de1SFilipe David Borba Manana } 2829eb653de1SFilipe David Borba Manana } 2830b4ce94deSChris Mason 2831d7396f07SFilipe David Borba Manana ret = key_search(b, key, level, &prev_cmp, &slot); 2832b4ce94deSChris Mason 28335f39d397SChris Mason if (level != 0) { 283433c66f43SYan Zheng int dec = 0; 283533c66f43SYan Zheng if (ret && slot > 0) { 283633c66f43SYan Zheng dec = 1; 2837be0e5c09SChris Mason slot -= 1; 283833c66f43SYan Zheng } 2839be0e5c09SChris Mason p->slots[level] = slot; 284033c66f43SYan Zheng err = setup_nodes_for_search(trans, root, p, b, level, 2841bd681513SChris Mason ins_len, &write_lock_level); 284233c66f43SYan Zheng if (err == -EAGAIN) 2843b4ce94deSChris Mason goto again; 284433c66f43SYan Zheng if (err) { 284533c66f43SYan Zheng ret = err; 284665b51a00SChris Mason goto done; 284733c66f43SYan Zheng } 28485c680ed6SChris Mason b = p->nodes[level]; 28495c680ed6SChris Mason slot = p->slots[level]; 2850b4ce94deSChris Mason 2851bd681513SChris Mason /* 2852bd681513SChris Mason * slot 0 is special, if we change the key 2853bd681513SChris Mason * we have to update the parent pointer 2854bd681513SChris Mason * which means we must have a write lock 2855bd681513SChris Mason * on the parent 2856bd681513SChris Mason */ 2857eb653de1SFilipe David Borba Manana if (slot == 0 && ins_len && 2858bd681513SChris Mason write_lock_level < level + 1) { 2859bd681513SChris Mason write_lock_level = level + 1; 2860bd681513SChris Mason btrfs_release_path(p); 2861bd681513SChris Mason goto again; 2862bd681513SChris Mason } 2863bd681513SChris Mason 2864f7c79f30SChris Mason unlock_up(p, level, lowest_unlock, 2865f7c79f30SChris Mason min_write_lock_level, &write_lock_level); 2866f9efa9c7SChris Mason 2867925baeddSChris Mason if (level == lowest_level) { 286833c66f43SYan Zheng if (dec) 286933c66f43SYan Zheng p->slots[level]++; 28705b21f2edSZheng Yan goto done; 2871925baeddSChris Mason } 2872ca7a79adSChris Mason 287333c66f43SYan Zheng err = read_block_for_search(trans, root, p, 28745d9e75c4SJan Schmidt &b, level, slot, key, 0); 287533c66f43SYan Zheng if (err == -EAGAIN) 2876051e1b9fSChris Mason goto again; 287733c66f43SYan Zheng if (err) { 287833c66f43SYan Zheng ret = err; 287976a05b35SChris Mason goto done; 288033c66f43SYan Zheng } 288176a05b35SChris Mason 2882b4ce94deSChris Mason if (!p->skip_locking) { 2883bd681513SChris Mason level = btrfs_header_level(b); 2884bd681513SChris Mason if (level <= write_lock_level) { 2885bd681513SChris Mason err = btrfs_try_tree_write_lock(b); 288633c66f43SYan Zheng if (!err) { 2887b4ce94deSChris Mason btrfs_set_path_blocking(p); 2888925baeddSChris Mason btrfs_tree_lock(b); 2889bd681513SChris Mason btrfs_clear_path_blocking(p, b, 2890bd681513SChris Mason BTRFS_WRITE_LOCK); 2891b4ce94deSChris Mason } 2892bd681513SChris Mason p->locks[level] = BTRFS_WRITE_LOCK; 2893bd681513SChris Mason } else { 2894f82c458aSChris Mason err = btrfs_tree_read_lock_atomic(b); 2895bd681513SChris Mason if (!err) { 2896bd681513SChris Mason btrfs_set_path_blocking(p); 2897bd681513SChris Mason btrfs_tree_read_lock(b); 2898bd681513SChris Mason btrfs_clear_path_blocking(p, b, 2899bd681513SChris Mason BTRFS_READ_LOCK); 2900bd681513SChris Mason } 2901bd681513SChris Mason p->locks[level] = BTRFS_READ_LOCK; 2902bd681513SChris Mason } 2903bd681513SChris Mason p->nodes[level] = b; 2904b4ce94deSChris Mason } 2905be0e5c09SChris Mason } else { 2906be0e5c09SChris Mason p->slots[level] = slot; 290787b29b20SYan Zheng if (ins_len > 0 && 290887b29b20SYan Zheng btrfs_leaf_free_space(root, b) < ins_len) { 2909bd681513SChris Mason if (write_lock_level < 1) { 2910bd681513SChris Mason write_lock_level = 1; 2911bd681513SChris Mason btrfs_release_path(p); 2912bd681513SChris Mason goto again; 2913bd681513SChris Mason } 2914bd681513SChris Mason 2915b4ce94deSChris Mason btrfs_set_path_blocking(p); 291633c66f43SYan Zheng err = split_leaf(trans, root, key, 2917cc0c5538SChris Mason p, ins_len, ret == 0); 2918bd681513SChris Mason btrfs_clear_path_blocking(p, NULL, 0); 2919b4ce94deSChris Mason 292033c66f43SYan Zheng BUG_ON(err > 0); 292133c66f43SYan Zheng if (err) { 292233c66f43SYan Zheng ret = err; 292365b51a00SChris Mason goto done; 292465b51a00SChris Mason } 29255c680ed6SChris Mason } 2926459931ecSChris Mason if (!p->search_for_split) 2927f7c79f30SChris Mason unlock_up(p, level, lowest_unlock, 2928f7c79f30SChris Mason min_write_lock_level, &write_lock_level); 292965b51a00SChris Mason goto done; 293065b51a00SChris Mason } 293165b51a00SChris Mason } 293265b51a00SChris Mason ret = 1; 293365b51a00SChris Mason done: 2934b4ce94deSChris Mason /* 2935b4ce94deSChris Mason * we don't really know what they plan on doing with the path 2936b4ce94deSChris Mason * from here on, so for now just mark it as blocking 2937b4ce94deSChris Mason */ 2938b9473439SChris Mason if (!p->leave_spinning) 2939b4ce94deSChris Mason btrfs_set_path_blocking(p); 29405f5bc6b1SFilipe Manana if (ret < 0 && !p->skip_release_on_error) 2941b3b4aa74SDavid Sterba btrfs_release_path(p); 2942be0e5c09SChris Mason return ret; 2943be0e5c09SChris Mason } 2944be0e5c09SChris Mason 294574123bd7SChris Mason /* 29465d9e75c4SJan Schmidt * Like btrfs_search_slot, this looks for a key in the given tree. It uses the 29475d9e75c4SJan Schmidt * current state of the tree together with the operations recorded in the tree 29485d9e75c4SJan Schmidt * modification log to search for the key in a previous version of this tree, as 29495d9e75c4SJan Schmidt * denoted by the time_seq parameter. 29505d9e75c4SJan Schmidt * 29515d9e75c4SJan Schmidt * Naturally, there is no support for insert, delete or cow operations. 29525d9e75c4SJan Schmidt * 29535d9e75c4SJan Schmidt * The resulting path and return value will be set up as if we called 29545d9e75c4SJan Schmidt * btrfs_search_slot at that point in time with ins_len and cow both set to 0. 29555d9e75c4SJan Schmidt */ 29565d9e75c4SJan Schmidt int btrfs_search_old_slot(struct btrfs_root *root, struct btrfs_key *key, 29575d9e75c4SJan Schmidt struct btrfs_path *p, u64 time_seq) 29585d9e75c4SJan Schmidt { 29595d9e75c4SJan Schmidt struct extent_buffer *b; 29605d9e75c4SJan Schmidt int slot; 29615d9e75c4SJan Schmidt int ret; 29625d9e75c4SJan Schmidt int err; 29635d9e75c4SJan Schmidt int level; 29645d9e75c4SJan Schmidt int lowest_unlock = 1; 29655d9e75c4SJan Schmidt u8 lowest_level = 0; 2966d4b4087cSJosef Bacik int prev_cmp = -1; 29675d9e75c4SJan Schmidt 29685d9e75c4SJan Schmidt lowest_level = p->lowest_level; 29695d9e75c4SJan Schmidt WARN_ON(p->nodes[0] != NULL); 29705d9e75c4SJan Schmidt 29715d9e75c4SJan Schmidt if (p->search_commit_root) { 29725d9e75c4SJan Schmidt BUG_ON(time_seq); 29735d9e75c4SJan Schmidt return btrfs_search_slot(NULL, root, key, p, 0, 0); 29745d9e75c4SJan Schmidt } 29755d9e75c4SJan Schmidt 29765d9e75c4SJan Schmidt again: 29775d9e75c4SJan Schmidt b = get_old_root(root, time_seq); 29785d9e75c4SJan Schmidt level = btrfs_header_level(b); 29795d9e75c4SJan Schmidt p->locks[level] = BTRFS_READ_LOCK; 29805d9e75c4SJan Schmidt 29815d9e75c4SJan Schmidt while (b) { 29825d9e75c4SJan Schmidt level = btrfs_header_level(b); 29835d9e75c4SJan Schmidt p->nodes[level] = b; 29845d9e75c4SJan Schmidt btrfs_clear_path_blocking(p, NULL, 0); 29855d9e75c4SJan Schmidt 29865d9e75c4SJan Schmidt /* 29875d9e75c4SJan Schmidt * we have a lock on b and as long as we aren't changing 29885d9e75c4SJan Schmidt * the tree, there is no way to for the items in b to change. 29895d9e75c4SJan Schmidt * It is safe to drop the lock on our parent before we 29905d9e75c4SJan Schmidt * go through the expensive btree search on b. 29915d9e75c4SJan Schmidt */ 29925d9e75c4SJan Schmidt btrfs_unlock_up_safe(p, level + 1); 29935d9e75c4SJan Schmidt 2994d4b4087cSJosef Bacik /* 2995d4b4087cSJosef Bacik * Since we can unwind eb's we want to do a real search every 2996d4b4087cSJosef Bacik * time. 2997d4b4087cSJosef Bacik */ 2998d4b4087cSJosef Bacik prev_cmp = -1; 2999d7396f07SFilipe David Borba Manana ret = key_search(b, key, level, &prev_cmp, &slot); 30005d9e75c4SJan Schmidt 30015d9e75c4SJan Schmidt if (level != 0) { 30025d9e75c4SJan Schmidt int dec = 0; 30035d9e75c4SJan Schmidt if (ret && slot > 0) { 30045d9e75c4SJan Schmidt dec = 1; 30055d9e75c4SJan Schmidt slot -= 1; 30065d9e75c4SJan Schmidt } 30075d9e75c4SJan Schmidt p->slots[level] = slot; 30085d9e75c4SJan Schmidt unlock_up(p, level, lowest_unlock, 0, NULL); 30095d9e75c4SJan Schmidt 30105d9e75c4SJan Schmidt if (level == lowest_level) { 30115d9e75c4SJan Schmidt if (dec) 30125d9e75c4SJan Schmidt p->slots[level]++; 30135d9e75c4SJan Schmidt goto done; 30145d9e75c4SJan Schmidt } 30155d9e75c4SJan Schmidt 30165d9e75c4SJan Schmidt err = read_block_for_search(NULL, root, p, &b, level, 30175d9e75c4SJan Schmidt slot, key, time_seq); 30185d9e75c4SJan Schmidt if (err == -EAGAIN) 30195d9e75c4SJan Schmidt goto again; 30205d9e75c4SJan Schmidt if (err) { 30215d9e75c4SJan Schmidt ret = err; 30225d9e75c4SJan Schmidt goto done; 30235d9e75c4SJan Schmidt } 30245d9e75c4SJan Schmidt 30255d9e75c4SJan Schmidt level = btrfs_header_level(b); 3026f82c458aSChris Mason err = btrfs_tree_read_lock_atomic(b); 30275d9e75c4SJan Schmidt if (!err) { 30285d9e75c4SJan Schmidt btrfs_set_path_blocking(p); 30295d9e75c4SJan Schmidt btrfs_tree_read_lock(b); 30305d9e75c4SJan Schmidt btrfs_clear_path_blocking(p, b, 30315d9e75c4SJan Schmidt BTRFS_READ_LOCK); 30325d9e75c4SJan Schmidt } 30339ec72677SJosef Bacik b = tree_mod_log_rewind(root->fs_info, p, b, time_seq); 3034db7f3436SJosef Bacik if (!b) { 3035db7f3436SJosef Bacik ret = -ENOMEM; 3036db7f3436SJosef Bacik goto done; 3037db7f3436SJosef Bacik } 30385d9e75c4SJan Schmidt p->locks[level] = BTRFS_READ_LOCK; 30395d9e75c4SJan Schmidt p->nodes[level] = b; 30405d9e75c4SJan Schmidt } else { 30415d9e75c4SJan Schmidt p->slots[level] = slot; 30425d9e75c4SJan Schmidt unlock_up(p, level, lowest_unlock, 0, NULL); 30435d9e75c4SJan Schmidt goto done; 30445d9e75c4SJan Schmidt } 30455d9e75c4SJan Schmidt } 30465d9e75c4SJan Schmidt ret = 1; 30475d9e75c4SJan Schmidt done: 30485d9e75c4SJan Schmidt if (!p->leave_spinning) 30495d9e75c4SJan Schmidt btrfs_set_path_blocking(p); 30505d9e75c4SJan Schmidt if (ret < 0) 30515d9e75c4SJan Schmidt btrfs_release_path(p); 30525d9e75c4SJan Schmidt 30535d9e75c4SJan Schmidt return ret; 30545d9e75c4SJan Schmidt } 30555d9e75c4SJan Schmidt 30565d9e75c4SJan Schmidt /* 30572f38b3e1SArne Jansen * helper to use instead of search slot if no exact match is needed but 30582f38b3e1SArne Jansen * instead the next or previous item should be returned. 30592f38b3e1SArne Jansen * When find_higher is true, the next higher item is returned, the next lower 30602f38b3e1SArne Jansen * otherwise. 30612f38b3e1SArne Jansen * When return_any and find_higher are both true, and no higher item is found, 30622f38b3e1SArne Jansen * return the next lower instead. 30632f38b3e1SArne Jansen * When return_any is true and find_higher is false, and no lower item is found, 30642f38b3e1SArne Jansen * return the next higher instead. 30652f38b3e1SArne Jansen * It returns 0 if any item is found, 1 if none is found (tree empty), and 30662f38b3e1SArne Jansen * < 0 on error 30672f38b3e1SArne Jansen */ 30682f38b3e1SArne Jansen int btrfs_search_slot_for_read(struct btrfs_root *root, 30692f38b3e1SArne Jansen struct btrfs_key *key, struct btrfs_path *p, 30702f38b3e1SArne Jansen int find_higher, int return_any) 30712f38b3e1SArne Jansen { 30722f38b3e1SArne Jansen int ret; 30732f38b3e1SArne Jansen struct extent_buffer *leaf; 30742f38b3e1SArne Jansen 30752f38b3e1SArne Jansen again: 30762f38b3e1SArne Jansen ret = btrfs_search_slot(NULL, root, key, p, 0, 0); 30772f38b3e1SArne Jansen if (ret <= 0) 30782f38b3e1SArne Jansen return ret; 30792f38b3e1SArne Jansen /* 30802f38b3e1SArne Jansen * a return value of 1 means the path is at the position where the 30812f38b3e1SArne Jansen * item should be inserted. Normally this is the next bigger item, 30822f38b3e1SArne Jansen * but in case the previous item is the last in a leaf, path points 30832f38b3e1SArne Jansen * to the first free slot in the previous leaf, i.e. at an invalid 30842f38b3e1SArne Jansen * item. 30852f38b3e1SArne Jansen */ 30862f38b3e1SArne Jansen leaf = p->nodes[0]; 30872f38b3e1SArne Jansen 30882f38b3e1SArne Jansen if (find_higher) { 30892f38b3e1SArne Jansen if (p->slots[0] >= btrfs_header_nritems(leaf)) { 30902f38b3e1SArne Jansen ret = btrfs_next_leaf(root, p); 30912f38b3e1SArne Jansen if (ret <= 0) 30922f38b3e1SArne Jansen return ret; 30932f38b3e1SArne Jansen if (!return_any) 30942f38b3e1SArne Jansen return 1; 30952f38b3e1SArne Jansen /* 30962f38b3e1SArne Jansen * no higher item found, return the next 30972f38b3e1SArne Jansen * lower instead 30982f38b3e1SArne Jansen */ 30992f38b3e1SArne Jansen return_any = 0; 31002f38b3e1SArne Jansen find_higher = 0; 31012f38b3e1SArne Jansen btrfs_release_path(p); 31022f38b3e1SArne Jansen goto again; 31032f38b3e1SArne Jansen } 31042f38b3e1SArne Jansen } else { 31052f38b3e1SArne Jansen if (p->slots[0] == 0) { 31062f38b3e1SArne Jansen ret = btrfs_prev_leaf(root, p); 3107e6793769SArne Jansen if (ret < 0) 31082f38b3e1SArne Jansen return ret; 3109e6793769SArne Jansen if (!ret) { 311023c6bf6aSFilipe David Borba Manana leaf = p->nodes[0]; 311123c6bf6aSFilipe David Borba Manana if (p->slots[0] == btrfs_header_nritems(leaf)) 311223c6bf6aSFilipe David Borba Manana p->slots[0]--; 3113e6793769SArne Jansen return 0; 3114e6793769SArne Jansen } 31152f38b3e1SArne Jansen if (!return_any) 31162f38b3e1SArne Jansen return 1; 31172f38b3e1SArne Jansen /* 31182f38b3e1SArne Jansen * no lower item found, return the next 31192f38b3e1SArne Jansen * higher instead 31202f38b3e1SArne Jansen */ 31212f38b3e1SArne Jansen return_any = 0; 31222f38b3e1SArne Jansen find_higher = 1; 31232f38b3e1SArne Jansen btrfs_release_path(p); 31242f38b3e1SArne Jansen goto again; 3125e6793769SArne Jansen } else { 31262f38b3e1SArne Jansen --p->slots[0]; 31272f38b3e1SArne Jansen } 31282f38b3e1SArne Jansen } 31292f38b3e1SArne Jansen return 0; 31302f38b3e1SArne Jansen } 31312f38b3e1SArne Jansen 31322f38b3e1SArne Jansen /* 313374123bd7SChris Mason * adjust the pointers going up the tree, starting at level 313474123bd7SChris Mason * making sure the right key of each node is points to 'key'. 313574123bd7SChris Mason * This is used after shifting pointers to the left, so it stops 313674123bd7SChris Mason * fixing up pointers when a given leaf/node is not in slot 0 of the 313774123bd7SChris Mason * higher levels 3138aa5d6bedSChris Mason * 313974123bd7SChris Mason */ 3140d6a0a126STsutomu Itoh static void fixup_low_keys(struct btrfs_root *root, struct btrfs_path *path, 31415f39d397SChris Mason struct btrfs_disk_key *key, int level) 3142be0e5c09SChris Mason { 3143be0e5c09SChris Mason int i; 31445f39d397SChris Mason struct extent_buffer *t; 31455f39d397SChris Mason 3146234b63a0SChris Mason for (i = level; i < BTRFS_MAX_LEVEL; i++) { 3147be0e5c09SChris Mason int tslot = path->slots[i]; 3148eb60ceacSChris Mason if (!path->nodes[i]) 3149be0e5c09SChris Mason break; 31505f39d397SChris Mason t = path->nodes[i]; 315132adf090SLiu Bo tree_mod_log_set_node_key(root->fs_info, t, tslot, 1); 31525f39d397SChris Mason btrfs_set_node_key(t, key, tslot); 3153d6025579SChris Mason btrfs_mark_buffer_dirty(path->nodes[i]); 3154be0e5c09SChris Mason if (tslot != 0) 3155be0e5c09SChris Mason break; 3156be0e5c09SChris Mason } 3157be0e5c09SChris Mason } 3158be0e5c09SChris Mason 315974123bd7SChris Mason /* 316031840ae1SZheng Yan * update item key. 316131840ae1SZheng Yan * 316231840ae1SZheng Yan * This function isn't completely safe. It's the caller's responsibility 316331840ae1SZheng Yan * that the new key won't break the order 316431840ae1SZheng Yan */ 3165afe5fea7STsutomu Itoh void btrfs_set_item_key_safe(struct btrfs_root *root, struct btrfs_path *path, 316631840ae1SZheng Yan struct btrfs_key *new_key) 316731840ae1SZheng Yan { 316831840ae1SZheng Yan struct btrfs_disk_key disk_key; 316931840ae1SZheng Yan struct extent_buffer *eb; 317031840ae1SZheng Yan int slot; 317131840ae1SZheng Yan 317231840ae1SZheng Yan eb = path->nodes[0]; 317331840ae1SZheng Yan slot = path->slots[0]; 317431840ae1SZheng Yan if (slot > 0) { 317531840ae1SZheng Yan btrfs_item_key(eb, &disk_key, slot - 1); 3176143bede5SJeff Mahoney BUG_ON(comp_keys(&disk_key, new_key) >= 0); 317731840ae1SZheng Yan } 317831840ae1SZheng Yan if (slot < btrfs_header_nritems(eb) - 1) { 317931840ae1SZheng Yan btrfs_item_key(eb, &disk_key, slot + 1); 3180143bede5SJeff Mahoney BUG_ON(comp_keys(&disk_key, new_key) <= 0); 318131840ae1SZheng Yan } 318231840ae1SZheng Yan 318331840ae1SZheng Yan btrfs_cpu_key_to_disk(&disk_key, new_key); 318431840ae1SZheng Yan btrfs_set_item_key(eb, &disk_key, slot); 318531840ae1SZheng Yan btrfs_mark_buffer_dirty(eb); 318631840ae1SZheng Yan if (slot == 0) 3187d6a0a126STsutomu Itoh fixup_low_keys(root, path, &disk_key, 1); 318831840ae1SZheng Yan } 318931840ae1SZheng Yan 319031840ae1SZheng Yan /* 319174123bd7SChris Mason * try to push data from one node into the next node left in the 319279f95c82SChris Mason * tree. 3193aa5d6bedSChris Mason * 3194aa5d6bedSChris Mason * returns 0 if some ptrs were pushed left, < 0 if there was some horrible 3195aa5d6bedSChris Mason * error, and > 0 if there was no room in the left hand block. 319674123bd7SChris Mason */ 319798ed5174SChris Mason static int push_node_left(struct btrfs_trans_handle *trans, 319898ed5174SChris Mason struct btrfs_root *root, struct extent_buffer *dst, 3199971a1f66SChris Mason struct extent_buffer *src, int empty) 3200be0e5c09SChris Mason { 3201be0e5c09SChris Mason int push_items = 0; 3202bb803951SChris Mason int src_nritems; 3203bb803951SChris Mason int dst_nritems; 3204aa5d6bedSChris Mason int ret = 0; 3205be0e5c09SChris Mason 32065f39d397SChris Mason src_nritems = btrfs_header_nritems(src); 32075f39d397SChris Mason dst_nritems = btrfs_header_nritems(dst); 3208123abc88SChris Mason push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; 32097bb86316SChris Mason WARN_ON(btrfs_header_generation(src) != trans->transid); 32107bb86316SChris Mason WARN_ON(btrfs_header_generation(dst) != trans->transid); 321154aa1f4dSChris Mason 3212bce4eae9SChris Mason if (!empty && src_nritems <= 8) 3213971a1f66SChris Mason return 1; 3214971a1f66SChris Mason 3215d397712bSChris Mason if (push_items <= 0) 3216be0e5c09SChris Mason return 1; 3217be0e5c09SChris Mason 3218bce4eae9SChris Mason if (empty) { 3219971a1f66SChris Mason push_items = min(src_nritems, push_items); 3220bce4eae9SChris Mason if (push_items < src_nritems) { 3221bce4eae9SChris Mason /* leave at least 8 pointers in the node if 3222bce4eae9SChris Mason * we aren't going to empty it 3223bce4eae9SChris Mason */ 3224bce4eae9SChris Mason if (src_nritems - push_items < 8) { 3225bce4eae9SChris Mason if (push_items <= 8) 3226bce4eae9SChris Mason return 1; 3227bce4eae9SChris Mason push_items -= 8; 3228bce4eae9SChris Mason } 3229bce4eae9SChris Mason } 3230bce4eae9SChris Mason } else 3231bce4eae9SChris Mason push_items = min(src_nritems - 8, push_items); 323279f95c82SChris Mason 32335de865eeSFilipe David Borba Manana ret = tree_mod_log_eb_copy(root->fs_info, dst, src, dst_nritems, 0, 323490f8d62eSJan Schmidt push_items); 32355de865eeSFilipe David Borba Manana if (ret) { 32365de865eeSFilipe David Borba Manana btrfs_abort_transaction(trans, root, ret); 32375de865eeSFilipe David Borba Manana return ret; 32385de865eeSFilipe David Borba Manana } 32395f39d397SChris Mason copy_extent_buffer(dst, src, 32405f39d397SChris Mason btrfs_node_key_ptr_offset(dst_nritems), 32415f39d397SChris Mason btrfs_node_key_ptr_offset(0), 3242123abc88SChris Mason push_items * sizeof(struct btrfs_key_ptr)); 32435f39d397SChris Mason 3244bb803951SChris Mason if (push_items < src_nritems) { 324557911b8bSJan Schmidt /* 324657911b8bSJan Schmidt * don't call tree_mod_log_eb_move here, key removal was already 324757911b8bSJan Schmidt * fully logged by tree_mod_log_eb_copy above. 324857911b8bSJan Schmidt */ 32495f39d397SChris Mason memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), 32505f39d397SChris Mason btrfs_node_key_ptr_offset(push_items), 3251e2fa7227SChris Mason (src_nritems - push_items) * 3252123abc88SChris Mason sizeof(struct btrfs_key_ptr)); 3253bb803951SChris Mason } 32545f39d397SChris Mason btrfs_set_header_nritems(src, src_nritems - push_items); 32555f39d397SChris Mason btrfs_set_header_nritems(dst, dst_nritems + push_items); 32565f39d397SChris Mason btrfs_mark_buffer_dirty(src); 32575f39d397SChris Mason btrfs_mark_buffer_dirty(dst); 325831840ae1SZheng Yan 3259bb803951SChris Mason return ret; 3260be0e5c09SChris Mason } 3261be0e5c09SChris Mason 326297571fd0SChris Mason /* 326379f95c82SChris Mason * try to push data from one node into the next node right in the 326479f95c82SChris Mason * tree. 326579f95c82SChris Mason * 326679f95c82SChris Mason * returns 0 if some ptrs were pushed, < 0 if there was some horrible 326779f95c82SChris Mason * error, and > 0 if there was no room in the right hand block. 326879f95c82SChris Mason * 326979f95c82SChris Mason * this will only push up to 1/2 the contents of the left node over 327079f95c82SChris Mason */ 32715f39d397SChris Mason static int balance_node_right(struct btrfs_trans_handle *trans, 32725f39d397SChris Mason struct btrfs_root *root, 32735f39d397SChris Mason struct extent_buffer *dst, 32745f39d397SChris Mason struct extent_buffer *src) 327579f95c82SChris Mason { 327679f95c82SChris Mason int push_items = 0; 327779f95c82SChris Mason int max_push; 327879f95c82SChris Mason int src_nritems; 327979f95c82SChris Mason int dst_nritems; 328079f95c82SChris Mason int ret = 0; 328179f95c82SChris Mason 32827bb86316SChris Mason WARN_ON(btrfs_header_generation(src) != trans->transid); 32837bb86316SChris Mason WARN_ON(btrfs_header_generation(dst) != trans->transid); 32847bb86316SChris Mason 32855f39d397SChris Mason src_nritems = btrfs_header_nritems(src); 32865f39d397SChris Mason dst_nritems = btrfs_header_nritems(dst); 3287123abc88SChris Mason push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; 3288d397712bSChris Mason if (push_items <= 0) 328979f95c82SChris Mason return 1; 3290bce4eae9SChris Mason 3291d397712bSChris Mason if (src_nritems < 4) 3292bce4eae9SChris Mason return 1; 329379f95c82SChris Mason 329479f95c82SChris Mason max_push = src_nritems / 2 + 1; 329579f95c82SChris Mason /* don't try to empty the node */ 3296d397712bSChris Mason if (max_push >= src_nritems) 329779f95c82SChris Mason return 1; 3298252c38f0SYan 329979f95c82SChris Mason if (max_push < push_items) 330079f95c82SChris Mason push_items = max_push; 330179f95c82SChris Mason 3302f230475eSJan Schmidt tree_mod_log_eb_move(root->fs_info, dst, push_items, 0, dst_nritems); 33035f39d397SChris Mason memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), 33045f39d397SChris Mason btrfs_node_key_ptr_offset(0), 33055f39d397SChris Mason (dst_nritems) * 33065f39d397SChris Mason sizeof(struct btrfs_key_ptr)); 3307d6025579SChris Mason 33085de865eeSFilipe David Borba Manana ret = tree_mod_log_eb_copy(root->fs_info, dst, src, 0, 330990f8d62eSJan Schmidt src_nritems - push_items, push_items); 33105de865eeSFilipe David Borba Manana if (ret) { 33115de865eeSFilipe David Borba Manana btrfs_abort_transaction(trans, root, ret); 33125de865eeSFilipe David Borba Manana return ret; 33135de865eeSFilipe David Borba Manana } 33145f39d397SChris Mason copy_extent_buffer(dst, src, 33155f39d397SChris Mason btrfs_node_key_ptr_offset(0), 33165f39d397SChris Mason btrfs_node_key_ptr_offset(src_nritems - push_items), 3317123abc88SChris Mason push_items * sizeof(struct btrfs_key_ptr)); 331879f95c82SChris Mason 33195f39d397SChris Mason btrfs_set_header_nritems(src, src_nritems - push_items); 33205f39d397SChris Mason btrfs_set_header_nritems(dst, dst_nritems + push_items); 332179f95c82SChris Mason 33225f39d397SChris Mason btrfs_mark_buffer_dirty(src); 33235f39d397SChris Mason btrfs_mark_buffer_dirty(dst); 332431840ae1SZheng Yan 332579f95c82SChris Mason return ret; 332679f95c82SChris Mason } 332779f95c82SChris Mason 332879f95c82SChris Mason /* 332997571fd0SChris Mason * helper function to insert a new root level in the tree. 333097571fd0SChris Mason * A new node is allocated, and a single item is inserted to 333197571fd0SChris Mason * point to the existing root 3332aa5d6bedSChris Mason * 3333aa5d6bedSChris Mason * returns zero on success or < 0 on failure. 333497571fd0SChris Mason */ 3335d397712bSChris Mason static noinline int insert_new_root(struct btrfs_trans_handle *trans, 33365f39d397SChris Mason struct btrfs_root *root, 3337fdd99c72SLiu Bo struct btrfs_path *path, int level) 333874123bd7SChris Mason { 33397bb86316SChris Mason u64 lower_gen; 33405f39d397SChris Mason struct extent_buffer *lower; 33415f39d397SChris Mason struct extent_buffer *c; 3342925baeddSChris Mason struct extent_buffer *old; 33435f39d397SChris Mason struct btrfs_disk_key lower_key; 33445c680ed6SChris Mason 33455c680ed6SChris Mason BUG_ON(path->nodes[level]); 33465c680ed6SChris Mason BUG_ON(path->nodes[level-1] != root->node); 33475c680ed6SChris Mason 33487bb86316SChris Mason lower = path->nodes[level-1]; 33497bb86316SChris Mason if (level == 1) 33507bb86316SChris Mason btrfs_item_key(lower, &lower_key, 0); 33517bb86316SChris Mason else 33527bb86316SChris Mason btrfs_node_key(lower, &lower_key, 0); 33537bb86316SChris Mason 33544d75f8a9SDavid Sterba c = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, 33554d75f8a9SDavid Sterba &lower_key, level, root->node->start, 0); 33565f39d397SChris Mason if (IS_ERR(c)) 33575f39d397SChris Mason return PTR_ERR(c); 3358925baeddSChris Mason 3359f0486c68SYan, Zheng root_add_used(root, root->nodesize); 3360f0486c68SYan, Zheng 33615d4f98a2SYan Zheng memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); 33625f39d397SChris Mason btrfs_set_header_nritems(c, 1); 33635f39d397SChris Mason btrfs_set_header_level(c, level); 3364db94535dSChris Mason btrfs_set_header_bytenr(c, c->start); 33655f39d397SChris Mason btrfs_set_header_generation(c, trans->transid); 33665d4f98a2SYan Zheng btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV); 33675f39d397SChris Mason btrfs_set_header_owner(c, root->root_key.objectid); 3368d5719762SChris Mason 33690a4e5586SRoss Kirk write_extent_buffer(c, root->fs_info->fsid, btrfs_header_fsid(), 33705f39d397SChris Mason BTRFS_FSID_SIZE); 3371e17cade2SChris Mason 3372e17cade2SChris Mason write_extent_buffer(c, root->fs_info->chunk_tree_uuid, 3373b308bc2fSGeert Uytterhoeven btrfs_header_chunk_tree_uuid(c), BTRFS_UUID_SIZE); 3374e17cade2SChris Mason 33755f39d397SChris Mason btrfs_set_node_key(c, &lower_key, 0); 3376db94535dSChris Mason btrfs_set_node_blockptr(c, 0, lower->start); 33777bb86316SChris Mason lower_gen = btrfs_header_generation(lower); 337831840ae1SZheng Yan WARN_ON(lower_gen != trans->transid); 33797bb86316SChris Mason 33807bb86316SChris Mason btrfs_set_node_ptr_generation(c, 0, lower_gen); 33815f39d397SChris Mason 33825f39d397SChris Mason btrfs_mark_buffer_dirty(c); 3383d5719762SChris Mason 3384925baeddSChris Mason old = root->node; 3385fdd99c72SLiu Bo tree_mod_log_set_root_pointer(root, c, 0); 3386240f62c8SChris Mason rcu_assign_pointer(root->node, c); 3387925baeddSChris Mason 3388925baeddSChris Mason /* the super has an extra ref to root->node */ 3389925baeddSChris Mason free_extent_buffer(old); 3390925baeddSChris Mason 33910b86a832SChris Mason add_root_to_dirty_list(root); 33925f39d397SChris Mason extent_buffer_get(c); 33935f39d397SChris Mason path->nodes[level] = c; 3394bd681513SChris Mason path->locks[level] = BTRFS_WRITE_LOCK; 339574123bd7SChris Mason path->slots[level] = 0; 339674123bd7SChris Mason return 0; 339774123bd7SChris Mason } 33985c680ed6SChris Mason 33995c680ed6SChris Mason /* 34005c680ed6SChris Mason * worker function to insert a single pointer in a node. 34015c680ed6SChris Mason * the node should have enough room for the pointer already 340297571fd0SChris Mason * 34035c680ed6SChris Mason * slot and level indicate where you want the key to go, and 34045c680ed6SChris Mason * blocknr is the block the key points to. 34055c680ed6SChris Mason */ 3406143bede5SJeff Mahoney static void insert_ptr(struct btrfs_trans_handle *trans, 3407143bede5SJeff Mahoney struct btrfs_root *root, struct btrfs_path *path, 3408143bede5SJeff Mahoney struct btrfs_disk_key *key, u64 bytenr, 3409c3e06965SJan Schmidt int slot, int level) 34105c680ed6SChris Mason { 34115f39d397SChris Mason struct extent_buffer *lower; 34125c680ed6SChris Mason int nritems; 3413f3ea38daSJan Schmidt int ret; 34145c680ed6SChris Mason 34155c680ed6SChris Mason BUG_ON(!path->nodes[level]); 3416f0486c68SYan, Zheng btrfs_assert_tree_locked(path->nodes[level]); 34175f39d397SChris Mason lower = path->nodes[level]; 34185f39d397SChris Mason nritems = btrfs_header_nritems(lower); 3419c293498bSStoyan Gaydarov BUG_ON(slot > nritems); 3420143bede5SJeff Mahoney BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(root)); 342174123bd7SChris Mason if (slot != nritems) { 3422c3e06965SJan Schmidt if (level) 3423f3ea38daSJan Schmidt tree_mod_log_eb_move(root->fs_info, lower, slot + 1, 3424f3ea38daSJan Schmidt slot, nritems - slot); 34255f39d397SChris Mason memmove_extent_buffer(lower, 34265f39d397SChris Mason btrfs_node_key_ptr_offset(slot + 1), 34275f39d397SChris Mason btrfs_node_key_ptr_offset(slot), 3428123abc88SChris Mason (nritems - slot) * sizeof(struct btrfs_key_ptr)); 342974123bd7SChris Mason } 3430c3e06965SJan Schmidt if (level) { 3431f3ea38daSJan Schmidt ret = tree_mod_log_insert_key(root->fs_info, lower, slot, 3432c8cc6341SJosef Bacik MOD_LOG_KEY_ADD, GFP_NOFS); 3433f3ea38daSJan Schmidt BUG_ON(ret < 0); 3434f3ea38daSJan Schmidt } 34355f39d397SChris Mason btrfs_set_node_key(lower, key, slot); 3436db94535dSChris Mason btrfs_set_node_blockptr(lower, slot, bytenr); 343774493f7aSChris Mason WARN_ON(trans->transid == 0); 343874493f7aSChris Mason btrfs_set_node_ptr_generation(lower, slot, trans->transid); 34395f39d397SChris Mason btrfs_set_header_nritems(lower, nritems + 1); 34405f39d397SChris Mason btrfs_mark_buffer_dirty(lower); 344174123bd7SChris Mason } 344274123bd7SChris Mason 344397571fd0SChris Mason /* 344497571fd0SChris Mason * split the node at the specified level in path in two. 344597571fd0SChris Mason * The path is corrected to point to the appropriate node after the split 344697571fd0SChris Mason * 344797571fd0SChris Mason * Before splitting this tries to make some room in the node by pushing 344897571fd0SChris Mason * left and right, if either one works, it returns right away. 3449aa5d6bedSChris Mason * 3450aa5d6bedSChris Mason * returns 0 on success and < 0 on failure 345197571fd0SChris Mason */ 3452e02119d5SChris Mason static noinline int split_node(struct btrfs_trans_handle *trans, 3453e02119d5SChris Mason struct btrfs_root *root, 3454e02119d5SChris Mason struct btrfs_path *path, int level) 3455be0e5c09SChris Mason { 34565f39d397SChris Mason struct extent_buffer *c; 34575f39d397SChris Mason struct extent_buffer *split; 34585f39d397SChris Mason struct btrfs_disk_key disk_key; 3459be0e5c09SChris Mason int mid; 34605c680ed6SChris Mason int ret; 34617518a238SChris Mason u32 c_nritems; 3462be0e5c09SChris Mason 34635f39d397SChris Mason c = path->nodes[level]; 34647bb86316SChris Mason WARN_ON(btrfs_header_generation(c) != trans->transid); 34655f39d397SChris Mason if (c == root->node) { 3466d9abbf1cSJan Schmidt /* 346790f8d62eSJan Schmidt * trying to split the root, lets make a new one 346890f8d62eSJan Schmidt * 3469fdd99c72SLiu Bo * tree mod log: We don't log_removal old root in 347090f8d62eSJan Schmidt * insert_new_root, because that root buffer will be kept as a 347190f8d62eSJan Schmidt * normal node. We are going to log removal of half of the 347290f8d62eSJan Schmidt * elements below with tree_mod_log_eb_copy. We're holding a 347390f8d62eSJan Schmidt * tree lock on the buffer, which is why we cannot race with 347490f8d62eSJan Schmidt * other tree_mod_log users. 3475d9abbf1cSJan Schmidt */ 3476fdd99c72SLiu Bo ret = insert_new_root(trans, root, path, level + 1); 34775c680ed6SChris Mason if (ret) 34785c680ed6SChris Mason return ret; 3479b3612421SChris Mason } else { 3480e66f709bSChris Mason ret = push_nodes_for_insert(trans, root, path, level); 34815f39d397SChris Mason c = path->nodes[level]; 34825f39d397SChris Mason if (!ret && btrfs_header_nritems(c) < 3483c448acf0SChris Mason BTRFS_NODEPTRS_PER_BLOCK(root) - 3) 3484e66f709bSChris Mason return 0; 348554aa1f4dSChris Mason if (ret < 0) 348654aa1f4dSChris Mason return ret; 34875c680ed6SChris Mason } 3488e66f709bSChris Mason 34895f39d397SChris Mason c_nritems = btrfs_header_nritems(c); 34905d4f98a2SYan Zheng mid = (c_nritems + 1) / 2; 34915d4f98a2SYan Zheng btrfs_node_key(c, &disk_key, mid); 34927bb86316SChris Mason 34934d75f8a9SDavid Sterba split = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, 34945581a51aSJan Schmidt &disk_key, level, c->start, 0); 34955f39d397SChris Mason if (IS_ERR(split)) 34965f39d397SChris Mason return PTR_ERR(split); 349754aa1f4dSChris Mason 3498f0486c68SYan, Zheng root_add_used(root, root->nodesize); 3499f0486c68SYan, Zheng 35005d4f98a2SYan Zheng memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header)); 35015f39d397SChris Mason btrfs_set_header_level(split, btrfs_header_level(c)); 3502db94535dSChris Mason btrfs_set_header_bytenr(split, split->start); 35035f39d397SChris Mason btrfs_set_header_generation(split, trans->transid); 35045d4f98a2SYan Zheng btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV); 35055f39d397SChris Mason btrfs_set_header_owner(split, root->root_key.objectid); 35065f39d397SChris Mason write_extent_buffer(split, root->fs_info->fsid, 35070a4e5586SRoss Kirk btrfs_header_fsid(), BTRFS_FSID_SIZE); 3508e17cade2SChris Mason write_extent_buffer(split, root->fs_info->chunk_tree_uuid, 3509b308bc2fSGeert Uytterhoeven btrfs_header_chunk_tree_uuid(split), 3510e17cade2SChris Mason BTRFS_UUID_SIZE); 35115f39d397SChris Mason 35125de865eeSFilipe David Borba Manana ret = tree_mod_log_eb_copy(root->fs_info, split, c, 0, 35135de865eeSFilipe David Borba Manana mid, c_nritems - mid); 35145de865eeSFilipe David Borba Manana if (ret) { 35155de865eeSFilipe David Borba Manana btrfs_abort_transaction(trans, root, ret); 35165de865eeSFilipe David Borba Manana return ret; 35175de865eeSFilipe David Borba Manana } 35185f39d397SChris Mason copy_extent_buffer(split, c, 35195f39d397SChris Mason btrfs_node_key_ptr_offset(0), 35205f39d397SChris Mason btrfs_node_key_ptr_offset(mid), 3521123abc88SChris Mason (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); 35225f39d397SChris Mason btrfs_set_header_nritems(split, c_nritems - mid); 35235f39d397SChris Mason btrfs_set_header_nritems(c, mid); 3524aa5d6bedSChris Mason ret = 0; 3525aa5d6bedSChris Mason 35265f39d397SChris Mason btrfs_mark_buffer_dirty(c); 35275f39d397SChris Mason btrfs_mark_buffer_dirty(split); 35285f39d397SChris Mason 3529143bede5SJeff Mahoney insert_ptr(trans, root, path, &disk_key, split->start, 3530c3e06965SJan Schmidt path->slots[level + 1] + 1, level + 1); 3531aa5d6bedSChris Mason 35325de08d7dSChris Mason if (path->slots[level] >= mid) { 35335c680ed6SChris Mason path->slots[level] -= mid; 3534925baeddSChris Mason btrfs_tree_unlock(c); 35355f39d397SChris Mason free_extent_buffer(c); 35365f39d397SChris Mason path->nodes[level] = split; 35375c680ed6SChris Mason path->slots[level + 1] += 1; 3538eb60ceacSChris Mason } else { 3539925baeddSChris Mason btrfs_tree_unlock(split); 35405f39d397SChris Mason free_extent_buffer(split); 3541be0e5c09SChris Mason } 3542aa5d6bedSChris Mason return ret; 3543be0e5c09SChris Mason } 3544be0e5c09SChris Mason 354574123bd7SChris Mason /* 354674123bd7SChris Mason * how many bytes are required to store the items in a leaf. start 354774123bd7SChris Mason * and nr indicate which items in the leaf to check. This totals up the 354874123bd7SChris Mason * space used both by the item structs and the item data 354974123bd7SChris Mason */ 35505f39d397SChris Mason static int leaf_space_used(struct extent_buffer *l, int start, int nr) 3551be0e5c09SChris Mason { 355241be1f3bSJosef Bacik struct btrfs_item *start_item; 355341be1f3bSJosef Bacik struct btrfs_item *end_item; 355441be1f3bSJosef Bacik struct btrfs_map_token token; 3555be0e5c09SChris Mason int data_len; 35565f39d397SChris Mason int nritems = btrfs_header_nritems(l); 3557d4dbff95SChris Mason int end = min(nritems, start + nr) - 1; 3558be0e5c09SChris Mason 3559be0e5c09SChris Mason if (!nr) 3560be0e5c09SChris Mason return 0; 356141be1f3bSJosef Bacik btrfs_init_map_token(&token); 3562dd3cc16bSRoss Kirk start_item = btrfs_item_nr(start); 3563dd3cc16bSRoss Kirk end_item = btrfs_item_nr(end); 356441be1f3bSJosef Bacik data_len = btrfs_token_item_offset(l, start_item, &token) + 356541be1f3bSJosef Bacik btrfs_token_item_size(l, start_item, &token); 356641be1f3bSJosef Bacik data_len = data_len - btrfs_token_item_offset(l, end_item, &token); 35670783fcfcSChris Mason data_len += sizeof(struct btrfs_item) * nr; 3568d4dbff95SChris Mason WARN_ON(data_len < 0); 3569be0e5c09SChris Mason return data_len; 3570be0e5c09SChris Mason } 3571be0e5c09SChris Mason 357274123bd7SChris Mason /* 3573d4dbff95SChris Mason * The space between the end of the leaf items and 3574d4dbff95SChris Mason * the start of the leaf data. IOW, how much room 3575d4dbff95SChris Mason * the leaf has left for both items and data 3576d4dbff95SChris Mason */ 3577d397712bSChris Mason noinline int btrfs_leaf_free_space(struct btrfs_root *root, 3578e02119d5SChris Mason struct extent_buffer *leaf) 3579d4dbff95SChris Mason { 35805f39d397SChris Mason int nritems = btrfs_header_nritems(leaf); 35815f39d397SChris Mason int ret; 35825f39d397SChris Mason ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); 35835f39d397SChris Mason if (ret < 0) { 3584efe120a0SFrank Holton btrfs_crit(root->fs_info, 3585efe120a0SFrank Holton "leaf free space ret %d, leaf data size %lu, used %d nritems %d", 3586ae2f5411SJens Axboe ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root), 35875f39d397SChris Mason leaf_space_used(leaf, 0, nritems), nritems); 35885f39d397SChris Mason } 35895f39d397SChris Mason return ret; 3590d4dbff95SChris Mason } 3591d4dbff95SChris Mason 359299d8f83cSChris Mason /* 359399d8f83cSChris Mason * min slot controls the lowest index we're willing to push to the 359499d8f83cSChris Mason * right. We'll push up to and including min_slot, but no lower 359599d8f83cSChris Mason */ 359644871b1bSChris Mason static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, 359744871b1bSChris Mason struct btrfs_root *root, 359844871b1bSChris Mason struct btrfs_path *path, 359944871b1bSChris Mason int data_size, int empty, 360044871b1bSChris Mason struct extent_buffer *right, 360199d8f83cSChris Mason int free_space, u32 left_nritems, 360299d8f83cSChris Mason u32 min_slot) 360300ec4c51SChris Mason { 36045f39d397SChris Mason struct extent_buffer *left = path->nodes[0]; 360544871b1bSChris Mason struct extent_buffer *upper = path->nodes[1]; 3606cfed81a0SChris Mason struct btrfs_map_token token; 36075f39d397SChris Mason struct btrfs_disk_key disk_key; 360800ec4c51SChris Mason int slot; 360934a38218SChris Mason u32 i; 361000ec4c51SChris Mason int push_space = 0; 361100ec4c51SChris Mason int push_items = 0; 36120783fcfcSChris Mason struct btrfs_item *item; 361334a38218SChris Mason u32 nr; 36147518a238SChris Mason u32 right_nritems; 36155f39d397SChris Mason u32 data_end; 3616db94535dSChris Mason u32 this_item_size; 361700ec4c51SChris Mason 3618cfed81a0SChris Mason btrfs_init_map_token(&token); 3619cfed81a0SChris Mason 362034a38218SChris Mason if (empty) 362134a38218SChris Mason nr = 0; 362234a38218SChris Mason else 362399d8f83cSChris Mason nr = max_t(u32, 1, min_slot); 362434a38218SChris Mason 362531840ae1SZheng Yan if (path->slots[0] >= left_nritems) 362687b29b20SYan Zheng push_space += data_size; 362731840ae1SZheng Yan 362844871b1bSChris Mason slot = path->slots[1]; 362934a38218SChris Mason i = left_nritems - 1; 363034a38218SChris Mason while (i >= nr) { 3631dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 3632db94535dSChris Mason 363331840ae1SZheng Yan if (!empty && push_items > 0) { 363431840ae1SZheng Yan if (path->slots[0] > i) 363531840ae1SZheng Yan break; 363631840ae1SZheng Yan if (path->slots[0] == i) { 363731840ae1SZheng Yan int space = btrfs_leaf_free_space(root, left); 363831840ae1SZheng Yan if (space + push_space * 2 > free_space) 363931840ae1SZheng Yan break; 364031840ae1SZheng Yan } 364131840ae1SZheng Yan } 364231840ae1SZheng Yan 364300ec4c51SChris Mason if (path->slots[0] == i) 364487b29b20SYan Zheng push_space += data_size; 3645db94535dSChris Mason 3646db94535dSChris Mason this_item_size = btrfs_item_size(left, item); 3647db94535dSChris Mason if (this_item_size + sizeof(*item) + push_space > free_space) 364800ec4c51SChris Mason break; 364931840ae1SZheng Yan 365000ec4c51SChris Mason push_items++; 3651db94535dSChris Mason push_space += this_item_size + sizeof(*item); 365234a38218SChris Mason if (i == 0) 365334a38218SChris Mason break; 365434a38218SChris Mason i--; 3655db94535dSChris Mason } 36565f39d397SChris Mason 3657925baeddSChris Mason if (push_items == 0) 3658925baeddSChris Mason goto out_unlock; 36595f39d397SChris Mason 36606c1500f2SJulia Lawall WARN_ON(!empty && push_items == left_nritems); 36615f39d397SChris Mason 366200ec4c51SChris Mason /* push left to right */ 36635f39d397SChris Mason right_nritems = btrfs_header_nritems(right); 366434a38218SChris Mason 36655f39d397SChris Mason push_space = btrfs_item_end_nr(left, left_nritems - push_items); 3666123abc88SChris Mason push_space -= leaf_data_end(root, left); 36675f39d397SChris Mason 366800ec4c51SChris Mason /* make room in the right data area */ 36695f39d397SChris Mason data_end = leaf_data_end(root, right); 36705f39d397SChris Mason memmove_extent_buffer(right, 36715f39d397SChris Mason btrfs_leaf_data(right) + data_end - push_space, 36725f39d397SChris Mason btrfs_leaf_data(right) + data_end, 36735f39d397SChris Mason BTRFS_LEAF_DATA_SIZE(root) - data_end); 36745f39d397SChris Mason 367500ec4c51SChris Mason /* copy from the left data area */ 36765f39d397SChris Mason copy_extent_buffer(right, left, btrfs_leaf_data(right) + 3677d6025579SChris Mason BTRFS_LEAF_DATA_SIZE(root) - push_space, 3678d6025579SChris Mason btrfs_leaf_data(left) + leaf_data_end(root, left), 3679d6025579SChris Mason push_space); 36805f39d397SChris Mason 36815f39d397SChris Mason memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), 36825f39d397SChris Mason btrfs_item_nr_offset(0), 36830783fcfcSChris Mason right_nritems * sizeof(struct btrfs_item)); 36845f39d397SChris Mason 368500ec4c51SChris Mason /* copy the items from left to right */ 36865f39d397SChris Mason copy_extent_buffer(right, left, btrfs_item_nr_offset(0), 36875f39d397SChris Mason btrfs_item_nr_offset(left_nritems - push_items), 36880783fcfcSChris Mason push_items * sizeof(struct btrfs_item)); 368900ec4c51SChris Mason 369000ec4c51SChris Mason /* update the item pointers */ 36917518a238SChris Mason right_nritems += push_items; 36925f39d397SChris Mason btrfs_set_header_nritems(right, right_nritems); 3693123abc88SChris Mason push_space = BTRFS_LEAF_DATA_SIZE(root); 36947518a238SChris Mason for (i = 0; i < right_nritems; i++) { 3695dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 3696cfed81a0SChris Mason push_space -= btrfs_token_item_size(right, item, &token); 3697cfed81a0SChris Mason btrfs_set_token_item_offset(right, item, push_space, &token); 3698db94535dSChris Mason } 3699db94535dSChris Mason 37007518a238SChris Mason left_nritems -= push_items; 37015f39d397SChris Mason btrfs_set_header_nritems(left, left_nritems); 370200ec4c51SChris Mason 370334a38218SChris Mason if (left_nritems) 37045f39d397SChris Mason btrfs_mark_buffer_dirty(left); 3705f0486c68SYan, Zheng else 3706f0486c68SYan, Zheng clean_tree_block(trans, root, left); 3707f0486c68SYan, Zheng 37085f39d397SChris Mason btrfs_mark_buffer_dirty(right); 3709a429e513SChris Mason 37105f39d397SChris Mason btrfs_item_key(right, &disk_key, 0); 37115f39d397SChris Mason btrfs_set_node_key(upper, &disk_key, slot + 1); 3712d6025579SChris Mason btrfs_mark_buffer_dirty(upper); 371302217ed2SChris Mason 371400ec4c51SChris Mason /* then fixup the leaf pointer in the path */ 37157518a238SChris Mason if (path->slots[0] >= left_nritems) { 37167518a238SChris Mason path->slots[0] -= left_nritems; 3717925baeddSChris Mason if (btrfs_header_nritems(path->nodes[0]) == 0) 3718925baeddSChris Mason clean_tree_block(trans, root, path->nodes[0]); 3719925baeddSChris Mason btrfs_tree_unlock(path->nodes[0]); 37205f39d397SChris Mason free_extent_buffer(path->nodes[0]); 37215f39d397SChris Mason path->nodes[0] = right; 372200ec4c51SChris Mason path->slots[1] += 1; 372300ec4c51SChris Mason } else { 3724925baeddSChris Mason btrfs_tree_unlock(right); 37255f39d397SChris Mason free_extent_buffer(right); 372600ec4c51SChris Mason } 372700ec4c51SChris Mason return 0; 3728925baeddSChris Mason 3729925baeddSChris Mason out_unlock: 3730925baeddSChris Mason btrfs_tree_unlock(right); 3731925baeddSChris Mason free_extent_buffer(right); 3732925baeddSChris Mason return 1; 373300ec4c51SChris Mason } 3734925baeddSChris Mason 373500ec4c51SChris Mason /* 373644871b1bSChris Mason * push some data in the path leaf to the right, trying to free up at 373774123bd7SChris Mason * least data_size bytes. returns zero if the push worked, nonzero otherwise 373844871b1bSChris Mason * 373944871b1bSChris Mason * returns 1 if the push failed because the other node didn't have enough 374044871b1bSChris Mason * room, 0 if everything worked out and < 0 if there were major errors. 374199d8f83cSChris Mason * 374299d8f83cSChris Mason * this will push starting from min_slot to the end of the leaf. It won't 374399d8f83cSChris Mason * push any slot lower than min_slot 374474123bd7SChris Mason */ 374544871b1bSChris Mason static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root 374699d8f83cSChris Mason *root, struct btrfs_path *path, 374799d8f83cSChris Mason int min_data_size, int data_size, 374899d8f83cSChris Mason int empty, u32 min_slot) 3749be0e5c09SChris Mason { 375044871b1bSChris Mason struct extent_buffer *left = path->nodes[0]; 375144871b1bSChris Mason struct extent_buffer *right; 375244871b1bSChris Mason struct extent_buffer *upper; 375344871b1bSChris Mason int slot; 375444871b1bSChris Mason int free_space; 375544871b1bSChris Mason u32 left_nritems; 375644871b1bSChris Mason int ret; 375744871b1bSChris Mason 375844871b1bSChris Mason if (!path->nodes[1]) 375944871b1bSChris Mason return 1; 376044871b1bSChris Mason 376144871b1bSChris Mason slot = path->slots[1]; 376244871b1bSChris Mason upper = path->nodes[1]; 376344871b1bSChris Mason if (slot >= btrfs_header_nritems(upper) - 1) 376444871b1bSChris Mason return 1; 376544871b1bSChris Mason 376644871b1bSChris Mason btrfs_assert_tree_locked(path->nodes[1]); 376744871b1bSChris Mason 376844871b1bSChris Mason right = read_node_slot(root, upper, slot + 1); 376991ca338dSTsutomu Itoh if (right == NULL) 377091ca338dSTsutomu Itoh return 1; 377191ca338dSTsutomu Itoh 377244871b1bSChris Mason btrfs_tree_lock(right); 377344871b1bSChris Mason btrfs_set_lock_blocking(right); 377444871b1bSChris Mason 377544871b1bSChris Mason free_space = btrfs_leaf_free_space(root, right); 377644871b1bSChris Mason if (free_space < data_size) 377744871b1bSChris Mason goto out_unlock; 377844871b1bSChris Mason 377944871b1bSChris Mason /* cow and double check */ 378044871b1bSChris Mason ret = btrfs_cow_block(trans, root, right, upper, 378144871b1bSChris Mason slot + 1, &right); 378244871b1bSChris Mason if (ret) 378344871b1bSChris Mason goto out_unlock; 378444871b1bSChris Mason 378544871b1bSChris Mason free_space = btrfs_leaf_free_space(root, right); 378644871b1bSChris Mason if (free_space < data_size) 378744871b1bSChris Mason goto out_unlock; 378844871b1bSChris Mason 378944871b1bSChris Mason left_nritems = btrfs_header_nritems(left); 379044871b1bSChris Mason if (left_nritems == 0) 379144871b1bSChris Mason goto out_unlock; 379244871b1bSChris Mason 37932ef1fed2SFilipe David Borba Manana if (path->slots[0] == left_nritems && !empty) { 37942ef1fed2SFilipe David Borba Manana /* Key greater than all keys in the leaf, right neighbor has 37952ef1fed2SFilipe David Borba Manana * enough room for it and we're not emptying our leaf to delete 37962ef1fed2SFilipe David Borba Manana * it, therefore use right neighbor to insert the new item and 37972ef1fed2SFilipe David Borba Manana * no need to touch/dirty our left leaft. */ 37982ef1fed2SFilipe David Borba Manana btrfs_tree_unlock(left); 37992ef1fed2SFilipe David Borba Manana free_extent_buffer(left); 38002ef1fed2SFilipe David Borba Manana path->nodes[0] = right; 38012ef1fed2SFilipe David Borba Manana path->slots[0] = 0; 38022ef1fed2SFilipe David Borba Manana path->slots[1]++; 38032ef1fed2SFilipe David Borba Manana return 0; 38042ef1fed2SFilipe David Borba Manana } 38052ef1fed2SFilipe David Borba Manana 380699d8f83cSChris Mason return __push_leaf_right(trans, root, path, min_data_size, empty, 380799d8f83cSChris Mason right, free_space, left_nritems, min_slot); 380844871b1bSChris Mason out_unlock: 380944871b1bSChris Mason btrfs_tree_unlock(right); 381044871b1bSChris Mason free_extent_buffer(right); 381144871b1bSChris Mason return 1; 381244871b1bSChris Mason } 381344871b1bSChris Mason 381444871b1bSChris Mason /* 381544871b1bSChris Mason * push some data in the path leaf to the left, trying to free up at 381644871b1bSChris Mason * least data_size bytes. returns zero if the push worked, nonzero otherwise 381799d8f83cSChris Mason * 381899d8f83cSChris Mason * max_slot can put a limit on how far into the leaf we'll push items. The 381999d8f83cSChris Mason * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the 382099d8f83cSChris Mason * items 382144871b1bSChris Mason */ 382244871b1bSChris Mason static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, 382344871b1bSChris Mason struct btrfs_root *root, 382444871b1bSChris Mason struct btrfs_path *path, int data_size, 382544871b1bSChris Mason int empty, struct extent_buffer *left, 382699d8f83cSChris Mason int free_space, u32 right_nritems, 382799d8f83cSChris Mason u32 max_slot) 382844871b1bSChris Mason { 38295f39d397SChris Mason struct btrfs_disk_key disk_key; 38305f39d397SChris Mason struct extent_buffer *right = path->nodes[0]; 3831be0e5c09SChris Mason int i; 3832be0e5c09SChris Mason int push_space = 0; 3833be0e5c09SChris Mason int push_items = 0; 38340783fcfcSChris Mason struct btrfs_item *item; 38357518a238SChris Mason u32 old_left_nritems; 383634a38218SChris Mason u32 nr; 3837aa5d6bedSChris Mason int ret = 0; 3838db94535dSChris Mason u32 this_item_size; 3839db94535dSChris Mason u32 old_left_item_size; 3840cfed81a0SChris Mason struct btrfs_map_token token; 3841cfed81a0SChris Mason 3842cfed81a0SChris Mason btrfs_init_map_token(&token); 3843be0e5c09SChris Mason 384434a38218SChris Mason if (empty) 384599d8f83cSChris Mason nr = min(right_nritems, max_slot); 384634a38218SChris Mason else 384799d8f83cSChris Mason nr = min(right_nritems - 1, max_slot); 384834a38218SChris Mason 384934a38218SChris Mason for (i = 0; i < nr; i++) { 3850dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 3851db94535dSChris Mason 385231840ae1SZheng Yan if (!empty && push_items > 0) { 385331840ae1SZheng Yan if (path->slots[0] < i) 385431840ae1SZheng Yan break; 385531840ae1SZheng Yan if (path->slots[0] == i) { 385631840ae1SZheng Yan int space = btrfs_leaf_free_space(root, right); 385731840ae1SZheng Yan if (space + push_space * 2 > free_space) 385831840ae1SZheng Yan break; 385931840ae1SZheng Yan } 386031840ae1SZheng Yan } 386131840ae1SZheng Yan 3862be0e5c09SChris Mason if (path->slots[0] == i) 386387b29b20SYan Zheng push_space += data_size; 3864db94535dSChris Mason 3865db94535dSChris Mason this_item_size = btrfs_item_size(right, item); 3866db94535dSChris Mason if (this_item_size + sizeof(*item) + push_space > free_space) 3867be0e5c09SChris Mason break; 3868db94535dSChris Mason 3869be0e5c09SChris Mason push_items++; 3870db94535dSChris Mason push_space += this_item_size + sizeof(*item); 3871be0e5c09SChris Mason } 3872db94535dSChris Mason 3873be0e5c09SChris Mason if (push_items == 0) { 3874925baeddSChris Mason ret = 1; 3875925baeddSChris Mason goto out; 3876be0e5c09SChris Mason } 3877fae7f21cSDulshani Gunawardhana WARN_ON(!empty && push_items == btrfs_header_nritems(right)); 38785f39d397SChris Mason 3879be0e5c09SChris Mason /* push data from right to left */ 38805f39d397SChris Mason copy_extent_buffer(left, right, 38815f39d397SChris Mason btrfs_item_nr_offset(btrfs_header_nritems(left)), 38825f39d397SChris Mason btrfs_item_nr_offset(0), 38835f39d397SChris Mason push_items * sizeof(struct btrfs_item)); 38845f39d397SChris Mason 3885123abc88SChris Mason push_space = BTRFS_LEAF_DATA_SIZE(root) - 38865f39d397SChris Mason btrfs_item_offset_nr(right, push_items - 1); 38875f39d397SChris Mason 38885f39d397SChris Mason copy_extent_buffer(left, right, btrfs_leaf_data(left) + 3889d6025579SChris Mason leaf_data_end(root, left) - push_space, 3890123abc88SChris Mason btrfs_leaf_data(right) + 38915f39d397SChris Mason btrfs_item_offset_nr(right, push_items - 1), 3892be0e5c09SChris Mason push_space); 38935f39d397SChris Mason old_left_nritems = btrfs_header_nritems(left); 389487b29b20SYan Zheng BUG_ON(old_left_nritems <= 0); 3895eb60ceacSChris Mason 3896db94535dSChris Mason old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); 3897be0e5c09SChris Mason for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { 38985f39d397SChris Mason u32 ioff; 3899db94535dSChris Mason 3900dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 3901db94535dSChris Mason 3902cfed81a0SChris Mason ioff = btrfs_token_item_offset(left, item, &token); 3903cfed81a0SChris Mason btrfs_set_token_item_offset(left, item, 3904cfed81a0SChris Mason ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size), 3905cfed81a0SChris Mason &token); 3906be0e5c09SChris Mason } 39075f39d397SChris Mason btrfs_set_header_nritems(left, old_left_nritems + push_items); 3908be0e5c09SChris Mason 3909be0e5c09SChris Mason /* fixup right node */ 391031b1a2bdSJulia Lawall if (push_items > right_nritems) 391131b1a2bdSJulia Lawall WARN(1, KERN_CRIT "push items %d nr %u\n", push_items, 3912d397712bSChris Mason right_nritems); 391334a38218SChris Mason 391434a38218SChris Mason if (push_items < right_nritems) { 39155f39d397SChris Mason push_space = btrfs_item_offset_nr(right, push_items - 1) - 3916123abc88SChris Mason leaf_data_end(root, right); 39175f39d397SChris Mason memmove_extent_buffer(right, btrfs_leaf_data(right) + 3918d6025579SChris Mason BTRFS_LEAF_DATA_SIZE(root) - push_space, 3919d6025579SChris Mason btrfs_leaf_data(right) + 3920123abc88SChris Mason leaf_data_end(root, right), push_space); 39215f39d397SChris Mason 39225f39d397SChris Mason memmove_extent_buffer(right, btrfs_item_nr_offset(0), 39235f39d397SChris Mason btrfs_item_nr_offset(push_items), 39245f39d397SChris Mason (btrfs_header_nritems(right) - push_items) * 39250783fcfcSChris Mason sizeof(struct btrfs_item)); 392634a38218SChris Mason } 3927eef1c494SYan right_nritems -= push_items; 3928eef1c494SYan btrfs_set_header_nritems(right, right_nritems); 3929123abc88SChris Mason push_space = BTRFS_LEAF_DATA_SIZE(root); 39305f39d397SChris Mason for (i = 0; i < right_nritems; i++) { 3931dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 3932db94535dSChris Mason 3933cfed81a0SChris Mason push_space = push_space - btrfs_token_item_size(right, 3934cfed81a0SChris Mason item, &token); 3935cfed81a0SChris Mason btrfs_set_token_item_offset(right, item, push_space, &token); 3936db94535dSChris Mason } 3937eb60ceacSChris Mason 39385f39d397SChris Mason btrfs_mark_buffer_dirty(left); 393934a38218SChris Mason if (right_nritems) 39405f39d397SChris Mason btrfs_mark_buffer_dirty(right); 3941f0486c68SYan, Zheng else 3942f0486c68SYan, Zheng clean_tree_block(trans, root, right); 3943098f59c2SChris Mason 39445f39d397SChris Mason btrfs_item_key(right, &disk_key, 0); 3945d6a0a126STsutomu Itoh fixup_low_keys(root, path, &disk_key, 1); 3946be0e5c09SChris Mason 3947be0e5c09SChris Mason /* then fixup the leaf pointer in the path */ 3948be0e5c09SChris Mason if (path->slots[0] < push_items) { 3949be0e5c09SChris Mason path->slots[0] += old_left_nritems; 3950925baeddSChris Mason btrfs_tree_unlock(path->nodes[0]); 39515f39d397SChris Mason free_extent_buffer(path->nodes[0]); 39525f39d397SChris Mason path->nodes[0] = left; 3953be0e5c09SChris Mason path->slots[1] -= 1; 3954be0e5c09SChris Mason } else { 3955925baeddSChris Mason btrfs_tree_unlock(left); 39565f39d397SChris Mason free_extent_buffer(left); 3957be0e5c09SChris Mason path->slots[0] -= push_items; 3958be0e5c09SChris Mason } 3959eb60ceacSChris Mason BUG_ON(path->slots[0] < 0); 3960aa5d6bedSChris Mason return ret; 3961925baeddSChris Mason out: 3962925baeddSChris Mason btrfs_tree_unlock(left); 3963925baeddSChris Mason free_extent_buffer(left); 3964925baeddSChris Mason return ret; 3965be0e5c09SChris Mason } 3966be0e5c09SChris Mason 396774123bd7SChris Mason /* 396844871b1bSChris Mason * push some data in the path leaf to the left, trying to free up at 396944871b1bSChris Mason * least data_size bytes. returns zero if the push worked, nonzero otherwise 397099d8f83cSChris Mason * 397199d8f83cSChris Mason * max_slot can put a limit on how far into the leaf we'll push items. The 397299d8f83cSChris Mason * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the 397399d8f83cSChris Mason * items 397444871b1bSChris Mason */ 397544871b1bSChris Mason static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root 397699d8f83cSChris Mason *root, struct btrfs_path *path, int min_data_size, 397799d8f83cSChris Mason int data_size, int empty, u32 max_slot) 397844871b1bSChris Mason { 397944871b1bSChris Mason struct extent_buffer *right = path->nodes[0]; 398044871b1bSChris Mason struct extent_buffer *left; 398144871b1bSChris Mason int slot; 398244871b1bSChris Mason int free_space; 398344871b1bSChris Mason u32 right_nritems; 398444871b1bSChris Mason int ret = 0; 398544871b1bSChris Mason 398644871b1bSChris Mason slot = path->slots[1]; 398744871b1bSChris Mason if (slot == 0) 398844871b1bSChris Mason return 1; 398944871b1bSChris Mason if (!path->nodes[1]) 399044871b1bSChris Mason return 1; 399144871b1bSChris Mason 399244871b1bSChris Mason right_nritems = btrfs_header_nritems(right); 399344871b1bSChris Mason if (right_nritems == 0) 399444871b1bSChris Mason return 1; 399544871b1bSChris Mason 399644871b1bSChris Mason btrfs_assert_tree_locked(path->nodes[1]); 399744871b1bSChris Mason 399844871b1bSChris Mason left = read_node_slot(root, path->nodes[1], slot - 1); 399991ca338dSTsutomu Itoh if (left == NULL) 400091ca338dSTsutomu Itoh return 1; 400191ca338dSTsutomu Itoh 400244871b1bSChris Mason btrfs_tree_lock(left); 400344871b1bSChris Mason btrfs_set_lock_blocking(left); 400444871b1bSChris Mason 400544871b1bSChris Mason free_space = btrfs_leaf_free_space(root, left); 400644871b1bSChris Mason if (free_space < data_size) { 400744871b1bSChris Mason ret = 1; 400844871b1bSChris Mason goto out; 400944871b1bSChris Mason } 401044871b1bSChris Mason 401144871b1bSChris Mason /* cow and double check */ 401244871b1bSChris Mason ret = btrfs_cow_block(trans, root, left, 401344871b1bSChris Mason path->nodes[1], slot - 1, &left); 401444871b1bSChris Mason if (ret) { 401544871b1bSChris Mason /* we hit -ENOSPC, but it isn't fatal here */ 401679787eaaSJeff Mahoney if (ret == -ENOSPC) 401744871b1bSChris Mason ret = 1; 401844871b1bSChris Mason goto out; 401944871b1bSChris Mason } 402044871b1bSChris Mason 402144871b1bSChris Mason free_space = btrfs_leaf_free_space(root, left); 402244871b1bSChris Mason if (free_space < data_size) { 402344871b1bSChris Mason ret = 1; 402444871b1bSChris Mason goto out; 402544871b1bSChris Mason } 402644871b1bSChris Mason 402799d8f83cSChris Mason return __push_leaf_left(trans, root, path, min_data_size, 402899d8f83cSChris Mason empty, left, free_space, right_nritems, 402999d8f83cSChris Mason max_slot); 403044871b1bSChris Mason out: 403144871b1bSChris Mason btrfs_tree_unlock(left); 403244871b1bSChris Mason free_extent_buffer(left); 403344871b1bSChris Mason return ret; 403444871b1bSChris Mason } 403544871b1bSChris Mason 403644871b1bSChris Mason /* 403774123bd7SChris Mason * split the path's leaf in two, making sure there is at least data_size 403874123bd7SChris Mason * available for the resulting leaf level of the path. 403974123bd7SChris Mason */ 4040143bede5SJeff Mahoney static noinline void copy_for_split(struct btrfs_trans_handle *trans, 4041e02119d5SChris Mason struct btrfs_root *root, 404244871b1bSChris Mason struct btrfs_path *path, 404344871b1bSChris Mason struct extent_buffer *l, 404444871b1bSChris Mason struct extent_buffer *right, 404544871b1bSChris Mason int slot, int mid, int nritems) 4046be0e5c09SChris Mason { 4047be0e5c09SChris Mason int data_copy_size; 4048be0e5c09SChris Mason int rt_data_off; 4049be0e5c09SChris Mason int i; 4050d4dbff95SChris Mason struct btrfs_disk_key disk_key; 4051cfed81a0SChris Mason struct btrfs_map_token token; 4052cfed81a0SChris Mason 4053cfed81a0SChris Mason btrfs_init_map_token(&token); 4054be0e5c09SChris Mason 40555f39d397SChris Mason nritems = nritems - mid; 40565f39d397SChris Mason btrfs_set_header_nritems(right, nritems); 40575f39d397SChris Mason data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); 40585f39d397SChris Mason 40595f39d397SChris Mason copy_extent_buffer(right, l, btrfs_item_nr_offset(0), 40605f39d397SChris Mason btrfs_item_nr_offset(mid), 40615f39d397SChris Mason nritems * sizeof(struct btrfs_item)); 40625f39d397SChris Mason 40635f39d397SChris Mason copy_extent_buffer(right, l, 4064d6025579SChris Mason btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - 4065123abc88SChris Mason data_copy_size, btrfs_leaf_data(l) + 4066123abc88SChris Mason leaf_data_end(root, l), data_copy_size); 406774123bd7SChris Mason 40685f39d397SChris Mason rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - 40695f39d397SChris Mason btrfs_item_end_nr(l, mid); 40705f39d397SChris Mason 40715f39d397SChris Mason for (i = 0; i < nritems; i++) { 4072dd3cc16bSRoss Kirk struct btrfs_item *item = btrfs_item_nr(i); 4073db94535dSChris Mason u32 ioff; 4074db94535dSChris Mason 4075cfed81a0SChris Mason ioff = btrfs_token_item_offset(right, item, &token); 4076cfed81a0SChris Mason btrfs_set_token_item_offset(right, item, 4077cfed81a0SChris Mason ioff + rt_data_off, &token); 40780783fcfcSChris Mason } 407974123bd7SChris Mason 40805f39d397SChris Mason btrfs_set_header_nritems(l, mid); 40815f39d397SChris Mason btrfs_item_key(right, &disk_key, 0); 4082143bede5SJeff Mahoney insert_ptr(trans, root, path, &disk_key, right->start, 4083c3e06965SJan Schmidt path->slots[1] + 1, 1); 40845f39d397SChris Mason 40855f39d397SChris Mason btrfs_mark_buffer_dirty(right); 40865f39d397SChris Mason btrfs_mark_buffer_dirty(l); 4087eb60ceacSChris Mason BUG_ON(path->slots[0] != slot); 40885f39d397SChris Mason 4089be0e5c09SChris Mason if (mid <= slot) { 4090925baeddSChris Mason btrfs_tree_unlock(path->nodes[0]); 40915f39d397SChris Mason free_extent_buffer(path->nodes[0]); 40925f39d397SChris Mason path->nodes[0] = right; 4093be0e5c09SChris Mason path->slots[0] -= mid; 4094be0e5c09SChris Mason path->slots[1] += 1; 4095925baeddSChris Mason } else { 4096925baeddSChris Mason btrfs_tree_unlock(right); 40975f39d397SChris Mason free_extent_buffer(right); 4098925baeddSChris Mason } 40995f39d397SChris Mason 4100eb60ceacSChris Mason BUG_ON(path->slots[0] < 0); 410144871b1bSChris Mason } 410244871b1bSChris Mason 410344871b1bSChris Mason /* 410499d8f83cSChris Mason * double splits happen when we need to insert a big item in the middle 410599d8f83cSChris Mason * of a leaf. A double split can leave us with 3 mostly empty leaves: 410699d8f83cSChris Mason * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] 410799d8f83cSChris Mason * A B C 410899d8f83cSChris Mason * 410999d8f83cSChris Mason * We avoid this by trying to push the items on either side of our target 411099d8f83cSChris Mason * into the adjacent leaves. If all goes well we can avoid the double split 411199d8f83cSChris Mason * completely. 411299d8f83cSChris Mason */ 411399d8f83cSChris Mason static noinline int push_for_double_split(struct btrfs_trans_handle *trans, 411499d8f83cSChris Mason struct btrfs_root *root, 411599d8f83cSChris Mason struct btrfs_path *path, 411699d8f83cSChris Mason int data_size) 411799d8f83cSChris Mason { 411899d8f83cSChris Mason int ret; 411999d8f83cSChris Mason int progress = 0; 412099d8f83cSChris Mason int slot; 412199d8f83cSChris Mason u32 nritems; 41225a4267caSFilipe David Borba Manana int space_needed = data_size; 412399d8f83cSChris Mason 412499d8f83cSChris Mason slot = path->slots[0]; 41255a4267caSFilipe David Borba Manana if (slot < btrfs_header_nritems(path->nodes[0])) 41265a4267caSFilipe David Borba Manana space_needed -= btrfs_leaf_free_space(root, path->nodes[0]); 412799d8f83cSChris Mason 412899d8f83cSChris Mason /* 412999d8f83cSChris Mason * try to push all the items after our slot into the 413099d8f83cSChris Mason * right leaf 413199d8f83cSChris Mason */ 41325a4267caSFilipe David Borba Manana ret = push_leaf_right(trans, root, path, 1, space_needed, 0, slot); 413399d8f83cSChris Mason if (ret < 0) 413499d8f83cSChris Mason return ret; 413599d8f83cSChris Mason 413699d8f83cSChris Mason if (ret == 0) 413799d8f83cSChris Mason progress++; 413899d8f83cSChris Mason 413999d8f83cSChris Mason nritems = btrfs_header_nritems(path->nodes[0]); 414099d8f83cSChris Mason /* 414199d8f83cSChris Mason * our goal is to get our slot at the start or end of a leaf. If 414299d8f83cSChris Mason * we've done so we're done 414399d8f83cSChris Mason */ 414499d8f83cSChris Mason if (path->slots[0] == 0 || path->slots[0] == nritems) 414599d8f83cSChris Mason return 0; 414699d8f83cSChris Mason 414799d8f83cSChris Mason if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) 414899d8f83cSChris Mason return 0; 414999d8f83cSChris Mason 415099d8f83cSChris Mason /* try to push all the items before our slot into the next leaf */ 415199d8f83cSChris Mason slot = path->slots[0]; 41525a4267caSFilipe David Borba Manana ret = push_leaf_left(trans, root, path, 1, space_needed, 0, slot); 415399d8f83cSChris Mason if (ret < 0) 415499d8f83cSChris Mason return ret; 415599d8f83cSChris Mason 415699d8f83cSChris Mason if (ret == 0) 415799d8f83cSChris Mason progress++; 415899d8f83cSChris Mason 415999d8f83cSChris Mason if (progress) 416099d8f83cSChris Mason return 0; 416199d8f83cSChris Mason return 1; 416299d8f83cSChris Mason } 416399d8f83cSChris Mason 416499d8f83cSChris Mason /* 416544871b1bSChris Mason * split the path's leaf in two, making sure there is at least data_size 416644871b1bSChris Mason * available for the resulting leaf level of the path. 416744871b1bSChris Mason * 416844871b1bSChris Mason * returns 0 if all went well and < 0 on failure. 416944871b1bSChris Mason */ 417044871b1bSChris Mason static noinline int split_leaf(struct btrfs_trans_handle *trans, 417144871b1bSChris Mason struct btrfs_root *root, 417244871b1bSChris Mason struct btrfs_key *ins_key, 417344871b1bSChris Mason struct btrfs_path *path, int data_size, 417444871b1bSChris Mason int extend) 417544871b1bSChris Mason { 41765d4f98a2SYan Zheng struct btrfs_disk_key disk_key; 417744871b1bSChris Mason struct extent_buffer *l; 417844871b1bSChris Mason u32 nritems; 417944871b1bSChris Mason int mid; 418044871b1bSChris Mason int slot; 418144871b1bSChris Mason struct extent_buffer *right; 418244871b1bSChris Mason int ret = 0; 418344871b1bSChris Mason int wret; 41845d4f98a2SYan Zheng int split; 418544871b1bSChris Mason int num_doubles = 0; 418699d8f83cSChris Mason int tried_avoid_double = 0; 418744871b1bSChris Mason 4188a5719521SYan, Zheng l = path->nodes[0]; 4189a5719521SYan, Zheng slot = path->slots[0]; 4190a5719521SYan, Zheng if (extend && data_size + btrfs_item_size_nr(l, slot) + 4191a5719521SYan, Zheng sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) 4192a5719521SYan, Zheng return -EOVERFLOW; 4193a5719521SYan, Zheng 419444871b1bSChris Mason /* first try to make some room by pushing left and right */ 419533157e05SLiu Bo if (data_size && path->nodes[1]) { 41965a4267caSFilipe David Borba Manana int space_needed = data_size; 41975a4267caSFilipe David Borba Manana 41985a4267caSFilipe David Borba Manana if (slot < btrfs_header_nritems(l)) 41995a4267caSFilipe David Borba Manana space_needed -= btrfs_leaf_free_space(root, l); 42005a4267caSFilipe David Borba Manana 42015a4267caSFilipe David Borba Manana wret = push_leaf_right(trans, root, path, space_needed, 42025a4267caSFilipe David Borba Manana space_needed, 0, 0); 420344871b1bSChris Mason if (wret < 0) 420444871b1bSChris Mason return wret; 420544871b1bSChris Mason if (wret) { 42065a4267caSFilipe David Borba Manana wret = push_leaf_left(trans, root, path, space_needed, 42075a4267caSFilipe David Borba Manana space_needed, 0, (u32)-1); 420844871b1bSChris Mason if (wret < 0) 420944871b1bSChris Mason return wret; 421044871b1bSChris Mason } 421144871b1bSChris Mason l = path->nodes[0]; 421244871b1bSChris Mason 421344871b1bSChris Mason /* did the pushes work? */ 421444871b1bSChris Mason if (btrfs_leaf_free_space(root, l) >= data_size) 421544871b1bSChris Mason return 0; 421644871b1bSChris Mason } 421744871b1bSChris Mason 421844871b1bSChris Mason if (!path->nodes[1]) { 4219fdd99c72SLiu Bo ret = insert_new_root(trans, root, path, 1); 422044871b1bSChris Mason if (ret) 422144871b1bSChris Mason return ret; 422244871b1bSChris Mason } 422344871b1bSChris Mason again: 42245d4f98a2SYan Zheng split = 1; 422544871b1bSChris Mason l = path->nodes[0]; 422644871b1bSChris Mason slot = path->slots[0]; 422744871b1bSChris Mason nritems = btrfs_header_nritems(l); 422844871b1bSChris Mason mid = (nritems + 1) / 2; 422944871b1bSChris Mason 42305d4f98a2SYan Zheng if (mid <= slot) { 42315d4f98a2SYan Zheng if (nritems == 1 || 42325d4f98a2SYan Zheng leaf_space_used(l, mid, nritems - mid) + data_size > 42335d4f98a2SYan Zheng BTRFS_LEAF_DATA_SIZE(root)) { 42345d4f98a2SYan Zheng if (slot >= nritems) { 42355d4f98a2SYan Zheng split = 0; 42365d4f98a2SYan Zheng } else { 42375d4f98a2SYan Zheng mid = slot; 42385d4f98a2SYan Zheng if (mid != nritems && 42395d4f98a2SYan Zheng leaf_space_used(l, mid, nritems - mid) + 42405d4f98a2SYan Zheng data_size > BTRFS_LEAF_DATA_SIZE(root)) { 424199d8f83cSChris Mason if (data_size && !tried_avoid_double) 424299d8f83cSChris Mason goto push_for_double; 42435d4f98a2SYan Zheng split = 2; 42445d4f98a2SYan Zheng } 42455d4f98a2SYan Zheng } 42465d4f98a2SYan Zheng } 42475d4f98a2SYan Zheng } else { 42485d4f98a2SYan Zheng if (leaf_space_used(l, 0, mid) + data_size > 42495d4f98a2SYan Zheng BTRFS_LEAF_DATA_SIZE(root)) { 42505d4f98a2SYan Zheng if (!extend && data_size && slot == 0) { 42515d4f98a2SYan Zheng split = 0; 42525d4f98a2SYan Zheng } else if ((extend || !data_size) && slot == 0) { 42535d4f98a2SYan Zheng mid = 1; 42545d4f98a2SYan Zheng } else { 42555d4f98a2SYan Zheng mid = slot; 42565d4f98a2SYan Zheng if (mid != nritems && 42575d4f98a2SYan Zheng leaf_space_used(l, mid, nritems - mid) + 42585d4f98a2SYan Zheng data_size > BTRFS_LEAF_DATA_SIZE(root)) { 425999d8f83cSChris Mason if (data_size && !tried_avoid_double) 426099d8f83cSChris Mason goto push_for_double; 42615d4f98a2SYan Zheng split = 2; 42625d4f98a2SYan Zheng } 42635d4f98a2SYan Zheng } 42645d4f98a2SYan Zheng } 42655d4f98a2SYan Zheng } 42665d4f98a2SYan Zheng 42675d4f98a2SYan Zheng if (split == 0) 42685d4f98a2SYan Zheng btrfs_cpu_key_to_disk(&disk_key, ins_key); 42695d4f98a2SYan Zheng else 42705d4f98a2SYan Zheng btrfs_item_key(l, &disk_key, mid); 42715d4f98a2SYan Zheng 42724d75f8a9SDavid Sterba right = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, 42735581a51aSJan Schmidt &disk_key, 0, l->start, 0); 4274f0486c68SYan, Zheng if (IS_ERR(right)) 427544871b1bSChris Mason return PTR_ERR(right); 4276f0486c68SYan, Zheng 4277707e8a07SDavid Sterba root_add_used(root, root->nodesize); 427844871b1bSChris Mason 427944871b1bSChris Mason memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); 428044871b1bSChris Mason btrfs_set_header_bytenr(right, right->start); 428144871b1bSChris Mason btrfs_set_header_generation(right, trans->transid); 42825d4f98a2SYan Zheng btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV); 428344871b1bSChris Mason btrfs_set_header_owner(right, root->root_key.objectid); 428444871b1bSChris Mason btrfs_set_header_level(right, 0); 428544871b1bSChris Mason write_extent_buffer(right, root->fs_info->fsid, 42860a4e5586SRoss Kirk btrfs_header_fsid(), BTRFS_FSID_SIZE); 428744871b1bSChris Mason 428844871b1bSChris Mason write_extent_buffer(right, root->fs_info->chunk_tree_uuid, 4289b308bc2fSGeert Uytterhoeven btrfs_header_chunk_tree_uuid(right), 429044871b1bSChris Mason BTRFS_UUID_SIZE); 429144871b1bSChris Mason 42925d4f98a2SYan Zheng if (split == 0) { 429344871b1bSChris Mason if (mid <= slot) { 429444871b1bSChris Mason btrfs_set_header_nritems(right, 0); 4295143bede5SJeff Mahoney insert_ptr(trans, root, path, &disk_key, right->start, 4296c3e06965SJan Schmidt path->slots[1] + 1, 1); 429744871b1bSChris Mason btrfs_tree_unlock(path->nodes[0]); 429844871b1bSChris Mason free_extent_buffer(path->nodes[0]); 429944871b1bSChris Mason path->nodes[0] = right; 430044871b1bSChris Mason path->slots[0] = 0; 430144871b1bSChris Mason path->slots[1] += 1; 430244871b1bSChris Mason } else { 430344871b1bSChris Mason btrfs_set_header_nritems(right, 0); 4304143bede5SJeff Mahoney insert_ptr(trans, root, path, &disk_key, right->start, 4305c3e06965SJan Schmidt path->slots[1], 1); 430644871b1bSChris Mason btrfs_tree_unlock(path->nodes[0]); 430744871b1bSChris Mason free_extent_buffer(path->nodes[0]); 430844871b1bSChris Mason path->nodes[0] = right; 430944871b1bSChris Mason path->slots[0] = 0; 4310143bede5SJeff Mahoney if (path->slots[1] == 0) 4311d6a0a126STsutomu Itoh fixup_low_keys(root, path, &disk_key, 1); 43125d4f98a2SYan Zheng } 431344871b1bSChris Mason btrfs_mark_buffer_dirty(right); 431444871b1bSChris Mason return ret; 431544871b1bSChris Mason } 431644871b1bSChris Mason 4317143bede5SJeff Mahoney copy_for_split(trans, root, path, l, right, slot, mid, nritems); 431844871b1bSChris Mason 43195d4f98a2SYan Zheng if (split == 2) { 4320cc0c5538SChris Mason BUG_ON(num_doubles != 0); 4321cc0c5538SChris Mason num_doubles++; 4322cc0c5538SChris Mason goto again; 43233326d1b0SChris Mason } 432444871b1bSChris Mason 4325143bede5SJeff Mahoney return 0; 432699d8f83cSChris Mason 432799d8f83cSChris Mason push_for_double: 432899d8f83cSChris Mason push_for_double_split(trans, root, path, data_size); 432999d8f83cSChris Mason tried_avoid_double = 1; 433099d8f83cSChris Mason if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) 433199d8f83cSChris Mason return 0; 433299d8f83cSChris Mason goto again; 4333be0e5c09SChris Mason } 4334be0e5c09SChris Mason 4335ad48fd75SYan, Zheng static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, 4336ad48fd75SYan, Zheng struct btrfs_root *root, 4337ad48fd75SYan, Zheng struct btrfs_path *path, int ins_len) 4338ad48fd75SYan, Zheng { 4339ad48fd75SYan, Zheng struct btrfs_key key; 4340ad48fd75SYan, Zheng struct extent_buffer *leaf; 4341ad48fd75SYan, Zheng struct btrfs_file_extent_item *fi; 4342ad48fd75SYan, Zheng u64 extent_len = 0; 4343ad48fd75SYan, Zheng u32 item_size; 4344ad48fd75SYan, Zheng int ret; 4345ad48fd75SYan, Zheng 4346ad48fd75SYan, Zheng leaf = path->nodes[0]; 4347ad48fd75SYan, Zheng btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 4348ad48fd75SYan, Zheng 4349ad48fd75SYan, Zheng BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && 4350ad48fd75SYan, Zheng key.type != BTRFS_EXTENT_CSUM_KEY); 4351ad48fd75SYan, Zheng 4352ad48fd75SYan, Zheng if (btrfs_leaf_free_space(root, leaf) >= ins_len) 4353ad48fd75SYan, Zheng return 0; 4354ad48fd75SYan, Zheng 4355ad48fd75SYan, Zheng item_size = btrfs_item_size_nr(leaf, path->slots[0]); 4356ad48fd75SYan, Zheng if (key.type == BTRFS_EXTENT_DATA_KEY) { 4357ad48fd75SYan, Zheng fi = btrfs_item_ptr(leaf, path->slots[0], 4358ad48fd75SYan, Zheng struct btrfs_file_extent_item); 4359ad48fd75SYan, Zheng extent_len = btrfs_file_extent_num_bytes(leaf, fi); 4360ad48fd75SYan, Zheng } 4361b3b4aa74SDavid Sterba btrfs_release_path(path); 4362ad48fd75SYan, Zheng 4363ad48fd75SYan, Zheng path->keep_locks = 1; 4364ad48fd75SYan, Zheng path->search_for_split = 1; 4365ad48fd75SYan, Zheng ret = btrfs_search_slot(trans, root, &key, path, 0, 1); 4366ad48fd75SYan, Zheng path->search_for_split = 0; 4367ad48fd75SYan, Zheng if (ret < 0) 4368ad48fd75SYan, Zheng goto err; 4369ad48fd75SYan, Zheng 4370ad48fd75SYan, Zheng ret = -EAGAIN; 4371ad48fd75SYan, Zheng leaf = path->nodes[0]; 4372ad48fd75SYan, Zheng /* if our item isn't there or got smaller, return now */ 4373ad48fd75SYan, Zheng if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0])) 4374ad48fd75SYan, Zheng goto err; 4375ad48fd75SYan, Zheng 4376109f6aefSChris Mason /* the leaf has changed, it now has room. return now */ 4377109f6aefSChris Mason if (btrfs_leaf_free_space(root, path->nodes[0]) >= ins_len) 4378109f6aefSChris Mason goto err; 4379109f6aefSChris Mason 4380ad48fd75SYan, Zheng if (key.type == BTRFS_EXTENT_DATA_KEY) { 4381ad48fd75SYan, Zheng fi = btrfs_item_ptr(leaf, path->slots[0], 4382ad48fd75SYan, Zheng struct btrfs_file_extent_item); 4383ad48fd75SYan, Zheng if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) 4384ad48fd75SYan, Zheng goto err; 4385ad48fd75SYan, Zheng } 4386ad48fd75SYan, Zheng 4387ad48fd75SYan, Zheng btrfs_set_path_blocking(path); 4388ad48fd75SYan, Zheng ret = split_leaf(trans, root, &key, path, ins_len, 1); 4389f0486c68SYan, Zheng if (ret) 4390f0486c68SYan, Zheng goto err; 4391ad48fd75SYan, Zheng 4392ad48fd75SYan, Zheng path->keep_locks = 0; 4393ad48fd75SYan, Zheng btrfs_unlock_up_safe(path, 1); 4394ad48fd75SYan, Zheng return 0; 4395ad48fd75SYan, Zheng err: 4396ad48fd75SYan, Zheng path->keep_locks = 0; 4397ad48fd75SYan, Zheng return ret; 4398ad48fd75SYan, Zheng } 4399ad48fd75SYan, Zheng 4400ad48fd75SYan, Zheng static noinline int split_item(struct btrfs_trans_handle *trans, 4401459931ecSChris Mason struct btrfs_root *root, 4402459931ecSChris Mason struct btrfs_path *path, 4403459931ecSChris Mason struct btrfs_key *new_key, 4404459931ecSChris Mason unsigned long split_offset) 4405459931ecSChris Mason { 4406459931ecSChris Mason struct extent_buffer *leaf; 4407459931ecSChris Mason struct btrfs_item *item; 4408459931ecSChris Mason struct btrfs_item *new_item; 4409459931ecSChris Mason int slot; 4410ad48fd75SYan, Zheng char *buf; 4411459931ecSChris Mason u32 nritems; 4412ad48fd75SYan, Zheng u32 item_size; 4413459931ecSChris Mason u32 orig_offset; 4414459931ecSChris Mason struct btrfs_disk_key disk_key; 4415459931ecSChris Mason 4416459931ecSChris Mason leaf = path->nodes[0]; 4417b9473439SChris Mason BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); 4418b9473439SChris Mason 4419b4ce94deSChris Mason btrfs_set_path_blocking(path); 4420b4ce94deSChris Mason 4421dd3cc16bSRoss Kirk item = btrfs_item_nr(path->slots[0]); 4422459931ecSChris Mason orig_offset = btrfs_item_offset(leaf, item); 4423459931ecSChris Mason item_size = btrfs_item_size(leaf, item); 4424459931ecSChris Mason 4425459931ecSChris Mason buf = kmalloc(item_size, GFP_NOFS); 4426ad48fd75SYan, Zheng if (!buf) 4427ad48fd75SYan, Zheng return -ENOMEM; 4428ad48fd75SYan, Zheng 4429459931ecSChris Mason read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, 4430459931ecSChris Mason path->slots[0]), item_size); 4431ad48fd75SYan, Zheng 4432459931ecSChris Mason slot = path->slots[0] + 1; 4433459931ecSChris Mason nritems = btrfs_header_nritems(leaf); 4434459931ecSChris Mason if (slot != nritems) { 4435459931ecSChris Mason /* shift the items */ 4436459931ecSChris Mason memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), 4437459931ecSChris Mason btrfs_item_nr_offset(slot), 4438459931ecSChris Mason (nritems - slot) * sizeof(struct btrfs_item)); 4439459931ecSChris Mason } 4440459931ecSChris Mason 4441459931ecSChris Mason btrfs_cpu_key_to_disk(&disk_key, new_key); 4442459931ecSChris Mason btrfs_set_item_key(leaf, &disk_key, slot); 4443459931ecSChris Mason 4444dd3cc16bSRoss Kirk new_item = btrfs_item_nr(slot); 4445459931ecSChris Mason 4446459931ecSChris Mason btrfs_set_item_offset(leaf, new_item, orig_offset); 4447459931ecSChris Mason btrfs_set_item_size(leaf, new_item, item_size - split_offset); 4448459931ecSChris Mason 4449459931ecSChris Mason btrfs_set_item_offset(leaf, item, 4450459931ecSChris Mason orig_offset + item_size - split_offset); 4451459931ecSChris Mason btrfs_set_item_size(leaf, item, split_offset); 4452459931ecSChris Mason 4453459931ecSChris Mason btrfs_set_header_nritems(leaf, nritems + 1); 4454459931ecSChris Mason 4455459931ecSChris Mason /* write the data for the start of the original item */ 4456459931ecSChris Mason write_extent_buffer(leaf, buf, 4457459931ecSChris Mason btrfs_item_ptr_offset(leaf, path->slots[0]), 4458459931ecSChris Mason split_offset); 4459459931ecSChris Mason 4460459931ecSChris Mason /* write the data for the new item */ 4461459931ecSChris Mason write_extent_buffer(leaf, buf + split_offset, 4462459931ecSChris Mason btrfs_item_ptr_offset(leaf, slot), 4463459931ecSChris Mason item_size - split_offset); 4464459931ecSChris Mason btrfs_mark_buffer_dirty(leaf); 4465459931ecSChris Mason 4466ad48fd75SYan, Zheng BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); 4467459931ecSChris Mason kfree(buf); 4468ad48fd75SYan, Zheng return 0; 4469ad48fd75SYan, Zheng } 4470ad48fd75SYan, Zheng 4471ad48fd75SYan, Zheng /* 4472ad48fd75SYan, Zheng * This function splits a single item into two items, 4473ad48fd75SYan, Zheng * giving 'new_key' to the new item and splitting the 4474ad48fd75SYan, Zheng * old one at split_offset (from the start of the item). 4475ad48fd75SYan, Zheng * 4476ad48fd75SYan, Zheng * The path may be released by this operation. After 4477ad48fd75SYan, Zheng * the split, the path is pointing to the old item. The 4478ad48fd75SYan, Zheng * new item is going to be in the same node as the old one. 4479ad48fd75SYan, Zheng * 4480ad48fd75SYan, Zheng * Note, the item being split must be smaller enough to live alone on 4481ad48fd75SYan, Zheng * a tree block with room for one extra struct btrfs_item 4482ad48fd75SYan, Zheng * 4483ad48fd75SYan, Zheng * This allows us to split the item in place, keeping a lock on the 4484ad48fd75SYan, Zheng * leaf the entire time. 4485ad48fd75SYan, Zheng */ 4486ad48fd75SYan, Zheng int btrfs_split_item(struct btrfs_trans_handle *trans, 4487ad48fd75SYan, Zheng struct btrfs_root *root, 4488ad48fd75SYan, Zheng struct btrfs_path *path, 4489ad48fd75SYan, Zheng struct btrfs_key *new_key, 4490ad48fd75SYan, Zheng unsigned long split_offset) 4491ad48fd75SYan, Zheng { 4492ad48fd75SYan, Zheng int ret; 4493ad48fd75SYan, Zheng ret = setup_leaf_for_split(trans, root, path, 4494ad48fd75SYan, Zheng sizeof(struct btrfs_item)); 4495ad48fd75SYan, Zheng if (ret) 4496459931ecSChris Mason return ret; 4497ad48fd75SYan, Zheng 4498ad48fd75SYan, Zheng ret = split_item(trans, root, path, new_key, split_offset); 4499ad48fd75SYan, Zheng return ret; 4500ad48fd75SYan, Zheng } 4501ad48fd75SYan, Zheng 4502ad48fd75SYan, Zheng /* 4503ad48fd75SYan, Zheng * This function duplicate a item, giving 'new_key' to the new item. 4504ad48fd75SYan, Zheng * It guarantees both items live in the same tree leaf and the new item 4505ad48fd75SYan, Zheng * is contiguous with the original item. 4506ad48fd75SYan, Zheng * 4507ad48fd75SYan, Zheng * This allows us to split file extent in place, keeping a lock on the 4508ad48fd75SYan, Zheng * leaf the entire time. 4509ad48fd75SYan, Zheng */ 4510ad48fd75SYan, Zheng int btrfs_duplicate_item(struct btrfs_trans_handle *trans, 4511ad48fd75SYan, Zheng struct btrfs_root *root, 4512ad48fd75SYan, Zheng struct btrfs_path *path, 4513ad48fd75SYan, Zheng struct btrfs_key *new_key) 4514ad48fd75SYan, Zheng { 4515ad48fd75SYan, Zheng struct extent_buffer *leaf; 4516ad48fd75SYan, Zheng int ret; 4517ad48fd75SYan, Zheng u32 item_size; 4518ad48fd75SYan, Zheng 4519ad48fd75SYan, Zheng leaf = path->nodes[0]; 4520ad48fd75SYan, Zheng item_size = btrfs_item_size_nr(leaf, path->slots[0]); 4521ad48fd75SYan, Zheng ret = setup_leaf_for_split(trans, root, path, 4522ad48fd75SYan, Zheng item_size + sizeof(struct btrfs_item)); 4523ad48fd75SYan, Zheng if (ret) 4524ad48fd75SYan, Zheng return ret; 4525ad48fd75SYan, Zheng 4526ad48fd75SYan, Zheng path->slots[0]++; 4527afe5fea7STsutomu Itoh setup_items_for_insert(root, path, new_key, &item_size, 4528ad48fd75SYan, Zheng item_size, item_size + 4529ad48fd75SYan, Zheng sizeof(struct btrfs_item), 1); 4530ad48fd75SYan, Zheng leaf = path->nodes[0]; 4531ad48fd75SYan, Zheng memcpy_extent_buffer(leaf, 4532ad48fd75SYan, Zheng btrfs_item_ptr_offset(leaf, path->slots[0]), 4533ad48fd75SYan, Zheng btrfs_item_ptr_offset(leaf, path->slots[0] - 1), 4534ad48fd75SYan, Zheng item_size); 4535ad48fd75SYan, Zheng return 0; 4536459931ecSChris Mason } 4537459931ecSChris Mason 4538459931ecSChris Mason /* 4539d352ac68SChris Mason * make the item pointed to by the path smaller. new_size indicates 4540d352ac68SChris Mason * how small to make it, and from_end tells us if we just chop bytes 4541d352ac68SChris Mason * off the end of the item or if we shift the item to chop bytes off 4542d352ac68SChris Mason * the front. 4543d352ac68SChris Mason */ 4544afe5fea7STsutomu Itoh void btrfs_truncate_item(struct btrfs_root *root, struct btrfs_path *path, 4545179e29e4SChris Mason u32 new_size, int from_end) 4546b18c6685SChris Mason { 4547b18c6685SChris Mason int slot; 45485f39d397SChris Mason struct extent_buffer *leaf; 45495f39d397SChris Mason struct btrfs_item *item; 4550b18c6685SChris Mason u32 nritems; 4551b18c6685SChris Mason unsigned int data_end; 4552b18c6685SChris Mason unsigned int old_data_start; 4553b18c6685SChris Mason unsigned int old_size; 4554b18c6685SChris Mason unsigned int size_diff; 4555b18c6685SChris Mason int i; 4556cfed81a0SChris Mason struct btrfs_map_token token; 4557cfed81a0SChris Mason 4558cfed81a0SChris Mason btrfs_init_map_token(&token); 4559b18c6685SChris Mason 45605f39d397SChris Mason leaf = path->nodes[0]; 4561179e29e4SChris Mason slot = path->slots[0]; 4562179e29e4SChris Mason 4563179e29e4SChris Mason old_size = btrfs_item_size_nr(leaf, slot); 4564179e29e4SChris Mason if (old_size == new_size) 4565143bede5SJeff Mahoney return; 4566b18c6685SChris Mason 45675f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 4568b18c6685SChris Mason data_end = leaf_data_end(root, leaf); 4569b18c6685SChris Mason 45705f39d397SChris Mason old_data_start = btrfs_item_offset_nr(leaf, slot); 4571179e29e4SChris Mason 4572b18c6685SChris Mason size_diff = old_size - new_size; 4573b18c6685SChris Mason 4574b18c6685SChris Mason BUG_ON(slot < 0); 4575b18c6685SChris Mason BUG_ON(slot >= nritems); 4576b18c6685SChris Mason 4577b18c6685SChris Mason /* 4578b18c6685SChris Mason * item0..itemN ... dataN.offset..dataN.size .. data0.size 4579b18c6685SChris Mason */ 4580b18c6685SChris Mason /* first correct the data pointers */ 4581b18c6685SChris Mason for (i = slot; i < nritems; i++) { 45825f39d397SChris Mason u32 ioff; 4583dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 4584db94535dSChris Mason 4585cfed81a0SChris Mason ioff = btrfs_token_item_offset(leaf, item, &token); 4586cfed81a0SChris Mason btrfs_set_token_item_offset(leaf, item, 4587cfed81a0SChris Mason ioff + size_diff, &token); 4588b18c6685SChris Mason } 4589db94535dSChris Mason 4590b18c6685SChris Mason /* shift the data */ 4591179e29e4SChris Mason if (from_end) { 45925f39d397SChris Mason memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + 4593b18c6685SChris Mason data_end + size_diff, btrfs_leaf_data(leaf) + 4594b18c6685SChris Mason data_end, old_data_start + new_size - data_end); 4595179e29e4SChris Mason } else { 4596179e29e4SChris Mason struct btrfs_disk_key disk_key; 4597179e29e4SChris Mason u64 offset; 4598179e29e4SChris Mason 4599179e29e4SChris Mason btrfs_item_key(leaf, &disk_key, slot); 4600179e29e4SChris Mason 4601179e29e4SChris Mason if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { 4602179e29e4SChris Mason unsigned long ptr; 4603179e29e4SChris Mason struct btrfs_file_extent_item *fi; 4604179e29e4SChris Mason 4605179e29e4SChris Mason fi = btrfs_item_ptr(leaf, slot, 4606179e29e4SChris Mason struct btrfs_file_extent_item); 4607179e29e4SChris Mason fi = (struct btrfs_file_extent_item *)( 4608179e29e4SChris Mason (unsigned long)fi - size_diff); 4609179e29e4SChris Mason 4610179e29e4SChris Mason if (btrfs_file_extent_type(leaf, fi) == 4611179e29e4SChris Mason BTRFS_FILE_EXTENT_INLINE) { 4612179e29e4SChris Mason ptr = btrfs_item_ptr_offset(leaf, slot); 4613179e29e4SChris Mason memmove_extent_buffer(leaf, ptr, 4614179e29e4SChris Mason (unsigned long)fi, 46157ec20afbSDavid Sterba BTRFS_FILE_EXTENT_INLINE_DATA_START); 4616179e29e4SChris Mason } 4617179e29e4SChris Mason } 4618179e29e4SChris Mason 4619179e29e4SChris Mason memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + 4620179e29e4SChris Mason data_end + size_diff, btrfs_leaf_data(leaf) + 4621179e29e4SChris Mason data_end, old_data_start - data_end); 4622179e29e4SChris Mason 4623179e29e4SChris Mason offset = btrfs_disk_key_offset(&disk_key); 4624179e29e4SChris Mason btrfs_set_disk_key_offset(&disk_key, offset + size_diff); 4625179e29e4SChris Mason btrfs_set_item_key(leaf, &disk_key, slot); 4626179e29e4SChris Mason if (slot == 0) 4627d6a0a126STsutomu Itoh fixup_low_keys(root, path, &disk_key, 1); 4628179e29e4SChris Mason } 46295f39d397SChris Mason 4630dd3cc16bSRoss Kirk item = btrfs_item_nr(slot); 46315f39d397SChris Mason btrfs_set_item_size(leaf, item, new_size); 46325f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 4633b18c6685SChris Mason 46345f39d397SChris Mason if (btrfs_leaf_free_space(root, leaf) < 0) { 46355f39d397SChris Mason btrfs_print_leaf(root, leaf); 4636b18c6685SChris Mason BUG(); 46375f39d397SChris Mason } 4638b18c6685SChris Mason } 4639b18c6685SChris Mason 4640d352ac68SChris Mason /* 46418f69dbd2SStefan Behrens * make the item pointed to by the path bigger, data_size is the added size. 4642d352ac68SChris Mason */ 46434b90c680STsutomu Itoh void btrfs_extend_item(struct btrfs_root *root, struct btrfs_path *path, 46445f39d397SChris Mason u32 data_size) 46456567e837SChris Mason { 46466567e837SChris Mason int slot; 46475f39d397SChris Mason struct extent_buffer *leaf; 46485f39d397SChris Mason struct btrfs_item *item; 46496567e837SChris Mason u32 nritems; 46506567e837SChris Mason unsigned int data_end; 46516567e837SChris Mason unsigned int old_data; 46526567e837SChris Mason unsigned int old_size; 46536567e837SChris Mason int i; 4654cfed81a0SChris Mason struct btrfs_map_token token; 4655cfed81a0SChris Mason 4656cfed81a0SChris Mason btrfs_init_map_token(&token); 46576567e837SChris Mason 46585f39d397SChris Mason leaf = path->nodes[0]; 46596567e837SChris Mason 46605f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 46616567e837SChris Mason data_end = leaf_data_end(root, leaf); 46626567e837SChris Mason 46635f39d397SChris Mason if (btrfs_leaf_free_space(root, leaf) < data_size) { 46645f39d397SChris Mason btrfs_print_leaf(root, leaf); 46656567e837SChris Mason BUG(); 46665f39d397SChris Mason } 46676567e837SChris Mason slot = path->slots[0]; 46685f39d397SChris Mason old_data = btrfs_item_end_nr(leaf, slot); 46696567e837SChris Mason 46706567e837SChris Mason BUG_ON(slot < 0); 46713326d1b0SChris Mason if (slot >= nritems) { 46723326d1b0SChris Mason btrfs_print_leaf(root, leaf); 4673efe120a0SFrank Holton btrfs_crit(root->fs_info, "slot %d too large, nritems %d", 4674d397712bSChris Mason slot, nritems); 46753326d1b0SChris Mason BUG_ON(1); 46763326d1b0SChris Mason } 46776567e837SChris Mason 46786567e837SChris Mason /* 46796567e837SChris Mason * item0..itemN ... dataN.offset..dataN.size .. data0.size 46806567e837SChris Mason */ 46816567e837SChris Mason /* first correct the data pointers */ 46826567e837SChris Mason for (i = slot; i < nritems; i++) { 46835f39d397SChris Mason u32 ioff; 4684dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 4685db94535dSChris Mason 4686cfed81a0SChris Mason ioff = btrfs_token_item_offset(leaf, item, &token); 4687cfed81a0SChris Mason btrfs_set_token_item_offset(leaf, item, 4688cfed81a0SChris Mason ioff - data_size, &token); 46896567e837SChris Mason } 46905f39d397SChris Mason 46916567e837SChris Mason /* shift the data */ 46925f39d397SChris Mason memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + 46936567e837SChris Mason data_end - data_size, btrfs_leaf_data(leaf) + 46946567e837SChris Mason data_end, old_data - data_end); 46955f39d397SChris Mason 46966567e837SChris Mason data_end = old_data; 46975f39d397SChris Mason old_size = btrfs_item_size_nr(leaf, slot); 4698dd3cc16bSRoss Kirk item = btrfs_item_nr(slot); 46995f39d397SChris Mason btrfs_set_item_size(leaf, item, old_size + data_size); 47005f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 47016567e837SChris Mason 47025f39d397SChris Mason if (btrfs_leaf_free_space(root, leaf) < 0) { 47035f39d397SChris Mason btrfs_print_leaf(root, leaf); 47046567e837SChris Mason BUG(); 47055f39d397SChris Mason } 47066567e837SChris Mason } 47076567e837SChris Mason 470874123bd7SChris Mason /* 470944871b1bSChris Mason * this is a helper for btrfs_insert_empty_items, the main goal here is 471044871b1bSChris Mason * to save stack depth by doing the bulk of the work in a function 471144871b1bSChris Mason * that doesn't call btrfs_search_slot 471274123bd7SChris Mason */ 4713afe5fea7STsutomu Itoh void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path, 47149c58309dSChris Mason struct btrfs_key *cpu_key, u32 *data_size, 471544871b1bSChris Mason u32 total_data, u32 total_size, int nr) 4716be0e5c09SChris Mason { 47175f39d397SChris Mason struct btrfs_item *item; 47189c58309dSChris Mason int i; 47197518a238SChris Mason u32 nritems; 4720be0e5c09SChris Mason unsigned int data_end; 4721e2fa7227SChris Mason struct btrfs_disk_key disk_key; 472244871b1bSChris Mason struct extent_buffer *leaf; 472344871b1bSChris Mason int slot; 4724cfed81a0SChris Mason struct btrfs_map_token token; 4725cfed81a0SChris Mason 472624cdc847SFilipe Manana if (path->slots[0] == 0) { 472724cdc847SFilipe Manana btrfs_cpu_key_to_disk(&disk_key, cpu_key); 472824cdc847SFilipe Manana fixup_low_keys(root, path, &disk_key, 1); 472924cdc847SFilipe Manana } 473024cdc847SFilipe Manana btrfs_unlock_up_safe(path, 1); 473124cdc847SFilipe Manana 4732cfed81a0SChris Mason btrfs_init_map_token(&token); 4733e2fa7227SChris Mason 47345f39d397SChris Mason leaf = path->nodes[0]; 473544871b1bSChris Mason slot = path->slots[0]; 473674123bd7SChris Mason 47375f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 4738123abc88SChris Mason data_end = leaf_data_end(root, leaf); 4739eb60ceacSChris Mason 4740f25956ccSChris Mason if (btrfs_leaf_free_space(root, leaf) < total_size) { 47413326d1b0SChris Mason btrfs_print_leaf(root, leaf); 4742efe120a0SFrank Holton btrfs_crit(root->fs_info, "not enough freespace need %u have %d", 47439c58309dSChris Mason total_size, btrfs_leaf_free_space(root, leaf)); 4744be0e5c09SChris Mason BUG(); 4745d4dbff95SChris Mason } 47465f39d397SChris Mason 4747be0e5c09SChris Mason if (slot != nritems) { 47485f39d397SChris Mason unsigned int old_data = btrfs_item_end_nr(leaf, slot); 4749be0e5c09SChris Mason 47505f39d397SChris Mason if (old_data < data_end) { 47515f39d397SChris Mason btrfs_print_leaf(root, leaf); 4752efe120a0SFrank Holton btrfs_crit(root->fs_info, "slot %d old_data %d data_end %d", 47535f39d397SChris Mason slot, old_data, data_end); 47545f39d397SChris Mason BUG_ON(1); 47555f39d397SChris Mason } 4756be0e5c09SChris Mason /* 4757be0e5c09SChris Mason * item0..itemN ... dataN.offset..dataN.size .. data0.size 4758be0e5c09SChris Mason */ 4759be0e5c09SChris Mason /* first correct the data pointers */ 47600783fcfcSChris Mason for (i = slot; i < nritems; i++) { 47615f39d397SChris Mason u32 ioff; 4762db94535dSChris Mason 4763dd3cc16bSRoss Kirk item = btrfs_item_nr( i); 4764cfed81a0SChris Mason ioff = btrfs_token_item_offset(leaf, item, &token); 4765cfed81a0SChris Mason btrfs_set_token_item_offset(leaf, item, 4766cfed81a0SChris Mason ioff - total_data, &token); 47670783fcfcSChris Mason } 4768be0e5c09SChris Mason /* shift the items */ 47699c58309dSChris Mason memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), 47705f39d397SChris Mason btrfs_item_nr_offset(slot), 47710783fcfcSChris Mason (nritems - slot) * sizeof(struct btrfs_item)); 4772be0e5c09SChris Mason 4773be0e5c09SChris Mason /* shift the data */ 47745f39d397SChris Mason memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + 47759c58309dSChris Mason data_end - total_data, btrfs_leaf_data(leaf) + 4776be0e5c09SChris Mason data_end, old_data - data_end); 4777be0e5c09SChris Mason data_end = old_data; 4778be0e5c09SChris Mason } 47795f39d397SChris Mason 478062e2749eSChris Mason /* setup the item for the new data */ 47819c58309dSChris Mason for (i = 0; i < nr; i++) { 47829c58309dSChris Mason btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); 47839c58309dSChris Mason btrfs_set_item_key(leaf, &disk_key, slot + i); 4784dd3cc16bSRoss Kirk item = btrfs_item_nr(slot + i); 4785cfed81a0SChris Mason btrfs_set_token_item_offset(leaf, item, 4786cfed81a0SChris Mason data_end - data_size[i], &token); 47879c58309dSChris Mason data_end -= data_size[i]; 4788cfed81a0SChris Mason btrfs_set_token_item_size(leaf, item, data_size[i], &token); 47899c58309dSChris Mason } 479044871b1bSChris Mason 47919c58309dSChris Mason btrfs_set_header_nritems(leaf, nritems + nr); 4792b9473439SChris Mason btrfs_mark_buffer_dirty(leaf); 4793aa5d6bedSChris Mason 47945f39d397SChris Mason if (btrfs_leaf_free_space(root, leaf) < 0) { 47955f39d397SChris Mason btrfs_print_leaf(root, leaf); 4796be0e5c09SChris Mason BUG(); 47975f39d397SChris Mason } 479844871b1bSChris Mason } 479944871b1bSChris Mason 480044871b1bSChris Mason /* 480144871b1bSChris Mason * Given a key and some data, insert items into the tree. 480244871b1bSChris Mason * This does all the path init required, making room in the tree if needed. 480344871b1bSChris Mason */ 480444871b1bSChris Mason int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, 480544871b1bSChris Mason struct btrfs_root *root, 480644871b1bSChris Mason struct btrfs_path *path, 480744871b1bSChris Mason struct btrfs_key *cpu_key, u32 *data_size, 480844871b1bSChris Mason int nr) 480944871b1bSChris Mason { 481044871b1bSChris Mason int ret = 0; 481144871b1bSChris Mason int slot; 481244871b1bSChris Mason int i; 481344871b1bSChris Mason u32 total_size = 0; 481444871b1bSChris Mason u32 total_data = 0; 481544871b1bSChris Mason 481644871b1bSChris Mason for (i = 0; i < nr; i++) 481744871b1bSChris Mason total_data += data_size[i]; 481844871b1bSChris Mason 481944871b1bSChris Mason total_size = total_data + (nr * sizeof(struct btrfs_item)); 482044871b1bSChris Mason ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); 482144871b1bSChris Mason if (ret == 0) 482244871b1bSChris Mason return -EEXIST; 482344871b1bSChris Mason if (ret < 0) 4824143bede5SJeff Mahoney return ret; 482544871b1bSChris Mason 482644871b1bSChris Mason slot = path->slots[0]; 482744871b1bSChris Mason BUG_ON(slot < 0); 482844871b1bSChris Mason 4829afe5fea7STsutomu Itoh setup_items_for_insert(root, path, cpu_key, data_size, 483044871b1bSChris Mason total_data, total_size, nr); 4831143bede5SJeff Mahoney return 0; 483262e2749eSChris Mason } 483362e2749eSChris Mason 483462e2749eSChris Mason /* 483562e2749eSChris Mason * Given a key and some data, insert an item into the tree. 483662e2749eSChris Mason * This does all the path init required, making room in the tree if needed. 483762e2749eSChris Mason */ 4838e089f05cSChris Mason int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root 4839e089f05cSChris Mason *root, struct btrfs_key *cpu_key, void *data, u32 4840e089f05cSChris Mason data_size) 484162e2749eSChris Mason { 484262e2749eSChris Mason int ret = 0; 48432c90e5d6SChris Mason struct btrfs_path *path; 48445f39d397SChris Mason struct extent_buffer *leaf; 48455f39d397SChris Mason unsigned long ptr; 484662e2749eSChris Mason 48472c90e5d6SChris Mason path = btrfs_alloc_path(); 4848db5b493aSTsutomu Itoh if (!path) 4849db5b493aSTsutomu Itoh return -ENOMEM; 48502c90e5d6SChris Mason ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); 485162e2749eSChris Mason if (!ret) { 48525f39d397SChris Mason leaf = path->nodes[0]; 48535f39d397SChris Mason ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); 48545f39d397SChris Mason write_extent_buffer(leaf, data, ptr, data_size); 48555f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 485662e2749eSChris Mason } 48572c90e5d6SChris Mason btrfs_free_path(path); 4858aa5d6bedSChris Mason return ret; 4859be0e5c09SChris Mason } 4860be0e5c09SChris Mason 486174123bd7SChris Mason /* 48625de08d7dSChris Mason * delete the pointer from a given node. 486374123bd7SChris Mason * 4864d352ac68SChris Mason * the tree should have been previously balanced so the deletion does not 4865d352ac68SChris Mason * empty a node. 486674123bd7SChris Mason */ 4867afe5fea7STsutomu Itoh static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, 4868afe5fea7STsutomu Itoh int level, int slot) 4869be0e5c09SChris Mason { 48705f39d397SChris Mason struct extent_buffer *parent = path->nodes[level]; 48717518a238SChris Mason u32 nritems; 4872f3ea38daSJan Schmidt int ret; 4873be0e5c09SChris Mason 48745f39d397SChris Mason nritems = btrfs_header_nritems(parent); 4875be0e5c09SChris Mason if (slot != nritems - 1) { 48760e411eceSLiu Bo if (level) 4877f3ea38daSJan Schmidt tree_mod_log_eb_move(root->fs_info, parent, slot, 4878f3ea38daSJan Schmidt slot + 1, nritems - slot - 1); 48795f39d397SChris Mason memmove_extent_buffer(parent, 48805f39d397SChris Mason btrfs_node_key_ptr_offset(slot), 48815f39d397SChris Mason btrfs_node_key_ptr_offset(slot + 1), 4882d6025579SChris Mason sizeof(struct btrfs_key_ptr) * 4883d6025579SChris Mason (nritems - slot - 1)); 488457ba86c0SChris Mason } else if (level) { 488557ba86c0SChris Mason ret = tree_mod_log_insert_key(root->fs_info, parent, slot, 4886c8cc6341SJosef Bacik MOD_LOG_KEY_REMOVE, GFP_NOFS); 488757ba86c0SChris Mason BUG_ON(ret < 0); 4888be0e5c09SChris Mason } 4889f3ea38daSJan Schmidt 48907518a238SChris Mason nritems--; 48915f39d397SChris Mason btrfs_set_header_nritems(parent, nritems); 48927518a238SChris Mason if (nritems == 0 && parent == root->node) { 48935f39d397SChris Mason BUG_ON(btrfs_header_level(root->node) != 1); 4894eb60ceacSChris Mason /* just turn the root into a leaf and break */ 48955f39d397SChris Mason btrfs_set_header_level(root->node, 0); 4896bb803951SChris Mason } else if (slot == 0) { 48975f39d397SChris Mason struct btrfs_disk_key disk_key; 48985f39d397SChris Mason 48995f39d397SChris Mason btrfs_node_key(parent, &disk_key, 0); 4900d6a0a126STsutomu Itoh fixup_low_keys(root, path, &disk_key, level + 1); 4901be0e5c09SChris Mason } 4902d6025579SChris Mason btrfs_mark_buffer_dirty(parent); 4903be0e5c09SChris Mason } 4904be0e5c09SChris Mason 490574123bd7SChris Mason /* 4906323ac95bSChris Mason * a helper function to delete the leaf pointed to by path->slots[1] and 49075d4f98a2SYan Zheng * path->nodes[1]. 4908323ac95bSChris Mason * 4909323ac95bSChris Mason * This deletes the pointer in path->nodes[1] and frees the leaf 4910323ac95bSChris Mason * block extent. zero is returned if it all worked out, < 0 otherwise. 4911323ac95bSChris Mason * 4912323ac95bSChris Mason * The path must have already been setup for deleting the leaf, including 4913323ac95bSChris Mason * all the proper balancing. path->nodes[1] must be locked. 4914323ac95bSChris Mason */ 4915143bede5SJeff Mahoney static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, 4916323ac95bSChris Mason struct btrfs_root *root, 49175d4f98a2SYan Zheng struct btrfs_path *path, 49185d4f98a2SYan Zheng struct extent_buffer *leaf) 4919323ac95bSChris Mason { 49205d4f98a2SYan Zheng WARN_ON(btrfs_header_generation(leaf) != trans->transid); 4921afe5fea7STsutomu Itoh del_ptr(root, path, 1, path->slots[1]); 4922323ac95bSChris Mason 49234d081c41SChris Mason /* 49244d081c41SChris Mason * btrfs_free_extent is expensive, we want to make sure we 49254d081c41SChris Mason * aren't holding any locks when we call it 49264d081c41SChris Mason */ 49274d081c41SChris Mason btrfs_unlock_up_safe(path, 0); 49284d081c41SChris Mason 4929f0486c68SYan, Zheng root_sub_used(root, leaf->len); 4930f0486c68SYan, Zheng 49313083ee2eSJosef Bacik extent_buffer_get(leaf); 49325581a51aSJan Schmidt btrfs_free_tree_block(trans, root, leaf, 0, 1); 49333083ee2eSJosef Bacik free_extent_buffer_stale(leaf); 4934323ac95bSChris Mason } 4935323ac95bSChris Mason /* 493674123bd7SChris Mason * delete the item at the leaf level in path. If that empties 493774123bd7SChris Mason * the leaf, remove it from the tree 493874123bd7SChris Mason */ 493985e21bacSChris Mason int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, 494085e21bacSChris Mason struct btrfs_path *path, int slot, int nr) 4941be0e5c09SChris Mason { 49425f39d397SChris Mason struct extent_buffer *leaf; 49435f39d397SChris Mason struct btrfs_item *item; 494485e21bacSChris Mason int last_off; 494585e21bacSChris Mason int dsize = 0; 4946aa5d6bedSChris Mason int ret = 0; 4947aa5d6bedSChris Mason int wret; 494885e21bacSChris Mason int i; 49497518a238SChris Mason u32 nritems; 4950cfed81a0SChris Mason struct btrfs_map_token token; 4951cfed81a0SChris Mason 4952cfed81a0SChris Mason btrfs_init_map_token(&token); 4953be0e5c09SChris Mason 49545f39d397SChris Mason leaf = path->nodes[0]; 495585e21bacSChris Mason last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); 495685e21bacSChris Mason 495785e21bacSChris Mason for (i = 0; i < nr; i++) 495885e21bacSChris Mason dsize += btrfs_item_size_nr(leaf, slot + i); 495985e21bacSChris Mason 49605f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 4961be0e5c09SChris Mason 496285e21bacSChris Mason if (slot + nr != nritems) { 4963123abc88SChris Mason int data_end = leaf_data_end(root, leaf); 49645f39d397SChris Mason 49655f39d397SChris Mason memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + 4966d6025579SChris Mason data_end + dsize, 4967123abc88SChris Mason btrfs_leaf_data(leaf) + data_end, 496885e21bacSChris Mason last_off - data_end); 49695f39d397SChris Mason 497085e21bacSChris Mason for (i = slot + nr; i < nritems; i++) { 49715f39d397SChris Mason u32 ioff; 4972db94535dSChris Mason 4973dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 4974cfed81a0SChris Mason ioff = btrfs_token_item_offset(leaf, item, &token); 4975cfed81a0SChris Mason btrfs_set_token_item_offset(leaf, item, 4976cfed81a0SChris Mason ioff + dsize, &token); 49770783fcfcSChris Mason } 4978db94535dSChris Mason 49795f39d397SChris Mason memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), 498085e21bacSChris Mason btrfs_item_nr_offset(slot + nr), 49810783fcfcSChris Mason sizeof(struct btrfs_item) * 498285e21bacSChris Mason (nritems - slot - nr)); 4983be0e5c09SChris Mason } 498485e21bacSChris Mason btrfs_set_header_nritems(leaf, nritems - nr); 498585e21bacSChris Mason nritems -= nr; 49865f39d397SChris Mason 498774123bd7SChris Mason /* delete the leaf if we've emptied it */ 49887518a238SChris Mason if (nritems == 0) { 49895f39d397SChris Mason if (leaf == root->node) { 49905f39d397SChris Mason btrfs_set_header_level(leaf, 0); 49919a8dd150SChris Mason } else { 4992f0486c68SYan, Zheng btrfs_set_path_blocking(path); 4993f0486c68SYan, Zheng clean_tree_block(trans, root, leaf); 4994143bede5SJeff Mahoney btrfs_del_leaf(trans, root, path, leaf); 49959a8dd150SChris Mason } 4996be0e5c09SChris Mason } else { 49977518a238SChris Mason int used = leaf_space_used(leaf, 0, nritems); 4998aa5d6bedSChris Mason if (slot == 0) { 49995f39d397SChris Mason struct btrfs_disk_key disk_key; 50005f39d397SChris Mason 50015f39d397SChris Mason btrfs_item_key(leaf, &disk_key, 0); 5002d6a0a126STsutomu Itoh fixup_low_keys(root, path, &disk_key, 1); 5003aa5d6bedSChris Mason } 5004aa5d6bedSChris Mason 500574123bd7SChris Mason /* delete the leaf if it is mostly empty */ 5006d717aa1dSYan Zheng if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { 5007be0e5c09SChris Mason /* push_leaf_left fixes the path. 5008be0e5c09SChris Mason * make sure the path still points to our leaf 5009be0e5c09SChris Mason * for possible call to del_ptr below 5010be0e5c09SChris Mason */ 50114920c9acSChris Mason slot = path->slots[1]; 50125f39d397SChris Mason extent_buffer_get(leaf); 50135f39d397SChris Mason 5014b9473439SChris Mason btrfs_set_path_blocking(path); 501599d8f83cSChris Mason wret = push_leaf_left(trans, root, path, 1, 1, 501699d8f83cSChris Mason 1, (u32)-1); 501754aa1f4dSChris Mason if (wret < 0 && wret != -ENOSPC) 5018aa5d6bedSChris Mason ret = wret; 50195f39d397SChris Mason 50205f39d397SChris Mason if (path->nodes[0] == leaf && 50215f39d397SChris Mason btrfs_header_nritems(leaf)) { 502299d8f83cSChris Mason wret = push_leaf_right(trans, root, path, 1, 502399d8f83cSChris Mason 1, 1, 0); 502454aa1f4dSChris Mason if (wret < 0 && wret != -ENOSPC) 5025aa5d6bedSChris Mason ret = wret; 5026aa5d6bedSChris Mason } 50275f39d397SChris Mason 50285f39d397SChris Mason if (btrfs_header_nritems(leaf) == 0) { 5029323ac95bSChris Mason path->slots[1] = slot; 5030143bede5SJeff Mahoney btrfs_del_leaf(trans, root, path, leaf); 50315f39d397SChris Mason free_extent_buffer(leaf); 5032143bede5SJeff Mahoney ret = 0; 50335de08d7dSChris Mason } else { 5034925baeddSChris Mason /* if we're still in the path, make sure 5035925baeddSChris Mason * we're dirty. Otherwise, one of the 5036925baeddSChris Mason * push_leaf functions must have already 5037925baeddSChris Mason * dirtied this buffer 5038925baeddSChris Mason */ 5039925baeddSChris Mason if (path->nodes[0] == leaf) 50405f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 50415f39d397SChris Mason free_extent_buffer(leaf); 5042be0e5c09SChris Mason } 5043d5719762SChris Mason } else { 50445f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 5045be0e5c09SChris Mason } 50469a8dd150SChris Mason } 5047aa5d6bedSChris Mason return ret; 50489a8dd150SChris Mason } 50499a8dd150SChris Mason 505097571fd0SChris Mason /* 5051925baeddSChris Mason * search the tree again to find a leaf with lesser keys 50527bb86316SChris Mason * returns 0 if it found something or 1 if there are no lesser leaves. 50537bb86316SChris Mason * returns < 0 on io errors. 5054d352ac68SChris Mason * 5055d352ac68SChris Mason * This may release the path, and so you may lose any locks held at the 5056d352ac68SChris Mason * time you call it. 50577bb86316SChris Mason */ 505816e7549fSJosef Bacik int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) 50597bb86316SChris Mason { 5060925baeddSChris Mason struct btrfs_key key; 5061925baeddSChris Mason struct btrfs_disk_key found_key; 5062925baeddSChris Mason int ret; 50637bb86316SChris Mason 5064925baeddSChris Mason btrfs_item_key_to_cpu(path->nodes[0], &key, 0); 5065925baeddSChris Mason 5066e8b0d724SFilipe David Borba Manana if (key.offset > 0) { 5067925baeddSChris Mason key.offset--; 5068e8b0d724SFilipe David Borba Manana } else if (key.type > 0) { 5069925baeddSChris Mason key.type--; 5070e8b0d724SFilipe David Borba Manana key.offset = (u64)-1; 5071e8b0d724SFilipe David Borba Manana } else if (key.objectid > 0) { 5072925baeddSChris Mason key.objectid--; 5073e8b0d724SFilipe David Borba Manana key.type = (u8)-1; 5074e8b0d724SFilipe David Borba Manana key.offset = (u64)-1; 5075e8b0d724SFilipe David Borba Manana } else { 50767bb86316SChris Mason return 1; 5077e8b0d724SFilipe David Borba Manana } 50787bb86316SChris Mason 5079b3b4aa74SDavid Sterba btrfs_release_path(path); 5080925baeddSChris Mason ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5081925baeddSChris Mason if (ret < 0) 5082925baeddSChris Mason return ret; 5083925baeddSChris Mason btrfs_item_key(path->nodes[0], &found_key, 0); 5084925baeddSChris Mason ret = comp_keys(&found_key, &key); 5085337c6f68SFilipe Manana /* 5086337c6f68SFilipe Manana * We might have had an item with the previous key in the tree right 5087337c6f68SFilipe Manana * before we released our path. And after we released our path, that 5088337c6f68SFilipe Manana * item might have been pushed to the first slot (0) of the leaf we 5089337c6f68SFilipe Manana * were holding due to a tree balance. Alternatively, an item with the 5090337c6f68SFilipe Manana * previous key can exist as the only element of a leaf (big fat item). 5091337c6f68SFilipe Manana * Therefore account for these 2 cases, so that our callers (like 5092337c6f68SFilipe Manana * btrfs_previous_item) don't miss an existing item with a key matching 5093337c6f68SFilipe Manana * the previous key we computed above. 5094337c6f68SFilipe Manana */ 5095337c6f68SFilipe Manana if (ret <= 0) 50967bb86316SChris Mason return 0; 5097925baeddSChris Mason return 1; 50987bb86316SChris Mason } 50997bb86316SChris Mason 51003f157a2fSChris Mason /* 51013f157a2fSChris Mason * A helper function to walk down the tree starting at min_key, and looking 5102de78b51aSEric Sandeen * for nodes or leaves that are have a minimum transaction id. 5103de78b51aSEric Sandeen * This is used by the btree defrag code, and tree logging 51043f157a2fSChris Mason * 51053f157a2fSChris Mason * This does not cow, but it does stuff the starting key it finds back 51063f157a2fSChris Mason * into min_key, so you can call btrfs_search_slot with cow=1 on the 51073f157a2fSChris Mason * key and get a writable path. 51083f157a2fSChris Mason * 51093f157a2fSChris Mason * This does lock as it descends, and path->keep_locks should be set 51103f157a2fSChris Mason * to 1 by the caller. 51113f157a2fSChris Mason * 51123f157a2fSChris Mason * This honors path->lowest_level to prevent descent past a given level 51133f157a2fSChris Mason * of the tree. 51143f157a2fSChris Mason * 5115d352ac68SChris Mason * min_trans indicates the oldest transaction that you are interested 5116d352ac68SChris Mason * in walking through. Any nodes or leaves older than min_trans are 5117d352ac68SChris Mason * skipped over (without reading them). 5118d352ac68SChris Mason * 51193f157a2fSChris Mason * returns zero if something useful was found, < 0 on error and 1 if there 51203f157a2fSChris Mason * was nothing in the tree that matched the search criteria. 51213f157a2fSChris Mason */ 51223f157a2fSChris Mason int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, 5123de78b51aSEric Sandeen struct btrfs_path *path, 51243f157a2fSChris Mason u64 min_trans) 51253f157a2fSChris Mason { 51263f157a2fSChris Mason struct extent_buffer *cur; 51273f157a2fSChris Mason struct btrfs_key found_key; 51283f157a2fSChris Mason int slot; 51299652480bSYan int sret; 51303f157a2fSChris Mason u32 nritems; 51313f157a2fSChris Mason int level; 51323f157a2fSChris Mason int ret = 1; 5133f98de9b9SFilipe Manana int keep_locks = path->keep_locks; 51343f157a2fSChris Mason 5135f98de9b9SFilipe Manana path->keep_locks = 1; 51363f157a2fSChris Mason again: 5137bd681513SChris Mason cur = btrfs_read_lock_root_node(root); 51383f157a2fSChris Mason level = btrfs_header_level(cur); 5139e02119d5SChris Mason WARN_ON(path->nodes[level]); 51403f157a2fSChris Mason path->nodes[level] = cur; 5141bd681513SChris Mason path->locks[level] = BTRFS_READ_LOCK; 51423f157a2fSChris Mason 51433f157a2fSChris Mason if (btrfs_header_generation(cur) < min_trans) { 51443f157a2fSChris Mason ret = 1; 51453f157a2fSChris Mason goto out; 51463f157a2fSChris Mason } 51473f157a2fSChris Mason while (1) { 51483f157a2fSChris Mason nritems = btrfs_header_nritems(cur); 51493f157a2fSChris Mason level = btrfs_header_level(cur); 51509652480bSYan sret = bin_search(cur, min_key, level, &slot); 51513f157a2fSChris Mason 5152323ac95bSChris Mason /* at the lowest level, we're done, setup the path and exit */ 5153323ac95bSChris Mason if (level == path->lowest_level) { 5154e02119d5SChris Mason if (slot >= nritems) 5155e02119d5SChris Mason goto find_next_key; 51563f157a2fSChris Mason ret = 0; 51573f157a2fSChris Mason path->slots[level] = slot; 51583f157a2fSChris Mason btrfs_item_key_to_cpu(cur, &found_key, slot); 51593f157a2fSChris Mason goto out; 51603f157a2fSChris Mason } 51619652480bSYan if (sret && slot > 0) 51629652480bSYan slot--; 51633f157a2fSChris Mason /* 5164de78b51aSEric Sandeen * check this node pointer against the min_trans parameters. 5165de78b51aSEric Sandeen * If it is too old, old, skip to the next one. 51663f157a2fSChris Mason */ 51673f157a2fSChris Mason while (slot < nritems) { 51683f157a2fSChris Mason u64 gen; 5169e02119d5SChris Mason 51703f157a2fSChris Mason gen = btrfs_node_ptr_generation(cur, slot); 51713f157a2fSChris Mason if (gen < min_trans) { 51723f157a2fSChris Mason slot++; 51733f157a2fSChris Mason continue; 51743f157a2fSChris Mason } 51753f157a2fSChris Mason break; 51763f157a2fSChris Mason } 5177e02119d5SChris Mason find_next_key: 51783f157a2fSChris Mason /* 51793f157a2fSChris Mason * we didn't find a candidate key in this node, walk forward 51803f157a2fSChris Mason * and find another one 51813f157a2fSChris Mason */ 51823f157a2fSChris Mason if (slot >= nritems) { 5183e02119d5SChris Mason path->slots[level] = slot; 5184b4ce94deSChris Mason btrfs_set_path_blocking(path); 5185e02119d5SChris Mason sret = btrfs_find_next_key(root, path, min_key, level, 5186de78b51aSEric Sandeen min_trans); 5187e02119d5SChris Mason if (sret == 0) { 5188b3b4aa74SDavid Sterba btrfs_release_path(path); 51893f157a2fSChris Mason goto again; 51903f157a2fSChris Mason } else { 51913f157a2fSChris Mason goto out; 51923f157a2fSChris Mason } 51933f157a2fSChris Mason } 51943f157a2fSChris Mason /* save our key for returning back */ 51953f157a2fSChris Mason btrfs_node_key_to_cpu(cur, &found_key, slot); 51963f157a2fSChris Mason path->slots[level] = slot; 51973f157a2fSChris Mason if (level == path->lowest_level) { 51983f157a2fSChris Mason ret = 0; 51993f157a2fSChris Mason goto out; 52003f157a2fSChris Mason } 5201b4ce94deSChris Mason btrfs_set_path_blocking(path); 52023f157a2fSChris Mason cur = read_node_slot(root, cur, slot); 520379787eaaSJeff Mahoney BUG_ON(!cur); /* -ENOMEM */ 52043f157a2fSChris Mason 5205bd681513SChris Mason btrfs_tree_read_lock(cur); 5206b4ce94deSChris Mason 5207bd681513SChris Mason path->locks[level - 1] = BTRFS_READ_LOCK; 52083f157a2fSChris Mason path->nodes[level - 1] = cur; 5209f7c79f30SChris Mason unlock_up(path, level, 1, 0, NULL); 5210bd681513SChris Mason btrfs_clear_path_blocking(path, NULL, 0); 52113f157a2fSChris Mason } 52123f157a2fSChris Mason out: 5213f98de9b9SFilipe Manana path->keep_locks = keep_locks; 5214f98de9b9SFilipe Manana if (ret == 0) { 5215f98de9b9SFilipe Manana btrfs_unlock_up_safe(path, path->lowest_level + 1); 5216b4ce94deSChris Mason btrfs_set_path_blocking(path); 5217f98de9b9SFilipe Manana memcpy(min_key, &found_key, sizeof(found_key)); 5218f98de9b9SFilipe Manana } 52193f157a2fSChris Mason return ret; 52203f157a2fSChris Mason } 52213f157a2fSChris Mason 52227069830aSAlexander Block static void tree_move_down(struct btrfs_root *root, 52237069830aSAlexander Block struct btrfs_path *path, 52247069830aSAlexander Block int *level, int root_level) 52257069830aSAlexander Block { 522674dd17fbSChris Mason BUG_ON(*level == 0); 52277069830aSAlexander Block path->nodes[*level - 1] = read_node_slot(root, path->nodes[*level], 52287069830aSAlexander Block path->slots[*level]); 52297069830aSAlexander Block path->slots[*level - 1] = 0; 52307069830aSAlexander Block (*level)--; 52317069830aSAlexander Block } 52327069830aSAlexander Block 52337069830aSAlexander Block static int tree_move_next_or_upnext(struct btrfs_root *root, 52347069830aSAlexander Block struct btrfs_path *path, 52357069830aSAlexander Block int *level, int root_level) 52367069830aSAlexander Block { 52377069830aSAlexander Block int ret = 0; 52387069830aSAlexander Block int nritems; 52397069830aSAlexander Block nritems = btrfs_header_nritems(path->nodes[*level]); 52407069830aSAlexander Block 52417069830aSAlexander Block path->slots[*level]++; 52427069830aSAlexander Block 524374dd17fbSChris Mason while (path->slots[*level] >= nritems) { 52447069830aSAlexander Block if (*level == root_level) 52457069830aSAlexander Block return -1; 52467069830aSAlexander Block 52477069830aSAlexander Block /* move upnext */ 52487069830aSAlexander Block path->slots[*level] = 0; 52497069830aSAlexander Block free_extent_buffer(path->nodes[*level]); 52507069830aSAlexander Block path->nodes[*level] = NULL; 52517069830aSAlexander Block (*level)++; 52527069830aSAlexander Block path->slots[*level]++; 52537069830aSAlexander Block 52547069830aSAlexander Block nritems = btrfs_header_nritems(path->nodes[*level]); 52557069830aSAlexander Block ret = 1; 52567069830aSAlexander Block } 52577069830aSAlexander Block return ret; 52587069830aSAlexander Block } 52597069830aSAlexander Block 52607069830aSAlexander Block /* 52617069830aSAlexander Block * Returns 1 if it had to move up and next. 0 is returned if it moved only next 52627069830aSAlexander Block * or down. 52637069830aSAlexander Block */ 52647069830aSAlexander Block static int tree_advance(struct btrfs_root *root, 52657069830aSAlexander Block struct btrfs_path *path, 52667069830aSAlexander Block int *level, int root_level, 52677069830aSAlexander Block int allow_down, 52687069830aSAlexander Block struct btrfs_key *key) 52697069830aSAlexander Block { 52707069830aSAlexander Block int ret; 52717069830aSAlexander Block 52727069830aSAlexander Block if (*level == 0 || !allow_down) { 52737069830aSAlexander Block ret = tree_move_next_or_upnext(root, path, level, root_level); 52747069830aSAlexander Block } else { 52757069830aSAlexander Block tree_move_down(root, path, level, root_level); 52767069830aSAlexander Block ret = 0; 52777069830aSAlexander Block } 52787069830aSAlexander Block if (ret >= 0) { 52797069830aSAlexander Block if (*level == 0) 52807069830aSAlexander Block btrfs_item_key_to_cpu(path->nodes[*level], key, 52817069830aSAlexander Block path->slots[*level]); 52827069830aSAlexander Block else 52837069830aSAlexander Block btrfs_node_key_to_cpu(path->nodes[*level], key, 52847069830aSAlexander Block path->slots[*level]); 52857069830aSAlexander Block } 52867069830aSAlexander Block return ret; 52877069830aSAlexander Block } 52887069830aSAlexander Block 52897069830aSAlexander Block static int tree_compare_item(struct btrfs_root *left_root, 52907069830aSAlexander Block struct btrfs_path *left_path, 52917069830aSAlexander Block struct btrfs_path *right_path, 52927069830aSAlexander Block char *tmp_buf) 52937069830aSAlexander Block { 52947069830aSAlexander Block int cmp; 52957069830aSAlexander Block int len1, len2; 52967069830aSAlexander Block unsigned long off1, off2; 52977069830aSAlexander Block 52987069830aSAlexander Block len1 = btrfs_item_size_nr(left_path->nodes[0], left_path->slots[0]); 52997069830aSAlexander Block len2 = btrfs_item_size_nr(right_path->nodes[0], right_path->slots[0]); 53007069830aSAlexander Block if (len1 != len2) 53017069830aSAlexander Block return 1; 53027069830aSAlexander Block 53037069830aSAlexander Block off1 = btrfs_item_ptr_offset(left_path->nodes[0], left_path->slots[0]); 53047069830aSAlexander Block off2 = btrfs_item_ptr_offset(right_path->nodes[0], 53057069830aSAlexander Block right_path->slots[0]); 53067069830aSAlexander Block 53077069830aSAlexander Block read_extent_buffer(left_path->nodes[0], tmp_buf, off1, len1); 53087069830aSAlexander Block 53097069830aSAlexander Block cmp = memcmp_extent_buffer(right_path->nodes[0], tmp_buf, off2, len1); 53107069830aSAlexander Block if (cmp) 53117069830aSAlexander Block return 1; 53127069830aSAlexander Block return 0; 53137069830aSAlexander Block } 53147069830aSAlexander Block 53157069830aSAlexander Block #define ADVANCE 1 53167069830aSAlexander Block #define ADVANCE_ONLY_NEXT -1 53177069830aSAlexander Block 53187069830aSAlexander Block /* 53197069830aSAlexander Block * This function compares two trees and calls the provided callback for 53207069830aSAlexander Block * every changed/new/deleted item it finds. 53217069830aSAlexander Block * If shared tree blocks are encountered, whole subtrees are skipped, making 53227069830aSAlexander Block * the compare pretty fast on snapshotted subvolumes. 53237069830aSAlexander Block * 53247069830aSAlexander Block * This currently works on commit roots only. As commit roots are read only, 53257069830aSAlexander Block * we don't do any locking. The commit roots are protected with transactions. 53267069830aSAlexander Block * Transactions are ended and rejoined when a commit is tried in between. 53277069830aSAlexander Block * 53287069830aSAlexander Block * This function checks for modifications done to the trees while comparing. 53297069830aSAlexander Block * If it detects a change, it aborts immediately. 53307069830aSAlexander Block */ 53317069830aSAlexander Block int btrfs_compare_trees(struct btrfs_root *left_root, 53327069830aSAlexander Block struct btrfs_root *right_root, 53337069830aSAlexander Block btrfs_changed_cb_t changed_cb, void *ctx) 53347069830aSAlexander Block { 53357069830aSAlexander Block int ret; 53367069830aSAlexander Block int cmp; 53377069830aSAlexander Block struct btrfs_path *left_path = NULL; 53387069830aSAlexander Block struct btrfs_path *right_path = NULL; 53397069830aSAlexander Block struct btrfs_key left_key; 53407069830aSAlexander Block struct btrfs_key right_key; 53417069830aSAlexander Block char *tmp_buf = NULL; 53427069830aSAlexander Block int left_root_level; 53437069830aSAlexander Block int right_root_level; 53447069830aSAlexander Block int left_level; 53457069830aSAlexander Block int right_level; 53467069830aSAlexander Block int left_end_reached; 53477069830aSAlexander Block int right_end_reached; 53487069830aSAlexander Block int advance_left; 53497069830aSAlexander Block int advance_right; 53507069830aSAlexander Block u64 left_blockptr; 53517069830aSAlexander Block u64 right_blockptr; 53526baa4293SFilipe Manana u64 left_gen; 53536baa4293SFilipe Manana u64 right_gen; 53547069830aSAlexander Block 53557069830aSAlexander Block left_path = btrfs_alloc_path(); 53567069830aSAlexander Block if (!left_path) { 53577069830aSAlexander Block ret = -ENOMEM; 53587069830aSAlexander Block goto out; 53597069830aSAlexander Block } 53607069830aSAlexander Block right_path = btrfs_alloc_path(); 53617069830aSAlexander Block if (!right_path) { 53627069830aSAlexander Block ret = -ENOMEM; 53637069830aSAlexander Block goto out; 53647069830aSAlexander Block } 53657069830aSAlexander Block 5366707e8a07SDavid Sterba tmp_buf = kmalloc(left_root->nodesize, GFP_NOFS); 53677069830aSAlexander Block if (!tmp_buf) { 53687069830aSAlexander Block ret = -ENOMEM; 53697069830aSAlexander Block goto out; 53707069830aSAlexander Block } 53717069830aSAlexander Block 53727069830aSAlexander Block left_path->search_commit_root = 1; 53737069830aSAlexander Block left_path->skip_locking = 1; 53747069830aSAlexander Block right_path->search_commit_root = 1; 53757069830aSAlexander Block right_path->skip_locking = 1; 53767069830aSAlexander Block 53777069830aSAlexander Block /* 53787069830aSAlexander Block * Strategy: Go to the first items of both trees. Then do 53797069830aSAlexander Block * 53807069830aSAlexander Block * If both trees are at level 0 53817069830aSAlexander Block * Compare keys of current items 53827069830aSAlexander Block * If left < right treat left item as new, advance left tree 53837069830aSAlexander Block * and repeat 53847069830aSAlexander Block * If left > right treat right item as deleted, advance right tree 53857069830aSAlexander Block * and repeat 53867069830aSAlexander Block * If left == right do deep compare of items, treat as changed if 53877069830aSAlexander Block * needed, advance both trees and repeat 53887069830aSAlexander Block * If both trees are at the same level but not at level 0 53897069830aSAlexander Block * Compare keys of current nodes/leafs 53907069830aSAlexander Block * If left < right advance left tree and repeat 53917069830aSAlexander Block * If left > right advance right tree and repeat 53927069830aSAlexander Block * If left == right compare blockptrs of the next nodes/leafs 53937069830aSAlexander Block * If they match advance both trees but stay at the same level 53947069830aSAlexander Block * and repeat 53957069830aSAlexander Block * If they don't match advance both trees while allowing to go 53967069830aSAlexander Block * deeper and repeat 53977069830aSAlexander Block * If tree levels are different 53987069830aSAlexander Block * Advance the tree that needs it and repeat 53997069830aSAlexander Block * 54007069830aSAlexander Block * Advancing a tree means: 54017069830aSAlexander Block * If we are at level 0, try to go to the next slot. If that's not 54027069830aSAlexander Block * possible, go one level up and repeat. Stop when we found a level 54037069830aSAlexander Block * where we could go to the next slot. We may at this point be on a 54047069830aSAlexander Block * node or a leaf. 54057069830aSAlexander Block * 54067069830aSAlexander Block * If we are not at level 0 and not on shared tree blocks, go one 54077069830aSAlexander Block * level deeper. 54087069830aSAlexander Block * 54097069830aSAlexander Block * If we are not at level 0 and on shared tree blocks, go one slot to 54107069830aSAlexander Block * the right if possible or go up and right. 54117069830aSAlexander Block */ 54127069830aSAlexander Block 54133f8a18ccSJosef Bacik down_read(&left_root->fs_info->commit_root_sem); 54147069830aSAlexander Block left_level = btrfs_header_level(left_root->commit_root); 54157069830aSAlexander Block left_root_level = left_level; 54167069830aSAlexander Block left_path->nodes[left_level] = left_root->commit_root; 54177069830aSAlexander Block extent_buffer_get(left_path->nodes[left_level]); 54187069830aSAlexander Block 54197069830aSAlexander Block right_level = btrfs_header_level(right_root->commit_root); 54207069830aSAlexander Block right_root_level = right_level; 54217069830aSAlexander Block right_path->nodes[right_level] = right_root->commit_root; 54227069830aSAlexander Block extent_buffer_get(right_path->nodes[right_level]); 54233f8a18ccSJosef Bacik up_read(&left_root->fs_info->commit_root_sem); 54247069830aSAlexander Block 54257069830aSAlexander Block if (left_level == 0) 54267069830aSAlexander Block btrfs_item_key_to_cpu(left_path->nodes[left_level], 54277069830aSAlexander Block &left_key, left_path->slots[left_level]); 54287069830aSAlexander Block else 54297069830aSAlexander Block btrfs_node_key_to_cpu(left_path->nodes[left_level], 54307069830aSAlexander Block &left_key, left_path->slots[left_level]); 54317069830aSAlexander Block if (right_level == 0) 54327069830aSAlexander Block btrfs_item_key_to_cpu(right_path->nodes[right_level], 54337069830aSAlexander Block &right_key, right_path->slots[right_level]); 54347069830aSAlexander Block else 54357069830aSAlexander Block btrfs_node_key_to_cpu(right_path->nodes[right_level], 54367069830aSAlexander Block &right_key, right_path->slots[right_level]); 54377069830aSAlexander Block 54387069830aSAlexander Block left_end_reached = right_end_reached = 0; 54397069830aSAlexander Block advance_left = advance_right = 0; 54407069830aSAlexander Block 54417069830aSAlexander Block while (1) { 54427069830aSAlexander Block if (advance_left && !left_end_reached) { 54437069830aSAlexander Block ret = tree_advance(left_root, left_path, &left_level, 54447069830aSAlexander Block left_root_level, 54457069830aSAlexander Block advance_left != ADVANCE_ONLY_NEXT, 54467069830aSAlexander Block &left_key); 54477069830aSAlexander Block if (ret < 0) 54487069830aSAlexander Block left_end_reached = ADVANCE; 54497069830aSAlexander Block advance_left = 0; 54507069830aSAlexander Block } 54517069830aSAlexander Block if (advance_right && !right_end_reached) { 54527069830aSAlexander Block ret = tree_advance(right_root, right_path, &right_level, 54537069830aSAlexander Block right_root_level, 54547069830aSAlexander Block advance_right != ADVANCE_ONLY_NEXT, 54557069830aSAlexander Block &right_key); 54567069830aSAlexander Block if (ret < 0) 54577069830aSAlexander Block right_end_reached = ADVANCE; 54587069830aSAlexander Block advance_right = 0; 54597069830aSAlexander Block } 54607069830aSAlexander Block 54617069830aSAlexander Block if (left_end_reached && right_end_reached) { 54627069830aSAlexander Block ret = 0; 54637069830aSAlexander Block goto out; 54647069830aSAlexander Block } else if (left_end_reached) { 54657069830aSAlexander Block if (right_level == 0) { 54667069830aSAlexander Block ret = changed_cb(left_root, right_root, 54677069830aSAlexander Block left_path, right_path, 54687069830aSAlexander Block &right_key, 54697069830aSAlexander Block BTRFS_COMPARE_TREE_DELETED, 54707069830aSAlexander Block ctx); 54717069830aSAlexander Block if (ret < 0) 54727069830aSAlexander Block goto out; 54737069830aSAlexander Block } 54747069830aSAlexander Block advance_right = ADVANCE; 54757069830aSAlexander Block continue; 54767069830aSAlexander Block } else if (right_end_reached) { 54777069830aSAlexander Block if (left_level == 0) { 54787069830aSAlexander Block ret = changed_cb(left_root, right_root, 54797069830aSAlexander Block left_path, right_path, 54807069830aSAlexander Block &left_key, 54817069830aSAlexander Block BTRFS_COMPARE_TREE_NEW, 54827069830aSAlexander Block ctx); 54837069830aSAlexander Block if (ret < 0) 54847069830aSAlexander Block goto out; 54857069830aSAlexander Block } 54867069830aSAlexander Block advance_left = ADVANCE; 54877069830aSAlexander Block continue; 54887069830aSAlexander Block } 54897069830aSAlexander Block 54907069830aSAlexander Block if (left_level == 0 && right_level == 0) { 54917069830aSAlexander Block cmp = btrfs_comp_cpu_keys(&left_key, &right_key); 54927069830aSAlexander Block if (cmp < 0) { 54937069830aSAlexander Block ret = changed_cb(left_root, right_root, 54947069830aSAlexander Block left_path, right_path, 54957069830aSAlexander Block &left_key, 54967069830aSAlexander Block BTRFS_COMPARE_TREE_NEW, 54977069830aSAlexander Block ctx); 54987069830aSAlexander Block if (ret < 0) 54997069830aSAlexander Block goto out; 55007069830aSAlexander Block advance_left = ADVANCE; 55017069830aSAlexander Block } else if (cmp > 0) { 55027069830aSAlexander Block ret = changed_cb(left_root, right_root, 55037069830aSAlexander Block left_path, right_path, 55047069830aSAlexander Block &right_key, 55057069830aSAlexander Block BTRFS_COMPARE_TREE_DELETED, 55067069830aSAlexander Block ctx); 55077069830aSAlexander Block if (ret < 0) 55087069830aSAlexander Block goto out; 55097069830aSAlexander Block advance_right = ADVANCE; 55107069830aSAlexander Block } else { 5511b99d9a6aSFabian Frederick enum btrfs_compare_tree_result result; 5512ba5e8f2eSJosef Bacik 551374dd17fbSChris Mason WARN_ON(!extent_buffer_uptodate(left_path->nodes[0])); 55147069830aSAlexander Block ret = tree_compare_item(left_root, left_path, 55157069830aSAlexander Block right_path, tmp_buf); 5516ba5e8f2eSJosef Bacik if (ret) 5517b99d9a6aSFabian Frederick result = BTRFS_COMPARE_TREE_CHANGED; 5518ba5e8f2eSJosef Bacik else 5519b99d9a6aSFabian Frederick result = BTRFS_COMPARE_TREE_SAME; 55207069830aSAlexander Block ret = changed_cb(left_root, right_root, 55217069830aSAlexander Block left_path, right_path, 5522b99d9a6aSFabian Frederick &left_key, result, ctx); 55237069830aSAlexander Block if (ret < 0) 55247069830aSAlexander Block goto out; 55257069830aSAlexander Block advance_left = ADVANCE; 55267069830aSAlexander Block advance_right = ADVANCE; 55277069830aSAlexander Block } 55287069830aSAlexander Block } else if (left_level == right_level) { 55297069830aSAlexander Block cmp = btrfs_comp_cpu_keys(&left_key, &right_key); 55307069830aSAlexander Block if (cmp < 0) { 55317069830aSAlexander Block advance_left = ADVANCE; 55327069830aSAlexander Block } else if (cmp > 0) { 55337069830aSAlexander Block advance_right = ADVANCE; 55347069830aSAlexander Block } else { 55357069830aSAlexander Block left_blockptr = btrfs_node_blockptr( 55367069830aSAlexander Block left_path->nodes[left_level], 55377069830aSAlexander Block left_path->slots[left_level]); 55387069830aSAlexander Block right_blockptr = btrfs_node_blockptr( 55397069830aSAlexander Block right_path->nodes[right_level], 55407069830aSAlexander Block right_path->slots[right_level]); 55416baa4293SFilipe Manana left_gen = btrfs_node_ptr_generation( 55426baa4293SFilipe Manana left_path->nodes[left_level], 55436baa4293SFilipe Manana left_path->slots[left_level]); 55446baa4293SFilipe Manana right_gen = btrfs_node_ptr_generation( 55456baa4293SFilipe Manana right_path->nodes[right_level], 55466baa4293SFilipe Manana right_path->slots[right_level]); 55476baa4293SFilipe Manana if (left_blockptr == right_blockptr && 55486baa4293SFilipe Manana left_gen == right_gen) { 55497069830aSAlexander Block /* 55507069830aSAlexander Block * As we're on a shared block, don't 55517069830aSAlexander Block * allow to go deeper. 55527069830aSAlexander Block */ 55537069830aSAlexander Block advance_left = ADVANCE_ONLY_NEXT; 55547069830aSAlexander Block advance_right = ADVANCE_ONLY_NEXT; 55557069830aSAlexander Block } else { 55567069830aSAlexander Block advance_left = ADVANCE; 55577069830aSAlexander Block advance_right = ADVANCE; 55587069830aSAlexander Block } 55597069830aSAlexander Block } 55607069830aSAlexander Block } else if (left_level < right_level) { 55617069830aSAlexander Block advance_right = ADVANCE; 55627069830aSAlexander Block } else { 55637069830aSAlexander Block advance_left = ADVANCE; 55647069830aSAlexander Block } 55657069830aSAlexander Block } 55667069830aSAlexander Block 55677069830aSAlexander Block out: 55687069830aSAlexander Block btrfs_free_path(left_path); 55697069830aSAlexander Block btrfs_free_path(right_path); 55707069830aSAlexander Block kfree(tmp_buf); 55717069830aSAlexander Block return ret; 55727069830aSAlexander Block } 55737069830aSAlexander Block 55743f157a2fSChris Mason /* 55753f157a2fSChris Mason * this is similar to btrfs_next_leaf, but does not try to preserve 55763f157a2fSChris Mason * and fixup the path. It looks for and returns the next key in the 5577de78b51aSEric Sandeen * tree based on the current path and the min_trans parameters. 55783f157a2fSChris Mason * 55793f157a2fSChris Mason * 0 is returned if another key is found, < 0 if there are any errors 55803f157a2fSChris Mason * and 1 is returned if there are no higher keys in the tree 55813f157a2fSChris Mason * 55823f157a2fSChris Mason * path->keep_locks should be set to 1 on the search made before 55833f157a2fSChris Mason * calling this function. 55843f157a2fSChris Mason */ 5585e7a84565SChris Mason int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, 5586de78b51aSEric Sandeen struct btrfs_key *key, int level, u64 min_trans) 5587e7a84565SChris Mason { 5588e7a84565SChris Mason int slot; 5589e7a84565SChris Mason struct extent_buffer *c; 5590e7a84565SChris Mason 5591934d375bSChris Mason WARN_ON(!path->keep_locks); 5592e7a84565SChris Mason while (level < BTRFS_MAX_LEVEL) { 5593e7a84565SChris Mason if (!path->nodes[level]) 5594e7a84565SChris Mason return 1; 5595e7a84565SChris Mason 5596e7a84565SChris Mason slot = path->slots[level] + 1; 5597e7a84565SChris Mason c = path->nodes[level]; 55983f157a2fSChris Mason next: 5599e7a84565SChris Mason if (slot >= btrfs_header_nritems(c)) { 560033c66f43SYan Zheng int ret; 560133c66f43SYan Zheng int orig_lowest; 560233c66f43SYan Zheng struct btrfs_key cur_key; 560333c66f43SYan Zheng if (level + 1 >= BTRFS_MAX_LEVEL || 560433c66f43SYan Zheng !path->nodes[level + 1]) 5605e7a84565SChris Mason return 1; 560633c66f43SYan Zheng 560733c66f43SYan Zheng if (path->locks[level + 1]) { 560833c66f43SYan Zheng level++; 5609e7a84565SChris Mason continue; 5610e7a84565SChris Mason } 561133c66f43SYan Zheng 561233c66f43SYan Zheng slot = btrfs_header_nritems(c) - 1; 561333c66f43SYan Zheng if (level == 0) 561433c66f43SYan Zheng btrfs_item_key_to_cpu(c, &cur_key, slot); 561533c66f43SYan Zheng else 561633c66f43SYan Zheng btrfs_node_key_to_cpu(c, &cur_key, slot); 561733c66f43SYan Zheng 561833c66f43SYan Zheng orig_lowest = path->lowest_level; 5619b3b4aa74SDavid Sterba btrfs_release_path(path); 562033c66f43SYan Zheng path->lowest_level = level; 562133c66f43SYan Zheng ret = btrfs_search_slot(NULL, root, &cur_key, path, 562233c66f43SYan Zheng 0, 0); 562333c66f43SYan Zheng path->lowest_level = orig_lowest; 562433c66f43SYan Zheng if (ret < 0) 562533c66f43SYan Zheng return ret; 562633c66f43SYan Zheng 562733c66f43SYan Zheng c = path->nodes[level]; 562833c66f43SYan Zheng slot = path->slots[level]; 562933c66f43SYan Zheng if (ret == 0) 563033c66f43SYan Zheng slot++; 563133c66f43SYan Zheng goto next; 563233c66f43SYan Zheng } 563333c66f43SYan Zheng 5634e7a84565SChris Mason if (level == 0) 5635e7a84565SChris Mason btrfs_item_key_to_cpu(c, key, slot); 56363f157a2fSChris Mason else { 56373f157a2fSChris Mason u64 gen = btrfs_node_ptr_generation(c, slot); 56383f157a2fSChris Mason 56393f157a2fSChris Mason if (gen < min_trans) { 56403f157a2fSChris Mason slot++; 56413f157a2fSChris Mason goto next; 56423f157a2fSChris Mason } 5643e7a84565SChris Mason btrfs_node_key_to_cpu(c, key, slot); 56443f157a2fSChris Mason } 5645e7a84565SChris Mason return 0; 5646e7a84565SChris Mason } 5647e7a84565SChris Mason return 1; 5648e7a84565SChris Mason } 5649e7a84565SChris Mason 56507bb86316SChris Mason /* 5651925baeddSChris Mason * search the tree again to find a leaf with greater keys 56520f70abe2SChris Mason * returns 0 if it found something or 1 if there are no greater leaves. 56530f70abe2SChris Mason * returns < 0 on io errors. 565497571fd0SChris Mason */ 5655234b63a0SChris Mason int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) 5656d97e63b6SChris Mason { 56573d7806ecSJan Schmidt return btrfs_next_old_leaf(root, path, 0); 56583d7806ecSJan Schmidt } 56593d7806ecSJan Schmidt 56603d7806ecSJan Schmidt int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, 56613d7806ecSJan Schmidt u64 time_seq) 56623d7806ecSJan Schmidt { 5663d97e63b6SChris Mason int slot; 56648e73f275SChris Mason int level; 56655f39d397SChris Mason struct extent_buffer *c; 56668e73f275SChris Mason struct extent_buffer *next; 5667925baeddSChris Mason struct btrfs_key key; 5668925baeddSChris Mason u32 nritems; 5669925baeddSChris Mason int ret; 56708e73f275SChris Mason int old_spinning = path->leave_spinning; 5671bd681513SChris Mason int next_rw_lock = 0; 5672925baeddSChris Mason 5673925baeddSChris Mason nritems = btrfs_header_nritems(path->nodes[0]); 5674d397712bSChris Mason if (nritems == 0) 5675925baeddSChris Mason return 1; 5676925baeddSChris Mason 56778e73f275SChris Mason btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); 56788e73f275SChris Mason again: 56798e73f275SChris Mason level = 1; 56808e73f275SChris Mason next = NULL; 5681bd681513SChris Mason next_rw_lock = 0; 5682b3b4aa74SDavid Sterba btrfs_release_path(path); 56838e73f275SChris Mason 5684a2135011SChris Mason path->keep_locks = 1; 56858e73f275SChris Mason path->leave_spinning = 1; 56868e73f275SChris Mason 56873d7806ecSJan Schmidt if (time_seq) 56883d7806ecSJan Schmidt ret = btrfs_search_old_slot(root, &key, path, time_seq); 56893d7806ecSJan Schmidt else 5690925baeddSChris Mason ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5691925baeddSChris Mason path->keep_locks = 0; 5692925baeddSChris Mason 5693925baeddSChris Mason if (ret < 0) 5694925baeddSChris Mason return ret; 5695925baeddSChris Mason 5696a2135011SChris Mason nritems = btrfs_header_nritems(path->nodes[0]); 5697168fd7d2SChris Mason /* 5698168fd7d2SChris Mason * by releasing the path above we dropped all our locks. A balance 5699168fd7d2SChris Mason * could have added more items next to the key that used to be 5700168fd7d2SChris Mason * at the very end of the block. So, check again here and 5701168fd7d2SChris Mason * advance the path if there are now more items available. 5702168fd7d2SChris Mason */ 5703a2135011SChris Mason if (nritems > 0 && path->slots[0] < nritems - 1) { 5704e457afecSYan Zheng if (ret == 0) 5705168fd7d2SChris Mason path->slots[0]++; 57068e73f275SChris Mason ret = 0; 5707925baeddSChris Mason goto done; 5708925baeddSChris Mason } 57090b43e04fSLiu Bo /* 57100b43e04fSLiu Bo * So the above check misses one case: 57110b43e04fSLiu Bo * - after releasing the path above, someone has removed the item that 57120b43e04fSLiu Bo * used to be at the very end of the block, and balance between leafs 57130b43e04fSLiu Bo * gets another one with bigger key.offset to replace it. 57140b43e04fSLiu Bo * 57150b43e04fSLiu Bo * This one should be returned as well, or we can get leaf corruption 57160b43e04fSLiu Bo * later(esp. in __btrfs_drop_extents()). 57170b43e04fSLiu Bo * 57180b43e04fSLiu Bo * And a bit more explanation about this check, 57190b43e04fSLiu Bo * with ret > 0, the key isn't found, the path points to the slot 57200b43e04fSLiu Bo * where it should be inserted, so the path->slots[0] item must be the 57210b43e04fSLiu Bo * bigger one. 57220b43e04fSLiu Bo */ 57230b43e04fSLiu Bo if (nritems > 0 && ret > 0 && path->slots[0] == nritems - 1) { 57240b43e04fSLiu Bo ret = 0; 57250b43e04fSLiu Bo goto done; 57260b43e04fSLiu Bo } 5727d97e63b6SChris Mason 5728234b63a0SChris Mason while (level < BTRFS_MAX_LEVEL) { 57298e73f275SChris Mason if (!path->nodes[level]) { 57308e73f275SChris Mason ret = 1; 57318e73f275SChris Mason goto done; 57328e73f275SChris Mason } 57335f39d397SChris Mason 5734d97e63b6SChris Mason slot = path->slots[level] + 1; 5735d97e63b6SChris Mason c = path->nodes[level]; 57365f39d397SChris Mason if (slot >= btrfs_header_nritems(c)) { 5737d97e63b6SChris Mason level++; 57388e73f275SChris Mason if (level == BTRFS_MAX_LEVEL) { 57398e73f275SChris Mason ret = 1; 57408e73f275SChris Mason goto done; 57418e73f275SChris Mason } 5742d97e63b6SChris Mason continue; 5743d97e63b6SChris Mason } 57445f39d397SChris Mason 5745925baeddSChris Mason if (next) { 5746bd681513SChris Mason btrfs_tree_unlock_rw(next, next_rw_lock); 57475f39d397SChris Mason free_extent_buffer(next); 5748925baeddSChris Mason } 57495f39d397SChris Mason 57508e73f275SChris Mason next = c; 5751bd681513SChris Mason next_rw_lock = path->locks[level]; 57528e73f275SChris Mason ret = read_block_for_search(NULL, root, path, &next, level, 57535d9e75c4SJan Schmidt slot, &key, 0); 57548e73f275SChris Mason if (ret == -EAGAIN) 57558e73f275SChris Mason goto again; 57565f39d397SChris Mason 575776a05b35SChris Mason if (ret < 0) { 5758b3b4aa74SDavid Sterba btrfs_release_path(path); 575976a05b35SChris Mason goto done; 576076a05b35SChris Mason } 576176a05b35SChris Mason 57625cd57b2cSChris Mason if (!path->skip_locking) { 5763bd681513SChris Mason ret = btrfs_try_tree_read_lock(next); 5764d42244a0SJan Schmidt if (!ret && time_seq) { 5765d42244a0SJan Schmidt /* 5766d42244a0SJan Schmidt * If we don't get the lock, we may be racing 5767d42244a0SJan Schmidt * with push_leaf_left, holding that lock while 5768d42244a0SJan Schmidt * itself waiting for the leaf we've currently 5769d42244a0SJan Schmidt * locked. To solve this situation, we give up 5770d42244a0SJan Schmidt * on our lock and cycle. 5771d42244a0SJan Schmidt */ 5772cf538830SJan Schmidt free_extent_buffer(next); 5773d42244a0SJan Schmidt btrfs_release_path(path); 5774d42244a0SJan Schmidt cond_resched(); 5775d42244a0SJan Schmidt goto again; 5776d42244a0SJan Schmidt } 57778e73f275SChris Mason if (!ret) { 57788e73f275SChris Mason btrfs_set_path_blocking(path); 5779bd681513SChris Mason btrfs_tree_read_lock(next); 5780bd681513SChris Mason btrfs_clear_path_blocking(path, next, 5781bd681513SChris Mason BTRFS_READ_LOCK); 57828e73f275SChris Mason } 5783bd681513SChris Mason next_rw_lock = BTRFS_READ_LOCK; 5784bd681513SChris Mason } 5785d97e63b6SChris Mason break; 5786d97e63b6SChris Mason } 5787d97e63b6SChris Mason path->slots[level] = slot; 5788d97e63b6SChris Mason while (1) { 5789d97e63b6SChris Mason level--; 5790d97e63b6SChris Mason c = path->nodes[level]; 5791925baeddSChris Mason if (path->locks[level]) 5792bd681513SChris Mason btrfs_tree_unlock_rw(c, path->locks[level]); 57938e73f275SChris Mason 57945f39d397SChris Mason free_extent_buffer(c); 5795d97e63b6SChris Mason path->nodes[level] = next; 5796d97e63b6SChris Mason path->slots[level] = 0; 5797a74a4b97SChris Mason if (!path->skip_locking) 5798bd681513SChris Mason path->locks[level] = next_rw_lock; 5799d97e63b6SChris Mason if (!level) 5800d97e63b6SChris Mason break; 5801b4ce94deSChris Mason 58028e73f275SChris Mason ret = read_block_for_search(NULL, root, path, &next, level, 58035d9e75c4SJan Schmidt 0, &key, 0); 58048e73f275SChris Mason if (ret == -EAGAIN) 58058e73f275SChris Mason goto again; 58068e73f275SChris Mason 580776a05b35SChris Mason if (ret < 0) { 5808b3b4aa74SDavid Sterba btrfs_release_path(path); 580976a05b35SChris Mason goto done; 581076a05b35SChris Mason } 581176a05b35SChris Mason 58125cd57b2cSChris Mason if (!path->skip_locking) { 5813bd681513SChris Mason ret = btrfs_try_tree_read_lock(next); 58148e73f275SChris Mason if (!ret) { 58158e73f275SChris Mason btrfs_set_path_blocking(path); 5816bd681513SChris Mason btrfs_tree_read_lock(next); 5817bd681513SChris Mason btrfs_clear_path_blocking(path, next, 5818bd681513SChris Mason BTRFS_READ_LOCK); 58198e73f275SChris Mason } 5820bd681513SChris Mason next_rw_lock = BTRFS_READ_LOCK; 5821bd681513SChris Mason } 5822d97e63b6SChris Mason } 58238e73f275SChris Mason ret = 0; 5824925baeddSChris Mason done: 5825f7c79f30SChris Mason unlock_up(path, 0, 1, 0, NULL); 58268e73f275SChris Mason path->leave_spinning = old_spinning; 58278e73f275SChris Mason if (!old_spinning) 58288e73f275SChris Mason btrfs_set_path_blocking(path); 58298e73f275SChris Mason 58308e73f275SChris Mason return ret; 5831d97e63b6SChris Mason } 58320b86a832SChris Mason 58333f157a2fSChris Mason /* 58343f157a2fSChris Mason * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps 58353f157a2fSChris Mason * searching until it gets past min_objectid or finds an item of 'type' 58363f157a2fSChris Mason * 58373f157a2fSChris Mason * returns 0 if something is found, 1 if nothing was found and < 0 on error 58383f157a2fSChris Mason */ 58390b86a832SChris Mason int btrfs_previous_item(struct btrfs_root *root, 58400b86a832SChris Mason struct btrfs_path *path, u64 min_objectid, 58410b86a832SChris Mason int type) 58420b86a832SChris Mason { 58430b86a832SChris Mason struct btrfs_key found_key; 58440b86a832SChris Mason struct extent_buffer *leaf; 5845e02119d5SChris Mason u32 nritems; 58460b86a832SChris Mason int ret; 58470b86a832SChris Mason 58480b86a832SChris Mason while (1) { 58490b86a832SChris Mason if (path->slots[0] == 0) { 5850b4ce94deSChris Mason btrfs_set_path_blocking(path); 58510b86a832SChris Mason ret = btrfs_prev_leaf(root, path); 58520b86a832SChris Mason if (ret != 0) 58530b86a832SChris Mason return ret; 58540b86a832SChris Mason } else { 58550b86a832SChris Mason path->slots[0]--; 58560b86a832SChris Mason } 58570b86a832SChris Mason leaf = path->nodes[0]; 5858e02119d5SChris Mason nritems = btrfs_header_nritems(leaf); 5859e02119d5SChris Mason if (nritems == 0) 5860e02119d5SChris Mason return 1; 5861e02119d5SChris Mason if (path->slots[0] == nritems) 5862e02119d5SChris Mason path->slots[0]--; 5863e02119d5SChris Mason 58640b86a832SChris Mason btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 5865e02119d5SChris Mason if (found_key.objectid < min_objectid) 5866e02119d5SChris Mason break; 58670a4eefbbSYan Zheng if (found_key.type == type) 58680a4eefbbSYan Zheng return 0; 5869e02119d5SChris Mason if (found_key.objectid == min_objectid && 5870e02119d5SChris Mason found_key.type < type) 5871e02119d5SChris Mason break; 58720b86a832SChris Mason } 58730b86a832SChris Mason return 1; 58740b86a832SChris Mason } 5875ade2e0b3SWang Shilong 5876ade2e0b3SWang Shilong /* 5877ade2e0b3SWang Shilong * search in extent tree to find a previous Metadata/Data extent item with 5878ade2e0b3SWang Shilong * min objecitd. 5879ade2e0b3SWang Shilong * 5880ade2e0b3SWang Shilong * returns 0 if something is found, 1 if nothing was found and < 0 on error 5881ade2e0b3SWang Shilong */ 5882ade2e0b3SWang Shilong int btrfs_previous_extent_item(struct btrfs_root *root, 5883ade2e0b3SWang Shilong struct btrfs_path *path, u64 min_objectid) 5884ade2e0b3SWang Shilong { 5885ade2e0b3SWang Shilong struct btrfs_key found_key; 5886ade2e0b3SWang Shilong struct extent_buffer *leaf; 5887ade2e0b3SWang Shilong u32 nritems; 5888ade2e0b3SWang Shilong int ret; 5889ade2e0b3SWang Shilong 5890ade2e0b3SWang Shilong while (1) { 5891ade2e0b3SWang Shilong if (path->slots[0] == 0) { 5892ade2e0b3SWang Shilong btrfs_set_path_blocking(path); 5893ade2e0b3SWang Shilong ret = btrfs_prev_leaf(root, path); 5894ade2e0b3SWang Shilong if (ret != 0) 5895ade2e0b3SWang Shilong return ret; 5896ade2e0b3SWang Shilong } else { 5897ade2e0b3SWang Shilong path->slots[0]--; 5898ade2e0b3SWang Shilong } 5899ade2e0b3SWang Shilong leaf = path->nodes[0]; 5900ade2e0b3SWang Shilong nritems = btrfs_header_nritems(leaf); 5901ade2e0b3SWang Shilong if (nritems == 0) 5902ade2e0b3SWang Shilong return 1; 5903ade2e0b3SWang Shilong if (path->slots[0] == nritems) 5904ade2e0b3SWang Shilong path->slots[0]--; 5905ade2e0b3SWang Shilong 5906ade2e0b3SWang Shilong btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 5907ade2e0b3SWang Shilong if (found_key.objectid < min_objectid) 5908ade2e0b3SWang Shilong break; 5909ade2e0b3SWang Shilong if (found_key.type == BTRFS_EXTENT_ITEM_KEY || 5910ade2e0b3SWang Shilong found_key.type == BTRFS_METADATA_ITEM_KEY) 5911ade2e0b3SWang Shilong return 0; 5912ade2e0b3SWang Shilong if (found_key.objectid == min_objectid && 5913ade2e0b3SWang Shilong found_key.type < BTRFS_EXTENT_ITEM_KEY) 5914ade2e0b3SWang Shilong break; 5915ade2e0b3SWang Shilong } 5916ade2e0b3SWang Shilong return 1; 5917ade2e0b3SWang Shilong } 5918