1c1d7c514SDavid Sterba // SPDX-License-Identifier: GPL-2.0 26cbd5570SChris Mason /* 3d352ac68SChris Mason * Copyright (C) 2007,2008 Oracle. All rights reserved. 46cbd5570SChris Mason */ 56cbd5570SChris Mason 6a6b6e75eSChris Mason #include <linux/sched.h> 75a0e3ad6STejun Heo #include <linux/slab.h> 8bd989ba3SJan Schmidt #include <linux/rbtree.h> 9adf02123SDavid Sterba #include <linux/mm.h> 10eb60ceacSChris Mason #include "ctree.h" 11eb60ceacSChris Mason #include "disk-io.h" 127f5c1516SChris Mason #include "transaction.h" 135f39d397SChris Mason #include "print-tree.h" 14925baeddSChris Mason #include "locking.h" 15de37aa51SNikolay Borisov #include "volumes.h" 16f616f5cdSQu Wenruo #include "qgroup.h" 179a8dd150SChris Mason 18e089f05cSChris Mason static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root 19e089f05cSChris Mason *root, struct btrfs_path *path, int level); 20310712b2SOmar Sandoval static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root *root, 21310712b2SOmar Sandoval const struct btrfs_key *ins_key, struct btrfs_path *path, 22310712b2SOmar Sandoval int data_size, int extend); 235f39d397SChris Mason static int push_node_left(struct btrfs_trans_handle *trans, 242ff7e61eSJeff Mahoney struct extent_buffer *dst, 25971a1f66SChris Mason struct extent_buffer *src, int empty); 265f39d397SChris Mason static int balance_node_right(struct btrfs_trans_handle *trans, 275f39d397SChris Mason struct extent_buffer *dst_buf, 285f39d397SChris Mason struct extent_buffer *src_buf); 29afe5fea7STsutomu Itoh static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, 30afe5fea7STsutomu Itoh int level, int slot); 31d97e63b6SChris Mason 32af024ed2SJohannes Thumshirn static const struct btrfs_csums { 33af024ed2SJohannes Thumshirn u16 size; 3459a0fcdbSDavid Sterba const char name[10]; 3559a0fcdbSDavid Sterba const char driver[12]; 36af024ed2SJohannes Thumshirn } btrfs_csums[] = { 37af024ed2SJohannes Thumshirn [BTRFS_CSUM_TYPE_CRC32] = { .size = 4, .name = "crc32c" }, 383951e7f0SJohannes Thumshirn [BTRFS_CSUM_TYPE_XXHASH] = { .size = 8, .name = "xxhash64" }, 393831bf00SJohannes Thumshirn [BTRFS_CSUM_TYPE_SHA256] = { .size = 32, .name = "sha256" }, 40352ae07bSDavid Sterba [BTRFS_CSUM_TYPE_BLAKE2] = { .size = 32, .name = "blake2b", 41352ae07bSDavid Sterba .driver = "blake2b-256" }, 42af024ed2SJohannes Thumshirn }; 43af024ed2SJohannes Thumshirn 44af024ed2SJohannes Thumshirn int btrfs_super_csum_size(const struct btrfs_super_block *s) 45af024ed2SJohannes Thumshirn { 46af024ed2SJohannes Thumshirn u16 t = btrfs_super_csum_type(s); 47af024ed2SJohannes Thumshirn /* 48af024ed2SJohannes Thumshirn * csum type is validated at mount time 49af024ed2SJohannes Thumshirn */ 50af024ed2SJohannes Thumshirn return btrfs_csums[t].size; 51af024ed2SJohannes Thumshirn } 52af024ed2SJohannes Thumshirn 53af024ed2SJohannes Thumshirn const char *btrfs_super_csum_name(u16 csum_type) 54af024ed2SJohannes Thumshirn { 55af024ed2SJohannes Thumshirn /* csum type is validated at mount time */ 56af024ed2SJohannes Thumshirn return btrfs_csums[csum_type].name; 57af024ed2SJohannes Thumshirn } 58af024ed2SJohannes Thumshirn 59b4e967beSDavid Sterba /* 60b4e967beSDavid Sterba * Return driver name if defined, otherwise the name that's also a valid driver 61b4e967beSDavid Sterba * name 62b4e967beSDavid Sterba */ 63b4e967beSDavid Sterba const char *btrfs_super_csum_driver(u16 csum_type) 64b4e967beSDavid Sterba { 65b4e967beSDavid Sterba /* csum type is validated at mount time */ 6659a0fcdbSDavid Sterba return btrfs_csums[csum_type].driver[0] ? 6759a0fcdbSDavid Sterba btrfs_csums[csum_type].driver : 68b4e967beSDavid Sterba btrfs_csums[csum_type].name; 69b4e967beSDavid Sterba } 70b4e967beSDavid Sterba 71604997b4SDavid Sterba size_t __attribute_const__ btrfs_get_num_csums(void) 72f7cea56cSDavid Sterba { 73f7cea56cSDavid Sterba return ARRAY_SIZE(btrfs_csums); 74f7cea56cSDavid Sterba } 75f7cea56cSDavid Sterba 762c90e5d6SChris Mason struct btrfs_path *btrfs_alloc_path(void) 772c90e5d6SChris Mason { 78e2c89907SMasahiro Yamada return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); 792c90e5d6SChris Mason } 802c90e5d6SChris Mason 81d352ac68SChris Mason /* this also releases the path */ 822c90e5d6SChris Mason void btrfs_free_path(struct btrfs_path *p) 832c90e5d6SChris Mason { 84ff175d57SJesper Juhl if (!p) 85ff175d57SJesper Juhl return; 86b3b4aa74SDavid Sterba btrfs_release_path(p); 872c90e5d6SChris Mason kmem_cache_free(btrfs_path_cachep, p); 882c90e5d6SChris Mason } 892c90e5d6SChris Mason 90d352ac68SChris Mason /* 91d352ac68SChris Mason * path release drops references on the extent buffers in the path 92d352ac68SChris Mason * and it drops any locks held by this path 93d352ac68SChris Mason * 94d352ac68SChris Mason * It is safe to call this on paths that no locks or extent buffers held. 95d352ac68SChris Mason */ 96b3b4aa74SDavid Sterba noinline void btrfs_release_path(struct btrfs_path *p) 97eb60ceacSChris Mason { 98eb60ceacSChris Mason int i; 99a2135011SChris Mason 100234b63a0SChris Mason for (i = 0; i < BTRFS_MAX_LEVEL; i++) { 1013f157a2fSChris Mason p->slots[i] = 0; 102eb60ceacSChris Mason if (!p->nodes[i]) 103925baeddSChris Mason continue; 104925baeddSChris Mason if (p->locks[i]) { 105bd681513SChris Mason btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); 106925baeddSChris Mason p->locks[i] = 0; 107925baeddSChris Mason } 1085f39d397SChris Mason free_extent_buffer(p->nodes[i]); 1093f157a2fSChris Mason p->nodes[i] = NULL; 110eb60ceacSChris Mason } 111eb60ceacSChris Mason } 112eb60ceacSChris Mason 113d352ac68SChris Mason /* 114d352ac68SChris Mason * safely gets a reference on the root node of a tree. A lock 115d352ac68SChris Mason * is not taken, so a concurrent writer may put a different node 116d352ac68SChris Mason * at the root of the tree. See btrfs_lock_root_node for the 117d352ac68SChris Mason * looping required. 118d352ac68SChris Mason * 119d352ac68SChris Mason * The extent buffer returned by this has a reference taken, so 120d352ac68SChris Mason * it won't disappear. It may stop being the root of the tree 121d352ac68SChris Mason * at any time because there are no locks held. 122d352ac68SChris Mason */ 123925baeddSChris Mason struct extent_buffer *btrfs_root_node(struct btrfs_root *root) 124925baeddSChris Mason { 125925baeddSChris Mason struct extent_buffer *eb; 126240f62c8SChris Mason 1273083ee2eSJosef Bacik while (1) { 128240f62c8SChris Mason rcu_read_lock(); 129240f62c8SChris Mason eb = rcu_dereference(root->node); 1303083ee2eSJosef Bacik 1313083ee2eSJosef Bacik /* 1323083ee2eSJosef Bacik * RCU really hurts here, we could free up the root node because 13301327610SNicholas D Steeves * it was COWed but we may not get the new root node yet so do 1343083ee2eSJosef Bacik * the inc_not_zero dance and if it doesn't work then 1353083ee2eSJosef Bacik * synchronize_rcu and try again. 1363083ee2eSJosef Bacik */ 1373083ee2eSJosef Bacik if (atomic_inc_not_zero(&eb->refs)) { 138240f62c8SChris Mason rcu_read_unlock(); 1393083ee2eSJosef Bacik break; 1403083ee2eSJosef Bacik } 1413083ee2eSJosef Bacik rcu_read_unlock(); 1423083ee2eSJosef Bacik synchronize_rcu(); 1433083ee2eSJosef Bacik } 144925baeddSChris Mason return eb; 145925baeddSChris Mason } 146925baeddSChris Mason 14792a7cc42SQu Wenruo /* 14892a7cc42SQu Wenruo * Cowonly root (not-shareable trees, everything not subvolume or reloc roots), 14992a7cc42SQu Wenruo * just get put onto a simple dirty list. Transaction walks this list to make 15092a7cc42SQu Wenruo * sure they get properly updated on disk. 151d352ac68SChris Mason */ 1520b86a832SChris Mason static void add_root_to_dirty_list(struct btrfs_root *root) 1530b86a832SChris Mason { 1540b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 1550b246afaSJeff Mahoney 156e7070be1SJosef Bacik if (test_bit(BTRFS_ROOT_DIRTY, &root->state) || 157e7070be1SJosef Bacik !test_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state)) 158e7070be1SJosef Bacik return; 159e7070be1SJosef Bacik 1600b246afaSJeff Mahoney spin_lock(&fs_info->trans_lock); 161e7070be1SJosef Bacik if (!test_and_set_bit(BTRFS_ROOT_DIRTY, &root->state)) { 162e7070be1SJosef Bacik /* Want the extent tree to be the last on the list */ 1634fd786e6SMisono Tomohiro if (root->root_key.objectid == BTRFS_EXTENT_TREE_OBJECTID) 164e7070be1SJosef Bacik list_move_tail(&root->dirty_list, 1650b246afaSJeff Mahoney &fs_info->dirty_cowonly_roots); 166e7070be1SJosef Bacik else 167e7070be1SJosef Bacik list_move(&root->dirty_list, 1680b246afaSJeff Mahoney &fs_info->dirty_cowonly_roots); 1690b86a832SChris Mason } 1700b246afaSJeff Mahoney spin_unlock(&fs_info->trans_lock); 1710b86a832SChris Mason } 1720b86a832SChris Mason 173d352ac68SChris Mason /* 174d352ac68SChris Mason * used by snapshot creation to make a copy of a root for a tree with 175d352ac68SChris Mason * a given objectid. The buffer with the new root node is returned in 176d352ac68SChris Mason * cow_ret, and this func returns zero on success or a negative error code. 177d352ac68SChris Mason */ 178be20aa9dSChris Mason int btrfs_copy_root(struct btrfs_trans_handle *trans, 179be20aa9dSChris Mason struct btrfs_root *root, 180be20aa9dSChris Mason struct extent_buffer *buf, 181be20aa9dSChris Mason struct extent_buffer **cow_ret, u64 new_root_objectid) 182be20aa9dSChris Mason { 1830b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 184be20aa9dSChris Mason struct extent_buffer *cow; 185be20aa9dSChris Mason int ret = 0; 186be20aa9dSChris Mason int level; 1875d4f98a2SYan Zheng struct btrfs_disk_key disk_key; 188be20aa9dSChris Mason 18992a7cc42SQu Wenruo WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && 1900b246afaSJeff Mahoney trans->transid != fs_info->running_transaction->transid); 19192a7cc42SQu Wenruo WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && 19227cdeb70SMiao Xie trans->transid != root->last_trans); 193be20aa9dSChris Mason 194be20aa9dSChris Mason level = btrfs_header_level(buf); 1955d4f98a2SYan Zheng if (level == 0) 1965d4f98a2SYan Zheng btrfs_item_key(buf, &disk_key, 0); 1975d4f98a2SYan Zheng else 1985d4f98a2SYan Zheng btrfs_node_key(buf, &disk_key, 0); 19931840ae1SZheng Yan 2004d75f8a9SDavid Sterba cow = btrfs_alloc_tree_block(trans, root, 0, new_root_objectid, 201cf6f34aaSJosef Bacik &disk_key, level, buf->start, 0, 202cf6f34aaSJosef Bacik BTRFS_NESTING_NEW_ROOT); 2035d4f98a2SYan Zheng if (IS_ERR(cow)) 204be20aa9dSChris Mason return PTR_ERR(cow); 205be20aa9dSChris Mason 20658e8012cSDavid Sterba copy_extent_buffer_full(cow, buf); 207be20aa9dSChris Mason btrfs_set_header_bytenr(cow, cow->start); 208be20aa9dSChris Mason btrfs_set_header_generation(cow, trans->transid); 2095d4f98a2SYan Zheng btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); 2105d4f98a2SYan Zheng btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | 2115d4f98a2SYan Zheng BTRFS_HEADER_FLAG_RELOC); 2125d4f98a2SYan Zheng if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) 2135d4f98a2SYan Zheng btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); 2145d4f98a2SYan Zheng else 215be20aa9dSChris Mason btrfs_set_header_owner(cow, new_root_objectid); 216be20aa9dSChris Mason 217de37aa51SNikolay Borisov write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); 2182b82032cSYan Zheng 219be20aa9dSChris Mason WARN_ON(btrfs_header_generation(buf) > trans->transid); 2205d4f98a2SYan Zheng if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) 221e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 1); 2225d4f98a2SYan Zheng else 223e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 0); 2244aec2b52SChris Mason 225be20aa9dSChris Mason if (ret) 226be20aa9dSChris Mason return ret; 227be20aa9dSChris Mason 228be20aa9dSChris Mason btrfs_mark_buffer_dirty(cow); 229be20aa9dSChris Mason *cow_ret = cow; 230be20aa9dSChris Mason return 0; 231be20aa9dSChris Mason } 232be20aa9dSChris Mason 233bd989ba3SJan Schmidt enum mod_log_op { 234bd989ba3SJan Schmidt MOD_LOG_KEY_REPLACE, 235bd989ba3SJan Schmidt MOD_LOG_KEY_ADD, 236bd989ba3SJan Schmidt MOD_LOG_KEY_REMOVE, 237bd989ba3SJan Schmidt MOD_LOG_KEY_REMOVE_WHILE_FREEING, 238bd989ba3SJan Schmidt MOD_LOG_KEY_REMOVE_WHILE_MOVING, 239bd989ba3SJan Schmidt MOD_LOG_MOVE_KEYS, 240bd989ba3SJan Schmidt MOD_LOG_ROOT_REPLACE, 241bd989ba3SJan Schmidt }; 242bd989ba3SJan Schmidt 243bd989ba3SJan Schmidt struct tree_mod_root { 244bd989ba3SJan Schmidt u64 logical; 245bd989ba3SJan Schmidt u8 level; 246bd989ba3SJan Schmidt }; 247bd989ba3SJan Schmidt 248bd989ba3SJan Schmidt struct tree_mod_elem { 249bd989ba3SJan Schmidt struct rb_node node; 250298cfd36SChandan Rajendra u64 logical; 251097b8a7cSJan Schmidt u64 seq; 252bd989ba3SJan Schmidt enum mod_log_op op; 253bd989ba3SJan Schmidt 254bd989ba3SJan Schmidt /* this is used for MOD_LOG_KEY_* and MOD_LOG_MOVE_KEYS operations */ 255bd989ba3SJan Schmidt int slot; 256bd989ba3SJan Schmidt 257bd989ba3SJan Schmidt /* this is used for MOD_LOG_KEY* and MOD_LOG_ROOT_REPLACE */ 258bd989ba3SJan Schmidt u64 generation; 259bd989ba3SJan Schmidt 260bd989ba3SJan Schmidt /* those are used for op == MOD_LOG_KEY_{REPLACE,REMOVE} */ 261bd989ba3SJan Schmidt struct btrfs_disk_key key; 262bd989ba3SJan Schmidt u64 blockptr; 263bd989ba3SJan Schmidt 264bd989ba3SJan Schmidt /* this is used for op == MOD_LOG_MOVE_KEYS */ 265b6dfa35bSDavid Sterba struct { 266b6dfa35bSDavid Sterba int dst_slot; 267b6dfa35bSDavid Sterba int nr_items; 268b6dfa35bSDavid Sterba } move; 269bd989ba3SJan Schmidt 270bd989ba3SJan Schmidt /* this is used for op == MOD_LOG_ROOT_REPLACE */ 271bd989ba3SJan Schmidt struct tree_mod_root old_root; 272bd989ba3SJan Schmidt }; 273bd989ba3SJan Schmidt 274097b8a7cSJan Schmidt /* 275fcebe456SJosef Bacik * Pull a new tree mod seq number for our operation. 276fc36ed7eSJan Schmidt */ 277fcebe456SJosef Bacik static inline u64 btrfs_inc_tree_mod_seq(struct btrfs_fs_info *fs_info) 278fc36ed7eSJan Schmidt { 279fc36ed7eSJan Schmidt return atomic64_inc_return(&fs_info->tree_mod_seq); 280fc36ed7eSJan Schmidt } 281fc36ed7eSJan Schmidt 282fc36ed7eSJan Schmidt /* 283097b8a7cSJan Schmidt * This adds a new blocker to the tree mod log's blocker list if the @elem 284097b8a7cSJan Schmidt * passed does not already have a sequence number set. So when a caller expects 285097b8a7cSJan Schmidt * to record tree modifications, it should ensure to set elem->seq to zero 286097b8a7cSJan Schmidt * before calling btrfs_get_tree_mod_seq. 287097b8a7cSJan Schmidt * Returns a fresh, unused tree log modification sequence number, even if no new 288097b8a7cSJan Schmidt * blocker was added. 289097b8a7cSJan Schmidt */ 290097b8a7cSJan Schmidt u64 btrfs_get_tree_mod_seq(struct btrfs_fs_info *fs_info, 291bd989ba3SJan Schmidt struct seq_list *elem) 292bd989ba3SJan Schmidt { 293b1a09f1eSDavid Sterba write_lock(&fs_info->tree_mod_log_lock); 294097b8a7cSJan Schmidt if (!elem->seq) { 295fcebe456SJosef Bacik elem->seq = btrfs_inc_tree_mod_seq(fs_info); 296097b8a7cSJan Schmidt list_add_tail(&elem->list, &fs_info->tree_mod_seq_list); 297097b8a7cSJan Schmidt } 298b1a09f1eSDavid Sterba write_unlock(&fs_info->tree_mod_log_lock); 299097b8a7cSJan Schmidt 300fcebe456SJosef Bacik return elem->seq; 301bd989ba3SJan Schmidt } 302bd989ba3SJan Schmidt 303bd989ba3SJan Schmidt void btrfs_put_tree_mod_seq(struct btrfs_fs_info *fs_info, 304bd989ba3SJan Schmidt struct seq_list *elem) 305bd989ba3SJan Schmidt { 306bd989ba3SJan Schmidt struct rb_root *tm_root; 307bd989ba3SJan Schmidt struct rb_node *node; 308bd989ba3SJan Schmidt struct rb_node *next; 309bd989ba3SJan Schmidt struct tree_mod_elem *tm; 310bd989ba3SJan Schmidt u64 min_seq = (u64)-1; 311bd989ba3SJan Schmidt u64 seq_putting = elem->seq; 312bd989ba3SJan Schmidt 313bd989ba3SJan Schmidt if (!seq_putting) 314bd989ba3SJan Schmidt return; 315bd989ba3SJan Schmidt 3167227ff4dSFilipe Manana write_lock(&fs_info->tree_mod_log_lock); 317bd989ba3SJan Schmidt list_del(&elem->list); 318097b8a7cSJan Schmidt elem->seq = 0; 319bd989ba3SJan Schmidt 32042836cf4SFilipe Manana if (!list_empty(&fs_info->tree_mod_seq_list)) { 32142836cf4SFilipe Manana struct seq_list *first; 32242836cf4SFilipe Manana 32342836cf4SFilipe Manana first = list_first_entry(&fs_info->tree_mod_seq_list, 32442836cf4SFilipe Manana struct seq_list, list); 32542836cf4SFilipe Manana if (seq_putting > first->seq) { 326bd989ba3SJan Schmidt /* 32742836cf4SFilipe Manana * Blocker with lower sequence number exists, we 32842836cf4SFilipe Manana * cannot remove anything from the log. 329bd989ba3SJan Schmidt */ 3307227ff4dSFilipe Manana write_unlock(&fs_info->tree_mod_log_lock); 331097b8a7cSJan Schmidt return; 332bd989ba3SJan Schmidt } 33342836cf4SFilipe Manana min_seq = first->seq; 334bd989ba3SJan Schmidt } 335097b8a7cSJan Schmidt 336097b8a7cSJan Schmidt /* 337bd989ba3SJan Schmidt * anything that's lower than the lowest existing (read: blocked) 338bd989ba3SJan Schmidt * sequence number can be removed from the tree. 339bd989ba3SJan Schmidt */ 340bd989ba3SJan Schmidt tm_root = &fs_info->tree_mod_log; 341bd989ba3SJan Schmidt for (node = rb_first(tm_root); node; node = next) { 342bd989ba3SJan Schmidt next = rb_next(node); 3436b4df8b6SGeliang Tang tm = rb_entry(node, struct tree_mod_elem, node); 3446609fee8SFilipe Manana if (tm->seq >= min_seq) 345bd989ba3SJan Schmidt continue; 346bd989ba3SJan Schmidt rb_erase(node, tm_root); 347bd989ba3SJan Schmidt kfree(tm); 348bd989ba3SJan Schmidt } 349b1a09f1eSDavid Sterba write_unlock(&fs_info->tree_mod_log_lock); 350bd989ba3SJan Schmidt } 351bd989ba3SJan Schmidt 352bd989ba3SJan Schmidt /* 353bd989ba3SJan Schmidt * key order of the log: 354298cfd36SChandan Rajendra * node/leaf start address -> sequence 355bd989ba3SJan Schmidt * 356298cfd36SChandan Rajendra * The 'start address' is the logical address of the *new* root node 357298cfd36SChandan Rajendra * for root replace operations, or the logical address of the affected 358298cfd36SChandan Rajendra * block for all other operations. 359bd989ba3SJan Schmidt */ 360bd989ba3SJan Schmidt static noinline int 361bd989ba3SJan Schmidt __tree_mod_log_insert(struct btrfs_fs_info *fs_info, struct tree_mod_elem *tm) 362bd989ba3SJan Schmidt { 363bd989ba3SJan Schmidt struct rb_root *tm_root; 364bd989ba3SJan Schmidt struct rb_node **new; 365bd989ba3SJan Schmidt struct rb_node *parent = NULL; 366bd989ba3SJan Schmidt struct tree_mod_elem *cur; 367bd989ba3SJan Schmidt 36873e82fe4SDavid Sterba lockdep_assert_held_write(&fs_info->tree_mod_log_lock); 36973e82fe4SDavid Sterba 370fcebe456SJosef Bacik tm->seq = btrfs_inc_tree_mod_seq(fs_info); 371bd989ba3SJan Schmidt 372bd989ba3SJan Schmidt tm_root = &fs_info->tree_mod_log; 373bd989ba3SJan Schmidt new = &tm_root->rb_node; 374bd989ba3SJan Schmidt while (*new) { 3756b4df8b6SGeliang Tang cur = rb_entry(*new, struct tree_mod_elem, node); 376bd989ba3SJan Schmidt parent = *new; 377298cfd36SChandan Rajendra if (cur->logical < tm->logical) 378bd989ba3SJan Schmidt new = &((*new)->rb_left); 379298cfd36SChandan Rajendra else if (cur->logical > tm->logical) 380bd989ba3SJan Schmidt new = &((*new)->rb_right); 381097b8a7cSJan Schmidt else if (cur->seq < tm->seq) 382bd989ba3SJan Schmidt new = &((*new)->rb_left); 383097b8a7cSJan Schmidt else if (cur->seq > tm->seq) 384bd989ba3SJan Schmidt new = &((*new)->rb_right); 3855de865eeSFilipe David Borba Manana else 3865de865eeSFilipe David Borba Manana return -EEXIST; 387bd989ba3SJan Schmidt } 388bd989ba3SJan Schmidt 389bd989ba3SJan Schmidt rb_link_node(&tm->node, parent, new); 390bd989ba3SJan Schmidt rb_insert_color(&tm->node, tm_root); 3915de865eeSFilipe David Borba Manana return 0; 392bd989ba3SJan Schmidt } 393bd989ba3SJan Schmidt 394097b8a7cSJan Schmidt /* 395097b8a7cSJan Schmidt * Determines if logging can be omitted. Returns 1 if it can. Otherwise, it 396097b8a7cSJan Schmidt * returns zero with the tree_mod_log_lock acquired. The caller must hold 397097b8a7cSJan Schmidt * this until all tree mod log insertions are recorded in the rb tree and then 398b1a09f1eSDavid Sterba * write unlock fs_info::tree_mod_log_lock. 399097b8a7cSJan Schmidt */ 400e9b7fd4dSJan Schmidt static inline int tree_mod_dont_log(struct btrfs_fs_info *fs_info, 401e9b7fd4dSJan Schmidt struct extent_buffer *eb) { 402e9b7fd4dSJan Schmidt smp_mb(); 403e9b7fd4dSJan Schmidt if (list_empty(&(fs_info)->tree_mod_seq_list)) 404e9b7fd4dSJan Schmidt return 1; 405097b8a7cSJan Schmidt if (eb && btrfs_header_level(eb) == 0) 406e9b7fd4dSJan Schmidt return 1; 4075de865eeSFilipe David Borba Manana 408b1a09f1eSDavid Sterba write_lock(&fs_info->tree_mod_log_lock); 4095de865eeSFilipe David Borba Manana if (list_empty(&(fs_info)->tree_mod_seq_list)) { 410b1a09f1eSDavid Sterba write_unlock(&fs_info->tree_mod_log_lock); 4115de865eeSFilipe David Borba Manana return 1; 4125de865eeSFilipe David Borba Manana } 4135de865eeSFilipe David Borba Manana 414e9b7fd4dSJan Schmidt return 0; 415e9b7fd4dSJan Schmidt } 416e9b7fd4dSJan Schmidt 4175de865eeSFilipe David Borba Manana /* Similar to tree_mod_dont_log, but doesn't acquire any locks. */ 4185de865eeSFilipe David Borba Manana static inline int tree_mod_need_log(const struct btrfs_fs_info *fs_info, 4195de865eeSFilipe David Borba Manana struct extent_buffer *eb) 4205de865eeSFilipe David Borba Manana { 4215de865eeSFilipe David Borba Manana smp_mb(); 4225de865eeSFilipe David Borba Manana if (list_empty(&(fs_info)->tree_mod_seq_list)) 4235de865eeSFilipe David Borba Manana return 0; 4245de865eeSFilipe David Borba Manana if (eb && btrfs_header_level(eb) == 0) 4255de865eeSFilipe David Borba Manana return 0; 4265de865eeSFilipe David Borba Manana 4275de865eeSFilipe David Borba Manana return 1; 4285de865eeSFilipe David Borba Manana } 4295de865eeSFilipe David Borba Manana 4305de865eeSFilipe David Borba Manana static struct tree_mod_elem * 4315de865eeSFilipe David Borba Manana alloc_tree_mod_elem(struct extent_buffer *eb, int slot, 432bd989ba3SJan Schmidt enum mod_log_op op, gfp_t flags) 433bd989ba3SJan Schmidt { 434097b8a7cSJan Schmidt struct tree_mod_elem *tm; 435bd989ba3SJan Schmidt 436c8cc6341SJosef Bacik tm = kzalloc(sizeof(*tm), flags); 437c8cc6341SJosef Bacik if (!tm) 4385de865eeSFilipe David Borba Manana return NULL; 439bd989ba3SJan Schmidt 440298cfd36SChandan Rajendra tm->logical = eb->start; 441bd989ba3SJan Schmidt if (op != MOD_LOG_KEY_ADD) { 442bd989ba3SJan Schmidt btrfs_node_key(eb, &tm->key, slot); 443bd989ba3SJan Schmidt tm->blockptr = btrfs_node_blockptr(eb, slot); 444bd989ba3SJan Schmidt } 445bd989ba3SJan Schmidt tm->op = op; 446bd989ba3SJan Schmidt tm->slot = slot; 447bd989ba3SJan Schmidt tm->generation = btrfs_node_ptr_generation(eb, slot); 4485de865eeSFilipe David Borba Manana RB_CLEAR_NODE(&tm->node); 449bd989ba3SJan Schmidt 4505de865eeSFilipe David Borba Manana return tm; 451097b8a7cSJan Schmidt } 452097b8a7cSJan Schmidt 453e09c2efeSDavid Sterba static noinline int tree_mod_log_insert_key(struct extent_buffer *eb, int slot, 454097b8a7cSJan Schmidt enum mod_log_op op, gfp_t flags) 455097b8a7cSJan Schmidt { 4565de865eeSFilipe David Borba Manana struct tree_mod_elem *tm; 4575de865eeSFilipe David Borba Manana int ret; 4585de865eeSFilipe David Borba Manana 459e09c2efeSDavid Sterba if (!tree_mod_need_log(eb->fs_info, eb)) 460097b8a7cSJan Schmidt return 0; 461097b8a7cSJan Schmidt 4625de865eeSFilipe David Borba Manana tm = alloc_tree_mod_elem(eb, slot, op, flags); 4635de865eeSFilipe David Borba Manana if (!tm) 4645de865eeSFilipe David Borba Manana return -ENOMEM; 4655de865eeSFilipe David Borba Manana 466e09c2efeSDavid Sterba if (tree_mod_dont_log(eb->fs_info, eb)) { 4675de865eeSFilipe David Borba Manana kfree(tm); 4685de865eeSFilipe David Borba Manana return 0; 4695de865eeSFilipe David Borba Manana } 4705de865eeSFilipe David Borba Manana 471e09c2efeSDavid Sterba ret = __tree_mod_log_insert(eb->fs_info, tm); 472b1a09f1eSDavid Sterba write_unlock(&eb->fs_info->tree_mod_log_lock); 4735de865eeSFilipe David Borba Manana if (ret) 4745de865eeSFilipe David Borba Manana kfree(tm); 4755de865eeSFilipe David Borba Manana 4765de865eeSFilipe David Borba Manana return ret; 477097b8a7cSJan Schmidt } 478097b8a7cSJan Schmidt 4796074d45fSDavid Sterba static noinline int tree_mod_log_insert_move(struct extent_buffer *eb, 4806074d45fSDavid Sterba int dst_slot, int src_slot, int nr_items) 481bd989ba3SJan Schmidt { 4825de865eeSFilipe David Borba Manana struct tree_mod_elem *tm = NULL; 4835de865eeSFilipe David Borba Manana struct tree_mod_elem **tm_list = NULL; 4845de865eeSFilipe David Borba Manana int ret = 0; 485bd989ba3SJan Schmidt int i; 4865de865eeSFilipe David Borba Manana int locked = 0; 487bd989ba3SJan Schmidt 4886074d45fSDavid Sterba if (!tree_mod_need_log(eb->fs_info, eb)) 489f395694cSJan Schmidt return 0; 490bd989ba3SJan Schmidt 491176ef8f5SDavid Sterba tm_list = kcalloc(nr_items, sizeof(struct tree_mod_elem *), GFP_NOFS); 4925de865eeSFilipe David Borba Manana if (!tm_list) 4935de865eeSFilipe David Borba Manana return -ENOMEM; 494bd989ba3SJan Schmidt 495176ef8f5SDavid Sterba tm = kzalloc(sizeof(*tm), GFP_NOFS); 4965de865eeSFilipe David Borba Manana if (!tm) { 4975de865eeSFilipe David Borba Manana ret = -ENOMEM; 4985de865eeSFilipe David Borba Manana goto free_tms; 4995de865eeSFilipe David Borba Manana } 500f395694cSJan Schmidt 501298cfd36SChandan Rajendra tm->logical = eb->start; 502bd989ba3SJan Schmidt tm->slot = src_slot; 503bd989ba3SJan Schmidt tm->move.dst_slot = dst_slot; 504bd989ba3SJan Schmidt tm->move.nr_items = nr_items; 505bd989ba3SJan Schmidt tm->op = MOD_LOG_MOVE_KEYS; 506bd989ba3SJan Schmidt 5075de865eeSFilipe David Borba Manana for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { 5085de865eeSFilipe David Borba Manana tm_list[i] = alloc_tree_mod_elem(eb, i + dst_slot, 509176ef8f5SDavid Sterba MOD_LOG_KEY_REMOVE_WHILE_MOVING, GFP_NOFS); 5105de865eeSFilipe David Borba Manana if (!tm_list[i]) { 5115de865eeSFilipe David Borba Manana ret = -ENOMEM; 5125de865eeSFilipe David Borba Manana goto free_tms; 5135de865eeSFilipe David Borba Manana } 514bd989ba3SJan Schmidt } 515bd989ba3SJan Schmidt 5166074d45fSDavid Sterba if (tree_mod_dont_log(eb->fs_info, eb)) 5175de865eeSFilipe David Borba Manana goto free_tms; 5185de865eeSFilipe David Borba Manana locked = 1; 5195de865eeSFilipe David Borba Manana 5205de865eeSFilipe David Borba Manana /* 5215de865eeSFilipe David Borba Manana * When we override something during the move, we log these removals. 5225de865eeSFilipe David Borba Manana * This can only happen when we move towards the beginning of the 5235de865eeSFilipe David Borba Manana * buffer, i.e. dst_slot < src_slot. 5245de865eeSFilipe David Borba Manana */ 5255de865eeSFilipe David Borba Manana for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { 5266074d45fSDavid Sterba ret = __tree_mod_log_insert(eb->fs_info, tm_list[i]); 5275de865eeSFilipe David Borba Manana if (ret) 5285de865eeSFilipe David Borba Manana goto free_tms; 5295de865eeSFilipe David Borba Manana } 5305de865eeSFilipe David Borba Manana 5316074d45fSDavid Sterba ret = __tree_mod_log_insert(eb->fs_info, tm); 5325de865eeSFilipe David Borba Manana if (ret) 5335de865eeSFilipe David Borba Manana goto free_tms; 534b1a09f1eSDavid Sterba write_unlock(&eb->fs_info->tree_mod_log_lock); 5355de865eeSFilipe David Borba Manana kfree(tm_list); 5365de865eeSFilipe David Borba Manana 5375de865eeSFilipe David Borba Manana return 0; 5385de865eeSFilipe David Borba Manana free_tms: 5395de865eeSFilipe David Borba Manana for (i = 0; i < nr_items; i++) { 5405de865eeSFilipe David Borba Manana if (tm_list[i] && !RB_EMPTY_NODE(&tm_list[i]->node)) 5416074d45fSDavid Sterba rb_erase(&tm_list[i]->node, &eb->fs_info->tree_mod_log); 5425de865eeSFilipe David Borba Manana kfree(tm_list[i]); 5435de865eeSFilipe David Borba Manana } 5445de865eeSFilipe David Borba Manana if (locked) 545b1a09f1eSDavid Sterba write_unlock(&eb->fs_info->tree_mod_log_lock); 5465de865eeSFilipe David Borba Manana kfree(tm_list); 5475de865eeSFilipe David Borba Manana kfree(tm); 5485de865eeSFilipe David Borba Manana 5495de865eeSFilipe David Borba Manana return ret; 5505de865eeSFilipe David Borba Manana } 5515de865eeSFilipe David Borba Manana 5525de865eeSFilipe David Borba Manana static inline int 5535de865eeSFilipe David Borba Manana __tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, 5545de865eeSFilipe David Borba Manana struct tree_mod_elem **tm_list, 5555de865eeSFilipe David Borba Manana int nritems) 556097b8a7cSJan Schmidt { 5575de865eeSFilipe David Borba Manana int i, j; 558097b8a7cSJan Schmidt int ret; 559097b8a7cSJan Schmidt 560097b8a7cSJan Schmidt for (i = nritems - 1; i >= 0; i--) { 5615de865eeSFilipe David Borba Manana ret = __tree_mod_log_insert(fs_info, tm_list[i]); 5625de865eeSFilipe David Borba Manana if (ret) { 5635de865eeSFilipe David Borba Manana for (j = nritems - 1; j > i; j--) 5645de865eeSFilipe David Borba Manana rb_erase(&tm_list[j]->node, 5655de865eeSFilipe David Borba Manana &fs_info->tree_mod_log); 5665de865eeSFilipe David Borba Manana return ret; 567097b8a7cSJan Schmidt } 568097b8a7cSJan Schmidt } 569097b8a7cSJan Schmidt 5705de865eeSFilipe David Borba Manana return 0; 5715de865eeSFilipe David Borba Manana } 5725de865eeSFilipe David Borba Manana 57395b757c1SDavid Sterba static noinline int tree_mod_log_insert_root(struct extent_buffer *old_root, 57495b757c1SDavid Sterba struct extent_buffer *new_root, int log_removal) 575bd989ba3SJan Schmidt { 57695b757c1SDavid Sterba struct btrfs_fs_info *fs_info = old_root->fs_info; 5775de865eeSFilipe David Borba Manana struct tree_mod_elem *tm = NULL; 5785de865eeSFilipe David Borba Manana struct tree_mod_elem **tm_list = NULL; 5795de865eeSFilipe David Borba Manana int nritems = 0; 5805de865eeSFilipe David Borba Manana int ret = 0; 5815de865eeSFilipe David Borba Manana int i; 582bd989ba3SJan Schmidt 5835de865eeSFilipe David Borba Manana if (!tree_mod_need_log(fs_info, NULL)) 584097b8a7cSJan Schmidt return 0; 585097b8a7cSJan Schmidt 5865de865eeSFilipe David Borba Manana if (log_removal && btrfs_header_level(old_root) > 0) { 5875de865eeSFilipe David Borba Manana nritems = btrfs_header_nritems(old_root); 58831e818feSDavid Sterba tm_list = kcalloc(nritems, sizeof(struct tree_mod_elem *), 589bcc8e07fSDavid Sterba GFP_NOFS); 5905de865eeSFilipe David Borba Manana if (!tm_list) { 5915de865eeSFilipe David Borba Manana ret = -ENOMEM; 5925de865eeSFilipe David Borba Manana goto free_tms; 5935de865eeSFilipe David Borba Manana } 5945de865eeSFilipe David Borba Manana for (i = 0; i < nritems; i++) { 5955de865eeSFilipe David Borba Manana tm_list[i] = alloc_tree_mod_elem(old_root, i, 596bcc8e07fSDavid Sterba MOD_LOG_KEY_REMOVE_WHILE_FREEING, GFP_NOFS); 5975de865eeSFilipe David Borba Manana if (!tm_list[i]) { 5985de865eeSFilipe David Borba Manana ret = -ENOMEM; 5995de865eeSFilipe David Borba Manana goto free_tms; 6005de865eeSFilipe David Borba Manana } 6015de865eeSFilipe David Borba Manana } 6025de865eeSFilipe David Borba Manana } 603d9abbf1cSJan Schmidt 604bcc8e07fSDavid Sterba tm = kzalloc(sizeof(*tm), GFP_NOFS); 6055de865eeSFilipe David Borba Manana if (!tm) { 6065de865eeSFilipe David Borba Manana ret = -ENOMEM; 6075de865eeSFilipe David Borba Manana goto free_tms; 6085de865eeSFilipe David Borba Manana } 609bd989ba3SJan Schmidt 610298cfd36SChandan Rajendra tm->logical = new_root->start; 611bd989ba3SJan Schmidt tm->old_root.logical = old_root->start; 612bd989ba3SJan Schmidt tm->old_root.level = btrfs_header_level(old_root); 613bd989ba3SJan Schmidt tm->generation = btrfs_header_generation(old_root); 614bd989ba3SJan Schmidt tm->op = MOD_LOG_ROOT_REPLACE; 615bd989ba3SJan Schmidt 6165de865eeSFilipe David Borba Manana if (tree_mod_dont_log(fs_info, NULL)) 6175de865eeSFilipe David Borba Manana goto free_tms; 6185de865eeSFilipe David Borba Manana 6195de865eeSFilipe David Borba Manana if (tm_list) 6205de865eeSFilipe David Borba Manana ret = __tree_mod_log_free_eb(fs_info, tm_list, nritems); 6215de865eeSFilipe David Borba Manana if (!ret) 6225de865eeSFilipe David Borba Manana ret = __tree_mod_log_insert(fs_info, tm); 6235de865eeSFilipe David Borba Manana 624b1a09f1eSDavid Sterba write_unlock(&fs_info->tree_mod_log_lock); 6255de865eeSFilipe David Borba Manana if (ret) 6265de865eeSFilipe David Borba Manana goto free_tms; 6275de865eeSFilipe David Borba Manana kfree(tm_list); 6285de865eeSFilipe David Borba Manana 6295de865eeSFilipe David Borba Manana return ret; 6305de865eeSFilipe David Borba Manana 6315de865eeSFilipe David Borba Manana free_tms: 6325de865eeSFilipe David Borba Manana if (tm_list) { 6335de865eeSFilipe David Borba Manana for (i = 0; i < nritems; i++) 6345de865eeSFilipe David Borba Manana kfree(tm_list[i]); 6355de865eeSFilipe David Borba Manana kfree(tm_list); 6365de865eeSFilipe David Borba Manana } 6375de865eeSFilipe David Borba Manana kfree(tm); 6385de865eeSFilipe David Borba Manana 6395de865eeSFilipe David Borba Manana return ret; 640bd989ba3SJan Schmidt } 641bd989ba3SJan Schmidt 642bd989ba3SJan Schmidt static struct tree_mod_elem * 643bd989ba3SJan Schmidt __tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq, 644bd989ba3SJan Schmidt int smallest) 645bd989ba3SJan Schmidt { 646bd989ba3SJan Schmidt struct rb_root *tm_root; 647bd989ba3SJan Schmidt struct rb_node *node; 648bd989ba3SJan Schmidt struct tree_mod_elem *cur = NULL; 649bd989ba3SJan Schmidt struct tree_mod_elem *found = NULL; 650bd989ba3SJan Schmidt 651b1a09f1eSDavid Sterba read_lock(&fs_info->tree_mod_log_lock); 652bd989ba3SJan Schmidt tm_root = &fs_info->tree_mod_log; 653bd989ba3SJan Schmidt node = tm_root->rb_node; 654bd989ba3SJan Schmidt while (node) { 6556b4df8b6SGeliang Tang cur = rb_entry(node, struct tree_mod_elem, node); 656298cfd36SChandan Rajendra if (cur->logical < start) { 657bd989ba3SJan Schmidt node = node->rb_left; 658298cfd36SChandan Rajendra } else if (cur->logical > start) { 659bd989ba3SJan Schmidt node = node->rb_right; 660097b8a7cSJan Schmidt } else if (cur->seq < min_seq) { 661bd989ba3SJan Schmidt node = node->rb_left; 662bd989ba3SJan Schmidt } else if (!smallest) { 663bd989ba3SJan Schmidt /* we want the node with the highest seq */ 664bd989ba3SJan Schmidt if (found) 665097b8a7cSJan Schmidt BUG_ON(found->seq > cur->seq); 666bd989ba3SJan Schmidt found = cur; 667bd989ba3SJan Schmidt node = node->rb_left; 668097b8a7cSJan Schmidt } else if (cur->seq > min_seq) { 669bd989ba3SJan Schmidt /* we want the node with the smallest seq */ 670bd989ba3SJan Schmidt if (found) 671097b8a7cSJan Schmidt BUG_ON(found->seq < cur->seq); 672bd989ba3SJan Schmidt found = cur; 673bd989ba3SJan Schmidt node = node->rb_right; 674bd989ba3SJan Schmidt } else { 675bd989ba3SJan Schmidt found = cur; 676bd989ba3SJan Schmidt break; 677bd989ba3SJan Schmidt } 678bd989ba3SJan Schmidt } 679b1a09f1eSDavid Sterba read_unlock(&fs_info->tree_mod_log_lock); 680bd989ba3SJan Schmidt 681bd989ba3SJan Schmidt return found; 682bd989ba3SJan Schmidt } 683bd989ba3SJan Schmidt 684bd989ba3SJan Schmidt /* 685bd989ba3SJan Schmidt * this returns the element from the log with the smallest time sequence 686bd989ba3SJan Schmidt * value that's in the log (the oldest log item). any element with a time 687bd989ba3SJan Schmidt * sequence lower than min_seq will be ignored. 688bd989ba3SJan Schmidt */ 689bd989ba3SJan Schmidt static struct tree_mod_elem * 690bd989ba3SJan Schmidt tree_mod_log_search_oldest(struct btrfs_fs_info *fs_info, u64 start, 691bd989ba3SJan Schmidt u64 min_seq) 692bd989ba3SJan Schmidt { 693bd989ba3SJan Schmidt return __tree_mod_log_search(fs_info, start, min_seq, 1); 694bd989ba3SJan Schmidt } 695bd989ba3SJan Schmidt 696bd989ba3SJan Schmidt /* 697bd989ba3SJan Schmidt * this returns the element from the log with the largest time sequence 698bd989ba3SJan Schmidt * value that's in the log (the most recent log item). any element with 699bd989ba3SJan Schmidt * a time sequence lower than min_seq will be ignored. 700bd989ba3SJan Schmidt */ 701bd989ba3SJan Schmidt static struct tree_mod_elem * 702bd989ba3SJan Schmidt tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq) 703bd989ba3SJan Schmidt { 704bd989ba3SJan Schmidt return __tree_mod_log_search(fs_info, start, min_seq, 0); 705bd989ba3SJan Schmidt } 706bd989ba3SJan Schmidt 707ed874f0dSDavid Sterba static noinline int tree_mod_log_eb_copy(struct extent_buffer *dst, 708bd989ba3SJan Schmidt struct extent_buffer *src, unsigned long dst_offset, 70990f8d62eSJan Schmidt unsigned long src_offset, int nr_items) 710bd989ba3SJan Schmidt { 711ed874f0dSDavid Sterba struct btrfs_fs_info *fs_info = dst->fs_info; 7125de865eeSFilipe David Borba Manana int ret = 0; 7135de865eeSFilipe David Borba Manana struct tree_mod_elem **tm_list = NULL; 7145de865eeSFilipe David Borba Manana struct tree_mod_elem **tm_list_add, **tm_list_rem; 715bd989ba3SJan Schmidt int i; 7165de865eeSFilipe David Borba Manana int locked = 0; 717bd989ba3SJan Schmidt 7185de865eeSFilipe David Borba Manana if (!tree_mod_need_log(fs_info, NULL)) 7195de865eeSFilipe David Borba Manana return 0; 720bd989ba3SJan Schmidt 721c8cc6341SJosef Bacik if (btrfs_header_level(dst) == 0 && btrfs_header_level(src) == 0) 7225de865eeSFilipe David Borba Manana return 0; 7235de865eeSFilipe David Borba Manana 72431e818feSDavid Sterba tm_list = kcalloc(nr_items * 2, sizeof(struct tree_mod_elem *), 7255de865eeSFilipe David Borba Manana GFP_NOFS); 7265de865eeSFilipe David Borba Manana if (!tm_list) 7275de865eeSFilipe David Borba Manana return -ENOMEM; 7285de865eeSFilipe David Borba Manana 7295de865eeSFilipe David Borba Manana tm_list_add = tm_list; 7305de865eeSFilipe David Borba Manana tm_list_rem = tm_list + nr_items; 7315de865eeSFilipe David Borba Manana for (i = 0; i < nr_items; i++) { 7325de865eeSFilipe David Borba Manana tm_list_rem[i] = alloc_tree_mod_elem(src, i + src_offset, 7335de865eeSFilipe David Borba Manana MOD_LOG_KEY_REMOVE, GFP_NOFS); 7345de865eeSFilipe David Borba Manana if (!tm_list_rem[i]) { 7355de865eeSFilipe David Borba Manana ret = -ENOMEM; 7365de865eeSFilipe David Borba Manana goto free_tms; 7375de865eeSFilipe David Borba Manana } 7385de865eeSFilipe David Borba Manana 7395de865eeSFilipe David Borba Manana tm_list_add[i] = alloc_tree_mod_elem(dst, i + dst_offset, 7405de865eeSFilipe David Borba Manana MOD_LOG_KEY_ADD, GFP_NOFS); 7415de865eeSFilipe David Borba Manana if (!tm_list_add[i]) { 7425de865eeSFilipe David Borba Manana ret = -ENOMEM; 7435de865eeSFilipe David Borba Manana goto free_tms; 7445de865eeSFilipe David Borba Manana } 7455de865eeSFilipe David Borba Manana } 7465de865eeSFilipe David Borba Manana 7475de865eeSFilipe David Borba Manana if (tree_mod_dont_log(fs_info, NULL)) 7485de865eeSFilipe David Borba Manana goto free_tms; 7495de865eeSFilipe David Borba Manana locked = 1; 750bd989ba3SJan Schmidt 751bd989ba3SJan Schmidt for (i = 0; i < nr_items; i++) { 7525de865eeSFilipe David Borba Manana ret = __tree_mod_log_insert(fs_info, tm_list_rem[i]); 7535de865eeSFilipe David Borba Manana if (ret) 7545de865eeSFilipe David Borba Manana goto free_tms; 7555de865eeSFilipe David Borba Manana ret = __tree_mod_log_insert(fs_info, tm_list_add[i]); 7565de865eeSFilipe David Borba Manana if (ret) 7575de865eeSFilipe David Borba Manana goto free_tms; 758bd989ba3SJan Schmidt } 7595de865eeSFilipe David Borba Manana 760b1a09f1eSDavid Sterba write_unlock(&fs_info->tree_mod_log_lock); 7615de865eeSFilipe David Borba Manana kfree(tm_list); 7625de865eeSFilipe David Borba Manana 7635de865eeSFilipe David Borba Manana return 0; 7645de865eeSFilipe David Borba Manana 7655de865eeSFilipe David Borba Manana free_tms: 7665de865eeSFilipe David Borba Manana for (i = 0; i < nr_items * 2; i++) { 7675de865eeSFilipe David Borba Manana if (tm_list[i] && !RB_EMPTY_NODE(&tm_list[i]->node)) 7685de865eeSFilipe David Borba Manana rb_erase(&tm_list[i]->node, &fs_info->tree_mod_log); 7695de865eeSFilipe David Borba Manana kfree(tm_list[i]); 7705de865eeSFilipe David Borba Manana } 7715de865eeSFilipe David Borba Manana if (locked) 772b1a09f1eSDavid Sterba write_unlock(&fs_info->tree_mod_log_lock); 7735de865eeSFilipe David Borba Manana kfree(tm_list); 7745de865eeSFilipe David Borba Manana 7755de865eeSFilipe David Borba Manana return ret; 776bd989ba3SJan Schmidt } 777bd989ba3SJan Schmidt 778db7279a2SDavid Sterba static noinline int tree_mod_log_free_eb(struct extent_buffer *eb) 779bd989ba3SJan Schmidt { 7805de865eeSFilipe David Borba Manana struct tree_mod_elem **tm_list = NULL; 7815de865eeSFilipe David Borba Manana int nritems = 0; 7825de865eeSFilipe David Borba Manana int i; 7835de865eeSFilipe David Borba Manana int ret = 0; 7845de865eeSFilipe David Borba Manana 7855de865eeSFilipe David Borba Manana if (btrfs_header_level(eb) == 0) 7865de865eeSFilipe David Borba Manana return 0; 7875de865eeSFilipe David Borba Manana 788db7279a2SDavid Sterba if (!tree_mod_need_log(eb->fs_info, NULL)) 7895de865eeSFilipe David Borba Manana return 0; 7905de865eeSFilipe David Borba Manana 7915de865eeSFilipe David Borba Manana nritems = btrfs_header_nritems(eb); 79231e818feSDavid Sterba tm_list = kcalloc(nritems, sizeof(struct tree_mod_elem *), GFP_NOFS); 7935de865eeSFilipe David Borba Manana if (!tm_list) 7945de865eeSFilipe David Borba Manana return -ENOMEM; 7955de865eeSFilipe David Borba Manana 7965de865eeSFilipe David Borba Manana for (i = 0; i < nritems; i++) { 7975de865eeSFilipe David Borba Manana tm_list[i] = alloc_tree_mod_elem(eb, i, 7985de865eeSFilipe David Borba Manana MOD_LOG_KEY_REMOVE_WHILE_FREEING, GFP_NOFS); 7995de865eeSFilipe David Borba Manana if (!tm_list[i]) { 8005de865eeSFilipe David Borba Manana ret = -ENOMEM; 8015de865eeSFilipe David Borba Manana goto free_tms; 8025de865eeSFilipe David Borba Manana } 8035de865eeSFilipe David Borba Manana } 8045de865eeSFilipe David Borba Manana 805db7279a2SDavid Sterba if (tree_mod_dont_log(eb->fs_info, eb)) 8065de865eeSFilipe David Borba Manana goto free_tms; 8075de865eeSFilipe David Borba Manana 808db7279a2SDavid Sterba ret = __tree_mod_log_free_eb(eb->fs_info, tm_list, nritems); 809b1a09f1eSDavid Sterba write_unlock(&eb->fs_info->tree_mod_log_lock); 8105de865eeSFilipe David Borba Manana if (ret) 8115de865eeSFilipe David Borba Manana goto free_tms; 8125de865eeSFilipe David Borba Manana kfree(tm_list); 8135de865eeSFilipe David Borba Manana 8145de865eeSFilipe David Borba Manana return 0; 8155de865eeSFilipe David Borba Manana 8165de865eeSFilipe David Borba Manana free_tms: 8175de865eeSFilipe David Borba Manana for (i = 0; i < nritems; i++) 8185de865eeSFilipe David Borba Manana kfree(tm_list[i]); 8195de865eeSFilipe David Borba Manana kfree(tm_list); 8205de865eeSFilipe David Borba Manana 8215de865eeSFilipe David Borba Manana return ret; 822bd989ba3SJan Schmidt } 823bd989ba3SJan Schmidt 824d352ac68SChris Mason /* 8255d4f98a2SYan Zheng * check if the tree block can be shared by multiple trees 8265d4f98a2SYan Zheng */ 8275d4f98a2SYan Zheng int btrfs_block_can_be_shared(struct btrfs_root *root, 8285d4f98a2SYan Zheng struct extent_buffer *buf) 8295d4f98a2SYan Zheng { 8305d4f98a2SYan Zheng /* 83192a7cc42SQu Wenruo * Tree blocks not in shareable trees and tree roots are never shared. 83292a7cc42SQu Wenruo * If a block was allocated after the last snapshot and the block was 83392a7cc42SQu Wenruo * not allocated by tree relocation, we know the block is not shared. 8345d4f98a2SYan Zheng */ 83592a7cc42SQu Wenruo if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && 8365d4f98a2SYan Zheng buf != root->node && buf != root->commit_root && 8375d4f98a2SYan Zheng (btrfs_header_generation(buf) <= 8385d4f98a2SYan Zheng btrfs_root_last_snapshot(&root->root_item) || 8395d4f98a2SYan Zheng btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) 8405d4f98a2SYan Zheng return 1; 841a79865c6SNikolay Borisov 8425d4f98a2SYan Zheng return 0; 8435d4f98a2SYan Zheng } 8445d4f98a2SYan Zheng 8455d4f98a2SYan Zheng static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, 8465d4f98a2SYan Zheng struct btrfs_root *root, 8475d4f98a2SYan Zheng struct extent_buffer *buf, 848f0486c68SYan, Zheng struct extent_buffer *cow, 849f0486c68SYan, Zheng int *last_ref) 8505d4f98a2SYan Zheng { 8510b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 8525d4f98a2SYan Zheng u64 refs; 8535d4f98a2SYan Zheng u64 owner; 8545d4f98a2SYan Zheng u64 flags; 8555d4f98a2SYan Zheng u64 new_flags = 0; 8565d4f98a2SYan Zheng int ret; 8575d4f98a2SYan Zheng 8585d4f98a2SYan Zheng /* 8595d4f98a2SYan Zheng * Backrefs update rules: 8605d4f98a2SYan Zheng * 8615d4f98a2SYan Zheng * Always use full backrefs for extent pointers in tree block 8625d4f98a2SYan Zheng * allocated by tree relocation. 8635d4f98a2SYan Zheng * 8645d4f98a2SYan Zheng * If a shared tree block is no longer referenced by its owner 8655d4f98a2SYan Zheng * tree (btrfs_header_owner(buf) == root->root_key.objectid), 8665d4f98a2SYan Zheng * use full backrefs for extent pointers in tree block. 8675d4f98a2SYan Zheng * 8685d4f98a2SYan Zheng * If a tree block is been relocating 8695d4f98a2SYan Zheng * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), 8705d4f98a2SYan Zheng * use full backrefs for extent pointers in tree block. 8715d4f98a2SYan Zheng * The reason for this is some operations (such as drop tree) 8725d4f98a2SYan Zheng * are only allowed for blocks use full backrefs. 8735d4f98a2SYan Zheng */ 8745d4f98a2SYan Zheng 8755d4f98a2SYan Zheng if (btrfs_block_can_be_shared(root, buf)) { 8762ff7e61eSJeff Mahoney ret = btrfs_lookup_extent_info(trans, fs_info, buf->start, 8773173a18fSJosef Bacik btrfs_header_level(buf), 1, 8783173a18fSJosef Bacik &refs, &flags); 879be1a5564SMark Fasheh if (ret) 880be1a5564SMark Fasheh return ret; 881e5df9573SMark Fasheh if (refs == 0) { 882e5df9573SMark Fasheh ret = -EROFS; 8830b246afaSJeff Mahoney btrfs_handle_fs_error(fs_info, ret, NULL); 884e5df9573SMark Fasheh return ret; 885e5df9573SMark Fasheh } 8865d4f98a2SYan Zheng } else { 8875d4f98a2SYan Zheng refs = 1; 8885d4f98a2SYan Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || 8895d4f98a2SYan Zheng btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) 8905d4f98a2SYan Zheng flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; 8915d4f98a2SYan Zheng else 8925d4f98a2SYan Zheng flags = 0; 8935d4f98a2SYan Zheng } 8945d4f98a2SYan Zheng 8955d4f98a2SYan Zheng owner = btrfs_header_owner(buf); 8965d4f98a2SYan Zheng BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && 8975d4f98a2SYan Zheng !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); 8985d4f98a2SYan Zheng 8995d4f98a2SYan Zheng if (refs > 1) { 9005d4f98a2SYan Zheng if ((owner == root->root_key.objectid || 9015d4f98a2SYan Zheng root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && 9025d4f98a2SYan Zheng !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { 903e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, buf, 1); 904692826b2SJeff Mahoney if (ret) 905692826b2SJeff Mahoney return ret; 9065d4f98a2SYan Zheng 9075d4f98a2SYan Zheng if (root->root_key.objectid == 9085d4f98a2SYan Zheng BTRFS_TREE_RELOC_OBJECTID) { 909e339a6b0SJosef Bacik ret = btrfs_dec_ref(trans, root, buf, 0); 910692826b2SJeff Mahoney if (ret) 911692826b2SJeff Mahoney return ret; 912e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 1); 913692826b2SJeff Mahoney if (ret) 914692826b2SJeff Mahoney return ret; 9155d4f98a2SYan Zheng } 9165d4f98a2SYan Zheng new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; 9175d4f98a2SYan Zheng } else { 9185d4f98a2SYan Zheng 9195d4f98a2SYan Zheng if (root->root_key.objectid == 9205d4f98a2SYan Zheng BTRFS_TREE_RELOC_OBJECTID) 921e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 1); 9225d4f98a2SYan Zheng else 923e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 0); 924692826b2SJeff Mahoney if (ret) 925692826b2SJeff Mahoney return ret; 9265d4f98a2SYan Zheng } 9275d4f98a2SYan Zheng if (new_flags != 0) { 928b1c79e09SJosef Bacik int level = btrfs_header_level(buf); 929b1c79e09SJosef Bacik 93042c9d0b5SDavid Sterba ret = btrfs_set_disk_extent_flags(trans, buf, 931b1c79e09SJosef Bacik new_flags, level, 0); 932be1a5564SMark Fasheh if (ret) 933be1a5564SMark Fasheh return ret; 9345d4f98a2SYan Zheng } 9355d4f98a2SYan Zheng } else { 9365d4f98a2SYan Zheng if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { 9375d4f98a2SYan Zheng if (root->root_key.objectid == 9385d4f98a2SYan Zheng BTRFS_TREE_RELOC_OBJECTID) 939e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 1); 9405d4f98a2SYan Zheng else 941e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 0); 942692826b2SJeff Mahoney if (ret) 943692826b2SJeff Mahoney return ret; 944e339a6b0SJosef Bacik ret = btrfs_dec_ref(trans, root, buf, 1); 945692826b2SJeff Mahoney if (ret) 946692826b2SJeff Mahoney return ret; 9475d4f98a2SYan Zheng } 9486a884d7dSDavid Sterba btrfs_clean_tree_block(buf); 949f0486c68SYan, Zheng *last_ref = 1; 9505d4f98a2SYan Zheng } 9515d4f98a2SYan Zheng return 0; 9525d4f98a2SYan Zheng } 9535d4f98a2SYan Zheng 954a6279470SFilipe Manana static struct extent_buffer *alloc_tree_block_no_bg_flush( 955a6279470SFilipe Manana struct btrfs_trans_handle *trans, 956a6279470SFilipe Manana struct btrfs_root *root, 957a6279470SFilipe Manana u64 parent_start, 958a6279470SFilipe Manana const struct btrfs_disk_key *disk_key, 959a6279470SFilipe Manana int level, 960a6279470SFilipe Manana u64 hint, 9619631e4ccSJosef Bacik u64 empty_size, 9629631e4ccSJosef Bacik enum btrfs_lock_nesting nest) 963a6279470SFilipe Manana { 964a6279470SFilipe Manana struct btrfs_fs_info *fs_info = root->fs_info; 965a6279470SFilipe Manana struct extent_buffer *ret; 966a6279470SFilipe Manana 967a6279470SFilipe Manana /* 968a6279470SFilipe Manana * If we are COWing a node/leaf from the extent, chunk, device or free 969a6279470SFilipe Manana * space trees, make sure that we do not finish block group creation of 970a6279470SFilipe Manana * pending block groups. We do this to avoid a deadlock. 971a6279470SFilipe Manana * COWing can result in allocation of a new chunk, and flushing pending 972a6279470SFilipe Manana * block groups (btrfs_create_pending_block_groups()) can be triggered 973a6279470SFilipe Manana * when finishing allocation of a new chunk. Creation of a pending block 974a6279470SFilipe Manana * group modifies the extent, chunk, device and free space trees, 975a6279470SFilipe Manana * therefore we could deadlock with ourselves since we are holding a 976a6279470SFilipe Manana * lock on an extent buffer that btrfs_create_pending_block_groups() may 977a6279470SFilipe Manana * try to COW later. 978a6279470SFilipe Manana * For similar reasons, we also need to delay flushing pending block 979a6279470SFilipe Manana * groups when splitting a leaf or node, from one of those trees, since 980a6279470SFilipe Manana * we are holding a write lock on it and its parent or when inserting a 981a6279470SFilipe Manana * new root node for one of those trees. 982a6279470SFilipe Manana */ 983a6279470SFilipe Manana if (root == fs_info->extent_root || 984a6279470SFilipe Manana root == fs_info->chunk_root || 985a6279470SFilipe Manana root == fs_info->dev_root || 986a6279470SFilipe Manana root == fs_info->free_space_root) 987a6279470SFilipe Manana trans->can_flush_pending_bgs = false; 988a6279470SFilipe Manana 989a6279470SFilipe Manana ret = btrfs_alloc_tree_block(trans, root, parent_start, 990a6279470SFilipe Manana root->root_key.objectid, disk_key, level, 9919631e4ccSJosef Bacik hint, empty_size, nest); 992a6279470SFilipe Manana trans->can_flush_pending_bgs = true; 993a6279470SFilipe Manana 994a6279470SFilipe Manana return ret; 995a6279470SFilipe Manana } 996a6279470SFilipe Manana 9975d4f98a2SYan Zheng /* 998d397712bSChris Mason * does the dirty work in cow of a single block. The parent block (if 999d397712bSChris Mason * supplied) is updated to point to the new cow copy. The new buffer is marked 1000d397712bSChris Mason * dirty and returned locked. If you modify the block it needs to be marked 1001d397712bSChris Mason * dirty again. 1002d352ac68SChris Mason * 1003d352ac68SChris Mason * search_start -- an allocation hint for the new block 1004d352ac68SChris Mason * 1005d397712bSChris Mason * empty_size -- a hint that you plan on doing more cow. This is the size in 1006d397712bSChris Mason * bytes the allocator should try to find free next to the block it returns. 1007d397712bSChris Mason * This is just a hint and may be ignored by the allocator. 1008d352ac68SChris Mason */ 1009d397712bSChris Mason static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, 10105f39d397SChris Mason struct btrfs_root *root, 10115f39d397SChris Mason struct extent_buffer *buf, 10125f39d397SChris Mason struct extent_buffer *parent, int parent_slot, 10135f39d397SChris Mason struct extent_buffer **cow_ret, 10149631e4ccSJosef Bacik u64 search_start, u64 empty_size, 10159631e4ccSJosef Bacik enum btrfs_lock_nesting nest) 10166702ed49SChris Mason { 10170b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 10185d4f98a2SYan Zheng struct btrfs_disk_key disk_key; 10195f39d397SChris Mason struct extent_buffer *cow; 1020be1a5564SMark Fasheh int level, ret; 1021f0486c68SYan, Zheng int last_ref = 0; 1022925baeddSChris Mason int unlock_orig = 0; 10230f5053ebSGoldwyn Rodrigues u64 parent_start = 0; 10246702ed49SChris Mason 1025925baeddSChris Mason if (*cow_ret == buf) 1026925baeddSChris Mason unlock_orig = 1; 1027925baeddSChris Mason 1028b9447ef8SChris Mason btrfs_assert_tree_locked(buf); 1029925baeddSChris Mason 103092a7cc42SQu Wenruo WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && 10310b246afaSJeff Mahoney trans->transid != fs_info->running_transaction->transid); 103292a7cc42SQu Wenruo WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && 103327cdeb70SMiao Xie trans->transid != root->last_trans); 10345f39d397SChris Mason 10357bb86316SChris Mason level = btrfs_header_level(buf); 103631840ae1SZheng Yan 10375d4f98a2SYan Zheng if (level == 0) 10385d4f98a2SYan Zheng btrfs_item_key(buf, &disk_key, 0); 10395d4f98a2SYan Zheng else 10405d4f98a2SYan Zheng btrfs_node_key(buf, &disk_key, 0); 10415d4f98a2SYan Zheng 10420f5053ebSGoldwyn Rodrigues if ((root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && parent) 10435d4f98a2SYan Zheng parent_start = parent->start; 10445d4f98a2SYan Zheng 1045a6279470SFilipe Manana cow = alloc_tree_block_no_bg_flush(trans, root, parent_start, &disk_key, 10469631e4ccSJosef Bacik level, search_start, empty_size, nest); 10476702ed49SChris Mason if (IS_ERR(cow)) 10486702ed49SChris Mason return PTR_ERR(cow); 10496702ed49SChris Mason 1050b4ce94deSChris Mason /* cow is set to blocking by btrfs_init_new_buffer */ 1051b4ce94deSChris Mason 105258e8012cSDavid Sterba copy_extent_buffer_full(cow, buf); 1053db94535dSChris Mason btrfs_set_header_bytenr(cow, cow->start); 10545f39d397SChris Mason btrfs_set_header_generation(cow, trans->transid); 10555d4f98a2SYan Zheng btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); 10565d4f98a2SYan Zheng btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | 10575d4f98a2SYan Zheng BTRFS_HEADER_FLAG_RELOC); 10585d4f98a2SYan Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) 10595d4f98a2SYan Zheng btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); 10605d4f98a2SYan Zheng else 10615f39d397SChris Mason btrfs_set_header_owner(cow, root->root_key.objectid); 10626702ed49SChris Mason 1063de37aa51SNikolay Borisov write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); 10642b82032cSYan Zheng 1065be1a5564SMark Fasheh ret = update_ref_for_cow(trans, root, buf, cow, &last_ref); 1066b68dc2a9SMark Fasheh if (ret) { 1067572c83acSJosef Bacik btrfs_tree_unlock(cow); 1068572c83acSJosef Bacik free_extent_buffer(cow); 106966642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 1070b68dc2a9SMark Fasheh return ret; 1071b68dc2a9SMark Fasheh } 10721a40e23bSZheng Yan 107392a7cc42SQu Wenruo if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) { 107483d4cfd4SJosef Bacik ret = btrfs_reloc_cow_block(trans, root, buf, cow); 107593314e3bSZhaolei if (ret) { 1076572c83acSJosef Bacik btrfs_tree_unlock(cow); 1077572c83acSJosef Bacik free_extent_buffer(cow); 107866642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 107983d4cfd4SJosef Bacik return ret; 108083d4cfd4SJosef Bacik } 108193314e3bSZhaolei } 10823fd0a558SYan, Zheng 10836702ed49SChris Mason if (buf == root->node) { 1084925baeddSChris Mason WARN_ON(parent && parent != buf); 10855d4f98a2SYan Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || 10865d4f98a2SYan Zheng btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) 10875d4f98a2SYan Zheng parent_start = buf->start; 1088925baeddSChris Mason 108967439dadSDavid Sterba atomic_inc(&cow->refs); 1090d9d19a01SDavid Sterba ret = tree_mod_log_insert_root(root->node, cow, 1); 1091d9d19a01SDavid Sterba BUG_ON(ret < 0); 1092240f62c8SChris Mason rcu_assign_pointer(root->node, cow); 1093925baeddSChris Mason 1094f0486c68SYan, Zheng btrfs_free_tree_block(trans, root, buf, parent_start, 10955581a51aSJan Schmidt last_ref); 10965f39d397SChris Mason free_extent_buffer(buf); 10970b86a832SChris Mason add_root_to_dirty_list(root); 10986702ed49SChris Mason } else { 10995d4f98a2SYan Zheng WARN_ON(trans->transid != btrfs_header_generation(parent)); 1100e09c2efeSDavid Sterba tree_mod_log_insert_key(parent, parent_slot, 1101c8cc6341SJosef Bacik MOD_LOG_KEY_REPLACE, GFP_NOFS); 11025f39d397SChris Mason btrfs_set_node_blockptr(parent, parent_slot, 1103db94535dSChris Mason cow->start); 110474493f7aSChris Mason btrfs_set_node_ptr_generation(parent, parent_slot, 110574493f7aSChris Mason trans->transid); 11066702ed49SChris Mason btrfs_mark_buffer_dirty(parent); 11075de865eeSFilipe David Borba Manana if (last_ref) { 1108db7279a2SDavid Sterba ret = tree_mod_log_free_eb(buf); 11095de865eeSFilipe David Borba Manana if (ret) { 1110572c83acSJosef Bacik btrfs_tree_unlock(cow); 1111572c83acSJosef Bacik free_extent_buffer(cow); 111266642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 11135de865eeSFilipe David Borba Manana return ret; 11145de865eeSFilipe David Borba Manana } 11155de865eeSFilipe David Borba Manana } 1116f0486c68SYan, Zheng btrfs_free_tree_block(trans, root, buf, parent_start, 11175581a51aSJan Schmidt last_ref); 11186702ed49SChris Mason } 1119925baeddSChris Mason if (unlock_orig) 1120925baeddSChris Mason btrfs_tree_unlock(buf); 11213083ee2eSJosef Bacik free_extent_buffer_stale(buf); 11226702ed49SChris Mason btrfs_mark_buffer_dirty(cow); 11236702ed49SChris Mason *cow_ret = cow; 11246702ed49SChris Mason return 0; 11256702ed49SChris Mason } 11266702ed49SChris Mason 11275d9e75c4SJan Schmidt /* 11285d9e75c4SJan Schmidt * returns the logical address of the oldest predecessor of the given root. 11295d9e75c4SJan Schmidt * entries older than time_seq are ignored. 11305d9e75c4SJan Schmidt */ 1131bcd24dabSDavid Sterba static struct tree_mod_elem *__tree_mod_log_oldest_root( 113230b0463aSJan Schmidt struct extent_buffer *eb_root, u64 time_seq) 11335d9e75c4SJan Schmidt { 11345d9e75c4SJan Schmidt struct tree_mod_elem *tm; 11355d9e75c4SJan Schmidt struct tree_mod_elem *found = NULL; 113630b0463aSJan Schmidt u64 root_logical = eb_root->start; 11375d9e75c4SJan Schmidt int looped = 0; 11385d9e75c4SJan Schmidt 11395d9e75c4SJan Schmidt if (!time_seq) 114035a3621bSStefan Behrens return NULL; 11415d9e75c4SJan Schmidt 11425d9e75c4SJan Schmidt /* 1143298cfd36SChandan Rajendra * the very last operation that's logged for a root is the 1144298cfd36SChandan Rajendra * replacement operation (if it is replaced at all). this has 1145298cfd36SChandan Rajendra * the logical address of the *new* root, making it the very 1146298cfd36SChandan Rajendra * first operation that's logged for this root. 11475d9e75c4SJan Schmidt */ 11485d9e75c4SJan Schmidt while (1) { 1149bcd24dabSDavid Sterba tm = tree_mod_log_search_oldest(eb_root->fs_info, root_logical, 11505d9e75c4SJan Schmidt time_seq); 11515d9e75c4SJan Schmidt if (!looped && !tm) 115235a3621bSStefan Behrens return NULL; 11535d9e75c4SJan Schmidt /* 115428da9fb4SJan Schmidt * if there are no tree operation for the oldest root, we simply 115528da9fb4SJan Schmidt * return it. this should only happen if that (old) root is at 115628da9fb4SJan Schmidt * level 0. 11575d9e75c4SJan Schmidt */ 115828da9fb4SJan Schmidt if (!tm) 115928da9fb4SJan Schmidt break; 11605d9e75c4SJan Schmidt 116128da9fb4SJan Schmidt /* 116228da9fb4SJan Schmidt * if there's an operation that's not a root replacement, we 116328da9fb4SJan Schmidt * found the oldest version of our root. normally, we'll find a 116428da9fb4SJan Schmidt * MOD_LOG_KEY_REMOVE_WHILE_FREEING operation here. 116528da9fb4SJan Schmidt */ 11665d9e75c4SJan Schmidt if (tm->op != MOD_LOG_ROOT_REPLACE) 11675d9e75c4SJan Schmidt break; 11685d9e75c4SJan Schmidt 11695d9e75c4SJan Schmidt found = tm; 11705d9e75c4SJan Schmidt root_logical = tm->old_root.logical; 11715d9e75c4SJan Schmidt looped = 1; 11725d9e75c4SJan Schmidt } 11735d9e75c4SJan Schmidt 1174a95236d9SJan Schmidt /* if there's no old root to return, return what we found instead */ 1175a95236d9SJan Schmidt if (!found) 1176a95236d9SJan Schmidt found = tm; 1177a95236d9SJan Schmidt 11785d9e75c4SJan Schmidt return found; 11795d9e75c4SJan Schmidt } 11805d9e75c4SJan Schmidt 11815d9e75c4SJan Schmidt /* 11825d9e75c4SJan Schmidt * tm is a pointer to the first operation to rewind within eb. then, all 118301327610SNicholas D Steeves * previous operations will be rewound (until we reach something older than 11845d9e75c4SJan Schmidt * time_seq). 11855d9e75c4SJan Schmidt */ 11865d9e75c4SJan Schmidt static void 1187f1ca7e98SJosef Bacik __tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, 1188f1ca7e98SJosef Bacik u64 time_seq, struct tree_mod_elem *first_tm) 11895d9e75c4SJan Schmidt { 11905d9e75c4SJan Schmidt u32 n; 11915d9e75c4SJan Schmidt struct rb_node *next; 11925d9e75c4SJan Schmidt struct tree_mod_elem *tm = first_tm; 11935d9e75c4SJan Schmidt unsigned long o_dst; 11945d9e75c4SJan Schmidt unsigned long o_src; 11955d9e75c4SJan Schmidt unsigned long p_size = sizeof(struct btrfs_key_ptr); 11965d9e75c4SJan Schmidt 11975d9e75c4SJan Schmidt n = btrfs_header_nritems(eb); 1198b1a09f1eSDavid Sterba read_lock(&fs_info->tree_mod_log_lock); 1199097b8a7cSJan Schmidt while (tm && tm->seq >= time_seq) { 12005d9e75c4SJan Schmidt /* 12015d9e75c4SJan Schmidt * all the operations are recorded with the operator used for 12025d9e75c4SJan Schmidt * the modification. as we're going backwards, we do the 12035d9e75c4SJan Schmidt * opposite of each operation here. 12045d9e75c4SJan Schmidt */ 12055d9e75c4SJan Schmidt switch (tm->op) { 12065d9e75c4SJan Schmidt case MOD_LOG_KEY_REMOVE_WHILE_FREEING: 12075d9e75c4SJan Schmidt BUG_ON(tm->slot < n); 1208c730ae0cSMarcos Paulo de Souza fallthrough; 120995c80bb1SLiu Bo case MOD_LOG_KEY_REMOVE_WHILE_MOVING: 12104c3e6969SChris Mason case MOD_LOG_KEY_REMOVE: 12115d9e75c4SJan Schmidt btrfs_set_node_key(eb, &tm->key, tm->slot); 12125d9e75c4SJan Schmidt btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr); 12135d9e75c4SJan Schmidt btrfs_set_node_ptr_generation(eb, tm->slot, 12145d9e75c4SJan Schmidt tm->generation); 12154c3e6969SChris Mason n++; 12165d9e75c4SJan Schmidt break; 12175d9e75c4SJan Schmidt case MOD_LOG_KEY_REPLACE: 12185d9e75c4SJan Schmidt BUG_ON(tm->slot >= n); 12195d9e75c4SJan Schmidt btrfs_set_node_key(eb, &tm->key, tm->slot); 12205d9e75c4SJan Schmidt btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr); 12215d9e75c4SJan Schmidt btrfs_set_node_ptr_generation(eb, tm->slot, 12225d9e75c4SJan Schmidt tm->generation); 12235d9e75c4SJan Schmidt break; 12245d9e75c4SJan Schmidt case MOD_LOG_KEY_ADD: 122519956c7eSJan Schmidt /* if a move operation is needed it's in the log */ 12265d9e75c4SJan Schmidt n--; 12275d9e75c4SJan Schmidt break; 12285d9e75c4SJan Schmidt case MOD_LOG_MOVE_KEYS: 1229c3193108SJan Schmidt o_dst = btrfs_node_key_ptr_offset(tm->slot); 1230c3193108SJan Schmidt o_src = btrfs_node_key_ptr_offset(tm->move.dst_slot); 1231c3193108SJan Schmidt memmove_extent_buffer(eb, o_dst, o_src, 12325d9e75c4SJan Schmidt tm->move.nr_items * p_size); 12335d9e75c4SJan Schmidt break; 12345d9e75c4SJan Schmidt case MOD_LOG_ROOT_REPLACE: 12355d9e75c4SJan Schmidt /* 12365d9e75c4SJan Schmidt * this operation is special. for roots, this must be 12375d9e75c4SJan Schmidt * handled explicitly before rewinding. 12385d9e75c4SJan Schmidt * for non-roots, this operation may exist if the node 12395d9e75c4SJan Schmidt * was a root: root A -> child B; then A gets empty and 12405d9e75c4SJan Schmidt * B is promoted to the new root. in the mod log, we'll 12415d9e75c4SJan Schmidt * have a root-replace operation for B, a tree block 12425d9e75c4SJan Schmidt * that is no root. we simply ignore that operation. 12435d9e75c4SJan Schmidt */ 12445d9e75c4SJan Schmidt break; 12455d9e75c4SJan Schmidt } 12465d9e75c4SJan Schmidt next = rb_next(&tm->node); 12475d9e75c4SJan Schmidt if (!next) 12485d9e75c4SJan Schmidt break; 12496b4df8b6SGeliang Tang tm = rb_entry(next, struct tree_mod_elem, node); 1250298cfd36SChandan Rajendra if (tm->logical != first_tm->logical) 12515d9e75c4SJan Schmidt break; 12525d9e75c4SJan Schmidt } 1253b1a09f1eSDavid Sterba read_unlock(&fs_info->tree_mod_log_lock); 12545d9e75c4SJan Schmidt btrfs_set_header_nritems(eb, n); 12555d9e75c4SJan Schmidt } 12565d9e75c4SJan Schmidt 125747fb091fSJan Schmidt /* 125801327610SNicholas D Steeves * Called with eb read locked. If the buffer cannot be rewound, the same buffer 125947fb091fSJan Schmidt * is returned. If rewind operations happen, a fresh buffer is returned. The 126047fb091fSJan Schmidt * returned buffer is always read-locked. If the returned buffer is not the 126147fb091fSJan Schmidt * input buffer, the lock on the input buffer is released and the input buffer 126247fb091fSJan Schmidt * is freed (its refcount is decremented). 126347fb091fSJan Schmidt */ 12645d9e75c4SJan Schmidt static struct extent_buffer * 12659ec72677SJosef Bacik tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct btrfs_path *path, 12669ec72677SJosef Bacik struct extent_buffer *eb, u64 time_seq) 12675d9e75c4SJan Schmidt { 12685d9e75c4SJan Schmidt struct extent_buffer *eb_rewin; 12695d9e75c4SJan Schmidt struct tree_mod_elem *tm; 12705d9e75c4SJan Schmidt 12715d9e75c4SJan Schmidt if (!time_seq) 12725d9e75c4SJan Schmidt return eb; 12735d9e75c4SJan Schmidt 12745d9e75c4SJan Schmidt if (btrfs_header_level(eb) == 0) 12755d9e75c4SJan Schmidt return eb; 12765d9e75c4SJan Schmidt 12775d9e75c4SJan Schmidt tm = tree_mod_log_search(fs_info, eb->start, time_seq); 12785d9e75c4SJan Schmidt if (!tm) 12795d9e75c4SJan Schmidt return eb; 12805d9e75c4SJan Schmidt 12815d9e75c4SJan Schmidt if (tm->op == MOD_LOG_KEY_REMOVE_WHILE_FREEING) { 12825d9e75c4SJan Schmidt BUG_ON(tm->slot != 0); 1283da17066cSJeff Mahoney eb_rewin = alloc_dummy_extent_buffer(fs_info, eb->start); 1284db7f3436SJosef Bacik if (!eb_rewin) { 1285ac5887c8SJosef Bacik btrfs_tree_read_unlock(eb); 1286db7f3436SJosef Bacik free_extent_buffer(eb); 1287db7f3436SJosef Bacik return NULL; 1288db7f3436SJosef Bacik } 12895d9e75c4SJan Schmidt btrfs_set_header_bytenr(eb_rewin, eb->start); 12905d9e75c4SJan Schmidt btrfs_set_header_backref_rev(eb_rewin, 12915d9e75c4SJan Schmidt btrfs_header_backref_rev(eb)); 12925d9e75c4SJan Schmidt btrfs_set_header_owner(eb_rewin, btrfs_header_owner(eb)); 1293c3193108SJan Schmidt btrfs_set_header_level(eb_rewin, btrfs_header_level(eb)); 12945d9e75c4SJan Schmidt } else { 12955d9e75c4SJan Schmidt eb_rewin = btrfs_clone_extent_buffer(eb); 1296db7f3436SJosef Bacik if (!eb_rewin) { 1297ac5887c8SJosef Bacik btrfs_tree_read_unlock(eb); 1298db7f3436SJosef Bacik free_extent_buffer(eb); 1299db7f3436SJosef Bacik return NULL; 1300db7f3436SJosef Bacik } 13015d9e75c4SJan Schmidt } 13025d9e75c4SJan Schmidt 1303ac5887c8SJosef Bacik btrfs_tree_read_unlock(eb); 13045d9e75c4SJan Schmidt free_extent_buffer(eb); 13055d9e75c4SJan Schmidt 1306d3beaa25SJosef Bacik btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb_rewin), 1307d3beaa25SJosef Bacik eb_rewin, btrfs_header_level(eb_rewin)); 130847fb091fSJan Schmidt btrfs_tree_read_lock(eb_rewin); 1309f1ca7e98SJosef Bacik __tree_mod_log_rewind(fs_info, eb_rewin, time_seq, tm); 131057911b8bSJan Schmidt WARN_ON(btrfs_header_nritems(eb_rewin) > 1311da17066cSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info)); 13125d9e75c4SJan Schmidt 13135d9e75c4SJan Schmidt return eb_rewin; 13145d9e75c4SJan Schmidt } 13155d9e75c4SJan Schmidt 13168ba97a15SJan Schmidt /* 13178ba97a15SJan Schmidt * get_old_root() rewinds the state of @root's root node to the given @time_seq 13188ba97a15SJan Schmidt * value. If there are no changes, the current root->root_node is returned. If 13198ba97a15SJan Schmidt * anything changed in between, there's a fresh buffer allocated on which the 13208ba97a15SJan Schmidt * rewind operations are done. In any case, the returned buffer is read locked. 13218ba97a15SJan Schmidt * Returns NULL on error (with no locks held). 13228ba97a15SJan Schmidt */ 13235d9e75c4SJan Schmidt static inline struct extent_buffer * 13245d9e75c4SJan Schmidt get_old_root(struct btrfs_root *root, u64 time_seq) 13255d9e75c4SJan Schmidt { 13260b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 13275d9e75c4SJan Schmidt struct tree_mod_elem *tm; 132830b0463aSJan Schmidt struct extent_buffer *eb = NULL; 132930b0463aSJan Schmidt struct extent_buffer *eb_root; 1330efad8a85SFilipe Manana u64 eb_root_owner = 0; 13317bfdcf7fSLiu Bo struct extent_buffer *old; 1332a95236d9SJan Schmidt struct tree_mod_root *old_root = NULL; 13334325edd0SChris Mason u64 old_generation = 0; 1334a95236d9SJan Schmidt u64 logical; 1335581c1760SQu Wenruo int level; 13365d9e75c4SJan Schmidt 133730b0463aSJan Schmidt eb_root = btrfs_read_lock_root_node(root); 1338bcd24dabSDavid Sterba tm = __tree_mod_log_oldest_root(eb_root, time_seq); 13395d9e75c4SJan Schmidt if (!tm) 134030b0463aSJan Schmidt return eb_root; 13415d9e75c4SJan Schmidt 1342a95236d9SJan Schmidt if (tm->op == MOD_LOG_ROOT_REPLACE) { 13435d9e75c4SJan Schmidt old_root = &tm->old_root; 13445d9e75c4SJan Schmidt old_generation = tm->generation; 1345a95236d9SJan Schmidt logical = old_root->logical; 1346581c1760SQu Wenruo level = old_root->level; 1347a95236d9SJan Schmidt } else { 134830b0463aSJan Schmidt logical = eb_root->start; 1349581c1760SQu Wenruo level = btrfs_header_level(eb_root); 1350a95236d9SJan Schmidt } 13515d9e75c4SJan Schmidt 13520b246afaSJeff Mahoney tm = tree_mod_log_search(fs_info, logical, time_seq); 1353834328a8SJan Schmidt if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) { 135430b0463aSJan Schmidt btrfs_tree_read_unlock(eb_root); 135530b0463aSJan Schmidt free_extent_buffer(eb_root); 1356581c1760SQu Wenruo old = read_tree_block(fs_info, logical, 0, level, NULL); 135764c043deSLiu Bo if (WARN_ON(IS_ERR(old) || !extent_buffer_uptodate(old))) { 135864c043deSLiu Bo if (!IS_ERR(old)) 1359416bc658SJosef Bacik free_extent_buffer(old); 13600b246afaSJeff Mahoney btrfs_warn(fs_info, 13610b246afaSJeff Mahoney "failed to read tree block %llu from get_old_root", 13620b246afaSJeff Mahoney logical); 1363834328a8SJan Schmidt } else { 13647bfdcf7fSLiu Bo eb = btrfs_clone_extent_buffer(old); 13657bfdcf7fSLiu Bo free_extent_buffer(old); 1366834328a8SJan Schmidt } 1367834328a8SJan Schmidt } else if (old_root) { 1368efad8a85SFilipe Manana eb_root_owner = btrfs_header_owner(eb_root); 136930b0463aSJan Schmidt btrfs_tree_read_unlock(eb_root); 137030b0463aSJan Schmidt free_extent_buffer(eb_root); 13710b246afaSJeff Mahoney eb = alloc_dummy_extent_buffer(fs_info, logical); 1372834328a8SJan Schmidt } else { 137330b0463aSJan Schmidt eb = btrfs_clone_extent_buffer(eb_root); 1374ac5887c8SJosef Bacik btrfs_tree_read_unlock(eb_root); 137530b0463aSJan Schmidt free_extent_buffer(eb_root); 1376834328a8SJan Schmidt } 1377834328a8SJan Schmidt 13788ba97a15SJan Schmidt if (!eb) 13798ba97a15SJan Schmidt return NULL; 1380a95236d9SJan Schmidt if (old_root) { 13815d9e75c4SJan Schmidt btrfs_set_header_bytenr(eb, eb->start); 13825d9e75c4SJan Schmidt btrfs_set_header_backref_rev(eb, BTRFS_MIXED_BACKREF_REV); 1383efad8a85SFilipe Manana btrfs_set_header_owner(eb, eb_root_owner); 13845d9e75c4SJan Schmidt btrfs_set_header_level(eb, old_root->level); 13855d9e75c4SJan Schmidt btrfs_set_header_generation(eb, old_generation); 1386a95236d9SJan Schmidt } 1387d3beaa25SJosef Bacik btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb), eb, 1388d3beaa25SJosef Bacik btrfs_header_level(eb)); 1389d3beaa25SJosef Bacik btrfs_tree_read_lock(eb); 139028da9fb4SJan Schmidt if (tm) 13910b246afaSJeff Mahoney __tree_mod_log_rewind(fs_info, eb, time_seq, tm); 139228da9fb4SJan Schmidt else 139328da9fb4SJan Schmidt WARN_ON(btrfs_header_level(eb) != 0); 13940b246afaSJeff Mahoney WARN_ON(btrfs_header_nritems(eb) > BTRFS_NODEPTRS_PER_BLOCK(fs_info)); 13955d9e75c4SJan Schmidt 13965d9e75c4SJan Schmidt return eb; 13975d9e75c4SJan Schmidt } 13985d9e75c4SJan Schmidt 13995b6602e7SJan Schmidt int btrfs_old_root_level(struct btrfs_root *root, u64 time_seq) 14005b6602e7SJan Schmidt { 14015b6602e7SJan Schmidt struct tree_mod_elem *tm; 14025b6602e7SJan Schmidt int level; 140330b0463aSJan Schmidt struct extent_buffer *eb_root = btrfs_root_node(root); 14045b6602e7SJan Schmidt 1405bcd24dabSDavid Sterba tm = __tree_mod_log_oldest_root(eb_root, time_seq); 14065b6602e7SJan Schmidt if (tm && tm->op == MOD_LOG_ROOT_REPLACE) { 14075b6602e7SJan Schmidt level = tm->old_root.level; 14085b6602e7SJan Schmidt } else { 140930b0463aSJan Schmidt level = btrfs_header_level(eb_root); 14105b6602e7SJan Schmidt } 141130b0463aSJan Schmidt free_extent_buffer(eb_root); 14125b6602e7SJan Schmidt 14135b6602e7SJan Schmidt return level; 14145b6602e7SJan Schmidt } 14155b6602e7SJan Schmidt 14165d4f98a2SYan Zheng static inline int should_cow_block(struct btrfs_trans_handle *trans, 14175d4f98a2SYan Zheng struct btrfs_root *root, 14185d4f98a2SYan Zheng struct extent_buffer *buf) 14195d4f98a2SYan Zheng { 1420f5ee5c9aSJeff Mahoney if (btrfs_is_testing(root->fs_info)) 1421faa2dbf0SJosef Bacik return 0; 1422fccb84c9SDavid Sterba 1423d1980131SDavid Sterba /* Ensure we can see the FORCE_COW bit */ 1424d1980131SDavid Sterba smp_mb__before_atomic(); 1425f1ebcc74SLiu Bo 1426f1ebcc74SLiu Bo /* 1427f1ebcc74SLiu Bo * We do not need to cow a block if 1428f1ebcc74SLiu Bo * 1) this block is not created or changed in this transaction; 1429f1ebcc74SLiu Bo * 2) this block does not belong to TREE_RELOC tree; 1430f1ebcc74SLiu Bo * 3) the root is not forced COW. 1431f1ebcc74SLiu Bo * 1432f1ebcc74SLiu Bo * What is forced COW: 143301327610SNicholas D Steeves * when we create snapshot during committing the transaction, 143452042d8eSAndrea Gelmini * after we've finished copying src root, we must COW the shared 1435f1ebcc74SLiu Bo * block to ensure the metadata consistency. 1436f1ebcc74SLiu Bo */ 14375d4f98a2SYan Zheng if (btrfs_header_generation(buf) == trans->transid && 14385d4f98a2SYan Zheng !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && 14395d4f98a2SYan Zheng !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && 1440f1ebcc74SLiu Bo btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && 144127cdeb70SMiao Xie !test_bit(BTRFS_ROOT_FORCE_COW, &root->state)) 14425d4f98a2SYan Zheng return 0; 14435d4f98a2SYan Zheng return 1; 14445d4f98a2SYan Zheng } 14455d4f98a2SYan Zheng 1446d352ac68SChris Mason /* 1447d352ac68SChris Mason * cows a single block, see __btrfs_cow_block for the real work. 144801327610SNicholas D Steeves * This version of it has extra checks so that a block isn't COWed more than 1449d352ac68SChris Mason * once per transaction, as long as it hasn't been written yet 1450d352ac68SChris Mason */ 1451d397712bSChris Mason noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, 14525f39d397SChris Mason struct btrfs_root *root, struct extent_buffer *buf, 14535f39d397SChris Mason struct extent_buffer *parent, int parent_slot, 14549631e4ccSJosef Bacik struct extent_buffer **cow_ret, 14559631e4ccSJosef Bacik enum btrfs_lock_nesting nest) 145602217ed2SChris Mason { 14570b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 14586702ed49SChris Mason u64 search_start; 1459f510cfecSChris Mason int ret; 1460dc17ff8fSChris Mason 146183354f07SJosef Bacik if (test_bit(BTRFS_ROOT_DELETING, &root->state)) 146283354f07SJosef Bacik btrfs_err(fs_info, 146383354f07SJosef Bacik "COW'ing blocks on a fs root that's being dropped"); 146483354f07SJosef Bacik 14650b246afaSJeff Mahoney if (trans->transaction != fs_info->running_transaction) 146631b1a2bdSJulia Lawall WARN(1, KERN_CRIT "trans %llu running %llu\n", 1467c1c9ff7cSGeert Uytterhoeven trans->transid, 14680b246afaSJeff Mahoney fs_info->running_transaction->transid); 146931b1a2bdSJulia Lawall 14700b246afaSJeff Mahoney if (trans->transid != fs_info->generation) 147131b1a2bdSJulia Lawall WARN(1, KERN_CRIT "trans %llu running %llu\n", 14720b246afaSJeff Mahoney trans->transid, fs_info->generation); 1473dc17ff8fSChris Mason 14745d4f98a2SYan Zheng if (!should_cow_block(trans, root, buf)) { 147564c12921SJeff Mahoney trans->dirty = true; 147602217ed2SChris Mason *cow_ret = buf; 147702217ed2SChris Mason return 0; 147802217ed2SChris Mason } 1479c487685dSChris Mason 1480ee22184bSByongho Lee search_start = buf->start & ~((u64)SZ_1G - 1); 1481b4ce94deSChris Mason 1482f616f5cdSQu Wenruo /* 1483f616f5cdSQu Wenruo * Before CoWing this block for later modification, check if it's 1484f616f5cdSQu Wenruo * the subtree root and do the delayed subtree trace if needed. 1485f616f5cdSQu Wenruo * 1486f616f5cdSQu Wenruo * Also We don't care about the error, as it's handled internally. 1487f616f5cdSQu Wenruo */ 1488f616f5cdSQu Wenruo btrfs_qgroup_trace_subtree_after_cow(trans, root, buf); 1489f510cfecSChris Mason ret = __btrfs_cow_block(trans, root, buf, parent, 14909631e4ccSJosef Bacik parent_slot, cow_ret, search_start, 0, nest); 14911abe9b8aSliubo 14921abe9b8aSliubo trace_btrfs_cow_block(root, buf, *cow_ret); 14931abe9b8aSliubo 1494f510cfecSChris Mason return ret; 14952c90e5d6SChris Mason } 14966702ed49SChris Mason 1497d352ac68SChris Mason /* 1498d352ac68SChris Mason * helper function for defrag to decide if two blocks pointed to by a 1499d352ac68SChris Mason * node are actually close by 1500d352ac68SChris Mason */ 15016b80053dSChris Mason static int close_blocks(u64 blocknr, u64 other, u32 blocksize) 15026702ed49SChris Mason { 15036b80053dSChris Mason if (blocknr < other && other - (blocknr + blocksize) < 32768) 15046702ed49SChris Mason return 1; 15056b80053dSChris Mason if (blocknr > other && blocknr - (other + blocksize) < 32768) 15066702ed49SChris Mason return 1; 150702217ed2SChris Mason return 0; 150802217ed2SChris Mason } 150902217ed2SChris Mason 1510ce6ef5abSDavid Sterba #ifdef __LITTLE_ENDIAN 1511ce6ef5abSDavid Sterba 1512ce6ef5abSDavid Sterba /* 1513ce6ef5abSDavid Sterba * Compare two keys, on little-endian the disk order is same as CPU order and 1514ce6ef5abSDavid Sterba * we can avoid the conversion. 1515ce6ef5abSDavid Sterba */ 1516ce6ef5abSDavid Sterba static int comp_keys(const struct btrfs_disk_key *disk_key, 1517ce6ef5abSDavid Sterba const struct btrfs_key *k2) 1518ce6ef5abSDavid Sterba { 1519ce6ef5abSDavid Sterba const struct btrfs_key *k1 = (const struct btrfs_key *)disk_key; 1520ce6ef5abSDavid Sterba 1521ce6ef5abSDavid Sterba return btrfs_comp_cpu_keys(k1, k2); 1522ce6ef5abSDavid Sterba } 1523ce6ef5abSDavid Sterba 1524ce6ef5abSDavid Sterba #else 1525ce6ef5abSDavid Sterba 1526081e9573SChris Mason /* 1527081e9573SChris Mason * compare two keys in a memcmp fashion 1528081e9573SChris Mason */ 1529310712b2SOmar Sandoval static int comp_keys(const struct btrfs_disk_key *disk, 1530310712b2SOmar Sandoval const struct btrfs_key *k2) 1531081e9573SChris Mason { 1532081e9573SChris Mason struct btrfs_key k1; 1533081e9573SChris Mason 1534081e9573SChris Mason btrfs_disk_key_to_cpu(&k1, disk); 1535081e9573SChris Mason 153620736abaSDiego Calleja return btrfs_comp_cpu_keys(&k1, k2); 1537081e9573SChris Mason } 1538ce6ef5abSDavid Sterba #endif 1539081e9573SChris Mason 1540f3465ca4SJosef Bacik /* 1541f3465ca4SJosef Bacik * same as comp_keys only with two btrfs_key's 1542f3465ca4SJosef Bacik */ 1543e1f60a65SDavid Sterba int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2) 1544f3465ca4SJosef Bacik { 1545f3465ca4SJosef Bacik if (k1->objectid > k2->objectid) 1546f3465ca4SJosef Bacik return 1; 1547f3465ca4SJosef Bacik if (k1->objectid < k2->objectid) 1548f3465ca4SJosef Bacik return -1; 1549f3465ca4SJosef Bacik if (k1->type > k2->type) 1550f3465ca4SJosef Bacik return 1; 1551f3465ca4SJosef Bacik if (k1->type < k2->type) 1552f3465ca4SJosef Bacik return -1; 1553f3465ca4SJosef Bacik if (k1->offset > k2->offset) 1554f3465ca4SJosef Bacik return 1; 1555f3465ca4SJosef Bacik if (k1->offset < k2->offset) 1556f3465ca4SJosef Bacik return -1; 1557f3465ca4SJosef Bacik return 0; 1558f3465ca4SJosef Bacik } 1559081e9573SChris Mason 1560d352ac68SChris Mason /* 1561d352ac68SChris Mason * this is used by the defrag code to go through all the 1562d352ac68SChris Mason * leaves pointed to by a node and reallocate them so that 1563d352ac68SChris Mason * disk order is close to key order 1564d352ac68SChris Mason */ 15656702ed49SChris Mason int btrfs_realloc_node(struct btrfs_trans_handle *trans, 15665f39d397SChris Mason struct btrfs_root *root, struct extent_buffer *parent, 1567de78b51aSEric Sandeen int start_slot, u64 *last_ret, 1568a6b6e75eSChris Mason struct btrfs_key *progress) 15696702ed49SChris Mason { 15700b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 15716b80053dSChris Mason struct extent_buffer *cur; 15726702ed49SChris Mason u64 blocknr; 1573e9d0b13bSChris Mason u64 search_start = *last_ret; 1574e9d0b13bSChris Mason u64 last_block = 0; 15756702ed49SChris Mason u64 other; 15766702ed49SChris Mason u32 parent_nritems; 15776702ed49SChris Mason int end_slot; 15786702ed49SChris Mason int i; 15796702ed49SChris Mason int err = 0; 15806b80053dSChris Mason u32 blocksize; 1581081e9573SChris Mason int progress_passed = 0; 1582081e9573SChris Mason struct btrfs_disk_key disk_key; 15836702ed49SChris Mason 15840b246afaSJeff Mahoney WARN_ON(trans->transaction != fs_info->running_transaction); 15850b246afaSJeff Mahoney WARN_ON(trans->transid != fs_info->generation); 158686479a04SChris Mason 15876b80053dSChris Mason parent_nritems = btrfs_header_nritems(parent); 15880b246afaSJeff Mahoney blocksize = fs_info->nodesize; 15895dfe2be7SFilipe Manana end_slot = parent_nritems - 1; 15906702ed49SChris Mason 15915dfe2be7SFilipe Manana if (parent_nritems <= 1) 15926702ed49SChris Mason return 0; 15936702ed49SChris Mason 15945dfe2be7SFilipe Manana for (i = start_slot; i <= end_slot; i++) { 15956702ed49SChris Mason int close = 1; 1596a6b6e75eSChris Mason 1597081e9573SChris Mason btrfs_node_key(parent, &disk_key, i); 1598081e9573SChris Mason if (!progress_passed && comp_keys(&disk_key, progress) < 0) 1599081e9573SChris Mason continue; 1600081e9573SChris Mason 1601081e9573SChris Mason progress_passed = 1; 16026b80053dSChris Mason blocknr = btrfs_node_blockptr(parent, i); 1603e9d0b13bSChris Mason if (last_block == 0) 1604e9d0b13bSChris Mason last_block = blocknr; 16055708b959SChris Mason 16066702ed49SChris Mason if (i > 0) { 16076b80053dSChris Mason other = btrfs_node_blockptr(parent, i - 1); 16086b80053dSChris Mason close = close_blocks(blocknr, other, blocksize); 16096702ed49SChris Mason } 16105dfe2be7SFilipe Manana if (!close && i < end_slot) { 16116b80053dSChris Mason other = btrfs_node_blockptr(parent, i + 1); 16126b80053dSChris Mason close = close_blocks(blocknr, other, blocksize); 16136702ed49SChris Mason } 1614e9d0b13bSChris Mason if (close) { 1615e9d0b13bSChris Mason last_block = blocknr; 16166702ed49SChris Mason continue; 1617e9d0b13bSChris Mason } 16186702ed49SChris Mason 1619*206983b7SJosef Bacik cur = btrfs_read_node_slot(parent, i); 1620*206983b7SJosef Bacik if (IS_ERR(cur)) 162164c043deSLiu Bo return PTR_ERR(cur); 1622e9d0b13bSChris Mason if (search_start == 0) 16236b80053dSChris Mason search_start = last_block; 1624e9d0b13bSChris Mason 1625e7a84565SChris Mason btrfs_tree_lock(cur); 16266b80053dSChris Mason err = __btrfs_cow_block(trans, root, cur, parent, i, 1627e7a84565SChris Mason &cur, search_start, 16286b80053dSChris Mason min(16 * blocksize, 16299631e4ccSJosef Bacik (end_slot - i) * blocksize), 16309631e4ccSJosef Bacik BTRFS_NESTING_COW); 1631252c38f0SYan if (err) { 1632e7a84565SChris Mason btrfs_tree_unlock(cur); 16336b80053dSChris Mason free_extent_buffer(cur); 16346702ed49SChris Mason break; 1635252c38f0SYan } 1636e7a84565SChris Mason search_start = cur->start; 1637e7a84565SChris Mason last_block = cur->start; 1638f2183bdeSChris Mason *last_ret = search_start; 1639e7a84565SChris Mason btrfs_tree_unlock(cur); 1640e7a84565SChris Mason free_extent_buffer(cur); 16416702ed49SChris Mason } 16426702ed49SChris Mason return err; 16436702ed49SChris Mason } 16446702ed49SChris Mason 164574123bd7SChris Mason /* 16465f39d397SChris Mason * search for key in the extent_buffer. The items start at offset p, 16475f39d397SChris Mason * and they are item_size apart. There are 'max' items in p. 16485f39d397SChris Mason * 164974123bd7SChris Mason * the slot in the array is returned via slot, and it points to 165074123bd7SChris Mason * the place where you would insert key if it is not found in 165174123bd7SChris Mason * the array. 165274123bd7SChris Mason * 165374123bd7SChris Mason * slot may point to max if the key is bigger than all of the keys 165474123bd7SChris Mason */ 1655e02119d5SChris Mason static noinline int generic_bin_search(struct extent_buffer *eb, 1656310712b2SOmar Sandoval unsigned long p, int item_size, 1657310712b2SOmar Sandoval const struct btrfs_key *key, 1658be0e5c09SChris Mason int max, int *slot) 1659be0e5c09SChris Mason { 1660be0e5c09SChris Mason int low = 0; 1661be0e5c09SChris Mason int high = max; 1662be0e5c09SChris Mason int ret; 16635cd17f34SDavid Sterba const int key_size = sizeof(struct btrfs_disk_key); 1664be0e5c09SChris Mason 16655e24e9afSLiu Bo if (low > high) { 16665e24e9afSLiu Bo btrfs_err(eb->fs_info, 16675e24e9afSLiu Bo "%s: low (%d) > high (%d) eb %llu owner %llu level %d", 16685e24e9afSLiu Bo __func__, low, high, eb->start, 16695e24e9afSLiu Bo btrfs_header_owner(eb), btrfs_header_level(eb)); 16705e24e9afSLiu Bo return -EINVAL; 16715e24e9afSLiu Bo } 16725e24e9afSLiu Bo 1673be0e5c09SChris Mason while (low < high) { 16745cd17f34SDavid Sterba unsigned long oip; 16755cd17f34SDavid Sterba unsigned long offset; 16765cd17f34SDavid Sterba struct btrfs_disk_key *tmp; 16775cd17f34SDavid Sterba struct btrfs_disk_key unaligned; 16785cd17f34SDavid Sterba int mid; 16795cd17f34SDavid Sterba 1680be0e5c09SChris Mason mid = (low + high) / 2; 16815f39d397SChris Mason offset = p + mid * item_size; 16825cd17f34SDavid Sterba oip = offset_in_page(offset); 16835f39d397SChris Mason 16845cd17f34SDavid Sterba if (oip + key_size <= PAGE_SIZE) { 16855cd17f34SDavid Sterba const unsigned long idx = offset >> PAGE_SHIFT; 16865cd17f34SDavid Sterba char *kaddr = page_address(eb->pages[idx]); 1687934d375bSChris Mason 16885cd17f34SDavid Sterba tmp = (struct btrfs_disk_key *)(kaddr + oip); 16895cd17f34SDavid Sterba } else { 16905cd17f34SDavid Sterba read_extent_buffer(eb, &unaligned, offset, key_size); 16915f39d397SChris Mason tmp = &unaligned; 1692479965d6SChris Mason } 1693479965d6SChris Mason 1694be0e5c09SChris Mason ret = comp_keys(tmp, key); 1695be0e5c09SChris Mason 1696be0e5c09SChris Mason if (ret < 0) 1697be0e5c09SChris Mason low = mid + 1; 1698be0e5c09SChris Mason else if (ret > 0) 1699be0e5c09SChris Mason high = mid; 1700be0e5c09SChris Mason else { 1701be0e5c09SChris Mason *slot = mid; 1702be0e5c09SChris Mason return 0; 1703be0e5c09SChris Mason } 1704be0e5c09SChris Mason } 1705be0e5c09SChris Mason *slot = low; 1706be0e5c09SChris Mason return 1; 1707be0e5c09SChris Mason } 1708be0e5c09SChris Mason 170997571fd0SChris Mason /* 171097571fd0SChris Mason * simple bin_search frontend that does the right thing for 171197571fd0SChris Mason * leaves vs nodes 171297571fd0SChris Mason */ 1713a74b35ecSNikolay Borisov int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key, 1714e3b83361SQu Wenruo int *slot) 1715be0e5c09SChris Mason { 1716e3b83361SQu Wenruo if (btrfs_header_level(eb) == 0) 17175f39d397SChris Mason return generic_bin_search(eb, 17185f39d397SChris Mason offsetof(struct btrfs_leaf, items), 17190783fcfcSChris Mason sizeof(struct btrfs_item), 17205f39d397SChris Mason key, btrfs_header_nritems(eb), 17217518a238SChris Mason slot); 1722f775738fSWang Sheng-Hui else 17235f39d397SChris Mason return generic_bin_search(eb, 17245f39d397SChris Mason offsetof(struct btrfs_node, ptrs), 1725123abc88SChris Mason sizeof(struct btrfs_key_ptr), 17265f39d397SChris Mason key, btrfs_header_nritems(eb), 17277518a238SChris Mason slot); 1728be0e5c09SChris Mason } 1729be0e5c09SChris Mason 1730f0486c68SYan, Zheng static void root_add_used(struct btrfs_root *root, u32 size) 1731f0486c68SYan, Zheng { 1732f0486c68SYan, Zheng spin_lock(&root->accounting_lock); 1733f0486c68SYan, Zheng btrfs_set_root_used(&root->root_item, 1734f0486c68SYan, Zheng btrfs_root_used(&root->root_item) + size); 1735f0486c68SYan, Zheng spin_unlock(&root->accounting_lock); 1736f0486c68SYan, Zheng } 1737f0486c68SYan, Zheng 1738f0486c68SYan, Zheng static void root_sub_used(struct btrfs_root *root, u32 size) 1739f0486c68SYan, Zheng { 1740f0486c68SYan, Zheng spin_lock(&root->accounting_lock); 1741f0486c68SYan, Zheng btrfs_set_root_used(&root->root_item, 1742f0486c68SYan, Zheng btrfs_root_used(&root->root_item) - size); 1743f0486c68SYan, Zheng spin_unlock(&root->accounting_lock); 1744f0486c68SYan, Zheng } 1745f0486c68SYan, Zheng 1746d352ac68SChris Mason /* given a node and slot number, this reads the blocks it points to. The 1747d352ac68SChris Mason * extent buffer is returned with a reference taken (but unlocked). 1748d352ac68SChris Mason */ 17494b231ae4SDavid Sterba struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent, 17504b231ae4SDavid Sterba int slot) 1751bb803951SChris Mason { 1752ca7a79adSChris Mason int level = btrfs_header_level(parent); 1753416bc658SJosef Bacik struct extent_buffer *eb; 1754581c1760SQu Wenruo struct btrfs_key first_key; 1755416bc658SJosef Bacik 1756fb770ae4SLiu Bo if (slot < 0 || slot >= btrfs_header_nritems(parent)) 1757fb770ae4SLiu Bo return ERR_PTR(-ENOENT); 1758ca7a79adSChris Mason 1759ca7a79adSChris Mason BUG_ON(level == 0); 1760ca7a79adSChris Mason 1761581c1760SQu Wenruo btrfs_node_key_to_cpu(parent, &first_key, slot); 1762d0d20b0fSDavid Sterba eb = read_tree_block(parent->fs_info, btrfs_node_blockptr(parent, slot), 1763581c1760SQu Wenruo btrfs_node_ptr_generation(parent, slot), 1764581c1760SQu Wenruo level - 1, &first_key); 1765fb770ae4SLiu Bo if (!IS_ERR(eb) && !extent_buffer_uptodate(eb)) { 1766416bc658SJosef Bacik free_extent_buffer(eb); 1767fb770ae4SLiu Bo eb = ERR_PTR(-EIO); 1768416bc658SJosef Bacik } 1769416bc658SJosef Bacik 1770416bc658SJosef Bacik return eb; 1771bb803951SChris Mason } 1772bb803951SChris Mason 1773d352ac68SChris Mason /* 1774d352ac68SChris Mason * node level balancing, used to make sure nodes are in proper order for 1775d352ac68SChris Mason * item deletion. We balance from the top down, so we have to make sure 1776d352ac68SChris Mason * that a deletion won't leave an node completely empty later on. 1777d352ac68SChris Mason */ 1778e02119d5SChris Mason static noinline int balance_level(struct btrfs_trans_handle *trans, 177998ed5174SChris Mason struct btrfs_root *root, 178098ed5174SChris Mason struct btrfs_path *path, int level) 1781bb803951SChris Mason { 17820b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 17835f39d397SChris Mason struct extent_buffer *right = NULL; 17845f39d397SChris Mason struct extent_buffer *mid; 17855f39d397SChris Mason struct extent_buffer *left = NULL; 17865f39d397SChris Mason struct extent_buffer *parent = NULL; 1787bb803951SChris Mason int ret = 0; 1788bb803951SChris Mason int wret; 1789bb803951SChris Mason int pslot; 1790bb803951SChris Mason int orig_slot = path->slots[level]; 179179f95c82SChris Mason u64 orig_ptr; 1792bb803951SChris Mason 179398e6b1ebSLiu Bo ASSERT(level > 0); 1794bb803951SChris Mason 17955f39d397SChris Mason mid = path->nodes[level]; 1796b4ce94deSChris Mason 1797ac5887c8SJosef Bacik WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK); 17987bb86316SChris Mason WARN_ON(btrfs_header_generation(mid) != trans->transid); 17997bb86316SChris Mason 18001d4f8a0cSChris Mason orig_ptr = btrfs_node_blockptr(mid, orig_slot); 180179f95c82SChris Mason 1802a05a9bb1SLi Zefan if (level < BTRFS_MAX_LEVEL - 1) { 18035f39d397SChris Mason parent = path->nodes[level + 1]; 1804bb803951SChris Mason pslot = path->slots[level + 1]; 1805a05a9bb1SLi Zefan } 1806bb803951SChris Mason 180740689478SChris Mason /* 180840689478SChris Mason * deal with the case where there is only one pointer in the root 180940689478SChris Mason * by promoting the node below to a root 181040689478SChris Mason */ 18115f39d397SChris Mason if (!parent) { 18125f39d397SChris Mason struct extent_buffer *child; 1813bb803951SChris Mason 18145f39d397SChris Mason if (btrfs_header_nritems(mid) != 1) 1815bb803951SChris Mason return 0; 1816bb803951SChris Mason 1817bb803951SChris Mason /* promote the child to a root */ 18184b231ae4SDavid Sterba child = btrfs_read_node_slot(mid, 0); 1819fb770ae4SLiu Bo if (IS_ERR(child)) { 1820fb770ae4SLiu Bo ret = PTR_ERR(child); 18210b246afaSJeff Mahoney btrfs_handle_fs_error(fs_info, ret, NULL); 1822305a26afSMark Fasheh goto enospc; 1823305a26afSMark Fasheh } 1824305a26afSMark Fasheh 1825925baeddSChris Mason btrfs_tree_lock(child); 18269631e4ccSJosef Bacik ret = btrfs_cow_block(trans, root, child, mid, 0, &child, 18279631e4ccSJosef Bacik BTRFS_NESTING_COW); 1828f0486c68SYan, Zheng if (ret) { 1829f0486c68SYan, Zheng btrfs_tree_unlock(child); 1830f0486c68SYan, Zheng free_extent_buffer(child); 1831f0486c68SYan, Zheng goto enospc; 1832f0486c68SYan, Zheng } 18332f375ab9SYan 1834d9d19a01SDavid Sterba ret = tree_mod_log_insert_root(root->node, child, 1); 1835d9d19a01SDavid Sterba BUG_ON(ret < 0); 1836240f62c8SChris Mason rcu_assign_pointer(root->node, child); 1837925baeddSChris Mason 18380b86a832SChris Mason add_root_to_dirty_list(root); 1839925baeddSChris Mason btrfs_tree_unlock(child); 1840b4ce94deSChris Mason 1841925baeddSChris Mason path->locks[level] = 0; 1842bb803951SChris Mason path->nodes[level] = NULL; 18436a884d7dSDavid Sterba btrfs_clean_tree_block(mid); 1844925baeddSChris Mason btrfs_tree_unlock(mid); 1845bb803951SChris Mason /* once for the path */ 18465f39d397SChris Mason free_extent_buffer(mid); 1847f0486c68SYan, Zheng 1848f0486c68SYan, Zheng root_sub_used(root, mid->len); 18495581a51aSJan Schmidt btrfs_free_tree_block(trans, root, mid, 0, 1); 1850bb803951SChris Mason /* once for the root ptr */ 18513083ee2eSJosef Bacik free_extent_buffer_stale(mid); 1852f0486c68SYan, Zheng return 0; 1853bb803951SChris Mason } 18545f39d397SChris Mason if (btrfs_header_nritems(mid) > 18550b246afaSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 4) 1856bb803951SChris Mason return 0; 1857bb803951SChris Mason 18584b231ae4SDavid Sterba left = btrfs_read_node_slot(parent, pslot - 1); 1859fb770ae4SLiu Bo if (IS_ERR(left)) 1860fb770ae4SLiu Bo left = NULL; 1861fb770ae4SLiu Bo 18625f39d397SChris Mason if (left) { 1863bf77467aSJosef Bacik __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); 18645f39d397SChris Mason wret = btrfs_cow_block(trans, root, left, 18659631e4ccSJosef Bacik parent, pslot - 1, &left, 1866bf59a5a2SJosef Bacik BTRFS_NESTING_LEFT_COW); 186754aa1f4dSChris Mason if (wret) { 186854aa1f4dSChris Mason ret = wret; 186954aa1f4dSChris Mason goto enospc; 187054aa1f4dSChris Mason } 18712cc58cf2SChris Mason } 1872fb770ae4SLiu Bo 18734b231ae4SDavid Sterba right = btrfs_read_node_slot(parent, pslot + 1); 1874fb770ae4SLiu Bo if (IS_ERR(right)) 1875fb770ae4SLiu Bo right = NULL; 1876fb770ae4SLiu Bo 18775f39d397SChris Mason if (right) { 1878bf77467aSJosef Bacik __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); 18795f39d397SChris Mason wret = btrfs_cow_block(trans, root, right, 18809631e4ccSJosef Bacik parent, pslot + 1, &right, 1881bf59a5a2SJosef Bacik BTRFS_NESTING_RIGHT_COW); 18822cc58cf2SChris Mason if (wret) { 18832cc58cf2SChris Mason ret = wret; 18842cc58cf2SChris Mason goto enospc; 18852cc58cf2SChris Mason } 18862cc58cf2SChris Mason } 18872cc58cf2SChris Mason 18882cc58cf2SChris Mason /* first, try to make some room in the middle buffer */ 18895f39d397SChris Mason if (left) { 18905f39d397SChris Mason orig_slot += btrfs_header_nritems(left); 1891d30a668fSDavid Sterba wret = push_node_left(trans, left, mid, 1); 189279f95c82SChris Mason if (wret < 0) 189379f95c82SChris Mason ret = wret; 1894bb803951SChris Mason } 189579f95c82SChris Mason 189679f95c82SChris Mason /* 189779f95c82SChris Mason * then try to empty the right most buffer into the middle 189879f95c82SChris Mason */ 18995f39d397SChris Mason if (right) { 1900d30a668fSDavid Sterba wret = push_node_left(trans, mid, right, 1); 190154aa1f4dSChris Mason if (wret < 0 && wret != -ENOSPC) 190279f95c82SChris Mason ret = wret; 19035f39d397SChris Mason if (btrfs_header_nritems(right) == 0) { 19046a884d7dSDavid Sterba btrfs_clean_tree_block(right); 1905925baeddSChris Mason btrfs_tree_unlock(right); 1906afe5fea7STsutomu Itoh del_ptr(root, path, level + 1, pslot + 1); 1907f0486c68SYan, Zheng root_sub_used(root, right->len); 19085581a51aSJan Schmidt btrfs_free_tree_block(trans, root, right, 0, 1); 19093083ee2eSJosef Bacik free_extent_buffer_stale(right); 1910f0486c68SYan, Zheng right = NULL; 1911bb803951SChris Mason } else { 19125f39d397SChris Mason struct btrfs_disk_key right_key; 19135f39d397SChris Mason btrfs_node_key(right, &right_key, 0); 19140e82bcfeSDavid Sterba ret = tree_mod_log_insert_key(parent, pslot + 1, 19150e82bcfeSDavid Sterba MOD_LOG_KEY_REPLACE, GFP_NOFS); 19160e82bcfeSDavid Sterba BUG_ON(ret < 0); 19175f39d397SChris Mason btrfs_set_node_key(parent, &right_key, pslot + 1); 19185f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 1919bb803951SChris Mason } 1920bb803951SChris Mason } 19215f39d397SChris Mason if (btrfs_header_nritems(mid) == 1) { 192279f95c82SChris Mason /* 192379f95c82SChris Mason * we're not allowed to leave a node with one item in the 192479f95c82SChris Mason * tree during a delete. A deletion from lower in the tree 192579f95c82SChris Mason * could try to delete the only pointer in this node. 192679f95c82SChris Mason * So, pull some keys from the left. 192779f95c82SChris Mason * There has to be a left pointer at this point because 192879f95c82SChris Mason * otherwise we would have pulled some pointers from the 192979f95c82SChris Mason * right 193079f95c82SChris Mason */ 1931305a26afSMark Fasheh if (!left) { 1932305a26afSMark Fasheh ret = -EROFS; 19330b246afaSJeff Mahoney btrfs_handle_fs_error(fs_info, ret, NULL); 1934305a26afSMark Fasheh goto enospc; 1935305a26afSMark Fasheh } 193655d32ed8SDavid Sterba wret = balance_node_right(trans, mid, left); 193754aa1f4dSChris Mason if (wret < 0) { 193879f95c82SChris Mason ret = wret; 193954aa1f4dSChris Mason goto enospc; 194054aa1f4dSChris Mason } 1941bce4eae9SChris Mason if (wret == 1) { 1942d30a668fSDavid Sterba wret = push_node_left(trans, left, mid, 1); 1943bce4eae9SChris Mason if (wret < 0) 1944bce4eae9SChris Mason ret = wret; 1945bce4eae9SChris Mason } 194679f95c82SChris Mason BUG_ON(wret == 1); 194779f95c82SChris Mason } 19485f39d397SChris Mason if (btrfs_header_nritems(mid) == 0) { 19496a884d7dSDavid Sterba btrfs_clean_tree_block(mid); 1950925baeddSChris Mason btrfs_tree_unlock(mid); 1951afe5fea7STsutomu Itoh del_ptr(root, path, level + 1, pslot); 1952f0486c68SYan, Zheng root_sub_used(root, mid->len); 19535581a51aSJan Schmidt btrfs_free_tree_block(trans, root, mid, 0, 1); 19543083ee2eSJosef Bacik free_extent_buffer_stale(mid); 1955f0486c68SYan, Zheng mid = NULL; 195679f95c82SChris Mason } else { 195779f95c82SChris Mason /* update the parent key to reflect our changes */ 19585f39d397SChris Mason struct btrfs_disk_key mid_key; 19595f39d397SChris Mason btrfs_node_key(mid, &mid_key, 0); 19600e82bcfeSDavid Sterba ret = tree_mod_log_insert_key(parent, pslot, 19610e82bcfeSDavid Sterba MOD_LOG_KEY_REPLACE, GFP_NOFS); 19620e82bcfeSDavid Sterba BUG_ON(ret < 0); 19635f39d397SChris Mason btrfs_set_node_key(parent, &mid_key, pslot); 19645f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 196579f95c82SChris Mason } 1966bb803951SChris Mason 196779f95c82SChris Mason /* update the path */ 19685f39d397SChris Mason if (left) { 19695f39d397SChris Mason if (btrfs_header_nritems(left) > orig_slot) { 197067439dadSDavid Sterba atomic_inc(&left->refs); 1971925baeddSChris Mason /* left was locked after cow */ 19725f39d397SChris Mason path->nodes[level] = left; 1973bb803951SChris Mason path->slots[level + 1] -= 1; 1974bb803951SChris Mason path->slots[level] = orig_slot; 1975925baeddSChris Mason if (mid) { 1976925baeddSChris Mason btrfs_tree_unlock(mid); 19775f39d397SChris Mason free_extent_buffer(mid); 1978925baeddSChris Mason } 1979bb803951SChris Mason } else { 19805f39d397SChris Mason orig_slot -= btrfs_header_nritems(left); 1981bb803951SChris Mason path->slots[level] = orig_slot; 1982bb803951SChris Mason } 1983bb803951SChris Mason } 198479f95c82SChris Mason /* double check we haven't messed things up */ 1985e20d96d6SChris Mason if (orig_ptr != 19865f39d397SChris Mason btrfs_node_blockptr(path->nodes[level], path->slots[level])) 198779f95c82SChris Mason BUG(); 198854aa1f4dSChris Mason enospc: 1989925baeddSChris Mason if (right) { 1990925baeddSChris Mason btrfs_tree_unlock(right); 19915f39d397SChris Mason free_extent_buffer(right); 1992925baeddSChris Mason } 1993925baeddSChris Mason if (left) { 1994925baeddSChris Mason if (path->nodes[level] != left) 1995925baeddSChris Mason btrfs_tree_unlock(left); 19965f39d397SChris Mason free_extent_buffer(left); 1997925baeddSChris Mason } 1998bb803951SChris Mason return ret; 1999bb803951SChris Mason } 2000bb803951SChris Mason 2001d352ac68SChris Mason /* Node balancing for insertion. Here we only split or push nodes around 2002d352ac68SChris Mason * when they are completely full. This is also done top down, so we 2003d352ac68SChris Mason * have to be pessimistic. 2004d352ac68SChris Mason */ 2005d397712bSChris Mason static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, 2006e66f709bSChris Mason struct btrfs_root *root, 2007e66f709bSChris Mason struct btrfs_path *path, int level) 2008e66f709bSChris Mason { 20090b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 20105f39d397SChris Mason struct extent_buffer *right = NULL; 20115f39d397SChris Mason struct extent_buffer *mid; 20125f39d397SChris Mason struct extent_buffer *left = NULL; 20135f39d397SChris Mason struct extent_buffer *parent = NULL; 2014e66f709bSChris Mason int ret = 0; 2015e66f709bSChris Mason int wret; 2016e66f709bSChris Mason int pslot; 2017e66f709bSChris Mason int orig_slot = path->slots[level]; 2018e66f709bSChris Mason 2019e66f709bSChris Mason if (level == 0) 2020e66f709bSChris Mason return 1; 2021e66f709bSChris Mason 20225f39d397SChris Mason mid = path->nodes[level]; 20237bb86316SChris Mason WARN_ON(btrfs_header_generation(mid) != trans->transid); 2024e66f709bSChris Mason 2025a05a9bb1SLi Zefan if (level < BTRFS_MAX_LEVEL - 1) { 20265f39d397SChris Mason parent = path->nodes[level + 1]; 2027e66f709bSChris Mason pslot = path->slots[level + 1]; 2028a05a9bb1SLi Zefan } 2029e66f709bSChris Mason 20305f39d397SChris Mason if (!parent) 2031e66f709bSChris Mason return 1; 2032e66f709bSChris Mason 20334b231ae4SDavid Sterba left = btrfs_read_node_slot(parent, pslot - 1); 2034fb770ae4SLiu Bo if (IS_ERR(left)) 2035fb770ae4SLiu Bo left = NULL; 2036e66f709bSChris Mason 2037e66f709bSChris Mason /* first, try to make some room in the middle buffer */ 20385f39d397SChris Mason if (left) { 2039e66f709bSChris Mason u32 left_nr; 2040925baeddSChris Mason 2041bf77467aSJosef Bacik __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); 2042b4ce94deSChris Mason 20435f39d397SChris Mason left_nr = btrfs_header_nritems(left); 20440b246afaSJeff Mahoney if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { 204533ade1f8SChris Mason wret = 1; 204633ade1f8SChris Mason } else { 20475f39d397SChris Mason ret = btrfs_cow_block(trans, root, left, parent, 20489631e4ccSJosef Bacik pslot - 1, &left, 2049bf59a5a2SJosef Bacik BTRFS_NESTING_LEFT_COW); 205054aa1f4dSChris Mason if (ret) 205154aa1f4dSChris Mason wret = 1; 205254aa1f4dSChris Mason else { 2053d30a668fSDavid Sterba wret = push_node_left(trans, left, mid, 0); 205454aa1f4dSChris Mason } 205533ade1f8SChris Mason } 2056e66f709bSChris Mason if (wret < 0) 2057e66f709bSChris Mason ret = wret; 2058e66f709bSChris Mason if (wret == 0) { 20595f39d397SChris Mason struct btrfs_disk_key disk_key; 2060e66f709bSChris Mason orig_slot += left_nr; 20615f39d397SChris Mason btrfs_node_key(mid, &disk_key, 0); 20620e82bcfeSDavid Sterba ret = tree_mod_log_insert_key(parent, pslot, 20630e82bcfeSDavid Sterba MOD_LOG_KEY_REPLACE, GFP_NOFS); 20640e82bcfeSDavid Sterba BUG_ON(ret < 0); 20655f39d397SChris Mason btrfs_set_node_key(parent, &disk_key, pslot); 20665f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 20675f39d397SChris Mason if (btrfs_header_nritems(left) > orig_slot) { 20685f39d397SChris Mason path->nodes[level] = left; 2069e66f709bSChris Mason path->slots[level + 1] -= 1; 2070e66f709bSChris Mason path->slots[level] = orig_slot; 2071925baeddSChris Mason btrfs_tree_unlock(mid); 20725f39d397SChris Mason free_extent_buffer(mid); 2073e66f709bSChris Mason } else { 2074e66f709bSChris Mason orig_slot -= 20755f39d397SChris Mason btrfs_header_nritems(left); 2076e66f709bSChris Mason path->slots[level] = orig_slot; 2077925baeddSChris Mason btrfs_tree_unlock(left); 20785f39d397SChris Mason free_extent_buffer(left); 2079e66f709bSChris Mason } 2080e66f709bSChris Mason return 0; 2081e66f709bSChris Mason } 2082925baeddSChris Mason btrfs_tree_unlock(left); 20835f39d397SChris Mason free_extent_buffer(left); 2084e66f709bSChris Mason } 20854b231ae4SDavid Sterba right = btrfs_read_node_slot(parent, pslot + 1); 2086fb770ae4SLiu Bo if (IS_ERR(right)) 2087fb770ae4SLiu Bo right = NULL; 2088e66f709bSChris Mason 2089e66f709bSChris Mason /* 2090e66f709bSChris Mason * then try to empty the right most buffer into the middle 2091e66f709bSChris Mason */ 20925f39d397SChris Mason if (right) { 209333ade1f8SChris Mason u32 right_nr; 2094b4ce94deSChris Mason 2095bf77467aSJosef Bacik __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); 2096b4ce94deSChris Mason 20975f39d397SChris Mason right_nr = btrfs_header_nritems(right); 20980b246afaSJeff Mahoney if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { 209933ade1f8SChris Mason wret = 1; 210033ade1f8SChris Mason } else { 21015f39d397SChris Mason ret = btrfs_cow_block(trans, root, right, 21025f39d397SChris Mason parent, pslot + 1, 2103bf59a5a2SJosef Bacik &right, BTRFS_NESTING_RIGHT_COW); 210454aa1f4dSChris Mason if (ret) 210554aa1f4dSChris Mason wret = 1; 210654aa1f4dSChris Mason else { 210755d32ed8SDavid Sterba wret = balance_node_right(trans, right, mid); 210833ade1f8SChris Mason } 210954aa1f4dSChris Mason } 2110e66f709bSChris Mason if (wret < 0) 2111e66f709bSChris Mason ret = wret; 2112e66f709bSChris Mason if (wret == 0) { 21135f39d397SChris Mason struct btrfs_disk_key disk_key; 21145f39d397SChris Mason 21155f39d397SChris Mason btrfs_node_key(right, &disk_key, 0); 21160e82bcfeSDavid Sterba ret = tree_mod_log_insert_key(parent, pslot + 1, 21170e82bcfeSDavid Sterba MOD_LOG_KEY_REPLACE, GFP_NOFS); 21180e82bcfeSDavid Sterba BUG_ON(ret < 0); 21195f39d397SChris Mason btrfs_set_node_key(parent, &disk_key, pslot + 1); 21205f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 21215f39d397SChris Mason 21225f39d397SChris Mason if (btrfs_header_nritems(mid) <= orig_slot) { 21235f39d397SChris Mason path->nodes[level] = right; 2124e66f709bSChris Mason path->slots[level + 1] += 1; 2125e66f709bSChris Mason path->slots[level] = orig_slot - 21265f39d397SChris Mason btrfs_header_nritems(mid); 2127925baeddSChris Mason btrfs_tree_unlock(mid); 21285f39d397SChris Mason free_extent_buffer(mid); 2129e66f709bSChris Mason } else { 2130925baeddSChris Mason btrfs_tree_unlock(right); 21315f39d397SChris Mason free_extent_buffer(right); 2132e66f709bSChris Mason } 2133e66f709bSChris Mason return 0; 2134e66f709bSChris Mason } 2135925baeddSChris Mason btrfs_tree_unlock(right); 21365f39d397SChris Mason free_extent_buffer(right); 2137e66f709bSChris Mason } 2138e66f709bSChris Mason return 1; 2139e66f709bSChris Mason } 2140e66f709bSChris Mason 214174123bd7SChris Mason /* 2142d352ac68SChris Mason * readahead one full node of leaves, finding things that are close 2143d352ac68SChris Mason * to the block in 'slot', and triggering ra on them. 21443c69faecSChris Mason */ 21452ff7e61eSJeff Mahoney static void reada_for_search(struct btrfs_fs_info *fs_info, 2146e02119d5SChris Mason struct btrfs_path *path, 214701f46658SChris Mason int level, int slot, u64 objectid) 21483c69faecSChris Mason { 21495f39d397SChris Mason struct extent_buffer *node; 215001f46658SChris Mason struct btrfs_disk_key disk_key; 21513c69faecSChris Mason u32 nritems; 21523c69faecSChris Mason u64 search; 2153a7175319SChris Mason u64 target; 21546b80053dSChris Mason u64 nread = 0; 21555f39d397SChris Mason struct extent_buffer *eb; 21566b80053dSChris Mason u32 nr; 21576b80053dSChris Mason u32 blocksize; 21586b80053dSChris Mason u32 nscan = 0; 2159db94535dSChris Mason 2160a6b6e75eSChris Mason if (level != 1) 21613c69faecSChris Mason return; 21623c69faecSChris Mason 21636702ed49SChris Mason if (!path->nodes[level]) 21646702ed49SChris Mason return; 21656702ed49SChris Mason 21665f39d397SChris Mason node = path->nodes[level]; 2167925baeddSChris Mason 21683c69faecSChris Mason search = btrfs_node_blockptr(node, slot); 21690b246afaSJeff Mahoney blocksize = fs_info->nodesize; 21700b246afaSJeff Mahoney eb = find_extent_buffer(fs_info, search); 21715f39d397SChris Mason if (eb) { 21725f39d397SChris Mason free_extent_buffer(eb); 21733c69faecSChris Mason return; 21743c69faecSChris Mason } 21753c69faecSChris Mason 2176a7175319SChris Mason target = search; 21776b80053dSChris Mason 21785f39d397SChris Mason nritems = btrfs_header_nritems(node); 21796b80053dSChris Mason nr = slot; 218025b8b936SJosef Bacik 21813c69faecSChris Mason while (1) { 2182e4058b54SDavid Sterba if (path->reada == READA_BACK) { 21836b80053dSChris Mason if (nr == 0) 21843c69faecSChris Mason break; 21856b80053dSChris Mason nr--; 2186e4058b54SDavid Sterba } else if (path->reada == READA_FORWARD) { 21876b80053dSChris Mason nr++; 21886b80053dSChris Mason if (nr >= nritems) 21896b80053dSChris Mason break; 21903c69faecSChris Mason } 2191e4058b54SDavid Sterba if (path->reada == READA_BACK && objectid) { 219201f46658SChris Mason btrfs_node_key(node, &disk_key, nr); 219301f46658SChris Mason if (btrfs_disk_key_objectid(&disk_key) != objectid) 219401f46658SChris Mason break; 219501f46658SChris Mason } 21966b80053dSChris Mason search = btrfs_node_blockptr(node, nr); 2197a7175319SChris Mason if ((search <= target && target - search <= 65536) || 2198a7175319SChris Mason (search > target && search - target <= 65536)) { 2199bfb484d9SJosef Bacik btrfs_readahead_node_child(node, nr); 22006b80053dSChris Mason nread += blocksize; 22013c69faecSChris Mason } 22026b80053dSChris Mason nscan++; 2203a7175319SChris Mason if ((nread > 65536 || nscan > 32)) 22046b80053dSChris Mason break; 22053c69faecSChris Mason } 22063c69faecSChris Mason } 2207925baeddSChris Mason 2208bfb484d9SJosef Bacik static noinline void reada_for_balance(struct btrfs_path *path, int level) 2209b4ce94deSChris Mason { 2210bfb484d9SJosef Bacik struct extent_buffer *parent; 2211b4ce94deSChris Mason int slot; 2212b4ce94deSChris Mason int nritems; 2213b4ce94deSChris Mason 22148c594ea8SChris Mason parent = path->nodes[level + 1]; 2215b4ce94deSChris Mason if (!parent) 22160b08851fSJosef Bacik return; 2217b4ce94deSChris Mason 2218b4ce94deSChris Mason nritems = btrfs_header_nritems(parent); 22198c594ea8SChris Mason slot = path->slots[level + 1]; 2220b4ce94deSChris Mason 2221bfb484d9SJosef Bacik if (slot > 0) 2222bfb484d9SJosef Bacik btrfs_readahead_node_child(parent, slot - 1); 2223bfb484d9SJosef Bacik if (slot + 1 < nritems) 2224bfb484d9SJosef Bacik btrfs_readahead_node_child(parent, slot + 1); 2225b4ce94deSChris Mason } 2226b4ce94deSChris Mason 2227b4ce94deSChris Mason 2228b4ce94deSChris Mason /* 2229d397712bSChris Mason * when we walk down the tree, it is usually safe to unlock the higher layers 2230d397712bSChris Mason * in the tree. The exceptions are when our path goes through slot 0, because 2231d397712bSChris Mason * operations on the tree might require changing key pointers higher up in the 2232d397712bSChris Mason * tree. 2233d352ac68SChris Mason * 2234d397712bSChris Mason * callers might also have set path->keep_locks, which tells this code to keep 2235d397712bSChris Mason * the lock if the path points to the last slot in the block. This is part of 2236d397712bSChris Mason * walking through the tree, and selecting the next slot in the higher block. 2237d352ac68SChris Mason * 2238d397712bSChris Mason * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so 2239d397712bSChris Mason * if lowest_unlock is 1, level 0 won't be unlocked 2240d352ac68SChris Mason */ 2241e02119d5SChris Mason static noinline void unlock_up(struct btrfs_path *path, int level, 2242f7c79f30SChris Mason int lowest_unlock, int min_write_lock_level, 2243f7c79f30SChris Mason int *write_lock_level) 2244925baeddSChris Mason { 2245925baeddSChris Mason int i; 2246925baeddSChris Mason int skip_level = level; 2247051e1b9fSChris Mason int no_skips = 0; 2248925baeddSChris Mason struct extent_buffer *t; 2249925baeddSChris Mason 2250925baeddSChris Mason for (i = level; i < BTRFS_MAX_LEVEL; i++) { 2251925baeddSChris Mason if (!path->nodes[i]) 2252925baeddSChris Mason break; 2253925baeddSChris Mason if (!path->locks[i]) 2254925baeddSChris Mason break; 2255051e1b9fSChris Mason if (!no_skips && path->slots[i] == 0) { 2256925baeddSChris Mason skip_level = i + 1; 2257925baeddSChris Mason continue; 2258925baeddSChris Mason } 2259051e1b9fSChris Mason if (!no_skips && path->keep_locks) { 2260925baeddSChris Mason u32 nritems; 2261925baeddSChris Mason t = path->nodes[i]; 2262925baeddSChris Mason nritems = btrfs_header_nritems(t); 2263051e1b9fSChris Mason if (nritems < 1 || path->slots[i] >= nritems - 1) { 2264925baeddSChris Mason skip_level = i + 1; 2265925baeddSChris Mason continue; 2266925baeddSChris Mason } 2267925baeddSChris Mason } 2268051e1b9fSChris Mason if (skip_level < i && i >= lowest_unlock) 2269051e1b9fSChris Mason no_skips = 1; 2270051e1b9fSChris Mason 2271925baeddSChris Mason t = path->nodes[i]; 2272d80bb3f9SLiu Bo if (i >= lowest_unlock && i > skip_level) { 2273bd681513SChris Mason btrfs_tree_unlock_rw(t, path->locks[i]); 2274925baeddSChris Mason path->locks[i] = 0; 2275f7c79f30SChris Mason if (write_lock_level && 2276f7c79f30SChris Mason i > min_write_lock_level && 2277f7c79f30SChris Mason i <= *write_lock_level) { 2278f7c79f30SChris Mason *write_lock_level = i - 1; 2279f7c79f30SChris Mason } 2280925baeddSChris Mason } 2281925baeddSChris Mason } 2282925baeddSChris Mason } 2283925baeddSChris Mason 22843c69faecSChris Mason /* 2285c8c42864SChris Mason * helper function for btrfs_search_slot. The goal is to find a block 2286c8c42864SChris Mason * in cache without setting the path to blocking. If we find the block 2287c8c42864SChris Mason * we return zero and the path is unchanged. 2288c8c42864SChris Mason * 2289c8c42864SChris Mason * If we can't find the block, we set the path blocking and do some 2290c8c42864SChris Mason * reada. -EAGAIN is returned and the search must be repeated. 2291c8c42864SChris Mason */ 2292c8c42864SChris Mason static int 2293d07b8528SLiu Bo read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, 2294c8c42864SChris Mason struct extent_buffer **eb_ret, int level, int slot, 2295cda79c54SDavid Sterba const struct btrfs_key *key) 2296c8c42864SChris Mason { 22970b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 2298c8c42864SChris Mason u64 blocknr; 2299c8c42864SChris Mason u64 gen; 2300c8c42864SChris Mason struct extent_buffer *tmp; 2301581c1760SQu Wenruo struct btrfs_key first_key; 230276a05b35SChris Mason int ret; 2303581c1760SQu Wenruo int parent_level; 2304c8c42864SChris Mason 2305213ff4b7SNikolay Borisov blocknr = btrfs_node_blockptr(*eb_ret, slot); 2306213ff4b7SNikolay Borisov gen = btrfs_node_ptr_generation(*eb_ret, slot); 2307213ff4b7SNikolay Borisov parent_level = btrfs_header_level(*eb_ret); 2308213ff4b7SNikolay Borisov btrfs_node_key_to_cpu(*eb_ret, &first_key, slot); 2309c8c42864SChris Mason 23100b246afaSJeff Mahoney tmp = find_extent_buffer(fs_info, blocknr); 2311cb44921aSChris Mason if (tmp) { 2312b9fab919SChris Mason /* first we do an atomic uptodate check */ 2313b9fab919SChris Mason if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { 2314448de471SQu Wenruo /* 2315448de471SQu Wenruo * Do extra check for first_key, eb can be stale due to 2316448de471SQu Wenruo * being cached, read from scrub, or have multiple 2317448de471SQu Wenruo * parents (shared tree blocks). 2318448de471SQu Wenruo */ 2319e064d5e9SDavid Sterba if (btrfs_verify_level_key(tmp, 2320448de471SQu Wenruo parent_level - 1, &first_key, gen)) { 2321448de471SQu Wenruo free_extent_buffer(tmp); 2322448de471SQu Wenruo return -EUCLEAN; 2323448de471SQu Wenruo } 2324c8c42864SChris Mason *eb_ret = tmp; 2325c8c42864SChris Mason return 0; 2326c8c42864SChris Mason } 2327bdf7c00eSJosef Bacik 2328b9fab919SChris Mason /* now we're allowed to do a blocking uptodate check */ 2329581c1760SQu Wenruo ret = btrfs_read_buffer(tmp, gen, parent_level - 1, &first_key); 2330bdf7c00eSJosef Bacik if (!ret) { 2331cb44921aSChris Mason *eb_ret = tmp; 2332cb44921aSChris Mason return 0; 2333cb44921aSChris Mason } 2334cb44921aSChris Mason free_extent_buffer(tmp); 2335b3b4aa74SDavid Sterba btrfs_release_path(p); 2336cb44921aSChris Mason return -EIO; 2337cb44921aSChris Mason } 2338c8c42864SChris Mason 2339c8c42864SChris Mason /* 2340c8c42864SChris Mason * reduce lock contention at high levels 2341c8c42864SChris Mason * of the btree by dropping locks before 234276a05b35SChris Mason * we read. Don't release the lock on the current 234376a05b35SChris Mason * level because we need to walk this node to figure 234476a05b35SChris Mason * out which blocks to read. 2345c8c42864SChris Mason */ 23468c594ea8SChris Mason btrfs_unlock_up_safe(p, level + 1); 23478c594ea8SChris Mason 2348e4058b54SDavid Sterba if (p->reada != READA_NONE) 23492ff7e61eSJeff Mahoney reada_for_search(fs_info, p, level, slot, key->objectid); 2350c8c42864SChris Mason 235176a05b35SChris Mason ret = -EAGAIN; 235202a3307aSLiu Bo tmp = read_tree_block(fs_info, blocknr, gen, parent_level - 1, 2353581c1760SQu Wenruo &first_key); 235464c043deSLiu Bo if (!IS_ERR(tmp)) { 235576a05b35SChris Mason /* 235676a05b35SChris Mason * If the read above didn't mark this buffer up to date, 235776a05b35SChris Mason * it will never end up being up to date. Set ret to EIO now 235876a05b35SChris Mason * and give up so that our caller doesn't loop forever 235976a05b35SChris Mason * on our EAGAINs. 236076a05b35SChris Mason */ 2361e6a1d6fdSLiu Bo if (!extent_buffer_uptodate(tmp)) 236276a05b35SChris Mason ret = -EIO; 2363c8c42864SChris Mason free_extent_buffer(tmp); 2364c871b0f2SLiu Bo } else { 2365c871b0f2SLiu Bo ret = PTR_ERR(tmp); 236676a05b35SChris Mason } 236702a3307aSLiu Bo 236802a3307aSLiu Bo btrfs_release_path(p); 236976a05b35SChris Mason return ret; 2370c8c42864SChris Mason } 2371c8c42864SChris Mason 2372c8c42864SChris Mason /* 2373c8c42864SChris Mason * helper function for btrfs_search_slot. This does all of the checks 2374c8c42864SChris Mason * for node-level blocks and does any balancing required based on 2375c8c42864SChris Mason * the ins_len. 2376c8c42864SChris Mason * 2377c8c42864SChris Mason * If no extra work was required, zero is returned. If we had to 2378c8c42864SChris Mason * drop the path, -EAGAIN is returned and btrfs_search_slot must 2379c8c42864SChris Mason * start over 2380c8c42864SChris Mason */ 2381c8c42864SChris Mason static int 2382c8c42864SChris Mason setup_nodes_for_search(struct btrfs_trans_handle *trans, 2383c8c42864SChris Mason struct btrfs_root *root, struct btrfs_path *p, 2384bd681513SChris Mason struct extent_buffer *b, int level, int ins_len, 2385bd681513SChris Mason int *write_lock_level) 2386c8c42864SChris Mason { 23870b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 2388c8c42864SChris Mason int ret; 23890b246afaSJeff Mahoney 2390c8c42864SChris Mason if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= 23910b246afaSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) { 2392c8c42864SChris Mason int sret; 2393c8c42864SChris Mason 2394bd681513SChris Mason if (*write_lock_level < level + 1) { 2395bd681513SChris Mason *write_lock_level = level + 1; 2396bd681513SChris Mason btrfs_release_path(p); 2397bd681513SChris Mason goto again; 2398bd681513SChris Mason } 2399bd681513SChris Mason 2400bfb484d9SJosef Bacik reada_for_balance(p, level); 2401c8c42864SChris Mason sret = split_node(trans, root, p, level); 2402c8c42864SChris Mason 2403c8c42864SChris Mason BUG_ON(sret > 0); 2404c8c42864SChris Mason if (sret) { 2405c8c42864SChris Mason ret = sret; 2406c8c42864SChris Mason goto done; 2407c8c42864SChris Mason } 2408c8c42864SChris Mason b = p->nodes[level]; 2409c8c42864SChris Mason } else if (ins_len < 0 && btrfs_header_nritems(b) < 24100b246afaSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 2) { 2411c8c42864SChris Mason int sret; 2412c8c42864SChris Mason 2413bd681513SChris Mason if (*write_lock_level < level + 1) { 2414bd681513SChris Mason *write_lock_level = level + 1; 2415bd681513SChris Mason btrfs_release_path(p); 2416bd681513SChris Mason goto again; 2417bd681513SChris Mason } 2418bd681513SChris Mason 2419bfb484d9SJosef Bacik reada_for_balance(p, level); 2420c8c42864SChris Mason sret = balance_level(trans, root, p, level); 2421c8c42864SChris Mason 2422c8c42864SChris Mason if (sret) { 2423c8c42864SChris Mason ret = sret; 2424c8c42864SChris Mason goto done; 2425c8c42864SChris Mason } 2426c8c42864SChris Mason b = p->nodes[level]; 2427c8c42864SChris Mason if (!b) { 2428b3b4aa74SDavid Sterba btrfs_release_path(p); 2429c8c42864SChris Mason goto again; 2430c8c42864SChris Mason } 2431c8c42864SChris Mason BUG_ON(btrfs_header_nritems(b) == 1); 2432c8c42864SChris Mason } 2433c8c42864SChris Mason return 0; 2434c8c42864SChris Mason 2435c8c42864SChris Mason again: 2436c8c42864SChris Mason ret = -EAGAIN; 2437c8c42864SChris Mason done: 2438c8c42864SChris Mason return ret; 2439c8c42864SChris Mason } 2440c8c42864SChris Mason 2441381cf658SDavid Sterba int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, 2442e33d5c3dSKelley Nielsen u64 iobjectid, u64 ioff, u8 key_type, 2443e33d5c3dSKelley Nielsen struct btrfs_key *found_key) 2444e33d5c3dSKelley Nielsen { 2445e33d5c3dSKelley Nielsen int ret; 2446e33d5c3dSKelley Nielsen struct btrfs_key key; 2447e33d5c3dSKelley Nielsen struct extent_buffer *eb; 2448381cf658SDavid Sterba 2449381cf658SDavid Sterba ASSERT(path); 24501d4c08e0SDavid Sterba ASSERT(found_key); 2451e33d5c3dSKelley Nielsen 2452e33d5c3dSKelley Nielsen key.type = key_type; 2453e33d5c3dSKelley Nielsen key.objectid = iobjectid; 2454e33d5c3dSKelley Nielsen key.offset = ioff; 2455e33d5c3dSKelley Nielsen 2456e33d5c3dSKelley Nielsen ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); 24571d4c08e0SDavid Sterba if (ret < 0) 2458e33d5c3dSKelley Nielsen return ret; 2459e33d5c3dSKelley Nielsen 2460e33d5c3dSKelley Nielsen eb = path->nodes[0]; 2461e33d5c3dSKelley Nielsen if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { 2462e33d5c3dSKelley Nielsen ret = btrfs_next_leaf(fs_root, path); 2463e33d5c3dSKelley Nielsen if (ret) 2464e33d5c3dSKelley Nielsen return ret; 2465e33d5c3dSKelley Nielsen eb = path->nodes[0]; 2466e33d5c3dSKelley Nielsen } 2467e33d5c3dSKelley Nielsen 2468e33d5c3dSKelley Nielsen btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); 2469e33d5c3dSKelley Nielsen if (found_key->type != key.type || 2470e33d5c3dSKelley Nielsen found_key->objectid != key.objectid) 2471e33d5c3dSKelley Nielsen return 1; 2472e33d5c3dSKelley Nielsen 2473e33d5c3dSKelley Nielsen return 0; 2474e33d5c3dSKelley Nielsen } 2475e33d5c3dSKelley Nielsen 24761fc28d8eSLiu Bo static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root, 24771fc28d8eSLiu Bo struct btrfs_path *p, 24781fc28d8eSLiu Bo int write_lock_level) 24791fc28d8eSLiu Bo { 24801fc28d8eSLiu Bo struct btrfs_fs_info *fs_info = root->fs_info; 24811fc28d8eSLiu Bo struct extent_buffer *b; 24821fc28d8eSLiu Bo int root_lock; 24831fc28d8eSLiu Bo int level = 0; 24841fc28d8eSLiu Bo 24851fc28d8eSLiu Bo /* We try very hard to do read locks on the root */ 24861fc28d8eSLiu Bo root_lock = BTRFS_READ_LOCK; 24871fc28d8eSLiu Bo 24881fc28d8eSLiu Bo if (p->search_commit_root) { 2489be6821f8SFilipe Manana /* 2490be6821f8SFilipe Manana * The commit roots are read only so we always do read locks, 2491be6821f8SFilipe Manana * and we always must hold the commit_root_sem when doing 2492be6821f8SFilipe Manana * searches on them, the only exception is send where we don't 2493be6821f8SFilipe Manana * want to block transaction commits for a long time, so 2494be6821f8SFilipe Manana * we need to clone the commit root in order to avoid races 2495be6821f8SFilipe Manana * with transaction commits that create a snapshot of one of 2496be6821f8SFilipe Manana * the roots used by a send operation. 2497be6821f8SFilipe Manana */ 2498be6821f8SFilipe Manana if (p->need_commit_sem) { 24991fc28d8eSLiu Bo down_read(&fs_info->commit_root_sem); 2500be6821f8SFilipe Manana b = btrfs_clone_extent_buffer(root->commit_root); 2501be6821f8SFilipe Manana up_read(&fs_info->commit_root_sem); 2502be6821f8SFilipe Manana if (!b) 2503be6821f8SFilipe Manana return ERR_PTR(-ENOMEM); 2504be6821f8SFilipe Manana 2505be6821f8SFilipe Manana } else { 25061fc28d8eSLiu Bo b = root->commit_root; 250767439dadSDavid Sterba atomic_inc(&b->refs); 2508be6821f8SFilipe Manana } 25091fc28d8eSLiu Bo level = btrfs_header_level(b); 2510f9ddfd05SLiu Bo /* 2511f9ddfd05SLiu Bo * Ensure that all callers have set skip_locking when 2512f9ddfd05SLiu Bo * p->search_commit_root = 1. 2513f9ddfd05SLiu Bo */ 2514f9ddfd05SLiu Bo ASSERT(p->skip_locking == 1); 25151fc28d8eSLiu Bo 25161fc28d8eSLiu Bo goto out; 25171fc28d8eSLiu Bo } 25181fc28d8eSLiu Bo 25191fc28d8eSLiu Bo if (p->skip_locking) { 25201fc28d8eSLiu Bo b = btrfs_root_node(root); 25211fc28d8eSLiu Bo level = btrfs_header_level(b); 25221fc28d8eSLiu Bo goto out; 25231fc28d8eSLiu Bo } 25241fc28d8eSLiu Bo 25251fc28d8eSLiu Bo /* 2526662c653bSLiu Bo * If the level is set to maximum, we can skip trying to get the read 2527662c653bSLiu Bo * lock. 2528662c653bSLiu Bo */ 2529662c653bSLiu Bo if (write_lock_level < BTRFS_MAX_LEVEL) { 2530662c653bSLiu Bo /* 2531662c653bSLiu Bo * We don't know the level of the root node until we actually 2532662c653bSLiu Bo * have it read locked 25331fc28d8eSLiu Bo */ 253451899412SJosef Bacik b = __btrfs_read_lock_root_node(root, p->recurse); 25351fc28d8eSLiu Bo level = btrfs_header_level(b); 25361fc28d8eSLiu Bo if (level > write_lock_level) 25371fc28d8eSLiu Bo goto out; 25381fc28d8eSLiu Bo 2539662c653bSLiu Bo /* Whoops, must trade for write lock */ 25401fc28d8eSLiu Bo btrfs_tree_read_unlock(b); 25411fc28d8eSLiu Bo free_extent_buffer(b); 2542662c653bSLiu Bo } 2543662c653bSLiu Bo 25441fc28d8eSLiu Bo b = btrfs_lock_root_node(root); 25451fc28d8eSLiu Bo root_lock = BTRFS_WRITE_LOCK; 25461fc28d8eSLiu Bo 25471fc28d8eSLiu Bo /* The level might have changed, check again */ 25481fc28d8eSLiu Bo level = btrfs_header_level(b); 25491fc28d8eSLiu Bo 25501fc28d8eSLiu Bo out: 25511fc28d8eSLiu Bo p->nodes[level] = b; 25521fc28d8eSLiu Bo if (!p->skip_locking) 25531fc28d8eSLiu Bo p->locks[level] = root_lock; 25541fc28d8eSLiu Bo /* 25551fc28d8eSLiu Bo * Callers are responsible for dropping b's references. 25561fc28d8eSLiu Bo */ 25571fc28d8eSLiu Bo return b; 25581fc28d8eSLiu Bo } 25591fc28d8eSLiu Bo 25601fc28d8eSLiu Bo 2561c8c42864SChris Mason /* 25624271eceaSNikolay Borisov * btrfs_search_slot - look for a key in a tree and perform necessary 25634271eceaSNikolay Borisov * modifications to preserve tree invariants. 256474123bd7SChris Mason * 25654271eceaSNikolay Borisov * @trans: Handle of transaction, used when modifying the tree 25664271eceaSNikolay Borisov * @p: Holds all btree nodes along the search path 25674271eceaSNikolay Borisov * @root: The root node of the tree 25684271eceaSNikolay Borisov * @key: The key we are looking for 25694271eceaSNikolay Borisov * @ins_len: Indicates purpose of search, for inserts it is 1, for 25704271eceaSNikolay Borisov * deletions it's -1. 0 for plain searches 25714271eceaSNikolay Borisov * @cow: boolean should CoW operations be performed. Must always be 1 25724271eceaSNikolay Borisov * when modifying the tree. 257397571fd0SChris Mason * 25744271eceaSNikolay Borisov * If @ins_len > 0, nodes and leaves will be split as we walk down the tree. 25754271eceaSNikolay Borisov * If @ins_len < 0, nodes will be merged as we walk down the tree (if possible) 25764271eceaSNikolay Borisov * 25774271eceaSNikolay Borisov * If @key is found, 0 is returned and you can find the item in the leaf level 25784271eceaSNikolay Borisov * of the path (level 0) 25794271eceaSNikolay Borisov * 25804271eceaSNikolay Borisov * If @key isn't found, 1 is returned and the leaf level of the path (level 0) 25814271eceaSNikolay Borisov * points to the slot where it should be inserted 25824271eceaSNikolay Borisov * 25834271eceaSNikolay Borisov * If an error is encountered while searching the tree a negative error number 25844271eceaSNikolay Borisov * is returned 258574123bd7SChris Mason */ 2586310712b2SOmar Sandoval int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, 2587310712b2SOmar Sandoval const struct btrfs_key *key, struct btrfs_path *p, 2588310712b2SOmar Sandoval int ins_len, int cow) 2589be0e5c09SChris Mason { 25905f39d397SChris Mason struct extent_buffer *b; 2591be0e5c09SChris Mason int slot; 2592be0e5c09SChris Mason int ret; 259333c66f43SYan Zheng int err; 2594be0e5c09SChris Mason int level; 2595925baeddSChris Mason int lowest_unlock = 1; 2596bd681513SChris Mason /* everything at write_lock_level or lower must be write locked */ 2597bd681513SChris Mason int write_lock_level = 0; 25989f3a7427SChris Mason u8 lowest_level = 0; 2599f7c79f30SChris Mason int min_write_lock_level; 2600d7396f07SFilipe David Borba Manana int prev_cmp; 26019f3a7427SChris Mason 26026702ed49SChris Mason lowest_level = p->lowest_level; 2603323ac95bSChris Mason WARN_ON(lowest_level && ins_len > 0); 260422b0ebdaSChris Mason WARN_ON(p->nodes[0] != NULL); 2605eb653de1SFilipe David Borba Manana BUG_ON(!cow && ins_len); 260625179201SJosef Bacik 2607bd681513SChris Mason if (ins_len < 0) { 2608925baeddSChris Mason lowest_unlock = 2; 260965b51a00SChris Mason 2610bd681513SChris Mason /* when we are removing items, we might have to go up to level 2611bd681513SChris Mason * two as we update tree pointers Make sure we keep write 2612bd681513SChris Mason * for those levels as well 2613bd681513SChris Mason */ 2614bd681513SChris Mason write_lock_level = 2; 2615bd681513SChris Mason } else if (ins_len > 0) { 2616bd681513SChris Mason /* 2617bd681513SChris Mason * for inserting items, make sure we have a write lock on 2618bd681513SChris Mason * level 1 so we can update keys 2619bd681513SChris Mason */ 2620bd681513SChris Mason write_lock_level = 1; 2621bd681513SChris Mason } 2622bd681513SChris Mason 2623bd681513SChris Mason if (!cow) 2624bd681513SChris Mason write_lock_level = -1; 2625bd681513SChris Mason 262609a2a8f9SJosef Bacik if (cow && (p->keep_locks || p->lowest_level)) 2627bd681513SChris Mason write_lock_level = BTRFS_MAX_LEVEL; 2628bd681513SChris Mason 2629f7c79f30SChris Mason min_write_lock_level = write_lock_level; 2630f7c79f30SChris Mason 2631bb803951SChris Mason again: 2632d7396f07SFilipe David Borba Manana prev_cmp = -1; 26331fc28d8eSLiu Bo b = btrfs_search_slot_get_root(root, p, write_lock_level); 2634be6821f8SFilipe Manana if (IS_ERR(b)) { 2635be6821f8SFilipe Manana ret = PTR_ERR(b); 2636be6821f8SFilipe Manana goto done; 2637be6821f8SFilipe Manana } 2638925baeddSChris Mason 2639eb60ceacSChris Mason while (b) { 2640f624d976SQu Wenruo int dec = 0; 2641f624d976SQu Wenruo 26425f39d397SChris Mason level = btrfs_header_level(b); 264365b51a00SChris Mason 264402217ed2SChris Mason if (cow) { 26459ea2c7c9SNikolay Borisov bool last_level = (level == (BTRFS_MAX_LEVEL - 1)); 26469ea2c7c9SNikolay Borisov 2647c8c42864SChris Mason /* 2648c8c42864SChris Mason * if we don't really need to cow this block 2649c8c42864SChris Mason * then we don't want to set the path blocking, 2650c8c42864SChris Mason * so we test it here 2651c8c42864SChris Mason */ 265264c12921SJeff Mahoney if (!should_cow_block(trans, root, b)) { 265364c12921SJeff Mahoney trans->dirty = true; 265465b51a00SChris Mason goto cow_done; 265564c12921SJeff Mahoney } 26565d4f98a2SYan Zheng 2657bd681513SChris Mason /* 2658bd681513SChris Mason * must have write locks on this node and the 2659bd681513SChris Mason * parent 2660bd681513SChris Mason */ 26615124e00eSJosef Bacik if (level > write_lock_level || 26625124e00eSJosef Bacik (level + 1 > write_lock_level && 26635124e00eSJosef Bacik level + 1 < BTRFS_MAX_LEVEL && 26645124e00eSJosef Bacik p->nodes[level + 1])) { 2665bd681513SChris Mason write_lock_level = level + 1; 2666bd681513SChris Mason btrfs_release_path(p); 2667bd681513SChris Mason goto again; 2668bd681513SChris Mason } 2669bd681513SChris Mason 26709ea2c7c9SNikolay Borisov if (last_level) 26719ea2c7c9SNikolay Borisov err = btrfs_cow_block(trans, root, b, NULL, 0, 26729631e4ccSJosef Bacik &b, 26739631e4ccSJosef Bacik BTRFS_NESTING_COW); 26749ea2c7c9SNikolay Borisov else 267533c66f43SYan Zheng err = btrfs_cow_block(trans, root, b, 2676e20d96d6SChris Mason p->nodes[level + 1], 26779631e4ccSJosef Bacik p->slots[level + 1], &b, 26789631e4ccSJosef Bacik BTRFS_NESTING_COW); 267933c66f43SYan Zheng if (err) { 268033c66f43SYan Zheng ret = err; 268165b51a00SChris Mason goto done; 268254aa1f4dSChris Mason } 268302217ed2SChris Mason } 268465b51a00SChris Mason cow_done: 2685eb60ceacSChris Mason p->nodes[level] = b; 268652398340SLiu Bo /* 268752398340SLiu Bo * Leave path with blocking locks to avoid massive 268852398340SLiu Bo * lock context switch, this is made on purpose. 268952398340SLiu Bo */ 2690b4ce94deSChris Mason 2691b4ce94deSChris Mason /* 2692b4ce94deSChris Mason * we have a lock on b and as long as we aren't changing 2693b4ce94deSChris Mason * the tree, there is no way to for the items in b to change. 2694b4ce94deSChris Mason * It is safe to drop the lock on our parent before we 2695b4ce94deSChris Mason * go through the expensive btree search on b. 2696b4ce94deSChris Mason * 2697eb653de1SFilipe David Borba Manana * If we're inserting or deleting (ins_len != 0), then we might 2698eb653de1SFilipe David Borba Manana * be changing slot zero, which may require changing the parent. 2699eb653de1SFilipe David Borba Manana * So, we can't drop the lock until after we know which slot 2700eb653de1SFilipe David Borba Manana * we're operating on. 2701b4ce94deSChris Mason */ 2702eb653de1SFilipe David Borba Manana if (!ins_len && !p->keep_locks) { 2703eb653de1SFilipe David Borba Manana int u = level + 1; 2704eb653de1SFilipe David Borba Manana 2705eb653de1SFilipe David Borba Manana if (u < BTRFS_MAX_LEVEL && p->locks[u]) { 2706eb653de1SFilipe David Borba Manana btrfs_tree_unlock_rw(p->nodes[u], p->locks[u]); 2707eb653de1SFilipe David Borba Manana p->locks[u] = 0; 2708eb653de1SFilipe David Borba Manana } 2709eb653de1SFilipe David Borba Manana } 2710b4ce94deSChris Mason 2711995e9a16SNikolay Borisov /* 2712995e9a16SNikolay Borisov * If btrfs_bin_search returns an exact match (prev_cmp == 0) 2713995e9a16SNikolay Borisov * we can safely assume the target key will always be in slot 0 2714995e9a16SNikolay Borisov * on lower levels due to the invariants BTRFS' btree provides, 2715995e9a16SNikolay Borisov * namely that a btrfs_key_ptr entry always points to the 2716995e9a16SNikolay Borisov * lowest key in the child node, thus we can skip searching 2717995e9a16SNikolay Borisov * lower levels 2718995e9a16SNikolay Borisov */ 2719995e9a16SNikolay Borisov if (prev_cmp == 0) { 2720995e9a16SNikolay Borisov slot = 0; 2721995e9a16SNikolay Borisov ret = 0; 2722995e9a16SNikolay Borisov } else { 2723995e9a16SNikolay Borisov ret = btrfs_bin_search(b, key, &slot); 2724995e9a16SNikolay Borisov prev_cmp = ret; 2725415b35a5SLiu Bo if (ret < 0) 2726415b35a5SLiu Bo goto done; 2727995e9a16SNikolay Borisov } 2728b4ce94deSChris Mason 2729f624d976SQu Wenruo if (level == 0) { 2730be0e5c09SChris Mason p->slots[level] = slot; 273187b29b20SYan Zheng if (ins_len > 0 && 2732e902baacSDavid Sterba btrfs_leaf_free_space(b) < ins_len) { 2733bd681513SChris Mason if (write_lock_level < 1) { 2734bd681513SChris Mason write_lock_level = 1; 2735bd681513SChris Mason btrfs_release_path(p); 2736bd681513SChris Mason goto again; 2737bd681513SChris Mason } 2738bd681513SChris Mason 273933c66f43SYan Zheng err = split_leaf(trans, root, key, 2740cc0c5538SChris Mason p, ins_len, ret == 0); 2741b4ce94deSChris Mason 274233c66f43SYan Zheng BUG_ON(err > 0); 274333c66f43SYan Zheng if (err) { 274433c66f43SYan Zheng ret = err; 274565b51a00SChris Mason goto done; 274665b51a00SChris Mason } 27475c680ed6SChris Mason } 2748459931ecSChris Mason if (!p->search_for_split) 2749f7c79f30SChris Mason unlock_up(p, level, lowest_unlock, 27504b6f8e96SLiu Bo min_write_lock_level, NULL); 275165b51a00SChris Mason goto done; 275265b51a00SChris Mason } 2753f624d976SQu Wenruo if (ret && slot > 0) { 2754f624d976SQu Wenruo dec = 1; 2755f624d976SQu Wenruo slot--; 2756f624d976SQu Wenruo } 2757f624d976SQu Wenruo p->slots[level] = slot; 2758f624d976SQu Wenruo err = setup_nodes_for_search(trans, root, p, b, level, ins_len, 2759f624d976SQu Wenruo &write_lock_level); 2760f624d976SQu Wenruo if (err == -EAGAIN) 2761f624d976SQu Wenruo goto again; 2762f624d976SQu Wenruo if (err) { 2763f624d976SQu Wenruo ret = err; 2764f624d976SQu Wenruo goto done; 2765f624d976SQu Wenruo } 2766f624d976SQu Wenruo b = p->nodes[level]; 2767f624d976SQu Wenruo slot = p->slots[level]; 2768f624d976SQu Wenruo 2769f624d976SQu Wenruo /* 2770f624d976SQu Wenruo * Slot 0 is special, if we change the key we have to update 2771f624d976SQu Wenruo * the parent pointer which means we must have a write lock on 2772f624d976SQu Wenruo * the parent 2773f624d976SQu Wenruo */ 2774f624d976SQu Wenruo if (slot == 0 && ins_len && write_lock_level < level + 1) { 2775f624d976SQu Wenruo write_lock_level = level + 1; 2776f624d976SQu Wenruo btrfs_release_path(p); 2777f624d976SQu Wenruo goto again; 2778f624d976SQu Wenruo } 2779f624d976SQu Wenruo 2780f624d976SQu Wenruo unlock_up(p, level, lowest_unlock, min_write_lock_level, 2781f624d976SQu Wenruo &write_lock_level); 2782f624d976SQu Wenruo 2783f624d976SQu Wenruo if (level == lowest_level) { 2784f624d976SQu Wenruo if (dec) 2785f624d976SQu Wenruo p->slots[level]++; 2786f624d976SQu Wenruo goto done; 2787f624d976SQu Wenruo } 2788f624d976SQu Wenruo 2789f624d976SQu Wenruo err = read_block_for_search(root, p, &b, level, slot, key); 2790f624d976SQu Wenruo if (err == -EAGAIN) 2791f624d976SQu Wenruo goto again; 2792f624d976SQu Wenruo if (err) { 2793f624d976SQu Wenruo ret = err; 2794f624d976SQu Wenruo goto done; 2795f624d976SQu Wenruo } 2796f624d976SQu Wenruo 2797f624d976SQu Wenruo if (!p->skip_locking) { 2798f624d976SQu Wenruo level = btrfs_header_level(b); 2799f624d976SQu Wenruo if (level <= write_lock_level) { 2800f624d976SQu Wenruo btrfs_tree_lock(b); 2801f624d976SQu Wenruo p->locks[level] = BTRFS_WRITE_LOCK; 2802f624d976SQu Wenruo } else { 2803fd7ba1c1SJosef Bacik __btrfs_tree_read_lock(b, BTRFS_NESTING_NORMAL, 2804fd7ba1c1SJosef Bacik p->recurse); 2805f624d976SQu Wenruo p->locks[level] = BTRFS_READ_LOCK; 2806f624d976SQu Wenruo } 2807f624d976SQu Wenruo p->nodes[level] = b; 2808f624d976SQu Wenruo } 280965b51a00SChris Mason } 281065b51a00SChris Mason ret = 1; 281165b51a00SChris Mason done: 28125f5bc6b1SFilipe Manana if (ret < 0 && !p->skip_release_on_error) 2813b3b4aa74SDavid Sterba btrfs_release_path(p); 2814be0e5c09SChris Mason return ret; 2815be0e5c09SChris Mason } 2816be0e5c09SChris Mason 281774123bd7SChris Mason /* 28185d9e75c4SJan Schmidt * Like btrfs_search_slot, this looks for a key in the given tree. It uses the 28195d9e75c4SJan Schmidt * current state of the tree together with the operations recorded in the tree 28205d9e75c4SJan Schmidt * modification log to search for the key in a previous version of this tree, as 28215d9e75c4SJan Schmidt * denoted by the time_seq parameter. 28225d9e75c4SJan Schmidt * 28235d9e75c4SJan Schmidt * Naturally, there is no support for insert, delete or cow operations. 28245d9e75c4SJan Schmidt * 28255d9e75c4SJan Schmidt * The resulting path and return value will be set up as if we called 28265d9e75c4SJan Schmidt * btrfs_search_slot at that point in time with ins_len and cow both set to 0. 28275d9e75c4SJan Schmidt */ 2828310712b2SOmar Sandoval int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key, 28295d9e75c4SJan Schmidt struct btrfs_path *p, u64 time_seq) 28305d9e75c4SJan Schmidt { 28310b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 28325d9e75c4SJan Schmidt struct extent_buffer *b; 28335d9e75c4SJan Schmidt int slot; 28345d9e75c4SJan Schmidt int ret; 28355d9e75c4SJan Schmidt int err; 28365d9e75c4SJan Schmidt int level; 28375d9e75c4SJan Schmidt int lowest_unlock = 1; 28385d9e75c4SJan Schmidt u8 lowest_level = 0; 28395d9e75c4SJan Schmidt 28405d9e75c4SJan Schmidt lowest_level = p->lowest_level; 28415d9e75c4SJan Schmidt WARN_ON(p->nodes[0] != NULL); 28425d9e75c4SJan Schmidt 28435d9e75c4SJan Schmidt if (p->search_commit_root) { 28445d9e75c4SJan Schmidt BUG_ON(time_seq); 28455d9e75c4SJan Schmidt return btrfs_search_slot(NULL, root, key, p, 0, 0); 28465d9e75c4SJan Schmidt } 28475d9e75c4SJan Schmidt 28485d9e75c4SJan Schmidt again: 28495d9e75c4SJan Schmidt b = get_old_root(root, time_seq); 2850315bed43SNikolay Borisov if (!b) { 2851315bed43SNikolay Borisov ret = -EIO; 2852315bed43SNikolay Borisov goto done; 2853315bed43SNikolay Borisov } 28545d9e75c4SJan Schmidt level = btrfs_header_level(b); 28555d9e75c4SJan Schmidt p->locks[level] = BTRFS_READ_LOCK; 28565d9e75c4SJan Schmidt 28575d9e75c4SJan Schmidt while (b) { 2858abe9339dSQu Wenruo int dec = 0; 2859abe9339dSQu Wenruo 28605d9e75c4SJan Schmidt level = btrfs_header_level(b); 28615d9e75c4SJan Schmidt p->nodes[level] = b; 28625d9e75c4SJan Schmidt 28635d9e75c4SJan Schmidt /* 28645d9e75c4SJan Schmidt * we have a lock on b and as long as we aren't changing 28655d9e75c4SJan Schmidt * the tree, there is no way to for the items in b to change. 28665d9e75c4SJan Schmidt * It is safe to drop the lock on our parent before we 28675d9e75c4SJan Schmidt * go through the expensive btree search on b. 28685d9e75c4SJan Schmidt */ 28695d9e75c4SJan Schmidt btrfs_unlock_up_safe(p, level + 1); 28705d9e75c4SJan Schmidt 2871995e9a16SNikolay Borisov ret = btrfs_bin_search(b, key, &slot); 2872cbca7d59SFilipe Manana if (ret < 0) 2873cbca7d59SFilipe Manana goto done; 28745d9e75c4SJan Schmidt 2875abe9339dSQu Wenruo if (level == 0) { 2876abe9339dSQu Wenruo p->slots[level] = slot; 2877abe9339dSQu Wenruo unlock_up(p, level, lowest_unlock, 0, NULL); 2878abe9339dSQu Wenruo goto done; 2879abe9339dSQu Wenruo } 2880abe9339dSQu Wenruo 28815d9e75c4SJan Schmidt if (ret && slot > 0) { 28825d9e75c4SJan Schmidt dec = 1; 2883abe9339dSQu Wenruo slot--; 28845d9e75c4SJan Schmidt } 28855d9e75c4SJan Schmidt p->slots[level] = slot; 28865d9e75c4SJan Schmidt unlock_up(p, level, lowest_unlock, 0, NULL); 28875d9e75c4SJan Schmidt 28885d9e75c4SJan Schmidt if (level == lowest_level) { 28895d9e75c4SJan Schmidt if (dec) 28905d9e75c4SJan Schmidt p->slots[level]++; 28915d9e75c4SJan Schmidt goto done; 28925d9e75c4SJan Schmidt } 28935d9e75c4SJan Schmidt 2894abe9339dSQu Wenruo err = read_block_for_search(root, p, &b, level, slot, key); 28955d9e75c4SJan Schmidt if (err == -EAGAIN) 28965d9e75c4SJan Schmidt goto again; 28975d9e75c4SJan Schmidt if (err) { 28985d9e75c4SJan Schmidt ret = err; 28995d9e75c4SJan Schmidt goto done; 29005d9e75c4SJan Schmidt } 29015d9e75c4SJan Schmidt 29025d9e75c4SJan Schmidt level = btrfs_header_level(b); 29035d9e75c4SJan Schmidt btrfs_tree_read_lock(b); 29040b246afaSJeff Mahoney b = tree_mod_log_rewind(fs_info, p, b, time_seq); 2905db7f3436SJosef Bacik if (!b) { 2906db7f3436SJosef Bacik ret = -ENOMEM; 2907db7f3436SJosef Bacik goto done; 2908db7f3436SJosef Bacik } 29095d9e75c4SJan Schmidt p->locks[level] = BTRFS_READ_LOCK; 29105d9e75c4SJan Schmidt p->nodes[level] = b; 29115d9e75c4SJan Schmidt } 29125d9e75c4SJan Schmidt ret = 1; 29135d9e75c4SJan Schmidt done: 29145d9e75c4SJan Schmidt if (ret < 0) 29155d9e75c4SJan Schmidt btrfs_release_path(p); 29165d9e75c4SJan Schmidt 29175d9e75c4SJan Schmidt return ret; 29185d9e75c4SJan Schmidt } 29195d9e75c4SJan Schmidt 29205d9e75c4SJan Schmidt /* 29212f38b3e1SArne Jansen * helper to use instead of search slot if no exact match is needed but 29222f38b3e1SArne Jansen * instead the next or previous item should be returned. 29232f38b3e1SArne Jansen * When find_higher is true, the next higher item is returned, the next lower 29242f38b3e1SArne Jansen * otherwise. 29252f38b3e1SArne Jansen * When return_any and find_higher are both true, and no higher item is found, 29262f38b3e1SArne Jansen * return the next lower instead. 29272f38b3e1SArne Jansen * When return_any is true and find_higher is false, and no lower item is found, 29282f38b3e1SArne Jansen * return the next higher instead. 29292f38b3e1SArne Jansen * It returns 0 if any item is found, 1 if none is found (tree empty), and 29302f38b3e1SArne Jansen * < 0 on error 29312f38b3e1SArne Jansen */ 29322f38b3e1SArne Jansen int btrfs_search_slot_for_read(struct btrfs_root *root, 2933310712b2SOmar Sandoval const struct btrfs_key *key, 2934310712b2SOmar Sandoval struct btrfs_path *p, int find_higher, 2935310712b2SOmar Sandoval int return_any) 29362f38b3e1SArne Jansen { 29372f38b3e1SArne Jansen int ret; 29382f38b3e1SArne Jansen struct extent_buffer *leaf; 29392f38b3e1SArne Jansen 29402f38b3e1SArne Jansen again: 29412f38b3e1SArne Jansen ret = btrfs_search_slot(NULL, root, key, p, 0, 0); 29422f38b3e1SArne Jansen if (ret <= 0) 29432f38b3e1SArne Jansen return ret; 29442f38b3e1SArne Jansen /* 29452f38b3e1SArne Jansen * a return value of 1 means the path is at the position where the 29462f38b3e1SArne Jansen * item should be inserted. Normally this is the next bigger item, 29472f38b3e1SArne Jansen * but in case the previous item is the last in a leaf, path points 29482f38b3e1SArne Jansen * to the first free slot in the previous leaf, i.e. at an invalid 29492f38b3e1SArne Jansen * item. 29502f38b3e1SArne Jansen */ 29512f38b3e1SArne Jansen leaf = p->nodes[0]; 29522f38b3e1SArne Jansen 29532f38b3e1SArne Jansen if (find_higher) { 29542f38b3e1SArne Jansen if (p->slots[0] >= btrfs_header_nritems(leaf)) { 29552f38b3e1SArne Jansen ret = btrfs_next_leaf(root, p); 29562f38b3e1SArne Jansen if (ret <= 0) 29572f38b3e1SArne Jansen return ret; 29582f38b3e1SArne Jansen if (!return_any) 29592f38b3e1SArne Jansen return 1; 29602f38b3e1SArne Jansen /* 29612f38b3e1SArne Jansen * no higher item found, return the next 29622f38b3e1SArne Jansen * lower instead 29632f38b3e1SArne Jansen */ 29642f38b3e1SArne Jansen return_any = 0; 29652f38b3e1SArne Jansen find_higher = 0; 29662f38b3e1SArne Jansen btrfs_release_path(p); 29672f38b3e1SArne Jansen goto again; 29682f38b3e1SArne Jansen } 29692f38b3e1SArne Jansen } else { 29702f38b3e1SArne Jansen if (p->slots[0] == 0) { 29712f38b3e1SArne Jansen ret = btrfs_prev_leaf(root, p); 2972e6793769SArne Jansen if (ret < 0) 29732f38b3e1SArne Jansen return ret; 2974e6793769SArne Jansen if (!ret) { 297523c6bf6aSFilipe David Borba Manana leaf = p->nodes[0]; 297623c6bf6aSFilipe David Borba Manana if (p->slots[0] == btrfs_header_nritems(leaf)) 297723c6bf6aSFilipe David Borba Manana p->slots[0]--; 2978e6793769SArne Jansen return 0; 2979e6793769SArne Jansen } 29802f38b3e1SArne Jansen if (!return_any) 29812f38b3e1SArne Jansen return 1; 29822f38b3e1SArne Jansen /* 29832f38b3e1SArne Jansen * no lower item found, return the next 29842f38b3e1SArne Jansen * higher instead 29852f38b3e1SArne Jansen */ 29862f38b3e1SArne Jansen return_any = 0; 29872f38b3e1SArne Jansen find_higher = 1; 29882f38b3e1SArne Jansen btrfs_release_path(p); 29892f38b3e1SArne Jansen goto again; 2990e6793769SArne Jansen } else { 29912f38b3e1SArne Jansen --p->slots[0]; 29922f38b3e1SArne Jansen } 29932f38b3e1SArne Jansen } 29942f38b3e1SArne Jansen return 0; 29952f38b3e1SArne Jansen } 29962f38b3e1SArne Jansen 29972f38b3e1SArne Jansen /* 299874123bd7SChris Mason * adjust the pointers going up the tree, starting at level 299974123bd7SChris Mason * making sure the right key of each node is points to 'key'. 300074123bd7SChris Mason * This is used after shifting pointers to the left, so it stops 300174123bd7SChris Mason * fixing up pointers when a given leaf/node is not in slot 0 of the 300274123bd7SChris Mason * higher levels 3003aa5d6bedSChris Mason * 300474123bd7SChris Mason */ 3005b167fa91SNikolay Borisov static void fixup_low_keys(struct btrfs_path *path, 30065f39d397SChris Mason struct btrfs_disk_key *key, int level) 3007be0e5c09SChris Mason { 3008be0e5c09SChris Mason int i; 30095f39d397SChris Mason struct extent_buffer *t; 30100e82bcfeSDavid Sterba int ret; 30115f39d397SChris Mason 3012234b63a0SChris Mason for (i = level; i < BTRFS_MAX_LEVEL; i++) { 3013be0e5c09SChris Mason int tslot = path->slots[i]; 30140e82bcfeSDavid Sterba 3015eb60ceacSChris Mason if (!path->nodes[i]) 3016be0e5c09SChris Mason break; 30175f39d397SChris Mason t = path->nodes[i]; 30180e82bcfeSDavid Sterba ret = tree_mod_log_insert_key(t, tslot, MOD_LOG_KEY_REPLACE, 30190e82bcfeSDavid Sterba GFP_ATOMIC); 30200e82bcfeSDavid Sterba BUG_ON(ret < 0); 30215f39d397SChris Mason btrfs_set_node_key(t, key, tslot); 3022d6025579SChris Mason btrfs_mark_buffer_dirty(path->nodes[i]); 3023be0e5c09SChris Mason if (tslot != 0) 3024be0e5c09SChris Mason break; 3025be0e5c09SChris Mason } 3026be0e5c09SChris Mason } 3027be0e5c09SChris Mason 302874123bd7SChris Mason /* 302931840ae1SZheng Yan * update item key. 303031840ae1SZheng Yan * 303131840ae1SZheng Yan * This function isn't completely safe. It's the caller's responsibility 303231840ae1SZheng Yan * that the new key won't break the order 303331840ae1SZheng Yan */ 3034b7a0365eSDaniel Dressler void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info, 3035b7a0365eSDaniel Dressler struct btrfs_path *path, 3036310712b2SOmar Sandoval const struct btrfs_key *new_key) 303731840ae1SZheng Yan { 303831840ae1SZheng Yan struct btrfs_disk_key disk_key; 303931840ae1SZheng Yan struct extent_buffer *eb; 304031840ae1SZheng Yan int slot; 304131840ae1SZheng Yan 304231840ae1SZheng Yan eb = path->nodes[0]; 304331840ae1SZheng Yan slot = path->slots[0]; 304431840ae1SZheng Yan if (slot > 0) { 304531840ae1SZheng Yan btrfs_item_key(eb, &disk_key, slot - 1); 30467c15d410SQu Wenruo if (unlikely(comp_keys(&disk_key, new_key) >= 0)) { 30477c15d410SQu Wenruo btrfs_crit(fs_info, 30487c15d410SQu Wenruo "slot %u key (%llu %u %llu) new key (%llu %u %llu)", 30497c15d410SQu Wenruo slot, btrfs_disk_key_objectid(&disk_key), 30507c15d410SQu Wenruo btrfs_disk_key_type(&disk_key), 30517c15d410SQu Wenruo btrfs_disk_key_offset(&disk_key), 30527c15d410SQu Wenruo new_key->objectid, new_key->type, 30537c15d410SQu Wenruo new_key->offset); 30547c15d410SQu Wenruo btrfs_print_leaf(eb); 30557c15d410SQu Wenruo BUG(); 30567c15d410SQu Wenruo } 305731840ae1SZheng Yan } 305831840ae1SZheng Yan if (slot < btrfs_header_nritems(eb) - 1) { 305931840ae1SZheng Yan btrfs_item_key(eb, &disk_key, slot + 1); 30607c15d410SQu Wenruo if (unlikely(comp_keys(&disk_key, new_key) <= 0)) { 30617c15d410SQu Wenruo btrfs_crit(fs_info, 30627c15d410SQu Wenruo "slot %u key (%llu %u %llu) new key (%llu %u %llu)", 30637c15d410SQu Wenruo slot, btrfs_disk_key_objectid(&disk_key), 30647c15d410SQu Wenruo btrfs_disk_key_type(&disk_key), 30657c15d410SQu Wenruo btrfs_disk_key_offset(&disk_key), 30667c15d410SQu Wenruo new_key->objectid, new_key->type, 30677c15d410SQu Wenruo new_key->offset); 30687c15d410SQu Wenruo btrfs_print_leaf(eb); 30697c15d410SQu Wenruo BUG(); 30707c15d410SQu Wenruo } 307131840ae1SZheng Yan } 307231840ae1SZheng Yan 307331840ae1SZheng Yan btrfs_cpu_key_to_disk(&disk_key, new_key); 307431840ae1SZheng Yan btrfs_set_item_key(eb, &disk_key, slot); 307531840ae1SZheng Yan btrfs_mark_buffer_dirty(eb); 307631840ae1SZheng Yan if (slot == 0) 3077b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 307831840ae1SZheng Yan } 307931840ae1SZheng Yan 308031840ae1SZheng Yan /* 3081d16c702fSQu Wenruo * Check key order of two sibling extent buffers. 3082d16c702fSQu Wenruo * 3083d16c702fSQu Wenruo * Return true if something is wrong. 3084d16c702fSQu Wenruo * Return false if everything is fine. 3085d16c702fSQu Wenruo * 3086d16c702fSQu Wenruo * Tree-checker only works inside one tree block, thus the following 3087d16c702fSQu Wenruo * corruption can not be detected by tree-checker: 3088d16c702fSQu Wenruo * 3089d16c702fSQu Wenruo * Leaf @left | Leaf @right 3090d16c702fSQu Wenruo * -------------------------------------------------------------- 3091d16c702fSQu Wenruo * | 1 | 2 | 3 | 4 | 5 | f6 | | 7 | 8 | 3092d16c702fSQu Wenruo * 3093d16c702fSQu Wenruo * Key f6 in leaf @left itself is valid, but not valid when the next 3094d16c702fSQu Wenruo * key in leaf @right is 7. 3095d16c702fSQu Wenruo * This can only be checked at tree block merge time. 3096d16c702fSQu Wenruo * And since tree checker has ensured all key order in each tree block 3097d16c702fSQu Wenruo * is correct, we only need to bother the last key of @left and the first 3098d16c702fSQu Wenruo * key of @right. 3099d16c702fSQu Wenruo */ 3100d16c702fSQu Wenruo static bool check_sibling_keys(struct extent_buffer *left, 3101d16c702fSQu Wenruo struct extent_buffer *right) 3102d16c702fSQu Wenruo { 3103d16c702fSQu Wenruo struct btrfs_key left_last; 3104d16c702fSQu Wenruo struct btrfs_key right_first; 3105d16c702fSQu Wenruo int level = btrfs_header_level(left); 3106d16c702fSQu Wenruo int nr_left = btrfs_header_nritems(left); 3107d16c702fSQu Wenruo int nr_right = btrfs_header_nritems(right); 3108d16c702fSQu Wenruo 3109d16c702fSQu Wenruo /* No key to check in one of the tree blocks */ 3110d16c702fSQu Wenruo if (!nr_left || !nr_right) 3111d16c702fSQu Wenruo return false; 3112d16c702fSQu Wenruo 3113d16c702fSQu Wenruo if (level) { 3114d16c702fSQu Wenruo btrfs_node_key_to_cpu(left, &left_last, nr_left - 1); 3115d16c702fSQu Wenruo btrfs_node_key_to_cpu(right, &right_first, 0); 3116d16c702fSQu Wenruo } else { 3117d16c702fSQu Wenruo btrfs_item_key_to_cpu(left, &left_last, nr_left - 1); 3118d16c702fSQu Wenruo btrfs_item_key_to_cpu(right, &right_first, 0); 3119d16c702fSQu Wenruo } 3120d16c702fSQu Wenruo 3121d16c702fSQu Wenruo if (btrfs_comp_cpu_keys(&left_last, &right_first) >= 0) { 3122d16c702fSQu Wenruo btrfs_crit(left->fs_info, 3123d16c702fSQu Wenruo "bad key order, sibling blocks, left last (%llu %u %llu) right first (%llu %u %llu)", 3124d16c702fSQu Wenruo left_last.objectid, left_last.type, 3125d16c702fSQu Wenruo left_last.offset, right_first.objectid, 3126d16c702fSQu Wenruo right_first.type, right_first.offset); 3127d16c702fSQu Wenruo return true; 3128d16c702fSQu Wenruo } 3129d16c702fSQu Wenruo return false; 3130d16c702fSQu Wenruo } 3131d16c702fSQu Wenruo 3132d16c702fSQu Wenruo /* 313374123bd7SChris Mason * try to push data from one node into the next node left in the 313479f95c82SChris Mason * tree. 3135aa5d6bedSChris Mason * 3136aa5d6bedSChris Mason * returns 0 if some ptrs were pushed left, < 0 if there was some horrible 3137aa5d6bedSChris Mason * error, and > 0 if there was no room in the left hand block. 313874123bd7SChris Mason */ 313998ed5174SChris Mason static int push_node_left(struct btrfs_trans_handle *trans, 31402ff7e61eSJeff Mahoney struct extent_buffer *dst, 3141971a1f66SChris Mason struct extent_buffer *src, int empty) 3142be0e5c09SChris Mason { 3143d30a668fSDavid Sterba struct btrfs_fs_info *fs_info = trans->fs_info; 3144be0e5c09SChris Mason int push_items = 0; 3145bb803951SChris Mason int src_nritems; 3146bb803951SChris Mason int dst_nritems; 3147aa5d6bedSChris Mason int ret = 0; 3148be0e5c09SChris Mason 31495f39d397SChris Mason src_nritems = btrfs_header_nritems(src); 31505f39d397SChris Mason dst_nritems = btrfs_header_nritems(dst); 31510b246afaSJeff Mahoney push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; 31527bb86316SChris Mason WARN_ON(btrfs_header_generation(src) != trans->transid); 31537bb86316SChris Mason WARN_ON(btrfs_header_generation(dst) != trans->transid); 315454aa1f4dSChris Mason 3155bce4eae9SChris Mason if (!empty && src_nritems <= 8) 3156971a1f66SChris Mason return 1; 3157971a1f66SChris Mason 3158d397712bSChris Mason if (push_items <= 0) 3159be0e5c09SChris Mason return 1; 3160be0e5c09SChris Mason 3161bce4eae9SChris Mason if (empty) { 3162971a1f66SChris Mason push_items = min(src_nritems, push_items); 3163bce4eae9SChris Mason if (push_items < src_nritems) { 3164bce4eae9SChris Mason /* leave at least 8 pointers in the node if 3165bce4eae9SChris Mason * we aren't going to empty it 3166bce4eae9SChris Mason */ 3167bce4eae9SChris Mason if (src_nritems - push_items < 8) { 3168bce4eae9SChris Mason if (push_items <= 8) 3169bce4eae9SChris Mason return 1; 3170bce4eae9SChris Mason push_items -= 8; 3171bce4eae9SChris Mason } 3172bce4eae9SChris Mason } 3173bce4eae9SChris Mason } else 3174bce4eae9SChris Mason push_items = min(src_nritems - 8, push_items); 317579f95c82SChris Mason 3176d16c702fSQu Wenruo /* dst is the left eb, src is the middle eb */ 3177d16c702fSQu Wenruo if (check_sibling_keys(dst, src)) { 3178d16c702fSQu Wenruo ret = -EUCLEAN; 3179d16c702fSQu Wenruo btrfs_abort_transaction(trans, ret); 3180d16c702fSQu Wenruo return ret; 3181d16c702fSQu Wenruo } 3182ed874f0dSDavid Sterba ret = tree_mod_log_eb_copy(dst, src, dst_nritems, 0, push_items); 31835de865eeSFilipe David Borba Manana if (ret) { 318466642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 31855de865eeSFilipe David Borba Manana return ret; 31865de865eeSFilipe David Borba Manana } 31875f39d397SChris Mason copy_extent_buffer(dst, src, 31885f39d397SChris Mason btrfs_node_key_ptr_offset(dst_nritems), 31895f39d397SChris Mason btrfs_node_key_ptr_offset(0), 3190123abc88SChris Mason push_items * sizeof(struct btrfs_key_ptr)); 31915f39d397SChris Mason 3192bb803951SChris Mason if (push_items < src_nritems) { 319357911b8bSJan Schmidt /* 3194bf1d3425SDavid Sterba * Don't call tree_mod_log_insert_move here, key removal was 3195bf1d3425SDavid Sterba * already fully logged by tree_mod_log_eb_copy above. 319657911b8bSJan Schmidt */ 31975f39d397SChris Mason memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), 31985f39d397SChris Mason btrfs_node_key_ptr_offset(push_items), 3199e2fa7227SChris Mason (src_nritems - push_items) * 3200123abc88SChris Mason sizeof(struct btrfs_key_ptr)); 3201bb803951SChris Mason } 32025f39d397SChris Mason btrfs_set_header_nritems(src, src_nritems - push_items); 32035f39d397SChris Mason btrfs_set_header_nritems(dst, dst_nritems + push_items); 32045f39d397SChris Mason btrfs_mark_buffer_dirty(src); 32055f39d397SChris Mason btrfs_mark_buffer_dirty(dst); 320631840ae1SZheng Yan 3207bb803951SChris Mason return ret; 3208be0e5c09SChris Mason } 3209be0e5c09SChris Mason 321097571fd0SChris Mason /* 321179f95c82SChris Mason * try to push data from one node into the next node right in the 321279f95c82SChris Mason * tree. 321379f95c82SChris Mason * 321479f95c82SChris Mason * returns 0 if some ptrs were pushed, < 0 if there was some horrible 321579f95c82SChris Mason * error, and > 0 if there was no room in the right hand block. 321679f95c82SChris Mason * 321779f95c82SChris Mason * this will only push up to 1/2 the contents of the left node over 321879f95c82SChris Mason */ 32195f39d397SChris Mason static int balance_node_right(struct btrfs_trans_handle *trans, 32205f39d397SChris Mason struct extent_buffer *dst, 32215f39d397SChris Mason struct extent_buffer *src) 322279f95c82SChris Mason { 322355d32ed8SDavid Sterba struct btrfs_fs_info *fs_info = trans->fs_info; 322479f95c82SChris Mason int push_items = 0; 322579f95c82SChris Mason int max_push; 322679f95c82SChris Mason int src_nritems; 322779f95c82SChris Mason int dst_nritems; 322879f95c82SChris Mason int ret = 0; 322979f95c82SChris Mason 32307bb86316SChris Mason WARN_ON(btrfs_header_generation(src) != trans->transid); 32317bb86316SChris Mason WARN_ON(btrfs_header_generation(dst) != trans->transid); 32327bb86316SChris Mason 32335f39d397SChris Mason src_nritems = btrfs_header_nritems(src); 32345f39d397SChris Mason dst_nritems = btrfs_header_nritems(dst); 32350b246afaSJeff Mahoney push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; 3236d397712bSChris Mason if (push_items <= 0) 323779f95c82SChris Mason return 1; 3238bce4eae9SChris Mason 3239d397712bSChris Mason if (src_nritems < 4) 3240bce4eae9SChris Mason return 1; 324179f95c82SChris Mason 324279f95c82SChris Mason max_push = src_nritems / 2 + 1; 324379f95c82SChris Mason /* don't try to empty the node */ 3244d397712bSChris Mason if (max_push >= src_nritems) 324579f95c82SChris Mason return 1; 3246252c38f0SYan 324779f95c82SChris Mason if (max_push < push_items) 324879f95c82SChris Mason push_items = max_push; 324979f95c82SChris Mason 3250d16c702fSQu Wenruo /* dst is the right eb, src is the middle eb */ 3251d16c702fSQu Wenruo if (check_sibling_keys(src, dst)) { 3252d16c702fSQu Wenruo ret = -EUCLEAN; 3253d16c702fSQu Wenruo btrfs_abort_transaction(trans, ret); 3254d16c702fSQu Wenruo return ret; 3255d16c702fSQu Wenruo } 3256bf1d3425SDavid Sterba ret = tree_mod_log_insert_move(dst, push_items, 0, dst_nritems); 3257bf1d3425SDavid Sterba BUG_ON(ret < 0); 32585f39d397SChris Mason memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), 32595f39d397SChris Mason btrfs_node_key_ptr_offset(0), 32605f39d397SChris Mason (dst_nritems) * 32615f39d397SChris Mason sizeof(struct btrfs_key_ptr)); 3262d6025579SChris Mason 3263ed874f0dSDavid Sterba ret = tree_mod_log_eb_copy(dst, src, 0, src_nritems - push_items, 3264ed874f0dSDavid Sterba push_items); 32655de865eeSFilipe David Borba Manana if (ret) { 326666642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 32675de865eeSFilipe David Borba Manana return ret; 32685de865eeSFilipe David Borba Manana } 32695f39d397SChris Mason copy_extent_buffer(dst, src, 32705f39d397SChris Mason btrfs_node_key_ptr_offset(0), 32715f39d397SChris Mason btrfs_node_key_ptr_offset(src_nritems - push_items), 3272123abc88SChris Mason push_items * sizeof(struct btrfs_key_ptr)); 327379f95c82SChris Mason 32745f39d397SChris Mason btrfs_set_header_nritems(src, src_nritems - push_items); 32755f39d397SChris Mason btrfs_set_header_nritems(dst, dst_nritems + push_items); 327679f95c82SChris Mason 32775f39d397SChris Mason btrfs_mark_buffer_dirty(src); 32785f39d397SChris Mason btrfs_mark_buffer_dirty(dst); 327931840ae1SZheng Yan 328079f95c82SChris Mason return ret; 328179f95c82SChris Mason } 328279f95c82SChris Mason 328379f95c82SChris Mason /* 328497571fd0SChris Mason * helper function to insert a new root level in the tree. 328597571fd0SChris Mason * A new node is allocated, and a single item is inserted to 328697571fd0SChris Mason * point to the existing root 3287aa5d6bedSChris Mason * 3288aa5d6bedSChris Mason * returns zero on success or < 0 on failure. 328997571fd0SChris Mason */ 3290d397712bSChris Mason static noinline int insert_new_root(struct btrfs_trans_handle *trans, 32915f39d397SChris Mason struct btrfs_root *root, 3292fdd99c72SLiu Bo struct btrfs_path *path, int level) 329374123bd7SChris Mason { 32940b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 32957bb86316SChris Mason u64 lower_gen; 32965f39d397SChris Mason struct extent_buffer *lower; 32975f39d397SChris Mason struct extent_buffer *c; 3298925baeddSChris Mason struct extent_buffer *old; 32995f39d397SChris Mason struct btrfs_disk_key lower_key; 3300d9d19a01SDavid Sterba int ret; 33015c680ed6SChris Mason 33025c680ed6SChris Mason BUG_ON(path->nodes[level]); 33035c680ed6SChris Mason BUG_ON(path->nodes[level-1] != root->node); 33045c680ed6SChris Mason 33057bb86316SChris Mason lower = path->nodes[level-1]; 33067bb86316SChris Mason if (level == 1) 33077bb86316SChris Mason btrfs_item_key(lower, &lower_key, 0); 33087bb86316SChris Mason else 33097bb86316SChris Mason btrfs_node_key(lower, &lower_key, 0); 33107bb86316SChris Mason 3311a6279470SFilipe Manana c = alloc_tree_block_no_bg_flush(trans, root, 0, &lower_key, level, 33129631e4ccSJosef Bacik root->node->start, 0, 3313cf6f34aaSJosef Bacik BTRFS_NESTING_NEW_ROOT); 33145f39d397SChris Mason if (IS_ERR(c)) 33155f39d397SChris Mason return PTR_ERR(c); 3316925baeddSChris Mason 33170b246afaSJeff Mahoney root_add_used(root, fs_info->nodesize); 3318f0486c68SYan, Zheng 33195f39d397SChris Mason btrfs_set_header_nritems(c, 1); 33205f39d397SChris Mason btrfs_set_node_key(c, &lower_key, 0); 3321db94535dSChris Mason btrfs_set_node_blockptr(c, 0, lower->start); 33227bb86316SChris Mason lower_gen = btrfs_header_generation(lower); 332331840ae1SZheng Yan WARN_ON(lower_gen != trans->transid); 33247bb86316SChris Mason 33257bb86316SChris Mason btrfs_set_node_ptr_generation(c, 0, lower_gen); 33265f39d397SChris Mason 33275f39d397SChris Mason btrfs_mark_buffer_dirty(c); 3328d5719762SChris Mason 3329925baeddSChris Mason old = root->node; 3330d9d19a01SDavid Sterba ret = tree_mod_log_insert_root(root->node, c, 0); 3331d9d19a01SDavid Sterba BUG_ON(ret < 0); 3332240f62c8SChris Mason rcu_assign_pointer(root->node, c); 3333925baeddSChris Mason 3334925baeddSChris Mason /* the super has an extra ref to root->node */ 3335925baeddSChris Mason free_extent_buffer(old); 3336925baeddSChris Mason 33370b86a832SChris Mason add_root_to_dirty_list(root); 333867439dadSDavid Sterba atomic_inc(&c->refs); 33395f39d397SChris Mason path->nodes[level] = c; 3340ac5887c8SJosef Bacik path->locks[level] = BTRFS_WRITE_LOCK; 334174123bd7SChris Mason path->slots[level] = 0; 334274123bd7SChris Mason return 0; 334374123bd7SChris Mason } 33445c680ed6SChris Mason 33455c680ed6SChris Mason /* 33465c680ed6SChris Mason * worker function to insert a single pointer in a node. 33475c680ed6SChris Mason * the node should have enough room for the pointer already 334897571fd0SChris Mason * 33495c680ed6SChris Mason * slot and level indicate where you want the key to go, and 33505c680ed6SChris Mason * blocknr is the block the key points to. 33515c680ed6SChris Mason */ 3352143bede5SJeff Mahoney static void insert_ptr(struct btrfs_trans_handle *trans, 33536ad3cf6dSDavid Sterba struct btrfs_path *path, 3354143bede5SJeff Mahoney struct btrfs_disk_key *key, u64 bytenr, 3355c3e06965SJan Schmidt int slot, int level) 33565c680ed6SChris Mason { 33575f39d397SChris Mason struct extent_buffer *lower; 33585c680ed6SChris Mason int nritems; 3359f3ea38daSJan Schmidt int ret; 33605c680ed6SChris Mason 33615c680ed6SChris Mason BUG_ON(!path->nodes[level]); 3362f0486c68SYan, Zheng btrfs_assert_tree_locked(path->nodes[level]); 33635f39d397SChris Mason lower = path->nodes[level]; 33645f39d397SChris Mason nritems = btrfs_header_nritems(lower); 3365c293498bSStoyan Gaydarov BUG_ON(slot > nritems); 33666ad3cf6dSDavid Sterba BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(trans->fs_info)); 336774123bd7SChris Mason if (slot != nritems) { 3368bf1d3425SDavid Sterba if (level) { 3369bf1d3425SDavid Sterba ret = tree_mod_log_insert_move(lower, slot + 1, slot, 3370a446a979SDavid Sterba nritems - slot); 3371bf1d3425SDavid Sterba BUG_ON(ret < 0); 3372bf1d3425SDavid Sterba } 33735f39d397SChris Mason memmove_extent_buffer(lower, 33745f39d397SChris Mason btrfs_node_key_ptr_offset(slot + 1), 33755f39d397SChris Mason btrfs_node_key_ptr_offset(slot), 3376123abc88SChris Mason (nritems - slot) * sizeof(struct btrfs_key_ptr)); 337774123bd7SChris Mason } 3378c3e06965SJan Schmidt if (level) { 3379e09c2efeSDavid Sterba ret = tree_mod_log_insert_key(lower, slot, MOD_LOG_KEY_ADD, 3380e09c2efeSDavid Sterba GFP_NOFS); 3381f3ea38daSJan Schmidt BUG_ON(ret < 0); 3382f3ea38daSJan Schmidt } 33835f39d397SChris Mason btrfs_set_node_key(lower, key, slot); 3384db94535dSChris Mason btrfs_set_node_blockptr(lower, slot, bytenr); 338574493f7aSChris Mason WARN_ON(trans->transid == 0); 338674493f7aSChris Mason btrfs_set_node_ptr_generation(lower, slot, trans->transid); 33875f39d397SChris Mason btrfs_set_header_nritems(lower, nritems + 1); 33885f39d397SChris Mason btrfs_mark_buffer_dirty(lower); 338974123bd7SChris Mason } 339074123bd7SChris Mason 339197571fd0SChris Mason /* 339297571fd0SChris Mason * split the node at the specified level in path in two. 339397571fd0SChris Mason * The path is corrected to point to the appropriate node after the split 339497571fd0SChris Mason * 339597571fd0SChris Mason * Before splitting this tries to make some room in the node by pushing 339697571fd0SChris Mason * left and right, if either one works, it returns right away. 3397aa5d6bedSChris Mason * 3398aa5d6bedSChris Mason * returns 0 on success and < 0 on failure 339997571fd0SChris Mason */ 3400e02119d5SChris Mason static noinline int split_node(struct btrfs_trans_handle *trans, 3401e02119d5SChris Mason struct btrfs_root *root, 3402e02119d5SChris Mason struct btrfs_path *path, int level) 3403be0e5c09SChris Mason { 34040b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 34055f39d397SChris Mason struct extent_buffer *c; 34065f39d397SChris Mason struct extent_buffer *split; 34075f39d397SChris Mason struct btrfs_disk_key disk_key; 3408be0e5c09SChris Mason int mid; 34095c680ed6SChris Mason int ret; 34107518a238SChris Mason u32 c_nritems; 3411be0e5c09SChris Mason 34125f39d397SChris Mason c = path->nodes[level]; 34137bb86316SChris Mason WARN_ON(btrfs_header_generation(c) != trans->transid); 34145f39d397SChris Mason if (c == root->node) { 3415d9abbf1cSJan Schmidt /* 341690f8d62eSJan Schmidt * trying to split the root, lets make a new one 341790f8d62eSJan Schmidt * 3418fdd99c72SLiu Bo * tree mod log: We don't log_removal old root in 341990f8d62eSJan Schmidt * insert_new_root, because that root buffer will be kept as a 342090f8d62eSJan Schmidt * normal node. We are going to log removal of half of the 342190f8d62eSJan Schmidt * elements below with tree_mod_log_eb_copy. We're holding a 342290f8d62eSJan Schmidt * tree lock on the buffer, which is why we cannot race with 342390f8d62eSJan Schmidt * other tree_mod_log users. 3424d9abbf1cSJan Schmidt */ 3425fdd99c72SLiu Bo ret = insert_new_root(trans, root, path, level + 1); 34265c680ed6SChris Mason if (ret) 34275c680ed6SChris Mason return ret; 3428b3612421SChris Mason } else { 3429e66f709bSChris Mason ret = push_nodes_for_insert(trans, root, path, level); 34305f39d397SChris Mason c = path->nodes[level]; 34315f39d397SChris Mason if (!ret && btrfs_header_nritems(c) < 34320b246afaSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) 3433e66f709bSChris Mason return 0; 343454aa1f4dSChris Mason if (ret < 0) 343554aa1f4dSChris Mason return ret; 34365c680ed6SChris Mason } 3437e66f709bSChris Mason 34385f39d397SChris Mason c_nritems = btrfs_header_nritems(c); 34395d4f98a2SYan Zheng mid = (c_nritems + 1) / 2; 34405d4f98a2SYan Zheng btrfs_node_key(c, &disk_key, mid); 34417bb86316SChris Mason 3442a6279470SFilipe Manana split = alloc_tree_block_no_bg_flush(trans, root, 0, &disk_key, level, 34434dff97e6SJosef Bacik c->start, 0, BTRFS_NESTING_SPLIT); 34445f39d397SChris Mason if (IS_ERR(split)) 34455f39d397SChris Mason return PTR_ERR(split); 344654aa1f4dSChris Mason 34470b246afaSJeff Mahoney root_add_used(root, fs_info->nodesize); 3448bc877d28SNikolay Borisov ASSERT(btrfs_header_level(c) == level); 34495f39d397SChris Mason 3450ed874f0dSDavid Sterba ret = tree_mod_log_eb_copy(split, c, 0, mid, c_nritems - mid); 34515de865eeSFilipe David Borba Manana if (ret) { 345266642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 34535de865eeSFilipe David Borba Manana return ret; 34545de865eeSFilipe David Borba Manana } 34555f39d397SChris Mason copy_extent_buffer(split, c, 34565f39d397SChris Mason btrfs_node_key_ptr_offset(0), 34575f39d397SChris Mason btrfs_node_key_ptr_offset(mid), 3458123abc88SChris Mason (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); 34595f39d397SChris Mason btrfs_set_header_nritems(split, c_nritems - mid); 34605f39d397SChris Mason btrfs_set_header_nritems(c, mid); 3461aa5d6bedSChris Mason ret = 0; 3462aa5d6bedSChris Mason 34635f39d397SChris Mason btrfs_mark_buffer_dirty(c); 34645f39d397SChris Mason btrfs_mark_buffer_dirty(split); 34655f39d397SChris Mason 34666ad3cf6dSDavid Sterba insert_ptr(trans, path, &disk_key, split->start, 3467c3e06965SJan Schmidt path->slots[level + 1] + 1, level + 1); 3468aa5d6bedSChris Mason 34695de08d7dSChris Mason if (path->slots[level] >= mid) { 34705c680ed6SChris Mason path->slots[level] -= mid; 3471925baeddSChris Mason btrfs_tree_unlock(c); 34725f39d397SChris Mason free_extent_buffer(c); 34735f39d397SChris Mason path->nodes[level] = split; 34745c680ed6SChris Mason path->slots[level + 1] += 1; 3475eb60ceacSChris Mason } else { 3476925baeddSChris Mason btrfs_tree_unlock(split); 34775f39d397SChris Mason free_extent_buffer(split); 3478be0e5c09SChris Mason } 3479aa5d6bedSChris Mason return ret; 3480be0e5c09SChris Mason } 3481be0e5c09SChris Mason 348274123bd7SChris Mason /* 348374123bd7SChris Mason * how many bytes are required to store the items in a leaf. start 348474123bd7SChris Mason * and nr indicate which items in the leaf to check. This totals up the 348574123bd7SChris Mason * space used both by the item structs and the item data 348674123bd7SChris Mason */ 34875f39d397SChris Mason static int leaf_space_used(struct extent_buffer *l, int start, int nr) 3488be0e5c09SChris Mason { 348941be1f3bSJosef Bacik struct btrfs_item *start_item; 349041be1f3bSJosef Bacik struct btrfs_item *end_item; 3491be0e5c09SChris Mason int data_len; 34925f39d397SChris Mason int nritems = btrfs_header_nritems(l); 3493d4dbff95SChris Mason int end = min(nritems, start + nr) - 1; 3494be0e5c09SChris Mason 3495be0e5c09SChris Mason if (!nr) 3496be0e5c09SChris Mason return 0; 3497dd3cc16bSRoss Kirk start_item = btrfs_item_nr(start); 3498dd3cc16bSRoss Kirk end_item = btrfs_item_nr(end); 3499a31356b9SDavid Sterba data_len = btrfs_item_offset(l, start_item) + 3500a31356b9SDavid Sterba btrfs_item_size(l, start_item); 3501a31356b9SDavid Sterba data_len = data_len - btrfs_item_offset(l, end_item); 35020783fcfcSChris Mason data_len += sizeof(struct btrfs_item) * nr; 3503d4dbff95SChris Mason WARN_ON(data_len < 0); 3504be0e5c09SChris Mason return data_len; 3505be0e5c09SChris Mason } 3506be0e5c09SChris Mason 350774123bd7SChris Mason /* 3508d4dbff95SChris Mason * The space between the end of the leaf items and 3509d4dbff95SChris Mason * the start of the leaf data. IOW, how much room 3510d4dbff95SChris Mason * the leaf has left for both items and data 3511d4dbff95SChris Mason */ 3512e902baacSDavid Sterba noinline int btrfs_leaf_free_space(struct extent_buffer *leaf) 3513d4dbff95SChris Mason { 3514e902baacSDavid Sterba struct btrfs_fs_info *fs_info = leaf->fs_info; 35155f39d397SChris Mason int nritems = btrfs_header_nritems(leaf); 35165f39d397SChris Mason int ret; 35170b246afaSJeff Mahoney 35180b246afaSJeff Mahoney ret = BTRFS_LEAF_DATA_SIZE(fs_info) - leaf_space_used(leaf, 0, nritems); 35195f39d397SChris Mason if (ret < 0) { 35200b246afaSJeff Mahoney btrfs_crit(fs_info, 3521efe120a0SFrank Holton "leaf free space ret %d, leaf data size %lu, used %d nritems %d", 3522da17066cSJeff Mahoney ret, 35230b246afaSJeff Mahoney (unsigned long) BTRFS_LEAF_DATA_SIZE(fs_info), 35245f39d397SChris Mason leaf_space_used(leaf, 0, nritems), nritems); 35255f39d397SChris Mason } 35265f39d397SChris Mason return ret; 3527d4dbff95SChris Mason } 3528d4dbff95SChris Mason 352999d8f83cSChris Mason /* 353099d8f83cSChris Mason * min slot controls the lowest index we're willing to push to the 353199d8f83cSChris Mason * right. We'll push up to and including min_slot, but no lower 353299d8f83cSChris Mason */ 3533f72f0010SDavid Sterba static noinline int __push_leaf_right(struct btrfs_path *path, 353444871b1bSChris Mason int data_size, int empty, 353544871b1bSChris Mason struct extent_buffer *right, 353699d8f83cSChris Mason int free_space, u32 left_nritems, 353799d8f83cSChris Mason u32 min_slot) 353800ec4c51SChris Mason { 3539f72f0010SDavid Sterba struct btrfs_fs_info *fs_info = right->fs_info; 35405f39d397SChris Mason struct extent_buffer *left = path->nodes[0]; 354144871b1bSChris Mason struct extent_buffer *upper = path->nodes[1]; 3542cfed81a0SChris Mason struct btrfs_map_token token; 35435f39d397SChris Mason struct btrfs_disk_key disk_key; 354400ec4c51SChris Mason int slot; 354534a38218SChris Mason u32 i; 354600ec4c51SChris Mason int push_space = 0; 354700ec4c51SChris Mason int push_items = 0; 35480783fcfcSChris Mason struct btrfs_item *item; 354934a38218SChris Mason u32 nr; 35507518a238SChris Mason u32 right_nritems; 35515f39d397SChris Mason u32 data_end; 3552db94535dSChris Mason u32 this_item_size; 355300ec4c51SChris Mason 355434a38218SChris Mason if (empty) 355534a38218SChris Mason nr = 0; 355634a38218SChris Mason else 355799d8f83cSChris Mason nr = max_t(u32, 1, min_slot); 355834a38218SChris Mason 355931840ae1SZheng Yan if (path->slots[0] >= left_nritems) 356087b29b20SYan Zheng push_space += data_size; 356131840ae1SZheng Yan 356244871b1bSChris Mason slot = path->slots[1]; 356334a38218SChris Mason i = left_nritems - 1; 356434a38218SChris Mason while (i >= nr) { 3565dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 3566db94535dSChris Mason 356731840ae1SZheng Yan if (!empty && push_items > 0) { 356831840ae1SZheng Yan if (path->slots[0] > i) 356931840ae1SZheng Yan break; 357031840ae1SZheng Yan if (path->slots[0] == i) { 3571e902baacSDavid Sterba int space = btrfs_leaf_free_space(left); 3572e902baacSDavid Sterba 357331840ae1SZheng Yan if (space + push_space * 2 > free_space) 357431840ae1SZheng Yan break; 357531840ae1SZheng Yan } 357631840ae1SZheng Yan } 357731840ae1SZheng Yan 357800ec4c51SChris Mason if (path->slots[0] == i) 357987b29b20SYan Zheng push_space += data_size; 3580db94535dSChris Mason 3581db94535dSChris Mason this_item_size = btrfs_item_size(left, item); 3582db94535dSChris Mason if (this_item_size + sizeof(*item) + push_space > free_space) 358300ec4c51SChris Mason break; 358431840ae1SZheng Yan 358500ec4c51SChris Mason push_items++; 3586db94535dSChris Mason push_space += this_item_size + sizeof(*item); 358734a38218SChris Mason if (i == 0) 358834a38218SChris Mason break; 358934a38218SChris Mason i--; 3590db94535dSChris Mason } 35915f39d397SChris Mason 3592925baeddSChris Mason if (push_items == 0) 3593925baeddSChris Mason goto out_unlock; 35945f39d397SChris Mason 35956c1500f2SJulia Lawall WARN_ON(!empty && push_items == left_nritems); 35965f39d397SChris Mason 359700ec4c51SChris Mason /* push left to right */ 35985f39d397SChris Mason right_nritems = btrfs_header_nritems(right); 359934a38218SChris Mason 36005f39d397SChris Mason push_space = btrfs_item_end_nr(left, left_nritems - push_items); 36018f881e8cSDavid Sterba push_space -= leaf_data_end(left); 36025f39d397SChris Mason 360300ec4c51SChris Mason /* make room in the right data area */ 36048f881e8cSDavid Sterba data_end = leaf_data_end(right); 36055f39d397SChris Mason memmove_extent_buffer(right, 36063d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + data_end - push_space, 36073d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + data_end, 36080b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info) - data_end); 36095f39d397SChris Mason 361000ec4c51SChris Mason /* copy from the left data area */ 36113d9ec8c4SNikolay Borisov copy_extent_buffer(right, left, BTRFS_LEAF_DATA_OFFSET + 36120b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, 36138f881e8cSDavid Sterba BTRFS_LEAF_DATA_OFFSET + leaf_data_end(left), 3614d6025579SChris Mason push_space); 36155f39d397SChris Mason 36165f39d397SChris Mason memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), 36175f39d397SChris Mason btrfs_item_nr_offset(0), 36180783fcfcSChris Mason right_nritems * sizeof(struct btrfs_item)); 36195f39d397SChris Mason 362000ec4c51SChris Mason /* copy the items from left to right */ 36215f39d397SChris Mason copy_extent_buffer(right, left, btrfs_item_nr_offset(0), 36225f39d397SChris Mason btrfs_item_nr_offset(left_nritems - push_items), 36230783fcfcSChris Mason push_items * sizeof(struct btrfs_item)); 362400ec4c51SChris Mason 362500ec4c51SChris Mason /* update the item pointers */ 3626c82f823cSDavid Sterba btrfs_init_map_token(&token, right); 36277518a238SChris Mason right_nritems += push_items; 36285f39d397SChris Mason btrfs_set_header_nritems(right, right_nritems); 36290b246afaSJeff Mahoney push_space = BTRFS_LEAF_DATA_SIZE(fs_info); 36307518a238SChris Mason for (i = 0; i < right_nritems; i++) { 3631dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 3632cc4c13d5SDavid Sterba push_space -= btrfs_token_item_size(&token, item); 3633cc4c13d5SDavid Sterba btrfs_set_token_item_offset(&token, item, push_space); 3634db94535dSChris Mason } 3635db94535dSChris Mason 36367518a238SChris Mason left_nritems -= push_items; 36375f39d397SChris Mason btrfs_set_header_nritems(left, left_nritems); 363800ec4c51SChris Mason 363934a38218SChris Mason if (left_nritems) 36405f39d397SChris Mason btrfs_mark_buffer_dirty(left); 3641f0486c68SYan, Zheng else 36426a884d7dSDavid Sterba btrfs_clean_tree_block(left); 3643f0486c68SYan, Zheng 36445f39d397SChris Mason btrfs_mark_buffer_dirty(right); 3645a429e513SChris Mason 36465f39d397SChris Mason btrfs_item_key(right, &disk_key, 0); 36475f39d397SChris Mason btrfs_set_node_key(upper, &disk_key, slot + 1); 3648d6025579SChris Mason btrfs_mark_buffer_dirty(upper); 364902217ed2SChris Mason 365000ec4c51SChris Mason /* then fixup the leaf pointer in the path */ 36517518a238SChris Mason if (path->slots[0] >= left_nritems) { 36527518a238SChris Mason path->slots[0] -= left_nritems; 3653925baeddSChris Mason if (btrfs_header_nritems(path->nodes[0]) == 0) 36546a884d7dSDavid Sterba btrfs_clean_tree_block(path->nodes[0]); 3655925baeddSChris Mason btrfs_tree_unlock(path->nodes[0]); 36565f39d397SChris Mason free_extent_buffer(path->nodes[0]); 36575f39d397SChris Mason path->nodes[0] = right; 365800ec4c51SChris Mason path->slots[1] += 1; 365900ec4c51SChris Mason } else { 3660925baeddSChris Mason btrfs_tree_unlock(right); 36615f39d397SChris Mason free_extent_buffer(right); 366200ec4c51SChris Mason } 366300ec4c51SChris Mason return 0; 3664925baeddSChris Mason 3665925baeddSChris Mason out_unlock: 3666925baeddSChris Mason btrfs_tree_unlock(right); 3667925baeddSChris Mason free_extent_buffer(right); 3668925baeddSChris Mason return 1; 366900ec4c51SChris Mason } 3670925baeddSChris Mason 367100ec4c51SChris Mason /* 367244871b1bSChris Mason * push some data in the path leaf to the right, trying to free up at 367374123bd7SChris Mason * least data_size bytes. returns zero if the push worked, nonzero otherwise 367444871b1bSChris Mason * 367544871b1bSChris Mason * returns 1 if the push failed because the other node didn't have enough 367644871b1bSChris Mason * room, 0 if everything worked out and < 0 if there were major errors. 367799d8f83cSChris Mason * 367899d8f83cSChris Mason * this will push starting from min_slot to the end of the leaf. It won't 367999d8f83cSChris Mason * push any slot lower than min_slot 368074123bd7SChris Mason */ 368144871b1bSChris Mason static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root 368299d8f83cSChris Mason *root, struct btrfs_path *path, 368399d8f83cSChris Mason int min_data_size, int data_size, 368499d8f83cSChris Mason int empty, u32 min_slot) 3685be0e5c09SChris Mason { 368644871b1bSChris Mason struct extent_buffer *left = path->nodes[0]; 368744871b1bSChris Mason struct extent_buffer *right; 368844871b1bSChris Mason struct extent_buffer *upper; 368944871b1bSChris Mason int slot; 369044871b1bSChris Mason int free_space; 369144871b1bSChris Mason u32 left_nritems; 369244871b1bSChris Mason int ret; 369344871b1bSChris Mason 369444871b1bSChris Mason if (!path->nodes[1]) 369544871b1bSChris Mason return 1; 369644871b1bSChris Mason 369744871b1bSChris Mason slot = path->slots[1]; 369844871b1bSChris Mason upper = path->nodes[1]; 369944871b1bSChris Mason if (slot >= btrfs_header_nritems(upper) - 1) 370044871b1bSChris Mason return 1; 370144871b1bSChris Mason 370244871b1bSChris Mason btrfs_assert_tree_locked(path->nodes[1]); 370344871b1bSChris Mason 37044b231ae4SDavid Sterba right = btrfs_read_node_slot(upper, slot + 1); 3705fb770ae4SLiu Bo /* 3706fb770ae4SLiu Bo * slot + 1 is not valid or we fail to read the right node, 3707fb770ae4SLiu Bo * no big deal, just return. 3708fb770ae4SLiu Bo */ 3709fb770ae4SLiu Bo if (IS_ERR(right)) 371091ca338dSTsutomu Itoh return 1; 371191ca338dSTsutomu Itoh 3712bf77467aSJosef Bacik __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); 371344871b1bSChris Mason 3714e902baacSDavid Sterba free_space = btrfs_leaf_free_space(right); 371544871b1bSChris Mason if (free_space < data_size) 371644871b1bSChris Mason goto out_unlock; 371744871b1bSChris Mason 371844871b1bSChris Mason /* cow and double check */ 371944871b1bSChris Mason ret = btrfs_cow_block(trans, root, right, upper, 3720bf59a5a2SJosef Bacik slot + 1, &right, BTRFS_NESTING_RIGHT_COW); 372144871b1bSChris Mason if (ret) 372244871b1bSChris Mason goto out_unlock; 372344871b1bSChris Mason 3724e902baacSDavid Sterba free_space = btrfs_leaf_free_space(right); 372544871b1bSChris Mason if (free_space < data_size) 372644871b1bSChris Mason goto out_unlock; 372744871b1bSChris Mason 372844871b1bSChris Mason left_nritems = btrfs_header_nritems(left); 372944871b1bSChris Mason if (left_nritems == 0) 373044871b1bSChris Mason goto out_unlock; 373144871b1bSChris Mason 3732d16c702fSQu Wenruo if (check_sibling_keys(left, right)) { 3733d16c702fSQu Wenruo ret = -EUCLEAN; 3734d16c702fSQu Wenruo btrfs_tree_unlock(right); 3735d16c702fSQu Wenruo free_extent_buffer(right); 3736d16c702fSQu Wenruo return ret; 3737d16c702fSQu Wenruo } 37382ef1fed2SFilipe David Borba Manana if (path->slots[0] == left_nritems && !empty) { 37392ef1fed2SFilipe David Borba Manana /* Key greater than all keys in the leaf, right neighbor has 37402ef1fed2SFilipe David Borba Manana * enough room for it and we're not emptying our leaf to delete 37412ef1fed2SFilipe David Borba Manana * it, therefore use right neighbor to insert the new item and 374252042d8eSAndrea Gelmini * no need to touch/dirty our left leaf. */ 37432ef1fed2SFilipe David Borba Manana btrfs_tree_unlock(left); 37442ef1fed2SFilipe David Borba Manana free_extent_buffer(left); 37452ef1fed2SFilipe David Borba Manana path->nodes[0] = right; 37462ef1fed2SFilipe David Borba Manana path->slots[0] = 0; 37472ef1fed2SFilipe David Borba Manana path->slots[1]++; 37482ef1fed2SFilipe David Borba Manana return 0; 37492ef1fed2SFilipe David Borba Manana } 37502ef1fed2SFilipe David Borba Manana 3751f72f0010SDavid Sterba return __push_leaf_right(path, min_data_size, empty, 375299d8f83cSChris Mason right, free_space, left_nritems, min_slot); 375344871b1bSChris Mason out_unlock: 375444871b1bSChris Mason btrfs_tree_unlock(right); 375544871b1bSChris Mason free_extent_buffer(right); 375644871b1bSChris Mason return 1; 375744871b1bSChris Mason } 375844871b1bSChris Mason 375944871b1bSChris Mason /* 376044871b1bSChris Mason * push some data in the path leaf to the left, trying to free up at 376144871b1bSChris Mason * least data_size bytes. returns zero if the push worked, nonzero otherwise 376299d8f83cSChris Mason * 376399d8f83cSChris Mason * max_slot can put a limit on how far into the leaf we'll push items. The 376499d8f83cSChris Mason * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the 376599d8f83cSChris Mason * items 376644871b1bSChris Mason */ 37678087c193SDavid Sterba static noinline int __push_leaf_left(struct btrfs_path *path, int data_size, 376844871b1bSChris Mason int empty, struct extent_buffer *left, 376999d8f83cSChris Mason int free_space, u32 right_nritems, 377099d8f83cSChris Mason u32 max_slot) 377144871b1bSChris Mason { 37728087c193SDavid Sterba struct btrfs_fs_info *fs_info = left->fs_info; 37735f39d397SChris Mason struct btrfs_disk_key disk_key; 37745f39d397SChris Mason struct extent_buffer *right = path->nodes[0]; 3775be0e5c09SChris Mason int i; 3776be0e5c09SChris Mason int push_space = 0; 3777be0e5c09SChris Mason int push_items = 0; 37780783fcfcSChris Mason struct btrfs_item *item; 37797518a238SChris Mason u32 old_left_nritems; 378034a38218SChris Mason u32 nr; 3781aa5d6bedSChris Mason int ret = 0; 3782db94535dSChris Mason u32 this_item_size; 3783db94535dSChris Mason u32 old_left_item_size; 3784cfed81a0SChris Mason struct btrfs_map_token token; 3785cfed81a0SChris Mason 378634a38218SChris Mason if (empty) 378799d8f83cSChris Mason nr = min(right_nritems, max_slot); 378834a38218SChris Mason else 378999d8f83cSChris Mason nr = min(right_nritems - 1, max_slot); 379034a38218SChris Mason 379134a38218SChris Mason for (i = 0; i < nr; i++) { 3792dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 3793db94535dSChris Mason 379431840ae1SZheng Yan if (!empty && push_items > 0) { 379531840ae1SZheng Yan if (path->slots[0] < i) 379631840ae1SZheng Yan break; 379731840ae1SZheng Yan if (path->slots[0] == i) { 3798e902baacSDavid Sterba int space = btrfs_leaf_free_space(right); 3799e902baacSDavid Sterba 380031840ae1SZheng Yan if (space + push_space * 2 > free_space) 380131840ae1SZheng Yan break; 380231840ae1SZheng Yan } 380331840ae1SZheng Yan } 380431840ae1SZheng Yan 3805be0e5c09SChris Mason if (path->slots[0] == i) 380687b29b20SYan Zheng push_space += data_size; 3807db94535dSChris Mason 3808db94535dSChris Mason this_item_size = btrfs_item_size(right, item); 3809db94535dSChris Mason if (this_item_size + sizeof(*item) + push_space > free_space) 3810be0e5c09SChris Mason break; 3811db94535dSChris Mason 3812be0e5c09SChris Mason push_items++; 3813db94535dSChris Mason push_space += this_item_size + sizeof(*item); 3814be0e5c09SChris Mason } 3815db94535dSChris Mason 3816be0e5c09SChris Mason if (push_items == 0) { 3817925baeddSChris Mason ret = 1; 3818925baeddSChris Mason goto out; 3819be0e5c09SChris Mason } 3820fae7f21cSDulshani Gunawardhana WARN_ON(!empty && push_items == btrfs_header_nritems(right)); 38215f39d397SChris Mason 3822be0e5c09SChris Mason /* push data from right to left */ 38235f39d397SChris Mason copy_extent_buffer(left, right, 38245f39d397SChris Mason btrfs_item_nr_offset(btrfs_header_nritems(left)), 38255f39d397SChris Mason btrfs_item_nr_offset(0), 38265f39d397SChris Mason push_items * sizeof(struct btrfs_item)); 38275f39d397SChris Mason 38280b246afaSJeff Mahoney push_space = BTRFS_LEAF_DATA_SIZE(fs_info) - 38295f39d397SChris Mason btrfs_item_offset_nr(right, push_items - 1); 38305f39d397SChris Mason 38313d9ec8c4SNikolay Borisov copy_extent_buffer(left, right, BTRFS_LEAF_DATA_OFFSET + 38328f881e8cSDavid Sterba leaf_data_end(left) - push_space, 38333d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + 38345f39d397SChris Mason btrfs_item_offset_nr(right, push_items - 1), 3835be0e5c09SChris Mason push_space); 38365f39d397SChris Mason old_left_nritems = btrfs_header_nritems(left); 383787b29b20SYan Zheng BUG_ON(old_left_nritems <= 0); 3838eb60ceacSChris Mason 3839c82f823cSDavid Sterba btrfs_init_map_token(&token, left); 3840db94535dSChris Mason old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); 3841be0e5c09SChris Mason for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { 38425f39d397SChris Mason u32 ioff; 3843db94535dSChris Mason 3844dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 3845db94535dSChris Mason 3846cc4c13d5SDavid Sterba ioff = btrfs_token_item_offset(&token, item); 3847cc4c13d5SDavid Sterba btrfs_set_token_item_offset(&token, item, 3848cc4c13d5SDavid Sterba ioff - (BTRFS_LEAF_DATA_SIZE(fs_info) - old_left_item_size)); 3849be0e5c09SChris Mason } 38505f39d397SChris Mason btrfs_set_header_nritems(left, old_left_nritems + push_items); 3851be0e5c09SChris Mason 3852be0e5c09SChris Mason /* fixup right node */ 385331b1a2bdSJulia Lawall if (push_items > right_nritems) 385431b1a2bdSJulia Lawall WARN(1, KERN_CRIT "push items %d nr %u\n", push_items, 3855d397712bSChris Mason right_nritems); 385634a38218SChris Mason 385734a38218SChris Mason if (push_items < right_nritems) { 38585f39d397SChris Mason push_space = btrfs_item_offset_nr(right, push_items - 1) - 38598f881e8cSDavid Sterba leaf_data_end(right); 38603d9ec8c4SNikolay Borisov memmove_extent_buffer(right, BTRFS_LEAF_DATA_OFFSET + 38610b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, 38623d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + 38638f881e8cSDavid Sterba leaf_data_end(right), push_space); 38645f39d397SChris Mason 38655f39d397SChris Mason memmove_extent_buffer(right, btrfs_item_nr_offset(0), 38665f39d397SChris Mason btrfs_item_nr_offset(push_items), 38675f39d397SChris Mason (btrfs_header_nritems(right) - push_items) * 38680783fcfcSChris Mason sizeof(struct btrfs_item)); 386934a38218SChris Mason } 3870c82f823cSDavid Sterba 3871c82f823cSDavid Sterba btrfs_init_map_token(&token, right); 3872eef1c494SYan right_nritems -= push_items; 3873eef1c494SYan btrfs_set_header_nritems(right, right_nritems); 38740b246afaSJeff Mahoney push_space = BTRFS_LEAF_DATA_SIZE(fs_info); 38755f39d397SChris Mason for (i = 0; i < right_nritems; i++) { 3876dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 3877db94535dSChris Mason 3878cc4c13d5SDavid Sterba push_space = push_space - btrfs_token_item_size(&token, item); 3879cc4c13d5SDavid Sterba btrfs_set_token_item_offset(&token, item, push_space); 3880db94535dSChris Mason } 3881eb60ceacSChris Mason 38825f39d397SChris Mason btrfs_mark_buffer_dirty(left); 388334a38218SChris Mason if (right_nritems) 38845f39d397SChris Mason btrfs_mark_buffer_dirty(right); 3885f0486c68SYan, Zheng else 38866a884d7dSDavid Sterba btrfs_clean_tree_block(right); 3887098f59c2SChris Mason 38885f39d397SChris Mason btrfs_item_key(right, &disk_key, 0); 3889b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 3890be0e5c09SChris Mason 3891be0e5c09SChris Mason /* then fixup the leaf pointer in the path */ 3892be0e5c09SChris Mason if (path->slots[0] < push_items) { 3893be0e5c09SChris Mason path->slots[0] += old_left_nritems; 3894925baeddSChris Mason btrfs_tree_unlock(path->nodes[0]); 38955f39d397SChris Mason free_extent_buffer(path->nodes[0]); 38965f39d397SChris Mason path->nodes[0] = left; 3897be0e5c09SChris Mason path->slots[1] -= 1; 3898be0e5c09SChris Mason } else { 3899925baeddSChris Mason btrfs_tree_unlock(left); 39005f39d397SChris Mason free_extent_buffer(left); 3901be0e5c09SChris Mason path->slots[0] -= push_items; 3902be0e5c09SChris Mason } 3903eb60ceacSChris Mason BUG_ON(path->slots[0] < 0); 3904aa5d6bedSChris Mason return ret; 3905925baeddSChris Mason out: 3906925baeddSChris Mason btrfs_tree_unlock(left); 3907925baeddSChris Mason free_extent_buffer(left); 3908925baeddSChris Mason return ret; 3909be0e5c09SChris Mason } 3910be0e5c09SChris Mason 391174123bd7SChris Mason /* 391244871b1bSChris Mason * push some data in the path leaf to the left, trying to free up at 391344871b1bSChris Mason * least data_size bytes. returns zero if the push worked, nonzero otherwise 391499d8f83cSChris Mason * 391599d8f83cSChris Mason * max_slot can put a limit on how far into the leaf we'll push items. The 391699d8f83cSChris Mason * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the 391799d8f83cSChris Mason * items 391844871b1bSChris Mason */ 391944871b1bSChris Mason static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root 392099d8f83cSChris Mason *root, struct btrfs_path *path, int min_data_size, 392199d8f83cSChris Mason int data_size, int empty, u32 max_slot) 392244871b1bSChris Mason { 392344871b1bSChris Mason struct extent_buffer *right = path->nodes[0]; 392444871b1bSChris Mason struct extent_buffer *left; 392544871b1bSChris Mason int slot; 392644871b1bSChris Mason int free_space; 392744871b1bSChris Mason u32 right_nritems; 392844871b1bSChris Mason int ret = 0; 392944871b1bSChris Mason 393044871b1bSChris Mason slot = path->slots[1]; 393144871b1bSChris Mason if (slot == 0) 393244871b1bSChris Mason return 1; 393344871b1bSChris Mason if (!path->nodes[1]) 393444871b1bSChris Mason return 1; 393544871b1bSChris Mason 393644871b1bSChris Mason right_nritems = btrfs_header_nritems(right); 393744871b1bSChris Mason if (right_nritems == 0) 393844871b1bSChris Mason return 1; 393944871b1bSChris Mason 394044871b1bSChris Mason btrfs_assert_tree_locked(path->nodes[1]); 394144871b1bSChris Mason 39424b231ae4SDavid Sterba left = btrfs_read_node_slot(path->nodes[1], slot - 1); 3943fb770ae4SLiu Bo /* 3944fb770ae4SLiu Bo * slot - 1 is not valid or we fail to read the left node, 3945fb770ae4SLiu Bo * no big deal, just return. 3946fb770ae4SLiu Bo */ 3947fb770ae4SLiu Bo if (IS_ERR(left)) 394891ca338dSTsutomu Itoh return 1; 394991ca338dSTsutomu Itoh 3950bf77467aSJosef Bacik __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); 395144871b1bSChris Mason 3952e902baacSDavid Sterba free_space = btrfs_leaf_free_space(left); 395344871b1bSChris Mason if (free_space < data_size) { 395444871b1bSChris Mason ret = 1; 395544871b1bSChris Mason goto out; 395644871b1bSChris Mason } 395744871b1bSChris Mason 395844871b1bSChris Mason /* cow and double check */ 395944871b1bSChris Mason ret = btrfs_cow_block(trans, root, left, 39609631e4ccSJosef Bacik path->nodes[1], slot - 1, &left, 3961bf59a5a2SJosef Bacik BTRFS_NESTING_LEFT_COW); 396244871b1bSChris Mason if (ret) { 396344871b1bSChris Mason /* we hit -ENOSPC, but it isn't fatal here */ 396479787eaaSJeff Mahoney if (ret == -ENOSPC) 396544871b1bSChris Mason ret = 1; 396644871b1bSChris Mason goto out; 396744871b1bSChris Mason } 396844871b1bSChris Mason 3969e902baacSDavid Sterba free_space = btrfs_leaf_free_space(left); 397044871b1bSChris Mason if (free_space < data_size) { 397144871b1bSChris Mason ret = 1; 397244871b1bSChris Mason goto out; 397344871b1bSChris Mason } 397444871b1bSChris Mason 3975d16c702fSQu Wenruo if (check_sibling_keys(left, right)) { 3976d16c702fSQu Wenruo ret = -EUCLEAN; 3977d16c702fSQu Wenruo goto out; 3978d16c702fSQu Wenruo } 39798087c193SDavid Sterba return __push_leaf_left(path, min_data_size, 398099d8f83cSChris Mason empty, left, free_space, right_nritems, 398199d8f83cSChris Mason max_slot); 398244871b1bSChris Mason out: 398344871b1bSChris Mason btrfs_tree_unlock(left); 398444871b1bSChris Mason free_extent_buffer(left); 398544871b1bSChris Mason return ret; 398644871b1bSChris Mason } 398744871b1bSChris Mason 398844871b1bSChris Mason /* 398974123bd7SChris Mason * split the path's leaf in two, making sure there is at least data_size 399074123bd7SChris Mason * available for the resulting leaf level of the path. 399174123bd7SChris Mason */ 3992143bede5SJeff Mahoney static noinline void copy_for_split(struct btrfs_trans_handle *trans, 399344871b1bSChris Mason struct btrfs_path *path, 399444871b1bSChris Mason struct extent_buffer *l, 399544871b1bSChris Mason struct extent_buffer *right, 399644871b1bSChris Mason int slot, int mid, int nritems) 3997be0e5c09SChris Mason { 399894f94ad9SDavid Sterba struct btrfs_fs_info *fs_info = trans->fs_info; 3999be0e5c09SChris Mason int data_copy_size; 4000be0e5c09SChris Mason int rt_data_off; 4001be0e5c09SChris Mason int i; 4002d4dbff95SChris Mason struct btrfs_disk_key disk_key; 4003cfed81a0SChris Mason struct btrfs_map_token token; 4004cfed81a0SChris Mason 40055f39d397SChris Mason nritems = nritems - mid; 40065f39d397SChris Mason btrfs_set_header_nritems(right, nritems); 40078f881e8cSDavid Sterba data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(l); 40085f39d397SChris Mason 40095f39d397SChris Mason copy_extent_buffer(right, l, btrfs_item_nr_offset(0), 40105f39d397SChris Mason btrfs_item_nr_offset(mid), 40115f39d397SChris Mason nritems * sizeof(struct btrfs_item)); 40125f39d397SChris Mason 40135f39d397SChris Mason copy_extent_buffer(right, l, 40143d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + BTRFS_LEAF_DATA_SIZE(fs_info) - 40153d9ec8c4SNikolay Borisov data_copy_size, BTRFS_LEAF_DATA_OFFSET + 40168f881e8cSDavid Sterba leaf_data_end(l), data_copy_size); 401774123bd7SChris Mason 40180b246afaSJeff Mahoney rt_data_off = BTRFS_LEAF_DATA_SIZE(fs_info) - btrfs_item_end_nr(l, mid); 40195f39d397SChris Mason 4020c82f823cSDavid Sterba btrfs_init_map_token(&token, right); 40215f39d397SChris Mason for (i = 0; i < nritems; i++) { 4022dd3cc16bSRoss Kirk struct btrfs_item *item = btrfs_item_nr(i); 4023db94535dSChris Mason u32 ioff; 4024db94535dSChris Mason 4025cc4c13d5SDavid Sterba ioff = btrfs_token_item_offset(&token, item); 4026cc4c13d5SDavid Sterba btrfs_set_token_item_offset(&token, item, ioff + rt_data_off); 40270783fcfcSChris Mason } 402874123bd7SChris Mason 40295f39d397SChris Mason btrfs_set_header_nritems(l, mid); 40305f39d397SChris Mason btrfs_item_key(right, &disk_key, 0); 40316ad3cf6dSDavid Sterba insert_ptr(trans, path, &disk_key, right->start, path->slots[1] + 1, 1); 40325f39d397SChris Mason 40335f39d397SChris Mason btrfs_mark_buffer_dirty(right); 40345f39d397SChris Mason btrfs_mark_buffer_dirty(l); 4035eb60ceacSChris Mason BUG_ON(path->slots[0] != slot); 40365f39d397SChris Mason 4037be0e5c09SChris Mason if (mid <= slot) { 4038925baeddSChris Mason btrfs_tree_unlock(path->nodes[0]); 40395f39d397SChris Mason free_extent_buffer(path->nodes[0]); 40405f39d397SChris Mason path->nodes[0] = right; 4041be0e5c09SChris Mason path->slots[0] -= mid; 4042be0e5c09SChris Mason path->slots[1] += 1; 4043925baeddSChris Mason } else { 4044925baeddSChris Mason btrfs_tree_unlock(right); 40455f39d397SChris Mason free_extent_buffer(right); 4046925baeddSChris Mason } 40475f39d397SChris Mason 4048eb60ceacSChris Mason BUG_ON(path->slots[0] < 0); 404944871b1bSChris Mason } 405044871b1bSChris Mason 405144871b1bSChris Mason /* 405299d8f83cSChris Mason * double splits happen when we need to insert a big item in the middle 405399d8f83cSChris Mason * of a leaf. A double split can leave us with 3 mostly empty leaves: 405499d8f83cSChris Mason * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] 405599d8f83cSChris Mason * A B C 405699d8f83cSChris Mason * 405799d8f83cSChris Mason * We avoid this by trying to push the items on either side of our target 405899d8f83cSChris Mason * into the adjacent leaves. If all goes well we can avoid the double split 405999d8f83cSChris Mason * completely. 406099d8f83cSChris Mason */ 406199d8f83cSChris Mason static noinline int push_for_double_split(struct btrfs_trans_handle *trans, 406299d8f83cSChris Mason struct btrfs_root *root, 406399d8f83cSChris Mason struct btrfs_path *path, 406499d8f83cSChris Mason int data_size) 406599d8f83cSChris Mason { 406699d8f83cSChris Mason int ret; 406799d8f83cSChris Mason int progress = 0; 406899d8f83cSChris Mason int slot; 406999d8f83cSChris Mason u32 nritems; 40705a4267caSFilipe David Borba Manana int space_needed = data_size; 407199d8f83cSChris Mason 407299d8f83cSChris Mason slot = path->slots[0]; 40735a4267caSFilipe David Borba Manana if (slot < btrfs_header_nritems(path->nodes[0])) 4074e902baacSDavid Sterba space_needed -= btrfs_leaf_free_space(path->nodes[0]); 407599d8f83cSChris Mason 407699d8f83cSChris Mason /* 407799d8f83cSChris Mason * try to push all the items after our slot into the 407899d8f83cSChris Mason * right leaf 407999d8f83cSChris Mason */ 40805a4267caSFilipe David Borba Manana ret = push_leaf_right(trans, root, path, 1, space_needed, 0, slot); 408199d8f83cSChris Mason if (ret < 0) 408299d8f83cSChris Mason return ret; 408399d8f83cSChris Mason 408499d8f83cSChris Mason if (ret == 0) 408599d8f83cSChris Mason progress++; 408699d8f83cSChris Mason 408799d8f83cSChris Mason nritems = btrfs_header_nritems(path->nodes[0]); 408899d8f83cSChris Mason /* 408999d8f83cSChris Mason * our goal is to get our slot at the start or end of a leaf. If 409099d8f83cSChris Mason * we've done so we're done 409199d8f83cSChris Mason */ 409299d8f83cSChris Mason if (path->slots[0] == 0 || path->slots[0] == nritems) 409399d8f83cSChris Mason return 0; 409499d8f83cSChris Mason 4095e902baacSDavid Sterba if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) 409699d8f83cSChris Mason return 0; 409799d8f83cSChris Mason 409899d8f83cSChris Mason /* try to push all the items before our slot into the next leaf */ 409999d8f83cSChris Mason slot = path->slots[0]; 4100263d3995SFilipe Manana space_needed = data_size; 4101263d3995SFilipe Manana if (slot > 0) 4102e902baacSDavid Sterba space_needed -= btrfs_leaf_free_space(path->nodes[0]); 41035a4267caSFilipe David Borba Manana ret = push_leaf_left(trans, root, path, 1, space_needed, 0, slot); 410499d8f83cSChris Mason if (ret < 0) 410599d8f83cSChris Mason return ret; 410699d8f83cSChris Mason 410799d8f83cSChris Mason if (ret == 0) 410899d8f83cSChris Mason progress++; 410999d8f83cSChris Mason 411099d8f83cSChris Mason if (progress) 411199d8f83cSChris Mason return 0; 411299d8f83cSChris Mason return 1; 411399d8f83cSChris Mason } 411499d8f83cSChris Mason 411599d8f83cSChris Mason /* 411644871b1bSChris Mason * split the path's leaf in two, making sure there is at least data_size 411744871b1bSChris Mason * available for the resulting leaf level of the path. 411844871b1bSChris Mason * 411944871b1bSChris Mason * returns 0 if all went well and < 0 on failure. 412044871b1bSChris Mason */ 412144871b1bSChris Mason static noinline int split_leaf(struct btrfs_trans_handle *trans, 412244871b1bSChris Mason struct btrfs_root *root, 4123310712b2SOmar Sandoval const struct btrfs_key *ins_key, 412444871b1bSChris Mason struct btrfs_path *path, int data_size, 412544871b1bSChris Mason int extend) 412644871b1bSChris Mason { 41275d4f98a2SYan Zheng struct btrfs_disk_key disk_key; 412844871b1bSChris Mason struct extent_buffer *l; 412944871b1bSChris Mason u32 nritems; 413044871b1bSChris Mason int mid; 413144871b1bSChris Mason int slot; 413244871b1bSChris Mason struct extent_buffer *right; 4133b7a0365eSDaniel Dressler struct btrfs_fs_info *fs_info = root->fs_info; 413444871b1bSChris Mason int ret = 0; 413544871b1bSChris Mason int wret; 41365d4f98a2SYan Zheng int split; 413744871b1bSChris Mason int num_doubles = 0; 413899d8f83cSChris Mason int tried_avoid_double = 0; 413944871b1bSChris Mason 4140a5719521SYan, Zheng l = path->nodes[0]; 4141a5719521SYan, Zheng slot = path->slots[0]; 4142a5719521SYan, Zheng if (extend && data_size + btrfs_item_size_nr(l, slot) + 41430b246afaSJeff Mahoney sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info)) 4144a5719521SYan, Zheng return -EOVERFLOW; 4145a5719521SYan, Zheng 414644871b1bSChris Mason /* first try to make some room by pushing left and right */ 414733157e05SLiu Bo if (data_size && path->nodes[1]) { 41485a4267caSFilipe David Borba Manana int space_needed = data_size; 41495a4267caSFilipe David Borba Manana 41505a4267caSFilipe David Borba Manana if (slot < btrfs_header_nritems(l)) 4151e902baacSDavid Sterba space_needed -= btrfs_leaf_free_space(l); 41525a4267caSFilipe David Borba Manana 41535a4267caSFilipe David Borba Manana wret = push_leaf_right(trans, root, path, space_needed, 41545a4267caSFilipe David Borba Manana space_needed, 0, 0); 415544871b1bSChris Mason if (wret < 0) 415644871b1bSChris Mason return wret; 415744871b1bSChris Mason if (wret) { 4158263d3995SFilipe Manana space_needed = data_size; 4159263d3995SFilipe Manana if (slot > 0) 4160e902baacSDavid Sterba space_needed -= btrfs_leaf_free_space(l); 41615a4267caSFilipe David Borba Manana wret = push_leaf_left(trans, root, path, space_needed, 41625a4267caSFilipe David Borba Manana space_needed, 0, (u32)-1); 416344871b1bSChris Mason if (wret < 0) 416444871b1bSChris Mason return wret; 416544871b1bSChris Mason } 416644871b1bSChris Mason l = path->nodes[0]; 416744871b1bSChris Mason 416844871b1bSChris Mason /* did the pushes work? */ 4169e902baacSDavid Sterba if (btrfs_leaf_free_space(l) >= data_size) 417044871b1bSChris Mason return 0; 417144871b1bSChris Mason } 417244871b1bSChris Mason 417344871b1bSChris Mason if (!path->nodes[1]) { 4174fdd99c72SLiu Bo ret = insert_new_root(trans, root, path, 1); 417544871b1bSChris Mason if (ret) 417644871b1bSChris Mason return ret; 417744871b1bSChris Mason } 417844871b1bSChris Mason again: 41795d4f98a2SYan Zheng split = 1; 418044871b1bSChris Mason l = path->nodes[0]; 418144871b1bSChris Mason slot = path->slots[0]; 418244871b1bSChris Mason nritems = btrfs_header_nritems(l); 418344871b1bSChris Mason mid = (nritems + 1) / 2; 418444871b1bSChris Mason 41855d4f98a2SYan Zheng if (mid <= slot) { 41865d4f98a2SYan Zheng if (nritems == 1 || 41875d4f98a2SYan Zheng leaf_space_used(l, mid, nritems - mid) + data_size > 41880b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info)) { 41895d4f98a2SYan Zheng if (slot >= nritems) { 41905d4f98a2SYan Zheng split = 0; 41915d4f98a2SYan Zheng } else { 41925d4f98a2SYan Zheng mid = slot; 41935d4f98a2SYan Zheng if (mid != nritems && 41945d4f98a2SYan Zheng leaf_space_used(l, mid, nritems - mid) + 41950b246afaSJeff Mahoney data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { 419699d8f83cSChris Mason if (data_size && !tried_avoid_double) 419799d8f83cSChris Mason goto push_for_double; 41985d4f98a2SYan Zheng split = 2; 41995d4f98a2SYan Zheng } 42005d4f98a2SYan Zheng } 42015d4f98a2SYan Zheng } 42025d4f98a2SYan Zheng } else { 42035d4f98a2SYan Zheng if (leaf_space_used(l, 0, mid) + data_size > 42040b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info)) { 42055d4f98a2SYan Zheng if (!extend && data_size && slot == 0) { 42065d4f98a2SYan Zheng split = 0; 42075d4f98a2SYan Zheng } else if ((extend || !data_size) && slot == 0) { 42085d4f98a2SYan Zheng mid = 1; 42095d4f98a2SYan Zheng } else { 42105d4f98a2SYan Zheng mid = slot; 42115d4f98a2SYan Zheng if (mid != nritems && 42125d4f98a2SYan Zheng leaf_space_used(l, mid, nritems - mid) + 42130b246afaSJeff Mahoney data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { 421499d8f83cSChris Mason if (data_size && !tried_avoid_double) 421599d8f83cSChris Mason goto push_for_double; 42165d4f98a2SYan Zheng split = 2; 42175d4f98a2SYan Zheng } 42185d4f98a2SYan Zheng } 42195d4f98a2SYan Zheng } 42205d4f98a2SYan Zheng } 42215d4f98a2SYan Zheng 42225d4f98a2SYan Zheng if (split == 0) 42235d4f98a2SYan Zheng btrfs_cpu_key_to_disk(&disk_key, ins_key); 42245d4f98a2SYan Zheng else 42255d4f98a2SYan Zheng btrfs_item_key(l, &disk_key, mid); 42265d4f98a2SYan Zheng 4227ca9d473aSJosef Bacik /* 4228ca9d473aSJosef Bacik * We have to about BTRFS_NESTING_NEW_ROOT here if we've done a double 4229ca9d473aSJosef Bacik * split, because we're only allowed to have MAX_LOCKDEP_SUBCLASSES 4230ca9d473aSJosef Bacik * subclasses, which is 8 at the time of this patch, and we've maxed it 4231ca9d473aSJosef Bacik * out. In the future we could add a 4232ca9d473aSJosef Bacik * BTRFS_NESTING_SPLIT_THE_SPLITTENING if we need to, but for now just 4233ca9d473aSJosef Bacik * use BTRFS_NESTING_NEW_ROOT. 4234ca9d473aSJosef Bacik */ 4235a6279470SFilipe Manana right = alloc_tree_block_no_bg_flush(trans, root, 0, &disk_key, 0, 4236ca9d473aSJosef Bacik l->start, 0, num_doubles ? 4237ca9d473aSJosef Bacik BTRFS_NESTING_NEW_ROOT : 4238ca9d473aSJosef Bacik BTRFS_NESTING_SPLIT); 4239f0486c68SYan, Zheng if (IS_ERR(right)) 424044871b1bSChris Mason return PTR_ERR(right); 4241f0486c68SYan, Zheng 42420b246afaSJeff Mahoney root_add_used(root, fs_info->nodesize); 424344871b1bSChris Mason 42445d4f98a2SYan Zheng if (split == 0) { 424544871b1bSChris Mason if (mid <= slot) { 424644871b1bSChris Mason btrfs_set_header_nritems(right, 0); 42476ad3cf6dSDavid Sterba insert_ptr(trans, path, &disk_key, 42482ff7e61eSJeff Mahoney right->start, path->slots[1] + 1, 1); 424944871b1bSChris Mason btrfs_tree_unlock(path->nodes[0]); 425044871b1bSChris Mason free_extent_buffer(path->nodes[0]); 425144871b1bSChris Mason path->nodes[0] = right; 425244871b1bSChris Mason path->slots[0] = 0; 425344871b1bSChris Mason path->slots[1] += 1; 425444871b1bSChris Mason } else { 425544871b1bSChris Mason btrfs_set_header_nritems(right, 0); 42566ad3cf6dSDavid Sterba insert_ptr(trans, path, &disk_key, 42572ff7e61eSJeff Mahoney right->start, path->slots[1], 1); 425844871b1bSChris Mason btrfs_tree_unlock(path->nodes[0]); 425944871b1bSChris Mason free_extent_buffer(path->nodes[0]); 426044871b1bSChris Mason path->nodes[0] = right; 426144871b1bSChris Mason path->slots[0] = 0; 4262143bede5SJeff Mahoney if (path->slots[1] == 0) 4263b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 42645d4f98a2SYan Zheng } 4265196e0249SLiu Bo /* 4266196e0249SLiu Bo * We create a new leaf 'right' for the required ins_len and 4267196e0249SLiu Bo * we'll do btrfs_mark_buffer_dirty() on this leaf after copying 4268196e0249SLiu Bo * the content of ins_len to 'right'. 4269196e0249SLiu Bo */ 427044871b1bSChris Mason return ret; 427144871b1bSChris Mason } 427244871b1bSChris Mason 427394f94ad9SDavid Sterba copy_for_split(trans, path, l, right, slot, mid, nritems); 427444871b1bSChris Mason 42755d4f98a2SYan Zheng if (split == 2) { 4276cc0c5538SChris Mason BUG_ON(num_doubles != 0); 4277cc0c5538SChris Mason num_doubles++; 4278cc0c5538SChris Mason goto again; 42793326d1b0SChris Mason } 428044871b1bSChris Mason 4281143bede5SJeff Mahoney return 0; 428299d8f83cSChris Mason 428399d8f83cSChris Mason push_for_double: 428499d8f83cSChris Mason push_for_double_split(trans, root, path, data_size); 428599d8f83cSChris Mason tried_avoid_double = 1; 4286e902baacSDavid Sterba if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) 428799d8f83cSChris Mason return 0; 428899d8f83cSChris Mason goto again; 4289be0e5c09SChris Mason } 4290be0e5c09SChris Mason 4291ad48fd75SYan, Zheng static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, 4292ad48fd75SYan, Zheng struct btrfs_root *root, 4293ad48fd75SYan, Zheng struct btrfs_path *path, int ins_len) 4294ad48fd75SYan, Zheng { 4295ad48fd75SYan, Zheng struct btrfs_key key; 4296ad48fd75SYan, Zheng struct extent_buffer *leaf; 4297ad48fd75SYan, Zheng struct btrfs_file_extent_item *fi; 4298ad48fd75SYan, Zheng u64 extent_len = 0; 4299ad48fd75SYan, Zheng u32 item_size; 4300ad48fd75SYan, Zheng int ret; 4301ad48fd75SYan, Zheng 4302ad48fd75SYan, Zheng leaf = path->nodes[0]; 4303ad48fd75SYan, Zheng btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 4304ad48fd75SYan, Zheng 4305ad48fd75SYan, Zheng BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && 4306ad48fd75SYan, Zheng key.type != BTRFS_EXTENT_CSUM_KEY); 4307ad48fd75SYan, Zheng 4308e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) >= ins_len) 4309ad48fd75SYan, Zheng return 0; 4310ad48fd75SYan, Zheng 4311ad48fd75SYan, Zheng item_size = btrfs_item_size_nr(leaf, path->slots[0]); 4312ad48fd75SYan, Zheng if (key.type == BTRFS_EXTENT_DATA_KEY) { 4313ad48fd75SYan, Zheng fi = btrfs_item_ptr(leaf, path->slots[0], 4314ad48fd75SYan, Zheng struct btrfs_file_extent_item); 4315ad48fd75SYan, Zheng extent_len = btrfs_file_extent_num_bytes(leaf, fi); 4316ad48fd75SYan, Zheng } 4317b3b4aa74SDavid Sterba btrfs_release_path(path); 4318ad48fd75SYan, Zheng 4319ad48fd75SYan, Zheng path->keep_locks = 1; 4320ad48fd75SYan, Zheng path->search_for_split = 1; 4321ad48fd75SYan, Zheng ret = btrfs_search_slot(trans, root, &key, path, 0, 1); 4322ad48fd75SYan, Zheng path->search_for_split = 0; 4323a8df6fe6SFilipe Manana if (ret > 0) 4324a8df6fe6SFilipe Manana ret = -EAGAIN; 4325ad48fd75SYan, Zheng if (ret < 0) 4326ad48fd75SYan, Zheng goto err; 4327ad48fd75SYan, Zheng 4328ad48fd75SYan, Zheng ret = -EAGAIN; 4329ad48fd75SYan, Zheng leaf = path->nodes[0]; 4330a8df6fe6SFilipe Manana /* if our item isn't there, return now */ 4331a8df6fe6SFilipe Manana if (item_size != btrfs_item_size_nr(leaf, path->slots[0])) 4332ad48fd75SYan, Zheng goto err; 4333ad48fd75SYan, Zheng 4334109f6aefSChris Mason /* the leaf has changed, it now has room. return now */ 4335e902baacSDavid Sterba if (btrfs_leaf_free_space(path->nodes[0]) >= ins_len) 4336109f6aefSChris Mason goto err; 4337109f6aefSChris Mason 4338ad48fd75SYan, Zheng if (key.type == BTRFS_EXTENT_DATA_KEY) { 4339ad48fd75SYan, Zheng fi = btrfs_item_ptr(leaf, path->slots[0], 4340ad48fd75SYan, Zheng struct btrfs_file_extent_item); 4341ad48fd75SYan, Zheng if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) 4342ad48fd75SYan, Zheng goto err; 4343ad48fd75SYan, Zheng } 4344ad48fd75SYan, Zheng 4345ad48fd75SYan, Zheng ret = split_leaf(trans, root, &key, path, ins_len, 1); 4346f0486c68SYan, Zheng if (ret) 4347f0486c68SYan, Zheng goto err; 4348ad48fd75SYan, Zheng 4349ad48fd75SYan, Zheng path->keep_locks = 0; 4350ad48fd75SYan, Zheng btrfs_unlock_up_safe(path, 1); 4351ad48fd75SYan, Zheng return 0; 4352ad48fd75SYan, Zheng err: 4353ad48fd75SYan, Zheng path->keep_locks = 0; 4354ad48fd75SYan, Zheng return ret; 4355ad48fd75SYan, Zheng } 4356ad48fd75SYan, Zheng 435725263cd7SDavid Sterba static noinline int split_item(struct btrfs_path *path, 4358310712b2SOmar Sandoval const struct btrfs_key *new_key, 4359459931ecSChris Mason unsigned long split_offset) 4360459931ecSChris Mason { 4361459931ecSChris Mason struct extent_buffer *leaf; 4362459931ecSChris Mason struct btrfs_item *item; 4363459931ecSChris Mason struct btrfs_item *new_item; 4364459931ecSChris Mason int slot; 4365ad48fd75SYan, Zheng char *buf; 4366459931ecSChris Mason u32 nritems; 4367ad48fd75SYan, Zheng u32 item_size; 4368459931ecSChris Mason u32 orig_offset; 4369459931ecSChris Mason struct btrfs_disk_key disk_key; 4370459931ecSChris Mason 4371459931ecSChris Mason leaf = path->nodes[0]; 4372e902baacSDavid Sterba BUG_ON(btrfs_leaf_free_space(leaf) < sizeof(struct btrfs_item)); 4373b9473439SChris Mason 4374dd3cc16bSRoss Kirk item = btrfs_item_nr(path->slots[0]); 4375459931ecSChris Mason orig_offset = btrfs_item_offset(leaf, item); 4376459931ecSChris Mason item_size = btrfs_item_size(leaf, item); 4377459931ecSChris Mason 4378459931ecSChris Mason buf = kmalloc(item_size, GFP_NOFS); 4379ad48fd75SYan, Zheng if (!buf) 4380ad48fd75SYan, Zheng return -ENOMEM; 4381ad48fd75SYan, Zheng 4382459931ecSChris Mason read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, 4383459931ecSChris Mason path->slots[0]), item_size); 4384ad48fd75SYan, Zheng 4385459931ecSChris Mason slot = path->slots[0] + 1; 4386459931ecSChris Mason nritems = btrfs_header_nritems(leaf); 4387459931ecSChris Mason if (slot != nritems) { 4388459931ecSChris Mason /* shift the items */ 4389459931ecSChris Mason memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), 4390459931ecSChris Mason btrfs_item_nr_offset(slot), 4391459931ecSChris Mason (nritems - slot) * sizeof(struct btrfs_item)); 4392459931ecSChris Mason } 4393459931ecSChris Mason 4394459931ecSChris Mason btrfs_cpu_key_to_disk(&disk_key, new_key); 4395459931ecSChris Mason btrfs_set_item_key(leaf, &disk_key, slot); 4396459931ecSChris Mason 4397dd3cc16bSRoss Kirk new_item = btrfs_item_nr(slot); 4398459931ecSChris Mason 4399459931ecSChris Mason btrfs_set_item_offset(leaf, new_item, orig_offset); 4400459931ecSChris Mason btrfs_set_item_size(leaf, new_item, item_size - split_offset); 4401459931ecSChris Mason 4402459931ecSChris Mason btrfs_set_item_offset(leaf, item, 4403459931ecSChris Mason orig_offset + item_size - split_offset); 4404459931ecSChris Mason btrfs_set_item_size(leaf, item, split_offset); 4405459931ecSChris Mason 4406459931ecSChris Mason btrfs_set_header_nritems(leaf, nritems + 1); 4407459931ecSChris Mason 4408459931ecSChris Mason /* write the data for the start of the original item */ 4409459931ecSChris Mason write_extent_buffer(leaf, buf, 4410459931ecSChris Mason btrfs_item_ptr_offset(leaf, path->slots[0]), 4411459931ecSChris Mason split_offset); 4412459931ecSChris Mason 4413459931ecSChris Mason /* write the data for the new item */ 4414459931ecSChris Mason write_extent_buffer(leaf, buf + split_offset, 4415459931ecSChris Mason btrfs_item_ptr_offset(leaf, slot), 4416459931ecSChris Mason item_size - split_offset); 4417459931ecSChris Mason btrfs_mark_buffer_dirty(leaf); 4418459931ecSChris Mason 4419e902baacSDavid Sterba BUG_ON(btrfs_leaf_free_space(leaf) < 0); 4420459931ecSChris Mason kfree(buf); 4421ad48fd75SYan, Zheng return 0; 4422ad48fd75SYan, Zheng } 4423ad48fd75SYan, Zheng 4424ad48fd75SYan, Zheng /* 4425ad48fd75SYan, Zheng * This function splits a single item into two items, 4426ad48fd75SYan, Zheng * giving 'new_key' to the new item and splitting the 4427ad48fd75SYan, Zheng * old one at split_offset (from the start of the item). 4428ad48fd75SYan, Zheng * 4429ad48fd75SYan, Zheng * The path may be released by this operation. After 4430ad48fd75SYan, Zheng * the split, the path is pointing to the old item. The 4431ad48fd75SYan, Zheng * new item is going to be in the same node as the old one. 4432ad48fd75SYan, Zheng * 4433ad48fd75SYan, Zheng * Note, the item being split must be smaller enough to live alone on 4434ad48fd75SYan, Zheng * a tree block with room for one extra struct btrfs_item 4435ad48fd75SYan, Zheng * 4436ad48fd75SYan, Zheng * This allows us to split the item in place, keeping a lock on the 4437ad48fd75SYan, Zheng * leaf the entire time. 4438ad48fd75SYan, Zheng */ 4439ad48fd75SYan, Zheng int btrfs_split_item(struct btrfs_trans_handle *trans, 4440ad48fd75SYan, Zheng struct btrfs_root *root, 4441ad48fd75SYan, Zheng struct btrfs_path *path, 4442310712b2SOmar Sandoval const struct btrfs_key *new_key, 4443ad48fd75SYan, Zheng unsigned long split_offset) 4444ad48fd75SYan, Zheng { 4445ad48fd75SYan, Zheng int ret; 4446ad48fd75SYan, Zheng ret = setup_leaf_for_split(trans, root, path, 4447ad48fd75SYan, Zheng sizeof(struct btrfs_item)); 4448ad48fd75SYan, Zheng if (ret) 4449459931ecSChris Mason return ret; 4450ad48fd75SYan, Zheng 445125263cd7SDavid Sterba ret = split_item(path, new_key, split_offset); 4452ad48fd75SYan, Zheng return ret; 4453ad48fd75SYan, Zheng } 4454ad48fd75SYan, Zheng 4455ad48fd75SYan, Zheng /* 4456ad48fd75SYan, Zheng * This function duplicate a item, giving 'new_key' to the new item. 4457ad48fd75SYan, Zheng * It guarantees both items live in the same tree leaf and the new item 4458ad48fd75SYan, Zheng * is contiguous with the original item. 4459ad48fd75SYan, Zheng * 4460ad48fd75SYan, Zheng * This allows us to split file extent in place, keeping a lock on the 4461ad48fd75SYan, Zheng * leaf the entire time. 4462ad48fd75SYan, Zheng */ 4463ad48fd75SYan, Zheng int btrfs_duplicate_item(struct btrfs_trans_handle *trans, 4464ad48fd75SYan, Zheng struct btrfs_root *root, 4465ad48fd75SYan, Zheng struct btrfs_path *path, 4466310712b2SOmar Sandoval const struct btrfs_key *new_key) 4467ad48fd75SYan, Zheng { 4468ad48fd75SYan, Zheng struct extent_buffer *leaf; 4469ad48fd75SYan, Zheng int ret; 4470ad48fd75SYan, Zheng u32 item_size; 4471ad48fd75SYan, Zheng 4472ad48fd75SYan, Zheng leaf = path->nodes[0]; 4473ad48fd75SYan, Zheng item_size = btrfs_item_size_nr(leaf, path->slots[0]); 4474ad48fd75SYan, Zheng ret = setup_leaf_for_split(trans, root, path, 4475ad48fd75SYan, Zheng item_size + sizeof(struct btrfs_item)); 4476ad48fd75SYan, Zheng if (ret) 4477ad48fd75SYan, Zheng return ret; 4478ad48fd75SYan, Zheng 4479ad48fd75SYan, Zheng path->slots[0]++; 4480fc0d82e1SNikolay Borisov setup_items_for_insert(root, path, new_key, &item_size, 1); 4481ad48fd75SYan, Zheng leaf = path->nodes[0]; 4482ad48fd75SYan, Zheng memcpy_extent_buffer(leaf, 4483ad48fd75SYan, Zheng btrfs_item_ptr_offset(leaf, path->slots[0]), 4484ad48fd75SYan, Zheng btrfs_item_ptr_offset(leaf, path->slots[0] - 1), 4485ad48fd75SYan, Zheng item_size); 4486ad48fd75SYan, Zheng return 0; 4487459931ecSChris Mason } 4488459931ecSChris Mason 4489459931ecSChris Mason /* 4490d352ac68SChris Mason * make the item pointed to by the path smaller. new_size indicates 4491d352ac68SChris Mason * how small to make it, and from_end tells us if we just chop bytes 4492d352ac68SChris Mason * off the end of the item or if we shift the item to chop bytes off 4493d352ac68SChris Mason * the front. 4494d352ac68SChris Mason */ 449578ac4f9eSDavid Sterba void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end) 4496b18c6685SChris Mason { 4497b18c6685SChris Mason int slot; 44985f39d397SChris Mason struct extent_buffer *leaf; 44995f39d397SChris Mason struct btrfs_item *item; 4500b18c6685SChris Mason u32 nritems; 4501b18c6685SChris Mason unsigned int data_end; 4502b18c6685SChris Mason unsigned int old_data_start; 4503b18c6685SChris Mason unsigned int old_size; 4504b18c6685SChris Mason unsigned int size_diff; 4505b18c6685SChris Mason int i; 4506cfed81a0SChris Mason struct btrfs_map_token token; 4507cfed81a0SChris Mason 45085f39d397SChris Mason leaf = path->nodes[0]; 4509179e29e4SChris Mason slot = path->slots[0]; 4510179e29e4SChris Mason 4511179e29e4SChris Mason old_size = btrfs_item_size_nr(leaf, slot); 4512179e29e4SChris Mason if (old_size == new_size) 4513143bede5SJeff Mahoney return; 4514b18c6685SChris Mason 45155f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 45168f881e8cSDavid Sterba data_end = leaf_data_end(leaf); 4517b18c6685SChris Mason 45185f39d397SChris Mason old_data_start = btrfs_item_offset_nr(leaf, slot); 4519179e29e4SChris Mason 4520b18c6685SChris Mason size_diff = old_size - new_size; 4521b18c6685SChris Mason 4522b18c6685SChris Mason BUG_ON(slot < 0); 4523b18c6685SChris Mason BUG_ON(slot >= nritems); 4524b18c6685SChris Mason 4525b18c6685SChris Mason /* 4526b18c6685SChris Mason * item0..itemN ... dataN.offset..dataN.size .. data0.size 4527b18c6685SChris Mason */ 4528b18c6685SChris Mason /* first correct the data pointers */ 4529c82f823cSDavid Sterba btrfs_init_map_token(&token, leaf); 4530b18c6685SChris Mason for (i = slot; i < nritems; i++) { 45315f39d397SChris Mason u32 ioff; 4532dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 4533db94535dSChris Mason 4534cc4c13d5SDavid Sterba ioff = btrfs_token_item_offset(&token, item); 4535cc4c13d5SDavid Sterba btrfs_set_token_item_offset(&token, item, ioff + size_diff); 4536b18c6685SChris Mason } 4537db94535dSChris Mason 4538b18c6685SChris Mason /* shift the data */ 4539179e29e4SChris Mason if (from_end) { 45403d9ec8c4SNikolay Borisov memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + 45413d9ec8c4SNikolay Borisov data_end + size_diff, BTRFS_LEAF_DATA_OFFSET + 4542b18c6685SChris Mason data_end, old_data_start + new_size - data_end); 4543179e29e4SChris Mason } else { 4544179e29e4SChris Mason struct btrfs_disk_key disk_key; 4545179e29e4SChris Mason u64 offset; 4546179e29e4SChris Mason 4547179e29e4SChris Mason btrfs_item_key(leaf, &disk_key, slot); 4548179e29e4SChris Mason 4549179e29e4SChris Mason if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { 4550179e29e4SChris Mason unsigned long ptr; 4551179e29e4SChris Mason struct btrfs_file_extent_item *fi; 4552179e29e4SChris Mason 4553179e29e4SChris Mason fi = btrfs_item_ptr(leaf, slot, 4554179e29e4SChris Mason struct btrfs_file_extent_item); 4555179e29e4SChris Mason fi = (struct btrfs_file_extent_item *)( 4556179e29e4SChris Mason (unsigned long)fi - size_diff); 4557179e29e4SChris Mason 4558179e29e4SChris Mason if (btrfs_file_extent_type(leaf, fi) == 4559179e29e4SChris Mason BTRFS_FILE_EXTENT_INLINE) { 4560179e29e4SChris Mason ptr = btrfs_item_ptr_offset(leaf, slot); 4561179e29e4SChris Mason memmove_extent_buffer(leaf, ptr, 4562179e29e4SChris Mason (unsigned long)fi, 45637ec20afbSDavid Sterba BTRFS_FILE_EXTENT_INLINE_DATA_START); 4564179e29e4SChris Mason } 4565179e29e4SChris Mason } 4566179e29e4SChris Mason 45673d9ec8c4SNikolay Borisov memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + 45683d9ec8c4SNikolay Borisov data_end + size_diff, BTRFS_LEAF_DATA_OFFSET + 4569179e29e4SChris Mason data_end, old_data_start - data_end); 4570179e29e4SChris Mason 4571179e29e4SChris Mason offset = btrfs_disk_key_offset(&disk_key); 4572179e29e4SChris Mason btrfs_set_disk_key_offset(&disk_key, offset + size_diff); 4573179e29e4SChris Mason btrfs_set_item_key(leaf, &disk_key, slot); 4574179e29e4SChris Mason if (slot == 0) 4575b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 4576179e29e4SChris Mason } 45775f39d397SChris Mason 4578dd3cc16bSRoss Kirk item = btrfs_item_nr(slot); 45795f39d397SChris Mason btrfs_set_item_size(leaf, item, new_size); 45805f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 4581b18c6685SChris Mason 4582e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < 0) { 4583a4f78750SDavid Sterba btrfs_print_leaf(leaf); 4584b18c6685SChris Mason BUG(); 45855f39d397SChris Mason } 4586b18c6685SChris Mason } 4587b18c6685SChris Mason 4588d352ac68SChris Mason /* 45898f69dbd2SStefan Behrens * make the item pointed to by the path bigger, data_size is the added size. 4590d352ac68SChris Mason */ 4591c71dd880SDavid Sterba void btrfs_extend_item(struct btrfs_path *path, u32 data_size) 45926567e837SChris Mason { 45936567e837SChris Mason int slot; 45945f39d397SChris Mason struct extent_buffer *leaf; 45955f39d397SChris Mason struct btrfs_item *item; 45966567e837SChris Mason u32 nritems; 45976567e837SChris Mason unsigned int data_end; 45986567e837SChris Mason unsigned int old_data; 45996567e837SChris Mason unsigned int old_size; 46006567e837SChris Mason int i; 4601cfed81a0SChris Mason struct btrfs_map_token token; 4602cfed81a0SChris Mason 46035f39d397SChris Mason leaf = path->nodes[0]; 46046567e837SChris Mason 46055f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 46068f881e8cSDavid Sterba data_end = leaf_data_end(leaf); 46076567e837SChris Mason 4608e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < data_size) { 4609a4f78750SDavid Sterba btrfs_print_leaf(leaf); 46106567e837SChris Mason BUG(); 46115f39d397SChris Mason } 46126567e837SChris Mason slot = path->slots[0]; 46135f39d397SChris Mason old_data = btrfs_item_end_nr(leaf, slot); 46146567e837SChris Mason 46156567e837SChris Mason BUG_ON(slot < 0); 46163326d1b0SChris Mason if (slot >= nritems) { 4617a4f78750SDavid Sterba btrfs_print_leaf(leaf); 4618c71dd880SDavid Sterba btrfs_crit(leaf->fs_info, "slot %d too large, nritems %d", 4619d397712bSChris Mason slot, nritems); 4620290342f6SArnd Bergmann BUG(); 46213326d1b0SChris Mason } 46226567e837SChris Mason 46236567e837SChris Mason /* 46246567e837SChris Mason * item0..itemN ... dataN.offset..dataN.size .. data0.size 46256567e837SChris Mason */ 46266567e837SChris Mason /* first correct the data pointers */ 4627c82f823cSDavid Sterba btrfs_init_map_token(&token, leaf); 46286567e837SChris Mason for (i = slot; i < nritems; i++) { 46295f39d397SChris Mason u32 ioff; 4630dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 4631db94535dSChris Mason 4632cc4c13d5SDavid Sterba ioff = btrfs_token_item_offset(&token, item); 4633cc4c13d5SDavid Sterba btrfs_set_token_item_offset(&token, item, ioff - data_size); 46346567e837SChris Mason } 46355f39d397SChris Mason 46366567e837SChris Mason /* shift the data */ 46373d9ec8c4SNikolay Borisov memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + 46383d9ec8c4SNikolay Borisov data_end - data_size, BTRFS_LEAF_DATA_OFFSET + 46396567e837SChris Mason data_end, old_data - data_end); 46405f39d397SChris Mason 46416567e837SChris Mason data_end = old_data; 46425f39d397SChris Mason old_size = btrfs_item_size_nr(leaf, slot); 4643dd3cc16bSRoss Kirk item = btrfs_item_nr(slot); 46445f39d397SChris Mason btrfs_set_item_size(leaf, item, old_size + data_size); 46455f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 46466567e837SChris Mason 4647e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < 0) { 4648a4f78750SDavid Sterba btrfs_print_leaf(leaf); 46496567e837SChris Mason BUG(); 46505f39d397SChris Mason } 46516567e837SChris Mason } 46526567e837SChris Mason 4653da9ffb24SNikolay Borisov /** 4654da9ffb24SNikolay Borisov * setup_items_for_insert - Helper called before inserting one or more items 4655da9ffb24SNikolay Borisov * to a leaf. Main purpose is to save stack depth by doing the bulk of the work 4656da9ffb24SNikolay Borisov * in a function that doesn't call btrfs_search_slot 4657da9ffb24SNikolay Borisov * 4658da9ffb24SNikolay Borisov * @root: root we are inserting items to 4659da9ffb24SNikolay Borisov * @path: points to the leaf/slot where we are going to insert new items 4660da9ffb24SNikolay Borisov * @cpu_key: array of keys for items to be inserted 4661da9ffb24SNikolay Borisov * @data_size: size of the body of each item we are going to insert 4662da9ffb24SNikolay Borisov * @nr: size of @cpu_key/@data_size arrays 466374123bd7SChris Mason */ 4664afe5fea7STsutomu Itoh void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path, 4665310712b2SOmar Sandoval const struct btrfs_key *cpu_key, u32 *data_size, 4666fc0d82e1SNikolay Borisov int nr) 4667be0e5c09SChris Mason { 46680b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 46695f39d397SChris Mason struct btrfs_item *item; 46709c58309dSChris Mason int i; 46717518a238SChris Mason u32 nritems; 4672be0e5c09SChris Mason unsigned int data_end; 4673e2fa7227SChris Mason struct btrfs_disk_key disk_key; 467444871b1bSChris Mason struct extent_buffer *leaf; 467544871b1bSChris Mason int slot; 4676cfed81a0SChris Mason struct btrfs_map_token token; 4677fc0d82e1SNikolay Borisov u32 total_size; 4678fc0d82e1SNikolay Borisov u32 total_data = 0; 4679fc0d82e1SNikolay Borisov 4680fc0d82e1SNikolay Borisov for (i = 0; i < nr; i++) 4681fc0d82e1SNikolay Borisov total_data += data_size[i]; 4682fc0d82e1SNikolay Borisov total_size = total_data + (nr * sizeof(struct btrfs_item)); 4683cfed81a0SChris Mason 468424cdc847SFilipe Manana if (path->slots[0] == 0) { 468524cdc847SFilipe Manana btrfs_cpu_key_to_disk(&disk_key, cpu_key); 4686b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 468724cdc847SFilipe Manana } 468824cdc847SFilipe Manana btrfs_unlock_up_safe(path, 1); 468924cdc847SFilipe Manana 46905f39d397SChris Mason leaf = path->nodes[0]; 469144871b1bSChris Mason slot = path->slots[0]; 469274123bd7SChris Mason 46935f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 46948f881e8cSDavid Sterba data_end = leaf_data_end(leaf); 4695eb60ceacSChris Mason 4696e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < total_size) { 4697a4f78750SDavid Sterba btrfs_print_leaf(leaf); 46980b246afaSJeff Mahoney btrfs_crit(fs_info, "not enough freespace need %u have %d", 4699e902baacSDavid Sterba total_size, btrfs_leaf_free_space(leaf)); 4700be0e5c09SChris Mason BUG(); 4701d4dbff95SChris Mason } 47025f39d397SChris Mason 4703c82f823cSDavid Sterba btrfs_init_map_token(&token, leaf); 4704be0e5c09SChris Mason if (slot != nritems) { 47055f39d397SChris Mason unsigned int old_data = btrfs_item_end_nr(leaf, slot); 4706be0e5c09SChris Mason 47075f39d397SChris Mason if (old_data < data_end) { 4708a4f78750SDavid Sterba btrfs_print_leaf(leaf); 47097269ddd2SNikolay Borisov btrfs_crit(fs_info, 47107269ddd2SNikolay Borisov "item at slot %d with data offset %u beyond data end of leaf %u", 47115f39d397SChris Mason slot, old_data, data_end); 4712290342f6SArnd Bergmann BUG(); 47135f39d397SChris Mason } 4714be0e5c09SChris Mason /* 4715be0e5c09SChris Mason * item0..itemN ... dataN.offset..dataN.size .. data0.size 4716be0e5c09SChris Mason */ 4717be0e5c09SChris Mason /* first correct the data pointers */ 47180783fcfcSChris Mason for (i = slot; i < nritems; i++) { 47195f39d397SChris Mason u32 ioff; 4720db94535dSChris Mason 4721dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 4722cc4c13d5SDavid Sterba ioff = btrfs_token_item_offset(&token, item); 4723cc4c13d5SDavid Sterba btrfs_set_token_item_offset(&token, item, 4724cc4c13d5SDavid Sterba ioff - total_data); 47250783fcfcSChris Mason } 4726be0e5c09SChris Mason /* shift the items */ 47279c58309dSChris Mason memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), 47285f39d397SChris Mason btrfs_item_nr_offset(slot), 47290783fcfcSChris Mason (nritems - slot) * sizeof(struct btrfs_item)); 4730be0e5c09SChris Mason 4731be0e5c09SChris Mason /* shift the data */ 47323d9ec8c4SNikolay Borisov memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + 47333d9ec8c4SNikolay Borisov data_end - total_data, BTRFS_LEAF_DATA_OFFSET + 4734be0e5c09SChris Mason data_end, old_data - data_end); 4735be0e5c09SChris Mason data_end = old_data; 4736be0e5c09SChris Mason } 47375f39d397SChris Mason 473862e2749eSChris Mason /* setup the item for the new data */ 47399c58309dSChris Mason for (i = 0; i < nr; i++) { 47409c58309dSChris Mason btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); 47419c58309dSChris Mason btrfs_set_item_key(leaf, &disk_key, slot + i); 4742dd3cc16bSRoss Kirk item = btrfs_item_nr(slot + i); 47439c58309dSChris Mason data_end -= data_size[i]; 4744fc0716c2SNikolay Borisov btrfs_set_token_item_offset(&token, item, data_end); 4745cc4c13d5SDavid Sterba btrfs_set_token_item_size(&token, item, data_size[i]); 47469c58309dSChris Mason } 474744871b1bSChris Mason 47489c58309dSChris Mason btrfs_set_header_nritems(leaf, nritems + nr); 4749b9473439SChris Mason btrfs_mark_buffer_dirty(leaf); 4750aa5d6bedSChris Mason 4751e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < 0) { 4752a4f78750SDavid Sterba btrfs_print_leaf(leaf); 4753be0e5c09SChris Mason BUG(); 47545f39d397SChris Mason } 475544871b1bSChris Mason } 475644871b1bSChris Mason 475744871b1bSChris Mason /* 475844871b1bSChris Mason * Given a key and some data, insert items into the tree. 475944871b1bSChris Mason * This does all the path init required, making room in the tree if needed. 476044871b1bSChris Mason */ 476144871b1bSChris Mason int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, 476244871b1bSChris Mason struct btrfs_root *root, 476344871b1bSChris Mason struct btrfs_path *path, 4764310712b2SOmar Sandoval const struct btrfs_key *cpu_key, u32 *data_size, 476544871b1bSChris Mason int nr) 476644871b1bSChris Mason { 476744871b1bSChris Mason int ret = 0; 476844871b1bSChris Mason int slot; 476944871b1bSChris Mason int i; 477044871b1bSChris Mason u32 total_size = 0; 477144871b1bSChris Mason u32 total_data = 0; 477244871b1bSChris Mason 477344871b1bSChris Mason for (i = 0; i < nr; i++) 477444871b1bSChris Mason total_data += data_size[i]; 477544871b1bSChris Mason 477644871b1bSChris Mason total_size = total_data + (nr * sizeof(struct btrfs_item)); 477744871b1bSChris Mason ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); 477844871b1bSChris Mason if (ret == 0) 477944871b1bSChris Mason return -EEXIST; 478044871b1bSChris Mason if (ret < 0) 4781143bede5SJeff Mahoney return ret; 478244871b1bSChris Mason 478344871b1bSChris Mason slot = path->slots[0]; 478444871b1bSChris Mason BUG_ON(slot < 0); 478544871b1bSChris Mason 4786fc0d82e1SNikolay Borisov setup_items_for_insert(root, path, cpu_key, data_size, nr); 4787143bede5SJeff Mahoney return 0; 478862e2749eSChris Mason } 478962e2749eSChris Mason 479062e2749eSChris Mason /* 479162e2749eSChris Mason * Given a key and some data, insert an item into the tree. 479262e2749eSChris Mason * This does all the path init required, making room in the tree if needed. 479362e2749eSChris Mason */ 4794310712b2SOmar Sandoval int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, 4795310712b2SOmar Sandoval const struct btrfs_key *cpu_key, void *data, 4796310712b2SOmar Sandoval u32 data_size) 479762e2749eSChris Mason { 479862e2749eSChris Mason int ret = 0; 47992c90e5d6SChris Mason struct btrfs_path *path; 48005f39d397SChris Mason struct extent_buffer *leaf; 48015f39d397SChris Mason unsigned long ptr; 480262e2749eSChris Mason 48032c90e5d6SChris Mason path = btrfs_alloc_path(); 4804db5b493aSTsutomu Itoh if (!path) 4805db5b493aSTsutomu Itoh return -ENOMEM; 48062c90e5d6SChris Mason ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); 480762e2749eSChris Mason if (!ret) { 48085f39d397SChris Mason leaf = path->nodes[0]; 48095f39d397SChris Mason ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); 48105f39d397SChris Mason write_extent_buffer(leaf, data, ptr, data_size); 48115f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 481262e2749eSChris Mason } 48132c90e5d6SChris Mason btrfs_free_path(path); 4814aa5d6bedSChris Mason return ret; 4815be0e5c09SChris Mason } 4816be0e5c09SChris Mason 481774123bd7SChris Mason /* 48185de08d7dSChris Mason * delete the pointer from a given node. 481974123bd7SChris Mason * 4820d352ac68SChris Mason * the tree should have been previously balanced so the deletion does not 4821d352ac68SChris Mason * empty a node. 482274123bd7SChris Mason */ 4823afe5fea7STsutomu Itoh static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, 4824afe5fea7STsutomu Itoh int level, int slot) 4825be0e5c09SChris Mason { 48265f39d397SChris Mason struct extent_buffer *parent = path->nodes[level]; 48277518a238SChris Mason u32 nritems; 4828f3ea38daSJan Schmidt int ret; 4829be0e5c09SChris Mason 48305f39d397SChris Mason nritems = btrfs_header_nritems(parent); 4831be0e5c09SChris Mason if (slot != nritems - 1) { 4832bf1d3425SDavid Sterba if (level) { 4833bf1d3425SDavid Sterba ret = tree_mod_log_insert_move(parent, slot, slot + 1, 4834a446a979SDavid Sterba nritems - slot - 1); 4835bf1d3425SDavid Sterba BUG_ON(ret < 0); 4836bf1d3425SDavid Sterba } 48375f39d397SChris Mason memmove_extent_buffer(parent, 48385f39d397SChris Mason btrfs_node_key_ptr_offset(slot), 48395f39d397SChris Mason btrfs_node_key_ptr_offset(slot + 1), 4840d6025579SChris Mason sizeof(struct btrfs_key_ptr) * 4841d6025579SChris Mason (nritems - slot - 1)); 484257ba86c0SChris Mason } else if (level) { 4843e09c2efeSDavid Sterba ret = tree_mod_log_insert_key(parent, slot, MOD_LOG_KEY_REMOVE, 4844e09c2efeSDavid Sterba GFP_NOFS); 484557ba86c0SChris Mason BUG_ON(ret < 0); 4846be0e5c09SChris Mason } 4847f3ea38daSJan Schmidt 48487518a238SChris Mason nritems--; 48495f39d397SChris Mason btrfs_set_header_nritems(parent, nritems); 48507518a238SChris Mason if (nritems == 0 && parent == root->node) { 48515f39d397SChris Mason BUG_ON(btrfs_header_level(root->node) != 1); 4852eb60ceacSChris Mason /* just turn the root into a leaf and break */ 48535f39d397SChris Mason btrfs_set_header_level(root->node, 0); 4854bb803951SChris Mason } else if (slot == 0) { 48555f39d397SChris Mason struct btrfs_disk_key disk_key; 48565f39d397SChris Mason 48575f39d397SChris Mason btrfs_node_key(parent, &disk_key, 0); 4858b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, level + 1); 4859be0e5c09SChris Mason } 4860d6025579SChris Mason btrfs_mark_buffer_dirty(parent); 4861be0e5c09SChris Mason } 4862be0e5c09SChris Mason 486374123bd7SChris Mason /* 4864323ac95bSChris Mason * a helper function to delete the leaf pointed to by path->slots[1] and 48655d4f98a2SYan Zheng * path->nodes[1]. 4866323ac95bSChris Mason * 4867323ac95bSChris Mason * This deletes the pointer in path->nodes[1] and frees the leaf 4868323ac95bSChris Mason * block extent. zero is returned if it all worked out, < 0 otherwise. 4869323ac95bSChris Mason * 4870323ac95bSChris Mason * The path must have already been setup for deleting the leaf, including 4871323ac95bSChris Mason * all the proper balancing. path->nodes[1] must be locked. 4872323ac95bSChris Mason */ 4873143bede5SJeff Mahoney static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, 4874323ac95bSChris Mason struct btrfs_root *root, 48755d4f98a2SYan Zheng struct btrfs_path *path, 48765d4f98a2SYan Zheng struct extent_buffer *leaf) 4877323ac95bSChris Mason { 48785d4f98a2SYan Zheng WARN_ON(btrfs_header_generation(leaf) != trans->transid); 4879afe5fea7STsutomu Itoh del_ptr(root, path, 1, path->slots[1]); 4880323ac95bSChris Mason 48814d081c41SChris Mason /* 48824d081c41SChris Mason * btrfs_free_extent is expensive, we want to make sure we 48834d081c41SChris Mason * aren't holding any locks when we call it 48844d081c41SChris Mason */ 48854d081c41SChris Mason btrfs_unlock_up_safe(path, 0); 48864d081c41SChris Mason 4887f0486c68SYan, Zheng root_sub_used(root, leaf->len); 4888f0486c68SYan, Zheng 488967439dadSDavid Sterba atomic_inc(&leaf->refs); 48905581a51aSJan Schmidt btrfs_free_tree_block(trans, root, leaf, 0, 1); 48913083ee2eSJosef Bacik free_extent_buffer_stale(leaf); 4892323ac95bSChris Mason } 4893323ac95bSChris Mason /* 489474123bd7SChris Mason * delete the item at the leaf level in path. If that empties 489574123bd7SChris Mason * the leaf, remove it from the tree 489674123bd7SChris Mason */ 489785e21bacSChris Mason int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, 489885e21bacSChris Mason struct btrfs_path *path, int slot, int nr) 4899be0e5c09SChris Mason { 49000b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 49015f39d397SChris Mason struct extent_buffer *leaf; 49025f39d397SChris Mason struct btrfs_item *item; 4903ce0eac2aSAlexandru Moise u32 last_off; 4904ce0eac2aSAlexandru Moise u32 dsize = 0; 4905aa5d6bedSChris Mason int ret = 0; 4906aa5d6bedSChris Mason int wret; 490785e21bacSChris Mason int i; 49087518a238SChris Mason u32 nritems; 4909be0e5c09SChris Mason 49105f39d397SChris Mason leaf = path->nodes[0]; 491185e21bacSChris Mason last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); 491285e21bacSChris Mason 491385e21bacSChris Mason for (i = 0; i < nr; i++) 491485e21bacSChris Mason dsize += btrfs_item_size_nr(leaf, slot + i); 491585e21bacSChris Mason 49165f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 4917be0e5c09SChris Mason 491885e21bacSChris Mason if (slot + nr != nritems) { 49198f881e8cSDavid Sterba int data_end = leaf_data_end(leaf); 4920c82f823cSDavid Sterba struct btrfs_map_token token; 49215f39d397SChris Mason 49223d9ec8c4SNikolay Borisov memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + 4923d6025579SChris Mason data_end + dsize, 49243d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + data_end, 492585e21bacSChris Mason last_off - data_end); 49265f39d397SChris Mason 4927c82f823cSDavid Sterba btrfs_init_map_token(&token, leaf); 492885e21bacSChris Mason for (i = slot + nr; i < nritems; i++) { 49295f39d397SChris Mason u32 ioff; 4930db94535dSChris Mason 4931dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 4932cc4c13d5SDavid Sterba ioff = btrfs_token_item_offset(&token, item); 4933cc4c13d5SDavid Sterba btrfs_set_token_item_offset(&token, item, ioff + dsize); 49340783fcfcSChris Mason } 4935db94535dSChris Mason 49365f39d397SChris Mason memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), 493785e21bacSChris Mason btrfs_item_nr_offset(slot + nr), 49380783fcfcSChris Mason sizeof(struct btrfs_item) * 493985e21bacSChris Mason (nritems - slot - nr)); 4940be0e5c09SChris Mason } 494185e21bacSChris Mason btrfs_set_header_nritems(leaf, nritems - nr); 494285e21bacSChris Mason nritems -= nr; 49435f39d397SChris Mason 494474123bd7SChris Mason /* delete the leaf if we've emptied it */ 49457518a238SChris Mason if (nritems == 0) { 49465f39d397SChris Mason if (leaf == root->node) { 49475f39d397SChris Mason btrfs_set_header_level(leaf, 0); 49489a8dd150SChris Mason } else { 49496a884d7dSDavid Sterba btrfs_clean_tree_block(leaf); 4950143bede5SJeff Mahoney btrfs_del_leaf(trans, root, path, leaf); 49519a8dd150SChris Mason } 4952be0e5c09SChris Mason } else { 49537518a238SChris Mason int used = leaf_space_used(leaf, 0, nritems); 4954aa5d6bedSChris Mason if (slot == 0) { 49555f39d397SChris Mason struct btrfs_disk_key disk_key; 49565f39d397SChris Mason 49575f39d397SChris Mason btrfs_item_key(leaf, &disk_key, 0); 4958b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 4959aa5d6bedSChris Mason } 4960aa5d6bedSChris Mason 496174123bd7SChris Mason /* delete the leaf if it is mostly empty */ 49620b246afaSJeff Mahoney if (used < BTRFS_LEAF_DATA_SIZE(fs_info) / 3) { 4963be0e5c09SChris Mason /* push_leaf_left fixes the path. 4964be0e5c09SChris Mason * make sure the path still points to our leaf 4965be0e5c09SChris Mason * for possible call to del_ptr below 4966be0e5c09SChris Mason */ 49674920c9acSChris Mason slot = path->slots[1]; 496867439dadSDavid Sterba atomic_inc(&leaf->refs); 49695f39d397SChris Mason 497099d8f83cSChris Mason wret = push_leaf_left(trans, root, path, 1, 1, 497199d8f83cSChris Mason 1, (u32)-1); 497254aa1f4dSChris Mason if (wret < 0 && wret != -ENOSPC) 4973aa5d6bedSChris Mason ret = wret; 49745f39d397SChris Mason 49755f39d397SChris Mason if (path->nodes[0] == leaf && 49765f39d397SChris Mason btrfs_header_nritems(leaf)) { 497799d8f83cSChris Mason wret = push_leaf_right(trans, root, path, 1, 497899d8f83cSChris Mason 1, 1, 0); 497954aa1f4dSChris Mason if (wret < 0 && wret != -ENOSPC) 4980aa5d6bedSChris Mason ret = wret; 4981aa5d6bedSChris Mason } 49825f39d397SChris Mason 49835f39d397SChris Mason if (btrfs_header_nritems(leaf) == 0) { 4984323ac95bSChris Mason path->slots[1] = slot; 4985143bede5SJeff Mahoney btrfs_del_leaf(trans, root, path, leaf); 49865f39d397SChris Mason free_extent_buffer(leaf); 4987143bede5SJeff Mahoney ret = 0; 49885de08d7dSChris Mason } else { 4989925baeddSChris Mason /* if we're still in the path, make sure 4990925baeddSChris Mason * we're dirty. Otherwise, one of the 4991925baeddSChris Mason * push_leaf functions must have already 4992925baeddSChris Mason * dirtied this buffer 4993925baeddSChris Mason */ 4994925baeddSChris Mason if (path->nodes[0] == leaf) 49955f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 49965f39d397SChris Mason free_extent_buffer(leaf); 4997be0e5c09SChris Mason } 4998d5719762SChris Mason } else { 49995f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 5000be0e5c09SChris Mason } 50019a8dd150SChris Mason } 5002aa5d6bedSChris Mason return ret; 50039a8dd150SChris Mason } 50049a8dd150SChris Mason 500597571fd0SChris Mason /* 5006925baeddSChris Mason * search the tree again to find a leaf with lesser keys 50077bb86316SChris Mason * returns 0 if it found something or 1 if there are no lesser leaves. 50087bb86316SChris Mason * returns < 0 on io errors. 5009d352ac68SChris Mason * 5010d352ac68SChris Mason * This may release the path, and so you may lose any locks held at the 5011d352ac68SChris Mason * time you call it. 50127bb86316SChris Mason */ 501316e7549fSJosef Bacik int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) 50147bb86316SChris Mason { 5015925baeddSChris Mason struct btrfs_key key; 5016925baeddSChris Mason struct btrfs_disk_key found_key; 5017925baeddSChris Mason int ret; 50187bb86316SChris Mason 5019925baeddSChris Mason btrfs_item_key_to_cpu(path->nodes[0], &key, 0); 5020925baeddSChris Mason 5021e8b0d724SFilipe David Borba Manana if (key.offset > 0) { 5022925baeddSChris Mason key.offset--; 5023e8b0d724SFilipe David Borba Manana } else if (key.type > 0) { 5024925baeddSChris Mason key.type--; 5025e8b0d724SFilipe David Borba Manana key.offset = (u64)-1; 5026e8b0d724SFilipe David Borba Manana } else if (key.objectid > 0) { 5027925baeddSChris Mason key.objectid--; 5028e8b0d724SFilipe David Borba Manana key.type = (u8)-1; 5029e8b0d724SFilipe David Borba Manana key.offset = (u64)-1; 5030e8b0d724SFilipe David Borba Manana } else { 50317bb86316SChris Mason return 1; 5032e8b0d724SFilipe David Borba Manana } 50337bb86316SChris Mason 5034b3b4aa74SDavid Sterba btrfs_release_path(path); 5035925baeddSChris Mason ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5036925baeddSChris Mason if (ret < 0) 5037925baeddSChris Mason return ret; 5038925baeddSChris Mason btrfs_item_key(path->nodes[0], &found_key, 0); 5039925baeddSChris Mason ret = comp_keys(&found_key, &key); 5040337c6f68SFilipe Manana /* 5041337c6f68SFilipe Manana * We might have had an item with the previous key in the tree right 5042337c6f68SFilipe Manana * before we released our path. And after we released our path, that 5043337c6f68SFilipe Manana * item might have been pushed to the first slot (0) of the leaf we 5044337c6f68SFilipe Manana * were holding due to a tree balance. Alternatively, an item with the 5045337c6f68SFilipe Manana * previous key can exist as the only element of a leaf (big fat item). 5046337c6f68SFilipe Manana * Therefore account for these 2 cases, so that our callers (like 5047337c6f68SFilipe Manana * btrfs_previous_item) don't miss an existing item with a key matching 5048337c6f68SFilipe Manana * the previous key we computed above. 5049337c6f68SFilipe Manana */ 5050337c6f68SFilipe Manana if (ret <= 0) 50517bb86316SChris Mason return 0; 5052925baeddSChris Mason return 1; 50537bb86316SChris Mason } 50547bb86316SChris Mason 50553f157a2fSChris Mason /* 50563f157a2fSChris Mason * A helper function to walk down the tree starting at min_key, and looking 5057de78b51aSEric Sandeen * for nodes or leaves that are have a minimum transaction id. 5058de78b51aSEric Sandeen * This is used by the btree defrag code, and tree logging 50593f157a2fSChris Mason * 50603f157a2fSChris Mason * This does not cow, but it does stuff the starting key it finds back 50613f157a2fSChris Mason * into min_key, so you can call btrfs_search_slot with cow=1 on the 50623f157a2fSChris Mason * key and get a writable path. 50633f157a2fSChris Mason * 50643f157a2fSChris Mason * This honors path->lowest_level to prevent descent past a given level 50653f157a2fSChris Mason * of the tree. 50663f157a2fSChris Mason * 5067d352ac68SChris Mason * min_trans indicates the oldest transaction that you are interested 5068d352ac68SChris Mason * in walking through. Any nodes or leaves older than min_trans are 5069d352ac68SChris Mason * skipped over (without reading them). 5070d352ac68SChris Mason * 50713f157a2fSChris Mason * returns zero if something useful was found, < 0 on error and 1 if there 50723f157a2fSChris Mason * was nothing in the tree that matched the search criteria. 50733f157a2fSChris Mason */ 50743f157a2fSChris Mason int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, 5075de78b51aSEric Sandeen struct btrfs_path *path, 50763f157a2fSChris Mason u64 min_trans) 50773f157a2fSChris Mason { 50783f157a2fSChris Mason struct extent_buffer *cur; 50793f157a2fSChris Mason struct btrfs_key found_key; 50803f157a2fSChris Mason int slot; 50819652480bSYan int sret; 50823f157a2fSChris Mason u32 nritems; 50833f157a2fSChris Mason int level; 50843f157a2fSChris Mason int ret = 1; 5085f98de9b9SFilipe Manana int keep_locks = path->keep_locks; 50863f157a2fSChris Mason 5087f98de9b9SFilipe Manana path->keep_locks = 1; 50883f157a2fSChris Mason again: 5089bd681513SChris Mason cur = btrfs_read_lock_root_node(root); 50903f157a2fSChris Mason level = btrfs_header_level(cur); 5091e02119d5SChris Mason WARN_ON(path->nodes[level]); 50923f157a2fSChris Mason path->nodes[level] = cur; 5093bd681513SChris Mason path->locks[level] = BTRFS_READ_LOCK; 50943f157a2fSChris Mason 50953f157a2fSChris Mason if (btrfs_header_generation(cur) < min_trans) { 50963f157a2fSChris Mason ret = 1; 50973f157a2fSChris Mason goto out; 50983f157a2fSChris Mason } 50993f157a2fSChris Mason while (1) { 51003f157a2fSChris Mason nritems = btrfs_header_nritems(cur); 51013f157a2fSChris Mason level = btrfs_header_level(cur); 5102e3b83361SQu Wenruo sret = btrfs_bin_search(cur, min_key, &slot); 5103cbca7d59SFilipe Manana if (sret < 0) { 5104cbca7d59SFilipe Manana ret = sret; 5105cbca7d59SFilipe Manana goto out; 5106cbca7d59SFilipe Manana } 51073f157a2fSChris Mason 5108323ac95bSChris Mason /* at the lowest level, we're done, setup the path and exit */ 5109323ac95bSChris Mason if (level == path->lowest_level) { 5110e02119d5SChris Mason if (slot >= nritems) 5111e02119d5SChris Mason goto find_next_key; 51123f157a2fSChris Mason ret = 0; 51133f157a2fSChris Mason path->slots[level] = slot; 51143f157a2fSChris Mason btrfs_item_key_to_cpu(cur, &found_key, slot); 51153f157a2fSChris Mason goto out; 51163f157a2fSChris Mason } 51179652480bSYan if (sret && slot > 0) 51189652480bSYan slot--; 51193f157a2fSChris Mason /* 5120de78b51aSEric Sandeen * check this node pointer against the min_trans parameters. 5121260db43cSRandy Dunlap * If it is too old, skip to the next one. 51223f157a2fSChris Mason */ 51233f157a2fSChris Mason while (slot < nritems) { 51243f157a2fSChris Mason u64 gen; 5125e02119d5SChris Mason 51263f157a2fSChris Mason gen = btrfs_node_ptr_generation(cur, slot); 51273f157a2fSChris Mason if (gen < min_trans) { 51283f157a2fSChris Mason slot++; 51293f157a2fSChris Mason continue; 51303f157a2fSChris Mason } 51313f157a2fSChris Mason break; 51323f157a2fSChris Mason } 5133e02119d5SChris Mason find_next_key: 51343f157a2fSChris Mason /* 51353f157a2fSChris Mason * we didn't find a candidate key in this node, walk forward 51363f157a2fSChris Mason * and find another one 51373f157a2fSChris Mason */ 51383f157a2fSChris Mason if (slot >= nritems) { 5139e02119d5SChris Mason path->slots[level] = slot; 5140e02119d5SChris Mason sret = btrfs_find_next_key(root, path, min_key, level, 5141de78b51aSEric Sandeen min_trans); 5142e02119d5SChris Mason if (sret == 0) { 5143b3b4aa74SDavid Sterba btrfs_release_path(path); 51443f157a2fSChris Mason goto again; 51453f157a2fSChris Mason } else { 51463f157a2fSChris Mason goto out; 51473f157a2fSChris Mason } 51483f157a2fSChris Mason } 51493f157a2fSChris Mason /* save our key for returning back */ 51503f157a2fSChris Mason btrfs_node_key_to_cpu(cur, &found_key, slot); 51513f157a2fSChris Mason path->slots[level] = slot; 51523f157a2fSChris Mason if (level == path->lowest_level) { 51533f157a2fSChris Mason ret = 0; 51543f157a2fSChris Mason goto out; 51553f157a2fSChris Mason } 51564b231ae4SDavid Sterba cur = btrfs_read_node_slot(cur, slot); 5157fb770ae4SLiu Bo if (IS_ERR(cur)) { 5158fb770ae4SLiu Bo ret = PTR_ERR(cur); 5159fb770ae4SLiu Bo goto out; 5160fb770ae4SLiu Bo } 51613f157a2fSChris Mason 5162bd681513SChris Mason btrfs_tree_read_lock(cur); 5163b4ce94deSChris Mason 5164bd681513SChris Mason path->locks[level - 1] = BTRFS_READ_LOCK; 51653f157a2fSChris Mason path->nodes[level - 1] = cur; 5166f7c79f30SChris Mason unlock_up(path, level, 1, 0, NULL); 51673f157a2fSChris Mason } 51683f157a2fSChris Mason out: 5169f98de9b9SFilipe Manana path->keep_locks = keep_locks; 5170f98de9b9SFilipe Manana if (ret == 0) { 5171f98de9b9SFilipe Manana btrfs_unlock_up_safe(path, path->lowest_level + 1); 5172f98de9b9SFilipe Manana memcpy(min_key, &found_key, sizeof(found_key)); 5173f98de9b9SFilipe Manana } 51743f157a2fSChris Mason return ret; 51753f157a2fSChris Mason } 51763f157a2fSChris Mason 51773f157a2fSChris Mason /* 51783f157a2fSChris Mason * this is similar to btrfs_next_leaf, but does not try to preserve 51793f157a2fSChris Mason * and fixup the path. It looks for and returns the next key in the 5180de78b51aSEric Sandeen * tree based on the current path and the min_trans parameters. 51813f157a2fSChris Mason * 51823f157a2fSChris Mason * 0 is returned if another key is found, < 0 if there are any errors 51833f157a2fSChris Mason * and 1 is returned if there are no higher keys in the tree 51843f157a2fSChris Mason * 51853f157a2fSChris Mason * path->keep_locks should be set to 1 on the search made before 51863f157a2fSChris Mason * calling this function. 51873f157a2fSChris Mason */ 5188e7a84565SChris Mason int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, 5189de78b51aSEric Sandeen struct btrfs_key *key, int level, u64 min_trans) 5190e7a84565SChris Mason { 5191e7a84565SChris Mason int slot; 5192e7a84565SChris Mason struct extent_buffer *c; 5193e7a84565SChris Mason 51946a9fb468SJosef Bacik WARN_ON(!path->keep_locks && !path->skip_locking); 5195e7a84565SChris Mason while (level < BTRFS_MAX_LEVEL) { 5196e7a84565SChris Mason if (!path->nodes[level]) 5197e7a84565SChris Mason return 1; 5198e7a84565SChris Mason 5199e7a84565SChris Mason slot = path->slots[level] + 1; 5200e7a84565SChris Mason c = path->nodes[level]; 52013f157a2fSChris Mason next: 5202e7a84565SChris Mason if (slot >= btrfs_header_nritems(c)) { 520333c66f43SYan Zheng int ret; 520433c66f43SYan Zheng int orig_lowest; 520533c66f43SYan Zheng struct btrfs_key cur_key; 520633c66f43SYan Zheng if (level + 1 >= BTRFS_MAX_LEVEL || 520733c66f43SYan Zheng !path->nodes[level + 1]) 5208e7a84565SChris Mason return 1; 520933c66f43SYan Zheng 52106a9fb468SJosef Bacik if (path->locks[level + 1] || path->skip_locking) { 521133c66f43SYan Zheng level++; 5212e7a84565SChris Mason continue; 5213e7a84565SChris Mason } 521433c66f43SYan Zheng 521533c66f43SYan Zheng slot = btrfs_header_nritems(c) - 1; 521633c66f43SYan Zheng if (level == 0) 521733c66f43SYan Zheng btrfs_item_key_to_cpu(c, &cur_key, slot); 521833c66f43SYan Zheng else 521933c66f43SYan Zheng btrfs_node_key_to_cpu(c, &cur_key, slot); 522033c66f43SYan Zheng 522133c66f43SYan Zheng orig_lowest = path->lowest_level; 5222b3b4aa74SDavid Sterba btrfs_release_path(path); 522333c66f43SYan Zheng path->lowest_level = level; 522433c66f43SYan Zheng ret = btrfs_search_slot(NULL, root, &cur_key, path, 522533c66f43SYan Zheng 0, 0); 522633c66f43SYan Zheng path->lowest_level = orig_lowest; 522733c66f43SYan Zheng if (ret < 0) 522833c66f43SYan Zheng return ret; 522933c66f43SYan Zheng 523033c66f43SYan Zheng c = path->nodes[level]; 523133c66f43SYan Zheng slot = path->slots[level]; 523233c66f43SYan Zheng if (ret == 0) 523333c66f43SYan Zheng slot++; 523433c66f43SYan Zheng goto next; 523533c66f43SYan Zheng } 523633c66f43SYan Zheng 5237e7a84565SChris Mason if (level == 0) 5238e7a84565SChris Mason btrfs_item_key_to_cpu(c, key, slot); 52393f157a2fSChris Mason else { 52403f157a2fSChris Mason u64 gen = btrfs_node_ptr_generation(c, slot); 52413f157a2fSChris Mason 52423f157a2fSChris Mason if (gen < min_trans) { 52433f157a2fSChris Mason slot++; 52443f157a2fSChris Mason goto next; 52453f157a2fSChris Mason } 5246e7a84565SChris Mason btrfs_node_key_to_cpu(c, key, slot); 52473f157a2fSChris Mason } 5248e7a84565SChris Mason return 0; 5249e7a84565SChris Mason } 5250e7a84565SChris Mason return 1; 5251e7a84565SChris Mason } 5252e7a84565SChris Mason 52537bb86316SChris Mason /* 5254925baeddSChris Mason * search the tree again to find a leaf with greater keys 52550f70abe2SChris Mason * returns 0 if it found something or 1 if there are no greater leaves. 52560f70abe2SChris Mason * returns < 0 on io errors. 525797571fd0SChris Mason */ 5258234b63a0SChris Mason int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) 5259d97e63b6SChris Mason { 52603d7806ecSJan Schmidt return btrfs_next_old_leaf(root, path, 0); 52613d7806ecSJan Schmidt } 52623d7806ecSJan Schmidt 52633d7806ecSJan Schmidt int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, 52643d7806ecSJan Schmidt u64 time_seq) 52653d7806ecSJan Schmidt { 5266d97e63b6SChris Mason int slot; 52678e73f275SChris Mason int level; 52685f39d397SChris Mason struct extent_buffer *c; 52698e73f275SChris Mason struct extent_buffer *next; 5270925baeddSChris Mason struct btrfs_key key; 5271925baeddSChris Mason u32 nritems; 5272925baeddSChris Mason int ret; 5273bd681513SChris Mason int next_rw_lock = 0; 5274925baeddSChris Mason 5275925baeddSChris Mason nritems = btrfs_header_nritems(path->nodes[0]); 5276d397712bSChris Mason if (nritems == 0) 5277925baeddSChris Mason return 1; 5278925baeddSChris Mason 52798e73f275SChris Mason btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); 52808e73f275SChris Mason again: 52818e73f275SChris Mason level = 1; 52828e73f275SChris Mason next = NULL; 5283bd681513SChris Mason next_rw_lock = 0; 5284b3b4aa74SDavid Sterba btrfs_release_path(path); 52858e73f275SChris Mason 5286a2135011SChris Mason path->keep_locks = 1; 52878e73f275SChris Mason 52883d7806ecSJan Schmidt if (time_seq) 52893d7806ecSJan Schmidt ret = btrfs_search_old_slot(root, &key, path, time_seq); 52903d7806ecSJan Schmidt else 5291925baeddSChris Mason ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5292925baeddSChris Mason path->keep_locks = 0; 5293925baeddSChris Mason 5294925baeddSChris Mason if (ret < 0) 5295925baeddSChris Mason return ret; 5296925baeddSChris Mason 5297a2135011SChris Mason nritems = btrfs_header_nritems(path->nodes[0]); 5298168fd7d2SChris Mason /* 5299168fd7d2SChris Mason * by releasing the path above we dropped all our locks. A balance 5300168fd7d2SChris Mason * could have added more items next to the key that used to be 5301168fd7d2SChris Mason * at the very end of the block. So, check again here and 5302168fd7d2SChris Mason * advance the path if there are now more items available. 5303168fd7d2SChris Mason */ 5304a2135011SChris Mason if (nritems > 0 && path->slots[0] < nritems - 1) { 5305e457afecSYan Zheng if (ret == 0) 5306168fd7d2SChris Mason path->slots[0]++; 53078e73f275SChris Mason ret = 0; 5308925baeddSChris Mason goto done; 5309925baeddSChris Mason } 53100b43e04fSLiu Bo /* 53110b43e04fSLiu Bo * So the above check misses one case: 53120b43e04fSLiu Bo * - after releasing the path above, someone has removed the item that 53130b43e04fSLiu Bo * used to be at the very end of the block, and balance between leafs 53140b43e04fSLiu Bo * gets another one with bigger key.offset to replace it. 53150b43e04fSLiu Bo * 53160b43e04fSLiu Bo * This one should be returned as well, or we can get leaf corruption 53170b43e04fSLiu Bo * later(esp. in __btrfs_drop_extents()). 53180b43e04fSLiu Bo * 53190b43e04fSLiu Bo * And a bit more explanation about this check, 53200b43e04fSLiu Bo * with ret > 0, the key isn't found, the path points to the slot 53210b43e04fSLiu Bo * where it should be inserted, so the path->slots[0] item must be the 53220b43e04fSLiu Bo * bigger one. 53230b43e04fSLiu Bo */ 53240b43e04fSLiu Bo if (nritems > 0 && ret > 0 && path->slots[0] == nritems - 1) { 53250b43e04fSLiu Bo ret = 0; 53260b43e04fSLiu Bo goto done; 53270b43e04fSLiu Bo } 5328d97e63b6SChris Mason 5329234b63a0SChris Mason while (level < BTRFS_MAX_LEVEL) { 53308e73f275SChris Mason if (!path->nodes[level]) { 53318e73f275SChris Mason ret = 1; 53328e73f275SChris Mason goto done; 53338e73f275SChris Mason } 53345f39d397SChris Mason 5335d97e63b6SChris Mason slot = path->slots[level] + 1; 5336d97e63b6SChris Mason c = path->nodes[level]; 53375f39d397SChris Mason if (slot >= btrfs_header_nritems(c)) { 5338d97e63b6SChris Mason level++; 53398e73f275SChris Mason if (level == BTRFS_MAX_LEVEL) { 53408e73f275SChris Mason ret = 1; 53418e73f275SChris Mason goto done; 53428e73f275SChris Mason } 5343d97e63b6SChris Mason continue; 5344d97e63b6SChris Mason } 53455f39d397SChris Mason 5346925baeddSChris Mason if (next) { 5347bd681513SChris Mason btrfs_tree_unlock_rw(next, next_rw_lock); 53485f39d397SChris Mason free_extent_buffer(next); 5349925baeddSChris Mason } 53505f39d397SChris Mason 53518e73f275SChris Mason next = c; 5352bd681513SChris Mason next_rw_lock = path->locks[level]; 5353d07b8528SLiu Bo ret = read_block_for_search(root, path, &next, level, 5354cda79c54SDavid Sterba slot, &key); 53558e73f275SChris Mason if (ret == -EAGAIN) 53568e73f275SChris Mason goto again; 53575f39d397SChris Mason 535876a05b35SChris Mason if (ret < 0) { 5359b3b4aa74SDavid Sterba btrfs_release_path(path); 536076a05b35SChris Mason goto done; 536176a05b35SChris Mason } 536276a05b35SChris Mason 53635cd57b2cSChris Mason if (!path->skip_locking) { 5364bd681513SChris Mason ret = btrfs_try_tree_read_lock(next); 5365d42244a0SJan Schmidt if (!ret && time_seq) { 5366d42244a0SJan Schmidt /* 5367d42244a0SJan Schmidt * If we don't get the lock, we may be racing 5368d42244a0SJan Schmidt * with push_leaf_left, holding that lock while 5369d42244a0SJan Schmidt * itself waiting for the leaf we've currently 5370d42244a0SJan Schmidt * locked. To solve this situation, we give up 5371d42244a0SJan Schmidt * on our lock and cycle. 5372d42244a0SJan Schmidt */ 5373cf538830SJan Schmidt free_extent_buffer(next); 5374d42244a0SJan Schmidt btrfs_release_path(path); 5375d42244a0SJan Schmidt cond_resched(); 5376d42244a0SJan Schmidt goto again; 5377d42244a0SJan Schmidt } 53788e73f275SChris Mason if (!ret) { 5379fd7ba1c1SJosef Bacik __btrfs_tree_read_lock(next, 5380bf77467aSJosef Bacik BTRFS_NESTING_RIGHT, 5381fd7ba1c1SJosef Bacik path->recurse); 53828e73f275SChris Mason } 5383bd681513SChris Mason next_rw_lock = BTRFS_READ_LOCK; 5384bd681513SChris Mason } 5385d97e63b6SChris Mason break; 5386d97e63b6SChris Mason } 5387d97e63b6SChris Mason path->slots[level] = slot; 5388d97e63b6SChris Mason while (1) { 5389d97e63b6SChris Mason level--; 5390d97e63b6SChris Mason c = path->nodes[level]; 5391925baeddSChris Mason if (path->locks[level]) 5392bd681513SChris Mason btrfs_tree_unlock_rw(c, path->locks[level]); 53938e73f275SChris Mason 53945f39d397SChris Mason free_extent_buffer(c); 5395d97e63b6SChris Mason path->nodes[level] = next; 5396d97e63b6SChris Mason path->slots[level] = 0; 5397a74a4b97SChris Mason if (!path->skip_locking) 5398bd681513SChris Mason path->locks[level] = next_rw_lock; 5399d97e63b6SChris Mason if (!level) 5400d97e63b6SChris Mason break; 5401b4ce94deSChris Mason 5402d07b8528SLiu Bo ret = read_block_for_search(root, path, &next, level, 5403cda79c54SDavid Sterba 0, &key); 54048e73f275SChris Mason if (ret == -EAGAIN) 54058e73f275SChris Mason goto again; 54068e73f275SChris Mason 540776a05b35SChris Mason if (ret < 0) { 5408b3b4aa74SDavid Sterba btrfs_release_path(path); 540976a05b35SChris Mason goto done; 541076a05b35SChris Mason } 541176a05b35SChris Mason 54125cd57b2cSChris Mason if (!path->skip_locking) { 5413ac5887c8SJosef Bacik __btrfs_tree_read_lock(next, BTRFS_NESTING_RIGHT, 5414fd7ba1c1SJosef Bacik path->recurse); 5415bd681513SChris Mason next_rw_lock = BTRFS_READ_LOCK; 5416bd681513SChris Mason } 5417d97e63b6SChris Mason } 54188e73f275SChris Mason ret = 0; 5419925baeddSChris Mason done: 5420f7c79f30SChris Mason unlock_up(path, 0, 1, 0, NULL); 54218e73f275SChris Mason 54228e73f275SChris Mason return ret; 5423d97e63b6SChris Mason } 54240b86a832SChris Mason 54253f157a2fSChris Mason /* 54263f157a2fSChris Mason * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps 54273f157a2fSChris Mason * searching until it gets past min_objectid or finds an item of 'type' 54283f157a2fSChris Mason * 54293f157a2fSChris Mason * returns 0 if something is found, 1 if nothing was found and < 0 on error 54303f157a2fSChris Mason */ 54310b86a832SChris Mason int btrfs_previous_item(struct btrfs_root *root, 54320b86a832SChris Mason struct btrfs_path *path, u64 min_objectid, 54330b86a832SChris Mason int type) 54340b86a832SChris Mason { 54350b86a832SChris Mason struct btrfs_key found_key; 54360b86a832SChris Mason struct extent_buffer *leaf; 5437e02119d5SChris Mason u32 nritems; 54380b86a832SChris Mason int ret; 54390b86a832SChris Mason 54400b86a832SChris Mason while (1) { 54410b86a832SChris Mason if (path->slots[0] == 0) { 54420b86a832SChris Mason ret = btrfs_prev_leaf(root, path); 54430b86a832SChris Mason if (ret != 0) 54440b86a832SChris Mason return ret; 54450b86a832SChris Mason } else { 54460b86a832SChris Mason path->slots[0]--; 54470b86a832SChris Mason } 54480b86a832SChris Mason leaf = path->nodes[0]; 5449e02119d5SChris Mason nritems = btrfs_header_nritems(leaf); 5450e02119d5SChris Mason if (nritems == 0) 5451e02119d5SChris Mason return 1; 5452e02119d5SChris Mason if (path->slots[0] == nritems) 5453e02119d5SChris Mason path->slots[0]--; 5454e02119d5SChris Mason 54550b86a832SChris Mason btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 5456e02119d5SChris Mason if (found_key.objectid < min_objectid) 5457e02119d5SChris Mason break; 54580a4eefbbSYan Zheng if (found_key.type == type) 54590a4eefbbSYan Zheng return 0; 5460e02119d5SChris Mason if (found_key.objectid == min_objectid && 5461e02119d5SChris Mason found_key.type < type) 5462e02119d5SChris Mason break; 54630b86a832SChris Mason } 54640b86a832SChris Mason return 1; 54650b86a832SChris Mason } 5466ade2e0b3SWang Shilong 5467ade2e0b3SWang Shilong /* 5468ade2e0b3SWang Shilong * search in extent tree to find a previous Metadata/Data extent item with 5469ade2e0b3SWang Shilong * min objecitd. 5470ade2e0b3SWang Shilong * 5471ade2e0b3SWang Shilong * returns 0 if something is found, 1 if nothing was found and < 0 on error 5472ade2e0b3SWang Shilong */ 5473ade2e0b3SWang Shilong int btrfs_previous_extent_item(struct btrfs_root *root, 5474ade2e0b3SWang Shilong struct btrfs_path *path, u64 min_objectid) 5475ade2e0b3SWang Shilong { 5476ade2e0b3SWang Shilong struct btrfs_key found_key; 5477ade2e0b3SWang Shilong struct extent_buffer *leaf; 5478ade2e0b3SWang Shilong u32 nritems; 5479ade2e0b3SWang Shilong int ret; 5480ade2e0b3SWang Shilong 5481ade2e0b3SWang Shilong while (1) { 5482ade2e0b3SWang Shilong if (path->slots[0] == 0) { 5483ade2e0b3SWang Shilong ret = btrfs_prev_leaf(root, path); 5484ade2e0b3SWang Shilong if (ret != 0) 5485ade2e0b3SWang Shilong return ret; 5486ade2e0b3SWang Shilong } else { 5487ade2e0b3SWang Shilong path->slots[0]--; 5488ade2e0b3SWang Shilong } 5489ade2e0b3SWang Shilong leaf = path->nodes[0]; 5490ade2e0b3SWang Shilong nritems = btrfs_header_nritems(leaf); 5491ade2e0b3SWang Shilong if (nritems == 0) 5492ade2e0b3SWang Shilong return 1; 5493ade2e0b3SWang Shilong if (path->slots[0] == nritems) 5494ade2e0b3SWang Shilong path->slots[0]--; 5495ade2e0b3SWang Shilong 5496ade2e0b3SWang Shilong btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 5497ade2e0b3SWang Shilong if (found_key.objectid < min_objectid) 5498ade2e0b3SWang Shilong break; 5499ade2e0b3SWang Shilong if (found_key.type == BTRFS_EXTENT_ITEM_KEY || 5500ade2e0b3SWang Shilong found_key.type == BTRFS_METADATA_ITEM_KEY) 5501ade2e0b3SWang Shilong return 0; 5502ade2e0b3SWang Shilong if (found_key.objectid == min_objectid && 5503ade2e0b3SWang Shilong found_key.type < BTRFS_EXTENT_ITEM_KEY) 5504ade2e0b3SWang Shilong break; 5505ade2e0b3SWang Shilong } 5506ade2e0b3SWang Shilong return 1; 5507ade2e0b3SWang Shilong } 5508