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); 13561b7ec85eSJosef Bacik old = read_tree_block(fs_info, logical, root->root_key.objectid, 13571b7ec85eSJosef Bacik 0, level, NULL); 135864c043deSLiu Bo if (WARN_ON(IS_ERR(old) || !extent_buffer_uptodate(old))) { 135964c043deSLiu Bo if (!IS_ERR(old)) 1360416bc658SJosef Bacik free_extent_buffer(old); 13610b246afaSJeff Mahoney btrfs_warn(fs_info, 13620b246afaSJeff Mahoney "failed to read tree block %llu from get_old_root", 13630b246afaSJeff Mahoney logical); 1364834328a8SJan Schmidt } else { 13657bfdcf7fSLiu Bo eb = btrfs_clone_extent_buffer(old); 13667bfdcf7fSLiu Bo free_extent_buffer(old); 1367834328a8SJan Schmidt } 1368834328a8SJan Schmidt } else if (old_root) { 1369efad8a85SFilipe Manana eb_root_owner = btrfs_header_owner(eb_root); 137030b0463aSJan Schmidt btrfs_tree_read_unlock(eb_root); 137130b0463aSJan Schmidt free_extent_buffer(eb_root); 13720b246afaSJeff Mahoney eb = alloc_dummy_extent_buffer(fs_info, logical); 1373834328a8SJan Schmidt } else { 137430b0463aSJan Schmidt eb = btrfs_clone_extent_buffer(eb_root); 1375ac5887c8SJosef Bacik btrfs_tree_read_unlock(eb_root); 137630b0463aSJan Schmidt free_extent_buffer(eb_root); 1377834328a8SJan Schmidt } 1378834328a8SJan Schmidt 13798ba97a15SJan Schmidt if (!eb) 13808ba97a15SJan Schmidt return NULL; 1381a95236d9SJan Schmidt if (old_root) { 13825d9e75c4SJan Schmidt btrfs_set_header_bytenr(eb, eb->start); 13835d9e75c4SJan Schmidt btrfs_set_header_backref_rev(eb, BTRFS_MIXED_BACKREF_REV); 1384efad8a85SFilipe Manana btrfs_set_header_owner(eb, eb_root_owner); 13855d9e75c4SJan Schmidt btrfs_set_header_level(eb, old_root->level); 13865d9e75c4SJan Schmidt btrfs_set_header_generation(eb, old_generation); 1387a95236d9SJan Schmidt } 1388d3beaa25SJosef Bacik btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb), eb, 1389d3beaa25SJosef Bacik btrfs_header_level(eb)); 1390d3beaa25SJosef Bacik btrfs_tree_read_lock(eb); 139128da9fb4SJan Schmidt if (tm) 13920b246afaSJeff Mahoney __tree_mod_log_rewind(fs_info, eb, time_seq, tm); 139328da9fb4SJan Schmidt else 139428da9fb4SJan Schmidt WARN_ON(btrfs_header_level(eb) != 0); 13950b246afaSJeff Mahoney WARN_ON(btrfs_header_nritems(eb) > BTRFS_NODEPTRS_PER_BLOCK(fs_info)); 13965d9e75c4SJan Schmidt 13975d9e75c4SJan Schmidt return eb; 13985d9e75c4SJan Schmidt } 13995d9e75c4SJan Schmidt 14005b6602e7SJan Schmidt int btrfs_old_root_level(struct btrfs_root *root, u64 time_seq) 14015b6602e7SJan Schmidt { 14025b6602e7SJan Schmidt struct tree_mod_elem *tm; 14035b6602e7SJan Schmidt int level; 140430b0463aSJan Schmidt struct extent_buffer *eb_root = btrfs_root_node(root); 14055b6602e7SJan Schmidt 1406bcd24dabSDavid Sterba tm = __tree_mod_log_oldest_root(eb_root, time_seq); 14075b6602e7SJan Schmidt if (tm && tm->op == MOD_LOG_ROOT_REPLACE) { 14085b6602e7SJan Schmidt level = tm->old_root.level; 14095b6602e7SJan Schmidt } else { 141030b0463aSJan Schmidt level = btrfs_header_level(eb_root); 14115b6602e7SJan Schmidt } 141230b0463aSJan Schmidt free_extent_buffer(eb_root); 14135b6602e7SJan Schmidt 14145b6602e7SJan Schmidt return level; 14155b6602e7SJan Schmidt } 14165b6602e7SJan Schmidt 14175d4f98a2SYan Zheng static inline int should_cow_block(struct btrfs_trans_handle *trans, 14185d4f98a2SYan Zheng struct btrfs_root *root, 14195d4f98a2SYan Zheng struct extent_buffer *buf) 14205d4f98a2SYan Zheng { 1421f5ee5c9aSJeff Mahoney if (btrfs_is_testing(root->fs_info)) 1422faa2dbf0SJosef Bacik return 0; 1423fccb84c9SDavid Sterba 1424d1980131SDavid Sterba /* Ensure we can see the FORCE_COW bit */ 1425d1980131SDavid Sterba smp_mb__before_atomic(); 1426f1ebcc74SLiu Bo 1427f1ebcc74SLiu Bo /* 1428f1ebcc74SLiu Bo * We do not need to cow a block if 1429f1ebcc74SLiu Bo * 1) this block is not created or changed in this transaction; 1430f1ebcc74SLiu Bo * 2) this block does not belong to TREE_RELOC tree; 1431f1ebcc74SLiu Bo * 3) the root is not forced COW. 1432f1ebcc74SLiu Bo * 1433f1ebcc74SLiu Bo * What is forced COW: 143401327610SNicholas D Steeves * when we create snapshot during committing the transaction, 143552042d8eSAndrea Gelmini * after we've finished copying src root, we must COW the shared 1436f1ebcc74SLiu Bo * block to ensure the metadata consistency. 1437f1ebcc74SLiu Bo */ 14385d4f98a2SYan Zheng if (btrfs_header_generation(buf) == trans->transid && 14395d4f98a2SYan Zheng !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && 14405d4f98a2SYan Zheng !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && 1441f1ebcc74SLiu Bo btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && 144227cdeb70SMiao Xie !test_bit(BTRFS_ROOT_FORCE_COW, &root->state)) 14435d4f98a2SYan Zheng return 0; 14445d4f98a2SYan Zheng return 1; 14455d4f98a2SYan Zheng } 14465d4f98a2SYan Zheng 1447d352ac68SChris Mason /* 1448d352ac68SChris Mason * cows a single block, see __btrfs_cow_block for the real work. 144901327610SNicholas D Steeves * This version of it has extra checks so that a block isn't COWed more than 1450d352ac68SChris Mason * once per transaction, as long as it hasn't been written yet 1451d352ac68SChris Mason */ 1452d397712bSChris Mason noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, 14535f39d397SChris Mason struct btrfs_root *root, struct extent_buffer *buf, 14545f39d397SChris Mason struct extent_buffer *parent, int parent_slot, 14559631e4ccSJosef Bacik struct extent_buffer **cow_ret, 14569631e4ccSJosef Bacik enum btrfs_lock_nesting nest) 145702217ed2SChris Mason { 14580b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 14596702ed49SChris Mason u64 search_start; 1460f510cfecSChris Mason int ret; 1461dc17ff8fSChris Mason 146283354f07SJosef Bacik if (test_bit(BTRFS_ROOT_DELETING, &root->state)) 146383354f07SJosef Bacik btrfs_err(fs_info, 146483354f07SJosef Bacik "COW'ing blocks on a fs root that's being dropped"); 146583354f07SJosef Bacik 14660b246afaSJeff Mahoney if (trans->transaction != fs_info->running_transaction) 146731b1a2bdSJulia Lawall WARN(1, KERN_CRIT "trans %llu running %llu\n", 1468c1c9ff7cSGeert Uytterhoeven trans->transid, 14690b246afaSJeff Mahoney fs_info->running_transaction->transid); 147031b1a2bdSJulia Lawall 14710b246afaSJeff Mahoney if (trans->transid != fs_info->generation) 147231b1a2bdSJulia Lawall WARN(1, KERN_CRIT "trans %llu running %llu\n", 14730b246afaSJeff Mahoney trans->transid, fs_info->generation); 1474dc17ff8fSChris Mason 14755d4f98a2SYan Zheng if (!should_cow_block(trans, root, buf)) { 147664c12921SJeff Mahoney trans->dirty = true; 147702217ed2SChris Mason *cow_ret = buf; 147802217ed2SChris Mason return 0; 147902217ed2SChris Mason } 1480c487685dSChris Mason 1481ee22184bSByongho Lee search_start = buf->start & ~((u64)SZ_1G - 1); 1482b4ce94deSChris Mason 1483f616f5cdSQu Wenruo /* 1484f616f5cdSQu Wenruo * Before CoWing this block for later modification, check if it's 1485f616f5cdSQu Wenruo * the subtree root and do the delayed subtree trace if needed. 1486f616f5cdSQu Wenruo * 1487f616f5cdSQu Wenruo * Also We don't care about the error, as it's handled internally. 1488f616f5cdSQu Wenruo */ 1489f616f5cdSQu Wenruo btrfs_qgroup_trace_subtree_after_cow(trans, root, buf); 1490f510cfecSChris Mason ret = __btrfs_cow_block(trans, root, buf, parent, 14919631e4ccSJosef Bacik parent_slot, cow_ret, search_start, 0, nest); 14921abe9b8aSliubo 14931abe9b8aSliubo trace_btrfs_cow_block(root, buf, *cow_ret); 14941abe9b8aSliubo 1495f510cfecSChris Mason return ret; 14962c90e5d6SChris Mason } 1497*f75e2b79SJosef Bacik ALLOW_ERROR_INJECTION(btrfs_cow_block, ERRNO); 14986702ed49SChris Mason 1499d352ac68SChris Mason /* 1500d352ac68SChris Mason * helper function for defrag to decide if two blocks pointed to by a 1501d352ac68SChris Mason * node are actually close by 1502d352ac68SChris Mason */ 15036b80053dSChris Mason static int close_blocks(u64 blocknr, u64 other, u32 blocksize) 15046702ed49SChris Mason { 15056b80053dSChris Mason if (blocknr < other && other - (blocknr + blocksize) < 32768) 15066702ed49SChris Mason return 1; 15076b80053dSChris Mason if (blocknr > other && blocknr - (other + blocksize) < 32768) 15086702ed49SChris Mason return 1; 150902217ed2SChris Mason return 0; 151002217ed2SChris Mason } 151102217ed2SChris Mason 1512ce6ef5abSDavid Sterba #ifdef __LITTLE_ENDIAN 1513ce6ef5abSDavid Sterba 1514ce6ef5abSDavid Sterba /* 1515ce6ef5abSDavid Sterba * Compare two keys, on little-endian the disk order is same as CPU order and 1516ce6ef5abSDavid Sterba * we can avoid the conversion. 1517ce6ef5abSDavid Sterba */ 1518ce6ef5abSDavid Sterba static int comp_keys(const struct btrfs_disk_key *disk_key, 1519ce6ef5abSDavid Sterba const struct btrfs_key *k2) 1520ce6ef5abSDavid Sterba { 1521ce6ef5abSDavid Sterba const struct btrfs_key *k1 = (const struct btrfs_key *)disk_key; 1522ce6ef5abSDavid Sterba 1523ce6ef5abSDavid Sterba return btrfs_comp_cpu_keys(k1, k2); 1524ce6ef5abSDavid Sterba } 1525ce6ef5abSDavid Sterba 1526ce6ef5abSDavid Sterba #else 1527ce6ef5abSDavid Sterba 1528081e9573SChris Mason /* 1529081e9573SChris Mason * compare two keys in a memcmp fashion 1530081e9573SChris Mason */ 1531310712b2SOmar Sandoval static int comp_keys(const struct btrfs_disk_key *disk, 1532310712b2SOmar Sandoval const struct btrfs_key *k2) 1533081e9573SChris Mason { 1534081e9573SChris Mason struct btrfs_key k1; 1535081e9573SChris Mason 1536081e9573SChris Mason btrfs_disk_key_to_cpu(&k1, disk); 1537081e9573SChris Mason 153820736abaSDiego Calleja return btrfs_comp_cpu_keys(&k1, k2); 1539081e9573SChris Mason } 1540ce6ef5abSDavid Sterba #endif 1541081e9573SChris Mason 1542f3465ca4SJosef Bacik /* 1543f3465ca4SJosef Bacik * same as comp_keys only with two btrfs_key's 1544f3465ca4SJosef Bacik */ 1545e1f60a65SDavid Sterba int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2) 1546f3465ca4SJosef Bacik { 1547f3465ca4SJosef Bacik if (k1->objectid > k2->objectid) 1548f3465ca4SJosef Bacik return 1; 1549f3465ca4SJosef Bacik if (k1->objectid < k2->objectid) 1550f3465ca4SJosef Bacik return -1; 1551f3465ca4SJosef Bacik if (k1->type > k2->type) 1552f3465ca4SJosef Bacik return 1; 1553f3465ca4SJosef Bacik if (k1->type < k2->type) 1554f3465ca4SJosef Bacik return -1; 1555f3465ca4SJosef Bacik if (k1->offset > k2->offset) 1556f3465ca4SJosef Bacik return 1; 1557f3465ca4SJosef Bacik if (k1->offset < k2->offset) 1558f3465ca4SJosef Bacik return -1; 1559f3465ca4SJosef Bacik return 0; 1560f3465ca4SJosef Bacik } 1561081e9573SChris Mason 1562d352ac68SChris Mason /* 1563d352ac68SChris Mason * this is used by the defrag code to go through all the 1564d352ac68SChris Mason * leaves pointed to by a node and reallocate them so that 1565d352ac68SChris Mason * disk order is close to key order 1566d352ac68SChris Mason */ 15676702ed49SChris Mason int btrfs_realloc_node(struct btrfs_trans_handle *trans, 15685f39d397SChris Mason struct btrfs_root *root, struct extent_buffer *parent, 1569de78b51aSEric Sandeen int start_slot, u64 *last_ret, 1570a6b6e75eSChris Mason struct btrfs_key *progress) 15716702ed49SChris Mason { 15720b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 15736b80053dSChris Mason struct extent_buffer *cur; 15746702ed49SChris Mason u64 blocknr; 1575e9d0b13bSChris Mason u64 search_start = *last_ret; 1576e9d0b13bSChris Mason u64 last_block = 0; 15776702ed49SChris Mason u64 other; 15786702ed49SChris Mason u32 parent_nritems; 15796702ed49SChris Mason int end_slot; 15806702ed49SChris Mason int i; 15816702ed49SChris Mason int err = 0; 15826b80053dSChris Mason u32 blocksize; 1583081e9573SChris Mason int progress_passed = 0; 1584081e9573SChris Mason struct btrfs_disk_key disk_key; 15856702ed49SChris Mason 15860b246afaSJeff Mahoney WARN_ON(trans->transaction != fs_info->running_transaction); 15870b246afaSJeff Mahoney WARN_ON(trans->transid != fs_info->generation); 158886479a04SChris Mason 15896b80053dSChris Mason parent_nritems = btrfs_header_nritems(parent); 15900b246afaSJeff Mahoney blocksize = fs_info->nodesize; 15915dfe2be7SFilipe Manana end_slot = parent_nritems - 1; 15926702ed49SChris Mason 15935dfe2be7SFilipe Manana if (parent_nritems <= 1) 15946702ed49SChris Mason return 0; 15956702ed49SChris Mason 15965dfe2be7SFilipe Manana for (i = start_slot; i <= end_slot; i++) { 15976702ed49SChris Mason int close = 1; 1598a6b6e75eSChris Mason 1599081e9573SChris Mason btrfs_node_key(parent, &disk_key, i); 1600081e9573SChris Mason if (!progress_passed && comp_keys(&disk_key, progress) < 0) 1601081e9573SChris Mason continue; 1602081e9573SChris Mason 1603081e9573SChris Mason progress_passed = 1; 16046b80053dSChris Mason blocknr = btrfs_node_blockptr(parent, i); 1605e9d0b13bSChris Mason if (last_block == 0) 1606e9d0b13bSChris Mason last_block = blocknr; 16075708b959SChris Mason 16086702ed49SChris Mason if (i > 0) { 16096b80053dSChris Mason other = btrfs_node_blockptr(parent, i - 1); 16106b80053dSChris Mason close = close_blocks(blocknr, other, blocksize); 16116702ed49SChris Mason } 16125dfe2be7SFilipe Manana if (!close && i < end_slot) { 16136b80053dSChris Mason other = btrfs_node_blockptr(parent, i + 1); 16146b80053dSChris Mason close = close_blocks(blocknr, other, blocksize); 16156702ed49SChris Mason } 1616e9d0b13bSChris Mason if (close) { 1617e9d0b13bSChris Mason last_block = blocknr; 16186702ed49SChris Mason continue; 1619e9d0b13bSChris Mason } 16206702ed49SChris Mason 1621206983b7SJosef Bacik cur = btrfs_read_node_slot(parent, i); 1622206983b7SJosef Bacik if (IS_ERR(cur)) 162364c043deSLiu Bo return PTR_ERR(cur); 1624e9d0b13bSChris Mason if (search_start == 0) 16256b80053dSChris Mason search_start = last_block; 1626e9d0b13bSChris Mason 1627e7a84565SChris Mason btrfs_tree_lock(cur); 16286b80053dSChris Mason err = __btrfs_cow_block(trans, root, cur, parent, i, 1629e7a84565SChris Mason &cur, search_start, 16306b80053dSChris Mason min(16 * blocksize, 16319631e4ccSJosef Bacik (end_slot - i) * blocksize), 16329631e4ccSJosef Bacik BTRFS_NESTING_COW); 1633252c38f0SYan if (err) { 1634e7a84565SChris Mason btrfs_tree_unlock(cur); 16356b80053dSChris Mason free_extent_buffer(cur); 16366702ed49SChris Mason break; 1637252c38f0SYan } 1638e7a84565SChris Mason search_start = cur->start; 1639e7a84565SChris Mason last_block = cur->start; 1640f2183bdeSChris Mason *last_ret = search_start; 1641e7a84565SChris Mason btrfs_tree_unlock(cur); 1642e7a84565SChris Mason free_extent_buffer(cur); 16436702ed49SChris Mason } 16446702ed49SChris Mason return err; 16456702ed49SChris Mason } 16466702ed49SChris Mason 164774123bd7SChris Mason /* 16485f39d397SChris Mason * search for key in the extent_buffer. The items start at offset p, 16495f39d397SChris Mason * and they are item_size apart. There are 'max' items in p. 16505f39d397SChris Mason * 165174123bd7SChris Mason * the slot in the array is returned via slot, and it points to 165274123bd7SChris Mason * the place where you would insert key if it is not found in 165374123bd7SChris Mason * the array. 165474123bd7SChris Mason * 165574123bd7SChris Mason * slot may point to max if the key is bigger than all of the keys 165674123bd7SChris Mason */ 1657e02119d5SChris Mason static noinline int generic_bin_search(struct extent_buffer *eb, 1658310712b2SOmar Sandoval unsigned long p, int item_size, 1659310712b2SOmar Sandoval const struct btrfs_key *key, 1660be0e5c09SChris Mason int max, int *slot) 1661be0e5c09SChris Mason { 1662be0e5c09SChris Mason int low = 0; 1663be0e5c09SChris Mason int high = max; 1664be0e5c09SChris Mason int ret; 16655cd17f34SDavid Sterba const int key_size = sizeof(struct btrfs_disk_key); 1666be0e5c09SChris Mason 16675e24e9afSLiu Bo if (low > high) { 16685e24e9afSLiu Bo btrfs_err(eb->fs_info, 16695e24e9afSLiu Bo "%s: low (%d) > high (%d) eb %llu owner %llu level %d", 16705e24e9afSLiu Bo __func__, low, high, eb->start, 16715e24e9afSLiu Bo btrfs_header_owner(eb), btrfs_header_level(eb)); 16725e24e9afSLiu Bo return -EINVAL; 16735e24e9afSLiu Bo } 16745e24e9afSLiu Bo 1675be0e5c09SChris Mason while (low < high) { 16765cd17f34SDavid Sterba unsigned long oip; 16775cd17f34SDavid Sterba unsigned long offset; 16785cd17f34SDavid Sterba struct btrfs_disk_key *tmp; 16795cd17f34SDavid Sterba struct btrfs_disk_key unaligned; 16805cd17f34SDavid Sterba int mid; 16815cd17f34SDavid Sterba 1682be0e5c09SChris Mason mid = (low + high) / 2; 16835f39d397SChris Mason offset = p + mid * item_size; 16845cd17f34SDavid Sterba oip = offset_in_page(offset); 16855f39d397SChris Mason 16865cd17f34SDavid Sterba if (oip + key_size <= PAGE_SIZE) { 1687884b07d0SQu Wenruo const unsigned long idx = get_eb_page_index(offset); 16885cd17f34SDavid Sterba char *kaddr = page_address(eb->pages[idx]); 1689934d375bSChris Mason 1690884b07d0SQu Wenruo oip = get_eb_offset_in_page(eb, offset); 16915cd17f34SDavid Sterba tmp = (struct btrfs_disk_key *)(kaddr + oip); 16925cd17f34SDavid Sterba } else { 16935cd17f34SDavid Sterba read_extent_buffer(eb, &unaligned, offset, key_size); 16945f39d397SChris Mason tmp = &unaligned; 1695479965d6SChris Mason } 1696479965d6SChris Mason 1697be0e5c09SChris Mason ret = comp_keys(tmp, key); 1698be0e5c09SChris Mason 1699be0e5c09SChris Mason if (ret < 0) 1700be0e5c09SChris Mason low = mid + 1; 1701be0e5c09SChris Mason else if (ret > 0) 1702be0e5c09SChris Mason high = mid; 1703be0e5c09SChris Mason else { 1704be0e5c09SChris Mason *slot = mid; 1705be0e5c09SChris Mason return 0; 1706be0e5c09SChris Mason } 1707be0e5c09SChris Mason } 1708be0e5c09SChris Mason *slot = low; 1709be0e5c09SChris Mason return 1; 1710be0e5c09SChris Mason } 1711be0e5c09SChris Mason 171297571fd0SChris Mason /* 171397571fd0SChris Mason * simple bin_search frontend that does the right thing for 171497571fd0SChris Mason * leaves vs nodes 171597571fd0SChris Mason */ 1716a74b35ecSNikolay Borisov int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key, 1717e3b83361SQu Wenruo int *slot) 1718be0e5c09SChris Mason { 1719e3b83361SQu Wenruo if (btrfs_header_level(eb) == 0) 17205f39d397SChris Mason return generic_bin_search(eb, 17215f39d397SChris Mason offsetof(struct btrfs_leaf, items), 17220783fcfcSChris Mason sizeof(struct btrfs_item), 17235f39d397SChris Mason key, btrfs_header_nritems(eb), 17247518a238SChris Mason slot); 1725f775738fSWang Sheng-Hui else 17265f39d397SChris Mason return generic_bin_search(eb, 17275f39d397SChris Mason offsetof(struct btrfs_node, ptrs), 1728123abc88SChris Mason sizeof(struct btrfs_key_ptr), 17295f39d397SChris Mason key, btrfs_header_nritems(eb), 17307518a238SChris Mason slot); 1731be0e5c09SChris Mason } 1732be0e5c09SChris Mason 1733f0486c68SYan, Zheng static void root_add_used(struct btrfs_root *root, u32 size) 1734f0486c68SYan, Zheng { 1735f0486c68SYan, Zheng spin_lock(&root->accounting_lock); 1736f0486c68SYan, Zheng btrfs_set_root_used(&root->root_item, 1737f0486c68SYan, Zheng btrfs_root_used(&root->root_item) + size); 1738f0486c68SYan, Zheng spin_unlock(&root->accounting_lock); 1739f0486c68SYan, Zheng } 1740f0486c68SYan, Zheng 1741f0486c68SYan, Zheng static void root_sub_used(struct btrfs_root *root, u32 size) 1742f0486c68SYan, Zheng { 1743f0486c68SYan, Zheng spin_lock(&root->accounting_lock); 1744f0486c68SYan, Zheng btrfs_set_root_used(&root->root_item, 1745f0486c68SYan, Zheng btrfs_root_used(&root->root_item) - size); 1746f0486c68SYan, Zheng spin_unlock(&root->accounting_lock); 1747f0486c68SYan, Zheng } 1748f0486c68SYan, Zheng 1749d352ac68SChris Mason /* given a node and slot number, this reads the blocks it points to. The 1750d352ac68SChris Mason * extent buffer is returned with a reference taken (but unlocked). 1751d352ac68SChris Mason */ 17524b231ae4SDavid Sterba struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent, 17534b231ae4SDavid Sterba int slot) 1754bb803951SChris Mason { 1755ca7a79adSChris Mason int level = btrfs_header_level(parent); 1756416bc658SJosef Bacik struct extent_buffer *eb; 1757581c1760SQu Wenruo struct btrfs_key first_key; 1758416bc658SJosef Bacik 1759fb770ae4SLiu Bo if (slot < 0 || slot >= btrfs_header_nritems(parent)) 1760fb770ae4SLiu Bo return ERR_PTR(-ENOENT); 1761ca7a79adSChris Mason 1762ca7a79adSChris Mason BUG_ON(level == 0); 1763ca7a79adSChris Mason 1764581c1760SQu Wenruo btrfs_node_key_to_cpu(parent, &first_key, slot); 1765d0d20b0fSDavid Sterba eb = read_tree_block(parent->fs_info, btrfs_node_blockptr(parent, slot), 17661b7ec85eSJosef Bacik btrfs_header_owner(parent), 1767581c1760SQu Wenruo btrfs_node_ptr_generation(parent, slot), 1768581c1760SQu Wenruo level - 1, &first_key); 1769fb770ae4SLiu Bo if (!IS_ERR(eb) && !extent_buffer_uptodate(eb)) { 1770416bc658SJosef Bacik free_extent_buffer(eb); 1771fb770ae4SLiu Bo eb = ERR_PTR(-EIO); 1772416bc658SJosef Bacik } 1773416bc658SJosef Bacik 1774416bc658SJosef Bacik return eb; 1775bb803951SChris Mason } 1776bb803951SChris Mason 1777d352ac68SChris Mason /* 1778d352ac68SChris Mason * node level balancing, used to make sure nodes are in proper order for 1779d352ac68SChris Mason * item deletion. We balance from the top down, so we have to make sure 1780d352ac68SChris Mason * that a deletion won't leave an node completely empty later on. 1781d352ac68SChris Mason */ 1782e02119d5SChris Mason static noinline int balance_level(struct btrfs_trans_handle *trans, 178398ed5174SChris Mason struct btrfs_root *root, 178498ed5174SChris Mason struct btrfs_path *path, int level) 1785bb803951SChris Mason { 17860b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 17875f39d397SChris Mason struct extent_buffer *right = NULL; 17885f39d397SChris Mason struct extent_buffer *mid; 17895f39d397SChris Mason struct extent_buffer *left = NULL; 17905f39d397SChris Mason struct extent_buffer *parent = NULL; 1791bb803951SChris Mason int ret = 0; 1792bb803951SChris Mason int wret; 1793bb803951SChris Mason int pslot; 1794bb803951SChris Mason int orig_slot = path->slots[level]; 179579f95c82SChris Mason u64 orig_ptr; 1796bb803951SChris Mason 179798e6b1ebSLiu Bo ASSERT(level > 0); 1798bb803951SChris Mason 17995f39d397SChris Mason mid = path->nodes[level]; 1800b4ce94deSChris Mason 1801ac5887c8SJosef Bacik WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK); 18027bb86316SChris Mason WARN_ON(btrfs_header_generation(mid) != trans->transid); 18037bb86316SChris Mason 18041d4f8a0cSChris Mason orig_ptr = btrfs_node_blockptr(mid, orig_slot); 180579f95c82SChris Mason 1806a05a9bb1SLi Zefan if (level < BTRFS_MAX_LEVEL - 1) { 18075f39d397SChris Mason parent = path->nodes[level + 1]; 1808bb803951SChris Mason pslot = path->slots[level + 1]; 1809a05a9bb1SLi Zefan } 1810bb803951SChris Mason 181140689478SChris Mason /* 181240689478SChris Mason * deal with the case where there is only one pointer in the root 181340689478SChris Mason * by promoting the node below to a root 181440689478SChris Mason */ 18155f39d397SChris Mason if (!parent) { 18165f39d397SChris Mason struct extent_buffer *child; 1817bb803951SChris Mason 18185f39d397SChris Mason if (btrfs_header_nritems(mid) != 1) 1819bb803951SChris Mason return 0; 1820bb803951SChris Mason 1821bb803951SChris Mason /* promote the child to a root */ 18224b231ae4SDavid Sterba child = btrfs_read_node_slot(mid, 0); 1823fb770ae4SLiu Bo if (IS_ERR(child)) { 1824fb770ae4SLiu Bo ret = PTR_ERR(child); 18250b246afaSJeff Mahoney btrfs_handle_fs_error(fs_info, ret, NULL); 1826305a26afSMark Fasheh goto enospc; 1827305a26afSMark Fasheh } 1828305a26afSMark Fasheh 1829925baeddSChris Mason btrfs_tree_lock(child); 18309631e4ccSJosef Bacik ret = btrfs_cow_block(trans, root, child, mid, 0, &child, 18319631e4ccSJosef Bacik BTRFS_NESTING_COW); 1832f0486c68SYan, Zheng if (ret) { 1833f0486c68SYan, Zheng btrfs_tree_unlock(child); 1834f0486c68SYan, Zheng free_extent_buffer(child); 1835f0486c68SYan, Zheng goto enospc; 1836f0486c68SYan, Zheng } 18372f375ab9SYan 1838d9d19a01SDavid Sterba ret = tree_mod_log_insert_root(root->node, child, 1); 1839d9d19a01SDavid Sterba BUG_ON(ret < 0); 1840240f62c8SChris Mason rcu_assign_pointer(root->node, child); 1841925baeddSChris Mason 18420b86a832SChris Mason add_root_to_dirty_list(root); 1843925baeddSChris Mason btrfs_tree_unlock(child); 1844b4ce94deSChris Mason 1845925baeddSChris Mason path->locks[level] = 0; 1846bb803951SChris Mason path->nodes[level] = NULL; 18476a884d7dSDavid Sterba btrfs_clean_tree_block(mid); 1848925baeddSChris Mason btrfs_tree_unlock(mid); 1849bb803951SChris Mason /* once for the path */ 18505f39d397SChris Mason free_extent_buffer(mid); 1851f0486c68SYan, Zheng 1852f0486c68SYan, Zheng root_sub_used(root, mid->len); 18535581a51aSJan Schmidt btrfs_free_tree_block(trans, root, mid, 0, 1); 1854bb803951SChris Mason /* once for the root ptr */ 18553083ee2eSJosef Bacik free_extent_buffer_stale(mid); 1856f0486c68SYan, Zheng return 0; 1857bb803951SChris Mason } 18585f39d397SChris Mason if (btrfs_header_nritems(mid) > 18590b246afaSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 4) 1860bb803951SChris Mason return 0; 1861bb803951SChris Mason 18624b231ae4SDavid Sterba left = btrfs_read_node_slot(parent, pslot - 1); 1863fb770ae4SLiu Bo if (IS_ERR(left)) 1864fb770ae4SLiu Bo left = NULL; 1865fb770ae4SLiu Bo 18665f39d397SChris Mason if (left) { 1867bf77467aSJosef Bacik __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); 18685f39d397SChris Mason wret = btrfs_cow_block(trans, root, left, 18699631e4ccSJosef Bacik parent, pslot - 1, &left, 1870bf59a5a2SJosef Bacik BTRFS_NESTING_LEFT_COW); 187154aa1f4dSChris Mason if (wret) { 187254aa1f4dSChris Mason ret = wret; 187354aa1f4dSChris Mason goto enospc; 187454aa1f4dSChris Mason } 18752cc58cf2SChris Mason } 1876fb770ae4SLiu Bo 18774b231ae4SDavid Sterba right = btrfs_read_node_slot(parent, pslot + 1); 1878fb770ae4SLiu Bo if (IS_ERR(right)) 1879fb770ae4SLiu Bo right = NULL; 1880fb770ae4SLiu Bo 18815f39d397SChris Mason if (right) { 1882bf77467aSJosef Bacik __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); 18835f39d397SChris Mason wret = btrfs_cow_block(trans, root, right, 18849631e4ccSJosef Bacik parent, pslot + 1, &right, 1885bf59a5a2SJosef Bacik BTRFS_NESTING_RIGHT_COW); 18862cc58cf2SChris Mason if (wret) { 18872cc58cf2SChris Mason ret = wret; 18882cc58cf2SChris Mason goto enospc; 18892cc58cf2SChris Mason } 18902cc58cf2SChris Mason } 18912cc58cf2SChris Mason 18922cc58cf2SChris Mason /* first, try to make some room in the middle buffer */ 18935f39d397SChris Mason if (left) { 18945f39d397SChris Mason orig_slot += btrfs_header_nritems(left); 1895d30a668fSDavid Sterba wret = push_node_left(trans, left, mid, 1); 189679f95c82SChris Mason if (wret < 0) 189779f95c82SChris Mason ret = wret; 1898bb803951SChris Mason } 189979f95c82SChris Mason 190079f95c82SChris Mason /* 190179f95c82SChris Mason * then try to empty the right most buffer into the middle 190279f95c82SChris Mason */ 19035f39d397SChris Mason if (right) { 1904d30a668fSDavid Sterba wret = push_node_left(trans, mid, right, 1); 190554aa1f4dSChris Mason if (wret < 0 && wret != -ENOSPC) 190679f95c82SChris Mason ret = wret; 19075f39d397SChris Mason if (btrfs_header_nritems(right) == 0) { 19086a884d7dSDavid Sterba btrfs_clean_tree_block(right); 1909925baeddSChris Mason btrfs_tree_unlock(right); 1910afe5fea7STsutomu Itoh del_ptr(root, path, level + 1, pslot + 1); 1911f0486c68SYan, Zheng root_sub_used(root, right->len); 19125581a51aSJan Schmidt btrfs_free_tree_block(trans, root, right, 0, 1); 19133083ee2eSJosef Bacik free_extent_buffer_stale(right); 1914f0486c68SYan, Zheng right = NULL; 1915bb803951SChris Mason } else { 19165f39d397SChris Mason struct btrfs_disk_key right_key; 19175f39d397SChris Mason btrfs_node_key(right, &right_key, 0); 19180e82bcfeSDavid Sterba ret = tree_mod_log_insert_key(parent, pslot + 1, 19190e82bcfeSDavid Sterba MOD_LOG_KEY_REPLACE, GFP_NOFS); 19200e82bcfeSDavid Sterba BUG_ON(ret < 0); 19215f39d397SChris Mason btrfs_set_node_key(parent, &right_key, pslot + 1); 19225f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 1923bb803951SChris Mason } 1924bb803951SChris Mason } 19255f39d397SChris Mason if (btrfs_header_nritems(mid) == 1) { 192679f95c82SChris Mason /* 192779f95c82SChris Mason * we're not allowed to leave a node with one item in the 192879f95c82SChris Mason * tree during a delete. A deletion from lower in the tree 192979f95c82SChris Mason * could try to delete the only pointer in this node. 193079f95c82SChris Mason * So, pull some keys from the left. 193179f95c82SChris Mason * There has to be a left pointer at this point because 193279f95c82SChris Mason * otherwise we would have pulled some pointers from the 193379f95c82SChris Mason * right 193479f95c82SChris Mason */ 1935305a26afSMark Fasheh if (!left) { 1936305a26afSMark Fasheh ret = -EROFS; 19370b246afaSJeff Mahoney btrfs_handle_fs_error(fs_info, ret, NULL); 1938305a26afSMark Fasheh goto enospc; 1939305a26afSMark Fasheh } 194055d32ed8SDavid Sterba wret = balance_node_right(trans, mid, left); 194154aa1f4dSChris Mason if (wret < 0) { 194279f95c82SChris Mason ret = wret; 194354aa1f4dSChris Mason goto enospc; 194454aa1f4dSChris Mason } 1945bce4eae9SChris Mason if (wret == 1) { 1946d30a668fSDavid Sterba wret = push_node_left(trans, left, mid, 1); 1947bce4eae9SChris Mason if (wret < 0) 1948bce4eae9SChris Mason ret = wret; 1949bce4eae9SChris Mason } 195079f95c82SChris Mason BUG_ON(wret == 1); 195179f95c82SChris Mason } 19525f39d397SChris Mason if (btrfs_header_nritems(mid) == 0) { 19536a884d7dSDavid Sterba btrfs_clean_tree_block(mid); 1954925baeddSChris Mason btrfs_tree_unlock(mid); 1955afe5fea7STsutomu Itoh del_ptr(root, path, level + 1, pslot); 1956f0486c68SYan, Zheng root_sub_used(root, mid->len); 19575581a51aSJan Schmidt btrfs_free_tree_block(trans, root, mid, 0, 1); 19583083ee2eSJosef Bacik free_extent_buffer_stale(mid); 1959f0486c68SYan, Zheng mid = NULL; 196079f95c82SChris Mason } else { 196179f95c82SChris Mason /* update the parent key to reflect our changes */ 19625f39d397SChris Mason struct btrfs_disk_key mid_key; 19635f39d397SChris Mason btrfs_node_key(mid, &mid_key, 0); 19640e82bcfeSDavid Sterba ret = tree_mod_log_insert_key(parent, pslot, 19650e82bcfeSDavid Sterba MOD_LOG_KEY_REPLACE, GFP_NOFS); 19660e82bcfeSDavid Sterba BUG_ON(ret < 0); 19675f39d397SChris Mason btrfs_set_node_key(parent, &mid_key, pslot); 19685f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 196979f95c82SChris Mason } 1970bb803951SChris Mason 197179f95c82SChris Mason /* update the path */ 19725f39d397SChris Mason if (left) { 19735f39d397SChris Mason if (btrfs_header_nritems(left) > orig_slot) { 197467439dadSDavid Sterba atomic_inc(&left->refs); 1975925baeddSChris Mason /* left was locked after cow */ 19765f39d397SChris Mason path->nodes[level] = left; 1977bb803951SChris Mason path->slots[level + 1] -= 1; 1978bb803951SChris Mason path->slots[level] = orig_slot; 1979925baeddSChris Mason if (mid) { 1980925baeddSChris Mason btrfs_tree_unlock(mid); 19815f39d397SChris Mason free_extent_buffer(mid); 1982925baeddSChris Mason } 1983bb803951SChris Mason } else { 19845f39d397SChris Mason orig_slot -= btrfs_header_nritems(left); 1985bb803951SChris Mason path->slots[level] = orig_slot; 1986bb803951SChris Mason } 1987bb803951SChris Mason } 198879f95c82SChris Mason /* double check we haven't messed things up */ 1989e20d96d6SChris Mason if (orig_ptr != 19905f39d397SChris Mason btrfs_node_blockptr(path->nodes[level], path->slots[level])) 199179f95c82SChris Mason BUG(); 199254aa1f4dSChris Mason enospc: 1993925baeddSChris Mason if (right) { 1994925baeddSChris Mason btrfs_tree_unlock(right); 19955f39d397SChris Mason free_extent_buffer(right); 1996925baeddSChris Mason } 1997925baeddSChris Mason if (left) { 1998925baeddSChris Mason if (path->nodes[level] != left) 1999925baeddSChris Mason btrfs_tree_unlock(left); 20005f39d397SChris Mason free_extent_buffer(left); 2001925baeddSChris Mason } 2002bb803951SChris Mason return ret; 2003bb803951SChris Mason } 2004bb803951SChris Mason 2005d352ac68SChris Mason /* Node balancing for insertion. Here we only split or push nodes around 2006d352ac68SChris Mason * when they are completely full. This is also done top down, so we 2007d352ac68SChris Mason * have to be pessimistic. 2008d352ac68SChris Mason */ 2009d397712bSChris Mason static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, 2010e66f709bSChris Mason struct btrfs_root *root, 2011e66f709bSChris Mason struct btrfs_path *path, int level) 2012e66f709bSChris Mason { 20130b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 20145f39d397SChris Mason struct extent_buffer *right = NULL; 20155f39d397SChris Mason struct extent_buffer *mid; 20165f39d397SChris Mason struct extent_buffer *left = NULL; 20175f39d397SChris Mason struct extent_buffer *parent = NULL; 2018e66f709bSChris Mason int ret = 0; 2019e66f709bSChris Mason int wret; 2020e66f709bSChris Mason int pslot; 2021e66f709bSChris Mason int orig_slot = path->slots[level]; 2022e66f709bSChris Mason 2023e66f709bSChris Mason if (level == 0) 2024e66f709bSChris Mason return 1; 2025e66f709bSChris Mason 20265f39d397SChris Mason mid = path->nodes[level]; 20277bb86316SChris Mason WARN_ON(btrfs_header_generation(mid) != trans->transid); 2028e66f709bSChris Mason 2029a05a9bb1SLi Zefan if (level < BTRFS_MAX_LEVEL - 1) { 20305f39d397SChris Mason parent = path->nodes[level + 1]; 2031e66f709bSChris Mason pslot = path->slots[level + 1]; 2032a05a9bb1SLi Zefan } 2033e66f709bSChris Mason 20345f39d397SChris Mason if (!parent) 2035e66f709bSChris Mason return 1; 2036e66f709bSChris Mason 20374b231ae4SDavid Sterba left = btrfs_read_node_slot(parent, pslot - 1); 2038fb770ae4SLiu Bo if (IS_ERR(left)) 2039fb770ae4SLiu Bo left = NULL; 2040e66f709bSChris Mason 2041e66f709bSChris Mason /* first, try to make some room in the middle buffer */ 20425f39d397SChris Mason if (left) { 2043e66f709bSChris Mason u32 left_nr; 2044925baeddSChris Mason 2045bf77467aSJosef Bacik __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); 2046b4ce94deSChris Mason 20475f39d397SChris Mason left_nr = btrfs_header_nritems(left); 20480b246afaSJeff Mahoney if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { 204933ade1f8SChris Mason wret = 1; 205033ade1f8SChris Mason } else { 20515f39d397SChris Mason ret = btrfs_cow_block(trans, root, left, parent, 20529631e4ccSJosef Bacik pslot - 1, &left, 2053bf59a5a2SJosef Bacik BTRFS_NESTING_LEFT_COW); 205454aa1f4dSChris Mason if (ret) 205554aa1f4dSChris Mason wret = 1; 205654aa1f4dSChris Mason else { 2057d30a668fSDavid Sterba wret = push_node_left(trans, left, mid, 0); 205854aa1f4dSChris Mason } 205933ade1f8SChris Mason } 2060e66f709bSChris Mason if (wret < 0) 2061e66f709bSChris Mason ret = wret; 2062e66f709bSChris Mason if (wret == 0) { 20635f39d397SChris Mason struct btrfs_disk_key disk_key; 2064e66f709bSChris Mason orig_slot += left_nr; 20655f39d397SChris Mason btrfs_node_key(mid, &disk_key, 0); 20660e82bcfeSDavid Sterba ret = tree_mod_log_insert_key(parent, pslot, 20670e82bcfeSDavid Sterba MOD_LOG_KEY_REPLACE, GFP_NOFS); 20680e82bcfeSDavid Sterba BUG_ON(ret < 0); 20695f39d397SChris Mason btrfs_set_node_key(parent, &disk_key, pslot); 20705f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 20715f39d397SChris Mason if (btrfs_header_nritems(left) > orig_slot) { 20725f39d397SChris Mason path->nodes[level] = left; 2073e66f709bSChris Mason path->slots[level + 1] -= 1; 2074e66f709bSChris Mason path->slots[level] = orig_slot; 2075925baeddSChris Mason btrfs_tree_unlock(mid); 20765f39d397SChris Mason free_extent_buffer(mid); 2077e66f709bSChris Mason } else { 2078e66f709bSChris Mason orig_slot -= 20795f39d397SChris Mason btrfs_header_nritems(left); 2080e66f709bSChris Mason path->slots[level] = orig_slot; 2081925baeddSChris Mason btrfs_tree_unlock(left); 20825f39d397SChris Mason free_extent_buffer(left); 2083e66f709bSChris Mason } 2084e66f709bSChris Mason return 0; 2085e66f709bSChris Mason } 2086925baeddSChris Mason btrfs_tree_unlock(left); 20875f39d397SChris Mason free_extent_buffer(left); 2088e66f709bSChris Mason } 20894b231ae4SDavid Sterba right = btrfs_read_node_slot(parent, pslot + 1); 2090fb770ae4SLiu Bo if (IS_ERR(right)) 2091fb770ae4SLiu Bo right = NULL; 2092e66f709bSChris Mason 2093e66f709bSChris Mason /* 2094e66f709bSChris Mason * then try to empty the right most buffer into the middle 2095e66f709bSChris Mason */ 20965f39d397SChris Mason if (right) { 209733ade1f8SChris Mason u32 right_nr; 2098b4ce94deSChris Mason 2099bf77467aSJosef Bacik __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); 2100b4ce94deSChris Mason 21015f39d397SChris Mason right_nr = btrfs_header_nritems(right); 21020b246afaSJeff Mahoney if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { 210333ade1f8SChris Mason wret = 1; 210433ade1f8SChris Mason } else { 21055f39d397SChris Mason ret = btrfs_cow_block(trans, root, right, 21065f39d397SChris Mason parent, pslot + 1, 2107bf59a5a2SJosef Bacik &right, BTRFS_NESTING_RIGHT_COW); 210854aa1f4dSChris Mason if (ret) 210954aa1f4dSChris Mason wret = 1; 211054aa1f4dSChris Mason else { 211155d32ed8SDavid Sterba wret = balance_node_right(trans, right, mid); 211233ade1f8SChris Mason } 211354aa1f4dSChris Mason } 2114e66f709bSChris Mason if (wret < 0) 2115e66f709bSChris Mason ret = wret; 2116e66f709bSChris Mason if (wret == 0) { 21175f39d397SChris Mason struct btrfs_disk_key disk_key; 21185f39d397SChris Mason 21195f39d397SChris Mason btrfs_node_key(right, &disk_key, 0); 21200e82bcfeSDavid Sterba ret = tree_mod_log_insert_key(parent, pslot + 1, 21210e82bcfeSDavid Sterba MOD_LOG_KEY_REPLACE, GFP_NOFS); 21220e82bcfeSDavid Sterba BUG_ON(ret < 0); 21235f39d397SChris Mason btrfs_set_node_key(parent, &disk_key, pslot + 1); 21245f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 21255f39d397SChris Mason 21265f39d397SChris Mason if (btrfs_header_nritems(mid) <= orig_slot) { 21275f39d397SChris Mason path->nodes[level] = right; 2128e66f709bSChris Mason path->slots[level + 1] += 1; 2129e66f709bSChris Mason path->slots[level] = orig_slot - 21305f39d397SChris Mason btrfs_header_nritems(mid); 2131925baeddSChris Mason btrfs_tree_unlock(mid); 21325f39d397SChris Mason free_extent_buffer(mid); 2133e66f709bSChris Mason } else { 2134925baeddSChris Mason btrfs_tree_unlock(right); 21355f39d397SChris Mason free_extent_buffer(right); 2136e66f709bSChris Mason } 2137e66f709bSChris Mason return 0; 2138e66f709bSChris Mason } 2139925baeddSChris Mason btrfs_tree_unlock(right); 21405f39d397SChris Mason free_extent_buffer(right); 2141e66f709bSChris Mason } 2142e66f709bSChris Mason return 1; 2143e66f709bSChris Mason } 2144e66f709bSChris Mason 214574123bd7SChris Mason /* 2146d352ac68SChris Mason * readahead one full node of leaves, finding things that are close 2147d352ac68SChris Mason * to the block in 'slot', and triggering ra on them. 21483c69faecSChris Mason */ 21492ff7e61eSJeff Mahoney static void reada_for_search(struct btrfs_fs_info *fs_info, 2150e02119d5SChris Mason struct btrfs_path *path, 215101f46658SChris Mason int level, int slot, u64 objectid) 21523c69faecSChris Mason { 21535f39d397SChris Mason struct extent_buffer *node; 215401f46658SChris Mason struct btrfs_disk_key disk_key; 21553c69faecSChris Mason u32 nritems; 21563c69faecSChris Mason u64 search; 2157a7175319SChris Mason u64 target; 21586b80053dSChris Mason u64 nread = 0; 21595f39d397SChris Mason struct extent_buffer *eb; 21606b80053dSChris Mason u32 nr; 21616b80053dSChris Mason u32 blocksize; 21626b80053dSChris Mason u32 nscan = 0; 2163db94535dSChris Mason 2164a6b6e75eSChris Mason if (level != 1) 21653c69faecSChris Mason return; 21663c69faecSChris Mason 21676702ed49SChris Mason if (!path->nodes[level]) 21686702ed49SChris Mason return; 21696702ed49SChris Mason 21705f39d397SChris Mason node = path->nodes[level]; 2171925baeddSChris Mason 21723c69faecSChris Mason search = btrfs_node_blockptr(node, slot); 21730b246afaSJeff Mahoney blocksize = fs_info->nodesize; 21740b246afaSJeff Mahoney eb = find_extent_buffer(fs_info, search); 21755f39d397SChris Mason if (eb) { 21765f39d397SChris Mason free_extent_buffer(eb); 21773c69faecSChris Mason return; 21783c69faecSChris Mason } 21793c69faecSChris Mason 2180a7175319SChris Mason target = search; 21816b80053dSChris Mason 21825f39d397SChris Mason nritems = btrfs_header_nritems(node); 21836b80053dSChris Mason nr = slot; 218425b8b936SJosef Bacik 21853c69faecSChris Mason while (1) { 2186e4058b54SDavid Sterba if (path->reada == READA_BACK) { 21876b80053dSChris Mason if (nr == 0) 21883c69faecSChris Mason break; 21896b80053dSChris Mason nr--; 2190e4058b54SDavid Sterba } else if (path->reada == READA_FORWARD) { 21916b80053dSChris Mason nr++; 21926b80053dSChris Mason if (nr >= nritems) 21936b80053dSChris Mason break; 21943c69faecSChris Mason } 2195e4058b54SDavid Sterba if (path->reada == READA_BACK && objectid) { 219601f46658SChris Mason btrfs_node_key(node, &disk_key, nr); 219701f46658SChris Mason if (btrfs_disk_key_objectid(&disk_key) != objectid) 219801f46658SChris Mason break; 219901f46658SChris Mason } 22006b80053dSChris Mason search = btrfs_node_blockptr(node, nr); 2201a7175319SChris Mason if ((search <= target && target - search <= 65536) || 2202a7175319SChris Mason (search > target && search - target <= 65536)) { 2203bfb484d9SJosef Bacik btrfs_readahead_node_child(node, nr); 22046b80053dSChris Mason nread += blocksize; 22053c69faecSChris Mason } 22066b80053dSChris Mason nscan++; 2207a7175319SChris Mason if ((nread > 65536 || nscan > 32)) 22086b80053dSChris Mason break; 22093c69faecSChris Mason } 22103c69faecSChris Mason } 2211925baeddSChris Mason 2212bfb484d9SJosef Bacik static noinline void reada_for_balance(struct btrfs_path *path, int level) 2213b4ce94deSChris Mason { 2214bfb484d9SJosef Bacik struct extent_buffer *parent; 2215b4ce94deSChris Mason int slot; 2216b4ce94deSChris Mason int nritems; 2217b4ce94deSChris Mason 22188c594ea8SChris Mason parent = path->nodes[level + 1]; 2219b4ce94deSChris Mason if (!parent) 22200b08851fSJosef Bacik return; 2221b4ce94deSChris Mason 2222b4ce94deSChris Mason nritems = btrfs_header_nritems(parent); 22238c594ea8SChris Mason slot = path->slots[level + 1]; 2224b4ce94deSChris Mason 2225bfb484d9SJosef Bacik if (slot > 0) 2226bfb484d9SJosef Bacik btrfs_readahead_node_child(parent, slot - 1); 2227bfb484d9SJosef Bacik if (slot + 1 < nritems) 2228bfb484d9SJosef Bacik btrfs_readahead_node_child(parent, slot + 1); 2229b4ce94deSChris Mason } 2230b4ce94deSChris Mason 2231b4ce94deSChris Mason 2232b4ce94deSChris Mason /* 2233d397712bSChris Mason * when we walk down the tree, it is usually safe to unlock the higher layers 2234d397712bSChris Mason * in the tree. The exceptions are when our path goes through slot 0, because 2235d397712bSChris Mason * operations on the tree might require changing key pointers higher up in the 2236d397712bSChris Mason * tree. 2237d352ac68SChris Mason * 2238d397712bSChris Mason * callers might also have set path->keep_locks, which tells this code to keep 2239d397712bSChris Mason * the lock if the path points to the last slot in the block. This is part of 2240d397712bSChris Mason * walking through the tree, and selecting the next slot in the higher block. 2241d352ac68SChris Mason * 2242d397712bSChris Mason * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so 2243d397712bSChris Mason * if lowest_unlock is 1, level 0 won't be unlocked 2244d352ac68SChris Mason */ 2245e02119d5SChris Mason static noinline void unlock_up(struct btrfs_path *path, int level, 2246f7c79f30SChris Mason int lowest_unlock, int min_write_lock_level, 2247f7c79f30SChris Mason int *write_lock_level) 2248925baeddSChris Mason { 2249925baeddSChris Mason int i; 2250925baeddSChris Mason int skip_level = level; 2251051e1b9fSChris Mason int no_skips = 0; 2252925baeddSChris Mason struct extent_buffer *t; 2253925baeddSChris Mason 2254925baeddSChris Mason for (i = level; i < BTRFS_MAX_LEVEL; i++) { 2255925baeddSChris Mason if (!path->nodes[i]) 2256925baeddSChris Mason break; 2257925baeddSChris Mason if (!path->locks[i]) 2258925baeddSChris Mason break; 2259051e1b9fSChris Mason if (!no_skips && path->slots[i] == 0) { 2260925baeddSChris Mason skip_level = i + 1; 2261925baeddSChris Mason continue; 2262925baeddSChris Mason } 2263051e1b9fSChris Mason if (!no_skips && path->keep_locks) { 2264925baeddSChris Mason u32 nritems; 2265925baeddSChris Mason t = path->nodes[i]; 2266925baeddSChris Mason nritems = btrfs_header_nritems(t); 2267051e1b9fSChris Mason if (nritems < 1 || path->slots[i] >= nritems - 1) { 2268925baeddSChris Mason skip_level = i + 1; 2269925baeddSChris Mason continue; 2270925baeddSChris Mason } 2271925baeddSChris Mason } 2272051e1b9fSChris Mason if (skip_level < i && i >= lowest_unlock) 2273051e1b9fSChris Mason no_skips = 1; 2274051e1b9fSChris Mason 2275925baeddSChris Mason t = path->nodes[i]; 2276d80bb3f9SLiu Bo if (i >= lowest_unlock && i > skip_level) { 2277bd681513SChris Mason btrfs_tree_unlock_rw(t, path->locks[i]); 2278925baeddSChris Mason path->locks[i] = 0; 2279f7c79f30SChris Mason if (write_lock_level && 2280f7c79f30SChris Mason i > min_write_lock_level && 2281f7c79f30SChris Mason i <= *write_lock_level) { 2282f7c79f30SChris Mason *write_lock_level = i - 1; 2283f7c79f30SChris Mason } 2284925baeddSChris Mason } 2285925baeddSChris Mason } 2286925baeddSChris Mason } 2287925baeddSChris Mason 22883c69faecSChris Mason /* 2289c8c42864SChris Mason * helper function for btrfs_search_slot. The goal is to find a block 2290c8c42864SChris Mason * in cache without setting the path to blocking. If we find the block 2291c8c42864SChris Mason * we return zero and the path is unchanged. 2292c8c42864SChris Mason * 2293c8c42864SChris Mason * If we can't find the block, we set the path blocking and do some 2294c8c42864SChris Mason * reada. -EAGAIN is returned and the search must be repeated. 2295c8c42864SChris Mason */ 2296c8c42864SChris Mason static int 2297d07b8528SLiu Bo read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, 2298c8c42864SChris Mason struct extent_buffer **eb_ret, int level, int slot, 2299cda79c54SDavid Sterba const struct btrfs_key *key) 2300c8c42864SChris Mason { 23010b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 2302c8c42864SChris Mason u64 blocknr; 2303c8c42864SChris Mason u64 gen; 2304c8c42864SChris Mason struct extent_buffer *tmp; 2305581c1760SQu Wenruo struct btrfs_key first_key; 230676a05b35SChris Mason int ret; 2307581c1760SQu Wenruo int parent_level; 2308c8c42864SChris Mason 2309213ff4b7SNikolay Borisov blocknr = btrfs_node_blockptr(*eb_ret, slot); 2310213ff4b7SNikolay Borisov gen = btrfs_node_ptr_generation(*eb_ret, slot); 2311213ff4b7SNikolay Borisov parent_level = btrfs_header_level(*eb_ret); 2312213ff4b7SNikolay Borisov btrfs_node_key_to_cpu(*eb_ret, &first_key, slot); 2313c8c42864SChris Mason 23140b246afaSJeff Mahoney tmp = find_extent_buffer(fs_info, blocknr); 2315cb44921aSChris Mason if (tmp) { 2316b9fab919SChris Mason /* first we do an atomic uptodate check */ 2317b9fab919SChris Mason if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { 2318448de471SQu Wenruo /* 2319448de471SQu Wenruo * Do extra check for first_key, eb can be stale due to 2320448de471SQu Wenruo * being cached, read from scrub, or have multiple 2321448de471SQu Wenruo * parents (shared tree blocks). 2322448de471SQu Wenruo */ 2323e064d5e9SDavid Sterba if (btrfs_verify_level_key(tmp, 2324448de471SQu Wenruo parent_level - 1, &first_key, gen)) { 2325448de471SQu Wenruo free_extent_buffer(tmp); 2326448de471SQu Wenruo return -EUCLEAN; 2327448de471SQu Wenruo } 2328c8c42864SChris Mason *eb_ret = tmp; 2329c8c42864SChris Mason return 0; 2330c8c42864SChris Mason } 2331bdf7c00eSJosef Bacik 2332b9fab919SChris Mason /* now we're allowed to do a blocking uptodate check */ 2333581c1760SQu Wenruo ret = btrfs_read_buffer(tmp, gen, parent_level - 1, &first_key); 2334bdf7c00eSJosef Bacik if (!ret) { 2335cb44921aSChris Mason *eb_ret = tmp; 2336cb44921aSChris Mason return 0; 2337cb44921aSChris Mason } 2338cb44921aSChris Mason free_extent_buffer(tmp); 2339b3b4aa74SDavid Sterba btrfs_release_path(p); 2340cb44921aSChris Mason return -EIO; 2341cb44921aSChris Mason } 2342c8c42864SChris Mason 2343c8c42864SChris Mason /* 2344c8c42864SChris Mason * reduce lock contention at high levels 2345c8c42864SChris Mason * of the btree by dropping locks before 234676a05b35SChris Mason * we read. Don't release the lock on the current 234776a05b35SChris Mason * level because we need to walk this node to figure 234876a05b35SChris Mason * out which blocks to read. 2349c8c42864SChris Mason */ 23508c594ea8SChris Mason btrfs_unlock_up_safe(p, level + 1); 23518c594ea8SChris Mason 2352e4058b54SDavid Sterba if (p->reada != READA_NONE) 23532ff7e61eSJeff Mahoney reada_for_search(fs_info, p, level, slot, key->objectid); 2354c8c42864SChris Mason 235576a05b35SChris Mason ret = -EAGAIN; 23561b7ec85eSJosef Bacik tmp = read_tree_block(fs_info, blocknr, root->root_key.objectid, 23571b7ec85eSJosef Bacik gen, parent_level - 1, &first_key); 235864c043deSLiu Bo if (!IS_ERR(tmp)) { 235976a05b35SChris Mason /* 236076a05b35SChris Mason * If the read above didn't mark this buffer up to date, 236176a05b35SChris Mason * it will never end up being up to date. Set ret to EIO now 236276a05b35SChris Mason * and give up so that our caller doesn't loop forever 236376a05b35SChris Mason * on our EAGAINs. 236476a05b35SChris Mason */ 2365e6a1d6fdSLiu Bo if (!extent_buffer_uptodate(tmp)) 236676a05b35SChris Mason ret = -EIO; 2367c8c42864SChris Mason free_extent_buffer(tmp); 2368c871b0f2SLiu Bo } else { 2369c871b0f2SLiu Bo ret = PTR_ERR(tmp); 237076a05b35SChris Mason } 237102a3307aSLiu Bo 237202a3307aSLiu Bo btrfs_release_path(p); 237376a05b35SChris Mason return ret; 2374c8c42864SChris Mason } 2375c8c42864SChris Mason 2376c8c42864SChris Mason /* 2377c8c42864SChris Mason * helper function for btrfs_search_slot. This does all of the checks 2378c8c42864SChris Mason * for node-level blocks and does any balancing required based on 2379c8c42864SChris Mason * the ins_len. 2380c8c42864SChris Mason * 2381c8c42864SChris Mason * If no extra work was required, zero is returned. If we had to 2382c8c42864SChris Mason * drop the path, -EAGAIN is returned and btrfs_search_slot must 2383c8c42864SChris Mason * start over 2384c8c42864SChris Mason */ 2385c8c42864SChris Mason static int 2386c8c42864SChris Mason setup_nodes_for_search(struct btrfs_trans_handle *trans, 2387c8c42864SChris Mason struct btrfs_root *root, struct btrfs_path *p, 2388bd681513SChris Mason struct extent_buffer *b, int level, int ins_len, 2389bd681513SChris Mason int *write_lock_level) 2390c8c42864SChris Mason { 23910b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 239295b982deSNikolay Borisov int ret = 0; 23930b246afaSJeff Mahoney 2394c8c42864SChris Mason if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= 23950b246afaSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) { 2396c8c42864SChris Mason 2397bd681513SChris Mason if (*write_lock_level < level + 1) { 2398bd681513SChris Mason *write_lock_level = level + 1; 2399bd681513SChris Mason btrfs_release_path(p); 240095b982deSNikolay Borisov return -EAGAIN; 2401bd681513SChris Mason } 2402bd681513SChris Mason 2403bfb484d9SJosef Bacik reada_for_balance(p, level); 240495b982deSNikolay Borisov ret = split_node(trans, root, p, level); 2405c8c42864SChris Mason 2406c8c42864SChris Mason b = p->nodes[level]; 2407c8c42864SChris Mason } else if (ins_len < 0 && btrfs_header_nritems(b) < 24080b246afaSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 2) { 2409c8c42864SChris Mason 2410bd681513SChris Mason if (*write_lock_level < level + 1) { 2411bd681513SChris Mason *write_lock_level = level + 1; 2412bd681513SChris Mason btrfs_release_path(p); 241395b982deSNikolay Borisov return -EAGAIN; 2414bd681513SChris Mason } 2415bd681513SChris Mason 2416bfb484d9SJosef Bacik reada_for_balance(p, level); 241795b982deSNikolay Borisov ret = balance_level(trans, root, p, level); 241895b982deSNikolay Borisov if (ret) 241995b982deSNikolay Borisov return ret; 2420c8c42864SChris Mason 2421c8c42864SChris Mason b = p->nodes[level]; 2422c8c42864SChris Mason if (!b) { 2423b3b4aa74SDavid Sterba btrfs_release_path(p); 242495b982deSNikolay Borisov return -EAGAIN; 2425c8c42864SChris Mason } 2426c8c42864SChris Mason BUG_ON(btrfs_header_nritems(b) == 1); 2427c8c42864SChris Mason } 2428c8c42864SChris Mason return ret; 2429c8c42864SChris Mason } 2430c8c42864SChris Mason 2431381cf658SDavid Sterba int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, 2432e33d5c3dSKelley Nielsen u64 iobjectid, u64 ioff, u8 key_type, 2433e33d5c3dSKelley Nielsen struct btrfs_key *found_key) 2434e33d5c3dSKelley Nielsen { 2435e33d5c3dSKelley Nielsen int ret; 2436e33d5c3dSKelley Nielsen struct btrfs_key key; 2437e33d5c3dSKelley Nielsen struct extent_buffer *eb; 2438381cf658SDavid Sterba 2439381cf658SDavid Sterba ASSERT(path); 24401d4c08e0SDavid Sterba ASSERT(found_key); 2441e33d5c3dSKelley Nielsen 2442e33d5c3dSKelley Nielsen key.type = key_type; 2443e33d5c3dSKelley Nielsen key.objectid = iobjectid; 2444e33d5c3dSKelley Nielsen key.offset = ioff; 2445e33d5c3dSKelley Nielsen 2446e33d5c3dSKelley Nielsen ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); 24471d4c08e0SDavid Sterba if (ret < 0) 2448e33d5c3dSKelley Nielsen return ret; 2449e33d5c3dSKelley Nielsen 2450e33d5c3dSKelley Nielsen eb = path->nodes[0]; 2451e33d5c3dSKelley Nielsen if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { 2452e33d5c3dSKelley Nielsen ret = btrfs_next_leaf(fs_root, path); 2453e33d5c3dSKelley Nielsen if (ret) 2454e33d5c3dSKelley Nielsen return ret; 2455e33d5c3dSKelley Nielsen eb = path->nodes[0]; 2456e33d5c3dSKelley Nielsen } 2457e33d5c3dSKelley Nielsen 2458e33d5c3dSKelley Nielsen btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); 2459e33d5c3dSKelley Nielsen if (found_key->type != key.type || 2460e33d5c3dSKelley Nielsen found_key->objectid != key.objectid) 2461e33d5c3dSKelley Nielsen return 1; 2462e33d5c3dSKelley Nielsen 2463e33d5c3dSKelley Nielsen return 0; 2464e33d5c3dSKelley Nielsen } 2465e33d5c3dSKelley Nielsen 24661fc28d8eSLiu Bo static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root, 24671fc28d8eSLiu Bo struct btrfs_path *p, 24681fc28d8eSLiu Bo int write_lock_level) 24691fc28d8eSLiu Bo { 24701fc28d8eSLiu Bo struct btrfs_fs_info *fs_info = root->fs_info; 24711fc28d8eSLiu Bo struct extent_buffer *b; 24721fc28d8eSLiu Bo int root_lock; 24731fc28d8eSLiu Bo int level = 0; 24741fc28d8eSLiu Bo 24751fc28d8eSLiu Bo /* We try very hard to do read locks on the root */ 24761fc28d8eSLiu Bo root_lock = BTRFS_READ_LOCK; 24771fc28d8eSLiu Bo 24781fc28d8eSLiu Bo if (p->search_commit_root) { 2479be6821f8SFilipe Manana /* 2480be6821f8SFilipe Manana * The commit roots are read only so we always do read locks, 2481be6821f8SFilipe Manana * and we always must hold the commit_root_sem when doing 2482be6821f8SFilipe Manana * searches on them, the only exception is send where we don't 2483be6821f8SFilipe Manana * want to block transaction commits for a long time, so 2484be6821f8SFilipe Manana * we need to clone the commit root in order to avoid races 2485be6821f8SFilipe Manana * with transaction commits that create a snapshot of one of 2486be6821f8SFilipe Manana * the roots used by a send operation. 2487be6821f8SFilipe Manana */ 2488be6821f8SFilipe Manana if (p->need_commit_sem) { 24891fc28d8eSLiu Bo down_read(&fs_info->commit_root_sem); 2490be6821f8SFilipe Manana b = btrfs_clone_extent_buffer(root->commit_root); 2491be6821f8SFilipe Manana up_read(&fs_info->commit_root_sem); 2492be6821f8SFilipe Manana if (!b) 2493be6821f8SFilipe Manana return ERR_PTR(-ENOMEM); 2494be6821f8SFilipe Manana 2495be6821f8SFilipe Manana } else { 24961fc28d8eSLiu Bo b = root->commit_root; 249767439dadSDavid Sterba atomic_inc(&b->refs); 2498be6821f8SFilipe Manana } 24991fc28d8eSLiu Bo level = btrfs_header_level(b); 2500f9ddfd05SLiu Bo /* 2501f9ddfd05SLiu Bo * Ensure that all callers have set skip_locking when 2502f9ddfd05SLiu Bo * p->search_commit_root = 1. 2503f9ddfd05SLiu Bo */ 2504f9ddfd05SLiu Bo ASSERT(p->skip_locking == 1); 25051fc28d8eSLiu Bo 25061fc28d8eSLiu Bo goto out; 25071fc28d8eSLiu Bo } 25081fc28d8eSLiu Bo 25091fc28d8eSLiu Bo if (p->skip_locking) { 25101fc28d8eSLiu Bo b = btrfs_root_node(root); 25111fc28d8eSLiu Bo level = btrfs_header_level(b); 25121fc28d8eSLiu Bo goto out; 25131fc28d8eSLiu Bo } 25141fc28d8eSLiu Bo 25151fc28d8eSLiu Bo /* 2516662c653bSLiu Bo * If the level is set to maximum, we can skip trying to get the read 2517662c653bSLiu Bo * lock. 2518662c653bSLiu Bo */ 2519662c653bSLiu Bo if (write_lock_level < BTRFS_MAX_LEVEL) { 2520662c653bSLiu Bo /* 2521662c653bSLiu Bo * We don't know the level of the root node until we actually 2522662c653bSLiu Bo * have it read locked 25231fc28d8eSLiu Bo */ 25241bb96598SJosef Bacik b = btrfs_read_lock_root_node(root); 25251fc28d8eSLiu Bo level = btrfs_header_level(b); 25261fc28d8eSLiu Bo if (level > write_lock_level) 25271fc28d8eSLiu Bo goto out; 25281fc28d8eSLiu Bo 2529662c653bSLiu Bo /* Whoops, must trade for write lock */ 25301fc28d8eSLiu Bo btrfs_tree_read_unlock(b); 25311fc28d8eSLiu Bo free_extent_buffer(b); 2532662c653bSLiu Bo } 2533662c653bSLiu Bo 25341fc28d8eSLiu Bo b = btrfs_lock_root_node(root); 25351fc28d8eSLiu Bo root_lock = BTRFS_WRITE_LOCK; 25361fc28d8eSLiu Bo 25371fc28d8eSLiu Bo /* The level might have changed, check again */ 25381fc28d8eSLiu Bo level = btrfs_header_level(b); 25391fc28d8eSLiu Bo 25401fc28d8eSLiu Bo out: 25411fc28d8eSLiu Bo p->nodes[level] = b; 25421fc28d8eSLiu Bo if (!p->skip_locking) 25431fc28d8eSLiu Bo p->locks[level] = root_lock; 25441fc28d8eSLiu Bo /* 25451fc28d8eSLiu Bo * Callers are responsible for dropping b's references. 25461fc28d8eSLiu Bo */ 25471fc28d8eSLiu Bo return b; 25481fc28d8eSLiu Bo } 25491fc28d8eSLiu Bo 25501fc28d8eSLiu Bo 2551c8c42864SChris Mason /* 25524271eceaSNikolay Borisov * btrfs_search_slot - look for a key in a tree and perform necessary 25534271eceaSNikolay Borisov * modifications to preserve tree invariants. 255474123bd7SChris Mason * 25554271eceaSNikolay Borisov * @trans: Handle of transaction, used when modifying the tree 25564271eceaSNikolay Borisov * @p: Holds all btree nodes along the search path 25574271eceaSNikolay Borisov * @root: The root node of the tree 25584271eceaSNikolay Borisov * @key: The key we are looking for 25599a664971Sethanwu * @ins_len: Indicates purpose of search: 25609a664971Sethanwu * >0 for inserts it's size of item inserted (*) 25619a664971Sethanwu * <0 for deletions 25629a664971Sethanwu * 0 for plain searches, not modifying the tree 25639a664971Sethanwu * 25649a664971Sethanwu * (*) If size of item inserted doesn't include 25659a664971Sethanwu * sizeof(struct btrfs_item), then p->search_for_extension must 25669a664971Sethanwu * be set. 25674271eceaSNikolay Borisov * @cow: boolean should CoW operations be performed. Must always be 1 25684271eceaSNikolay Borisov * when modifying the tree. 256997571fd0SChris Mason * 25704271eceaSNikolay Borisov * If @ins_len > 0, nodes and leaves will be split as we walk down the tree. 25714271eceaSNikolay Borisov * If @ins_len < 0, nodes will be merged as we walk down the tree (if possible) 25724271eceaSNikolay Borisov * 25734271eceaSNikolay Borisov * If @key is found, 0 is returned and you can find the item in the leaf level 25744271eceaSNikolay Borisov * of the path (level 0) 25754271eceaSNikolay Borisov * 25764271eceaSNikolay Borisov * If @key isn't found, 1 is returned and the leaf level of the path (level 0) 25774271eceaSNikolay Borisov * points to the slot where it should be inserted 25784271eceaSNikolay Borisov * 25794271eceaSNikolay Borisov * If an error is encountered while searching the tree a negative error number 25804271eceaSNikolay Borisov * is returned 258174123bd7SChris Mason */ 2582310712b2SOmar Sandoval int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, 2583310712b2SOmar Sandoval const struct btrfs_key *key, struct btrfs_path *p, 2584310712b2SOmar Sandoval int ins_len, int cow) 2585be0e5c09SChris Mason { 25865f39d397SChris Mason struct extent_buffer *b; 2587be0e5c09SChris Mason int slot; 2588be0e5c09SChris Mason int ret; 258933c66f43SYan Zheng int err; 2590be0e5c09SChris Mason int level; 2591925baeddSChris Mason int lowest_unlock = 1; 2592bd681513SChris Mason /* everything at write_lock_level or lower must be write locked */ 2593bd681513SChris Mason int write_lock_level = 0; 25949f3a7427SChris Mason u8 lowest_level = 0; 2595f7c79f30SChris Mason int min_write_lock_level; 2596d7396f07SFilipe David Borba Manana int prev_cmp; 25979f3a7427SChris Mason 25986702ed49SChris Mason lowest_level = p->lowest_level; 2599323ac95bSChris Mason WARN_ON(lowest_level && ins_len > 0); 260022b0ebdaSChris Mason WARN_ON(p->nodes[0] != NULL); 2601eb653de1SFilipe David Borba Manana BUG_ON(!cow && ins_len); 260225179201SJosef Bacik 2603bd681513SChris Mason if (ins_len < 0) { 2604925baeddSChris Mason lowest_unlock = 2; 260565b51a00SChris Mason 2606bd681513SChris Mason /* when we are removing items, we might have to go up to level 2607bd681513SChris Mason * two as we update tree pointers Make sure we keep write 2608bd681513SChris Mason * for those levels as well 2609bd681513SChris Mason */ 2610bd681513SChris Mason write_lock_level = 2; 2611bd681513SChris Mason } else if (ins_len > 0) { 2612bd681513SChris Mason /* 2613bd681513SChris Mason * for inserting items, make sure we have a write lock on 2614bd681513SChris Mason * level 1 so we can update keys 2615bd681513SChris Mason */ 2616bd681513SChris Mason write_lock_level = 1; 2617bd681513SChris Mason } 2618bd681513SChris Mason 2619bd681513SChris Mason if (!cow) 2620bd681513SChris Mason write_lock_level = -1; 2621bd681513SChris Mason 262209a2a8f9SJosef Bacik if (cow && (p->keep_locks || p->lowest_level)) 2623bd681513SChris Mason write_lock_level = BTRFS_MAX_LEVEL; 2624bd681513SChris Mason 2625f7c79f30SChris Mason min_write_lock_level = write_lock_level; 2626f7c79f30SChris Mason 2627bb803951SChris Mason again: 2628d7396f07SFilipe David Borba Manana prev_cmp = -1; 26291fc28d8eSLiu Bo b = btrfs_search_slot_get_root(root, p, write_lock_level); 2630be6821f8SFilipe Manana if (IS_ERR(b)) { 2631be6821f8SFilipe Manana ret = PTR_ERR(b); 2632be6821f8SFilipe Manana goto done; 2633be6821f8SFilipe Manana } 2634925baeddSChris Mason 2635eb60ceacSChris Mason while (b) { 2636f624d976SQu Wenruo int dec = 0; 2637f624d976SQu Wenruo 26385f39d397SChris Mason level = btrfs_header_level(b); 263965b51a00SChris Mason 264002217ed2SChris Mason if (cow) { 26419ea2c7c9SNikolay Borisov bool last_level = (level == (BTRFS_MAX_LEVEL - 1)); 26429ea2c7c9SNikolay Borisov 2643c8c42864SChris Mason /* 2644c8c42864SChris Mason * if we don't really need to cow this block 2645c8c42864SChris Mason * then we don't want to set the path blocking, 2646c8c42864SChris Mason * so we test it here 2647c8c42864SChris Mason */ 264864c12921SJeff Mahoney if (!should_cow_block(trans, root, b)) { 264964c12921SJeff Mahoney trans->dirty = true; 265065b51a00SChris Mason goto cow_done; 265164c12921SJeff Mahoney } 26525d4f98a2SYan Zheng 2653bd681513SChris Mason /* 2654bd681513SChris Mason * must have write locks on this node and the 2655bd681513SChris Mason * parent 2656bd681513SChris Mason */ 26575124e00eSJosef Bacik if (level > write_lock_level || 26585124e00eSJosef Bacik (level + 1 > write_lock_level && 26595124e00eSJosef Bacik level + 1 < BTRFS_MAX_LEVEL && 26605124e00eSJosef Bacik p->nodes[level + 1])) { 2661bd681513SChris Mason write_lock_level = level + 1; 2662bd681513SChris Mason btrfs_release_path(p); 2663bd681513SChris Mason goto again; 2664bd681513SChris Mason } 2665bd681513SChris Mason 26669ea2c7c9SNikolay Borisov if (last_level) 26679ea2c7c9SNikolay Borisov err = btrfs_cow_block(trans, root, b, NULL, 0, 26689631e4ccSJosef Bacik &b, 26699631e4ccSJosef Bacik BTRFS_NESTING_COW); 26709ea2c7c9SNikolay Borisov else 267133c66f43SYan Zheng err = btrfs_cow_block(trans, root, b, 2672e20d96d6SChris Mason p->nodes[level + 1], 26739631e4ccSJosef Bacik p->slots[level + 1], &b, 26749631e4ccSJosef Bacik BTRFS_NESTING_COW); 267533c66f43SYan Zheng if (err) { 267633c66f43SYan Zheng ret = err; 267765b51a00SChris Mason goto done; 267854aa1f4dSChris Mason } 267902217ed2SChris Mason } 268065b51a00SChris Mason cow_done: 2681eb60ceacSChris Mason p->nodes[level] = b; 268252398340SLiu Bo /* 268352398340SLiu Bo * Leave path with blocking locks to avoid massive 268452398340SLiu Bo * lock context switch, this is made on purpose. 268552398340SLiu Bo */ 2686b4ce94deSChris Mason 2687b4ce94deSChris Mason /* 2688b4ce94deSChris Mason * we have a lock on b and as long as we aren't changing 2689b4ce94deSChris Mason * the tree, there is no way to for the items in b to change. 2690b4ce94deSChris Mason * It is safe to drop the lock on our parent before we 2691b4ce94deSChris Mason * go through the expensive btree search on b. 2692b4ce94deSChris Mason * 2693eb653de1SFilipe David Borba Manana * If we're inserting or deleting (ins_len != 0), then we might 2694eb653de1SFilipe David Borba Manana * be changing slot zero, which may require changing the parent. 2695eb653de1SFilipe David Borba Manana * So, we can't drop the lock until after we know which slot 2696eb653de1SFilipe David Borba Manana * we're operating on. 2697b4ce94deSChris Mason */ 2698eb653de1SFilipe David Borba Manana if (!ins_len && !p->keep_locks) { 2699eb653de1SFilipe David Borba Manana int u = level + 1; 2700eb653de1SFilipe David Borba Manana 2701eb653de1SFilipe David Borba Manana if (u < BTRFS_MAX_LEVEL && p->locks[u]) { 2702eb653de1SFilipe David Borba Manana btrfs_tree_unlock_rw(p->nodes[u], p->locks[u]); 2703eb653de1SFilipe David Borba Manana p->locks[u] = 0; 2704eb653de1SFilipe David Borba Manana } 2705eb653de1SFilipe David Borba Manana } 2706b4ce94deSChris Mason 2707995e9a16SNikolay Borisov /* 2708995e9a16SNikolay Borisov * If btrfs_bin_search returns an exact match (prev_cmp == 0) 2709995e9a16SNikolay Borisov * we can safely assume the target key will always be in slot 0 2710995e9a16SNikolay Borisov * on lower levels due to the invariants BTRFS' btree provides, 2711995e9a16SNikolay Borisov * namely that a btrfs_key_ptr entry always points to the 2712995e9a16SNikolay Borisov * lowest key in the child node, thus we can skip searching 2713995e9a16SNikolay Borisov * lower levels 2714995e9a16SNikolay Borisov */ 2715995e9a16SNikolay Borisov if (prev_cmp == 0) { 2716995e9a16SNikolay Borisov slot = 0; 2717995e9a16SNikolay Borisov ret = 0; 2718995e9a16SNikolay Borisov } else { 2719995e9a16SNikolay Borisov ret = btrfs_bin_search(b, key, &slot); 2720995e9a16SNikolay Borisov prev_cmp = ret; 2721415b35a5SLiu Bo if (ret < 0) 2722415b35a5SLiu Bo goto done; 2723995e9a16SNikolay Borisov } 2724b4ce94deSChris Mason 2725f624d976SQu Wenruo if (level == 0) { 2726be0e5c09SChris Mason p->slots[level] = slot; 27279a664971Sethanwu /* 27289a664971Sethanwu * Item key already exists. In this case, if we are 27299a664971Sethanwu * allowed to insert the item (for example, in dir_item 27309a664971Sethanwu * case, item key collision is allowed), it will be 27319a664971Sethanwu * merged with the original item. Only the item size 27329a664971Sethanwu * grows, no new btrfs item will be added. If 27339a664971Sethanwu * search_for_extension is not set, ins_len already 27349a664971Sethanwu * accounts the size btrfs_item, deduct it here so leaf 27359a664971Sethanwu * space check will be correct. 27369a664971Sethanwu */ 27379a664971Sethanwu if (ret == 0 && ins_len > 0 && !p->search_for_extension) { 27389a664971Sethanwu ASSERT(ins_len >= sizeof(struct btrfs_item)); 27399a664971Sethanwu ins_len -= sizeof(struct btrfs_item); 27409a664971Sethanwu } 274187b29b20SYan Zheng if (ins_len > 0 && 2742e902baacSDavid Sterba btrfs_leaf_free_space(b) < ins_len) { 2743bd681513SChris Mason if (write_lock_level < 1) { 2744bd681513SChris Mason write_lock_level = 1; 2745bd681513SChris Mason btrfs_release_path(p); 2746bd681513SChris Mason goto again; 2747bd681513SChris Mason } 2748bd681513SChris Mason 274933c66f43SYan Zheng err = split_leaf(trans, root, key, 2750cc0c5538SChris Mason p, ins_len, ret == 0); 2751b4ce94deSChris Mason 275233c66f43SYan Zheng BUG_ON(err > 0); 275333c66f43SYan Zheng if (err) { 275433c66f43SYan Zheng ret = err; 275565b51a00SChris Mason goto done; 275665b51a00SChris Mason } 27575c680ed6SChris Mason } 2758459931ecSChris Mason if (!p->search_for_split) 2759f7c79f30SChris Mason unlock_up(p, level, lowest_unlock, 27604b6f8e96SLiu Bo min_write_lock_level, NULL); 276165b51a00SChris Mason goto done; 276265b51a00SChris Mason } 2763f624d976SQu Wenruo if (ret && slot > 0) { 2764f624d976SQu Wenruo dec = 1; 2765f624d976SQu Wenruo slot--; 2766f624d976SQu Wenruo } 2767f624d976SQu Wenruo p->slots[level] = slot; 2768f624d976SQu Wenruo err = setup_nodes_for_search(trans, root, p, b, level, ins_len, 2769f624d976SQu Wenruo &write_lock_level); 2770f624d976SQu Wenruo if (err == -EAGAIN) 2771f624d976SQu Wenruo goto again; 2772f624d976SQu Wenruo if (err) { 2773f624d976SQu Wenruo ret = err; 2774f624d976SQu Wenruo goto done; 2775f624d976SQu Wenruo } 2776f624d976SQu Wenruo b = p->nodes[level]; 2777f624d976SQu Wenruo slot = p->slots[level]; 2778f624d976SQu Wenruo 2779f624d976SQu Wenruo /* 2780f624d976SQu Wenruo * Slot 0 is special, if we change the key we have to update 2781f624d976SQu Wenruo * the parent pointer which means we must have a write lock on 2782f624d976SQu Wenruo * the parent 2783f624d976SQu Wenruo */ 2784f624d976SQu Wenruo if (slot == 0 && ins_len && write_lock_level < level + 1) { 2785f624d976SQu Wenruo write_lock_level = level + 1; 2786f624d976SQu Wenruo btrfs_release_path(p); 2787f624d976SQu Wenruo goto again; 2788f624d976SQu Wenruo } 2789f624d976SQu Wenruo 2790f624d976SQu Wenruo unlock_up(p, level, lowest_unlock, min_write_lock_level, 2791f624d976SQu Wenruo &write_lock_level); 2792f624d976SQu Wenruo 2793f624d976SQu Wenruo if (level == lowest_level) { 2794f624d976SQu Wenruo if (dec) 2795f624d976SQu Wenruo p->slots[level]++; 2796f624d976SQu Wenruo goto done; 2797f624d976SQu Wenruo } 2798f624d976SQu Wenruo 2799f624d976SQu Wenruo err = read_block_for_search(root, p, &b, level, slot, key); 2800f624d976SQu Wenruo if (err == -EAGAIN) 2801f624d976SQu Wenruo goto again; 2802f624d976SQu Wenruo if (err) { 2803f624d976SQu Wenruo ret = err; 2804f624d976SQu Wenruo goto done; 2805f624d976SQu Wenruo } 2806f624d976SQu Wenruo 2807f624d976SQu Wenruo if (!p->skip_locking) { 2808f624d976SQu Wenruo level = btrfs_header_level(b); 2809f624d976SQu Wenruo if (level <= write_lock_level) { 2810f624d976SQu Wenruo btrfs_tree_lock(b); 2811f624d976SQu Wenruo p->locks[level] = BTRFS_WRITE_LOCK; 2812f624d976SQu Wenruo } else { 2813fe596ca3SJosef Bacik btrfs_tree_read_lock(b); 2814f624d976SQu Wenruo p->locks[level] = BTRFS_READ_LOCK; 2815f624d976SQu Wenruo } 2816f624d976SQu Wenruo p->nodes[level] = b; 2817f624d976SQu Wenruo } 281865b51a00SChris Mason } 281965b51a00SChris Mason ret = 1; 282065b51a00SChris Mason done: 28215f5bc6b1SFilipe Manana if (ret < 0 && !p->skip_release_on_error) 2822b3b4aa74SDavid Sterba btrfs_release_path(p); 2823be0e5c09SChris Mason return ret; 2824be0e5c09SChris Mason } 2825*f75e2b79SJosef Bacik ALLOW_ERROR_INJECTION(btrfs_search_slot, ERRNO); 2826be0e5c09SChris Mason 282774123bd7SChris Mason /* 28285d9e75c4SJan Schmidt * Like btrfs_search_slot, this looks for a key in the given tree. It uses the 28295d9e75c4SJan Schmidt * current state of the tree together with the operations recorded in the tree 28305d9e75c4SJan Schmidt * modification log to search for the key in a previous version of this tree, as 28315d9e75c4SJan Schmidt * denoted by the time_seq parameter. 28325d9e75c4SJan Schmidt * 28335d9e75c4SJan Schmidt * Naturally, there is no support for insert, delete or cow operations. 28345d9e75c4SJan Schmidt * 28355d9e75c4SJan Schmidt * The resulting path and return value will be set up as if we called 28365d9e75c4SJan Schmidt * btrfs_search_slot at that point in time with ins_len and cow both set to 0. 28375d9e75c4SJan Schmidt */ 2838310712b2SOmar Sandoval int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key, 28395d9e75c4SJan Schmidt struct btrfs_path *p, u64 time_seq) 28405d9e75c4SJan Schmidt { 28410b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 28425d9e75c4SJan Schmidt struct extent_buffer *b; 28435d9e75c4SJan Schmidt int slot; 28445d9e75c4SJan Schmidt int ret; 28455d9e75c4SJan Schmidt int err; 28465d9e75c4SJan Schmidt int level; 28475d9e75c4SJan Schmidt int lowest_unlock = 1; 28485d9e75c4SJan Schmidt u8 lowest_level = 0; 28495d9e75c4SJan Schmidt 28505d9e75c4SJan Schmidt lowest_level = p->lowest_level; 28515d9e75c4SJan Schmidt WARN_ON(p->nodes[0] != NULL); 28525d9e75c4SJan Schmidt 28535d9e75c4SJan Schmidt if (p->search_commit_root) { 28545d9e75c4SJan Schmidt BUG_ON(time_seq); 28555d9e75c4SJan Schmidt return btrfs_search_slot(NULL, root, key, p, 0, 0); 28565d9e75c4SJan Schmidt } 28575d9e75c4SJan Schmidt 28585d9e75c4SJan Schmidt again: 28595d9e75c4SJan Schmidt b = get_old_root(root, time_seq); 2860315bed43SNikolay Borisov if (!b) { 2861315bed43SNikolay Borisov ret = -EIO; 2862315bed43SNikolay Borisov goto done; 2863315bed43SNikolay Borisov } 28645d9e75c4SJan Schmidt level = btrfs_header_level(b); 28655d9e75c4SJan Schmidt p->locks[level] = BTRFS_READ_LOCK; 28665d9e75c4SJan Schmidt 28675d9e75c4SJan Schmidt while (b) { 2868abe9339dSQu Wenruo int dec = 0; 2869abe9339dSQu Wenruo 28705d9e75c4SJan Schmidt level = btrfs_header_level(b); 28715d9e75c4SJan Schmidt p->nodes[level] = b; 28725d9e75c4SJan Schmidt 28735d9e75c4SJan Schmidt /* 28745d9e75c4SJan Schmidt * we have a lock on b and as long as we aren't changing 28755d9e75c4SJan Schmidt * the tree, there is no way to for the items in b to change. 28765d9e75c4SJan Schmidt * It is safe to drop the lock on our parent before we 28775d9e75c4SJan Schmidt * go through the expensive btree search on b. 28785d9e75c4SJan Schmidt */ 28795d9e75c4SJan Schmidt btrfs_unlock_up_safe(p, level + 1); 28805d9e75c4SJan Schmidt 2881995e9a16SNikolay Borisov ret = btrfs_bin_search(b, key, &slot); 2882cbca7d59SFilipe Manana if (ret < 0) 2883cbca7d59SFilipe Manana goto done; 28845d9e75c4SJan Schmidt 2885abe9339dSQu Wenruo if (level == 0) { 2886abe9339dSQu Wenruo p->slots[level] = slot; 2887abe9339dSQu Wenruo unlock_up(p, level, lowest_unlock, 0, NULL); 2888abe9339dSQu Wenruo goto done; 2889abe9339dSQu Wenruo } 2890abe9339dSQu Wenruo 28915d9e75c4SJan Schmidt if (ret && slot > 0) { 28925d9e75c4SJan Schmidt dec = 1; 2893abe9339dSQu Wenruo slot--; 28945d9e75c4SJan Schmidt } 28955d9e75c4SJan Schmidt p->slots[level] = slot; 28965d9e75c4SJan Schmidt unlock_up(p, level, lowest_unlock, 0, NULL); 28975d9e75c4SJan Schmidt 28985d9e75c4SJan Schmidt if (level == lowest_level) { 28995d9e75c4SJan Schmidt if (dec) 29005d9e75c4SJan Schmidt p->slots[level]++; 29015d9e75c4SJan Schmidt goto done; 29025d9e75c4SJan Schmidt } 29035d9e75c4SJan Schmidt 2904abe9339dSQu Wenruo err = read_block_for_search(root, p, &b, level, slot, key); 29055d9e75c4SJan Schmidt if (err == -EAGAIN) 29065d9e75c4SJan Schmidt goto again; 29075d9e75c4SJan Schmidt if (err) { 29085d9e75c4SJan Schmidt ret = err; 29095d9e75c4SJan Schmidt goto done; 29105d9e75c4SJan Schmidt } 29115d9e75c4SJan Schmidt 29125d9e75c4SJan Schmidt level = btrfs_header_level(b); 29135d9e75c4SJan Schmidt btrfs_tree_read_lock(b); 29140b246afaSJeff Mahoney b = tree_mod_log_rewind(fs_info, p, b, time_seq); 2915db7f3436SJosef Bacik if (!b) { 2916db7f3436SJosef Bacik ret = -ENOMEM; 2917db7f3436SJosef Bacik goto done; 2918db7f3436SJosef Bacik } 29195d9e75c4SJan Schmidt p->locks[level] = BTRFS_READ_LOCK; 29205d9e75c4SJan Schmidt p->nodes[level] = b; 29215d9e75c4SJan Schmidt } 29225d9e75c4SJan Schmidt ret = 1; 29235d9e75c4SJan Schmidt done: 29245d9e75c4SJan Schmidt if (ret < 0) 29255d9e75c4SJan Schmidt btrfs_release_path(p); 29265d9e75c4SJan Schmidt 29275d9e75c4SJan Schmidt return ret; 29285d9e75c4SJan Schmidt } 29295d9e75c4SJan Schmidt 29305d9e75c4SJan Schmidt /* 29312f38b3e1SArne Jansen * helper to use instead of search slot if no exact match is needed but 29322f38b3e1SArne Jansen * instead the next or previous item should be returned. 29332f38b3e1SArne Jansen * When find_higher is true, the next higher item is returned, the next lower 29342f38b3e1SArne Jansen * otherwise. 29352f38b3e1SArne Jansen * When return_any and find_higher are both true, and no higher item is found, 29362f38b3e1SArne Jansen * return the next lower instead. 29372f38b3e1SArne Jansen * When return_any is true and find_higher is false, and no lower item is found, 29382f38b3e1SArne Jansen * return the next higher instead. 29392f38b3e1SArne Jansen * It returns 0 if any item is found, 1 if none is found (tree empty), and 29402f38b3e1SArne Jansen * < 0 on error 29412f38b3e1SArne Jansen */ 29422f38b3e1SArne Jansen int btrfs_search_slot_for_read(struct btrfs_root *root, 2943310712b2SOmar Sandoval const struct btrfs_key *key, 2944310712b2SOmar Sandoval struct btrfs_path *p, int find_higher, 2945310712b2SOmar Sandoval int return_any) 29462f38b3e1SArne Jansen { 29472f38b3e1SArne Jansen int ret; 29482f38b3e1SArne Jansen struct extent_buffer *leaf; 29492f38b3e1SArne Jansen 29502f38b3e1SArne Jansen again: 29512f38b3e1SArne Jansen ret = btrfs_search_slot(NULL, root, key, p, 0, 0); 29522f38b3e1SArne Jansen if (ret <= 0) 29532f38b3e1SArne Jansen return ret; 29542f38b3e1SArne Jansen /* 29552f38b3e1SArne Jansen * a return value of 1 means the path is at the position where the 29562f38b3e1SArne Jansen * item should be inserted. Normally this is the next bigger item, 29572f38b3e1SArne Jansen * but in case the previous item is the last in a leaf, path points 29582f38b3e1SArne Jansen * to the first free slot in the previous leaf, i.e. at an invalid 29592f38b3e1SArne Jansen * item. 29602f38b3e1SArne Jansen */ 29612f38b3e1SArne Jansen leaf = p->nodes[0]; 29622f38b3e1SArne Jansen 29632f38b3e1SArne Jansen if (find_higher) { 29642f38b3e1SArne Jansen if (p->slots[0] >= btrfs_header_nritems(leaf)) { 29652f38b3e1SArne Jansen ret = btrfs_next_leaf(root, p); 29662f38b3e1SArne Jansen if (ret <= 0) 29672f38b3e1SArne Jansen return ret; 29682f38b3e1SArne Jansen if (!return_any) 29692f38b3e1SArne Jansen return 1; 29702f38b3e1SArne Jansen /* 29712f38b3e1SArne Jansen * no higher item found, return the next 29722f38b3e1SArne Jansen * lower instead 29732f38b3e1SArne Jansen */ 29742f38b3e1SArne Jansen return_any = 0; 29752f38b3e1SArne Jansen find_higher = 0; 29762f38b3e1SArne Jansen btrfs_release_path(p); 29772f38b3e1SArne Jansen goto again; 29782f38b3e1SArne Jansen } 29792f38b3e1SArne Jansen } else { 29802f38b3e1SArne Jansen if (p->slots[0] == 0) { 29812f38b3e1SArne Jansen ret = btrfs_prev_leaf(root, p); 2982e6793769SArne Jansen if (ret < 0) 29832f38b3e1SArne Jansen return ret; 2984e6793769SArne Jansen if (!ret) { 298523c6bf6aSFilipe David Borba Manana leaf = p->nodes[0]; 298623c6bf6aSFilipe David Borba Manana if (p->slots[0] == btrfs_header_nritems(leaf)) 298723c6bf6aSFilipe David Borba Manana p->slots[0]--; 2988e6793769SArne Jansen return 0; 2989e6793769SArne Jansen } 29902f38b3e1SArne Jansen if (!return_any) 29912f38b3e1SArne Jansen return 1; 29922f38b3e1SArne Jansen /* 29932f38b3e1SArne Jansen * no lower item found, return the next 29942f38b3e1SArne Jansen * higher instead 29952f38b3e1SArne Jansen */ 29962f38b3e1SArne Jansen return_any = 0; 29972f38b3e1SArne Jansen find_higher = 1; 29982f38b3e1SArne Jansen btrfs_release_path(p); 29992f38b3e1SArne Jansen goto again; 3000e6793769SArne Jansen } else { 30012f38b3e1SArne Jansen --p->slots[0]; 30022f38b3e1SArne Jansen } 30032f38b3e1SArne Jansen } 30042f38b3e1SArne Jansen return 0; 30052f38b3e1SArne Jansen } 30062f38b3e1SArne Jansen 30072f38b3e1SArne Jansen /* 300874123bd7SChris Mason * adjust the pointers going up the tree, starting at level 300974123bd7SChris Mason * making sure the right key of each node is points to 'key'. 301074123bd7SChris Mason * This is used after shifting pointers to the left, so it stops 301174123bd7SChris Mason * fixing up pointers when a given leaf/node is not in slot 0 of the 301274123bd7SChris Mason * higher levels 3013aa5d6bedSChris Mason * 301474123bd7SChris Mason */ 3015b167fa91SNikolay Borisov static void fixup_low_keys(struct btrfs_path *path, 30165f39d397SChris Mason struct btrfs_disk_key *key, int level) 3017be0e5c09SChris Mason { 3018be0e5c09SChris Mason int i; 30195f39d397SChris Mason struct extent_buffer *t; 30200e82bcfeSDavid Sterba int ret; 30215f39d397SChris Mason 3022234b63a0SChris Mason for (i = level; i < BTRFS_MAX_LEVEL; i++) { 3023be0e5c09SChris Mason int tslot = path->slots[i]; 30240e82bcfeSDavid Sterba 3025eb60ceacSChris Mason if (!path->nodes[i]) 3026be0e5c09SChris Mason break; 30275f39d397SChris Mason t = path->nodes[i]; 30280e82bcfeSDavid Sterba ret = tree_mod_log_insert_key(t, tslot, MOD_LOG_KEY_REPLACE, 30290e82bcfeSDavid Sterba GFP_ATOMIC); 30300e82bcfeSDavid Sterba BUG_ON(ret < 0); 30315f39d397SChris Mason btrfs_set_node_key(t, key, tslot); 3032d6025579SChris Mason btrfs_mark_buffer_dirty(path->nodes[i]); 3033be0e5c09SChris Mason if (tslot != 0) 3034be0e5c09SChris Mason break; 3035be0e5c09SChris Mason } 3036be0e5c09SChris Mason } 3037be0e5c09SChris Mason 303874123bd7SChris Mason /* 303931840ae1SZheng Yan * update item key. 304031840ae1SZheng Yan * 304131840ae1SZheng Yan * This function isn't completely safe. It's the caller's responsibility 304231840ae1SZheng Yan * that the new key won't break the order 304331840ae1SZheng Yan */ 3044b7a0365eSDaniel Dressler void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info, 3045b7a0365eSDaniel Dressler struct btrfs_path *path, 3046310712b2SOmar Sandoval const struct btrfs_key *new_key) 304731840ae1SZheng Yan { 304831840ae1SZheng Yan struct btrfs_disk_key disk_key; 304931840ae1SZheng Yan struct extent_buffer *eb; 305031840ae1SZheng Yan int slot; 305131840ae1SZheng Yan 305231840ae1SZheng Yan eb = path->nodes[0]; 305331840ae1SZheng Yan slot = path->slots[0]; 305431840ae1SZheng Yan if (slot > 0) { 305531840ae1SZheng Yan btrfs_item_key(eb, &disk_key, slot - 1); 30567c15d410SQu Wenruo if (unlikely(comp_keys(&disk_key, new_key) >= 0)) { 30577c15d410SQu Wenruo btrfs_crit(fs_info, 30587c15d410SQu Wenruo "slot %u key (%llu %u %llu) new key (%llu %u %llu)", 30597c15d410SQu Wenruo slot, btrfs_disk_key_objectid(&disk_key), 30607c15d410SQu Wenruo btrfs_disk_key_type(&disk_key), 30617c15d410SQu Wenruo btrfs_disk_key_offset(&disk_key), 30627c15d410SQu Wenruo new_key->objectid, new_key->type, 30637c15d410SQu Wenruo new_key->offset); 30647c15d410SQu Wenruo btrfs_print_leaf(eb); 30657c15d410SQu Wenruo BUG(); 30667c15d410SQu Wenruo } 306731840ae1SZheng Yan } 306831840ae1SZheng Yan if (slot < btrfs_header_nritems(eb) - 1) { 306931840ae1SZheng Yan btrfs_item_key(eb, &disk_key, slot + 1); 30707c15d410SQu Wenruo if (unlikely(comp_keys(&disk_key, new_key) <= 0)) { 30717c15d410SQu Wenruo btrfs_crit(fs_info, 30727c15d410SQu Wenruo "slot %u key (%llu %u %llu) new key (%llu %u %llu)", 30737c15d410SQu Wenruo slot, btrfs_disk_key_objectid(&disk_key), 30747c15d410SQu Wenruo btrfs_disk_key_type(&disk_key), 30757c15d410SQu Wenruo btrfs_disk_key_offset(&disk_key), 30767c15d410SQu Wenruo new_key->objectid, new_key->type, 30777c15d410SQu Wenruo new_key->offset); 30787c15d410SQu Wenruo btrfs_print_leaf(eb); 30797c15d410SQu Wenruo BUG(); 30807c15d410SQu Wenruo } 308131840ae1SZheng Yan } 308231840ae1SZheng Yan 308331840ae1SZheng Yan btrfs_cpu_key_to_disk(&disk_key, new_key); 308431840ae1SZheng Yan btrfs_set_item_key(eb, &disk_key, slot); 308531840ae1SZheng Yan btrfs_mark_buffer_dirty(eb); 308631840ae1SZheng Yan if (slot == 0) 3087b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 308831840ae1SZheng Yan } 308931840ae1SZheng Yan 309031840ae1SZheng Yan /* 3091d16c702fSQu Wenruo * Check key order of two sibling extent buffers. 3092d16c702fSQu Wenruo * 3093d16c702fSQu Wenruo * Return true if something is wrong. 3094d16c702fSQu Wenruo * Return false if everything is fine. 3095d16c702fSQu Wenruo * 3096d16c702fSQu Wenruo * Tree-checker only works inside one tree block, thus the following 3097d16c702fSQu Wenruo * corruption can not be detected by tree-checker: 3098d16c702fSQu Wenruo * 3099d16c702fSQu Wenruo * Leaf @left | Leaf @right 3100d16c702fSQu Wenruo * -------------------------------------------------------------- 3101d16c702fSQu Wenruo * | 1 | 2 | 3 | 4 | 5 | f6 | | 7 | 8 | 3102d16c702fSQu Wenruo * 3103d16c702fSQu Wenruo * Key f6 in leaf @left itself is valid, but not valid when the next 3104d16c702fSQu Wenruo * key in leaf @right is 7. 3105d16c702fSQu Wenruo * This can only be checked at tree block merge time. 3106d16c702fSQu Wenruo * And since tree checker has ensured all key order in each tree block 3107d16c702fSQu Wenruo * is correct, we only need to bother the last key of @left and the first 3108d16c702fSQu Wenruo * key of @right. 3109d16c702fSQu Wenruo */ 3110d16c702fSQu Wenruo static bool check_sibling_keys(struct extent_buffer *left, 3111d16c702fSQu Wenruo struct extent_buffer *right) 3112d16c702fSQu Wenruo { 3113d16c702fSQu Wenruo struct btrfs_key left_last; 3114d16c702fSQu Wenruo struct btrfs_key right_first; 3115d16c702fSQu Wenruo int level = btrfs_header_level(left); 3116d16c702fSQu Wenruo int nr_left = btrfs_header_nritems(left); 3117d16c702fSQu Wenruo int nr_right = btrfs_header_nritems(right); 3118d16c702fSQu Wenruo 3119d16c702fSQu Wenruo /* No key to check in one of the tree blocks */ 3120d16c702fSQu Wenruo if (!nr_left || !nr_right) 3121d16c702fSQu Wenruo return false; 3122d16c702fSQu Wenruo 3123d16c702fSQu Wenruo if (level) { 3124d16c702fSQu Wenruo btrfs_node_key_to_cpu(left, &left_last, nr_left - 1); 3125d16c702fSQu Wenruo btrfs_node_key_to_cpu(right, &right_first, 0); 3126d16c702fSQu Wenruo } else { 3127d16c702fSQu Wenruo btrfs_item_key_to_cpu(left, &left_last, nr_left - 1); 3128d16c702fSQu Wenruo btrfs_item_key_to_cpu(right, &right_first, 0); 3129d16c702fSQu Wenruo } 3130d16c702fSQu Wenruo 3131d16c702fSQu Wenruo if (btrfs_comp_cpu_keys(&left_last, &right_first) >= 0) { 3132d16c702fSQu Wenruo btrfs_crit(left->fs_info, 3133d16c702fSQu Wenruo "bad key order, sibling blocks, left last (%llu %u %llu) right first (%llu %u %llu)", 3134d16c702fSQu Wenruo left_last.objectid, left_last.type, 3135d16c702fSQu Wenruo left_last.offset, right_first.objectid, 3136d16c702fSQu Wenruo right_first.type, right_first.offset); 3137d16c702fSQu Wenruo return true; 3138d16c702fSQu Wenruo } 3139d16c702fSQu Wenruo return false; 3140d16c702fSQu Wenruo } 3141d16c702fSQu Wenruo 3142d16c702fSQu Wenruo /* 314374123bd7SChris Mason * try to push data from one node into the next node left in the 314479f95c82SChris Mason * tree. 3145aa5d6bedSChris Mason * 3146aa5d6bedSChris Mason * returns 0 if some ptrs were pushed left, < 0 if there was some horrible 3147aa5d6bedSChris Mason * error, and > 0 if there was no room in the left hand block. 314874123bd7SChris Mason */ 314998ed5174SChris Mason static int push_node_left(struct btrfs_trans_handle *trans, 31502ff7e61eSJeff Mahoney struct extent_buffer *dst, 3151971a1f66SChris Mason struct extent_buffer *src, int empty) 3152be0e5c09SChris Mason { 3153d30a668fSDavid Sterba struct btrfs_fs_info *fs_info = trans->fs_info; 3154be0e5c09SChris Mason int push_items = 0; 3155bb803951SChris Mason int src_nritems; 3156bb803951SChris Mason int dst_nritems; 3157aa5d6bedSChris Mason int ret = 0; 3158be0e5c09SChris Mason 31595f39d397SChris Mason src_nritems = btrfs_header_nritems(src); 31605f39d397SChris Mason dst_nritems = btrfs_header_nritems(dst); 31610b246afaSJeff Mahoney push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; 31627bb86316SChris Mason WARN_ON(btrfs_header_generation(src) != trans->transid); 31637bb86316SChris Mason WARN_ON(btrfs_header_generation(dst) != trans->transid); 316454aa1f4dSChris Mason 3165bce4eae9SChris Mason if (!empty && src_nritems <= 8) 3166971a1f66SChris Mason return 1; 3167971a1f66SChris Mason 3168d397712bSChris Mason if (push_items <= 0) 3169be0e5c09SChris Mason return 1; 3170be0e5c09SChris Mason 3171bce4eae9SChris Mason if (empty) { 3172971a1f66SChris Mason push_items = min(src_nritems, push_items); 3173bce4eae9SChris Mason if (push_items < src_nritems) { 3174bce4eae9SChris Mason /* leave at least 8 pointers in the node if 3175bce4eae9SChris Mason * we aren't going to empty it 3176bce4eae9SChris Mason */ 3177bce4eae9SChris Mason if (src_nritems - push_items < 8) { 3178bce4eae9SChris Mason if (push_items <= 8) 3179bce4eae9SChris Mason return 1; 3180bce4eae9SChris Mason push_items -= 8; 3181bce4eae9SChris Mason } 3182bce4eae9SChris Mason } 3183bce4eae9SChris Mason } else 3184bce4eae9SChris Mason push_items = min(src_nritems - 8, push_items); 318579f95c82SChris Mason 3186d16c702fSQu Wenruo /* dst is the left eb, src is the middle eb */ 3187d16c702fSQu Wenruo if (check_sibling_keys(dst, src)) { 3188d16c702fSQu Wenruo ret = -EUCLEAN; 3189d16c702fSQu Wenruo btrfs_abort_transaction(trans, ret); 3190d16c702fSQu Wenruo return ret; 3191d16c702fSQu Wenruo } 3192ed874f0dSDavid Sterba ret = tree_mod_log_eb_copy(dst, src, dst_nritems, 0, push_items); 31935de865eeSFilipe David Borba Manana if (ret) { 319466642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 31955de865eeSFilipe David Borba Manana return ret; 31965de865eeSFilipe David Borba Manana } 31975f39d397SChris Mason copy_extent_buffer(dst, src, 31985f39d397SChris Mason btrfs_node_key_ptr_offset(dst_nritems), 31995f39d397SChris Mason btrfs_node_key_ptr_offset(0), 3200123abc88SChris Mason push_items * sizeof(struct btrfs_key_ptr)); 32015f39d397SChris Mason 3202bb803951SChris Mason if (push_items < src_nritems) { 320357911b8bSJan Schmidt /* 3204bf1d3425SDavid Sterba * Don't call tree_mod_log_insert_move here, key removal was 3205bf1d3425SDavid Sterba * already fully logged by tree_mod_log_eb_copy above. 320657911b8bSJan Schmidt */ 32075f39d397SChris Mason memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), 32085f39d397SChris Mason btrfs_node_key_ptr_offset(push_items), 3209e2fa7227SChris Mason (src_nritems - push_items) * 3210123abc88SChris Mason sizeof(struct btrfs_key_ptr)); 3211bb803951SChris Mason } 32125f39d397SChris Mason btrfs_set_header_nritems(src, src_nritems - push_items); 32135f39d397SChris Mason btrfs_set_header_nritems(dst, dst_nritems + push_items); 32145f39d397SChris Mason btrfs_mark_buffer_dirty(src); 32155f39d397SChris Mason btrfs_mark_buffer_dirty(dst); 321631840ae1SZheng Yan 3217bb803951SChris Mason return ret; 3218be0e5c09SChris Mason } 3219be0e5c09SChris Mason 322097571fd0SChris Mason /* 322179f95c82SChris Mason * try to push data from one node into the next node right in the 322279f95c82SChris Mason * tree. 322379f95c82SChris Mason * 322479f95c82SChris Mason * returns 0 if some ptrs were pushed, < 0 if there was some horrible 322579f95c82SChris Mason * error, and > 0 if there was no room in the right hand block. 322679f95c82SChris Mason * 322779f95c82SChris Mason * this will only push up to 1/2 the contents of the left node over 322879f95c82SChris Mason */ 32295f39d397SChris Mason static int balance_node_right(struct btrfs_trans_handle *trans, 32305f39d397SChris Mason struct extent_buffer *dst, 32315f39d397SChris Mason struct extent_buffer *src) 323279f95c82SChris Mason { 323355d32ed8SDavid Sterba struct btrfs_fs_info *fs_info = trans->fs_info; 323479f95c82SChris Mason int push_items = 0; 323579f95c82SChris Mason int max_push; 323679f95c82SChris Mason int src_nritems; 323779f95c82SChris Mason int dst_nritems; 323879f95c82SChris Mason int ret = 0; 323979f95c82SChris Mason 32407bb86316SChris Mason WARN_ON(btrfs_header_generation(src) != trans->transid); 32417bb86316SChris Mason WARN_ON(btrfs_header_generation(dst) != trans->transid); 32427bb86316SChris Mason 32435f39d397SChris Mason src_nritems = btrfs_header_nritems(src); 32445f39d397SChris Mason dst_nritems = btrfs_header_nritems(dst); 32450b246afaSJeff Mahoney push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; 3246d397712bSChris Mason if (push_items <= 0) 324779f95c82SChris Mason return 1; 3248bce4eae9SChris Mason 3249d397712bSChris Mason if (src_nritems < 4) 3250bce4eae9SChris Mason return 1; 325179f95c82SChris Mason 325279f95c82SChris Mason max_push = src_nritems / 2 + 1; 325379f95c82SChris Mason /* don't try to empty the node */ 3254d397712bSChris Mason if (max_push >= src_nritems) 325579f95c82SChris Mason return 1; 3256252c38f0SYan 325779f95c82SChris Mason if (max_push < push_items) 325879f95c82SChris Mason push_items = max_push; 325979f95c82SChris Mason 3260d16c702fSQu Wenruo /* dst is the right eb, src is the middle eb */ 3261d16c702fSQu Wenruo if (check_sibling_keys(src, dst)) { 3262d16c702fSQu Wenruo ret = -EUCLEAN; 3263d16c702fSQu Wenruo btrfs_abort_transaction(trans, ret); 3264d16c702fSQu Wenruo return ret; 3265d16c702fSQu Wenruo } 3266bf1d3425SDavid Sterba ret = tree_mod_log_insert_move(dst, push_items, 0, dst_nritems); 3267bf1d3425SDavid Sterba BUG_ON(ret < 0); 32685f39d397SChris Mason memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), 32695f39d397SChris Mason btrfs_node_key_ptr_offset(0), 32705f39d397SChris Mason (dst_nritems) * 32715f39d397SChris Mason sizeof(struct btrfs_key_ptr)); 3272d6025579SChris Mason 3273ed874f0dSDavid Sterba ret = tree_mod_log_eb_copy(dst, src, 0, src_nritems - push_items, 3274ed874f0dSDavid Sterba push_items); 32755de865eeSFilipe David Borba Manana if (ret) { 327666642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 32775de865eeSFilipe David Borba Manana return ret; 32785de865eeSFilipe David Borba Manana } 32795f39d397SChris Mason copy_extent_buffer(dst, src, 32805f39d397SChris Mason btrfs_node_key_ptr_offset(0), 32815f39d397SChris Mason btrfs_node_key_ptr_offset(src_nritems - push_items), 3282123abc88SChris Mason push_items * sizeof(struct btrfs_key_ptr)); 328379f95c82SChris Mason 32845f39d397SChris Mason btrfs_set_header_nritems(src, src_nritems - push_items); 32855f39d397SChris Mason btrfs_set_header_nritems(dst, dst_nritems + push_items); 328679f95c82SChris Mason 32875f39d397SChris Mason btrfs_mark_buffer_dirty(src); 32885f39d397SChris Mason btrfs_mark_buffer_dirty(dst); 328931840ae1SZheng Yan 329079f95c82SChris Mason return ret; 329179f95c82SChris Mason } 329279f95c82SChris Mason 329379f95c82SChris Mason /* 329497571fd0SChris Mason * helper function to insert a new root level in the tree. 329597571fd0SChris Mason * A new node is allocated, and a single item is inserted to 329697571fd0SChris Mason * point to the existing root 3297aa5d6bedSChris Mason * 3298aa5d6bedSChris Mason * returns zero on success or < 0 on failure. 329997571fd0SChris Mason */ 3300d397712bSChris Mason static noinline int insert_new_root(struct btrfs_trans_handle *trans, 33015f39d397SChris Mason struct btrfs_root *root, 3302fdd99c72SLiu Bo struct btrfs_path *path, int level) 330374123bd7SChris Mason { 33040b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 33057bb86316SChris Mason u64 lower_gen; 33065f39d397SChris Mason struct extent_buffer *lower; 33075f39d397SChris Mason struct extent_buffer *c; 3308925baeddSChris Mason struct extent_buffer *old; 33095f39d397SChris Mason struct btrfs_disk_key lower_key; 3310d9d19a01SDavid Sterba int ret; 33115c680ed6SChris Mason 33125c680ed6SChris Mason BUG_ON(path->nodes[level]); 33135c680ed6SChris Mason BUG_ON(path->nodes[level-1] != root->node); 33145c680ed6SChris Mason 33157bb86316SChris Mason lower = path->nodes[level-1]; 33167bb86316SChris Mason if (level == 1) 33177bb86316SChris Mason btrfs_item_key(lower, &lower_key, 0); 33187bb86316SChris Mason else 33197bb86316SChris Mason btrfs_node_key(lower, &lower_key, 0); 33207bb86316SChris Mason 3321a6279470SFilipe Manana c = alloc_tree_block_no_bg_flush(trans, root, 0, &lower_key, level, 33229631e4ccSJosef Bacik root->node->start, 0, 3323cf6f34aaSJosef Bacik BTRFS_NESTING_NEW_ROOT); 33245f39d397SChris Mason if (IS_ERR(c)) 33255f39d397SChris Mason return PTR_ERR(c); 3326925baeddSChris Mason 33270b246afaSJeff Mahoney root_add_used(root, fs_info->nodesize); 3328f0486c68SYan, Zheng 33295f39d397SChris Mason btrfs_set_header_nritems(c, 1); 33305f39d397SChris Mason btrfs_set_node_key(c, &lower_key, 0); 3331db94535dSChris Mason btrfs_set_node_blockptr(c, 0, lower->start); 33327bb86316SChris Mason lower_gen = btrfs_header_generation(lower); 333331840ae1SZheng Yan WARN_ON(lower_gen != trans->transid); 33347bb86316SChris Mason 33357bb86316SChris Mason btrfs_set_node_ptr_generation(c, 0, lower_gen); 33365f39d397SChris Mason 33375f39d397SChris Mason btrfs_mark_buffer_dirty(c); 3338d5719762SChris Mason 3339925baeddSChris Mason old = root->node; 3340d9d19a01SDavid Sterba ret = tree_mod_log_insert_root(root->node, c, 0); 3341d9d19a01SDavid Sterba BUG_ON(ret < 0); 3342240f62c8SChris Mason rcu_assign_pointer(root->node, c); 3343925baeddSChris Mason 3344925baeddSChris Mason /* the super has an extra ref to root->node */ 3345925baeddSChris Mason free_extent_buffer(old); 3346925baeddSChris Mason 33470b86a832SChris Mason add_root_to_dirty_list(root); 334867439dadSDavid Sterba atomic_inc(&c->refs); 33495f39d397SChris Mason path->nodes[level] = c; 3350ac5887c8SJosef Bacik path->locks[level] = BTRFS_WRITE_LOCK; 335174123bd7SChris Mason path->slots[level] = 0; 335274123bd7SChris Mason return 0; 335374123bd7SChris Mason } 33545c680ed6SChris Mason 33555c680ed6SChris Mason /* 33565c680ed6SChris Mason * worker function to insert a single pointer in a node. 33575c680ed6SChris Mason * the node should have enough room for the pointer already 335897571fd0SChris Mason * 33595c680ed6SChris Mason * slot and level indicate where you want the key to go, and 33605c680ed6SChris Mason * blocknr is the block the key points to. 33615c680ed6SChris Mason */ 3362143bede5SJeff Mahoney static void insert_ptr(struct btrfs_trans_handle *trans, 33636ad3cf6dSDavid Sterba struct btrfs_path *path, 3364143bede5SJeff Mahoney struct btrfs_disk_key *key, u64 bytenr, 3365c3e06965SJan Schmidt int slot, int level) 33665c680ed6SChris Mason { 33675f39d397SChris Mason struct extent_buffer *lower; 33685c680ed6SChris Mason int nritems; 3369f3ea38daSJan Schmidt int ret; 33705c680ed6SChris Mason 33715c680ed6SChris Mason BUG_ON(!path->nodes[level]); 3372f0486c68SYan, Zheng btrfs_assert_tree_locked(path->nodes[level]); 33735f39d397SChris Mason lower = path->nodes[level]; 33745f39d397SChris Mason nritems = btrfs_header_nritems(lower); 3375c293498bSStoyan Gaydarov BUG_ON(slot > nritems); 33766ad3cf6dSDavid Sterba BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(trans->fs_info)); 337774123bd7SChris Mason if (slot != nritems) { 3378bf1d3425SDavid Sterba if (level) { 3379bf1d3425SDavid Sterba ret = tree_mod_log_insert_move(lower, slot + 1, slot, 3380a446a979SDavid Sterba nritems - slot); 3381bf1d3425SDavid Sterba BUG_ON(ret < 0); 3382bf1d3425SDavid Sterba } 33835f39d397SChris Mason memmove_extent_buffer(lower, 33845f39d397SChris Mason btrfs_node_key_ptr_offset(slot + 1), 33855f39d397SChris Mason btrfs_node_key_ptr_offset(slot), 3386123abc88SChris Mason (nritems - slot) * sizeof(struct btrfs_key_ptr)); 338774123bd7SChris Mason } 3388c3e06965SJan Schmidt if (level) { 3389e09c2efeSDavid Sterba ret = tree_mod_log_insert_key(lower, slot, MOD_LOG_KEY_ADD, 3390e09c2efeSDavid Sterba GFP_NOFS); 3391f3ea38daSJan Schmidt BUG_ON(ret < 0); 3392f3ea38daSJan Schmidt } 33935f39d397SChris Mason btrfs_set_node_key(lower, key, slot); 3394db94535dSChris Mason btrfs_set_node_blockptr(lower, slot, bytenr); 339574493f7aSChris Mason WARN_ON(trans->transid == 0); 339674493f7aSChris Mason btrfs_set_node_ptr_generation(lower, slot, trans->transid); 33975f39d397SChris Mason btrfs_set_header_nritems(lower, nritems + 1); 33985f39d397SChris Mason btrfs_mark_buffer_dirty(lower); 339974123bd7SChris Mason } 340074123bd7SChris Mason 340197571fd0SChris Mason /* 340297571fd0SChris Mason * split the node at the specified level in path in two. 340397571fd0SChris Mason * The path is corrected to point to the appropriate node after the split 340497571fd0SChris Mason * 340597571fd0SChris Mason * Before splitting this tries to make some room in the node by pushing 340697571fd0SChris Mason * left and right, if either one works, it returns right away. 3407aa5d6bedSChris Mason * 3408aa5d6bedSChris Mason * returns 0 on success and < 0 on failure 340997571fd0SChris Mason */ 3410e02119d5SChris Mason static noinline int split_node(struct btrfs_trans_handle *trans, 3411e02119d5SChris Mason struct btrfs_root *root, 3412e02119d5SChris Mason struct btrfs_path *path, int level) 3413be0e5c09SChris Mason { 34140b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 34155f39d397SChris Mason struct extent_buffer *c; 34165f39d397SChris Mason struct extent_buffer *split; 34175f39d397SChris Mason struct btrfs_disk_key disk_key; 3418be0e5c09SChris Mason int mid; 34195c680ed6SChris Mason int ret; 34207518a238SChris Mason u32 c_nritems; 3421be0e5c09SChris Mason 34225f39d397SChris Mason c = path->nodes[level]; 34237bb86316SChris Mason WARN_ON(btrfs_header_generation(c) != trans->transid); 34245f39d397SChris Mason if (c == root->node) { 3425d9abbf1cSJan Schmidt /* 342690f8d62eSJan Schmidt * trying to split the root, lets make a new one 342790f8d62eSJan Schmidt * 3428fdd99c72SLiu Bo * tree mod log: We don't log_removal old root in 342990f8d62eSJan Schmidt * insert_new_root, because that root buffer will be kept as a 343090f8d62eSJan Schmidt * normal node. We are going to log removal of half of the 343190f8d62eSJan Schmidt * elements below with tree_mod_log_eb_copy. We're holding a 343290f8d62eSJan Schmidt * tree lock on the buffer, which is why we cannot race with 343390f8d62eSJan Schmidt * other tree_mod_log users. 3434d9abbf1cSJan Schmidt */ 3435fdd99c72SLiu Bo ret = insert_new_root(trans, root, path, level + 1); 34365c680ed6SChris Mason if (ret) 34375c680ed6SChris Mason return ret; 3438b3612421SChris Mason } else { 3439e66f709bSChris Mason ret = push_nodes_for_insert(trans, root, path, level); 34405f39d397SChris Mason c = path->nodes[level]; 34415f39d397SChris Mason if (!ret && btrfs_header_nritems(c) < 34420b246afaSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) 3443e66f709bSChris Mason return 0; 344454aa1f4dSChris Mason if (ret < 0) 344554aa1f4dSChris Mason return ret; 34465c680ed6SChris Mason } 3447e66f709bSChris Mason 34485f39d397SChris Mason c_nritems = btrfs_header_nritems(c); 34495d4f98a2SYan Zheng mid = (c_nritems + 1) / 2; 34505d4f98a2SYan Zheng btrfs_node_key(c, &disk_key, mid); 34517bb86316SChris Mason 3452a6279470SFilipe Manana split = alloc_tree_block_no_bg_flush(trans, root, 0, &disk_key, level, 34534dff97e6SJosef Bacik c->start, 0, BTRFS_NESTING_SPLIT); 34545f39d397SChris Mason if (IS_ERR(split)) 34555f39d397SChris Mason return PTR_ERR(split); 345654aa1f4dSChris Mason 34570b246afaSJeff Mahoney root_add_used(root, fs_info->nodesize); 3458bc877d28SNikolay Borisov ASSERT(btrfs_header_level(c) == level); 34595f39d397SChris Mason 3460ed874f0dSDavid Sterba ret = tree_mod_log_eb_copy(split, c, 0, mid, c_nritems - mid); 34615de865eeSFilipe David Borba Manana if (ret) { 346266642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 34635de865eeSFilipe David Borba Manana return ret; 34645de865eeSFilipe David Borba Manana } 34655f39d397SChris Mason copy_extent_buffer(split, c, 34665f39d397SChris Mason btrfs_node_key_ptr_offset(0), 34675f39d397SChris Mason btrfs_node_key_ptr_offset(mid), 3468123abc88SChris Mason (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); 34695f39d397SChris Mason btrfs_set_header_nritems(split, c_nritems - mid); 34705f39d397SChris Mason btrfs_set_header_nritems(c, mid); 3471aa5d6bedSChris Mason 34725f39d397SChris Mason btrfs_mark_buffer_dirty(c); 34735f39d397SChris Mason btrfs_mark_buffer_dirty(split); 34745f39d397SChris Mason 34756ad3cf6dSDavid Sterba insert_ptr(trans, path, &disk_key, split->start, 3476c3e06965SJan Schmidt path->slots[level + 1] + 1, level + 1); 3477aa5d6bedSChris Mason 34785de08d7dSChris Mason if (path->slots[level] >= mid) { 34795c680ed6SChris Mason path->slots[level] -= mid; 3480925baeddSChris Mason btrfs_tree_unlock(c); 34815f39d397SChris Mason free_extent_buffer(c); 34825f39d397SChris Mason path->nodes[level] = split; 34835c680ed6SChris Mason path->slots[level + 1] += 1; 3484eb60ceacSChris Mason } else { 3485925baeddSChris Mason btrfs_tree_unlock(split); 34865f39d397SChris Mason free_extent_buffer(split); 3487be0e5c09SChris Mason } 3488d5286a92SNikolay Borisov return 0; 3489be0e5c09SChris Mason } 3490be0e5c09SChris Mason 349174123bd7SChris Mason /* 349274123bd7SChris Mason * how many bytes are required to store the items in a leaf. start 349374123bd7SChris Mason * and nr indicate which items in the leaf to check. This totals up the 349474123bd7SChris Mason * space used both by the item structs and the item data 349574123bd7SChris Mason */ 34965f39d397SChris Mason static int leaf_space_used(struct extent_buffer *l, int start, int nr) 3497be0e5c09SChris Mason { 349841be1f3bSJosef Bacik struct btrfs_item *start_item; 349941be1f3bSJosef Bacik struct btrfs_item *end_item; 3500be0e5c09SChris Mason int data_len; 35015f39d397SChris Mason int nritems = btrfs_header_nritems(l); 3502d4dbff95SChris Mason int end = min(nritems, start + nr) - 1; 3503be0e5c09SChris Mason 3504be0e5c09SChris Mason if (!nr) 3505be0e5c09SChris Mason return 0; 3506dd3cc16bSRoss Kirk start_item = btrfs_item_nr(start); 3507dd3cc16bSRoss Kirk end_item = btrfs_item_nr(end); 3508a31356b9SDavid Sterba data_len = btrfs_item_offset(l, start_item) + 3509a31356b9SDavid Sterba btrfs_item_size(l, start_item); 3510a31356b9SDavid Sterba data_len = data_len - btrfs_item_offset(l, end_item); 35110783fcfcSChris Mason data_len += sizeof(struct btrfs_item) * nr; 3512d4dbff95SChris Mason WARN_ON(data_len < 0); 3513be0e5c09SChris Mason return data_len; 3514be0e5c09SChris Mason } 3515be0e5c09SChris Mason 351674123bd7SChris Mason /* 3517d4dbff95SChris Mason * The space between the end of the leaf items and 3518d4dbff95SChris Mason * the start of the leaf data. IOW, how much room 3519d4dbff95SChris Mason * the leaf has left for both items and data 3520d4dbff95SChris Mason */ 3521e902baacSDavid Sterba noinline int btrfs_leaf_free_space(struct extent_buffer *leaf) 3522d4dbff95SChris Mason { 3523e902baacSDavid Sterba struct btrfs_fs_info *fs_info = leaf->fs_info; 35245f39d397SChris Mason int nritems = btrfs_header_nritems(leaf); 35255f39d397SChris Mason int ret; 35260b246afaSJeff Mahoney 35270b246afaSJeff Mahoney ret = BTRFS_LEAF_DATA_SIZE(fs_info) - leaf_space_used(leaf, 0, nritems); 35285f39d397SChris Mason if (ret < 0) { 35290b246afaSJeff Mahoney btrfs_crit(fs_info, 3530efe120a0SFrank Holton "leaf free space ret %d, leaf data size %lu, used %d nritems %d", 3531da17066cSJeff Mahoney ret, 35320b246afaSJeff Mahoney (unsigned long) BTRFS_LEAF_DATA_SIZE(fs_info), 35335f39d397SChris Mason leaf_space_used(leaf, 0, nritems), nritems); 35345f39d397SChris Mason } 35355f39d397SChris Mason return ret; 3536d4dbff95SChris Mason } 3537d4dbff95SChris Mason 353899d8f83cSChris Mason /* 353999d8f83cSChris Mason * min slot controls the lowest index we're willing to push to the 354099d8f83cSChris Mason * right. We'll push up to and including min_slot, but no lower 354199d8f83cSChris Mason */ 3542f72f0010SDavid Sterba static noinline int __push_leaf_right(struct btrfs_path *path, 354344871b1bSChris Mason int data_size, int empty, 354444871b1bSChris Mason struct extent_buffer *right, 354599d8f83cSChris Mason int free_space, u32 left_nritems, 354699d8f83cSChris Mason u32 min_slot) 354700ec4c51SChris Mason { 3548f72f0010SDavid Sterba struct btrfs_fs_info *fs_info = right->fs_info; 35495f39d397SChris Mason struct extent_buffer *left = path->nodes[0]; 355044871b1bSChris Mason struct extent_buffer *upper = path->nodes[1]; 3551cfed81a0SChris Mason struct btrfs_map_token token; 35525f39d397SChris Mason struct btrfs_disk_key disk_key; 355300ec4c51SChris Mason int slot; 355434a38218SChris Mason u32 i; 355500ec4c51SChris Mason int push_space = 0; 355600ec4c51SChris Mason int push_items = 0; 35570783fcfcSChris Mason struct btrfs_item *item; 355834a38218SChris Mason u32 nr; 35597518a238SChris Mason u32 right_nritems; 35605f39d397SChris Mason u32 data_end; 3561db94535dSChris Mason u32 this_item_size; 356200ec4c51SChris Mason 356334a38218SChris Mason if (empty) 356434a38218SChris Mason nr = 0; 356534a38218SChris Mason else 356699d8f83cSChris Mason nr = max_t(u32, 1, min_slot); 356734a38218SChris Mason 356831840ae1SZheng Yan if (path->slots[0] >= left_nritems) 356987b29b20SYan Zheng push_space += data_size; 357031840ae1SZheng Yan 357144871b1bSChris Mason slot = path->slots[1]; 357234a38218SChris Mason i = left_nritems - 1; 357334a38218SChris Mason while (i >= nr) { 3574dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 3575db94535dSChris Mason 357631840ae1SZheng Yan if (!empty && push_items > 0) { 357731840ae1SZheng Yan if (path->slots[0] > i) 357831840ae1SZheng Yan break; 357931840ae1SZheng Yan if (path->slots[0] == i) { 3580e902baacSDavid Sterba int space = btrfs_leaf_free_space(left); 3581e902baacSDavid Sterba 358231840ae1SZheng Yan if (space + push_space * 2 > free_space) 358331840ae1SZheng Yan break; 358431840ae1SZheng Yan } 358531840ae1SZheng Yan } 358631840ae1SZheng Yan 358700ec4c51SChris Mason if (path->slots[0] == i) 358887b29b20SYan Zheng push_space += data_size; 3589db94535dSChris Mason 3590db94535dSChris Mason this_item_size = btrfs_item_size(left, item); 3591db94535dSChris Mason if (this_item_size + sizeof(*item) + push_space > free_space) 359200ec4c51SChris Mason break; 359331840ae1SZheng Yan 359400ec4c51SChris Mason push_items++; 3595db94535dSChris Mason push_space += this_item_size + sizeof(*item); 359634a38218SChris Mason if (i == 0) 359734a38218SChris Mason break; 359834a38218SChris Mason i--; 3599db94535dSChris Mason } 36005f39d397SChris Mason 3601925baeddSChris Mason if (push_items == 0) 3602925baeddSChris Mason goto out_unlock; 36035f39d397SChris Mason 36046c1500f2SJulia Lawall WARN_ON(!empty && push_items == left_nritems); 36055f39d397SChris Mason 360600ec4c51SChris Mason /* push left to right */ 36075f39d397SChris Mason right_nritems = btrfs_header_nritems(right); 360834a38218SChris Mason 36095f39d397SChris Mason push_space = btrfs_item_end_nr(left, left_nritems - push_items); 36108f881e8cSDavid Sterba push_space -= leaf_data_end(left); 36115f39d397SChris Mason 361200ec4c51SChris Mason /* make room in the right data area */ 36138f881e8cSDavid Sterba data_end = leaf_data_end(right); 36145f39d397SChris Mason memmove_extent_buffer(right, 36153d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + data_end - push_space, 36163d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + data_end, 36170b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info) - data_end); 36185f39d397SChris Mason 361900ec4c51SChris Mason /* copy from the left data area */ 36203d9ec8c4SNikolay Borisov copy_extent_buffer(right, left, BTRFS_LEAF_DATA_OFFSET + 36210b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, 36228f881e8cSDavid Sterba BTRFS_LEAF_DATA_OFFSET + leaf_data_end(left), 3623d6025579SChris Mason push_space); 36245f39d397SChris Mason 36255f39d397SChris Mason memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), 36265f39d397SChris Mason btrfs_item_nr_offset(0), 36270783fcfcSChris Mason right_nritems * sizeof(struct btrfs_item)); 36285f39d397SChris Mason 362900ec4c51SChris Mason /* copy the items from left to right */ 36305f39d397SChris Mason copy_extent_buffer(right, left, btrfs_item_nr_offset(0), 36315f39d397SChris Mason btrfs_item_nr_offset(left_nritems - push_items), 36320783fcfcSChris Mason push_items * sizeof(struct btrfs_item)); 363300ec4c51SChris Mason 363400ec4c51SChris Mason /* update the item pointers */ 3635c82f823cSDavid Sterba btrfs_init_map_token(&token, right); 36367518a238SChris Mason right_nritems += push_items; 36375f39d397SChris Mason btrfs_set_header_nritems(right, right_nritems); 36380b246afaSJeff Mahoney push_space = BTRFS_LEAF_DATA_SIZE(fs_info); 36397518a238SChris Mason for (i = 0; i < right_nritems; i++) { 3640dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 3641cc4c13d5SDavid Sterba push_space -= btrfs_token_item_size(&token, item); 3642cc4c13d5SDavid Sterba btrfs_set_token_item_offset(&token, item, push_space); 3643db94535dSChris Mason } 3644db94535dSChris Mason 36457518a238SChris Mason left_nritems -= push_items; 36465f39d397SChris Mason btrfs_set_header_nritems(left, left_nritems); 364700ec4c51SChris Mason 364834a38218SChris Mason if (left_nritems) 36495f39d397SChris Mason btrfs_mark_buffer_dirty(left); 3650f0486c68SYan, Zheng else 36516a884d7dSDavid Sterba btrfs_clean_tree_block(left); 3652f0486c68SYan, Zheng 36535f39d397SChris Mason btrfs_mark_buffer_dirty(right); 3654a429e513SChris Mason 36555f39d397SChris Mason btrfs_item_key(right, &disk_key, 0); 36565f39d397SChris Mason btrfs_set_node_key(upper, &disk_key, slot + 1); 3657d6025579SChris Mason btrfs_mark_buffer_dirty(upper); 365802217ed2SChris Mason 365900ec4c51SChris Mason /* then fixup the leaf pointer in the path */ 36607518a238SChris Mason if (path->slots[0] >= left_nritems) { 36617518a238SChris Mason path->slots[0] -= left_nritems; 3662925baeddSChris Mason if (btrfs_header_nritems(path->nodes[0]) == 0) 36636a884d7dSDavid Sterba btrfs_clean_tree_block(path->nodes[0]); 3664925baeddSChris Mason btrfs_tree_unlock(path->nodes[0]); 36655f39d397SChris Mason free_extent_buffer(path->nodes[0]); 36665f39d397SChris Mason path->nodes[0] = right; 366700ec4c51SChris Mason path->slots[1] += 1; 366800ec4c51SChris Mason } else { 3669925baeddSChris Mason btrfs_tree_unlock(right); 36705f39d397SChris Mason free_extent_buffer(right); 367100ec4c51SChris Mason } 367200ec4c51SChris Mason return 0; 3673925baeddSChris Mason 3674925baeddSChris Mason out_unlock: 3675925baeddSChris Mason btrfs_tree_unlock(right); 3676925baeddSChris Mason free_extent_buffer(right); 3677925baeddSChris Mason return 1; 367800ec4c51SChris Mason } 3679925baeddSChris Mason 368000ec4c51SChris Mason /* 368144871b1bSChris Mason * push some data in the path leaf to the right, trying to free up at 368274123bd7SChris Mason * least data_size bytes. returns zero if the push worked, nonzero otherwise 368344871b1bSChris Mason * 368444871b1bSChris Mason * returns 1 if the push failed because the other node didn't have enough 368544871b1bSChris Mason * room, 0 if everything worked out and < 0 if there were major errors. 368699d8f83cSChris Mason * 368799d8f83cSChris Mason * this will push starting from min_slot to the end of the leaf. It won't 368899d8f83cSChris Mason * push any slot lower than min_slot 368974123bd7SChris Mason */ 369044871b1bSChris Mason static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root 369199d8f83cSChris Mason *root, struct btrfs_path *path, 369299d8f83cSChris Mason int min_data_size, int data_size, 369399d8f83cSChris Mason int empty, u32 min_slot) 3694be0e5c09SChris Mason { 369544871b1bSChris Mason struct extent_buffer *left = path->nodes[0]; 369644871b1bSChris Mason struct extent_buffer *right; 369744871b1bSChris Mason struct extent_buffer *upper; 369844871b1bSChris Mason int slot; 369944871b1bSChris Mason int free_space; 370044871b1bSChris Mason u32 left_nritems; 370144871b1bSChris Mason int ret; 370244871b1bSChris Mason 370344871b1bSChris Mason if (!path->nodes[1]) 370444871b1bSChris Mason return 1; 370544871b1bSChris Mason 370644871b1bSChris Mason slot = path->slots[1]; 370744871b1bSChris Mason upper = path->nodes[1]; 370844871b1bSChris Mason if (slot >= btrfs_header_nritems(upper) - 1) 370944871b1bSChris Mason return 1; 371044871b1bSChris Mason 371144871b1bSChris Mason btrfs_assert_tree_locked(path->nodes[1]); 371244871b1bSChris Mason 37134b231ae4SDavid Sterba right = btrfs_read_node_slot(upper, slot + 1); 3714fb770ae4SLiu Bo /* 3715fb770ae4SLiu Bo * slot + 1 is not valid or we fail to read the right node, 3716fb770ae4SLiu Bo * no big deal, just return. 3717fb770ae4SLiu Bo */ 3718fb770ae4SLiu Bo if (IS_ERR(right)) 371991ca338dSTsutomu Itoh return 1; 372091ca338dSTsutomu Itoh 3721bf77467aSJosef Bacik __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); 372244871b1bSChris Mason 3723e902baacSDavid Sterba free_space = btrfs_leaf_free_space(right); 372444871b1bSChris Mason if (free_space < data_size) 372544871b1bSChris Mason goto out_unlock; 372644871b1bSChris Mason 372744871b1bSChris Mason /* cow and double check */ 372844871b1bSChris Mason ret = btrfs_cow_block(trans, root, right, upper, 3729bf59a5a2SJosef Bacik slot + 1, &right, BTRFS_NESTING_RIGHT_COW); 373044871b1bSChris Mason if (ret) 373144871b1bSChris Mason goto out_unlock; 373244871b1bSChris Mason 3733e902baacSDavid Sterba free_space = btrfs_leaf_free_space(right); 373444871b1bSChris Mason if (free_space < data_size) 373544871b1bSChris Mason goto out_unlock; 373644871b1bSChris Mason 373744871b1bSChris Mason left_nritems = btrfs_header_nritems(left); 373844871b1bSChris Mason if (left_nritems == 0) 373944871b1bSChris Mason goto out_unlock; 374044871b1bSChris Mason 3741d16c702fSQu Wenruo if (check_sibling_keys(left, right)) { 3742d16c702fSQu Wenruo ret = -EUCLEAN; 3743d16c702fSQu Wenruo btrfs_tree_unlock(right); 3744d16c702fSQu Wenruo free_extent_buffer(right); 3745d16c702fSQu Wenruo return ret; 3746d16c702fSQu Wenruo } 37472ef1fed2SFilipe David Borba Manana if (path->slots[0] == left_nritems && !empty) { 37482ef1fed2SFilipe David Borba Manana /* Key greater than all keys in the leaf, right neighbor has 37492ef1fed2SFilipe David Borba Manana * enough room for it and we're not emptying our leaf to delete 37502ef1fed2SFilipe David Borba Manana * it, therefore use right neighbor to insert the new item and 375152042d8eSAndrea Gelmini * no need to touch/dirty our left leaf. */ 37522ef1fed2SFilipe David Borba Manana btrfs_tree_unlock(left); 37532ef1fed2SFilipe David Borba Manana free_extent_buffer(left); 37542ef1fed2SFilipe David Borba Manana path->nodes[0] = right; 37552ef1fed2SFilipe David Borba Manana path->slots[0] = 0; 37562ef1fed2SFilipe David Borba Manana path->slots[1]++; 37572ef1fed2SFilipe David Borba Manana return 0; 37582ef1fed2SFilipe David Borba Manana } 37592ef1fed2SFilipe David Borba Manana 3760f72f0010SDavid Sterba return __push_leaf_right(path, min_data_size, empty, 376199d8f83cSChris Mason right, free_space, left_nritems, min_slot); 376244871b1bSChris Mason out_unlock: 376344871b1bSChris Mason btrfs_tree_unlock(right); 376444871b1bSChris Mason free_extent_buffer(right); 376544871b1bSChris Mason return 1; 376644871b1bSChris Mason } 376744871b1bSChris Mason 376844871b1bSChris Mason /* 376944871b1bSChris Mason * push some data in the path leaf to the left, trying to free up at 377044871b1bSChris Mason * least data_size bytes. returns zero if the push worked, nonzero otherwise 377199d8f83cSChris Mason * 377299d8f83cSChris Mason * max_slot can put a limit on how far into the leaf we'll push items. The 377399d8f83cSChris Mason * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the 377499d8f83cSChris Mason * items 377544871b1bSChris Mason */ 37768087c193SDavid Sterba static noinline int __push_leaf_left(struct btrfs_path *path, int data_size, 377744871b1bSChris Mason int empty, struct extent_buffer *left, 377899d8f83cSChris Mason int free_space, u32 right_nritems, 377999d8f83cSChris Mason u32 max_slot) 378044871b1bSChris Mason { 37818087c193SDavid Sterba struct btrfs_fs_info *fs_info = left->fs_info; 37825f39d397SChris Mason struct btrfs_disk_key disk_key; 37835f39d397SChris Mason struct extent_buffer *right = path->nodes[0]; 3784be0e5c09SChris Mason int i; 3785be0e5c09SChris Mason int push_space = 0; 3786be0e5c09SChris Mason int push_items = 0; 37870783fcfcSChris Mason struct btrfs_item *item; 37887518a238SChris Mason u32 old_left_nritems; 378934a38218SChris Mason u32 nr; 3790aa5d6bedSChris Mason int ret = 0; 3791db94535dSChris Mason u32 this_item_size; 3792db94535dSChris Mason u32 old_left_item_size; 3793cfed81a0SChris Mason struct btrfs_map_token token; 3794cfed81a0SChris Mason 379534a38218SChris Mason if (empty) 379699d8f83cSChris Mason nr = min(right_nritems, max_slot); 379734a38218SChris Mason else 379899d8f83cSChris Mason nr = min(right_nritems - 1, max_slot); 379934a38218SChris Mason 380034a38218SChris Mason for (i = 0; i < nr; i++) { 3801dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 3802db94535dSChris Mason 380331840ae1SZheng Yan if (!empty && push_items > 0) { 380431840ae1SZheng Yan if (path->slots[0] < i) 380531840ae1SZheng Yan break; 380631840ae1SZheng Yan if (path->slots[0] == i) { 3807e902baacSDavid Sterba int space = btrfs_leaf_free_space(right); 3808e902baacSDavid Sterba 380931840ae1SZheng Yan if (space + push_space * 2 > free_space) 381031840ae1SZheng Yan break; 381131840ae1SZheng Yan } 381231840ae1SZheng Yan } 381331840ae1SZheng Yan 3814be0e5c09SChris Mason if (path->slots[0] == i) 381587b29b20SYan Zheng push_space += data_size; 3816db94535dSChris Mason 3817db94535dSChris Mason this_item_size = btrfs_item_size(right, item); 3818db94535dSChris Mason if (this_item_size + sizeof(*item) + push_space > free_space) 3819be0e5c09SChris Mason break; 3820db94535dSChris Mason 3821be0e5c09SChris Mason push_items++; 3822db94535dSChris Mason push_space += this_item_size + sizeof(*item); 3823be0e5c09SChris Mason } 3824db94535dSChris Mason 3825be0e5c09SChris Mason if (push_items == 0) { 3826925baeddSChris Mason ret = 1; 3827925baeddSChris Mason goto out; 3828be0e5c09SChris Mason } 3829fae7f21cSDulshani Gunawardhana WARN_ON(!empty && push_items == btrfs_header_nritems(right)); 38305f39d397SChris Mason 3831be0e5c09SChris Mason /* push data from right to left */ 38325f39d397SChris Mason copy_extent_buffer(left, right, 38335f39d397SChris Mason btrfs_item_nr_offset(btrfs_header_nritems(left)), 38345f39d397SChris Mason btrfs_item_nr_offset(0), 38355f39d397SChris Mason push_items * sizeof(struct btrfs_item)); 38365f39d397SChris Mason 38370b246afaSJeff Mahoney push_space = BTRFS_LEAF_DATA_SIZE(fs_info) - 38385f39d397SChris Mason btrfs_item_offset_nr(right, push_items - 1); 38395f39d397SChris Mason 38403d9ec8c4SNikolay Borisov copy_extent_buffer(left, right, BTRFS_LEAF_DATA_OFFSET + 38418f881e8cSDavid Sterba leaf_data_end(left) - push_space, 38423d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + 38435f39d397SChris Mason btrfs_item_offset_nr(right, push_items - 1), 3844be0e5c09SChris Mason push_space); 38455f39d397SChris Mason old_left_nritems = btrfs_header_nritems(left); 384687b29b20SYan Zheng BUG_ON(old_left_nritems <= 0); 3847eb60ceacSChris Mason 3848c82f823cSDavid Sterba btrfs_init_map_token(&token, left); 3849db94535dSChris Mason old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); 3850be0e5c09SChris Mason for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { 38515f39d397SChris Mason u32 ioff; 3852db94535dSChris Mason 3853dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 3854db94535dSChris Mason 3855cc4c13d5SDavid Sterba ioff = btrfs_token_item_offset(&token, item); 3856cc4c13d5SDavid Sterba btrfs_set_token_item_offset(&token, item, 3857cc4c13d5SDavid Sterba ioff - (BTRFS_LEAF_DATA_SIZE(fs_info) - old_left_item_size)); 3858be0e5c09SChris Mason } 38595f39d397SChris Mason btrfs_set_header_nritems(left, old_left_nritems + push_items); 3860be0e5c09SChris Mason 3861be0e5c09SChris Mason /* fixup right node */ 386231b1a2bdSJulia Lawall if (push_items > right_nritems) 386331b1a2bdSJulia Lawall WARN(1, KERN_CRIT "push items %d nr %u\n", push_items, 3864d397712bSChris Mason right_nritems); 386534a38218SChris Mason 386634a38218SChris Mason if (push_items < right_nritems) { 38675f39d397SChris Mason push_space = btrfs_item_offset_nr(right, push_items - 1) - 38688f881e8cSDavid Sterba leaf_data_end(right); 38693d9ec8c4SNikolay Borisov memmove_extent_buffer(right, BTRFS_LEAF_DATA_OFFSET + 38700b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, 38713d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + 38728f881e8cSDavid Sterba leaf_data_end(right), push_space); 38735f39d397SChris Mason 38745f39d397SChris Mason memmove_extent_buffer(right, btrfs_item_nr_offset(0), 38755f39d397SChris Mason btrfs_item_nr_offset(push_items), 38765f39d397SChris Mason (btrfs_header_nritems(right) - push_items) * 38770783fcfcSChris Mason sizeof(struct btrfs_item)); 387834a38218SChris Mason } 3879c82f823cSDavid Sterba 3880c82f823cSDavid Sterba btrfs_init_map_token(&token, right); 3881eef1c494SYan right_nritems -= push_items; 3882eef1c494SYan btrfs_set_header_nritems(right, right_nritems); 38830b246afaSJeff Mahoney push_space = BTRFS_LEAF_DATA_SIZE(fs_info); 38845f39d397SChris Mason for (i = 0; i < right_nritems; i++) { 3885dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 3886db94535dSChris Mason 3887cc4c13d5SDavid Sterba push_space = push_space - btrfs_token_item_size(&token, item); 3888cc4c13d5SDavid Sterba btrfs_set_token_item_offset(&token, item, push_space); 3889db94535dSChris Mason } 3890eb60ceacSChris Mason 38915f39d397SChris Mason btrfs_mark_buffer_dirty(left); 389234a38218SChris Mason if (right_nritems) 38935f39d397SChris Mason btrfs_mark_buffer_dirty(right); 3894f0486c68SYan, Zheng else 38956a884d7dSDavid Sterba btrfs_clean_tree_block(right); 3896098f59c2SChris Mason 38975f39d397SChris Mason btrfs_item_key(right, &disk_key, 0); 3898b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 3899be0e5c09SChris Mason 3900be0e5c09SChris Mason /* then fixup the leaf pointer in the path */ 3901be0e5c09SChris Mason if (path->slots[0] < push_items) { 3902be0e5c09SChris Mason path->slots[0] += old_left_nritems; 3903925baeddSChris Mason btrfs_tree_unlock(path->nodes[0]); 39045f39d397SChris Mason free_extent_buffer(path->nodes[0]); 39055f39d397SChris Mason path->nodes[0] = left; 3906be0e5c09SChris Mason path->slots[1] -= 1; 3907be0e5c09SChris Mason } else { 3908925baeddSChris Mason btrfs_tree_unlock(left); 39095f39d397SChris Mason free_extent_buffer(left); 3910be0e5c09SChris Mason path->slots[0] -= push_items; 3911be0e5c09SChris Mason } 3912eb60ceacSChris Mason BUG_ON(path->slots[0] < 0); 3913aa5d6bedSChris Mason return ret; 3914925baeddSChris Mason out: 3915925baeddSChris Mason btrfs_tree_unlock(left); 3916925baeddSChris Mason free_extent_buffer(left); 3917925baeddSChris Mason return ret; 3918be0e5c09SChris Mason } 3919be0e5c09SChris Mason 392074123bd7SChris Mason /* 392144871b1bSChris Mason * push some data in the path leaf to the left, trying to free up at 392244871b1bSChris Mason * least data_size bytes. returns zero if the push worked, nonzero otherwise 392399d8f83cSChris Mason * 392499d8f83cSChris Mason * max_slot can put a limit on how far into the leaf we'll push items. The 392599d8f83cSChris Mason * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the 392699d8f83cSChris Mason * items 392744871b1bSChris Mason */ 392844871b1bSChris Mason static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root 392999d8f83cSChris Mason *root, struct btrfs_path *path, int min_data_size, 393099d8f83cSChris Mason int data_size, int empty, u32 max_slot) 393144871b1bSChris Mason { 393244871b1bSChris Mason struct extent_buffer *right = path->nodes[0]; 393344871b1bSChris Mason struct extent_buffer *left; 393444871b1bSChris Mason int slot; 393544871b1bSChris Mason int free_space; 393644871b1bSChris Mason u32 right_nritems; 393744871b1bSChris Mason int ret = 0; 393844871b1bSChris Mason 393944871b1bSChris Mason slot = path->slots[1]; 394044871b1bSChris Mason if (slot == 0) 394144871b1bSChris Mason return 1; 394244871b1bSChris Mason if (!path->nodes[1]) 394344871b1bSChris Mason return 1; 394444871b1bSChris Mason 394544871b1bSChris Mason right_nritems = btrfs_header_nritems(right); 394644871b1bSChris Mason if (right_nritems == 0) 394744871b1bSChris Mason return 1; 394844871b1bSChris Mason 394944871b1bSChris Mason btrfs_assert_tree_locked(path->nodes[1]); 395044871b1bSChris Mason 39514b231ae4SDavid Sterba left = btrfs_read_node_slot(path->nodes[1], slot - 1); 3952fb770ae4SLiu Bo /* 3953fb770ae4SLiu Bo * slot - 1 is not valid or we fail to read the left node, 3954fb770ae4SLiu Bo * no big deal, just return. 3955fb770ae4SLiu Bo */ 3956fb770ae4SLiu Bo if (IS_ERR(left)) 395791ca338dSTsutomu Itoh return 1; 395891ca338dSTsutomu Itoh 3959bf77467aSJosef Bacik __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); 396044871b1bSChris Mason 3961e902baacSDavid Sterba free_space = btrfs_leaf_free_space(left); 396244871b1bSChris Mason if (free_space < data_size) { 396344871b1bSChris Mason ret = 1; 396444871b1bSChris Mason goto out; 396544871b1bSChris Mason } 396644871b1bSChris Mason 396744871b1bSChris Mason /* cow and double check */ 396844871b1bSChris Mason ret = btrfs_cow_block(trans, root, left, 39699631e4ccSJosef Bacik path->nodes[1], slot - 1, &left, 3970bf59a5a2SJosef Bacik BTRFS_NESTING_LEFT_COW); 397144871b1bSChris Mason if (ret) { 397244871b1bSChris Mason /* we hit -ENOSPC, but it isn't fatal here */ 397379787eaaSJeff Mahoney if (ret == -ENOSPC) 397444871b1bSChris Mason ret = 1; 397544871b1bSChris Mason goto out; 397644871b1bSChris Mason } 397744871b1bSChris Mason 3978e902baacSDavid Sterba free_space = btrfs_leaf_free_space(left); 397944871b1bSChris Mason if (free_space < data_size) { 398044871b1bSChris Mason ret = 1; 398144871b1bSChris Mason goto out; 398244871b1bSChris Mason } 398344871b1bSChris Mason 3984d16c702fSQu Wenruo if (check_sibling_keys(left, right)) { 3985d16c702fSQu Wenruo ret = -EUCLEAN; 3986d16c702fSQu Wenruo goto out; 3987d16c702fSQu Wenruo } 39888087c193SDavid Sterba return __push_leaf_left(path, min_data_size, 398999d8f83cSChris Mason empty, left, free_space, right_nritems, 399099d8f83cSChris Mason max_slot); 399144871b1bSChris Mason out: 399244871b1bSChris Mason btrfs_tree_unlock(left); 399344871b1bSChris Mason free_extent_buffer(left); 399444871b1bSChris Mason return ret; 399544871b1bSChris Mason } 399644871b1bSChris Mason 399744871b1bSChris Mason /* 399874123bd7SChris Mason * split the path's leaf in two, making sure there is at least data_size 399974123bd7SChris Mason * available for the resulting leaf level of the path. 400074123bd7SChris Mason */ 4001143bede5SJeff Mahoney static noinline void copy_for_split(struct btrfs_trans_handle *trans, 400244871b1bSChris Mason struct btrfs_path *path, 400344871b1bSChris Mason struct extent_buffer *l, 400444871b1bSChris Mason struct extent_buffer *right, 400544871b1bSChris Mason int slot, int mid, int nritems) 4006be0e5c09SChris Mason { 400794f94ad9SDavid Sterba struct btrfs_fs_info *fs_info = trans->fs_info; 4008be0e5c09SChris Mason int data_copy_size; 4009be0e5c09SChris Mason int rt_data_off; 4010be0e5c09SChris Mason int i; 4011d4dbff95SChris Mason struct btrfs_disk_key disk_key; 4012cfed81a0SChris Mason struct btrfs_map_token token; 4013cfed81a0SChris Mason 40145f39d397SChris Mason nritems = nritems - mid; 40155f39d397SChris Mason btrfs_set_header_nritems(right, nritems); 40168f881e8cSDavid Sterba data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(l); 40175f39d397SChris Mason 40185f39d397SChris Mason copy_extent_buffer(right, l, btrfs_item_nr_offset(0), 40195f39d397SChris Mason btrfs_item_nr_offset(mid), 40205f39d397SChris Mason nritems * sizeof(struct btrfs_item)); 40215f39d397SChris Mason 40225f39d397SChris Mason copy_extent_buffer(right, l, 40233d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + BTRFS_LEAF_DATA_SIZE(fs_info) - 40243d9ec8c4SNikolay Borisov data_copy_size, BTRFS_LEAF_DATA_OFFSET + 40258f881e8cSDavid Sterba leaf_data_end(l), data_copy_size); 402674123bd7SChris Mason 40270b246afaSJeff Mahoney rt_data_off = BTRFS_LEAF_DATA_SIZE(fs_info) - btrfs_item_end_nr(l, mid); 40285f39d397SChris Mason 4029c82f823cSDavid Sterba btrfs_init_map_token(&token, right); 40305f39d397SChris Mason for (i = 0; i < nritems; i++) { 4031dd3cc16bSRoss Kirk struct btrfs_item *item = btrfs_item_nr(i); 4032db94535dSChris Mason u32 ioff; 4033db94535dSChris Mason 4034cc4c13d5SDavid Sterba ioff = btrfs_token_item_offset(&token, item); 4035cc4c13d5SDavid Sterba btrfs_set_token_item_offset(&token, item, ioff + rt_data_off); 40360783fcfcSChris Mason } 403774123bd7SChris Mason 40385f39d397SChris Mason btrfs_set_header_nritems(l, mid); 40395f39d397SChris Mason btrfs_item_key(right, &disk_key, 0); 40406ad3cf6dSDavid Sterba insert_ptr(trans, path, &disk_key, right->start, path->slots[1] + 1, 1); 40415f39d397SChris Mason 40425f39d397SChris Mason btrfs_mark_buffer_dirty(right); 40435f39d397SChris Mason btrfs_mark_buffer_dirty(l); 4044eb60ceacSChris Mason BUG_ON(path->slots[0] != slot); 40455f39d397SChris Mason 4046be0e5c09SChris Mason if (mid <= slot) { 4047925baeddSChris Mason btrfs_tree_unlock(path->nodes[0]); 40485f39d397SChris Mason free_extent_buffer(path->nodes[0]); 40495f39d397SChris Mason path->nodes[0] = right; 4050be0e5c09SChris Mason path->slots[0] -= mid; 4051be0e5c09SChris Mason path->slots[1] += 1; 4052925baeddSChris Mason } else { 4053925baeddSChris Mason btrfs_tree_unlock(right); 40545f39d397SChris Mason free_extent_buffer(right); 4055925baeddSChris Mason } 40565f39d397SChris Mason 4057eb60ceacSChris Mason BUG_ON(path->slots[0] < 0); 405844871b1bSChris Mason } 405944871b1bSChris Mason 406044871b1bSChris Mason /* 406199d8f83cSChris Mason * double splits happen when we need to insert a big item in the middle 406299d8f83cSChris Mason * of a leaf. A double split can leave us with 3 mostly empty leaves: 406399d8f83cSChris Mason * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] 406499d8f83cSChris Mason * A B C 406599d8f83cSChris Mason * 406699d8f83cSChris Mason * We avoid this by trying to push the items on either side of our target 406799d8f83cSChris Mason * into the adjacent leaves. If all goes well we can avoid the double split 406899d8f83cSChris Mason * completely. 406999d8f83cSChris Mason */ 407099d8f83cSChris Mason static noinline int push_for_double_split(struct btrfs_trans_handle *trans, 407199d8f83cSChris Mason struct btrfs_root *root, 407299d8f83cSChris Mason struct btrfs_path *path, 407399d8f83cSChris Mason int data_size) 407499d8f83cSChris Mason { 407599d8f83cSChris Mason int ret; 407699d8f83cSChris Mason int progress = 0; 407799d8f83cSChris Mason int slot; 407899d8f83cSChris Mason u32 nritems; 40795a4267caSFilipe David Borba Manana int space_needed = data_size; 408099d8f83cSChris Mason 408199d8f83cSChris Mason slot = path->slots[0]; 40825a4267caSFilipe David Borba Manana if (slot < btrfs_header_nritems(path->nodes[0])) 4083e902baacSDavid Sterba space_needed -= btrfs_leaf_free_space(path->nodes[0]); 408499d8f83cSChris Mason 408599d8f83cSChris Mason /* 408699d8f83cSChris Mason * try to push all the items after our slot into the 408799d8f83cSChris Mason * right leaf 408899d8f83cSChris Mason */ 40895a4267caSFilipe David Borba Manana ret = push_leaf_right(trans, root, path, 1, space_needed, 0, slot); 409099d8f83cSChris Mason if (ret < 0) 409199d8f83cSChris Mason return ret; 409299d8f83cSChris Mason 409399d8f83cSChris Mason if (ret == 0) 409499d8f83cSChris Mason progress++; 409599d8f83cSChris Mason 409699d8f83cSChris Mason nritems = btrfs_header_nritems(path->nodes[0]); 409799d8f83cSChris Mason /* 409899d8f83cSChris Mason * our goal is to get our slot at the start or end of a leaf. If 409999d8f83cSChris Mason * we've done so we're done 410099d8f83cSChris Mason */ 410199d8f83cSChris Mason if (path->slots[0] == 0 || path->slots[0] == nritems) 410299d8f83cSChris Mason return 0; 410399d8f83cSChris Mason 4104e902baacSDavid Sterba if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) 410599d8f83cSChris Mason return 0; 410699d8f83cSChris Mason 410799d8f83cSChris Mason /* try to push all the items before our slot into the next leaf */ 410899d8f83cSChris Mason slot = path->slots[0]; 4109263d3995SFilipe Manana space_needed = data_size; 4110263d3995SFilipe Manana if (slot > 0) 4111e902baacSDavid Sterba space_needed -= btrfs_leaf_free_space(path->nodes[0]); 41125a4267caSFilipe David Borba Manana ret = push_leaf_left(trans, root, path, 1, space_needed, 0, slot); 411399d8f83cSChris Mason if (ret < 0) 411499d8f83cSChris Mason return ret; 411599d8f83cSChris Mason 411699d8f83cSChris Mason if (ret == 0) 411799d8f83cSChris Mason progress++; 411899d8f83cSChris Mason 411999d8f83cSChris Mason if (progress) 412099d8f83cSChris Mason return 0; 412199d8f83cSChris Mason return 1; 412299d8f83cSChris Mason } 412399d8f83cSChris Mason 412499d8f83cSChris Mason /* 412544871b1bSChris Mason * split the path's leaf in two, making sure there is at least data_size 412644871b1bSChris Mason * available for the resulting leaf level of the path. 412744871b1bSChris Mason * 412844871b1bSChris Mason * returns 0 if all went well and < 0 on failure. 412944871b1bSChris Mason */ 413044871b1bSChris Mason static noinline int split_leaf(struct btrfs_trans_handle *trans, 413144871b1bSChris Mason struct btrfs_root *root, 4132310712b2SOmar Sandoval const struct btrfs_key *ins_key, 413344871b1bSChris Mason struct btrfs_path *path, int data_size, 413444871b1bSChris Mason int extend) 413544871b1bSChris Mason { 41365d4f98a2SYan Zheng struct btrfs_disk_key disk_key; 413744871b1bSChris Mason struct extent_buffer *l; 413844871b1bSChris Mason u32 nritems; 413944871b1bSChris Mason int mid; 414044871b1bSChris Mason int slot; 414144871b1bSChris Mason struct extent_buffer *right; 4142b7a0365eSDaniel Dressler struct btrfs_fs_info *fs_info = root->fs_info; 414344871b1bSChris Mason int ret = 0; 414444871b1bSChris Mason int wret; 41455d4f98a2SYan Zheng int split; 414644871b1bSChris Mason int num_doubles = 0; 414799d8f83cSChris Mason int tried_avoid_double = 0; 414844871b1bSChris Mason 4149a5719521SYan, Zheng l = path->nodes[0]; 4150a5719521SYan, Zheng slot = path->slots[0]; 4151a5719521SYan, Zheng if (extend && data_size + btrfs_item_size_nr(l, slot) + 41520b246afaSJeff Mahoney sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info)) 4153a5719521SYan, Zheng return -EOVERFLOW; 4154a5719521SYan, Zheng 415544871b1bSChris Mason /* first try to make some room by pushing left and right */ 415633157e05SLiu Bo if (data_size && path->nodes[1]) { 41575a4267caSFilipe David Borba Manana int space_needed = data_size; 41585a4267caSFilipe David Borba Manana 41595a4267caSFilipe David Borba Manana if (slot < btrfs_header_nritems(l)) 4160e902baacSDavid Sterba space_needed -= btrfs_leaf_free_space(l); 41615a4267caSFilipe David Borba Manana 41625a4267caSFilipe David Borba Manana wret = push_leaf_right(trans, root, path, space_needed, 41635a4267caSFilipe David Borba Manana space_needed, 0, 0); 416444871b1bSChris Mason if (wret < 0) 416544871b1bSChris Mason return wret; 416644871b1bSChris Mason if (wret) { 4167263d3995SFilipe Manana space_needed = data_size; 4168263d3995SFilipe Manana if (slot > 0) 4169e902baacSDavid Sterba space_needed -= btrfs_leaf_free_space(l); 41705a4267caSFilipe David Borba Manana wret = push_leaf_left(trans, root, path, space_needed, 41715a4267caSFilipe David Borba Manana space_needed, 0, (u32)-1); 417244871b1bSChris Mason if (wret < 0) 417344871b1bSChris Mason return wret; 417444871b1bSChris Mason } 417544871b1bSChris Mason l = path->nodes[0]; 417644871b1bSChris Mason 417744871b1bSChris Mason /* did the pushes work? */ 4178e902baacSDavid Sterba if (btrfs_leaf_free_space(l) >= data_size) 417944871b1bSChris Mason return 0; 418044871b1bSChris Mason } 418144871b1bSChris Mason 418244871b1bSChris Mason if (!path->nodes[1]) { 4183fdd99c72SLiu Bo ret = insert_new_root(trans, root, path, 1); 418444871b1bSChris Mason if (ret) 418544871b1bSChris Mason return ret; 418644871b1bSChris Mason } 418744871b1bSChris Mason again: 41885d4f98a2SYan Zheng split = 1; 418944871b1bSChris Mason l = path->nodes[0]; 419044871b1bSChris Mason slot = path->slots[0]; 419144871b1bSChris Mason nritems = btrfs_header_nritems(l); 419244871b1bSChris Mason mid = (nritems + 1) / 2; 419344871b1bSChris Mason 41945d4f98a2SYan Zheng if (mid <= slot) { 41955d4f98a2SYan Zheng if (nritems == 1 || 41965d4f98a2SYan Zheng leaf_space_used(l, mid, nritems - mid) + data_size > 41970b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info)) { 41985d4f98a2SYan Zheng if (slot >= nritems) { 41995d4f98a2SYan Zheng split = 0; 42005d4f98a2SYan Zheng } else { 42015d4f98a2SYan Zheng mid = slot; 42025d4f98a2SYan Zheng if (mid != nritems && 42035d4f98a2SYan Zheng leaf_space_used(l, mid, nritems - mid) + 42040b246afaSJeff Mahoney data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { 420599d8f83cSChris Mason if (data_size && !tried_avoid_double) 420699d8f83cSChris Mason goto push_for_double; 42075d4f98a2SYan Zheng split = 2; 42085d4f98a2SYan Zheng } 42095d4f98a2SYan Zheng } 42105d4f98a2SYan Zheng } 42115d4f98a2SYan Zheng } else { 42125d4f98a2SYan Zheng if (leaf_space_used(l, 0, mid) + data_size > 42130b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info)) { 42145d4f98a2SYan Zheng if (!extend && data_size && slot == 0) { 42155d4f98a2SYan Zheng split = 0; 42165d4f98a2SYan Zheng } else if ((extend || !data_size) && slot == 0) { 42175d4f98a2SYan Zheng mid = 1; 42185d4f98a2SYan Zheng } else { 42195d4f98a2SYan Zheng mid = slot; 42205d4f98a2SYan Zheng if (mid != nritems && 42215d4f98a2SYan Zheng leaf_space_used(l, mid, nritems - mid) + 42220b246afaSJeff Mahoney data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { 422399d8f83cSChris Mason if (data_size && !tried_avoid_double) 422499d8f83cSChris Mason goto push_for_double; 42255d4f98a2SYan Zheng split = 2; 42265d4f98a2SYan Zheng } 42275d4f98a2SYan Zheng } 42285d4f98a2SYan Zheng } 42295d4f98a2SYan Zheng } 42305d4f98a2SYan Zheng 42315d4f98a2SYan Zheng if (split == 0) 42325d4f98a2SYan Zheng btrfs_cpu_key_to_disk(&disk_key, ins_key); 42335d4f98a2SYan Zheng else 42345d4f98a2SYan Zheng btrfs_item_key(l, &disk_key, mid); 42355d4f98a2SYan Zheng 4236ca9d473aSJosef Bacik /* 4237ca9d473aSJosef Bacik * We have to about BTRFS_NESTING_NEW_ROOT here if we've done a double 4238ca9d473aSJosef Bacik * split, because we're only allowed to have MAX_LOCKDEP_SUBCLASSES 4239ca9d473aSJosef Bacik * subclasses, which is 8 at the time of this patch, and we've maxed it 4240ca9d473aSJosef Bacik * out. In the future we could add a 4241ca9d473aSJosef Bacik * BTRFS_NESTING_SPLIT_THE_SPLITTENING if we need to, but for now just 4242ca9d473aSJosef Bacik * use BTRFS_NESTING_NEW_ROOT. 4243ca9d473aSJosef Bacik */ 4244a6279470SFilipe Manana right = alloc_tree_block_no_bg_flush(trans, root, 0, &disk_key, 0, 4245ca9d473aSJosef Bacik l->start, 0, num_doubles ? 4246ca9d473aSJosef Bacik BTRFS_NESTING_NEW_ROOT : 4247ca9d473aSJosef Bacik BTRFS_NESTING_SPLIT); 4248f0486c68SYan, Zheng if (IS_ERR(right)) 424944871b1bSChris Mason return PTR_ERR(right); 4250f0486c68SYan, Zheng 42510b246afaSJeff Mahoney root_add_used(root, fs_info->nodesize); 425244871b1bSChris Mason 42535d4f98a2SYan Zheng if (split == 0) { 425444871b1bSChris Mason if (mid <= slot) { 425544871b1bSChris Mason btrfs_set_header_nritems(right, 0); 42566ad3cf6dSDavid Sterba insert_ptr(trans, path, &disk_key, 42572ff7e61eSJeff Mahoney right->start, path->slots[1] + 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; 426244871b1bSChris Mason path->slots[1] += 1; 426344871b1bSChris Mason } else { 426444871b1bSChris Mason btrfs_set_header_nritems(right, 0); 42656ad3cf6dSDavid Sterba insert_ptr(trans, path, &disk_key, 42662ff7e61eSJeff Mahoney right->start, path->slots[1], 1); 426744871b1bSChris Mason btrfs_tree_unlock(path->nodes[0]); 426844871b1bSChris Mason free_extent_buffer(path->nodes[0]); 426944871b1bSChris Mason path->nodes[0] = right; 427044871b1bSChris Mason path->slots[0] = 0; 4271143bede5SJeff Mahoney if (path->slots[1] == 0) 4272b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 42735d4f98a2SYan Zheng } 4274196e0249SLiu Bo /* 4275196e0249SLiu Bo * We create a new leaf 'right' for the required ins_len and 4276196e0249SLiu Bo * we'll do btrfs_mark_buffer_dirty() on this leaf after copying 4277196e0249SLiu Bo * the content of ins_len to 'right'. 4278196e0249SLiu Bo */ 427944871b1bSChris Mason return ret; 428044871b1bSChris Mason } 428144871b1bSChris Mason 428294f94ad9SDavid Sterba copy_for_split(trans, path, l, right, slot, mid, nritems); 428344871b1bSChris Mason 42845d4f98a2SYan Zheng if (split == 2) { 4285cc0c5538SChris Mason BUG_ON(num_doubles != 0); 4286cc0c5538SChris Mason num_doubles++; 4287cc0c5538SChris Mason goto again; 42883326d1b0SChris Mason } 428944871b1bSChris Mason 4290143bede5SJeff Mahoney return 0; 429199d8f83cSChris Mason 429299d8f83cSChris Mason push_for_double: 429399d8f83cSChris Mason push_for_double_split(trans, root, path, data_size); 429499d8f83cSChris Mason tried_avoid_double = 1; 4295e902baacSDavid Sterba if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) 429699d8f83cSChris Mason return 0; 429799d8f83cSChris Mason goto again; 4298be0e5c09SChris Mason } 4299be0e5c09SChris Mason 4300ad48fd75SYan, Zheng static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, 4301ad48fd75SYan, Zheng struct btrfs_root *root, 4302ad48fd75SYan, Zheng struct btrfs_path *path, int ins_len) 4303ad48fd75SYan, Zheng { 4304ad48fd75SYan, Zheng struct btrfs_key key; 4305ad48fd75SYan, Zheng struct extent_buffer *leaf; 4306ad48fd75SYan, Zheng struct btrfs_file_extent_item *fi; 4307ad48fd75SYan, Zheng u64 extent_len = 0; 4308ad48fd75SYan, Zheng u32 item_size; 4309ad48fd75SYan, Zheng int ret; 4310ad48fd75SYan, Zheng 4311ad48fd75SYan, Zheng leaf = path->nodes[0]; 4312ad48fd75SYan, Zheng btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 4313ad48fd75SYan, Zheng 4314ad48fd75SYan, Zheng BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && 4315ad48fd75SYan, Zheng key.type != BTRFS_EXTENT_CSUM_KEY); 4316ad48fd75SYan, Zheng 4317e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) >= ins_len) 4318ad48fd75SYan, Zheng return 0; 4319ad48fd75SYan, Zheng 4320ad48fd75SYan, Zheng item_size = btrfs_item_size_nr(leaf, path->slots[0]); 4321ad48fd75SYan, Zheng if (key.type == BTRFS_EXTENT_DATA_KEY) { 4322ad48fd75SYan, Zheng fi = btrfs_item_ptr(leaf, path->slots[0], 4323ad48fd75SYan, Zheng struct btrfs_file_extent_item); 4324ad48fd75SYan, Zheng extent_len = btrfs_file_extent_num_bytes(leaf, fi); 4325ad48fd75SYan, Zheng } 4326b3b4aa74SDavid Sterba btrfs_release_path(path); 4327ad48fd75SYan, Zheng 4328ad48fd75SYan, Zheng path->keep_locks = 1; 4329ad48fd75SYan, Zheng path->search_for_split = 1; 4330ad48fd75SYan, Zheng ret = btrfs_search_slot(trans, root, &key, path, 0, 1); 4331ad48fd75SYan, Zheng path->search_for_split = 0; 4332a8df6fe6SFilipe Manana if (ret > 0) 4333a8df6fe6SFilipe Manana ret = -EAGAIN; 4334ad48fd75SYan, Zheng if (ret < 0) 4335ad48fd75SYan, Zheng goto err; 4336ad48fd75SYan, Zheng 4337ad48fd75SYan, Zheng ret = -EAGAIN; 4338ad48fd75SYan, Zheng leaf = path->nodes[0]; 4339a8df6fe6SFilipe Manana /* if our item isn't there, return now */ 4340a8df6fe6SFilipe Manana if (item_size != btrfs_item_size_nr(leaf, path->slots[0])) 4341ad48fd75SYan, Zheng goto err; 4342ad48fd75SYan, Zheng 4343109f6aefSChris Mason /* the leaf has changed, it now has room. return now */ 4344e902baacSDavid Sterba if (btrfs_leaf_free_space(path->nodes[0]) >= ins_len) 4345109f6aefSChris Mason goto err; 4346109f6aefSChris Mason 4347ad48fd75SYan, Zheng if (key.type == BTRFS_EXTENT_DATA_KEY) { 4348ad48fd75SYan, Zheng fi = btrfs_item_ptr(leaf, path->slots[0], 4349ad48fd75SYan, Zheng struct btrfs_file_extent_item); 4350ad48fd75SYan, Zheng if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) 4351ad48fd75SYan, Zheng goto err; 4352ad48fd75SYan, Zheng } 4353ad48fd75SYan, Zheng 4354ad48fd75SYan, Zheng ret = split_leaf(trans, root, &key, path, ins_len, 1); 4355f0486c68SYan, Zheng if (ret) 4356f0486c68SYan, Zheng goto err; 4357ad48fd75SYan, Zheng 4358ad48fd75SYan, Zheng path->keep_locks = 0; 4359ad48fd75SYan, Zheng btrfs_unlock_up_safe(path, 1); 4360ad48fd75SYan, Zheng return 0; 4361ad48fd75SYan, Zheng err: 4362ad48fd75SYan, Zheng path->keep_locks = 0; 4363ad48fd75SYan, Zheng return ret; 4364ad48fd75SYan, Zheng } 4365ad48fd75SYan, Zheng 436625263cd7SDavid Sterba static noinline int split_item(struct btrfs_path *path, 4367310712b2SOmar Sandoval const struct btrfs_key *new_key, 4368459931ecSChris Mason unsigned long split_offset) 4369459931ecSChris Mason { 4370459931ecSChris Mason struct extent_buffer *leaf; 4371459931ecSChris Mason struct btrfs_item *item; 4372459931ecSChris Mason struct btrfs_item *new_item; 4373459931ecSChris Mason int slot; 4374ad48fd75SYan, Zheng char *buf; 4375459931ecSChris Mason u32 nritems; 4376ad48fd75SYan, Zheng u32 item_size; 4377459931ecSChris Mason u32 orig_offset; 4378459931ecSChris Mason struct btrfs_disk_key disk_key; 4379459931ecSChris Mason 4380459931ecSChris Mason leaf = path->nodes[0]; 4381e902baacSDavid Sterba BUG_ON(btrfs_leaf_free_space(leaf) < sizeof(struct btrfs_item)); 4382b9473439SChris Mason 4383dd3cc16bSRoss Kirk item = btrfs_item_nr(path->slots[0]); 4384459931ecSChris Mason orig_offset = btrfs_item_offset(leaf, item); 4385459931ecSChris Mason item_size = btrfs_item_size(leaf, item); 4386459931ecSChris Mason 4387459931ecSChris Mason buf = kmalloc(item_size, GFP_NOFS); 4388ad48fd75SYan, Zheng if (!buf) 4389ad48fd75SYan, Zheng return -ENOMEM; 4390ad48fd75SYan, Zheng 4391459931ecSChris Mason read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, 4392459931ecSChris Mason path->slots[0]), item_size); 4393ad48fd75SYan, Zheng 4394459931ecSChris Mason slot = path->slots[0] + 1; 4395459931ecSChris Mason nritems = btrfs_header_nritems(leaf); 4396459931ecSChris Mason if (slot != nritems) { 4397459931ecSChris Mason /* shift the items */ 4398459931ecSChris Mason memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), 4399459931ecSChris Mason btrfs_item_nr_offset(slot), 4400459931ecSChris Mason (nritems - slot) * sizeof(struct btrfs_item)); 4401459931ecSChris Mason } 4402459931ecSChris Mason 4403459931ecSChris Mason btrfs_cpu_key_to_disk(&disk_key, new_key); 4404459931ecSChris Mason btrfs_set_item_key(leaf, &disk_key, slot); 4405459931ecSChris Mason 4406dd3cc16bSRoss Kirk new_item = btrfs_item_nr(slot); 4407459931ecSChris Mason 4408459931ecSChris Mason btrfs_set_item_offset(leaf, new_item, orig_offset); 4409459931ecSChris Mason btrfs_set_item_size(leaf, new_item, item_size - split_offset); 4410459931ecSChris Mason 4411459931ecSChris Mason btrfs_set_item_offset(leaf, item, 4412459931ecSChris Mason orig_offset + item_size - split_offset); 4413459931ecSChris Mason btrfs_set_item_size(leaf, item, split_offset); 4414459931ecSChris Mason 4415459931ecSChris Mason btrfs_set_header_nritems(leaf, nritems + 1); 4416459931ecSChris Mason 4417459931ecSChris Mason /* write the data for the start of the original item */ 4418459931ecSChris Mason write_extent_buffer(leaf, buf, 4419459931ecSChris Mason btrfs_item_ptr_offset(leaf, path->slots[0]), 4420459931ecSChris Mason split_offset); 4421459931ecSChris Mason 4422459931ecSChris Mason /* write the data for the new item */ 4423459931ecSChris Mason write_extent_buffer(leaf, buf + split_offset, 4424459931ecSChris Mason btrfs_item_ptr_offset(leaf, slot), 4425459931ecSChris Mason item_size - split_offset); 4426459931ecSChris Mason btrfs_mark_buffer_dirty(leaf); 4427459931ecSChris Mason 4428e902baacSDavid Sterba BUG_ON(btrfs_leaf_free_space(leaf) < 0); 4429459931ecSChris Mason kfree(buf); 4430ad48fd75SYan, Zheng return 0; 4431ad48fd75SYan, Zheng } 4432ad48fd75SYan, Zheng 4433ad48fd75SYan, Zheng /* 4434ad48fd75SYan, Zheng * This function splits a single item into two items, 4435ad48fd75SYan, Zheng * giving 'new_key' to the new item and splitting the 4436ad48fd75SYan, Zheng * old one at split_offset (from the start of the item). 4437ad48fd75SYan, Zheng * 4438ad48fd75SYan, Zheng * The path may be released by this operation. After 4439ad48fd75SYan, Zheng * the split, the path is pointing to the old item. The 4440ad48fd75SYan, Zheng * new item is going to be in the same node as the old one. 4441ad48fd75SYan, Zheng * 4442ad48fd75SYan, Zheng * Note, the item being split must be smaller enough to live alone on 4443ad48fd75SYan, Zheng * a tree block with room for one extra struct btrfs_item 4444ad48fd75SYan, Zheng * 4445ad48fd75SYan, Zheng * This allows us to split the item in place, keeping a lock on the 4446ad48fd75SYan, Zheng * leaf the entire time. 4447ad48fd75SYan, Zheng */ 4448ad48fd75SYan, Zheng int btrfs_split_item(struct btrfs_trans_handle *trans, 4449ad48fd75SYan, Zheng struct btrfs_root *root, 4450ad48fd75SYan, Zheng struct btrfs_path *path, 4451310712b2SOmar Sandoval const struct btrfs_key *new_key, 4452ad48fd75SYan, Zheng unsigned long split_offset) 4453ad48fd75SYan, Zheng { 4454ad48fd75SYan, Zheng int ret; 4455ad48fd75SYan, Zheng ret = setup_leaf_for_split(trans, root, path, 4456ad48fd75SYan, Zheng sizeof(struct btrfs_item)); 4457ad48fd75SYan, Zheng if (ret) 4458459931ecSChris Mason return ret; 4459ad48fd75SYan, Zheng 446025263cd7SDavid Sterba ret = split_item(path, new_key, split_offset); 4461ad48fd75SYan, Zheng return ret; 4462ad48fd75SYan, Zheng } 4463ad48fd75SYan, Zheng 4464ad48fd75SYan, Zheng /* 4465ad48fd75SYan, Zheng * This function duplicate a item, giving 'new_key' to the new item. 4466ad48fd75SYan, Zheng * It guarantees both items live in the same tree leaf and the new item 4467ad48fd75SYan, Zheng * is contiguous with the original item. 4468ad48fd75SYan, Zheng * 4469ad48fd75SYan, Zheng * This allows us to split file extent in place, keeping a lock on the 4470ad48fd75SYan, Zheng * leaf the entire time. 4471ad48fd75SYan, Zheng */ 4472ad48fd75SYan, Zheng int btrfs_duplicate_item(struct btrfs_trans_handle *trans, 4473ad48fd75SYan, Zheng struct btrfs_root *root, 4474ad48fd75SYan, Zheng struct btrfs_path *path, 4475310712b2SOmar Sandoval const struct btrfs_key *new_key) 4476ad48fd75SYan, Zheng { 4477ad48fd75SYan, Zheng struct extent_buffer *leaf; 4478ad48fd75SYan, Zheng int ret; 4479ad48fd75SYan, Zheng u32 item_size; 4480ad48fd75SYan, Zheng 4481ad48fd75SYan, Zheng leaf = path->nodes[0]; 4482ad48fd75SYan, Zheng item_size = btrfs_item_size_nr(leaf, path->slots[0]); 4483ad48fd75SYan, Zheng ret = setup_leaf_for_split(trans, root, path, 4484ad48fd75SYan, Zheng item_size + sizeof(struct btrfs_item)); 4485ad48fd75SYan, Zheng if (ret) 4486ad48fd75SYan, Zheng return ret; 4487ad48fd75SYan, Zheng 4488ad48fd75SYan, Zheng path->slots[0]++; 4489fc0d82e1SNikolay Borisov setup_items_for_insert(root, path, new_key, &item_size, 1); 4490ad48fd75SYan, Zheng leaf = path->nodes[0]; 4491ad48fd75SYan, Zheng memcpy_extent_buffer(leaf, 4492ad48fd75SYan, Zheng btrfs_item_ptr_offset(leaf, path->slots[0]), 4493ad48fd75SYan, Zheng btrfs_item_ptr_offset(leaf, path->slots[0] - 1), 4494ad48fd75SYan, Zheng item_size); 4495ad48fd75SYan, Zheng return 0; 4496459931ecSChris Mason } 4497459931ecSChris Mason 4498459931ecSChris Mason /* 4499d352ac68SChris Mason * make the item pointed to by the path smaller. new_size indicates 4500d352ac68SChris Mason * how small to make it, and from_end tells us if we just chop bytes 4501d352ac68SChris Mason * off the end of the item or if we shift the item to chop bytes off 4502d352ac68SChris Mason * the front. 4503d352ac68SChris Mason */ 450478ac4f9eSDavid Sterba void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end) 4505b18c6685SChris Mason { 4506b18c6685SChris Mason int slot; 45075f39d397SChris Mason struct extent_buffer *leaf; 45085f39d397SChris Mason struct btrfs_item *item; 4509b18c6685SChris Mason u32 nritems; 4510b18c6685SChris Mason unsigned int data_end; 4511b18c6685SChris Mason unsigned int old_data_start; 4512b18c6685SChris Mason unsigned int old_size; 4513b18c6685SChris Mason unsigned int size_diff; 4514b18c6685SChris Mason int i; 4515cfed81a0SChris Mason struct btrfs_map_token token; 4516cfed81a0SChris Mason 45175f39d397SChris Mason leaf = path->nodes[0]; 4518179e29e4SChris Mason slot = path->slots[0]; 4519179e29e4SChris Mason 4520179e29e4SChris Mason old_size = btrfs_item_size_nr(leaf, slot); 4521179e29e4SChris Mason if (old_size == new_size) 4522143bede5SJeff Mahoney return; 4523b18c6685SChris Mason 45245f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 45258f881e8cSDavid Sterba data_end = leaf_data_end(leaf); 4526b18c6685SChris Mason 45275f39d397SChris Mason old_data_start = btrfs_item_offset_nr(leaf, slot); 4528179e29e4SChris Mason 4529b18c6685SChris Mason size_diff = old_size - new_size; 4530b18c6685SChris Mason 4531b18c6685SChris Mason BUG_ON(slot < 0); 4532b18c6685SChris Mason BUG_ON(slot >= nritems); 4533b18c6685SChris Mason 4534b18c6685SChris Mason /* 4535b18c6685SChris Mason * item0..itemN ... dataN.offset..dataN.size .. data0.size 4536b18c6685SChris Mason */ 4537b18c6685SChris Mason /* first correct the data pointers */ 4538c82f823cSDavid Sterba btrfs_init_map_token(&token, leaf); 4539b18c6685SChris Mason for (i = slot; i < nritems; i++) { 45405f39d397SChris Mason u32 ioff; 4541dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 4542db94535dSChris Mason 4543cc4c13d5SDavid Sterba ioff = btrfs_token_item_offset(&token, item); 4544cc4c13d5SDavid Sterba btrfs_set_token_item_offset(&token, item, ioff + size_diff); 4545b18c6685SChris Mason } 4546db94535dSChris Mason 4547b18c6685SChris Mason /* shift the data */ 4548179e29e4SChris Mason if (from_end) { 45493d9ec8c4SNikolay Borisov memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + 45503d9ec8c4SNikolay Borisov data_end + size_diff, BTRFS_LEAF_DATA_OFFSET + 4551b18c6685SChris Mason data_end, old_data_start + new_size - data_end); 4552179e29e4SChris Mason } else { 4553179e29e4SChris Mason struct btrfs_disk_key disk_key; 4554179e29e4SChris Mason u64 offset; 4555179e29e4SChris Mason 4556179e29e4SChris Mason btrfs_item_key(leaf, &disk_key, slot); 4557179e29e4SChris Mason 4558179e29e4SChris Mason if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { 4559179e29e4SChris Mason unsigned long ptr; 4560179e29e4SChris Mason struct btrfs_file_extent_item *fi; 4561179e29e4SChris Mason 4562179e29e4SChris Mason fi = btrfs_item_ptr(leaf, slot, 4563179e29e4SChris Mason struct btrfs_file_extent_item); 4564179e29e4SChris Mason fi = (struct btrfs_file_extent_item *)( 4565179e29e4SChris Mason (unsigned long)fi - size_diff); 4566179e29e4SChris Mason 4567179e29e4SChris Mason if (btrfs_file_extent_type(leaf, fi) == 4568179e29e4SChris Mason BTRFS_FILE_EXTENT_INLINE) { 4569179e29e4SChris Mason ptr = btrfs_item_ptr_offset(leaf, slot); 4570179e29e4SChris Mason memmove_extent_buffer(leaf, ptr, 4571179e29e4SChris Mason (unsigned long)fi, 45727ec20afbSDavid Sterba BTRFS_FILE_EXTENT_INLINE_DATA_START); 4573179e29e4SChris Mason } 4574179e29e4SChris Mason } 4575179e29e4SChris Mason 45763d9ec8c4SNikolay Borisov memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + 45773d9ec8c4SNikolay Borisov data_end + size_diff, BTRFS_LEAF_DATA_OFFSET + 4578179e29e4SChris Mason data_end, old_data_start - data_end); 4579179e29e4SChris Mason 4580179e29e4SChris Mason offset = btrfs_disk_key_offset(&disk_key); 4581179e29e4SChris Mason btrfs_set_disk_key_offset(&disk_key, offset + size_diff); 4582179e29e4SChris Mason btrfs_set_item_key(leaf, &disk_key, slot); 4583179e29e4SChris Mason if (slot == 0) 4584b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 4585179e29e4SChris Mason } 45865f39d397SChris Mason 4587dd3cc16bSRoss Kirk item = btrfs_item_nr(slot); 45885f39d397SChris Mason btrfs_set_item_size(leaf, item, new_size); 45895f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 4590b18c6685SChris Mason 4591e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < 0) { 4592a4f78750SDavid Sterba btrfs_print_leaf(leaf); 4593b18c6685SChris Mason BUG(); 45945f39d397SChris Mason } 4595b18c6685SChris Mason } 4596b18c6685SChris Mason 4597d352ac68SChris Mason /* 45988f69dbd2SStefan Behrens * make the item pointed to by the path bigger, data_size is the added size. 4599d352ac68SChris Mason */ 4600c71dd880SDavid Sterba void btrfs_extend_item(struct btrfs_path *path, u32 data_size) 46016567e837SChris Mason { 46026567e837SChris Mason int slot; 46035f39d397SChris Mason struct extent_buffer *leaf; 46045f39d397SChris Mason struct btrfs_item *item; 46056567e837SChris Mason u32 nritems; 46066567e837SChris Mason unsigned int data_end; 46076567e837SChris Mason unsigned int old_data; 46086567e837SChris Mason unsigned int old_size; 46096567e837SChris Mason int i; 4610cfed81a0SChris Mason struct btrfs_map_token token; 4611cfed81a0SChris Mason 46125f39d397SChris Mason leaf = path->nodes[0]; 46136567e837SChris Mason 46145f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 46158f881e8cSDavid Sterba data_end = leaf_data_end(leaf); 46166567e837SChris Mason 4617e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < data_size) { 4618a4f78750SDavid Sterba btrfs_print_leaf(leaf); 46196567e837SChris Mason BUG(); 46205f39d397SChris Mason } 46216567e837SChris Mason slot = path->slots[0]; 46225f39d397SChris Mason old_data = btrfs_item_end_nr(leaf, slot); 46236567e837SChris Mason 46246567e837SChris Mason BUG_ON(slot < 0); 46253326d1b0SChris Mason if (slot >= nritems) { 4626a4f78750SDavid Sterba btrfs_print_leaf(leaf); 4627c71dd880SDavid Sterba btrfs_crit(leaf->fs_info, "slot %d too large, nritems %d", 4628d397712bSChris Mason slot, nritems); 4629290342f6SArnd Bergmann BUG(); 46303326d1b0SChris Mason } 46316567e837SChris Mason 46326567e837SChris Mason /* 46336567e837SChris Mason * item0..itemN ... dataN.offset..dataN.size .. data0.size 46346567e837SChris Mason */ 46356567e837SChris Mason /* first correct the data pointers */ 4636c82f823cSDavid Sterba btrfs_init_map_token(&token, leaf); 46376567e837SChris Mason for (i = slot; i < nritems; i++) { 46385f39d397SChris Mason u32 ioff; 4639dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 4640db94535dSChris Mason 4641cc4c13d5SDavid Sterba ioff = btrfs_token_item_offset(&token, item); 4642cc4c13d5SDavid Sterba btrfs_set_token_item_offset(&token, item, ioff - data_size); 46436567e837SChris Mason } 46445f39d397SChris Mason 46456567e837SChris Mason /* shift the data */ 46463d9ec8c4SNikolay Borisov memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + 46473d9ec8c4SNikolay Borisov data_end - data_size, BTRFS_LEAF_DATA_OFFSET + 46486567e837SChris Mason data_end, old_data - data_end); 46495f39d397SChris Mason 46506567e837SChris Mason data_end = old_data; 46515f39d397SChris Mason old_size = btrfs_item_size_nr(leaf, slot); 4652dd3cc16bSRoss Kirk item = btrfs_item_nr(slot); 46535f39d397SChris Mason btrfs_set_item_size(leaf, item, old_size + data_size); 46545f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 46556567e837SChris Mason 4656e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < 0) { 4657a4f78750SDavid Sterba btrfs_print_leaf(leaf); 46586567e837SChris Mason BUG(); 46595f39d397SChris Mason } 46606567e837SChris Mason } 46616567e837SChris Mason 4662da9ffb24SNikolay Borisov /** 4663da9ffb24SNikolay Borisov * setup_items_for_insert - Helper called before inserting one or more items 4664da9ffb24SNikolay Borisov * to a leaf. Main purpose is to save stack depth by doing the bulk of the work 4665da9ffb24SNikolay Borisov * in a function that doesn't call btrfs_search_slot 4666da9ffb24SNikolay Borisov * 4667da9ffb24SNikolay Borisov * @root: root we are inserting items to 4668da9ffb24SNikolay Borisov * @path: points to the leaf/slot where we are going to insert new items 4669da9ffb24SNikolay Borisov * @cpu_key: array of keys for items to be inserted 4670da9ffb24SNikolay Borisov * @data_size: size of the body of each item we are going to insert 4671da9ffb24SNikolay Borisov * @nr: size of @cpu_key/@data_size arrays 467274123bd7SChris Mason */ 4673afe5fea7STsutomu Itoh void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path, 4674310712b2SOmar Sandoval const struct btrfs_key *cpu_key, u32 *data_size, 4675fc0d82e1SNikolay Borisov int nr) 4676be0e5c09SChris Mason { 46770b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 46785f39d397SChris Mason struct btrfs_item *item; 46799c58309dSChris Mason int i; 46807518a238SChris Mason u32 nritems; 4681be0e5c09SChris Mason unsigned int data_end; 4682e2fa7227SChris Mason struct btrfs_disk_key disk_key; 468344871b1bSChris Mason struct extent_buffer *leaf; 468444871b1bSChris Mason int slot; 4685cfed81a0SChris Mason struct btrfs_map_token token; 4686fc0d82e1SNikolay Borisov u32 total_size; 4687fc0d82e1SNikolay Borisov u32 total_data = 0; 4688fc0d82e1SNikolay Borisov 4689fc0d82e1SNikolay Borisov for (i = 0; i < nr; i++) 4690fc0d82e1SNikolay Borisov total_data += data_size[i]; 4691fc0d82e1SNikolay Borisov total_size = total_data + (nr * sizeof(struct btrfs_item)); 4692cfed81a0SChris Mason 469324cdc847SFilipe Manana if (path->slots[0] == 0) { 469424cdc847SFilipe Manana btrfs_cpu_key_to_disk(&disk_key, cpu_key); 4695b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 469624cdc847SFilipe Manana } 469724cdc847SFilipe Manana btrfs_unlock_up_safe(path, 1); 469824cdc847SFilipe Manana 46995f39d397SChris Mason leaf = path->nodes[0]; 470044871b1bSChris Mason slot = path->slots[0]; 470174123bd7SChris Mason 47025f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 47038f881e8cSDavid Sterba data_end = leaf_data_end(leaf); 4704eb60ceacSChris Mason 4705e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < total_size) { 4706a4f78750SDavid Sterba btrfs_print_leaf(leaf); 47070b246afaSJeff Mahoney btrfs_crit(fs_info, "not enough freespace need %u have %d", 4708e902baacSDavid Sterba total_size, btrfs_leaf_free_space(leaf)); 4709be0e5c09SChris Mason BUG(); 4710d4dbff95SChris Mason } 47115f39d397SChris Mason 4712c82f823cSDavid Sterba btrfs_init_map_token(&token, leaf); 4713be0e5c09SChris Mason if (slot != nritems) { 47145f39d397SChris Mason unsigned int old_data = btrfs_item_end_nr(leaf, slot); 4715be0e5c09SChris Mason 47165f39d397SChris Mason if (old_data < data_end) { 4717a4f78750SDavid Sterba btrfs_print_leaf(leaf); 47187269ddd2SNikolay Borisov btrfs_crit(fs_info, 47197269ddd2SNikolay Borisov "item at slot %d with data offset %u beyond data end of leaf %u", 47205f39d397SChris Mason slot, old_data, data_end); 4721290342f6SArnd Bergmann BUG(); 47225f39d397SChris Mason } 4723be0e5c09SChris Mason /* 4724be0e5c09SChris Mason * item0..itemN ... dataN.offset..dataN.size .. data0.size 4725be0e5c09SChris Mason */ 4726be0e5c09SChris Mason /* first correct the data pointers */ 47270783fcfcSChris Mason for (i = slot; i < nritems; i++) { 47285f39d397SChris Mason u32 ioff; 4729db94535dSChris Mason 4730dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 4731cc4c13d5SDavid Sterba ioff = btrfs_token_item_offset(&token, item); 4732cc4c13d5SDavid Sterba btrfs_set_token_item_offset(&token, item, 4733cc4c13d5SDavid Sterba ioff - total_data); 47340783fcfcSChris Mason } 4735be0e5c09SChris Mason /* shift the items */ 47369c58309dSChris Mason memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), 47375f39d397SChris Mason btrfs_item_nr_offset(slot), 47380783fcfcSChris Mason (nritems - slot) * sizeof(struct btrfs_item)); 4739be0e5c09SChris Mason 4740be0e5c09SChris Mason /* shift the data */ 47413d9ec8c4SNikolay Borisov memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + 47423d9ec8c4SNikolay Borisov data_end - total_data, BTRFS_LEAF_DATA_OFFSET + 4743be0e5c09SChris Mason data_end, old_data - data_end); 4744be0e5c09SChris Mason data_end = old_data; 4745be0e5c09SChris Mason } 47465f39d397SChris Mason 474762e2749eSChris Mason /* setup the item for the new data */ 47489c58309dSChris Mason for (i = 0; i < nr; i++) { 47499c58309dSChris Mason btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); 47509c58309dSChris Mason btrfs_set_item_key(leaf, &disk_key, slot + i); 4751dd3cc16bSRoss Kirk item = btrfs_item_nr(slot + i); 47529c58309dSChris Mason data_end -= data_size[i]; 4753fc0716c2SNikolay Borisov btrfs_set_token_item_offset(&token, item, data_end); 4754cc4c13d5SDavid Sterba btrfs_set_token_item_size(&token, item, data_size[i]); 47559c58309dSChris Mason } 475644871b1bSChris Mason 47579c58309dSChris Mason btrfs_set_header_nritems(leaf, nritems + nr); 4758b9473439SChris Mason btrfs_mark_buffer_dirty(leaf); 4759aa5d6bedSChris Mason 4760e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < 0) { 4761a4f78750SDavid Sterba btrfs_print_leaf(leaf); 4762be0e5c09SChris Mason BUG(); 47635f39d397SChris Mason } 476444871b1bSChris Mason } 476544871b1bSChris Mason 476644871b1bSChris Mason /* 476744871b1bSChris Mason * Given a key and some data, insert items into the tree. 476844871b1bSChris Mason * This does all the path init required, making room in the tree if needed. 476944871b1bSChris Mason */ 477044871b1bSChris Mason int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, 477144871b1bSChris Mason struct btrfs_root *root, 477244871b1bSChris Mason struct btrfs_path *path, 4773310712b2SOmar Sandoval const struct btrfs_key *cpu_key, u32 *data_size, 477444871b1bSChris Mason int nr) 477544871b1bSChris Mason { 477644871b1bSChris Mason int ret = 0; 477744871b1bSChris Mason int slot; 477844871b1bSChris Mason int i; 477944871b1bSChris Mason u32 total_size = 0; 478044871b1bSChris Mason u32 total_data = 0; 478144871b1bSChris Mason 478244871b1bSChris Mason for (i = 0; i < nr; i++) 478344871b1bSChris Mason total_data += data_size[i]; 478444871b1bSChris Mason 478544871b1bSChris Mason total_size = total_data + (nr * sizeof(struct btrfs_item)); 478644871b1bSChris Mason ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); 478744871b1bSChris Mason if (ret == 0) 478844871b1bSChris Mason return -EEXIST; 478944871b1bSChris Mason if (ret < 0) 4790143bede5SJeff Mahoney return ret; 479144871b1bSChris Mason 479244871b1bSChris Mason slot = path->slots[0]; 479344871b1bSChris Mason BUG_ON(slot < 0); 479444871b1bSChris Mason 4795fc0d82e1SNikolay Borisov setup_items_for_insert(root, path, cpu_key, data_size, nr); 4796143bede5SJeff Mahoney return 0; 479762e2749eSChris Mason } 479862e2749eSChris Mason 479962e2749eSChris Mason /* 480062e2749eSChris Mason * Given a key and some data, insert an item into the tree. 480162e2749eSChris Mason * This does all the path init required, making room in the tree if needed. 480262e2749eSChris Mason */ 4803310712b2SOmar Sandoval int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, 4804310712b2SOmar Sandoval const struct btrfs_key *cpu_key, void *data, 4805310712b2SOmar Sandoval u32 data_size) 480662e2749eSChris Mason { 480762e2749eSChris Mason int ret = 0; 48082c90e5d6SChris Mason struct btrfs_path *path; 48095f39d397SChris Mason struct extent_buffer *leaf; 48105f39d397SChris Mason unsigned long ptr; 481162e2749eSChris Mason 48122c90e5d6SChris Mason path = btrfs_alloc_path(); 4813db5b493aSTsutomu Itoh if (!path) 4814db5b493aSTsutomu Itoh return -ENOMEM; 48152c90e5d6SChris Mason ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); 481662e2749eSChris Mason if (!ret) { 48175f39d397SChris Mason leaf = path->nodes[0]; 48185f39d397SChris Mason ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); 48195f39d397SChris Mason write_extent_buffer(leaf, data, ptr, data_size); 48205f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 482162e2749eSChris Mason } 48222c90e5d6SChris Mason btrfs_free_path(path); 4823aa5d6bedSChris Mason return ret; 4824be0e5c09SChris Mason } 4825be0e5c09SChris Mason 482674123bd7SChris Mason /* 48275de08d7dSChris Mason * delete the pointer from a given node. 482874123bd7SChris Mason * 4829d352ac68SChris Mason * the tree should have been previously balanced so the deletion does not 4830d352ac68SChris Mason * empty a node. 483174123bd7SChris Mason */ 4832afe5fea7STsutomu Itoh static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, 4833afe5fea7STsutomu Itoh int level, int slot) 4834be0e5c09SChris Mason { 48355f39d397SChris Mason struct extent_buffer *parent = path->nodes[level]; 48367518a238SChris Mason u32 nritems; 4837f3ea38daSJan Schmidt int ret; 4838be0e5c09SChris Mason 48395f39d397SChris Mason nritems = btrfs_header_nritems(parent); 4840be0e5c09SChris Mason if (slot != nritems - 1) { 4841bf1d3425SDavid Sterba if (level) { 4842bf1d3425SDavid Sterba ret = tree_mod_log_insert_move(parent, slot, slot + 1, 4843a446a979SDavid Sterba nritems - slot - 1); 4844bf1d3425SDavid Sterba BUG_ON(ret < 0); 4845bf1d3425SDavid Sterba } 48465f39d397SChris Mason memmove_extent_buffer(parent, 48475f39d397SChris Mason btrfs_node_key_ptr_offset(slot), 48485f39d397SChris Mason btrfs_node_key_ptr_offset(slot + 1), 4849d6025579SChris Mason sizeof(struct btrfs_key_ptr) * 4850d6025579SChris Mason (nritems - slot - 1)); 485157ba86c0SChris Mason } else if (level) { 4852e09c2efeSDavid Sterba ret = tree_mod_log_insert_key(parent, slot, MOD_LOG_KEY_REMOVE, 4853e09c2efeSDavid Sterba GFP_NOFS); 485457ba86c0SChris Mason BUG_ON(ret < 0); 4855be0e5c09SChris Mason } 4856f3ea38daSJan Schmidt 48577518a238SChris Mason nritems--; 48585f39d397SChris Mason btrfs_set_header_nritems(parent, nritems); 48597518a238SChris Mason if (nritems == 0 && parent == root->node) { 48605f39d397SChris Mason BUG_ON(btrfs_header_level(root->node) != 1); 4861eb60ceacSChris Mason /* just turn the root into a leaf and break */ 48625f39d397SChris Mason btrfs_set_header_level(root->node, 0); 4863bb803951SChris Mason } else if (slot == 0) { 48645f39d397SChris Mason struct btrfs_disk_key disk_key; 48655f39d397SChris Mason 48665f39d397SChris Mason btrfs_node_key(parent, &disk_key, 0); 4867b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, level + 1); 4868be0e5c09SChris Mason } 4869d6025579SChris Mason btrfs_mark_buffer_dirty(parent); 4870be0e5c09SChris Mason } 4871be0e5c09SChris Mason 487274123bd7SChris Mason /* 4873323ac95bSChris Mason * a helper function to delete the leaf pointed to by path->slots[1] and 48745d4f98a2SYan Zheng * path->nodes[1]. 4875323ac95bSChris Mason * 4876323ac95bSChris Mason * This deletes the pointer in path->nodes[1] and frees the leaf 4877323ac95bSChris Mason * block extent. zero is returned if it all worked out, < 0 otherwise. 4878323ac95bSChris Mason * 4879323ac95bSChris Mason * The path must have already been setup for deleting the leaf, including 4880323ac95bSChris Mason * all the proper balancing. path->nodes[1] must be locked. 4881323ac95bSChris Mason */ 4882143bede5SJeff Mahoney static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, 4883323ac95bSChris Mason struct btrfs_root *root, 48845d4f98a2SYan Zheng struct btrfs_path *path, 48855d4f98a2SYan Zheng struct extent_buffer *leaf) 4886323ac95bSChris Mason { 48875d4f98a2SYan Zheng WARN_ON(btrfs_header_generation(leaf) != trans->transid); 4888afe5fea7STsutomu Itoh del_ptr(root, path, 1, path->slots[1]); 4889323ac95bSChris Mason 48904d081c41SChris Mason /* 48914d081c41SChris Mason * btrfs_free_extent is expensive, we want to make sure we 48924d081c41SChris Mason * aren't holding any locks when we call it 48934d081c41SChris Mason */ 48944d081c41SChris Mason btrfs_unlock_up_safe(path, 0); 48954d081c41SChris Mason 4896f0486c68SYan, Zheng root_sub_used(root, leaf->len); 4897f0486c68SYan, Zheng 489867439dadSDavid Sterba atomic_inc(&leaf->refs); 48995581a51aSJan Schmidt btrfs_free_tree_block(trans, root, leaf, 0, 1); 49003083ee2eSJosef Bacik free_extent_buffer_stale(leaf); 4901323ac95bSChris Mason } 4902323ac95bSChris Mason /* 490374123bd7SChris Mason * delete the item at the leaf level in path. If that empties 490474123bd7SChris Mason * the leaf, remove it from the tree 490574123bd7SChris Mason */ 490685e21bacSChris Mason int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, 490785e21bacSChris Mason struct btrfs_path *path, int slot, int nr) 4908be0e5c09SChris Mason { 49090b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 49105f39d397SChris Mason struct extent_buffer *leaf; 49115f39d397SChris Mason struct btrfs_item *item; 4912ce0eac2aSAlexandru Moise u32 last_off; 4913ce0eac2aSAlexandru Moise u32 dsize = 0; 4914aa5d6bedSChris Mason int ret = 0; 4915aa5d6bedSChris Mason int wret; 491685e21bacSChris Mason int i; 49177518a238SChris Mason u32 nritems; 4918be0e5c09SChris Mason 49195f39d397SChris Mason leaf = path->nodes[0]; 492085e21bacSChris Mason last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); 492185e21bacSChris Mason 492285e21bacSChris Mason for (i = 0; i < nr; i++) 492385e21bacSChris Mason dsize += btrfs_item_size_nr(leaf, slot + i); 492485e21bacSChris Mason 49255f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 4926be0e5c09SChris Mason 492785e21bacSChris Mason if (slot + nr != nritems) { 49288f881e8cSDavid Sterba int data_end = leaf_data_end(leaf); 4929c82f823cSDavid Sterba struct btrfs_map_token token; 49305f39d397SChris Mason 49313d9ec8c4SNikolay Borisov memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + 4932d6025579SChris Mason data_end + dsize, 49333d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + data_end, 493485e21bacSChris Mason last_off - data_end); 49355f39d397SChris Mason 4936c82f823cSDavid Sterba btrfs_init_map_token(&token, leaf); 493785e21bacSChris Mason for (i = slot + nr; i < nritems; i++) { 49385f39d397SChris Mason u32 ioff; 4939db94535dSChris Mason 4940dd3cc16bSRoss Kirk item = btrfs_item_nr(i); 4941cc4c13d5SDavid Sterba ioff = btrfs_token_item_offset(&token, item); 4942cc4c13d5SDavid Sterba btrfs_set_token_item_offset(&token, item, ioff + dsize); 49430783fcfcSChris Mason } 4944db94535dSChris Mason 49455f39d397SChris Mason memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), 494685e21bacSChris Mason btrfs_item_nr_offset(slot + nr), 49470783fcfcSChris Mason sizeof(struct btrfs_item) * 494885e21bacSChris Mason (nritems - slot - nr)); 4949be0e5c09SChris Mason } 495085e21bacSChris Mason btrfs_set_header_nritems(leaf, nritems - nr); 495185e21bacSChris Mason nritems -= nr; 49525f39d397SChris Mason 495374123bd7SChris Mason /* delete the leaf if we've emptied it */ 49547518a238SChris Mason if (nritems == 0) { 49555f39d397SChris Mason if (leaf == root->node) { 49565f39d397SChris Mason btrfs_set_header_level(leaf, 0); 49579a8dd150SChris Mason } else { 49586a884d7dSDavid Sterba btrfs_clean_tree_block(leaf); 4959143bede5SJeff Mahoney btrfs_del_leaf(trans, root, path, leaf); 49609a8dd150SChris Mason } 4961be0e5c09SChris Mason } else { 49627518a238SChris Mason int used = leaf_space_used(leaf, 0, nritems); 4963aa5d6bedSChris Mason if (slot == 0) { 49645f39d397SChris Mason struct btrfs_disk_key disk_key; 49655f39d397SChris Mason 49665f39d397SChris Mason btrfs_item_key(leaf, &disk_key, 0); 4967b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 4968aa5d6bedSChris Mason } 4969aa5d6bedSChris Mason 497074123bd7SChris Mason /* delete the leaf if it is mostly empty */ 49710b246afaSJeff Mahoney if (used < BTRFS_LEAF_DATA_SIZE(fs_info) / 3) { 4972be0e5c09SChris Mason /* push_leaf_left fixes the path. 4973be0e5c09SChris Mason * make sure the path still points to our leaf 4974be0e5c09SChris Mason * for possible call to del_ptr below 4975be0e5c09SChris Mason */ 49764920c9acSChris Mason slot = path->slots[1]; 497767439dadSDavid Sterba atomic_inc(&leaf->refs); 49785f39d397SChris Mason 497999d8f83cSChris Mason wret = push_leaf_left(trans, root, path, 1, 1, 498099d8f83cSChris Mason 1, (u32)-1); 498154aa1f4dSChris Mason if (wret < 0 && wret != -ENOSPC) 4982aa5d6bedSChris Mason ret = wret; 49835f39d397SChris Mason 49845f39d397SChris Mason if (path->nodes[0] == leaf && 49855f39d397SChris Mason btrfs_header_nritems(leaf)) { 498699d8f83cSChris Mason wret = push_leaf_right(trans, root, path, 1, 498799d8f83cSChris Mason 1, 1, 0); 498854aa1f4dSChris Mason if (wret < 0 && wret != -ENOSPC) 4989aa5d6bedSChris Mason ret = wret; 4990aa5d6bedSChris Mason } 49915f39d397SChris Mason 49925f39d397SChris Mason if (btrfs_header_nritems(leaf) == 0) { 4993323ac95bSChris Mason path->slots[1] = slot; 4994143bede5SJeff Mahoney btrfs_del_leaf(trans, root, path, leaf); 49955f39d397SChris Mason free_extent_buffer(leaf); 4996143bede5SJeff Mahoney ret = 0; 49975de08d7dSChris Mason } else { 4998925baeddSChris Mason /* if we're still in the path, make sure 4999925baeddSChris Mason * we're dirty. Otherwise, one of the 5000925baeddSChris Mason * push_leaf functions must have already 5001925baeddSChris Mason * dirtied this buffer 5002925baeddSChris Mason */ 5003925baeddSChris Mason if (path->nodes[0] == leaf) 50045f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 50055f39d397SChris Mason free_extent_buffer(leaf); 5006be0e5c09SChris Mason } 5007d5719762SChris Mason } else { 50085f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 5009be0e5c09SChris Mason } 50109a8dd150SChris Mason } 5011aa5d6bedSChris Mason return ret; 50129a8dd150SChris Mason } 50139a8dd150SChris Mason 501497571fd0SChris Mason /* 5015925baeddSChris Mason * search the tree again to find a leaf with lesser keys 50167bb86316SChris Mason * returns 0 if it found something or 1 if there are no lesser leaves. 50177bb86316SChris Mason * returns < 0 on io errors. 5018d352ac68SChris Mason * 5019d352ac68SChris Mason * This may release the path, and so you may lose any locks held at the 5020d352ac68SChris Mason * time you call it. 50217bb86316SChris Mason */ 502216e7549fSJosef Bacik int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) 50237bb86316SChris Mason { 5024925baeddSChris Mason struct btrfs_key key; 5025925baeddSChris Mason struct btrfs_disk_key found_key; 5026925baeddSChris Mason int ret; 50277bb86316SChris Mason 5028925baeddSChris Mason btrfs_item_key_to_cpu(path->nodes[0], &key, 0); 5029925baeddSChris Mason 5030e8b0d724SFilipe David Borba Manana if (key.offset > 0) { 5031925baeddSChris Mason key.offset--; 5032e8b0d724SFilipe David Borba Manana } else if (key.type > 0) { 5033925baeddSChris Mason key.type--; 5034e8b0d724SFilipe David Borba Manana key.offset = (u64)-1; 5035e8b0d724SFilipe David Borba Manana } else if (key.objectid > 0) { 5036925baeddSChris Mason key.objectid--; 5037e8b0d724SFilipe David Borba Manana key.type = (u8)-1; 5038e8b0d724SFilipe David Borba Manana key.offset = (u64)-1; 5039e8b0d724SFilipe David Borba Manana } else { 50407bb86316SChris Mason return 1; 5041e8b0d724SFilipe David Borba Manana } 50427bb86316SChris Mason 5043b3b4aa74SDavid Sterba btrfs_release_path(path); 5044925baeddSChris Mason ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5045925baeddSChris Mason if (ret < 0) 5046925baeddSChris Mason return ret; 5047925baeddSChris Mason btrfs_item_key(path->nodes[0], &found_key, 0); 5048925baeddSChris Mason ret = comp_keys(&found_key, &key); 5049337c6f68SFilipe Manana /* 5050337c6f68SFilipe Manana * We might have had an item with the previous key in the tree right 5051337c6f68SFilipe Manana * before we released our path. And after we released our path, that 5052337c6f68SFilipe Manana * item might have been pushed to the first slot (0) of the leaf we 5053337c6f68SFilipe Manana * were holding due to a tree balance. Alternatively, an item with the 5054337c6f68SFilipe Manana * previous key can exist as the only element of a leaf (big fat item). 5055337c6f68SFilipe Manana * Therefore account for these 2 cases, so that our callers (like 5056337c6f68SFilipe Manana * btrfs_previous_item) don't miss an existing item with a key matching 5057337c6f68SFilipe Manana * the previous key we computed above. 5058337c6f68SFilipe Manana */ 5059337c6f68SFilipe Manana if (ret <= 0) 50607bb86316SChris Mason return 0; 5061925baeddSChris Mason return 1; 50627bb86316SChris Mason } 50637bb86316SChris Mason 50643f157a2fSChris Mason /* 50653f157a2fSChris Mason * A helper function to walk down the tree starting at min_key, and looking 5066de78b51aSEric Sandeen * for nodes or leaves that are have a minimum transaction id. 5067de78b51aSEric Sandeen * This is used by the btree defrag code, and tree logging 50683f157a2fSChris Mason * 50693f157a2fSChris Mason * This does not cow, but it does stuff the starting key it finds back 50703f157a2fSChris Mason * into min_key, so you can call btrfs_search_slot with cow=1 on the 50713f157a2fSChris Mason * key and get a writable path. 50723f157a2fSChris Mason * 50733f157a2fSChris Mason * This honors path->lowest_level to prevent descent past a given level 50743f157a2fSChris Mason * of the tree. 50753f157a2fSChris Mason * 5076d352ac68SChris Mason * min_trans indicates the oldest transaction that you are interested 5077d352ac68SChris Mason * in walking through. Any nodes or leaves older than min_trans are 5078d352ac68SChris Mason * skipped over (without reading them). 5079d352ac68SChris Mason * 50803f157a2fSChris Mason * returns zero if something useful was found, < 0 on error and 1 if there 50813f157a2fSChris Mason * was nothing in the tree that matched the search criteria. 50823f157a2fSChris Mason */ 50833f157a2fSChris Mason int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, 5084de78b51aSEric Sandeen struct btrfs_path *path, 50853f157a2fSChris Mason u64 min_trans) 50863f157a2fSChris Mason { 50873f157a2fSChris Mason struct extent_buffer *cur; 50883f157a2fSChris Mason struct btrfs_key found_key; 50893f157a2fSChris Mason int slot; 50909652480bSYan int sret; 50913f157a2fSChris Mason u32 nritems; 50923f157a2fSChris Mason int level; 50933f157a2fSChris Mason int ret = 1; 5094f98de9b9SFilipe Manana int keep_locks = path->keep_locks; 50953f157a2fSChris Mason 5096f98de9b9SFilipe Manana path->keep_locks = 1; 50973f157a2fSChris Mason again: 5098bd681513SChris Mason cur = btrfs_read_lock_root_node(root); 50993f157a2fSChris Mason level = btrfs_header_level(cur); 5100e02119d5SChris Mason WARN_ON(path->nodes[level]); 51013f157a2fSChris Mason path->nodes[level] = cur; 5102bd681513SChris Mason path->locks[level] = BTRFS_READ_LOCK; 51033f157a2fSChris Mason 51043f157a2fSChris Mason if (btrfs_header_generation(cur) < min_trans) { 51053f157a2fSChris Mason ret = 1; 51063f157a2fSChris Mason goto out; 51073f157a2fSChris Mason } 51083f157a2fSChris Mason while (1) { 51093f157a2fSChris Mason nritems = btrfs_header_nritems(cur); 51103f157a2fSChris Mason level = btrfs_header_level(cur); 5111e3b83361SQu Wenruo sret = btrfs_bin_search(cur, min_key, &slot); 5112cbca7d59SFilipe Manana if (sret < 0) { 5113cbca7d59SFilipe Manana ret = sret; 5114cbca7d59SFilipe Manana goto out; 5115cbca7d59SFilipe Manana } 51163f157a2fSChris Mason 5117323ac95bSChris Mason /* at the lowest level, we're done, setup the path and exit */ 5118323ac95bSChris Mason if (level == path->lowest_level) { 5119e02119d5SChris Mason if (slot >= nritems) 5120e02119d5SChris Mason goto find_next_key; 51213f157a2fSChris Mason ret = 0; 51223f157a2fSChris Mason path->slots[level] = slot; 51233f157a2fSChris Mason btrfs_item_key_to_cpu(cur, &found_key, slot); 51243f157a2fSChris Mason goto out; 51253f157a2fSChris Mason } 51269652480bSYan if (sret && slot > 0) 51279652480bSYan slot--; 51283f157a2fSChris Mason /* 5129de78b51aSEric Sandeen * check this node pointer against the min_trans parameters. 5130260db43cSRandy Dunlap * If it is too old, skip to the next one. 51313f157a2fSChris Mason */ 51323f157a2fSChris Mason while (slot < nritems) { 51333f157a2fSChris Mason u64 gen; 5134e02119d5SChris Mason 51353f157a2fSChris Mason gen = btrfs_node_ptr_generation(cur, slot); 51363f157a2fSChris Mason if (gen < min_trans) { 51373f157a2fSChris Mason slot++; 51383f157a2fSChris Mason continue; 51393f157a2fSChris Mason } 51403f157a2fSChris Mason break; 51413f157a2fSChris Mason } 5142e02119d5SChris Mason find_next_key: 51433f157a2fSChris Mason /* 51443f157a2fSChris Mason * we didn't find a candidate key in this node, walk forward 51453f157a2fSChris Mason * and find another one 51463f157a2fSChris Mason */ 51473f157a2fSChris Mason if (slot >= nritems) { 5148e02119d5SChris Mason path->slots[level] = slot; 5149e02119d5SChris Mason sret = btrfs_find_next_key(root, path, min_key, level, 5150de78b51aSEric Sandeen min_trans); 5151e02119d5SChris Mason if (sret == 0) { 5152b3b4aa74SDavid Sterba btrfs_release_path(path); 51533f157a2fSChris Mason goto again; 51543f157a2fSChris Mason } else { 51553f157a2fSChris Mason goto out; 51563f157a2fSChris Mason } 51573f157a2fSChris Mason } 51583f157a2fSChris Mason /* save our key for returning back */ 51593f157a2fSChris Mason btrfs_node_key_to_cpu(cur, &found_key, slot); 51603f157a2fSChris Mason path->slots[level] = slot; 51613f157a2fSChris Mason if (level == path->lowest_level) { 51623f157a2fSChris Mason ret = 0; 51633f157a2fSChris Mason goto out; 51643f157a2fSChris Mason } 51654b231ae4SDavid Sterba cur = btrfs_read_node_slot(cur, slot); 5166fb770ae4SLiu Bo if (IS_ERR(cur)) { 5167fb770ae4SLiu Bo ret = PTR_ERR(cur); 5168fb770ae4SLiu Bo goto out; 5169fb770ae4SLiu Bo } 51703f157a2fSChris Mason 5171bd681513SChris Mason btrfs_tree_read_lock(cur); 5172b4ce94deSChris Mason 5173bd681513SChris Mason path->locks[level - 1] = BTRFS_READ_LOCK; 51743f157a2fSChris Mason path->nodes[level - 1] = cur; 5175f7c79f30SChris Mason unlock_up(path, level, 1, 0, NULL); 51763f157a2fSChris Mason } 51773f157a2fSChris Mason out: 5178f98de9b9SFilipe Manana path->keep_locks = keep_locks; 5179f98de9b9SFilipe Manana if (ret == 0) { 5180f98de9b9SFilipe Manana btrfs_unlock_up_safe(path, path->lowest_level + 1); 5181f98de9b9SFilipe Manana memcpy(min_key, &found_key, sizeof(found_key)); 5182f98de9b9SFilipe Manana } 51833f157a2fSChris Mason return ret; 51843f157a2fSChris Mason } 51853f157a2fSChris Mason 51863f157a2fSChris Mason /* 51873f157a2fSChris Mason * this is similar to btrfs_next_leaf, but does not try to preserve 51883f157a2fSChris Mason * and fixup the path. It looks for and returns the next key in the 5189de78b51aSEric Sandeen * tree based on the current path and the min_trans parameters. 51903f157a2fSChris Mason * 51913f157a2fSChris Mason * 0 is returned if another key is found, < 0 if there are any errors 51923f157a2fSChris Mason * and 1 is returned if there are no higher keys in the tree 51933f157a2fSChris Mason * 51943f157a2fSChris Mason * path->keep_locks should be set to 1 on the search made before 51953f157a2fSChris Mason * calling this function. 51963f157a2fSChris Mason */ 5197e7a84565SChris Mason int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, 5198de78b51aSEric Sandeen struct btrfs_key *key, int level, u64 min_trans) 5199e7a84565SChris Mason { 5200e7a84565SChris Mason int slot; 5201e7a84565SChris Mason struct extent_buffer *c; 5202e7a84565SChris Mason 52036a9fb468SJosef Bacik WARN_ON(!path->keep_locks && !path->skip_locking); 5204e7a84565SChris Mason while (level < BTRFS_MAX_LEVEL) { 5205e7a84565SChris Mason if (!path->nodes[level]) 5206e7a84565SChris Mason return 1; 5207e7a84565SChris Mason 5208e7a84565SChris Mason slot = path->slots[level] + 1; 5209e7a84565SChris Mason c = path->nodes[level]; 52103f157a2fSChris Mason next: 5211e7a84565SChris Mason if (slot >= btrfs_header_nritems(c)) { 521233c66f43SYan Zheng int ret; 521333c66f43SYan Zheng int orig_lowest; 521433c66f43SYan Zheng struct btrfs_key cur_key; 521533c66f43SYan Zheng if (level + 1 >= BTRFS_MAX_LEVEL || 521633c66f43SYan Zheng !path->nodes[level + 1]) 5217e7a84565SChris Mason return 1; 521833c66f43SYan Zheng 52196a9fb468SJosef Bacik if (path->locks[level + 1] || path->skip_locking) { 522033c66f43SYan Zheng level++; 5221e7a84565SChris Mason continue; 5222e7a84565SChris Mason } 522333c66f43SYan Zheng 522433c66f43SYan Zheng slot = btrfs_header_nritems(c) - 1; 522533c66f43SYan Zheng if (level == 0) 522633c66f43SYan Zheng btrfs_item_key_to_cpu(c, &cur_key, slot); 522733c66f43SYan Zheng else 522833c66f43SYan Zheng btrfs_node_key_to_cpu(c, &cur_key, slot); 522933c66f43SYan Zheng 523033c66f43SYan Zheng orig_lowest = path->lowest_level; 5231b3b4aa74SDavid Sterba btrfs_release_path(path); 523233c66f43SYan Zheng path->lowest_level = level; 523333c66f43SYan Zheng ret = btrfs_search_slot(NULL, root, &cur_key, path, 523433c66f43SYan Zheng 0, 0); 523533c66f43SYan Zheng path->lowest_level = orig_lowest; 523633c66f43SYan Zheng if (ret < 0) 523733c66f43SYan Zheng return ret; 523833c66f43SYan Zheng 523933c66f43SYan Zheng c = path->nodes[level]; 524033c66f43SYan Zheng slot = path->slots[level]; 524133c66f43SYan Zheng if (ret == 0) 524233c66f43SYan Zheng slot++; 524333c66f43SYan Zheng goto next; 524433c66f43SYan Zheng } 524533c66f43SYan Zheng 5246e7a84565SChris Mason if (level == 0) 5247e7a84565SChris Mason btrfs_item_key_to_cpu(c, key, slot); 52483f157a2fSChris Mason else { 52493f157a2fSChris Mason u64 gen = btrfs_node_ptr_generation(c, slot); 52503f157a2fSChris Mason 52513f157a2fSChris Mason if (gen < min_trans) { 52523f157a2fSChris Mason slot++; 52533f157a2fSChris Mason goto next; 52543f157a2fSChris Mason } 5255e7a84565SChris Mason btrfs_node_key_to_cpu(c, key, slot); 52563f157a2fSChris Mason } 5257e7a84565SChris Mason return 0; 5258e7a84565SChris Mason } 5259e7a84565SChris Mason return 1; 5260e7a84565SChris Mason } 5261e7a84565SChris Mason 52627bb86316SChris Mason /* 5263925baeddSChris Mason * search the tree again to find a leaf with greater keys 52640f70abe2SChris Mason * returns 0 if it found something or 1 if there are no greater leaves. 52650f70abe2SChris Mason * returns < 0 on io errors. 526697571fd0SChris Mason */ 5267234b63a0SChris Mason int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) 5268d97e63b6SChris Mason { 52693d7806ecSJan Schmidt return btrfs_next_old_leaf(root, path, 0); 52703d7806ecSJan Schmidt } 52713d7806ecSJan Schmidt 52723d7806ecSJan Schmidt int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, 52733d7806ecSJan Schmidt u64 time_seq) 52743d7806ecSJan Schmidt { 5275d97e63b6SChris Mason int slot; 52768e73f275SChris Mason int level; 52775f39d397SChris Mason struct extent_buffer *c; 52788e73f275SChris Mason struct extent_buffer *next; 5279925baeddSChris Mason struct btrfs_key key; 5280925baeddSChris Mason u32 nritems; 5281925baeddSChris Mason int ret; 52820e46318dSJosef Bacik int i; 5283925baeddSChris Mason 5284925baeddSChris Mason nritems = btrfs_header_nritems(path->nodes[0]); 5285d397712bSChris Mason if (nritems == 0) 5286925baeddSChris Mason return 1; 5287925baeddSChris Mason 52888e73f275SChris Mason btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); 52898e73f275SChris Mason again: 52908e73f275SChris Mason level = 1; 52918e73f275SChris Mason next = NULL; 5292b3b4aa74SDavid Sterba btrfs_release_path(path); 52938e73f275SChris Mason 5294a2135011SChris Mason path->keep_locks = 1; 52958e73f275SChris Mason 52963d7806ecSJan Schmidt if (time_seq) 52973d7806ecSJan Schmidt ret = btrfs_search_old_slot(root, &key, path, time_seq); 52983d7806ecSJan Schmidt else 5299925baeddSChris Mason ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5300925baeddSChris Mason path->keep_locks = 0; 5301925baeddSChris Mason 5302925baeddSChris Mason if (ret < 0) 5303925baeddSChris Mason return ret; 5304925baeddSChris Mason 5305a2135011SChris Mason nritems = btrfs_header_nritems(path->nodes[0]); 5306168fd7d2SChris Mason /* 5307168fd7d2SChris Mason * by releasing the path above we dropped all our locks. A balance 5308168fd7d2SChris Mason * could have added more items next to the key that used to be 5309168fd7d2SChris Mason * at the very end of the block. So, check again here and 5310168fd7d2SChris Mason * advance the path if there are now more items available. 5311168fd7d2SChris Mason */ 5312a2135011SChris Mason if (nritems > 0 && path->slots[0] < nritems - 1) { 5313e457afecSYan Zheng if (ret == 0) 5314168fd7d2SChris Mason path->slots[0]++; 53158e73f275SChris Mason ret = 0; 5316925baeddSChris Mason goto done; 5317925baeddSChris Mason } 53180b43e04fSLiu Bo /* 53190b43e04fSLiu Bo * So the above check misses one case: 53200b43e04fSLiu Bo * - after releasing the path above, someone has removed the item that 53210b43e04fSLiu Bo * used to be at the very end of the block, and balance between leafs 53220b43e04fSLiu Bo * gets another one with bigger key.offset to replace it. 53230b43e04fSLiu Bo * 53240b43e04fSLiu Bo * This one should be returned as well, or we can get leaf corruption 53250b43e04fSLiu Bo * later(esp. in __btrfs_drop_extents()). 53260b43e04fSLiu Bo * 53270b43e04fSLiu Bo * And a bit more explanation about this check, 53280b43e04fSLiu Bo * with ret > 0, the key isn't found, the path points to the slot 53290b43e04fSLiu Bo * where it should be inserted, so the path->slots[0] item must be the 53300b43e04fSLiu Bo * bigger one. 53310b43e04fSLiu Bo */ 53320b43e04fSLiu Bo if (nritems > 0 && ret > 0 && path->slots[0] == nritems - 1) { 53330b43e04fSLiu Bo ret = 0; 53340b43e04fSLiu Bo goto done; 53350b43e04fSLiu Bo } 5336d97e63b6SChris Mason 5337234b63a0SChris Mason while (level < BTRFS_MAX_LEVEL) { 53388e73f275SChris Mason if (!path->nodes[level]) { 53398e73f275SChris Mason ret = 1; 53408e73f275SChris Mason goto done; 53418e73f275SChris Mason } 53425f39d397SChris Mason 5343d97e63b6SChris Mason slot = path->slots[level] + 1; 5344d97e63b6SChris Mason c = path->nodes[level]; 53455f39d397SChris Mason if (slot >= btrfs_header_nritems(c)) { 5346d97e63b6SChris Mason level++; 53478e73f275SChris Mason if (level == BTRFS_MAX_LEVEL) { 53488e73f275SChris Mason ret = 1; 53498e73f275SChris Mason goto done; 53508e73f275SChris Mason } 5351d97e63b6SChris Mason continue; 5352d97e63b6SChris Mason } 53535f39d397SChris Mason 53540e46318dSJosef Bacik 53550e46318dSJosef Bacik /* 53560e46318dSJosef Bacik * Our current level is where we're going to start from, and to 53570e46318dSJosef Bacik * make sure lockdep doesn't complain we need to drop our locks 53580e46318dSJosef Bacik * and nodes from 0 to our current level. 53590e46318dSJosef Bacik */ 53600e46318dSJosef Bacik for (i = 0; i < level; i++) { 53610e46318dSJosef Bacik if (path->locks[level]) { 53620e46318dSJosef Bacik btrfs_tree_read_unlock(path->nodes[i]); 53630e46318dSJosef Bacik path->locks[i] = 0; 53640e46318dSJosef Bacik } 53650e46318dSJosef Bacik free_extent_buffer(path->nodes[i]); 53660e46318dSJosef Bacik path->nodes[i] = NULL; 5367925baeddSChris Mason } 53685f39d397SChris Mason 53698e73f275SChris Mason next = c; 5370d07b8528SLiu Bo ret = read_block_for_search(root, path, &next, level, 5371cda79c54SDavid Sterba slot, &key); 53728e73f275SChris Mason if (ret == -EAGAIN) 53738e73f275SChris Mason goto again; 53745f39d397SChris Mason 537576a05b35SChris Mason if (ret < 0) { 5376b3b4aa74SDavid Sterba btrfs_release_path(path); 537776a05b35SChris Mason goto done; 537876a05b35SChris Mason } 537976a05b35SChris Mason 53805cd57b2cSChris Mason if (!path->skip_locking) { 5381bd681513SChris Mason ret = btrfs_try_tree_read_lock(next); 5382d42244a0SJan Schmidt if (!ret && time_seq) { 5383d42244a0SJan Schmidt /* 5384d42244a0SJan Schmidt * If we don't get the lock, we may be racing 5385d42244a0SJan Schmidt * with push_leaf_left, holding that lock while 5386d42244a0SJan Schmidt * itself waiting for the leaf we've currently 5387d42244a0SJan Schmidt * locked. To solve this situation, we give up 5388d42244a0SJan Schmidt * on our lock and cycle. 5389d42244a0SJan Schmidt */ 5390cf538830SJan Schmidt free_extent_buffer(next); 5391d42244a0SJan Schmidt btrfs_release_path(path); 5392d42244a0SJan Schmidt cond_resched(); 5393d42244a0SJan Schmidt goto again; 5394d42244a0SJan Schmidt } 53950e46318dSJosef Bacik if (!ret) 53960e46318dSJosef Bacik btrfs_tree_read_lock(next); 5397bd681513SChris Mason } 5398d97e63b6SChris Mason break; 5399d97e63b6SChris Mason } 5400d97e63b6SChris Mason path->slots[level] = slot; 5401d97e63b6SChris Mason while (1) { 5402d97e63b6SChris Mason level--; 5403d97e63b6SChris Mason path->nodes[level] = next; 5404d97e63b6SChris Mason path->slots[level] = 0; 5405a74a4b97SChris Mason if (!path->skip_locking) 5406ffeb03cfSJosef Bacik path->locks[level] = BTRFS_READ_LOCK; 5407d97e63b6SChris Mason if (!level) 5408d97e63b6SChris Mason break; 5409b4ce94deSChris Mason 5410d07b8528SLiu Bo ret = read_block_for_search(root, path, &next, level, 5411cda79c54SDavid Sterba 0, &key); 54128e73f275SChris Mason if (ret == -EAGAIN) 54138e73f275SChris Mason goto again; 54148e73f275SChris Mason 541576a05b35SChris Mason if (ret < 0) { 5416b3b4aa74SDavid Sterba btrfs_release_path(path); 541776a05b35SChris Mason goto done; 541876a05b35SChris Mason } 541976a05b35SChris Mason 5420ffeb03cfSJosef Bacik if (!path->skip_locking) 54210e46318dSJosef Bacik btrfs_tree_read_lock(next); 5422d97e63b6SChris Mason } 54238e73f275SChris Mason ret = 0; 5424925baeddSChris Mason done: 5425f7c79f30SChris Mason unlock_up(path, 0, 1, 0, NULL); 54268e73f275SChris Mason 54278e73f275SChris Mason return ret; 5428d97e63b6SChris Mason } 54290b86a832SChris Mason 54303f157a2fSChris Mason /* 54313f157a2fSChris Mason * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps 54323f157a2fSChris Mason * searching until it gets past min_objectid or finds an item of 'type' 54333f157a2fSChris Mason * 54343f157a2fSChris Mason * returns 0 if something is found, 1 if nothing was found and < 0 on error 54353f157a2fSChris Mason */ 54360b86a832SChris Mason int btrfs_previous_item(struct btrfs_root *root, 54370b86a832SChris Mason struct btrfs_path *path, u64 min_objectid, 54380b86a832SChris Mason int type) 54390b86a832SChris Mason { 54400b86a832SChris Mason struct btrfs_key found_key; 54410b86a832SChris Mason struct extent_buffer *leaf; 5442e02119d5SChris Mason u32 nritems; 54430b86a832SChris Mason int ret; 54440b86a832SChris Mason 54450b86a832SChris Mason while (1) { 54460b86a832SChris Mason if (path->slots[0] == 0) { 54470b86a832SChris Mason ret = btrfs_prev_leaf(root, path); 54480b86a832SChris Mason if (ret != 0) 54490b86a832SChris Mason return ret; 54500b86a832SChris Mason } else { 54510b86a832SChris Mason path->slots[0]--; 54520b86a832SChris Mason } 54530b86a832SChris Mason leaf = path->nodes[0]; 5454e02119d5SChris Mason nritems = btrfs_header_nritems(leaf); 5455e02119d5SChris Mason if (nritems == 0) 5456e02119d5SChris Mason return 1; 5457e02119d5SChris Mason if (path->slots[0] == nritems) 5458e02119d5SChris Mason path->slots[0]--; 5459e02119d5SChris Mason 54600b86a832SChris Mason btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 5461e02119d5SChris Mason if (found_key.objectid < min_objectid) 5462e02119d5SChris Mason break; 54630a4eefbbSYan Zheng if (found_key.type == type) 54640a4eefbbSYan Zheng return 0; 5465e02119d5SChris Mason if (found_key.objectid == min_objectid && 5466e02119d5SChris Mason found_key.type < type) 5467e02119d5SChris Mason break; 54680b86a832SChris Mason } 54690b86a832SChris Mason return 1; 54700b86a832SChris Mason } 5471ade2e0b3SWang Shilong 5472ade2e0b3SWang Shilong /* 5473ade2e0b3SWang Shilong * search in extent tree to find a previous Metadata/Data extent item with 5474ade2e0b3SWang Shilong * min objecitd. 5475ade2e0b3SWang Shilong * 5476ade2e0b3SWang Shilong * returns 0 if something is found, 1 if nothing was found and < 0 on error 5477ade2e0b3SWang Shilong */ 5478ade2e0b3SWang Shilong int btrfs_previous_extent_item(struct btrfs_root *root, 5479ade2e0b3SWang Shilong struct btrfs_path *path, u64 min_objectid) 5480ade2e0b3SWang Shilong { 5481ade2e0b3SWang Shilong struct btrfs_key found_key; 5482ade2e0b3SWang Shilong struct extent_buffer *leaf; 5483ade2e0b3SWang Shilong u32 nritems; 5484ade2e0b3SWang Shilong int ret; 5485ade2e0b3SWang Shilong 5486ade2e0b3SWang Shilong while (1) { 5487ade2e0b3SWang Shilong if (path->slots[0] == 0) { 5488ade2e0b3SWang Shilong ret = btrfs_prev_leaf(root, path); 5489ade2e0b3SWang Shilong if (ret != 0) 5490ade2e0b3SWang Shilong return ret; 5491ade2e0b3SWang Shilong } else { 5492ade2e0b3SWang Shilong path->slots[0]--; 5493ade2e0b3SWang Shilong } 5494ade2e0b3SWang Shilong leaf = path->nodes[0]; 5495ade2e0b3SWang Shilong nritems = btrfs_header_nritems(leaf); 5496ade2e0b3SWang Shilong if (nritems == 0) 5497ade2e0b3SWang Shilong return 1; 5498ade2e0b3SWang Shilong if (path->slots[0] == nritems) 5499ade2e0b3SWang Shilong path->slots[0]--; 5500ade2e0b3SWang Shilong 5501ade2e0b3SWang Shilong btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 5502ade2e0b3SWang Shilong if (found_key.objectid < min_objectid) 5503ade2e0b3SWang Shilong break; 5504ade2e0b3SWang Shilong if (found_key.type == BTRFS_EXTENT_ITEM_KEY || 5505ade2e0b3SWang Shilong found_key.type == BTRFS_METADATA_ITEM_KEY) 5506ade2e0b3SWang Shilong return 0; 5507ade2e0b3SWang Shilong if (found_key.objectid == min_objectid && 5508ade2e0b3SWang Shilong found_key.type < BTRFS_EXTENT_ITEM_KEY) 5509ade2e0b3SWang Shilong break; 5510ade2e0b3SWang Shilong } 5511ade2e0b3SWang Shilong return 1; 5512ade2e0b3SWang Shilong } 5513