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> 10e41d12f5SChristoph Hellwig #include <linux/error-injection.h> 119b569ea0SJosef Bacik #include "messages.h" 12eb60ceacSChris Mason #include "ctree.h" 13eb60ceacSChris Mason #include "disk-io.h" 147f5c1516SChris Mason #include "transaction.h" 155f39d397SChris Mason #include "print-tree.h" 16925baeddSChris Mason #include "locking.h" 17de37aa51SNikolay Borisov #include "volumes.h" 18f616f5cdSQu Wenruo #include "qgroup.h" 19f3a84ccdSFilipe Manana #include "tree-mod-log.h" 2088c602abSQu Wenruo #include "tree-checker.h" 21ec8eb376SJosef Bacik #include "fs.h" 22ad1ac501SJosef Bacik #include "accessors.h" 23a0231804SJosef Bacik #include "extent-tree.h" 2467707479SJosef Bacik #include "relocation.h" 256bfd0ffaSJosef Bacik #include "file-item.h" 269a8dd150SChris Mason 27226463d7SJosef Bacik static struct kmem_cache *btrfs_path_cachep; 28226463d7SJosef Bacik 29e089f05cSChris Mason static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root 30e089f05cSChris Mason *root, struct btrfs_path *path, int level); 31310712b2SOmar Sandoval static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root *root, 32310712b2SOmar Sandoval const struct btrfs_key *ins_key, struct btrfs_path *path, 33310712b2SOmar Sandoval int data_size, int extend); 345f39d397SChris Mason static int push_node_left(struct btrfs_trans_handle *trans, 352ff7e61eSJeff Mahoney struct extent_buffer *dst, 36971a1f66SChris Mason struct extent_buffer *src, int empty); 375f39d397SChris Mason static int balance_node_right(struct btrfs_trans_handle *trans, 385f39d397SChris Mason struct extent_buffer *dst_buf, 395f39d397SChris Mason struct extent_buffer *src_buf); 40d97e63b6SChris Mason 41af024ed2SJohannes Thumshirn static const struct btrfs_csums { 42af024ed2SJohannes Thumshirn u16 size; 4359a0fcdbSDavid Sterba const char name[10]; 4459a0fcdbSDavid Sterba const char driver[12]; 45af024ed2SJohannes Thumshirn } btrfs_csums[] = { 46af024ed2SJohannes Thumshirn [BTRFS_CSUM_TYPE_CRC32] = { .size = 4, .name = "crc32c" }, 473951e7f0SJohannes Thumshirn [BTRFS_CSUM_TYPE_XXHASH] = { .size = 8, .name = "xxhash64" }, 483831bf00SJohannes Thumshirn [BTRFS_CSUM_TYPE_SHA256] = { .size = 32, .name = "sha256" }, 49352ae07bSDavid Sterba [BTRFS_CSUM_TYPE_BLAKE2] = { .size = 32, .name = "blake2b", 50352ae07bSDavid Sterba .driver = "blake2b-256" }, 51af024ed2SJohannes Thumshirn }; 52af024ed2SJohannes Thumshirn 533a3178c7SJosef Bacik /* 543a3178c7SJosef Bacik * The leaf data grows from end-to-front in the node. this returns the address 553a3178c7SJosef Bacik * of the start of the last item, which is the stop of the leaf data stack. 563a3178c7SJosef Bacik */ 573a3178c7SJosef Bacik static unsigned int leaf_data_end(const struct extent_buffer *leaf) 583a3178c7SJosef Bacik { 593a3178c7SJosef Bacik u32 nr = btrfs_header_nritems(leaf); 603a3178c7SJosef Bacik 613a3178c7SJosef Bacik if (nr == 0) 623a3178c7SJosef Bacik return BTRFS_LEAF_DATA_SIZE(leaf->fs_info); 633a3178c7SJosef Bacik return btrfs_item_offset(leaf, nr - 1); 643a3178c7SJosef Bacik } 653a3178c7SJosef Bacik 66637e3b48SJosef Bacik /* 67637e3b48SJosef Bacik * Move data in a @leaf (using memmove, safe for overlapping ranges). 68637e3b48SJosef Bacik * 69637e3b48SJosef Bacik * @leaf: leaf that we're doing a memmove on 70637e3b48SJosef Bacik * @dst_offset: item data offset we're moving to 71637e3b48SJosef Bacik * @src_offset: item data offset were' moving from 72637e3b48SJosef Bacik * @len: length of the data we're moving 73637e3b48SJosef Bacik * 74637e3b48SJosef Bacik * Wrapper around memmove_extent_buffer() that takes into account the header on 75637e3b48SJosef Bacik * the leaf. The btrfs_item offset's start directly after the header, so we 76637e3b48SJosef Bacik * have to adjust any offsets to account for the header in the leaf. This 77637e3b48SJosef Bacik * handles that math to simplify the callers. 78637e3b48SJosef Bacik */ 79637e3b48SJosef Bacik static inline void memmove_leaf_data(const struct extent_buffer *leaf, 80637e3b48SJosef Bacik unsigned long dst_offset, 81637e3b48SJosef Bacik unsigned long src_offset, 82637e3b48SJosef Bacik unsigned long len) 83637e3b48SJosef Bacik { 848009adf3SJosef Bacik memmove_extent_buffer(leaf, btrfs_item_nr_offset(leaf, 0) + dst_offset, 858009adf3SJosef Bacik btrfs_item_nr_offset(leaf, 0) + src_offset, len); 86637e3b48SJosef Bacik } 87637e3b48SJosef Bacik 88637e3b48SJosef Bacik /* 89637e3b48SJosef Bacik * Copy item data from @src into @dst at the given @offset. 90637e3b48SJosef Bacik * 91637e3b48SJosef Bacik * @dst: destination leaf that we're copying into 92637e3b48SJosef Bacik * @src: source leaf that we're copying from 93637e3b48SJosef Bacik * @dst_offset: item data offset we're copying to 94637e3b48SJosef Bacik * @src_offset: item data offset were' copying from 95637e3b48SJosef Bacik * @len: length of the data we're copying 96637e3b48SJosef Bacik * 97637e3b48SJosef Bacik * Wrapper around copy_extent_buffer() that takes into account the header on 98637e3b48SJosef Bacik * the leaf. The btrfs_item offset's start directly after the header, so we 99637e3b48SJosef Bacik * have to adjust any offsets to account for the header in the leaf. This 100637e3b48SJosef Bacik * handles that math to simplify the callers. 101637e3b48SJosef Bacik */ 102637e3b48SJosef Bacik static inline void copy_leaf_data(const struct extent_buffer *dst, 103637e3b48SJosef Bacik const struct extent_buffer *src, 104637e3b48SJosef Bacik unsigned long dst_offset, 105637e3b48SJosef Bacik unsigned long src_offset, unsigned long len) 106637e3b48SJosef Bacik { 1078009adf3SJosef Bacik copy_extent_buffer(dst, src, btrfs_item_nr_offset(dst, 0) + dst_offset, 1088009adf3SJosef Bacik btrfs_item_nr_offset(src, 0) + src_offset, len); 109637e3b48SJosef Bacik } 110637e3b48SJosef Bacik 111637e3b48SJosef Bacik /* 112637e3b48SJosef Bacik * Move items in a @leaf (using memmove). 113637e3b48SJosef Bacik * 114637e3b48SJosef Bacik * @dst: destination leaf for the items 115637e3b48SJosef Bacik * @dst_item: the item nr we're copying into 116637e3b48SJosef Bacik * @src_item: the item nr we're copying from 117637e3b48SJosef Bacik * @nr_items: the number of items to copy 118637e3b48SJosef Bacik * 119637e3b48SJosef Bacik * Wrapper around memmove_extent_buffer() that does the math to get the 120637e3b48SJosef Bacik * appropriate offsets into the leaf from the item numbers. 121637e3b48SJosef Bacik */ 122637e3b48SJosef Bacik static inline void memmove_leaf_items(const struct extent_buffer *leaf, 123637e3b48SJosef Bacik int dst_item, int src_item, int nr_items) 124637e3b48SJosef Bacik { 125637e3b48SJosef Bacik memmove_extent_buffer(leaf, btrfs_item_nr_offset(leaf, dst_item), 126637e3b48SJosef Bacik btrfs_item_nr_offset(leaf, src_item), 127637e3b48SJosef Bacik nr_items * sizeof(struct btrfs_item)); 128637e3b48SJosef Bacik } 129637e3b48SJosef Bacik 130637e3b48SJosef Bacik /* 131637e3b48SJosef Bacik * Copy items from @src into @dst at the given @offset. 132637e3b48SJosef Bacik * 133637e3b48SJosef Bacik * @dst: destination leaf for the items 134637e3b48SJosef Bacik * @src: source leaf for the items 135637e3b48SJosef Bacik * @dst_item: the item nr we're copying into 136637e3b48SJosef Bacik * @src_item: the item nr we're copying from 137637e3b48SJosef Bacik * @nr_items: the number of items to copy 138637e3b48SJosef Bacik * 139637e3b48SJosef Bacik * Wrapper around copy_extent_buffer() that does the math to get the 140637e3b48SJosef Bacik * appropriate offsets into the leaf from the item numbers. 141637e3b48SJosef Bacik */ 142637e3b48SJosef Bacik static inline void copy_leaf_items(const struct extent_buffer *dst, 143637e3b48SJosef Bacik const struct extent_buffer *src, 144637e3b48SJosef Bacik int dst_item, int src_item, int nr_items) 145637e3b48SJosef Bacik { 146637e3b48SJosef Bacik copy_extent_buffer(dst, src, btrfs_item_nr_offset(dst, dst_item), 147637e3b48SJosef Bacik btrfs_item_nr_offset(src, src_item), 148637e3b48SJosef Bacik nr_items * sizeof(struct btrfs_item)); 149637e3b48SJosef Bacik } 150637e3b48SJosef Bacik 151b3cbfb0dSJosef Bacik /* This exists for btrfs-progs usages. */ 152b3cbfb0dSJosef Bacik u16 btrfs_csum_type_size(u16 type) 153b3cbfb0dSJosef Bacik { 154b3cbfb0dSJosef Bacik return btrfs_csums[type].size; 155b3cbfb0dSJosef Bacik } 156b3cbfb0dSJosef Bacik 157af024ed2SJohannes Thumshirn int btrfs_super_csum_size(const struct btrfs_super_block *s) 158af024ed2SJohannes Thumshirn { 159af024ed2SJohannes Thumshirn u16 t = btrfs_super_csum_type(s); 160af024ed2SJohannes Thumshirn /* 161af024ed2SJohannes Thumshirn * csum type is validated at mount time 162af024ed2SJohannes Thumshirn */ 163b3cbfb0dSJosef Bacik return btrfs_csum_type_size(t); 164af024ed2SJohannes Thumshirn } 165af024ed2SJohannes Thumshirn 166af024ed2SJohannes Thumshirn const char *btrfs_super_csum_name(u16 csum_type) 167af024ed2SJohannes Thumshirn { 168af024ed2SJohannes Thumshirn /* csum type is validated at mount time */ 169af024ed2SJohannes Thumshirn return btrfs_csums[csum_type].name; 170af024ed2SJohannes Thumshirn } 171af024ed2SJohannes Thumshirn 172b4e967beSDavid Sterba /* 173b4e967beSDavid Sterba * Return driver name if defined, otherwise the name that's also a valid driver 174b4e967beSDavid Sterba * name 175b4e967beSDavid Sterba */ 176b4e967beSDavid Sterba const char *btrfs_super_csum_driver(u16 csum_type) 177b4e967beSDavid Sterba { 178b4e967beSDavid Sterba /* csum type is validated at mount time */ 17959a0fcdbSDavid Sterba return btrfs_csums[csum_type].driver[0] ? 18059a0fcdbSDavid Sterba btrfs_csums[csum_type].driver : 181b4e967beSDavid Sterba btrfs_csums[csum_type].name; 182b4e967beSDavid Sterba } 183b4e967beSDavid Sterba 184604997b4SDavid Sterba size_t __attribute_const__ btrfs_get_num_csums(void) 185f7cea56cSDavid Sterba { 186f7cea56cSDavid Sterba return ARRAY_SIZE(btrfs_csums); 187f7cea56cSDavid Sterba } 188f7cea56cSDavid Sterba 1892c90e5d6SChris Mason struct btrfs_path *btrfs_alloc_path(void) 1902c90e5d6SChris Mason { 191a4c853afSChenXiaoSong might_sleep(); 192a4c853afSChenXiaoSong 193e2c89907SMasahiro Yamada return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); 1942c90e5d6SChris Mason } 1952c90e5d6SChris Mason 196d352ac68SChris Mason /* this also releases the path */ 1972c90e5d6SChris Mason void btrfs_free_path(struct btrfs_path *p) 1982c90e5d6SChris Mason { 199ff175d57SJesper Juhl if (!p) 200ff175d57SJesper Juhl return; 201b3b4aa74SDavid Sterba btrfs_release_path(p); 2022c90e5d6SChris Mason kmem_cache_free(btrfs_path_cachep, p); 2032c90e5d6SChris Mason } 2042c90e5d6SChris Mason 205d352ac68SChris Mason /* 206d352ac68SChris Mason * path release drops references on the extent buffers in the path 207d352ac68SChris Mason * and it drops any locks held by this path 208d352ac68SChris Mason * 209d352ac68SChris Mason * It is safe to call this on paths that no locks or extent buffers held. 210d352ac68SChris Mason */ 211b3b4aa74SDavid Sterba noinline void btrfs_release_path(struct btrfs_path *p) 212eb60ceacSChris Mason { 213eb60ceacSChris Mason int i; 214a2135011SChris Mason 215234b63a0SChris Mason for (i = 0; i < BTRFS_MAX_LEVEL; i++) { 2163f157a2fSChris Mason p->slots[i] = 0; 217eb60ceacSChris Mason if (!p->nodes[i]) 218925baeddSChris Mason continue; 219925baeddSChris Mason if (p->locks[i]) { 220bd681513SChris Mason btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); 221925baeddSChris Mason p->locks[i] = 0; 222925baeddSChris Mason } 2235f39d397SChris Mason free_extent_buffer(p->nodes[i]); 2243f157a2fSChris Mason p->nodes[i] = NULL; 225eb60ceacSChris Mason } 226eb60ceacSChris Mason } 227eb60ceacSChris Mason 228d352ac68SChris Mason /* 2298bb808c6SDavid Sterba * We want the transaction abort to print stack trace only for errors where the 2308bb808c6SDavid Sterba * cause could be a bug, eg. due to ENOSPC, and not for common errors that are 2318bb808c6SDavid Sterba * caused by external factors. 2328bb808c6SDavid Sterba */ 2338bb808c6SDavid Sterba bool __cold abort_should_print_stack(int errno) 2348bb808c6SDavid Sterba { 2358bb808c6SDavid Sterba switch (errno) { 2368bb808c6SDavid Sterba case -EIO: 2378bb808c6SDavid Sterba case -EROFS: 2388bb808c6SDavid Sterba case -ENOMEM: 2398bb808c6SDavid Sterba return false; 2408bb808c6SDavid Sterba } 2418bb808c6SDavid Sterba return true; 2428bb808c6SDavid Sterba } 2438bb808c6SDavid Sterba 2448bb808c6SDavid Sterba /* 245d352ac68SChris Mason * safely gets a reference on the root node of a tree. A lock 246d352ac68SChris Mason * is not taken, so a concurrent writer may put a different node 247d352ac68SChris Mason * at the root of the tree. See btrfs_lock_root_node for the 248d352ac68SChris Mason * looping required. 249d352ac68SChris Mason * 250d352ac68SChris Mason * The extent buffer returned by this has a reference taken, so 251d352ac68SChris Mason * it won't disappear. It may stop being the root of the tree 252d352ac68SChris Mason * at any time because there are no locks held. 253d352ac68SChris Mason */ 254925baeddSChris Mason struct extent_buffer *btrfs_root_node(struct btrfs_root *root) 255925baeddSChris Mason { 256925baeddSChris Mason struct extent_buffer *eb; 257240f62c8SChris Mason 2583083ee2eSJosef Bacik while (1) { 259240f62c8SChris Mason rcu_read_lock(); 260240f62c8SChris Mason eb = rcu_dereference(root->node); 2613083ee2eSJosef Bacik 2623083ee2eSJosef Bacik /* 2633083ee2eSJosef Bacik * RCU really hurts here, we could free up the root node because 26401327610SNicholas D Steeves * it was COWed but we may not get the new root node yet so do 2653083ee2eSJosef Bacik * the inc_not_zero dance and if it doesn't work then 2663083ee2eSJosef Bacik * synchronize_rcu and try again. 2673083ee2eSJosef Bacik */ 2683083ee2eSJosef Bacik if (atomic_inc_not_zero(&eb->refs)) { 269240f62c8SChris Mason rcu_read_unlock(); 2703083ee2eSJosef Bacik break; 2713083ee2eSJosef Bacik } 2723083ee2eSJosef Bacik rcu_read_unlock(); 2733083ee2eSJosef Bacik synchronize_rcu(); 2743083ee2eSJosef Bacik } 275925baeddSChris Mason return eb; 276925baeddSChris Mason } 277925baeddSChris Mason 27892a7cc42SQu Wenruo /* 27992a7cc42SQu Wenruo * Cowonly root (not-shareable trees, everything not subvolume or reloc roots), 28092a7cc42SQu Wenruo * just get put onto a simple dirty list. Transaction walks this list to make 28192a7cc42SQu Wenruo * sure they get properly updated on disk. 282d352ac68SChris Mason */ 2830b86a832SChris Mason static void add_root_to_dirty_list(struct btrfs_root *root) 2840b86a832SChris Mason { 2850b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 2860b246afaSJeff Mahoney 287e7070be1SJosef Bacik if (test_bit(BTRFS_ROOT_DIRTY, &root->state) || 288e7070be1SJosef Bacik !test_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state)) 289e7070be1SJosef Bacik return; 290e7070be1SJosef Bacik 2910b246afaSJeff Mahoney spin_lock(&fs_info->trans_lock); 292e7070be1SJosef Bacik if (!test_and_set_bit(BTRFS_ROOT_DIRTY, &root->state)) { 293e7070be1SJosef Bacik /* Want the extent tree to be the last on the list */ 2944fd786e6SMisono Tomohiro if (root->root_key.objectid == BTRFS_EXTENT_TREE_OBJECTID) 295e7070be1SJosef Bacik list_move_tail(&root->dirty_list, 2960b246afaSJeff Mahoney &fs_info->dirty_cowonly_roots); 297e7070be1SJosef Bacik else 298e7070be1SJosef Bacik list_move(&root->dirty_list, 2990b246afaSJeff Mahoney &fs_info->dirty_cowonly_roots); 3000b86a832SChris Mason } 3010b246afaSJeff Mahoney spin_unlock(&fs_info->trans_lock); 3020b86a832SChris Mason } 3030b86a832SChris Mason 304d352ac68SChris Mason /* 305d352ac68SChris Mason * used by snapshot creation to make a copy of a root for a tree with 306d352ac68SChris Mason * a given objectid. The buffer with the new root node is returned in 307d352ac68SChris Mason * cow_ret, and this func returns zero on success or a negative error code. 308d352ac68SChris Mason */ 309be20aa9dSChris Mason int btrfs_copy_root(struct btrfs_trans_handle *trans, 310be20aa9dSChris Mason struct btrfs_root *root, 311be20aa9dSChris Mason struct extent_buffer *buf, 312be20aa9dSChris Mason struct extent_buffer **cow_ret, u64 new_root_objectid) 313be20aa9dSChris Mason { 3140b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 315be20aa9dSChris Mason struct extent_buffer *cow; 316be20aa9dSChris Mason int ret = 0; 317be20aa9dSChris Mason int level; 3185d4f98a2SYan Zheng struct btrfs_disk_key disk_key; 319be20aa9dSChris Mason 32092a7cc42SQu Wenruo WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && 3210b246afaSJeff Mahoney trans->transid != fs_info->running_transaction->transid); 32292a7cc42SQu Wenruo WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && 32327cdeb70SMiao Xie trans->transid != root->last_trans); 324be20aa9dSChris Mason 325be20aa9dSChris Mason level = btrfs_header_level(buf); 3265d4f98a2SYan Zheng if (level == 0) 3275d4f98a2SYan Zheng btrfs_item_key(buf, &disk_key, 0); 3285d4f98a2SYan Zheng else 3295d4f98a2SYan Zheng btrfs_node_key(buf, &disk_key, 0); 33031840ae1SZheng Yan 3314d75f8a9SDavid Sterba cow = btrfs_alloc_tree_block(trans, root, 0, new_root_objectid, 332cf6f34aaSJosef Bacik &disk_key, level, buf->start, 0, 333cf6f34aaSJosef Bacik BTRFS_NESTING_NEW_ROOT); 3345d4f98a2SYan Zheng if (IS_ERR(cow)) 335be20aa9dSChris Mason return PTR_ERR(cow); 336be20aa9dSChris Mason 33758e8012cSDavid Sterba copy_extent_buffer_full(cow, buf); 338be20aa9dSChris Mason btrfs_set_header_bytenr(cow, cow->start); 339be20aa9dSChris Mason btrfs_set_header_generation(cow, trans->transid); 3405d4f98a2SYan Zheng btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); 3415d4f98a2SYan Zheng btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | 3425d4f98a2SYan Zheng BTRFS_HEADER_FLAG_RELOC); 3435d4f98a2SYan Zheng if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) 3445d4f98a2SYan Zheng btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); 3455d4f98a2SYan Zheng else 346be20aa9dSChris Mason btrfs_set_header_owner(cow, new_root_objectid); 347be20aa9dSChris Mason 348de37aa51SNikolay Borisov write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); 3492b82032cSYan Zheng 350be20aa9dSChris Mason WARN_ON(btrfs_header_generation(buf) > trans->transid); 3515d4f98a2SYan Zheng if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) 352e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 1); 3535d4f98a2SYan Zheng else 354e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 0); 355867ed321SJosef Bacik if (ret) { 35672c9925fSFilipe Manana btrfs_tree_unlock(cow); 35772c9925fSFilipe Manana free_extent_buffer(cow); 358867ed321SJosef Bacik btrfs_abort_transaction(trans, ret); 359be20aa9dSChris Mason return ret; 360867ed321SJosef Bacik } 361be20aa9dSChris Mason 362be20aa9dSChris Mason btrfs_mark_buffer_dirty(cow); 363be20aa9dSChris Mason *cow_ret = cow; 364be20aa9dSChris Mason return 0; 365be20aa9dSChris Mason } 366be20aa9dSChris Mason 367d352ac68SChris Mason /* 3685d4f98a2SYan Zheng * check if the tree block can be shared by multiple trees 3695d4f98a2SYan Zheng */ 3705d4f98a2SYan Zheng int btrfs_block_can_be_shared(struct btrfs_root *root, 3715d4f98a2SYan Zheng struct extent_buffer *buf) 3725d4f98a2SYan Zheng { 3735d4f98a2SYan Zheng /* 37492a7cc42SQu Wenruo * Tree blocks not in shareable trees and tree roots are never shared. 37592a7cc42SQu Wenruo * If a block was allocated after the last snapshot and the block was 37692a7cc42SQu Wenruo * not allocated by tree relocation, we know the block is not shared. 3775d4f98a2SYan Zheng */ 37892a7cc42SQu Wenruo if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && 3795d4f98a2SYan Zheng buf != root->node && buf != root->commit_root && 3805d4f98a2SYan Zheng (btrfs_header_generation(buf) <= 3815d4f98a2SYan Zheng btrfs_root_last_snapshot(&root->root_item) || 3825d4f98a2SYan Zheng btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) 3835d4f98a2SYan Zheng return 1; 384a79865c6SNikolay Borisov 3855d4f98a2SYan Zheng return 0; 3865d4f98a2SYan Zheng } 3875d4f98a2SYan Zheng 3885d4f98a2SYan Zheng static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, 3895d4f98a2SYan Zheng struct btrfs_root *root, 3905d4f98a2SYan Zheng struct extent_buffer *buf, 391f0486c68SYan, Zheng struct extent_buffer *cow, 392f0486c68SYan, Zheng int *last_ref) 3935d4f98a2SYan Zheng { 3940b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 3955d4f98a2SYan Zheng u64 refs; 3965d4f98a2SYan Zheng u64 owner; 3975d4f98a2SYan Zheng u64 flags; 3985d4f98a2SYan Zheng u64 new_flags = 0; 3995d4f98a2SYan Zheng int ret; 4005d4f98a2SYan Zheng 4015d4f98a2SYan Zheng /* 4025d4f98a2SYan Zheng * Backrefs update rules: 4035d4f98a2SYan Zheng * 4045d4f98a2SYan Zheng * Always use full backrefs for extent pointers in tree block 4055d4f98a2SYan Zheng * allocated by tree relocation. 4065d4f98a2SYan Zheng * 4075d4f98a2SYan Zheng * If a shared tree block is no longer referenced by its owner 4085d4f98a2SYan Zheng * tree (btrfs_header_owner(buf) == root->root_key.objectid), 4095d4f98a2SYan Zheng * use full backrefs for extent pointers in tree block. 4105d4f98a2SYan Zheng * 4115d4f98a2SYan Zheng * If a tree block is been relocating 4125d4f98a2SYan Zheng * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), 4135d4f98a2SYan Zheng * use full backrefs for extent pointers in tree block. 4145d4f98a2SYan Zheng * The reason for this is some operations (such as drop tree) 4155d4f98a2SYan Zheng * are only allowed for blocks use full backrefs. 4165d4f98a2SYan Zheng */ 4175d4f98a2SYan Zheng 4185d4f98a2SYan Zheng if (btrfs_block_can_be_shared(root, buf)) { 4192ff7e61eSJeff Mahoney ret = btrfs_lookup_extent_info(trans, fs_info, buf->start, 4203173a18fSJosef Bacik btrfs_header_level(buf), 1, 4213173a18fSJosef Bacik &refs, &flags); 422be1a5564SMark Fasheh if (ret) 423be1a5564SMark Fasheh return ret; 424e5df9573SMark Fasheh if (refs == 0) { 425e5df9573SMark Fasheh ret = -EROFS; 4260b246afaSJeff Mahoney btrfs_handle_fs_error(fs_info, ret, NULL); 427e5df9573SMark Fasheh return ret; 428e5df9573SMark Fasheh } 4295d4f98a2SYan Zheng } else { 4305d4f98a2SYan Zheng refs = 1; 4315d4f98a2SYan Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || 4325d4f98a2SYan Zheng btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) 4335d4f98a2SYan Zheng flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; 4345d4f98a2SYan Zheng else 4355d4f98a2SYan Zheng flags = 0; 4365d4f98a2SYan Zheng } 4375d4f98a2SYan Zheng 4385d4f98a2SYan Zheng owner = btrfs_header_owner(buf); 4395d4f98a2SYan Zheng BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && 4405d4f98a2SYan Zheng !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); 4415d4f98a2SYan Zheng 4425d4f98a2SYan Zheng if (refs > 1) { 4435d4f98a2SYan Zheng if ((owner == root->root_key.objectid || 4445d4f98a2SYan Zheng root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && 4455d4f98a2SYan Zheng !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { 446e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, buf, 1); 447692826b2SJeff Mahoney if (ret) 448692826b2SJeff Mahoney return ret; 4495d4f98a2SYan Zheng 4505d4f98a2SYan Zheng if (root->root_key.objectid == 4515d4f98a2SYan Zheng BTRFS_TREE_RELOC_OBJECTID) { 452e339a6b0SJosef Bacik ret = btrfs_dec_ref(trans, root, buf, 0); 453692826b2SJeff Mahoney if (ret) 454692826b2SJeff Mahoney return ret; 455e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 1); 456692826b2SJeff Mahoney if (ret) 457692826b2SJeff Mahoney return ret; 4585d4f98a2SYan Zheng } 4595d4f98a2SYan Zheng new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; 4605d4f98a2SYan Zheng } else { 4615d4f98a2SYan Zheng 4625d4f98a2SYan Zheng if (root->root_key.objectid == 4635d4f98a2SYan Zheng BTRFS_TREE_RELOC_OBJECTID) 464e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 1); 4655d4f98a2SYan Zheng else 466e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 0); 467692826b2SJeff Mahoney if (ret) 468692826b2SJeff Mahoney return ret; 4695d4f98a2SYan Zheng } 4705d4f98a2SYan Zheng if (new_flags != 0) { 4714aec05faSJosef Bacik ret = btrfs_set_disk_extent_flags(trans, buf, new_flags); 472be1a5564SMark Fasheh if (ret) 473be1a5564SMark Fasheh return ret; 4745d4f98a2SYan Zheng } 4755d4f98a2SYan Zheng } else { 4765d4f98a2SYan Zheng if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { 4775d4f98a2SYan Zheng if (root->root_key.objectid == 4785d4f98a2SYan Zheng BTRFS_TREE_RELOC_OBJECTID) 479e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 1); 4805d4f98a2SYan Zheng else 481e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 0); 482692826b2SJeff Mahoney if (ret) 483692826b2SJeff Mahoney return ret; 484e339a6b0SJosef Bacik ret = btrfs_dec_ref(trans, root, buf, 1); 485692826b2SJeff Mahoney if (ret) 486692826b2SJeff Mahoney return ret; 4875d4f98a2SYan Zheng } 488190a8339SJosef Bacik btrfs_clear_buffer_dirty(trans, buf); 489f0486c68SYan, Zheng *last_ref = 1; 4905d4f98a2SYan Zheng } 4915d4f98a2SYan Zheng return 0; 4925d4f98a2SYan Zheng } 4935d4f98a2SYan Zheng 4945d4f98a2SYan Zheng /* 495d397712bSChris Mason * does the dirty work in cow of a single block. The parent block (if 496d397712bSChris Mason * supplied) is updated to point to the new cow copy. The new buffer is marked 497d397712bSChris Mason * dirty and returned locked. If you modify the block it needs to be marked 498d397712bSChris Mason * dirty again. 499d352ac68SChris Mason * 500d352ac68SChris Mason * search_start -- an allocation hint for the new block 501d352ac68SChris Mason * 502d397712bSChris Mason * empty_size -- a hint that you plan on doing more cow. This is the size in 503d397712bSChris Mason * bytes the allocator should try to find free next to the block it returns. 504d397712bSChris Mason * This is just a hint and may be ignored by the allocator. 505d352ac68SChris Mason */ 506d397712bSChris Mason static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, 5075f39d397SChris Mason struct btrfs_root *root, 5085f39d397SChris Mason struct extent_buffer *buf, 5095f39d397SChris Mason struct extent_buffer *parent, int parent_slot, 5105f39d397SChris Mason struct extent_buffer **cow_ret, 5119631e4ccSJosef Bacik u64 search_start, u64 empty_size, 5129631e4ccSJosef Bacik enum btrfs_lock_nesting nest) 5136702ed49SChris Mason { 5140b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 5155d4f98a2SYan Zheng struct btrfs_disk_key disk_key; 5165f39d397SChris Mason struct extent_buffer *cow; 517be1a5564SMark Fasheh int level, ret; 518f0486c68SYan, Zheng int last_ref = 0; 519925baeddSChris Mason int unlock_orig = 0; 5200f5053ebSGoldwyn Rodrigues u64 parent_start = 0; 5216702ed49SChris Mason 522925baeddSChris Mason if (*cow_ret == buf) 523925baeddSChris Mason unlock_orig = 1; 524925baeddSChris Mason 52549d0c642SFilipe Manana btrfs_assert_tree_write_locked(buf); 526925baeddSChris Mason 52792a7cc42SQu Wenruo WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && 5280b246afaSJeff Mahoney trans->transid != fs_info->running_transaction->transid); 52992a7cc42SQu Wenruo WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && 53027cdeb70SMiao Xie trans->transid != root->last_trans); 5315f39d397SChris Mason 5327bb86316SChris Mason level = btrfs_header_level(buf); 53331840ae1SZheng Yan 5345d4f98a2SYan Zheng if (level == 0) 5355d4f98a2SYan Zheng btrfs_item_key(buf, &disk_key, 0); 5365d4f98a2SYan Zheng else 5375d4f98a2SYan Zheng btrfs_node_key(buf, &disk_key, 0); 5385d4f98a2SYan Zheng 5390f5053ebSGoldwyn Rodrigues if ((root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && parent) 5405d4f98a2SYan Zheng parent_start = parent->start; 5415d4f98a2SYan Zheng 54279bd3712SFilipe Manana cow = btrfs_alloc_tree_block(trans, root, parent_start, 54379bd3712SFilipe Manana root->root_key.objectid, &disk_key, level, 54479bd3712SFilipe Manana search_start, empty_size, nest); 5456702ed49SChris Mason if (IS_ERR(cow)) 5466702ed49SChris Mason return PTR_ERR(cow); 5476702ed49SChris Mason 548b4ce94deSChris Mason /* cow is set to blocking by btrfs_init_new_buffer */ 549b4ce94deSChris Mason 55058e8012cSDavid Sterba copy_extent_buffer_full(cow, buf); 551db94535dSChris Mason btrfs_set_header_bytenr(cow, cow->start); 5525f39d397SChris Mason btrfs_set_header_generation(cow, trans->transid); 5535d4f98a2SYan Zheng btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); 5545d4f98a2SYan Zheng btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | 5555d4f98a2SYan Zheng BTRFS_HEADER_FLAG_RELOC); 5565d4f98a2SYan Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) 5575d4f98a2SYan Zheng btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); 5585d4f98a2SYan Zheng else 5595f39d397SChris Mason btrfs_set_header_owner(cow, root->root_key.objectid); 5606702ed49SChris Mason 561de37aa51SNikolay Borisov write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); 5622b82032cSYan Zheng 563be1a5564SMark Fasheh ret = update_ref_for_cow(trans, root, buf, cow, &last_ref); 564b68dc2a9SMark Fasheh if (ret) { 565572c83acSJosef Bacik btrfs_tree_unlock(cow); 566572c83acSJosef Bacik free_extent_buffer(cow); 56766642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 568b68dc2a9SMark Fasheh return ret; 569b68dc2a9SMark Fasheh } 5701a40e23bSZheng Yan 57192a7cc42SQu Wenruo if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) { 57283d4cfd4SJosef Bacik ret = btrfs_reloc_cow_block(trans, root, buf, cow); 57393314e3bSZhaolei if (ret) { 574572c83acSJosef Bacik btrfs_tree_unlock(cow); 575572c83acSJosef Bacik free_extent_buffer(cow); 57666642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 57783d4cfd4SJosef Bacik return ret; 57883d4cfd4SJosef Bacik } 57993314e3bSZhaolei } 5803fd0a558SYan, Zheng 5816702ed49SChris Mason if (buf == root->node) { 582925baeddSChris Mason WARN_ON(parent && parent != buf); 5835d4f98a2SYan Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || 5845d4f98a2SYan Zheng btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) 5855d4f98a2SYan Zheng parent_start = buf->start; 586925baeddSChris Mason 587406808abSFilipe Manana ret = btrfs_tree_mod_log_insert_root(root->node, cow, true); 58840b0a749SFilipe Manana if (ret < 0) { 58940b0a749SFilipe Manana btrfs_tree_unlock(cow); 59040b0a749SFilipe Manana free_extent_buffer(cow); 59140b0a749SFilipe Manana btrfs_abort_transaction(trans, ret); 59240b0a749SFilipe Manana return ret; 59340b0a749SFilipe Manana } 59440b0a749SFilipe Manana atomic_inc(&cow->refs); 595240f62c8SChris Mason rcu_assign_pointer(root->node, cow); 596925baeddSChris Mason 5977a163608SFilipe Manana btrfs_free_tree_block(trans, btrfs_root_id(root), buf, 5987a163608SFilipe Manana parent_start, last_ref); 5995f39d397SChris Mason free_extent_buffer(buf); 6000b86a832SChris Mason add_root_to_dirty_list(root); 6016702ed49SChris Mason } else { 6025d4f98a2SYan Zheng WARN_ON(trans->transid != btrfs_header_generation(parent)); 603d09c5152SFilipe Manana ret = btrfs_tree_mod_log_insert_key(parent, parent_slot, 60433cff222SFilipe Manana BTRFS_MOD_LOG_KEY_REPLACE); 605d09c5152SFilipe Manana if (ret) { 606d09c5152SFilipe Manana btrfs_tree_unlock(cow); 607d09c5152SFilipe Manana free_extent_buffer(cow); 608d09c5152SFilipe Manana btrfs_abort_transaction(trans, ret); 609d09c5152SFilipe Manana return ret; 610d09c5152SFilipe Manana } 6115f39d397SChris Mason btrfs_set_node_blockptr(parent, parent_slot, 612db94535dSChris Mason cow->start); 61374493f7aSChris Mason btrfs_set_node_ptr_generation(parent, parent_slot, 61474493f7aSChris Mason trans->transid); 6156702ed49SChris Mason btrfs_mark_buffer_dirty(parent); 6165de865eeSFilipe David Borba Manana if (last_ref) { 617f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_free_eb(buf); 6185de865eeSFilipe David Borba Manana if (ret) { 619572c83acSJosef Bacik btrfs_tree_unlock(cow); 620572c83acSJosef Bacik free_extent_buffer(cow); 62166642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 6225de865eeSFilipe David Borba Manana return ret; 6235de865eeSFilipe David Borba Manana } 6245de865eeSFilipe David Borba Manana } 6257a163608SFilipe Manana btrfs_free_tree_block(trans, btrfs_root_id(root), buf, 6267a163608SFilipe Manana parent_start, last_ref); 6276702ed49SChris Mason } 628925baeddSChris Mason if (unlock_orig) 629925baeddSChris Mason btrfs_tree_unlock(buf); 6303083ee2eSJosef Bacik free_extent_buffer_stale(buf); 6316702ed49SChris Mason btrfs_mark_buffer_dirty(cow); 6326702ed49SChris Mason *cow_ret = cow; 6336702ed49SChris Mason return 0; 6346702ed49SChris Mason } 6356702ed49SChris Mason 6365d4f98a2SYan Zheng static inline int should_cow_block(struct btrfs_trans_handle *trans, 6375d4f98a2SYan Zheng struct btrfs_root *root, 6385d4f98a2SYan Zheng struct extent_buffer *buf) 6395d4f98a2SYan Zheng { 640f5ee5c9aSJeff Mahoney if (btrfs_is_testing(root->fs_info)) 641faa2dbf0SJosef Bacik return 0; 642fccb84c9SDavid Sterba 643d1980131SDavid Sterba /* Ensure we can see the FORCE_COW bit */ 644d1980131SDavid Sterba smp_mb__before_atomic(); 645f1ebcc74SLiu Bo 646f1ebcc74SLiu Bo /* 647f1ebcc74SLiu Bo * We do not need to cow a block if 648f1ebcc74SLiu Bo * 1) this block is not created or changed in this transaction; 649f1ebcc74SLiu Bo * 2) this block does not belong to TREE_RELOC tree; 650f1ebcc74SLiu Bo * 3) the root is not forced COW. 651f1ebcc74SLiu Bo * 652f1ebcc74SLiu Bo * What is forced COW: 65301327610SNicholas D Steeves * when we create snapshot during committing the transaction, 65452042d8eSAndrea Gelmini * after we've finished copying src root, we must COW the shared 655f1ebcc74SLiu Bo * block to ensure the metadata consistency. 656f1ebcc74SLiu Bo */ 6575d4f98a2SYan Zheng if (btrfs_header_generation(buf) == trans->transid && 6585d4f98a2SYan Zheng !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && 6595d4f98a2SYan Zheng !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && 660f1ebcc74SLiu Bo btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && 66127cdeb70SMiao Xie !test_bit(BTRFS_ROOT_FORCE_COW, &root->state)) 6625d4f98a2SYan Zheng return 0; 6635d4f98a2SYan Zheng return 1; 6645d4f98a2SYan Zheng } 6655d4f98a2SYan Zheng 666d352ac68SChris Mason /* 667d352ac68SChris Mason * cows a single block, see __btrfs_cow_block for the real work. 66801327610SNicholas D Steeves * This version of it has extra checks so that a block isn't COWed more than 669d352ac68SChris Mason * once per transaction, as long as it hasn't been written yet 670d352ac68SChris Mason */ 671d397712bSChris Mason noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, 6725f39d397SChris Mason struct btrfs_root *root, struct extent_buffer *buf, 6735f39d397SChris Mason struct extent_buffer *parent, int parent_slot, 6749631e4ccSJosef Bacik struct extent_buffer **cow_ret, 6759631e4ccSJosef Bacik enum btrfs_lock_nesting nest) 67602217ed2SChris Mason { 6770b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 6786702ed49SChris Mason u64 search_start; 679f510cfecSChris Mason int ret; 680dc17ff8fSChris Mason 68183354f07SJosef Bacik if (test_bit(BTRFS_ROOT_DELETING, &root->state)) 68283354f07SJosef Bacik btrfs_err(fs_info, 68383354f07SJosef Bacik "COW'ing blocks on a fs root that's being dropped"); 68483354f07SJosef Bacik 6850b246afaSJeff Mahoney if (trans->transaction != fs_info->running_transaction) 68631b1a2bdSJulia Lawall WARN(1, KERN_CRIT "trans %llu running %llu\n", 687c1c9ff7cSGeert Uytterhoeven trans->transid, 6880b246afaSJeff Mahoney fs_info->running_transaction->transid); 68931b1a2bdSJulia Lawall 6900b246afaSJeff Mahoney if (trans->transid != fs_info->generation) 69131b1a2bdSJulia Lawall WARN(1, KERN_CRIT "trans %llu running %llu\n", 6920b246afaSJeff Mahoney trans->transid, fs_info->generation); 693dc17ff8fSChris Mason 6945d4f98a2SYan Zheng if (!should_cow_block(trans, root, buf)) { 69502217ed2SChris Mason *cow_ret = buf; 69602217ed2SChris Mason return 0; 69702217ed2SChris Mason } 698c487685dSChris Mason 699ee22184bSByongho Lee search_start = buf->start & ~((u64)SZ_1G - 1); 700b4ce94deSChris Mason 701f616f5cdSQu Wenruo /* 702f616f5cdSQu Wenruo * Before CoWing this block for later modification, check if it's 703f616f5cdSQu Wenruo * the subtree root and do the delayed subtree trace if needed. 704f616f5cdSQu Wenruo * 705f616f5cdSQu Wenruo * Also We don't care about the error, as it's handled internally. 706f616f5cdSQu Wenruo */ 707f616f5cdSQu Wenruo btrfs_qgroup_trace_subtree_after_cow(trans, root, buf); 708f510cfecSChris Mason ret = __btrfs_cow_block(trans, root, buf, parent, 7099631e4ccSJosef Bacik parent_slot, cow_ret, search_start, 0, nest); 7101abe9b8aSliubo 7111abe9b8aSliubo trace_btrfs_cow_block(root, buf, *cow_ret); 7121abe9b8aSliubo 713f510cfecSChris Mason return ret; 7142c90e5d6SChris Mason } 715f75e2b79SJosef Bacik ALLOW_ERROR_INJECTION(btrfs_cow_block, ERRNO); 7166702ed49SChris Mason 717d352ac68SChris Mason /* 718d352ac68SChris Mason * helper function for defrag to decide if two blocks pointed to by a 719d352ac68SChris Mason * node are actually close by 720d352ac68SChris Mason */ 7216b80053dSChris Mason static int close_blocks(u64 blocknr, u64 other, u32 blocksize) 7226702ed49SChris Mason { 7236b80053dSChris Mason if (blocknr < other && other - (blocknr + blocksize) < 32768) 7246702ed49SChris Mason return 1; 7256b80053dSChris Mason if (blocknr > other && blocknr - (other + blocksize) < 32768) 7266702ed49SChris Mason return 1; 72702217ed2SChris Mason return 0; 72802217ed2SChris Mason } 72902217ed2SChris Mason 730ce6ef5abSDavid Sterba #ifdef __LITTLE_ENDIAN 731ce6ef5abSDavid Sterba 732ce6ef5abSDavid Sterba /* 733ce6ef5abSDavid Sterba * Compare two keys, on little-endian the disk order is same as CPU order and 734ce6ef5abSDavid Sterba * we can avoid the conversion. 735ce6ef5abSDavid Sterba */ 736ce6ef5abSDavid Sterba static int comp_keys(const struct btrfs_disk_key *disk_key, 737ce6ef5abSDavid Sterba const struct btrfs_key *k2) 738ce6ef5abSDavid Sterba { 739ce6ef5abSDavid Sterba const struct btrfs_key *k1 = (const struct btrfs_key *)disk_key; 740ce6ef5abSDavid Sterba 741ce6ef5abSDavid Sterba return btrfs_comp_cpu_keys(k1, k2); 742ce6ef5abSDavid Sterba } 743ce6ef5abSDavid Sterba 744ce6ef5abSDavid Sterba #else 745ce6ef5abSDavid Sterba 746081e9573SChris Mason /* 747081e9573SChris Mason * compare two keys in a memcmp fashion 748081e9573SChris Mason */ 749310712b2SOmar Sandoval static int comp_keys(const struct btrfs_disk_key *disk, 750310712b2SOmar Sandoval const struct btrfs_key *k2) 751081e9573SChris Mason { 752081e9573SChris Mason struct btrfs_key k1; 753081e9573SChris Mason 754081e9573SChris Mason btrfs_disk_key_to_cpu(&k1, disk); 755081e9573SChris Mason 75620736abaSDiego Calleja return btrfs_comp_cpu_keys(&k1, k2); 757081e9573SChris Mason } 758ce6ef5abSDavid Sterba #endif 759081e9573SChris Mason 760f3465ca4SJosef Bacik /* 761f3465ca4SJosef Bacik * same as comp_keys only with two btrfs_key's 762f3465ca4SJosef Bacik */ 763e1f60a65SDavid Sterba int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2) 764f3465ca4SJosef Bacik { 765f3465ca4SJosef Bacik if (k1->objectid > k2->objectid) 766f3465ca4SJosef Bacik return 1; 767f3465ca4SJosef Bacik if (k1->objectid < k2->objectid) 768f3465ca4SJosef Bacik return -1; 769f3465ca4SJosef Bacik if (k1->type > k2->type) 770f3465ca4SJosef Bacik return 1; 771f3465ca4SJosef Bacik if (k1->type < k2->type) 772f3465ca4SJosef Bacik return -1; 773f3465ca4SJosef Bacik if (k1->offset > k2->offset) 774f3465ca4SJosef Bacik return 1; 775f3465ca4SJosef Bacik if (k1->offset < k2->offset) 776f3465ca4SJosef Bacik return -1; 777f3465ca4SJosef Bacik return 0; 778f3465ca4SJosef Bacik } 779081e9573SChris Mason 780d352ac68SChris Mason /* 781d352ac68SChris Mason * this is used by the defrag code to go through all the 782d352ac68SChris Mason * leaves pointed to by a node and reallocate them so that 783d352ac68SChris Mason * disk order is close to key order 784d352ac68SChris Mason */ 7856702ed49SChris Mason int btrfs_realloc_node(struct btrfs_trans_handle *trans, 7865f39d397SChris Mason struct btrfs_root *root, struct extent_buffer *parent, 787de78b51aSEric Sandeen int start_slot, u64 *last_ret, 788a6b6e75eSChris Mason struct btrfs_key *progress) 7896702ed49SChris Mason { 7900b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 7916b80053dSChris Mason struct extent_buffer *cur; 7926702ed49SChris Mason u64 blocknr; 793e9d0b13bSChris Mason u64 search_start = *last_ret; 794e9d0b13bSChris Mason u64 last_block = 0; 7956702ed49SChris Mason u64 other; 7966702ed49SChris Mason u32 parent_nritems; 7976702ed49SChris Mason int end_slot; 7986702ed49SChris Mason int i; 7996702ed49SChris Mason int err = 0; 8006b80053dSChris Mason u32 blocksize; 801081e9573SChris Mason int progress_passed = 0; 802081e9573SChris Mason struct btrfs_disk_key disk_key; 8036702ed49SChris Mason 8040b246afaSJeff Mahoney WARN_ON(trans->transaction != fs_info->running_transaction); 8050b246afaSJeff Mahoney WARN_ON(trans->transid != fs_info->generation); 80686479a04SChris Mason 8076b80053dSChris Mason parent_nritems = btrfs_header_nritems(parent); 8080b246afaSJeff Mahoney blocksize = fs_info->nodesize; 8095dfe2be7SFilipe Manana end_slot = parent_nritems - 1; 8106702ed49SChris Mason 8115dfe2be7SFilipe Manana if (parent_nritems <= 1) 8126702ed49SChris Mason return 0; 8136702ed49SChris Mason 8145dfe2be7SFilipe Manana for (i = start_slot; i <= end_slot; i++) { 8156702ed49SChris Mason int close = 1; 816a6b6e75eSChris Mason 817081e9573SChris Mason btrfs_node_key(parent, &disk_key, i); 818081e9573SChris Mason if (!progress_passed && comp_keys(&disk_key, progress) < 0) 819081e9573SChris Mason continue; 820081e9573SChris Mason 821081e9573SChris Mason progress_passed = 1; 8226b80053dSChris Mason blocknr = btrfs_node_blockptr(parent, i); 823e9d0b13bSChris Mason if (last_block == 0) 824e9d0b13bSChris Mason last_block = blocknr; 8255708b959SChris Mason 8266702ed49SChris Mason if (i > 0) { 8276b80053dSChris Mason other = btrfs_node_blockptr(parent, i - 1); 8286b80053dSChris Mason close = close_blocks(blocknr, other, blocksize); 8296702ed49SChris Mason } 8305dfe2be7SFilipe Manana if (!close && i < end_slot) { 8316b80053dSChris Mason other = btrfs_node_blockptr(parent, i + 1); 8326b80053dSChris Mason close = close_blocks(blocknr, other, blocksize); 8336702ed49SChris Mason } 834e9d0b13bSChris Mason if (close) { 835e9d0b13bSChris Mason last_block = blocknr; 8366702ed49SChris Mason continue; 837e9d0b13bSChris Mason } 8386702ed49SChris Mason 839206983b7SJosef Bacik cur = btrfs_read_node_slot(parent, i); 840206983b7SJosef Bacik if (IS_ERR(cur)) 84164c043deSLiu Bo return PTR_ERR(cur); 842e9d0b13bSChris Mason if (search_start == 0) 8436b80053dSChris Mason search_start = last_block; 844e9d0b13bSChris Mason 845e7a84565SChris Mason btrfs_tree_lock(cur); 8466b80053dSChris Mason err = __btrfs_cow_block(trans, root, cur, parent, i, 847e7a84565SChris Mason &cur, search_start, 8486b80053dSChris Mason min(16 * blocksize, 8499631e4ccSJosef Bacik (end_slot - i) * blocksize), 8509631e4ccSJosef Bacik BTRFS_NESTING_COW); 851252c38f0SYan if (err) { 852e7a84565SChris Mason btrfs_tree_unlock(cur); 8536b80053dSChris Mason free_extent_buffer(cur); 8546702ed49SChris Mason break; 855252c38f0SYan } 856e7a84565SChris Mason search_start = cur->start; 857e7a84565SChris Mason last_block = cur->start; 858f2183bdeSChris Mason *last_ret = search_start; 859e7a84565SChris Mason btrfs_tree_unlock(cur); 860e7a84565SChris Mason free_extent_buffer(cur); 8616702ed49SChris Mason } 8626702ed49SChris Mason return err; 8636702ed49SChris Mason } 8646702ed49SChris Mason 86574123bd7SChris Mason /* 866fb81212cSFilipe Manana * Search for a key in the given extent_buffer. 8675f39d397SChris Mason * 868a724f313SFilipe Manana * The lower boundary for the search is specified by the slot number @first_slot. 869fdf8d595SAnand Jain * Use a value of 0 to search over the whole extent buffer. Works for both 870fdf8d595SAnand Jain * leaves and nodes. 87174123bd7SChris Mason * 872fb81212cSFilipe Manana * The slot in the extent buffer is returned via @slot. If the key exists in the 873fb81212cSFilipe Manana * extent buffer, then @slot will point to the slot where the key is, otherwise 874fb81212cSFilipe Manana * it points to the slot where you would insert the key. 875fb81212cSFilipe Manana * 876fb81212cSFilipe Manana * Slot may point to the total number of items (i.e. one position beyond the last 877fb81212cSFilipe Manana * key) if the key is bigger than the last key in the extent buffer. 87874123bd7SChris Mason */ 879fdf8d595SAnand Jain int btrfs_bin_search(struct extent_buffer *eb, int first_slot, 88067d5e289SMarcos Paulo de Souza const struct btrfs_key *key, int *slot) 881be0e5c09SChris Mason { 882fb81212cSFilipe Manana unsigned long p; 883fb81212cSFilipe Manana int item_size; 884a724f313SFilipe Manana /* 885a724f313SFilipe Manana * Use unsigned types for the low and high slots, so that we get a more 886a724f313SFilipe Manana * efficient division in the search loop below. 887a724f313SFilipe Manana */ 888a724f313SFilipe Manana u32 low = first_slot; 889a724f313SFilipe Manana u32 high = btrfs_header_nritems(eb); 890be0e5c09SChris Mason int ret; 8915cd17f34SDavid Sterba const int key_size = sizeof(struct btrfs_disk_key); 892be0e5c09SChris Mason 893a724f313SFilipe Manana if (unlikely(low > high)) { 8945e24e9afSLiu Bo btrfs_err(eb->fs_info, 895a724f313SFilipe Manana "%s: low (%u) > high (%u) eb %llu owner %llu level %d", 8965e24e9afSLiu Bo __func__, low, high, eb->start, 8975e24e9afSLiu Bo btrfs_header_owner(eb), btrfs_header_level(eb)); 8985e24e9afSLiu Bo return -EINVAL; 8995e24e9afSLiu Bo } 9005e24e9afSLiu Bo 901fb81212cSFilipe Manana if (btrfs_header_level(eb) == 0) { 902fb81212cSFilipe Manana p = offsetof(struct btrfs_leaf, items); 903fb81212cSFilipe Manana item_size = sizeof(struct btrfs_item); 904fb81212cSFilipe Manana } else { 905fb81212cSFilipe Manana p = offsetof(struct btrfs_node, ptrs); 906fb81212cSFilipe Manana item_size = sizeof(struct btrfs_key_ptr); 907fb81212cSFilipe Manana } 908fb81212cSFilipe Manana 909be0e5c09SChris Mason while (low < high) { 9105cd17f34SDavid Sterba unsigned long oip; 9115cd17f34SDavid Sterba unsigned long offset; 9125cd17f34SDavid Sterba struct btrfs_disk_key *tmp; 9135cd17f34SDavid Sterba struct btrfs_disk_key unaligned; 9145cd17f34SDavid Sterba int mid; 9155cd17f34SDavid Sterba 916be0e5c09SChris Mason mid = (low + high) / 2; 9175f39d397SChris Mason offset = p + mid * item_size; 9185cd17f34SDavid Sterba oip = offset_in_page(offset); 9195f39d397SChris Mason 9205cd17f34SDavid Sterba if (oip + key_size <= PAGE_SIZE) { 921884b07d0SQu Wenruo const unsigned long idx = get_eb_page_index(offset); 9225cd17f34SDavid Sterba char *kaddr = page_address(eb->pages[idx]); 923934d375bSChris Mason 924884b07d0SQu Wenruo oip = get_eb_offset_in_page(eb, offset); 9255cd17f34SDavid Sterba tmp = (struct btrfs_disk_key *)(kaddr + oip); 9265cd17f34SDavid Sterba } else { 9275cd17f34SDavid Sterba read_extent_buffer(eb, &unaligned, offset, key_size); 9285f39d397SChris Mason tmp = &unaligned; 929479965d6SChris Mason } 930479965d6SChris Mason 931be0e5c09SChris Mason ret = comp_keys(tmp, key); 932be0e5c09SChris Mason 933be0e5c09SChris Mason if (ret < 0) 934be0e5c09SChris Mason low = mid + 1; 935be0e5c09SChris Mason else if (ret > 0) 936be0e5c09SChris Mason high = mid; 937be0e5c09SChris Mason else { 938be0e5c09SChris Mason *slot = mid; 939be0e5c09SChris Mason return 0; 940be0e5c09SChris Mason } 941be0e5c09SChris Mason } 942be0e5c09SChris Mason *slot = low; 943be0e5c09SChris Mason return 1; 944be0e5c09SChris Mason } 945be0e5c09SChris Mason 946f0486c68SYan, Zheng static void root_add_used(struct btrfs_root *root, u32 size) 947f0486c68SYan, Zheng { 948f0486c68SYan, Zheng spin_lock(&root->accounting_lock); 949f0486c68SYan, Zheng btrfs_set_root_used(&root->root_item, 950f0486c68SYan, Zheng btrfs_root_used(&root->root_item) + size); 951f0486c68SYan, Zheng spin_unlock(&root->accounting_lock); 952f0486c68SYan, Zheng } 953f0486c68SYan, Zheng 954f0486c68SYan, Zheng static void root_sub_used(struct btrfs_root *root, u32 size) 955f0486c68SYan, Zheng { 956f0486c68SYan, Zheng spin_lock(&root->accounting_lock); 957f0486c68SYan, Zheng btrfs_set_root_used(&root->root_item, 958f0486c68SYan, Zheng btrfs_root_used(&root->root_item) - size); 959f0486c68SYan, Zheng spin_unlock(&root->accounting_lock); 960f0486c68SYan, Zheng } 961f0486c68SYan, Zheng 962d352ac68SChris Mason /* given a node and slot number, this reads the blocks it points to. The 963d352ac68SChris Mason * extent buffer is returned with a reference taken (but unlocked). 964d352ac68SChris Mason */ 9654b231ae4SDavid Sterba struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent, 9664b231ae4SDavid Sterba int slot) 967bb803951SChris Mason { 968ca7a79adSChris Mason int level = btrfs_header_level(parent); 969789d6a3aSQu Wenruo struct btrfs_tree_parent_check check = { 0 }; 970416bc658SJosef Bacik struct extent_buffer *eb; 971416bc658SJosef Bacik 972fb770ae4SLiu Bo if (slot < 0 || slot >= btrfs_header_nritems(parent)) 973fb770ae4SLiu Bo return ERR_PTR(-ENOENT); 974ca7a79adSChris Mason 975d4694728SJosef Bacik ASSERT(level); 976ca7a79adSChris Mason 977789d6a3aSQu Wenruo check.level = level - 1; 978789d6a3aSQu Wenruo check.transid = btrfs_node_ptr_generation(parent, slot); 979789d6a3aSQu Wenruo check.owner_root = btrfs_header_owner(parent); 980789d6a3aSQu Wenruo check.has_first_key = true; 981789d6a3aSQu Wenruo btrfs_node_key_to_cpu(parent, &check.first_key, slot); 982789d6a3aSQu Wenruo 983d0d20b0fSDavid Sterba eb = read_tree_block(parent->fs_info, btrfs_node_blockptr(parent, slot), 984789d6a3aSQu Wenruo &check); 9854eb150d6SQu Wenruo if (IS_ERR(eb)) 9864eb150d6SQu Wenruo return eb; 9874eb150d6SQu Wenruo if (!extent_buffer_uptodate(eb)) { 988416bc658SJosef Bacik free_extent_buffer(eb); 9894eb150d6SQu Wenruo return ERR_PTR(-EIO); 990416bc658SJosef Bacik } 991416bc658SJosef Bacik 992416bc658SJosef Bacik return eb; 993bb803951SChris Mason } 994bb803951SChris Mason 995d352ac68SChris Mason /* 996d352ac68SChris Mason * node level balancing, used to make sure nodes are in proper order for 997d352ac68SChris Mason * item deletion. We balance from the top down, so we have to make sure 998d352ac68SChris Mason * that a deletion won't leave an node completely empty later on. 999d352ac68SChris Mason */ 1000e02119d5SChris Mason static noinline int balance_level(struct btrfs_trans_handle *trans, 100198ed5174SChris Mason struct btrfs_root *root, 100298ed5174SChris Mason struct btrfs_path *path, int level) 1003bb803951SChris Mason { 10040b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 10055f39d397SChris Mason struct extent_buffer *right = NULL; 10065f39d397SChris Mason struct extent_buffer *mid; 10075f39d397SChris Mason struct extent_buffer *left = NULL; 10085f39d397SChris Mason struct extent_buffer *parent = NULL; 1009bb803951SChris Mason int ret = 0; 1010bb803951SChris Mason int wret; 1011bb803951SChris Mason int pslot; 1012bb803951SChris Mason int orig_slot = path->slots[level]; 101379f95c82SChris Mason u64 orig_ptr; 1014bb803951SChris Mason 101598e6b1ebSLiu Bo ASSERT(level > 0); 1016bb803951SChris Mason 10175f39d397SChris Mason mid = path->nodes[level]; 1018b4ce94deSChris Mason 1019ac5887c8SJosef Bacik WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK); 10207bb86316SChris Mason WARN_ON(btrfs_header_generation(mid) != trans->transid); 10217bb86316SChris Mason 10221d4f8a0cSChris Mason orig_ptr = btrfs_node_blockptr(mid, orig_slot); 102379f95c82SChris Mason 1024a05a9bb1SLi Zefan if (level < BTRFS_MAX_LEVEL - 1) { 10255f39d397SChris Mason parent = path->nodes[level + 1]; 1026bb803951SChris Mason pslot = path->slots[level + 1]; 1027a05a9bb1SLi Zefan } 1028bb803951SChris Mason 102940689478SChris Mason /* 103040689478SChris Mason * deal with the case where there is only one pointer in the root 103140689478SChris Mason * by promoting the node below to a root 103240689478SChris Mason */ 10335f39d397SChris Mason if (!parent) { 10345f39d397SChris Mason struct extent_buffer *child; 1035bb803951SChris Mason 10365f39d397SChris Mason if (btrfs_header_nritems(mid) != 1) 1037bb803951SChris Mason return 0; 1038bb803951SChris Mason 1039bb803951SChris Mason /* promote the child to a root */ 10404b231ae4SDavid Sterba child = btrfs_read_node_slot(mid, 0); 1041fb770ae4SLiu Bo if (IS_ERR(child)) { 1042fb770ae4SLiu Bo ret = PTR_ERR(child); 1043daefe4d4SFilipe Manana goto out; 1044305a26afSMark Fasheh } 1045305a26afSMark Fasheh 1046925baeddSChris Mason btrfs_tree_lock(child); 10479631e4ccSJosef Bacik ret = btrfs_cow_block(trans, root, child, mid, 0, &child, 10489631e4ccSJosef Bacik BTRFS_NESTING_COW); 1049f0486c68SYan, Zheng if (ret) { 1050f0486c68SYan, Zheng btrfs_tree_unlock(child); 1051f0486c68SYan, Zheng free_extent_buffer(child); 1052daefe4d4SFilipe Manana goto out; 1053f0486c68SYan, Zheng } 10542f375ab9SYan 1055406808abSFilipe Manana ret = btrfs_tree_mod_log_insert_root(root->node, child, true); 105639020d8aSFilipe Manana if (ret < 0) { 105739020d8aSFilipe Manana btrfs_tree_unlock(child); 105839020d8aSFilipe Manana free_extent_buffer(child); 105939020d8aSFilipe Manana btrfs_abort_transaction(trans, ret); 1060daefe4d4SFilipe Manana goto out; 106139020d8aSFilipe Manana } 1062240f62c8SChris Mason rcu_assign_pointer(root->node, child); 1063925baeddSChris Mason 10640b86a832SChris Mason add_root_to_dirty_list(root); 1065925baeddSChris Mason btrfs_tree_unlock(child); 1066b4ce94deSChris Mason 1067925baeddSChris Mason path->locks[level] = 0; 1068bb803951SChris Mason path->nodes[level] = NULL; 1069190a8339SJosef Bacik btrfs_clear_buffer_dirty(trans, mid); 1070925baeddSChris Mason btrfs_tree_unlock(mid); 1071bb803951SChris Mason /* once for the path */ 10725f39d397SChris Mason free_extent_buffer(mid); 1073f0486c68SYan, Zheng 1074f0486c68SYan, Zheng root_sub_used(root, mid->len); 10757a163608SFilipe Manana btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1); 1076bb803951SChris Mason /* once for the root ptr */ 10773083ee2eSJosef Bacik free_extent_buffer_stale(mid); 1078f0486c68SYan, Zheng return 0; 1079bb803951SChris Mason } 10805f39d397SChris Mason if (btrfs_header_nritems(mid) > 10810b246afaSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 4) 1082bb803951SChris Mason return 0; 1083bb803951SChris Mason 10849cf14029SJosef Bacik if (pslot) { 10854b231ae4SDavid Sterba left = btrfs_read_node_slot(parent, pslot - 1); 10869cf14029SJosef Bacik if (IS_ERR(left)) { 10879cf14029SJosef Bacik ret = PTR_ERR(left); 1088fb770ae4SLiu Bo left = NULL; 1089daefe4d4SFilipe Manana goto out; 10909cf14029SJosef Bacik } 1091fb770ae4SLiu Bo 1092bf77467aSJosef Bacik __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); 10935f39d397SChris Mason wret = btrfs_cow_block(trans, root, left, 10949631e4ccSJosef Bacik parent, pslot - 1, &left, 1095bf59a5a2SJosef Bacik BTRFS_NESTING_LEFT_COW); 109654aa1f4dSChris Mason if (wret) { 109754aa1f4dSChris Mason ret = wret; 1098daefe4d4SFilipe Manana goto out; 109954aa1f4dSChris Mason } 11002cc58cf2SChris Mason } 1101fb770ae4SLiu Bo 11029cf14029SJosef Bacik if (pslot + 1 < btrfs_header_nritems(parent)) { 11034b231ae4SDavid Sterba right = btrfs_read_node_slot(parent, pslot + 1); 11049cf14029SJosef Bacik if (IS_ERR(right)) { 11059cf14029SJosef Bacik ret = PTR_ERR(right); 1106fb770ae4SLiu Bo right = NULL; 1107daefe4d4SFilipe Manana goto out; 11089cf14029SJosef Bacik } 1109fb770ae4SLiu Bo 1110bf77467aSJosef Bacik __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); 11115f39d397SChris Mason wret = btrfs_cow_block(trans, root, right, 11129631e4ccSJosef Bacik parent, pslot + 1, &right, 1113bf59a5a2SJosef Bacik BTRFS_NESTING_RIGHT_COW); 11142cc58cf2SChris Mason if (wret) { 11152cc58cf2SChris Mason ret = wret; 1116daefe4d4SFilipe Manana goto out; 11172cc58cf2SChris Mason } 11182cc58cf2SChris Mason } 11192cc58cf2SChris Mason 11202cc58cf2SChris Mason /* first, try to make some room in the middle buffer */ 11215f39d397SChris Mason if (left) { 11225f39d397SChris Mason orig_slot += btrfs_header_nritems(left); 1123d30a668fSDavid Sterba wret = push_node_left(trans, left, mid, 1); 112479f95c82SChris Mason if (wret < 0) 112579f95c82SChris Mason ret = wret; 1126bb803951SChris Mason } 112779f95c82SChris Mason 112879f95c82SChris Mason /* 112979f95c82SChris Mason * then try to empty the right most buffer into the middle 113079f95c82SChris Mason */ 11315f39d397SChris Mason if (right) { 1132d30a668fSDavid Sterba wret = push_node_left(trans, mid, right, 1); 113354aa1f4dSChris Mason if (wret < 0 && wret != -ENOSPC) 113479f95c82SChris Mason ret = wret; 11355f39d397SChris Mason if (btrfs_header_nritems(right) == 0) { 1136190a8339SJosef Bacik btrfs_clear_buffer_dirty(trans, right); 1137925baeddSChris Mason btrfs_tree_unlock(right); 1138016f9d0bSJosef Bacik btrfs_del_ptr(root, path, level + 1, pslot + 1); 1139f0486c68SYan, Zheng root_sub_used(root, right->len); 11407a163608SFilipe Manana btrfs_free_tree_block(trans, btrfs_root_id(root), right, 11417a163608SFilipe Manana 0, 1); 11423083ee2eSJosef Bacik free_extent_buffer_stale(right); 1143f0486c68SYan, Zheng right = NULL; 1144bb803951SChris Mason } else { 11455f39d397SChris Mason struct btrfs_disk_key right_key; 11465f39d397SChris Mason btrfs_node_key(right, &right_key, 0); 1147f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, 114833cff222SFilipe Manana BTRFS_MOD_LOG_KEY_REPLACE); 114939020d8aSFilipe Manana if (ret < 0) { 115039020d8aSFilipe Manana btrfs_abort_transaction(trans, ret); 1151daefe4d4SFilipe Manana goto out; 115239020d8aSFilipe Manana } 11535f39d397SChris Mason btrfs_set_node_key(parent, &right_key, pslot + 1); 11545f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 1155bb803951SChris Mason } 1156bb803951SChris Mason } 11575f39d397SChris Mason if (btrfs_header_nritems(mid) == 1) { 115879f95c82SChris Mason /* 115979f95c82SChris Mason * we're not allowed to leave a node with one item in the 116079f95c82SChris Mason * tree during a delete. A deletion from lower in the tree 116179f95c82SChris Mason * could try to delete the only pointer in this node. 116279f95c82SChris Mason * So, pull some keys from the left. 116379f95c82SChris Mason * There has to be a left pointer at this point because 116479f95c82SChris Mason * otherwise we would have pulled some pointers from the 116579f95c82SChris Mason * right 116679f95c82SChris Mason */ 1167*725026edSFilipe Manana if (unlikely(!left)) { 1168*725026edSFilipe Manana btrfs_crit(fs_info, 1169*725026edSFilipe Manana "missing left child when middle child only has 1 item, parent bytenr %llu level %d mid bytenr %llu root %llu", 1170*725026edSFilipe Manana parent->start, btrfs_header_level(parent), 1171*725026edSFilipe Manana mid->start, btrfs_root_id(root)); 1172*725026edSFilipe Manana ret = -EUCLEAN; 1173*725026edSFilipe Manana btrfs_abort_transaction(trans, ret); 1174daefe4d4SFilipe Manana goto out; 1175305a26afSMark Fasheh } 117655d32ed8SDavid Sterba wret = balance_node_right(trans, mid, left); 117754aa1f4dSChris Mason if (wret < 0) { 117879f95c82SChris Mason ret = wret; 1179daefe4d4SFilipe Manana goto out; 118054aa1f4dSChris Mason } 1181bce4eae9SChris Mason if (wret == 1) { 1182d30a668fSDavid Sterba wret = push_node_left(trans, left, mid, 1); 1183bce4eae9SChris Mason if (wret < 0) 1184bce4eae9SChris Mason ret = wret; 1185bce4eae9SChris Mason } 118679f95c82SChris Mason BUG_ON(wret == 1); 118779f95c82SChris Mason } 11885f39d397SChris Mason if (btrfs_header_nritems(mid) == 0) { 1189190a8339SJosef Bacik btrfs_clear_buffer_dirty(trans, mid); 1190925baeddSChris Mason btrfs_tree_unlock(mid); 1191016f9d0bSJosef Bacik btrfs_del_ptr(root, path, level + 1, pslot); 1192f0486c68SYan, Zheng root_sub_used(root, mid->len); 11937a163608SFilipe Manana btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1); 11943083ee2eSJosef Bacik free_extent_buffer_stale(mid); 1195f0486c68SYan, Zheng mid = NULL; 119679f95c82SChris Mason } else { 119779f95c82SChris Mason /* update the parent key to reflect our changes */ 11985f39d397SChris Mason struct btrfs_disk_key mid_key; 11995f39d397SChris Mason btrfs_node_key(mid, &mid_key, 0); 1200f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_key(parent, pslot, 120133cff222SFilipe Manana BTRFS_MOD_LOG_KEY_REPLACE); 120239020d8aSFilipe Manana if (ret < 0) { 120339020d8aSFilipe Manana btrfs_abort_transaction(trans, ret); 1204daefe4d4SFilipe Manana goto out; 120539020d8aSFilipe Manana } 12065f39d397SChris Mason btrfs_set_node_key(parent, &mid_key, pslot); 12075f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 120879f95c82SChris Mason } 1209bb803951SChris Mason 121079f95c82SChris Mason /* update the path */ 12115f39d397SChris Mason if (left) { 12125f39d397SChris Mason if (btrfs_header_nritems(left) > orig_slot) { 121367439dadSDavid Sterba atomic_inc(&left->refs); 1214925baeddSChris Mason /* left was locked after cow */ 12155f39d397SChris Mason path->nodes[level] = left; 1216bb803951SChris Mason path->slots[level + 1] -= 1; 1217bb803951SChris Mason path->slots[level] = orig_slot; 1218925baeddSChris Mason if (mid) { 1219925baeddSChris Mason btrfs_tree_unlock(mid); 12205f39d397SChris Mason free_extent_buffer(mid); 1221925baeddSChris Mason } 1222bb803951SChris Mason } else { 12235f39d397SChris Mason orig_slot -= btrfs_header_nritems(left); 1224bb803951SChris Mason path->slots[level] = orig_slot; 1225bb803951SChris Mason } 1226bb803951SChris Mason } 122779f95c82SChris Mason /* double check we haven't messed things up */ 1228e20d96d6SChris Mason if (orig_ptr != 12295f39d397SChris Mason btrfs_node_blockptr(path->nodes[level], path->slots[level])) 123079f95c82SChris Mason BUG(); 1231daefe4d4SFilipe Manana out: 1232925baeddSChris Mason if (right) { 1233925baeddSChris Mason btrfs_tree_unlock(right); 12345f39d397SChris Mason free_extent_buffer(right); 1235925baeddSChris Mason } 1236925baeddSChris Mason if (left) { 1237925baeddSChris Mason if (path->nodes[level] != left) 1238925baeddSChris Mason btrfs_tree_unlock(left); 12395f39d397SChris Mason free_extent_buffer(left); 1240925baeddSChris Mason } 1241bb803951SChris Mason return ret; 1242bb803951SChris Mason } 1243bb803951SChris Mason 1244d352ac68SChris Mason /* Node balancing for insertion. Here we only split or push nodes around 1245d352ac68SChris Mason * when they are completely full. This is also done top down, so we 1246d352ac68SChris Mason * have to be pessimistic. 1247d352ac68SChris Mason */ 1248d397712bSChris Mason static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, 1249e66f709bSChris Mason struct btrfs_root *root, 1250e66f709bSChris Mason struct btrfs_path *path, int level) 1251e66f709bSChris Mason { 12520b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 12535f39d397SChris Mason struct extent_buffer *right = NULL; 12545f39d397SChris Mason struct extent_buffer *mid; 12555f39d397SChris Mason struct extent_buffer *left = NULL; 12565f39d397SChris Mason struct extent_buffer *parent = NULL; 1257e66f709bSChris Mason int ret = 0; 1258e66f709bSChris Mason int wret; 1259e66f709bSChris Mason int pslot; 1260e66f709bSChris Mason int orig_slot = path->slots[level]; 1261e66f709bSChris Mason 1262e66f709bSChris Mason if (level == 0) 1263e66f709bSChris Mason return 1; 1264e66f709bSChris Mason 12655f39d397SChris Mason mid = path->nodes[level]; 12667bb86316SChris Mason WARN_ON(btrfs_header_generation(mid) != trans->transid); 1267e66f709bSChris Mason 1268a05a9bb1SLi Zefan if (level < BTRFS_MAX_LEVEL - 1) { 12695f39d397SChris Mason parent = path->nodes[level + 1]; 1270e66f709bSChris Mason pslot = path->slots[level + 1]; 1271a05a9bb1SLi Zefan } 1272e66f709bSChris Mason 12735f39d397SChris Mason if (!parent) 1274e66f709bSChris Mason return 1; 1275e66f709bSChris Mason 12769cf14029SJosef Bacik /* first, try to make some room in the middle buffer */ 12779cf14029SJosef Bacik if (pslot) { 12789cf14029SJosef Bacik u32 left_nr; 12799cf14029SJosef Bacik 12804b231ae4SDavid Sterba left = btrfs_read_node_slot(parent, pslot - 1); 1281fb770ae4SLiu Bo if (IS_ERR(left)) 12829cf14029SJosef Bacik return PTR_ERR(left); 1283925baeddSChris Mason 1284bf77467aSJosef Bacik __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); 1285b4ce94deSChris Mason 12865f39d397SChris Mason left_nr = btrfs_header_nritems(left); 12870b246afaSJeff Mahoney if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { 128833ade1f8SChris Mason wret = 1; 128933ade1f8SChris Mason } else { 12905f39d397SChris Mason ret = btrfs_cow_block(trans, root, left, parent, 12919631e4ccSJosef Bacik pslot - 1, &left, 1292bf59a5a2SJosef Bacik BTRFS_NESTING_LEFT_COW); 129354aa1f4dSChris Mason if (ret) 129454aa1f4dSChris Mason wret = 1; 129554aa1f4dSChris Mason else { 1296d30a668fSDavid Sterba wret = push_node_left(trans, left, mid, 0); 129754aa1f4dSChris Mason } 129833ade1f8SChris Mason } 1299e66f709bSChris Mason if (wret < 0) 1300e66f709bSChris Mason ret = wret; 1301e66f709bSChris Mason if (wret == 0) { 13025f39d397SChris Mason struct btrfs_disk_key disk_key; 1303e66f709bSChris Mason orig_slot += left_nr; 13045f39d397SChris Mason btrfs_node_key(mid, &disk_key, 0); 1305f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_key(parent, pslot, 130633cff222SFilipe Manana BTRFS_MOD_LOG_KEY_REPLACE); 13070e82bcfeSDavid Sterba BUG_ON(ret < 0); 13085f39d397SChris Mason btrfs_set_node_key(parent, &disk_key, pslot); 13095f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 13105f39d397SChris Mason if (btrfs_header_nritems(left) > orig_slot) { 13115f39d397SChris Mason path->nodes[level] = left; 1312e66f709bSChris Mason path->slots[level + 1] -= 1; 1313e66f709bSChris Mason path->slots[level] = orig_slot; 1314925baeddSChris Mason btrfs_tree_unlock(mid); 13155f39d397SChris Mason free_extent_buffer(mid); 1316e66f709bSChris Mason } else { 1317e66f709bSChris Mason orig_slot -= 13185f39d397SChris Mason btrfs_header_nritems(left); 1319e66f709bSChris Mason path->slots[level] = orig_slot; 1320925baeddSChris Mason btrfs_tree_unlock(left); 13215f39d397SChris Mason free_extent_buffer(left); 1322e66f709bSChris Mason } 1323e66f709bSChris Mason return 0; 1324e66f709bSChris Mason } 1325925baeddSChris Mason btrfs_tree_unlock(left); 13265f39d397SChris Mason free_extent_buffer(left); 1327e66f709bSChris Mason } 1328e66f709bSChris Mason 1329e66f709bSChris Mason /* 1330e66f709bSChris Mason * then try to empty the right most buffer into the middle 1331e66f709bSChris Mason */ 13329cf14029SJosef Bacik if (pslot + 1 < btrfs_header_nritems(parent)) { 133333ade1f8SChris Mason u32 right_nr; 1334b4ce94deSChris Mason 13359cf14029SJosef Bacik right = btrfs_read_node_slot(parent, pslot + 1); 13369cf14029SJosef Bacik if (IS_ERR(right)) 13379cf14029SJosef Bacik return PTR_ERR(right); 13389cf14029SJosef Bacik 1339bf77467aSJosef Bacik __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); 1340b4ce94deSChris Mason 13415f39d397SChris Mason right_nr = btrfs_header_nritems(right); 13420b246afaSJeff Mahoney if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { 134333ade1f8SChris Mason wret = 1; 134433ade1f8SChris Mason } else { 13455f39d397SChris Mason ret = btrfs_cow_block(trans, root, right, 13465f39d397SChris Mason parent, pslot + 1, 1347bf59a5a2SJosef Bacik &right, BTRFS_NESTING_RIGHT_COW); 134854aa1f4dSChris Mason if (ret) 134954aa1f4dSChris Mason wret = 1; 135054aa1f4dSChris Mason else { 135155d32ed8SDavid Sterba wret = balance_node_right(trans, right, mid); 135233ade1f8SChris Mason } 135354aa1f4dSChris Mason } 1354e66f709bSChris Mason if (wret < 0) 1355e66f709bSChris Mason ret = wret; 1356e66f709bSChris Mason if (wret == 0) { 13575f39d397SChris Mason struct btrfs_disk_key disk_key; 13585f39d397SChris Mason 13595f39d397SChris Mason btrfs_node_key(right, &disk_key, 0); 1360f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, 136133cff222SFilipe Manana BTRFS_MOD_LOG_KEY_REPLACE); 13620e82bcfeSDavid Sterba BUG_ON(ret < 0); 13635f39d397SChris Mason btrfs_set_node_key(parent, &disk_key, pslot + 1); 13645f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 13655f39d397SChris Mason 13665f39d397SChris Mason if (btrfs_header_nritems(mid) <= orig_slot) { 13675f39d397SChris Mason path->nodes[level] = right; 1368e66f709bSChris Mason path->slots[level + 1] += 1; 1369e66f709bSChris Mason path->slots[level] = orig_slot - 13705f39d397SChris Mason btrfs_header_nritems(mid); 1371925baeddSChris Mason btrfs_tree_unlock(mid); 13725f39d397SChris Mason free_extent_buffer(mid); 1373e66f709bSChris Mason } else { 1374925baeddSChris Mason btrfs_tree_unlock(right); 13755f39d397SChris Mason free_extent_buffer(right); 1376e66f709bSChris Mason } 1377e66f709bSChris Mason return 0; 1378e66f709bSChris Mason } 1379925baeddSChris Mason btrfs_tree_unlock(right); 13805f39d397SChris Mason free_extent_buffer(right); 1381e66f709bSChris Mason } 1382e66f709bSChris Mason return 1; 1383e66f709bSChris Mason } 1384e66f709bSChris Mason 138574123bd7SChris Mason /* 1386d352ac68SChris Mason * readahead one full node of leaves, finding things that are close 1387d352ac68SChris Mason * to the block in 'slot', and triggering ra on them. 13883c69faecSChris Mason */ 13892ff7e61eSJeff Mahoney static void reada_for_search(struct btrfs_fs_info *fs_info, 1390e02119d5SChris Mason struct btrfs_path *path, 139101f46658SChris Mason int level, int slot, u64 objectid) 13923c69faecSChris Mason { 13935f39d397SChris Mason struct extent_buffer *node; 139401f46658SChris Mason struct btrfs_disk_key disk_key; 13953c69faecSChris Mason u32 nritems; 13963c69faecSChris Mason u64 search; 1397a7175319SChris Mason u64 target; 13986b80053dSChris Mason u64 nread = 0; 1399ace75066SFilipe Manana u64 nread_max; 14006b80053dSChris Mason u32 nr; 14016b80053dSChris Mason u32 blocksize; 14026b80053dSChris Mason u32 nscan = 0; 1403db94535dSChris Mason 1404ace75066SFilipe Manana if (level != 1 && path->reada != READA_FORWARD_ALWAYS) 14053c69faecSChris Mason return; 14063c69faecSChris Mason 14076702ed49SChris Mason if (!path->nodes[level]) 14086702ed49SChris Mason return; 14096702ed49SChris Mason 14105f39d397SChris Mason node = path->nodes[level]; 1411925baeddSChris Mason 1412ace75066SFilipe Manana /* 1413ace75066SFilipe Manana * Since the time between visiting leaves is much shorter than the time 1414ace75066SFilipe Manana * between visiting nodes, limit read ahead of nodes to 1, to avoid too 1415ace75066SFilipe Manana * much IO at once (possibly random). 1416ace75066SFilipe Manana */ 1417ace75066SFilipe Manana if (path->reada == READA_FORWARD_ALWAYS) { 1418ace75066SFilipe Manana if (level > 1) 1419ace75066SFilipe Manana nread_max = node->fs_info->nodesize; 1420ace75066SFilipe Manana else 1421ace75066SFilipe Manana nread_max = SZ_128K; 1422ace75066SFilipe Manana } else { 1423ace75066SFilipe Manana nread_max = SZ_64K; 1424ace75066SFilipe Manana } 1425ace75066SFilipe Manana 14263c69faecSChris Mason search = btrfs_node_blockptr(node, slot); 14270b246afaSJeff Mahoney blocksize = fs_info->nodesize; 1428069a2e37SFilipe Manana if (path->reada != READA_FORWARD_ALWAYS) { 1429069a2e37SFilipe Manana struct extent_buffer *eb; 1430069a2e37SFilipe Manana 14310b246afaSJeff Mahoney eb = find_extent_buffer(fs_info, search); 14325f39d397SChris Mason if (eb) { 14335f39d397SChris Mason free_extent_buffer(eb); 14343c69faecSChris Mason return; 14353c69faecSChris Mason } 1436069a2e37SFilipe Manana } 14373c69faecSChris Mason 1438a7175319SChris Mason target = search; 14396b80053dSChris Mason 14405f39d397SChris Mason nritems = btrfs_header_nritems(node); 14416b80053dSChris Mason nr = slot; 144225b8b936SJosef Bacik 14433c69faecSChris Mason while (1) { 1444e4058b54SDavid Sterba if (path->reada == READA_BACK) { 14456b80053dSChris Mason if (nr == 0) 14463c69faecSChris Mason break; 14476b80053dSChris Mason nr--; 1448ace75066SFilipe Manana } else if (path->reada == READA_FORWARD || 1449ace75066SFilipe Manana path->reada == READA_FORWARD_ALWAYS) { 14506b80053dSChris Mason nr++; 14516b80053dSChris Mason if (nr >= nritems) 14526b80053dSChris Mason break; 14533c69faecSChris Mason } 1454e4058b54SDavid Sterba if (path->reada == READA_BACK && objectid) { 145501f46658SChris Mason btrfs_node_key(node, &disk_key, nr); 145601f46658SChris Mason if (btrfs_disk_key_objectid(&disk_key) != objectid) 145701f46658SChris Mason break; 145801f46658SChris Mason } 14596b80053dSChris Mason search = btrfs_node_blockptr(node, nr); 1460ace75066SFilipe Manana if (path->reada == READA_FORWARD_ALWAYS || 1461ace75066SFilipe Manana (search <= target && target - search <= 65536) || 1462a7175319SChris Mason (search > target && search - target <= 65536)) { 1463bfb484d9SJosef Bacik btrfs_readahead_node_child(node, nr); 14646b80053dSChris Mason nread += blocksize; 14653c69faecSChris Mason } 14666b80053dSChris Mason nscan++; 1467ace75066SFilipe Manana if (nread > nread_max || nscan > 32) 14686b80053dSChris Mason break; 14693c69faecSChris Mason } 14703c69faecSChris Mason } 1471925baeddSChris Mason 1472bfb484d9SJosef Bacik static noinline void reada_for_balance(struct btrfs_path *path, int level) 1473b4ce94deSChris Mason { 1474bfb484d9SJosef Bacik struct extent_buffer *parent; 1475b4ce94deSChris Mason int slot; 1476b4ce94deSChris Mason int nritems; 1477b4ce94deSChris Mason 14788c594ea8SChris Mason parent = path->nodes[level + 1]; 1479b4ce94deSChris Mason if (!parent) 14800b08851fSJosef Bacik return; 1481b4ce94deSChris Mason 1482b4ce94deSChris Mason nritems = btrfs_header_nritems(parent); 14838c594ea8SChris Mason slot = path->slots[level + 1]; 1484b4ce94deSChris Mason 1485bfb484d9SJosef Bacik if (slot > 0) 1486bfb484d9SJosef Bacik btrfs_readahead_node_child(parent, slot - 1); 1487bfb484d9SJosef Bacik if (slot + 1 < nritems) 1488bfb484d9SJosef Bacik btrfs_readahead_node_child(parent, slot + 1); 1489b4ce94deSChris Mason } 1490b4ce94deSChris Mason 1491b4ce94deSChris Mason 1492b4ce94deSChris Mason /* 1493d397712bSChris Mason * when we walk down the tree, it is usually safe to unlock the higher layers 1494d397712bSChris Mason * in the tree. The exceptions are when our path goes through slot 0, because 1495d397712bSChris Mason * operations on the tree might require changing key pointers higher up in the 1496d397712bSChris Mason * tree. 1497d352ac68SChris Mason * 1498d397712bSChris Mason * callers might also have set path->keep_locks, which tells this code to keep 1499d397712bSChris Mason * the lock if the path points to the last slot in the block. This is part of 1500d397712bSChris Mason * walking through the tree, and selecting the next slot in the higher block. 1501d352ac68SChris Mason * 1502d397712bSChris Mason * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so 1503d397712bSChris Mason * if lowest_unlock is 1, level 0 won't be unlocked 1504d352ac68SChris Mason */ 1505e02119d5SChris Mason static noinline void unlock_up(struct btrfs_path *path, int level, 1506f7c79f30SChris Mason int lowest_unlock, int min_write_lock_level, 1507f7c79f30SChris Mason int *write_lock_level) 1508925baeddSChris Mason { 1509925baeddSChris Mason int i; 1510925baeddSChris Mason int skip_level = level; 1511c1227996SNikolay Borisov bool check_skip = true; 1512925baeddSChris Mason 1513925baeddSChris Mason for (i = level; i < BTRFS_MAX_LEVEL; i++) { 1514925baeddSChris Mason if (!path->nodes[i]) 1515925baeddSChris Mason break; 1516925baeddSChris Mason if (!path->locks[i]) 1517925baeddSChris Mason break; 1518c1227996SNikolay Borisov 1519c1227996SNikolay Borisov if (check_skip) { 1520c1227996SNikolay Borisov if (path->slots[i] == 0) { 1521925baeddSChris Mason skip_level = i + 1; 1522925baeddSChris Mason continue; 1523925baeddSChris Mason } 1524c1227996SNikolay Borisov 1525c1227996SNikolay Borisov if (path->keep_locks) { 1526925baeddSChris Mason u32 nritems; 1527c1227996SNikolay Borisov 1528c1227996SNikolay Borisov nritems = btrfs_header_nritems(path->nodes[i]); 1529051e1b9fSChris Mason if (nritems < 1 || path->slots[i] >= nritems - 1) { 1530925baeddSChris Mason skip_level = i + 1; 1531925baeddSChris Mason continue; 1532925baeddSChris Mason } 1533925baeddSChris Mason } 1534c1227996SNikolay Borisov } 1535051e1b9fSChris Mason 1536d80bb3f9SLiu Bo if (i >= lowest_unlock && i > skip_level) { 1537c1227996SNikolay Borisov check_skip = false; 1538c1227996SNikolay Borisov btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); 1539925baeddSChris Mason path->locks[i] = 0; 1540f7c79f30SChris Mason if (write_lock_level && 1541f7c79f30SChris Mason i > min_write_lock_level && 1542f7c79f30SChris Mason i <= *write_lock_level) { 1543f7c79f30SChris Mason *write_lock_level = i - 1; 1544f7c79f30SChris Mason } 1545925baeddSChris Mason } 1546925baeddSChris Mason } 1547925baeddSChris Mason } 1548925baeddSChris Mason 15493c69faecSChris Mason /* 1550376a21d7SFilipe Manana * Helper function for btrfs_search_slot() and other functions that do a search 1551376a21d7SFilipe Manana * on a btree. The goal is to find a tree block in the cache (the radix tree at 1552376a21d7SFilipe Manana * fs_info->buffer_radix), but if we can't find it, or it's not up to date, read 1553376a21d7SFilipe Manana * its pages from disk. 1554c8c42864SChris Mason * 1555376a21d7SFilipe Manana * Returns -EAGAIN, with the path unlocked, if the caller needs to repeat the 1556376a21d7SFilipe Manana * whole btree search, starting again from the current root node. 1557c8c42864SChris Mason */ 1558c8c42864SChris Mason static int 1559d07b8528SLiu Bo read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, 1560c8c42864SChris Mason struct extent_buffer **eb_ret, int level, int slot, 1561cda79c54SDavid Sterba const struct btrfs_key *key) 1562c8c42864SChris Mason { 15630b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 1564789d6a3aSQu Wenruo struct btrfs_tree_parent_check check = { 0 }; 1565c8c42864SChris Mason u64 blocknr; 1566c8c42864SChris Mason u64 gen; 1567c8c42864SChris Mason struct extent_buffer *tmp; 156876a05b35SChris Mason int ret; 1569581c1760SQu Wenruo int parent_level; 1570b246666eSFilipe Manana bool unlock_up; 1571c8c42864SChris Mason 1572b246666eSFilipe Manana unlock_up = ((level + 1 < BTRFS_MAX_LEVEL) && p->locks[level + 1]); 1573213ff4b7SNikolay Borisov blocknr = btrfs_node_blockptr(*eb_ret, slot); 1574213ff4b7SNikolay Borisov gen = btrfs_node_ptr_generation(*eb_ret, slot); 1575213ff4b7SNikolay Borisov parent_level = btrfs_header_level(*eb_ret); 1576789d6a3aSQu Wenruo btrfs_node_key_to_cpu(*eb_ret, &check.first_key, slot); 1577789d6a3aSQu Wenruo check.has_first_key = true; 1578789d6a3aSQu Wenruo check.level = parent_level - 1; 1579789d6a3aSQu Wenruo check.transid = gen; 1580789d6a3aSQu Wenruo check.owner_root = root->root_key.objectid; 1581c8c42864SChris Mason 1582b246666eSFilipe Manana /* 1583b246666eSFilipe Manana * If we need to read an extent buffer from disk and we are holding locks 1584b246666eSFilipe Manana * on upper level nodes, we unlock all the upper nodes before reading the 1585b246666eSFilipe Manana * extent buffer, and then return -EAGAIN to the caller as it needs to 1586b246666eSFilipe Manana * restart the search. We don't release the lock on the current level 1587b246666eSFilipe Manana * because we need to walk this node to figure out which blocks to read. 1588b246666eSFilipe Manana */ 15890b246afaSJeff Mahoney tmp = find_extent_buffer(fs_info, blocknr); 1590cb44921aSChris Mason if (tmp) { 1591ace75066SFilipe Manana if (p->reada == READA_FORWARD_ALWAYS) 1592ace75066SFilipe Manana reada_for_search(fs_info, p, level, slot, key->objectid); 1593ace75066SFilipe Manana 1594b9fab919SChris Mason /* first we do an atomic uptodate check */ 1595b9fab919SChris Mason if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { 1596448de471SQu Wenruo /* 1597448de471SQu Wenruo * Do extra check for first_key, eb can be stale due to 1598448de471SQu Wenruo * being cached, read from scrub, or have multiple 1599448de471SQu Wenruo * parents (shared tree blocks). 1600448de471SQu Wenruo */ 1601e064d5e9SDavid Sterba if (btrfs_verify_level_key(tmp, 1602789d6a3aSQu Wenruo parent_level - 1, &check.first_key, gen)) { 1603448de471SQu Wenruo free_extent_buffer(tmp); 1604448de471SQu Wenruo return -EUCLEAN; 1605448de471SQu Wenruo } 1606c8c42864SChris Mason *eb_ret = tmp; 1607c8c42864SChris Mason return 0; 1608c8c42864SChris Mason } 1609bdf7c00eSJosef Bacik 1610857bc13fSJosef Bacik if (p->nowait) { 1611857bc13fSJosef Bacik free_extent_buffer(tmp); 1612857bc13fSJosef Bacik return -EAGAIN; 1613857bc13fSJosef Bacik } 1614857bc13fSJosef Bacik 1615b246666eSFilipe Manana if (unlock_up) 1616b246666eSFilipe Manana btrfs_unlock_up_safe(p, level + 1); 1617b246666eSFilipe Manana 1618b9fab919SChris Mason /* now we're allowed to do a blocking uptodate check */ 1619789d6a3aSQu Wenruo ret = btrfs_read_extent_buffer(tmp, &check); 16209a4ffa1bSQu Wenruo if (ret) { 1621cb44921aSChris Mason free_extent_buffer(tmp); 1622b3b4aa74SDavid Sterba btrfs_release_path(p); 1623cb44921aSChris Mason return -EIO; 1624cb44921aSChris Mason } 162588c602abSQu Wenruo if (btrfs_check_eb_owner(tmp, root->root_key.objectid)) { 162688c602abSQu Wenruo free_extent_buffer(tmp); 162788c602abSQu Wenruo btrfs_release_path(p); 162888c602abSQu Wenruo return -EUCLEAN; 162988c602abSQu Wenruo } 1630b246666eSFilipe Manana 1631b246666eSFilipe Manana if (unlock_up) 1632b246666eSFilipe Manana ret = -EAGAIN; 1633b246666eSFilipe Manana 1634b246666eSFilipe Manana goto out; 1635857bc13fSJosef Bacik } else if (p->nowait) { 1636857bc13fSJosef Bacik return -EAGAIN; 16379a4ffa1bSQu Wenruo } 1638c8c42864SChris Mason 1639b246666eSFilipe Manana if (unlock_up) { 16408c594ea8SChris Mason btrfs_unlock_up_safe(p, level + 1); 16414bb59055SFilipe Manana ret = -EAGAIN; 16424bb59055SFilipe Manana } else { 16434bb59055SFilipe Manana ret = 0; 16444bb59055SFilipe Manana } 16458c594ea8SChris Mason 1646e4058b54SDavid Sterba if (p->reada != READA_NONE) 16472ff7e61eSJeff Mahoney reada_for_search(fs_info, p, level, slot, key->objectid); 1648c8c42864SChris Mason 1649789d6a3aSQu Wenruo tmp = read_tree_block(fs_info, blocknr, &check); 16504eb150d6SQu Wenruo if (IS_ERR(tmp)) { 16514eb150d6SQu Wenruo btrfs_release_path(p); 16524eb150d6SQu Wenruo return PTR_ERR(tmp); 16534eb150d6SQu Wenruo } 165476a05b35SChris Mason /* 165576a05b35SChris Mason * If the read above didn't mark this buffer up to date, 165676a05b35SChris Mason * it will never end up being up to date. Set ret to EIO now 165776a05b35SChris Mason * and give up so that our caller doesn't loop forever 165876a05b35SChris Mason * on our EAGAINs. 165976a05b35SChris Mason */ 1660e6a1d6fdSLiu Bo if (!extent_buffer_uptodate(tmp)) 166176a05b35SChris Mason ret = -EIO; 166202a3307aSLiu Bo 1663b246666eSFilipe Manana out: 16644bb59055SFilipe Manana if (ret == 0) { 16654bb59055SFilipe Manana *eb_ret = tmp; 16664bb59055SFilipe Manana } else { 16674bb59055SFilipe Manana free_extent_buffer(tmp); 166802a3307aSLiu Bo btrfs_release_path(p); 16694bb59055SFilipe Manana } 16704bb59055SFilipe Manana 167176a05b35SChris Mason return ret; 1672c8c42864SChris Mason } 1673c8c42864SChris Mason 1674c8c42864SChris Mason /* 1675c8c42864SChris Mason * helper function for btrfs_search_slot. This does all of the checks 1676c8c42864SChris Mason * for node-level blocks and does any balancing required based on 1677c8c42864SChris Mason * the ins_len. 1678c8c42864SChris Mason * 1679c8c42864SChris Mason * If no extra work was required, zero is returned. If we had to 1680c8c42864SChris Mason * drop the path, -EAGAIN is returned and btrfs_search_slot must 1681c8c42864SChris Mason * start over 1682c8c42864SChris Mason */ 1683c8c42864SChris Mason static int 1684c8c42864SChris Mason setup_nodes_for_search(struct btrfs_trans_handle *trans, 1685c8c42864SChris Mason struct btrfs_root *root, struct btrfs_path *p, 1686bd681513SChris Mason struct extent_buffer *b, int level, int ins_len, 1687bd681513SChris Mason int *write_lock_level) 1688c8c42864SChris Mason { 16890b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 169095b982deSNikolay Borisov int ret = 0; 16910b246afaSJeff Mahoney 1692c8c42864SChris Mason if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= 16930b246afaSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) { 1694c8c42864SChris Mason 1695bd681513SChris Mason if (*write_lock_level < level + 1) { 1696bd681513SChris Mason *write_lock_level = level + 1; 1697bd681513SChris Mason btrfs_release_path(p); 169895b982deSNikolay Borisov return -EAGAIN; 1699bd681513SChris Mason } 1700bd681513SChris Mason 1701bfb484d9SJosef Bacik reada_for_balance(p, level); 170295b982deSNikolay Borisov ret = split_node(trans, root, p, level); 1703c8c42864SChris Mason 1704c8c42864SChris Mason b = p->nodes[level]; 1705c8c42864SChris Mason } else if (ins_len < 0 && btrfs_header_nritems(b) < 17060b246afaSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 2) { 1707c8c42864SChris Mason 1708bd681513SChris Mason if (*write_lock_level < level + 1) { 1709bd681513SChris Mason *write_lock_level = level + 1; 1710bd681513SChris Mason btrfs_release_path(p); 171195b982deSNikolay Borisov return -EAGAIN; 1712bd681513SChris Mason } 1713bd681513SChris Mason 1714bfb484d9SJosef Bacik reada_for_balance(p, level); 171595b982deSNikolay Borisov ret = balance_level(trans, root, p, level); 171695b982deSNikolay Borisov if (ret) 171795b982deSNikolay Borisov return ret; 1718c8c42864SChris Mason 1719c8c42864SChris Mason b = p->nodes[level]; 1720c8c42864SChris Mason if (!b) { 1721b3b4aa74SDavid Sterba btrfs_release_path(p); 172295b982deSNikolay Borisov return -EAGAIN; 1723c8c42864SChris Mason } 1724c8c42864SChris Mason BUG_ON(btrfs_header_nritems(b) == 1); 1725c8c42864SChris Mason } 1726c8c42864SChris Mason return ret; 1727c8c42864SChris Mason } 1728c8c42864SChris Mason 1729381cf658SDavid Sterba int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, 1730e33d5c3dSKelley Nielsen u64 iobjectid, u64 ioff, u8 key_type, 1731e33d5c3dSKelley Nielsen struct btrfs_key *found_key) 1732e33d5c3dSKelley Nielsen { 1733e33d5c3dSKelley Nielsen int ret; 1734e33d5c3dSKelley Nielsen struct btrfs_key key; 1735e33d5c3dSKelley Nielsen struct extent_buffer *eb; 1736381cf658SDavid Sterba 1737381cf658SDavid Sterba ASSERT(path); 17381d4c08e0SDavid Sterba ASSERT(found_key); 1739e33d5c3dSKelley Nielsen 1740e33d5c3dSKelley Nielsen key.type = key_type; 1741e33d5c3dSKelley Nielsen key.objectid = iobjectid; 1742e33d5c3dSKelley Nielsen key.offset = ioff; 1743e33d5c3dSKelley Nielsen 1744e33d5c3dSKelley Nielsen ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); 17451d4c08e0SDavid Sterba if (ret < 0) 1746e33d5c3dSKelley Nielsen return ret; 1747e33d5c3dSKelley Nielsen 1748e33d5c3dSKelley Nielsen eb = path->nodes[0]; 1749e33d5c3dSKelley Nielsen if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { 1750e33d5c3dSKelley Nielsen ret = btrfs_next_leaf(fs_root, path); 1751e33d5c3dSKelley Nielsen if (ret) 1752e33d5c3dSKelley Nielsen return ret; 1753e33d5c3dSKelley Nielsen eb = path->nodes[0]; 1754e33d5c3dSKelley Nielsen } 1755e33d5c3dSKelley Nielsen 1756e33d5c3dSKelley Nielsen btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); 1757e33d5c3dSKelley Nielsen if (found_key->type != key.type || 1758e33d5c3dSKelley Nielsen found_key->objectid != key.objectid) 1759e33d5c3dSKelley Nielsen return 1; 1760e33d5c3dSKelley Nielsen 1761e33d5c3dSKelley Nielsen return 0; 1762e33d5c3dSKelley Nielsen } 1763e33d5c3dSKelley Nielsen 17641fc28d8eSLiu Bo static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root, 17651fc28d8eSLiu Bo struct btrfs_path *p, 17661fc28d8eSLiu Bo int write_lock_level) 17671fc28d8eSLiu Bo { 17681fc28d8eSLiu Bo struct extent_buffer *b; 1769120de408SJosef Bacik int root_lock = 0; 17701fc28d8eSLiu Bo int level = 0; 17711fc28d8eSLiu Bo 17721fc28d8eSLiu Bo if (p->search_commit_root) { 17731fc28d8eSLiu Bo b = root->commit_root; 177467439dadSDavid Sterba atomic_inc(&b->refs); 17751fc28d8eSLiu Bo level = btrfs_header_level(b); 1776f9ddfd05SLiu Bo /* 1777f9ddfd05SLiu Bo * Ensure that all callers have set skip_locking when 1778f9ddfd05SLiu Bo * p->search_commit_root = 1. 1779f9ddfd05SLiu Bo */ 1780f9ddfd05SLiu Bo ASSERT(p->skip_locking == 1); 17811fc28d8eSLiu Bo 17821fc28d8eSLiu Bo goto out; 17831fc28d8eSLiu Bo } 17841fc28d8eSLiu Bo 17851fc28d8eSLiu Bo if (p->skip_locking) { 17861fc28d8eSLiu Bo b = btrfs_root_node(root); 17871fc28d8eSLiu Bo level = btrfs_header_level(b); 17881fc28d8eSLiu Bo goto out; 17891fc28d8eSLiu Bo } 17901fc28d8eSLiu Bo 1791120de408SJosef Bacik /* We try very hard to do read locks on the root */ 1792120de408SJosef Bacik root_lock = BTRFS_READ_LOCK; 1793120de408SJosef Bacik 17941fc28d8eSLiu Bo /* 1795662c653bSLiu Bo * If the level is set to maximum, we can skip trying to get the read 1796662c653bSLiu Bo * lock. 1797662c653bSLiu Bo */ 1798662c653bSLiu Bo if (write_lock_level < BTRFS_MAX_LEVEL) { 1799662c653bSLiu Bo /* 1800662c653bSLiu Bo * We don't know the level of the root node until we actually 1801662c653bSLiu Bo * have it read locked 18021fc28d8eSLiu Bo */ 1803857bc13fSJosef Bacik if (p->nowait) { 1804857bc13fSJosef Bacik b = btrfs_try_read_lock_root_node(root); 1805857bc13fSJosef Bacik if (IS_ERR(b)) 1806857bc13fSJosef Bacik return b; 1807857bc13fSJosef Bacik } else { 18081bb96598SJosef Bacik b = btrfs_read_lock_root_node(root); 1809857bc13fSJosef Bacik } 18101fc28d8eSLiu Bo level = btrfs_header_level(b); 18111fc28d8eSLiu Bo if (level > write_lock_level) 18121fc28d8eSLiu Bo goto out; 18131fc28d8eSLiu Bo 1814662c653bSLiu Bo /* Whoops, must trade for write lock */ 18151fc28d8eSLiu Bo btrfs_tree_read_unlock(b); 18161fc28d8eSLiu Bo free_extent_buffer(b); 1817662c653bSLiu Bo } 1818662c653bSLiu Bo 18191fc28d8eSLiu Bo b = btrfs_lock_root_node(root); 18201fc28d8eSLiu Bo root_lock = BTRFS_WRITE_LOCK; 18211fc28d8eSLiu Bo 18221fc28d8eSLiu Bo /* The level might have changed, check again */ 18231fc28d8eSLiu Bo level = btrfs_header_level(b); 18241fc28d8eSLiu Bo 18251fc28d8eSLiu Bo out: 1826120de408SJosef Bacik /* 1827120de408SJosef Bacik * The root may have failed to write out at some point, and thus is no 1828120de408SJosef Bacik * longer valid, return an error in this case. 1829120de408SJosef Bacik */ 1830120de408SJosef Bacik if (!extent_buffer_uptodate(b)) { 1831120de408SJosef Bacik if (root_lock) 1832120de408SJosef Bacik btrfs_tree_unlock_rw(b, root_lock); 1833120de408SJosef Bacik free_extent_buffer(b); 1834120de408SJosef Bacik return ERR_PTR(-EIO); 1835120de408SJosef Bacik } 1836120de408SJosef Bacik 18371fc28d8eSLiu Bo p->nodes[level] = b; 18381fc28d8eSLiu Bo if (!p->skip_locking) 18391fc28d8eSLiu Bo p->locks[level] = root_lock; 18401fc28d8eSLiu Bo /* 18411fc28d8eSLiu Bo * Callers are responsible for dropping b's references. 18421fc28d8eSLiu Bo */ 18431fc28d8eSLiu Bo return b; 18441fc28d8eSLiu Bo } 18451fc28d8eSLiu Bo 1846d96b3424SFilipe Manana /* 1847d96b3424SFilipe Manana * Replace the extent buffer at the lowest level of the path with a cloned 1848d96b3424SFilipe Manana * version. The purpose is to be able to use it safely, after releasing the 1849d96b3424SFilipe Manana * commit root semaphore, even if relocation is happening in parallel, the 1850d96b3424SFilipe Manana * transaction used for relocation is committed and the extent buffer is 1851d96b3424SFilipe Manana * reallocated in the next transaction. 1852d96b3424SFilipe Manana * 1853d96b3424SFilipe Manana * This is used in a context where the caller does not prevent transaction 1854d96b3424SFilipe Manana * commits from happening, either by holding a transaction handle or holding 1855d96b3424SFilipe Manana * some lock, while it's doing searches through a commit root. 1856d96b3424SFilipe Manana * At the moment it's only used for send operations. 1857d96b3424SFilipe Manana */ 1858d96b3424SFilipe Manana static int finish_need_commit_sem_search(struct btrfs_path *path) 1859d96b3424SFilipe Manana { 1860d96b3424SFilipe Manana const int i = path->lowest_level; 1861d96b3424SFilipe Manana const int slot = path->slots[i]; 1862d96b3424SFilipe Manana struct extent_buffer *lowest = path->nodes[i]; 1863d96b3424SFilipe Manana struct extent_buffer *clone; 1864d96b3424SFilipe Manana 1865d96b3424SFilipe Manana ASSERT(path->need_commit_sem); 1866d96b3424SFilipe Manana 1867d96b3424SFilipe Manana if (!lowest) 1868d96b3424SFilipe Manana return 0; 1869d96b3424SFilipe Manana 1870d96b3424SFilipe Manana lockdep_assert_held_read(&lowest->fs_info->commit_root_sem); 1871d96b3424SFilipe Manana 1872d96b3424SFilipe Manana clone = btrfs_clone_extent_buffer(lowest); 1873d96b3424SFilipe Manana if (!clone) 1874d96b3424SFilipe Manana return -ENOMEM; 1875d96b3424SFilipe Manana 1876d96b3424SFilipe Manana btrfs_release_path(path); 1877d96b3424SFilipe Manana path->nodes[i] = clone; 1878d96b3424SFilipe Manana path->slots[i] = slot; 1879d96b3424SFilipe Manana 1880d96b3424SFilipe Manana return 0; 1881d96b3424SFilipe Manana } 18821fc28d8eSLiu Bo 1883e2e58d0fSFilipe Manana static inline int search_for_key_slot(struct extent_buffer *eb, 1884e2e58d0fSFilipe Manana int search_low_slot, 1885e2e58d0fSFilipe Manana const struct btrfs_key *key, 1886e2e58d0fSFilipe Manana int prev_cmp, 1887e2e58d0fSFilipe Manana int *slot) 1888e2e58d0fSFilipe Manana { 1889e2e58d0fSFilipe Manana /* 1890e2e58d0fSFilipe Manana * If a previous call to btrfs_bin_search() on a parent node returned an 1891e2e58d0fSFilipe Manana * exact match (prev_cmp == 0), we can safely assume the target key will 1892e2e58d0fSFilipe Manana * always be at slot 0 on lower levels, since each key pointer 1893e2e58d0fSFilipe Manana * (struct btrfs_key_ptr) refers to the lowest key accessible from the 1894e2e58d0fSFilipe Manana * subtree it points to. Thus we can skip searching lower levels. 1895e2e58d0fSFilipe Manana */ 1896e2e58d0fSFilipe Manana if (prev_cmp == 0) { 1897e2e58d0fSFilipe Manana *slot = 0; 1898e2e58d0fSFilipe Manana return 0; 1899e2e58d0fSFilipe Manana } 1900e2e58d0fSFilipe Manana 1901fdf8d595SAnand Jain return btrfs_bin_search(eb, search_low_slot, key, slot); 1902e2e58d0fSFilipe Manana } 1903e2e58d0fSFilipe Manana 1904109324cfSFilipe Manana static int search_leaf(struct btrfs_trans_handle *trans, 1905109324cfSFilipe Manana struct btrfs_root *root, 1906109324cfSFilipe Manana const struct btrfs_key *key, 1907109324cfSFilipe Manana struct btrfs_path *path, 1908109324cfSFilipe Manana int ins_len, 1909109324cfSFilipe Manana int prev_cmp) 1910109324cfSFilipe Manana { 1911109324cfSFilipe Manana struct extent_buffer *leaf = path->nodes[0]; 1912109324cfSFilipe Manana int leaf_free_space = -1; 1913109324cfSFilipe Manana int search_low_slot = 0; 1914109324cfSFilipe Manana int ret; 1915109324cfSFilipe Manana bool do_bin_search = true; 1916109324cfSFilipe Manana 1917109324cfSFilipe Manana /* 1918109324cfSFilipe Manana * If we are doing an insertion, the leaf has enough free space and the 1919109324cfSFilipe Manana * destination slot for the key is not slot 0, then we can unlock our 1920109324cfSFilipe Manana * write lock on the parent, and any other upper nodes, before doing the 1921109324cfSFilipe Manana * binary search on the leaf (with search_for_key_slot()), allowing other 1922109324cfSFilipe Manana * tasks to lock the parent and any other upper nodes. 1923109324cfSFilipe Manana */ 1924109324cfSFilipe Manana if (ins_len > 0) { 1925109324cfSFilipe Manana /* 1926109324cfSFilipe Manana * Cache the leaf free space, since we will need it later and it 1927109324cfSFilipe Manana * will not change until then. 1928109324cfSFilipe Manana */ 1929109324cfSFilipe Manana leaf_free_space = btrfs_leaf_free_space(leaf); 1930109324cfSFilipe Manana 1931109324cfSFilipe Manana /* 1932109324cfSFilipe Manana * !path->locks[1] means we have a single node tree, the leaf is 1933109324cfSFilipe Manana * the root of the tree. 1934109324cfSFilipe Manana */ 1935109324cfSFilipe Manana if (path->locks[1] && leaf_free_space >= ins_len) { 1936109324cfSFilipe Manana struct btrfs_disk_key first_key; 1937109324cfSFilipe Manana 1938109324cfSFilipe Manana ASSERT(btrfs_header_nritems(leaf) > 0); 1939109324cfSFilipe Manana btrfs_item_key(leaf, &first_key, 0); 1940109324cfSFilipe Manana 1941109324cfSFilipe Manana /* 1942109324cfSFilipe Manana * Doing the extra comparison with the first key is cheap, 1943109324cfSFilipe Manana * taking into account that the first key is very likely 1944109324cfSFilipe Manana * already in a cache line because it immediately follows 1945109324cfSFilipe Manana * the extent buffer's header and we have recently accessed 1946109324cfSFilipe Manana * the header's level field. 1947109324cfSFilipe Manana */ 1948109324cfSFilipe Manana ret = comp_keys(&first_key, key); 1949109324cfSFilipe Manana if (ret < 0) { 1950109324cfSFilipe Manana /* 1951109324cfSFilipe Manana * The first key is smaller than the key we want 1952109324cfSFilipe Manana * to insert, so we are safe to unlock all upper 1953109324cfSFilipe Manana * nodes and we have to do the binary search. 1954109324cfSFilipe Manana * 1955109324cfSFilipe Manana * We do use btrfs_unlock_up_safe() and not 1956109324cfSFilipe Manana * unlock_up() because the later does not unlock 1957109324cfSFilipe Manana * nodes with a slot of 0 - we can safely unlock 1958109324cfSFilipe Manana * any node even if its slot is 0 since in this 1959109324cfSFilipe Manana * case the key does not end up at slot 0 of the 1960109324cfSFilipe Manana * leaf and there's no need to split the leaf. 1961109324cfSFilipe Manana */ 1962109324cfSFilipe Manana btrfs_unlock_up_safe(path, 1); 1963109324cfSFilipe Manana search_low_slot = 1; 1964109324cfSFilipe Manana } else { 1965109324cfSFilipe Manana /* 1966109324cfSFilipe Manana * The first key is >= then the key we want to 1967109324cfSFilipe Manana * insert, so we can skip the binary search as 1968109324cfSFilipe Manana * the target key will be at slot 0. 1969109324cfSFilipe Manana * 1970109324cfSFilipe Manana * We can not unlock upper nodes when the key is 1971109324cfSFilipe Manana * less than the first key, because we will need 1972109324cfSFilipe Manana * to update the key at slot 0 of the parent node 1973109324cfSFilipe Manana * and possibly of other upper nodes too. 1974109324cfSFilipe Manana * If the key matches the first key, then we can 1975109324cfSFilipe Manana * unlock all the upper nodes, using 1976109324cfSFilipe Manana * btrfs_unlock_up_safe() instead of unlock_up() 1977109324cfSFilipe Manana * as stated above. 1978109324cfSFilipe Manana */ 1979109324cfSFilipe Manana if (ret == 0) 1980109324cfSFilipe Manana btrfs_unlock_up_safe(path, 1); 1981109324cfSFilipe Manana /* 1982109324cfSFilipe Manana * ret is already 0 or 1, matching the result of 1983109324cfSFilipe Manana * a btrfs_bin_search() call, so there is no need 1984109324cfSFilipe Manana * to adjust it. 1985109324cfSFilipe Manana */ 1986109324cfSFilipe Manana do_bin_search = false; 1987109324cfSFilipe Manana path->slots[0] = 0; 1988109324cfSFilipe Manana } 1989109324cfSFilipe Manana } 1990109324cfSFilipe Manana } 1991109324cfSFilipe Manana 1992109324cfSFilipe Manana if (do_bin_search) { 1993109324cfSFilipe Manana ret = search_for_key_slot(leaf, search_low_slot, key, 1994109324cfSFilipe Manana prev_cmp, &path->slots[0]); 1995109324cfSFilipe Manana if (ret < 0) 1996109324cfSFilipe Manana return ret; 1997109324cfSFilipe Manana } 1998109324cfSFilipe Manana 1999109324cfSFilipe Manana if (ins_len > 0) { 2000109324cfSFilipe Manana /* 2001109324cfSFilipe Manana * Item key already exists. In this case, if we are allowed to 2002109324cfSFilipe Manana * insert the item (for example, in dir_item case, item key 2003109324cfSFilipe Manana * collision is allowed), it will be merged with the original 2004109324cfSFilipe Manana * item. Only the item size grows, no new btrfs item will be 2005109324cfSFilipe Manana * added. If search_for_extension is not set, ins_len already 2006109324cfSFilipe Manana * accounts the size btrfs_item, deduct it here so leaf space 2007109324cfSFilipe Manana * check will be correct. 2008109324cfSFilipe Manana */ 2009109324cfSFilipe Manana if (ret == 0 && !path->search_for_extension) { 2010109324cfSFilipe Manana ASSERT(ins_len >= sizeof(struct btrfs_item)); 2011109324cfSFilipe Manana ins_len -= sizeof(struct btrfs_item); 2012109324cfSFilipe Manana } 2013109324cfSFilipe Manana 2014109324cfSFilipe Manana ASSERT(leaf_free_space >= 0); 2015109324cfSFilipe Manana 2016109324cfSFilipe Manana if (leaf_free_space < ins_len) { 2017109324cfSFilipe Manana int err; 2018109324cfSFilipe Manana 2019109324cfSFilipe Manana err = split_leaf(trans, root, key, path, ins_len, 2020109324cfSFilipe Manana (ret == 0)); 2021bb8e9a60SFilipe Manana ASSERT(err <= 0); 2022bb8e9a60SFilipe Manana if (WARN_ON(err > 0)) 2023bb8e9a60SFilipe Manana err = -EUCLEAN; 2024109324cfSFilipe Manana if (err) 2025109324cfSFilipe Manana ret = err; 2026109324cfSFilipe Manana } 2027109324cfSFilipe Manana } 2028109324cfSFilipe Manana 2029109324cfSFilipe Manana return ret; 2030109324cfSFilipe Manana } 2031109324cfSFilipe Manana 2032c8c42864SChris Mason /* 20334271eceaSNikolay Borisov * btrfs_search_slot - look for a key in a tree and perform necessary 20344271eceaSNikolay Borisov * modifications to preserve tree invariants. 203574123bd7SChris Mason * 20364271eceaSNikolay Borisov * @trans: Handle of transaction, used when modifying the tree 20374271eceaSNikolay Borisov * @p: Holds all btree nodes along the search path 20384271eceaSNikolay Borisov * @root: The root node of the tree 20394271eceaSNikolay Borisov * @key: The key we are looking for 20409a664971Sethanwu * @ins_len: Indicates purpose of search: 20419a664971Sethanwu * >0 for inserts it's size of item inserted (*) 20429a664971Sethanwu * <0 for deletions 20439a664971Sethanwu * 0 for plain searches, not modifying the tree 20449a664971Sethanwu * 20459a664971Sethanwu * (*) If size of item inserted doesn't include 20469a664971Sethanwu * sizeof(struct btrfs_item), then p->search_for_extension must 20479a664971Sethanwu * be set. 20484271eceaSNikolay Borisov * @cow: boolean should CoW operations be performed. Must always be 1 20494271eceaSNikolay Borisov * when modifying the tree. 205097571fd0SChris Mason * 20514271eceaSNikolay Borisov * If @ins_len > 0, nodes and leaves will be split as we walk down the tree. 20524271eceaSNikolay Borisov * If @ins_len < 0, nodes will be merged as we walk down the tree (if possible) 20534271eceaSNikolay Borisov * 20544271eceaSNikolay Borisov * If @key is found, 0 is returned and you can find the item in the leaf level 20554271eceaSNikolay Borisov * of the path (level 0) 20564271eceaSNikolay Borisov * 20574271eceaSNikolay Borisov * If @key isn't found, 1 is returned and the leaf level of the path (level 0) 20584271eceaSNikolay Borisov * points to the slot where it should be inserted 20594271eceaSNikolay Borisov * 20604271eceaSNikolay Borisov * If an error is encountered while searching the tree a negative error number 20614271eceaSNikolay Borisov * is returned 206274123bd7SChris Mason */ 2063310712b2SOmar Sandoval int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, 2064310712b2SOmar Sandoval const struct btrfs_key *key, struct btrfs_path *p, 2065310712b2SOmar Sandoval int ins_len, int cow) 2066be0e5c09SChris Mason { 2067d96b3424SFilipe Manana struct btrfs_fs_info *fs_info = root->fs_info; 20685f39d397SChris Mason struct extent_buffer *b; 2069be0e5c09SChris Mason int slot; 2070be0e5c09SChris Mason int ret; 207133c66f43SYan Zheng int err; 2072be0e5c09SChris Mason int level; 2073925baeddSChris Mason int lowest_unlock = 1; 2074bd681513SChris Mason /* everything at write_lock_level or lower must be write locked */ 2075bd681513SChris Mason int write_lock_level = 0; 20769f3a7427SChris Mason u8 lowest_level = 0; 2077f7c79f30SChris Mason int min_write_lock_level; 2078d7396f07SFilipe David Borba Manana int prev_cmp; 20799f3a7427SChris Mason 2080a4c853afSChenXiaoSong might_sleep(); 2081a4c853afSChenXiaoSong 20826702ed49SChris Mason lowest_level = p->lowest_level; 2083323ac95bSChris Mason WARN_ON(lowest_level && ins_len > 0); 208422b0ebdaSChris Mason WARN_ON(p->nodes[0] != NULL); 2085eb653de1SFilipe David Borba Manana BUG_ON(!cow && ins_len); 208625179201SJosef Bacik 2087857bc13fSJosef Bacik /* 2088857bc13fSJosef Bacik * For now only allow nowait for read only operations. There's no 2089857bc13fSJosef Bacik * strict reason why we can't, we just only need it for reads so it's 2090857bc13fSJosef Bacik * only implemented for reads. 2091857bc13fSJosef Bacik */ 2092857bc13fSJosef Bacik ASSERT(!p->nowait || !cow); 2093857bc13fSJosef Bacik 2094bd681513SChris Mason if (ins_len < 0) { 2095925baeddSChris Mason lowest_unlock = 2; 209665b51a00SChris Mason 2097bd681513SChris Mason /* when we are removing items, we might have to go up to level 2098bd681513SChris Mason * two as we update tree pointers Make sure we keep write 2099bd681513SChris Mason * for those levels as well 2100bd681513SChris Mason */ 2101bd681513SChris Mason write_lock_level = 2; 2102bd681513SChris Mason } else if (ins_len > 0) { 2103bd681513SChris Mason /* 2104bd681513SChris Mason * for inserting items, make sure we have a write lock on 2105bd681513SChris Mason * level 1 so we can update keys 2106bd681513SChris Mason */ 2107bd681513SChris Mason write_lock_level = 1; 2108bd681513SChris Mason } 2109bd681513SChris Mason 2110bd681513SChris Mason if (!cow) 2111bd681513SChris Mason write_lock_level = -1; 2112bd681513SChris Mason 211309a2a8f9SJosef Bacik if (cow && (p->keep_locks || p->lowest_level)) 2114bd681513SChris Mason write_lock_level = BTRFS_MAX_LEVEL; 2115bd681513SChris Mason 2116f7c79f30SChris Mason min_write_lock_level = write_lock_level; 2117f7c79f30SChris Mason 2118d96b3424SFilipe Manana if (p->need_commit_sem) { 2119d96b3424SFilipe Manana ASSERT(p->search_commit_root); 2120857bc13fSJosef Bacik if (p->nowait) { 2121857bc13fSJosef Bacik if (!down_read_trylock(&fs_info->commit_root_sem)) 2122857bc13fSJosef Bacik return -EAGAIN; 2123857bc13fSJosef Bacik } else { 2124d96b3424SFilipe Manana down_read(&fs_info->commit_root_sem); 2125d96b3424SFilipe Manana } 2126857bc13fSJosef Bacik } 2127d96b3424SFilipe Manana 2128bb803951SChris Mason again: 2129d7396f07SFilipe David Borba Manana prev_cmp = -1; 21301fc28d8eSLiu Bo b = btrfs_search_slot_get_root(root, p, write_lock_level); 2131be6821f8SFilipe Manana if (IS_ERR(b)) { 2132be6821f8SFilipe Manana ret = PTR_ERR(b); 2133be6821f8SFilipe Manana goto done; 2134be6821f8SFilipe Manana } 2135925baeddSChris Mason 2136eb60ceacSChris Mason while (b) { 2137f624d976SQu Wenruo int dec = 0; 2138f624d976SQu Wenruo 21395f39d397SChris Mason level = btrfs_header_level(b); 214065b51a00SChris Mason 214102217ed2SChris Mason if (cow) { 21429ea2c7c9SNikolay Borisov bool last_level = (level == (BTRFS_MAX_LEVEL - 1)); 21439ea2c7c9SNikolay Borisov 2144c8c42864SChris Mason /* 2145c8c42864SChris Mason * if we don't really need to cow this block 2146c8c42864SChris Mason * then we don't want to set the path blocking, 2147c8c42864SChris Mason * so we test it here 2148c8c42864SChris Mason */ 21495963ffcaSJosef Bacik if (!should_cow_block(trans, root, b)) 215065b51a00SChris Mason goto cow_done; 21515d4f98a2SYan Zheng 2152bd681513SChris Mason /* 2153bd681513SChris Mason * must have write locks on this node and the 2154bd681513SChris Mason * parent 2155bd681513SChris Mason */ 21565124e00eSJosef Bacik if (level > write_lock_level || 21575124e00eSJosef Bacik (level + 1 > write_lock_level && 21585124e00eSJosef Bacik level + 1 < BTRFS_MAX_LEVEL && 21595124e00eSJosef Bacik p->nodes[level + 1])) { 2160bd681513SChris Mason write_lock_level = level + 1; 2161bd681513SChris Mason btrfs_release_path(p); 2162bd681513SChris Mason goto again; 2163bd681513SChris Mason } 2164bd681513SChris Mason 21659ea2c7c9SNikolay Borisov if (last_level) 21669ea2c7c9SNikolay Borisov err = btrfs_cow_block(trans, root, b, NULL, 0, 21679631e4ccSJosef Bacik &b, 21689631e4ccSJosef Bacik BTRFS_NESTING_COW); 21699ea2c7c9SNikolay Borisov else 217033c66f43SYan Zheng err = btrfs_cow_block(trans, root, b, 2171e20d96d6SChris Mason p->nodes[level + 1], 21729631e4ccSJosef Bacik p->slots[level + 1], &b, 21739631e4ccSJosef Bacik BTRFS_NESTING_COW); 217433c66f43SYan Zheng if (err) { 217533c66f43SYan Zheng ret = err; 217665b51a00SChris Mason goto done; 217754aa1f4dSChris Mason } 217802217ed2SChris Mason } 217965b51a00SChris Mason cow_done: 2180eb60ceacSChris Mason p->nodes[level] = b; 2181b4ce94deSChris Mason 2182b4ce94deSChris Mason /* 2183b4ce94deSChris Mason * we have a lock on b and as long as we aren't changing 2184b4ce94deSChris Mason * the tree, there is no way to for the items in b to change. 2185b4ce94deSChris Mason * It is safe to drop the lock on our parent before we 2186b4ce94deSChris Mason * go through the expensive btree search on b. 2187b4ce94deSChris Mason * 2188eb653de1SFilipe David Borba Manana * If we're inserting or deleting (ins_len != 0), then we might 2189eb653de1SFilipe David Borba Manana * be changing slot zero, which may require changing the parent. 2190eb653de1SFilipe David Borba Manana * So, we can't drop the lock until after we know which slot 2191eb653de1SFilipe David Borba Manana * we're operating on. 2192b4ce94deSChris Mason */ 2193eb653de1SFilipe David Borba Manana if (!ins_len && !p->keep_locks) { 2194eb653de1SFilipe David Borba Manana int u = level + 1; 2195eb653de1SFilipe David Borba Manana 2196eb653de1SFilipe David Borba Manana if (u < BTRFS_MAX_LEVEL && p->locks[u]) { 2197eb653de1SFilipe David Borba Manana btrfs_tree_unlock_rw(p->nodes[u], p->locks[u]); 2198eb653de1SFilipe David Borba Manana p->locks[u] = 0; 2199eb653de1SFilipe David Borba Manana } 2200eb653de1SFilipe David Borba Manana } 2201b4ce94deSChris Mason 2202e2e58d0fSFilipe Manana if (level == 0) { 2203109324cfSFilipe Manana if (ins_len > 0) 2204e5e1c174SFilipe Manana ASSERT(write_lock_level >= 1); 2205bd681513SChris Mason 2206109324cfSFilipe Manana ret = search_leaf(trans, root, key, p, ins_len, prev_cmp); 2207459931ecSChris Mason if (!p->search_for_split) 2208f7c79f30SChris Mason unlock_up(p, level, lowest_unlock, 22094b6f8e96SLiu Bo min_write_lock_level, NULL); 221065b51a00SChris Mason goto done; 221165b51a00SChris Mason } 2212e2e58d0fSFilipe Manana 2213e2e58d0fSFilipe Manana ret = search_for_key_slot(b, 0, key, prev_cmp, &slot); 2214e2e58d0fSFilipe Manana if (ret < 0) 2215e2e58d0fSFilipe Manana goto done; 2216e2e58d0fSFilipe Manana prev_cmp = ret; 2217e2e58d0fSFilipe Manana 2218f624d976SQu Wenruo if (ret && slot > 0) { 2219f624d976SQu Wenruo dec = 1; 2220f624d976SQu Wenruo slot--; 2221f624d976SQu Wenruo } 2222f624d976SQu Wenruo p->slots[level] = slot; 2223f624d976SQu Wenruo err = setup_nodes_for_search(trans, root, p, b, level, ins_len, 2224f624d976SQu Wenruo &write_lock_level); 2225f624d976SQu Wenruo if (err == -EAGAIN) 2226f624d976SQu Wenruo goto again; 2227f624d976SQu Wenruo if (err) { 2228f624d976SQu Wenruo ret = err; 2229f624d976SQu Wenruo goto done; 2230f624d976SQu Wenruo } 2231f624d976SQu Wenruo b = p->nodes[level]; 2232f624d976SQu Wenruo slot = p->slots[level]; 2233f624d976SQu Wenruo 2234f624d976SQu Wenruo /* 2235f624d976SQu Wenruo * Slot 0 is special, if we change the key we have to update 2236f624d976SQu Wenruo * the parent pointer which means we must have a write lock on 2237f624d976SQu Wenruo * the parent 2238f624d976SQu Wenruo */ 2239f624d976SQu Wenruo if (slot == 0 && ins_len && write_lock_level < level + 1) { 2240f624d976SQu Wenruo write_lock_level = level + 1; 2241f624d976SQu Wenruo btrfs_release_path(p); 2242f624d976SQu Wenruo goto again; 2243f624d976SQu Wenruo } 2244f624d976SQu Wenruo 2245f624d976SQu Wenruo unlock_up(p, level, lowest_unlock, min_write_lock_level, 2246f624d976SQu Wenruo &write_lock_level); 2247f624d976SQu Wenruo 2248f624d976SQu Wenruo if (level == lowest_level) { 2249f624d976SQu Wenruo if (dec) 2250f624d976SQu Wenruo p->slots[level]++; 2251f624d976SQu Wenruo goto done; 2252f624d976SQu Wenruo } 2253f624d976SQu Wenruo 2254f624d976SQu Wenruo err = read_block_for_search(root, p, &b, level, slot, key); 2255f624d976SQu Wenruo if (err == -EAGAIN) 2256f624d976SQu Wenruo goto again; 2257f624d976SQu Wenruo if (err) { 2258f624d976SQu Wenruo ret = err; 2259f624d976SQu Wenruo goto done; 2260f624d976SQu Wenruo } 2261f624d976SQu Wenruo 2262f624d976SQu Wenruo if (!p->skip_locking) { 2263f624d976SQu Wenruo level = btrfs_header_level(b); 2264b40130b2SJosef Bacik 2265b40130b2SJosef Bacik btrfs_maybe_reset_lockdep_class(root, b); 2266b40130b2SJosef Bacik 2267f624d976SQu Wenruo if (level <= write_lock_level) { 2268f624d976SQu Wenruo btrfs_tree_lock(b); 2269f624d976SQu Wenruo p->locks[level] = BTRFS_WRITE_LOCK; 2270f624d976SQu Wenruo } else { 2271857bc13fSJosef Bacik if (p->nowait) { 2272857bc13fSJosef Bacik if (!btrfs_try_tree_read_lock(b)) { 2273857bc13fSJosef Bacik free_extent_buffer(b); 2274857bc13fSJosef Bacik ret = -EAGAIN; 2275857bc13fSJosef Bacik goto done; 2276857bc13fSJosef Bacik } 2277857bc13fSJosef Bacik } else { 2278fe596ca3SJosef Bacik btrfs_tree_read_lock(b); 2279857bc13fSJosef Bacik } 2280f624d976SQu Wenruo p->locks[level] = BTRFS_READ_LOCK; 2281f624d976SQu Wenruo } 2282f624d976SQu Wenruo p->nodes[level] = b; 2283f624d976SQu Wenruo } 228465b51a00SChris Mason } 228565b51a00SChris Mason ret = 1; 228665b51a00SChris Mason done: 22875f5bc6b1SFilipe Manana if (ret < 0 && !p->skip_release_on_error) 2288b3b4aa74SDavid Sterba btrfs_release_path(p); 2289d96b3424SFilipe Manana 2290d96b3424SFilipe Manana if (p->need_commit_sem) { 2291d96b3424SFilipe Manana int ret2; 2292d96b3424SFilipe Manana 2293d96b3424SFilipe Manana ret2 = finish_need_commit_sem_search(p); 2294d96b3424SFilipe Manana up_read(&fs_info->commit_root_sem); 2295d96b3424SFilipe Manana if (ret2) 2296d96b3424SFilipe Manana ret = ret2; 2297d96b3424SFilipe Manana } 2298d96b3424SFilipe Manana 2299be0e5c09SChris Mason return ret; 2300be0e5c09SChris Mason } 2301f75e2b79SJosef Bacik ALLOW_ERROR_INJECTION(btrfs_search_slot, ERRNO); 2302be0e5c09SChris Mason 230374123bd7SChris Mason /* 23045d9e75c4SJan Schmidt * Like btrfs_search_slot, this looks for a key in the given tree. It uses the 23055d9e75c4SJan Schmidt * current state of the tree together with the operations recorded in the tree 23065d9e75c4SJan Schmidt * modification log to search for the key in a previous version of this tree, as 23075d9e75c4SJan Schmidt * denoted by the time_seq parameter. 23085d9e75c4SJan Schmidt * 23095d9e75c4SJan Schmidt * Naturally, there is no support for insert, delete or cow operations. 23105d9e75c4SJan Schmidt * 23115d9e75c4SJan Schmidt * The resulting path and return value will be set up as if we called 23125d9e75c4SJan Schmidt * btrfs_search_slot at that point in time with ins_len and cow both set to 0. 23135d9e75c4SJan Schmidt */ 2314310712b2SOmar Sandoval int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key, 23155d9e75c4SJan Schmidt struct btrfs_path *p, u64 time_seq) 23165d9e75c4SJan Schmidt { 23170b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 23185d9e75c4SJan Schmidt struct extent_buffer *b; 23195d9e75c4SJan Schmidt int slot; 23205d9e75c4SJan Schmidt int ret; 23215d9e75c4SJan Schmidt int err; 23225d9e75c4SJan Schmidt int level; 23235d9e75c4SJan Schmidt int lowest_unlock = 1; 23245d9e75c4SJan Schmidt u8 lowest_level = 0; 23255d9e75c4SJan Schmidt 23265d9e75c4SJan Schmidt lowest_level = p->lowest_level; 23275d9e75c4SJan Schmidt WARN_ON(p->nodes[0] != NULL); 2328c922b016SStefan Roesch ASSERT(!p->nowait); 23295d9e75c4SJan Schmidt 23305d9e75c4SJan Schmidt if (p->search_commit_root) { 23315d9e75c4SJan Schmidt BUG_ON(time_seq); 23325d9e75c4SJan Schmidt return btrfs_search_slot(NULL, root, key, p, 0, 0); 23335d9e75c4SJan Schmidt } 23345d9e75c4SJan Schmidt 23355d9e75c4SJan Schmidt again: 2336f3a84ccdSFilipe Manana b = btrfs_get_old_root(root, time_seq); 2337315bed43SNikolay Borisov if (!b) { 2338315bed43SNikolay Borisov ret = -EIO; 2339315bed43SNikolay Borisov goto done; 2340315bed43SNikolay Borisov } 23415d9e75c4SJan Schmidt level = btrfs_header_level(b); 23425d9e75c4SJan Schmidt p->locks[level] = BTRFS_READ_LOCK; 23435d9e75c4SJan Schmidt 23445d9e75c4SJan Schmidt while (b) { 2345abe9339dSQu Wenruo int dec = 0; 2346abe9339dSQu Wenruo 23475d9e75c4SJan Schmidt level = btrfs_header_level(b); 23485d9e75c4SJan Schmidt p->nodes[level] = b; 23495d9e75c4SJan Schmidt 23505d9e75c4SJan Schmidt /* 23515d9e75c4SJan Schmidt * we have a lock on b and as long as we aren't changing 23525d9e75c4SJan Schmidt * the tree, there is no way to for the items in b to change. 23535d9e75c4SJan Schmidt * It is safe to drop the lock on our parent before we 23545d9e75c4SJan Schmidt * go through the expensive btree search on b. 23555d9e75c4SJan Schmidt */ 23565d9e75c4SJan Schmidt btrfs_unlock_up_safe(p, level + 1); 23575d9e75c4SJan Schmidt 2358fdf8d595SAnand Jain ret = btrfs_bin_search(b, 0, key, &slot); 2359cbca7d59SFilipe Manana if (ret < 0) 2360cbca7d59SFilipe Manana goto done; 23615d9e75c4SJan Schmidt 2362abe9339dSQu Wenruo if (level == 0) { 2363abe9339dSQu Wenruo p->slots[level] = slot; 2364abe9339dSQu Wenruo unlock_up(p, level, lowest_unlock, 0, NULL); 2365abe9339dSQu Wenruo goto done; 2366abe9339dSQu Wenruo } 2367abe9339dSQu Wenruo 23685d9e75c4SJan Schmidt if (ret && slot > 0) { 23695d9e75c4SJan Schmidt dec = 1; 2370abe9339dSQu Wenruo slot--; 23715d9e75c4SJan Schmidt } 23725d9e75c4SJan Schmidt p->slots[level] = slot; 23735d9e75c4SJan Schmidt unlock_up(p, level, lowest_unlock, 0, NULL); 23745d9e75c4SJan Schmidt 23755d9e75c4SJan Schmidt if (level == lowest_level) { 23765d9e75c4SJan Schmidt if (dec) 23775d9e75c4SJan Schmidt p->slots[level]++; 23785d9e75c4SJan Schmidt goto done; 23795d9e75c4SJan Schmidt } 23805d9e75c4SJan Schmidt 2381abe9339dSQu Wenruo err = read_block_for_search(root, p, &b, level, slot, key); 23825d9e75c4SJan Schmidt if (err == -EAGAIN) 23835d9e75c4SJan Schmidt goto again; 23845d9e75c4SJan Schmidt if (err) { 23855d9e75c4SJan Schmidt ret = err; 23865d9e75c4SJan Schmidt goto done; 23875d9e75c4SJan Schmidt } 23885d9e75c4SJan Schmidt 23895d9e75c4SJan Schmidt level = btrfs_header_level(b); 23905d9e75c4SJan Schmidt btrfs_tree_read_lock(b); 2391f3a84ccdSFilipe Manana b = btrfs_tree_mod_log_rewind(fs_info, p, b, time_seq); 2392db7f3436SJosef Bacik if (!b) { 2393db7f3436SJosef Bacik ret = -ENOMEM; 2394db7f3436SJosef Bacik goto done; 2395db7f3436SJosef Bacik } 23965d9e75c4SJan Schmidt p->locks[level] = BTRFS_READ_LOCK; 23975d9e75c4SJan Schmidt p->nodes[level] = b; 23985d9e75c4SJan Schmidt } 23995d9e75c4SJan Schmidt ret = 1; 24005d9e75c4SJan Schmidt done: 24015d9e75c4SJan Schmidt if (ret < 0) 24025d9e75c4SJan Schmidt btrfs_release_path(p); 24035d9e75c4SJan Schmidt 24045d9e75c4SJan Schmidt return ret; 24055d9e75c4SJan Schmidt } 24065d9e75c4SJan Schmidt 24075d9e75c4SJan Schmidt /* 2408f469c8bdSFilipe Manana * Search the tree again to find a leaf with smaller keys. 2409f469c8bdSFilipe Manana * Returns 0 if it found something. 2410f469c8bdSFilipe Manana * Returns 1 if there are no smaller keys. 2411f469c8bdSFilipe Manana * Returns < 0 on error. 2412f469c8bdSFilipe Manana * 2413f469c8bdSFilipe Manana * This may release the path, and so you may lose any locks held at the 2414f469c8bdSFilipe Manana * time you call it. 2415f469c8bdSFilipe Manana */ 2416f469c8bdSFilipe Manana static int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) 2417f469c8bdSFilipe Manana { 2418f469c8bdSFilipe Manana struct btrfs_key key; 2419f469c8bdSFilipe Manana struct btrfs_key orig_key; 2420f469c8bdSFilipe Manana struct btrfs_disk_key found_key; 2421f469c8bdSFilipe Manana int ret; 2422f469c8bdSFilipe Manana 2423f469c8bdSFilipe Manana btrfs_item_key_to_cpu(path->nodes[0], &key, 0); 2424f469c8bdSFilipe Manana orig_key = key; 2425f469c8bdSFilipe Manana 2426f469c8bdSFilipe Manana if (key.offset > 0) { 2427f469c8bdSFilipe Manana key.offset--; 2428f469c8bdSFilipe Manana } else if (key.type > 0) { 2429f469c8bdSFilipe Manana key.type--; 2430f469c8bdSFilipe Manana key.offset = (u64)-1; 2431f469c8bdSFilipe Manana } else if (key.objectid > 0) { 2432f469c8bdSFilipe Manana key.objectid--; 2433f469c8bdSFilipe Manana key.type = (u8)-1; 2434f469c8bdSFilipe Manana key.offset = (u64)-1; 2435f469c8bdSFilipe Manana } else { 2436f469c8bdSFilipe Manana return 1; 2437f469c8bdSFilipe Manana } 2438f469c8bdSFilipe Manana 2439f469c8bdSFilipe Manana btrfs_release_path(path); 2440f469c8bdSFilipe Manana ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2441f469c8bdSFilipe Manana if (ret <= 0) 2442f469c8bdSFilipe Manana return ret; 2443f469c8bdSFilipe Manana 2444f469c8bdSFilipe Manana /* 2445f469c8bdSFilipe Manana * Previous key not found. Even if we were at slot 0 of the leaf we had 2446f469c8bdSFilipe Manana * before releasing the path and calling btrfs_search_slot(), we now may 2447f469c8bdSFilipe Manana * be in a slot pointing to the same original key - this can happen if 2448f469c8bdSFilipe Manana * after we released the path, one of more items were moved from a 2449f469c8bdSFilipe Manana * sibling leaf into the front of the leaf we had due to an insertion 2450f469c8bdSFilipe Manana * (see push_leaf_right()). 2451f469c8bdSFilipe Manana * If we hit this case and our slot is > 0 and just decrement the slot 2452f469c8bdSFilipe Manana * so that the caller does not process the same key again, which may or 2453f469c8bdSFilipe Manana * may not break the caller, depending on its logic. 2454f469c8bdSFilipe Manana */ 2455f469c8bdSFilipe Manana if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) { 2456f469c8bdSFilipe Manana btrfs_item_key(path->nodes[0], &found_key, path->slots[0]); 2457f469c8bdSFilipe Manana ret = comp_keys(&found_key, &orig_key); 2458f469c8bdSFilipe Manana if (ret == 0) { 2459f469c8bdSFilipe Manana if (path->slots[0] > 0) { 2460f469c8bdSFilipe Manana path->slots[0]--; 2461f469c8bdSFilipe Manana return 0; 2462f469c8bdSFilipe Manana } 2463f469c8bdSFilipe Manana /* 2464f469c8bdSFilipe Manana * At slot 0, same key as before, it means orig_key is 2465f469c8bdSFilipe Manana * the lowest, leftmost, key in the tree. We're done. 2466f469c8bdSFilipe Manana */ 2467f469c8bdSFilipe Manana return 1; 2468f469c8bdSFilipe Manana } 2469f469c8bdSFilipe Manana } 2470f469c8bdSFilipe Manana 2471f469c8bdSFilipe Manana btrfs_item_key(path->nodes[0], &found_key, 0); 2472f469c8bdSFilipe Manana ret = comp_keys(&found_key, &key); 2473f469c8bdSFilipe Manana /* 2474f469c8bdSFilipe Manana * We might have had an item with the previous key in the tree right 2475f469c8bdSFilipe Manana * before we released our path. And after we released our path, that 2476f469c8bdSFilipe Manana * item might have been pushed to the first slot (0) of the leaf we 2477f469c8bdSFilipe Manana * were holding due to a tree balance. Alternatively, an item with the 2478f469c8bdSFilipe Manana * previous key can exist as the only element of a leaf (big fat item). 2479f469c8bdSFilipe Manana * Therefore account for these 2 cases, so that our callers (like 2480f469c8bdSFilipe Manana * btrfs_previous_item) don't miss an existing item with a key matching 2481f469c8bdSFilipe Manana * the previous key we computed above. 2482f469c8bdSFilipe Manana */ 2483f469c8bdSFilipe Manana if (ret <= 0) 2484f469c8bdSFilipe Manana return 0; 2485f469c8bdSFilipe Manana return 1; 2486f469c8bdSFilipe Manana } 2487f469c8bdSFilipe Manana 2488f469c8bdSFilipe Manana /* 24892f38b3e1SArne Jansen * helper to use instead of search slot if no exact match is needed but 24902f38b3e1SArne Jansen * instead the next or previous item should be returned. 24912f38b3e1SArne Jansen * When find_higher is true, the next higher item is returned, the next lower 24922f38b3e1SArne Jansen * otherwise. 24932f38b3e1SArne Jansen * When return_any and find_higher are both true, and no higher item is found, 24942f38b3e1SArne Jansen * return the next lower instead. 24952f38b3e1SArne Jansen * When return_any is true and find_higher is false, and no lower item is found, 24962f38b3e1SArne Jansen * return the next higher instead. 24972f38b3e1SArne Jansen * It returns 0 if any item is found, 1 if none is found (tree empty), and 24982f38b3e1SArne Jansen * < 0 on error 24992f38b3e1SArne Jansen */ 25002f38b3e1SArne Jansen int btrfs_search_slot_for_read(struct btrfs_root *root, 2501310712b2SOmar Sandoval const struct btrfs_key *key, 2502310712b2SOmar Sandoval struct btrfs_path *p, int find_higher, 2503310712b2SOmar Sandoval int return_any) 25042f38b3e1SArne Jansen { 25052f38b3e1SArne Jansen int ret; 25062f38b3e1SArne Jansen struct extent_buffer *leaf; 25072f38b3e1SArne Jansen 25082f38b3e1SArne Jansen again: 25092f38b3e1SArne Jansen ret = btrfs_search_slot(NULL, root, key, p, 0, 0); 25102f38b3e1SArne Jansen if (ret <= 0) 25112f38b3e1SArne Jansen return ret; 25122f38b3e1SArne Jansen /* 25132f38b3e1SArne Jansen * a return value of 1 means the path is at the position where the 25142f38b3e1SArne Jansen * item should be inserted. Normally this is the next bigger item, 25152f38b3e1SArne Jansen * but in case the previous item is the last in a leaf, path points 25162f38b3e1SArne Jansen * to the first free slot in the previous leaf, i.e. at an invalid 25172f38b3e1SArne Jansen * item. 25182f38b3e1SArne Jansen */ 25192f38b3e1SArne Jansen leaf = p->nodes[0]; 25202f38b3e1SArne Jansen 25212f38b3e1SArne Jansen if (find_higher) { 25222f38b3e1SArne Jansen if (p->slots[0] >= btrfs_header_nritems(leaf)) { 25232f38b3e1SArne Jansen ret = btrfs_next_leaf(root, p); 25242f38b3e1SArne Jansen if (ret <= 0) 25252f38b3e1SArne Jansen return ret; 25262f38b3e1SArne Jansen if (!return_any) 25272f38b3e1SArne Jansen return 1; 25282f38b3e1SArne Jansen /* 25292f38b3e1SArne Jansen * no higher item found, return the next 25302f38b3e1SArne Jansen * lower instead 25312f38b3e1SArne Jansen */ 25322f38b3e1SArne Jansen return_any = 0; 25332f38b3e1SArne Jansen find_higher = 0; 25342f38b3e1SArne Jansen btrfs_release_path(p); 25352f38b3e1SArne Jansen goto again; 25362f38b3e1SArne Jansen } 25372f38b3e1SArne Jansen } else { 25382f38b3e1SArne Jansen if (p->slots[0] == 0) { 25392f38b3e1SArne Jansen ret = btrfs_prev_leaf(root, p); 2540e6793769SArne Jansen if (ret < 0) 25412f38b3e1SArne Jansen return ret; 2542e6793769SArne Jansen if (!ret) { 254323c6bf6aSFilipe David Borba Manana leaf = p->nodes[0]; 254423c6bf6aSFilipe David Borba Manana if (p->slots[0] == btrfs_header_nritems(leaf)) 254523c6bf6aSFilipe David Borba Manana p->slots[0]--; 2546e6793769SArne Jansen return 0; 2547e6793769SArne Jansen } 25482f38b3e1SArne Jansen if (!return_any) 25492f38b3e1SArne Jansen return 1; 25502f38b3e1SArne Jansen /* 25512f38b3e1SArne Jansen * no lower item found, return the next 25522f38b3e1SArne Jansen * higher instead 25532f38b3e1SArne Jansen */ 25542f38b3e1SArne Jansen return_any = 0; 25552f38b3e1SArne Jansen find_higher = 1; 25562f38b3e1SArne Jansen btrfs_release_path(p); 25572f38b3e1SArne Jansen goto again; 2558e6793769SArne Jansen } else { 25592f38b3e1SArne Jansen --p->slots[0]; 25602f38b3e1SArne Jansen } 25612f38b3e1SArne Jansen } 25622f38b3e1SArne Jansen return 0; 25632f38b3e1SArne Jansen } 25642f38b3e1SArne Jansen 25652f38b3e1SArne Jansen /* 25660ff40a91SMarcos Paulo de Souza * Execute search and call btrfs_previous_item to traverse backwards if the item 25670ff40a91SMarcos Paulo de Souza * was not found. 25680ff40a91SMarcos Paulo de Souza * 25690ff40a91SMarcos Paulo de Souza * Return 0 if found, 1 if not found and < 0 if error. 25700ff40a91SMarcos Paulo de Souza */ 25710ff40a91SMarcos Paulo de Souza int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key, 25720ff40a91SMarcos Paulo de Souza struct btrfs_path *path) 25730ff40a91SMarcos Paulo de Souza { 25740ff40a91SMarcos Paulo de Souza int ret; 25750ff40a91SMarcos Paulo de Souza 25760ff40a91SMarcos Paulo de Souza ret = btrfs_search_slot(NULL, root, key, path, 0, 0); 25770ff40a91SMarcos Paulo de Souza if (ret > 0) 25780ff40a91SMarcos Paulo de Souza ret = btrfs_previous_item(root, path, key->objectid, key->type); 25790ff40a91SMarcos Paulo de Souza 25800ff40a91SMarcos Paulo de Souza if (ret == 0) 25810ff40a91SMarcos Paulo de Souza btrfs_item_key_to_cpu(path->nodes[0], key, path->slots[0]); 25820ff40a91SMarcos Paulo de Souza 25830ff40a91SMarcos Paulo de Souza return ret; 25840ff40a91SMarcos Paulo de Souza } 25850ff40a91SMarcos Paulo de Souza 258643dd529aSDavid Sterba /* 258762142be3SGabriel Niebler * Search for a valid slot for the given path. 258862142be3SGabriel Niebler * 258962142be3SGabriel Niebler * @root: The root node of the tree. 259062142be3SGabriel Niebler * @key: Will contain a valid item if found. 259162142be3SGabriel Niebler * @path: The starting point to validate the slot. 259262142be3SGabriel Niebler * 259362142be3SGabriel Niebler * Return: 0 if the item is valid 259462142be3SGabriel Niebler * 1 if not found 259562142be3SGabriel Niebler * <0 if error. 259662142be3SGabriel Niebler */ 259762142be3SGabriel Niebler int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key, 259862142be3SGabriel Niebler struct btrfs_path *path) 259962142be3SGabriel Niebler { 2600524f14bbSFilipe Manana if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { 260162142be3SGabriel Niebler int ret; 260262142be3SGabriel Niebler 260362142be3SGabriel Niebler ret = btrfs_next_leaf(root, path); 260462142be3SGabriel Niebler if (ret) 260562142be3SGabriel Niebler return ret; 260662142be3SGabriel Niebler } 2607524f14bbSFilipe Manana 2608524f14bbSFilipe Manana btrfs_item_key_to_cpu(path->nodes[0], key, path->slots[0]); 260962142be3SGabriel Niebler return 0; 261062142be3SGabriel Niebler } 261162142be3SGabriel Niebler 26120ff40a91SMarcos Paulo de Souza /* 261374123bd7SChris Mason * adjust the pointers going up the tree, starting at level 261474123bd7SChris Mason * making sure the right key of each node is points to 'key'. 261574123bd7SChris Mason * This is used after shifting pointers to the left, so it stops 261674123bd7SChris Mason * fixing up pointers when a given leaf/node is not in slot 0 of the 261774123bd7SChris Mason * higher levels 2618aa5d6bedSChris Mason * 261974123bd7SChris Mason */ 2620b167fa91SNikolay Borisov static void fixup_low_keys(struct btrfs_path *path, 26215f39d397SChris Mason struct btrfs_disk_key *key, int level) 2622be0e5c09SChris Mason { 2623be0e5c09SChris Mason int i; 26245f39d397SChris Mason struct extent_buffer *t; 26250e82bcfeSDavid Sterba int ret; 26265f39d397SChris Mason 2627234b63a0SChris Mason for (i = level; i < BTRFS_MAX_LEVEL; i++) { 2628be0e5c09SChris Mason int tslot = path->slots[i]; 26290e82bcfeSDavid Sterba 2630eb60ceacSChris Mason if (!path->nodes[i]) 2631be0e5c09SChris Mason break; 26325f39d397SChris Mason t = path->nodes[i]; 2633f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_key(t, tslot, 263433cff222SFilipe Manana BTRFS_MOD_LOG_KEY_REPLACE); 26350e82bcfeSDavid Sterba BUG_ON(ret < 0); 26365f39d397SChris Mason btrfs_set_node_key(t, key, tslot); 2637d6025579SChris Mason btrfs_mark_buffer_dirty(path->nodes[i]); 2638be0e5c09SChris Mason if (tslot != 0) 2639be0e5c09SChris Mason break; 2640be0e5c09SChris Mason } 2641be0e5c09SChris Mason } 2642be0e5c09SChris Mason 264374123bd7SChris Mason /* 264431840ae1SZheng Yan * update item key. 264531840ae1SZheng Yan * 264631840ae1SZheng Yan * This function isn't completely safe. It's the caller's responsibility 264731840ae1SZheng Yan * that the new key won't break the order 264831840ae1SZheng Yan */ 2649b7a0365eSDaniel Dressler void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info, 2650b7a0365eSDaniel Dressler struct btrfs_path *path, 2651310712b2SOmar Sandoval const struct btrfs_key *new_key) 265231840ae1SZheng Yan { 265331840ae1SZheng Yan struct btrfs_disk_key disk_key; 265431840ae1SZheng Yan struct extent_buffer *eb; 265531840ae1SZheng Yan int slot; 265631840ae1SZheng Yan 265731840ae1SZheng Yan eb = path->nodes[0]; 265831840ae1SZheng Yan slot = path->slots[0]; 265931840ae1SZheng Yan if (slot > 0) { 266031840ae1SZheng Yan btrfs_item_key(eb, &disk_key, slot - 1); 26617c15d410SQu Wenruo if (unlikely(comp_keys(&disk_key, new_key) >= 0)) { 2662eee3b811SQu Wenruo btrfs_print_leaf(eb); 26637c15d410SQu Wenruo btrfs_crit(fs_info, 26647c15d410SQu Wenruo "slot %u key (%llu %u %llu) new key (%llu %u %llu)", 26657c15d410SQu Wenruo slot, btrfs_disk_key_objectid(&disk_key), 26667c15d410SQu Wenruo btrfs_disk_key_type(&disk_key), 26677c15d410SQu Wenruo btrfs_disk_key_offset(&disk_key), 26687c15d410SQu Wenruo new_key->objectid, new_key->type, 26697c15d410SQu Wenruo new_key->offset); 26707c15d410SQu Wenruo BUG(); 26717c15d410SQu Wenruo } 267231840ae1SZheng Yan } 267331840ae1SZheng Yan if (slot < btrfs_header_nritems(eb) - 1) { 267431840ae1SZheng Yan btrfs_item_key(eb, &disk_key, slot + 1); 26757c15d410SQu Wenruo if (unlikely(comp_keys(&disk_key, new_key) <= 0)) { 2676eee3b811SQu Wenruo btrfs_print_leaf(eb); 26777c15d410SQu Wenruo btrfs_crit(fs_info, 26787c15d410SQu Wenruo "slot %u key (%llu %u %llu) new key (%llu %u %llu)", 26797c15d410SQu Wenruo slot, btrfs_disk_key_objectid(&disk_key), 26807c15d410SQu Wenruo btrfs_disk_key_type(&disk_key), 26817c15d410SQu Wenruo btrfs_disk_key_offset(&disk_key), 26827c15d410SQu Wenruo new_key->objectid, new_key->type, 26837c15d410SQu Wenruo new_key->offset); 26847c15d410SQu Wenruo BUG(); 26857c15d410SQu Wenruo } 268631840ae1SZheng Yan } 268731840ae1SZheng Yan 268831840ae1SZheng Yan btrfs_cpu_key_to_disk(&disk_key, new_key); 268931840ae1SZheng Yan btrfs_set_item_key(eb, &disk_key, slot); 269031840ae1SZheng Yan btrfs_mark_buffer_dirty(eb); 269131840ae1SZheng Yan if (slot == 0) 2692b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 269331840ae1SZheng Yan } 269431840ae1SZheng Yan 269531840ae1SZheng Yan /* 2696d16c702fSQu Wenruo * Check key order of two sibling extent buffers. 2697d16c702fSQu Wenruo * 2698d16c702fSQu Wenruo * Return true if something is wrong. 2699d16c702fSQu Wenruo * Return false if everything is fine. 2700d16c702fSQu Wenruo * 2701d16c702fSQu Wenruo * Tree-checker only works inside one tree block, thus the following 2702d16c702fSQu Wenruo * corruption can not be detected by tree-checker: 2703d16c702fSQu Wenruo * 2704d16c702fSQu Wenruo * Leaf @left | Leaf @right 2705d16c702fSQu Wenruo * -------------------------------------------------------------- 2706d16c702fSQu Wenruo * | 1 | 2 | 3 | 4 | 5 | f6 | | 7 | 8 | 2707d16c702fSQu Wenruo * 2708d16c702fSQu Wenruo * Key f6 in leaf @left itself is valid, but not valid when the next 2709d16c702fSQu Wenruo * key in leaf @right is 7. 2710d16c702fSQu Wenruo * This can only be checked at tree block merge time. 2711d16c702fSQu Wenruo * And since tree checker has ensured all key order in each tree block 2712d16c702fSQu Wenruo * is correct, we only need to bother the last key of @left and the first 2713d16c702fSQu Wenruo * key of @right. 2714d16c702fSQu Wenruo */ 2715d16c702fSQu Wenruo static bool check_sibling_keys(struct extent_buffer *left, 2716d16c702fSQu Wenruo struct extent_buffer *right) 2717d16c702fSQu Wenruo { 2718d16c702fSQu Wenruo struct btrfs_key left_last; 2719d16c702fSQu Wenruo struct btrfs_key right_first; 2720d16c702fSQu Wenruo int level = btrfs_header_level(left); 2721d16c702fSQu Wenruo int nr_left = btrfs_header_nritems(left); 2722d16c702fSQu Wenruo int nr_right = btrfs_header_nritems(right); 2723d16c702fSQu Wenruo 2724d16c702fSQu Wenruo /* No key to check in one of the tree blocks */ 2725d16c702fSQu Wenruo if (!nr_left || !nr_right) 2726d16c702fSQu Wenruo return false; 2727d16c702fSQu Wenruo 2728d16c702fSQu Wenruo if (level) { 2729d16c702fSQu Wenruo btrfs_node_key_to_cpu(left, &left_last, nr_left - 1); 2730d16c702fSQu Wenruo btrfs_node_key_to_cpu(right, &right_first, 0); 2731d16c702fSQu Wenruo } else { 2732d16c702fSQu Wenruo btrfs_item_key_to_cpu(left, &left_last, nr_left - 1); 2733d16c702fSQu Wenruo btrfs_item_key_to_cpu(right, &right_first, 0); 2734d16c702fSQu Wenruo } 2735d16c702fSQu Wenruo 273688ad95b0SFilipe Manana if (unlikely(btrfs_comp_cpu_keys(&left_last, &right_first) >= 0)) { 2737a2cea677SFilipe Manana btrfs_crit(left->fs_info, "left extent buffer:"); 2738a2cea677SFilipe Manana btrfs_print_tree(left, false); 2739a2cea677SFilipe Manana btrfs_crit(left->fs_info, "right extent buffer:"); 2740a2cea677SFilipe Manana btrfs_print_tree(right, false); 2741d16c702fSQu Wenruo btrfs_crit(left->fs_info, 2742d16c702fSQu Wenruo "bad key order, sibling blocks, left last (%llu %u %llu) right first (%llu %u %llu)", 2743d16c702fSQu Wenruo left_last.objectid, left_last.type, 2744d16c702fSQu Wenruo left_last.offset, right_first.objectid, 2745d16c702fSQu Wenruo right_first.type, right_first.offset); 2746d16c702fSQu Wenruo return true; 2747d16c702fSQu Wenruo } 2748d16c702fSQu Wenruo return false; 2749d16c702fSQu Wenruo } 2750d16c702fSQu Wenruo 2751d16c702fSQu Wenruo /* 275274123bd7SChris Mason * try to push data from one node into the next node left in the 275379f95c82SChris Mason * tree. 2754aa5d6bedSChris Mason * 2755aa5d6bedSChris Mason * returns 0 if some ptrs were pushed left, < 0 if there was some horrible 2756aa5d6bedSChris Mason * error, and > 0 if there was no room in the left hand block. 275774123bd7SChris Mason */ 275898ed5174SChris Mason static int push_node_left(struct btrfs_trans_handle *trans, 27592ff7e61eSJeff Mahoney struct extent_buffer *dst, 2760971a1f66SChris Mason struct extent_buffer *src, int empty) 2761be0e5c09SChris Mason { 2762d30a668fSDavid Sterba struct btrfs_fs_info *fs_info = trans->fs_info; 2763be0e5c09SChris Mason int push_items = 0; 2764bb803951SChris Mason int src_nritems; 2765bb803951SChris Mason int dst_nritems; 2766aa5d6bedSChris Mason int ret = 0; 2767be0e5c09SChris Mason 27685f39d397SChris Mason src_nritems = btrfs_header_nritems(src); 27695f39d397SChris Mason dst_nritems = btrfs_header_nritems(dst); 27700b246afaSJeff Mahoney push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; 27717bb86316SChris Mason WARN_ON(btrfs_header_generation(src) != trans->transid); 27727bb86316SChris Mason WARN_ON(btrfs_header_generation(dst) != trans->transid); 277354aa1f4dSChris Mason 2774bce4eae9SChris Mason if (!empty && src_nritems <= 8) 2775971a1f66SChris Mason return 1; 2776971a1f66SChris Mason 2777d397712bSChris Mason if (push_items <= 0) 2778be0e5c09SChris Mason return 1; 2779be0e5c09SChris Mason 2780bce4eae9SChris Mason if (empty) { 2781971a1f66SChris Mason push_items = min(src_nritems, push_items); 2782bce4eae9SChris Mason if (push_items < src_nritems) { 2783bce4eae9SChris Mason /* leave at least 8 pointers in the node if 2784bce4eae9SChris Mason * we aren't going to empty it 2785bce4eae9SChris Mason */ 2786bce4eae9SChris Mason if (src_nritems - push_items < 8) { 2787bce4eae9SChris Mason if (push_items <= 8) 2788bce4eae9SChris Mason return 1; 2789bce4eae9SChris Mason push_items -= 8; 2790bce4eae9SChris Mason } 2791bce4eae9SChris Mason } 2792bce4eae9SChris Mason } else 2793bce4eae9SChris Mason push_items = min(src_nritems - 8, push_items); 279479f95c82SChris Mason 2795d16c702fSQu Wenruo /* dst is the left eb, src is the middle eb */ 2796d16c702fSQu Wenruo if (check_sibling_keys(dst, src)) { 2797d16c702fSQu Wenruo ret = -EUCLEAN; 2798d16c702fSQu Wenruo btrfs_abort_transaction(trans, ret); 2799d16c702fSQu Wenruo return ret; 2800d16c702fSQu Wenruo } 2801f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_eb_copy(dst, src, dst_nritems, 0, push_items); 28025de865eeSFilipe David Borba Manana if (ret) { 280366642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 28045de865eeSFilipe David Borba Manana return ret; 28055de865eeSFilipe David Borba Manana } 28065f39d397SChris Mason copy_extent_buffer(dst, src, 2807e23efd8eSJosef Bacik btrfs_node_key_ptr_offset(dst, dst_nritems), 2808e23efd8eSJosef Bacik btrfs_node_key_ptr_offset(src, 0), 2809123abc88SChris Mason push_items * sizeof(struct btrfs_key_ptr)); 28105f39d397SChris Mason 2811bb803951SChris Mason if (push_items < src_nritems) { 281257911b8bSJan Schmidt /* 28135cead542SBoris Burkov * btrfs_tree_mod_log_eb_copy handles logging the move, so we 28145cead542SBoris Burkov * don't need to do an explicit tree mod log operation for it. 281557911b8bSJan Schmidt */ 2816e23efd8eSJosef Bacik memmove_extent_buffer(src, btrfs_node_key_ptr_offset(src, 0), 2817e23efd8eSJosef Bacik btrfs_node_key_ptr_offset(src, push_items), 2818e2fa7227SChris Mason (src_nritems - push_items) * 2819123abc88SChris Mason sizeof(struct btrfs_key_ptr)); 2820bb803951SChris Mason } 28215f39d397SChris Mason btrfs_set_header_nritems(src, src_nritems - push_items); 28225f39d397SChris Mason btrfs_set_header_nritems(dst, dst_nritems + push_items); 28235f39d397SChris Mason btrfs_mark_buffer_dirty(src); 28245f39d397SChris Mason btrfs_mark_buffer_dirty(dst); 282531840ae1SZheng Yan 2826bb803951SChris Mason return ret; 2827be0e5c09SChris Mason } 2828be0e5c09SChris Mason 282997571fd0SChris Mason /* 283079f95c82SChris Mason * try to push data from one node into the next node right in the 283179f95c82SChris Mason * tree. 283279f95c82SChris Mason * 283379f95c82SChris Mason * returns 0 if some ptrs were pushed, < 0 if there was some horrible 283479f95c82SChris Mason * error, and > 0 if there was no room in the right hand block. 283579f95c82SChris Mason * 283679f95c82SChris Mason * this will only push up to 1/2 the contents of the left node over 283779f95c82SChris Mason */ 28385f39d397SChris Mason static int balance_node_right(struct btrfs_trans_handle *trans, 28395f39d397SChris Mason struct extent_buffer *dst, 28405f39d397SChris Mason struct extent_buffer *src) 284179f95c82SChris Mason { 284255d32ed8SDavid Sterba struct btrfs_fs_info *fs_info = trans->fs_info; 284379f95c82SChris Mason int push_items = 0; 284479f95c82SChris Mason int max_push; 284579f95c82SChris Mason int src_nritems; 284679f95c82SChris Mason int dst_nritems; 284779f95c82SChris Mason int ret = 0; 284879f95c82SChris Mason 28497bb86316SChris Mason WARN_ON(btrfs_header_generation(src) != trans->transid); 28507bb86316SChris Mason WARN_ON(btrfs_header_generation(dst) != trans->transid); 28517bb86316SChris Mason 28525f39d397SChris Mason src_nritems = btrfs_header_nritems(src); 28535f39d397SChris Mason dst_nritems = btrfs_header_nritems(dst); 28540b246afaSJeff Mahoney push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; 2855d397712bSChris Mason if (push_items <= 0) 285679f95c82SChris Mason return 1; 2857bce4eae9SChris Mason 2858d397712bSChris Mason if (src_nritems < 4) 2859bce4eae9SChris Mason return 1; 286079f95c82SChris Mason 286179f95c82SChris Mason max_push = src_nritems / 2 + 1; 286279f95c82SChris Mason /* don't try to empty the node */ 2863d397712bSChris Mason if (max_push >= src_nritems) 286479f95c82SChris Mason return 1; 2865252c38f0SYan 286679f95c82SChris Mason if (max_push < push_items) 286779f95c82SChris Mason push_items = max_push; 286879f95c82SChris Mason 2869d16c702fSQu Wenruo /* dst is the right eb, src is the middle eb */ 2870d16c702fSQu Wenruo if (check_sibling_keys(src, dst)) { 2871d16c702fSQu Wenruo ret = -EUCLEAN; 2872d16c702fSQu Wenruo btrfs_abort_transaction(trans, ret); 2873d16c702fSQu Wenruo return ret; 2874d16c702fSQu Wenruo } 28755cead542SBoris Burkov 28765cead542SBoris Burkov /* 28775cead542SBoris Burkov * btrfs_tree_mod_log_eb_copy handles logging the move, so we don't 28785cead542SBoris Burkov * need to do an explicit tree mod log operation for it. 28795cead542SBoris Burkov */ 2880e23efd8eSJosef Bacik memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(dst, push_items), 2881e23efd8eSJosef Bacik btrfs_node_key_ptr_offset(dst, 0), 28825f39d397SChris Mason (dst_nritems) * 28835f39d397SChris Mason sizeof(struct btrfs_key_ptr)); 2884d6025579SChris Mason 2885f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_eb_copy(dst, src, 0, src_nritems - push_items, 2886ed874f0dSDavid Sterba push_items); 28875de865eeSFilipe David Borba Manana if (ret) { 288866642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 28895de865eeSFilipe David Borba Manana return ret; 28905de865eeSFilipe David Borba Manana } 28915f39d397SChris Mason copy_extent_buffer(dst, src, 2892e23efd8eSJosef Bacik btrfs_node_key_ptr_offset(dst, 0), 2893e23efd8eSJosef Bacik btrfs_node_key_ptr_offset(src, src_nritems - push_items), 2894123abc88SChris Mason push_items * sizeof(struct btrfs_key_ptr)); 289579f95c82SChris Mason 28965f39d397SChris Mason btrfs_set_header_nritems(src, src_nritems - push_items); 28975f39d397SChris Mason btrfs_set_header_nritems(dst, dst_nritems + push_items); 289879f95c82SChris Mason 28995f39d397SChris Mason btrfs_mark_buffer_dirty(src); 29005f39d397SChris Mason btrfs_mark_buffer_dirty(dst); 290131840ae1SZheng Yan 290279f95c82SChris Mason return ret; 290379f95c82SChris Mason } 290479f95c82SChris Mason 290579f95c82SChris Mason /* 290697571fd0SChris Mason * helper function to insert a new root level in the tree. 290797571fd0SChris Mason * A new node is allocated, and a single item is inserted to 290897571fd0SChris Mason * point to the existing root 2909aa5d6bedSChris Mason * 2910aa5d6bedSChris Mason * returns zero on success or < 0 on failure. 291197571fd0SChris Mason */ 2912d397712bSChris Mason static noinline int insert_new_root(struct btrfs_trans_handle *trans, 29135f39d397SChris Mason struct btrfs_root *root, 2914fdd99c72SLiu Bo struct btrfs_path *path, int level) 291574123bd7SChris Mason { 29160b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 29177bb86316SChris Mason u64 lower_gen; 29185f39d397SChris Mason struct extent_buffer *lower; 29195f39d397SChris Mason struct extent_buffer *c; 2920925baeddSChris Mason struct extent_buffer *old; 29215f39d397SChris Mason struct btrfs_disk_key lower_key; 2922d9d19a01SDavid Sterba int ret; 29235c680ed6SChris Mason 29245c680ed6SChris Mason BUG_ON(path->nodes[level]); 29255c680ed6SChris Mason BUG_ON(path->nodes[level-1] != root->node); 29265c680ed6SChris Mason 29277bb86316SChris Mason lower = path->nodes[level-1]; 29287bb86316SChris Mason if (level == 1) 29297bb86316SChris Mason btrfs_item_key(lower, &lower_key, 0); 29307bb86316SChris Mason else 29317bb86316SChris Mason btrfs_node_key(lower, &lower_key, 0); 29327bb86316SChris Mason 293379bd3712SFilipe Manana c = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, 293479bd3712SFilipe Manana &lower_key, level, root->node->start, 0, 2935cf6f34aaSJosef Bacik BTRFS_NESTING_NEW_ROOT); 29365f39d397SChris Mason if (IS_ERR(c)) 29375f39d397SChris Mason return PTR_ERR(c); 2938925baeddSChris Mason 29390b246afaSJeff Mahoney root_add_used(root, fs_info->nodesize); 2940f0486c68SYan, Zheng 29415f39d397SChris Mason btrfs_set_header_nritems(c, 1); 29425f39d397SChris Mason btrfs_set_node_key(c, &lower_key, 0); 2943db94535dSChris Mason btrfs_set_node_blockptr(c, 0, lower->start); 29447bb86316SChris Mason lower_gen = btrfs_header_generation(lower); 294531840ae1SZheng Yan WARN_ON(lower_gen != trans->transid); 29467bb86316SChris Mason 29477bb86316SChris Mason btrfs_set_node_ptr_generation(c, 0, lower_gen); 29485f39d397SChris Mason 29495f39d397SChris Mason btrfs_mark_buffer_dirty(c); 2950d5719762SChris Mason 2951925baeddSChris Mason old = root->node; 2952406808abSFilipe Manana ret = btrfs_tree_mod_log_insert_root(root->node, c, false); 2953d9d19a01SDavid Sterba BUG_ON(ret < 0); 2954240f62c8SChris Mason rcu_assign_pointer(root->node, c); 2955925baeddSChris Mason 2956925baeddSChris Mason /* the super has an extra ref to root->node */ 2957925baeddSChris Mason free_extent_buffer(old); 2958925baeddSChris Mason 29590b86a832SChris Mason add_root_to_dirty_list(root); 296067439dadSDavid Sterba atomic_inc(&c->refs); 29615f39d397SChris Mason path->nodes[level] = c; 2962ac5887c8SJosef Bacik path->locks[level] = BTRFS_WRITE_LOCK; 296374123bd7SChris Mason path->slots[level] = 0; 296474123bd7SChris Mason return 0; 296574123bd7SChris Mason } 29665c680ed6SChris Mason 29675c680ed6SChris Mason /* 29685c680ed6SChris Mason * worker function to insert a single pointer in a node. 29695c680ed6SChris Mason * the node should have enough room for the pointer already 297097571fd0SChris Mason * 29715c680ed6SChris Mason * slot and level indicate where you want the key to go, and 29725c680ed6SChris Mason * blocknr is the block the key points to. 29735c680ed6SChris Mason */ 2974143bede5SJeff Mahoney static void insert_ptr(struct btrfs_trans_handle *trans, 29756ad3cf6dSDavid Sterba struct btrfs_path *path, 2976143bede5SJeff Mahoney struct btrfs_disk_key *key, u64 bytenr, 2977c3e06965SJan Schmidt int slot, int level) 29785c680ed6SChris Mason { 29795f39d397SChris Mason struct extent_buffer *lower; 29805c680ed6SChris Mason int nritems; 2981f3ea38daSJan Schmidt int ret; 29825c680ed6SChris Mason 29835c680ed6SChris Mason BUG_ON(!path->nodes[level]); 298449d0c642SFilipe Manana btrfs_assert_tree_write_locked(path->nodes[level]); 29855f39d397SChris Mason lower = path->nodes[level]; 29865f39d397SChris Mason nritems = btrfs_header_nritems(lower); 2987c293498bSStoyan Gaydarov BUG_ON(slot > nritems); 29886ad3cf6dSDavid Sterba BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(trans->fs_info)); 298974123bd7SChris Mason if (slot != nritems) { 2990bf1d3425SDavid Sterba if (level) { 2991f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_move(lower, slot + 1, 2992f3a84ccdSFilipe Manana slot, nritems - slot); 2993bf1d3425SDavid Sterba BUG_ON(ret < 0); 2994bf1d3425SDavid Sterba } 29955f39d397SChris Mason memmove_extent_buffer(lower, 2996e23efd8eSJosef Bacik btrfs_node_key_ptr_offset(lower, slot + 1), 2997e23efd8eSJosef Bacik btrfs_node_key_ptr_offset(lower, slot), 2998123abc88SChris Mason (nritems - slot) * sizeof(struct btrfs_key_ptr)); 299974123bd7SChris Mason } 3000c3e06965SJan Schmidt if (level) { 3001f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_key(lower, slot, 300233cff222SFilipe Manana BTRFS_MOD_LOG_KEY_ADD); 3003f3ea38daSJan Schmidt BUG_ON(ret < 0); 3004f3ea38daSJan Schmidt } 30055f39d397SChris Mason btrfs_set_node_key(lower, key, slot); 3006db94535dSChris Mason btrfs_set_node_blockptr(lower, slot, bytenr); 300774493f7aSChris Mason WARN_ON(trans->transid == 0); 300874493f7aSChris Mason btrfs_set_node_ptr_generation(lower, slot, trans->transid); 30095f39d397SChris Mason btrfs_set_header_nritems(lower, nritems + 1); 30105f39d397SChris Mason btrfs_mark_buffer_dirty(lower); 301174123bd7SChris Mason } 301274123bd7SChris Mason 301397571fd0SChris Mason /* 301497571fd0SChris Mason * split the node at the specified level in path in two. 301597571fd0SChris Mason * The path is corrected to point to the appropriate node after the split 301697571fd0SChris Mason * 301797571fd0SChris Mason * Before splitting this tries to make some room in the node by pushing 301897571fd0SChris Mason * left and right, if either one works, it returns right away. 3019aa5d6bedSChris Mason * 3020aa5d6bedSChris Mason * returns 0 on success and < 0 on failure 302197571fd0SChris Mason */ 3022e02119d5SChris Mason static noinline int split_node(struct btrfs_trans_handle *trans, 3023e02119d5SChris Mason struct btrfs_root *root, 3024e02119d5SChris Mason struct btrfs_path *path, int level) 3025be0e5c09SChris Mason { 30260b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 30275f39d397SChris Mason struct extent_buffer *c; 30285f39d397SChris Mason struct extent_buffer *split; 30295f39d397SChris Mason struct btrfs_disk_key disk_key; 3030be0e5c09SChris Mason int mid; 30315c680ed6SChris Mason int ret; 30327518a238SChris Mason u32 c_nritems; 3033be0e5c09SChris Mason 30345f39d397SChris Mason c = path->nodes[level]; 30357bb86316SChris Mason WARN_ON(btrfs_header_generation(c) != trans->transid); 30365f39d397SChris Mason if (c == root->node) { 3037d9abbf1cSJan Schmidt /* 303890f8d62eSJan Schmidt * trying to split the root, lets make a new one 303990f8d62eSJan Schmidt * 3040fdd99c72SLiu Bo * tree mod log: We don't log_removal old root in 304190f8d62eSJan Schmidt * insert_new_root, because that root buffer will be kept as a 304290f8d62eSJan Schmidt * normal node. We are going to log removal of half of the 3043f3a84ccdSFilipe Manana * elements below with btrfs_tree_mod_log_eb_copy(). We're 3044f3a84ccdSFilipe Manana * holding a tree lock on the buffer, which is why we cannot 3045f3a84ccdSFilipe Manana * race with other tree_mod_log users. 3046d9abbf1cSJan Schmidt */ 3047fdd99c72SLiu Bo ret = insert_new_root(trans, root, path, level + 1); 30485c680ed6SChris Mason if (ret) 30495c680ed6SChris Mason return ret; 3050b3612421SChris Mason } else { 3051e66f709bSChris Mason ret = push_nodes_for_insert(trans, root, path, level); 30525f39d397SChris Mason c = path->nodes[level]; 30535f39d397SChris Mason if (!ret && btrfs_header_nritems(c) < 30540b246afaSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) 3055e66f709bSChris Mason return 0; 305654aa1f4dSChris Mason if (ret < 0) 305754aa1f4dSChris Mason return ret; 30585c680ed6SChris Mason } 3059e66f709bSChris Mason 30605f39d397SChris Mason c_nritems = btrfs_header_nritems(c); 30615d4f98a2SYan Zheng mid = (c_nritems + 1) / 2; 30625d4f98a2SYan Zheng btrfs_node_key(c, &disk_key, mid); 30637bb86316SChris Mason 306479bd3712SFilipe Manana split = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, 306579bd3712SFilipe Manana &disk_key, level, c->start, 0, 306679bd3712SFilipe Manana BTRFS_NESTING_SPLIT); 30675f39d397SChris Mason if (IS_ERR(split)) 30685f39d397SChris Mason return PTR_ERR(split); 306954aa1f4dSChris Mason 30700b246afaSJeff Mahoney root_add_used(root, fs_info->nodesize); 3071bc877d28SNikolay Borisov ASSERT(btrfs_header_level(c) == level); 30725f39d397SChris Mason 3073f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_eb_copy(split, c, 0, mid, c_nritems - mid); 30745de865eeSFilipe David Borba Manana if (ret) { 3075ede600e4SFilipe Manana btrfs_tree_unlock(split); 3076ede600e4SFilipe Manana free_extent_buffer(split); 307766642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 30785de865eeSFilipe David Borba Manana return ret; 30795de865eeSFilipe David Borba Manana } 30805f39d397SChris Mason copy_extent_buffer(split, c, 3081e23efd8eSJosef Bacik btrfs_node_key_ptr_offset(split, 0), 3082e23efd8eSJosef Bacik btrfs_node_key_ptr_offset(c, mid), 3083123abc88SChris Mason (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); 30845f39d397SChris Mason btrfs_set_header_nritems(split, c_nritems - mid); 30855f39d397SChris Mason btrfs_set_header_nritems(c, mid); 3086aa5d6bedSChris Mason 30875f39d397SChris Mason btrfs_mark_buffer_dirty(c); 30885f39d397SChris Mason btrfs_mark_buffer_dirty(split); 30895f39d397SChris Mason 30906ad3cf6dSDavid Sterba insert_ptr(trans, path, &disk_key, split->start, 3091c3e06965SJan Schmidt path->slots[level + 1] + 1, level + 1); 3092aa5d6bedSChris Mason 30935de08d7dSChris Mason if (path->slots[level] >= mid) { 30945c680ed6SChris Mason path->slots[level] -= mid; 3095925baeddSChris Mason btrfs_tree_unlock(c); 30965f39d397SChris Mason free_extent_buffer(c); 30975f39d397SChris Mason path->nodes[level] = split; 30985c680ed6SChris Mason path->slots[level + 1] += 1; 3099eb60ceacSChris Mason } else { 3100925baeddSChris Mason btrfs_tree_unlock(split); 31015f39d397SChris Mason free_extent_buffer(split); 3102be0e5c09SChris Mason } 3103d5286a92SNikolay Borisov return 0; 3104be0e5c09SChris Mason } 3105be0e5c09SChris Mason 310674123bd7SChris Mason /* 310774123bd7SChris Mason * how many bytes are required to store the items in a leaf. start 310874123bd7SChris Mason * and nr indicate which items in the leaf to check. This totals up the 310974123bd7SChris Mason * space used both by the item structs and the item data 311074123bd7SChris Mason */ 31116c75a589SQu Wenruo static int leaf_space_used(const struct extent_buffer *l, int start, int nr) 3112be0e5c09SChris Mason { 3113be0e5c09SChris Mason int data_len; 31145f39d397SChris Mason int nritems = btrfs_header_nritems(l); 3115d4dbff95SChris Mason int end = min(nritems, start + nr) - 1; 3116be0e5c09SChris Mason 3117be0e5c09SChris Mason if (!nr) 3118be0e5c09SChris Mason return 0; 31193212fa14SJosef Bacik data_len = btrfs_item_offset(l, start) + btrfs_item_size(l, start); 31203212fa14SJosef Bacik data_len = data_len - btrfs_item_offset(l, end); 31210783fcfcSChris Mason data_len += sizeof(struct btrfs_item) * nr; 3122d4dbff95SChris Mason WARN_ON(data_len < 0); 3123be0e5c09SChris Mason return data_len; 3124be0e5c09SChris Mason } 3125be0e5c09SChris Mason 312674123bd7SChris Mason /* 3127d4dbff95SChris Mason * The space between the end of the leaf items and 3128d4dbff95SChris Mason * the start of the leaf data. IOW, how much room 3129d4dbff95SChris Mason * the leaf has left for both items and data 3130d4dbff95SChris Mason */ 31316c75a589SQu Wenruo int btrfs_leaf_free_space(const struct extent_buffer *leaf) 3132d4dbff95SChris Mason { 3133e902baacSDavid Sterba struct btrfs_fs_info *fs_info = leaf->fs_info; 31345f39d397SChris Mason int nritems = btrfs_header_nritems(leaf); 31355f39d397SChris Mason int ret; 31360b246afaSJeff Mahoney 31370b246afaSJeff Mahoney ret = BTRFS_LEAF_DATA_SIZE(fs_info) - leaf_space_used(leaf, 0, nritems); 31385f39d397SChris Mason if (ret < 0) { 31390b246afaSJeff Mahoney btrfs_crit(fs_info, 3140efe120a0SFrank Holton "leaf free space ret %d, leaf data size %lu, used %d nritems %d", 3141da17066cSJeff Mahoney ret, 31420b246afaSJeff Mahoney (unsigned long) BTRFS_LEAF_DATA_SIZE(fs_info), 31435f39d397SChris Mason leaf_space_used(leaf, 0, nritems), nritems); 31445f39d397SChris Mason } 31455f39d397SChris Mason return ret; 3146d4dbff95SChris Mason } 3147d4dbff95SChris Mason 314899d8f83cSChris Mason /* 314999d8f83cSChris Mason * min slot controls the lowest index we're willing to push to the 315099d8f83cSChris Mason * right. We'll push up to and including min_slot, but no lower 315199d8f83cSChris Mason */ 3152ed25dab3SJosef Bacik static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, 3153ed25dab3SJosef Bacik struct btrfs_path *path, 315444871b1bSChris Mason int data_size, int empty, 315544871b1bSChris Mason struct extent_buffer *right, 315699d8f83cSChris Mason int free_space, u32 left_nritems, 315799d8f83cSChris Mason u32 min_slot) 315800ec4c51SChris Mason { 3159f72f0010SDavid Sterba struct btrfs_fs_info *fs_info = right->fs_info; 31605f39d397SChris Mason struct extent_buffer *left = path->nodes[0]; 316144871b1bSChris Mason struct extent_buffer *upper = path->nodes[1]; 3162cfed81a0SChris Mason struct btrfs_map_token token; 31635f39d397SChris Mason struct btrfs_disk_key disk_key; 316400ec4c51SChris Mason int slot; 316534a38218SChris Mason u32 i; 316600ec4c51SChris Mason int push_space = 0; 316700ec4c51SChris Mason int push_items = 0; 316834a38218SChris Mason u32 nr; 31697518a238SChris Mason u32 right_nritems; 31705f39d397SChris Mason u32 data_end; 3171db94535dSChris Mason u32 this_item_size; 317200ec4c51SChris Mason 317334a38218SChris Mason if (empty) 317434a38218SChris Mason nr = 0; 317534a38218SChris Mason else 317699d8f83cSChris Mason nr = max_t(u32, 1, min_slot); 317734a38218SChris Mason 317831840ae1SZheng Yan if (path->slots[0] >= left_nritems) 317987b29b20SYan Zheng push_space += data_size; 318031840ae1SZheng Yan 318144871b1bSChris Mason slot = path->slots[1]; 318234a38218SChris Mason i = left_nritems - 1; 318334a38218SChris Mason while (i >= nr) { 318431840ae1SZheng Yan if (!empty && push_items > 0) { 318531840ae1SZheng Yan if (path->slots[0] > i) 318631840ae1SZheng Yan break; 318731840ae1SZheng Yan if (path->slots[0] == i) { 3188e902baacSDavid Sterba int space = btrfs_leaf_free_space(left); 3189e902baacSDavid Sterba 319031840ae1SZheng Yan if (space + push_space * 2 > free_space) 319131840ae1SZheng Yan break; 319231840ae1SZheng Yan } 319331840ae1SZheng Yan } 319431840ae1SZheng Yan 319500ec4c51SChris Mason if (path->slots[0] == i) 319687b29b20SYan Zheng push_space += data_size; 3197db94535dSChris Mason 31983212fa14SJosef Bacik this_item_size = btrfs_item_size(left, i); 319974794207SJosef Bacik if (this_item_size + sizeof(struct btrfs_item) + 320074794207SJosef Bacik push_space > free_space) 320100ec4c51SChris Mason break; 320231840ae1SZheng Yan 320300ec4c51SChris Mason push_items++; 320474794207SJosef Bacik push_space += this_item_size + sizeof(struct btrfs_item); 320534a38218SChris Mason if (i == 0) 320634a38218SChris Mason break; 320734a38218SChris Mason i--; 3208db94535dSChris Mason } 32095f39d397SChris Mason 3210925baeddSChris Mason if (push_items == 0) 3211925baeddSChris Mason goto out_unlock; 32125f39d397SChris Mason 32136c1500f2SJulia Lawall WARN_ON(!empty && push_items == left_nritems); 32145f39d397SChris Mason 321500ec4c51SChris Mason /* push left to right */ 32165f39d397SChris Mason right_nritems = btrfs_header_nritems(right); 321734a38218SChris Mason 3218dc2e724eSJosef Bacik push_space = btrfs_item_data_end(left, left_nritems - push_items); 32198f881e8cSDavid Sterba push_space -= leaf_data_end(left); 32205f39d397SChris Mason 322100ec4c51SChris Mason /* make room in the right data area */ 32228f881e8cSDavid Sterba data_end = leaf_data_end(right); 3223637e3b48SJosef Bacik memmove_leaf_data(right, data_end - push_space, data_end, 32240b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info) - data_end); 32255f39d397SChris Mason 322600ec4c51SChris Mason /* copy from the left data area */ 3227637e3b48SJosef Bacik copy_leaf_data(right, left, BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, 3228637e3b48SJosef Bacik leaf_data_end(left), push_space); 32295f39d397SChris Mason 3230637e3b48SJosef Bacik memmove_leaf_items(right, push_items, 0, right_nritems); 32315f39d397SChris Mason 323200ec4c51SChris Mason /* copy the items from left to right */ 3233637e3b48SJosef Bacik copy_leaf_items(right, left, 0, left_nritems - push_items, push_items); 323400ec4c51SChris Mason 323500ec4c51SChris Mason /* update the item pointers */ 3236c82f823cSDavid Sterba btrfs_init_map_token(&token, right); 32377518a238SChris Mason right_nritems += push_items; 32385f39d397SChris Mason btrfs_set_header_nritems(right, right_nritems); 32390b246afaSJeff Mahoney push_space = BTRFS_LEAF_DATA_SIZE(fs_info); 32407518a238SChris Mason for (i = 0; i < right_nritems; i++) { 32413212fa14SJosef Bacik push_space -= btrfs_token_item_size(&token, i); 32423212fa14SJosef Bacik btrfs_set_token_item_offset(&token, i, push_space); 3243db94535dSChris Mason } 3244db94535dSChris Mason 32457518a238SChris Mason left_nritems -= push_items; 32465f39d397SChris Mason btrfs_set_header_nritems(left, left_nritems); 324700ec4c51SChris Mason 324834a38218SChris Mason if (left_nritems) 32495f39d397SChris Mason btrfs_mark_buffer_dirty(left); 3250f0486c68SYan, Zheng else 3251190a8339SJosef Bacik btrfs_clear_buffer_dirty(trans, left); 3252f0486c68SYan, Zheng 32535f39d397SChris Mason btrfs_mark_buffer_dirty(right); 3254a429e513SChris Mason 32555f39d397SChris Mason btrfs_item_key(right, &disk_key, 0); 32565f39d397SChris Mason btrfs_set_node_key(upper, &disk_key, slot + 1); 3257d6025579SChris Mason btrfs_mark_buffer_dirty(upper); 325802217ed2SChris Mason 325900ec4c51SChris Mason /* then fixup the leaf pointer in the path */ 32607518a238SChris Mason if (path->slots[0] >= left_nritems) { 32617518a238SChris Mason path->slots[0] -= left_nritems; 3262925baeddSChris Mason if (btrfs_header_nritems(path->nodes[0]) == 0) 3263190a8339SJosef Bacik btrfs_clear_buffer_dirty(trans, path->nodes[0]); 3264925baeddSChris Mason btrfs_tree_unlock(path->nodes[0]); 32655f39d397SChris Mason free_extent_buffer(path->nodes[0]); 32665f39d397SChris Mason path->nodes[0] = right; 326700ec4c51SChris Mason path->slots[1] += 1; 326800ec4c51SChris Mason } else { 3269925baeddSChris Mason btrfs_tree_unlock(right); 32705f39d397SChris Mason free_extent_buffer(right); 327100ec4c51SChris Mason } 327200ec4c51SChris Mason return 0; 3273925baeddSChris Mason 3274925baeddSChris Mason out_unlock: 3275925baeddSChris Mason btrfs_tree_unlock(right); 3276925baeddSChris Mason free_extent_buffer(right); 3277925baeddSChris Mason return 1; 327800ec4c51SChris Mason } 3279925baeddSChris Mason 328000ec4c51SChris Mason /* 328144871b1bSChris Mason * push some data in the path leaf to the right, trying to free up at 328274123bd7SChris Mason * least data_size bytes. returns zero if the push worked, nonzero otherwise 328344871b1bSChris Mason * 328444871b1bSChris Mason * returns 1 if the push failed because the other node didn't have enough 328544871b1bSChris Mason * room, 0 if everything worked out and < 0 if there were major errors. 328699d8f83cSChris Mason * 328799d8f83cSChris Mason * this will push starting from min_slot to the end of the leaf. It won't 328899d8f83cSChris Mason * push any slot lower than min_slot 328974123bd7SChris Mason */ 329044871b1bSChris Mason static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root 329199d8f83cSChris Mason *root, struct btrfs_path *path, 329299d8f83cSChris Mason int min_data_size, int data_size, 329399d8f83cSChris Mason int empty, u32 min_slot) 3294be0e5c09SChris Mason { 329544871b1bSChris Mason struct extent_buffer *left = path->nodes[0]; 329644871b1bSChris Mason struct extent_buffer *right; 329744871b1bSChris Mason struct extent_buffer *upper; 329844871b1bSChris Mason int slot; 329944871b1bSChris Mason int free_space; 330044871b1bSChris Mason u32 left_nritems; 330144871b1bSChris Mason int ret; 330244871b1bSChris Mason 330344871b1bSChris Mason if (!path->nodes[1]) 330444871b1bSChris Mason return 1; 330544871b1bSChris Mason 330644871b1bSChris Mason slot = path->slots[1]; 330744871b1bSChris Mason upper = path->nodes[1]; 330844871b1bSChris Mason if (slot >= btrfs_header_nritems(upper) - 1) 330944871b1bSChris Mason return 1; 331044871b1bSChris Mason 331149d0c642SFilipe Manana btrfs_assert_tree_write_locked(path->nodes[1]); 331244871b1bSChris Mason 33134b231ae4SDavid Sterba right = btrfs_read_node_slot(upper, slot + 1); 3314fb770ae4SLiu Bo if (IS_ERR(right)) 33159cf14029SJosef Bacik return PTR_ERR(right); 331691ca338dSTsutomu Itoh 3317bf77467aSJosef Bacik __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); 331844871b1bSChris Mason 3319e902baacSDavid Sterba free_space = btrfs_leaf_free_space(right); 332044871b1bSChris Mason if (free_space < data_size) 332144871b1bSChris Mason goto out_unlock; 332244871b1bSChris Mason 332344871b1bSChris Mason ret = btrfs_cow_block(trans, root, right, upper, 3324bf59a5a2SJosef Bacik slot + 1, &right, BTRFS_NESTING_RIGHT_COW); 332544871b1bSChris Mason if (ret) 332644871b1bSChris Mason goto out_unlock; 332744871b1bSChris Mason 332844871b1bSChris Mason left_nritems = btrfs_header_nritems(left); 332944871b1bSChris Mason if (left_nritems == 0) 333044871b1bSChris Mason goto out_unlock; 333144871b1bSChris Mason 3332d16c702fSQu Wenruo if (check_sibling_keys(left, right)) { 3333d16c702fSQu Wenruo ret = -EUCLEAN; 33349ae5afd0SFilipe Manana btrfs_abort_transaction(trans, ret); 3335d16c702fSQu Wenruo btrfs_tree_unlock(right); 3336d16c702fSQu Wenruo free_extent_buffer(right); 3337d16c702fSQu Wenruo return ret; 3338d16c702fSQu Wenruo } 33392ef1fed2SFilipe David Borba Manana if (path->slots[0] == left_nritems && !empty) { 33402ef1fed2SFilipe David Borba Manana /* Key greater than all keys in the leaf, right neighbor has 33412ef1fed2SFilipe David Borba Manana * enough room for it and we're not emptying our leaf to delete 33422ef1fed2SFilipe David Borba Manana * it, therefore use right neighbor to insert the new item and 334352042d8eSAndrea Gelmini * no need to touch/dirty our left leaf. */ 33442ef1fed2SFilipe David Borba Manana btrfs_tree_unlock(left); 33452ef1fed2SFilipe David Borba Manana free_extent_buffer(left); 33462ef1fed2SFilipe David Borba Manana path->nodes[0] = right; 33472ef1fed2SFilipe David Borba Manana path->slots[0] = 0; 33482ef1fed2SFilipe David Borba Manana path->slots[1]++; 33492ef1fed2SFilipe David Borba Manana return 0; 33502ef1fed2SFilipe David Borba Manana } 33512ef1fed2SFilipe David Borba Manana 3352ed25dab3SJosef Bacik return __push_leaf_right(trans, path, min_data_size, empty, right, 3353ed25dab3SJosef Bacik free_space, left_nritems, min_slot); 335444871b1bSChris Mason out_unlock: 335544871b1bSChris Mason btrfs_tree_unlock(right); 335644871b1bSChris Mason free_extent_buffer(right); 335744871b1bSChris Mason return 1; 335844871b1bSChris Mason } 335944871b1bSChris Mason 336044871b1bSChris Mason /* 336144871b1bSChris Mason * push some data in the path leaf to the left, trying to free up at 336244871b1bSChris Mason * least data_size bytes. returns zero if the push worked, nonzero otherwise 336399d8f83cSChris Mason * 336499d8f83cSChris Mason * max_slot can put a limit on how far into the leaf we'll push items. The 336599d8f83cSChris Mason * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the 336699d8f83cSChris Mason * items 336744871b1bSChris Mason */ 3368ed25dab3SJosef Bacik static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, 3369ed25dab3SJosef Bacik struct btrfs_path *path, int data_size, 337044871b1bSChris Mason int empty, struct extent_buffer *left, 337199d8f83cSChris Mason int free_space, u32 right_nritems, 337299d8f83cSChris Mason u32 max_slot) 337344871b1bSChris Mason { 33748087c193SDavid Sterba struct btrfs_fs_info *fs_info = left->fs_info; 33755f39d397SChris Mason struct btrfs_disk_key disk_key; 33765f39d397SChris Mason struct extent_buffer *right = path->nodes[0]; 3377be0e5c09SChris Mason int i; 3378be0e5c09SChris Mason int push_space = 0; 3379be0e5c09SChris Mason int push_items = 0; 33807518a238SChris Mason u32 old_left_nritems; 338134a38218SChris Mason u32 nr; 3382aa5d6bedSChris Mason int ret = 0; 3383db94535dSChris Mason u32 this_item_size; 3384db94535dSChris Mason u32 old_left_item_size; 3385cfed81a0SChris Mason struct btrfs_map_token token; 3386cfed81a0SChris Mason 338734a38218SChris Mason if (empty) 338899d8f83cSChris Mason nr = min(right_nritems, max_slot); 338934a38218SChris Mason else 339099d8f83cSChris Mason nr = min(right_nritems - 1, max_slot); 339134a38218SChris Mason 339234a38218SChris Mason for (i = 0; i < nr; i++) { 339331840ae1SZheng Yan if (!empty && push_items > 0) { 339431840ae1SZheng Yan if (path->slots[0] < i) 339531840ae1SZheng Yan break; 339631840ae1SZheng Yan if (path->slots[0] == i) { 3397e902baacSDavid Sterba int space = btrfs_leaf_free_space(right); 3398e902baacSDavid Sterba 339931840ae1SZheng Yan if (space + push_space * 2 > free_space) 340031840ae1SZheng Yan break; 340131840ae1SZheng Yan } 340231840ae1SZheng Yan } 340331840ae1SZheng Yan 3404be0e5c09SChris Mason if (path->slots[0] == i) 340587b29b20SYan Zheng push_space += data_size; 3406db94535dSChris Mason 34073212fa14SJosef Bacik this_item_size = btrfs_item_size(right, i); 340874794207SJosef Bacik if (this_item_size + sizeof(struct btrfs_item) + push_space > 340974794207SJosef Bacik free_space) 3410be0e5c09SChris Mason break; 3411db94535dSChris Mason 3412be0e5c09SChris Mason push_items++; 341374794207SJosef Bacik push_space += this_item_size + sizeof(struct btrfs_item); 3414be0e5c09SChris Mason } 3415db94535dSChris Mason 3416be0e5c09SChris Mason if (push_items == 0) { 3417925baeddSChris Mason ret = 1; 3418925baeddSChris Mason goto out; 3419be0e5c09SChris Mason } 3420fae7f21cSDulshani Gunawardhana WARN_ON(!empty && push_items == btrfs_header_nritems(right)); 34215f39d397SChris Mason 3422be0e5c09SChris Mason /* push data from right to left */ 3423637e3b48SJosef Bacik copy_leaf_items(left, right, btrfs_header_nritems(left), 0, push_items); 34245f39d397SChris Mason 34250b246afaSJeff Mahoney push_space = BTRFS_LEAF_DATA_SIZE(fs_info) - 34263212fa14SJosef Bacik btrfs_item_offset(right, push_items - 1); 34275f39d397SChris Mason 3428637e3b48SJosef Bacik copy_leaf_data(left, right, leaf_data_end(left) - push_space, 3429637e3b48SJosef Bacik btrfs_item_offset(right, push_items - 1), push_space); 34305f39d397SChris Mason old_left_nritems = btrfs_header_nritems(left); 343187b29b20SYan Zheng BUG_ON(old_left_nritems <= 0); 3432eb60ceacSChris Mason 3433c82f823cSDavid Sterba btrfs_init_map_token(&token, left); 34343212fa14SJosef Bacik old_left_item_size = btrfs_item_offset(left, old_left_nritems - 1); 3435be0e5c09SChris Mason for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { 34365f39d397SChris Mason u32 ioff; 3437db94535dSChris Mason 34383212fa14SJosef Bacik ioff = btrfs_token_item_offset(&token, i); 34393212fa14SJosef Bacik btrfs_set_token_item_offset(&token, i, 3440cc4c13d5SDavid Sterba ioff - (BTRFS_LEAF_DATA_SIZE(fs_info) - old_left_item_size)); 3441be0e5c09SChris Mason } 34425f39d397SChris Mason btrfs_set_header_nritems(left, old_left_nritems + push_items); 3443be0e5c09SChris Mason 3444be0e5c09SChris Mason /* fixup right node */ 344531b1a2bdSJulia Lawall if (push_items > right_nritems) 344631b1a2bdSJulia Lawall WARN(1, KERN_CRIT "push items %d nr %u\n", push_items, 3447d397712bSChris Mason right_nritems); 344834a38218SChris Mason 344934a38218SChris Mason if (push_items < right_nritems) { 34503212fa14SJosef Bacik push_space = btrfs_item_offset(right, push_items - 1) - 34518f881e8cSDavid Sterba leaf_data_end(right); 3452637e3b48SJosef Bacik memmove_leaf_data(right, 34530b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, 34548f881e8cSDavid Sterba leaf_data_end(right), push_space); 34555f39d397SChris Mason 3456637e3b48SJosef Bacik memmove_leaf_items(right, 0, push_items, 3457637e3b48SJosef Bacik btrfs_header_nritems(right) - push_items); 345834a38218SChris Mason } 3459c82f823cSDavid Sterba 3460c82f823cSDavid Sterba btrfs_init_map_token(&token, right); 3461eef1c494SYan right_nritems -= push_items; 3462eef1c494SYan btrfs_set_header_nritems(right, right_nritems); 34630b246afaSJeff Mahoney push_space = BTRFS_LEAF_DATA_SIZE(fs_info); 34645f39d397SChris Mason for (i = 0; i < right_nritems; i++) { 34653212fa14SJosef Bacik push_space = push_space - btrfs_token_item_size(&token, i); 34663212fa14SJosef Bacik btrfs_set_token_item_offset(&token, i, push_space); 3467db94535dSChris Mason } 3468eb60ceacSChris Mason 34695f39d397SChris Mason btrfs_mark_buffer_dirty(left); 347034a38218SChris Mason if (right_nritems) 34715f39d397SChris Mason btrfs_mark_buffer_dirty(right); 3472f0486c68SYan, Zheng else 3473190a8339SJosef Bacik btrfs_clear_buffer_dirty(trans, right); 3474098f59c2SChris Mason 34755f39d397SChris Mason btrfs_item_key(right, &disk_key, 0); 3476b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 3477be0e5c09SChris Mason 3478be0e5c09SChris Mason /* then fixup the leaf pointer in the path */ 3479be0e5c09SChris Mason if (path->slots[0] < push_items) { 3480be0e5c09SChris Mason path->slots[0] += old_left_nritems; 3481925baeddSChris Mason btrfs_tree_unlock(path->nodes[0]); 34825f39d397SChris Mason free_extent_buffer(path->nodes[0]); 34835f39d397SChris Mason path->nodes[0] = left; 3484be0e5c09SChris Mason path->slots[1] -= 1; 3485be0e5c09SChris Mason } else { 3486925baeddSChris Mason btrfs_tree_unlock(left); 34875f39d397SChris Mason free_extent_buffer(left); 3488be0e5c09SChris Mason path->slots[0] -= push_items; 3489be0e5c09SChris Mason } 3490eb60ceacSChris Mason BUG_ON(path->slots[0] < 0); 3491aa5d6bedSChris Mason return ret; 3492925baeddSChris Mason out: 3493925baeddSChris Mason btrfs_tree_unlock(left); 3494925baeddSChris Mason free_extent_buffer(left); 3495925baeddSChris Mason return ret; 3496be0e5c09SChris Mason } 3497be0e5c09SChris Mason 349874123bd7SChris Mason /* 349944871b1bSChris Mason * push some data in the path leaf to the left, trying to free up at 350044871b1bSChris Mason * least data_size bytes. returns zero if the push worked, nonzero otherwise 350199d8f83cSChris Mason * 350299d8f83cSChris Mason * max_slot can put a limit on how far into the leaf we'll push items. The 350399d8f83cSChris Mason * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the 350499d8f83cSChris Mason * items 350544871b1bSChris Mason */ 350644871b1bSChris Mason static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root 350799d8f83cSChris Mason *root, struct btrfs_path *path, int min_data_size, 350899d8f83cSChris Mason int data_size, int empty, u32 max_slot) 350944871b1bSChris Mason { 351044871b1bSChris Mason struct extent_buffer *right = path->nodes[0]; 351144871b1bSChris Mason struct extent_buffer *left; 351244871b1bSChris Mason int slot; 351344871b1bSChris Mason int free_space; 351444871b1bSChris Mason u32 right_nritems; 351544871b1bSChris Mason int ret = 0; 351644871b1bSChris Mason 351744871b1bSChris Mason slot = path->slots[1]; 351844871b1bSChris Mason if (slot == 0) 351944871b1bSChris Mason return 1; 352044871b1bSChris Mason if (!path->nodes[1]) 352144871b1bSChris Mason return 1; 352244871b1bSChris Mason 352344871b1bSChris Mason right_nritems = btrfs_header_nritems(right); 352444871b1bSChris Mason if (right_nritems == 0) 352544871b1bSChris Mason return 1; 352644871b1bSChris Mason 352749d0c642SFilipe Manana btrfs_assert_tree_write_locked(path->nodes[1]); 352844871b1bSChris Mason 35294b231ae4SDavid Sterba left = btrfs_read_node_slot(path->nodes[1], slot - 1); 3530fb770ae4SLiu Bo if (IS_ERR(left)) 35319cf14029SJosef Bacik return PTR_ERR(left); 353291ca338dSTsutomu Itoh 3533bf77467aSJosef Bacik __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); 353444871b1bSChris Mason 3535e902baacSDavid Sterba free_space = btrfs_leaf_free_space(left); 353644871b1bSChris Mason if (free_space < data_size) { 353744871b1bSChris Mason ret = 1; 353844871b1bSChris Mason goto out; 353944871b1bSChris Mason } 354044871b1bSChris Mason 354144871b1bSChris Mason ret = btrfs_cow_block(trans, root, left, 35429631e4ccSJosef Bacik path->nodes[1], slot - 1, &left, 3543bf59a5a2SJosef Bacik BTRFS_NESTING_LEFT_COW); 354444871b1bSChris Mason if (ret) { 354544871b1bSChris Mason /* we hit -ENOSPC, but it isn't fatal here */ 354679787eaaSJeff Mahoney if (ret == -ENOSPC) 354744871b1bSChris Mason ret = 1; 354844871b1bSChris Mason goto out; 354944871b1bSChris Mason } 355044871b1bSChris Mason 3551d16c702fSQu Wenruo if (check_sibling_keys(left, right)) { 3552d16c702fSQu Wenruo ret = -EUCLEAN; 35539ae5afd0SFilipe Manana btrfs_abort_transaction(trans, ret); 3554d16c702fSQu Wenruo goto out; 3555d16c702fSQu Wenruo } 3556ed25dab3SJosef Bacik return __push_leaf_left(trans, path, min_data_size, empty, left, 3557ed25dab3SJosef Bacik free_space, right_nritems, max_slot); 355844871b1bSChris Mason out: 355944871b1bSChris Mason btrfs_tree_unlock(left); 356044871b1bSChris Mason free_extent_buffer(left); 356144871b1bSChris Mason return ret; 356244871b1bSChris Mason } 356344871b1bSChris Mason 356444871b1bSChris Mason /* 356574123bd7SChris Mason * split the path's leaf in two, making sure there is at least data_size 356674123bd7SChris Mason * available for the resulting leaf level of the path. 356774123bd7SChris Mason */ 3568143bede5SJeff Mahoney static noinline void copy_for_split(struct btrfs_trans_handle *trans, 356944871b1bSChris Mason struct btrfs_path *path, 357044871b1bSChris Mason struct extent_buffer *l, 357144871b1bSChris Mason struct extent_buffer *right, 357244871b1bSChris Mason int slot, int mid, int nritems) 3573be0e5c09SChris Mason { 357494f94ad9SDavid Sterba struct btrfs_fs_info *fs_info = trans->fs_info; 3575be0e5c09SChris Mason int data_copy_size; 3576be0e5c09SChris Mason int rt_data_off; 3577be0e5c09SChris Mason int i; 3578d4dbff95SChris Mason struct btrfs_disk_key disk_key; 3579cfed81a0SChris Mason struct btrfs_map_token token; 3580cfed81a0SChris Mason 35815f39d397SChris Mason nritems = nritems - mid; 35825f39d397SChris Mason btrfs_set_header_nritems(right, nritems); 3583dc2e724eSJosef Bacik data_copy_size = btrfs_item_data_end(l, mid) - leaf_data_end(l); 35845f39d397SChris Mason 3585637e3b48SJosef Bacik copy_leaf_items(right, l, 0, mid, nritems); 35865f39d397SChris Mason 3587637e3b48SJosef Bacik copy_leaf_data(right, l, BTRFS_LEAF_DATA_SIZE(fs_info) - data_copy_size, 35888f881e8cSDavid Sterba leaf_data_end(l), data_copy_size); 358974123bd7SChris Mason 3590dc2e724eSJosef Bacik rt_data_off = BTRFS_LEAF_DATA_SIZE(fs_info) - btrfs_item_data_end(l, mid); 35915f39d397SChris Mason 3592c82f823cSDavid Sterba btrfs_init_map_token(&token, right); 35935f39d397SChris Mason for (i = 0; i < nritems; i++) { 3594db94535dSChris Mason u32 ioff; 3595db94535dSChris Mason 35963212fa14SJosef Bacik ioff = btrfs_token_item_offset(&token, i); 35973212fa14SJosef Bacik btrfs_set_token_item_offset(&token, i, ioff + rt_data_off); 35980783fcfcSChris Mason } 359974123bd7SChris Mason 36005f39d397SChris Mason btrfs_set_header_nritems(l, mid); 36015f39d397SChris Mason btrfs_item_key(right, &disk_key, 0); 36026ad3cf6dSDavid Sterba insert_ptr(trans, path, &disk_key, right->start, path->slots[1] + 1, 1); 36035f39d397SChris Mason 36045f39d397SChris Mason btrfs_mark_buffer_dirty(right); 36055f39d397SChris Mason btrfs_mark_buffer_dirty(l); 3606eb60ceacSChris Mason BUG_ON(path->slots[0] != slot); 36075f39d397SChris Mason 3608be0e5c09SChris Mason if (mid <= slot) { 3609925baeddSChris Mason btrfs_tree_unlock(path->nodes[0]); 36105f39d397SChris Mason free_extent_buffer(path->nodes[0]); 36115f39d397SChris Mason path->nodes[0] = right; 3612be0e5c09SChris Mason path->slots[0] -= mid; 3613be0e5c09SChris Mason path->slots[1] += 1; 3614925baeddSChris Mason } else { 3615925baeddSChris Mason btrfs_tree_unlock(right); 36165f39d397SChris Mason free_extent_buffer(right); 3617925baeddSChris Mason } 36185f39d397SChris Mason 3619eb60ceacSChris Mason BUG_ON(path->slots[0] < 0); 362044871b1bSChris Mason } 362144871b1bSChris Mason 362244871b1bSChris Mason /* 362399d8f83cSChris Mason * double splits happen when we need to insert a big item in the middle 362499d8f83cSChris Mason * of a leaf. A double split can leave us with 3 mostly empty leaves: 362599d8f83cSChris Mason * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] 362699d8f83cSChris Mason * A B C 362799d8f83cSChris Mason * 362899d8f83cSChris Mason * We avoid this by trying to push the items on either side of our target 362999d8f83cSChris Mason * into the adjacent leaves. If all goes well we can avoid the double split 363099d8f83cSChris Mason * completely. 363199d8f83cSChris Mason */ 363299d8f83cSChris Mason static noinline int push_for_double_split(struct btrfs_trans_handle *trans, 363399d8f83cSChris Mason struct btrfs_root *root, 363499d8f83cSChris Mason struct btrfs_path *path, 363599d8f83cSChris Mason int data_size) 363699d8f83cSChris Mason { 363799d8f83cSChris Mason int ret; 363899d8f83cSChris Mason int progress = 0; 363999d8f83cSChris Mason int slot; 364099d8f83cSChris Mason u32 nritems; 36415a4267caSFilipe David Borba Manana int space_needed = data_size; 364299d8f83cSChris Mason 364399d8f83cSChris Mason slot = path->slots[0]; 36445a4267caSFilipe David Borba Manana if (slot < btrfs_header_nritems(path->nodes[0])) 3645e902baacSDavid Sterba space_needed -= btrfs_leaf_free_space(path->nodes[0]); 364699d8f83cSChris Mason 364799d8f83cSChris Mason /* 364899d8f83cSChris Mason * try to push all the items after our slot into the 364999d8f83cSChris Mason * right leaf 365099d8f83cSChris Mason */ 36515a4267caSFilipe David Borba Manana ret = push_leaf_right(trans, root, path, 1, space_needed, 0, slot); 365299d8f83cSChris Mason if (ret < 0) 365399d8f83cSChris Mason return ret; 365499d8f83cSChris Mason 365599d8f83cSChris Mason if (ret == 0) 365699d8f83cSChris Mason progress++; 365799d8f83cSChris Mason 365899d8f83cSChris Mason nritems = btrfs_header_nritems(path->nodes[0]); 365999d8f83cSChris Mason /* 366099d8f83cSChris Mason * our goal is to get our slot at the start or end of a leaf. If 366199d8f83cSChris Mason * we've done so we're done 366299d8f83cSChris Mason */ 366399d8f83cSChris Mason if (path->slots[0] == 0 || path->slots[0] == nritems) 366499d8f83cSChris Mason return 0; 366599d8f83cSChris Mason 3666e902baacSDavid Sterba if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) 366799d8f83cSChris Mason return 0; 366899d8f83cSChris Mason 366999d8f83cSChris Mason /* try to push all the items before our slot into the next leaf */ 367099d8f83cSChris Mason slot = path->slots[0]; 3671263d3995SFilipe Manana space_needed = data_size; 3672263d3995SFilipe Manana if (slot > 0) 3673e902baacSDavid Sterba space_needed -= btrfs_leaf_free_space(path->nodes[0]); 36745a4267caSFilipe David Borba Manana ret = push_leaf_left(trans, root, path, 1, space_needed, 0, slot); 367599d8f83cSChris Mason if (ret < 0) 367699d8f83cSChris Mason return ret; 367799d8f83cSChris Mason 367899d8f83cSChris Mason if (ret == 0) 367999d8f83cSChris Mason progress++; 368099d8f83cSChris Mason 368199d8f83cSChris Mason if (progress) 368299d8f83cSChris Mason return 0; 368399d8f83cSChris Mason return 1; 368499d8f83cSChris Mason } 368599d8f83cSChris Mason 368699d8f83cSChris Mason /* 368744871b1bSChris Mason * split the path's leaf in two, making sure there is at least data_size 368844871b1bSChris Mason * available for the resulting leaf level of the path. 368944871b1bSChris Mason * 369044871b1bSChris Mason * returns 0 if all went well and < 0 on failure. 369144871b1bSChris Mason */ 369244871b1bSChris Mason static noinline int split_leaf(struct btrfs_trans_handle *trans, 369344871b1bSChris Mason struct btrfs_root *root, 3694310712b2SOmar Sandoval const struct btrfs_key *ins_key, 369544871b1bSChris Mason struct btrfs_path *path, int data_size, 369644871b1bSChris Mason int extend) 369744871b1bSChris Mason { 36985d4f98a2SYan Zheng struct btrfs_disk_key disk_key; 369944871b1bSChris Mason struct extent_buffer *l; 370044871b1bSChris Mason u32 nritems; 370144871b1bSChris Mason int mid; 370244871b1bSChris Mason int slot; 370344871b1bSChris Mason struct extent_buffer *right; 3704b7a0365eSDaniel Dressler struct btrfs_fs_info *fs_info = root->fs_info; 370544871b1bSChris Mason int ret = 0; 370644871b1bSChris Mason int wret; 37075d4f98a2SYan Zheng int split; 370844871b1bSChris Mason int num_doubles = 0; 370999d8f83cSChris Mason int tried_avoid_double = 0; 371044871b1bSChris Mason 3711a5719521SYan, Zheng l = path->nodes[0]; 3712a5719521SYan, Zheng slot = path->slots[0]; 37133212fa14SJosef Bacik if (extend && data_size + btrfs_item_size(l, slot) + 37140b246afaSJeff Mahoney sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info)) 3715a5719521SYan, Zheng return -EOVERFLOW; 3716a5719521SYan, Zheng 371744871b1bSChris Mason /* first try to make some room by pushing left and right */ 371833157e05SLiu Bo if (data_size && path->nodes[1]) { 37195a4267caSFilipe David Borba Manana int space_needed = data_size; 37205a4267caSFilipe David Borba Manana 37215a4267caSFilipe David Borba Manana if (slot < btrfs_header_nritems(l)) 3722e902baacSDavid Sterba space_needed -= btrfs_leaf_free_space(l); 37235a4267caSFilipe David Borba Manana 37245a4267caSFilipe David Borba Manana wret = push_leaf_right(trans, root, path, space_needed, 37255a4267caSFilipe David Borba Manana space_needed, 0, 0); 372644871b1bSChris Mason if (wret < 0) 372744871b1bSChris Mason return wret; 372844871b1bSChris Mason if (wret) { 3729263d3995SFilipe Manana space_needed = data_size; 3730263d3995SFilipe Manana if (slot > 0) 3731e902baacSDavid Sterba space_needed -= btrfs_leaf_free_space(l); 37325a4267caSFilipe David Borba Manana wret = push_leaf_left(trans, root, path, space_needed, 37335a4267caSFilipe David Borba Manana space_needed, 0, (u32)-1); 373444871b1bSChris Mason if (wret < 0) 373544871b1bSChris Mason return wret; 373644871b1bSChris Mason } 373744871b1bSChris Mason l = path->nodes[0]; 373844871b1bSChris Mason 373944871b1bSChris Mason /* did the pushes work? */ 3740e902baacSDavid Sterba if (btrfs_leaf_free_space(l) >= data_size) 374144871b1bSChris Mason return 0; 374244871b1bSChris Mason } 374344871b1bSChris Mason 374444871b1bSChris Mason if (!path->nodes[1]) { 3745fdd99c72SLiu Bo ret = insert_new_root(trans, root, path, 1); 374644871b1bSChris Mason if (ret) 374744871b1bSChris Mason return ret; 374844871b1bSChris Mason } 374944871b1bSChris Mason again: 37505d4f98a2SYan Zheng split = 1; 375144871b1bSChris Mason l = path->nodes[0]; 375244871b1bSChris Mason slot = path->slots[0]; 375344871b1bSChris Mason nritems = btrfs_header_nritems(l); 375444871b1bSChris Mason mid = (nritems + 1) / 2; 375544871b1bSChris Mason 37565d4f98a2SYan Zheng if (mid <= slot) { 37575d4f98a2SYan Zheng if (nritems == 1 || 37585d4f98a2SYan Zheng leaf_space_used(l, mid, nritems - mid) + data_size > 37590b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info)) { 37605d4f98a2SYan Zheng if (slot >= nritems) { 37615d4f98a2SYan Zheng split = 0; 37625d4f98a2SYan Zheng } else { 37635d4f98a2SYan Zheng mid = slot; 37645d4f98a2SYan Zheng if (mid != nritems && 37655d4f98a2SYan Zheng leaf_space_used(l, mid, nritems - mid) + 37660b246afaSJeff Mahoney data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { 376799d8f83cSChris Mason if (data_size && !tried_avoid_double) 376899d8f83cSChris Mason goto push_for_double; 37695d4f98a2SYan Zheng split = 2; 37705d4f98a2SYan Zheng } 37715d4f98a2SYan Zheng } 37725d4f98a2SYan Zheng } 37735d4f98a2SYan Zheng } else { 37745d4f98a2SYan Zheng if (leaf_space_used(l, 0, mid) + data_size > 37750b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info)) { 37765d4f98a2SYan Zheng if (!extend && data_size && slot == 0) { 37775d4f98a2SYan Zheng split = 0; 37785d4f98a2SYan Zheng } else if ((extend || !data_size) && slot == 0) { 37795d4f98a2SYan Zheng mid = 1; 37805d4f98a2SYan Zheng } else { 37815d4f98a2SYan Zheng mid = slot; 37825d4f98a2SYan Zheng if (mid != nritems && 37835d4f98a2SYan Zheng leaf_space_used(l, mid, nritems - mid) + 37840b246afaSJeff Mahoney data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { 378599d8f83cSChris Mason if (data_size && !tried_avoid_double) 378699d8f83cSChris Mason goto push_for_double; 37875d4f98a2SYan Zheng split = 2; 37885d4f98a2SYan Zheng } 37895d4f98a2SYan Zheng } 37905d4f98a2SYan Zheng } 37915d4f98a2SYan Zheng } 37925d4f98a2SYan Zheng 37935d4f98a2SYan Zheng if (split == 0) 37945d4f98a2SYan Zheng btrfs_cpu_key_to_disk(&disk_key, ins_key); 37955d4f98a2SYan Zheng else 37965d4f98a2SYan Zheng btrfs_item_key(l, &disk_key, mid); 37975d4f98a2SYan Zheng 3798ca9d473aSJosef Bacik /* 3799ca9d473aSJosef Bacik * We have to about BTRFS_NESTING_NEW_ROOT here if we've done a double 3800ca9d473aSJosef Bacik * split, because we're only allowed to have MAX_LOCKDEP_SUBCLASSES 3801ca9d473aSJosef Bacik * subclasses, which is 8 at the time of this patch, and we've maxed it 3802ca9d473aSJosef Bacik * out. In the future we could add a 3803ca9d473aSJosef Bacik * BTRFS_NESTING_SPLIT_THE_SPLITTENING if we need to, but for now just 3804ca9d473aSJosef Bacik * use BTRFS_NESTING_NEW_ROOT. 3805ca9d473aSJosef Bacik */ 380679bd3712SFilipe Manana right = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, 380779bd3712SFilipe Manana &disk_key, 0, l->start, 0, 380879bd3712SFilipe Manana num_doubles ? BTRFS_NESTING_NEW_ROOT : 3809ca9d473aSJosef Bacik BTRFS_NESTING_SPLIT); 3810f0486c68SYan, Zheng if (IS_ERR(right)) 381144871b1bSChris Mason return PTR_ERR(right); 3812f0486c68SYan, Zheng 38130b246afaSJeff Mahoney root_add_used(root, fs_info->nodesize); 381444871b1bSChris Mason 38155d4f98a2SYan Zheng if (split == 0) { 381644871b1bSChris Mason if (mid <= slot) { 381744871b1bSChris Mason btrfs_set_header_nritems(right, 0); 38186ad3cf6dSDavid Sterba insert_ptr(trans, path, &disk_key, 38192ff7e61eSJeff Mahoney right->start, path->slots[1] + 1, 1); 382044871b1bSChris Mason btrfs_tree_unlock(path->nodes[0]); 382144871b1bSChris Mason free_extent_buffer(path->nodes[0]); 382244871b1bSChris Mason path->nodes[0] = right; 382344871b1bSChris Mason path->slots[0] = 0; 382444871b1bSChris Mason path->slots[1] += 1; 382544871b1bSChris Mason } else { 382644871b1bSChris Mason btrfs_set_header_nritems(right, 0); 38276ad3cf6dSDavid Sterba insert_ptr(trans, path, &disk_key, 38282ff7e61eSJeff Mahoney right->start, path->slots[1], 1); 382944871b1bSChris Mason btrfs_tree_unlock(path->nodes[0]); 383044871b1bSChris Mason free_extent_buffer(path->nodes[0]); 383144871b1bSChris Mason path->nodes[0] = right; 383244871b1bSChris Mason path->slots[0] = 0; 3833143bede5SJeff Mahoney if (path->slots[1] == 0) 3834b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 38355d4f98a2SYan Zheng } 3836196e0249SLiu Bo /* 3837196e0249SLiu Bo * We create a new leaf 'right' for the required ins_len and 3838196e0249SLiu Bo * we'll do btrfs_mark_buffer_dirty() on this leaf after copying 3839196e0249SLiu Bo * the content of ins_len to 'right'. 3840196e0249SLiu Bo */ 384144871b1bSChris Mason return ret; 384244871b1bSChris Mason } 384344871b1bSChris Mason 384494f94ad9SDavid Sterba copy_for_split(trans, path, l, right, slot, mid, nritems); 384544871b1bSChris Mason 38465d4f98a2SYan Zheng if (split == 2) { 3847cc0c5538SChris Mason BUG_ON(num_doubles != 0); 3848cc0c5538SChris Mason num_doubles++; 3849cc0c5538SChris Mason goto again; 38503326d1b0SChris Mason } 385144871b1bSChris Mason 3852143bede5SJeff Mahoney return 0; 385399d8f83cSChris Mason 385499d8f83cSChris Mason push_for_double: 385599d8f83cSChris Mason push_for_double_split(trans, root, path, data_size); 385699d8f83cSChris Mason tried_avoid_double = 1; 3857e902baacSDavid Sterba if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) 385899d8f83cSChris Mason return 0; 385999d8f83cSChris Mason goto again; 3860be0e5c09SChris Mason } 3861be0e5c09SChris Mason 3862ad48fd75SYan, Zheng static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, 3863ad48fd75SYan, Zheng struct btrfs_root *root, 3864ad48fd75SYan, Zheng struct btrfs_path *path, int ins_len) 3865ad48fd75SYan, Zheng { 3866ad48fd75SYan, Zheng struct btrfs_key key; 3867ad48fd75SYan, Zheng struct extent_buffer *leaf; 3868ad48fd75SYan, Zheng struct btrfs_file_extent_item *fi; 3869ad48fd75SYan, Zheng u64 extent_len = 0; 3870ad48fd75SYan, Zheng u32 item_size; 3871ad48fd75SYan, Zheng int ret; 3872ad48fd75SYan, Zheng 3873ad48fd75SYan, Zheng leaf = path->nodes[0]; 3874ad48fd75SYan, Zheng btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 3875ad48fd75SYan, Zheng 3876ad48fd75SYan, Zheng BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && 3877ad48fd75SYan, Zheng key.type != BTRFS_EXTENT_CSUM_KEY); 3878ad48fd75SYan, Zheng 3879e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) >= ins_len) 3880ad48fd75SYan, Zheng return 0; 3881ad48fd75SYan, Zheng 38823212fa14SJosef Bacik item_size = btrfs_item_size(leaf, path->slots[0]); 3883ad48fd75SYan, Zheng if (key.type == BTRFS_EXTENT_DATA_KEY) { 3884ad48fd75SYan, Zheng fi = btrfs_item_ptr(leaf, path->slots[0], 3885ad48fd75SYan, Zheng struct btrfs_file_extent_item); 3886ad48fd75SYan, Zheng extent_len = btrfs_file_extent_num_bytes(leaf, fi); 3887ad48fd75SYan, Zheng } 3888b3b4aa74SDavid Sterba btrfs_release_path(path); 3889ad48fd75SYan, Zheng 3890ad48fd75SYan, Zheng path->keep_locks = 1; 3891ad48fd75SYan, Zheng path->search_for_split = 1; 3892ad48fd75SYan, Zheng ret = btrfs_search_slot(trans, root, &key, path, 0, 1); 3893ad48fd75SYan, Zheng path->search_for_split = 0; 3894a8df6fe6SFilipe Manana if (ret > 0) 3895a8df6fe6SFilipe Manana ret = -EAGAIN; 3896ad48fd75SYan, Zheng if (ret < 0) 3897ad48fd75SYan, Zheng goto err; 3898ad48fd75SYan, Zheng 3899ad48fd75SYan, Zheng ret = -EAGAIN; 3900ad48fd75SYan, Zheng leaf = path->nodes[0]; 3901a8df6fe6SFilipe Manana /* if our item isn't there, return now */ 39023212fa14SJosef Bacik if (item_size != btrfs_item_size(leaf, path->slots[0])) 3903ad48fd75SYan, Zheng goto err; 3904ad48fd75SYan, Zheng 3905109f6aefSChris Mason /* the leaf has changed, it now has room. return now */ 3906e902baacSDavid Sterba if (btrfs_leaf_free_space(path->nodes[0]) >= ins_len) 3907109f6aefSChris Mason goto err; 3908109f6aefSChris Mason 3909ad48fd75SYan, Zheng if (key.type == BTRFS_EXTENT_DATA_KEY) { 3910ad48fd75SYan, Zheng fi = btrfs_item_ptr(leaf, path->slots[0], 3911ad48fd75SYan, Zheng struct btrfs_file_extent_item); 3912ad48fd75SYan, Zheng if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) 3913ad48fd75SYan, Zheng goto err; 3914ad48fd75SYan, Zheng } 3915ad48fd75SYan, Zheng 3916ad48fd75SYan, Zheng ret = split_leaf(trans, root, &key, path, ins_len, 1); 3917f0486c68SYan, Zheng if (ret) 3918f0486c68SYan, Zheng goto err; 3919ad48fd75SYan, Zheng 3920ad48fd75SYan, Zheng path->keep_locks = 0; 3921ad48fd75SYan, Zheng btrfs_unlock_up_safe(path, 1); 3922ad48fd75SYan, Zheng return 0; 3923ad48fd75SYan, Zheng err: 3924ad48fd75SYan, Zheng path->keep_locks = 0; 3925ad48fd75SYan, Zheng return ret; 3926ad48fd75SYan, Zheng } 3927ad48fd75SYan, Zheng 392825263cd7SDavid Sterba static noinline int split_item(struct btrfs_path *path, 3929310712b2SOmar Sandoval const struct btrfs_key *new_key, 3930459931ecSChris Mason unsigned long split_offset) 3931459931ecSChris Mason { 3932459931ecSChris Mason struct extent_buffer *leaf; 3933c91666b1SJosef Bacik int orig_slot, slot; 3934ad48fd75SYan, Zheng char *buf; 3935459931ecSChris Mason u32 nritems; 3936ad48fd75SYan, Zheng u32 item_size; 3937459931ecSChris Mason u32 orig_offset; 3938459931ecSChris Mason struct btrfs_disk_key disk_key; 3939459931ecSChris Mason 3940459931ecSChris Mason leaf = path->nodes[0]; 3941e902baacSDavid Sterba BUG_ON(btrfs_leaf_free_space(leaf) < sizeof(struct btrfs_item)); 3942b9473439SChris Mason 3943c91666b1SJosef Bacik orig_slot = path->slots[0]; 39443212fa14SJosef Bacik orig_offset = btrfs_item_offset(leaf, path->slots[0]); 39453212fa14SJosef Bacik item_size = btrfs_item_size(leaf, path->slots[0]); 3946459931ecSChris Mason 3947459931ecSChris Mason buf = kmalloc(item_size, GFP_NOFS); 3948ad48fd75SYan, Zheng if (!buf) 3949ad48fd75SYan, Zheng return -ENOMEM; 3950ad48fd75SYan, Zheng 3951459931ecSChris Mason read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, 3952459931ecSChris Mason path->slots[0]), item_size); 3953ad48fd75SYan, Zheng 3954459931ecSChris Mason slot = path->slots[0] + 1; 3955459931ecSChris Mason nritems = btrfs_header_nritems(leaf); 3956459931ecSChris Mason if (slot != nritems) { 3957459931ecSChris Mason /* shift the items */ 3958637e3b48SJosef Bacik memmove_leaf_items(leaf, slot + 1, slot, nritems - slot); 3959459931ecSChris Mason } 3960459931ecSChris Mason 3961459931ecSChris Mason btrfs_cpu_key_to_disk(&disk_key, new_key); 3962459931ecSChris Mason btrfs_set_item_key(leaf, &disk_key, slot); 3963459931ecSChris Mason 39643212fa14SJosef Bacik btrfs_set_item_offset(leaf, slot, orig_offset); 39653212fa14SJosef Bacik btrfs_set_item_size(leaf, slot, item_size - split_offset); 3966459931ecSChris Mason 39673212fa14SJosef Bacik btrfs_set_item_offset(leaf, orig_slot, 3968459931ecSChris Mason orig_offset + item_size - split_offset); 39693212fa14SJosef Bacik btrfs_set_item_size(leaf, orig_slot, split_offset); 3970459931ecSChris Mason 3971459931ecSChris Mason btrfs_set_header_nritems(leaf, nritems + 1); 3972459931ecSChris Mason 3973459931ecSChris Mason /* write the data for the start of the original item */ 3974459931ecSChris Mason write_extent_buffer(leaf, buf, 3975459931ecSChris Mason btrfs_item_ptr_offset(leaf, path->slots[0]), 3976459931ecSChris Mason split_offset); 3977459931ecSChris Mason 3978459931ecSChris Mason /* write the data for the new item */ 3979459931ecSChris Mason write_extent_buffer(leaf, buf + split_offset, 3980459931ecSChris Mason btrfs_item_ptr_offset(leaf, slot), 3981459931ecSChris Mason item_size - split_offset); 3982459931ecSChris Mason btrfs_mark_buffer_dirty(leaf); 3983459931ecSChris Mason 3984e902baacSDavid Sterba BUG_ON(btrfs_leaf_free_space(leaf) < 0); 3985459931ecSChris Mason kfree(buf); 3986ad48fd75SYan, Zheng return 0; 3987ad48fd75SYan, Zheng } 3988ad48fd75SYan, Zheng 3989ad48fd75SYan, Zheng /* 3990ad48fd75SYan, Zheng * This function splits a single item into two items, 3991ad48fd75SYan, Zheng * giving 'new_key' to the new item and splitting the 3992ad48fd75SYan, Zheng * old one at split_offset (from the start of the item). 3993ad48fd75SYan, Zheng * 3994ad48fd75SYan, Zheng * The path may be released by this operation. After 3995ad48fd75SYan, Zheng * the split, the path is pointing to the old item. The 3996ad48fd75SYan, Zheng * new item is going to be in the same node as the old one. 3997ad48fd75SYan, Zheng * 3998ad48fd75SYan, Zheng * Note, the item being split must be smaller enough to live alone on 3999ad48fd75SYan, Zheng * a tree block with room for one extra struct btrfs_item 4000ad48fd75SYan, Zheng * 4001ad48fd75SYan, Zheng * This allows us to split the item in place, keeping a lock on the 4002ad48fd75SYan, Zheng * leaf the entire time. 4003ad48fd75SYan, Zheng */ 4004ad48fd75SYan, Zheng int btrfs_split_item(struct btrfs_trans_handle *trans, 4005ad48fd75SYan, Zheng struct btrfs_root *root, 4006ad48fd75SYan, Zheng struct btrfs_path *path, 4007310712b2SOmar Sandoval const struct btrfs_key *new_key, 4008ad48fd75SYan, Zheng unsigned long split_offset) 4009ad48fd75SYan, Zheng { 4010ad48fd75SYan, Zheng int ret; 4011ad48fd75SYan, Zheng ret = setup_leaf_for_split(trans, root, path, 4012ad48fd75SYan, Zheng sizeof(struct btrfs_item)); 4013ad48fd75SYan, Zheng if (ret) 4014459931ecSChris Mason return ret; 4015ad48fd75SYan, Zheng 401625263cd7SDavid Sterba ret = split_item(path, new_key, split_offset); 4017ad48fd75SYan, Zheng return ret; 4018ad48fd75SYan, Zheng } 4019ad48fd75SYan, Zheng 4020ad48fd75SYan, Zheng /* 4021d352ac68SChris Mason * make the item pointed to by the path smaller. new_size indicates 4022d352ac68SChris Mason * how small to make it, and from_end tells us if we just chop bytes 4023d352ac68SChris Mason * off the end of the item or if we shift the item to chop bytes off 4024d352ac68SChris Mason * the front. 4025d352ac68SChris Mason */ 402678ac4f9eSDavid Sterba void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end) 4027b18c6685SChris Mason { 4028b18c6685SChris Mason int slot; 40295f39d397SChris Mason struct extent_buffer *leaf; 4030b18c6685SChris Mason u32 nritems; 4031b18c6685SChris Mason unsigned int data_end; 4032b18c6685SChris Mason unsigned int old_data_start; 4033b18c6685SChris Mason unsigned int old_size; 4034b18c6685SChris Mason unsigned int size_diff; 4035b18c6685SChris Mason int i; 4036cfed81a0SChris Mason struct btrfs_map_token token; 4037cfed81a0SChris Mason 40385f39d397SChris Mason leaf = path->nodes[0]; 4039179e29e4SChris Mason slot = path->slots[0]; 4040179e29e4SChris Mason 40413212fa14SJosef Bacik old_size = btrfs_item_size(leaf, slot); 4042179e29e4SChris Mason if (old_size == new_size) 4043143bede5SJeff Mahoney return; 4044b18c6685SChris Mason 40455f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 40468f881e8cSDavid Sterba data_end = leaf_data_end(leaf); 4047b18c6685SChris Mason 40483212fa14SJosef Bacik old_data_start = btrfs_item_offset(leaf, slot); 4049179e29e4SChris Mason 4050b18c6685SChris Mason size_diff = old_size - new_size; 4051b18c6685SChris Mason 4052b18c6685SChris Mason BUG_ON(slot < 0); 4053b18c6685SChris Mason BUG_ON(slot >= nritems); 4054b18c6685SChris Mason 4055b18c6685SChris Mason /* 4056b18c6685SChris Mason * item0..itemN ... dataN.offset..dataN.size .. data0.size 4057b18c6685SChris Mason */ 4058b18c6685SChris Mason /* first correct the data pointers */ 4059c82f823cSDavid Sterba btrfs_init_map_token(&token, leaf); 4060b18c6685SChris Mason for (i = slot; i < nritems; i++) { 40615f39d397SChris Mason u32 ioff; 4062db94535dSChris Mason 40633212fa14SJosef Bacik ioff = btrfs_token_item_offset(&token, i); 40643212fa14SJosef Bacik btrfs_set_token_item_offset(&token, i, ioff + size_diff); 4065b18c6685SChris Mason } 4066db94535dSChris Mason 4067b18c6685SChris Mason /* shift the data */ 4068179e29e4SChris Mason if (from_end) { 4069637e3b48SJosef Bacik memmove_leaf_data(leaf, data_end + size_diff, data_end, 4070637e3b48SJosef Bacik old_data_start + new_size - data_end); 4071179e29e4SChris Mason } else { 4072179e29e4SChris Mason struct btrfs_disk_key disk_key; 4073179e29e4SChris Mason u64 offset; 4074179e29e4SChris Mason 4075179e29e4SChris Mason btrfs_item_key(leaf, &disk_key, slot); 4076179e29e4SChris Mason 4077179e29e4SChris Mason if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { 4078179e29e4SChris Mason unsigned long ptr; 4079179e29e4SChris Mason struct btrfs_file_extent_item *fi; 4080179e29e4SChris Mason 4081179e29e4SChris Mason fi = btrfs_item_ptr(leaf, slot, 4082179e29e4SChris Mason struct btrfs_file_extent_item); 4083179e29e4SChris Mason fi = (struct btrfs_file_extent_item *)( 4084179e29e4SChris Mason (unsigned long)fi - size_diff); 4085179e29e4SChris Mason 4086179e29e4SChris Mason if (btrfs_file_extent_type(leaf, fi) == 4087179e29e4SChris Mason BTRFS_FILE_EXTENT_INLINE) { 4088179e29e4SChris Mason ptr = btrfs_item_ptr_offset(leaf, slot); 4089179e29e4SChris Mason memmove_extent_buffer(leaf, ptr, 4090179e29e4SChris Mason (unsigned long)fi, 40917ec20afbSDavid Sterba BTRFS_FILE_EXTENT_INLINE_DATA_START); 4092179e29e4SChris Mason } 4093179e29e4SChris Mason } 4094179e29e4SChris Mason 4095637e3b48SJosef Bacik memmove_leaf_data(leaf, data_end + size_diff, data_end, 4096637e3b48SJosef Bacik old_data_start - data_end); 4097179e29e4SChris Mason 4098179e29e4SChris Mason offset = btrfs_disk_key_offset(&disk_key); 4099179e29e4SChris Mason btrfs_set_disk_key_offset(&disk_key, offset + size_diff); 4100179e29e4SChris Mason btrfs_set_item_key(leaf, &disk_key, slot); 4101179e29e4SChris Mason if (slot == 0) 4102b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 4103179e29e4SChris Mason } 41045f39d397SChris Mason 41053212fa14SJosef Bacik btrfs_set_item_size(leaf, slot, new_size); 41065f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 4107b18c6685SChris Mason 4108e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < 0) { 4109a4f78750SDavid Sterba btrfs_print_leaf(leaf); 4110b18c6685SChris Mason BUG(); 41115f39d397SChris Mason } 4112b18c6685SChris Mason } 4113b18c6685SChris Mason 4114d352ac68SChris Mason /* 41158f69dbd2SStefan Behrens * make the item pointed to by the path bigger, data_size is the added size. 4116d352ac68SChris Mason */ 4117c71dd880SDavid Sterba void btrfs_extend_item(struct btrfs_path *path, u32 data_size) 41186567e837SChris Mason { 41196567e837SChris Mason int slot; 41205f39d397SChris Mason struct extent_buffer *leaf; 41216567e837SChris Mason u32 nritems; 41226567e837SChris Mason unsigned int data_end; 41236567e837SChris Mason unsigned int old_data; 41246567e837SChris Mason unsigned int old_size; 41256567e837SChris Mason int i; 4126cfed81a0SChris Mason struct btrfs_map_token token; 4127cfed81a0SChris Mason 41285f39d397SChris Mason leaf = path->nodes[0]; 41296567e837SChris Mason 41305f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 41318f881e8cSDavid Sterba data_end = leaf_data_end(leaf); 41326567e837SChris Mason 4133e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < data_size) { 4134a4f78750SDavid Sterba btrfs_print_leaf(leaf); 41356567e837SChris Mason BUG(); 41365f39d397SChris Mason } 41376567e837SChris Mason slot = path->slots[0]; 4138dc2e724eSJosef Bacik old_data = btrfs_item_data_end(leaf, slot); 41396567e837SChris Mason 41406567e837SChris Mason BUG_ON(slot < 0); 41413326d1b0SChris Mason if (slot >= nritems) { 4142a4f78750SDavid Sterba btrfs_print_leaf(leaf); 4143c71dd880SDavid Sterba btrfs_crit(leaf->fs_info, "slot %d too large, nritems %d", 4144d397712bSChris Mason slot, nritems); 4145290342f6SArnd Bergmann BUG(); 41463326d1b0SChris Mason } 41476567e837SChris Mason 41486567e837SChris Mason /* 41496567e837SChris Mason * item0..itemN ... dataN.offset..dataN.size .. data0.size 41506567e837SChris Mason */ 41516567e837SChris Mason /* first correct the data pointers */ 4152c82f823cSDavid Sterba btrfs_init_map_token(&token, leaf); 41536567e837SChris Mason for (i = slot; i < nritems; i++) { 41545f39d397SChris Mason u32 ioff; 4155db94535dSChris Mason 41563212fa14SJosef Bacik ioff = btrfs_token_item_offset(&token, i); 41573212fa14SJosef Bacik btrfs_set_token_item_offset(&token, i, ioff - data_size); 41586567e837SChris Mason } 41595f39d397SChris Mason 41606567e837SChris Mason /* shift the data */ 4161637e3b48SJosef Bacik memmove_leaf_data(leaf, data_end - data_size, data_end, 4162637e3b48SJosef Bacik old_data - data_end); 41635f39d397SChris Mason 41646567e837SChris Mason data_end = old_data; 41653212fa14SJosef Bacik old_size = btrfs_item_size(leaf, slot); 41663212fa14SJosef Bacik btrfs_set_item_size(leaf, slot, old_size + data_size); 41675f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 41686567e837SChris Mason 4169e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < 0) { 4170a4f78750SDavid Sterba btrfs_print_leaf(leaf); 41716567e837SChris Mason BUG(); 41725f39d397SChris Mason } 41736567e837SChris Mason } 41746567e837SChris Mason 417543dd529aSDavid Sterba /* 417643dd529aSDavid Sterba * Make space in the node before inserting one or more items. 4177da9ffb24SNikolay Borisov * 4178da9ffb24SNikolay Borisov * @root: root we are inserting items to 4179da9ffb24SNikolay Borisov * @path: points to the leaf/slot where we are going to insert new items 4180b7ef5f3aSFilipe Manana * @batch: information about the batch of items to insert 418143dd529aSDavid Sterba * 418243dd529aSDavid Sterba * Main purpose is to save stack depth by doing the bulk of the work in a 418343dd529aSDavid Sterba * function that doesn't call btrfs_search_slot 418474123bd7SChris Mason */ 4185f0641656SFilipe Manana static void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path, 4186b7ef5f3aSFilipe Manana const struct btrfs_item_batch *batch) 4187be0e5c09SChris Mason { 41880b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 41899c58309dSChris Mason int i; 41907518a238SChris Mason u32 nritems; 4191be0e5c09SChris Mason unsigned int data_end; 4192e2fa7227SChris Mason struct btrfs_disk_key disk_key; 419344871b1bSChris Mason struct extent_buffer *leaf; 419444871b1bSChris Mason int slot; 4195cfed81a0SChris Mason struct btrfs_map_token token; 4196fc0d82e1SNikolay Borisov u32 total_size; 4197fc0d82e1SNikolay Borisov 4198b7ef5f3aSFilipe Manana /* 4199b7ef5f3aSFilipe Manana * Before anything else, update keys in the parent and other ancestors 4200b7ef5f3aSFilipe Manana * if needed, then release the write locks on them, so that other tasks 4201b7ef5f3aSFilipe Manana * can use them while we modify the leaf. 4202b7ef5f3aSFilipe Manana */ 420324cdc847SFilipe Manana if (path->slots[0] == 0) { 4204b7ef5f3aSFilipe Manana btrfs_cpu_key_to_disk(&disk_key, &batch->keys[0]); 4205b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 420624cdc847SFilipe Manana } 420724cdc847SFilipe Manana btrfs_unlock_up_safe(path, 1); 420824cdc847SFilipe Manana 42095f39d397SChris Mason leaf = path->nodes[0]; 421044871b1bSChris Mason slot = path->slots[0]; 421174123bd7SChris Mason 42125f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 42138f881e8cSDavid Sterba data_end = leaf_data_end(leaf); 4214b7ef5f3aSFilipe Manana total_size = batch->total_data_size + (batch->nr * sizeof(struct btrfs_item)); 4215eb60ceacSChris Mason 4216e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < total_size) { 4217a4f78750SDavid Sterba btrfs_print_leaf(leaf); 42180b246afaSJeff Mahoney btrfs_crit(fs_info, "not enough freespace need %u have %d", 4219e902baacSDavid Sterba total_size, btrfs_leaf_free_space(leaf)); 4220be0e5c09SChris Mason BUG(); 4221d4dbff95SChris Mason } 42225f39d397SChris Mason 4223c82f823cSDavid Sterba btrfs_init_map_token(&token, leaf); 4224be0e5c09SChris Mason if (slot != nritems) { 4225dc2e724eSJosef Bacik unsigned int old_data = btrfs_item_data_end(leaf, slot); 4226be0e5c09SChris Mason 42275f39d397SChris Mason if (old_data < data_end) { 4228a4f78750SDavid Sterba btrfs_print_leaf(leaf); 42297269ddd2SNikolay Borisov btrfs_crit(fs_info, 42307269ddd2SNikolay Borisov "item at slot %d with data offset %u beyond data end of leaf %u", 42315f39d397SChris Mason slot, old_data, data_end); 4232290342f6SArnd Bergmann BUG(); 42335f39d397SChris Mason } 4234be0e5c09SChris Mason /* 4235be0e5c09SChris Mason * item0..itemN ... dataN.offset..dataN.size .. data0.size 4236be0e5c09SChris Mason */ 4237be0e5c09SChris Mason /* first correct the data pointers */ 42380783fcfcSChris Mason for (i = slot; i < nritems; i++) { 42395f39d397SChris Mason u32 ioff; 4240db94535dSChris Mason 42413212fa14SJosef Bacik ioff = btrfs_token_item_offset(&token, i); 42423212fa14SJosef Bacik btrfs_set_token_item_offset(&token, i, 4243b7ef5f3aSFilipe Manana ioff - batch->total_data_size); 42440783fcfcSChris Mason } 4245be0e5c09SChris Mason /* shift the items */ 4246637e3b48SJosef Bacik memmove_leaf_items(leaf, slot + batch->nr, slot, nritems - slot); 4247be0e5c09SChris Mason 4248be0e5c09SChris Mason /* shift the data */ 4249637e3b48SJosef Bacik memmove_leaf_data(leaf, data_end - batch->total_data_size, 4250637e3b48SJosef Bacik data_end, old_data - data_end); 4251be0e5c09SChris Mason data_end = old_data; 4252be0e5c09SChris Mason } 42535f39d397SChris Mason 425462e2749eSChris Mason /* setup the item for the new data */ 4255b7ef5f3aSFilipe Manana for (i = 0; i < batch->nr; i++) { 4256b7ef5f3aSFilipe Manana btrfs_cpu_key_to_disk(&disk_key, &batch->keys[i]); 42579c58309dSChris Mason btrfs_set_item_key(leaf, &disk_key, slot + i); 4258b7ef5f3aSFilipe Manana data_end -= batch->data_sizes[i]; 42593212fa14SJosef Bacik btrfs_set_token_item_offset(&token, slot + i, data_end); 42603212fa14SJosef Bacik btrfs_set_token_item_size(&token, slot + i, batch->data_sizes[i]); 42619c58309dSChris Mason } 426244871b1bSChris Mason 4263b7ef5f3aSFilipe Manana btrfs_set_header_nritems(leaf, nritems + batch->nr); 4264b9473439SChris Mason btrfs_mark_buffer_dirty(leaf); 4265aa5d6bedSChris Mason 4266e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < 0) { 4267a4f78750SDavid Sterba btrfs_print_leaf(leaf); 4268be0e5c09SChris Mason BUG(); 42695f39d397SChris Mason } 427044871b1bSChris Mason } 427144871b1bSChris Mason 427244871b1bSChris Mason /* 4273f0641656SFilipe Manana * Insert a new item into a leaf. 4274f0641656SFilipe Manana * 4275f0641656SFilipe Manana * @root: The root of the btree. 4276f0641656SFilipe Manana * @path: A path pointing to the target leaf and slot. 4277f0641656SFilipe Manana * @key: The key of the new item. 4278f0641656SFilipe Manana * @data_size: The size of the data associated with the new key. 4279f0641656SFilipe Manana */ 4280f0641656SFilipe Manana void btrfs_setup_item_for_insert(struct btrfs_root *root, 4281f0641656SFilipe Manana struct btrfs_path *path, 4282f0641656SFilipe Manana const struct btrfs_key *key, 4283f0641656SFilipe Manana u32 data_size) 4284f0641656SFilipe Manana { 4285f0641656SFilipe Manana struct btrfs_item_batch batch; 4286f0641656SFilipe Manana 4287f0641656SFilipe Manana batch.keys = key; 4288f0641656SFilipe Manana batch.data_sizes = &data_size; 4289f0641656SFilipe Manana batch.total_data_size = data_size; 4290f0641656SFilipe Manana batch.nr = 1; 4291f0641656SFilipe Manana 4292f0641656SFilipe Manana setup_items_for_insert(root, path, &batch); 4293f0641656SFilipe Manana } 4294f0641656SFilipe Manana 4295f0641656SFilipe Manana /* 429644871b1bSChris Mason * Given a key and some data, insert items into the tree. 429744871b1bSChris Mason * This does all the path init required, making room in the tree if needed. 429844871b1bSChris Mason */ 429944871b1bSChris Mason int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, 430044871b1bSChris Mason struct btrfs_root *root, 430144871b1bSChris Mason struct btrfs_path *path, 4302b7ef5f3aSFilipe Manana const struct btrfs_item_batch *batch) 430344871b1bSChris Mason { 430444871b1bSChris Mason int ret = 0; 430544871b1bSChris Mason int slot; 4306b7ef5f3aSFilipe Manana u32 total_size; 430744871b1bSChris Mason 4308b7ef5f3aSFilipe Manana total_size = batch->total_data_size + (batch->nr * sizeof(struct btrfs_item)); 4309b7ef5f3aSFilipe Manana ret = btrfs_search_slot(trans, root, &batch->keys[0], path, total_size, 1); 431044871b1bSChris Mason if (ret == 0) 431144871b1bSChris Mason return -EEXIST; 431244871b1bSChris Mason if (ret < 0) 4313143bede5SJeff Mahoney return ret; 431444871b1bSChris Mason 431544871b1bSChris Mason slot = path->slots[0]; 431644871b1bSChris Mason BUG_ON(slot < 0); 431744871b1bSChris Mason 4318b7ef5f3aSFilipe Manana setup_items_for_insert(root, path, batch); 4319143bede5SJeff Mahoney return 0; 432062e2749eSChris Mason } 432162e2749eSChris Mason 432262e2749eSChris Mason /* 432362e2749eSChris Mason * Given a key and some data, insert an item into the tree. 432462e2749eSChris Mason * This does all the path init required, making room in the tree if needed. 432562e2749eSChris Mason */ 4326310712b2SOmar Sandoval int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, 4327310712b2SOmar Sandoval const struct btrfs_key *cpu_key, void *data, 4328310712b2SOmar Sandoval u32 data_size) 432962e2749eSChris Mason { 433062e2749eSChris Mason int ret = 0; 43312c90e5d6SChris Mason struct btrfs_path *path; 43325f39d397SChris Mason struct extent_buffer *leaf; 43335f39d397SChris Mason unsigned long ptr; 433462e2749eSChris Mason 43352c90e5d6SChris Mason path = btrfs_alloc_path(); 4336db5b493aSTsutomu Itoh if (!path) 4337db5b493aSTsutomu Itoh return -ENOMEM; 43382c90e5d6SChris Mason ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); 433962e2749eSChris Mason if (!ret) { 43405f39d397SChris Mason leaf = path->nodes[0]; 43415f39d397SChris Mason ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); 43425f39d397SChris Mason write_extent_buffer(leaf, data, ptr, data_size); 43435f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 434462e2749eSChris Mason } 43452c90e5d6SChris Mason btrfs_free_path(path); 4346aa5d6bedSChris Mason return ret; 4347be0e5c09SChris Mason } 4348be0e5c09SChris Mason 434974123bd7SChris Mason /* 4350f0641656SFilipe Manana * This function duplicates an item, giving 'new_key' to the new item. 4351f0641656SFilipe Manana * It guarantees both items live in the same tree leaf and the new item is 4352f0641656SFilipe Manana * contiguous with the original item. 4353f0641656SFilipe Manana * 4354f0641656SFilipe Manana * This allows us to split a file extent in place, keeping a lock on the leaf 4355f0641656SFilipe Manana * the entire time. 4356f0641656SFilipe Manana */ 4357f0641656SFilipe Manana int btrfs_duplicate_item(struct btrfs_trans_handle *trans, 4358f0641656SFilipe Manana struct btrfs_root *root, 4359f0641656SFilipe Manana struct btrfs_path *path, 4360f0641656SFilipe Manana const struct btrfs_key *new_key) 4361f0641656SFilipe Manana { 4362f0641656SFilipe Manana struct extent_buffer *leaf; 4363f0641656SFilipe Manana int ret; 4364f0641656SFilipe Manana u32 item_size; 4365f0641656SFilipe Manana 4366f0641656SFilipe Manana leaf = path->nodes[0]; 43673212fa14SJosef Bacik item_size = btrfs_item_size(leaf, path->slots[0]); 4368f0641656SFilipe Manana ret = setup_leaf_for_split(trans, root, path, 4369f0641656SFilipe Manana item_size + sizeof(struct btrfs_item)); 4370f0641656SFilipe Manana if (ret) 4371f0641656SFilipe Manana return ret; 4372f0641656SFilipe Manana 4373f0641656SFilipe Manana path->slots[0]++; 4374f0641656SFilipe Manana btrfs_setup_item_for_insert(root, path, new_key, item_size); 4375f0641656SFilipe Manana leaf = path->nodes[0]; 4376f0641656SFilipe Manana memcpy_extent_buffer(leaf, 4377f0641656SFilipe Manana btrfs_item_ptr_offset(leaf, path->slots[0]), 4378f0641656SFilipe Manana btrfs_item_ptr_offset(leaf, path->slots[0] - 1), 4379f0641656SFilipe Manana item_size); 4380f0641656SFilipe Manana return 0; 4381f0641656SFilipe Manana } 4382f0641656SFilipe Manana 4383f0641656SFilipe Manana /* 43845de08d7dSChris Mason * delete the pointer from a given node. 438574123bd7SChris Mason * 4386d352ac68SChris Mason * the tree should have been previously balanced so the deletion does not 4387d352ac68SChris Mason * empty a node. 4388016f9d0bSJosef Bacik * 4389016f9d0bSJosef Bacik * This is exported for use inside btrfs-progs, don't un-export it. 439074123bd7SChris Mason */ 4391016f9d0bSJosef Bacik void btrfs_del_ptr(struct btrfs_root *root, struct btrfs_path *path, int level, 4392016f9d0bSJosef Bacik int slot) 4393be0e5c09SChris Mason { 43945f39d397SChris Mason struct extent_buffer *parent = path->nodes[level]; 43957518a238SChris Mason u32 nritems; 4396f3ea38daSJan Schmidt int ret; 4397be0e5c09SChris Mason 43985f39d397SChris Mason nritems = btrfs_header_nritems(parent); 4399be0e5c09SChris Mason if (slot != nritems - 1) { 4400bf1d3425SDavid Sterba if (level) { 4401f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_move(parent, slot, 4402f3a84ccdSFilipe Manana slot + 1, nritems - slot - 1); 4403bf1d3425SDavid Sterba BUG_ON(ret < 0); 4404bf1d3425SDavid Sterba } 44055f39d397SChris Mason memmove_extent_buffer(parent, 4406e23efd8eSJosef Bacik btrfs_node_key_ptr_offset(parent, slot), 4407e23efd8eSJosef Bacik btrfs_node_key_ptr_offset(parent, slot + 1), 4408d6025579SChris Mason sizeof(struct btrfs_key_ptr) * 4409d6025579SChris Mason (nritems - slot - 1)); 441057ba86c0SChris Mason } else if (level) { 4411f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_key(parent, slot, 441233cff222SFilipe Manana BTRFS_MOD_LOG_KEY_REMOVE); 441357ba86c0SChris Mason BUG_ON(ret < 0); 4414be0e5c09SChris Mason } 4415f3ea38daSJan Schmidt 44167518a238SChris Mason nritems--; 44175f39d397SChris Mason btrfs_set_header_nritems(parent, nritems); 44187518a238SChris Mason if (nritems == 0 && parent == root->node) { 44195f39d397SChris Mason BUG_ON(btrfs_header_level(root->node) != 1); 4420eb60ceacSChris Mason /* just turn the root into a leaf and break */ 44215f39d397SChris Mason btrfs_set_header_level(root->node, 0); 4422bb803951SChris Mason } else if (slot == 0) { 44235f39d397SChris Mason struct btrfs_disk_key disk_key; 44245f39d397SChris Mason 44255f39d397SChris Mason btrfs_node_key(parent, &disk_key, 0); 4426b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, level + 1); 4427be0e5c09SChris Mason } 4428d6025579SChris Mason btrfs_mark_buffer_dirty(parent); 4429be0e5c09SChris Mason } 4430be0e5c09SChris Mason 443174123bd7SChris Mason /* 4432323ac95bSChris Mason * a helper function to delete the leaf pointed to by path->slots[1] and 44335d4f98a2SYan Zheng * path->nodes[1]. 4434323ac95bSChris Mason * 4435323ac95bSChris Mason * This deletes the pointer in path->nodes[1] and frees the leaf 4436323ac95bSChris Mason * block extent. zero is returned if it all worked out, < 0 otherwise. 4437323ac95bSChris Mason * 4438323ac95bSChris Mason * The path must have already been setup for deleting the leaf, including 4439323ac95bSChris Mason * all the proper balancing. path->nodes[1] must be locked. 4440323ac95bSChris Mason */ 4441143bede5SJeff Mahoney static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, 4442323ac95bSChris Mason struct btrfs_root *root, 44435d4f98a2SYan Zheng struct btrfs_path *path, 44445d4f98a2SYan Zheng struct extent_buffer *leaf) 4445323ac95bSChris Mason { 44465d4f98a2SYan Zheng WARN_ON(btrfs_header_generation(leaf) != trans->transid); 4447016f9d0bSJosef Bacik btrfs_del_ptr(root, path, 1, path->slots[1]); 4448323ac95bSChris Mason 44494d081c41SChris Mason /* 44504d081c41SChris Mason * btrfs_free_extent is expensive, we want to make sure we 44514d081c41SChris Mason * aren't holding any locks when we call it 44524d081c41SChris Mason */ 44534d081c41SChris Mason btrfs_unlock_up_safe(path, 0); 44544d081c41SChris Mason 4455f0486c68SYan, Zheng root_sub_used(root, leaf->len); 4456f0486c68SYan, Zheng 445767439dadSDavid Sterba atomic_inc(&leaf->refs); 44587a163608SFilipe Manana btrfs_free_tree_block(trans, btrfs_root_id(root), leaf, 0, 1); 44593083ee2eSJosef Bacik free_extent_buffer_stale(leaf); 4460323ac95bSChris Mason } 4461323ac95bSChris Mason /* 446274123bd7SChris Mason * delete the item at the leaf level in path. If that empties 446374123bd7SChris Mason * the leaf, remove it from the tree 446474123bd7SChris Mason */ 446585e21bacSChris Mason int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, 446685e21bacSChris Mason struct btrfs_path *path, int slot, int nr) 4467be0e5c09SChris Mason { 44680b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 44695f39d397SChris Mason struct extent_buffer *leaf; 4470aa5d6bedSChris Mason int ret = 0; 4471aa5d6bedSChris Mason int wret; 44727518a238SChris Mason u32 nritems; 4473be0e5c09SChris Mason 44745f39d397SChris Mason leaf = path->nodes[0]; 44755f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 4476be0e5c09SChris Mason 447785e21bacSChris Mason if (slot + nr != nritems) { 44780cae23b6SFilipe Manana const u32 last_off = btrfs_item_offset(leaf, slot + nr - 1); 44790cae23b6SFilipe Manana const int data_end = leaf_data_end(leaf); 4480c82f823cSDavid Sterba struct btrfs_map_token token; 44810cae23b6SFilipe Manana u32 dsize = 0; 44820cae23b6SFilipe Manana int i; 44830cae23b6SFilipe Manana 44840cae23b6SFilipe Manana for (i = 0; i < nr; i++) 44850cae23b6SFilipe Manana dsize += btrfs_item_size(leaf, slot + i); 44865f39d397SChris Mason 4487637e3b48SJosef Bacik memmove_leaf_data(leaf, data_end + dsize, data_end, 448885e21bacSChris Mason last_off - data_end); 44895f39d397SChris Mason 4490c82f823cSDavid Sterba btrfs_init_map_token(&token, leaf); 449185e21bacSChris Mason for (i = slot + nr; i < nritems; i++) { 44925f39d397SChris Mason u32 ioff; 4493db94535dSChris Mason 44943212fa14SJosef Bacik ioff = btrfs_token_item_offset(&token, i); 44953212fa14SJosef Bacik btrfs_set_token_item_offset(&token, i, ioff + dsize); 44960783fcfcSChris Mason } 4497db94535dSChris Mason 4498637e3b48SJosef Bacik memmove_leaf_items(leaf, slot, slot + nr, nritems - slot - nr); 4499be0e5c09SChris Mason } 450085e21bacSChris Mason btrfs_set_header_nritems(leaf, nritems - nr); 450185e21bacSChris Mason nritems -= nr; 45025f39d397SChris Mason 450374123bd7SChris Mason /* delete the leaf if we've emptied it */ 45047518a238SChris Mason if (nritems == 0) { 45055f39d397SChris Mason if (leaf == root->node) { 45065f39d397SChris Mason btrfs_set_header_level(leaf, 0); 45079a8dd150SChris Mason } else { 4508190a8339SJosef Bacik btrfs_clear_buffer_dirty(trans, leaf); 4509143bede5SJeff Mahoney btrfs_del_leaf(trans, root, path, leaf); 45109a8dd150SChris Mason } 4511be0e5c09SChris Mason } else { 45127518a238SChris Mason int used = leaf_space_used(leaf, 0, nritems); 4513aa5d6bedSChris Mason if (slot == 0) { 45145f39d397SChris Mason struct btrfs_disk_key disk_key; 45155f39d397SChris Mason 45165f39d397SChris Mason btrfs_item_key(leaf, &disk_key, 0); 4517b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 4518aa5d6bedSChris Mason } 4519aa5d6bedSChris Mason 45207c4063d1SFilipe Manana /* 45217c4063d1SFilipe Manana * Try to delete the leaf if it is mostly empty. We do this by 45227c4063d1SFilipe Manana * trying to move all its items into its left and right neighbours. 45237c4063d1SFilipe Manana * If we can't move all the items, then we don't delete it - it's 45247c4063d1SFilipe Manana * not ideal, but future insertions might fill the leaf with more 45257c4063d1SFilipe Manana * items, or items from other leaves might be moved later into our 45267c4063d1SFilipe Manana * leaf due to deletions on those leaves. 45277c4063d1SFilipe Manana */ 45280b246afaSJeff Mahoney if (used < BTRFS_LEAF_DATA_SIZE(fs_info) / 3) { 45297c4063d1SFilipe Manana u32 min_push_space; 45307c4063d1SFilipe Manana 4531be0e5c09SChris Mason /* push_leaf_left fixes the path. 4532be0e5c09SChris Mason * make sure the path still points to our leaf 4533016f9d0bSJosef Bacik * for possible call to btrfs_del_ptr below 4534be0e5c09SChris Mason */ 45354920c9acSChris Mason slot = path->slots[1]; 453667439dadSDavid Sterba atomic_inc(&leaf->refs); 45377c4063d1SFilipe Manana /* 45387c4063d1SFilipe Manana * We want to be able to at least push one item to the 45397c4063d1SFilipe Manana * left neighbour leaf, and that's the first item. 45407c4063d1SFilipe Manana */ 45417c4063d1SFilipe Manana min_push_space = sizeof(struct btrfs_item) + 45427c4063d1SFilipe Manana btrfs_item_size(leaf, 0); 45437c4063d1SFilipe Manana wret = push_leaf_left(trans, root, path, 0, 45447c4063d1SFilipe Manana min_push_space, 1, (u32)-1); 454554aa1f4dSChris Mason if (wret < 0 && wret != -ENOSPC) 4546aa5d6bedSChris Mason ret = wret; 45475f39d397SChris Mason 45485f39d397SChris Mason if (path->nodes[0] == leaf && 45495f39d397SChris Mason btrfs_header_nritems(leaf)) { 45507c4063d1SFilipe Manana /* 45517c4063d1SFilipe Manana * If we were not able to push all items from our 45527c4063d1SFilipe Manana * leaf to its left neighbour, then attempt to 45537c4063d1SFilipe Manana * either push all the remaining items to the 45547c4063d1SFilipe Manana * right neighbour or none. There's no advantage 45557c4063d1SFilipe Manana * in pushing only some items, instead of all, as 45567c4063d1SFilipe Manana * it's pointless to end up with a leaf having 45577c4063d1SFilipe Manana * too few items while the neighbours can be full 45587c4063d1SFilipe Manana * or nearly full. 45597c4063d1SFilipe Manana */ 45607c4063d1SFilipe Manana nritems = btrfs_header_nritems(leaf); 45617c4063d1SFilipe Manana min_push_space = leaf_space_used(leaf, 0, nritems); 45627c4063d1SFilipe Manana wret = push_leaf_right(trans, root, path, 0, 45637c4063d1SFilipe Manana min_push_space, 1, 0); 456454aa1f4dSChris Mason if (wret < 0 && wret != -ENOSPC) 4565aa5d6bedSChris Mason ret = wret; 4566aa5d6bedSChris Mason } 45675f39d397SChris Mason 45685f39d397SChris Mason if (btrfs_header_nritems(leaf) == 0) { 4569323ac95bSChris Mason path->slots[1] = slot; 4570143bede5SJeff Mahoney btrfs_del_leaf(trans, root, path, leaf); 45715f39d397SChris Mason free_extent_buffer(leaf); 4572143bede5SJeff Mahoney ret = 0; 45735de08d7dSChris Mason } else { 4574925baeddSChris Mason /* if we're still in the path, make sure 4575925baeddSChris Mason * we're dirty. Otherwise, one of the 4576925baeddSChris Mason * push_leaf functions must have already 4577925baeddSChris Mason * dirtied this buffer 4578925baeddSChris Mason */ 4579925baeddSChris Mason if (path->nodes[0] == leaf) 45805f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 45815f39d397SChris Mason free_extent_buffer(leaf); 4582be0e5c09SChris Mason } 4583d5719762SChris Mason } else { 45845f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 4585be0e5c09SChris Mason } 45869a8dd150SChris Mason } 4587aa5d6bedSChris Mason return ret; 45889a8dd150SChris Mason } 45899a8dd150SChris Mason 459097571fd0SChris Mason /* 45913f157a2fSChris Mason * A helper function to walk down the tree starting at min_key, and looking 4592de78b51aSEric Sandeen * for nodes or leaves that are have a minimum transaction id. 4593de78b51aSEric Sandeen * This is used by the btree defrag code, and tree logging 45943f157a2fSChris Mason * 45953f157a2fSChris Mason * This does not cow, but it does stuff the starting key it finds back 45963f157a2fSChris Mason * into min_key, so you can call btrfs_search_slot with cow=1 on the 45973f157a2fSChris Mason * key and get a writable path. 45983f157a2fSChris Mason * 45993f157a2fSChris Mason * This honors path->lowest_level to prevent descent past a given level 46003f157a2fSChris Mason * of the tree. 46013f157a2fSChris Mason * 4602d352ac68SChris Mason * min_trans indicates the oldest transaction that you are interested 4603d352ac68SChris Mason * in walking through. Any nodes or leaves older than min_trans are 4604d352ac68SChris Mason * skipped over (without reading them). 4605d352ac68SChris Mason * 46063f157a2fSChris Mason * returns zero if something useful was found, < 0 on error and 1 if there 46073f157a2fSChris Mason * was nothing in the tree that matched the search criteria. 46083f157a2fSChris Mason */ 46093f157a2fSChris Mason int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, 4610de78b51aSEric Sandeen struct btrfs_path *path, 46113f157a2fSChris Mason u64 min_trans) 46123f157a2fSChris Mason { 46133f157a2fSChris Mason struct extent_buffer *cur; 46143f157a2fSChris Mason struct btrfs_key found_key; 46153f157a2fSChris Mason int slot; 46169652480bSYan int sret; 46173f157a2fSChris Mason u32 nritems; 46183f157a2fSChris Mason int level; 46193f157a2fSChris Mason int ret = 1; 4620f98de9b9SFilipe Manana int keep_locks = path->keep_locks; 46213f157a2fSChris Mason 4622c922b016SStefan Roesch ASSERT(!path->nowait); 4623f98de9b9SFilipe Manana path->keep_locks = 1; 46243f157a2fSChris Mason again: 4625bd681513SChris Mason cur = btrfs_read_lock_root_node(root); 46263f157a2fSChris Mason level = btrfs_header_level(cur); 4627e02119d5SChris Mason WARN_ON(path->nodes[level]); 46283f157a2fSChris Mason path->nodes[level] = cur; 4629bd681513SChris Mason path->locks[level] = BTRFS_READ_LOCK; 46303f157a2fSChris Mason 46313f157a2fSChris Mason if (btrfs_header_generation(cur) < min_trans) { 46323f157a2fSChris Mason ret = 1; 46333f157a2fSChris Mason goto out; 46343f157a2fSChris Mason } 46353f157a2fSChris Mason while (1) { 46363f157a2fSChris Mason nritems = btrfs_header_nritems(cur); 46373f157a2fSChris Mason level = btrfs_header_level(cur); 4638fdf8d595SAnand Jain sret = btrfs_bin_search(cur, 0, min_key, &slot); 4639cbca7d59SFilipe Manana if (sret < 0) { 4640cbca7d59SFilipe Manana ret = sret; 4641cbca7d59SFilipe Manana goto out; 4642cbca7d59SFilipe Manana } 46433f157a2fSChris Mason 4644323ac95bSChris Mason /* at the lowest level, we're done, setup the path and exit */ 4645323ac95bSChris Mason if (level == path->lowest_level) { 4646e02119d5SChris Mason if (slot >= nritems) 4647e02119d5SChris Mason goto find_next_key; 46483f157a2fSChris Mason ret = 0; 46493f157a2fSChris Mason path->slots[level] = slot; 46503f157a2fSChris Mason btrfs_item_key_to_cpu(cur, &found_key, slot); 46513f157a2fSChris Mason goto out; 46523f157a2fSChris Mason } 46539652480bSYan if (sret && slot > 0) 46549652480bSYan slot--; 46553f157a2fSChris Mason /* 4656de78b51aSEric Sandeen * check this node pointer against the min_trans parameters. 4657260db43cSRandy Dunlap * If it is too old, skip to the next one. 46583f157a2fSChris Mason */ 46593f157a2fSChris Mason while (slot < nritems) { 46603f157a2fSChris Mason u64 gen; 4661e02119d5SChris Mason 46623f157a2fSChris Mason gen = btrfs_node_ptr_generation(cur, slot); 46633f157a2fSChris Mason if (gen < min_trans) { 46643f157a2fSChris Mason slot++; 46653f157a2fSChris Mason continue; 46663f157a2fSChris Mason } 46673f157a2fSChris Mason break; 46683f157a2fSChris Mason } 4669e02119d5SChris Mason find_next_key: 46703f157a2fSChris Mason /* 46713f157a2fSChris Mason * we didn't find a candidate key in this node, walk forward 46723f157a2fSChris Mason * and find another one 46733f157a2fSChris Mason */ 46743f157a2fSChris Mason if (slot >= nritems) { 4675e02119d5SChris Mason path->slots[level] = slot; 4676e02119d5SChris Mason sret = btrfs_find_next_key(root, path, min_key, level, 4677de78b51aSEric Sandeen min_trans); 4678e02119d5SChris Mason if (sret == 0) { 4679b3b4aa74SDavid Sterba btrfs_release_path(path); 46803f157a2fSChris Mason goto again; 46813f157a2fSChris Mason } else { 46823f157a2fSChris Mason goto out; 46833f157a2fSChris Mason } 46843f157a2fSChris Mason } 46853f157a2fSChris Mason /* save our key for returning back */ 46863f157a2fSChris Mason btrfs_node_key_to_cpu(cur, &found_key, slot); 46873f157a2fSChris Mason path->slots[level] = slot; 46883f157a2fSChris Mason if (level == path->lowest_level) { 46893f157a2fSChris Mason ret = 0; 46903f157a2fSChris Mason goto out; 46913f157a2fSChris Mason } 46924b231ae4SDavid Sterba cur = btrfs_read_node_slot(cur, slot); 4693fb770ae4SLiu Bo if (IS_ERR(cur)) { 4694fb770ae4SLiu Bo ret = PTR_ERR(cur); 4695fb770ae4SLiu Bo goto out; 4696fb770ae4SLiu Bo } 46973f157a2fSChris Mason 4698bd681513SChris Mason btrfs_tree_read_lock(cur); 4699b4ce94deSChris Mason 4700bd681513SChris Mason path->locks[level - 1] = BTRFS_READ_LOCK; 47013f157a2fSChris Mason path->nodes[level - 1] = cur; 4702f7c79f30SChris Mason unlock_up(path, level, 1, 0, NULL); 47033f157a2fSChris Mason } 47043f157a2fSChris Mason out: 4705f98de9b9SFilipe Manana path->keep_locks = keep_locks; 4706f98de9b9SFilipe Manana if (ret == 0) { 4707f98de9b9SFilipe Manana btrfs_unlock_up_safe(path, path->lowest_level + 1); 4708f98de9b9SFilipe Manana memcpy(min_key, &found_key, sizeof(found_key)); 4709f98de9b9SFilipe Manana } 47103f157a2fSChris Mason return ret; 47113f157a2fSChris Mason } 47123f157a2fSChris Mason 47133f157a2fSChris Mason /* 47143f157a2fSChris Mason * this is similar to btrfs_next_leaf, but does not try to preserve 47153f157a2fSChris Mason * and fixup the path. It looks for and returns the next key in the 4716de78b51aSEric Sandeen * tree based on the current path and the min_trans parameters. 47173f157a2fSChris Mason * 47183f157a2fSChris Mason * 0 is returned if another key is found, < 0 if there are any errors 47193f157a2fSChris Mason * and 1 is returned if there are no higher keys in the tree 47203f157a2fSChris Mason * 47213f157a2fSChris Mason * path->keep_locks should be set to 1 on the search made before 47223f157a2fSChris Mason * calling this function. 47233f157a2fSChris Mason */ 4724e7a84565SChris Mason int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, 4725de78b51aSEric Sandeen struct btrfs_key *key, int level, u64 min_trans) 4726e7a84565SChris Mason { 4727e7a84565SChris Mason int slot; 4728e7a84565SChris Mason struct extent_buffer *c; 4729e7a84565SChris Mason 47306a9fb468SJosef Bacik WARN_ON(!path->keep_locks && !path->skip_locking); 4731e7a84565SChris Mason while (level < BTRFS_MAX_LEVEL) { 4732e7a84565SChris Mason if (!path->nodes[level]) 4733e7a84565SChris Mason return 1; 4734e7a84565SChris Mason 4735e7a84565SChris Mason slot = path->slots[level] + 1; 4736e7a84565SChris Mason c = path->nodes[level]; 47373f157a2fSChris Mason next: 4738e7a84565SChris Mason if (slot >= btrfs_header_nritems(c)) { 473933c66f43SYan Zheng int ret; 474033c66f43SYan Zheng int orig_lowest; 474133c66f43SYan Zheng struct btrfs_key cur_key; 474233c66f43SYan Zheng if (level + 1 >= BTRFS_MAX_LEVEL || 474333c66f43SYan Zheng !path->nodes[level + 1]) 4744e7a84565SChris Mason return 1; 474533c66f43SYan Zheng 47466a9fb468SJosef Bacik if (path->locks[level + 1] || path->skip_locking) { 474733c66f43SYan Zheng level++; 4748e7a84565SChris Mason continue; 4749e7a84565SChris Mason } 475033c66f43SYan Zheng 475133c66f43SYan Zheng slot = btrfs_header_nritems(c) - 1; 475233c66f43SYan Zheng if (level == 0) 475333c66f43SYan Zheng btrfs_item_key_to_cpu(c, &cur_key, slot); 475433c66f43SYan Zheng else 475533c66f43SYan Zheng btrfs_node_key_to_cpu(c, &cur_key, slot); 475633c66f43SYan Zheng 475733c66f43SYan Zheng orig_lowest = path->lowest_level; 4758b3b4aa74SDavid Sterba btrfs_release_path(path); 475933c66f43SYan Zheng path->lowest_level = level; 476033c66f43SYan Zheng ret = btrfs_search_slot(NULL, root, &cur_key, path, 476133c66f43SYan Zheng 0, 0); 476233c66f43SYan Zheng path->lowest_level = orig_lowest; 476333c66f43SYan Zheng if (ret < 0) 476433c66f43SYan Zheng return ret; 476533c66f43SYan Zheng 476633c66f43SYan Zheng c = path->nodes[level]; 476733c66f43SYan Zheng slot = path->slots[level]; 476833c66f43SYan Zheng if (ret == 0) 476933c66f43SYan Zheng slot++; 477033c66f43SYan Zheng goto next; 477133c66f43SYan Zheng } 477233c66f43SYan Zheng 4773e7a84565SChris Mason if (level == 0) 4774e7a84565SChris Mason btrfs_item_key_to_cpu(c, key, slot); 47753f157a2fSChris Mason else { 47763f157a2fSChris Mason u64 gen = btrfs_node_ptr_generation(c, slot); 47773f157a2fSChris Mason 47783f157a2fSChris Mason if (gen < min_trans) { 47793f157a2fSChris Mason slot++; 47803f157a2fSChris Mason goto next; 47813f157a2fSChris Mason } 4782e7a84565SChris Mason btrfs_node_key_to_cpu(c, key, slot); 47833f157a2fSChris Mason } 4784e7a84565SChris Mason return 0; 4785e7a84565SChris Mason } 4786e7a84565SChris Mason return 1; 4787e7a84565SChris Mason } 4788e7a84565SChris Mason 47893d7806ecSJan Schmidt int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, 47903d7806ecSJan Schmidt u64 time_seq) 47913d7806ecSJan Schmidt { 4792d97e63b6SChris Mason int slot; 47938e73f275SChris Mason int level; 47945f39d397SChris Mason struct extent_buffer *c; 47958e73f275SChris Mason struct extent_buffer *next; 4796d96b3424SFilipe Manana struct btrfs_fs_info *fs_info = root->fs_info; 4797925baeddSChris Mason struct btrfs_key key; 4798d96b3424SFilipe Manana bool need_commit_sem = false; 4799925baeddSChris Mason u32 nritems; 4800925baeddSChris Mason int ret; 48010e46318dSJosef Bacik int i; 4802925baeddSChris Mason 4803bdcdd86cSFilipe Manana /* 4804bdcdd86cSFilipe Manana * The nowait semantics are used only for write paths, where we don't 4805bdcdd86cSFilipe Manana * use the tree mod log and sequence numbers. 4806bdcdd86cSFilipe Manana */ 4807bdcdd86cSFilipe Manana if (time_seq) 4808c922b016SStefan Roesch ASSERT(!path->nowait); 4809c922b016SStefan Roesch 4810925baeddSChris Mason nritems = btrfs_header_nritems(path->nodes[0]); 4811d397712bSChris Mason if (nritems == 0) 4812925baeddSChris Mason return 1; 4813925baeddSChris Mason 48148e73f275SChris Mason btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); 48158e73f275SChris Mason again: 48168e73f275SChris Mason level = 1; 48178e73f275SChris Mason next = NULL; 4818b3b4aa74SDavid Sterba btrfs_release_path(path); 48198e73f275SChris Mason 4820a2135011SChris Mason path->keep_locks = 1; 48218e73f275SChris Mason 4822d96b3424SFilipe Manana if (time_seq) { 48233d7806ecSJan Schmidt ret = btrfs_search_old_slot(root, &key, path, time_seq); 4824d96b3424SFilipe Manana } else { 4825d96b3424SFilipe Manana if (path->need_commit_sem) { 4826d96b3424SFilipe Manana path->need_commit_sem = 0; 4827d96b3424SFilipe Manana need_commit_sem = true; 4828bdcdd86cSFilipe Manana if (path->nowait) { 4829bdcdd86cSFilipe Manana if (!down_read_trylock(&fs_info->commit_root_sem)) { 4830bdcdd86cSFilipe Manana ret = -EAGAIN; 4831bdcdd86cSFilipe Manana goto done; 4832bdcdd86cSFilipe Manana } 4833bdcdd86cSFilipe Manana } else { 4834d96b3424SFilipe Manana down_read(&fs_info->commit_root_sem); 4835d96b3424SFilipe Manana } 4836bdcdd86cSFilipe Manana } 4837925baeddSChris Mason ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 4838d96b3424SFilipe Manana } 4839925baeddSChris Mason path->keep_locks = 0; 4840925baeddSChris Mason 4841925baeddSChris Mason if (ret < 0) 4842d96b3424SFilipe Manana goto done; 4843925baeddSChris Mason 4844a2135011SChris Mason nritems = btrfs_header_nritems(path->nodes[0]); 4845168fd7d2SChris Mason /* 4846168fd7d2SChris Mason * by releasing the path above we dropped all our locks. A balance 4847168fd7d2SChris Mason * could have added more items next to the key that used to be 4848168fd7d2SChris Mason * at the very end of the block. So, check again here and 4849168fd7d2SChris Mason * advance the path if there are now more items available. 4850168fd7d2SChris Mason */ 4851a2135011SChris Mason if (nritems > 0 && path->slots[0] < nritems - 1) { 4852e457afecSYan Zheng if (ret == 0) 4853168fd7d2SChris Mason path->slots[0]++; 48548e73f275SChris Mason ret = 0; 4855925baeddSChris Mason goto done; 4856925baeddSChris Mason } 48570b43e04fSLiu Bo /* 48580b43e04fSLiu Bo * So the above check misses one case: 48590b43e04fSLiu Bo * - after releasing the path above, someone has removed the item that 48600b43e04fSLiu Bo * used to be at the very end of the block, and balance between leafs 48610b43e04fSLiu Bo * gets another one with bigger key.offset to replace it. 48620b43e04fSLiu Bo * 48630b43e04fSLiu Bo * This one should be returned as well, or we can get leaf corruption 48640b43e04fSLiu Bo * later(esp. in __btrfs_drop_extents()). 48650b43e04fSLiu Bo * 48660b43e04fSLiu Bo * And a bit more explanation about this check, 48670b43e04fSLiu Bo * with ret > 0, the key isn't found, the path points to the slot 48680b43e04fSLiu Bo * where it should be inserted, so the path->slots[0] item must be the 48690b43e04fSLiu Bo * bigger one. 48700b43e04fSLiu Bo */ 48710b43e04fSLiu Bo if (nritems > 0 && ret > 0 && path->slots[0] == nritems - 1) { 48720b43e04fSLiu Bo ret = 0; 48730b43e04fSLiu Bo goto done; 48740b43e04fSLiu Bo } 4875d97e63b6SChris Mason 4876234b63a0SChris Mason while (level < BTRFS_MAX_LEVEL) { 48778e73f275SChris Mason if (!path->nodes[level]) { 48788e73f275SChris Mason ret = 1; 48798e73f275SChris Mason goto done; 48808e73f275SChris Mason } 48815f39d397SChris Mason 4882d97e63b6SChris Mason slot = path->slots[level] + 1; 4883d97e63b6SChris Mason c = path->nodes[level]; 48845f39d397SChris Mason if (slot >= btrfs_header_nritems(c)) { 4885d97e63b6SChris Mason level++; 48868e73f275SChris Mason if (level == BTRFS_MAX_LEVEL) { 48878e73f275SChris Mason ret = 1; 48888e73f275SChris Mason goto done; 48898e73f275SChris Mason } 4890d97e63b6SChris Mason continue; 4891d97e63b6SChris Mason } 48925f39d397SChris Mason 48930e46318dSJosef Bacik 48940e46318dSJosef Bacik /* 48950e46318dSJosef Bacik * Our current level is where we're going to start from, and to 48960e46318dSJosef Bacik * make sure lockdep doesn't complain we need to drop our locks 48970e46318dSJosef Bacik * and nodes from 0 to our current level. 48980e46318dSJosef Bacik */ 48990e46318dSJosef Bacik for (i = 0; i < level; i++) { 49000e46318dSJosef Bacik if (path->locks[level]) { 49010e46318dSJosef Bacik btrfs_tree_read_unlock(path->nodes[i]); 49020e46318dSJosef Bacik path->locks[i] = 0; 49030e46318dSJosef Bacik } 49040e46318dSJosef Bacik free_extent_buffer(path->nodes[i]); 49050e46318dSJosef Bacik path->nodes[i] = NULL; 4906925baeddSChris Mason } 49075f39d397SChris Mason 49088e73f275SChris Mason next = c; 4909d07b8528SLiu Bo ret = read_block_for_search(root, path, &next, level, 4910cda79c54SDavid Sterba slot, &key); 4911bdcdd86cSFilipe Manana if (ret == -EAGAIN && !path->nowait) 49128e73f275SChris Mason goto again; 49135f39d397SChris Mason 491476a05b35SChris Mason if (ret < 0) { 4915b3b4aa74SDavid Sterba btrfs_release_path(path); 491676a05b35SChris Mason goto done; 491776a05b35SChris Mason } 491876a05b35SChris Mason 49195cd57b2cSChris Mason if (!path->skip_locking) { 4920bd681513SChris Mason ret = btrfs_try_tree_read_lock(next); 4921bdcdd86cSFilipe Manana if (!ret && path->nowait) { 4922bdcdd86cSFilipe Manana ret = -EAGAIN; 4923bdcdd86cSFilipe Manana goto done; 4924bdcdd86cSFilipe Manana } 4925d42244a0SJan Schmidt if (!ret && time_seq) { 4926d42244a0SJan Schmidt /* 4927d42244a0SJan Schmidt * If we don't get the lock, we may be racing 4928d42244a0SJan Schmidt * with push_leaf_left, holding that lock while 4929d42244a0SJan Schmidt * itself waiting for the leaf we've currently 4930d42244a0SJan Schmidt * locked. To solve this situation, we give up 4931d42244a0SJan Schmidt * on our lock and cycle. 4932d42244a0SJan Schmidt */ 4933cf538830SJan Schmidt free_extent_buffer(next); 4934d42244a0SJan Schmidt btrfs_release_path(path); 4935d42244a0SJan Schmidt cond_resched(); 4936d42244a0SJan Schmidt goto again; 4937d42244a0SJan Schmidt } 49380e46318dSJosef Bacik if (!ret) 49390e46318dSJosef Bacik btrfs_tree_read_lock(next); 4940bd681513SChris Mason } 4941d97e63b6SChris Mason break; 4942d97e63b6SChris Mason } 4943d97e63b6SChris Mason path->slots[level] = slot; 4944d97e63b6SChris Mason while (1) { 4945d97e63b6SChris Mason level--; 4946d97e63b6SChris Mason path->nodes[level] = next; 4947d97e63b6SChris Mason path->slots[level] = 0; 4948a74a4b97SChris Mason if (!path->skip_locking) 4949ffeb03cfSJosef Bacik path->locks[level] = BTRFS_READ_LOCK; 4950d97e63b6SChris Mason if (!level) 4951d97e63b6SChris Mason break; 4952b4ce94deSChris Mason 4953d07b8528SLiu Bo ret = read_block_for_search(root, path, &next, level, 4954cda79c54SDavid Sterba 0, &key); 4955bdcdd86cSFilipe Manana if (ret == -EAGAIN && !path->nowait) 49568e73f275SChris Mason goto again; 49578e73f275SChris Mason 495876a05b35SChris Mason if (ret < 0) { 4959b3b4aa74SDavid Sterba btrfs_release_path(path); 496076a05b35SChris Mason goto done; 496176a05b35SChris Mason } 496276a05b35SChris Mason 4963bdcdd86cSFilipe Manana if (!path->skip_locking) { 4964bdcdd86cSFilipe Manana if (path->nowait) { 4965bdcdd86cSFilipe Manana if (!btrfs_try_tree_read_lock(next)) { 4966bdcdd86cSFilipe Manana ret = -EAGAIN; 4967bdcdd86cSFilipe Manana goto done; 4968bdcdd86cSFilipe Manana } 4969bdcdd86cSFilipe Manana } else { 49700e46318dSJosef Bacik btrfs_tree_read_lock(next); 4971d97e63b6SChris Mason } 4972bdcdd86cSFilipe Manana } 4973bdcdd86cSFilipe Manana } 49748e73f275SChris Mason ret = 0; 4975925baeddSChris Mason done: 4976f7c79f30SChris Mason unlock_up(path, 0, 1, 0, NULL); 4977d96b3424SFilipe Manana if (need_commit_sem) { 4978d96b3424SFilipe Manana int ret2; 4979d96b3424SFilipe Manana 4980d96b3424SFilipe Manana path->need_commit_sem = 1; 4981d96b3424SFilipe Manana ret2 = finish_need_commit_sem_search(path); 4982d96b3424SFilipe Manana up_read(&fs_info->commit_root_sem); 4983d96b3424SFilipe Manana if (ret2) 4984d96b3424SFilipe Manana ret = ret2; 4985d96b3424SFilipe Manana } 49868e73f275SChris Mason 49878e73f275SChris Mason return ret; 4988d97e63b6SChris Mason } 49890b86a832SChris Mason 4990890d2b1aSJosef Bacik int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq) 4991890d2b1aSJosef Bacik { 4992890d2b1aSJosef Bacik path->slots[0]++; 4993890d2b1aSJosef Bacik if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) 4994890d2b1aSJosef Bacik return btrfs_next_old_leaf(root, path, time_seq); 4995890d2b1aSJosef Bacik return 0; 4996890d2b1aSJosef Bacik } 4997890d2b1aSJosef Bacik 49983f157a2fSChris Mason /* 49993f157a2fSChris Mason * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps 50003f157a2fSChris Mason * searching until it gets past min_objectid or finds an item of 'type' 50013f157a2fSChris Mason * 50023f157a2fSChris Mason * returns 0 if something is found, 1 if nothing was found and < 0 on error 50033f157a2fSChris Mason */ 50040b86a832SChris Mason int btrfs_previous_item(struct btrfs_root *root, 50050b86a832SChris Mason struct btrfs_path *path, u64 min_objectid, 50060b86a832SChris Mason int type) 50070b86a832SChris Mason { 50080b86a832SChris Mason struct btrfs_key found_key; 50090b86a832SChris Mason struct extent_buffer *leaf; 5010e02119d5SChris Mason u32 nritems; 50110b86a832SChris Mason int ret; 50120b86a832SChris Mason 50130b86a832SChris Mason while (1) { 50140b86a832SChris Mason if (path->slots[0] == 0) { 50150b86a832SChris Mason ret = btrfs_prev_leaf(root, path); 50160b86a832SChris Mason if (ret != 0) 50170b86a832SChris Mason return ret; 50180b86a832SChris Mason } else { 50190b86a832SChris Mason path->slots[0]--; 50200b86a832SChris Mason } 50210b86a832SChris Mason leaf = path->nodes[0]; 5022e02119d5SChris Mason nritems = btrfs_header_nritems(leaf); 5023e02119d5SChris Mason if (nritems == 0) 5024e02119d5SChris Mason return 1; 5025e02119d5SChris Mason if (path->slots[0] == nritems) 5026e02119d5SChris Mason path->slots[0]--; 5027e02119d5SChris Mason 50280b86a832SChris Mason btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 5029e02119d5SChris Mason if (found_key.objectid < min_objectid) 5030e02119d5SChris Mason break; 50310a4eefbbSYan Zheng if (found_key.type == type) 50320a4eefbbSYan Zheng return 0; 5033e02119d5SChris Mason if (found_key.objectid == min_objectid && 5034e02119d5SChris Mason found_key.type < type) 5035e02119d5SChris Mason break; 50360b86a832SChris Mason } 50370b86a832SChris Mason return 1; 50380b86a832SChris Mason } 5039ade2e0b3SWang Shilong 5040ade2e0b3SWang Shilong /* 5041ade2e0b3SWang Shilong * search in extent tree to find a previous Metadata/Data extent item with 5042ade2e0b3SWang Shilong * min objecitd. 5043ade2e0b3SWang Shilong * 5044ade2e0b3SWang Shilong * returns 0 if something is found, 1 if nothing was found and < 0 on error 5045ade2e0b3SWang Shilong */ 5046ade2e0b3SWang Shilong int btrfs_previous_extent_item(struct btrfs_root *root, 5047ade2e0b3SWang Shilong struct btrfs_path *path, u64 min_objectid) 5048ade2e0b3SWang Shilong { 5049ade2e0b3SWang Shilong struct btrfs_key found_key; 5050ade2e0b3SWang Shilong struct extent_buffer *leaf; 5051ade2e0b3SWang Shilong u32 nritems; 5052ade2e0b3SWang Shilong int ret; 5053ade2e0b3SWang Shilong 5054ade2e0b3SWang Shilong while (1) { 5055ade2e0b3SWang Shilong if (path->slots[0] == 0) { 5056ade2e0b3SWang Shilong ret = btrfs_prev_leaf(root, path); 5057ade2e0b3SWang Shilong if (ret != 0) 5058ade2e0b3SWang Shilong return ret; 5059ade2e0b3SWang Shilong } else { 5060ade2e0b3SWang Shilong path->slots[0]--; 5061ade2e0b3SWang Shilong } 5062ade2e0b3SWang Shilong leaf = path->nodes[0]; 5063ade2e0b3SWang Shilong nritems = btrfs_header_nritems(leaf); 5064ade2e0b3SWang Shilong if (nritems == 0) 5065ade2e0b3SWang Shilong return 1; 5066ade2e0b3SWang Shilong if (path->slots[0] == nritems) 5067ade2e0b3SWang Shilong path->slots[0]--; 5068ade2e0b3SWang Shilong 5069ade2e0b3SWang Shilong btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 5070ade2e0b3SWang Shilong if (found_key.objectid < min_objectid) 5071ade2e0b3SWang Shilong break; 5072ade2e0b3SWang Shilong if (found_key.type == BTRFS_EXTENT_ITEM_KEY || 5073ade2e0b3SWang Shilong found_key.type == BTRFS_METADATA_ITEM_KEY) 5074ade2e0b3SWang Shilong return 0; 5075ade2e0b3SWang Shilong if (found_key.objectid == min_objectid && 5076ade2e0b3SWang Shilong found_key.type < BTRFS_EXTENT_ITEM_KEY) 5077ade2e0b3SWang Shilong break; 5078ade2e0b3SWang Shilong } 5079ade2e0b3SWang Shilong return 1; 5080ade2e0b3SWang Shilong } 5081226463d7SJosef Bacik 5082226463d7SJosef Bacik int __init btrfs_ctree_init(void) 5083226463d7SJosef Bacik { 5084226463d7SJosef Bacik btrfs_path_cachep = kmem_cache_create("btrfs_path", 5085226463d7SJosef Bacik sizeof(struct btrfs_path), 0, 5086226463d7SJosef Bacik SLAB_MEM_SPREAD, NULL); 5087226463d7SJosef Bacik if (!btrfs_path_cachep) 5088226463d7SJosef Bacik return -ENOMEM; 5089226463d7SJosef Bacik return 0; 5090226463d7SJosef Bacik } 5091226463d7SJosef Bacik 5092226463d7SJosef Bacik void __cold btrfs_ctree_exit(void) 5093226463d7SJosef Bacik { 5094226463d7SJosef Bacik kmem_cache_destroy(btrfs_path_cachep); 5095226463d7SJosef Bacik } 5096