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> 11eb60ceacSChris Mason #include "ctree.h" 12eb60ceacSChris Mason #include "disk-io.h" 137f5c1516SChris Mason #include "transaction.h" 145f39d397SChris Mason #include "print-tree.h" 15925baeddSChris Mason #include "locking.h" 16de37aa51SNikolay Borisov #include "volumes.h" 17f616f5cdSQu Wenruo #include "qgroup.h" 18f3a84ccdSFilipe Manana #include "tree-mod-log.h" 199a8dd150SChris Mason 20e089f05cSChris Mason static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root 21e089f05cSChris Mason *root, struct btrfs_path *path, int level); 22310712b2SOmar Sandoval static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root *root, 23310712b2SOmar Sandoval const struct btrfs_key *ins_key, struct btrfs_path *path, 24310712b2SOmar Sandoval int data_size, int extend); 255f39d397SChris Mason static int push_node_left(struct btrfs_trans_handle *trans, 262ff7e61eSJeff Mahoney struct extent_buffer *dst, 27971a1f66SChris Mason struct extent_buffer *src, int empty); 285f39d397SChris Mason static int balance_node_right(struct btrfs_trans_handle *trans, 295f39d397SChris Mason struct extent_buffer *dst_buf, 305f39d397SChris Mason struct extent_buffer *src_buf); 31afe5fea7STsutomu Itoh static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, 32afe5fea7STsutomu Itoh int level, int slot); 33d97e63b6SChris Mason 34af024ed2SJohannes Thumshirn static const struct btrfs_csums { 35af024ed2SJohannes Thumshirn u16 size; 3659a0fcdbSDavid Sterba const char name[10]; 3759a0fcdbSDavid Sterba const char driver[12]; 38af024ed2SJohannes Thumshirn } btrfs_csums[] = { 39af024ed2SJohannes Thumshirn [BTRFS_CSUM_TYPE_CRC32] = { .size = 4, .name = "crc32c" }, 403951e7f0SJohannes Thumshirn [BTRFS_CSUM_TYPE_XXHASH] = { .size = 8, .name = "xxhash64" }, 413831bf00SJohannes Thumshirn [BTRFS_CSUM_TYPE_SHA256] = { .size = 32, .name = "sha256" }, 42352ae07bSDavid Sterba [BTRFS_CSUM_TYPE_BLAKE2] = { .size = 32, .name = "blake2b", 43352ae07bSDavid Sterba .driver = "blake2b-256" }, 44af024ed2SJohannes Thumshirn }; 45af024ed2SJohannes Thumshirn 46af024ed2SJohannes Thumshirn int btrfs_super_csum_size(const struct btrfs_super_block *s) 47af024ed2SJohannes Thumshirn { 48af024ed2SJohannes Thumshirn u16 t = btrfs_super_csum_type(s); 49af024ed2SJohannes Thumshirn /* 50af024ed2SJohannes Thumshirn * csum type is validated at mount time 51af024ed2SJohannes Thumshirn */ 52af024ed2SJohannes Thumshirn return btrfs_csums[t].size; 53af024ed2SJohannes Thumshirn } 54af024ed2SJohannes Thumshirn 55af024ed2SJohannes Thumshirn const char *btrfs_super_csum_name(u16 csum_type) 56af024ed2SJohannes Thumshirn { 57af024ed2SJohannes Thumshirn /* csum type is validated at mount time */ 58af024ed2SJohannes Thumshirn return btrfs_csums[csum_type].name; 59af024ed2SJohannes Thumshirn } 60af024ed2SJohannes Thumshirn 61b4e967beSDavid Sterba /* 62b4e967beSDavid Sterba * Return driver name if defined, otherwise the name that's also a valid driver 63b4e967beSDavid Sterba * name 64b4e967beSDavid Sterba */ 65b4e967beSDavid Sterba const char *btrfs_super_csum_driver(u16 csum_type) 66b4e967beSDavid Sterba { 67b4e967beSDavid Sterba /* csum type is validated at mount time */ 6859a0fcdbSDavid Sterba return btrfs_csums[csum_type].driver[0] ? 6959a0fcdbSDavid Sterba btrfs_csums[csum_type].driver : 70b4e967beSDavid Sterba btrfs_csums[csum_type].name; 71b4e967beSDavid Sterba } 72b4e967beSDavid Sterba 73604997b4SDavid Sterba size_t __attribute_const__ btrfs_get_num_csums(void) 74f7cea56cSDavid Sterba { 75f7cea56cSDavid Sterba return ARRAY_SIZE(btrfs_csums); 76f7cea56cSDavid Sterba } 77f7cea56cSDavid Sterba 782c90e5d6SChris Mason struct btrfs_path *btrfs_alloc_path(void) 792c90e5d6SChris Mason { 80e2c89907SMasahiro Yamada return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); 812c90e5d6SChris Mason } 822c90e5d6SChris Mason 83d352ac68SChris Mason /* this also releases the path */ 842c90e5d6SChris Mason void btrfs_free_path(struct btrfs_path *p) 852c90e5d6SChris Mason { 86ff175d57SJesper Juhl if (!p) 87ff175d57SJesper Juhl return; 88b3b4aa74SDavid Sterba btrfs_release_path(p); 892c90e5d6SChris Mason kmem_cache_free(btrfs_path_cachep, p); 902c90e5d6SChris Mason } 912c90e5d6SChris Mason 92d352ac68SChris Mason /* 93d352ac68SChris Mason * path release drops references on the extent buffers in the path 94d352ac68SChris Mason * and it drops any locks held by this path 95d352ac68SChris Mason * 96d352ac68SChris Mason * It is safe to call this on paths that no locks or extent buffers held. 97d352ac68SChris Mason */ 98b3b4aa74SDavid Sterba noinline void btrfs_release_path(struct btrfs_path *p) 99eb60ceacSChris Mason { 100eb60ceacSChris Mason int i; 101a2135011SChris Mason 102234b63a0SChris Mason for (i = 0; i < BTRFS_MAX_LEVEL; i++) { 1033f157a2fSChris Mason p->slots[i] = 0; 104eb60ceacSChris Mason if (!p->nodes[i]) 105925baeddSChris Mason continue; 106925baeddSChris Mason if (p->locks[i]) { 107bd681513SChris Mason btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); 108925baeddSChris Mason p->locks[i] = 0; 109925baeddSChris Mason } 1105f39d397SChris Mason free_extent_buffer(p->nodes[i]); 1113f157a2fSChris Mason p->nodes[i] = NULL; 112eb60ceacSChris Mason } 113eb60ceacSChris Mason } 114eb60ceacSChris Mason 115d352ac68SChris Mason /* 116d352ac68SChris Mason * safely gets a reference on the root node of a tree. A lock 117d352ac68SChris Mason * is not taken, so a concurrent writer may put a different node 118d352ac68SChris Mason * at the root of the tree. See btrfs_lock_root_node for the 119d352ac68SChris Mason * looping required. 120d352ac68SChris Mason * 121d352ac68SChris Mason * The extent buffer returned by this has a reference taken, so 122d352ac68SChris Mason * it won't disappear. It may stop being the root of the tree 123d352ac68SChris Mason * at any time because there are no locks held. 124d352ac68SChris Mason */ 125925baeddSChris Mason struct extent_buffer *btrfs_root_node(struct btrfs_root *root) 126925baeddSChris Mason { 127925baeddSChris Mason struct extent_buffer *eb; 128240f62c8SChris Mason 1293083ee2eSJosef Bacik while (1) { 130240f62c8SChris Mason rcu_read_lock(); 131240f62c8SChris Mason eb = rcu_dereference(root->node); 1323083ee2eSJosef Bacik 1333083ee2eSJosef Bacik /* 1343083ee2eSJosef Bacik * RCU really hurts here, we could free up the root node because 13501327610SNicholas D Steeves * it was COWed but we may not get the new root node yet so do 1363083ee2eSJosef Bacik * the inc_not_zero dance and if it doesn't work then 1373083ee2eSJosef Bacik * synchronize_rcu and try again. 1383083ee2eSJosef Bacik */ 1393083ee2eSJosef Bacik if (atomic_inc_not_zero(&eb->refs)) { 140240f62c8SChris Mason rcu_read_unlock(); 1413083ee2eSJosef Bacik break; 1423083ee2eSJosef Bacik } 1433083ee2eSJosef Bacik rcu_read_unlock(); 1443083ee2eSJosef Bacik synchronize_rcu(); 1453083ee2eSJosef Bacik } 146925baeddSChris Mason return eb; 147925baeddSChris Mason } 148925baeddSChris Mason 14992a7cc42SQu Wenruo /* 15092a7cc42SQu Wenruo * Cowonly root (not-shareable trees, everything not subvolume or reloc roots), 15192a7cc42SQu Wenruo * just get put onto a simple dirty list. Transaction walks this list to make 15292a7cc42SQu Wenruo * sure they get properly updated on disk. 153d352ac68SChris Mason */ 1540b86a832SChris Mason static void add_root_to_dirty_list(struct btrfs_root *root) 1550b86a832SChris Mason { 1560b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 1570b246afaSJeff Mahoney 158e7070be1SJosef Bacik if (test_bit(BTRFS_ROOT_DIRTY, &root->state) || 159e7070be1SJosef Bacik !test_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state)) 160e7070be1SJosef Bacik return; 161e7070be1SJosef Bacik 1620b246afaSJeff Mahoney spin_lock(&fs_info->trans_lock); 163e7070be1SJosef Bacik if (!test_and_set_bit(BTRFS_ROOT_DIRTY, &root->state)) { 164e7070be1SJosef Bacik /* Want the extent tree to be the last on the list */ 1654fd786e6SMisono Tomohiro if (root->root_key.objectid == BTRFS_EXTENT_TREE_OBJECTID) 166e7070be1SJosef Bacik list_move_tail(&root->dirty_list, 1670b246afaSJeff Mahoney &fs_info->dirty_cowonly_roots); 168e7070be1SJosef Bacik else 169e7070be1SJosef Bacik list_move(&root->dirty_list, 1700b246afaSJeff Mahoney &fs_info->dirty_cowonly_roots); 1710b86a832SChris Mason } 1720b246afaSJeff Mahoney spin_unlock(&fs_info->trans_lock); 1730b86a832SChris Mason } 1740b86a832SChris Mason 175d352ac68SChris Mason /* 176d352ac68SChris Mason * used by snapshot creation to make a copy of a root for a tree with 177d352ac68SChris Mason * a given objectid. The buffer with the new root node is returned in 178d352ac68SChris Mason * cow_ret, and this func returns zero on success or a negative error code. 179d352ac68SChris Mason */ 180be20aa9dSChris Mason int btrfs_copy_root(struct btrfs_trans_handle *trans, 181be20aa9dSChris Mason struct btrfs_root *root, 182be20aa9dSChris Mason struct extent_buffer *buf, 183be20aa9dSChris Mason struct extent_buffer **cow_ret, u64 new_root_objectid) 184be20aa9dSChris Mason { 1850b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 186be20aa9dSChris Mason struct extent_buffer *cow; 187be20aa9dSChris Mason int ret = 0; 188be20aa9dSChris Mason int level; 1895d4f98a2SYan Zheng struct btrfs_disk_key disk_key; 190be20aa9dSChris Mason 19192a7cc42SQu Wenruo WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && 1920b246afaSJeff Mahoney trans->transid != fs_info->running_transaction->transid); 19392a7cc42SQu Wenruo WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && 19427cdeb70SMiao Xie trans->transid != root->last_trans); 195be20aa9dSChris Mason 196be20aa9dSChris Mason level = btrfs_header_level(buf); 1975d4f98a2SYan Zheng if (level == 0) 1985d4f98a2SYan Zheng btrfs_item_key(buf, &disk_key, 0); 1995d4f98a2SYan Zheng else 2005d4f98a2SYan Zheng btrfs_node_key(buf, &disk_key, 0); 20131840ae1SZheng Yan 2024d75f8a9SDavid Sterba cow = btrfs_alloc_tree_block(trans, root, 0, new_root_objectid, 203cf6f34aaSJosef Bacik &disk_key, level, buf->start, 0, 204cf6f34aaSJosef Bacik BTRFS_NESTING_NEW_ROOT); 2055d4f98a2SYan Zheng if (IS_ERR(cow)) 206be20aa9dSChris Mason return PTR_ERR(cow); 207be20aa9dSChris Mason 20858e8012cSDavid Sterba copy_extent_buffer_full(cow, buf); 209be20aa9dSChris Mason btrfs_set_header_bytenr(cow, cow->start); 210be20aa9dSChris Mason btrfs_set_header_generation(cow, trans->transid); 2115d4f98a2SYan Zheng btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); 2125d4f98a2SYan Zheng btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | 2135d4f98a2SYan Zheng BTRFS_HEADER_FLAG_RELOC); 2145d4f98a2SYan Zheng if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) 2155d4f98a2SYan Zheng btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); 2165d4f98a2SYan Zheng else 217be20aa9dSChris Mason btrfs_set_header_owner(cow, new_root_objectid); 218be20aa9dSChris Mason 219de37aa51SNikolay Borisov write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); 2202b82032cSYan Zheng 221be20aa9dSChris Mason WARN_ON(btrfs_header_generation(buf) > trans->transid); 2225d4f98a2SYan Zheng if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) 223e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 1); 2245d4f98a2SYan Zheng else 225e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 0); 226867ed321SJosef Bacik if (ret) { 22772c9925fSFilipe Manana btrfs_tree_unlock(cow); 22872c9925fSFilipe Manana free_extent_buffer(cow); 229867ed321SJosef Bacik btrfs_abort_transaction(trans, ret); 230be20aa9dSChris Mason return ret; 231867ed321SJosef Bacik } 232be20aa9dSChris Mason 233be20aa9dSChris Mason btrfs_mark_buffer_dirty(cow); 234be20aa9dSChris Mason *cow_ret = cow; 235be20aa9dSChris Mason return 0; 236be20aa9dSChris Mason } 237be20aa9dSChris Mason 238d352ac68SChris Mason /* 2395d4f98a2SYan Zheng * check if the tree block can be shared by multiple trees 2405d4f98a2SYan Zheng */ 2415d4f98a2SYan Zheng int btrfs_block_can_be_shared(struct btrfs_root *root, 2425d4f98a2SYan Zheng struct extent_buffer *buf) 2435d4f98a2SYan Zheng { 2445d4f98a2SYan Zheng /* 24592a7cc42SQu Wenruo * Tree blocks not in shareable trees and tree roots are never shared. 24692a7cc42SQu Wenruo * If a block was allocated after the last snapshot and the block was 24792a7cc42SQu Wenruo * not allocated by tree relocation, we know the block is not shared. 2485d4f98a2SYan Zheng */ 24992a7cc42SQu Wenruo if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && 2505d4f98a2SYan Zheng buf != root->node && buf != root->commit_root && 2515d4f98a2SYan Zheng (btrfs_header_generation(buf) <= 2525d4f98a2SYan Zheng btrfs_root_last_snapshot(&root->root_item) || 2535d4f98a2SYan Zheng btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) 2545d4f98a2SYan Zheng return 1; 255a79865c6SNikolay Borisov 2565d4f98a2SYan Zheng return 0; 2575d4f98a2SYan Zheng } 2585d4f98a2SYan Zheng 2595d4f98a2SYan Zheng static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, 2605d4f98a2SYan Zheng struct btrfs_root *root, 2615d4f98a2SYan Zheng struct extent_buffer *buf, 262f0486c68SYan, Zheng struct extent_buffer *cow, 263f0486c68SYan, Zheng int *last_ref) 2645d4f98a2SYan Zheng { 2650b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 2665d4f98a2SYan Zheng u64 refs; 2675d4f98a2SYan Zheng u64 owner; 2685d4f98a2SYan Zheng u64 flags; 2695d4f98a2SYan Zheng u64 new_flags = 0; 2705d4f98a2SYan Zheng int ret; 2715d4f98a2SYan Zheng 2725d4f98a2SYan Zheng /* 2735d4f98a2SYan Zheng * Backrefs update rules: 2745d4f98a2SYan Zheng * 2755d4f98a2SYan Zheng * Always use full backrefs for extent pointers in tree block 2765d4f98a2SYan Zheng * allocated by tree relocation. 2775d4f98a2SYan Zheng * 2785d4f98a2SYan Zheng * If a shared tree block is no longer referenced by its owner 2795d4f98a2SYan Zheng * tree (btrfs_header_owner(buf) == root->root_key.objectid), 2805d4f98a2SYan Zheng * use full backrefs for extent pointers in tree block. 2815d4f98a2SYan Zheng * 2825d4f98a2SYan Zheng * If a tree block is been relocating 2835d4f98a2SYan Zheng * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), 2845d4f98a2SYan Zheng * use full backrefs for extent pointers in tree block. 2855d4f98a2SYan Zheng * The reason for this is some operations (such as drop tree) 2865d4f98a2SYan Zheng * are only allowed for blocks use full backrefs. 2875d4f98a2SYan Zheng */ 2885d4f98a2SYan Zheng 2895d4f98a2SYan Zheng if (btrfs_block_can_be_shared(root, buf)) { 2902ff7e61eSJeff Mahoney ret = btrfs_lookup_extent_info(trans, fs_info, buf->start, 2913173a18fSJosef Bacik btrfs_header_level(buf), 1, 2923173a18fSJosef Bacik &refs, &flags); 293be1a5564SMark Fasheh if (ret) 294be1a5564SMark Fasheh return ret; 295e5df9573SMark Fasheh if (refs == 0) { 296e5df9573SMark Fasheh ret = -EROFS; 2970b246afaSJeff Mahoney btrfs_handle_fs_error(fs_info, ret, NULL); 298e5df9573SMark Fasheh return ret; 299e5df9573SMark Fasheh } 3005d4f98a2SYan Zheng } else { 3015d4f98a2SYan Zheng refs = 1; 3025d4f98a2SYan Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || 3035d4f98a2SYan Zheng btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) 3045d4f98a2SYan Zheng flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; 3055d4f98a2SYan Zheng else 3065d4f98a2SYan Zheng flags = 0; 3075d4f98a2SYan Zheng } 3085d4f98a2SYan Zheng 3095d4f98a2SYan Zheng owner = btrfs_header_owner(buf); 3105d4f98a2SYan Zheng BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && 3115d4f98a2SYan Zheng !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); 3125d4f98a2SYan Zheng 3135d4f98a2SYan Zheng if (refs > 1) { 3145d4f98a2SYan Zheng if ((owner == root->root_key.objectid || 3155d4f98a2SYan Zheng root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && 3165d4f98a2SYan Zheng !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { 317e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, buf, 1); 318692826b2SJeff Mahoney if (ret) 319692826b2SJeff Mahoney return ret; 3205d4f98a2SYan Zheng 3215d4f98a2SYan Zheng if (root->root_key.objectid == 3225d4f98a2SYan Zheng BTRFS_TREE_RELOC_OBJECTID) { 323e339a6b0SJosef Bacik ret = btrfs_dec_ref(trans, root, buf, 0); 324692826b2SJeff Mahoney if (ret) 325692826b2SJeff Mahoney return ret; 326e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 1); 327692826b2SJeff Mahoney if (ret) 328692826b2SJeff Mahoney return ret; 3295d4f98a2SYan Zheng } 3305d4f98a2SYan Zheng new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; 3315d4f98a2SYan Zheng } else { 3325d4f98a2SYan Zheng 3335d4f98a2SYan Zheng if (root->root_key.objectid == 3345d4f98a2SYan Zheng BTRFS_TREE_RELOC_OBJECTID) 335e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 1); 3365d4f98a2SYan Zheng else 337e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 0); 338692826b2SJeff Mahoney if (ret) 339692826b2SJeff Mahoney return ret; 3405d4f98a2SYan Zheng } 3415d4f98a2SYan Zheng if (new_flags != 0) { 342b1c79e09SJosef Bacik int level = btrfs_header_level(buf); 343b1c79e09SJosef Bacik 34442c9d0b5SDavid Sterba ret = btrfs_set_disk_extent_flags(trans, buf, 345b1c79e09SJosef Bacik new_flags, level, 0); 346be1a5564SMark Fasheh if (ret) 347be1a5564SMark Fasheh return ret; 3485d4f98a2SYan Zheng } 3495d4f98a2SYan Zheng } else { 3505d4f98a2SYan Zheng if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { 3515d4f98a2SYan Zheng if (root->root_key.objectid == 3525d4f98a2SYan Zheng BTRFS_TREE_RELOC_OBJECTID) 353e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 1); 3545d4f98a2SYan Zheng else 355e339a6b0SJosef Bacik ret = btrfs_inc_ref(trans, root, cow, 0); 356692826b2SJeff Mahoney if (ret) 357692826b2SJeff Mahoney return ret; 358e339a6b0SJosef Bacik ret = btrfs_dec_ref(trans, root, buf, 1); 359692826b2SJeff Mahoney if (ret) 360692826b2SJeff Mahoney return ret; 3615d4f98a2SYan Zheng } 3626a884d7dSDavid Sterba btrfs_clean_tree_block(buf); 363f0486c68SYan, Zheng *last_ref = 1; 3645d4f98a2SYan Zheng } 3655d4f98a2SYan Zheng return 0; 3665d4f98a2SYan Zheng } 3675d4f98a2SYan Zheng 3685d4f98a2SYan Zheng /* 369d397712bSChris Mason * does the dirty work in cow of a single block. The parent block (if 370d397712bSChris Mason * supplied) is updated to point to the new cow copy. The new buffer is marked 371d397712bSChris Mason * dirty and returned locked. If you modify the block it needs to be marked 372d397712bSChris Mason * dirty again. 373d352ac68SChris Mason * 374d352ac68SChris Mason * search_start -- an allocation hint for the new block 375d352ac68SChris Mason * 376d397712bSChris Mason * empty_size -- a hint that you plan on doing more cow. This is the size in 377d397712bSChris Mason * bytes the allocator should try to find free next to the block it returns. 378d397712bSChris Mason * This is just a hint and may be ignored by the allocator. 379d352ac68SChris Mason */ 380d397712bSChris Mason static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, 3815f39d397SChris Mason struct btrfs_root *root, 3825f39d397SChris Mason struct extent_buffer *buf, 3835f39d397SChris Mason struct extent_buffer *parent, int parent_slot, 3845f39d397SChris Mason struct extent_buffer **cow_ret, 3859631e4ccSJosef Bacik u64 search_start, u64 empty_size, 3869631e4ccSJosef Bacik enum btrfs_lock_nesting nest) 3876702ed49SChris Mason { 3880b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 3895d4f98a2SYan Zheng struct btrfs_disk_key disk_key; 3905f39d397SChris Mason struct extent_buffer *cow; 391be1a5564SMark Fasheh int level, ret; 392f0486c68SYan, Zheng int last_ref = 0; 393925baeddSChris Mason int unlock_orig = 0; 3940f5053ebSGoldwyn Rodrigues u64 parent_start = 0; 3956702ed49SChris Mason 396925baeddSChris Mason if (*cow_ret == buf) 397925baeddSChris Mason unlock_orig = 1; 398925baeddSChris Mason 39949d0c642SFilipe Manana btrfs_assert_tree_write_locked(buf); 400925baeddSChris Mason 40192a7cc42SQu Wenruo WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && 4020b246afaSJeff Mahoney trans->transid != fs_info->running_transaction->transid); 40392a7cc42SQu Wenruo WARN_ON(test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && 40427cdeb70SMiao Xie trans->transid != root->last_trans); 4055f39d397SChris Mason 4067bb86316SChris Mason level = btrfs_header_level(buf); 40731840ae1SZheng Yan 4085d4f98a2SYan Zheng if (level == 0) 4095d4f98a2SYan Zheng btrfs_item_key(buf, &disk_key, 0); 4105d4f98a2SYan Zheng else 4115d4f98a2SYan Zheng btrfs_node_key(buf, &disk_key, 0); 4125d4f98a2SYan Zheng 4130f5053ebSGoldwyn Rodrigues if ((root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && parent) 4145d4f98a2SYan Zheng parent_start = parent->start; 4155d4f98a2SYan Zheng 41679bd3712SFilipe Manana cow = btrfs_alloc_tree_block(trans, root, parent_start, 41779bd3712SFilipe Manana root->root_key.objectid, &disk_key, level, 41879bd3712SFilipe Manana search_start, empty_size, nest); 4196702ed49SChris Mason if (IS_ERR(cow)) 4206702ed49SChris Mason return PTR_ERR(cow); 4216702ed49SChris Mason 422b4ce94deSChris Mason /* cow is set to blocking by btrfs_init_new_buffer */ 423b4ce94deSChris Mason 42458e8012cSDavid Sterba copy_extent_buffer_full(cow, buf); 425db94535dSChris Mason btrfs_set_header_bytenr(cow, cow->start); 4265f39d397SChris Mason btrfs_set_header_generation(cow, trans->transid); 4275d4f98a2SYan Zheng btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); 4285d4f98a2SYan Zheng btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | 4295d4f98a2SYan Zheng BTRFS_HEADER_FLAG_RELOC); 4305d4f98a2SYan Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) 4315d4f98a2SYan Zheng btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); 4325d4f98a2SYan Zheng else 4335f39d397SChris Mason btrfs_set_header_owner(cow, root->root_key.objectid); 4346702ed49SChris Mason 435de37aa51SNikolay Borisov write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); 4362b82032cSYan Zheng 437be1a5564SMark Fasheh ret = update_ref_for_cow(trans, root, buf, cow, &last_ref); 438b68dc2a9SMark Fasheh if (ret) { 439572c83acSJosef Bacik btrfs_tree_unlock(cow); 440572c83acSJosef Bacik free_extent_buffer(cow); 44166642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 442b68dc2a9SMark Fasheh return ret; 443b68dc2a9SMark Fasheh } 4441a40e23bSZheng Yan 44592a7cc42SQu Wenruo if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) { 44683d4cfd4SJosef Bacik ret = btrfs_reloc_cow_block(trans, root, buf, cow); 44793314e3bSZhaolei if (ret) { 448572c83acSJosef Bacik btrfs_tree_unlock(cow); 449572c83acSJosef Bacik free_extent_buffer(cow); 45066642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 45183d4cfd4SJosef Bacik return ret; 45283d4cfd4SJosef Bacik } 45393314e3bSZhaolei } 4543fd0a558SYan, Zheng 4556702ed49SChris Mason if (buf == root->node) { 456925baeddSChris Mason WARN_ON(parent && parent != buf); 4575d4f98a2SYan Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || 4585d4f98a2SYan Zheng btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) 4595d4f98a2SYan Zheng parent_start = buf->start; 460925baeddSChris Mason 46167439dadSDavid Sterba atomic_inc(&cow->refs); 462406808abSFilipe Manana ret = btrfs_tree_mod_log_insert_root(root->node, cow, true); 463d9d19a01SDavid Sterba BUG_ON(ret < 0); 464240f62c8SChris Mason rcu_assign_pointer(root->node, cow); 465925baeddSChris Mason 4667a163608SFilipe Manana btrfs_free_tree_block(trans, btrfs_root_id(root), buf, 4677a163608SFilipe Manana parent_start, last_ref); 4685f39d397SChris Mason free_extent_buffer(buf); 4690b86a832SChris Mason add_root_to_dirty_list(root); 4706702ed49SChris Mason } else { 4715d4f98a2SYan Zheng WARN_ON(trans->transid != btrfs_header_generation(parent)); 472f3a84ccdSFilipe Manana btrfs_tree_mod_log_insert_key(parent, parent_slot, 473f3a84ccdSFilipe Manana BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS); 4745f39d397SChris Mason btrfs_set_node_blockptr(parent, parent_slot, 475db94535dSChris Mason cow->start); 47674493f7aSChris Mason btrfs_set_node_ptr_generation(parent, parent_slot, 47774493f7aSChris Mason trans->transid); 4786702ed49SChris Mason btrfs_mark_buffer_dirty(parent); 4795de865eeSFilipe David Borba Manana if (last_ref) { 480f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_free_eb(buf); 4815de865eeSFilipe David Borba Manana if (ret) { 482572c83acSJosef Bacik btrfs_tree_unlock(cow); 483572c83acSJosef Bacik free_extent_buffer(cow); 48466642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 4855de865eeSFilipe David Borba Manana return ret; 4865de865eeSFilipe David Borba Manana } 4875de865eeSFilipe David Borba Manana } 4887a163608SFilipe Manana btrfs_free_tree_block(trans, btrfs_root_id(root), buf, 4897a163608SFilipe Manana parent_start, last_ref); 4906702ed49SChris Mason } 491925baeddSChris Mason if (unlock_orig) 492925baeddSChris Mason btrfs_tree_unlock(buf); 4933083ee2eSJosef Bacik free_extent_buffer_stale(buf); 4946702ed49SChris Mason btrfs_mark_buffer_dirty(cow); 4956702ed49SChris Mason *cow_ret = cow; 4966702ed49SChris Mason return 0; 4976702ed49SChris Mason } 4986702ed49SChris Mason 4995d4f98a2SYan Zheng static inline int should_cow_block(struct btrfs_trans_handle *trans, 5005d4f98a2SYan Zheng struct btrfs_root *root, 5015d4f98a2SYan Zheng struct extent_buffer *buf) 5025d4f98a2SYan Zheng { 503f5ee5c9aSJeff Mahoney if (btrfs_is_testing(root->fs_info)) 504faa2dbf0SJosef Bacik return 0; 505fccb84c9SDavid Sterba 506d1980131SDavid Sterba /* Ensure we can see the FORCE_COW bit */ 507d1980131SDavid Sterba smp_mb__before_atomic(); 508f1ebcc74SLiu Bo 509f1ebcc74SLiu Bo /* 510f1ebcc74SLiu Bo * We do not need to cow a block if 511f1ebcc74SLiu Bo * 1) this block is not created or changed in this transaction; 512f1ebcc74SLiu Bo * 2) this block does not belong to TREE_RELOC tree; 513f1ebcc74SLiu Bo * 3) the root is not forced COW. 514f1ebcc74SLiu Bo * 515f1ebcc74SLiu Bo * What is forced COW: 51601327610SNicholas D Steeves * when we create snapshot during committing the transaction, 51752042d8eSAndrea Gelmini * after we've finished copying src root, we must COW the shared 518f1ebcc74SLiu Bo * block to ensure the metadata consistency. 519f1ebcc74SLiu Bo */ 5205d4f98a2SYan Zheng if (btrfs_header_generation(buf) == trans->transid && 5215d4f98a2SYan Zheng !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && 5225d4f98a2SYan Zheng !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && 523f1ebcc74SLiu Bo btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && 52427cdeb70SMiao Xie !test_bit(BTRFS_ROOT_FORCE_COW, &root->state)) 5255d4f98a2SYan Zheng return 0; 5265d4f98a2SYan Zheng return 1; 5275d4f98a2SYan Zheng } 5285d4f98a2SYan Zheng 529d352ac68SChris Mason /* 530d352ac68SChris Mason * cows a single block, see __btrfs_cow_block for the real work. 53101327610SNicholas D Steeves * This version of it has extra checks so that a block isn't COWed more than 532d352ac68SChris Mason * once per transaction, as long as it hasn't been written yet 533d352ac68SChris Mason */ 534d397712bSChris Mason noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, 5355f39d397SChris Mason struct btrfs_root *root, struct extent_buffer *buf, 5365f39d397SChris Mason struct extent_buffer *parent, int parent_slot, 5379631e4ccSJosef Bacik struct extent_buffer **cow_ret, 5389631e4ccSJosef Bacik enum btrfs_lock_nesting nest) 53902217ed2SChris Mason { 5400b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 5416702ed49SChris Mason u64 search_start; 542f510cfecSChris Mason int ret; 543dc17ff8fSChris Mason 54483354f07SJosef Bacik if (test_bit(BTRFS_ROOT_DELETING, &root->state)) 54583354f07SJosef Bacik btrfs_err(fs_info, 54683354f07SJosef Bacik "COW'ing blocks on a fs root that's being dropped"); 54783354f07SJosef Bacik 5480b246afaSJeff Mahoney if (trans->transaction != fs_info->running_transaction) 54931b1a2bdSJulia Lawall WARN(1, KERN_CRIT "trans %llu running %llu\n", 550c1c9ff7cSGeert Uytterhoeven trans->transid, 5510b246afaSJeff Mahoney fs_info->running_transaction->transid); 55231b1a2bdSJulia Lawall 5530b246afaSJeff Mahoney if (trans->transid != fs_info->generation) 55431b1a2bdSJulia Lawall WARN(1, KERN_CRIT "trans %llu running %llu\n", 5550b246afaSJeff Mahoney trans->transid, fs_info->generation); 556dc17ff8fSChris Mason 5575d4f98a2SYan Zheng if (!should_cow_block(trans, root, buf)) { 55802217ed2SChris Mason *cow_ret = buf; 55902217ed2SChris Mason return 0; 56002217ed2SChris Mason } 561c487685dSChris Mason 562ee22184bSByongho Lee search_start = buf->start & ~((u64)SZ_1G - 1); 563b4ce94deSChris Mason 564f616f5cdSQu Wenruo /* 565f616f5cdSQu Wenruo * Before CoWing this block for later modification, check if it's 566f616f5cdSQu Wenruo * the subtree root and do the delayed subtree trace if needed. 567f616f5cdSQu Wenruo * 568f616f5cdSQu Wenruo * Also We don't care about the error, as it's handled internally. 569f616f5cdSQu Wenruo */ 570f616f5cdSQu Wenruo btrfs_qgroup_trace_subtree_after_cow(trans, root, buf); 571f510cfecSChris Mason ret = __btrfs_cow_block(trans, root, buf, parent, 5729631e4ccSJosef Bacik parent_slot, cow_ret, search_start, 0, nest); 5731abe9b8aSliubo 5741abe9b8aSliubo trace_btrfs_cow_block(root, buf, *cow_ret); 5751abe9b8aSliubo 576f510cfecSChris Mason return ret; 5772c90e5d6SChris Mason } 578f75e2b79SJosef Bacik ALLOW_ERROR_INJECTION(btrfs_cow_block, ERRNO); 5796702ed49SChris Mason 580d352ac68SChris Mason /* 581d352ac68SChris Mason * helper function for defrag to decide if two blocks pointed to by a 582d352ac68SChris Mason * node are actually close by 583d352ac68SChris Mason */ 5846b80053dSChris Mason static int close_blocks(u64 blocknr, u64 other, u32 blocksize) 5856702ed49SChris Mason { 5866b80053dSChris Mason if (blocknr < other && other - (blocknr + blocksize) < 32768) 5876702ed49SChris Mason return 1; 5886b80053dSChris Mason if (blocknr > other && blocknr - (other + blocksize) < 32768) 5896702ed49SChris Mason return 1; 59002217ed2SChris Mason return 0; 59102217ed2SChris Mason } 59202217ed2SChris Mason 593ce6ef5abSDavid Sterba #ifdef __LITTLE_ENDIAN 594ce6ef5abSDavid Sterba 595ce6ef5abSDavid Sterba /* 596ce6ef5abSDavid Sterba * Compare two keys, on little-endian the disk order is same as CPU order and 597ce6ef5abSDavid Sterba * we can avoid the conversion. 598ce6ef5abSDavid Sterba */ 599ce6ef5abSDavid Sterba static int comp_keys(const struct btrfs_disk_key *disk_key, 600ce6ef5abSDavid Sterba const struct btrfs_key *k2) 601ce6ef5abSDavid Sterba { 602ce6ef5abSDavid Sterba const struct btrfs_key *k1 = (const struct btrfs_key *)disk_key; 603ce6ef5abSDavid Sterba 604ce6ef5abSDavid Sterba return btrfs_comp_cpu_keys(k1, k2); 605ce6ef5abSDavid Sterba } 606ce6ef5abSDavid Sterba 607ce6ef5abSDavid Sterba #else 608ce6ef5abSDavid Sterba 609081e9573SChris Mason /* 610081e9573SChris Mason * compare two keys in a memcmp fashion 611081e9573SChris Mason */ 612310712b2SOmar Sandoval static int comp_keys(const struct btrfs_disk_key *disk, 613310712b2SOmar Sandoval const struct btrfs_key *k2) 614081e9573SChris Mason { 615081e9573SChris Mason struct btrfs_key k1; 616081e9573SChris Mason 617081e9573SChris Mason btrfs_disk_key_to_cpu(&k1, disk); 618081e9573SChris Mason 61920736abaSDiego Calleja return btrfs_comp_cpu_keys(&k1, k2); 620081e9573SChris Mason } 621ce6ef5abSDavid Sterba #endif 622081e9573SChris Mason 623f3465ca4SJosef Bacik /* 624f3465ca4SJosef Bacik * same as comp_keys only with two btrfs_key's 625f3465ca4SJosef Bacik */ 626e1f60a65SDavid Sterba int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2) 627f3465ca4SJosef Bacik { 628f3465ca4SJosef Bacik if (k1->objectid > k2->objectid) 629f3465ca4SJosef Bacik return 1; 630f3465ca4SJosef Bacik if (k1->objectid < k2->objectid) 631f3465ca4SJosef Bacik return -1; 632f3465ca4SJosef Bacik if (k1->type > k2->type) 633f3465ca4SJosef Bacik return 1; 634f3465ca4SJosef Bacik if (k1->type < k2->type) 635f3465ca4SJosef Bacik return -1; 636f3465ca4SJosef Bacik if (k1->offset > k2->offset) 637f3465ca4SJosef Bacik return 1; 638f3465ca4SJosef Bacik if (k1->offset < k2->offset) 639f3465ca4SJosef Bacik return -1; 640f3465ca4SJosef Bacik return 0; 641f3465ca4SJosef Bacik } 642081e9573SChris Mason 643d352ac68SChris Mason /* 644d352ac68SChris Mason * this is used by the defrag code to go through all the 645d352ac68SChris Mason * leaves pointed to by a node and reallocate them so that 646d352ac68SChris Mason * disk order is close to key order 647d352ac68SChris Mason */ 6486702ed49SChris Mason int btrfs_realloc_node(struct btrfs_trans_handle *trans, 6495f39d397SChris Mason struct btrfs_root *root, struct extent_buffer *parent, 650de78b51aSEric Sandeen int start_slot, u64 *last_ret, 651a6b6e75eSChris Mason struct btrfs_key *progress) 6526702ed49SChris Mason { 6530b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 6546b80053dSChris Mason struct extent_buffer *cur; 6556702ed49SChris Mason u64 blocknr; 656e9d0b13bSChris Mason u64 search_start = *last_ret; 657e9d0b13bSChris Mason u64 last_block = 0; 6586702ed49SChris Mason u64 other; 6596702ed49SChris Mason u32 parent_nritems; 6606702ed49SChris Mason int end_slot; 6616702ed49SChris Mason int i; 6626702ed49SChris Mason int err = 0; 6636b80053dSChris Mason u32 blocksize; 664081e9573SChris Mason int progress_passed = 0; 665081e9573SChris Mason struct btrfs_disk_key disk_key; 6666702ed49SChris Mason 6670b246afaSJeff Mahoney WARN_ON(trans->transaction != fs_info->running_transaction); 6680b246afaSJeff Mahoney WARN_ON(trans->transid != fs_info->generation); 66986479a04SChris Mason 6706b80053dSChris Mason parent_nritems = btrfs_header_nritems(parent); 6710b246afaSJeff Mahoney blocksize = fs_info->nodesize; 6725dfe2be7SFilipe Manana end_slot = parent_nritems - 1; 6736702ed49SChris Mason 6745dfe2be7SFilipe Manana if (parent_nritems <= 1) 6756702ed49SChris Mason return 0; 6766702ed49SChris Mason 6775dfe2be7SFilipe Manana for (i = start_slot; i <= end_slot; i++) { 6786702ed49SChris Mason int close = 1; 679a6b6e75eSChris Mason 680081e9573SChris Mason btrfs_node_key(parent, &disk_key, i); 681081e9573SChris Mason if (!progress_passed && comp_keys(&disk_key, progress) < 0) 682081e9573SChris Mason continue; 683081e9573SChris Mason 684081e9573SChris Mason progress_passed = 1; 6856b80053dSChris Mason blocknr = btrfs_node_blockptr(parent, i); 686e9d0b13bSChris Mason if (last_block == 0) 687e9d0b13bSChris Mason last_block = blocknr; 6885708b959SChris Mason 6896702ed49SChris Mason if (i > 0) { 6906b80053dSChris Mason other = btrfs_node_blockptr(parent, i - 1); 6916b80053dSChris Mason close = close_blocks(blocknr, other, blocksize); 6926702ed49SChris Mason } 6935dfe2be7SFilipe Manana if (!close && i < end_slot) { 6946b80053dSChris Mason other = btrfs_node_blockptr(parent, i + 1); 6956b80053dSChris Mason close = close_blocks(blocknr, other, blocksize); 6966702ed49SChris Mason } 697e9d0b13bSChris Mason if (close) { 698e9d0b13bSChris Mason last_block = blocknr; 6996702ed49SChris Mason continue; 700e9d0b13bSChris Mason } 7016702ed49SChris Mason 702206983b7SJosef Bacik cur = btrfs_read_node_slot(parent, i); 703206983b7SJosef Bacik if (IS_ERR(cur)) 70464c043deSLiu Bo return PTR_ERR(cur); 705e9d0b13bSChris Mason if (search_start == 0) 7066b80053dSChris Mason search_start = last_block; 707e9d0b13bSChris Mason 708e7a84565SChris Mason btrfs_tree_lock(cur); 7096b80053dSChris Mason err = __btrfs_cow_block(trans, root, cur, parent, i, 710e7a84565SChris Mason &cur, search_start, 7116b80053dSChris Mason min(16 * blocksize, 7129631e4ccSJosef Bacik (end_slot - i) * blocksize), 7139631e4ccSJosef Bacik BTRFS_NESTING_COW); 714252c38f0SYan if (err) { 715e7a84565SChris Mason btrfs_tree_unlock(cur); 7166b80053dSChris Mason free_extent_buffer(cur); 7176702ed49SChris Mason break; 718252c38f0SYan } 719e7a84565SChris Mason search_start = cur->start; 720e7a84565SChris Mason last_block = cur->start; 721f2183bdeSChris Mason *last_ret = search_start; 722e7a84565SChris Mason btrfs_tree_unlock(cur); 723e7a84565SChris Mason free_extent_buffer(cur); 7246702ed49SChris Mason } 7256702ed49SChris Mason return err; 7266702ed49SChris Mason } 7276702ed49SChris Mason 72874123bd7SChris Mason /* 729fb81212cSFilipe Manana * Search for a key in the given extent_buffer. 7305f39d397SChris Mason * 731fb81212cSFilipe Manana * The lower boundary for the search is specified by the slot number @low. Use a 732fb81212cSFilipe Manana * value of 0 to search over the whole extent buffer. 73374123bd7SChris Mason * 734fb81212cSFilipe Manana * The slot in the extent buffer is returned via @slot. If the key exists in the 735fb81212cSFilipe Manana * extent buffer, then @slot will point to the slot where the key is, otherwise 736fb81212cSFilipe Manana * it points to the slot where you would insert the key. 737fb81212cSFilipe Manana * 738fb81212cSFilipe Manana * Slot may point to the total number of items (i.e. one position beyond the last 739fb81212cSFilipe Manana * key) if the key is bigger than the last key in the extent buffer. 74074123bd7SChris Mason */ 741fb81212cSFilipe Manana static noinline int generic_bin_search(struct extent_buffer *eb, int low, 74267d5e289SMarcos Paulo de Souza const struct btrfs_key *key, int *slot) 743be0e5c09SChris Mason { 744fb81212cSFilipe Manana unsigned long p; 745fb81212cSFilipe Manana int item_size; 74667d5e289SMarcos Paulo de Souza int high = btrfs_header_nritems(eb); 747be0e5c09SChris Mason int ret; 7485cd17f34SDavid Sterba const int key_size = sizeof(struct btrfs_disk_key); 749be0e5c09SChris Mason 7505e24e9afSLiu Bo if (low > high) { 7515e24e9afSLiu Bo btrfs_err(eb->fs_info, 7525e24e9afSLiu Bo "%s: low (%d) > high (%d) eb %llu owner %llu level %d", 7535e24e9afSLiu Bo __func__, low, high, eb->start, 7545e24e9afSLiu Bo btrfs_header_owner(eb), btrfs_header_level(eb)); 7555e24e9afSLiu Bo return -EINVAL; 7565e24e9afSLiu Bo } 7575e24e9afSLiu Bo 758fb81212cSFilipe Manana if (btrfs_header_level(eb) == 0) { 759fb81212cSFilipe Manana p = offsetof(struct btrfs_leaf, items); 760fb81212cSFilipe Manana item_size = sizeof(struct btrfs_item); 761fb81212cSFilipe Manana } else { 762fb81212cSFilipe Manana p = offsetof(struct btrfs_node, ptrs); 763fb81212cSFilipe Manana item_size = sizeof(struct btrfs_key_ptr); 764fb81212cSFilipe Manana } 765fb81212cSFilipe Manana 766be0e5c09SChris Mason while (low < high) { 7675cd17f34SDavid Sterba unsigned long oip; 7685cd17f34SDavid Sterba unsigned long offset; 7695cd17f34SDavid Sterba struct btrfs_disk_key *tmp; 7705cd17f34SDavid Sterba struct btrfs_disk_key unaligned; 7715cd17f34SDavid Sterba int mid; 7725cd17f34SDavid Sterba 773be0e5c09SChris Mason mid = (low + high) / 2; 7745f39d397SChris Mason offset = p + mid * item_size; 7755cd17f34SDavid Sterba oip = offset_in_page(offset); 7765f39d397SChris Mason 7775cd17f34SDavid Sterba if (oip + key_size <= PAGE_SIZE) { 778884b07d0SQu Wenruo const unsigned long idx = get_eb_page_index(offset); 7795cd17f34SDavid Sterba char *kaddr = page_address(eb->pages[idx]); 780934d375bSChris Mason 781884b07d0SQu Wenruo oip = get_eb_offset_in_page(eb, offset); 7825cd17f34SDavid Sterba tmp = (struct btrfs_disk_key *)(kaddr + oip); 7835cd17f34SDavid Sterba } else { 7845cd17f34SDavid Sterba read_extent_buffer(eb, &unaligned, offset, key_size); 7855f39d397SChris Mason tmp = &unaligned; 786479965d6SChris Mason } 787479965d6SChris Mason 788be0e5c09SChris Mason ret = comp_keys(tmp, key); 789be0e5c09SChris Mason 790be0e5c09SChris Mason if (ret < 0) 791be0e5c09SChris Mason low = mid + 1; 792be0e5c09SChris Mason else if (ret > 0) 793be0e5c09SChris Mason high = mid; 794be0e5c09SChris Mason else { 795be0e5c09SChris Mason *slot = mid; 796be0e5c09SChris Mason return 0; 797be0e5c09SChris Mason } 798be0e5c09SChris Mason } 799be0e5c09SChris Mason *slot = low; 800be0e5c09SChris Mason return 1; 801be0e5c09SChris Mason } 802be0e5c09SChris Mason 80397571fd0SChris Mason /* 804fb81212cSFilipe Manana * Simple binary search on an extent buffer. Works for both leaves and nodes, and 805fb81212cSFilipe Manana * always searches over the whole range of keys (slot 0 to slot 'nritems - 1'). 80697571fd0SChris Mason */ 807a74b35ecSNikolay Borisov int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key, 808e3b83361SQu Wenruo int *slot) 809be0e5c09SChris Mason { 810fb81212cSFilipe Manana return generic_bin_search(eb, 0, key, slot); 811be0e5c09SChris Mason } 812be0e5c09SChris Mason 813f0486c68SYan, Zheng static void root_add_used(struct btrfs_root *root, u32 size) 814f0486c68SYan, Zheng { 815f0486c68SYan, Zheng spin_lock(&root->accounting_lock); 816f0486c68SYan, Zheng btrfs_set_root_used(&root->root_item, 817f0486c68SYan, Zheng btrfs_root_used(&root->root_item) + size); 818f0486c68SYan, Zheng spin_unlock(&root->accounting_lock); 819f0486c68SYan, Zheng } 820f0486c68SYan, Zheng 821f0486c68SYan, Zheng static void root_sub_used(struct btrfs_root *root, u32 size) 822f0486c68SYan, Zheng { 823f0486c68SYan, Zheng spin_lock(&root->accounting_lock); 824f0486c68SYan, Zheng btrfs_set_root_used(&root->root_item, 825f0486c68SYan, Zheng btrfs_root_used(&root->root_item) - size); 826f0486c68SYan, Zheng spin_unlock(&root->accounting_lock); 827f0486c68SYan, Zheng } 828f0486c68SYan, Zheng 829d352ac68SChris Mason /* given a node and slot number, this reads the blocks it points to. The 830d352ac68SChris Mason * extent buffer is returned with a reference taken (but unlocked). 831d352ac68SChris Mason */ 8324b231ae4SDavid Sterba struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent, 8334b231ae4SDavid Sterba int slot) 834bb803951SChris Mason { 835ca7a79adSChris Mason int level = btrfs_header_level(parent); 836416bc658SJosef Bacik struct extent_buffer *eb; 837581c1760SQu Wenruo struct btrfs_key first_key; 838416bc658SJosef Bacik 839fb770ae4SLiu Bo if (slot < 0 || slot >= btrfs_header_nritems(parent)) 840fb770ae4SLiu Bo return ERR_PTR(-ENOENT); 841ca7a79adSChris Mason 842ca7a79adSChris Mason BUG_ON(level == 0); 843ca7a79adSChris Mason 844581c1760SQu Wenruo btrfs_node_key_to_cpu(parent, &first_key, slot); 845d0d20b0fSDavid Sterba eb = read_tree_block(parent->fs_info, btrfs_node_blockptr(parent, slot), 8461b7ec85eSJosef Bacik btrfs_header_owner(parent), 847581c1760SQu Wenruo btrfs_node_ptr_generation(parent, slot), 848581c1760SQu Wenruo level - 1, &first_key); 8494eb150d6SQu Wenruo if (IS_ERR(eb)) 8504eb150d6SQu Wenruo return eb; 8514eb150d6SQu Wenruo if (!extent_buffer_uptodate(eb)) { 852416bc658SJosef Bacik free_extent_buffer(eb); 8534eb150d6SQu Wenruo return ERR_PTR(-EIO); 854416bc658SJosef Bacik } 855416bc658SJosef Bacik 856416bc658SJosef Bacik return eb; 857bb803951SChris Mason } 858bb803951SChris Mason 859d352ac68SChris Mason /* 860d352ac68SChris Mason * node level balancing, used to make sure nodes are in proper order for 861d352ac68SChris Mason * item deletion. We balance from the top down, so we have to make sure 862d352ac68SChris Mason * that a deletion won't leave an node completely empty later on. 863d352ac68SChris Mason */ 864e02119d5SChris Mason static noinline int balance_level(struct btrfs_trans_handle *trans, 86598ed5174SChris Mason struct btrfs_root *root, 86698ed5174SChris Mason struct btrfs_path *path, int level) 867bb803951SChris Mason { 8680b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 8695f39d397SChris Mason struct extent_buffer *right = NULL; 8705f39d397SChris Mason struct extent_buffer *mid; 8715f39d397SChris Mason struct extent_buffer *left = NULL; 8725f39d397SChris Mason struct extent_buffer *parent = NULL; 873bb803951SChris Mason int ret = 0; 874bb803951SChris Mason int wret; 875bb803951SChris Mason int pslot; 876bb803951SChris Mason int orig_slot = path->slots[level]; 87779f95c82SChris Mason u64 orig_ptr; 878bb803951SChris Mason 87998e6b1ebSLiu Bo ASSERT(level > 0); 880bb803951SChris Mason 8815f39d397SChris Mason mid = path->nodes[level]; 882b4ce94deSChris Mason 883ac5887c8SJosef Bacik WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK); 8847bb86316SChris Mason WARN_ON(btrfs_header_generation(mid) != trans->transid); 8857bb86316SChris Mason 8861d4f8a0cSChris Mason orig_ptr = btrfs_node_blockptr(mid, orig_slot); 88779f95c82SChris Mason 888a05a9bb1SLi Zefan if (level < BTRFS_MAX_LEVEL - 1) { 8895f39d397SChris Mason parent = path->nodes[level + 1]; 890bb803951SChris Mason pslot = path->slots[level + 1]; 891a05a9bb1SLi Zefan } 892bb803951SChris Mason 89340689478SChris Mason /* 89440689478SChris Mason * deal with the case where there is only one pointer in the root 89540689478SChris Mason * by promoting the node below to a root 89640689478SChris Mason */ 8975f39d397SChris Mason if (!parent) { 8985f39d397SChris Mason struct extent_buffer *child; 899bb803951SChris Mason 9005f39d397SChris Mason if (btrfs_header_nritems(mid) != 1) 901bb803951SChris Mason return 0; 902bb803951SChris Mason 903bb803951SChris Mason /* promote the child to a root */ 9044b231ae4SDavid Sterba child = btrfs_read_node_slot(mid, 0); 905fb770ae4SLiu Bo if (IS_ERR(child)) { 906fb770ae4SLiu Bo ret = PTR_ERR(child); 9070b246afaSJeff Mahoney btrfs_handle_fs_error(fs_info, ret, NULL); 908305a26afSMark Fasheh goto enospc; 909305a26afSMark Fasheh } 910305a26afSMark Fasheh 911925baeddSChris Mason btrfs_tree_lock(child); 9129631e4ccSJosef Bacik ret = btrfs_cow_block(trans, root, child, mid, 0, &child, 9139631e4ccSJosef Bacik BTRFS_NESTING_COW); 914f0486c68SYan, Zheng if (ret) { 915f0486c68SYan, Zheng btrfs_tree_unlock(child); 916f0486c68SYan, Zheng free_extent_buffer(child); 917f0486c68SYan, Zheng goto enospc; 918f0486c68SYan, Zheng } 9192f375ab9SYan 920406808abSFilipe Manana ret = btrfs_tree_mod_log_insert_root(root->node, child, true); 921d9d19a01SDavid Sterba BUG_ON(ret < 0); 922240f62c8SChris Mason rcu_assign_pointer(root->node, child); 923925baeddSChris Mason 9240b86a832SChris Mason add_root_to_dirty_list(root); 925925baeddSChris Mason btrfs_tree_unlock(child); 926b4ce94deSChris Mason 927925baeddSChris Mason path->locks[level] = 0; 928bb803951SChris Mason path->nodes[level] = NULL; 9296a884d7dSDavid Sterba btrfs_clean_tree_block(mid); 930925baeddSChris Mason btrfs_tree_unlock(mid); 931bb803951SChris Mason /* once for the path */ 9325f39d397SChris Mason free_extent_buffer(mid); 933f0486c68SYan, Zheng 934f0486c68SYan, Zheng root_sub_used(root, mid->len); 9357a163608SFilipe Manana btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1); 936bb803951SChris Mason /* once for the root ptr */ 9373083ee2eSJosef Bacik free_extent_buffer_stale(mid); 938f0486c68SYan, Zheng return 0; 939bb803951SChris Mason } 9405f39d397SChris Mason if (btrfs_header_nritems(mid) > 9410b246afaSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 4) 942bb803951SChris Mason return 0; 943bb803951SChris Mason 9444b231ae4SDavid Sterba left = btrfs_read_node_slot(parent, pslot - 1); 945fb770ae4SLiu Bo if (IS_ERR(left)) 946fb770ae4SLiu Bo left = NULL; 947fb770ae4SLiu Bo 9485f39d397SChris Mason if (left) { 949bf77467aSJosef Bacik __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); 9505f39d397SChris Mason wret = btrfs_cow_block(trans, root, left, 9519631e4ccSJosef Bacik parent, pslot - 1, &left, 952bf59a5a2SJosef Bacik BTRFS_NESTING_LEFT_COW); 95354aa1f4dSChris Mason if (wret) { 95454aa1f4dSChris Mason ret = wret; 95554aa1f4dSChris Mason goto enospc; 95654aa1f4dSChris Mason } 9572cc58cf2SChris Mason } 958fb770ae4SLiu Bo 9594b231ae4SDavid Sterba right = btrfs_read_node_slot(parent, pslot + 1); 960fb770ae4SLiu Bo if (IS_ERR(right)) 961fb770ae4SLiu Bo right = NULL; 962fb770ae4SLiu Bo 9635f39d397SChris Mason if (right) { 964bf77467aSJosef Bacik __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); 9655f39d397SChris Mason wret = btrfs_cow_block(trans, root, right, 9669631e4ccSJosef Bacik parent, pslot + 1, &right, 967bf59a5a2SJosef Bacik BTRFS_NESTING_RIGHT_COW); 9682cc58cf2SChris Mason if (wret) { 9692cc58cf2SChris Mason ret = wret; 9702cc58cf2SChris Mason goto enospc; 9712cc58cf2SChris Mason } 9722cc58cf2SChris Mason } 9732cc58cf2SChris Mason 9742cc58cf2SChris Mason /* first, try to make some room in the middle buffer */ 9755f39d397SChris Mason if (left) { 9765f39d397SChris Mason orig_slot += btrfs_header_nritems(left); 977d30a668fSDavid Sterba wret = push_node_left(trans, left, mid, 1); 97879f95c82SChris Mason if (wret < 0) 97979f95c82SChris Mason ret = wret; 980bb803951SChris Mason } 98179f95c82SChris Mason 98279f95c82SChris Mason /* 98379f95c82SChris Mason * then try to empty the right most buffer into the middle 98479f95c82SChris Mason */ 9855f39d397SChris Mason if (right) { 986d30a668fSDavid Sterba wret = push_node_left(trans, mid, right, 1); 98754aa1f4dSChris Mason if (wret < 0 && wret != -ENOSPC) 98879f95c82SChris Mason ret = wret; 9895f39d397SChris Mason if (btrfs_header_nritems(right) == 0) { 9906a884d7dSDavid Sterba btrfs_clean_tree_block(right); 991925baeddSChris Mason btrfs_tree_unlock(right); 992afe5fea7STsutomu Itoh del_ptr(root, path, level + 1, pslot + 1); 993f0486c68SYan, Zheng root_sub_used(root, right->len); 9947a163608SFilipe Manana btrfs_free_tree_block(trans, btrfs_root_id(root), right, 9957a163608SFilipe Manana 0, 1); 9963083ee2eSJosef Bacik free_extent_buffer_stale(right); 997f0486c68SYan, Zheng right = NULL; 998bb803951SChris Mason } else { 9995f39d397SChris Mason struct btrfs_disk_key right_key; 10005f39d397SChris Mason btrfs_node_key(right, &right_key, 0); 1001f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, 1002f3a84ccdSFilipe Manana BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS); 10030e82bcfeSDavid Sterba BUG_ON(ret < 0); 10045f39d397SChris Mason btrfs_set_node_key(parent, &right_key, pslot + 1); 10055f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 1006bb803951SChris Mason } 1007bb803951SChris Mason } 10085f39d397SChris Mason if (btrfs_header_nritems(mid) == 1) { 100979f95c82SChris Mason /* 101079f95c82SChris Mason * we're not allowed to leave a node with one item in the 101179f95c82SChris Mason * tree during a delete. A deletion from lower in the tree 101279f95c82SChris Mason * could try to delete the only pointer in this node. 101379f95c82SChris Mason * So, pull some keys from the left. 101479f95c82SChris Mason * There has to be a left pointer at this point because 101579f95c82SChris Mason * otherwise we would have pulled some pointers from the 101679f95c82SChris Mason * right 101779f95c82SChris Mason */ 1018305a26afSMark Fasheh if (!left) { 1019305a26afSMark Fasheh ret = -EROFS; 10200b246afaSJeff Mahoney btrfs_handle_fs_error(fs_info, ret, NULL); 1021305a26afSMark Fasheh goto enospc; 1022305a26afSMark Fasheh } 102355d32ed8SDavid Sterba wret = balance_node_right(trans, mid, left); 102454aa1f4dSChris Mason if (wret < 0) { 102579f95c82SChris Mason ret = wret; 102654aa1f4dSChris Mason goto enospc; 102754aa1f4dSChris Mason } 1028bce4eae9SChris Mason if (wret == 1) { 1029d30a668fSDavid Sterba wret = push_node_left(trans, left, mid, 1); 1030bce4eae9SChris Mason if (wret < 0) 1031bce4eae9SChris Mason ret = wret; 1032bce4eae9SChris Mason } 103379f95c82SChris Mason BUG_ON(wret == 1); 103479f95c82SChris Mason } 10355f39d397SChris Mason if (btrfs_header_nritems(mid) == 0) { 10366a884d7dSDavid Sterba btrfs_clean_tree_block(mid); 1037925baeddSChris Mason btrfs_tree_unlock(mid); 1038afe5fea7STsutomu Itoh del_ptr(root, path, level + 1, pslot); 1039f0486c68SYan, Zheng root_sub_used(root, mid->len); 10407a163608SFilipe Manana btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1); 10413083ee2eSJosef Bacik free_extent_buffer_stale(mid); 1042f0486c68SYan, Zheng mid = NULL; 104379f95c82SChris Mason } else { 104479f95c82SChris Mason /* update the parent key to reflect our changes */ 10455f39d397SChris Mason struct btrfs_disk_key mid_key; 10465f39d397SChris Mason btrfs_node_key(mid, &mid_key, 0); 1047f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_key(parent, pslot, 1048f3a84ccdSFilipe Manana BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS); 10490e82bcfeSDavid Sterba BUG_ON(ret < 0); 10505f39d397SChris Mason btrfs_set_node_key(parent, &mid_key, pslot); 10515f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 105279f95c82SChris Mason } 1053bb803951SChris Mason 105479f95c82SChris Mason /* update the path */ 10555f39d397SChris Mason if (left) { 10565f39d397SChris Mason if (btrfs_header_nritems(left) > orig_slot) { 105767439dadSDavid Sterba atomic_inc(&left->refs); 1058925baeddSChris Mason /* left was locked after cow */ 10595f39d397SChris Mason path->nodes[level] = left; 1060bb803951SChris Mason path->slots[level + 1] -= 1; 1061bb803951SChris Mason path->slots[level] = orig_slot; 1062925baeddSChris Mason if (mid) { 1063925baeddSChris Mason btrfs_tree_unlock(mid); 10645f39d397SChris Mason free_extent_buffer(mid); 1065925baeddSChris Mason } 1066bb803951SChris Mason } else { 10675f39d397SChris Mason orig_slot -= btrfs_header_nritems(left); 1068bb803951SChris Mason path->slots[level] = orig_slot; 1069bb803951SChris Mason } 1070bb803951SChris Mason } 107179f95c82SChris Mason /* double check we haven't messed things up */ 1072e20d96d6SChris Mason if (orig_ptr != 10735f39d397SChris Mason btrfs_node_blockptr(path->nodes[level], path->slots[level])) 107479f95c82SChris Mason BUG(); 107554aa1f4dSChris Mason enospc: 1076925baeddSChris Mason if (right) { 1077925baeddSChris Mason btrfs_tree_unlock(right); 10785f39d397SChris Mason free_extent_buffer(right); 1079925baeddSChris Mason } 1080925baeddSChris Mason if (left) { 1081925baeddSChris Mason if (path->nodes[level] != left) 1082925baeddSChris Mason btrfs_tree_unlock(left); 10835f39d397SChris Mason free_extent_buffer(left); 1084925baeddSChris Mason } 1085bb803951SChris Mason return ret; 1086bb803951SChris Mason } 1087bb803951SChris Mason 1088d352ac68SChris Mason /* Node balancing for insertion. Here we only split or push nodes around 1089d352ac68SChris Mason * when they are completely full. This is also done top down, so we 1090d352ac68SChris Mason * have to be pessimistic. 1091d352ac68SChris Mason */ 1092d397712bSChris Mason static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, 1093e66f709bSChris Mason struct btrfs_root *root, 1094e66f709bSChris Mason struct btrfs_path *path, int level) 1095e66f709bSChris Mason { 10960b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 10975f39d397SChris Mason struct extent_buffer *right = NULL; 10985f39d397SChris Mason struct extent_buffer *mid; 10995f39d397SChris Mason struct extent_buffer *left = NULL; 11005f39d397SChris Mason struct extent_buffer *parent = NULL; 1101e66f709bSChris Mason int ret = 0; 1102e66f709bSChris Mason int wret; 1103e66f709bSChris Mason int pslot; 1104e66f709bSChris Mason int orig_slot = path->slots[level]; 1105e66f709bSChris Mason 1106e66f709bSChris Mason if (level == 0) 1107e66f709bSChris Mason return 1; 1108e66f709bSChris Mason 11095f39d397SChris Mason mid = path->nodes[level]; 11107bb86316SChris Mason WARN_ON(btrfs_header_generation(mid) != trans->transid); 1111e66f709bSChris Mason 1112a05a9bb1SLi Zefan if (level < BTRFS_MAX_LEVEL - 1) { 11135f39d397SChris Mason parent = path->nodes[level + 1]; 1114e66f709bSChris Mason pslot = path->slots[level + 1]; 1115a05a9bb1SLi Zefan } 1116e66f709bSChris Mason 11175f39d397SChris Mason if (!parent) 1118e66f709bSChris Mason return 1; 1119e66f709bSChris Mason 11204b231ae4SDavid Sterba left = btrfs_read_node_slot(parent, pslot - 1); 1121fb770ae4SLiu Bo if (IS_ERR(left)) 1122fb770ae4SLiu Bo left = NULL; 1123e66f709bSChris Mason 1124e66f709bSChris Mason /* first, try to make some room in the middle buffer */ 11255f39d397SChris Mason if (left) { 1126e66f709bSChris Mason u32 left_nr; 1127925baeddSChris Mason 1128bf77467aSJosef Bacik __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); 1129b4ce94deSChris Mason 11305f39d397SChris Mason left_nr = btrfs_header_nritems(left); 11310b246afaSJeff Mahoney if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { 113233ade1f8SChris Mason wret = 1; 113333ade1f8SChris Mason } else { 11345f39d397SChris Mason ret = btrfs_cow_block(trans, root, left, parent, 11359631e4ccSJosef Bacik pslot - 1, &left, 1136bf59a5a2SJosef Bacik BTRFS_NESTING_LEFT_COW); 113754aa1f4dSChris Mason if (ret) 113854aa1f4dSChris Mason wret = 1; 113954aa1f4dSChris Mason else { 1140d30a668fSDavid Sterba wret = push_node_left(trans, left, mid, 0); 114154aa1f4dSChris Mason } 114233ade1f8SChris Mason } 1143e66f709bSChris Mason if (wret < 0) 1144e66f709bSChris Mason ret = wret; 1145e66f709bSChris Mason if (wret == 0) { 11465f39d397SChris Mason struct btrfs_disk_key disk_key; 1147e66f709bSChris Mason orig_slot += left_nr; 11485f39d397SChris Mason btrfs_node_key(mid, &disk_key, 0); 1149f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_key(parent, pslot, 1150f3a84ccdSFilipe Manana BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS); 11510e82bcfeSDavid Sterba BUG_ON(ret < 0); 11525f39d397SChris Mason btrfs_set_node_key(parent, &disk_key, pslot); 11535f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 11545f39d397SChris Mason if (btrfs_header_nritems(left) > orig_slot) { 11555f39d397SChris Mason path->nodes[level] = left; 1156e66f709bSChris Mason path->slots[level + 1] -= 1; 1157e66f709bSChris Mason path->slots[level] = orig_slot; 1158925baeddSChris Mason btrfs_tree_unlock(mid); 11595f39d397SChris Mason free_extent_buffer(mid); 1160e66f709bSChris Mason } else { 1161e66f709bSChris Mason orig_slot -= 11625f39d397SChris Mason btrfs_header_nritems(left); 1163e66f709bSChris Mason path->slots[level] = orig_slot; 1164925baeddSChris Mason btrfs_tree_unlock(left); 11655f39d397SChris Mason free_extent_buffer(left); 1166e66f709bSChris Mason } 1167e66f709bSChris Mason return 0; 1168e66f709bSChris Mason } 1169925baeddSChris Mason btrfs_tree_unlock(left); 11705f39d397SChris Mason free_extent_buffer(left); 1171e66f709bSChris Mason } 11724b231ae4SDavid Sterba right = btrfs_read_node_slot(parent, pslot + 1); 1173fb770ae4SLiu Bo if (IS_ERR(right)) 1174fb770ae4SLiu Bo right = NULL; 1175e66f709bSChris Mason 1176e66f709bSChris Mason /* 1177e66f709bSChris Mason * then try to empty the right most buffer into the middle 1178e66f709bSChris Mason */ 11795f39d397SChris Mason if (right) { 118033ade1f8SChris Mason u32 right_nr; 1181b4ce94deSChris Mason 1182bf77467aSJosef Bacik __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); 1183b4ce94deSChris Mason 11845f39d397SChris Mason right_nr = btrfs_header_nritems(right); 11850b246afaSJeff Mahoney if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { 118633ade1f8SChris Mason wret = 1; 118733ade1f8SChris Mason } else { 11885f39d397SChris Mason ret = btrfs_cow_block(trans, root, right, 11895f39d397SChris Mason parent, pslot + 1, 1190bf59a5a2SJosef Bacik &right, BTRFS_NESTING_RIGHT_COW); 119154aa1f4dSChris Mason if (ret) 119254aa1f4dSChris Mason wret = 1; 119354aa1f4dSChris Mason else { 119455d32ed8SDavid Sterba wret = balance_node_right(trans, right, mid); 119533ade1f8SChris Mason } 119654aa1f4dSChris Mason } 1197e66f709bSChris Mason if (wret < 0) 1198e66f709bSChris Mason ret = wret; 1199e66f709bSChris Mason if (wret == 0) { 12005f39d397SChris Mason struct btrfs_disk_key disk_key; 12015f39d397SChris Mason 12025f39d397SChris Mason btrfs_node_key(right, &disk_key, 0); 1203f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, 1204f3a84ccdSFilipe Manana BTRFS_MOD_LOG_KEY_REPLACE, GFP_NOFS); 12050e82bcfeSDavid Sterba BUG_ON(ret < 0); 12065f39d397SChris Mason btrfs_set_node_key(parent, &disk_key, pslot + 1); 12075f39d397SChris Mason btrfs_mark_buffer_dirty(parent); 12085f39d397SChris Mason 12095f39d397SChris Mason if (btrfs_header_nritems(mid) <= orig_slot) { 12105f39d397SChris Mason path->nodes[level] = right; 1211e66f709bSChris Mason path->slots[level + 1] += 1; 1212e66f709bSChris Mason path->slots[level] = orig_slot - 12135f39d397SChris Mason btrfs_header_nritems(mid); 1214925baeddSChris Mason btrfs_tree_unlock(mid); 12155f39d397SChris Mason free_extent_buffer(mid); 1216e66f709bSChris Mason } else { 1217925baeddSChris Mason btrfs_tree_unlock(right); 12185f39d397SChris Mason free_extent_buffer(right); 1219e66f709bSChris Mason } 1220e66f709bSChris Mason return 0; 1221e66f709bSChris Mason } 1222925baeddSChris Mason btrfs_tree_unlock(right); 12235f39d397SChris Mason free_extent_buffer(right); 1224e66f709bSChris Mason } 1225e66f709bSChris Mason return 1; 1226e66f709bSChris Mason } 1227e66f709bSChris Mason 122874123bd7SChris Mason /* 1229d352ac68SChris Mason * readahead one full node of leaves, finding things that are close 1230d352ac68SChris Mason * to the block in 'slot', and triggering ra on them. 12313c69faecSChris Mason */ 12322ff7e61eSJeff Mahoney static void reada_for_search(struct btrfs_fs_info *fs_info, 1233e02119d5SChris Mason struct btrfs_path *path, 123401f46658SChris Mason int level, int slot, u64 objectid) 12353c69faecSChris Mason { 12365f39d397SChris Mason struct extent_buffer *node; 123701f46658SChris Mason struct btrfs_disk_key disk_key; 12383c69faecSChris Mason u32 nritems; 12393c69faecSChris Mason u64 search; 1240a7175319SChris Mason u64 target; 12416b80053dSChris Mason u64 nread = 0; 1242ace75066SFilipe Manana u64 nread_max; 12436b80053dSChris Mason u32 nr; 12446b80053dSChris Mason u32 blocksize; 12456b80053dSChris Mason u32 nscan = 0; 1246db94535dSChris Mason 1247ace75066SFilipe Manana if (level != 1 && path->reada != READA_FORWARD_ALWAYS) 12483c69faecSChris Mason return; 12493c69faecSChris Mason 12506702ed49SChris Mason if (!path->nodes[level]) 12516702ed49SChris Mason return; 12526702ed49SChris Mason 12535f39d397SChris Mason node = path->nodes[level]; 1254925baeddSChris Mason 1255ace75066SFilipe Manana /* 1256ace75066SFilipe Manana * Since the time between visiting leaves is much shorter than the time 1257ace75066SFilipe Manana * between visiting nodes, limit read ahead of nodes to 1, to avoid too 1258ace75066SFilipe Manana * much IO at once (possibly random). 1259ace75066SFilipe Manana */ 1260ace75066SFilipe Manana if (path->reada == READA_FORWARD_ALWAYS) { 1261ace75066SFilipe Manana if (level > 1) 1262ace75066SFilipe Manana nread_max = node->fs_info->nodesize; 1263ace75066SFilipe Manana else 1264ace75066SFilipe Manana nread_max = SZ_128K; 1265ace75066SFilipe Manana } else { 1266ace75066SFilipe Manana nread_max = SZ_64K; 1267ace75066SFilipe Manana } 1268ace75066SFilipe Manana 12693c69faecSChris Mason search = btrfs_node_blockptr(node, slot); 12700b246afaSJeff Mahoney blocksize = fs_info->nodesize; 1271069a2e37SFilipe Manana if (path->reada != READA_FORWARD_ALWAYS) { 1272069a2e37SFilipe Manana struct extent_buffer *eb; 1273069a2e37SFilipe Manana 12740b246afaSJeff Mahoney eb = find_extent_buffer(fs_info, search); 12755f39d397SChris Mason if (eb) { 12765f39d397SChris Mason free_extent_buffer(eb); 12773c69faecSChris Mason return; 12783c69faecSChris Mason } 1279069a2e37SFilipe Manana } 12803c69faecSChris Mason 1281a7175319SChris Mason target = search; 12826b80053dSChris Mason 12835f39d397SChris Mason nritems = btrfs_header_nritems(node); 12846b80053dSChris Mason nr = slot; 128525b8b936SJosef Bacik 12863c69faecSChris Mason while (1) { 1287e4058b54SDavid Sterba if (path->reada == READA_BACK) { 12886b80053dSChris Mason if (nr == 0) 12893c69faecSChris Mason break; 12906b80053dSChris Mason nr--; 1291ace75066SFilipe Manana } else if (path->reada == READA_FORWARD || 1292ace75066SFilipe Manana path->reada == READA_FORWARD_ALWAYS) { 12936b80053dSChris Mason nr++; 12946b80053dSChris Mason if (nr >= nritems) 12956b80053dSChris Mason break; 12963c69faecSChris Mason } 1297e4058b54SDavid Sterba if (path->reada == READA_BACK && objectid) { 129801f46658SChris Mason btrfs_node_key(node, &disk_key, nr); 129901f46658SChris Mason if (btrfs_disk_key_objectid(&disk_key) != objectid) 130001f46658SChris Mason break; 130101f46658SChris Mason } 13026b80053dSChris Mason search = btrfs_node_blockptr(node, nr); 1303ace75066SFilipe Manana if (path->reada == READA_FORWARD_ALWAYS || 1304ace75066SFilipe Manana (search <= target && target - search <= 65536) || 1305a7175319SChris Mason (search > target && search - target <= 65536)) { 1306bfb484d9SJosef Bacik btrfs_readahead_node_child(node, nr); 13076b80053dSChris Mason nread += blocksize; 13083c69faecSChris Mason } 13096b80053dSChris Mason nscan++; 1310ace75066SFilipe Manana if (nread > nread_max || nscan > 32) 13116b80053dSChris Mason break; 13123c69faecSChris Mason } 13133c69faecSChris Mason } 1314925baeddSChris Mason 1315bfb484d9SJosef Bacik static noinline void reada_for_balance(struct btrfs_path *path, int level) 1316b4ce94deSChris Mason { 1317bfb484d9SJosef Bacik struct extent_buffer *parent; 1318b4ce94deSChris Mason int slot; 1319b4ce94deSChris Mason int nritems; 1320b4ce94deSChris Mason 13218c594ea8SChris Mason parent = path->nodes[level + 1]; 1322b4ce94deSChris Mason if (!parent) 13230b08851fSJosef Bacik return; 1324b4ce94deSChris Mason 1325b4ce94deSChris Mason nritems = btrfs_header_nritems(parent); 13268c594ea8SChris Mason slot = path->slots[level + 1]; 1327b4ce94deSChris Mason 1328bfb484d9SJosef Bacik if (slot > 0) 1329bfb484d9SJosef Bacik btrfs_readahead_node_child(parent, slot - 1); 1330bfb484d9SJosef Bacik if (slot + 1 < nritems) 1331bfb484d9SJosef Bacik btrfs_readahead_node_child(parent, slot + 1); 1332b4ce94deSChris Mason } 1333b4ce94deSChris Mason 1334b4ce94deSChris Mason 1335b4ce94deSChris Mason /* 1336d397712bSChris Mason * when we walk down the tree, it is usually safe to unlock the higher layers 1337d397712bSChris Mason * in the tree. The exceptions are when our path goes through slot 0, because 1338d397712bSChris Mason * operations on the tree might require changing key pointers higher up in the 1339d397712bSChris Mason * tree. 1340d352ac68SChris Mason * 1341d397712bSChris Mason * callers might also have set path->keep_locks, which tells this code to keep 1342d397712bSChris Mason * the lock if the path points to the last slot in the block. This is part of 1343d397712bSChris Mason * walking through the tree, and selecting the next slot in the higher block. 1344d352ac68SChris Mason * 1345d397712bSChris Mason * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so 1346d397712bSChris Mason * if lowest_unlock is 1, level 0 won't be unlocked 1347d352ac68SChris Mason */ 1348e02119d5SChris Mason static noinline void unlock_up(struct btrfs_path *path, int level, 1349f7c79f30SChris Mason int lowest_unlock, int min_write_lock_level, 1350f7c79f30SChris Mason int *write_lock_level) 1351925baeddSChris Mason { 1352925baeddSChris Mason int i; 1353925baeddSChris Mason int skip_level = level; 1354c1227996SNikolay Borisov bool check_skip = true; 1355925baeddSChris Mason 1356925baeddSChris Mason for (i = level; i < BTRFS_MAX_LEVEL; i++) { 1357925baeddSChris Mason if (!path->nodes[i]) 1358925baeddSChris Mason break; 1359925baeddSChris Mason if (!path->locks[i]) 1360925baeddSChris Mason break; 1361c1227996SNikolay Borisov 1362c1227996SNikolay Borisov if (check_skip) { 1363c1227996SNikolay Borisov if (path->slots[i] == 0) { 1364925baeddSChris Mason skip_level = i + 1; 1365925baeddSChris Mason continue; 1366925baeddSChris Mason } 1367c1227996SNikolay Borisov 1368c1227996SNikolay Borisov if (path->keep_locks) { 1369925baeddSChris Mason u32 nritems; 1370c1227996SNikolay Borisov 1371c1227996SNikolay Borisov nritems = btrfs_header_nritems(path->nodes[i]); 1372051e1b9fSChris Mason if (nritems < 1 || path->slots[i] >= nritems - 1) { 1373925baeddSChris Mason skip_level = i + 1; 1374925baeddSChris Mason continue; 1375925baeddSChris Mason } 1376925baeddSChris Mason } 1377c1227996SNikolay Borisov } 1378051e1b9fSChris Mason 1379d80bb3f9SLiu Bo if (i >= lowest_unlock && i > skip_level) { 1380c1227996SNikolay Borisov check_skip = false; 1381c1227996SNikolay Borisov btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); 1382925baeddSChris Mason path->locks[i] = 0; 1383f7c79f30SChris Mason if (write_lock_level && 1384f7c79f30SChris Mason i > min_write_lock_level && 1385f7c79f30SChris Mason i <= *write_lock_level) { 1386f7c79f30SChris Mason *write_lock_level = i - 1; 1387f7c79f30SChris Mason } 1388925baeddSChris Mason } 1389925baeddSChris Mason } 1390925baeddSChris Mason } 1391925baeddSChris Mason 13923c69faecSChris Mason /* 1393c8c42864SChris Mason * helper function for btrfs_search_slot. The goal is to find a block 1394c8c42864SChris Mason * in cache without setting the path to blocking. If we find the block 1395c8c42864SChris Mason * we return zero and the path is unchanged. 1396c8c42864SChris Mason * 1397c8c42864SChris Mason * If we can't find the block, we set the path blocking and do some 1398c8c42864SChris Mason * reada. -EAGAIN is returned and the search must be repeated. 1399c8c42864SChris Mason */ 1400c8c42864SChris Mason static int 1401d07b8528SLiu Bo read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, 1402c8c42864SChris Mason struct extent_buffer **eb_ret, int level, int slot, 1403cda79c54SDavid Sterba const struct btrfs_key *key) 1404c8c42864SChris Mason { 14050b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 1406c8c42864SChris Mason u64 blocknr; 1407c8c42864SChris Mason u64 gen; 1408c8c42864SChris Mason struct extent_buffer *tmp; 1409581c1760SQu Wenruo struct btrfs_key first_key; 141076a05b35SChris Mason int ret; 1411581c1760SQu Wenruo int parent_level; 1412*b246666eSFilipe Manana bool unlock_up; 1413c8c42864SChris Mason 1414*b246666eSFilipe Manana unlock_up = ((level + 1 < BTRFS_MAX_LEVEL) && p->locks[level + 1]); 1415213ff4b7SNikolay Borisov blocknr = btrfs_node_blockptr(*eb_ret, slot); 1416213ff4b7SNikolay Borisov gen = btrfs_node_ptr_generation(*eb_ret, slot); 1417213ff4b7SNikolay Borisov parent_level = btrfs_header_level(*eb_ret); 1418213ff4b7SNikolay Borisov btrfs_node_key_to_cpu(*eb_ret, &first_key, slot); 1419c8c42864SChris Mason 1420*b246666eSFilipe Manana /* 1421*b246666eSFilipe Manana * If we need to read an extent buffer from disk and we are holding locks 1422*b246666eSFilipe Manana * on upper level nodes, we unlock all the upper nodes before reading the 1423*b246666eSFilipe Manana * extent buffer, and then return -EAGAIN to the caller as it needs to 1424*b246666eSFilipe Manana * restart the search. We don't release the lock on the current level 1425*b246666eSFilipe Manana * because we need to walk this node to figure out which blocks to read. 1426*b246666eSFilipe Manana */ 14270b246afaSJeff Mahoney tmp = find_extent_buffer(fs_info, blocknr); 1428cb44921aSChris Mason if (tmp) { 1429ace75066SFilipe Manana if (p->reada == READA_FORWARD_ALWAYS) 1430ace75066SFilipe Manana reada_for_search(fs_info, p, level, slot, key->objectid); 1431ace75066SFilipe Manana 1432b9fab919SChris Mason /* first we do an atomic uptodate check */ 1433b9fab919SChris Mason if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { 1434448de471SQu Wenruo /* 1435448de471SQu Wenruo * Do extra check for first_key, eb can be stale due to 1436448de471SQu Wenruo * being cached, read from scrub, or have multiple 1437448de471SQu Wenruo * parents (shared tree blocks). 1438448de471SQu Wenruo */ 1439e064d5e9SDavid Sterba if (btrfs_verify_level_key(tmp, 1440448de471SQu Wenruo parent_level - 1, &first_key, gen)) { 1441448de471SQu Wenruo free_extent_buffer(tmp); 1442448de471SQu Wenruo return -EUCLEAN; 1443448de471SQu Wenruo } 1444c8c42864SChris Mason *eb_ret = tmp; 1445c8c42864SChris Mason return 0; 1446c8c42864SChris Mason } 1447bdf7c00eSJosef Bacik 1448*b246666eSFilipe Manana if (unlock_up) 1449*b246666eSFilipe Manana btrfs_unlock_up_safe(p, level + 1); 1450*b246666eSFilipe Manana 1451b9fab919SChris Mason /* now we're allowed to do a blocking uptodate check */ 1452581c1760SQu Wenruo ret = btrfs_read_buffer(tmp, gen, parent_level - 1, &first_key); 14539a4ffa1bSQu Wenruo if (ret) { 1454cb44921aSChris Mason free_extent_buffer(tmp); 1455b3b4aa74SDavid Sterba btrfs_release_path(p); 1456cb44921aSChris Mason return -EIO; 1457cb44921aSChris Mason } 1458*b246666eSFilipe Manana 1459*b246666eSFilipe Manana if (unlock_up) 1460*b246666eSFilipe Manana ret = -EAGAIN; 1461*b246666eSFilipe Manana 1462*b246666eSFilipe Manana goto out; 14639a4ffa1bSQu Wenruo } 1464c8c42864SChris Mason 1465*b246666eSFilipe Manana if (unlock_up) { 14668c594ea8SChris Mason btrfs_unlock_up_safe(p, level + 1); 14674bb59055SFilipe Manana ret = -EAGAIN; 14684bb59055SFilipe Manana } else { 14694bb59055SFilipe Manana ret = 0; 14704bb59055SFilipe Manana } 14718c594ea8SChris Mason 1472e4058b54SDavid Sterba if (p->reada != READA_NONE) 14732ff7e61eSJeff Mahoney reada_for_search(fs_info, p, level, slot, key->objectid); 1474c8c42864SChris Mason 14751b7ec85eSJosef Bacik tmp = read_tree_block(fs_info, blocknr, root->root_key.objectid, 14761b7ec85eSJosef Bacik gen, parent_level - 1, &first_key); 14774eb150d6SQu Wenruo if (IS_ERR(tmp)) { 14784eb150d6SQu Wenruo btrfs_release_path(p); 14794eb150d6SQu Wenruo return PTR_ERR(tmp); 14804eb150d6SQu Wenruo } 148176a05b35SChris Mason /* 148276a05b35SChris Mason * If the read above didn't mark this buffer up to date, 148376a05b35SChris Mason * it will never end up being up to date. Set ret to EIO now 148476a05b35SChris Mason * and give up so that our caller doesn't loop forever 148576a05b35SChris Mason * on our EAGAINs. 148676a05b35SChris Mason */ 1487e6a1d6fdSLiu Bo if (!extent_buffer_uptodate(tmp)) 148876a05b35SChris Mason ret = -EIO; 148902a3307aSLiu Bo 1490*b246666eSFilipe Manana out: 14914bb59055SFilipe Manana if (ret == 0) { 14924bb59055SFilipe Manana *eb_ret = tmp; 14934bb59055SFilipe Manana } else { 14944bb59055SFilipe Manana free_extent_buffer(tmp); 149502a3307aSLiu Bo btrfs_release_path(p); 14964bb59055SFilipe Manana } 14974bb59055SFilipe Manana 149876a05b35SChris Mason return ret; 1499c8c42864SChris Mason } 1500c8c42864SChris Mason 1501c8c42864SChris Mason /* 1502c8c42864SChris Mason * helper function for btrfs_search_slot. This does all of the checks 1503c8c42864SChris Mason * for node-level blocks and does any balancing required based on 1504c8c42864SChris Mason * the ins_len. 1505c8c42864SChris Mason * 1506c8c42864SChris Mason * If no extra work was required, zero is returned. If we had to 1507c8c42864SChris Mason * drop the path, -EAGAIN is returned and btrfs_search_slot must 1508c8c42864SChris Mason * start over 1509c8c42864SChris Mason */ 1510c8c42864SChris Mason static int 1511c8c42864SChris Mason setup_nodes_for_search(struct btrfs_trans_handle *trans, 1512c8c42864SChris Mason struct btrfs_root *root, struct btrfs_path *p, 1513bd681513SChris Mason struct extent_buffer *b, int level, int ins_len, 1514bd681513SChris Mason int *write_lock_level) 1515c8c42864SChris Mason { 15160b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 151795b982deSNikolay Borisov int ret = 0; 15180b246afaSJeff Mahoney 1519c8c42864SChris Mason if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= 15200b246afaSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) { 1521c8c42864SChris Mason 1522bd681513SChris Mason if (*write_lock_level < level + 1) { 1523bd681513SChris Mason *write_lock_level = level + 1; 1524bd681513SChris Mason btrfs_release_path(p); 152595b982deSNikolay Borisov return -EAGAIN; 1526bd681513SChris Mason } 1527bd681513SChris Mason 1528bfb484d9SJosef Bacik reada_for_balance(p, level); 152995b982deSNikolay Borisov ret = split_node(trans, root, p, level); 1530c8c42864SChris Mason 1531c8c42864SChris Mason b = p->nodes[level]; 1532c8c42864SChris Mason } else if (ins_len < 0 && btrfs_header_nritems(b) < 15330b246afaSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 2) { 1534c8c42864SChris Mason 1535bd681513SChris Mason if (*write_lock_level < level + 1) { 1536bd681513SChris Mason *write_lock_level = level + 1; 1537bd681513SChris Mason btrfs_release_path(p); 153895b982deSNikolay Borisov return -EAGAIN; 1539bd681513SChris Mason } 1540bd681513SChris Mason 1541bfb484d9SJosef Bacik reada_for_balance(p, level); 154295b982deSNikolay Borisov ret = balance_level(trans, root, p, level); 154395b982deSNikolay Borisov if (ret) 154495b982deSNikolay Borisov return ret; 1545c8c42864SChris Mason 1546c8c42864SChris Mason b = p->nodes[level]; 1547c8c42864SChris Mason if (!b) { 1548b3b4aa74SDavid Sterba btrfs_release_path(p); 154995b982deSNikolay Borisov return -EAGAIN; 1550c8c42864SChris Mason } 1551c8c42864SChris Mason BUG_ON(btrfs_header_nritems(b) == 1); 1552c8c42864SChris Mason } 1553c8c42864SChris Mason return ret; 1554c8c42864SChris Mason } 1555c8c42864SChris Mason 1556381cf658SDavid Sterba int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, 1557e33d5c3dSKelley Nielsen u64 iobjectid, u64 ioff, u8 key_type, 1558e33d5c3dSKelley Nielsen struct btrfs_key *found_key) 1559e33d5c3dSKelley Nielsen { 1560e33d5c3dSKelley Nielsen int ret; 1561e33d5c3dSKelley Nielsen struct btrfs_key key; 1562e33d5c3dSKelley Nielsen struct extent_buffer *eb; 1563381cf658SDavid Sterba 1564381cf658SDavid Sterba ASSERT(path); 15651d4c08e0SDavid Sterba ASSERT(found_key); 1566e33d5c3dSKelley Nielsen 1567e33d5c3dSKelley Nielsen key.type = key_type; 1568e33d5c3dSKelley Nielsen key.objectid = iobjectid; 1569e33d5c3dSKelley Nielsen key.offset = ioff; 1570e33d5c3dSKelley Nielsen 1571e33d5c3dSKelley Nielsen ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); 15721d4c08e0SDavid Sterba if (ret < 0) 1573e33d5c3dSKelley Nielsen return ret; 1574e33d5c3dSKelley Nielsen 1575e33d5c3dSKelley Nielsen eb = path->nodes[0]; 1576e33d5c3dSKelley Nielsen if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { 1577e33d5c3dSKelley Nielsen ret = btrfs_next_leaf(fs_root, path); 1578e33d5c3dSKelley Nielsen if (ret) 1579e33d5c3dSKelley Nielsen return ret; 1580e33d5c3dSKelley Nielsen eb = path->nodes[0]; 1581e33d5c3dSKelley Nielsen } 1582e33d5c3dSKelley Nielsen 1583e33d5c3dSKelley Nielsen btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); 1584e33d5c3dSKelley Nielsen if (found_key->type != key.type || 1585e33d5c3dSKelley Nielsen found_key->objectid != key.objectid) 1586e33d5c3dSKelley Nielsen return 1; 1587e33d5c3dSKelley Nielsen 1588e33d5c3dSKelley Nielsen return 0; 1589e33d5c3dSKelley Nielsen } 1590e33d5c3dSKelley Nielsen 15911fc28d8eSLiu Bo static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root, 15921fc28d8eSLiu Bo struct btrfs_path *p, 15931fc28d8eSLiu Bo int write_lock_level) 15941fc28d8eSLiu Bo { 15951fc28d8eSLiu Bo struct extent_buffer *b; 1596120de408SJosef Bacik int root_lock = 0; 15971fc28d8eSLiu Bo int level = 0; 15981fc28d8eSLiu Bo 15991fc28d8eSLiu Bo if (p->search_commit_root) { 16001fc28d8eSLiu Bo b = root->commit_root; 160167439dadSDavid Sterba atomic_inc(&b->refs); 16021fc28d8eSLiu Bo level = btrfs_header_level(b); 1603f9ddfd05SLiu Bo /* 1604f9ddfd05SLiu Bo * Ensure that all callers have set skip_locking when 1605f9ddfd05SLiu Bo * p->search_commit_root = 1. 1606f9ddfd05SLiu Bo */ 1607f9ddfd05SLiu Bo ASSERT(p->skip_locking == 1); 16081fc28d8eSLiu Bo 16091fc28d8eSLiu Bo goto out; 16101fc28d8eSLiu Bo } 16111fc28d8eSLiu Bo 16121fc28d8eSLiu Bo if (p->skip_locking) { 16131fc28d8eSLiu Bo b = btrfs_root_node(root); 16141fc28d8eSLiu Bo level = btrfs_header_level(b); 16151fc28d8eSLiu Bo goto out; 16161fc28d8eSLiu Bo } 16171fc28d8eSLiu Bo 1618120de408SJosef Bacik /* We try very hard to do read locks on the root */ 1619120de408SJosef Bacik root_lock = BTRFS_READ_LOCK; 1620120de408SJosef Bacik 16211fc28d8eSLiu Bo /* 1622662c653bSLiu Bo * If the level is set to maximum, we can skip trying to get the read 1623662c653bSLiu Bo * lock. 1624662c653bSLiu Bo */ 1625662c653bSLiu Bo if (write_lock_level < BTRFS_MAX_LEVEL) { 1626662c653bSLiu Bo /* 1627662c653bSLiu Bo * We don't know the level of the root node until we actually 1628662c653bSLiu Bo * have it read locked 16291fc28d8eSLiu Bo */ 16301bb96598SJosef Bacik b = btrfs_read_lock_root_node(root); 16311fc28d8eSLiu Bo level = btrfs_header_level(b); 16321fc28d8eSLiu Bo if (level > write_lock_level) 16331fc28d8eSLiu Bo goto out; 16341fc28d8eSLiu Bo 1635662c653bSLiu Bo /* Whoops, must trade for write lock */ 16361fc28d8eSLiu Bo btrfs_tree_read_unlock(b); 16371fc28d8eSLiu Bo free_extent_buffer(b); 1638662c653bSLiu Bo } 1639662c653bSLiu Bo 16401fc28d8eSLiu Bo b = btrfs_lock_root_node(root); 16411fc28d8eSLiu Bo root_lock = BTRFS_WRITE_LOCK; 16421fc28d8eSLiu Bo 16431fc28d8eSLiu Bo /* The level might have changed, check again */ 16441fc28d8eSLiu Bo level = btrfs_header_level(b); 16451fc28d8eSLiu Bo 16461fc28d8eSLiu Bo out: 1647120de408SJosef Bacik /* 1648120de408SJosef Bacik * The root may have failed to write out at some point, and thus is no 1649120de408SJosef Bacik * longer valid, return an error in this case. 1650120de408SJosef Bacik */ 1651120de408SJosef Bacik if (!extent_buffer_uptodate(b)) { 1652120de408SJosef Bacik if (root_lock) 1653120de408SJosef Bacik btrfs_tree_unlock_rw(b, root_lock); 1654120de408SJosef Bacik free_extent_buffer(b); 1655120de408SJosef Bacik return ERR_PTR(-EIO); 1656120de408SJosef Bacik } 1657120de408SJosef Bacik 16581fc28d8eSLiu Bo p->nodes[level] = b; 16591fc28d8eSLiu Bo if (!p->skip_locking) 16601fc28d8eSLiu Bo p->locks[level] = root_lock; 16611fc28d8eSLiu Bo /* 16621fc28d8eSLiu Bo * Callers are responsible for dropping b's references. 16631fc28d8eSLiu Bo */ 16641fc28d8eSLiu Bo return b; 16651fc28d8eSLiu Bo } 16661fc28d8eSLiu Bo 1667d96b3424SFilipe Manana /* 1668d96b3424SFilipe Manana * Replace the extent buffer at the lowest level of the path with a cloned 1669d96b3424SFilipe Manana * version. The purpose is to be able to use it safely, after releasing the 1670d96b3424SFilipe Manana * commit root semaphore, even if relocation is happening in parallel, the 1671d96b3424SFilipe Manana * transaction used for relocation is committed and the extent buffer is 1672d96b3424SFilipe Manana * reallocated in the next transaction. 1673d96b3424SFilipe Manana * 1674d96b3424SFilipe Manana * This is used in a context where the caller does not prevent transaction 1675d96b3424SFilipe Manana * commits from happening, either by holding a transaction handle or holding 1676d96b3424SFilipe Manana * some lock, while it's doing searches through a commit root. 1677d96b3424SFilipe Manana * At the moment it's only used for send operations. 1678d96b3424SFilipe Manana */ 1679d96b3424SFilipe Manana static int finish_need_commit_sem_search(struct btrfs_path *path) 1680d96b3424SFilipe Manana { 1681d96b3424SFilipe Manana const int i = path->lowest_level; 1682d96b3424SFilipe Manana const int slot = path->slots[i]; 1683d96b3424SFilipe Manana struct extent_buffer *lowest = path->nodes[i]; 1684d96b3424SFilipe Manana struct extent_buffer *clone; 1685d96b3424SFilipe Manana 1686d96b3424SFilipe Manana ASSERT(path->need_commit_sem); 1687d96b3424SFilipe Manana 1688d96b3424SFilipe Manana if (!lowest) 1689d96b3424SFilipe Manana return 0; 1690d96b3424SFilipe Manana 1691d96b3424SFilipe Manana lockdep_assert_held_read(&lowest->fs_info->commit_root_sem); 1692d96b3424SFilipe Manana 1693d96b3424SFilipe Manana clone = btrfs_clone_extent_buffer(lowest); 1694d96b3424SFilipe Manana if (!clone) 1695d96b3424SFilipe Manana return -ENOMEM; 1696d96b3424SFilipe Manana 1697d96b3424SFilipe Manana btrfs_release_path(path); 1698d96b3424SFilipe Manana path->nodes[i] = clone; 1699d96b3424SFilipe Manana path->slots[i] = slot; 1700d96b3424SFilipe Manana 1701d96b3424SFilipe Manana return 0; 1702d96b3424SFilipe Manana } 17031fc28d8eSLiu Bo 1704e2e58d0fSFilipe Manana static inline int search_for_key_slot(struct extent_buffer *eb, 1705e2e58d0fSFilipe Manana int search_low_slot, 1706e2e58d0fSFilipe Manana const struct btrfs_key *key, 1707e2e58d0fSFilipe Manana int prev_cmp, 1708e2e58d0fSFilipe Manana int *slot) 1709e2e58d0fSFilipe Manana { 1710e2e58d0fSFilipe Manana /* 1711e2e58d0fSFilipe Manana * If a previous call to btrfs_bin_search() on a parent node returned an 1712e2e58d0fSFilipe Manana * exact match (prev_cmp == 0), we can safely assume the target key will 1713e2e58d0fSFilipe Manana * always be at slot 0 on lower levels, since each key pointer 1714e2e58d0fSFilipe Manana * (struct btrfs_key_ptr) refers to the lowest key accessible from the 1715e2e58d0fSFilipe Manana * subtree it points to. Thus we can skip searching lower levels. 1716e2e58d0fSFilipe Manana */ 1717e2e58d0fSFilipe Manana if (prev_cmp == 0) { 1718e2e58d0fSFilipe Manana *slot = 0; 1719e2e58d0fSFilipe Manana return 0; 1720e2e58d0fSFilipe Manana } 1721e2e58d0fSFilipe Manana 1722e2e58d0fSFilipe Manana return generic_bin_search(eb, search_low_slot, key, slot); 1723e2e58d0fSFilipe Manana } 1724e2e58d0fSFilipe Manana 1725109324cfSFilipe Manana static int search_leaf(struct btrfs_trans_handle *trans, 1726109324cfSFilipe Manana struct btrfs_root *root, 1727109324cfSFilipe Manana const struct btrfs_key *key, 1728109324cfSFilipe Manana struct btrfs_path *path, 1729109324cfSFilipe Manana int ins_len, 1730109324cfSFilipe Manana int prev_cmp) 1731109324cfSFilipe Manana { 1732109324cfSFilipe Manana struct extent_buffer *leaf = path->nodes[0]; 1733109324cfSFilipe Manana int leaf_free_space = -1; 1734109324cfSFilipe Manana int search_low_slot = 0; 1735109324cfSFilipe Manana int ret; 1736109324cfSFilipe Manana bool do_bin_search = true; 1737109324cfSFilipe Manana 1738109324cfSFilipe Manana /* 1739109324cfSFilipe Manana * If we are doing an insertion, the leaf has enough free space and the 1740109324cfSFilipe Manana * destination slot for the key is not slot 0, then we can unlock our 1741109324cfSFilipe Manana * write lock on the parent, and any other upper nodes, before doing the 1742109324cfSFilipe Manana * binary search on the leaf (with search_for_key_slot()), allowing other 1743109324cfSFilipe Manana * tasks to lock the parent and any other upper nodes. 1744109324cfSFilipe Manana */ 1745109324cfSFilipe Manana if (ins_len > 0) { 1746109324cfSFilipe Manana /* 1747109324cfSFilipe Manana * Cache the leaf free space, since we will need it later and it 1748109324cfSFilipe Manana * will not change until then. 1749109324cfSFilipe Manana */ 1750109324cfSFilipe Manana leaf_free_space = btrfs_leaf_free_space(leaf); 1751109324cfSFilipe Manana 1752109324cfSFilipe Manana /* 1753109324cfSFilipe Manana * !path->locks[1] means we have a single node tree, the leaf is 1754109324cfSFilipe Manana * the root of the tree. 1755109324cfSFilipe Manana */ 1756109324cfSFilipe Manana if (path->locks[1] && leaf_free_space >= ins_len) { 1757109324cfSFilipe Manana struct btrfs_disk_key first_key; 1758109324cfSFilipe Manana 1759109324cfSFilipe Manana ASSERT(btrfs_header_nritems(leaf) > 0); 1760109324cfSFilipe Manana btrfs_item_key(leaf, &first_key, 0); 1761109324cfSFilipe Manana 1762109324cfSFilipe Manana /* 1763109324cfSFilipe Manana * Doing the extra comparison with the first key is cheap, 1764109324cfSFilipe Manana * taking into account that the first key is very likely 1765109324cfSFilipe Manana * already in a cache line because it immediately follows 1766109324cfSFilipe Manana * the extent buffer's header and we have recently accessed 1767109324cfSFilipe Manana * the header's level field. 1768109324cfSFilipe Manana */ 1769109324cfSFilipe Manana ret = comp_keys(&first_key, key); 1770109324cfSFilipe Manana if (ret < 0) { 1771109324cfSFilipe Manana /* 1772109324cfSFilipe Manana * The first key is smaller than the key we want 1773109324cfSFilipe Manana * to insert, so we are safe to unlock all upper 1774109324cfSFilipe Manana * nodes and we have to do the binary search. 1775109324cfSFilipe Manana * 1776109324cfSFilipe Manana * We do use btrfs_unlock_up_safe() and not 1777109324cfSFilipe Manana * unlock_up() because the later does not unlock 1778109324cfSFilipe Manana * nodes with a slot of 0 - we can safely unlock 1779109324cfSFilipe Manana * any node even if its slot is 0 since in this 1780109324cfSFilipe Manana * case the key does not end up at slot 0 of the 1781109324cfSFilipe Manana * leaf and there's no need to split the leaf. 1782109324cfSFilipe Manana */ 1783109324cfSFilipe Manana btrfs_unlock_up_safe(path, 1); 1784109324cfSFilipe Manana search_low_slot = 1; 1785109324cfSFilipe Manana } else { 1786109324cfSFilipe Manana /* 1787109324cfSFilipe Manana * The first key is >= then the key we want to 1788109324cfSFilipe Manana * insert, so we can skip the binary search as 1789109324cfSFilipe Manana * the target key will be at slot 0. 1790109324cfSFilipe Manana * 1791109324cfSFilipe Manana * We can not unlock upper nodes when the key is 1792109324cfSFilipe Manana * less than the first key, because we will need 1793109324cfSFilipe Manana * to update the key at slot 0 of the parent node 1794109324cfSFilipe Manana * and possibly of other upper nodes too. 1795109324cfSFilipe Manana * If the key matches the first key, then we can 1796109324cfSFilipe Manana * unlock all the upper nodes, using 1797109324cfSFilipe Manana * btrfs_unlock_up_safe() instead of unlock_up() 1798109324cfSFilipe Manana * as stated above. 1799109324cfSFilipe Manana */ 1800109324cfSFilipe Manana if (ret == 0) 1801109324cfSFilipe Manana btrfs_unlock_up_safe(path, 1); 1802109324cfSFilipe Manana /* 1803109324cfSFilipe Manana * ret is already 0 or 1, matching the result of 1804109324cfSFilipe Manana * a btrfs_bin_search() call, so there is no need 1805109324cfSFilipe Manana * to adjust it. 1806109324cfSFilipe Manana */ 1807109324cfSFilipe Manana do_bin_search = false; 1808109324cfSFilipe Manana path->slots[0] = 0; 1809109324cfSFilipe Manana } 1810109324cfSFilipe Manana } 1811109324cfSFilipe Manana } 1812109324cfSFilipe Manana 1813109324cfSFilipe Manana if (do_bin_search) { 1814109324cfSFilipe Manana ret = search_for_key_slot(leaf, search_low_slot, key, 1815109324cfSFilipe Manana prev_cmp, &path->slots[0]); 1816109324cfSFilipe Manana if (ret < 0) 1817109324cfSFilipe Manana return ret; 1818109324cfSFilipe Manana } 1819109324cfSFilipe Manana 1820109324cfSFilipe Manana if (ins_len > 0) { 1821109324cfSFilipe Manana /* 1822109324cfSFilipe Manana * Item key already exists. In this case, if we are allowed to 1823109324cfSFilipe Manana * insert the item (for example, in dir_item case, item key 1824109324cfSFilipe Manana * collision is allowed), it will be merged with the original 1825109324cfSFilipe Manana * item. Only the item size grows, no new btrfs item will be 1826109324cfSFilipe Manana * added. If search_for_extension is not set, ins_len already 1827109324cfSFilipe Manana * accounts the size btrfs_item, deduct it here so leaf space 1828109324cfSFilipe Manana * check will be correct. 1829109324cfSFilipe Manana */ 1830109324cfSFilipe Manana if (ret == 0 && !path->search_for_extension) { 1831109324cfSFilipe Manana ASSERT(ins_len >= sizeof(struct btrfs_item)); 1832109324cfSFilipe Manana ins_len -= sizeof(struct btrfs_item); 1833109324cfSFilipe Manana } 1834109324cfSFilipe Manana 1835109324cfSFilipe Manana ASSERT(leaf_free_space >= 0); 1836109324cfSFilipe Manana 1837109324cfSFilipe Manana if (leaf_free_space < ins_len) { 1838109324cfSFilipe Manana int err; 1839109324cfSFilipe Manana 1840109324cfSFilipe Manana err = split_leaf(trans, root, key, path, ins_len, 1841109324cfSFilipe Manana (ret == 0)); 1842bb8e9a60SFilipe Manana ASSERT(err <= 0); 1843bb8e9a60SFilipe Manana if (WARN_ON(err > 0)) 1844bb8e9a60SFilipe Manana err = -EUCLEAN; 1845109324cfSFilipe Manana if (err) 1846109324cfSFilipe Manana ret = err; 1847109324cfSFilipe Manana } 1848109324cfSFilipe Manana } 1849109324cfSFilipe Manana 1850109324cfSFilipe Manana return ret; 1851109324cfSFilipe Manana } 1852109324cfSFilipe Manana 1853c8c42864SChris Mason /* 18544271eceaSNikolay Borisov * btrfs_search_slot - look for a key in a tree and perform necessary 18554271eceaSNikolay Borisov * modifications to preserve tree invariants. 185674123bd7SChris Mason * 18574271eceaSNikolay Borisov * @trans: Handle of transaction, used when modifying the tree 18584271eceaSNikolay Borisov * @p: Holds all btree nodes along the search path 18594271eceaSNikolay Borisov * @root: The root node of the tree 18604271eceaSNikolay Borisov * @key: The key we are looking for 18619a664971Sethanwu * @ins_len: Indicates purpose of search: 18629a664971Sethanwu * >0 for inserts it's size of item inserted (*) 18639a664971Sethanwu * <0 for deletions 18649a664971Sethanwu * 0 for plain searches, not modifying the tree 18659a664971Sethanwu * 18669a664971Sethanwu * (*) If size of item inserted doesn't include 18679a664971Sethanwu * sizeof(struct btrfs_item), then p->search_for_extension must 18689a664971Sethanwu * be set. 18694271eceaSNikolay Borisov * @cow: boolean should CoW operations be performed. Must always be 1 18704271eceaSNikolay Borisov * when modifying the tree. 187197571fd0SChris Mason * 18724271eceaSNikolay Borisov * If @ins_len > 0, nodes and leaves will be split as we walk down the tree. 18734271eceaSNikolay Borisov * If @ins_len < 0, nodes will be merged as we walk down the tree (if possible) 18744271eceaSNikolay Borisov * 18754271eceaSNikolay Borisov * If @key is found, 0 is returned and you can find the item in the leaf level 18764271eceaSNikolay Borisov * of the path (level 0) 18774271eceaSNikolay Borisov * 18784271eceaSNikolay Borisov * If @key isn't found, 1 is returned and the leaf level of the path (level 0) 18794271eceaSNikolay Borisov * points to the slot where it should be inserted 18804271eceaSNikolay Borisov * 18814271eceaSNikolay Borisov * If an error is encountered while searching the tree a negative error number 18824271eceaSNikolay Borisov * is returned 188374123bd7SChris Mason */ 1884310712b2SOmar Sandoval int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, 1885310712b2SOmar Sandoval const struct btrfs_key *key, struct btrfs_path *p, 1886310712b2SOmar Sandoval int ins_len, int cow) 1887be0e5c09SChris Mason { 1888d96b3424SFilipe Manana struct btrfs_fs_info *fs_info = root->fs_info; 18895f39d397SChris Mason struct extent_buffer *b; 1890be0e5c09SChris Mason int slot; 1891be0e5c09SChris Mason int ret; 189233c66f43SYan Zheng int err; 1893be0e5c09SChris Mason int level; 1894925baeddSChris Mason int lowest_unlock = 1; 1895bd681513SChris Mason /* everything at write_lock_level or lower must be write locked */ 1896bd681513SChris Mason int write_lock_level = 0; 18979f3a7427SChris Mason u8 lowest_level = 0; 1898f7c79f30SChris Mason int min_write_lock_level; 1899d7396f07SFilipe David Borba Manana int prev_cmp; 19009f3a7427SChris Mason 19016702ed49SChris Mason lowest_level = p->lowest_level; 1902323ac95bSChris Mason WARN_ON(lowest_level && ins_len > 0); 190322b0ebdaSChris Mason WARN_ON(p->nodes[0] != NULL); 1904eb653de1SFilipe David Borba Manana BUG_ON(!cow && ins_len); 190525179201SJosef Bacik 1906bd681513SChris Mason if (ins_len < 0) { 1907925baeddSChris Mason lowest_unlock = 2; 190865b51a00SChris Mason 1909bd681513SChris Mason /* when we are removing items, we might have to go up to level 1910bd681513SChris Mason * two as we update tree pointers Make sure we keep write 1911bd681513SChris Mason * for those levels as well 1912bd681513SChris Mason */ 1913bd681513SChris Mason write_lock_level = 2; 1914bd681513SChris Mason } else if (ins_len > 0) { 1915bd681513SChris Mason /* 1916bd681513SChris Mason * for inserting items, make sure we have a write lock on 1917bd681513SChris Mason * level 1 so we can update keys 1918bd681513SChris Mason */ 1919bd681513SChris Mason write_lock_level = 1; 1920bd681513SChris Mason } 1921bd681513SChris Mason 1922bd681513SChris Mason if (!cow) 1923bd681513SChris Mason write_lock_level = -1; 1924bd681513SChris Mason 192509a2a8f9SJosef Bacik if (cow && (p->keep_locks || p->lowest_level)) 1926bd681513SChris Mason write_lock_level = BTRFS_MAX_LEVEL; 1927bd681513SChris Mason 1928f7c79f30SChris Mason min_write_lock_level = write_lock_level; 1929f7c79f30SChris Mason 1930d96b3424SFilipe Manana if (p->need_commit_sem) { 1931d96b3424SFilipe Manana ASSERT(p->search_commit_root); 1932d96b3424SFilipe Manana down_read(&fs_info->commit_root_sem); 1933d96b3424SFilipe Manana } 1934d96b3424SFilipe Manana 1935bb803951SChris Mason again: 1936d7396f07SFilipe David Borba Manana prev_cmp = -1; 19371fc28d8eSLiu Bo b = btrfs_search_slot_get_root(root, p, write_lock_level); 1938be6821f8SFilipe Manana if (IS_ERR(b)) { 1939be6821f8SFilipe Manana ret = PTR_ERR(b); 1940be6821f8SFilipe Manana goto done; 1941be6821f8SFilipe Manana } 1942925baeddSChris Mason 1943eb60ceacSChris Mason while (b) { 1944f624d976SQu Wenruo int dec = 0; 1945f624d976SQu Wenruo 19465f39d397SChris Mason level = btrfs_header_level(b); 194765b51a00SChris Mason 194802217ed2SChris Mason if (cow) { 19499ea2c7c9SNikolay Borisov bool last_level = (level == (BTRFS_MAX_LEVEL - 1)); 19509ea2c7c9SNikolay Borisov 1951c8c42864SChris Mason /* 1952c8c42864SChris Mason * if we don't really need to cow this block 1953c8c42864SChris Mason * then we don't want to set the path blocking, 1954c8c42864SChris Mason * so we test it here 1955c8c42864SChris Mason */ 19565963ffcaSJosef Bacik if (!should_cow_block(trans, root, b)) 195765b51a00SChris Mason goto cow_done; 19585d4f98a2SYan Zheng 1959bd681513SChris Mason /* 1960bd681513SChris Mason * must have write locks on this node and the 1961bd681513SChris Mason * parent 1962bd681513SChris Mason */ 19635124e00eSJosef Bacik if (level > write_lock_level || 19645124e00eSJosef Bacik (level + 1 > write_lock_level && 19655124e00eSJosef Bacik level + 1 < BTRFS_MAX_LEVEL && 19665124e00eSJosef Bacik p->nodes[level + 1])) { 1967bd681513SChris Mason write_lock_level = level + 1; 1968bd681513SChris Mason btrfs_release_path(p); 1969bd681513SChris Mason goto again; 1970bd681513SChris Mason } 1971bd681513SChris Mason 19729ea2c7c9SNikolay Borisov if (last_level) 19739ea2c7c9SNikolay Borisov err = btrfs_cow_block(trans, root, b, NULL, 0, 19749631e4ccSJosef Bacik &b, 19759631e4ccSJosef Bacik BTRFS_NESTING_COW); 19769ea2c7c9SNikolay Borisov else 197733c66f43SYan Zheng err = btrfs_cow_block(trans, root, b, 1978e20d96d6SChris Mason p->nodes[level + 1], 19799631e4ccSJosef Bacik p->slots[level + 1], &b, 19809631e4ccSJosef Bacik BTRFS_NESTING_COW); 198133c66f43SYan Zheng if (err) { 198233c66f43SYan Zheng ret = err; 198365b51a00SChris Mason goto done; 198454aa1f4dSChris Mason } 198502217ed2SChris Mason } 198665b51a00SChris Mason cow_done: 1987eb60ceacSChris Mason p->nodes[level] = b; 1988b4ce94deSChris Mason 1989b4ce94deSChris Mason /* 1990b4ce94deSChris Mason * we have a lock on b and as long as we aren't changing 1991b4ce94deSChris Mason * the tree, there is no way to for the items in b to change. 1992b4ce94deSChris Mason * It is safe to drop the lock on our parent before we 1993b4ce94deSChris Mason * go through the expensive btree search on b. 1994b4ce94deSChris Mason * 1995eb653de1SFilipe David Borba Manana * If we're inserting or deleting (ins_len != 0), then we might 1996eb653de1SFilipe David Borba Manana * be changing slot zero, which may require changing the parent. 1997eb653de1SFilipe David Borba Manana * So, we can't drop the lock until after we know which slot 1998eb653de1SFilipe David Borba Manana * we're operating on. 1999b4ce94deSChris Mason */ 2000eb653de1SFilipe David Borba Manana if (!ins_len && !p->keep_locks) { 2001eb653de1SFilipe David Borba Manana int u = level + 1; 2002eb653de1SFilipe David Borba Manana 2003eb653de1SFilipe David Borba Manana if (u < BTRFS_MAX_LEVEL && p->locks[u]) { 2004eb653de1SFilipe David Borba Manana btrfs_tree_unlock_rw(p->nodes[u], p->locks[u]); 2005eb653de1SFilipe David Borba Manana p->locks[u] = 0; 2006eb653de1SFilipe David Borba Manana } 2007eb653de1SFilipe David Borba Manana } 2008b4ce94deSChris Mason 2009e2e58d0fSFilipe Manana if (level == 0) { 2010109324cfSFilipe Manana if (ins_len > 0) 2011e5e1c174SFilipe Manana ASSERT(write_lock_level >= 1); 2012bd681513SChris Mason 2013109324cfSFilipe Manana ret = search_leaf(trans, root, key, p, ins_len, prev_cmp); 2014459931ecSChris Mason if (!p->search_for_split) 2015f7c79f30SChris Mason unlock_up(p, level, lowest_unlock, 20164b6f8e96SLiu Bo min_write_lock_level, NULL); 201765b51a00SChris Mason goto done; 201865b51a00SChris Mason } 2019e2e58d0fSFilipe Manana 2020e2e58d0fSFilipe Manana ret = search_for_key_slot(b, 0, key, prev_cmp, &slot); 2021e2e58d0fSFilipe Manana if (ret < 0) 2022e2e58d0fSFilipe Manana goto done; 2023e2e58d0fSFilipe Manana prev_cmp = ret; 2024e2e58d0fSFilipe Manana 2025f624d976SQu Wenruo if (ret && slot > 0) { 2026f624d976SQu Wenruo dec = 1; 2027f624d976SQu Wenruo slot--; 2028f624d976SQu Wenruo } 2029f624d976SQu Wenruo p->slots[level] = slot; 2030f624d976SQu Wenruo err = setup_nodes_for_search(trans, root, p, b, level, ins_len, 2031f624d976SQu Wenruo &write_lock_level); 2032f624d976SQu Wenruo if (err == -EAGAIN) 2033f624d976SQu Wenruo goto again; 2034f624d976SQu Wenruo if (err) { 2035f624d976SQu Wenruo ret = err; 2036f624d976SQu Wenruo goto done; 2037f624d976SQu Wenruo } 2038f624d976SQu Wenruo b = p->nodes[level]; 2039f624d976SQu Wenruo slot = p->slots[level]; 2040f624d976SQu Wenruo 2041f624d976SQu Wenruo /* 2042f624d976SQu Wenruo * Slot 0 is special, if we change the key we have to update 2043f624d976SQu Wenruo * the parent pointer which means we must have a write lock on 2044f624d976SQu Wenruo * the parent 2045f624d976SQu Wenruo */ 2046f624d976SQu Wenruo if (slot == 0 && ins_len && write_lock_level < level + 1) { 2047f624d976SQu Wenruo write_lock_level = level + 1; 2048f624d976SQu Wenruo btrfs_release_path(p); 2049f624d976SQu Wenruo goto again; 2050f624d976SQu Wenruo } 2051f624d976SQu Wenruo 2052f624d976SQu Wenruo unlock_up(p, level, lowest_unlock, min_write_lock_level, 2053f624d976SQu Wenruo &write_lock_level); 2054f624d976SQu Wenruo 2055f624d976SQu Wenruo if (level == lowest_level) { 2056f624d976SQu Wenruo if (dec) 2057f624d976SQu Wenruo p->slots[level]++; 2058f624d976SQu Wenruo goto done; 2059f624d976SQu Wenruo } 2060f624d976SQu Wenruo 2061f624d976SQu Wenruo err = read_block_for_search(root, p, &b, level, slot, key); 2062f624d976SQu Wenruo if (err == -EAGAIN) 2063f624d976SQu Wenruo goto again; 2064f624d976SQu Wenruo if (err) { 2065f624d976SQu Wenruo ret = err; 2066f624d976SQu Wenruo goto done; 2067f624d976SQu Wenruo } 2068f624d976SQu Wenruo 2069f624d976SQu Wenruo if (!p->skip_locking) { 2070f624d976SQu Wenruo level = btrfs_header_level(b); 2071f624d976SQu Wenruo if (level <= write_lock_level) { 2072f624d976SQu Wenruo btrfs_tree_lock(b); 2073f624d976SQu Wenruo p->locks[level] = BTRFS_WRITE_LOCK; 2074f624d976SQu Wenruo } else { 2075fe596ca3SJosef Bacik btrfs_tree_read_lock(b); 2076f624d976SQu Wenruo p->locks[level] = BTRFS_READ_LOCK; 2077f624d976SQu Wenruo } 2078f624d976SQu Wenruo p->nodes[level] = b; 2079f624d976SQu Wenruo } 208065b51a00SChris Mason } 208165b51a00SChris Mason ret = 1; 208265b51a00SChris Mason done: 20835f5bc6b1SFilipe Manana if (ret < 0 && !p->skip_release_on_error) 2084b3b4aa74SDavid Sterba btrfs_release_path(p); 2085d96b3424SFilipe Manana 2086d96b3424SFilipe Manana if (p->need_commit_sem) { 2087d96b3424SFilipe Manana int ret2; 2088d96b3424SFilipe Manana 2089d96b3424SFilipe Manana ret2 = finish_need_commit_sem_search(p); 2090d96b3424SFilipe Manana up_read(&fs_info->commit_root_sem); 2091d96b3424SFilipe Manana if (ret2) 2092d96b3424SFilipe Manana ret = ret2; 2093d96b3424SFilipe Manana } 2094d96b3424SFilipe Manana 2095be0e5c09SChris Mason return ret; 2096be0e5c09SChris Mason } 2097f75e2b79SJosef Bacik ALLOW_ERROR_INJECTION(btrfs_search_slot, ERRNO); 2098be0e5c09SChris Mason 209974123bd7SChris Mason /* 21005d9e75c4SJan Schmidt * Like btrfs_search_slot, this looks for a key in the given tree. It uses the 21015d9e75c4SJan Schmidt * current state of the tree together with the operations recorded in the tree 21025d9e75c4SJan Schmidt * modification log to search for the key in a previous version of this tree, as 21035d9e75c4SJan Schmidt * denoted by the time_seq parameter. 21045d9e75c4SJan Schmidt * 21055d9e75c4SJan Schmidt * Naturally, there is no support for insert, delete or cow operations. 21065d9e75c4SJan Schmidt * 21075d9e75c4SJan Schmidt * The resulting path and return value will be set up as if we called 21085d9e75c4SJan Schmidt * btrfs_search_slot at that point in time with ins_len and cow both set to 0. 21095d9e75c4SJan Schmidt */ 2110310712b2SOmar Sandoval int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key, 21115d9e75c4SJan Schmidt struct btrfs_path *p, u64 time_seq) 21125d9e75c4SJan Schmidt { 21130b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 21145d9e75c4SJan Schmidt struct extent_buffer *b; 21155d9e75c4SJan Schmidt int slot; 21165d9e75c4SJan Schmidt int ret; 21175d9e75c4SJan Schmidt int err; 21185d9e75c4SJan Schmidt int level; 21195d9e75c4SJan Schmidt int lowest_unlock = 1; 21205d9e75c4SJan Schmidt u8 lowest_level = 0; 21215d9e75c4SJan Schmidt 21225d9e75c4SJan Schmidt lowest_level = p->lowest_level; 21235d9e75c4SJan Schmidt WARN_ON(p->nodes[0] != NULL); 21245d9e75c4SJan Schmidt 21255d9e75c4SJan Schmidt if (p->search_commit_root) { 21265d9e75c4SJan Schmidt BUG_ON(time_seq); 21275d9e75c4SJan Schmidt return btrfs_search_slot(NULL, root, key, p, 0, 0); 21285d9e75c4SJan Schmidt } 21295d9e75c4SJan Schmidt 21305d9e75c4SJan Schmidt again: 2131f3a84ccdSFilipe Manana b = btrfs_get_old_root(root, time_seq); 2132315bed43SNikolay Borisov if (!b) { 2133315bed43SNikolay Borisov ret = -EIO; 2134315bed43SNikolay Borisov goto done; 2135315bed43SNikolay Borisov } 21365d9e75c4SJan Schmidt level = btrfs_header_level(b); 21375d9e75c4SJan Schmidt p->locks[level] = BTRFS_READ_LOCK; 21385d9e75c4SJan Schmidt 21395d9e75c4SJan Schmidt while (b) { 2140abe9339dSQu Wenruo int dec = 0; 2141abe9339dSQu Wenruo 21425d9e75c4SJan Schmidt level = btrfs_header_level(b); 21435d9e75c4SJan Schmidt p->nodes[level] = b; 21445d9e75c4SJan Schmidt 21455d9e75c4SJan Schmidt /* 21465d9e75c4SJan Schmidt * we have a lock on b and as long as we aren't changing 21475d9e75c4SJan Schmidt * the tree, there is no way to for the items in b to change. 21485d9e75c4SJan Schmidt * It is safe to drop the lock on our parent before we 21495d9e75c4SJan Schmidt * go through the expensive btree search on b. 21505d9e75c4SJan Schmidt */ 21515d9e75c4SJan Schmidt btrfs_unlock_up_safe(p, level + 1); 21525d9e75c4SJan Schmidt 2153995e9a16SNikolay Borisov ret = btrfs_bin_search(b, key, &slot); 2154cbca7d59SFilipe Manana if (ret < 0) 2155cbca7d59SFilipe Manana goto done; 21565d9e75c4SJan Schmidt 2157abe9339dSQu Wenruo if (level == 0) { 2158abe9339dSQu Wenruo p->slots[level] = slot; 2159abe9339dSQu Wenruo unlock_up(p, level, lowest_unlock, 0, NULL); 2160abe9339dSQu Wenruo goto done; 2161abe9339dSQu Wenruo } 2162abe9339dSQu Wenruo 21635d9e75c4SJan Schmidt if (ret && slot > 0) { 21645d9e75c4SJan Schmidt dec = 1; 2165abe9339dSQu Wenruo slot--; 21665d9e75c4SJan Schmidt } 21675d9e75c4SJan Schmidt p->slots[level] = slot; 21685d9e75c4SJan Schmidt unlock_up(p, level, lowest_unlock, 0, NULL); 21695d9e75c4SJan Schmidt 21705d9e75c4SJan Schmidt if (level == lowest_level) { 21715d9e75c4SJan Schmidt if (dec) 21725d9e75c4SJan Schmidt p->slots[level]++; 21735d9e75c4SJan Schmidt goto done; 21745d9e75c4SJan Schmidt } 21755d9e75c4SJan Schmidt 2176abe9339dSQu Wenruo err = read_block_for_search(root, p, &b, level, slot, key); 21775d9e75c4SJan Schmidt if (err == -EAGAIN) 21785d9e75c4SJan Schmidt goto again; 21795d9e75c4SJan Schmidt if (err) { 21805d9e75c4SJan Schmidt ret = err; 21815d9e75c4SJan Schmidt goto done; 21825d9e75c4SJan Schmidt } 21835d9e75c4SJan Schmidt 21845d9e75c4SJan Schmidt level = btrfs_header_level(b); 21855d9e75c4SJan Schmidt btrfs_tree_read_lock(b); 2186f3a84ccdSFilipe Manana b = btrfs_tree_mod_log_rewind(fs_info, p, b, time_seq); 2187db7f3436SJosef Bacik if (!b) { 2188db7f3436SJosef Bacik ret = -ENOMEM; 2189db7f3436SJosef Bacik goto done; 2190db7f3436SJosef Bacik } 21915d9e75c4SJan Schmidt p->locks[level] = BTRFS_READ_LOCK; 21925d9e75c4SJan Schmidt p->nodes[level] = b; 21935d9e75c4SJan Schmidt } 21945d9e75c4SJan Schmidt ret = 1; 21955d9e75c4SJan Schmidt done: 21965d9e75c4SJan Schmidt if (ret < 0) 21975d9e75c4SJan Schmidt btrfs_release_path(p); 21985d9e75c4SJan Schmidt 21995d9e75c4SJan Schmidt return ret; 22005d9e75c4SJan Schmidt } 22015d9e75c4SJan Schmidt 22025d9e75c4SJan Schmidt /* 22032f38b3e1SArne Jansen * helper to use instead of search slot if no exact match is needed but 22042f38b3e1SArne Jansen * instead the next or previous item should be returned. 22052f38b3e1SArne Jansen * When find_higher is true, the next higher item is returned, the next lower 22062f38b3e1SArne Jansen * otherwise. 22072f38b3e1SArne Jansen * When return_any and find_higher are both true, and no higher item is found, 22082f38b3e1SArne Jansen * return the next lower instead. 22092f38b3e1SArne Jansen * When return_any is true and find_higher is false, and no lower item is found, 22102f38b3e1SArne Jansen * return the next higher instead. 22112f38b3e1SArne Jansen * It returns 0 if any item is found, 1 if none is found (tree empty), and 22122f38b3e1SArne Jansen * < 0 on error 22132f38b3e1SArne Jansen */ 22142f38b3e1SArne Jansen int btrfs_search_slot_for_read(struct btrfs_root *root, 2215310712b2SOmar Sandoval const struct btrfs_key *key, 2216310712b2SOmar Sandoval struct btrfs_path *p, int find_higher, 2217310712b2SOmar Sandoval int return_any) 22182f38b3e1SArne Jansen { 22192f38b3e1SArne Jansen int ret; 22202f38b3e1SArne Jansen struct extent_buffer *leaf; 22212f38b3e1SArne Jansen 22222f38b3e1SArne Jansen again: 22232f38b3e1SArne Jansen ret = btrfs_search_slot(NULL, root, key, p, 0, 0); 22242f38b3e1SArne Jansen if (ret <= 0) 22252f38b3e1SArne Jansen return ret; 22262f38b3e1SArne Jansen /* 22272f38b3e1SArne Jansen * a return value of 1 means the path is at the position where the 22282f38b3e1SArne Jansen * item should be inserted. Normally this is the next bigger item, 22292f38b3e1SArne Jansen * but in case the previous item is the last in a leaf, path points 22302f38b3e1SArne Jansen * to the first free slot in the previous leaf, i.e. at an invalid 22312f38b3e1SArne Jansen * item. 22322f38b3e1SArne Jansen */ 22332f38b3e1SArne Jansen leaf = p->nodes[0]; 22342f38b3e1SArne Jansen 22352f38b3e1SArne Jansen if (find_higher) { 22362f38b3e1SArne Jansen if (p->slots[0] >= btrfs_header_nritems(leaf)) { 22372f38b3e1SArne Jansen ret = btrfs_next_leaf(root, p); 22382f38b3e1SArne Jansen if (ret <= 0) 22392f38b3e1SArne Jansen return ret; 22402f38b3e1SArne Jansen if (!return_any) 22412f38b3e1SArne Jansen return 1; 22422f38b3e1SArne Jansen /* 22432f38b3e1SArne Jansen * no higher item found, return the next 22442f38b3e1SArne Jansen * lower instead 22452f38b3e1SArne Jansen */ 22462f38b3e1SArne Jansen return_any = 0; 22472f38b3e1SArne Jansen find_higher = 0; 22482f38b3e1SArne Jansen btrfs_release_path(p); 22492f38b3e1SArne Jansen goto again; 22502f38b3e1SArne Jansen } 22512f38b3e1SArne Jansen } else { 22522f38b3e1SArne Jansen if (p->slots[0] == 0) { 22532f38b3e1SArne Jansen ret = btrfs_prev_leaf(root, p); 2254e6793769SArne Jansen if (ret < 0) 22552f38b3e1SArne Jansen return ret; 2256e6793769SArne Jansen if (!ret) { 225723c6bf6aSFilipe David Borba Manana leaf = p->nodes[0]; 225823c6bf6aSFilipe David Borba Manana if (p->slots[0] == btrfs_header_nritems(leaf)) 225923c6bf6aSFilipe David Borba Manana p->slots[0]--; 2260e6793769SArne Jansen return 0; 2261e6793769SArne Jansen } 22622f38b3e1SArne Jansen if (!return_any) 22632f38b3e1SArne Jansen return 1; 22642f38b3e1SArne Jansen /* 22652f38b3e1SArne Jansen * no lower item found, return the next 22662f38b3e1SArne Jansen * higher instead 22672f38b3e1SArne Jansen */ 22682f38b3e1SArne Jansen return_any = 0; 22692f38b3e1SArne Jansen find_higher = 1; 22702f38b3e1SArne Jansen btrfs_release_path(p); 22712f38b3e1SArne Jansen goto again; 2272e6793769SArne Jansen } else { 22732f38b3e1SArne Jansen --p->slots[0]; 22742f38b3e1SArne Jansen } 22752f38b3e1SArne Jansen } 22762f38b3e1SArne Jansen return 0; 22772f38b3e1SArne Jansen } 22782f38b3e1SArne Jansen 22792f38b3e1SArne Jansen /* 22800ff40a91SMarcos Paulo de Souza * Execute search and call btrfs_previous_item to traverse backwards if the item 22810ff40a91SMarcos Paulo de Souza * was not found. 22820ff40a91SMarcos Paulo de Souza * 22830ff40a91SMarcos Paulo de Souza * Return 0 if found, 1 if not found and < 0 if error. 22840ff40a91SMarcos Paulo de Souza */ 22850ff40a91SMarcos Paulo de Souza int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key, 22860ff40a91SMarcos Paulo de Souza struct btrfs_path *path) 22870ff40a91SMarcos Paulo de Souza { 22880ff40a91SMarcos Paulo de Souza int ret; 22890ff40a91SMarcos Paulo de Souza 22900ff40a91SMarcos Paulo de Souza ret = btrfs_search_slot(NULL, root, key, path, 0, 0); 22910ff40a91SMarcos Paulo de Souza if (ret > 0) 22920ff40a91SMarcos Paulo de Souza ret = btrfs_previous_item(root, path, key->objectid, key->type); 22930ff40a91SMarcos Paulo de Souza 22940ff40a91SMarcos Paulo de Souza if (ret == 0) 22950ff40a91SMarcos Paulo de Souza btrfs_item_key_to_cpu(path->nodes[0], key, path->slots[0]); 22960ff40a91SMarcos Paulo de Souza 22970ff40a91SMarcos Paulo de Souza return ret; 22980ff40a91SMarcos Paulo de Souza } 22990ff40a91SMarcos Paulo de Souza 23000ff40a91SMarcos Paulo de Souza /* 230174123bd7SChris Mason * adjust the pointers going up the tree, starting at level 230274123bd7SChris Mason * making sure the right key of each node is points to 'key'. 230374123bd7SChris Mason * This is used after shifting pointers to the left, so it stops 230474123bd7SChris Mason * fixing up pointers when a given leaf/node is not in slot 0 of the 230574123bd7SChris Mason * higher levels 2306aa5d6bedSChris Mason * 230774123bd7SChris Mason */ 2308b167fa91SNikolay Borisov static void fixup_low_keys(struct btrfs_path *path, 23095f39d397SChris Mason struct btrfs_disk_key *key, int level) 2310be0e5c09SChris Mason { 2311be0e5c09SChris Mason int i; 23125f39d397SChris Mason struct extent_buffer *t; 23130e82bcfeSDavid Sterba int ret; 23145f39d397SChris Mason 2315234b63a0SChris Mason for (i = level; i < BTRFS_MAX_LEVEL; i++) { 2316be0e5c09SChris Mason int tslot = path->slots[i]; 23170e82bcfeSDavid Sterba 2318eb60ceacSChris Mason if (!path->nodes[i]) 2319be0e5c09SChris Mason break; 23205f39d397SChris Mason t = path->nodes[i]; 2321f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_key(t, tslot, 2322f3a84ccdSFilipe Manana BTRFS_MOD_LOG_KEY_REPLACE, GFP_ATOMIC); 23230e82bcfeSDavid Sterba BUG_ON(ret < 0); 23245f39d397SChris Mason btrfs_set_node_key(t, key, tslot); 2325d6025579SChris Mason btrfs_mark_buffer_dirty(path->nodes[i]); 2326be0e5c09SChris Mason if (tslot != 0) 2327be0e5c09SChris Mason break; 2328be0e5c09SChris Mason } 2329be0e5c09SChris Mason } 2330be0e5c09SChris Mason 233174123bd7SChris Mason /* 233231840ae1SZheng Yan * update item key. 233331840ae1SZheng Yan * 233431840ae1SZheng Yan * This function isn't completely safe. It's the caller's responsibility 233531840ae1SZheng Yan * that the new key won't break the order 233631840ae1SZheng Yan */ 2337b7a0365eSDaniel Dressler void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info, 2338b7a0365eSDaniel Dressler struct btrfs_path *path, 2339310712b2SOmar Sandoval const struct btrfs_key *new_key) 234031840ae1SZheng Yan { 234131840ae1SZheng Yan struct btrfs_disk_key disk_key; 234231840ae1SZheng Yan struct extent_buffer *eb; 234331840ae1SZheng Yan int slot; 234431840ae1SZheng Yan 234531840ae1SZheng Yan eb = path->nodes[0]; 234631840ae1SZheng Yan slot = path->slots[0]; 234731840ae1SZheng Yan if (slot > 0) { 234831840ae1SZheng Yan btrfs_item_key(eb, &disk_key, slot - 1); 23497c15d410SQu Wenruo if (unlikely(comp_keys(&disk_key, new_key) >= 0)) { 23507c15d410SQu Wenruo btrfs_crit(fs_info, 23517c15d410SQu Wenruo "slot %u key (%llu %u %llu) new key (%llu %u %llu)", 23527c15d410SQu Wenruo slot, btrfs_disk_key_objectid(&disk_key), 23537c15d410SQu Wenruo btrfs_disk_key_type(&disk_key), 23547c15d410SQu Wenruo btrfs_disk_key_offset(&disk_key), 23557c15d410SQu Wenruo new_key->objectid, new_key->type, 23567c15d410SQu Wenruo new_key->offset); 23577c15d410SQu Wenruo btrfs_print_leaf(eb); 23587c15d410SQu Wenruo BUG(); 23597c15d410SQu Wenruo } 236031840ae1SZheng Yan } 236131840ae1SZheng Yan if (slot < btrfs_header_nritems(eb) - 1) { 236231840ae1SZheng Yan btrfs_item_key(eb, &disk_key, slot + 1); 23637c15d410SQu Wenruo if (unlikely(comp_keys(&disk_key, new_key) <= 0)) { 23647c15d410SQu Wenruo btrfs_crit(fs_info, 23657c15d410SQu Wenruo "slot %u key (%llu %u %llu) new key (%llu %u %llu)", 23667c15d410SQu Wenruo slot, btrfs_disk_key_objectid(&disk_key), 23677c15d410SQu Wenruo btrfs_disk_key_type(&disk_key), 23687c15d410SQu Wenruo btrfs_disk_key_offset(&disk_key), 23697c15d410SQu Wenruo new_key->objectid, new_key->type, 23707c15d410SQu Wenruo new_key->offset); 23717c15d410SQu Wenruo btrfs_print_leaf(eb); 23727c15d410SQu Wenruo BUG(); 23737c15d410SQu Wenruo } 237431840ae1SZheng Yan } 237531840ae1SZheng Yan 237631840ae1SZheng Yan btrfs_cpu_key_to_disk(&disk_key, new_key); 237731840ae1SZheng Yan btrfs_set_item_key(eb, &disk_key, slot); 237831840ae1SZheng Yan btrfs_mark_buffer_dirty(eb); 237931840ae1SZheng Yan if (slot == 0) 2380b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 238131840ae1SZheng Yan } 238231840ae1SZheng Yan 238331840ae1SZheng Yan /* 2384d16c702fSQu Wenruo * Check key order of two sibling extent buffers. 2385d16c702fSQu Wenruo * 2386d16c702fSQu Wenruo * Return true if something is wrong. 2387d16c702fSQu Wenruo * Return false if everything is fine. 2388d16c702fSQu Wenruo * 2389d16c702fSQu Wenruo * Tree-checker only works inside one tree block, thus the following 2390d16c702fSQu Wenruo * corruption can not be detected by tree-checker: 2391d16c702fSQu Wenruo * 2392d16c702fSQu Wenruo * Leaf @left | Leaf @right 2393d16c702fSQu Wenruo * -------------------------------------------------------------- 2394d16c702fSQu Wenruo * | 1 | 2 | 3 | 4 | 5 | f6 | | 7 | 8 | 2395d16c702fSQu Wenruo * 2396d16c702fSQu Wenruo * Key f6 in leaf @left itself is valid, but not valid when the next 2397d16c702fSQu Wenruo * key in leaf @right is 7. 2398d16c702fSQu Wenruo * This can only be checked at tree block merge time. 2399d16c702fSQu Wenruo * And since tree checker has ensured all key order in each tree block 2400d16c702fSQu Wenruo * is correct, we only need to bother the last key of @left and the first 2401d16c702fSQu Wenruo * key of @right. 2402d16c702fSQu Wenruo */ 2403d16c702fSQu Wenruo static bool check_sibling_keys(struct extent_buffer *left, 2404d16c702fSQu Wenruo struct extent_buffer *right) 2405d16c702fSQu Wenruo { 2406d16c702fSQu Wenruo struct btrfs_key left_last; 2407d16c702fSQu Wenruo struct btrfs_key right_first; 2408d16c702fSQu Wenruo int level = btrfs_header_level(left); 2409d16c702fSQu Wenruo int nr_left = btrfs_header_nritems(left); 2410d16c702fSQu Wenruo int nr_right = btrfs_header_nritems(right); 2411d16c702fSQu Wenruo 2412d16c702fSQu Wenruo /* No key to check in one of the tree blocks */ 2413d16c702fSQu Wenruo if (!nr_left || !nr_right) 2414d16c702fSQu Wenruo return false; 2415d16c702fSQu Wenruo 2416d16c702fSQu Wenruo if (level) { 2417d16c702fSQu Wenruo btrfs_node_key_to_cpu(left, &left_last, nr_left - 1); 2418d16c702fSQu Wenruo btrfs_node_key_to_cpu(right, &right_first, 0); 2419d16c702fSQu Wenruo } else { 2420d16c702fSQu Wenruo btrfs_item_key_to_cpu(left, &left_last, nr_left - 1); 2421d16c702fSQu Wenruo btrfs_item_key_to_cpu(right, &right_first, 0); 2422d16c702fSQu Wenruo } 2423d16c702fSQu Wenruo 2424d16c702fSQu Wenruo if (btrfs_comp_cpu_keys(&left_last, &right_first) >= 0) { 2425d16c702fSQu Wenruo btrfs_crit(left->fs_info, 2426d16c702fSQu Wenruo "bad key order, sibling blocks, left last (%llu %u %llu) right first (%llu %u %llu)", 2427d16c702fSQu Wenruo left_last.objectid, left_last.type, 2428d16c702fSQu Wenruo left_last.offset, right_first.objectid, 2429d16c702fSQu Wenruo right_first.type, right_first.offset); 2430d16c702fSQu Wenruo return true; 2431d16c702fSQu Wenruo } 2432d16c702fSQu Wenruo return false; 2433d16c702fSQu Wenruo } 2434d16c702fSQu Wenruo 2435d16c702fSQu Wenruo /* 243674123bd7SChris Mason * try to push data from one node into the next node left in the 243779f95c82SChris Mason * tree. 2438aa5d6bedSChris Mason * 2439aa5d6bedSChris Mason * returns 0 if some ptrs were pushed left, < 0 if there was some horrible 2440aa5d6bedSChris Mason * error, and > 0 if there was no room in the left hand block. 244174123bd7SChris Mason */ 244298ed5174SChris Mason static int push_node_left(struct btrfs_trans_handle *trans, 24432ff7e61eSJeff Mahoney struct extent_buffer *dst, 2444971a1f66SChris Mason struct extent_buffer *src, int empty) 2445be0e5c09SChris Mason { 2446d30a668fSDavid Sterba struct btrfs_fs_info *fs_info = trans->fs_info; 2447be0e5c09SChris Mason int push_items = 0; 2448bb803951SChris Mason int src_nritems; 2449bb803951SChris Mason int dst_nritems; 2450aa5d6bedSChris Mason int ret = 0; 2451be0e5c09SChris Mason 24525f39d397SChris Mason src_nritems = btrfs_header_nritems(src); 24535f39d397SChris Mason dst_nritems = btrfs_header_nritems(dst); 24540b246afaSJeff Mahoney push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; 24557bb86316SChris Mason WARN_ON(btrfs_header_generation(src) != trans->transid); 24567bb86316SChris Mason WARN_ON(btrfs_header_generation(dst) != trans->transid); 245754aa1f4dSChris Mason 2458bce4eae9SChris Mason if (!empty && src_nritems <= 8) 2459971a1f66SChris Mason return 1; 2460971a1f66SChris Mason 2461d397712bSChris Mason if (push_items <= 0) 2462be0e5c09SChris Mason return 1; 2463be0e5c09SChris Mason 2464bce4eae9SChris Mason if (empty) { 2465971a1f66SChris Mason push_items = min(src_nritems, push_items); 2466bce4eae9SChris Mason if (push_items < src_nritems) { 2467bce4eae9SChris Mason /* leave at least 8 pointers in the node if 2468bce4eae9SChris Mason * we aren't going to empty it 2469bce4eae9SChris Mason */ 2470bce4eae9SChris Mason if (src_nritems - push_items < 8) { 2471bce4eae9SChris Mason if (push_items <= 8) 2472bce4eae9SChris Mason return 1; 2473bce4eae9SChris Mason push_items -= 8; 2474bce4eae9SChris Mason } 2475bce4eae9SChris Mason } 2476bce4eae9SChris Mason } else 2477bce4eae9SChris Mason push_items = min(src_nritems - 8, push_items); 247879f95c82SChris Mason 2479d16c702fSQu Wenruo /* dst is the left eb, src is the middle eb */ 2480d16c702fSQu Wenruo if (check_sibling_keys(dst, src)) { 2481d16c702fSQu Wenruo ret = -EUCLEAN; 2482d16c702fSQu Wenruo btrfs_abort_transaction(trans, ret); 2483d16c702fSQu Wenruo return ret; 2484d16c702fSQu Wenruo } 2485f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_eb_copy(dst, src, dst_nritems, 0, push_items); 24865de865eeSFilipe David Borba Manana if (ret) { 248766642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 24885de865eeSFilipe David Borba Manana return ret; 24895de865eeSFilipe David Borba Manana } 24905f39d397SChris Mason copy_extent_buffer(dst, src, 24915f39d397SChris Mason btrfs_node_key_ptr_offset(dst_nritems), 24925f39d397SChris Mason btrfs_node_key_ptr_offset(0), 2493123abc88SChris Mason push_items * sizeof(struct btrfs_key_ptr)); 24945f39d397SChris Mason 2495bb803951SChris Mason if (push_items < src_nritems) { 249657911b8bSJan Schmidt /* 2497f3a84ccdSFilipe Manana * Don't call btrfs_tree_mod_log_insert_move() here, key removal 2498f3a84ccdSFilipe Manana * was already fully logged by btrfs_tree_mod_log_eb_copy() above. 249957911b8bSJan Schmidt */ 25005f39d397SChris Mason memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), 25015f39d397SChris Mason btrfs_node_key_ptr_offset(push_items), 2502e2fa7227SChris Mason (src_nritems - push_items) * 2503123abc88SChris Mason sizeof(struct btrfs_key_ptr)); 2504bb803951SChris Mason } 25055f39d397SChris Mason btrfs_set_header_nritems(src, src_nritems - push_items); 25065f39d397SChris Mason btrfs_set_header_nritems(dst, dst_nritems + push_items); 25075f39d397SChris Mason btrfs_mark_buffer_dirty(src); 25085f39d397SChris Mason btrfs_mark_buffer_dirty(dst); 250931840ae1SZheng Yan 2510bb803951SChris Mason return ret; 2511be0e5c09SChris Mason } 2512be0e5c09SChris Mason 251397571fd0SChris Mason /* 251479f95c82SChris Mason * try to push data from one node into the next node right in the 251579f95c82SChris Mason * tree. 251679f95c82SChris Mason * 251779f95c82SChris Mason * returns 0 if some ptrs were pushed, < 0 if there was some horrible 251879f95c82SChris Mason * error, and > 0 if there was no room in the right hand block. 251979f95c82SChris Mason * 252079f95c82SChris Mason * this will only push up to 1/2 the contents of the left node over 252179f95c82SChris Mason */ 25225f39d397SChris Mason static int balance_node_right(struct btrfs_trans_handle *trans, 25235f39d397SChris Mason struct extent_buffer *dst, 25245f39d397SChris Mason struct extent_buffer *src) 252579f95c82SChris Mason { 252655d32ed8SDavid Sterba struct btrfs_fs_info *fs_info = trans->fs_info; 252779f95c82SChris Mason int push_items = 0; 252879f95c82SChris Mason int max_push; 252979f95c82SChris Mason int src_nritems; 253079f95c82SChris Mason int dst_nritems; 253179f95c82SChris Mason int ret = 0; 253279f95c82SChris Mason 25337bb86316SChris Mason WARN_ON(btrfs_header_generation(src) != trans->transid); 25347bb86316SChris Mason WARN_ON(btrfs_header_generation(dst) != trans->transid); 25357bb86316SChris Mason 25365f39d397SChris Mason src_nritems = btrfs_header_nritems(src); 25375f39d397SChris Mason dst_nritems = btrfs_header_nritems(dst); 25380b246afaSJeff Mahoney push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; 2539d397712bSChris Mason if (push_items <= 0) 254079f95c82SChris Mason return 1; 2541bce4eae9SChris Mason 2542d397712bSChris Mason if (src_nritems < 4) 2543bce4eae9SChris Mason return 1; 254479f95c82SChris Mason 254579f95c82SChris Mason max_push = src_nritems / 2 + 1; 254679f95c82SChris Mason /* don't try to empty the node */ 2547d397712bSChris Mason if (max_push >= src_nritems) 254879f95c82SChris Mason return 1; 2549252c38f0SYan 255079f95c82SChris Mason if (max_push < push_items) 255179f95c82SChris Mason push_items = max_push; 255279f95c82SChris Mason 2553d16c702fSQu Wenruo /* dst is the right eb, src is the middle eb */ 2554d16c702fSQu Wenruo if (check_sibling_keys(src, dst)) { 2555d16c702fSQu Wenruo ret = -EUCLEAN; 2556d16c702fSQu Wenruo btrfs_abort_transaction(trans, ret); 2557d16c702fSQu Wenruo return ret; 2558d16c702fSQu Wenruo } 2559f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_move(dst, push_items, 0, dst_nritems); 2560bf1d3425SDavid Sterba BUG_ON(ret < 0); 25615f39d397SChris Mason memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), 25625f39d397SChris Mason btrfs_node_key_ptr_offset(0), 25635f39d397SChris Mason (dst_nritems) * 25645f39d397SChris Mason sizeof(struct btrfs_key_ptr)); 2565d6025579SChris Mason 2566f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_eb_copy(dst, src, 0, src_nritems - push_items, 2567ed874f0dSDavid Sterba push_items); 25685de865eeSFilipe David Borba Manana if (ret) { 256966642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 25705de865eeSFilipe David Borba Manana return ret; 25715de865eeSFilipe David Borba Manana } 25725f39d397SChris Mason copy_extent_buffer(dst, src, 25735f39d397SChris Mason btrfs_node_key_ptr_offset(0), 25745f39d397SChris Mason btrfs_node_key_ptr_offset(src_nritems - push_items), 2575123abc88SChris Mason push_items * sizeof(struct btrfs_key_ptr)); 257679f95c82SChris Mason 25775f39d397SChris Mason btrfs_set_header_nritems(src, src_nritems - push_items); 25785f39d397SChris Mason btrfs_set_header_nritems(dst, dst_nritems + push_items); 257979f95c82SChris Mason 25805f39d397SChris Mason btrfs_mark_buffer_dirty(src); 25815f39d397SChris Mason btrfs_mark_buffer_dirty(dst); 258231840ae1SZheng Yan 258379f95c82SChris Mason return ret; 258479f95c82SChris Mason } 258579f95c82SChris Mason 258679f95c82SChris Mason /* 258797571fd0SChris Mason * helper function to insert a new root level in the tree. 258897571fd0SChris Mason * A new node is allocated, and a single item is inserted to 258997571fd0SChris Mason * point to the existing root 2590aa5d6bedSChris Mason * 2591aa5d6bedSChris Mason * returns zero on success or < 0 on failure. 259297571fd0SChris Mason */ 2593d397712bSChris Mason static noinline int insert_new_root(struct btrfs_trans_handle *trans, 25945f39d397SChris Mason struct btrfs_root *root, 2595fdd99c72SLiu Bo struct btrfs_path *path, int level) 259674123bd7SChris Mason { 25970b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 25987bb86316SChris Mason u64 lower_gen; 25995f39d397SChris Mason struct extent_buffer *lower; 26005f39d397SChris Mason struct extent_buffer *c; 2601925baeddSChris Mason struct extent_buffer *old; 26025f39d397SChris Mason struct btrfs_disk_key lower_key; 2603d9d19a01SDavid Sterba int ret; 26045c680ed6SChris Mason 26055c680ed6SChris Mason BUG_ON(path->nodes[level]); 26065c680ed6SChris Mason BUG_ON(path->nodes[level-1] != root->node); 26075c680ed6SChris Mason 26087bb86316SChris Mason lower = path->nodes[level-1]; 26097bb86316SChris Mason if (level == 1) 26107bb86316SChris Mason btrfs_item_key(lower, &lower_key, 0); 26117bb86316SChris Mason else 26127bb86316SChris Mason btrfs_node_key(lower, &lower_key, 0); 26137bb86316SChris Mason 261479bd3712SFilipe Manana c = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, 261579bd3712SFilipe Manana &lower_key, level, root->node->start, 0, 2616cf6f34aaSJosef Bacik BTRFS_NESTING_NEW_ROOT); 26175f39d397SChris Mason if (IS_ERR(c)) 26185f39d397SChris Mason return PTR_ERR(c); 2619925baeddSChris Mason 26200b246afaSJeff Mahoney root_add_used(root, fs_info->nodesize); 2621f0486c68SYan, Zheng 26225f39d397SChris Mason btrfs_set_header_nritems(c, 1); 26235f39d397SChris Mason btrfs_set_node_key(c, &lower_key, 0); 2624db94535dSChris Mason btrfs_set_node_blockptr(c, 0, lower->start); 26257bb86316SChris Mason lower_gen = btrfs_header_generation(lower); 262631840ae1SZheng Yan WARN_ON(lower_gen != trans->transid); 26277bb86316SChris Mason 26287bb86316SChris Mason btrfs_set_node_ptr_generation(c, 0, lower_gen); 26295f39d397SChris Mason 26305f39d397SChris Mason btrfs_mark_buffer_dirty(c); 2631d5719762SChris Mason 2632925baeddSChris Mason old = root->node; 2633406808abSFilipe Manana ret = btrfs_tree_mod_log_insert_root(root->node, c, false); 2634d9d19a01SDavid Sterba BUG_ON(ret < 0); 2635240f62c8SChris Mason rcu_assign_pointer(root->node, c); 2636925baeddSChris Mason 2637925baeddSChris Mason /* the super has an extra ref to root->node */ 2638925baeddSChris Mason free_extent_buffer(old); 2639925baeddSChris Mason 26400b86a832SChris Mason add_root_to_dirty_list(root); 264167439dadSDavid Sterba atomic_inc(&c->refs); 26425f39d397SChris Mason path->nodes[level] = c; 2643ac5887c8SJosef Bacik path->locks[level] = BTRFS_WRITE_LOCK; 264474123bd7SChris Mason path->slots[level] = 0; 264574123bd7SChris Mason return 0; 264674123bd7SChris Mason } 26475c680ed6SChris Mason 26485c680ed6SChris Mason /* 26495c680ed6SChris Mason * worker function to insert a single pointer in a node. 26505c680ed6SChris Mason * the node should have enough room for the pointer already 265197571fd0SChris Mason * 26525c680ed6SChris Mason * slot and level indicate where you want the key to go, and 26535c680ed6SChris Mason * blocknr is the block the key points to. 26545c680ed6SChris Mason */ 2655143bede5SJeff Mahoney static void insert_ptr(struct btrfs_trans_handle *trans, 26566ad3cf6dSDavid Sterba struct btrfs_path *path, 2657143bede5SJeff Mahoney struct btrfs_disk_key *key, u64 bytenr, 2658c3e06965SJan Schmidt int slot, int level) 26595c680ed6SChris Mason { 26605f39d397SChris Mason struct extent_buffer *lower; 26615c680ed6SChris Mason int nritems; 2662f3ea38daSJan Schmidt int ret; 26635c680ed6SChris Mason 26645c680ed6SChris Mason BUG_ON(!path->nodes[level]); 266549d0c642SFilipe Manana btrfs_assert_tree_write_locked(path->nodes[level]); 26665f39d397SChris Mason lower = path->nodes[level]; 26675f39d397SChris Mason nritems = btrfs_header_nritems(lower); 2668c293498bSStoyan Gaydarov BUG_ON(slot > nritems); 26696ad3cf6dSDavid Sterba BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(trans->fs_info)); 267074123bd7SChris Mason if (slot != nritems) { 2671bf1d3425SDavid Sterba if (level) { 2672f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_move(lower, slot + 1, 2673f3a84ccdSFilipe Manana slot, nritems - slot); 2674bf1d3425SDavid Sterba BUG_ON(ret < 0); 2675bf1d3425SDavid Sterba } 26765f39d397SChris Mason memmove_extent_buffer(lower, 26775f39d397SChris Mason btrfs_node_key_ptr_offset(slot + 1), 26785f39d397SChris Mason btrfs_node_key_ptr_offset(slot), 2679123abc88SChris Mason (nritems - slot) * sizeof(struct btrfs_key_ptr)); 268074123bd7SChris Mason } 2681c3e06965SJan Schmidt if (level) { 2682f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_key(lower, slot, 2683f3a84ccdSFilipe Manana BTRFS_MOD_LOG_KEY_ADD, GFP_NOFS); 2684f3ea38daSJan Schmidt BUG_ON(ret < 0); 2685f3ea38daSJan Schmidt } 26865f39d397SChris Mason btrfs_set_node_key(lower, key, slot); 2687db94535dSChris Mason btrfs_set_node_blockptr(lower, slot, bytenr); 268874493f7aSChris Mason WARN_ON(trans->transid == 0); 268974493f7aSChris Mason btrfs_set_node_ptr_generation(lower, slot, trans->transid); 26905f39d397SChris Mason btrfs_set_header_nritems(lower, nritems + 1); 26915f39d397SChris Mason btrfs_mark_buffer_dirty(lower); 269274123bd7SChris Mason } 269374123bd7SChris Mason 269497571fd0SChris Mason /* 269597571fd0SChris Mason * split the node at the specified level in path in two. 269697571fd0SChris Mason * The path is corrected to point to the appropriate node after the split 269797571fd0SChris Mason * 269897571fd0SChris Mason * Before splitting this tries to make some room in the node by pushing 269997571fd0SChris Mason * left and right, if either one works, it returns right away. 2700aa5d6bedSChris Mason * 2701aa5d6bedSChris Mason * returns 0 on success and < 0 on failure 270297571fd0SChris Mason */ 2703e02119d5SChris Mason static noinline int split_node(struct btrfs_trans_handle *trans, 2704e02119d5SChris Mason struct btrfs_root *root, 2705e02119d5SChris Mason struct btrfs_path *path, int level) 2706be0e5c09SChris Mason { 27070b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 27085f39d397SChris Mason struct extent_buffer *c; 27095f39d397SChris Mason struct extent_buffer *split; 27105f39d397SChris Mason struct btrfs_disk_key disk_key; 2711be0e5c09SChris Mason int mid; 27125c680ed6SChris Mason int ret; 27137518a238SChris Mason u32 c_nritems; 2714be0e5c09SChris Mason 27155f39d397SChris Mason c = path->nodes[level]; 27167bb86316SChris Mason WARN_ON(btrfs_header_generation(c) != trans->transid); 27175f39d397SChris Mason if (c == root->node) { 2718d9abbf1cSJan Schmidt /* 271990f8d62eSJan Schmidt * trying to split the root, lets make a new one 272090f8d62eSJan Schmidt * 2721fdd99c72SLiu Bo * tree mod log: We don't log_removal old root in 272290f8d62eSJan Schmidt * insert_new_root, because that root buffer will be kept as a 272390f8d62eSJan Schmidt * normal node. We are going to log removal of half of the 2724f3a84ccdSFilipe Manana * elements below with btrfs_tree_mod_log_eb_copy(). We're 2725f3a84ccdSFilipe Manana * holding a tree lock on the buffer, which is why we cannot 2726f3a84ccdSFilipe Manana * race with other tree_mod_log users. 2727d9abbf1cSJan Schmidt */ 2728fdd99c72SLiu Bo ret = insert_new_root(trans, root, path, level + 1); 27295c680ed6SChris Mason if (ret) 27305c680ed6SChris Mason return ret; 2731b3612421SChris Mason } else { 2732e66f709bSChris Mason ret = push_nodes_for_insert(trans, root, path, level); 27335f39d397SChris Mason c = path->nodes[level]; 27345f39d397SChris Mason if (!ret && btrfs_header_nritems(c) < 27350b246afaSJeff Mahoney BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) 2736e66f709bSChris Mason return 0; 273754aa1f4dSChris Mason if (ret < 0) 273854aa1f4dSChris Mason return ret; 27395c680ed6SChris Mason } 2740e66f709bSChris Mason 27415f39d397SChris Mason c_nritems = btrfs_header_nritems(c); 27425d4f98a2SYan Zheng mid = (c_nritems + 1) / 2; 27435d4f98a2SYan Zheng btrfs_node_key(c, &disk_key, mid); 27447bb86316SChris Mason 274579bd3712SFilipe Manana split = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, 274679bd3712SFilipe Manana &disk_key, level, c->start, 0, 274779bd3712SFilipe Manana BTRFS_NESTING_SPLIT); 27485f39d397SChris Mason if (IS_ERR(split)) 27495f39d397SChris Mason return PTR_ERR(split); 275054aa1f4dSChris Mason 27510b246afaSJeff Mahoney root_add_used(root, fs_info->nodesize); 2752bc877d28SNikolay Borisov ASSERT(btrfs_header_level(c) == level); 27535f39d397SChris Mason 2754f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_eb_copy(split, c, 0, mid, c_nritems - mid); 27555de865eeSFilipe David Borba Manana if (ret) { 275666642832SJeff Mahoney btrfs_abort_transaction(trans, ret); 27575de865eeSFilipe David Borba Manana return ret; 27585de865eeSFilipe David Borba Manana } 27595f39d397SChris Mason copy_extent_buffer(split, c, 27605f39d397SChris Mason btrfs_node_key_ptr_offset(0), 27615f39d397SChris Mason btrfs_node_key_ptr_offset(mid), 2762123abc88SChris Mason (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); 27635f39d397SChris Mason btrfs_set_header_nritems(split, c_nritems - mid); 27645f39d397SChris Mason btrfs_set_header_nritems(c, mid); 2765aa5d6bedSChris Mason 27665f39d397SChris Mason btrfs_mark_buffer_dirty(c); 27675f39d397SChris Mason btrfs_mark_buffer_dirty(split); 27685f39d397SChris Mason 27696ad3cf6dSDavid Sterba insert_ptr(trans, path, &disk_key, split->start, 2770c3e06965SJan Schmidt path->slots[level + 1] + 1, level + 1); 2771aa5d6bedSChris Mason 27725de08d7dSChris Mason if (path->slots[level] >= mid) { 27735c680ed6SChris Mason path->slots[level] -= mid; 2774925baeddSChris Mason btrfs_tree_unlock(c); 27755f39d397SChris Mason free_extent_buffer(c); 27765f39d397SChris Mason path->nodes[level] = split; 27775c680ed6SChris Mason path->slots[level + 1] += 1; 2778eb60ceacSChris Mason } else { 2779925baeddSChris Mason btrfs_tree_unlock(split); 27805f39d397SChris Mason free_extent_buffer(split); 2781be0e5c09SChris Mason } 2782d5286a92SNikolay Borisov return 0; 2783be0e5c09SChris Mason } 2784be0e5c09SChris Mason 278574123bd7SChris Mason /* 278674123bd7SChris Mason * how many bytes are required to store the items in a leaf. start 278774123bd7SChris Mason * and nr indicate which items in the leaf to check. This totals up the 278874123bd7SChris Mason * space used both by the item structs and the item data 278974123bd7SChris Mason */ 27905f39d397SChris Mason static int leaf_space_used(struct extent_buffer *l, int start, int nr) 2791be0e5c09SChris Mason { 2792be0e5c09SChris Mason int data_len; 27935f39d397SChris Mason int nritems = btrfs_header_nritems(l); 2794d4dbff95SChris Mason int end = min(nritems, start + nr) - 1; 2795be0e5c09SChris Mason 2796be0e5c09SChris Mason if (!nr) 2797be0e5c09SChris Mason return 0; 27983212fa14SJosef Bacik data_len = btrfs_item_offset(l, start) + btrfs_item_size(l, start); 27993212fa14SJosef Bacik data_len = data_len - btrfs_item_offset(l, end); 28000783fcfcSChris Mason data_len += sizeof(struct btrfs_item) * nr; 2801d4dbff95SChris Mason WARN_ON(data_len < 0); 2802be0e5c09SChris Mason return data_len; 2803be0e5c09SChris Mason } 2804be0e5c09SChris Mason 280574123bd7SChris Mason /* 2806d4dbff95SChris Mason * The space between the end of the leaf items and 2807d4dbff95SChris Mason * the start of the leaf data. IOW, how much room 2808d4dbff95SChris Mason * the leaf has left for both items and data 2809d4dbff95SChris Mason */ 2810e902baacSDavid Sterba noinline int btrfs_leaf_free_space(struct extent_buffer *leaf) 2811d4dbff95SChris Mason { 2812e902baacSDavid Sterba struct btrfs_fs_info *fs_info = leaf->fs_info; 28135f39d397SChris Mason int nritems = btrfs_header_nritems(leaf); 28145f39d397SChris Mason int ret; 28150b246afaSJeff Mahoney 28160b246afaSJeff Mahoney ret = BTRFS_LEAF_DATA_SIZE(fs_info) - leaf_space_used(leaf, 0, nritems); 28175f39d397SChris Mason if (ret < 0) { 28180b246afaSJeff Mahoney btrfs_crit(fs_info, 2819efe120a0SFrank Holton "leaf free space ret %d, leaf data size %lu, used %d nritems %d", 2820da17066cSJeff Mahoney ret, 28210b246afaSJeff Mahoney (unsigned long) BTRFS_LEAF_DATA_SIZE(fs_info), 28225f39d397SChris Mason leaf_space_used(leaf, 0, nritems), nritems); 28235f39d397SChris Mason } 28245f39d397SChris Mason return ret; 2825d4dbff95SChris Mason } 2826d4dbff95SChris Mason 282799d8f83cSChris Mason /* 282899d8f83cSChris Mason * min slot controls the lowest index we're willing to push to the 282999d8f83cSChris Mason * right. We'll push up to and including min_slot, but no lower 283099d8f83cSChris Mason */ 2831f72f0010SDavid Sterba static noinline int __push_leaf_right(struct btrfs_path *path, 283244871b1bSChris Mason int data_size, int empty, 283344871b1bSChris Mason struct extent_buffer *right, 283499d8f83cSChris Mason int free_space, u32 left_nritems, 283599d8f83cSChris Mason u32 min_slot) 283600ec4c51SChris Mason { 2837f72f0010SDavid Sterba struct btrfs_fs_info *fs_info = right->fs_info; 28385f39d397SChris Mason struct extent_buffer *left = path->nodes[0]; 283944871b1bSChris Mason struct extent_buffer *upper = path->nodes[1]; 2840cfed81a0SChris Mason struct btrfs_map_token token; 28415f39d397SChris Mason struct btrfs_disk_key disk_key; 284200ec4c51SChris Mason int slot; 284334a38218SChris Mason u32 i; 284400ec4c51SChris Mason int push_space = 0; 284500ec4c51SChris Mason int push_items = 0; 284634a38218SChris Mason u32 nr; 28477518a238SChris Mason u32 right_nritems; 28485f39d397SChris Mason u32 data_end; 2849db94535dSChris Mason u32 this_item_size; 285000ec4c51SChris Mason 285134a38218SChris Mason if (empty) 285234a38218SChris Mason nr = 0; 285334a38218SChris Mason else 285499d8f83cSChris Mason nr = max_t(u32, 1, min_slot); 285534a38218SChris Mason 285631840ae1SZheng Yan if (path->slots[0] >= left_nritems) 285787b29b20SYan Zheng push_space += data_size; 285831840ae1SZheng Yan 285944871b1bSChris Mason slot = path->slots[1]; 286034a38218SChris Mason i = left_nritems - 1; 286134a38218SChris Mason while (i >= nr) { 286231840ae1SZheng Yan if (!empty && push_items > 0) { 286331840ae1SZheng Yan if (path->slots[0] > i) 286431840ae1SZheng Yan break; 286531840ae1SZheng Yan if (path->slots[0] == i) { 2866e902baacSDavid Sterba int space = btrfs_leaf_free_space(left); 2867e902baacSDavid Sterba 286831840ae1SZheng Yan if (space + push_space * 2 > free_space) 286931840ae1SZheng Yan break; 287031840ae1SZheng Yan } 287131840ae1SZheng Yan } 287231840ae1SZheng Yan 287300ec4c51SChris Mason if (path->slots[0] == i) 287487b29b20SYan Zheng push_space += data_size; 2875db94535dSChris Mason 28763212fa14SJosef Bacik this_item_size = btrfs_item_size(left, i); 287774794207SJosef Bacik if (this_item_size + sizeof(struct btrfs_item) + 287874794207SJosef Bacik push_space > free_space) 287900ec4c51SChris Mason break; 288031840ae1SZheng Yan 288100ec4c51SChris Mason push_items++; 288274794207SJosef Bacik push_space += this_item_size + sizeof(struct btrfs_item); 288334a38218SChris Mason if (i == 0) 288434a38218SChris Mason break; 288534a38218SChris Mason i--; 2886db94535dSChris Mason } 28875f39d397SChris Mason 2888925baeddSChris Mason if (push_items == 0) 2889925baeddSChris Mason goto out_unlock; 28905f39d397SChris Mason 28916c1500f2SJulia Lawall WARN_ON(!empty && push_items == left_nritems); 28925f39d397SChris Mason 289300ec4c51SChris Mason /* push left to right */ 28945f39d397SChris Mason right_nritems = btrfs_header_nritems(right); 289534a38218SChris Mason 2896dc2e724eSJosef Bacik push_space = btrfs_item_data_end(left, left_nritems - push_items); 28978f881e8cSDavid Sterba push_space -= leaf_data_end(left); 28985f39d397SChris Mason 289900ec4c51SChris Mason /* make room in the right data area */ 29008f881e8cSDavid Sterba data_end = leaf_data_end(right); 29015f39d397SChris Mason memmove_extent_buffer(right, 29023d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + data_end - push_space, 29033d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + data_end, 29040b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info) - data_end); 29055f39d397SChris Mason 290600ec4c51SChris Mason /* copy from the left data area */ 29073d9ec8c4SNikolay Borisov copy_extent_buffer(right, left, BTRFS_LEAF_DATA_OFFSET + 29080b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, 29098f881e8cSDavid Sterba BTRFS_LEAF_DATA_OFFSET + leaf_data_end(left), 2910d6025579SChris Mason push_space); 29115f39d397SChris Mason 29125f39d397SChris Mason memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), 29135f39d397SChris Mason btrfs_item_nr_offset(0), 29140783fcfcSChris Mason right_nritems * sizeof(struct btrfs_item)); 29155f39d397SChris Mason 291600ec4c51SChris Mason /* copy the items from left to right */ 29175f39d397SChris Mason copy_extent_buffer(right, left, btrfs_item_nr_offset(0), 29185f39d397SChris Mason btrfs_item_nr_offset(left_nritems - push_items), 29190783fcfcSChris Mason push_items * sizeof(struct btrfs_item)); 292000ec4c51SChris Mason 292100ec4c51SChris Mason /* update the item pointers */ 2922c82f823cSDavid Sterba btrfs_init_map_token(&token, right); 29237518a238SChris Mason right_nritems += push_items; 29245f39d397SChris Mason btrfs_set_header_nritems(right, right_nritems); 29250b246afaSJeff Mahoney push_space = BTRFS_LEAF_DATA_SIZE(fs_info); 29267518a238SChris Mason for (i = 0; i < right_nritems; i++) { 29273212fa14SJosef Bacik push_space -= btrfs_token_item_size(&token, i); 29283212fa14SJosef Bacik btrfs_set_token_item_offset(&token, i, push_space); 2929db94535dSChris Mason } 2930db94535dSChris Mason 29317518a238SChris Mason left_nritems -= push_items; 29325f39d397SChris Mason btrfs_set_header_nritems(left, left_nritems); 293300ec4c51SChris Mason 293434a38218SChris Mason if (left_nritems) 29355f39d397SChris Mason btrfs_mark_buffer_dirty(left); 2936f0486c68SYan, Zheng else 29376a884d7dSDavid Sterba btrfs_clean_tree_block(left); 2938f0486c68SYan, Zheng 29395f39d397SChris Mason btrfs_mark_buffer_dirty(right); 2940a429e513SChris Mason 29415f39d397SChris Mason btrfs_item_key(right, &disk_key, 0); 29425f39d397SChris Mason btrfs_set_node_key(upper, &disk_key, slot + 1); 2943d6025579SChris Mason btrfs_mark_buffer_dirty(upper); 294402217ed2SChris Mason 294500ec4c51SChris Mason /* then fixup the leaf pointer in the path */ 29467518a238SChris Mason if (path->slots[0] >= left_nritems) { 29477518a238SChris Mason path->slots[0] -= left_nritems; 2948925baeddSChris Mason if (btrfs_header_nritems(path->nodes[0]) == 0) 29496a884d7dSDavid Sterba btrfs_clean_tree_block(path->nodes[0]); 2950925baeddSChris Mason btrfs_tree_unlock(path->nodes[0]); 29515f39d397SChris Mason free_extent_buffer(path->nodes[0]); 29525f39d397SChris Mason path->nodes[0] = right; 295300ec4c51SChris Mason path->slots[1] += 1; 295400ec4c51SChris Mason } else { 2955925baeddSChris Mason btrfs_tree_unlock(right); 29565f39d397SChris Mason free_extent_buffer(right); 295700ec4c51SChris Mason } 295800ec4c51SChris Mason return 0; 2959925baeddSChris Mason 2960925baeddSChris Mason out_unlock: 2961925baeddSChris Mason btrfs_tree_unlock(right); 2962925baeddSChris Mason free_extent_buffer(right); 2963925baeddSChris Mason return 1; 296400ec4c51SChris Mason } 2965925baeddSChris Mason 296600ec4c51SChris Mason /* 296744871b1bSChris Mason * push some data in the path leaf to the right, trying to free up at 296874123bd7SChris Mason * least data_size bytes. returns zero if the push worked, nonzero otherwise 296944871b1bSChris Mason * 297044871b1bSChris Mason * returns 1 if the push failed because the other node didn't have enough 297144871b1bSChris Mason * room, 0 if everything worked out and < 0 if there were major errors. 297299d8f83cSChris Mason * 297399d8f83cSChris Mason * this will push starting from min_slot to the end of the leaf. It won't 297499d8f83cSChris Mason * push any slot lower than min_slot 297574123bd7SChris Mason */ 297644871b1bSChris Mason static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root 297799d8f83cSChris Mason *root, struct btrfs_path *path, 297899d8f83cSChris Mason int min_data_size, int data_size, 297999d8f83cSChris Mason int empty, u32 min_slot) 2980be0e5c09SChris Mason { 298144871b1bSChris Mason struct extent_buffer *left = path->nodes[0]; 298244871b1bSChris Mason struct extent_buffer *right; 298344871b1bSChris Mason struct extent_buffer *upper; 298444871b1bSChris Mason int slot; 298544871b1bSChris Mason int free_space; 298644871b1bSChris Mason u32 left_nritems; 298744871b1bSChris Mason int ret; 298844871b1bSChris Mason 298944871b1bSChris Mason if (!path->nodes[1]) 299044871b1bSChris Mason return 1; 299144871b1bSChris Mason 299244871b1bSChris Mason slot = path->slots[1]; 299344871b1bSChris Mason upper = path->nodes[1]; 299444871b1bSChris Mason if (slot >= btrfs_header_nritems(upper) - 1) 299544871b1bSChris Mason return 1; 299644871b1bSChris Mason 299749d0c642SFilipe Manana btrfs_assert_tree_write_locked(path->nodes[1]); 299844871b1bSChris Mason 29994b231ae4SDavid Sterba right = btrfs_read_node_slot(upper, slot + 1); 3000fb770ae4SLiu Bo /* 3001fb770ae4SLiu Bo * slot + 1 is not valid or we fail to read the right node, 3002fb770ae4SLiu Bo * no big deal, just return. 3003fb770ae4SLiu Bo */ 3004fb770ae4SLiu Bo if (IS_ERR(right)) 300591ca338dSTsutomu Itoh return 1; 300691ca338dSTsutomu Itoh 3007bf77467aSJosef Bacik __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); 300844871b1bSChris Mason 3009e902baacSDavid Sterba free_space = btrfs_leaf_free_space(right); 301044871b1bSChris Mason if (free_space < data_size) 301144871b1bSChris Mason goto out_unlock; 301244871b1bSChris Mason 301344871b1bSChris Mason ret = btrfs_cow_block(trans, root, right, upper, 3014bf59a5a2SJosef Bacik slot + 1, &right, BTRFS_NESTING_RIGHT_COW); 301544871b1bSChris Mason if (ret) 301644871b1bSChris Mason goto out_unlock; 301744871b1bSChris Mason 301844871b1bSChris Mason left_nritems = btrfs_header_nritems(left); 301944871b1bSChris Mason if (left_nritems == 0) 302044871b1bSChris Mason goto out_unlock; 302144871b1bSChris Mason 3022d16c702fSQu Wenruo if (check_sibling_keys(left, right)) { 3023d16c702fSQu Wenruo ret = -EUCLEAN; 3024d16c702fSQu Wenruo btrfs_tree_unlock(right); 3025d16c702fSQu Wenruo free_extent_buffer(right); 3026d16c702fSQu Wenruo return ret; 3027d16c702fSQu Wenruo } 30282ef1fed2SFilipe David Borba Manana if (path->slots[0] == left_nritems && !empty) { 30292ef1fed2SFilipe David Borba Manana /* Key greater than all keys in the leaf, right neighbor has 30302ef1fed2SFilipe David Borba Manana * enough room for it and we're not emptying our leaf to delete 30312ef1fed2SFilipe David Borba Manana * it, therefore use right neighbor to insert the new item and 303252042d8eSAndrea Gelmini * no need to touch/dirty our left leaf. */ 30332ef1fed2SFilipe David Borba Manana btrfs_tree_unlock(left); 30342ef1fed2SFilipe David Borba Manana free_extent_buffer(left); 30352ef1fed2SFilipe David Borba Manana path->nodes[0] = right; 30362ef1fed2SFilipe David Borba Manana path->slots[0] = 0; 30372ef1fed2SFilipe David Borba Manana path->slots[1]++; 30382ef1fed2SFilipe David Borba Manana return 0; 30392ef1fed2SFilipe David Borba Manana } 30402ef1fed2SFilipe David Borba Manana 3041f72f0010SDavid Sterba return __push_leaf_right(path, min_data_size, empty, 304299d8f83cSChris Mason right, free_space, left_nritems, min_slot); 304344871b1bSChris Mason out_unlock: 304444871b1bSChris Mason btrfs_tree_unlock(right); 304544871b1bSChris Mason free_extent_buffer(right); 304644871b1bSChris Mason return 1; 304744871b1bSChris Mason } 304844871b1bSChris Mason 304944871b1bSChris Mason /* 305044871b1bSChris Mason * push some data in the path leaf to the left, trying to free up at 305144871b1bSChris Mason * least data_size bytes. returns zero if the push worked, nonzero otherwise 305299d8f83cSChris Mason * 305399d8f83cSChris Mason * max_slot can put a limit on how far into the leaf we'll push items. The 305499d8f83cSChris Mason * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the 305599d8f83cSChris Mason * items 305644871b1bSChris Mason */ 30578087c193SDavid Sterba static noinline int __push_leaf_left(struct btrfs_path *path, int data_size, 305844871b1bSChris Mason int empty, struct extent_buffer *left, 305999d8f83cSChris Mason int free_space, u32 right_nritems, 306099d8f83cSChris Mason u32 max_slot) 306144871b1bSChris Mason { 30628087c193SDavid Sterba struct btrfs_fs_info *fs_info = left->fs_info; 30635f39d397SChris Mason struct btrfs_disk_key disk_key; 30645f39d397SChris Mason struct extent_buffer *right = path->nodes[0]; 3065be0e5c09SChris Mason int i; 3066be0e5c09SChris Mason int push_space = 0; 3067be0e5c09SChris Mason int push_items = 0; 30687518a238SChris Mason u32 old_left_nritems; 306934a38218SChris Mason u32 nr; 3070aa5d6bedSChris Mason int ret = 0; 3071db94535dSChris Mason u32 this_item_size; 3072db94535dSChris Mason u32 old_left_item_size; 3073cfed81a0SChris Mason struct btrfs_map_token token; 3074cfed81a0SChris Mason 307534a38218SChris Mason if (empty) 307699d8f83cSChris Mason nr = min(right_nritems, max_slot); 307734a38218SChris Mason else 307899d8f83cSChris Mason nr = min(right_nritems - 1, max_slot); 307934a38218SChris Mason 308034a38218SChris Mason for (i = 0; i < nr; i++) { 308131840ae1SZheng Yan if (!empty && push_items > 0) { 308231840ae1SZheng Yan if (path->slots[0] < i) 308331840ae1SZheng Yan break; 308431840ae1SZheng Yan if (path->slots[0] == i) { 3085e902baacSDavid Sterba int space = btrfs_leaf_free_space(right); 3086e902baacSDavid Sterba 308731840ae1SZheng Yan if (space + push_space * 2 > free_space) 308831840ae1SZheng Yan break; 308931840ae1SZheng Yan } 309031840ae1SZheng Yan } 309131840ae1SZheng Yan 3092be0e5c09SChris Mason if (path->slots[0] == i) 309387b29b20SYan Zheng push_space += data_size; 3094db94535dSChris Mason 30953212fa14SJosef Bacik this_item_size = btrfs_item_size(right, i); 309674794207SJosef Bacik if (this_item_size + sizeof(struct btrfs_item) + push_space > 309774794207SJosef Bacik free_space) 3098be0e5c09SChris Mason break; 3099db94535dSChris Mason 3100be0e5c09SChris Mason push_items++; 310174794207SJosef Bacik push_space += this_item_size + sizeof(struct btrfs_item); 3102be0e5c09SChris Mason } 3103db94535dSChris Mason 3104be0e5c09SChris Mason if (push_items == 0) { 3105925baeddSChris Mason ret = 1; 3106925baeddSChris Mason goto out; 3107be0e5c09SChris Mason } 3108fae7f21cSDulshani Gunawardhana WARN_ON(!empty && push_items == btrfs_header_nritems(right)); 31095f39d397SChris Mason 3110be0e5c09SChris Mason /* push data from right to left */ 31115f39d397SChris Mason copy_extent_buffer(left, right, 31125f39d397SChris Mason btrfs_item_nr_offset(btrfs_header_nritems(left)), 31135f39d397SChris Mason btrfs_item_nr_offset(0), 31145f39d397SChris Mason push_items * sizeof(struct btrfs_item)); 31155f39d397SChris Mason 31160b246afaSJeff Mahoney push_space = BTRFS_LEAF_DATA_SIZE(fs_info) - 31173212fa14SJosef Bacik btrfs_item_offset(right, push_items - 1); 31185f39d397SChris Mason 31193d9ec8c4SNikolay Borisov copy_extent_buffer(left, right, BTRFS_LEAF_DATA_OFFSET + 31208f881e8cSDavid Sterba leaf_data_end(left) - push_space, 31213d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + 31223212fa14SJosef Bacik btrfs_item_offset(right, push_items - 1), 3123be0e5c09SChris Mason push_space); 31245f39d397SChris Mason old_left_nritems = btrfs_header_nritems(left); 312587b29b20SYan Zheng BUG_ON(old_left_nritems <= 0); 3126eb60ceacSChris Mason 3127c82f823cSDavid Sterba btrfs_init_map_token(&token, left); 31283212fa14SJosef Bacik old_left_item_size = btrfs_item_offset(left, old_left_nritems - 1); 3129be0e5c09SChris Mason for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { 31305f39d397SChris Mason u32 ioff; 3131db94535dSChris Mason 31323212fa14SJosef Bacik ioff = btrfs_token_item_offset(&token, i); 31333212fa14SJosef Bacik btrfs_set_token_item_offset(&token, i, 3134cc4c13d5SDavid Sterba ioff - (BTRFS_LEAF_DATA_SIZE(fs_info) - old_left_item_size)); 3135be0e5c09SChris Mason } 31365f39d397SChris Mason btrfs_set_header_nritems(left, old_left_nritems + push_items); 3137be0e5c09SChris Mason 3138be0e5c09SChris Mason /* fixup right node */ 313931b1a2bdSJulia Lawall if (push_items > right_nritems) 314031b1a2bdSJulia Lawall WARN(1, KERN_CRIT "push items %d nr %u\n", push_items, 3141d397712bSChris Mason right_nritems); 314234a38218SChris Mason 314334a38218SChris Mason if (push_items < right_nritems) { 31443212fa14SJosef Bacik push_space = btrfs_item_offset(right, push_items - 1) - 31458f881e8cSDavid Sterba leaf_data_end(right); 31463d9ec8c4SNikolay Borisov memmove_extent_buffer(right, BTRFS_LEAF_DATA_OFFSET + 31470b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, 31483d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + 31498f881e8cSDavid Sterba leaf_data_end(right), push_space); 31505f39d397SChris Mason 31515f39d397SChris Mason memmove_extent_buffer(right, btrfs_item_nr_offset(0), 31525f39d397SChris Mason btrfs_item_nr_offset(push_items), 31535f39d397SChris Mason (btrfs_header_nritems(right) - push_items) * 31540783fcfcSChris Mason sizeof(struct btrfs_item)); 315534a38218SChris Mason } 3156c82f823cSDavid Sterba 3157c82f823cSDavid Sterba btrfs_init_map_token(&token, right); 3158eef1c494SYan right_nritems -= push_items; 3159eef1c494SYan btrfs_set_header_nritems(right, right_nritems); 31600b246afaSJeff Mahoney push_space = BTRFS_LEAF_DATA_SIZE(fs_info); 31615f39d397SChris Mason for (i = 0; i < right_nritems; i++) { 31623212fa14SJosef Bacik push_space = push_space - btrfs_token_item_size(&token, i); 31633212fa14SJosef Bacik btrfs_set_token_item_offset(&token, i, push_space); 3164db94535dSChris Mason } 3165eb60ceacSChris Mason 31665f39d397SChris Mason btrfs_mark_buffer_dirty(left); 316734a38218SChris Mason if (right_nritems) 31685f39d397SChris Mason btrfs_mark_buffer_dirty(right); 3169f0486c68SYan, Zheng else 31706a884d7dSDavid Sterba btrfs_clean_tree_block(right); 3171098f59c2SChris Mason 31725f39d397SChris Mason btrfs_item_key(right, &disk_key, 0); 3173b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 3174be0e5c09SChris Mason 3175be0e5c09SChris Mason /* then fixup the leaf pointer in the path */ 3176be0e5c09SChris Mason if (path->slots[0] < push_items) { 3177be0e5c09SChris Mason path->slots[0] += old_left_nritems; 3178925baeddSChris Mason btrfs_tree_unlock(path->nodes[0]); 31795f39d397SChris Mason free_extent_buffer(path->nodes[0]); 31805f39d397SChris Mason path->nodes[0] = left; 3181be0e5c09SChris Mason path->slots[1] -= 1; 3182be0e5c09SChris Mason } else { 3183925baeddSChris Mason btrfs_tree_unlock(left); 31845f39d397SChris Mason free_extent_buffer(left); 3185be0e5c09SChris Mason path->slots[0] -= push_items; 3186be0e5c09SChris Mason } 3187eb60ceacSChris Mason BUG_ON(path->slots[0] < 0); 3188aa5d6bedSChris Mason return ret; 3189925baeddSChris Mason out: 3190925baeddSChris Mason btrfs_tree_unlock(left); 3191925baeddSChris Mason free_extent_buffer(left); 3192925baeddSChris Mason return ret; 3193be0e5c09SChris Mason } 3194be0e5c09SChris Mason 319574123bd7SChris Mason /* 319644871b1bSChris Mason * push some data in the path leaf to the left, trying to free up at 319744871b1bSChris Mason * least data_size bytes. returns zero if the push worked, nonzero otherwise 319899d8f83cSChris Mason * 319999d8f83cSChris Mason * max_slot can put a limit on how far into the leaf we'll push items. The 320099d8f83cSChris Mason * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the 320199d8f83cSChris Mason * items 320244871b1bSChris Mason */ 320344871b1bSChris Mason static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root 320499d8f83cSChris Mason *root, struct btrfs_path *path, int min_data_size, 320599d8f83cSChris Mason int data_size, int empty, u32 max_slot) 320644871b1bSChris Mason { 320744871b1bSChris Mason struct extent_buffer *right = path->nodes[0]; 320844871b1bSChris Mason struct extent_buffer *left; 320944871b1bSChris Mason int slot; 321044871b1bSChris Mason int free_space; 321144871b1bSChris Mason u32 right_nritems; 321244871b1bSChris Mason int ret = 0; 321344871b1bSChris Mason 321444871b1bSChris Mason slot = path->slots[1]; 321544871b1bSChris Mason if (slot == 0) 321644871b1bSChris Mason return 1; 321744871b1bSChris Mason if (!path->nodes[1]) 321844871b1bSChris Mason return 1; 321944871b1bSChris Mason 322044871b1bSChris Mason right_nritems = btrfs_header_nritems(right); 322144871b1bSChris Mason if (right_nritems == 0) 322244871b1bSChris Mason return 1; 322344871b1bSChris Mason 322449d0c642SFilipe Manana btrfs_assert_tree_write_locked(path->nodes[1]); 322544871b1bSChris Mason 32264b231ae4SDavid Sterba left = btrfs_read_node_slot(path->nodes[1], slot - 1); 3227fb770ae4SLiu Bo /* 3228fb770ae4SLiu Bo * slot - 1 is not valid or we fail to read the left node, 3229fb770ae4SLiu Bo * no big deal, just return. 3230fb770ae4SLiu Bo */ 3231fb770ae4SLiu Bo if (IS_ERR(left)) 323291ca338dSTsutomu Itoh return 1; 323391ca338dSTsutomu Itoh 3234bf77467aSJosef Bacik __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); 323544871b1bSChris Mason 3236e902baacSDavid Sterba free_space = btrfs_leaf_free_space(left); 323744871b1bSChris Mason if (free_space < data_size) { 323844871b1bSChris Mason ret = 1; 323944871b1bSChris Mason goto out; 324044871b1bSChris Mason } 324144871b1bSChris Mason 324244871b1bSChris Mason ret = btrfs_cow_block(trans, root, left, 32439631e4ccSJosef Bacik path->nodes[1], slot - 1, &left, 3244bf59a5a2SJosef Bacik BTRFS_NESTING_LEFT_COW); 324544871b1bSChris Mason if (ret) { 324644871b1bSChris Mason /* we hit -ENOSPC, but it isn't fatal here */ 324779787eaaSJeff Mahoney if (ret == -ENOSPC) 324844871b1bSChris Mason ret = 1; 324944871b1bSChris Mason goto out; 325044871b1bSChris Mason } 325144871b1bSChris Mason 3252d16c702fSQu Wenruo if (check_sibling_keys(left, right)) { 3253d16c702fSQu Wenruo ret = -EUCLEAN; 3254d16c702fSQu Wenruo goto out; 3255d16c702fSQu Wenruo } 32568087c193SDavid Sterba return __push_leaf_left(path, min_data_size, 325799d8f83cSChris Mason empty, left, free_space, right_nritems, 325899d8f83cSChris Mason max_slot); 325944871b1bSChris Mason out: 326044871b1bSChris Mason btrfs_tree_unlock(left); 326144871b1bSChris Mason free_extent_buffer(left); 326244871b1bSChris Mason return ret; 326344871b1bSChris Mason } 326444871b1bSChris Mason 326544871b1bSChris Mason /* 326674123bd7SChris Mason * split the path's leaf in two, making sure there is at least data_size 326774123bd7SChris Mason * available for the resulting leaf level of the path. 326874123bd7SChris Mason */ 3269143bede5SJeff Mahoney static noinline void copy_for_split(struct btrfs_trans_handle *trans, 327044871b1bSChris Mason struct btrfs_path *path, 327144871b1bSChris Mason struct extent_buffer *l, 327244871b1bSChris Mason struct extent_buffer *right, 327344871b1bSChris Mason int slot, int mid, int nritems) 3274be0e5c09SChris Mason { 327594f94ad9SDavid Sterba struct btrfs_fs_info *fs_info = trans->fs_info; 3276be0e5c09SChris Mason int data_copy_size; 3277be0e5c09SChris Mason int rt_data_off; 3278be0e5c09SChris Mason int i; 3279d4dbff95SChris Mason struct btrfs_disk_key disk_key; 3280cfed81a0SChris Mason struct btrfs_map_token token; 3281cfed81a0SChris Mason 32825f39d397SChris Mason nritems = nritems - mid; 32835f39d397SChris Mason btrfs_set_header_nritems(right, nritems); 3284dc2e724eSJosef Bacik data_copy_size = btrfs_item_data_end(l, mid) - leaf_data_end(l); 32855f39d397SChris Mason 32865f39d397SChris Mason copy_extent_buffer(right, l, btrfs_item_nr_offset(0), 32875f39d397SChris Mason btrfs_item_nr_offset(mid), 32885f39d397SChris Mason nritems * sizeof(struct btrfs_item)); 32895f39d397SChris Mason 32905f39d397SChris Mason copy_extent_buffer(right, l, 32913d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + BTRFS_LEAF_DATA_SIZE(fs_info) - 32923d9ec8c4SNikolay Borisov data_copy_size, BTRFS_LEAF_DATA_OFFSET + 32938f881e8cSDavid Sterba leaf_data_end(l), data_copy_size); 329474123bd7SChris Mason 3295dc2e724eSJosef Bacik rt_data_off = BTRFS_LEAF_DATA_SIZE(fs_info) - btrfs_item_data_end(l, mid); 32965f39d397SChris Mason 3297c82f823cSDavid Sterba btrfs_init_map_token(&token, right); 32985f39d397SChris Mason for (i = 0; i < nritems; i++) { 3299db94535dSChris Mason u32 ioff; 3300db94535dSChris Mason 33013212fa14SJosef Bacik ioff = btrfs_token_item_offset(&token, i); 33023212fa14SJosef Bacik btrfs_set_token_item_offset(&token, i, ioff + rt_data_off); 33030783fcfcSChris Mason } 330474123bd7SChris Mason 33055f39d397SChris Mason btrfs_set_header_nritems(l, mid); 33065f39d397SChris Mason btrfs_item_key(right, &disk_key, 0); 33076ad3cf6dSDavid Sterba insert_ptr(trans, path, &disk_key, right->start, path->slots[1] + 1, 1); 33085f39d397SChris Mason 33095f39d397SChris Mason btrfs_mark_buffer_dirty(right); 33105f39d397SChris Mason btrfs_mark_buffer_dirty(l); 3311eb60ceacSChris Mason BUG_ON(path->slots[0] != slot); 33125f39d397SChris Mason 3313be0e5c09SChris Mason if (mid <= slot) { 3314925baeddSChris Mason btrfs_tree_unlock(path->nodes[0]); 33155f39d397SChris Mason free_extent_buffer(path->nodes[0]); 33165f39d397SChris Mason path->nodes[0] = right; 3317be0e5c09SChris Mason path->slots[0] -= mid; 3318be0e5c09SChris Mason path->slots[1] += 1; 3319925baeddSChris Mason } else { 3320925baeddSChris Mason btrfs_tree_unlock(right); 33215f39d397SChris Mason free_extent_buffer(right); 3322925baeddSChris Mason } 33235f39d397SChris Mason 3324eb60ceacSChris Mason BUG_ON(path->slots[0] < 0); 332544871b1bSChris Mason } 332644871b1bSChris Mason 332744871b1bSChris Mason /* 332899d8f83cSChris Mason * double splits happen when we need to insert a big item in the middle 332999d8f83cSChris Mason * of a leaf. A double split can leave us with 3 mostly empty leaves: 333099d8f83cSChris Mason * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] 333199d8f83cSChris Mason * A B C 333299d8f83cSChris Mason * 333399d8f83cSChris Mason * We avoid this by trying to push the items on either side of our target 333499d8f83cSChris Mason * into the adjacent leaves. If all goes well we can avoid the double split 333599d8f83cSChris Mason * completely. 333699d8f83cSChris Mason */ 333799d8f83cSChris Mason static noinline int push_for_double_split(struct btrfs_trans_handle *trans, 333899d8f83cSChris Mason struct btrfs_root *root, 333999d8f83cSChris Mason struct btrfs_path *path, 334099d8f83cSChris Mason int data_size) 334199d8f83cSChris Mason { 334299d8f83cSChris Mason int ret; 334399d8f83cSChris Mason int progress = 0; 334499d8f83cSChris Mason int slot; 334599d8f83cSChris Mason u32 nritems; 33465a4267caSFilipe David Borba Manana int space_needed = data_size; 334799d8f83cSChris Mason 334899d8f83cSChris Mason slot = path->slots[0]; 33495a4267caSFilipe David Borba Manana if (slot < btrfs_header_nritems(path->nodes[0])) 3350e902baacSDavid Sterba space_needed -= btrfs_leaf_free_space(path->nodes[0]); 335199d8f83cSChris Mason 335299d8f83cSChris Mason /* 335399d8f83cSChris Mason * try to push all the items after our slot into the 335499d8f83cSChris Mason * right leaf 335599d8f83cSChris Mason */ 33565a4267caSFilipe David Borba Manana ret = push_leaf_right(trans, root, path, 1, space_needed, 0, slot); 335799d8f83cSChris Mason if (ret < 0) 335899d8f83cSChris Mason return ret; 335999d8f83cSChris Mason 336099d8f83cSChris Mason if (ret == 0) 336199d8f83cSChris Mason progress++; 336299d8f83cSChris Mason 336399d8f83cSChris Mason nritems = btrfs_header_nritems(path->nodes[0]); 336499d8f83cSChris Mason /* 336599d8f83cSChris Mason * our goal is to get our slot at the start or end of a leaf. If 336699d8f83cSChris Mason * we've done so we're done 336799d8f83cSChris Mason */ 336899d8f83cSChris Mason if (path->slots[0] == 0 || path->slots[0] == nritems) 336999d8f83cSChris Mason return 0; 337099d8f83cSChris Mason 3371e902baacSDavid Sterba if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) 337299d8f83cSChris Mason return 0; 337399d8f83cSChris Mason 337499d8f83cSChris Mason /* try to push all the items before our slot into the next leaf */ 337599d8f83cSChris Mason slot = path->slots[0]; 3376263d3995SFilipe Manana space_needed = data_size; 3377263d3995SFilipe Manana if (slot > 0) 3378e902baacSDavid Sterba space_needed -= btrfs_leaf_free_space(path->nodes[0]); 33795a4267caSFilipe David Borba Manana ret = push_leaf_left(trans, root, path, 1, space_needed, 0, slot); 338099d8f83cSChris Mason if (ret < 0) 338199d8f83cSChris Mason return ret; 338299d8f83cSChris Mason 338399d8f83cSChris Mason if (ret == 0) 338499d8f83cSChris Mason progress++; 338599d8f83cSChris Mason 338699d8f83cSChris Mason if (progress) 338799d8f83cSChris Mason return 0; 338899d8f83cSChris Mason return 1; 338999d8f83cSChris Mason } 339099d8f83cSChris Mason 339199d8f83cSChris Mason /* 339244871b1bSChris Mason * split the path's leaf in two, making sure there is at least data_size 339344871b1bSChris Mason * available for the resulting leaf level of the path. 339444871b1bSChris Mason * 339544871b1bSChris Mason * returns 0 if all went well and < 0 on failure. 339644871b1bSChris Mason */ 339744871b1bSChris Mason static noinline int split_leaf(struct btrfs_trans_handle *trans, 339844871b1bSChris Mason struct btrfs_root *root, 3399310712b2SOmar Sandoval const struct btrfs_key *ins_key, 340044871b1bSChris Mason struct btrfs_path *path, int data_size, 340144871b1bSChris Mason int extend) 340244871b1bSChris Mason { 34035d4f98a2SYan Zheng struct btrfs_disk_key disk_key; 340444871b1bSChris Mason struct extent_buffer *l; 340544871b1bSChris Mason u32 nritems; 340644871b1bSChris Mason int mid; 340744871b1bSChris Mason int slot; 340844871b1bSChris Mason struct extent_buffer *right; 3409b7a0365eSDaniel Dressler struct btrfs_fs_info *fs_info = root->fs_info; 341044871b1bSChris Mason int ret = 0; 341144871b1bSChris Mason int wret; 34125d4f98a2SYan Zheng int split; 341344871b1bSChris Mason int num_doubles = 0; 341499d8f83cSChris Mason int tried_avoid_double = 0; 341544871b1bSChris Mason 3416a5719521SYan, Zheng l = path->nodes[0]; 3417a5719521SYan, Zheng slot = path->slots[0]; 34183212fa14SJosef Bacik if (extend && data_size + btrfs_item_size(l, slot) + 34190b246afaSJeff Mahoney sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info)) 3420a5719521SYan, Zheng return -EOVERFLOW; 3421a5719521SYan, Zheng 342244871b1bSChris Mason /* first try to make some room by pushing left and right */ 342333157e05SLiu Bo if (data_size && path->nodes[1]) { 34245a4267caSFilipe David Borba Manana int space_needed = data_size; 34255a4267caSFilipe David Borba Manana 34265a4267caSFilipe David Borba Manana if (slot < btrfs_header_nritems(l)) 3427e902baacSDavid Sterba space_needed -= btrfs_leaf_free_space(l); 34285a4267caSFilipe David Borba Manana 34295a4267caSFilipe David Borba Manana wret = push_leaf_right(trans, root, path, space_needed, 34305a4267caSFilipe David Borba Manana space_needed, 0, 0); 343144871b1bSChris Mason if (wret < 0) 343244871b1bSChris Mason return wret; 343344871b1bSChris Mason if (wret) { 3434263d3995SFilipe Manana space_needed = data_size; 3435263d3995SFilipe Manana if (slot > 0) 3436e902baacSDavid Sterba space_needed -= btrfs_leaf_free_space(l); 34375a4267caSFilipe David Borba Manana wret = push_leaf_left(trans, root, path, space_needed, 34385a4267caSFilipe David Borba Manana space_needed, 0, (u32)-1); 343944871b1bSChris Mason if (wret < 0) 344044871b1bSChris Mason return wret; 344144871b1bSChris Mason } 344244871b1bSChris Mason l = path->nodes[0]; 344344871b1bSChris Mason 344444871b1bSChris Mason /* did the pushes work? */ 3445e902baacSDavid Sterba if (btrfs_leaf_free_space(l) >= data_size) 344644871b1bSChris Mason return 0; 344744871b1bSChris Mason } 344844871b1bSChris Mason 344944871b1bSChris Mason if (!path->nodes[1]) { 3450fdd99c72SLiu Bo ret = insert_new_root(trans, root, path, 1); 345144871b1bSChris Mason if (ret) 345244871b1bSChris Mason return ret; 345344871b1bSChris Mason } 345444871b1bSChris Mason again: 34555d4f98a2SYan Zheng split = 1; 345644871b1bSChris Mason l = path->nodes[0]; 345744871b1bSChris Mason slot = path->slots[0]; 345844871b1bSChris Mason nritems = btrfs_header_nritems(l); 345944871b1bSChris Mason mid = (nritems + 1) / 2; 346044871b1bSChris Mason 34615d4f98a2SYan Zheng if (mid <= slot) { 34625d4f98a2SYan Zheng if (nritems == 1 || 34635d4f98a2SYan Zheng leaf_space_used(l, mid, nritems - mid) + data_size > 34640b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info)) { 34655d4f98a2SYan Zheng if (slot >= nritems) { 34665d4f98a2SYan Zheng split = 0; 34675d4f98a2SYan Zheng } else { 34685d4f98a2SYan Zheng mid = slot; 34695d4f98a2SYan Zheng if (mid != nritems && 34705d4f98a2SYan Zheng leaf_space_used(l, mid, nritems - mid) + 34710b246afaSJeff Mahoney data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { 347299d8f83cSChris Mason if (data_size && !tried_avoid_double) 347399d8f83cSChris Mason goto push_for_double; 34745d4f98a2SYan Zheng split = 2; 34755d4f98a2SYan Zheng } 34765d4f98a2SYan Zheng } 34775d4f98a2SYan Zheng } 34785d4f98a2SYan Zheng } else { 34795d4f98a2SYan Zheng if (leaf_space_used(l, 0, mid) + data_size > 34800b246afaSJeff Mahoney BTRFS_LEAF_DATA_SIZE(fs_info)) { 34815d4f98a2SYan Zheng if (!extend && data_size && slot == 0) { 34825d4f98a2SYan Zheng split = 0; 34835d4f98a2SYan Zheng } else if ((extend || !data_size) && slot == 0) { 34845d4f98a2SYan Zheng mid = 1; 34855d4f98a2SYan Zheng } else { 34865d4f98a2SYan Zheng mid = slot; 34875d4f98a2SYan Zheng if (mid != nritems && 34885d4f98a2SYan Zheng leaf_space_used(l, mid, nritems - mid) + 34890b246afaSJeff Mahoney data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { 349099d8f83cSChris Mason if (data_size && !tried_avoid_double) 349199d8f83cSChris Mason goto push_for_double; 34925d4f98a2SYan Zheng split = 2; 34935d4f98a2SYan Zheng } 34945d4f98a2SYan Zheng } 34955d4f98a2SYan Zheng } 34965d4f98a2SYan Zheng } 34975d4f98a2SYan Zheng 34985d4f98a2SYan Zheng if (split == 0) 34995d4f98a2SYan Zheng btrfs_cpu_key_to_disk(&disk_key, ins_key); 35005d4f98a2SYan Zheng else 35015d4f98a2SYan Zheng btrfs_item_key(l, &disk_key, mid); 35025d4f98a2SYan Zheng 3503ca9d473aSJosef Bacik /* 3504ca9d473aSJosef Bacik * We have to about BTRFS_NESTING_NEW_ROOT here if we've done a double 3505ca9d473aSJosef Bacik * split, because we're only allowed to have MAX_LOCKDEP_SUBCLASSES 3506ca9d473aSJosef Bacik * subclasses, which is 8 at the time of this patch, and we've maxed it 3507ca9d473aSJosef Bacik * out. In the future we could add a 3508ca9d473aSJosef Bacik * BTRFS_NESTING_SPLIT_THE_SPLITTENING if we need to, but for now just 3509ca9d473aSJosef Bacik * use BTRFS_NESTING_NEW_ROOT. 3510ca9d473aSJosef Bacik */ 351179bd3712SFilipe Manana right = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, 351279bd3712SFilipe Manana &disk_key, 0, l->start, 0, 351379bd3712SFilipe Manana num_doubles ? BTRFS_NESTING_NEW_ROOT : 3514ca9d473aSJosef Bacik BTRFS_NESTING_SPLIT); 3515f0486c68SYan, Zheng if (IS_ERR(right)) 351644871b1bSChris Mason return PTR_ERR(right); 3517f0486c68SYan, Zheng 35180b246afaSJeff Mahoney root_add_used(root, fs_info->nodesize); 351944871b1bSChris Mason 35205d4f98a2SYan Zheng if (split == 0) { 352144871b1bSChris Mason if (mid <= slot) { 352244871b1bSChris Mason btrfs_set_header_nritems(right, 0); 35236ad3cf6dSDavid Sterba insert_ptr(trans, path, &disk_key, 35242ff7e61eSJeff Mahoney right->start, path->slots[1] + 1, 1); 352544871b1bSChris Mason btrfs_tree_unlock(path->nodes[0]); 352644871b1bSChris Mason free_extent_buffer(path->nodes[0]); 352744871b1bSChris Mason path->nodes[0] = right; 352844871b1bSChris Mason path->slots[0] = 0; 352944871b1bSChris Mason path->slots[1] += 1; 353044871b1bSChris Mason } else { 353144871b1bSChris Mason btrfs_set_header_nritems(right, 0); 35326ad3cf6dSDavid Sterba insert_ptr(trans, path, &disk_key, 35332ff7e61eSJeff Mahoney right->start, path->slots[1], 1); 353444871b1bSChris Mason btrfs_tree_unlock(path->nodes[0]); 353544871b1bSChris Mason free_extent_buffer(path->nodes[0]); 353644871b1bSChris Mason path->nodes[0] = right; 353744871b1bSChris Mason path->slots[0] = 0; 3538143bede5SJeff Mahoney if (path->slots[1] == 0) 3539b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 35405d4f98a2SYan Zheng } 3541196e0249SLiu Bo /* 3542196e0249SLiu Bo * We create a new leaf 'right' for the required ins_len and 3543196e0249SLiu Bo * we'll do btrfs_mark_buffer_dirty() on this leaf after copying 3544196e0249SLiu Bo * the content of ins_len to 'right'. 3545196e0249SLiu Bo */ 354644871b1bSChris Mason return ret; 354744871b1bSChris Mason } 354844871b1bSChris Mason 354994f94ad9SDavid Sterba copy_for_split(trans, path, l, right, slot, mid, nritems); 355044871b1bSChris Mason 35515d4f98a2SYan Zheng if (split == 2) { 3552cc0c5538SChris Mason BUG_ON(num_doubles != 0); 3553cc0c5538SChris Mason num_doubles++; 3554cc0c5538SChris Mason goto again; 35553326d1b0SChris Mason } 355644871b1bSChris Mason 3557143bede5SJeff Mahoney return 0; 355899d8f83cSChris Mason 355999d8f83cSChris Mason push_for_double: 356099d8f83cSChris Mason push_for_double_split(trans, root, path, data_size); 356199d8f83cSChris Mason tried_avoid_double = 1; 3562e902baacSDavid Sterba if (btrfs_leaf_free_space(path->nodes[0]) >= data_size) 356399d8f83cSChris Mason return 0; 356499d8f83cSChris Mason goto again; 3565be0e5c09SChris Mason } 3566be0e5c09SChris Mason 3567ad48fd75SYan, Zheng static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, 3568ad48fd75SYan, Zheng struct btrfs_root *root, 3569ad48fd75SYan, Zheng struct btrfs_path *path, int ins_len) 3570ad48fd75SYan, Zheng { 3571ad48fd75SYan, Zheng struct btrfs_key key; 3572ad48fd75SYan, Zheng struct extent_buffer *leaf; 3573ad48fd75SYan, Zheng struct btrfs_file_extent_item *fi; 3574ad48fd75SYan, Zheng u64 extent_len = 0; 3575ad48fd75SYan, Zheng u32 item_size; 3576ad48fd75SYan, Zheng int ret; 3577ad48fd75SYan, Zheng 3578ad48fd75SYan, Zheng leaf = path->nodes[0]; 3579ad48fd75SYan, Zheng btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 3580ad48fd75SYan, Zheng 3581ad48fd75SYan, Zheng BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && 3582ad48fd75SYan, Zheng key.type != BTRFS_EXTENT_CSUM_KEY); 3583ad48fd75SYan, Zheng 3584e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) >= ins_len) 3585ad48fd75SYan, Zheng return 0; 3586ad48fd75SYan, Zheng 35873212fa14SJosef Bacik item_size = btrfs_item_size(leaf, path->slots[0]); 3588ad48fd75SYan, Zheng if (key.type == BTRFS_EXTENT_DATA_KEY) { 3589ad48fd75SYan, Zheng fi = btrfs_item_ptr(leaf, path->slots[0], 3590ad48fd75SYan, Zheng struct btrfs_file_extent_item); 3591ad48fd75SYan, Zheng extent_len = btrfs_file_extent_num_bytes(leaf, fi); 3592ad48fd75SYan, Zheng } 3593b3b4aa74SDavid Sterba btrfs_release_path(path); 3594ad48fd75SYan, Zheng 3595ad48fd75SYan, Zheng path->keep_locks = 1; 3596ad48fd75SYan, Zheng path->search_for_split = 1; 3597ad48fd75SYan, Zheng ret = btrfs_search_slot(trans, root, &key, path, 0, 1); 3598ad48fd75SYan, Zheng path->search_for_split = 0; 3599a8df6fe6SFilipe Manana if (ret > 0) 3600a8df6fe6SFilipe Manana ret = -EAGAIN; 3601ad48fd75SYan, Zheng if (ret < 0) 3602ad48fd75SYan, Zheng goto err; 3603ad48fd75SYan, Zheng 3604ad48fd75SYan, Zheng ret = -EAGAIN; 3605ad48fd75SYan, Zheng leaf = path->nodes[0]; 3606a8df6fe6SFilipe Manana /* if our item isn't there, return now */ 36073212fa14SJosef Bacik if (item_size != btrfs_item_size(leaf, path->slots[0])) 3608ad48fd75SYan, Zheng goto err; 3609ad48fd75SYan, Zheng 3610109f6aefSChris Mason /* the leaf has changed, it now has room. return now */ 3611e902baacSDavid Sterba if (btrfs_leaf_free_space(path->nodes[0]) >= ins_len) 3612109f6aefSChris Mason goto err; 3613109f6aefSChris Mason 3614ad48fd75SYan, Zheng if (key.type == BTRFS_EXTENT_DATA_KEY) { 3615ad48fd75SYan, Zheng fi = btrfs_item_ptr(leaf, path->slots[0], 3616ad48fd75SYan, Zheng struct btrfs_file_extent_item); 3617ad48fd75SYan, Zheng if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) 3618ad48fd75SYan, Zheng goto err; 3619ad48fd75SYan, Zheng } 3620ad48fd75SYan, Zheng 3621ad48fd75SYan, Zheng ret = split_leaf(trans, root, &key, path, ins_len, 1); 3622f0486c68SYan, Zheng if (ret) 3623f0486c68SYan, Zheng goto err; 3624ad48fd75SYan, Zheng 3625ad48fd75SYan, Zheng path->keep_locks = 0; 3626ad48fd75SYan, Zheng btrfs_unlock_up_safe(path, 1); 3627ad48fd75SYan, Zheng return 0; 3628ad48fd75SYan, Zheng err: 3629ad48fd75SYan, Zheng path->keep_locks = 0; 3630ad48fd75SYan, Zheng return ret; 3631ad48fd75SYan, Zheng } 3632ad48fd75SYan, Zheng 363325263cd7SDavid Sterba static noinline int split_item(struct btrfs_path *path, 3634310712b2SOmar Sandoval const struct btrfs_key *new_key, 3635459931ecSChris Mason unsigned long split_offset) 3636459931ecSChris Mason { 3637459931ecSChris Mason struct extent_buffer *leaf; 3638c91666b1SJosef Bacik int orig_slot, slot; 3639ad48fd75SYan, Zheng char *buf; 3640459931ecSChris Mason u32 nritems; 3641ad48fd75SYan, Zheng u32 item_size; 3642459931ecSChris Mason u32 orig_offset; 3643459931ecSChris Mason struct btrfs_disk_key disk_key; 3644459931ecSChris Mason 3645459931ecSChris Mason leaf = path->nodes[0]; 3646e902baacSDavid Sterba BUG_ON(btrfs_leaf_free_space(leaf) < sizeof(struct btrfs_item)); 3647b9473439SChris Mason 3648c91666b1SJosef Bacik orig_slot = path->slots[0]; 36493212fa14SJosef Bacik orig_offset = btrfs_item_offset(leaf, path->slots[0]); 36503212fa14SJosef Bacik item_size = btrfs_item_size(leaf, path->slots[0]); 3651459931ecSChris Mason 3652459931ecSChris Mason buf = kmalloc(item_size, GFP_NOFS); 3653ad48fd75SYan, Zheng if (!buf) 3654ad48fd75SYan, Zheng return -ENOMEM; 3655ad48fd75SYan, Zheng 3656459931ecSChris Mason read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, 3657459931ecSChris Mason path->slots[0]), item_size); 3658ad48fd75SYan, Zheng 3659459931ecSChris Mason slot = path->slots[0] + 1; 3660459931ecSChris Mason nritems = btrfs_header_nritems(leaf); 3661459931ecSChris Mason if (slot != nritems) { 3662459931ecSChris Mason /* shift the items */ 3663459931ecSChris Mason memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), 3664459931ecSChris Mason btrfs_item_nr_offset(slot), 3665459931ecSChris Mason (nritems - slot) * sizeof(struct btrfs_item)); 3666459931ecSChris Mason } 3667459931ecSChris Mason 3668459931ecSChris Mason btrfs_cpu_key_to_disk(&disk_key, new_key); 3669459931ecSChris Mason btrfs_set_item_key(leaf, &disk_key, slot); 3670459931ecSChris Mason 36713212fa14SJosef Bacik btrfs_set_item_offset(leaf, slot, orig_offset); 36723212fa14SJosef Bacik btrfs_set_item_size(leaf, slot, item_size - split_offset); 3673459931ecSChris Mason 36743212fa14SJosef Bacik btrfs_set_item_offset(leaf, orig_slot, 3675459931ecSChris Mason orig_offset + item_size - split_offset); 36763212fa14SJosef Bacik btrfs_set_item_size(leaf, orig_slot, split_offset); 3677459931ecSChris Mason 3678459931ecSChris Mason btrfs_set_header_nritems(leaf, nritems + 1); 3679459931ecSChris Mason 3680459931ecSChris Mason /* write the data for the start of the original item */ 3681459931ecSChris Mason write_extent_buffer(leaf, buf, 3682459931ecSChris Mason btrfs_item_ptr_offset(leaf, path->slots[0]), 3683459931ecSChris Mason split_offset); 3684459931ecSChris Mason 3685459931ecSChris Mason /* write the data for the new item */ 3686459931ecSChris Mason write_extent_buffer(leaf, buf + split_offset, 3687459931ecSChris Mason btrfs_item_ptr_offset(leaf, slot), 3688459931ecSChris Mason item_size - split_offset); 3689459931ecSChris Mason btrfs_mark_buffer_dirty(leaf); 3690459931ecSChris Mason 3691e902baacSDavid Sterba BUG_ON(btrfs_leaf_free_space(leaf) < 0); 3692459931ecSChris Mason kfree(buf); 3693ad48fd75SYan, Zheng return 0; 3694ad48fd75SYan, Zheng } 3695ad48fd75SYan, Zheng 3696ad48fd75SYan, Zheng /* 3697ad48fd75SYan, Zheng * This function splits a single item into two items, 3698ad48fd75SYan, Zheng * giving 'new_key' to the new item and splitting the 3699ad48fd75SYan, Zheng * old one at split_offset (from the start of the item). 3700ad48fd75SYan, Zheng * 3701ad48fd75SYan, Zheng * The path may be released by this operation. After 3702ad48fd75SYan, Zheng * the split, the path is pointing to the old item. The 3703ad48fd75SYan, Zheng * new item is going to be in the same node as the old one. 3704ad48fd75SYan, Zheng * 3705ad48fd75SYan, Zheng * Note, the item being split must be smaller enough to live alone on 3706ad48fd75SYan, Zheng * a tree block with room for one extra struct btrfs_item 3707ad48fd75SYan, Zheng * 3708ad48fd75SYan, Zheng * This allows us to split the item in place, keeping a lock on the 3709ad48fd75SYan, Zheng * leaf the entire time. 3710ad48fd75SYan, Zheng */ 3711ad48fd75SYan, Zheng int btrfs_split_item(struct btrfs_trans_handle *trans, 3712ad48fd75SYan, Zheng struct btrfs_root *root, 3713ad48fd75SYan, Zheng struct btrfs_path *path, 3714310712b2SOmar Sandoval const struct btrfs_key *new_key, 3715ad48fd75SYan, Zheng unsigned long split_offset) 3716ad48fd75SYan, Zheng { 3717ad48fd75SYan, Zheng int ret; 3718ad48fd75SYan, Zheng ret = setup_leaf_for_split(trans, root, path, 3719ad48fd75SYan, Zheng sizeof(struct btrfs_item)); 3720ad48fd75SYan, Zheng if (ret) 3721459931ecSChris Mason return ret; 3722ad48fd75SYan, Zheng 372325263cd7SDavid Sterba ret = split_item(path, new_key, split_offset); 3724ad48fd75SYan, Zheng return ret; 3725ad48fd75SYan, Zheng } 3726ad48fd75SYan, Zheng 3727ad48fd75SYan, Zheng /* 3728d352ac68SChris Mason * make the item pointed to by the path smaller. new_size indicates 3729d352ac68SChris Mason * how small to make it, and from_end tells us if we just chop bytes 3730d352ac68SChris Mason * off the end of the item or if we shift the item to chop bytes off 3731d352ac68SChris Mason * the front. 3732d352ac68SChris Mason */ 373378ac4f9eSDavid Sterba void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end) 3734b18c6685SChris Mason { 3735b18c6685SChris Mason int slot; 37365f39d397SChris Mason struct extent_buffer *leaf; 3737b18c6685SChris Mason u32 nritems; 3738b18c6685SChris Mason unsigned int data_end; 3739b18c6685SChris Mason unsigned int old_data_start; 3740b18c6685SChris Mason unsigned int old_size; 3741b18c6685SChris Mason unsigned int size_diff; 3742b18c6685SChris Mason int i; 3743cfed81a0SChris Mason struct btrfs_map_token token; 3744cfed81a0SChris Mason 37455f39d397SChris Mason leaf = path->nodes[0]; 3746179e29e4SChris Mason slot = path->slots[0]; 3747179e29e4SChris Mason 37483212fa14SJosef Bacik old_size = btrfs_item_size(leaf, slot); 3749179e29e4SChris Mason if (old_size == new_size) 3750143bede5SJeff Mahoney return; 3751b18c6685SChris Mason 37525f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 37538f881e8cSDavid Sterba data_end = leaf_data_end(leaf); 3754b18c6685SChris Mason 37553212fa14SJosef Bacik old_data_start = btrfs_item_offset(leaf, slot); 3756179e29e4SChris Mason 3757b18c6685SChris Mason size_diff = old_size - new_size; 3758b18c6685SChris Mason 3759b18c6685SChris Mason BUG_ON(slot < 0); 3760b18c6685SChris Mason BUG_ON(slot >= nritems); 3761b18c6685SChris Mason 3762b18c6685SChris Mason /* 3763b18c6685SChris Mason * item0..itemN ... dataN.offset..dataN.size .. data0.size 3764b18c6685SChris Mason */ 3765b18c6685SChris Mason /* first correct the data pointers */ 3766c82f823cSDavid Sterba btrfs_init_map_token(&token, leaf); 3767b18c6685SChris Mason for (i = slot; i < nritems; i++) { 37685f39d397SChris Mason u32 ioff; 3769db94535dSChris Mason 37703212fa14SJosef Bacik ioff = btrfs_token_item_offset(&token, i); 37713212fa14SJosef Bacik btrfs_set_token_item_offset(&token, i, ioff + size_diff); 3772b18c6685SChris Mason } 3773db94535dSChris Mason 3774b18c6685SChris Mason /* shift the data */ 3775179e29e4SChris Mason if (from_end) { 37763d9ec8c4SNikolay Borisov memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + 37773d9ec8c4SNikolay Borisov data_end + size_diff, BTRFS_LEAF_DATA_OFFSET + 3778b18c6685SChris Mason data_end, old_data_start + new_size - data_end); 3779179e29e4SChris Mason } else { 3780179e29e4SChris Mason struct btrfs_disk_key disk_key; 3781179e29e4SChris Mason u64 offset; 3782179e29e4SChris Mason 3783179e29e4SChris Mason btrfs_item_key(leaf, &disk_key, slot); 3784179e29e4SChris Mason 3785179e29e4SChris Mason if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { 3786179e29e4SChris Mason unsigned long ptr; 3787179e29e4SChris Mason struct btrfs_file_extent_item *fi; 3788179e29e4SChris Mason 3789179e29e4SChris Mason fi = btrfs_item_ptr(leaf, slot, 3790179e29e4SChris Mason struct btrfs_file_extent_item); 3791179e29e4SChris Mason fi = (struct btrfs_file_extent_item *)( 3792179e29e4SChris Mason (unsigned long)fi - size_diff); 3793179e29e4SChris Mason 3794179e29e4SChris Mason if (btrfs_file_extent_type(leaf, fi) == 3795179e29e4SChris Mason BTRFS_FILE_EXTENT_INLINE) { 3796179e29e4SChris Mason ptr = btrfs_item_ptr_offset(leaf, slot); 3797179e29e4SChris Mason memmove_extent_buffer(leaf, ptr, 3798179e29e4SChris Mason (unsigned long)fi, 37997ec20afbSDavid Sterba BTRFS_FILE_EXTENT_INLINE_DATA_START); 3800179e29e4SChris Mason } 3801179e29e4SChris Mason } 3802179e29e4SChris Mason 38033d9ec8c4SNikolay Borisov memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + 38043d9ec8c4SNikolay Borisov data_end + size_diff, BTRFS_LEAF_DATA_OFFSET + 3805179e29e4SChris Mason data_end, old_data_start - data_end); 3806179e29e4SChris Mason 3807179e29e4SChris Mason offset = btrfs_disk_key_offset(&disk_key); 3808179e29e4SChris Mason btrfs_set_disk_key_offset(&disk_key, offset + size_diff); 3809179e29e4SChris Mason btrfs_set_item_key(leaf, &disk_key, slot); 3810179e29e4SChris Mason if (slot == 0) 3811b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 3812179e29e4SChris Mason } 38135f39d397SChris Mason 38143212fa14SJosef Bacik btrfs_set_item_size(leaf, slot, new_size); 38155f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 3816b18c6685SChris Mason 3817e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < 0) { 3818a4f78750SDavid Sterba btrfs_print_leaf(leaf); 3819b18c6685SChris Mason BUG(); 38205f39d397SChris Mason } 3821b18c6685SChris Mason } 3822b18c6685SChris Mason 3823d352ac68SChris Mason /* 38248f69dbd2SStefan Behrens * make the item pointed to by the path bigger, data_size is the added size. 3825d352ac68SChris Mason */ 3826c71dd880SDavid Sterba void btrfs_extend_item(struct btrfs_path *path, u32 data_size) 38276567e837SChris Mason { 38286567e837SChris Mason int slot; 38295f39d397SChris Mason struct extent_buffer *leaf; 38306567e837SChris Mason u32 nritems; 38316567e837SChris Mason unsigned int data_end; 38326567e837SChris Mason unsigned int old_data; 38336567e837SChris Mason unsigned int old_size; 38346567e837SChris Mason int i; 3835cfed81a0SChris Mason struct btrfs_map_token token; 3836cfed81a0SChris Mason 38375f39d397SChris Mason leaf = path->nodes[0]; 38386567e837SChris Mason 38395f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 38408f881e8cSDavid Sterba data_end = leaf_data_end(leaf); 38416567e837SChris Mason 3842e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < data_size) { 3843a4f78750SDavid Sterba btrfs_print_leaf(leaf); 38446567e837SChris Mason BUG(); 38455f39d397SChris Mason } 38466567e837SChris Mason slot = path->slots[0]; 3847dc2e724eSJosef Bacik old_data = btrfs_item_data_end(leaf, slot); 38486567e837SChris Mason 38496567e837SChris Mason BUG_ON(slot < 0); 38503326d1b0SChris Mason if (slot >= nritems) { 3851a4f78750SDavid Sterba btrfs_print_leaf(leaf); 3852c71dd880SDavid Sterba btrfs_crit(leaf->fs_info, "slot %d too large, nritems %d", 3853d397712bSChris Mason slot, nritems); 3854290342f6SArnd Bergmann BUG(); 38553326d1b0SChris Mason } 38566567e837SChris Mason 38576567e837SChris Mason /* 38586567e837SChris Mason * item0..itemN ... dataN.offset..dataN.size .. data0.size 38596567e837SChris Mason */ 38606567e837SChris Mason /* first correct the data pointers */ 3861c82f823cSDavid Sterba btrfs_init_map_token(&token, leaf); 38626567e837SChris Mason for (i = slot; i < nritems; i++) { 38635f39d397SChris Mason u32 ioff; 3864db94535dSChris Mason 38653212fa14SJosef Bacik ioff = btrfs_token_item_offset(&token, i); 38663212fa14SJosef Bacik btrfs_set_token_item_offset(&token, i, ioff - data_size); 38676567e837SChris Mason } 38685f39d397SChris Mason 38696567e837SChris Mason /* shift the data */ 38703d9ec8c4SNikolay Borisov memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + 38713d9ec8c4SNikolay Borisov data_end - data_size, BTRFS_LEAF_DATA_OFFSET + 38726567e837SChris Mason data_end, old_data - data_end); 38735f39d397SChris Mason 38746567e837SChris Mason data_end = old_data; 38753212fa14SJosef Bacik old_size = btrfs_item_size(leaf, slot); 38763212fa14SJosef Bacik btrfs_set_item_size(leaf, slot, old_size + data_size); 38775f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 38786567e837SChris Mason 3879e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < 0) { 3880a4f78750SDavid Sterba btrfs_print_leaf(leaf); 38816567e837SChris Mason BUG(); 38825f39d397SChris Mason } 38836567e837SChris Mason } 38846567e837SChris Mason 3885da9ffb24SNikolay Borisov /** 3886da9ffb24SNikolay Borisov * setup_items_for_insert - Helper called before inserting one or more items 3887da9ffb24SNikolay Borisov * to a leaf. Main purpose is to save stack depth by doing the bulk of the work 3888da9ffb24SNikolay Borisov * in a function that doesn't call btrfs_search_slot 3889da9ffb24SNikolay Borisov * 3890da9ffb24SNikolay Borisov * @root: root we are inserting items to 3891da9ffb24SNikolay Borisov * @path: points to the leaf/slot where we are going to insert new items 3892b7ef5f3aSFilipe Manana * @batch: information about the batch of items to insert 389374123bd7SChris Mason */ 3894f0641656SFilipe Manana static void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path, 3895b7ef5f3aSFilipe Manana const struct btrfs_item_batch *batch) 3896be0e5c09SChris Mason { 38970b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 38989c58309dSChris Mason int i; 38997518a238SChris Mason u32 nritems; 3900be0e5c09SChris Mason unsigned int data_end; 3901e2fa7227SChris Mason struct btrfs_disk_key disk_key; 390244871b1bSChris Mason struct extent_buffer *leaf; 390344871b1bSChris Mason int slot; 3904cfed81a0SChris Mason struct btrfs_map_token token; 3905fc0d82e1SNikolay Borisov u32 total_size; 3906fc0d82e1SNikolay Borisov 3907b7ef5f3aSFilipe Manana /* 3908b7ef5f3aSFilipe Manana * Before anything else, update keys in the parent and other ancestors 3909b7ef5f3aSFilipe Manana * if needed, then release the write locks on them, so that other tasks 3910b7ef5f3aSFilipe Manana * can use them while we modify the leaf. 3911b7ef5f3aSFilipe Manana */ 391224cdc847SFilipe Manana if (path->slots[0] == 0) { 3913b7ef5f3aSFilipe Manana btrfs_cpu_key_to_disk(&disk_key, &batch->keys[0]); 3914b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 391524cdc847SFilipe Manana } 391624cdc847SFilipe Manana btrfs_unlock_up_safe(path, 1); 391724cdc847SFilipe Manana 39185f39d397SChris Mason leaf = path->nodes[0]; 391944871b1bSChris Mason slot = path->slots[0]; 392074123bd7SChris Mason 39215f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 39228f881e8cSDavid Sterba data_end = leaf_data_end(leaf); 3923b7ef5f3aSFilipe Manana total_size = batch->total_data_size + (batch->nr * sizeof(struct btrfs_item)); 3924eb60ceacSChris Mason 3925e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < total_size) { 3926a4f78750SDavid Sterba btrfs_print_leaf(leaf); 39270b246afaSJeff Mahoney btrfs_crit(fs_info, "not enough freespace need %u have %d", 3928e902baacSDavid Sterba total_size, btrfs_leaf_free_space(leaf)); 3929be0e5c09SChris Mason BUG(); 3930d4dbff95SChris Mason } 39315f39d397SChris Mason 3932c82f823cSDavid Sterba btrfs_init_map_token(&token, leaf); 3933be0e5c09SChris Mason if (slot != nritems) { 3934dc2e724eSJosef Bacik unsigned int old_data = btrfs_item_data_end(leaf, slot); 3935be0e5c09SChris Mason 39365f39d397SChris Mason if (old_data < data_end) { 3937a4f78750SDavid Sterba btrfs_print_leaf(leaf); 39387269ddd2SNikolay Borisov btrfs_crit(fs_info, 39397269ddd2SNikolay Borisov "item at slot %d with data offset %u beyond data end of leaf %u", 39405f39d397SChris Mason slot, old_data, data_end); 3941290342f6SArnd Bergmann BUG(); 39425f39d397SChris Mason } 3943be0e5c09SChris Mason /* 3944be0e5c09SChris Mason * item0..itemN ... dataN.offset..dataN.size .. data0.size 3945be0e5c09SChris Mason */ 3946be0e5c09SChris Mason /* first correct the data pointers */ 39470783fcfcSChris Mason for (i = slot; i < nritems; i++) { 39485f39d397SChris Mason u32 ioff; 3949db94535dSChris Mason 39503212fa14SJosef Bacik ioff = btrfs_token_item_offset(&token, i); 39513212fa14SJosef Bacik btrfs_set_token_item_offset(&token, i, 3952b7ef5f3aSFilipe Manana ioff - batch->total_data_size); 39530783fcfcSChris Mason } 3954be0e5c09SChris Mason /* shift the items */ 3955b7ef5f3aSFilipe Manana memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + batch->nr), 39565f39d397SChris Mason btrfs_item_nr_offset(slot), 39570783fcfcSChris Mason (nritems - slot) * sizeof(struct btrfs_item)); 3958be0e5c09SChris Mason 3959be0e5c09SChris Mason /* shift the data */ 39603d9ec8c4SNikolay Borisov memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + 3961b7ef5f3aSFilipe Manana data_end - batch->total_data_size, 3962b7ef5f3aSFilipe Manana BTRFS_LEAF_DATA_OFFSET + data_end, 3963b7ef5f3aSFilipe Manana old_data - data_end); 3964be0e5c09SChris Mason data_end = old_data; 3965be0e5c09SChris Mason } 39665f39d397SChris Mason 396762e2749eSChris Mason /* setup the item for the new data */ 3968b7ef5f3aSFilipe Manana for (i = 0; i < batch->nr; i++) { 3969b7ef5f3aSFilipe Manana btrfs_cpu_key_to_disk(&disk_key, &batch->keys[i]); 39709c58309dSChris Mason btrfs_set_item_key(leaf, &disk_key, slot + i); 3971b7ef5f3aSFilipe Manana data_end -= batch->data_sizes[i]; 39723212fa14SJosef Bacik btrfs_set_token_item_offset(&token, slot + i, data_end); 39733212fa14SJosef Bacik btrfs_set_token_item_size(&token, slot + i, batch->data_sizes[i]); 39749c58309dSChris Mason } 397544871b1bSChris Mason 3976b7ef5f3aSFilipe Manana btrfs_set_header_nritems(leaf, nritems + batch->nr); 3977b9473439SChris Mason btrfs_mark_buffer_dirty(leaf); 3978aa5d6bedSChris Mason 3979e902baacSDavid Sterba if (btrfs_leaf_free_space(leaf) < 0) { 3980a4f78750SDavid Sterba btrfs_print_leaf(leaf); 3981be0e5c09SChris Mason BUG(); 39825f39d397SChris Mason } 398344871b1bSChris Mason } 398444871b1bSChris Mason 398544871b1bSChris Mason /* 3986f0641656SFilipe Manana * Insert a new item into a leaf. 3987f0641656SFilipe Manana * 3988f0641656SFilipe Manana * @root: The root of the btree. 3989f0641656SFilipe Manana * @path: A path pointing to the target leaf and slot. 3990f0641656SFilipe Manana * @key: The key of the new item. 3991f0641656SFilipe Manana * @data_size: The size of the data associated with the new key. 3992f0641656SFilipe Manana */ 3993f0641656SFilipe Manana void btrfs_setup_item_for_insert(struct btrfs_root *root, 3994f0641656SFilipe Manana struct btrfs_path *path, 3995f0641656SFilipe Manana const struct btrfs_key *key, 3996f0641656SFilipe Manana u32 data_size) 3997f0641656SFilipe Manana { 3998f0641656SFilipe Manana struct btrfs_item_batch batch; 3999f0641656SFilipe Manana 4000f0641656SFilipe Manana batch.keys = key; 4001f0641656SFilipe Manana batch.data_sizes = &data_size; 4002f0641656SFilipe Manana batch.total_data_size = data_size; 4003f0641656SFilipe Manana batch.nr = 1; 4004f0641656SFilipe Manana 4005f0641656SFilipe Manana setup_items_for_insert(root, path, &batch); 4006f0641656SFilipe Manana } 4007f0641656SFilipe Manana 4008f0641656SFilipe Manana /* 400944871b1bSChris Mason * Given a key and some data, insert items into the tree. 401044871b1bSChris Mason * This does all the path init required, making room in the tree if needed. 401144871b1bSChris Mason */ 401244871b1bSChris Mason int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, 401344871b1bSChris Mason struct btrfs_root *root, 401444871b1bSChris Mason struct btrfs_path *path, 4015b7ef5f3aSFilipe Manana const struct btrfs_item_batch *batch) 401644871b1bSChris Mason { 401744871b1bSChris Mason int ret = 0; 401844871b1bSChris Mason int slot; 4019b7ef5f3aSFilipe Manana u32 total_size; 402044871b1bSChris Mason 4021b7ef5f3aSFilipe Manana total_size = batch->total_data_size + (batch->nr * sizeof(struct btrfs_item)); 4022b7ef5f3aSFilipe Manana ret = btrfs_search_slot(trans, root, &batch->keys[0], path, total_size, 1); 402344871b1bSChris Mason if (ret == 0) 402444871b1bSChris Mason return -EEXIST; 402544871b1bSChris Mason if (ret < 0) 4026143bede5SJeff Mahoney return ret; 402744871b1bSChris Mason 402844871b1bSChris Mason slot = path->slots[0]; 402944871b1bSChris Mason BUG_ON(slot < 0); 403044871b1bSChris Mason 4031b7ef5f3aSFilipe Manana setup_items_for_insert(root, path, batch); 4032143bede5SJeff Mahoney return 0; 403362e2749eSChris Mason } 403462e2749eSChris Mason 403562e2749eSChris Mason /* 403662e2749eSChris Mason * Given a key and some data, insert an item into the tree. 403762e2749eSChris Mason * This does all the path init required, making room in the tree if needed. 403862e2749eSChris Mason */ 4039310712b2SOmar Sandoval int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, 4040310712b2SOmar Sandoval const struct btrfs_key *cpu_key, void *data, 4041310712b2SOmar Sandoval u32 data_size) 404262e2749eSChris Mason { 404362e2749eSChris Mason int ret = 0; 40442c90e5d6SChris Mason struct btrfs_path *path; 40455f39d397SChris Mason struct extent_buffer *leaf; 40465f39d397SChris Mason unsigned long ptr; 404762e2749eSChris Mason 40482c90e5d6SChris Mason path = btrfs_alloc_path(); 4049db5b493aSTsutomu Itoh if (!path) 4050db5b493aSTsutomu Itoh return -ENOMEM; 40512c90e5d6SChris Mason ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); 405262e2749eSChris Mason if (!ret) { 40535f39d397SChris Mason leaf = path->nodes[0]; 40545f39d397SChris Mason ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); 40555f39d397SChris Mason write_extent_buffer(leaf, data, ptr, data_size); 40565f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 405762e2749eSChris Mason } 40582c90e5d6SChris Mason btrfs_free_path(path); 4059aa5d6bedSChris Mason return ret; 4060be0e5c09SChris Mason } 4061be0e5c09SChris Mason 406274123bd7SChris Mason /* 4063f0641656SFilipe Manana * This function duplicates an item, giving 'new_key' to the new item. 4064f0641656SFilipe Manana * It guarantees both items live in the same tree leaf and the new item is 4065f0641656SFilipe Manana * contiguous with the original item. 4066f0641656SFilipe Manana * 4067f0641656SFilipe Manana * This allows us to split a file extent in place, keeping a lock on the leaf 4068f0641656SFilipe Manana * the entire time. 4069f0641656SFilipe Manana */ 4070f0641656SFilipe Manana int btrfs_duplicate_item(struct btrfs_trans_handle *trans, 4071f0641656SFilipe Manana struct btrfs_root *root, 4072f0641656SFilipe Manana struct btrfs_path *path, 4073f0641656SFilipe Manana const struct btrfs_key *new_key) 4074f0641656SFilipe Manana { 4075f0641656SFilipe Manana struct extent_buffer *leaf; 4076f0641656SFilipe Manana int ret; 4077f0641656SFilipe Manana u32 item_size; 4078f0641656SFilipe Manana 4079f0641656SFilipe Manana leaf = path->nodes[0]; 40803212fa14SJosef Bacik item_size = btrfs_item_size(leaf, path->slots[0]); 4081f0641656SFilipe Manana ret = setup_leaf_for_split(trans, root, path, 4082f0641656SFilipe Manana item_size + sizeof(struct btrfs_item)); 4083f0641656SFilipe Manana if (ret) 4084f0641656SFilipe Manana return ret; 4085f0641656SFilipe Manana 4086f0641656SFilipe Manana path->slots[0]++; 4087f0641656SFilipe Manana btrfs_setup_item_for_insert(root, path, new_key, item_size); 4088f0641656SFilipe Manana leaf = path->nodes[0]; 4089f0641656SFilipe Manana memcpy_extent_buffer(leaf, 4090f0641656SFilipe Manana btrfs_item_ptr_offset(leaf, path->slots[0]), 4091f0641656SFilipe Manana btrfs_item_ptr_offset(leaf, path->slots[0] - 1), 4092f0641656SFilipe Manana item_size); 4093f0641656SFilipe Manana return 0; 4094f0641656SFilipe Manana } 4095f0641656SFilipe Manana 4096f0641656SFilipe Manana /* 40975de08d7dSChris Mason * delete the pointer from a given node. 409874123bd7SChris Mason * 4099d352ac68SChris Mason * the tree should have been previously balanced so the deletion does not 4100d352ac68SChris Mason * empty a node. 410174123bd7SChris Mason */ 4102afe5fea7STsutomu Itoh static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, 4103afe5fea7STsutomu Itoh int level, int slot) 4104be0e5c09SChris Mason { 41055f39d397SChris Mason struct extent_buffer *parent = path->nodes[level]; 41067518a238SChris Mason u32 nritems; 4107f3ea38daSJan Schmidt int ret; 4108be0e5c09SChris Mason 41095f39d397SChris Mason nritems = btrfs_header_nritems(parent); 4110be0e5c09SChris Mason if (slot != nritems - 1) { 4111bf1d3425SDavid Sterba if (level) { 4112f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_move(parent, slot, 4113f3a84ccdSFilipe Manana slot + 1, nritems - slot - 1); 4114bf1d3425SDavid Sterba BUG_ON(ret < 0); 4115bf1d3425SDavid Sterba } 41165f39d397SChris Mason memmove_extent_buffer(parent, 41175f39d397SChris Mason btrfs_node_key_ptr_offset(slot), 41185f39d397SChris Mason btrfs_node_key_ptr_offset(slot + 1), 4119d6025579SChris Mason sizeof(struct btrfs_key_ptr) * 4120d6025579SChris Mason (nritems - slot - 1)); 412157ba86c0SChris Mason } else if (level) { 4122f3a84ccdSFilipe Manana ret = btrfs_tree_mod_log_insert_key(parent, slot, 4123f3a84ccdSFilipe Manana BTRFS_MOD_LOG_KEY_REMOVE, GFP_NOFS); 412457ba86c0SChris Mason BUG_ON(ret < 0); 4125be0e5c09SChris Mason } 4126f3ea38daSJan Schmidt 41277518a238SChris Mason nritems--; 41285f39d397SChris Mason btrfs_set_header_nritems(parent, nritems); 41297518a238SChris Mason if (nritems == 0 && parent == root->node) { 41305f39d397SChris Mason BUG_ON(btrfs_header_level(root->node) != 1); 4131eb60ceacSChris Mason /* just turn the root into a leaf and break */ 41325f39d397SChris Mason btrfs_set_header_level(root->node, 0); 4133bb803951SChris Mason } else if (slot == 0) { 41345f39d397SChris Mason struct btrfs_disk_key disk_key; 41355f39d397SChris Mason 41365f39d397SChris Mason btrfs_node_key(parent, &disk_key, 0); 4137b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, level + 1); 4138be0e5c09SChris Mason } 4139d6025579SChris Mason btrfs_mark_buffer_dirty(parent); 4140be0e5c09SChris Mason } 4141be0e5c09SChris Mason 414274123bd7SChris Mason /* 4143323ac95bSChris Mason * a helper function to delete the leaf pointed to by path->slots[1] and 41445d4f98a2SYan Zheng * path->nodes[1]. 4145323ac95bSChris Mason * 4146323ac95bSChris Mason * This deletes the pointer in path->nodes[1] and frees the leaf 4147323ac95bSChris Mason * block extent. zero is returned if it all worked out, < 0 otherwise. 4148323ac95bSChris Mason * 4149323ac95bSChris Mason * The path must have already been setup for deleting the leaf, including 4150323ac95bSChris Mason * all the proper balancing. path->nodes[1] must be locked. 4151323ac95bSChris Mason */ 4152143bede5SJeff Mahoney static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, 4153323ac95bSChris Mason struct btrfs_root *root, 41545d4f98a2SYan Zheng struct btrfs_path *path, 41555d4f98a2SYan Zheng struct extent_buffer *leaf) 4156323ac95bSChris Mason { 41575d4f98a2SYan Zheng WARN_ON(btrfs_header_generation(leaf) != trans->transid); 4158afe5fea7STsutomu Itoh del_ptr(root, path, 1, path->slots[1]); 4159323ac95bSChris Mason 41604d081c41SChris Mason /* 41614d081c41SChris Mason * btrfs_free_extent is expensive, we want to make sure we 41624d081c41SChris Mason * aren't holding any locks when we call it 41634d081c41SChris Mason */ 41644d081c41SChris Mason btrfs_unlock_up_safe(path, 0); 41654d081c41SChris Mason 4166f0486c68SYan, Zheng root_sub_used(root, leaf->len); 4167f0486c68SYan, Zheng 416867439dadSDavid Sterba atomic_inc(&leaf->refs); 41697a163608SFilipe Manana btrfs_free_tree_block(trans, btrfs_root_id(root), leaf, 0, 1); 41703083ee2eSJosef Bacik free_extent_buffer_stale(leaf); 4171323ac95bSChris Mason } 4172323ac95bSChris Mason /* 417374123bd7SChris Mason * delete the item at the leaf level in path. If that empties 417474123bd7SChris Mason * the leaf, remove it from the tree 417574123bd7SChris Mason */ 417685e21bacSChris Mason int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, 417785e21bacSChris Mason struct btrfs_path *path, int slot, int nr) 4178be0e5c09SChris Mason { 41790b246afaSJeff Mahoney struct btrfs_fs_info *fs_info = root->fs_info; 41805f39d397SChris Mason struct extent_buffer *leaf; 4181aa5d6bedSChris Mason int ret = 0; 4182aa5d6bedSChris Mason int wret; 41837518a238SChris Mason u32 nritems; 4184be0e5c09SChris Mason 41855f39d397SChris Mason leaf = path->nodes[0]; 41865f39d397SChris Mason nritems = btrfs_header_nritems(leaf); 4187be0e5c09SChris Mason 418885e21bacSChris Mason if (slot + nr != nritems) { 41890cae23b6SFilipe Manana const u32 last_off = btrfs_item_offset(leaf, slot + nr - 1); 41900cae23b6SFilipe Manana const int data_end = leaf_data_end(leaf); 4191c82f823cSDavid Sterba struct btrfs_map_token token; 41920cae23b6SFilipe Manana u32 dsize = 0; 41930cae23b6SFilipe Manana int i; 41940cae23b6SFilipe Manana 41950cae23b6SFilipe Manana for (i = 0; i < nr; i++) 41960cae23b6SFilipe Manana dsize += btrfs_item_size(leaf, slot + i); 41975f39d397SChris Mason 41983d9ec8c4SNikolay Borisov memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + 4199d6025579SChris Mason data_end + dsize, 42003d9ec8c4SNikolay Borisov BTRFS_LEAF_DATA_OFFSET + data_end, 420185e21bacSChris Mason last_off - data_end); 42025f39d397SChris Mason 4203c82f823cSDavid Sterba btrfs_init_map_token(&token, leaf); 420485e21bacSChris Mason for (i = slot + nr; i < nritems; i++) { 42055f39d397SChris Mason u32 ioff; 4206db94535dSChris Mason 42073212fa14SJosef Bacik ioff = btrfs_token_item_offset(&token, i); 42083212fa14SJosef Bacik btrfs_set_token_item_offset(&token, i, ioff + dsize); 42090783fcfcSChris Mason } 4210db94535dSChris Mason 42115f39d397SChris Mason memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), 421285e21bacSChris Mason btrfs_item_nr_offset(slot + nr), 42130783fcfcSChris Mason sizeof(struct btrfs_item) * 421485e21bacSChris Mason (nritems - slot - nr)); 4215be0e5c09SChris Mason } 421685e21bacSChris Mason btrfs_set_header_nritems(leaf, nritems - nr); 421785e21bacSChris Mason nritems -= nr; 42185f39d397SChris Mason 421974123bd7SChris Mason /* delete the leaf if we've emptied it */ 42207518a238SChris Mason if (nritems == 0) { 42215f39d397SChris Mason if (leaf == root->node) { 42225f39d397SChris Mason btrfs_set_header_level(leaf, 0); 42239a8dd150SChris Mason } else { 42246a884d7dSDavid Sterba btrfs_clean_tree_block(leaf); 4225143bede5SJeff Mahoney btrfs_del_leaf(trans, root, path, leaf); 42269a8dd150SChris Mason } 4227be0e5c09SChris Mason } else { 42287518a238SChris Mason int used = leaf_space_used(leaf, 0, nritems); 4229aa5d6bedSChris Mason if (slot == 0) { 42305f39d397SChris Mason struct btrfs_disk_key disk_key; 42315f39d397SChris Mason 42325f39d397SChris Mason btrfs_item_key(leaf, &disk_key, 0); 4233b167fa91SNikolay Borisov fixup_low_keys(path, &disk_key, 1); 4234aa5d6bedSChris Mason } 4235aa5d6bedSChris Mason 42367c4063d1SFilipe Manana /* 42377c4063d1SFilipe Manana * Try to delete the leaf if it is mostly empty. We do this by 42387c4063d1SFilipe Manana * trying to move all its items into its left and right neighbours. 42397c4063d1SFilipe Manana * If we can't move all the items, then we don't delete it - it's 42407c4063d1SFilipe Manana * not ideal, but future insertions might fill the leaf with more 42417c4063d1SFilipe Manana * items, or items from other leaves might be moved later into our 42427c4063d1SFilipe Manana * leaf due to deletions on those leaves. 42437c4063d1SFilipe Manana */ 42440b246afaSJeff Mahoney if (used < BTRFS_LEAF_DATA_SIZE(fs_info) / 3) { 42457c4063d1SFilipe Manana u32 min_push_space; 42467c4063d1SFilipe Manana 4247be0e5c09SChris Mason /* push_leaf_left fixes the path. 4248be0e5c09SChris Mason * make sure the path still points to our leaf 4249be0e5c09SChris Mason * for possible call to del_ptr below 4250be0e5c09SChris Mason */ 42514920c9acSChris Mason slot = path->slots[1]; 425267439dadSDavid Sterba atomic_inc(&leaf->refs); 42537c4063d1SFilipe Manana /* 42547c4063d1SFilipe Manana * We want to be able to at least push one item to the 42557c4063d1SFilipe Manana * left neighbour leaf, and that's the first item. 42567c4063d1SFilipe Manana */ 42577c4063d1SFilipe Manana min_push_space = sizeof(struct btrfs_item) + 42587c4063d1SFilipe Manana btrfs_item_size(leaf, 0); 42597c4063d1SFilipe Manana wret = push_leaf_left(trans, root, path, 0, 42607c4063d1SFilipe Manana min_push_space, 1, (u32)-1); 426154aa1f4dSChris Mason if (wret < 0 && wret != -ENOSPC) 4262aa5d6bedSChris Mason ret = wret; 42635f39d397SChris Mason 42645f39d397SChris Mason if (path->nodes[0] == leaf && 42655f39d397SChris Mason btrfs_header_nritems(leaf)) { 42667c4063d1SFilipe Manana /* 42677c4063d1SFilipe Manana * If we were not able to push all items from our 42687c4063d1SFilipe Manana * leaf to its left neighbour, then attempt to 42697c4063d1SFilipe Manana * either push all the remaining items to the 42707c4063d1SFilipe Manana * right neighbour or none. There's no advantage 42717c4063d1SFilipe Manana * in pushing only some items, instead of all, as 42727c4063d1SFilipe Manana * it's pointless to end up with a leaf having 42737c4063d1SFilipe Manana * too few items while the neighbours can be full 42747c4063d1SFilipe Manana * or nearly full. 42757c4063d1SFilipe Manana */ 42767c4063d1SFilipe Manana nritems = btrfs_header_nritems(leaf); 42777c4063d1SFilipe Manana min_push_space = leaf_space_used(leaf, 0, nritems); 42787c4063d1SFilipe Manana wret = push_leaf_right(trans, root, path, 0, 42797c4063d1SFilipe Manana min_push_space, 1, 0); 428054aa1f4dSChris Mason if (wret < 0 && wret != -ENOSPC) 4281aa5d6bedSChris Mason ret = wret; 4282aa5d6bedSChris Mason } 42835f39d397SChris Mason 42845f39d397SChris Mason if (btrfs_header_nritems(leaf) == 0) { 4285323ac95bSChris Mason path->slots[1] = slot; 4286143bede5SJeff Mahoney btrfs_del_leaf(trans, root, path, leaf); 42875f39d397SChris Mason free_extent_buffer(leaf); 4288143bede5SJeff Mahoney ret = 0; 42895de08d7dSChris Mason } else { 4290925baeddSChris Mason /* if we're still in the path, make sure 4291925baeddSChris Mason * we're dirty. Otherwise, one of the 4292925baeddSChris Mason * push_leaf functions must have already 4293925baeddSChris Mason * dirtied this buffer 4294925baeddSChris Mason */ 4295925baeddSChris Mason if (path->nodes[0] == leaf) 42965f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 42975f39d397SChris Mason free_extent_buffer(leaf); 4298be0e5c09SChris Mason } 4299d5719762SChris Mason } else { 43005f39d397SChris Mason btrfs_mark_buffer_dirty(leaf); 4301be0e5c09SChris Mason } 43029a8dd150SChris Mason } 4303aa5d6bedSChris Mason return ret; 43049a8dd150SChris Mason } 43059a8dd150SChris Mason 430697571fd0SChris Mason /* 4307925baeddSChris Mason * search the tree again to find a leaf with lesser keys 43087bb86316SChris Mason * returns 0 if it found something or 1 if there are no lesser leaves. 43097bb86316SChris Mason * returns < 0 on io errors. 4310d352ac68SChris Mason * 4311d352ac68SChris Mason * This may release the path, and so you may lose any locks held at the 4312d352ac68SChris Mason * time you call it. 43137bb86316SChris Mason */ 431416e7549fSJosef Bacik int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) 43157bb86316SChris Mason { 4316925baeddSChris Mason struct btrfs_key key; 4317925baeddSChris Mason struct btrfs_disk_key found_key; 4318925baeddSChris Mason int ret; 43197bb86316SChris Mason 4320925baeddSChris Mason btrfs_item_key_to_cpu(path->nodes[0], &key, 0); 4321925baeddSChris Mason 4322e8b0d724SFilipe David Borba Manana if (key.offset > 0) { 4323925baeddSChris Mason key.offset--; 4324e8b0d724SFilipe David Borba Manana } else if (key.type > 0) { 4325925baeddSChris Mason key.type--; 4326e8b0d724SFilipe David Borba Manana key.offset = (u64)-1; 4327e8b0d724SFilipe David Borba Manana } else if (key.objectid > 0) { 4328925baeddSChris Mason key.objectid--; 4329e8b0d724SFilipe David Borba Manana key.type = (u8)-1; 4330e8b0d724SFilipe David Borba Manana key.offset = (u64)-1; 4331e8b0d724SFilipe David Borba Manana } else { 43327bb86316SChris Mason return 1; 4333e8b0d724SFilipe David Borba Manana } 43347bb86316SChris Mason 4335b3b4aa74SDavid Sterba btrfs_release_path(path); 4336925baeddSChris Mason ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 4337925baeddSChris Mason if (ret < 0) 4338925baeddSChris Mason return ret; 4339925baeddSChris Mason btrfs_item_key(path->nodes[0], &found_key, 0); 4340925baeddSChris Mason ret = comp_keys(&found_key, &key); 4341337c6f68SFilipe Manana /* 4342337c6f68SFilipe Manana * We might have had an item with the previous key in the tree right 4343337c6f68SFilipe Manana * before we released our path. And after we released our path, that 4344337c6f68SFilipe Manana * item might have been pushed to the first slot (0) of the leaf we 4345337c6f68SFilipe Manana * were holding due to a tree balance. Alternatively, an item with the 4346337c6f68SFilipe Manana * previous key can exist as the only element of a leaf (big fat item). 4347337c6f68SFilipe Manana * Therefore account for these 2 cases, so that our callers (like 4348337c6f68SFilipe Manana * btrfs_previous_item) don't miss an existing item with a key matching 4349337c6f68SFilipe Manana * the previous key we computed above. 4350337c6f68SFilipe Manana */ 4351337c6f68SFilipe Manana if (ret <= 0) 43527bb86316SChris Mason return 0; 4353925baeddSChris Mason return 1; 43547bb86316SChris Mason } 43557bb86316SChris Mason 43563f157a2fSChris Mason /* 43573f157a2fSChris Mason * A helper function to walk down the tree starting at min_key, and looking 4358de78b51aSEric Sandeen * for nodes or leaves that are have a minimum transaction id. 4359de78b51aSEric Sandeen * This is used by the btree defrag code, and tree logging 43603f157a2fSChris Mason * 43613f157a2fSChris Mason * This does not cow, but it does stuff the starting key it finds back 43623f157a2fSChris Mason * into min_key, so you can call btrfs_search_slot with cow=1 on the 43633f157a2fSChris Mason * key and get a writable path. 43643f157a2fSChris Mason * 43653f157a2fSChris Mason * This honors path->lowest_level to prevent descent past a given level 43663f157a2fSChris Mason * of the tree. 43673f157a2fSChris Mason * 4368d352ac68SChris Mason * min_trans indicates the oldest transaction that you are interested 4369d352ac68SChris Mason * in walking through. Any nodes or leaves older than min_trans are 4370d352ac68SChris Mason * skipped over (without reading them). 4371d352ac68SChris Mason * 43723f157a2fSChris Mason * returns zero if something useful was found, < 0 on error and 1 if there 43733f157a2fSChris Mason * was nothing in the tree that matched the search criteria. 43743f157a2fSChris Mason */ 43753f157a2fSChris Mason int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, 4376de78b51aSEric Sandeen struct btrfs_path *path, 43773f157a2fSChris Mason u64 min_trans) 43783f157a2fSChris Mason { 43793f157a2fSChris Mason struct extent_buffer *cur; 43803f157a2fSChris Mason struct btrfs_key found_key; 43813f157a2fSChris Mason int slot; 43829652480bSYan int sret; 43833f157a2fSChris Mason u32 nritems; 43843f157a2fSChris Mason int level; 43853f157a2fSChris Mason int ret = 1; 4386f98de9b9SFilipe Manana int keep_locks = path->keep_locks; 43873f157a2fSChris Mason 4388f98de9b9SFilipe Manana path->keep_locks = 1; 43893f157a2fSChris Mason again: 4390bd681513SChris Mason cur = btrfs_read_lock_root_node(root); 43913f157a2fSChris Mason level = btrfs_header_level(cur); 4392e02119d5SChris Mason WARN_ON(path->nodes[level]); 43933f157a2fSChris Mason path->nodes[level] = cur; 4394bd681513SChris Mason path->locks[level] = BTRFS_READ_LOCK; 43953f157a2fSChris Mason 43963f157a2fSChris Mason if (btrfs_header_generation(cur) < min_trans) { 43973f157a2fSChris Mason ret = 1; 43983f157a2fSChris Mason goto out; 43993f157a2fSChris Mason } 44003f157a2fSChris Mason while (1) { 44013f157a2fSChris Mason nritems = btrfs_header_nritems(cur); 44023f157a2fSChris Mason level = btrfs_header_level(cur); 4403e3b83361SQu Wenruo sret = btrfs_bin_search(cur, min_key, &slot); 4404cbca7d59SFilipe Manana if (sret < 0) { 4405cbca7d59SFilipe Manana ret = sret; 4406cbca7d59SFilipe Manana goto out; 4407cbca7d59SFilipe Manana } 44083f157a2fSChris Mason 4409323ac95bSChris Mason /* at the lowest level, we're done, setup the path and exit */ 4410323ac95bSChris Mason if (level == path->lowest_level) { 4411e02119d5SChris Mason if (slot >= nritems) 4412e02119d5SChris Mason goto find_next_key; 44133f157a2fSChris Mason ret = 0; 44143f157a2fSChris Mason path->slots[level] = slot; 44153f157a2fSChris Mason btrfs_item_key_to_cpu(cur, &found_key, slot); 44163f157a2fSChris Mason goto out; 44173f157a2fSChris Mason } 44189652480bSYan if (sret && slot > 0) 44199652480bSYan slot--; 44203f157a2fSChris Mason /* 4421de78b51aSEric Sandeen * check this node pointer against the min_trans parameters. 4422260db43cSRandy Dunlap * If it is too old, skip to the next one. 44233f157a2fSChris Mason */ 44243f157a2fSChris Mason while (slot < nritems) { 44253f157a2fSChris Mason u64 gen; 4426e02119d5SChris Mason 44273f157a2fSChris Mason gen = btrfs_node_ptr_generation(cur, slot); 44283f157a2fSChris Mason if (gen < min_trans) { 44293f157a2fSChris Mason slot++; 44303f157a2fSChris Mason continue; 44313f157a2fSChris Mason } 44323f157a2fSChris Mason break; 44333f157a2fSChris Mason } 4434e02119d5SChris Mason find_next_key: 44353f157a2fSChris Mason /* 44363f157a2fSChris Mason * we didn't find a candidate key in this node, walk forward 44373f157a2fSChris Mason * and find another one 44383f157a2fSChris Mason */ 44393f157a2fSChris Mason if (slot >= nritems) { 4440e02119d5SChris Mason path->slots[level] = slot; 4441e02119d5SChris Mason sret = btrfs_find_next_key(root, path, min_key, level, 4442de78b51aSEric Sandeen min_trans); 4443e02119d5SChris Mason if (sret == 0) { 4444b3b4aa74SDavid Sterba btrfs_release_path(path); 44453f157a2fSChris Mason goto again; 44463f157a2fSChris Mason } else { 44473f157a2fSChris Mason goto out; 44483f157a2fSChris Mason } 44493f157a2fSChris Mason } 44503f157a2fSChris Mason /* save our key for returning back */ 44513f157a2fSChris Mason btrfs_node_key_to_cpu(cur, &found_key, slot); 44523f157a2fSChris Mason path->slots[level] = slot; 44533f157a2fSChris Mason if (level == path->lowest_level) { 44543f157a2fSChris Mason ret = 0; 44553f157a2fSChris Mason goto out; 44563f157a2fSChris Mason } 44574b231ae4SDavid Sterba cur = btrfs_read_node_slot(cur, slot); 4458fb770ae4SLiu Bo if (IS_ERR(cur)) { 4459fb770ae4SLiu Bo ret = PTR_ERR(cur); 4460fb770ae4SLiu Bo goto out; 4461fb770ae4SLiu Bo } 44623f157a2fSChris Mason 4463bd681513SChris Mason btrfs_tree_read_lock(cur); 4464b4ce94deSChris Mason 4465bd681513SChris Mason path->locks[level - 1] = BTRFS_READ_LOCK; 44663f157a2fSChris Mason path->nodes[level - 1] = cur; 4467f7c79f30SChris Mason unlock_up(path, level, 1, 0, NULL); 44683f157a2fSChris Mason } 44693f157a2fSChris Mason out: 4470f98de9b9SFilipe Manana path->keep_locks = keep_locks; 4471f98de9b9SFilipe Manana if (ret == 0) { 4472f98de9b9SFilipe Manana btrfs_unlock_up_safe(path, path->lowest_level + 1); 4473f98de9b9SFilipe Manana memcpy(min_key, &found_key, sizeof(found_key)); 4474f98de9b9SFilipe Manana } 44753f157a2fSChris Mason return ret; 44763f157a2fSChris Mason } 44773f157a2fSChris Mason 44783f157a2fSChris Mason /* 44793f157a2fSChris Mason * this is similar to btrfs_next_leaf, but does not try to preserve 44803f157a2fSChris Mason * and fixup the path. It looks for and returns the next key in the 4481de78b51aSEric Sandeen * tree based on the current path and the min_trans parameters. 44823f157a2fSChris Mason * 44833f157a2fSChris Mason * 0 is returned if another key is found, < 0 if there are any errors 44843f157a2fSChris Mason * and 1 is returned if there are no higher keys in the tree 44853f157a2fSChris Mason * 44863f157a2fSChris Mason * path->keep_locks should be set to 1 on the search made before 44873f157a2fSChris Mason * calling this function. 44883f157a2fSChris Mason */ 4489e7a84565SChris Mason int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, 4490de78b51aSEric Sandeen struct btrfs_key *key, int level, u64 min_trans) 4491e7a84565SChris Mason { 4492e7a84565SChris Mason int slot; 4493e7a84565SChris Mason struct extent_buffer *c; 4494e7a84565SChris Mason 44956a9fb468SJosef Bacik WARN_ON(!path->keep_locks && !path->skip_locking); 4496e7a84565SChris Mason while (level < BTRFS_MAX_LEVEL) { 4497e7a84565SChris Mason if (!path->nodes[level]) 4498e7a84565SChris Mason return 1; 4499e7a84565SChris Mason 4500e7a84565SChris Mason slot = path->slots[level] + 1; 4501e7a84565SChris Mason c = path->nodes[level]; 45023f157a2fSChris Mason next: 4503e7a84565SChris Mason if (slot >= btrfs_header_nritems(c)) { 450433c66f43SYan Zheng int ret; 450533c66f43SYan Zheng int orig_lowest; 450633c66f43SYan Zheng struct btrfs_key cur_key; 450733c66f43SYan Zheng if (level + 1 >= BTRFS_MAX_LEVEL || 450833c66f43SYan Zheng !path->nodes[level + 1]) 4509e7a84565SChris Mason return 1; 451033c66f43SYan Zheng 45116a9fb468SJosef Bacik if (path->locks[level + 1] || path->skip_locking) { 451233c66f43SYan Zheng level++; 4513e7a84565SChris Mason continue; 4514e7a84565SChris Mason } 451533c66f43SYan Zheng 451633c66f43SYan Zheng slot = btrfs_header_nritems(c) - 1; 451733c66f43SYan Zheng if (level == 0) 451833c66f43SYan Zheng btrfs_item_key_to_cpu(c, &cur_key, slot); 451933c66f43SYan Zheng else 452033c66f43SYan Zheng btrfs_node_key_to_cpu(c, &cur_key, slot); 452133c66f43SYan Zheng 452233c66f43SYan Zheng orig_lowest = path->lowest_level; 4523b3b4aa74SDavid Sterba btrfs_release_path(path); 452433c66f43SYan Zheng path->lowest_level = level; 452533c66f43SYan Zheng ret = btrfs_search_slot(NULL, root, &cur_key, path, 452633c66f43SYan Zheng 0, 0); 452733c66f43SYan Zheng path->lowest_level = orig_lowest; 452833c66f43SYan Zheng if (ret < 0) 452933c66f43SYan Zheng return ret; 453033c66f43SYan Zheng 453133c66f43SYan Zheng c = path->nodes[level]; 453233c66f43SYan Zheng slot = path->slots[level]; 453333c66f43SYan Zheng if (ret == 0) 453433c66f43SYan Zheng slot++; 453533c66f43SYan Zheng goto next; 453633c66f43SYan Zheng } 453733c66f43SYan Zheng 4538e7a84565SChris Mason if (level == 0) 4539e7a84565SChris Mason btrfs_item_key_to_cpu(c, key, slot); 45403f157a2fSChris Mason else { 45413f157a2fSChris Mason u64 gen = btrfs_node_ptr_generation(c, slot); 45423f157a2fSChris Mason 45433f157a2fSChris Mason if (gen < min_trans) { 45443f157a2fSChris Mason slot++; 45453f157a2fSChris Mason goto next; 45463f157a2fSChris Mason } 4547e7a84565SChris Mason btrfs_node_key_to_cpu(c, key, slot); 45483f157a2fSChris Mason } 4549e7a84565SChris Mason return 0; 4550e7a84565SChris Mason } 4551e7a84565SChris Mason return 1; 4552e7a84565SChris Mason } 4553e7a84565SChris Mason 45543d7806ecSJan Schmidt int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, 45553d7806ecSJan Schmidt u64 time_seq) 45563d7806ecSJan Schmidt { 4557d97e63b6SChris Mason int slot; 45588e73f275SChris Mason int level; 45595f39d397SChris Mason struct extent_buffer *c; 45608e73f275SChris Mason struct extent_buffer *next; 4561d96b3424SFilipe Manana struct btrfs_fs_info *fs_info = root->fs_info; 4562925baeddSChris Mason struct btrfs_key key; 4563d96b3424SFilipe Manana bool need_commit_sem = false; 4564925baeddSChris Mason u32 nritems; 4565925baeddSChris Mason int ret; 45660e46318dSJosef Bacik int i; 4567925baeddSChris Mason 4568925baeddSChris Mason nritems = btrfs_header_nritems(path->nodes[0]); 4569d397712bSChris Mason if (nritems == 0) 4570925baeddSChris Mason return 1; 4571925baeddSChris Mason 45728e73f275SChris Mason btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); 45738e73f275SChris Mason again: 45748e73f275SChris Mason level = 1; 45758e73f275SChris Mason next = NULL; 4576b3b4aa74SDavid Sterba btrfs_release_path(path); 45778e73f275SChris Mason 4578a2135011SChris Mason path->keep_locks = 1; 45798e73f275SChris Mason 4580d96b3424SFilipe Manana if (time_seq) { 45813d7806ecSJan Schmidt ret = btrfs_search_old_slot(root, &key, path, time_seq); 4582d96b3424SFilipe Manana } else { 4583d96b3424SFilipe Manana if (path->need_commit_sem) { 4584d96b3424SFilipe Manana path->need_commit_sem = 0; 4585d96b3424SFilipe Manana need_commit_sem = true; 4586d96b3424SFilipe Manana down_read(&fs_info->commit_root_sem); 4587d96b3424SFilipe Manana } 4588925baeddSChris Mason ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 4589d96b3424SFilipe Manana } 4590925baeddSChris Mason path->keep_locks = 0; 4591925baeddSChris Mason 4592925baeddSChris Mason if (ret < 0) 4593d96b3424SFilipe Manana goto done; 4594925baeddSChris Mason 4595a2135011SChris Mason nritems = btrfs_header_nritems(path->nodes[0]); 4596168fd7d2SChris Mason /* 4597168fd7d2SChris Mason * by releasing the path above we dropped all our locks. A balance 4598168fd7d2SChris Mason * could have added more items next to the key that used to be 4599168fd7d2SChris Mason * at the very end of the block. So, check again here and 4600168fd7d2SChris Mason * advance the path if there are now more items available. 4601168fd7d2SChris Mason */ 4602a2135011SChris Mason if (nritems > 0 && path->slots[0] < nritems - 1) { 4603e457afecSYan Zheng if (ret == 0) 4604168fd7d2SChris Mason path->slots[0]++; 46058e73f275SChris Mason ret = 0; 4606925baeddSChris Mason goto done; 4607925baeddSChris Mason } 46080b43e04fSLiu Bo /* 46090b43e04fSLiu Bo * So the above check misses one case: 46100b43e04fSLiu Bo * - after releasing the path above, someone has removed the item that 46110b43e04fSLiu Bo * used to be at the very end of the block, and balance between leafs 46120b43e04fSLiu Bo * gets another one with bigger key.offset to replace it. 46130b43e04fSLiu Bo * 46140b43e04fSLiu Bo * This one should be returned as well, or we can get leaf corruption 46150b43e04fSLiu Bo * later(esp. in __btrfs_drop_extents()). 46160b43e04fSLiu Bo * 46170b43e04fSLiu Bo * And a bit more explanation about this check, 46180b43e04fSLiu Bo * with ret > 0, the key isn't found, the path points to the slot 46190b43e04fSLiu Bo * where it should be inserted, so the path->slots[0] item must be the 46200b43e04fSLiu Bo * bigger one. 46210b43e04fSLiu Bo */ 46220b43e04fSLiu Bo if (nritems > 0 && ret > 0 && path->slots[0] == nritems - 1) { 46230b43e04fSLiu Bo ret = 0; 46240b43e04fSLiu Bo goto done; 46250b43e04fSLiu Bo } 4626d97e63b6SChris Mason 4627234b63a0SChris Mason while (level < BTRFS_MAX_LEVEL) { 46288e73f275SChris Mason if (!path->nodes[level]) { 46298e73f275SChris Mason ret = 1; 46308e73f275SChris Mason goto done; 46318e73f275SChris Mason } 46325f39d397SChris Mason 4633d97e63b6SChris Mason slot = path->slots[level] + 1; 4634d97e63b6SChris Mason c = path->nodes[level]; 46355f39d397SChris Mason if (slot >= btrfs_header_nritems(c)) { 4636d97e63b6SChris Mason level++; 46378e73f275SChris Mason if (level == BTRFS_MAX_LEVEL) { 46388e73f275SChris Mason ret = 1; 46398e73f275SChris Mason goto done; 46408e73f275SChris Mason } 4641d97e63b6SChris Mason continue; 4642d97e63b6SChris Mason } 46435f39d397SChris Mason 46440e46318dSJosef Bacik 46450e46318dSJosef Bacik /* 46460e46318dSJosef Bacik * Our current level is where we're going to start from, and to 46470e46318dSJosef Bacik * make sure lockdep doesn't complain we need to drop our locks 46480e46318dSJosef Bacik * and nodes from 0 to our current level. 46490e46318dSJosef Bacik */ 46500e46318dSJosef Bacik for (i = 0; i < level; i++) { 46510e46318dSJosef Bacik if (path->locks[level]) { 46520e46318dSJosef Bacik btrfs_tree_read_unlock(path->nodes[i]); 46530e46318dSJosef Bacik path->locks[i] = 0; 46540e46318dSJosef Bacik } 46550e46318dSJosef Bacik free_extent_buffer(path->nodes[i]); 46560e46318dSJosef Bacik path->nodes[i] = NULL; 4657925baeddSChris Mason } 46585f39d397SChris Mason 46598e73f275SChris Mason next = c; 4660d07b8528SLiu Bo ret = read_block_for_search(root, path, &next, level, 4661cda79c54SDavid Sterba slot, &key); 46628e73f275SChris Mason if (ret == -EAGAIN) 46638e73f275SChris Mason goto again; 46645f39d397SChris Mason 466576a05b35SChris Mason if (ret < 0) { 4666b3b4aa74SDavid Sterba btrfs_release_path(path); 466776a05b35SChris Mason goto done; 466876a05b35SChris Mason } 466976a05b35SChris Mason 46705cd57b2cSChris Mason if (!path->skip_locking) { 4671bd681513SChris Mason ret = btrfs_try_tree_read_lock(next); 4672d42244a0SJan Schmidt if (!ret && time_seq) { 4673d42244a0SJan Schmidt /* 4674d42244a0SJan Schmidt * If we don't get the lock, we may be racing 4675d42244a0SJan Schmidt * with push_leaf_left, holding that lock while 4676d42244a0SJan Schmidt * itself waiting for the leaf we've currently 4677d42244a0SJan Schmidt * locked. To solve this situation, we give up 4678d42244a0SJan Schmidt * on our lock and cycle. 4679d42244a0SJan Schmidt */ 4680cf538830SJan Schmidt free_extent_buffer(next); 4681d42244a0SJan Schmidt btrfs_release_path(path); 4682d42244a0SJan Schmidt cond_resched(); 4683d42244a0SJan Schmidt goto again; 4684d42244a0SJan Schmidt } 46850e46318dSJosef Bacik if (!ret) 46860e46318dSJosef Bacik btrfs_tree_read_lock(next); 4687bd681513SChris Mason } 4688d97e63b6SChris Mason break; 4689d97e63b6SChris Mason } 4690d97e63b6SChris Mason path->slots[level] = slot; 4691d97e63b6SChris Mason while (1) { 4692d97e63b6SChris Mason level--; 4693d97e63b6SChris Mason path->nodes[level] = next; 4694d97e63b6SChris Mason path->slots[level] = 0; 4695a74a4b97SChris Mason if (!path->skip_locking) 4696ffeb03cfSJosef Bacik path->locks[level] = BTRFS_READ_LOCK; 4697d97e63b6SChris Mason if (!level) 4698d97e63b6SChris Mason break; 4699b4ce94deSChris Mason 4700d07b8528SLiu Bo ret = read_block_for_search(root, path, &next, level, 4701cda79c54SDavid Sterba 0, &key); 47028e73f275SChris Mason if (ret == -EAGAIN) 47038e73f275SChris Mason goto again; 47048e73f275SChris Mason 470576a05b35SChris Mason if (ret < 0) { 4706b3b4aa74SDavid Sterba btrfs_release_path(path); 470776a05b35SChris Mason goto done; 470876a05b35SChris Mason } 470976a05b35SChris Mason 4710ffeb03cfSJosef Bacik if (!path->skip_locking) 47110e46318dSJosef Bacik btrfs_tree_read_lock(next); 4712d97e63b6SChris Mason } 47138e73f275SChris Mason ret = 0; 4714925baeddSChris Mason done: 4715f7c79f30SChris Mason unlock_up(path, 0, 1, 0, NULL); 4716d96b3424SFilipe Manana if (need_commit_sem) { 4717d96b3424SFilipe Manana int ret2; 4718d96b3424SFilipe Manana 4719d96b3424SFilipe Manana path->need_commit_sem = 1; 4720d96b3424SFilipe Manana ret2 = finish_need_commit_sem_search(path); 4721d96b3424SFilipe Manana up_read(&fs_info->commit_root_sem); 4722d96b3424SFilipe Manana if (ret2) 4723d96b3424SFilipe Manana ret = ret2; 4724d96b3424SFilipe Manana } 47258e73f275SChris Mason 47268e73f275SChris Mason return ret; 4727d97e63b6SChris Mason } 47280b86a832SChris Mason 47293f157a2fSChris Mason /* 47303f157a2fSChris Mason * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps 47313f157a2fSChris Mason * searching until it gets past min_objectid or finds an item of 'type' 47323f157a2fSChris Mason * 47333f157a2fSChris Mason * returns 0 if something is found, 1 if nothing was found and < 0 on error 47343f157a2fSChris Mason */ 47350b86a832SChris Mason int btrfs_previous_item(struct btrfs_root *root, 47360b86a832SChris Mason struct btrfs_path *path, u64 min_objectid, 47370b86a832SChris Mason int type) 47380b86a832SChris Mason { 47390b86a832SChris Mason struct btrfs_key found_key; 47400b86a832SChris Mason struct extent_buffer *leaf; 4741e02119d5SChris Mason u32 nritems; 47420b86a832SChris Mason int ret; 47430b86a832SChris Mason 47440b86a832SChris Mason while (1) { 47450b86a832SChris Mason if (path->slots[0] == 0) { 47460b86a832SChris Mason ret = btrfs_prev_leaf(root, path); 47470b86a832SChris Mason if (ret != 0) 47480b86a832SChris Mason return ret; 47490b86a832SChris Mason } else { 47500b86a832SChris Mason path->slots[0]--; 47510b86a832SChris Mason } 47520b86a832SChris Mason leaf = path->nodes[0]; 4753e02119d5SChris Mason nritems = btrfs_header_nritems(leaf); 4754e02119d5SChris Mason if (nritems == 0) 4755e02119d5SChris Mason return 1; 4756e02119d5SChris Mason if (path->slots[0] == nritems) 4757e02119d5SChris Mason path->slots[0]--; 4758e02119d5SChris Mason 47590b86a832SChris Mason btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 4760e02119d5SChris Mason if (found_key.objectid < min_objectid) 4761e02119d5SChris Mason break; 47620a4eefbbSYan Zheng if (found_key.type == type) 47630a4eefbbSYan Zheng return 0; 4764e02119d5SChris Mason if (found_key.objectid == min_objectid && 4765e02119d5SChris Mason found_key.type < type) 4766e02119d5SChris Mason break; 47670b86a832SChris Mason } 47680b86a832SChris Mason return 1; 47690b86a832SChris Mason } 4770ade2e0b3SWang Shilong 4771ade2e0b3SWang Shilong /* 4772ade2e0b3SWang Shilong * search in extent tree to find a previous Metadata/Data extent item with 4773ade2e0b3SWang Shilong * min objecitd. 4774ade2e0b3SWang Shilong * 4775ade2e0b3SWang Shilong * returns 0 if something is found, 1 if nothing was found and < 0 on error 4776ade2e0b3SWang Shilong */ 4777ade2e0b3SWang Shilong int btrfs_previous_extent_item(struct btrfs_root *root, 4778ade2e0b3SWang Shilong struct btrfs_path *path, u64 min_objectid) 4779ade2e0b3SWang Shilong { 4780ade2e0b3SWang Shilong struct btrfs_key found_key; 4781ade2e0b3SWang Shilong struct extent_buffer *leaf; 4782ade2e0b3SWang Shilong u32 nritems; 4783ade2e0b3SWang Shilong int ret; 4784ade2e0b3SWang Shilong 4785ade2e0b3SWang Shilong while (1) { 4786ade2e0b3SWang Shilong if (path->slots[0] == 0) { 4787ade2e0b3SWang Shilong ret = btrfs_prev_leaf(root, path); 4788ade2e0b3SWang Shilong if (ret != 0) 4789ade2e0b3SWang Shilong return ret; 4790ade2e0b3SWang Shilong } else { 4791ade2e0b3SWang Shilong path->slots[0]--; 4792ade2e0b3SWang Shilong } 4793ade2e0b3SWang Shilong leaf = path->nodes[0]; 4794ade2e0b3SWang Shilong nritems = btrfs_header_nritems(leaf); 4795ade2e0b3SWang Shilong if (nritems == 0) 4796ade2e0b3SWang Shilong return 1; 4797ade2e0b3SWang Shilong if (path->slots[0] == nritems) 4798ade2e0b3SWang Shilong path->slots[0]--; 4799ade2e0b3SWang Shilong 4800ade2e0b3SWang Shilong btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 4801ade2e0b3SWang Shilong if (found_key.objectid < min_objectid) 4802ade2e0b3SWang Shilong break; 4803ade2e0b3SWang Shilong if (found_key.type == BTRFS_EXTENT_ITEM_KEY || 4804ade2e0b3SWang Shilong found_key.type == BTRFS_METADATA_ITEM_KEY) 4805ade2e0b3SWang Shilong return 0; 4806ade2e0b3SWang Shilong if (found_key.objectid == min_objectid && 4807ade2e0b3SWang Shilong found_key.type < BTRFS_EXTENT_ITEM_KEY) 4808ade2e0b3SWang Shilong break; 4809ade2e0b3SWang Shilong } 4810ade2e0b3SWang Shilong return 1; 4811ade2e0b3SWang Shilong } 4812