| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Chris Mason | 1988 | 20.70% | 68 | 19.15% |
| Josef Bacik | 1673 | 17.42% | 53 | 14.93% |
| Miao Xie | 1319 | 13.73% | 34 | 9.58% |
| Jeff Mahoney | 824 | 8.58% | 18 | 5.07% |
| Zheng Yan | 812 | 8.45% | 24 | 6.76% |
| Filipe David Borba Manana | 576 | 6.00% | 15 | 4.23% |
| Qu Wenruo | 451 | 4.70% | 16 | 4.51% |
| Sage Weil | 426 | 4.44% | 8 | 2.25% |
| David Sterba | 368 | 3.83% | 25 | 7.04% |
| Nikolay Borisov | 221 | 2.30% | 18 | 5.07% |
| Stefan Behrens | 163 | 1.70% | 6 | 1.69% |
| Liu Bo | 155 | 1.61% | 13 | 3.66% |
| Josef Whiter | 134 | 1.40% | 9 | 2.54% |
| Alexander Block | 108 | 1.12% | 1 | 0.28% |
| Jan Schmidt | 68 | 0.71% | 3 | 0.85% |
| Li Zefan | 64 | 0.67% | 7 | 1.97% |
| Arne Jansen | 55 | 0.57% | 6 | 1.69% |
| Tsutomu Itoh | 48 | 0.50% | 2 | 0.56% |
| Shilong Wang | 25 | 0.26% | 4 | 1.13% |
| Alexandru Moise | 23 | 0.24% | 4 | 1.13% |
| Dave Jones | 17 | 0.18% | 1 | 0.28% |
| Jan Kara | 14 | 0.15% | 1 | 0.28% |
| Zhao Lei | 12 | 0.12% | 1 | 0.28% |
| Deepa Dinamani | 12 | 0.12% | 3 | 0.85% |
| Elena Reshetova | 10 | 0.10% | 1 | 0.28% |
| Julia Lawall | 6 | 0.06% | 1 | 0.28% |
| Anand Jain | 6 | 0.06% | 2 | 0.56% |
| Misono, Tomohiro | 4 | 0.04% | 1 | 0.28% |
| Oleg Nesterov | 4 | 0.04% | 1 | 0.28% |
| Al Viro | 3 | 0.03% | 1 | 0.28% |
| Seraphime Kirkovski | 3 | 0.03% | 1 | 0.28% |
| Tejun Heo | 3 | 0.03% | 1 | 0.28% |
| Qinghuang Feng | 2 | 0.02% | 1 | 0.28% |
| Simon Kirby | 2 | 0.02% | 1 | 0.28% |
| Andrea Gelmini | 2 | 0.02% | 1 | 0.28% |
| Eric Sandeen | 1 | 0.01% | 1 | 0.28% |
| Arnd Bergmann | 1 | 0.01% | 1 | 0.28% |
| Sergei Trofimovich | 1 | 0.01% | 1 | 0.28% |
| Total | 9604 | 355 |
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// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2007 Oracle. All rights reserved. */ #include <linux/fs.h> #include <linux/slab.h> #include <linux/sched.h> #include <linux/writeback.h> #include <linux/pagemap.h> #include <linux/blkdev.h> #include <linux/uuid.h> #include "misc.h" #include "ctree.h" #include "disk-io.h" #include "transaction.h" #include "locking.h" #include "tree-log.h" #include "inode-map.h" #include "volumes.h" #include "dev-replace.h" #include "qgroup.h" #include "block-group.h" #define BTRFS_ROOT_TRANS_TAG 0 /* * Transaction states and transitions * * No running transaction (fs tree blocks are not modified) * | * | To next stage: * | Call start_transaction() variants. Except btrfs_join_transaction_nostart(). * V * Transaction N [[TRANS_STATE_RUNNING]] * | * | New trans handles can be attached to transaction N by calling all * | start_transaction() variants. * | * | To next stage: * | Call btrfs_commit_transaction() on any trans handle attached to * | transaction N * V * Transaction N [[TRANS_STATE_COMMIT_START]] * | * | Will wait for previous running transaction to completely finish if there * | is one * | * | Then one of the following happes: * | - Wait for all other trans handle holders to release. * | The btrfs_commit_transaction() caller will do the commit work. * | - Wait for current transaction to be committed by others. * | Other btrfs_commit_transaction() caller will do the commit work. * | * | At this stage, only btrfs_join_transaction*() variants can attach * | to this running transaction. * | All other variants will wait for current one to finish and attach to * | transaction N+1. * | * | To next stage: * | Caller is chosen to commit transaction N, and all other trans handle * | haven been released. * V * Transaction N [[TRANS_STATE_COMMIT_DOING]] * | * | The heavy lifting transaction work is started. * | From running delayed refs (modifying extent tree) to creating pending * | snapshots, running qgroups. * | In short, modify supporting trees to reflect modifications of subvolume * | trees. * | * | At this stage, all start_transaction() calls will wait for this * | transaction to finish and attach to transaction N+1. * | * | To next stage: * | Until all supporting trees are updated. * V * Transaction N [[TRANS_STATE_UNBLOCKED]] * | Transaction N+1 * | All needed trees are modified, thus we only [[TRANS_STATE_RUNNING]] * | need to write them back to disk and update | * | super blocks. | * | | * | At this stage, new transaction is allowed to | * | start. | * | All new start_transaction() calls will be | * | attached to transid N+1. | * | | * | To next stage: | * | Until all tree blocks are super blocks are | * | written to block devices | * V | * Transaction N [[TRANS_STATE_COMPLETED]] V * All tree blocks and super blocks are written. Transaction N+1 * This transaction is finished and all its [[TRANS_STATE_COMMIT_START]] * data structures will be cleaned up. | Life goes on */ static const unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = { [TRANS_STATE_RUNNING] = 0U, [TRANS_STATE_COMMIT_START] = (__TRANS_START | __TRANS_ATTACH), [TRANS_STATE_COMMIT_DOING] = (__TRANS_START | __TRANS_ATTACH | __TRANS_JOIN | __TRANS_JOIN_NOSTART), [TRANS_STATE_UNBLOCKED] = (__TRANS_START | __TRANS_ATTACH | __TRANS_JOIN | __TRANS_JOIN_NOLOCK | __TRANS_JOIN_NOSTART), [TRANS_STATE_COMPLETED] = (__TRANS_START | __TRANS_ATTACH | __TRANS_JOIN | __TRANS_JOIN_NOLOCK | __TRANS_JOIN_NOSTART), }; void btrfs_put_transaction(struct btrfs_transaction *transaction) { WARN_ON(refcount_read(&transaction->use_count) == 0); if (refcount_dec_and_test(&transaction->use_count)) { BUG_ON(!list_empty(&transaction->list)); WARN_ON(!RB_EMPTY_ROOT( &transaction->delayed_refs.href_root.rb_root)); WARN_ON(!RB_EMPTY_ROOT( &transaction->delayed_refs.dirty_extent_root)); if (transaction->delayed_refs.pending_csums) btrfs_err(transaction->fs_info, "pending csums is %llu", transaction->delayed_refs.pending_csums); /* * If any block groups are found in ->deleted_bgs then it's * because the transaction was aborted and a commit did not * happen (things failed before writing the new superblock * and calling btrfs_finish_extent_commit()), so we can not * discard the physical locations of the block groups. */ while (!list_empty(&transaction->deleted_bgs)) { struct btrfs_block_group *cache; cache = list_first_entry(&transaction->deleted_bgs, struct btrfs_block_group, bg_list); list_del_init(&cache->bg_list); btrfs_put_block_group_trimming(cache); btrfs_put_block_group(cache); } WARN_ON(!list_empty(&transaction->dev_update_list)); kfree(transaction); } } static noinline void switch_commit_roots(struct btrfs_trans_handle *trans) { struct btrfs_transaction *cur_trans = trans->transaction; struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_root *root, *tmp; down_write(&fs_info->commit_root_sem); list_for_each_entry_safe(root, tmp, &cur_trans->switch_commits, dirty_list) { list_del_init(&root->dirty_list); free_extent_buffer(root->commit_root); root->commit_root = btrfs_root_node(root); if (is_fstree(root->root_key.objectid)) btrfs_unpin_free_ino(root); extent_io_tree_release(&root->dirty_log_pages); btrfs_qgroup_clean_swapped_blocks(root); } /* We can free old roots now. */ spin_lock(&cur_trans->dropped_roots_lock); while (!list_empty(&cur_trans->dropped_roots)) { root = list_first_entry(&cur_trans->dropped_roots, struct btrfs_root, root_list); list_del_init(&root->root_list); spin_unlock(&cur_trans->dropped_roots_lock); btrfs_free_log(trans, root); btrfs_drop_and_free_fs_root(fs_info, root); spin_lock(&cur_trans->dropped_roots_lock); } spin_unlock(&cur_trans->dropped_roots_lock); up_write(&fs_info->commit_root_sem); } static inline void extwriter_counter_inc(struct btrfs_transaction *trans, unsigned int type) { if (type & TRANS_EXTWRITERS) atomic_inc(&trans->num_extwriters); } static inline void extwriter_counter_dec(struct btrfs_transaction *trans, unsigned int type) { if (type & TRANS_EXTWRITERS) atomic_dec(&trans->num_extwriters); } static inline void extwriter_counter_init(struct btrfs_transaction *trans, unsigned int type) { atomic_set(&trans->num_extwriters, ((type & TRANS_EXTWRITERS) ? 1 : 0)); } static inline int extwriter_counter_read(struct btrfs_transaction *trans) { return atomic_read(&trans->num_extwriters); } /* * To be called after all the new block groups attached to the transaction * handle have been created (btrfs_create_pending_block_groups()). */ void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; if (!trans->chunk_bytes_reserved) return; WARN_ON_ONCE(!list_empty(&trans->new_bgs)); btrfs_block_rsv_release(fs_info, &fs_info->chunk_block_rsv, trans->chunk_bytes_reserved); trans->chunk_bytes_reserved = 0; } /* * either allocate a new transaction or hop into the existing one */ static noinline int join_transaction(struct btrfs_fs_info *fs_info, unsigned int type) { struct btrfs_transaction *cur_trans; spin_lock(&fs_info->trans_lock); loop: /* The file system has been taken offline. No new transactions. */ if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { spin_unlock(&fs_info->trans_lock); return -EROFS; } cur_trans = fs_info->running_transaction; if (cur_trans) { if (cur_trans->aborted) { spin_unlock(&fs_info->trans_lock); return cur_trans->aborted; } if (btrfs_blocked_trans_types[cur_trans->state] & type) { spin_unlock(&fs_info->trans_lock); return -EBUSY; } refcount_inc(&cur_trans->use_count); atomic_inc(&cur_trans->num_writers); extwriter_counter_inc(cur_trans, type); spin_unlock(&fs_info->trans_lock); return 0; } spin_unlock(&fs_info->trans_lock); /* * If we are ATTACH, we just want to catch the current transaction, * and commit it. If there is no transaction, just return ENOENT. */ if (type == TRANS_ATTACH) return -ENOENT; /* * JOIN_NOLOCK only happens during the transaction commit, so * it is impossible that ->running_transaction is NULL */ BUG_ON(type == TRANS_JOIN_NOLOCK); cur_trans = kmalloc(sizeof(*cur_trans), GFP_NOFS); if (!cur_trans) return -ENOMEM; spin_lock(&fs_info->trans_lock); if (fs_info->running_transaction) { /* * someone started a transaction after we unlocked. Make sure * to redo the checks above */ kfree(cur_trans); goto loop; } else if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { spin_unlock(&fs_info->trans_lock); kfree(cur_trans); return -EROFS; } cur_trans->fs_info = fs_info; atomic_set(&cur_trans->num_writers, 1); extwriter_counter_init(cur_trans, type); init_waitqueue_head(&cur_trans->writer_wait); init_waitqueue_head(&cur_trans->commit_wait); cur_trans->state = TRANS_STATE_RUNNING; /* * One for this trans handle, one so it will live on until we * commit the transaction. */ refcount_set(&cur_trans->use_count, 2); cur_trans->flags = 0; cur_trans->start_time = ktime_get_seconds(); memset(&cur_trans->delayed_refs, 0, sizeof(cur_trans->delayed_refs)); cur_trans->delayed_refs.href_root = RB_ROOT_CACHED; cur_trans->delayed_refs.dirty_extent_root = RB_ROOT; atomic_set(&cur_trans->delayed_refs.num_entries, 0); /* * although the tree mod log is per file system and not per transaction, * the log must never go across transaction boundaries. */ smp_mb(); if (!list_empty(&fs_info->tree_mod_seq_list)) WARN(1, KERN_ERR "BTRFS: tree_mod_seq_list not empty when creating a fresh transaction\n"); if (!RB_EMPTY_ROOT(&fs_info->tree_mod_log)) WARN(1, KERN_ERR "BTRFS: tree_mod_log rb tree not empty when creating a fresh transaction\n"); atomic64_set(&fs_info->tree_mod_seq, 0); spin_lock_init(&cur_trans->delayed_refs.lock); INIT_LIST_HEAD(&cur_trans->pending_snapshots); INIT_LIST_HEAD(&cur_trans->dev_update_list); INIT_LIST_HEAD(&cur_trans->switch_commits); INIT_LIST_HEAD(&cur_trans->dirty_bgs); INIT_LIST_HEAD(&cur_trans->io_bgs); INIT_LIST_HEAD(&cur_trans->dropped_roots); mutex_init(&cur_trans->cache_write_mutex); spin_lock_init(&cur_trans->dirty_bgs_lock); INIT_LIST_HEAD(&cur_trans->deleted_bgs); spin_lock_init(&cur_trans->dropped_roots_lock); list_add_tail(&cur_trans->list, &fs_info->trans_list); extent_io_tree_init(fs_info, &cur_trans->dirty_pages, IO_TREE_TRANS_DIRTY_PAGES, fs_info->btree_inode); fs_info->generation++; cur_trans->transid = fs_info->generation; fs_info->running_transaction = cur_trans; cur_trans->aborted = 0; spin_unlock(&fs_info->trans_lock); return 0; } /* * this does all the record keeping required to make sure that a reference * counted root is properly recorded in a given transaction. This is required * to make sure the old root from before we joined the transaction is deleted * when the transaction commits */ static int record_root_in_trans(struct btrfs_trans_handle *trans, struct btrfs_root *root, int force) { struct btrfs_fs_info *fs_info = root->fs_info; if ((test_bit(BTRFS_ROOT_REF_COWS, &root->state) && root->last_trans < trans->transid) || force) { WARN_ON(root == fs_info->extent_root); WARN_ON(!force && root->commit_root != root->node); /* * see below for IN_TRANS_SETUP usage rules * we have the reloc mutex held now, so there * is only one writer in this function */ set_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state); /* make sure readers find IN_TRANS_SETUP before * they find our root->last_trans update */ smp_wmb(); spin_lock(&fs_info->fs_roots_radix_lock); if (root->last_trans == trans->transid && !force) { spin_unlock(&fs_info->fs_roots_radix_lock); return 0; } radix_tree_tag_set(&fs_info->fs_roots_radix, (unsigned long)root->root_key.objectid, BTRFS_ROOT_TRANS_TAG); spin_unlock(&fs_info->fs_roots_radix_lock); root->last_trans = trans->transid; /* this is pretty tricky. We don't want to * take the relocation lock in btrfs_record_root_in_trans * unless we're really doing the first setup for this root in * this transaction. * * Normally we'd use root->last_trans as a flag to decide * if we want to take the expensive mutex. * * But, we have to set root->last_trans before we * init the relocation root, otherwise, we trip over warnings * in ctree.c. The solution used here is to flag ourselves * with root IN_TRANS_SETUP. When this is 1, we're still * fixing up the reloc trees and everyone must wait. * * When this is zero, they can trust root->last_trans and fly * through btrfs_record_root_in_trans without having to take the * lock. smp_wmb() makes sure that all the writes above are * done before we pop in the zero below */ btrfs_init_reloc_root(trans, root); smp_mb__before_atomic(); clear_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state); } return 0; } void btrfs_add_dropped_root(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_transaction *cur_trans = trans->transaction; /* Add ourselves to the transaction dropped list */ spin_lock(&cur_trans->dropped_roots_lock); list_add_tail(&root->root_list, &cur_trans->dropped_roots); spin_unlock(&cur_trans->dropped_roots_lock); /* Make sure we don't try to update the root at commit time */ spin_lock(&fs_info->fs_roots_radix_lock); radix_tree_tag_clear(&fs_info->fs_roots_radix, (unsigned long)root->root_key.objectid, BTRFS_ROOT_TRANS_TAG); spin_unlock(&fs_info->fs_roots_radix_lock); } int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_fs_info *fs_info = root->fs_info; if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state)) return 0; /* * see record_root_in_trans for comments about IN_TRANS_SETUP usage * and barriers */ smp_rmb(); if (root->last_trans == trans->transid && !test_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state)) return 0; mutex_lock(&fs_info->reloc_mutex); record_root_in_trans(trans, root, 0); mutex_unlock(&fs_info->reloc_mutex); return 0; } static inline int is_transaction_blocked(struct btrfs_transaction *trans) { return (trans->state >= TRANS_STATE_COMMIT_START && trans->state < TRANS_STATE_UNBLOCKED && !trans->aborted); } /* wait for commit against the current transaction to become unblocked * when this is done, it is safe to start a new transaction, but the current * transaction might not be fully on disk. */ static void wait_current_trans(struct btrfs_fs_info *fs_info) { struct btrfs_transaction *cur_trans; spin_lock(&fs_info->trans_lock); cur_trans = fs_info->running_transaction; if (cur_trans && is_transaction_blocked(cur_trans)) { refcount_inc(&cur_trans->use_count); spin_unlock(&fs_info->trans_lock); wait_event(fs_info->transaction_wait, cur_trans->state >= TRANS_STATE_UNBLOCKED || cur_trans->aborted); btrfs_put_transaction(cur_trans); } else { spin_unlock(&fs_info->trans_lock); } } static int may_wait_transaction(struct btrfs_fs_info *fs_info, int type) { if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) return 0; if (type == TRANS_START) return 1; return 0; } static inline bool need_reserve_reloc_root(struct btrfs_root *root) { struct btrfs_fs_info *fs_info = root->fs_info; if (!fs_info->reloc_ctl || !test_bit(BTRFS_ROOT_REF_COWS, &root->state) || root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || root->reloc_root) return false; return true; } static struct btrfs_trans_handle * start_transaction(struct btrfs_root *root, unsigned int num_items, unsigned int type, enum btrfs_reserve_flush_enum flush, bool enforce_qgroups) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_block_rsv *delayed_refs_rsv = &fs_info->delayed_refs_rsv; struct btrfs_trans_handle *h; struct btrfs_transaction *cur_trans; u64 num_bytes = 0; u64 qgroup_reserved = 0; bool reloc_reserved = false; int ret; /* Send isn't supposed to start transactions. */ ASSERT(current->journal_info != BTRFS_SEND_TRANS_STUB); if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) return ERR_PTR(-EROFS); if (current->journal_info) { WARN_ON(type & TRANS_EXTWRITERS); h = current->journal_info; refcount_inc(&h->use_count); WARN_ON(refcount_read(&h->use_count) > 2); h->orig_rsv = h->block_rsv; h->block_rsv = NULL; goto got_it; } /* * Do the reservation before we join the transaction so we can do all * the appropriate flushing if need be. */ if (num_items && root != fs_info->chunk_root) { struct btrfs_block_rsv *rsv = &fs_info->trans_block_rsv; u64 delayed_refs_bytes = 0; qgroup_reserved = num_items * fs_info->nodesize; ret = btrfs_qgroup_reserve_meta_pertrans(root, qgroup_reserved, enforce_qgroups); if (ret) return ERR_PTR(ret); /* * We want to reserve all the bytes we may need all at once, so * we only do 1 enospc flushing cycle per transaction start. We * accomplish this by simply assuming we'll do 2 x num_items * worth of delayed refs updates in this trans handle, and * refill that amount for whatever is missing in the reserve. */ num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_items); if (delayed_refs_rsv->full == 0) { delayed_refs_bytes = num_bytes; num_bytes <<= 1; } /* * Do the reservation for the relocation root creation */ if (need_reserve_reloc_root(root)) { num_bytes += fs_info->nodesize; reloc_reserved = true; } ret = btrfs_block_rsv_add(root, rsv, num_bytes, flush); if (ret) goto reserve_fail; if (delayed_refs_bytes) { btrfs_migrate_to_delayed_refs_rsv(fs_info, rsv, delayed_refs_bytes); num_bytes -= delayed_refs_bytes; } } else if (num_items == 0 && flush == BTRFS_RESERVE_FLUSH_ALL && !delayed_refs_rsv->full) { /* * Some people call with btrfs_start_transaction(root, 0) * because they can be throttled, but have some other mechanism * for reserving space. We still want these guys to refill the * delayed block_rsv so just add 1 items worth of reservation * here. */ ret = btrfs_delayed_refs_rsv_refill(fs_info, flush); if (ret) goto reserve_fail; } again: h = kmem_cache_zalloc(btrfs_trans_handle_cachep, GFP_NOFS); if (!h) { ret = -ENOMEM; goto alloc_fail; } /* * If we are JOIN_NOLOCK we're already committing a transaction and * waiting on this guy, so we don't need to do the sb_start_intwrite * because we're already holding a ref. We need this because we could * have raced in and did an fsync() on a file which can kick a commit * and then we deadlock with somebody doing a freeze. * * If we are ATTACH, it means we just want to catch the current * transaction and commit it, so we needn't do sb_start_intwrite(). */ if (type & __TRANS_FREEZABLE) sb_start_intwrite(fs_info->sb); if (may_wait_transaction(fs_info, type)) wait_current_trans(fs_info); do { ret = join_transaction(fs_info, type); if (ret == -EBUSY) { wait_current_trans(fs_info); if (unlikely(type == TRANS_ATTACH || type == TRANS_JOIN_NOSTART)) ret = -ENOENT; } } while (ret == -EBUSY); if (ret < 0) goto join_fail; cur_trans = fs_info->running_transaction; h->transid = cur_trans->transid; h->transaction = cur_trans; h->root = root; refcount_set(&h->use_count, 1); h->fs_info = root->fs_info; h->type = type; h->can_flush_pending_bgs = true; INIT_LIST_HEAD(&h->new_bgs); smp_mb(); if (cur_trans->state >= TRANS_STATE_COMMIT_START && may_wait_transaction(fs_info, type)) { current->journal_info = h; btrfs_commit_transaction(h); goto again; } if (num_bytes) { trace_btrfs_space_reservation(fs_info, "transaction", h->transid, num_bytes, 1); h->block_rsv = &fs_info->trans_block_rsv; h->bytes_reserved = num_bytes; h->reloc_reserved = reloc_reserved; } got_it: btrfs_record_root_in_trans(h, root); if (!current->journal_info) current->journal_info = h; return h; join_fail: if (type & __TRANS_FREEZABLE) sb_end_intwrite(fs_info->sb); kmem_cache_free(btrfs_trans_handle_cachep, h); alloc_fail: if (num_bytes) btrfs_block_rsv_release(fs_info, &fs_info->trans_block_rsv, num_bytes); reserve_fail: btrfs_qgroup_free_meta_pertrans(root, qgroup_reserved); return ERR_PTR(ret); } struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, unsigned int num_items) { return start_transaction(root, num_items, TRANS_START, BTRFS_RESERVE_FLUSH_ALL, true); } struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv( struct btrfs_root *root, unsigned int num_items, int min_factor) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_trans_handle *trans; u64 num_bytes; int ret; /* * We have two callers: unlink and block group removal. The * former should succeed even if we will temporarily exceed * quota and the latter operates on the extent root so * qgroup enforcement is ignored anyway. */ trans = start_transaction(root, num_items, TRANS_START, BTRFS_RESERVE_FLUSH_ALL, false); if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC) return trans; trans = btrfs_start_transaction(root, 0); if (IS_ERR(trans)) return trans; num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_items); ret = btrfs_cond_migrate_bytes(fs_info, &fs_info->trans_block_rsv, num_bytes, min_factor); if (ret) { btrfs_end_transaction(trans); return ERR_PTR(ret); } trans->block_rsv = &fs_info->trans_block_rsv; trans->bytes_reserved = num_bytes; trace_btrfs_space_reservation(fs_info, "transaction", trans->transid, num_bytes, 1); return trans; } struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root) { return start_transaction(root, 0, TRANS_JOIN, BTRFS_RESERVE_NO_FLUSH, true); } struct btrfs_trans_handle *btrfs_join_transaction_spacecache(struct btrfs_root *root) { return start_transaction(root, 0, TRANS_JOIN_NOLOCK, BTRFS_RESERVE_NO_FLUSH, true); } /* * Similar to regular join but it never starts a transaction when none is * running or after waiting for the current one to finish. */ struct btrfs_trans_handle *btrfs_join_transaction_nostart(struct btrfs_root *root) { return start_transaction(root, 0, TRANS_JOIN_NOSTART, BTRFS_RESERVE_NO_FLUSH, true); } /* * btrfs_attach_transaction() - catch the running transaction * * It is used when we want to commit the current the transaction, but * don't want to start a new one. * * Note: If this function return -ENOENT, it just means there is no * running transaction. But it is possible that the inactive transaction * is still in the memory, not fully on disk. If you hope there is no * inactive transaction in the fs when -ENOENT is returned, you should * invoke * btrfs_attach_transaction_barrier() */ struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root) { return start_transaction(root, 0, TRANS_ATTACH, BTRFS_RESERVE_NO_FLUSH, true); } /* * btrfs_attach_transaction_barrier() - catch the running transaction * * It is similar to the above function, the difference is this one * will wait for all the inactive transactions until they fully * complete. */ struct btrfs_trans_handle * btrfs_attach_transaction_barrier(struct btrfs_root *root) { struct btrfs_trans_handle *trans; trans = start_transaction(root, 0, TRANS_ATTACH, BTRFS_RESERVE_NO_FLUSH, true); if (trans == ERR_PTR(-ENOENT)) btrfs_wait_for_commit(root->fs_info, 0); return trans; } /* wait for a transaction commit to be fully complete */ static noinline void wait_for_commit(struct btrfs_transaction *commit) { wait_event(commit->commit_wait, commit->state == TRANS_STATE_COMPLETED); } int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid) { struct btrfs_transaction *cur_trans = NULL, *t; int ret = 0; if (transid) { if (transid <= fs_info->last_trans_committed) goto out; /* find specified transaction */ spin_lock(&fs_info->trans_lock); list_for_each_entry(t, &fs_info->trans_list, list) { if (t->transid == transid) { cur_trans = t; refcount_inc(&cur_trans->use_count); ret = 0; break; } if (t->transid > transid) { ret = 0; break; } } spin_unlock(&fs_info->trans_lock); /* * The specified transaction doesn't exist, or we * raced with btrfs_commit_transaction */ if (!cur_trans) { if (transid > fs_info->last_trans_committed) ret = -EINVAL; goto out; } } else { /* find newest transaction that is committing | committed */ spin_lock(&fs_info->trans_lock); list_for_each_entry_reverse(t, &fs_info->trans_list, list) { if (t->state >= TRANS_STATE_COMMIT_START) { if (t->state == TRANS_STATE_COMPLETED) break; cur_trans = t; refcount_inc(&cur_trans->use_count); break; } } spin_unlock(&fs_info->trans_lock); if (!cur_trans) goto out; /* nothing committing|committed */ } wait_for_commit(cur_trans); btrfs_put_transaction(cur_trans); out: return ret; } void btrfs_throttle(struct btrfs_fs_info *fs_info) { wait_current_trans(fs_info); } static int should_end_transaction(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; if (btrfs_check_space_for_delayed_refs(fs_info)) return 1; return !!btrfs_block_rsv_check(&fs_info->global_block_rsv, 5); } int btrfs_should_end_transaction(struct btrfs_trans_handle *trans) { struct btrfs_transaction *cur_trans = trans->transaction; smp_mb(); if (cur_trans->state >= TRANS_STATE_COMMIT_START || cur_trans->delayed_refs.flushing) return 1; return should_end_transaction(trans); } static void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; if (!trans->block_rsv) { ASSERT(!trans->bytes_reserved); return; } if (!trans->bytes_reserved) return; ASSERT(trans->block_rsv == &fs_info->trans_block_rsv); trace_btrfs_space_reservation(fs_info, "transaction", trans->transid, trans->bytes_reserved, 0); btrfs_block_rsv_release(fs_info, trans->block_rsv, trans->bytes_reserved); trans->bytes_reserved = 0; } static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, int throttle) { struct btrfs_fs_info *info = trans->fs_info; struct btrfs_transaction *cur_trans = trans->transaction; int err = 0; if (refcount_read(&trans->use_count) > 1) { refcount_dec(&trans->use_count); trans->block_rsv = trans->orig_rsv; return 0; } btrfs_trans_release_metadata(trans); trans->block_rsv = NULL; btrfs_create_pending_block_groups(trans); btrfs_trans_release_chunk_metadata(trans); if (trans->type & __TRANS_FREEZABLE) sb_end_intwrite(info->sb); WARN_ON(cur_trans != info->running_transaction); WARN_ON(atomic_read(&cur_trans->num_writers) < 1); atomic_dec(&cur_trans->num_writers); extwriter_counter_dec(cur_trans, trans->type); cond_wake_up(&cur_trans->writer_wait); btrfs_put_transaction(cur_trans); if (current->journal_info == trans) current->journal_info = NULL; if (throttle) btrfs_run_delayed_iputs(info); if (trans->aborted || test_bit(BTRFS_FS_STATE_ERROR, &info->fs_state)) { wake_up_process(info->transaction_kthread); err = -EIO; } kmem_cache_free(btrfs_trans_handle_cachep, trans); return err; } int btrfs_end_transaction(struct btrfs_trans_handle *trans) { return __btrfs_end_transaction(trans, 0); } int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans) { return __btrfs_end_transaction(trans, 1); } /* * when btree blocks are allocated, they have some corresponding bits set for * them in one of two extent_io trees. This is used to make sure all of * those extents are sent to disk but does not wait on them */ int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info, struct extent_io_tree *dirty_pages, int mark) { int err = 0; int werr = 0; struct address_space *mapping = fs_info->btree_inode->i_mapping; struct extent_state *cached_state = NULL; u64 start = 0; u64 end; atomic_inc(&BTRFS_I(fs_info->btree_inode)->sync_writers); while (!find_first_extent_bit(dirty_pages, start, &start, &end, mark, &cached_state)) { bool wait_writeback = false; err = convert_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT, mark, &cached_state); /* * convert_extent_bit can return -ENOMEM, which is most of the * time a temporary error. So when it happens, ignore the error * and wait for writeback of this range to finish - because we * failed to set the bit EXTENT_NEED_WAIT for the range, a call * to __btrfs_wait_marked_extents() would not know that * writeback for this range started and therefore wouldn't * wait for it to finish - we don't want to commit a * superblock that points to btree nodes/leafs for which * writeback hasn't finished yet (and without errors). * We cleanup any entries left in the io tree when committing * the transaction (through extent_io_tree_release()). */ if (err == -ENOMEM) { err = 0; wait_writeback = true; } if (!err) err = filemap_fdatawrite_range(mapping, start, end); if (err) werr = err; else if (wait_writeback) werr = filemap_fdatawait_range(mapping, start, end); free_extent_state(cached_state); cached_state = NULL; cond_resched(); start = end + 1; } atomic_dec(&BTRFS_I(fs_info->btree_inode)->sync_writers); return werr; } /* * when btree blocks are allocated, they have some corresponding bits set for * them in one of two extent_io trees. This is used to make sure all of * those extents are on disk for transaction or log commit. We wait * on all the pages and clear them from the dirty pages state tree */ static int __btrfs_wait_marked_extents(struct btrfs_fs_info *fs_info, struct extent_io_tree *dirty_pages) { int err = 0; int werr = 0; struct address_space *mapping = fs_info->btree_inode->i_mapping; struct extent_state *cached_state = NULL; u64 start = 0; u64 end; while (!find_first_extent_bit(dirty_pages, start, &start, &end, EXTENT_NEED_WAIT, &cached_state)) { /* * Ignore -ENOMEM errors returned by clear_extent_bit(). * When committing the transaction, we'll remove any entries * left in the io tree. For a log commit, we don't remove them * after committing the log because the tree can be accessed * concurrently - we do it only at transaction commit time when * it's safe to do it (through extent_io_tree_release()). */ err = clear_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT, 0, 0, &cached_state); if (err == -ENOMEM) err = 0; if (!err) err = filemap_fdatawait_range(mapping, start, end); if (err) werr = err; free_extent_state(cached_state); cached_state = NULL; cond_resched(); start = end + 1; } if (err) werr = err; return werr; } static int btrfs_wait_extents(struct btrfs_fs_info *fs_info, struct extent_io_tree *dirty_pages) { bool errors = false; int err; err = __btrfs_wait_marked_extents(fs_info, dirty_pages); if (test_and_clear_bit(BTRFS_FS_BTREE_ERR, &fs_info->flags)) errors = true; if (errors && !err) err = -EIO; return err; } int btrfs_wait_tree_log_extents(struct btrfs_root *log_root, int mark) { struct btrfs_fs_info *fs_info = log_root->fs_info; struct extent_io_tree *dirty_pages = &log_root->dirty_log_pages; bool errors = false; int err; ASSERT(log_root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID); err = __btrfs_wait_marked_extents(fs_info, dirty_pages); if ((mark & EXTENT_DIRTY) && test_and_clear_bit(BTRFS_FS_LOG1_ERR, &fs_info->flags)) errors = true; if ((mark & EXTENT_NEW) && test_and_clear_bit(BTRFS_FS_LOG2_ERR, &fs_info->flags)) errors = true; if (errors && !err) err = -EIO; return err; } /* * When btree blocks are allocated the corresponding extents are marked dirty. * This function ensures such extents are persisted on disk for transaction or * log commit. * * @trans: transaction whose dirty pages we'd like to write */ static int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans) { int ret; int ret2; struct extent_io_tree *dirty_pages = &trans->transaction->dirty_pages; struct btrfs_fs_info *fs_info = trans->fs_info; struct blk_plug plug; blk_start_plug(&plug); ret = btrfs_write_marked_extents(fs_info, dirty_pages, EXTENT_DIRTY); blk_finish_plug(&plug); ret2 = btrfs_wait_extents(fs_info, dirty_pages); extent_io_tree_release(&trans->transaction->dirty_pages); if (ret) return ret; else if (ret2) return ret2; else return 0; } /* * this is used to update the root pointer in the tree of tree roots. * * But, in the case of the extent allocation tree, updating the root * pointer may allocate blocks which may change the root of the extent * allocation tree. * * So, this loops and repeats and makes sure the cowonly root didn't * change while the root pointer was being updated in the metadata. */ static int update_cowonly_root(struct btrfs_trans_handle *trans, struct btrfs_root *root) { int ret; u64 old_root_bytenr; u64 old_root_used; struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_root *tree_root = fs_info->tree_root; old_root_used = btrfs_root_used(&root->root_item); while (1) { old_root_bytenr = btrfs_root_bytenr(&root->root_item); if (old_root_bytenr == root->node->start && old_root_used == btrfs_root_used(&root->root_item)) break; btrfs_set_root_node(&root->root_item, root->node); ret = btrfs_update_root(trans, tree_root, &root->root_key, &root->root_item); if (ret) return ret; old_root_used = btrfs_root_used(&root->root_item); } return 0; } /* * update all the cowonly tree roots on disk * * The error handling in this function may not be obvious. Any of the * failures will cause the file system to go offline. We still need * to clean up the delayed refs. */ static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; struct list_head *dirty_bgs = &trans->transaction->dirty_bgs; struct list_head *io_bgs = &trans->transaction->io_bgs; struct list_head *next; struct extent_buffer *eb; int ret; eb = btrfs_lock_root_node(fs_info->tree_root); ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb); btrfs_tree_unlock(eb); free_extent_buffer(eb); if (ret) return ret; ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); if (ret) return ret; ret = btrfs_run_dev_stats(trans); if (ret) return ret; ret = btrfs_run_dev_replace(trans); if (ret) return ret; ret = btrfs_run_qgroups(trans); if (ret) return ret; ret = btrfs_setup_space_cache(trans); if (ret) return ret; /* run_qgroups might have added some more refs */ ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); if (ret) return ret; again: while (!list_empty(&fs_info->dirty_cowonly_roots)) { struct btrfs_root *root; next = fs_info->dirty_cowonly_roots.next; list_del_init(next); root = list_entry(next, struct btrfs_root, dirty_list); clear_bit(BTRFS_ROOT_DIRTY, &root->state); if (root != fs_info->extent_root) list_add_tail(&root->dirty_list, &trans->transaction->switch_commits); ret = update_cowonly_root(trans, root); if (ret) return ret; ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); if (ret) return ret; } while (!list_empty(dirty_bgs) || !list_empty(io_bgs)) { ret = btrfs_write_dirty_block_groups(trans); if (ret) return ret; ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); if (ret) return ret; } if (!list_empty(&fs_info->dirty_cowonly_roots)) goto again; list_add_tail(&fs_info->extent_root->dirty_list, &trans->transaction->switch_commits); /* Update dev-replace pointer once everything is committed */ fs_info->dev_replace.committed_cursor_left = fs_info->dev_replace.cursor_left_last_write_of_item; return 0; } /* * dead roots are old snapshots that need to be deleted. This allocates * a dirty root struct and adds it into the list of dead roots that need to * be deleted */ void btrfs_add_dead_root(struct btrfs_root *root) { struct btrfs_fs_info *fs_info = root->fs_info; spin_lock(&fs_info->trans_lock); if (list_empty(&root->root_list)) list_add_tail(&root->root_list, &fs_info->dead_roots); spin_unlock(&fs_info->trans_lock); } /* * update all the cowonly tree roots on disk */ static noinline int commit_fs_roots(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_root *gang[8]; int i; int ret; int err = 0; spin_lock(&fs_info->fs_roots_radix_lock); while (1) { ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix, (void **)gang, 0, ARRAY_SIZE(gang), BTRFS_ROOT_TRANS_TAG); if (ret == 0) break; for (i = 0; i < ret; i++) { struct btrfs_root *root = gang[i]; radix_tree_tag_clear(&fs_info->fs_roots_radix, (unsigned long)root->root_key.objectid, BTRFS_ROOT_TRANS_TAG); spin_unlock(&fs_info->fs_roots_radix_lock); btrfs_free_log(trans, root); btrfs_update_reloc_root(trans, root); btrfs_save_ino_cache(root, trans); /* see comments in should_cow_block() */ clear_bit(BTRFS_ROOT_FORCE_COW, &root->state); smp_mb__after_atomic(); if (root->commit_root != root->node) { list_add_tail(&root->dirty_list, &trans->transaction->switch_commits); btrfs_set_root_node(&root->root_item, root->node); } err = btrfs_update_root(trans, fs_info->tree_root, &root->root_key, &root->root_item); spin_lock(&fs_info->fs_roots_radix_lock); if (err) break; btrfs_qgroup_free_meta_all_pertrans(root); } } spin_unlock(&fs_info->fs_roots_radix_lock); return err; } /* * defrag a given btree. * Every leaf in the btree is read and defragged. */ int btrfs_defrag_root(struct btrfs_root *root) { struct btrfs_fs_info *info = root->fs_info; struct btrfs_trans_handle *trans; int ret; if (test_and_set_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state)) return 0; while (1) { trans = btrfs_start_transaction(root, 0); if (IS_ERR(trans)) return PTR_ERR(trans); ret = btrfs_defrag_leaves(trans, root); btrfs_end_transaction(trans); btrfs_btree_balance_dirty(info); cond_resched(); if (btrfs_fs_closing(info) || ret != -EAGAIN) break; if (btrfs_defrag_cancelled(info)) { btrfs_debug(info, "defrag_root cancelled"); ret = -EAGAIN; break; } } clear_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state); return ret; } /* * Do all special snapshot related qgroup dirty hack. * * Will do all needed qgroup inherit and dirty hack like switch commit * roots inside one transaction and write all btree into disk, to make * qgroup works. */ static int qgroup_account_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root *src, struct btrfs_root *parent, struct btrfs_qgroup_inherit *inherit, u64 dst_objectid) { struct btrfs_fs_info *fs_info = src->fs_info; int ret; /* * Save some performance in the case that qgroups are not * enabled. If this check races with the ioctl, rescan will * kick in anyway. */ if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) return 0; /* * Ensure dirty @src will be committed. Or, after coming * commit_fs_roots() and switch_commit_roots(), any dirty but not * recorded root will never be updated again, causing an outdated root * item. */ record_root_in_trans(trans, src, 1); /* * We are going to commit transaction, see btrfs_commit_transaction() * comment for reason locking tree_log_mutex */ mutex_lock(&fs_info->tree_log_mutex); ret = commit_fs_roots(trans); if (ret) goto out; ret = btrfs_qgroup_account_extents(trans); if (ret < 0) goto out; /* Now qgroup are all updated, we can inherit it to new qgroups */ ret = btrfs_qgroup_inherit(trans, src->root_key.objectid, dst_objectid, inherit); if (ret < 0) goto out; /* * Now we do a simplified commit transaction, which will: * 1) commit all subvolume and extent tree * To ensure all subvolume and extent tree have a valid * commit_root to accounting later insert_dir_item() * 2) write all btree blocks onto disk * This is to make sure later btree modification will be cowed * Or commit_root can be populated and cause wrong qgroup numbers * In this simplified commit, we don't really care about other trees * like chunk and root tree, as they won't affect qgroup. * And we don't write super to avoid half committed status. */ ret = commit_cowonly_roots(trans); if (ret) goto out; switch_commit_roots(trans); ret = btrfs_write_and_wait_transaction(trans); if (ret) btrfs_handle_fs_error(fs_info, ret, "Error while writing out transaction for qgroup"); out: mutex_unlock(&fs_info->tree_log_mutex); /* * Force parent root to be updated, as we recorded it before so its * last_trans == cur_transid. * Or it won't be committed again onto disk after later * insert_dir_item() */ if (!ret) record_root_in_trans(trans, parent, 1); return ret; } /* * new snapshots need to be created at a very specific time in the * transaction commit. This does the actual creation. * * Note: * If the error which may affect the commitment of the current transaction * happens, we should return the error number. If the error which just affect * the creation of the pending snapshots, just return 0. */ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, struct btrfs_pending_snapshot *pending) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_key key; struct btrfs_root_item *new_root_item; struct btrfs_root *tree_root = fs_info->tree_root; struct btrfs_root *root = pending->root; struct btrfs_root *parent_root; struct btrfs_block_rsv *rsv; struct inode *parent_inode; struct btrfs_path *path; struct btrfs_dir_item *dir_item; struct dentry *dentry; struct extent_buffer *tmp; struct extent_buffer *old; struct timespec64 cur_time; int ret = 0; u64 to_reserve = 0; u64 index = 0; u64 objectid; u64 root_flags; uuid_le new_uuid; ASSERT(pending->path); path = pending->path; ASSERT(pending->root_item); new_root_item = pending->root_item; pending->error = btrfs_find_free_objectid(tree_root, &objectid); if (pending->error) goto no_free_objectid; /* * Make qgroup to skip current new snapshot's qgroupid, as it is * accounted by later btrfs_qgroup_inherit(). */ btrfs_set_skip_qgroup(trans, objectid); btrfs_reloc_pre_snapshot(pending, &to_reserve); if (to_reserve > 0) { pending->error = btrfs_block_rsv_add(root, &pending->block_rsv, to_reserve, BTRFS_RESERVE_NO_FLUSH); if (pending->error) goto clear_skip_qgroup; } key.objectid = objectid; key.offset = (u64)-1; key.type = BTRFS_ROOT_ITEM_KEY; rsv = trans->block_rsv; trans->block_rsv = &pending->block_rsv; trans->bytes_reserved = trans->block_rsv->reserved; trace_btrfs_space_reservation(fs_info, "transaction", trans->transid, trans->bytes_reserved, 1); dentry = pending->dentry; parent_inode = pending->dir; parent_root = BTRFS_I(parent_inode)->root; record_root_in_trans(trans, parent_root, 0); cur_time = current_time(parent_inode); /* * insert the directory item */ ret = btrfs_set_inode_index(BTRFS_I(parent_inode), &index); BUG_ON(ret); /* -ENOMEM */ /* check if there is a file/dir which has the same name. */ dir_item = btrfs_lookup_dir_item(NULL, parent_root, path, btrfs_ino(BTRFS_I(parent_inode)), dentry->d_name.name, dentry->d_name.len, 0); if (dir_item != NULL && !IS_ERR(dir_item)) { pending->error = -EEXIST; goto dir_item_existed; } else if (IS_ERR(dir_item)) { ret = PTR_ERR(dir_item); btrfs_abort_transaction(trans, ret); goto fail; } btrfs_release_path(path); /* * pull in the delayed directory update * and the delayed inode item * otherwise we corrupt the FS during * snapshot */ ret = btrfs_run_delayed_items(trans); if (ret) { /* Transaction aborted */ btrfs_abort_transaction(trans, ret); goto fail; } record_root_in_trans(trans, root, 0); btrfs_set_root_last_snapshot(&root->root_item, trans->transid); memcpy(new_root_item, &root->root_item, sizeof(*new_root_item)); btrfs_check_and_init_root_item(new_root_item); root_flags = btrfs_root_flags(new_root_item); if (pending->readonly) root_flags |= BTRFS_ROOT_SUBVOL_RDONLY; else root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY; btrfs_set_root_flags(new_root_item, root_flags); btrfs_set_root_generation_v2(new_root_item, trans->transid); uuid_le_gen(&new_uuid); memcpy(new_root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE); memcpy(new_root_item->parent_uuid, root->root_item.uuid, BTRFS_UUID_SIZE); if (!(root_flags & BTRFS_ROOT_SUBVOL_RDONLY)) { memset(new_root_item->received_uuid, 0, sizeof(new_root_item->received_uuid)); memset(&new_root_item->stime, 0, sizeof(new_root_item->stime)); memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime)); btrfs_set_root_stransid(new_root_item, 0); btrfs_set_root_rtransid(new_root_item, 0); } btrfs_set_stack_timespec_sec(&new_root_item->otime, cur_time.tv_sec); btrfs_set_stack_timespec_nsec(&new_root_item->otime, cur_time.tv_nsec); btrfs_set_root_otransid(new_root_item, trans->transid); old = btrfs_lock_root_node(root); ret = btrfs_cow_block(trans, root, old, NULL, 0, &old); if (ret) { btrfs_tree_unlock(old); free_extent_buffer(old); btrfs_abort_transaction(trans, ret); goto fail; } btrfs_set_lock_blocking_write(old); ret = btrfs_copy_root(trans, root, old, &tmp, objectid); /* clean up in any case */ btrfs_tree_unlock(old); free_extent_buffer(old); if (ret) { btrfs_abort_transaction(trans, ret); goto fail; } /* see comments in should_cow_block() */ set_bit(BTRFS_ROOT_FORCE_COW, &root->state); smp_wmb(); btrfs_set_root_node(new_root_item, tmp); /* record when the snapshot was created in key.offset */ key.offset = trans->transid; ret = btrfs_insert_root(trans, tree_root, &key, new_root_item); btrfs_tree_unlock(tmp); free_extent_buffer(tmp); if (ret) { btrfs_abort_transaction(trans, ret); goto fail; } /* * insert root back/forward references */ ret = btrfs_add_root_ref(trans, objectid, parent_root->root_key.objectid, btrfs_ino(BTRFS_I(parent_inode)), index, dentry->d_name.name, dentry->d_name.len); if (ret) { btrfs_abort_transaction(trans, ret); goto fail; } key.offset = (u64)-1; pending->snap = btrfs_read_fs_root_no_name(fs_info, &key); if (IS_ERR(pending->snap)) { ret = PTR_ERR(pending->snap); btrfs_abort_transaction(trans, ret); goto fail; } ret = btrfs_reloc_post_snapshot(trans, pending); if (ret) { btrfs_abort_transaction(trans, ret); goto fail; } ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); if (ret) { btrfs_abort_transaction(trans, ret); goto fail; } /* * Do special qgroup accounting for snapshot, as we do some qgroup * snapshot hack to do fast snapshot. * To co-operate with that hack, we do hack again. * Or snapshot will be greatly slowed down by a subtree qgroup rescan */ ret = qgroup_account_snapshot(trans, root, parent_root, pending->inherit, objectid); if (ret < 0) goto fail; ret = btrfs_insert_dir_item(trans, dentry->d_name.name, dentry->d_name.len, BTRFS_I(parent_inode), &key, BTRFS_FT_DIR, index); /* We have check then name at the beginning, so it is impossible. */ BUG_ON(ret == -EEXIST || ret == -EOVERFLOW); if (ret) { btrfs_abort_transaction(trans, ret); goto fail; } btrfs_i_size_write(BTRFS_I(parent_inode), parent_inode->i_size + dentry->d_name.len * 2); parent_inode->i_mtime = parent_inode->i_ctime = current_time(parent_inode); ret = btrfs_update_inode_fallback(trans, parent_root, parent_inode); if (ret) { btrfs_abort_transaction(trans, ret); goto fail; } ret = btrfs_uuid_tree_add(trans, new_uuid.b, BTRFS_UUID_KEY_SUBVOL, objectid); if (ret) { btrfs_abort_transaction(trans, ret); goto fail; } if (!btrfs_is_empty_uuid(new_root_item->received_uuid)) { ret = btrfs_uuid_tree_add(trans, new_root_item->received_uuid, BTRFS_UUID_KEY_RECEIVED_SUBVOL, objectid); if (ret && ret != -EEXIST) { btrfs_abort_transaction(trans, ret); goto fail; } } ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); if (ret) { btrfs_abort_transaction(trans, ret); goto fail; } fail: pending->error = ret; dir_item_existed: trans->block_rsv = rsv; trans->bytes_reserved = 0; clear_skip_qgroup: btrfs_clear_skip_qgroup(trans); no_free_objectid: kfree(new_root_item); pending->root_item = NULL; btrfs_free_path(path); pending->path = NULL; return ret; } /* * create all the snapshots we've scheduled for creation */ static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans) { struct btrfs_pending_snapshot *pending, *next; struct list_head *head = &trans->transaction->pending_snapshots; int ret = 0; list_for_each_entry_safe(pending, next, head, list) { list_del(&pending->list); ret = create_pending_snapshot(trans, pending); if (ret) break; } return ret; } static void update_super_roots(struct btrfs_fs_info *fs_info) { struct btrfs_root_item *root_item; struct btrfs_super_block *super; super = fs_info->super_copy; root_item = &fs_info->chunk_root->root_item; super->chunk_root = root_item->bytenr; super->chunk_root_generation = root_item->generation; super->chunk_root_level = root_item->level; root_item = &fs_info->tree_root->root_item; super->root = root_item->bytenr; super->generation = root_item->generation; super->root_level = root_item->level; if (btrfs_test_opt(fs_info, SPACE_CACHE)) super->cache_generation = root_item->generation; if (test_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags)) super->uuid_tree_generation = root_item->generation; } int btrfs_transaction_in_commit(struct btrfs_fs_info *info) { struct btrfs_transaction *trans; int ret = 0; spin_lock(&info->trans_lock); trans = info->running_transaction; if (trans) ret = (trans->state >= TRANS_STATE_COMMIT_START); spin_unlock(&info->trans_lock); return ret; } int btrfs_transaction_blocked(struct btrfs_fs_info *info) { struct btrfs_transaction *trans; int ret = 0; spin_lock(&info->trans_lock); trans = info->running_transaction; if (trans) ret = is_transaction_blocked(trans); spin_unlock(&info->trans_lock); return ret; } /* * wait for the current transaction commit to start and block subsequent * transaction joins */ static void wait_current_trans_commit_start(struct btrfs_fs_info *fs_info, struct btrfs_transaction *trans) { wait_event(fs_info->transaction_blocked_wait, trans->state >= TRANS_STATE_COMMIT_START || trans->aborted); } /* * wait for the current transaction to start and then become unblocked. * caller holds ref. */ static void wait_current_trans_commit_start_and_unblock( struct btrfs_fs_info *fs_info, struct btrfs_transaction *trans) { wait_event(fs_info->transaction_wait, trans->state >= TRANS_STATE_UNBLOCKED || trans->aborted); } /* * commit transactions asynchronously. once btrfs_commit_transaction_async * returns, any subsequent transaction will not be allowed to join. */ struct btrfs_async_commit { struct btrfs_trans_handle *newtrans; struct work_struct work; }; static void do_async_commit(struct work_struct *work) { struct btrfs_async_commit *ac = container_of(work, struct btrfs_async_commit, work); /* * We've got freeze protection passed with the transaction. * Tell lockdep about it. */ if (ac->newtrans->type & __TRANS_FREEZABLE) __sb_writers_acquired(ac->newtrans->fs_info->sb, SB_FREEZE_FS); current->journal_info = ac->newtrans; btrfs_commit_transaction(ac->newtrans); kfree(ac); } int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans, int wait_for_unblock) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_async_commit *ac; struct btrfs_transaction *cur_trans; ac = kmalloc(sizeof(*ac), GFP_NOFS); if (!ac) return -ENOMEM; INIT_WORK(&ac->work, do_async_commit); ac->newtrans = btrfs_join_transaction(trans->root); if (IS_ERR(ac->newtrans)) { int err = PTR_ERR(ac->newtrans); kfree(ac); return err; } /* take transaction reference */ cur_trans = trans->transaction; refcount_inc(&cur_trans->use_count); btrfs_end_transaction(trans); /* * Tell lockdep we've released the freeze rwsem, since the * async commit thread will be the one to unlock it. */ if (ac->newtrans->type & __TRANS_FREEZABLE) __sb_writers_release(fs_info->sb, SB_FREEZE_FS); schedule_work(&ac->work); /* wait for transaction to start and unblock */ if (wait_for_unblock) wait_current_trans_commit_start_and_unblock(fs_info, cur_trans); else wait_current_trans_commit_start(fs_info, cur_trans); if (current->journal_info == trans) current->journal_info = NULL; btrfs_put_transaction(cur_trans); return 0; } static void cleanup_transaction(struct btrfs_trans_handle *trans, int err) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_transaction *cur_trans = trans->transaction; WARN_ON(refcount_read(&trans->use_count) > 1); btrfs_abort_transaction(trans, err); spin_lock(&fs_info->trans_lock); /* * If the transaction is removed from the list, it means this * transaction has been committed successfully, so it is impossible * to call the cleanup function. */ BUG_ON(list_empty(&cur_trans->list)); list_del_init(&cur_trans->list); if (cur_trans == fs_info->running_transaction) { cur_trans->state = TRANS_STATE_COMMIT_DOING; spin_unlock(&fs_info->trans_lock); wait_event(cur_trans->writer_wait, atomic_read(&cur_trans->num_writers) == 1); spin_lock(&fs_info->trans_lock); } spin_unlock(&fs_info->trans_lock); btrfs_cleanup_one_transaction(trans->transaction, fs_info); spin_lock(&fs_info->trans_lock); if (cur_trans == fs_info->running_transaction) fs_info->running_transaction = NULL; spin_unlock(&fs_info->trans_lock); if (trans->type & __TRANS_FREEZABLE) sb_end_intwrite(fs_info->sb); btrfs_put_transaction(cur_trans); btrfs_put_transaction(cur_trans); trace_btrfs_transaction_commit(trans->root); if (current->journal_info == trans) current->journal_info = NULL; btrfs_scrub_cancel(fs_info); kmem_cache_free(btrfs_trans_handle_cachep, trans); } /* * Release reserved delayed ref space of all pending block groups of the * transaction and remove them from the list */ static void btrfs_cleanup_pending_block_groups(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_block_group *block_group, *tmp; list_for_each_entry_safe(block_group, tmp, &trans->new_bgs, bg_list) { btrfs_delayed_refs_rsv_release(fs_info, 1); list_del_init(&block_group->bg_list); } } static inline int btrfs_start_delalloc_flush(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; /* * We use writeback_inodes_sb here because if we used * btrfs_start_delalloc_roots we would deadlock with fs freeze. * Currently are holding the fs freeze lock, if we do an async flush * we'll do btrfs_join_transaction() and deadlock because we need to * wait for the fs freeze lock. Using the direct flushing we benefit * from already being in a transaction and our join_transaction doesn't * have to re-take the fs freeze lock. */ if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) { writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC); } else { struct btrfs_pending_snapshot *pending; struct list_head *head = &trans->transaction->pending_snapshots; /* * Flush dellaloc for any root that is going to be snapshotted. * This is done to avoid a corrupted version of files, in the * snapshots, that had both buffered and direct IO writes (even * if they were done sequentially) due to an unordered update of * the inode's size on disk. */ list_for_each_entry(pending, head, list) { int ret; ret = btrfs_start_delalloc_snapshot(pending->root); if (ret) return ret; } } return 0; } static inline void btrfs_wait_delalloc_flush(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) { btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); } else { struct btrfs_pending_snapshot *pending; struct list_head *head = &trans->transaction->pending_snapshots; /* * Wait for any dellaloc that we started previously for the roots * that are going to be snapshotted. This is to avoid a corrupted * version of files in the snapshots that had both buffered and * direct IO writes (even if they were done sequentially). */ list_for_each_entry(pending, head, list) btrfs_wait_ordered_extents(pending->root, U64_MAX, 0, U64_MAX); } } int btrfs_commit_transaction(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_transaction *cur_trans = trans->transaction; struct btrfs_transaction *prev_trans = NULL; int ret; ASSERT(refcount_read(&trans->use_count) == 1); /* * Some places just start a transaction to commit it. We need to make * sure that if this commit fails that the abort code actually marks the * transaction as failed, so set trans->dirty to make the abort code do * the right thing. */ trans->dirty = true; /* Stop the commit early if ->aborted is set */ if (unlikely(READ_ONCE(cur_trans->aborted))) { ret = cur_trans->aborted; btrfs_end_transaction(trans); return ret; } btrfs_trans_release_metadata(trans); trans->block_rsv = NULL; /* make a pass through all the delayed refs we have so far * any runnings procs may add more while we are here */ ret = btrfs_run_delayed_refs(trans, 0); if (ret) { btrfs_end_transaction(trans); return ret; } cur_trans = trans->transaction; /* * set the flushing flag so procs in this transaction have to * start sending their work down. */ cur_trans->delayed_refs.flushing = 1; smp_wmb(); btrfs_create_pending_block_groups(trans); ret = btrfs_run_delayed_refs(trans, 0); if (ret) { btrfs_end_transaction(trans); return ret; } if (!test_bit(BTRFS_TRANS_DIRTY_BG_RUN, &cur_trans->flags)) { int run_it = 0; /* this mutex is also taken before trying to set * block groups readonly. We need to make sure * that nobody has set a block group readonly * after a extents from that block group have been * allocated for cache files. btrfs_set_block_group_ro * will wait for the transaction to commit if it * finds BTRFS_TRANS_DIRTY_BG_RUN set. * * The BTRFS_TRANS_DIRTY_BG_RUN flag is also used to make sure * only one process starts all the block group IO. It wouldn't * hurt to have more than one go through, but there's no * real advantage to it either. */ mutex_lock(&fs_info->ro_block_group_mutex); if (!test_and_set_bit(BTRFS_TRANS_DIRTY_BG_RUN, &cur_trans->flags)) run_it = 1; mutex_unlock(&fs_info->ro_block_group_mutex); if (run_it) { ret = btrfs_start_dirty_block_groups(trans); if (ret) { btrfs_end_transaction(trans); return ret; } } } spin_lock(&fs_info->trans_lock); if (cur_trans->state >= TRANS_STATE_COMMIT_START) { spin_unlock(&fs_info->trans_lock); refcount_inc(&cur_trans->use_count); ret = btrfs_end_transaction(trans); wait_for_commit(cur_trans); if (unlikely(cur_trans->aborted)) ret = cur_trans->aborted; btrfs_put_transaction(cur_trans); return ret; } cur_trans->state = TRANS_STATE_COMMIT_START; wake_up(&fs_info->transaction_blocked_wait); if (cur_trans->list.prev != &fs_info->trans_list) { prev_trans = list_entry(cur_trans->list.prev, struct btrfs_transaction, list); if (prev_trans->state != TRANS_STATE_COMPLETED) { refcount_inc(&prev_trans->use_count); spin_unlock(&fs_info->trans_lock); wait_for_commit(prev_trans); ret = prev_trans->aborted; btrfs_put_transaction(prev_trans); if (ret) goto cleanup_transaction; } else { spin_unlock(&fs_info->trans_lock); } } else { spin_unlock(&fs_info->trans_lock); /* * The previous transaction was aborted and was already removed * from the list of transactions at fs_info->trans_list. So we * abort to prevent writing a new superblock that reflects a * corrupt state (pointing to trees with unwritten nodes/leafs). */ if (test_bit(BTRFS_FS_STATE_TRANS_ABORTED, &fs_info->fs_state)) { ret = -EROFS; goto cleanup_transaction; } } extwriter_counter_dec(cur_trans, trans->type); ret = btrfs_start_delalloc_flush(trans); if (ret) goto cleanup_transaction; ret = btrfs_run_delayed_items(trans); if (ret) goto cleanup_transaction; wait_event(cur_trans->writer_wait, extwriter_counter_read(cur_trans) == 0); /* some pending stuffs might be added after the previous flush. */ ret = btrfs_run_delayed_items(trans); if (ret) goto cleanup_transaction; btrfs_wait_delalloc_flush(trans); btrfs_scrub_pause(fs_info); /* * Ok now we need to make sure to block out any other joins while we * commit the transaction. We could have started a join before setting * COMMIT_DOING so make sure to wait for num_writers to == 1 again. */ spin_lock(&fs_info->trans_lock); cur_trans->state = TRANS_STATE_COMMIT_DOING; spin_unlock(&fs_info->trans_lock); wait_event(cur_trans->writer_wait, atomic_read(&cur_trans->num_writers) == 1); /* ->aborted might be set after the previous check, so check it */ if (unlikely(READ_ONCE(cur_trans->aborted))) { ret = cur_trans->aborted; goto scrub_continue; } /* * the reloc mutex makes sure that we stop * the balancing code from coming in and moving * extents around in the middle of the commit */ mutex_lock(&fs_info->reloc_mutex); /* * We needn't worry about the delayed items because we will * deal with them in create_pending_snapshot(), which is the * core function of the snapshot creation. */ ret = create_pending_snapshots(trans); if (ret) { mutex_unlock(&fs_info->reloc_mutex); goto scrub_continue; } /* * We insert the dir indexes of the snapshots and update the inode * of the snapshots' parents after the snapshot creation, so there * are some delayed items which are not dealt with. Now deal with * them. * * We needn't worry that this operation will corrupt the snapshots, * because all the tree which are snapshoted will be forced to COW * the nodes and leaves. */ ret = btrfs_run_delayed_items(trans); if (ret) { mutex_unlock(&fs_info->reloc_mutex); goto scrub_continue; } ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); if (ret) { mutex_unlock(&fs_info->reloc_mutex); goto scrub_continue; } /* * make sure none of the code above managed to slip in a * delayed item */ btrfs_assert_delayed_root_empty(fs_info); WARN_ON(cur_trans != trans->transaction); /* btrfs_commit_tree_roots is responsible for getting the * various roots consistent with each other. Every pointer * in the tree of tree roots has to point to the most up to date * root for every subvolume and other tree. So, we have to keep * the tree logging code from jumping in and changing any * of the trees. * * At this point in the commit, there can't be any tree-log * writers, but a little lower down we drop the trans mutex * and let new people in. By holding the tree_log_mutex * from now until after the super is written, we avoid races * with the tree-log code. */ mutex_lock(&fs_info->tree_log_mutex); ret = commit_fs_roots(trans); if (ret) { mutex_unlock(&fs_info->tree_log_mutex); mutex_unlock(&fs_info->reloc_mutex); goto scrub_continue; } /* * Since the transaction is done, we can apply the pending changes * before the next transaction. */ btrfs_apply_pending_changes(fs_info); /* commit_fs_roots gets rid of all the tree log roots, it is now * safe to free the root of tree log roots */ btrfs_free_log_root_tree(trans, fs_info); /* * commit_fs_roots() can call btrfs_save_ino_cache(), which generates * new delayed refs. Must handle them or qgroup can be wrong. */ ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); if (ret) { mutex_unlock(&fs_info->tree_log_mutex); mutex_unlock(&fs_info->reloc_mutex); goto scrub_continue; } /* * Since fs roots are all committed, we can get a quite accurate * new_roots. So let's do quota accounting. */ ret = btrfs_qgroup_account_extents(trans); if (ret < 0) { mutex_unlock(&fs_info->tree_log_mutex); mutex_unlock(&fs_info->reloc_mutex); goto scrub_continue; } ret = commit_cowonly_roots(trans); if (ret) { mutex_unlock(&fs_info->tree_log_mutex); mutex_unlock(&fs_info->reloc_mutex); goto scrub_continue; } /* * The tasks which save the space cache and inode cache may also * update ->aborted, check it. */ if (unlikely(READ_ONCE(cur_trans->aborted))) { ret = cur_trans->aborted; mutex_unlock(&fs_info->tree_log_mutex); mutex_unlock(&fs_info->reloc_mutex); goto scrub_continue; } btrfs_prepare_extent_commit(fs_info); cur_trans = fs_info->running_transaction; btrfs_set_root_node(&fs_info->tree_root->root_item, fs_info->tree_root->node); list_add_tail(&fs_info->tree_root->dirty_list, &cur_trans->switch_commits); btrfs_set_root_node(&fs_info->chunk_root->root_item, fs_info->chunk_root->node); list_add_tail(&fs_info->chunk_root->dirty_list, &cur_trans->switch_commits); switch_commit_roots(trans); ASSERT(list_empty(&cur_trans->dirty_bgs)); ASSERT(list_empty(&cur_trans->io_bgs)); update_super_roots(fs_info); btrfs_set_super_log_root(fs_info->super_copy, 0); btrfs_set_super_log_root_level(fs_info->super_copy, 0); memcpy(fs_info->super_for_commit, fs_info->super_copy, sizeof(*fs_info->super_copy)); btrfs_commit_device_sizes(cur_trans); clear_bit(BTRFS_FS_LOG1_ERR, &fs_info->flags); clear_bit(BTRFS_FS_LOG2_ERR, &fs_info->flags); btrfs_trans_release_chunk_metadata(trans); spin_lock(&fs_info->trans_lock); cur_trans->state = TRANS_STATE_UNBLOCKED; fs_info->running_transaction = NULL; spin_unlock(&fs_info->trans_lock); mutex_unlock(&fs_info->reloc_mutex); wake_up(&fs_info->transaction_wait); ret = btrfs_write_and_wait_transaction(trans); if (ret) { btrfs_handle_fs_error(fs_info, ret, "Error while writing out transaction"); mutex_unlock(&fs_info->tree_log_mutex); goto scrub_continue; } ret = write_all_supers(fs_info, 0); /* * the super is written, we can safely allow the tree-loggers * to go about their business */ mutex_unlock(&fs_info->tree_log_mutex); if (ret) goto scrub_continue; btrfs_finish_extent_commit(trans); if (test_bit(BTRFS_TRANS_HAVE_FREE_BGS, &cur_trans->flags)) btrfs_clear_space_info_full(fs_info); fs_info->last_trans_committed = cur_trans->transid; /* * We needn't acquire the lock here because there is no other task * which can change it. */ cur_trans->state = TRANS_STATE_COMPLETED; wake_up(&cur_trans->commit_wait); clear_bit(BTRFS_FS_NEED_ASYNC_COMMIT, &fs_info->flags); spin_lock(&fs_info->trans_lock); list_del_init(&cur_trans->list); spin_unlock(&fs_info->trans_lock); btrfs_put_transaction(cur_trans); btrfs_put_transaction(cur_trans); if (trans->type & __TRANS_FREEZABLE) sb_end_intwrite(fs_info->sb); trace_btrfs_transaction_commit(trans->root); btrfs_scrub_continue(fs_info); if (current->journal_info == trans) current->journal_info = NULL; kmem_cache_free(btrfs_trans_handle_cachep, trans); return ret; scrub_continue: btrfs_scrub_continue(fs_info); cleanup_transaction: btrfs_trans_release_metadata(trans); btrfs_cleanup_pending_block_groups(trans); btrfs_trans_release_chunk_metadata(trans); trans->block_rsv = NULL; btrfs_warn(fs_info, "Skipping commit of aborted transaction."); if (current->journal_info == trans) current->journal_info = NULL; cleanup_transaction(trans, ret); return ret; } /* * return < 0 if error * 0 if there are no more dead_roots at the time of call * 1 there are more to be processed, call me again * * The return value indicates there are certainly more snapshots to delete, but * if there comes a new one during processing, it may return 0. We don't mind, * because btrfs_commit_super will poke cleaner thread and it will process it a * few seconds later. */ int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root) { int ret; struct btrfs_fs_info *fs_info = root->fs_info; spin_lock(&fs_info->trans_lock); if (list_empty(&fs_info->dead_roots)) { spin_unlock(&fs_info->trans_lock); return 0; } root = list_first_entry(&fs_info->dead_roots, struct btrfs_root, root_list); list_del_init(&root->root_list); spin_unlock(&fs_info->trans_lock); btrfs_debug(fs_info, "cleaner removing %llu", root->root_key.objectid); btrfs_kill_all_delayed_nodes(root); if (btrfs_header_backref_rev(root->node) < BTRFS_MIXED_BACKREF_REV) ret = btrfs_drop_snapshot(root, NULL, 0, 0); else ret = btrfs_drop_snapshot(root, NULL, 1, 0); return (ret < 0) ? 0 : 1; } void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info) { unsigned long prev; unsigned long bit; prev = xchg(&fs_info->pending_changes, 0); if (!prev) return; bit = 1 << BTRFS_PENDING_SET_INODE_MAP_CACHE; if (prev & bit) btrfs_set_opt(fs_info->mount_opt, INODE_MAP_CACHE); prev &= ~bit; bit = 1 << BTRFS_PENDING_CLEAR_INODE_MAP_CACHE; if (prev & bit) btrfs_clear_opt(fs_info->mount_opt, INODE_MAP_CACHE); prev &= ~bit; bit = 1 << BTRFS_PENDING_COMMIT; if (prev & bit) btrfs_debug(fs_info, "pending commit done"); prev &= ~bit; if (prev) btrfs_warn(fs_info, "unknown pending changes left 0x%lx, ignoring", prev); }
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