diff options
Diffstat (limited to 'fs/btrfs/transaction.c')
| -rw-r--r-- | fs/btrfs/transaction.c | 946 |
1 files changed, 537 insertions, 409 deletions
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index beb6c69cd1e5..d1f1da6820fb 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -10,17 +10,19 @@ #include <linux/pagemap.h> #include <linux/blkdev.h> #include <linux/uuid.h> +#include <linux/timekeeping.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" +#include "space-info.h" +#include "zoned.h" #define BTRFS_ROOT_TRANS_TAG 0 @@ -107,6 +109,11 @@ static const unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = { __TRANS_JOIN | __TRANS_JOIN_NOLOCK | __TRANS_JOIN_NOSTART), + [TRANS_STATE_SUPER_COMMITTED] = (__TRANS_START | + __TRANS_ATTACH | + __TRANS_JOIN | + __TRANS_JOIN_NOLOCK | + __TRANS_JOIN_NOSTART), [TRANS_STATE_COMPLETED] = (__TRANS_START | __TRANS_ATTACH | __TRANS_JOIN | @@ -141,7 +148,7 @@ void btrfs_put_transaction(struct btrfs_transaction *transaction) struct btrfs_block_group, bg_list); list_del_init(&cache->bg_list); - btrfs_put_block_group_trimming(cache); + btrfs_unfreeze_block_group(cache); btrfs_put_block_group(cache); } WARN_ON(!list_empty(&transaction->dev_update_list)); @@ -155,14 +162,22 @@ static noinline void switch_commit_roots(struct btrfs_trans_handle *trans) struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_root *root, *tmp; + /* + * At this point no one can be using this transaction to modify any tree + * and no one can start another transaction to modify any tree either. + */ + ASSERT(cur_trans->state == TRANS_STATE_COMMIT_DOING); + down_write(&fs_info->commit_root_sem); + + if (test_bit(BTRFS_FS_RELOC_RUNNING, &fs_info->flags)) + fs_info->last_reloc_trans = trans->transid; + 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); } @@ -179,6 +194,7 @@ static noinline void switch_commit_roots(struct btrfs_trans_handle *trans) spin_lock(&cur_trans->dropped_roots_lock); } spin_unlock(&cur_trans->dropped_roots_lock); + up_write(&fs_info->commit_root_sem); } @@ -208,8 +224,11 @@ static inline int extwriter_counter_read(struct btrfs_transaction *trans) } /* - * To be called after all the new block groups attached to the transaction - * handle have been created (btrfs_create_pending_block_groups()). + * To be called after doing the chunk btree updates right after allocating a new + * chunk (after btrfs_chunk_alloc_add_chunk_item() is called), when removing a + * chunk after all chunk btree updates and after finishing the second phase of + * chunk allocation (btrfs_create_pending_block_groups()) in case some block + * group had its chunk item insertion delayed to the second phase. */ void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans) { @@ -218,10 +237,8 @@ void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans) 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, NULL); trans->chunk_bytes_reserved = 0; } @@ -236,14 +253,14 @@ static noinline int join_transaction(struct btrfs_fs_info *fs_info, 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)) { + if (BTRFS_FS_ERROR(fs_info)) { spin_unlock(&fs_info->trans_lock); return -EROFS; } cur_trans = fs_info->running_transaction; if (cur_trans) { - if (cur_trans->aborted) { + if (TRANS_ABORTED(cur_trans)) { spin_unlock(&fs_info->trans_lock); return cur_trans->aborted; } @@ -255,6 +272,8 @@ loop: atomic_inc(&cur_trans->num_writers); extwriter_counter_inc(cur_trans, type); spin_unlock(&fs_info->trans_lock); + btrfs_lockdep_acquire(fs_info, btrfs_trans_num_writers); + btrfs_lockdep_acquire(fs_info, btrfs_trans_num_extwriters); return 0; } spin_unlock(&fs_info->trans_lock); @@ -276,21 +295,30 @@ loop: if (!cur_trans) return -ENOMEM; + btrfs_lockdep_acquire(fs_info, btrfs_trans_num_writers); + btrfs_lockdep_acquire(fs_info, btrfs_trans_num_extwriters); + 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 */ + btrfs_lockdep_release(fs_info, btrfs_trans_num_extwriters); + btrfs_lockdep_release(fs_info, btrfs_trans_num_writers); kfree(cur_trans); goto loop; - } else if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { + } else if (BTRFS_FS_ERROR(fs_info)) { spin_unlock(&fs_info->trans_lock); + btrfs_lockdep_release(fs_info, btrfs_trans_num_extwriters); + btrfs_lockdep_release(fs_info, btrfs_trans_num_writers); kfree(cur_trans); return -EROFS; } cur_trans->fs_info = fs_info; + atomic_set(&cur_trans->pending_ordered, 0); + init_waitqueue_head(&cur_trans->pending_wait); atomic_set(&cur_trans->num_writers, 1); extwriter_counter_init(cur_trans, type); init_waitqueue_head(&cur_trans->writer_wait); @@ -333,9 +361,13 @@ loop: spin_lock_init(&cur_trans->dirty_bgs_lock); INIT_LIST_HEAD(&cur_trans->deleted_bgs); spin_lock_init(&cur_trans->dropped_roots_lock); + INIT_LIST_HEAD(&cur_trans->releasing_ebs); + spin_lock_init(&cur_trans->releasing_ebs_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); + IO_TREE_TRANS_DIRTY_PAGES, NULL); + extent_io_tree_init(fs_info, &cur_trans->pinned_extents, + IO_TREE_FS_PINNED_EXTENTS, NULL); fs_info->generation++; cur_trans->transid = fs_info->generation; fs_info->running_transaction = cur_trans; @@ -346,20 +378,20 @@ loop: } /* - * 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 + * This does all the record keeping required to make sure that a shareable 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; + int ret = 0; - if ((test_bit(BTRFS_ROOT_REF_COWS, &root->state) && + if ((test_bit(BTRFS_ROOT_SHAREABLE, &root->state) && root->last_trans < trans->transid) || force) { - WARN_ON(root == fs_info->extent_root); WARN_ON(!force && root->commit_root != root->node); /* @@ -404,11 +436,11 @@ static int record_root_in_trans(struct btrfs_trans_handle *trans, * 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); + ret = btrfs_init_reloc_root(trans, root); smp_mb__before_atomic(); clear_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state); } - return 0; + return ret; } @@ -435,8 +467,9 @@ int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_fs_info *fs_info = root->fs_info; + int ret; - if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state)) + if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) return 0; /* @@ -449,17 +482,17 @@ int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans, return 0; mutex_lock(&fs_info->reloc_mutex); - record_root_in_trans(trans, root, 0); + ret = record_root_in_trans(trans, root, 0); mutex_unlock(&fs_info->reloc_mutex); - return 0; + return ret; } static inline int is_transaction_blocked(struct btrfs_transaction *trans) { return (trans->state >= TRANS_STATE_COMMIT_START && trans->state < TRANS_STATE_UNBLOCKED && - !trans->aborted); + !TRANS_ABORTED(trans)); } /* wait for commit against the current transaction to become unblocked @@ -476,9 +509,10 @@ static void wait_current_trans(struct btrfs_fs_info *fs_info) refcount_inc(&cur_trans->use_count); spin_unlock(&fs_info->trans_lock); + btrfs_might_wait_for_state(fs_info, BTRFS_LOCKDEP_TRANS_UNBLOCKED); wait_event(fs_info->transaction_wait, cur_trans->state >= TRANS_STATE_UNBLOCKED || - cur_trans->aborted); + TRANS_ABORTED(cur_trans)); btrfs_put_transaction(cur_trans); } else { spin_unlock(&fs_info->trans_lock); @@ -501,7 +535,7 @@ 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) || + !test_bit(BTRFS_ROOT_SHAREABLE, &root->state) || root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || root->reloc_root) return false; @@ -521,12 +555,10 @@ start_transaction(struct btrfs_root *root, unsigned int num_items, u64 num_bytes = 0; u64 qgroup_reserved = 0; bool reloc_reserved = false; + bool do_chunk_alloc = 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)) + if (BTRFS_FS_ERROR(fs_info)) return ERR_PTR(-EROFS); if (current->journal_info) { @@ -561,7 +593,8 @@ start_transaction(struct btrfs_root *root, unsigned int num_items, * 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) { + if (flush == BTRFS_RESERVE_FLUSH_ALL && + btrfs_block_rsv_full(delayed_refs_rsv) == 0) { delayed_refs_bytes = num_bytes; num_bytes <<= 1; } @@ -574,7 +607,7 @@ start_transaction(struct btrfs_root *root, unsigned int num_items, reloc_reserved = true; } - ret = btrfs_block_rsv_add(root, rsv, num_bytes, flush); + ret = btrfs_block_rsv_add(fs_info, rsv, num_bytes, flush); if (ret) goto reserve_fail; if (delayed_refs_bytes) { @@ -582,8 +615,11 @@ start_transaction(struct btrfs_root *root, unsigned int num_items, delayed_refs_bytes); num_bytes -= delayed_refs_bytes; } + + if (rsv->space_info->force_alloc) + do_chunk_alloc = true; } else if (num_items == 0 && flush == BTRFS_RESERVE_FLUSH_ALL && - !delayed_refs_rsv->full) { + !btrfs_block_rsv_full(delayed_refs_rsv)) { /* * Some people call with btrfs_start_transaction(root, 0) * because they can be throttled, but have some other mechanism @@ -635,12 +671,10 @@ again: 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(); @@ -660,10 +694,41 @@ again: } got_it: - btrfs_record_root_in_trans(h, root); - if (!current->journal_info) current->journal_info = h; + + /* + * If the space_info is marked ALLOC_FORCE then we'll get upgraded to + * ALLOC_FORCE the first run through, and then we won't allocate for + * anybody else who races in later. We don't care about the return + * value here. + */ + if (do_chunk_alloc && num_bytes) { + u64 flags = h->block_rsv->space_info->flags; + + btrfs_chunk_alloc(h, btrfs_get_alloc_profile(fs_info, flags), + CHUNK_ALLOC_NO_FORCE); + } + + /* + * btrfs_record_root_in_trans() needs to alloc new extents, and may + * call btrfs_join_transaction() while we're also starting a + * transaction. + * + * Thus it need to be called after current->journal_info initialized, + * or we can deadlock. + */ + ret = btrfs_record_root_in_trans(h, root); + if (ret) { + /* + * The transaction handle is fully initialized and linked with + * other structures so it needs to be ended in case of errors, + * not just freed. + */ + btrfs_end_transaction(h); + return ERR_PTR(ret); + } + return h; join_fail: @@ -673,7 +738,7 @@ join_fail: alloc_fail: if (num_bytes) btrfs_block_rsv_release(fs_info, &fs_info->trans_block_rsv, - num_bytes); + num_bytes, NULL); reserve_fail: btrfs_qgroup_free_meta_pertrans(root, qgroup_reserved); return ERR_PTR(ret); @@ -688,43 +753,10 @@ struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv( struct btrfs_root *root, - unsigned int num_items, - int min_factor) + unsigned int num_items) { - 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; + return start_transaction(root, num_items, TRANS_START, + BTRFS_RESERVE_FLUSH_ALL_STEAL, false); } struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root) @@ -788,10 +820,50 @@ btrfs_attach_transaction_barrier(struct btrfs_root *root) return trans; } -/* wait for a transaction commit to be fully complete */ -static noinline void wait_for_commit(struct btrfs_transaction *commit) +/* Wait for a transaction commit to reach at least the given state. */ +static noinline void wait_for_commit(struct btrfs_transaction *commit, + const enum btrfs_trans_state min_state) { - wait_event(commit->commit_wait, commit->state == TRANS_STATE_COMPLETED); + struct btrfs_fs_info *fs_info = commit->fs_info; + u64 transid = commit->transid; + bool put = false; + + /* + * At the moment this function is called with min_state either being + * TRANS_STATE_COMPLETED or TRANS_STATE_SUPER_COMMITTED. + */ + if (min_state == TRANS_STATE_COMPLETED) + btrfs_might_wait_for_state(fs_info, BTRFS_LOCKDEP_TRANS_COMPLETED); + else + btrfs_might_wait_for_state(fs_info, BTRFS_LOCKDEP_TRANS_SUPER_COMMITTED); + + while (1) { + wait_event(commit->commit_wait, commit->state >= min_state); + if (put) + btrfs_put_transaction(commit); + + if (min_state < TRANS_STATE_COMPLETED) + break; + + /* + * A transaction isn't really completed until all of the + * previous transactions are completed, but with fsync we can + * end up with SUPER_COMMITTED transactions before a COMPLETED + * transaction. Wait for those. + */ + + spin_lock(&fs_info->trans_lock); + commit = list_first_entry_or_null(&fs_info->trans_list, + struct btrfs_transaction, + list); + if (!commit || commit->transid > transid) { + spin_unlock(&fs_info->trans_lock); + break; + } + refcount_inc(&commit->use_count); + put = true; + spin_unlock(&fs_info->trans_lock); + } } int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid) @@ -846,7 +918,7 @@ int btrfs_wait_for_commit(struct btrfs_fs_info *fs_info, u64 transid) goto out; /* nothing committing|committed */ } - wait_for_commit(cur_trans); + wait_for_commit(cur_trans, TRANS_STATE_COMPLETED); btrfs_put_transaction(cur_trans); out: return ret; @@ -857,24 +929,23 @@ void btrfs_throttle(struct btrfs_fs_info *fs_info) wait_current_trans(fs_info); } -static int should_end_transaction(struct btrfs_trans_handle *trans) +static bool 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 true; return !!btrfs_block_rsv_check(&fs_info->global_block_rsv, 5); } -int btrfs_should_end_transaction(struct btrfs_trans_handle *trans) +bool 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; + test_bit(BTRFS_DELAYED_REFS_FLUSHING, &cur_trans->delayed_refs.flags)) + return true; return should_end_transaction(trans); } @@ -896,7 +967,7 @@ static void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans) 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, NULL); trans->bytes_reserved = 0; } @@ -929,6 +1000,10 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, extwriter_counter_dec(cur_trans, trans->type); cond_wake_up(&cur_trans->writer_wait); + + btrfs_lockdep_release(info, btrfs_trans_num_extwriters); + btrfs_lockdep_release(info, btrfs_trans_num_writers); + btrfs_put_transaction(cur_trans); if (current->journal_info == trans) @@ -937,10 +1012,12 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, if (throttle) btrfs_run_delayed_iputs(info); - if (trans->aborted || - test_bit(BTRFS_FS_STATE_ERROR, &info->fs_state)) { + if (TRANS_ABORTED(trans) || BTRFS_FS_ERROR(info)) { wake_up_process(info->transaction_kthread); - err = -EIO; + if (TRANS_ABORTED(trans)) + err = trans->aborted; + else + err = -EROFS; } kmem_cache_free(btrfs_trans_handle_cachep, trans); @@ -1039,7 +1116,7 @@ static int __btrfs_wait_marked_extents(struct btrfs_fs_info *fs_info, * 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); + EXTENT_NEED_WAIT, &cached_state); if (err == -ENOMEM) err = 0; if (!err) @@ -1180,19 +1257,21 @@ static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans) struct extent_buffer *eb; int ret; + /* + * At this point no one can be using this transaction to modify any tree + * and no one can start another transaction to modify any tree either. + */ + ASSERT(trans->transaction->state == TRANS_STATE_COMMIT_DOING); + eb = btrfs_lock_root_node(fs_info->tree_root); ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, - 0, &eb); + 0, &eb, BTRFS_NESTING_COW); 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; @@ -1207,10 +1286,6 @@ static noinline int commit_cowonly_roots(struct btrfs_trans_handle *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; @@ -1219,21 +1294,29 @@ again: 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); + 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; } + /* Now flush any delayed refs generated by updating all of the roots */ + 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; + + /* + * We're writing the dirty block groups, which could generate + * delayed refs, which could generate more dirty block groups, + * so we want to keep this flushing in this loop to make sure + * everything gets run. + */ ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); if (ret) return ret; @@ -1242,9 +1325,6 @@ again: 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; @@ -1253,6 +1333,32 @@ again: } /* + * If we had a pending drop we need to see if there are any others left in our + * dead roots list, and if not clear our bit and wake any waiters. + */ +void btrfs_maybe_wake_unfinished_drop(struct btrfs_fs_info *fs_info) +{ + /* + * We put the drop in progress roots at the front of the list, so if the + * first entry doesn't have UNFINISHED_DROP set we can wake everybody + * up. + */ + spin_lock(&fs_info->trans_lock); + if (!list_empty(&fs_info->dead_roots)) { + struct btrfs_root *root = list_first_entry(&fs_info->dead_roots, + struct btrfs_root, + root_list); + if (test_bit(BTRFS_ROOT_UNFINISHED_DROP, &root->state)) { + spin_unlock(&fs_info->trans_lock); + return; + } + } + spin_unlock(&fs_info->trans_lock); + + btrfs_wake_unfinished_drop(fs_info); +} + +/* * 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 @@ -1262,13 +1368,21 @@ 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); + if (list_empty(&root->root_list)) { + btrfs_grab_root(root); + + /* We want to process the partially complete drops first. */ + if (test_bit(BTRFS_ROOT_UNFINISHED_DROP, &root->state)) + list_add(&root->root_list, &fs_info->dead_roots); + else + list_add_tail(&root->root_list, &fs_info->dead_roots); + } spin_unlock(&fs_info->trans_lock); } /* - * update all the cowonly tree roots on disk + * Update each subvolume root and its relocation root, if it exists, in the tree + * of tree roots. Also free log roots if they exist. */ static noinline int commit_fs_roots(struct btrfs_trans_handle *trans) { @@ -1276,7 +1390,12 @@ static noinline int commit_fs_roots(struct btrfs_trans_handle *trans) struct btrfs_root *gang[8]; int i; int ret; - int err = 0; + + /* + * At this point no one can be using this transaction to modify any tree + * and no one can start another transaction to modify any tree either. + */ + ASSERT(trans->transaction->state == TRANS_STATE_COMMIT_DOING); spin_lock(&fs_info->fs_roots_radix_lock); while (1) { @@ -1288,15 +1407,25 @@ static noinline int commit_fs_roots(struct btrfs_trans_handle *trans) break; for (i = 0; i < ret; i++) { struct btrfs_root *root = gang[i]; + int ret2; + + /* + * At this point we can neither have tasks logging inodes + * from a root nor trying to commit a log tree. + */ + ASSERT(atomic_read(&root->log_writers) == 0); + ASSERT(atomic_read(&root->log_commit[0]) == 0); + ASSERT(atomic_read(&root->log_commit[1]) == 0); + 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); + ret2 = btrfs_update_reloc_root(trans, root); + if (ret2) + return ret2; /* see comments in should_cow_block() */ clear_bit(BTRFS_ROOT_FORCE_COW, &root->state); @@ -1309,17 +1438,17 @@ static noinline int commit_fs_roots(struct btrfs_trans_handle *trans) root->node); } - err = btrfs_update_root(trans, fs_info->tree_root, + ret2 = btrfs_update_root(trans, fs_info->tree_root, &root->root_key, &root->root_item); + if (ret2) + return ret2; 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; + return 0; } /* @@ -1337,8 +1466,10 @@ int btrfs_defrag_root(struct btrfs_root *root) while (1) { trans = btrfs_start_transaction(root, 0); - if (IS_ERR(trans)) - return PTR_ERR(trans); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + break; + } ret = btrfs_defrag_leaves(trans, root); @@ -1389,13 +1520,26 @@ static int qgroup_account_snapshot(struct btrfs_trans_handle *trans, * recorded root will never be updated again, causing an outdated root * item. */ - record_root_in_trans(trans, src, 1); + ret = record_root_in_trans(trans, src, 1); + if (ret) + return ret; /* - * We are going to commit transaction, see btrfs_commit_transaction() - * comment for reason locking tree_log_mutex + * btrfs_qgroup_inherit relies on a consistent view of the usage for the + * src root, so we must run the delayed refs here. + * + * However this isn't particularly fool proof, because there's no + * synchronization keeping us from changing the tree after this point + * before we do the qgroup_inherit, or even from making changes while + * we're doing the qgroup_inherit. But that's a problem for the future, + * for now flush the delayed refs to narrow the race window where the + * qgroup counters could end up wrong. */ - mutex_lock(&fs_info->tree_log_mutex); + ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); + if (ret) { + btrfs_abort_transaction(trans, ret); + return ret; + } ret = commit_fs_roots(trans); if (ret) @@ -1432,8 +1576,6 @@ static int qgroup_account_snapshot(struct btrfs_trans_handle *trans, "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. @@ -1441,7 +1583,7 @@ out: * insert_dir_item() */ if (!ret) - record_root_in_trans(trans, parent, 1); + ret = record_root_in_trans(trans, parent, 1); return ret; } @@ -1477,7 +1619,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, u64 index = 0; u64 objectid; u64 root_flags; - uuid_le new_uuid; ASSERT(pending->path); path = pending->path; @@ -1485,7 +1626,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, ASSERT(pending->root_item); new_root_item = pending->root_item; - pending->error = btrfs_find_free_objectid(tree_root, &objectid); + pending->error = btrfs_get_free_objectid(tree_root, &objectid); if (pending->error) goto no_free_objectid; @@ -1498,7 +1639,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, btrfs_reloc_pre_snapshot(pending, &to_reserve); if (to_reserve > 0) { - pending->error = btrfs_block_rsv_add(root, + pending->error = btrfs_block_rsv_add(fs_info, &pending->block_rsv, to_reserve, BTRFS_RESERVE_NO_FLUSH); @@ -1519,8 +1660,9 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, dentry = pending->dentry; parent_inode = pending->dir; parent_root = BTRFS_I(parent_inode)->root; - record_root_in_trans(trans, parent_root, 0); - + ret = record_root_in_trans(trans, parent_root, 0); + if (ret) + goto fail; cur_time = current_time(parent_inode); /* @@ -1556,7 +1698,11 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, goto fail; } - record_root_in_trans(trans, root, 0); + ret = record_root_in_trans(trans, root, 0); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto fail; + } 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); @@ -1570,8 +1716,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 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); + generate_random_guid(new_root_item->uuid); memcpy(new_root_item->parent_uuid, root->root_item.uuid, BTRFS_UUID_SIZE); if (!(root_flags & BTRFS_ROOT_SUBVOL_RDONLY)) { @@ -1587,7 +1732,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 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); + ret = btrfs_cow_block(trans, root, old, NULL, 0, &old, + BTRFS_NESTING_COW); if (ret) { btrfs_tree_unlock(old); free_extent_buffer(old); @@ -1595,8 +1741,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 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); @@ -1633,9 +1777,10 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, } key.offset = (u64)-1; - pending->snap = btrfs_read_fs_root_no_name(fs_info, &key); + pending->snap = btrfs_get_new_fs_root(fs_info, objectid, pending->anon_dev); if (IS_ERR(pending->snap)) { ret = PTR_ERR(pending->snap); + pending->snap = NULL; btrfs_abort_transaction(trans, ret); goto fail; } @@ -1646,12 +1791,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 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. @@ -1675,14 +1814,15 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 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); + parent_inode->i_mtime = current_time(parent_inode); + parent_inode->i_ctime = parent_inode->i_mtime; + ret = btrfs_update_inode_fallback(trans, parent_root, BTRFS_I(parent_inode)); if (ret) { btrfs_abort_transaction(trans, ret); goto fail; } - ret = btrfs_uuid_tree_add(trans, new_uuid.b, BTRFS_UUID_KEY_SUBVOL, + ret = btrfs_uuid_tree_add(trans, new_root_item->uuid, + BTRFS_UUID_KEY_SUBVOL, objectid); if (ret) { btrfs_abort_transaction(trans, ret); @@ -1698,12 +1838,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, } } - 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: @@ -1756,6 +1890,8 @@ static void update_super_roots(struct btrfs_fs_info *fs_info) super->root_level = root_item->level; if (btrfs_test_opt(fs_info, SPACE_CACHE)) super->cache_generation = root_item->generation; + else if (test_bit(BTRFS_FS_CLEANUP_SPACE_CACHE_V1, &fs_info->flags)) + super->cache_generation = 0; if (test_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags)) super->uuid_tree_generation = root_item->generation; } @@ -1786,74 +1922,14 @@ int btrfs_transaction_blocked(struct btrfs_fs_info *info) 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) +void btrfs_commit_transaction_async(struct btrfs_trans_handle *trans) { 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; - } + /* Kick the transaction kthread. */ + set_bit(BTRFS_FS_COMMIT_TRANS, &fs_info->flags); + wake_up_process(fs_info->transaction_kthread); /* take transaction reference */ cur_trans = trans->transaction; @@ -1862,28 +1938,16 @@ int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans, btrfs_end_transaction(trans); /* - * Tell lockdep we've released the freeze rwsem, since the - * async commit thread will be the one to unlock it. + * Wait for the current transaction commit to start and block + * subsequent transaction joins */ - 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_might_wait_for_state(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_START); + wait_event(fs_info->transaction_blocked_wait, + cur_trans->state >= TRANS_STATE_COMMIT_START || + TRANS_ABORTED(cur_trans)); 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; @@ -1902,15 +1966,31 @@ static void cleanup_transaction(struct btrfs_trans_handle *trans, int err) */ 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); + + /* + * The thread has already released the lockdep map as reader + * already in btrfs_commit_transaction(). + */ + btrfs_might_wait_for_event(fs_info, btrfs_trans_num_writers); wait_event(cur_trans->writer_wait, atomic_read(&cur_trans->num_writers) == 1); spin_lock(&fs_info->trans_lock); } + + /* + * Now that we know no one else is still using the transaction we can + * remove the transaction from the list of transactions. This avoids + * the transaction kthread from cleaning up the transaction while some + * other task is still using it, which could result in a use-after-free + * on things like log trees, as it forces the transaction kthread to + * wait for this transaction to be cleaned up by us. + */ + list_del_init(&cur_trans->list); + spin_unlock(&fs_info->trans_lock); btrfs_cleanup_one_transaction(trans->transaction, fs_info); @@ -1925,7 +2005,7 @@ static void cleanup_transaction(struct btrfs_trans_handle *trans, int err) btrfs_put_transaction(cur_trans); btrfs_put_transaction(cur_trans); - trace_btrfs_transaction_commit(trans->root); + trace_btrfs_transaction_commit(fs_info); if (current->journal_info == trans) current->journal_info = NULL; @@ -1949,63 +2029,64 @@ static void btrfs_cleanup_pending_block_groups(struct btrfs_trans_handle *trans) } } -static inline int btrfs_start_delalloc_flush(struct btrfs_trans_handle *trans) +static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info) { - struct btrfs_fs_info *fs_info = trans->fs_info; - /* - * We use writeback_inodes_sb here because if we used + * We use try_to_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. + * + * Note that try_to_writeback_inodes_sb() will only trigger writeback + * if it can read lock sb->s_umount. It will always be able to lock it, + * except when the filesystem is being unmounted or being frozen, but in + * those cases sync_filesystem() is called, which results in calling + * writeback_inodes_sb() while holding a write lock on sb->s_umount. + * Note that we don't call writeback_inodes_sb() directly, because it + * will emit a warning if sb->s_umount is not locked. */ - 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; - } - } + if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) + try_to_writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC); return 0; } -static inline void btrfs_wait_delalloc_flush(struct btrfs_trans_handle *trans) +static inline void btrfs_wait_delalloc_flush(struct btrfs_fs_info *fs_info) { - struct btrfs_fs_info *fs_info = trans->fs_info; - - if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) { + 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); - } +/* + * Add a pending snapshot associated with the given transaction handle to the + * respective handle. This must be called after the transaction commit started + * and while holding fs_info->trans_lock. + * This serves to guarantee a caller of btrfs_commit_transaction() that it can + * safely free the pending snapshot pointer in case btrfs_commit_transaction() + * returns an error. + */ +static void add_pending_snapshot(struct btrfs_trans_handle *trans) +{ + struct btrfs_transaction *cur_trans = trans->transaction; + + if (!trans->pending_snapshot) + return; + + lockdep_assert_held(&trans->fs_info->trans_lock); + ASSERT(cur_trans->state >= TRANS_STATE_COMMIT_START); + + list_add(&trans->pending_snapshot->list, &cur_trans->pending_snapshots); +} + +static void update_commit_stats(struct btrfs_fs_info *fs_info, ktime_t interval) +{ + fs_info->commit_stats.commit_count++; + fs_info->commit_stats.last_commit_dur = interval; + fs_info->commit_stats.max_commit_dur = + max_t(u64, fs_info->commit_stats.max_commit_dur, interval); + fs_info->commit_stats.total_commit_dur += interval; } int btrfs_commit_transaction(struct btrfs_trans_handle *trans) @@ -2014,53 +2095,38 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) struct btrfs_transaction *cur_trans = trans->transaction; struct btrfs_transaction *prev_trans = NULL; int ret; + ktime_t start_time; + ktime_t interval; 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; + btrfs_trans_state_lockdep_acquire(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_START); /* Stop the commit early if ->aborted is set */ - if (unlikely(READ_ONCE(cur_trans->aborted))) { + if (TRANS_ABORTED(cur_trans)) { ret = cur_trans->aborted; - btrfs_end_transaction(trans); - return ret; + goto lockdep_trans_commit_start_release; } 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. + * We only want one transaction commit doing the flushing so we do not + * waste a bunch of time on lock contention on the extent root node. */ - cur_trans->delayed_refs.flushing = 1; - smp_wmb(); + if (!test_and_set_bit(BTRFS_DELAYED_REFS_FLUSHING, + &cur_trans->delayed_refs.flags)) { + /* + * Make a pass through all the delayed refs we have so far. + * Any running threads may add more while we are here. + */ + ret = btrfs_run_delayed_refs(trans, 0); + if (ret) + goto lockdep_trans_commit_start_release; + } 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; @@ -2085,22 +2151,29 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) if (run_it) { ret = btrfs_start_dirty_block_groups(trans); - if (ret) { - btrfs_end_transaction(trans); - return ret; - } + if (ret) + goto lockdep_trans_commit_start_release; } } spin_lock(&fs_info->trans_lock); if (cur_trans->state >= TRANS_STATE_COMMIT_START) { + enum btrfs_trans_state want_state = TRANS_STATE_COMPLETED; + + add_pending_snapshot(trans); + spin_unlock(&fs_info->trans_lock); refcount_inc(&cur_trans->use_count); - ret = btrfs_end_transaction(trans); - wait_for_commit(cur_trans); + if (trans->in_fsync) + want_state = TRANS_STATE_SUPER_COMMITTED; + + btrfs_trans_state_lockdep_release(fs_info, + BTRFS_LOCKDEP_TRANS_COMMIT_START); + ret = btrfs_end_transaction(trans); + wait_for_commit(cur_trans, want_state); - if (unlikely(cur_trans->aborted)) + if (TRANS_ABORTED(cur_trans)) ret = cur_trans->aborted; btrfs_put_transaction(cur_trans); @@ -2110,20 +2183,27 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) cur_trans->state = TRANS_STATE_COMMIT_START; wake_up(&fs_info->transaction_blocked_wait); + btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_START); if (cur_trans->list.prev != &fs_info->trans_list) { + enum btrfs_trans_state want_state = TRANS_STATE_COMPLETED; + + if (trans->in_fsync) + want_state = TRANS_STATE_SUPER_COMMITTED; + prev_trans = list_entry(cur_trans->list.prev, struct btrfs_transaction, list); - if (prev_trans->state != TRANS_STATE_COMPLETED) { + if (prev_trans->state < want_state) { refcount_inc(&prev_trans->use_count); spin_unlock(&fs_info->trans_lock); - wait_for_commit(prev_trans); - ret = prev_trans->aborted; + wait_for_commit(prev_trans, want_state); + + ret = READ_ONCE(prev_trans->aborted); btrfs_put_transaction(prev_trans); if (ret) - goto cleanup_transaction; + goto lockdep_release; } else { spin_unlock(&fs_info->trans_lock); } @@ -2135,31 +2215,55 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) * 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)) { + if (BTRFS_FS_ERROR(fs_info)) { ret = -EROFS; - goto cleanup_transaction; + goto lockdep_release; } } + /* + * Get the time spent on the work done by the commit thread and not + * the time spent waiting on a previous commit + */ + start_time = ktime_get_ns(); + extwriter_counter_dec(cur_trans, trans->type); - ret = btrfs_start_delalloc_flush(trans); + ret = btrfs_start_delalloc_flush(fs_info); if (ret) - goto cleanup_transaction; + goto lockdep_release; ret = btrfs_run_delayed_items(trans); if (ret) - goto cleanup_transaction; + goto lockdep_release; + /* + * The thread has started/joined the transaction thus it holds the + * lockdep map as a reader. It has to release it before acquiring the + * lockdep map as a writer. + */ + btrfs_lockdep_release(fs_info, btrfs_trans_num_extwriters); + btrfs_might_wait_for_event(fs_info, btrfs_trans_num_extwriters); 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) + if (ret) { + btrfs_lockdep_release(fs_info, btrfs_trans_num_writers); goto cleanup_transaction; + } - btrfs_wait_delalloc_flush(trans); + btrfs_wait_delalloc_flush(fs_info); + + /* + * Wait for all ordered extents started by a fast fsync that joined this + * transaction. Otherwise if this transaction commits before the ordered + * extents complete we lose logged data after a power failure. + */ + btrfs_might_wait_for_event(fs_info, btrfs_trans_pending_ordered); + wait_event(cur_trans->pending_wait, + atomic_read(&cur_trans->pending_ordered) == 0); btrfs_scrub_pause(fs_info); /* @@ -2168,14 +2272,40 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) * COMMIT_DOING so make sure to wait for num_writers to == 1 again. */ spin_lock(&fs_info->trans_lock); + add_pending_snapshot(trans); cur_trans->state = TRANS_STATE_COMMIT_DOING; spin_unlock(&fs_info->trans_lock); + + /* + * The thread has started/joined the transaction thus it holds the + * lockdep map as a reader. It has to release it before acquiring the + * lockdep map as a writer. + */ + btrfs_lockdep_release(fs_info, btrfs_trans_num_writers); + btrfs_might_wait_for_event(fs_info, btrfs_trans_num_writers); 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))) { + /* + * Make lockdep happy by acquiring the state locks after + * btrfs_trans_num_writers is released. If we acquired the state locks + * before releasing the btrfs_trans_num_writers lock then lockdep would + * complain because we did not follow the reverse order unlocking rule. + */ + btrfs_trans_state_lockdep_acquire(fs_info, BTRFS_LOCKDEP_TRANS_COMPLETED); + btrfs_trans_state_lockdep_acquire(fs_info, BTRFS_LOCKDEP_TRANS_SUPER_COMMITTED); + btrfs_trans_state_lockdep_acquire(fs_info, BTRFS_LOCKDEP_TRANS_UNBLOCKED); + + /* + * We've started the commit, clear the flag in case we were triggered to + * do an async commit but somebody else started before the transaction + * kthread could do the work. + */ + clear_bit(BTRFS_FS_COMMIT_TRANS, &fs_info->flags); + + if (TRANS_ABORTED(cur_trans)) { ret = cur_trans->aborted; + btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_UNBLOCKED); goto scrub_continue; } /* @@ -2191,10 +2321,8 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) * core function of the snapshot creation. */ ret = create_pending_snapshots(trans); - if (ret) { - mutex_unlock(&fs_info->reloc_mutex); - goto scrub_continue; - } + if (ret) + goto unlock_reloc; /* * We insert the dir indexes of the snapshots and update the inode @@ -2207,16 +2335,12 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) * the nodes and leaves. */ ret = btrfs_run_delayed_items(trans); - if (ret) { - mutex_unlock(&fs_info->reloc_mutex); - goto scrub_continue; - } + if (ret) + goto unlock_reloc; ret = btrfs_run_delayed_refs(trans, (unsigned long)-1); - if (ret) { - mutex_unlock(&fs_info->reloc_mutex); - goto scrub_continue; - } + if (ret) + goto unlock_reloc; /* * make sure none of the code above managed to slip in a @@ -2226,27 +2350,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) 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; - } + if (ret) + goto unlock_reloc; /* * Since the transaction is done, we can apply the pending changes @@ -2260,47 +2366,26 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) 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; - } + if (ret < 0) + goto unlock_reloc; ret = commit_cowonly_roots(trans); - if (ret) { - mutex_unlock(&fs_info->tree_log_mutex); - mutex_unlock(&fs_info->reloc_mutex); - goto scrub_continue; - } + if (ret) + goto unlock_reloc; /* * The tasks which save the space cache and inode cache may also * update ->aborted, check it. */ - if (unlikely(READ_ONCE(cur_trans->aborted))) { + if (TRANS_ABORTED(cur_trans)) { ret = cur_trans->aborted; - mutex_unlock(&fs_info->tree_log_mutex); - mutex_unlock(&fs_info->reloc_mutex); - goto scrub_continue; + goto unlock_reloc; } - btrfs_prepare_extent_commit(fs_info); - cur_trans = fs_info->running_transaction; btrfs_set_root_node(&fs_info->tree_root->root_item, @@ -2313,6 +2398,13 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) list_add_tail(&fs_info->chunk_root->dirty_list, &cur_trans->switch_commits); + if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) { + btrfs_set_root_node(&fs_info->block_group_root->root_item, + fs_info->block_group_root->node); + list_add_tail(&fs_info->block_group_root->dirty_list, + &cur_trans->switch_commits); + } + switch_commit_roots(trans); ASSERT(list_empty(&cur_trans->dirty_bgs)); @@ -2331,6 +2423,16 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) btrfs_trans_release_chunk_metadata(trans); + /* + * Before changing the transaction state to TRANS_STATE_UNBLOCKED and + * setting fs_info->running_transaction to NULL, lock tree_log_mutex to + * make sure that before we commit our superblock, no other task can + * start a new transaction and commit a log tree before we commit our + * superblock. Anyone trying to commit a log tree locks this mutex before + * writing its superblock. + */ + mutex_lock(&fs_info->tree_log_mutex); + spin_lock(&fs_info->trans_lock); cur_trans->state = TRANS_STATE_UNBLOCKED; fs_info->running_transaction = NULL; @@ -2338,6 +2440,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) mutex_unlock(&fs_info->reloc_mutex); wake_up(&fs_info->transaction_wait); + btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_UNBLOCKED); ret = btrfs_write_and_wait_transaction(trans); if (ret) { @@ -2347,6 +2450,13 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) goto scrub_continue; } + /* + * At this point, we should have written all the tree blocks allocated + * in this transaction. So it's now safe to free the redirtyied extent + * buffers. + */ + btrfs_free_redirty_list(cur_trans); + ret = write_all_supers(fs_info, 0); /* * the super is written, we can safely allow the tree-loggers @@ -2356,6 +2466,14 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) if (ret) goto scrub_continue; + /* + * We needn't acquire the lock here because there is no other task + * which can change it. + */ + cur_trans->state = TRANS_STATE_SUPER_COMMITTED; + wake_up(&cur_trans->commit_wait); + btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_SUPER_COMMITTED); + btrfs_finish_extent_commit(trans); if (test_bit(BTRFS_TRANS_HAVE_FREE_BGS, &cur_trans->flags)) @@ -2368,7 +2486,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) */ cur_trans->state = TRANS_STATE_COMPLETED; wake_up(&cur_trans->commit_wait); - clear_bit(BTRFS_FS_NEED_ASYNC_COMMIT, &fs_info->flags); + btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_COMPLETED); spin_lock(&fs_info->trans_lock); list_del_init(&cur_trans->list); @@ -2380,7 +2498,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) if (trans->type & __TRANS_FREEZABLE) sb_end_intwrite(fs_info->sb); - trace_btrfs_transaction_commit(trans->root); + trace_btrfs_transaction_commit(fs_info); + + interval = ktime_get_ns() - start_time; btrfs_scrub_continue(fs_info); @@ -2389,9 +2509,16 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) kmem_cache_free(btrfs_trans_handle_cachep, trans); + update_commit_stats(fs_info, interval); + return ret; +unlock_reloc: + mutex_unlock(&fs_info->reloc_mutex); + btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_UNBLOCKED); scrub_continue: + btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_SUPER_COMMITTED); + btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_COMPLETED); btrfs_scrub_continue(fs_info); cleanup_transaction: btrfs_trans_release_metadata(trans); @@ -2404,6 +2531,16 @@ cleanup_transaction: cleanup_transaction(trans, ret); return ret; + +lockdep_release: + btrfs_lockdep_release(fs_info, btrfs_trans_num_extwriters); + btrfs_lockdep_release(fs_info, btrfs_trans_num_writers); + goto cleanup_transaction; + +lockdep_trans_commit_start_release: + btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_START); + btrfs_end_transaction(trans); + return ret; } /* @@ -2416,10 +2553,10 @@ cleanup_transaction: * 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 btrfs_clean_one_deleted_snapshot(struct btrfs_fs_info *fs_info) { + 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)) { @@ -2437,10 +2574,11 @@ int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root) if (btrfs_header_backref_rev(root->node) < BTRFS_MIXED_BACKREF_REV) - ret = btrfs_drop_snapshot(root, NULL, 0, 0); + ret = btrfs_drop_snapshot(root, 0, 0); else - ret = btrfs_drop_snapshot(root, NULL, 1, 0); + ret = btrfs_drop_snapshot(root, 1, 0); + btrfs_put_root(root); return (ret < 0) ? 0 : 1; } @@ -2453,16 +2591,6 @@ void btrfs_apply_pending_changes(struct btrfs_fs_info *fs_info) 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"); |