diff options
Diffstat (limited to 'fs/btrfs/transaction.c')
| -rw-r--r-- | fs/btrfs/transaction.c | 1905 |
1 files changed, 1257 insertions, 648 deletions
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 1fffbc017bd..5f379affdf2 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -22,75 +22,214 @@ #include <linux/writeback.h> #include <linux/pagemap.h> #include <linux/blkdev.h> +#include <linux/uuid.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" #define BTRFS_ROOT_TRANS_TAG 0 -static noinline void put_transaction(struct btrfs_transaction *transaction) +static unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = { + [TRANS_STATE_RUNNING] = 0U, + [TRANS_STATE_BLOCKED] = (__TRANS_USERSPACE | + __TRANS_START), + [TRANS_STATE_COMMIT_START] = (__TRANS_USERSPACE | + __TRANS_START | + __TRANS_ATTACH), + [TRANS_STATE_COMMIT_DOING] = (__TRANS_USERSPACE | + __TRANS_START | + __TRANS_ATTACH | + __TRANS_JOIN), + [TRANS_STATE_UNBLOCKED] = (__TRANS_USERSPACE | + __TRANS_START | + __TRANS_ATTACH | + __TRANS_JOIN | + __TRANS_JOIN_NOLOCK), + [TRANS_STATE_COMPLETED] = (__TRANS_USERSPACE | + __TRANS_START | + __TRANS_ATTACH | + __TRANS_JOIN | + __TRANS_JOIN_NOLOCK), +}; + +void btrfs_put_transaction(struct btrfs_transaction *transaction) { - WARN_ON(transaction->use_count == 0); - transaction->use_count--; - if (transaction->use_count == 0) { - list_del_init(&transaction->list); - memset(transaction, 0, sizeof(*transaction)); + WARN_ON(atomic_read(&transaction->use_count) == 0); + if (atomic_dec_and_test(&transaction->use_count)) { + BUG_ON(!list_empty(&transaction->list)); + WARN_ON(!RB_EMPTY_ROOT(&transaction->delayed_refs.href_root)); + while (!list_empty(&transaction->pending_chunks)) { + struct extent_map *em; + + em = list_first_entry(&transaction->pending_chunks, + struct extent_map, list); + list_del_init(&em->list); + free_extent_map(em); + } kmem_cache_free(btrfs_transaction_cachep, transaction); } } -static noinline void switch_commit_root(struct btrfs_root *root) +static noinline void switch_commit_roots(struct btrfs_transaction *trans, + struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *root, *tmp; + + down_write(&fs_info->commit_root_sem); + list_for_each_entry_safe(root, tmp, &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->objectid)) + btrfs_unpin_free_ino(root); + } + 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) { - free_extent_buffer(root->commit_root); - root->commit_root = btrfs_root_node(root); + return atomic_read(&trans->num_extwriters); } /* * either allocate a new transaction or hop into the existing one */ -static noinline int join_transaction(struct btrfs_root *root) +static noinline int join_transaction(struct btrfs_root *root, unsigned int type) { struct btrfs_transaction *cur_trans; - cur_trans = root->fs_info->running_transaction; - if (!cur_trans) { - cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, - GFP_NOFS); - BUG_ON(!cur_trans); - root->fs_info->generation++; - cur_trans->num_writers = 1; - cur_trans->num_joined = 0; - cur_trans->transid = root->fs_info->generation; - init_waitqueue_head(&cur_trans->writer_wait); - init_waitqueue_head(&cur_trans->commit_wait); - cur_trans->in_commit = 0; - cur_trans->blocked = 0; - cur_trans->use_count = 1; - cur_trans->commit_done = 0; - cur_trans->start_time = get_seconds(); - - cur_trans->delayed_refs.root = RB_ROOT; - cur_trans->delayed_refs.num_entries = 0; - cur_trans->delayed_refs.num_heads_ready = 0; - cur_trans->delayed_refs.num_heads = 0; - cur_trans->delayed_refs.flushing = 0; - cur_trans->delayed_refs.run_delayed_start = 0; - spin_lock_init(&cur_trans->delayed_refs.lock); - - INIT_LIST_HEAD(&cur_trans->pending_snapshots); - list_add_tail(&cur_trans->list, &root->fs_info->trans_list); - extent_io_tree_init(&cur_trans->dirty_pages, - root->fs_info->btree_inode->i_mapping, - GFP_NOFS); - spin_lock(&root->fs_info->new_trans_lock); - root->fs_info->running_transaction = cur_trans; - spin_unlock(&root->fs_info->new_trans_lock); - } else { - cur_trans->num_writers++; - cur_trans->num_joined++; + struct btrfs_fs_info *fs_info = root->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)) { + 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; + } + atomic_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 = kmem_cache_alloc(btrfs_transaction_cachep, 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 + */ + kmem_cache_free(btrfs_transaction_cachep, cur_trans); + goto loop; + } else if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { + spin_unlock(&fs_info->trans_lock); + kmem_cache_free(btrfs_transaction_cachep, cur_trans); + return -EROFS; } + 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. + */ + atomic_set(&cur_trans->use_count, 2); + cur_trans->start_time = get_seconds(); + + cur_trans->delayed_refs.href_root = RB_ROOT; + atomic_set(&cur_trans->delayed_refs.num_entries, 0); + cur_trans->delayed_refs.num_heads_ready = 0; + cur_trans->delayed_refs.num_heads = 0; + cur_trans->delayed_refs.flushing = 0; + cur_trans->delayed_refs.run_delayed_start = 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->ordered_operations); + INIT_LIST_HEAD(&cur_trans->pending_chunks); + INIT_LIST_HEAD(&cur_trans->switch_commits); + list_add_tail(&cur_trans->list, &fs_info->trans_list); + extent_io_tree_init(&cur_trans->dirty_pages, + fs_info->btree_inode->i_mapping); + 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; } @@ -100,39 +239,93 @@ static noinline int join_transaction(struct btrfs_root *root) * to make sure the old root from before we joined the transaction is deleted * when the transaction commits */ -static noinline int record_root_in_trans(struct btrfs_trans_handle *trans, - struct btrfs_root *root) +static int record_root_in_trans(struct btrfs_trans_handle *trans, + struct btrfs_root *root) { - if (root->ref_cows && root->last_trans < trans->transid) { + if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) && + root->last_trans < trans->transid) { WARN_ON(root == root->fs_info->extent_root); WARN_ON(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(&root->fs_info->fs_roots_radix_lock); + if (root->last_trans == trans->transid) { + spin_unlock(&root->fs_info->fs_roots_radix_lock); + return 0; + } radix_tree_tag_set(&root->fs_info->fs_roots_radix, (unsigned long)root->root_key.objectid, BTRFS_ROOT_TRANS_TAG); + spin_unlock(&root->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; } + int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans, struct btrfs_root *root) { - if (!root->ref_cows) + if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state)) return 0; - mutex_lock(&root->fs_info->trans_mutex); - if (root->last_trans == trans->transid) { - mutex_unlock(&root->fs_info->trans_mutex); + /* + * 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(&root->fs_info->reloc_mutex); record_root_in_trans(trans, root); - mutex_unlock(&root->fs_info->trans_mutex); + mutex_unlock(&root->fs_info->reloc_mutex); + return 0; } +static inline int is_transaction_blocked(struct btrfs_transaction *trans) +{ + return (trans->state >= TRANS_STATE_BLOCKED && + 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. @@ -141,254 +334,339 @@ static void wait_current_trans(struct btrfs_root *root) { struct btrfs_transaction *cur_trans; + spin_lock(&root->fs_info->trans_lock); cur_trans = root->fs_info->running_transaction; - if (cur_trans && cur_trans->blocked) { - DEFINE_WAIT(wait); - cur_trans->use_count++; - while (1) { - prepare_to_wait(&root->fs_info->transaction_wait, &wait, - TASK_UNINTERRUPTIBLE); - if (!cur_trans->blocked) - break; - mutex_unlock(&root->fs_info->trans_mutex); - schedule(); - mutex_lock(&root->fs_info->trans_mutex); - } - finish_wait(&root->fs_info->transaction_wait, &wait); - put_transaction(cur_trans); + if (cur_trans && is_transaction_blocked(cur_trans)) { + atomic_inc(&cur_trans->use_count); + spin_unlock(&root->fs_info->trans_lock); + + wait_event(root->fs_info->transaction_wait, + cur_trans->state >= TRANS_STATE_UNBLOCKED || + cur_trans->aborted); + btrfs_put_transaction(cur_trans); + } else { + spin_unlock(&root->fs_info->trans_lock); } } -enum btrfs_trans_type { - TRANS_START, - TRANS_JOIN, - TRANS_USERSPACE, - TRANS_JOIN_NOLOCK, -}; - static int may_wait_transaction(struct btrfs_root *root, int type) { - if (!root->fs_info->log_root_recovering && - ((type == TRANS_START && !root->fs_info->open_ioctl_trans) || - type == TRANS_USERSPACE)) + if (root->fs_info->log_root_recovering) + return 0; + + if (type == TRANS_USERSPACE) + return 1; + + if (type == TRANS_START && + !atomic_read(&root->fs_info->open_ioctl_trans)) return 1; + return 0; } -static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root, - u64 num_items, int type) +static inline bool need_reserve_reloc_root(struct btrfs_root *root) +{ + if (!root->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, u64 num_items, unsigned int type, + enum btrfs_reserve_flush_enum flush) { 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 != (void *)BTRFS_SEND_TRANS_STUB); + + if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) + return ERR_PTR(-EROFS); + + if (current->journal_info) { + WARN_ON(type & TRANS_EXTWRITERS); + h = current->journal_info; + h->use_count++; + WARN_ON(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 > 0 && root != root->fs_info->chunk_root) { + if (root->fs_info->quota_enabled && + is_fstree(root->root_key.objectid)) { + qgroup_reserved = num_items * root->leafsize; + ret = btrfs_qgroup_reserve(root, qgroup_reserved); + if (ret) + return ERR_PTR(ret); + } + + num_bytes = btrfs_calc_trans_metadata_size(root, num_items); + /* + * Do the reservation for the relocation root creation + */ + if (unlikely(need_reserve_reloc_root(root))) { + num_bytes += root->nodesize; + reloc_reserved = true; + } + + ret = btrfs_block_rsv_add(root, + &root->fs_info->trans_block_rsv, + num_bytes, flush); + if (ret) + goto reserve_fail; + } again: h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS); - if (!h) - return ERR_PTR(-ENOMEM); + 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(root->fs_info->sb); - if (type != TRANS_JOIN_NOLOCK) - mutex_lock(&root->fs_info->trans_mutex); if (may_wait_transaction(root, type)) wait_current_trans(root); - ret = join_transaction(root); - BUG_ON(ret); + do { + ret = join_transaction(root, type); + if (ret == -EBUSY) { + wait_current_trans(root); + if (unlikely(type == TRANS_ATTACH)) + ret = -ENOENT; + } + } while (ret == -EBUSY); + + if (ret < 0) { + /* We must get the transaction if we are JOIN_NOLOCK. */ + BUG_ON(type == TRANS_JOIN_NOLOCK); + goto join_fail; + } cur_trans = root->fs_info->running_transaction; - cur_trans->use_count++; - if (type != TRANS_JOIN_NOLOCK) - mutex_unlock(&root->fs_info->trans_mutex); h->transid = cur_trans->transid; h->transaction = cur_trans; h->blocks_used = 0; - h->block_group = 0; h->bytes_reserved = 0; + h->root = root; h->delayed_ref_updates = 0; + h->use_count = 1; + h->adding_csums = 0; h->block_rsv = NULL; + h->orig_rsv = NULL; + h->aborted = 0; + h->qgroup_reserved = 0; + h->delayed_ref_elem.seq = 0; + h->type = type; + h->allocating_chunk = false; + h->reloc_reserved = false; + h->sync = false; + INIT_LIST_HEAD(&h->qgroup_ref_list); + INIT_LIST_HEAD(&h->new_bgs); smp_mb(); - if (cur_trans->blocked && may_wait_transaction(root, type)) { + if (cur_trans->state >= TRANS_STATE_BLOCKED && + may_wait_transaction(root, type)) { + current->journal_info = h; btrfs_commit_transaction(h, root); goto again; } - if (num_items > 0) { - ret = btrfs_trans_reserve_metadata(h, root, num_items); - if (ret == -EAGAIN) { - btrfs_commit_transaction(h, root); - goto again; - } - if (ret < 0) { - btrfs_end_transaction(h, root); - return ERR_PTR(ret); - } + if (num_bytes) { + trace_btrfs_space_reservation(root->fs_info, "transaction", + h->transid, num_bytes, 1); + h->block_rsv = &root->fs_info->trans_block_rsv; + h->bytes_reserved = num_bytes; + h->reloc_reserved = reloc_reserved; } + h->qgroup_reserved = qgroup_reserved; - if (type != TRANS_JOIN_NOLOCK) - mutex_lock(&root->fs_info->trans_mutex); - record_root_in_trans(h, root); - if (type != TRANS_JOIN_NOLOCK) - mutex_unlock(&root->fs_info->trans_mutex); +got_it: + btrfs_record_root_in_trans(h, root); if (!current->journal_info && type != TRANS_USERSPACE) current->journal_info = h; return h; + +join_fail: + if (type & __TRANS_FREEZABLE) + sb_end_intwrite(root->fs_info->sb); + kmem_cache_free(btrfs_trans_handle_cachep, h); +alloc_fail: + if (num_bytes) + btrfs_block_rsv_release(root, &root->fs_info->trans_block_rsv, + num_bytes); +reserve_fail: + if (qgroup_reserved) + btrfs_qgroup_free(root, qgroup_reserved); + return ERR_PTR(ret); } struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root, int num_items) { - return start_transaction(root, num_items, TRANS_START); + return start_transaction(root, num_items, TRANS_START, + BTRFS_RESERVE_FLUSH_ALL); } -struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root, - int num_blocks) + +struct btrfs_trans_handle *btrfs_start_transaction_lflush( + struct btrfs_root *root, int num_items) +{ + return start_transaction(root, num_items, TRANS_START, + BTRFS_RESERVE_FLUSH_LIMIT); +} + +struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root) { - return start_transaction(root, 0, TRANS_JOIN); + return start_transaction(root, 0, TRANS_JOIN, 0); } -struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root, - int num_blocks) +struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root) { - return start_transaction(root, 0, TRANS_JOIN_NOLOCK); + return start_transaction(root, 0, TRANS_JOIN_NOLOCK, 0); } -struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *r, - int num_blocks) +struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root) { - return start_transaction(r, 0, TRANS_USERSPACE); + return start_transaction(root, 0, TRANS_USERSPACE, 0); +} + +/* + * 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, 0); +} + +/* + * btrfs_attach_transaction_barrier() - catch the running transaction + * + * It is similar to the above function, the differentia 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, 0); + if (IS_ERR(trans) && PTR_ERR(trans) == -ENOENT) + btrfs_wait_for_commit(root, 0); + + return trans; } /* wait for a transaction commit to be fully complete */ -static noinline int wait_for_commit(struct btrfs_root *root, +static noinline void wait_for_commit(struct btrfs_root *root, struct btrfs_transaction *commit) { - DEFINE_WAIT(wait); - mutex_lock(&root->fs_info->trans_mutex); - while (!commit->commit_done) { - prepare_to_wait(&commit->commit_wait, &wait, - TASK_UNINTERRUPTIBLE); - if (commit->commit_done) - break; - mutex_unlock(&root->fs_info->trans_mutex); - schedule(); - mutex_lock(&root->fs_info->trans_mutex); - } - mutex_unlock(&root->fs_info->trans_mutex); - finish_wait(&commit->commit_wait, &wait); - return 0; + wait_event(commit->commit_wait, commit->state == TRANS_STATE_COMPLETED); } int btrfs_wait_for_commit(struct btrfs_root *root, u64 transid) { struct btrfs_transaction *cur_trans = NULL, *t; - int ret; - - mutex_lock(&root->fs_info->trans_mutex); + int ret = 0; - ret = 0; if (transid) { if (transid <= root->fs_info->last_trans_committed) - goto out_unlock; + goto out; + ret = -EINVAL; /* find specified transaction */ + spin_lock(&root->fs_info->trans_lock); list_for_each_entry(t, &root->fs_info->trans_list, list) { if (t->transid == transid) { cur_trans = t; + atomic_inc(&cur_trans->use_count); + ret = 0; break; } - if (t->transid > transid) + if (t->transid > transid) { + ret = 0; break; + } } - ret = -EINVAL; + spin_unlock(&root->fs_info->trans_lock); + /* The specified transaction doesn't exist */ if (!cur_trans) - goto out_unlock; /* bad transid */ + goto out; } else { /* find newest transaction that is committing | committed */ + spin_lock(&root->fs_info->trans_lock); list_for_each_entry_reverse(t, &root->fs_info->trans_list, list) { - if (t->in_commit) { - if (t->commit_done) - goto out_unlock; + if (t->state >= TRANS_STATE_COMMIT_START) { + if (t->state == TRANS_STATE_COMPLETED) + break; cur_trans = t; + atomic_inc(&cur_trans->use_count); break; } } + spin_unlock(&root->fs_info->trans_lock); if (!cur_trans) - goto out_unlock; /* nothing committing|committed */ + goto out; /* nothing committing|committed */ } - cur_trans->use_count++; - mutex_unlock(&root->fs_info->trans_mutex); - wait_for_commit(root, cur_trans); - - mutex_lock(&root->fs_info->trans_mutex); - put_transaction(cur_trans); - ret = 0; -out_unlock: - mutex_unlock(&root->fs_info->trans_mutex); + btrfs_put_transaction(cur_trans); +out: return ret; } -#if 0 -/* - * rate limit against the drop_snapshot code. This helps to slow down new - * operations if the drop_snapshot code isn't able to keep up. - */ -static void throttle_on_drops(struct btrfs_root *root) -{ - struct btrfs_fs_info *info = root->fs_info; - int harder_count = 0; - -harder: - if (atomic_read(&info->throttles)) { - DEFINE_WAIT(wait); - int thr; - thr = atomic_read(&info->throttle_gen); - - do { - prepare_to_wait(&info->transaction_throttle, - &wait, TASK_UNINTERRUPTIBLE); - if (!atomic_read(&info->throttles)) { - finish_wait(&info->transaction_throttle, &wait); - break; - } - schedule(); - finish_wait(&info->transaction_throttle, &wait); - } while (thr == atomic_read(&info->throttle_gen)); - harder_count++; - - if (root->fs_info->total_ref_cache_size > 1 * 1024 * 1024 && - harder_count < 2) - goto harder; - - if (root->fs_info->total_ref_cache_size > 5 * 1024 * 1024 && - harder_count < 10) - goto harder; - - if (root->fs_info->total_ref_cache_size > 10 * 1024 * 1024 && - harder_count < 20) - goto harder; - } -} -#endif - void btrfs_throttle(struct btrfs_root *root) { - mutex_lock(&root->fs_info->trans_mutex); - if (!root->fs_info->open_ioctl_trans) + if (!atomic_read(&root->fs_info->open_ioctl_trans)) wait_current_trans(root); - mutex_unlock(&root->fs_info->trans_mutex); } static int should_end_transaction(struct btrfs_trans_handle *trans, struct btrfs_root *root) { - int ret; - ret = btrfs_block_rsv_check(trans, root, - &root->fs_info->global_block_rsv, 0, 5); - return ret ? 1 : 0; + if (root->fs_info->global_block_rsv.space_info->full && + btrfs_check_space_for_delayed_refs(trans, root)) + return 1; + + return !!btrfs_block_rsv_check(root, &root->fs_info->global_block_rsv, 5); } int btrfs_should_end_transaction(struct btrfs_trans_handle *trans, @@ -396,98 +674,136 @@ int btrfs_should_end_transaction(struct btrfs_trans_handle *trans, { struct btrfs_transaction *cur_trans = trans->transaction; int updates; + int err; - if (cur_trans->blocked || cur_trans->delayed_refs.flushing) + smp_mb(); + if (cur_trans->state >= TRANS_STATE_BLOCKED || + cur_trans->delayed_refs.flushing) return 1; updates = trans->delayed_ref_updates; trans->delayed_ref_updates = 0; - if (updates) - btrfs_run_delayed_refs(trans, root, updates); + if (updates) { + err = btrfs_run_delayed_refs(trans, root, updates); + if (err) /* Error code will also eval true */ + return err; + } return should_end_transaction(trans, root); } static int __btrfs_end_transaction(struct btrfs_trans_handle *trans, - struct btrfs_root *root, int throttle, int lock) + struct btrfs_root *root, int throttle) { struct btrfs_transaction *cur_trans = trans->transaction; struct btrfs_fs_info *info = root->fs_info; - int count = 0; - - while (count < 4) { - unsigned long cur = trans->delayed_ref_updates; - trans->delayed_ref_updates = 0; - if (cur && - trans->transaction->delayed_refs.num_heads_ready > 64) { - trans->delayed_ref_updates = 0; - - /* - * do a full flush if the transaction is trying - * to close - */ - if (trans->transaction->delayed_refs.flushing) - cur = 0; - btrfs_run_delayed_refs(trans, root, cur); - } else { - break; - } - count++; + unsigned long cur = trans->delayed_ref_updates; + int lock = (trans->type != TRANS_JOIN_NOLOCK); + int err = 0; + int must_run_delayed_refs = 0; + + if (trans->use_count > 1) { + trans->use_count--; + trans->block_rsv = trans->orig_rsv; + return 0; } btrfs_trans_release_metadata(trans, root); + trans->block_rsv = NULL; - if (lock && !root->fs_info->open_ioctl_trans && - should_end_transaction(trans, root)) - trans->transaction->blocked = 1; + if (!list_empty(&trans->new_bgs)) + btrfs_create_pending_block_groups(trans, root); - if (lock && cur_trans->blocked && !cur_trans->in_commit) { + trans->delayed_ref_updates = 0; + if (!trans->sync) { + must_run_delayed_refs = + btrfs_should_throttle_delayed_refs(trans, root); + cur = max_t(unsigned long, cur, 32); + + /* + * don't make the caller wait if they are from a NOLOCK + * or ATTACH transaction, it will deadlock with commit + */ + if (must_run_delayed_refs == 1 && + (trans->type & (__TRANS_JOIN_NOLOCK | __TRANS_ATTACH))) + must_run_delayed_refs = 2; + } + + if (trans->qgroup_reserved) { + /* + * the same root has to be passed here between start_transaction + * and end_transaction. Subvolume quota depends on this. + */ + btrfs_qgroup_free(trans->root, trans->qgroup_reserved); + trans->qgroup_reserved = 0; + } + + btrfs_trans_release_metadata(trans, root); + trans->block_rsv = NULL; + + if (!list_empty(&trans->new_bgs)) + btrfs_create_pending_block_groups(trans, root); + + if (lock && !atomic_read(&root->fs_info->open_ioctl_trans) && + should_end_transaction(trans, root) && + ACCESS_ONCE(cur_trans->state) == TRANS_STATE_RUNNING) { + spin_lock(&info->trans_lock); + if (cur_trans->state == TRANS_STATE_RUNNING) + cur_trans->state = TRANS_STATE_BLOCKED; + spin_unlock(&info->trans_lock); + } + + if (lock && ACCESS_ONCE(cur_trans->state) == TRANS_STATE_BLOCKED) { if (throttle) return btrfs_commit_transaction(trans, root); else wake_up_process(info->transaction_kthread); } - if (lock) - mutex_lock(&info->trans_mutex); + if (trans->type & __TRANS_FREEZABLE) + sb_end_intwrite(root->fs_info->sb); + WARN_ON(cur_trans != info->running_transaction); - WARN_ON(cur_trans->num_writers < 1); - cur_trans->num_writers--; + WARN_ON(atomic_read(&cur_trans->num_writers) < 1); + atomic_dec(&cur_trans->num_writers); + extwriter_counter_dec(cur_trans, trans->type); smp_mb(); if (waitqueue_active(&cur_trans->writer_wait)) wake_up(&cur_trans->writer_wait); - put_transaction(cur_trans); - if (lock) - mutex_unlock(&info->trans_mutex); + btrfs_put_transaction(cur_trans); if (current->journal_info == trans) current->journal_info = NULL; - memset(trans, 0, sizeof(*trans)); - kmem_cache_free(btrfs_trans_handle_cachep, trans); if (throttle) btrfs_run_delayed_iputs(root); - return 0; + if (trans->aborted || + test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) { + wake_up_process(info->transaction_kthread); + err = -EIO; + } + assert_qgroups_uptodate(trans); + + kmem_cache_free(btrfs_trans_handle_cachep, trans); + if (must_run_delayed_refs) { + btrfs_async_run_delayed_refs(root, cur, + must_run_delayed_refs == 1); + } + return err; } int btrfs_end_transaction(struct btrfs_trans_handle *trans, struct btrfs_root *root) { - return __btrfs_end_transaction(trans, root, 0, 1); + return __btrfs_end_transaction(trans, root, 0); } int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans, struct btrfs_root *root) { - return __btrfs_end_transaction(trans, root, 1, 1); -} - -int btrfs_end_transaction_nolock(struct btrfs_trans_handle *trans, - struct btrfs_root *root) -{ - return __btrfs_end_transaction(trans, root, 0, 0); + return __btrfs_end_transaction(trans, root, 1); } /* @@ -498,50 +814,23 @@ int btrfs_end_transaction_nolock(struct btrfs_trans_handle *trans, int btrfs_write_marked_extents(struct btrfs_root *root, struct extent_io_tree *dirty_pages, int mark) { - int ret; int err = 0; int werr = 0; - struct page *page; - struct inode *btree_inode = root->fs_info->btree_inode; + struct address_space *mapping = root->fs_info->btree_inode->i_mapping; + struct extent_state *cached_state = NULL; u64 start = 0; u64 end; - unsigned long index; - - while (1) { - ret = find_first_extent_bit(dirty_pages, start, &start, &end, - mark); - if (ret) - break; - while (start <= end) { - cond_resched(); - - index = start >> PAGE_CACHE_SHIFT; - start = (u64)(index + 1) << PAGE_CACHE_SHIFT; - page = find_get_page(btree_inode->i_mapping, index); - if (!page) - continue; - - btree_lock_page_hook(page); - if (!page->mapping) { - unlock_page(page); - page_cache_release(page); - continue; - } - if (PageWriteback(page)) { - if (PageDirty(page)) - wait_on_page_writeback(page); - else { - unlock_page(page); - page_cache_release(page); - continue; - } - } - err = write_one_page(page, 0); - if (err) - werr = err; - page_cache_release(page); - } + while (!find_first_extent_bit(dirty_pages, start, &start, &end, + mark, &cached_state)) { + convert_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT, + mark, &cached_state, GFP_NOFS); + cached_state = NULL; + err = filemap_fdatawrite_range(mapping, start, end); + if (err) + werr = err; + cond_resched(); + start = end + 1; } if (err) werr = err; @@ -557,39 +846,22 @@ int btrfs_write_marked_extents(struct btrfs_root *root, int btrfs_wait_marked_extents(struct btrfs_root *root, struct extent_io_tree *dirty_pages, int mark) { - int ret; int err = 0; int werr = 0; - struct page *page; - struct inode *btree_inode = root->fs_info->btree_inode; + struct address_space *mapping = root->fs_info->btree_inode->i_mapping; + struct extent_state *cached_state = NULL; u64 start = 0; u64 end; - unsigned long index; - - while (1) { - ret = find_first_extent_bit(dirty_pages, start, &start, &end, - mark); - if (ret) - break; - clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS); - while (start <= end) { - index = start >> PAGE_CACHE_SHIFT; - start = (u64)(index + 1) << PAGE_CACHE_SHIFT; - page = find_get_page(btree_inode->i_mapping, index); - if (!page) - continue; - if (PageDirty(page)) { - btree_lock_page_hook(page); - wait_on_page_writeback(page); - err = write_one_page(page, 0); - if (err) - werr = err; - } - wait_on_page_writeback(page); - page_cache_release(page); - cond_resched(); - } + while (!find_first_extent_bit(dirty_pages, start, &start, &end, + EXTENT_NEED_WAIT, &cached_state)) { + clear_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT, + 0, 0, &cached_state, GFP_NOFS); + err = filemap_fdatawait_range(mapping, start, end); + if (err) + werr = err; + cond_resched(); + start = end + 1; } if (err) werr = err; @@ -601,15 +873,23 @@ int btrfs_wait_marked_extents(struct btrfs_root *root, * 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 */ -int btrfs_write_and_wait_marked_extents(struct btrfs_root *root, +static int btrfs_write_and_wait_marked_extents(struct btrfs_root *root, struct extent_io_tree *dirty_pages, int mark) { int ret; int ret2; + struct blk_plug plug; + blk_start_plug(&plug); ret = btrfs_write_marked_extents(root, dirty_pages, mark); + blk_finish_plug(&plug); ret2 = btrfs_wait_marked_extents(root, dirty_pages, mark); - return ret || ret2; + + if (ret) + return ret; + if (ret2) + return ret2; + return 0; } int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans, @@ -656,21 +936,24 @@ static int update_cowonly_root(struct btrfs_trans_handle *trans, ret = btrfs_update_root(trans, tree_root, &root->root_key, &root->root_item); - BUG_ON(ret); + if (ret) + return ret; old_root_used = btrfs_root_used(&root->root_item); ret = btrfs_write_dirty_block_groups(trans, root); - BUG_ON(ret); + if (ret) + return ret; } - if (root != root->fs_info->extent_root) - switch_commit_root(root); - 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_root *root) @@ -681,27 +964,53 @@ static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans, int ret; ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); - BUG_ON(ret); + if (ret) + return ret; eb = btrfs_lock_root_node(fs_info->tree_root); - btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb); + 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, root, (unsigned long)-1); - BUG_ON(ret); + if (ret) + return ret; + + ret = btrfs_run_dev_stats(trans, root->fs_info); + if (ret) + return ret; + ret = btrfs_run_dev_replace(trans, root->fs_info); + if (ret) + return ret; + ret = btrfs_run_qgroups(trans, root->fs_info); + if (ret) + return ret; + + /* run_qgroups might have added some more refs */ + ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); + if (ret) + return ret; while (!list_empty(&fs_info->dirty_cowonly_roots)) { next = fs_info->dirty_cowonly_roots.next; list_del_init(next); root = list_entry(next, struct btrfs_root, dirty_list); - update_cowonly_root(trans, root); + 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; } - down_write(&fs_info->extent_commit_sem); - switch_commit_root(fs_info->extent_root); - up_write(&fs_info->extent_commit_sem); + list_add_tail(&fs_info->extent_root->dirty_list, + &trans->transaction->switch_commits); + btrfs_after_dev_replace_commit(fs_info); return 0; } @@ -711,12 +1020,12 @@ static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans, * a dirty root struct and adds it into the list of dead roots that need to * be deleted */ -int btrfs_add_dead_root(struct btrfs_root *root) +void btrfs_add_dead_root(struct btrfs_root *root) { - mutex_lock(&root->fs_info->trans_mutex); - list_add(&root->root_list, &root->fs_info->dead_roots); - mutex_unlock(&root->fs_info->trans_mutex); - return 0; + spin_lock(&root->fs_info->trans_lock); + if (list_empty(&root->root_list)) + list_add_tail(&root->root_list, &root->fs_info->dead_roots); + spin_unlock(&root->fs_info->trans_lock); } /* @@ -731,6 +1040,7 @@ static noinline int commit_fs_roots(struct btrfs_trans_handle *trans, 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, @@ -743,13 +1053,21 @@ static noinline int commit_fs_roots(struct btrfs_trans_handle *trans, 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_orphan_commit_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) { - switch_commit_root(root); + list_add_tail(&root->dirty_list, + &trans->transaction->switch_commits); btrfs_set_root_node(&root->root_item, root->node); } @@ -757,25 +1075,26 @@ static noinline int commit_fs_roots(struct btrfs_trans_handle *trans, 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; } } + spin_unlock(&fs_info->fs_roots_radix_lock); return err; } /* - * defrag a given btree. If cacheonly == 1, this won't read from the disk, - * otherwise every leaf in the btree is read and defragged. + * defrag a given btree. + * Every leaf in the btree is read and defragged. */ -int btrfs_defrag_root(struct btrfs_root *root, int cacheonly) +int btrfs_defrag_root(struct btrfs_root *root) { struct btrfs_fs_info *info = root->fs_info; struct btrfs_trans_handle *trans; int ret; - unsigned long nr; - if (xchg(&root->defrag_running, 1)) + if (test_and_set_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state)) return 0; while (1) { @@ -783,114 +1102,33 @@ int btrfs_defrag_root(struct btrfs_root *root, int cacheonly) if (IS_ERR(trans)) return PTR_ERR(trans); - ret = btrfs_defrag_leaves(trans, root, cacheonly); + ret = btrfs_defrag_leaves(trans, root); - nr = trans->blocks_used; btrfs_end_transaction(trans, root); - btrfs_btree_balance_dirty(info->tree_root, nr); + btrfs_btree_balance_dirty(info->tree_root); cond_resched(); - if (root->fs_info->closing || ret != -EAGAIN) + if (btrfs_fs_closing(root->fs_info) || ret != -EAGAIN) break; - } - root->defrag_running = 0; - return ret; -} - -#if 0 -/* - * when dropping snapshots, we generate a ton of delayed refs, and it makes - * sense not to join the transaction while it is trying to flush the current - * queue of delayed refs out. - * - * This is used by the drop snapshot code only - */ -static noinline int wait_transaction_pre_flush(struct btrfs_fs_info *info) -{ - DEFINE_WAIT(wait); - mutex_lock(&info->trans_mutex); - while (info->running_transaction && - info->running_transaction->delayed_refs.flushing) { - prepare_to_wait(&info->transaction_wait, &wait, - TASK_UNINTERRUPTIBLE); - mutex_unlock(&info->trans_mutex); - - schedule(); - - mutex_lock(&info->trans_mutex); - finish_wait(&info->transaction_wait, &wait); - } - mutex_unlock(&info->trans_mutex); - return 0; -} - -/* - * Given a list of roots that need to be deleted, call btrfs_drop_snapshot on - * all of them - */ -int btrfs_drop_dead_root(struct btrfs_root *root) -{ - struct btrfs_trans_handle *trans; - struct btrfs_root *tree_root = root->fs_info->tree_root; - unsigned long nr; - int ret; - - while (1) { - /* - * we don't want to jump in and create a bunch of - * delayed refs if the transaction is starting to close - */ - wait_transaction_pre_flush(tree_root->fs_info); - trans = btrfs_start_transaction(tree_root, 1); - - /* - * we've joined a transaction, make sure it isn't - * closing right now - */ - if (trans->transaction->delayed_refs.flushing) { - btrfs_end_transaction(trans, tree_root); - continue; - } - - ret = btrfs_drop_snapshot(trans, root); - if (ret != -EAGAIN) + if (btrfs_defrag_cancelled(root->fs_info)) { + pr_debug("BTRFS: defrag_root cancelled\n"); + ret = -EAGAIN; break; - - ret = btrfs_update_root(trans, tree_root, - &root->root_key, - &root->root_item); - if (ret) - break; - - nr = trans->blocks_used; - ret = btrfs_end_transaction(trans, tree_root); - BUG_ON(ret); - - btrfs_btree_balance_dirty(tree_root, nr); - cond_resched(); + } } - BUG_ON(ret); - - ret = btrfs_del_root(trans, tree_root, &root->root_key); - BUG_ON(ret); - - nr = trans->blocks_used; - ret = btrfs_end_transaction(trans, tree_root); - BUG_ON(ret); - - free_extent_buffer(root->node); - free_extent_buffer(root->commit_root); - kfree(root); - - btrfs_btree_balance_dirty(tree_root, nr); + clear_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state); return ret; } -#endif /* * new snapshots need to be created at a very specific time in the - * transaction commit. This does the actual creation + * 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_fs_info *fs_info, @@ -901,47 +1139,58 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, 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; - int ret; + struct timespec cur_time = CURRENT_TIME; + int ret = 0; u64 to_reserve = 0; u64 index = 0; u64 objectid; + u64 root_flags; + uuid_le new_uuid; + + path = btrfs_alloc_path(); + if (!path) { + pending->error = -ENOMEM; + return 0; + } new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS); if (!new_root_item) { pending->error = -ENOMEM; - goto fail; + goto root_item_alloc_fail; } - ret = btrfs_find_free_objectid(trans, tree_root, 0, &objectid); - if (ret) { - pending->error = ret; - goto fail; - } + pending->error = btrfs_find_free_objectid(tree_root, &objectid); + if (pending->error) + goto no_free_objectid; btrfs_reloc_pre_snapshot(trans, pending, &to_reserve); - btrfs_orphan_pre_snapshot(trans, pending, &to_reserve); if (to_reserve > 0) { - ret = btrfs_block_rsv_add(trans, root, &pending->block_rsv, - to_reserve); - if (ret) { - pending->error = ret; - goto fail; - } + pending->error = btrfs_block_rsv_add(root, + &pending->block_rsv, + to_reserve, + BTRFS_RESERVE_NO_FLUSH); + if (pending->error) + goto no_free_objectid; } 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; dentry = pending->dentry; - parent_inode = dentry->d_parent->d_inode; + parent_inode = pending->dir; parent_root = BTRFS_I(parent_inode)->root; record_root_in_trans(trans, parent_root); @@ -949,29 +1198,106 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, * insert the directory item */ ret = btrfs_set_inode_index(parent_inode, &index); - BUG_ON(ret); - ret = btrfs_insert_dir_item(trans, parent_root, - dentry->d_name.name, dentry->d_name.len, - parent_inode->i_ino, &key, - BTRFS_FT_DIR, index); - BUG_ON(ret); + 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(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, root, ret); + goto fail; + } + btrfs_release_path(path); - btrfs_i_size_write(parent_inode, parent_inode->i_size + - dentry->d_name.len * 2); - ret = btrfs_update_inode(trans, parent_root, parent_inode); - BUG_ON(ret); + /* + * pull in the delayed directory update + * and the delayed inode item + * otherwise we corrupt the FS during + * snapshot + */ + ret = btrfs_run_delayed_items(trans, root); + if (ret) { /* Transaction aborted */ + btrfs_abort_transaction(trans, root, ret); + goto fail; + } record_root_in_trans(trans, root); 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); - btrfs_cow_block(trans, root, old, NULL, 0, &old); + ret = btrfs_cow_block(trans, root, old, NULL, 0, &old); + if (ret) { + btrfs_tree_unlock(old); + free_extent_buffer(old); + btrfs_abort_transaction(trans, root, ret); + goto fail; + } + btrfs_set_lock_blocking(old); - btrfs_copy_root(trans, root, old, &tmp, objectid); + 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, root, ret); + goto fail; + } + + /* + * We need to flush delayed refs in order to make sure all of our quota + * operations have been done before we call btrfs_qgroup_inherit. + */ + ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto fail; + } + + ret = btrfs_qgroup_inherit(trans, fs_info, + root->root_key.objectid, + objectid, pending->inherit); + if (ret) { + btrfs_abort_transaction(trans, root, 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 */ @@ -979,27 +1305,88 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, ret = btrfs_insert_root(trans, tree_root, &key, new_root_item); btrfs_tree_unlock(tmp); free_extent_buffer(tmp); - BUG_ON(ret); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto fail; + } /* * insert root back/forward references */ ret = btrfs_add_root_ref(trans, tree_root, objectid, parent_root->root_key.objectid, - parent_inode->i_ino, index, + btrfs_ino(parent_inode), index, dentry->d_name.name, dentry->d_name.len); - BUG_ON(ret); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto fail; + } key.offset = (u64)-1; pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key); - BUG_ON(IS_ERR(pending->snap)); + if (IS_ERR(pending->snap)) { + ret = PTR_ERR(pending->snap); + btrfs_abort_transaction(trans, root, ret); + goto fail; + } - btrfs_reloc_post_snapshot(trans, pending); - btrfs_orphan_post_snapshot(trans, pending); + ret = btrfs_reloc_post_snapshot(trans, pending); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto fail; + } + + ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto fail; + } + + ret = btrfs_insert_dir_item(trans, parent_root, + dentry->d_name.name, dentry->d_name.len, + 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, root, ret); + goto fail; + } + + btrfs_i_size_write(parent_inode, parent_inode->i_size + + dentry->d_name.len * 2); + parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME; + ret = btrfs_update_inode_fallback(trans, parent_root, parent_inode); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto fail; + } + ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root, new_uuid.b, + BTRFS_UUID_KEY_SUBVOL, objectid); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto fail; + } + if (!btrfs_is_empty_uuid(new_root_item->received_uuid)) { + ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root, + new_root_item->received_uuid, + BTRFS_UUID_KEY_RECEIVED_SUBVOL, + objectid); + if (ret && ret != -EEXIST) { + btrfs_abort_transaction(trans, root, ret); + goto fail; + } + } fail: + pending->error = ret; +dir_item_existed: + trans->block_rsv = rsv; + trans->bytes_reserved = 0; +no_free_objectid: kfree(new_root_item); - btrfs_block_rsv_release(root, &pending->block_rsv, (u64)-1); - return 0; +root_item_alloc_fail: + btrfs_free_path(path); + return ret; } /* @@ -1008,15 +1395,17 @@ fail: static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info) { - struct btrfs_pending_snapshot *pending; + struct btrfs_pending_snapshot *pending, *next; struct list_head *head = &trans->transaction->pending_snapshots; - int ret; + int ret = 0; - list_for_each_entry(pending, head, list) { + list_for_each_entry_safe(pending, next, head, list) { + list_del(&pending->list); ret = create_pending_snapshot(trans, fs_info, pending); - BUG_ON(ret); + if (ret) + break; } - return 0; + return ret; } static void update_super_roots(struct btrfs_root *root) @@ -1024,7 +1413,7 @@ static void update_super_roots(struct btrfs_root *root) struct btrfs_root_item *root_item; struct btrfs_super_block *super; - super = &root->fs_info->super_copy; + super = root->fs_info->super_copy; root_item = &root->fs_info->chunk_root->root_item; super->chunk_root = root_item->bytenr; @@ -1035,27 +1424,35 @@ static void update_super_roots(struct btrfs_root *root) super->root = root_item->bytenr; super->generation = root_item->generation; super->root_level = root_item->level; - if (super->cache_generation != 0 || btrfs_test_opt(root, SPACE_CACHE)) + if (btrfs_test_opt(root, SPACE_CACHE)) super->cache_generation = root_item->generation; + if (root->fs_info->update_uuid_tree_gen) + 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->new_trans_lock); - if (info->running_transaction) - ret = info->running_transaction->in_commit; - spin_unlock(&info->new_trans_lock); + + 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->new_trans_lock); - if (info->running_transaction) - ret = info->running_transaction->blocked; - spin_unlock(&info->new_trans_lock); + + spin_lock(&info->trans_lock); + trans = info->running_transaction; + if (trans) + ret = is_transaction_blocked(trans); + spin_unlock(&info->trans_lock); return ret; } @@ -1066,24 +1463,9 @@ int btrfs_transaction_blocked(struct btrfs_fs_info *info) static void wait_current_trans_commit_start(struct btrfs_root *root, struct btrfs_transaction *trans) { - DEFINE_WAIT(wait); - - if (trans->in_commit) - return; - - while (1) { - prepare_to_wait(&root->fs_info->transaction_blocked_wait, &wait, - TASK_UNINTERRUPTIBLE); - if (trans->in_commit) { - finish_wait(&root->fs_info->transaction_blocked_wait, - &wait); - break; - } - mutex_unlock(&root->fs_info->trans_mutex); - schedule(); - mutex_lock(&root->fs_info->trans_mutex); - finish_wait(&root->fs_info->transaction_blocked_wait, &wait); - } + wait_event(root->fs_info->transaction_blocked_wait, + trans->state >= TRANS_STATE_COMMIT_START || + trans->aborted); } /* @@ -1093,26 +1475,9 @@ static void wait_current_trans_commit_start(struct btrfs_root *root, static void wait_current_trans_commit_start_and_unblock(struct btrfs_root *root, struct btrfs_transaction *trans) { - DEFINE_WAIT(wait); - - if (trans->commit_done || (trans->in_commit && !trans->blocked)) - return; - - while (1) { - prepare_to_wait(&root->fs_info->transaction_wait, &wait, - TASK_UNINTERRUPTIBLE); - if (trans->commit_done || - (trans->in_commit && !trans->blocked)) { - finish_wait(&root->fs_info->transaction_wait, - &wait); - break; - } - mutex_unlock(&root->fs_info->trans_mutex); - schedule(); - mutex_lock(&root->fs_info->trans_mutex); - finish_wait(&root->fs_info->transaction_wait, - &wait); - } + wait_event(root->fs_info->transaction_wait, + trans->state >= TRANS_STATE_UNBLOCKED || + trans->aborted); } /* @@ -1122,13 +1487,24 @@ static void wait_current_trans_commit_start_and_unblock(struct btrfs_root *root, struct btrfs_async_commit { struct btrfs_trans_handle *newtrans; struct btrfs_root *root; - struct delayed_work work; + 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.work); + 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) + rwsem_acquire_read( + &ac->root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1], + 0, 1, _THIS_IP_); + + current->journal_info = ac->newtrans; btrfs_commit_transaction(ac->newtrans, ac->root); kfree(ac); @@ -1142,152 +1518,304 @@ int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans, struct btrfs_transaction *cur_trans; ac = kmalloc(sizeof(*ac), GFP_NOFS); - BUG_ON(!ac); + if (!ac) + return -ENOMEM; - INIT_DELAYED_WORK(&ac->work, do_async_commit); + INIT_WORK(&ac->work, do_async_commit); ac->root = root; - ac->newtrans = btrfs_join_transaction(root, 0); + ac->newtrans = btrfs_join_transaction(root); + if (IS_ERR(ac->newtrans)) { + int err = PTR_ERR(ac->newtrans); + kfree(ac); + return err; + } /* take transaction reference */ - mutex_lock(&root->fs_info->trans_mutex); cur_trans = trans->transaction; - cur_trans->use_count++; - mutex_unlock(&root->fs_info->trans_mutex); + atomic_inc(&cur_trans->use_count); btrfs_end_transaction(trans, root); - schedule_delayed_work(&ac->work, 0); + + /* + * 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) + rwsem_release( + &root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1], + 1, _THIS_IP_); + + schedule_work(&ac->work); /* wait for transaction to start and unblock */ - mutex_lock(&root->fs_info->trans_mutex); if (wait_for_unblock) wait_current_trans_commit_start_and_unblock(root, cur_trans); else wait_current_trans_commit_start(root, cur_trans); - put_transaction(cur_trans); - mutex_unlock(&root->fs_info->trans_mutex); + if (current->journal_info == trans) + current->journal_info = NULL; + + btrfs_put_transaction(cur_trans); return 0; } -/* - * btrfs_transaction state sequence: - * in_commit = 0, blocked = 0 (initial) - * in_commit = 1, blocked = 1 - * blocked = 0 - * commit_done = 1 - */ + +static void cleanup_transaction(struct btrfs_trans_handle *trans, + struct btrfs_root *root, int err) +{ + struct btrfs_transaction *cur_trans = trans->transaction; + DEFINE_WAIT(wait); + + WARN_ON(trans->use_count > 1); + + btrfs_abort_transaction(trans, root, err); + + spin_lock(&root->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 == root->fs_info->running_transaction) { + cur_trans->state = TRANS_STATE_COMMIT_DOING; + spin_unlock(&root->fs_info->trans_lock); + wait_event(cur_trans->writer_wait, + atomic_read(&cur_trans->num_writers) == 1); + + spin_lock(&root->fs_info->trans_lock); + } + spin_unlock(&root->fs_info->trans_lock); + + btrfs_cleanup_one_transaction(trans->transaction, root); + + spin_lock(&root->fs_info->trans_lock); + if (cur_trans == root->fs_info->running_transaction) + root->fs_info->running_transaction = NULL; + spin_unlock(&root->fs_info->trans_lock); + + if (trans->type & __TRANS_FREEZABLE) + sb_end_intwrite(root->fs_info->sb); + btrfs_put_transaction(cur_trans); + btrfs_put_transaction(cur_trans); + + trace_btrfs_transaction_commit(root); + + if (current->journal_info == trans) + current->journal_info = NULL; + btrfs_scrub_cancel(root->fs_info); + + kmem_cache_free(btrfs_trans_handle_cachep, trans); +} + +static int btrfs_flush_all_pending_stuffs(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + int ret; + + ret = btrfs_run_delayed_items(trans, root); + if (ret) + return ret; + + /* + * rename don't use btrfs_join_transaction, so, once we + * set the transaction to blocked above, we aren't going + * to get any new ordered operations. We can safely run + * it here and no for sure that nothing new will be added + * to the list + */ + ret = btrfs_run_ordered_operations(trans, root, 1); + + return ret; +} + +static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info) +{ + if (btrfs_test_opt(fs_info->tree_root, FLUSHONCOMMIT)) + return btrfs_start_delalloc_roots(fs_info, 1, -1); + return 0; +} + +static inline void btrfs_wait_delalloc_flush(struct btrfs_fs_info *fs_info) +{ + if (btrfs_test_opt(fs_info->tree_root, FLUSHONCOMMIT)) + btrfs_wait_ordered_roots(fs_info, -1); +} + int btrfs_commit_transaction(struct btrfs_trans_handle *trans, struct btrfs_root *root) { - unsigned long joined = 0; - struct btrfs_transaction *cur_trans; + struct btrfs_transaction *cur_trans = trans->transaction; struct btrfs_transaction *prev_trans = NULL; - DEFINE_WAIT(wait); int ret; - int should_grow = 0; - unsigned long now = get_seconds(); - int flush_on_commit = btrfs_test_opt(root, FLUSHONCOMMIT); - btrfs_run_ordered_operations(root, 0); + ret = btrfs_run_ordered_operations(trans, root, 0); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + btrfs_end_transaction(trans, root); + return ret; + } + + /* Stop the commit early if ->aborted is set */ + if (unlikely(ACCESS_ONCE(cur_trans->aborted))) { + ret = cur_trans->aborted; + btrfs_end_transaction(trans, root); + return ret; + } /* 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, root, 0); - BUG_ON(ret); + if (ret) { + btrfs_end_transaction(trans, root); + return ret; + } btrfs_trans_release_metadata(trans, root); + trans->block_rsv = NULL; + if (trans->qgroup_reserved) { + btrfs_qgroup_free(root, trans->qgroup_reserved); + trans->qgroup_reserved = 0; + } 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(); - ret = btrfs_run_delayed_refs(trans, root, 0); - BUG_ON(ret); + if (!list_empty(&trans->new_bgs)) + btrfs_create_pending_block_groups(trans, root); - mutex_lock(&root->fs_info->trans_mutex); - if (cur_trans->in_commit) { - cur_trans->use_count++; - mutex_unlock(&root->fs_info->trans_mutex); + ret = btrfs_run_delayed_refs(trans, root, 0); + if (ret) { btrfs_end_transaction(trans, root); + return ret; + } - ret = wait_for_commit(root, cur_trans); - BUG_ON(ret); + spin_lock(&root->fs_info->trans_lock); + if (cur_trans->state >= TRANS_STATE_COMMIT_START) { + spin_unlock(&root->fs_info->trans_lock); + atomic_inc(&cur_trans->use_count); + ret = btrfs_end_transaction(trans, root); - mutex_lock(&root->fs_info->trans_mutex); - put_transaction(cur_trans); - mutex_unlock(&root->fs_info->trans_mutex); + wait_for_commit(root, cur_trans); - return 0; + btrfs_put_transaction(cur_trans); + + return ret; } - trans->transaction->in_commit = 1; - trans->transaction->blocked = 1; + cur_trans->state = TRANS_STATE_COMMIT_START; wake_up(&root->fs_info->transaction_blocked_wait); if (cur_trans->list.prev != &root->fs_info->trans_list) { prev_trans = list_entry(cur_trans->list.prev, struct btrfs_transaction, list); - if (!prev_trans->commit_done) { - prev_trans->use_count++; - mutex_unlock(&root->fs_info->trans_mutex); + if (prev_trans->state != TRANS_STATE_COMPLETED) { + atomic_inc(&prev_trans->use_count); + spin_unlock(&root->fs_info->trans_lock); wait_for_commit(root, prev_trans); - mutex_lock(&root->fs_info->trans_mutex); - put_transaction(prev_trans); + btrfs_put_transaction(prev_trans); + } else { + spin_unlock(&root->fs_info->trans_lock); } + } else { + spin_unlock(&root->fs_info->trans_lock); } - if (now < cur_trans->start_time || now - cur_trans->start_time < 1) - should_grow = 1; + extwriter_counter_dec(cur_trans, trans->type); - do { - int snap_pending = 0; - joined = cur_trans->num_joined; - if (!list_empty(&trans->transaction->pending_snapshots)) - snap_pending = 1; - - WARN_ON(cur_trans != trans->transaction); - mutex_unlock(&root->fs_info->trans_mutex); - - if (flush_on_commit || snap_pending) { - btrfs_start_delalloc_inodes(root, 1); - ret = btrfs_wait_ordered_extents(root, 0, 1); - BUG_ON(ret); - } + ret = btrfs_start_delalloc_flush(root->fs_info); + if (ret) + goto cleanup_transaction; - /* - * rename don't use btrfs_join_transaction, so, once we - * set the transaction to blocked above, we aren't going - * to get any new ordered operations. We can safely run - * it here and no for sure that nothing new will be added - * to the list - */ - btrfs_run_ordered_operations(root, 1); + ret = btrfs_flush_all_pending_stuffs(trans, root); + if (ret) + goto cleanup_transaction; + + wait_event(cur_trans->writer_wait, + extwriter_counter_read(cur_trans) == 0); - prepare_to_wait(&cur_trans->writer_wait, &wait, - TASK_UNINTERRUPTIBLE); + /* some pending stuffs might be added after the previous flush. */ + ret = btrfs_flush_all_pending_stuffs(trans, root); + if (ret) + goto cleanup_transaction; - smp_mb(); - if (cur_trans->num_writers > 1) - schedule_timeout(MAX_SCHEDULE_TIMEOUT); - else if (should_grow) - schedule_timeout(1); + btrfs_wait_delalloc_flush(root->fs_info); - mutex_lock(&root->fs_info->trans_mutex); - finish_wait(&cur_trans->writer_wait, &wait); - } while (cur_trans->num_writers > 1 || - (should_grow && cur_trans->num_joined != joined)); + btrfs_scrub_pause(root); + /* + * 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(&root->fs_info->trans_lock); + cur_trans->state = TRANS_STATE_COMMIT_DOING; + spin_unlock(&root->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(ACCESS_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(&root->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, root->fs_info); - BUG_ON(ret); + if (ret) { + mutex_unlock(&root->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, root); + if (ret) { + mutex_unlock(&root->fs_info->reloc_mutex); + goto scrub_continue; + } ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); - BUG_ON(ret); + if (ret) { + mutex_unlock(&root->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(root); WARN_ON(cur_trans != trans->transaction); @@ -1307,7 +1835,20 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, mutex_lock(&root->fs_info->tree_log_mutex); ret = commit_fs_roots(trans, root); - BUG_ON(ret); + if (ret) { + mutex_unlock(&root->fs_info->tree_log_mutex); + mutex_unlock(&root->fs_info->reloc_mutex); + goto scrub_continue; + } + + /* + * Since the transaction is done, we should set the inode map cache flag + * before any other comming transaction. + */ + if (btrfs_test_opt(root, CHANGE_INODE_CACHE)) + btrfs_set_opt(root->fs_info->mount_opt, INODE_MAP_CACHE); + else + btrfs_clear_opt(root->fs_info->mount_opt, INODE_MAP_CACHE); /* commit_fs_roots gets rid of all the tree log roots, it is now * safe to free the root of tree log roots @@ -1315,41 +1856,68 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, btrfs_free_log_root_tree(trans, root->fs_info); ret = commit_cowonly_roots(trans, root); - BUG_ON(ret); + if (ret) { + mutex_unlock(&root->fs_info->tree_log_mutex); + mutex_unlock(&root->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(ACCESS_ONCE(cur_trans->aborted))) { + ret = cur_trans->aborted; + mutex_unlock(&root->fs_info->tree_log_mutex); + mutex_unlock(&root->fs_info->reloc_mutex); + goto scrub_continue; + } btrfs_prepare_extent_commit(trans, root); cur_trans = root->fs_info->running_transaction; - spin_lock(&root->fs_info->new_trans_lock); - root->fs_info->running_transaction = NULL; - spin_unlock(&root->fs_info->new_trans_lock); btrfs_set_root_node(&root->fs_info->tree_root->root_item, root->fs_info->tree_root->node); - switch_commit_root(root->fs_info->tree_root); + list_add_tail(&root->fs_info->tree_root->dirty_list, + &cur_trans->switch_commits); btrfs_set_root_node(&root->fs_info->chunk_root->root_item, root->fs_info->chunk_root->node); - switch_commit_root(root->fs_info->chunk_root); + list_add_tail(&root->fs_info->chunk_root->dirty_list, + &cur_trans->switch_commits); - update_super_roots(root); + switch_commit_roots(cur_trans, root->fs_info); - if (!root->fs_info->log_root_recovering) { - btrfs_set_super_log_root(&root->fs_info->super_copy, 0); - btrfs_set_super_log_root_level(&root->fs_info->super_copy, 0); - } + assert_qgroups_uptodate(trans); + update_super_roots(root); - memcpy(&root->fs_info->super_for_commit, &root->fs_info->super_copy, - sizeof(root->fs_info->super_copy)); + btrfs_set_super_log_root(root->fs_info->super_copy, 0); + btrfs_set_super_log_root_level(root->fs_info->super_copy, 0); + memcpy(root->fs_info->super_for_commit, root->fs_info->super_copy, + sizeof(*root->fs_info->super_copy)); - trans->transaction->blocked = 0; + spin_lock(&root->fs_info->trans_lock); + cur_trans->state = TRANS_STATE_UNBLOCKED; + root->fs_info->running_transaction = NULL; + spin_unlock(&root->fs_info->trans_lock); + mutex_unlock(&root->fs_info->reloc_mutex); wake_up(&root->fs_info->transaction_wait); - mutex_unlock(&root->fs_info->trans_mutex); ret = btrfs_write_and_wait_transaction(trans, root); - BUG_ON(ret); - write_ctree_super(trans, root, 0); + if (ret) { + btrfs_error(root->fs_info, ret, + "Error while writing out transaction"); + mutex_unlock(&root->fs_info->tree_log_mutex); + goto scrub_continue; + } + + ret = write_ctree_super(trans, root, 0); + if (ret) { + mutex_unlock(&root->fs_info->tree_log_mutex); + goto scrub_continue; + } /* * the super is written, we can safely allow the tree-loggers @@ -1359,18 +1927,27 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, btrfs_finish_extent_commit(trans, root); - mutex_lock(&root->fs_info->trans_mutex); + root->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); - cur_trans->commit_done = 1; + spin_lock(&root->fs_info->trans_lock); + list_del_init(&cur_trans->list); + spin_unlock(&root->fs_info->trans_lock); - root->fs_info->last_trans_committed = cur_trans->transid; + btrfs_put_transaction(cur_trans); + btrfs_put_transaction(cur_trans); - wake_up(&cur_trans->commit_wait); + if (trans->type & __TRANS_FREEZABLE) + sb_end_intwrite(root->fs_info->sb); - put_transaction(cur_trans); - put_transaction(cur_trans); + trace_btrfs_transaction_commit(root); - mutex_unlock(&root->fs_info->trans_mutex); + btrfs_scrub_continue(root); if (current->journal_info == trans) current->journal_info = NULL; @@ -1381,29 +1958,61 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, btrfs_run_delayed_iputs(root); return ret; + +scrub_continue: + btrfs_scrub_continue(root); +cleanup_transaction: + btrfs_trans_release_metadata(trans, root); + trans->block_rsv = NULL; + if (trans->qgroup_reserved) { + btrfs_qgroup_free(root, trans->qgroup_reserved); + trans->qgroup_reserved = 0; + } + btrfs_warn(root->fs_info, "Skipping commit of aborted transaction."); + if (current->journal_info == trans) + current->journal_info = NULL; + cleanup_transaction(trans, root, ret); + + return ret; } /* - * interface function to delete all the snapshots we have scheduled for deletion + * 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_old_snapshots(struct btrfs_root *root) +int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root) { - LIST_HEAD(list); + int ret; struct btrfs_fs_info *fs_info = root->fs_info; - mutex_lock(&fs_info->trans_mutex); - list_splice_init(&fs_info->dead_roots, &list); - mutex_unlock(&fs_info->trans_mutex); + 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); - while (!list_empty(&list)) { - root = list_entry(list.next, struct btrfs_root, root_list); - list_del(&root->root_list); + pr_debug("BTRFS: cleaner removing %llu\n", root->objectid); - if (btrfs_header_backref_rev(root->node) < - BTRFS_MIXED_BACKREF_REV) - btrfs_drop_snapshot(root, NULL, 0); - else - btrfs_drop_snapshot(root, NULL, 1); - } - return 0; + 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); + /* + * If we encounter a transaction abort during snapshot cleaning, we + * don't want to crash here + */ + return (ret < 0) ? 0 : 1; } |