diff options
Diffstat (limited to 'fs/btrfs/tree-log.c')
-rw-r--r-- | fs/btrfs/tree-log.c | 84 |
1 files changed, 68 insertions, 16 deletions
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 8ac6a64d0422..e35301e5fe8e 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -2729,7 +2729,8 @@ out: * in the tree of log roots */ static int update_log_root(struct btrfs_trans_handle *trans, - struct btrfs_root *log) + struct btrfs_root *log, + struct btrfs_root_item *root_item) { struct btrfs_fs_info *fs_info = log->fs_info; int ret; @@ -2737,10 +2738,10 @@ static int update_log_root(struct btrfs_trans_handle *trans, if (log->log_transid == 1) { /* insert root item on the first sync */ ret = btrfs_insert_root(trans, fs_info->log_root_tree, - &log->root_key, &log->root_item); + &log->root_key, root_item); } else { ret = btrfs_update_root(trans, fs_info->log_root_tree, - &log->root_key, &log->root_item); + &log->root_key, root_item); } return ret; } @@ -2836,6 +2837,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_root *log = root->log_root; struct btrfs_root *log_root_tree = fs_info->log_root_tree; + struct btrfs_root_item new_root_item; int log_transid = 0; struct btrfs_log_ctx root_log_ctx; struct blk_plug plug; @@ -2901,18 +2903,26 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans, goto out; } + /* + * We _must_ update under the root->log_mutex in order to make sure we + * have a consistent view of the log root we are trying to commit at + * this moment. + * + * We _must_ copy this into a local copy, because we are not holding the + * log_root_tree->log_mutex yet. This is important because when we + * commit the log_root_tree we must have a consistent view of the + * log_root_tree when we update the super block to point at the + * log_root_tree bytenr. If we update the log_root_tree here we'll race + * with the commit and possibly point at the new block which we may not + * have written out. + */ btrfs_set_root_node(&log->root_item, log->node); + memcpy(&new_root_item, &log->root_item, sizeof(new_root_item)); root->log_transid++; log->log_transid = root->log_transid; root->log_start_pid = 0; /* - * Update or create log root item under the root's log_mutex to prevent - * races with concurrent log syncs that can lead to failure to update - * log root item because it was not created yet. - */ - ret = update_log_root(trans, log); - /* * IO has been started, blocks of the log tree have WRITTEN flag set * in their headers. new modifications of the log will be written to * new positions. so it's safe to allow log writers to go in. @@ -2932,6 +2942,14 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans, mutex_unlock(&log_root_tree->log_mutex); mutex_lock(&log_root_tree->log_mutex); + + /* + * Now we are safe to update the log_root_tree because we're under the + * log_mutex, and we're a current writer so we're holding the commit + * open until we drop the log_mutex. + */ + ret = update_log_root(trans, log, &new_root_item); + if (atomic_dec_and_test(&log_root_tree->log_writers)) { /* * Implicit memory barrier after atomic_dec_and_test @@ -3153,6 +3171,30 @@ int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans, } /* + * Check if an inode was logged in the current transaction. We can't always rely + * on an inode's logged_trans value, because it's an in-memory only field and + * therefore not persisted. This means that its value is lost if the inode gets + * evicted and loaded again from disk (in which case it has a value of 0, and + * certainly it is smaller then any possible transaction ID), when that happens + * the full_sync flag is set in the inode's runtime flags, so on that case we + * assume eviction happened and ignore the logged_trans value, assuming the + * worst case, that the inode was logged before in the current transaction. + */ +static bool inode_logged(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode) +{ + if (inode->logged_trans == trans->transid) + return true; + + if (inode->last_trans == trans->transid && + test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) && + !test_bit(BTRFS_FS_LOG_RECOVERING, &trans->fs_info->flags)) + return true; + + return false; +} + +/* * If both a file and directory are logged, and unlinks or renames are * mixed in, we have a few interesting corners: * @@ -3186,7 +3228,7 @@ int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans, int bytes_del = 0; u64 dir_ino = btrfs_ino(dir); - if (dir->logged_trans < trans->transid) + if (!inode_logged(trans, dir)) return 0; ret = join_running_log_trans(root); @@ -3291,7 +3333,7 @@ int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans, u64 index; int ret; - if (inode->logged_trans < trans->transid) + if (!inode_logged(trans, inode)) return 0; ret = join_running_log_trans(root); @@ -5098,7 +5140,7 @@ again: BTRFS_I(other_inode), LOG_OTHER_INODE, 0, LLONG_MAX, ctx); - iput(other_inode); + btrfs_add_delayed_iput(other_inode); if (err) goto out_unlock; else @@ -5266,9 +5308,19 @@ log_extents: } } + /* + * Don't update last_log_commit if we logged that an inode exists after + * it was loaded to memory (full_sync bit set). + * This is to prevent data loss when we do a write to the inode, then + * the inode gets evicted after all delalloc was flushed, then we log + * it exists (due to a rename for example) and then fsync it. This last + * fsync would do nothing (not logging the extents previously written). + */ spin_lock(&inode->lock); inode->logged_trans = trans->transid; - inode->last_log_commit = inode->last_sub_trans; + if (inode_only != LOG_INODE_EXISTS || + !test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags)) + inode->last_log_commit = inode->last_sub_trans; spin_unlock(&inode->lock); out_unlock: if (unlikely(err)) @@ -5505,7 +5557,7 @@ process_leaf: } if (btrfs_inode_in_log(BTRFS_I(di_inode), trans->transid)) { - iput(di_inode); + btrfs_add_delayed_iput(di_inode); break; } @@ -5517,7 +5569,7 @@ process_leaf: if (!ret && btrfs_must_commit_transaction(trans, BTRFS_I(di_inode))) ret = 1; - iput(di_inode); + btrfs_add_delayed_iput(di_inode); if (ret) goto next_dir_inode; if (ctx->log_new_dentries) { @@ -5664,7 +5716,7 @@ static int btrfs_log_all_parents(struct btrfs_trans_handle *trans, if (!ret && ctx && ctx->log_new_dentries) ret = log_new_dir_dentries(trans, root, BTRFS_I(dir_inode), ctx); - iput(dir_inode); + btrfs_add_delayed_iput(dir_inode); if (ret) goto out; } |