From f2e0e1615d657ef37c084308a45bc20254eac68e Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Tue, 10 Jan 2023 14:56:37 +0000 Subject: [PATCH] btrfs: do not abort transaction on failure to write log tree when syncing log commit 16199ad9eb6db60a6b10794a09fc1ac6d09312ff upstream. When syncing the log, if we fail to write log tree extent buffers, we mark the log for a full commit and abort the transaction. However we don't need to abort the transaction, all we really need to do is to make sure no one can commit a superblock pointing to new log tree roots. Just because we got a failure writing extent buffers for a log tree, it does not mean we will also fail to do a transaction commit. One particular case is if due to a bug somewhere, when writing log tree extent buffers, the tree checker detects some corruption and the writeout fails because of that. Aborting the transaction can be very disruptive for a user, specially if the issue happened on a root filesystem. One example is the scenario in the Link tag below, where an isolated corruption on log tree leaves was causing transaction aborts when syncing the log. Link: https://lore.kernel.org/linux-btrfs/ae169fc6-f504-28f0-a098-6fa6a4dfb612@leemhuis.info/ CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Josef Bacik Signed-off-by: Filipe Manana Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/disk-io.c | 9 ++++++++- fs/btrfs/tree-log.c | 2 -- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 2c80fc9..ce2da06 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -380,7 +380,14 @@ error: btrfs_print_tree(eb, 0); btrfs_err(fs_info, "block=%llu write time tree block corruption detected", eb->start); - WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG)); + /* + * Be noisy if this is an extent buffer from a log tree. We don't abort + * a transaction in case there's a bad log tree extent buffer, we just + * fallback to a transaction commit. Still we want to know when there is + * a bad log tree extent buffer, as that may signal a bug somewhere. + */ + WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG) || + btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID); return ret; } diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 7272896..7c0c6fc 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -3141,7 +3141,6 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans, ret = 0; if (ret) { blk_finish_plug(&plug); - btrfs_abort_transaction(trans, ret); btrfs_set_log_full_commit(trans); mutex_unlock(&root->log_mutex); goto out; @@ -3273,7 +3272,6 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans, goto out_wake_log_root; } else if (ret) { btrfs_set_log_full_commit(trans); - btrfs_abort_transaction(trans, ret); mutex_unlock(&log_root_tree->log_mutex); goto out_wake_log_root; } -- 2.7.4