On 29/4/19 8:08 PM, fdmanana@xxxxxxxxxx wrote:
From: Filipe Manana <fdmanana@xxxxxxxx>
Currently when we fail to COW a path at btrfs_update_root() we end up
always aborting the transaction. However all the current callers of
btrfs_update_root() are able to deal with errors returned from it, many do
end up aborting the transaction themselves (directly or not, such as the
transaction commit path), other BUG_ON() or just gracefully cancel whatever
they were doing.
When syncing the fsync log, we call btrfs_update_root() through
tree-log.c:update_log_root(), and if it returns an -ENOSPC error, the log
sync code does not abort the transaction, instead it gracefully handles
the error and returns -EAGAIN to the fsync handler, so that it falls back
to a transaction commit. Any other error different from -ENOSPC, makes the
log sync code abort the transaction.
So remove the transaction abort from btrfs_update_log() when we fail to
COW a path to update the root item, so that if an -ENOSPC failure happens
we avoid aborting the current transaction and have a chance of the fsync
succeeding after falling back to a transaction commit.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203413
Fixes: 79787eaab46121 ("btrfs: replace many BUG_ONs with proper error handling")
Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
Reviewed-by: Anand Jain <anand.jain@xxxxxxxxxx>
---
fs/btrfs/root-tree.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 893d12fbfda0..1a92ad546f91 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -132,10 +132,8 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
return -ENOMEM;
ret = btrfs_search_slot(trans, root, key, path, 0, 1);
- if (ret < 0) {
- btrfs_abort_transaction(trans, ret);
+ if (ret < 0)
goto out;
- }
if (ret != 0) {
btrfs_print_leaf(path->nodes[0]);
