btrfs: check for commit error at btrfs_attach_transaction_barrier()

commit b28ff3a7d7 upstream.

btrfs_attach_transaction_barrier() is used to get a handle pointing to the
current running transaction if the transaction has not started its commit
yet (its state is < TRANS_STATE_COMMIT_START). If the transaction commit
has started, then we wait for the transaction to commit and finish before
returning - however we completely ignore if the transaction was aborted
due to some error during its commit, we simply return ERR_PT(-ENOENT),
which makes the caller assume everything is fine and no errors happened.

This could make an fsync return success (0) to user space when in fact we
had a transaction abort and the target inode changes were therefore not
persisted.

Fix this by checking for the return value from btrfs_wait_for_commit(),
and if it returned an error, return it back to the caller.

Fixes: d4edf39bd5 ("Btrfs: fix uncompleted transaction")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Filipe Manana 2023-07-21 10:49:21 +01:00 committed by Greg Kroah-Hartman
parent a7b85dc316
commit 360c98f583
1 changed files with 7 additions and 2 deletions

View File

@ -814,8 +814,13 @@ btrfs_attach_transaction_barrier(struct btrfs_root *root)
trans = start_transaction(root, 0, TRANS_ATTACH,
BTRFS_RESERVE_NO_FLUSH, true);
if (trans == ERR_PTR(-ENOENT))
btrfs_wait_for_commit(root->fs_info, 0);
if (trans == ERR_PTR(-ENOENT)) {
int ret;
ret = btrfs_wait_for_commit(root->fs_info, 0);
if (ret)
return ERR_PTR(ret);
}
return trans;
}