From: Brian Foster bfoster@redhat.com
[ Upstream commit 465fa17f4a303d9fdff9eac4d45f91ece92e96ca ]
As of commit e339dd8d8b ("xfs: use sync buffer I/O for sync delwri queue submission"), the delwri submission code uses sync buffer I/O for sync delwri I/O. Instead of waiting on async I/O to unlock the buffer, it uses the underlying sync I/O completion mechanism.
If delwri buffer submission fails due to a shutdown scenario, an error is set on the buffer and buffer completion never occurs. This can cause xfs_buf_delwri_submit() to deadlock waiting on a completion event.
We could check the error state before waiting on such buffers, but that doesn't serialize against the case of an error set via a racing I/O completion. Instead, invoke I/O completion in the shutdown case regardless of buffer I/O type.
Signed-off-by: Brian Foster bfoster@redhat.com Reviewed-by: Dave Chinner dchinner@redhat.com Reviewed-by: Darrick J. Wong darrick.wong@oracle.com Signed-off-by: Darrick J. Wong darrick.wong@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/xfs/xfs_buf.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index e36124546d0db..c1f7c0d5d608a 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -1506,8 +1506,7 @@ __xfs_buf_submit( xfs_buf_ioerror(bp, -EIO); bp->b_flags &= ~XBF_DONE; xfs_buf_stale(bp); - if (bp->b_flags & XBF_ASYNC) - xfs_buf_ioend(bp); + xfs_buf_ioend(bp); return -EIO; }