IOCB_NOWAIT can't just be ignored as it breaks applications expecting
it not to block. Just refuse the operation as applications must handle
that (e.g. by falling back to a thread pool).
Fixes: 8dcc1a9d90c1 ("fs: New zonefs file system")
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/zonefs/super.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
index 8bc6ef82d693..69aee3dfb660 100644
--- a/fs/zonefs/super.c
+++ b/fs/zonefs/super.c
@@ -601,13 +601,13 @@ static ssize_t zonefs_file_dio_write(struct kiocb *iocb, struct iov_iter *from)
ssize_t ret;
/*
- * For async direct IOs to sequential zone files, ignore IOCB_NOWAIT
+ * For async direct IOs to sequential zone files, refuse IOCB_NOWAIT
* as this can cause write reordering (e.g. the first aio gets EAGAIN
* on the inode lock but the second goes through but is now unaligned).
*/
- if (zi->i_ztype == ZONEFS_ZTYPE_SEQ && !is_sync_kiocb(iocb)
- && (iocb->ki_flags & IOCB_NOWAIT))
- iocb->ki_flags &= ~IOCB_NOWAIT;
+ if (zi->i_ztype == ZONEFS_ZTYPE_SEQ && !is_sync_kiocb(iocb) &&
+ (iocb->ki_flags & IOCB_NOWAIT))
+ return -EOPNOTSUPP;
if (iocb->ki_flags & IOCB_NOWAIT) {
if (!inode_trylock(inode))
--
2.24.1
