Fix netfs_perform_write() to set BDP_ASYNC if IOCB_NOWAIT is set rather than if IOCB_SYNC is not set. It reflects asynchronicity in the sense of not waiting rather than synchronicity in the sense of not returning until the op is complete. Without this, generic/590 fails on cifs in strict caching mode with a complaint that one of the writes fails with EAGAIN. The test can be distilled down to: mount -t cifs /my/share /mnt -ostuff xfs_io -i -c 'falloc 0 8191M -c fsync -f /mnt/file xfs_io -i -c 'pwrite -b 1M -W 0 8191M' /mnt/file Fixes: c38f4e96e605 ("netfs: Provide func to copy data to pagecache for buffered write") Signed-off-by: David Howells <dhowells@xxxxxxxxxx> cc: Jeff Layton <jlayton@xxxxxxxxxx> cc: Enzo Matsumiya <ematsumiya@xxxxxxx> cc: Jens Axboe <axboe@xxxxxxxxx> cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> cc: netfs@xxxxxxxxxxxxxxx cc: v9fs@xxxxxxxxxxxxxxx cc: linux-afs@xxxxxxxxxxxxxxxxxxx cc: linux-cifs@xxxxxxxxxxxxxxx cc: linux-fsdevel@xxxxxxxxxxxxxxx --- fs/netfs/buffered_write.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c index 1121601536d1..07bc1fd43530 100644 --- a/fs/netfs/buffered_write.c +++ b/fs/netfs/buffered_write.c @@ -181,7 +181,7 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter, struct folio *folio, *writethrough = NULL; enum netfs_how_to_modify howto; enum netfs_folio_trace trace; - unsigned int bdp_flags = (iocb->ki_flags & IOCB_SYNC) ? 0: BDP_ASYNC; + unsigned int bdp_flags = (iocb->ki_flags & IOCB_NOWAIT) ? BDP_ASYNC : 0; ssize_t written = 0, ret, ret2; loff_t i_size, pos = iocb->ki_pos, from, to; size_t max_chunk = PAGE_SIZE << MAX_PAGECACHE_ORDER;