6.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: David Howells <dhowells@xxxxxxxxxx>
[ Upstream commit 619606a7b8d5e54b71578ecc988d3f8e1896bbc6 ]
Fix the error return in netfs_perform_write() acting in writethrough-mode
to return any cached error in the case that netfs_end_writethrough()
returns 0.
This can affect the use of O_SYNC/O_DSYNC/RWF_SYNC/RWF_DSYNC in 9p and afs.
Fixes: 41d8e7673a77 ("netfs: Implement a write-through caching option")
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Link: https://lore.kernel.org/r/6736.1713343639@xxxxxxxxxxxxxxxxxxxxxx
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
cc: Eric Van Hensbergen <ericvh@xxxxxxxxxx>
cc: Latchesar Ionkov <lucho@xxxxxxxxxx>
cc: Dominique Martinet <asmadeus@xxxxxxxxxxxxx>
cc: Christian Schoenebeck <linux_oss@xxxxxxxxxxxxx>
cc: Marc Dionne <marc.dionne@xxxxxxxxxxxx>
cc: netfs@xxxxxxxxxxxxxxx
cc: linux-fsdevel@xxxxxxxxxxxxxxx
cc: v9fs@xxxxxxxxxxxxxxx
cc: linux-afs@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/netfs/buffered_write.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c
index 9a0d32e4b422a..8f13ca8fbc74d 100644
--- a/fs/netfs/buffered_write.c
+++ b/fs/netfs/buffered_write.c
@@ -164,7 +164,7 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
enum netfs_how_to_modify howto;
enum netfs_folio_trace trace;
unsigned int bdp_flags = (iocb->ki_flags & IOCB_SYNC) ? 0: BDP_ASYNC;
- ssize_t written = 0, ret;
+ 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;
bool maybe_trouble = false;
@@ -395,10 +395,12 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
out:
if (unlikely(wreq)) {
- ret = netfs_end_writethrough(wreq, iocb);
+ ret2 = netfs_end_writethrough(wreq, iocb);
wbc_detach_inode(&wbc);
- if (ret == -EIOCBQUEUED)
- return ret;
+ if (ret2 == -EIOCBQUEUED)
+ return ret2;
+ if (ret == 0)
+ ret = ret2;
}
iocb->ki_pos += written;
--
2.43.0
