6.8-stable review patch. If anyone has any objections, please let me know.
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From: David Howells dhowells@redhat.com
[ 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@redhat.com Link: https://lore.kernel.org/r/6736.1713343639@warthog.procyon.org.uk Reviewed-by: Jeff Layton jlayton@kernel.org cc: Eric Van Hensbergen ericvh@kernel.org cc: Latchesar Ionkov lucho@ionkov.net cc: Dominique Martinet asmadeus@codewreck.org cc: Christian Schoenebeck linux_oss@crudebyte.com cc: Marc Dionne marc.dionne@auristor.com cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org cc: v9fs@lists.linux.dev cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner brauner@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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;