[PATCH] erofs: handle end of filesystem properly for file-backed mounts

[Gao Xiang <hsiangkao@linux.alibaba.com>]

I/O requests beyond the end of the filesystem should be zeroed out,
similar to loopback devices and that is what we need.

Fixes: ce63cb62d794 ("erofs: support unencoded inodes for fileio")
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
---
 fs/erofs/fileio.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/fs/erofs/fileio.c b/fs/erofs/fileio.c
index c1d0081609dc..23d9e0c57fb3 100644
--- a/fs/erofs/fileio.c
+++ b/fs/erofs/fileio.c
@@ -24,12 +24,9 @@ static void erofs_fileio_ki_complete(struct kiocb *iocb, long ret)
 			container_of(iocb, struct erofs_fileio_rq, iocb);
 	struct folio_iter fi;
 
-	if (ret > 0) {
-		if (ret != rq->bio.bi_iter.bi_size) {
-			bio_advance(&rq->bio, ret);
-			zero_fill_bio(&rq->bio);
-		}
-		ret = 0;
+	if (ret >= 0 && ret != rq->bio.bi_iter.bi_size) {
+		bio_advance(&rq->bio, ret);
+		zero_fill_bio(&rq->bio);
 	}
 	if (rq->bio.bi_end_io) {
 		if (ret < 0 && !rq->bio.bi_status)
@@ -37,7 +34,7 @@ static void erofs_fileio_ki_complete(struct kiocb *iocb, long ret)
 	} else {
 		bio_for_each_folio_all(fi, &rq->bio) {
 			DBG_BUGON(folio_test_uptodate(fi.folio));
-			erofs_onlinefolio_end(fi.folio, ret, false);
+			erofs_onlinefolio_end(fi.folio, ret < 0, false);
 		}
 	}
 	bio_endio(&rq->bio);
@@ -48,7 +45,7 @@ static void erofs_fileio_ki_complete(struct kiocb *iocb, long ret)
 static void erofs_fileio_rq_submit(struct erofs_fileio_rq *rq)
 {
 	struct iov_iter iter;
-	int ret;
+	ssize_t ret;
 
 	if (!rq)
 		return;
-- 
2.43.5