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

[Gao Xiang]

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 <hsiang...@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