[PATCH review for 4.4 03/47] GFS2: Fix reference to ERR_PTR in gfs2_glock_iter_next

From: Levin, Alexander (Sasha Levin)
Date: Wed Sep 20 2017 - 00:45:35 EST


From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

[ Upstream commit 14d37564fa3dc4e5d4c6828afcd26ac14e6796c5 ]

This patch fixes a place where function gfs2_glock_iter_next can
reference an invalid error pointer.

Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Bob Peterson <rpeterso@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
---
fs/gfs2/glock.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 070901e76653..1a20817ee1d7 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1798,16 +1798,18 @@ void gfs2_glock_exit(void)

static void gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
{
- do {
- gi->gl = rhashtable_walk_next(&gi->hti);
+ while ((gi->gl = rhashtable_walk_next(&gi->hti))) {
if (IS_ERR(gi->gl)) {
if (PTR_ERR(gi->gl) == -EAGAIN)
continue;
gi->gl = NULL;
+ return;
}
- /* Skip entries for other sb and dead entries */
- } while ((gi->gl) && ((gi->sdp != gi->gl->gl_name.ln_sbd) ||
- __lockref_is_dead(&gi->gl->gl_lockref)));
+ /* Skip entries for other sb and dead entries */
+ if (gi->sdp == gi->gl->gl_name.ln_sbd &&
+ !__lockref_is_dead(&gi->gl->gl_lockref))
+ return;
+ }
}

static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
--
2.11.0