6.5-stable review patch. If anyone has any objections, please let me know.
------------------
From: Bob Peterson <rpeterso@xxxxxxxxxx>
[ Upstream commit 62862485a4c3a52029fc30f4bdde9af04afdafc9 ]
Before this patch, function gfs2_scan_glock_lru would only try to free
glocks that had a reference count of 0. But if the reference count ever
got to 0, the glock should have already been freed.
Shrinker function gfs2_dispose_glock_lru checks whether glocks on the
LRU are demote_ok, and if so, tries to demote them. But that's only
possible if the reference count is at least 1.
This patch changes gfs2_scan_glock_lru so it will try to demote and/or
dispose of glocks that have a reference count of 1 and which are either
demotable, or are already unlocked.
Signed-off-by: Bob Peterson <rpeterso@xxxxxxxxxx>
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/gfs2/glock.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 1438e7465e306..59c1aed0b9b90 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -2017,7 +2017,9 @@ static long gfs2_scan_glock_lru(int nr)
if (!test_bit(GLF_LOCK, &gl->gl_flags)) {
if (!spin_trylock(&gl->gl_lockref.lock))
continue;
- if (!gl->gl_lockref.count) {
+ if (gl->gl_lockref.count <= 1 &&
+ (gl->gl_state == LM_ST_UNLOCKED ||
+ demote_ok(gl))) {
list_move(&gl->gl_lru, &dispose);
atomic_dec(&lru_count);
freed++;
--
2.40.1
