| From a3762209990c77ea842a80185f68f88afb8a717e Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Tue, 12 Sep 2023 08:05:51 -0500 |
| Subject: gfs2: fix glock shrinker ref issues |
| |
| From: Bob Peterson <rpeterso@redhat.com> |
| |
| [ 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@redhat.com> |
| Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| 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 |
| |
