6.5-stable review patch. If anyone has any objections, please let me know.
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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++;