The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From da7d554f7c62d0c17c1ac3cc2586473c2d99f0bd Mon Sep 17 00:00:00 2001
From: Alexander Aring <aahringo@xxxxxxxxxx>
Date: Mon, 26 Oct 2020 10:52:29 -0400
Subject: [PATCH] gfs2: Wake up when sd_glock_disposal becomes zero
Commit fc0e38dae645 ("GFS2: Fix glock deallocation race") fixed a
sd_glock_disposal accounting bug by adding a missing atomic_dec
statement, but it failed to wake up sd_glock_wait when that decrement
causes sd_glock_disposal to reach zero. As a consequence,
gfs2_gl_hash_clear can now run into a 10-minute timeout instead of
being woken up. Add the missing wakeup.
Fixes: fc0e38dae645 ("GFS2: Fix glock deallocation race")
Cc: stable@xxxxxxxxxxxxxxx # v2.6.39+
Signed-off-by: Alexander Aring <aahringo@xxxxxxxxxx>
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 5441c17562c5..d98a2e5dab9f 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1078,7 +1078,8 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
out_free:
kfree(gl->gl_lksb.sb_lvbptr);
kmem_cache_free(cachep, gl);
- atomic_dec(&sdp->sd_glock_disposal);
+ if (atomic_dec_and_test(&sdp->sd_glock_disposal))
+ wake_up(&sdp->sd_glock_wait);
out:
return ret;
