6.5-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andreas Gruenbacher agruenba@redhat.com
[ Upstream commit 52954b750958dcab9e44935f0c32643279091c85 ]
On a thawed filesystem, the freeze glock is held in shared mode. In order to initiate a cluster-wide freeze, the node initiating the freeze drops the freeze glock and grabs it in exclusive mode. The other nodes recognize this as contention on the freeze glock; function freeze_go_callback is invoked. This indicates to them that they must freeze the filesystem locally, drop the freeze glock, and then re-acquire it in shared mode before being able to unfreeze the filesystem locally.
While a node is trying to re-acquire the freeze glock in shared mode, additional contention can occur. In that case, the node must behave in the same way as above.
Unfortunately, freeze_go_callback() contains a check that causes it to bail out when the freeze glock isn't held in shared mode. Fix that to allow the glock to be unlocked or held in shared mode.
In addition, update a reference to trylock_super() which has been renamed to super_trylock_shared() in the meantime.
Fixes: b77b4a4815a9 ("gfs2: Rework freeze / thaw logic") Signed-off-by: Andreas Gruenbacher agruenba@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/gfs2/glops.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c index 54319328b16b5..0a3b069386ec9 100644 --- a/fs/gfs2/glops.c +++ b/fs/gfs2/glops.c @@ -567,15 +567,16 @@ static void freeze_go_callback(struct gfs2_glock *gl, bool remote) struct super_block *sb = sdp->sd_vfs;
if (!remote || - gl->gl_state != LM_ST_SHARED || + (gl->gl_state != LM_ST_SHARED && + gl->gl_state != LM_ST_UNLOCKED) || gl->gl_demote_state != LM_ST_UNLOCKED) return;
/* * Try to get an active super block reference to prevent racing with - * unmount (see trylock_super()). But note that unmount isn't the only - * place where a write lock on s_umount is taken, and we can fail here - * because of things like remount as well. + * unmount (see super_trylock_shared()). But note that unmount isn't + * the only place where a write lock on s_umount is taken, and we can + * fail here because of things like remount as well. */ if (down_read_trylock(&sb->s_umount)) { atomic_inc(&sb->s_active);