From: Changwei Ge <gechangwei@xxxxxxx>
Subject: ocfs2: wait for recovering done after direct unlock request
There is a scenario causing ocfs2 umount hang when multiple hosts are
rebooting at the same time.
NODE1 NODE2 NODE3
send unlock requset to NODE2
dies
become recovery master
recover NODE2
find NODE2 dead
mark resource RECOVERING
directly remove lock from grant list
calculate usage but RECOVERING marked
**miss the window of purging
clear RECOVERING
To reproduce this issue, crash a host and then umount ocfs2
from another node.
To solve this, just let unlock progress wait for recovery done.
Link: http://lkml.kernel.org/r/1550124866-20367-1-git-send-email-gechangwei@xxxxxxx
Signed-off-by: Changwei Ge <gechangwei@xxxxxxx>
Reviewed-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
Cc: Mark Fasheh <mark@xxxxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx>
Cc: Changwei Ge <gechangwei@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/ocfs2/dlm/dlmunlock.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
--- a/fs/ocfs2/dlm/dlmunlock.c~ocfs2-wait-for-recovering-done-after-direct-unlock-request
+++ a/fs/ocfs2/dlm/dlmunlock.c
@@ -90,7 +90,8 @@ static enum dlm_status dlmunlock_common(
enum dlm_status status;
int actions = 0;
int in_use;
- u8 owner;
+ u8 owner;
+ int recovery_wait = 0;
mlog(0, "master_node = %d, valblk = %d\n", master_node,
flags & LKM_VALBLK);
@@ -193,9 +194,12 @@ static enum dlm_status dlmunlock_common(
}
if (flags & LKM_CANCEL)
lock->cancel_pending = 0;
- else
- lock->unlock_pending = 0;
-
+ else {
+ if (!lock->unlock_pending)
+ recovery_wait = 1;
+ else
+ lock->unlock_pending = 0;
+ }
}
/* get an extra ref on lock. if we are just switching
@@ -229,6 +233,17 @@ leave:
spin_unlock(&res->spinlock);
wake_up(&res->wq);
+ if (recovery_wait) {
+ spin_lock(&res->spinlock);
+ /* Unlock request will directly succeed after owner dies,
+ * and the lock is already removed from grant list. We have to
+ * wait for RECOVERING done or we miss the chance to purge it
+ * since the removement is much faster than RECOVERING proc.
+ */
+ __dlm_wait_on_lockres_flags(res, DLM_LOCK_RES_RECOVERING);
+ spin_unlock(&res->spinlock);
+ }
+
/* let the caller's final dlm_lock_put handle the actual kfree */
if (actions & DLM_UNLOCK_FREE_LOCK) {
/* this should always be coupled with list removal */
_
