[Ocfs2-devel] [PATCH v2] ocfs2/dlm: fix race between convert and recovery
Joseph Qi
joseph.qi at huawei.com
Fri Sep 18 04:25:46 PDT 2015
There is a race window between dlmconvert_remote and
dlm_move_lockres_to_recovery_list, which will cause a lock with
OCFS2_LOCK_BUSY in grant list, thus system hangs.
dlmconvert_remote
{
spin_lock(&res->spinlock);
list_move_tail(&lock->list, &res->converting);
lock->convert_pending = 1;
spin_unlock(&res->spinlock);
status = dlm_send_remote_convert_request();
>>>>>> race window, master has queued ast and return DLM_NORMAL,
and then down before sending ast.
this node detects master down and calls
dlm_move_lockres_to_recovery_list, which will revert the
lock to grant list.
Then OCFS2_LOCK_BUSY won't be cleared as new master won't
send ast any more because it thinks already be authorized.
spin_lock(&res->spinlock);
lock->convert_pending = 0;
if (status != DLM_NORMAL)
dlm_revert_pending_convert(res, lock);
spin_unlock(&res->spinlock);
}
In this case, just leave it in convert list and new master will take care
of it after recovery. And if convert request returns other than
DLM_NORMAL, convert thread will do the revert itself. So remove the
revert logic in dlm_move_lockres_to_recovery_list.
changelog since v1:
Clean up convert_pending since it is now useless.
Signed-off-by: Joseph Qi <joseph.qi at huawei.com>
Reported-by: Yiwen Jiang <jiangyiwen at huawei.com>
Cc: <stable at vger.kernel.org>
---
fs/ocfs2/dlm/dlmcommon.h | 1 -
fs/ocfs2/dlm/dlmconvert.c | 2 --
fs/ocfs2/dlm/dlmdebug.c | 7 +++----
fs/ocfs2/dlm/dlmlock.c | 1 -
fs/ocfs2/dlm/dlmrecovery.c | 10 +---------
5 files changed, 4 insertions(+), 17 deletions(-)
diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index e88ccf8..25853d7 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -369,7 +369,6 @@ struct dlm_lock
struct dlm_lockstatus *lksb;
unsigned ast_pending:1,
bast_pending:1,
- convert_pending:1,
lock_pending:1,
cancel_pending:1,
unlock_pending:1,
diff --git a/fs/ocfs2/dlm/dlmconvert.c b/fs/ocfs2/dlm/dlmconvert.c
index e36d63f..82ba8d5 100644
--- a/fs/ocfs2/dlm/dlmconvert.c
+++ b/fs/ocfs2/dlm/dlmconvert.c
@@ -291,7 +291,6 @@ enum dlm_status dlmconvert_remote(struct dlm_ctxt *dlm,
/* move lock to local convert queue */
/* do not alter lock refcount. switching lists. */
list_move_tail(&lock->list, &res->converting);
- lock->convert_pending = 1;
lock->ml.convert_type = type;
if (flags & LKM_VALBLK) {
@@ -315,7 +314,6 @@ enum dlm_status dlmconvert_remote(struct dlm_ctxt *dlm,
spin_lock(&res->spinlock);
res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
- lock->convert_pending = 0;
/* if it failed, move it back to granted queue */
if (status != DLM_NORMAL) {
if (status != DLM_NOTQUEUED)
diff --git a/fs/ocfs2/dlm/dlmdebug.c b/fs/ocfs2/dlm/dlmdebug.c
index 8251360..710e94c 100644
--- a/fs/ocfs2/dlm/dlmdebug.c
+++ b/fs/ocfs2/dlm/dlmdebug.c
@@ -77,7 +77,7 @@ static void __dlm_print_lock(struct dlm_lock *lock)
printk(" type=%d, conv=%d, node=%u, cookie=%u:%llu, "
"ref=%u, ast=(empty=%c,pend=%c), bast=(empty=%c,pend=%c), "
- "pending=(conv=%c,lock=%c,cancel=%c,unlock=%c)\n",
+ "pending=(lock=%c,cancel=%c,unlock=%c)\n",
lock->ml.type, lock->ml.convert_type, lock->ml.node,
dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
@@ -86,7 +86,6 @@ static void __dlm_print_lock(struct dlm_lock *lock)
(lock->ast_pending ? 'y' : 'n'),
(list_empty(&lock->bast_list) ? 'y' : 'n'),
(lock->bast_pending ? 'y' : 'n'),
- (lock->convert_pending ? 'y' : 'n'),
(lock->lock_pending ? 'y' : 'n'),
(lock->cancel_pending ? 'y' : 'n'),
(lock->unlock_pending ? 'y' : 'n'));
@@ -502,7 +501,7 @@ static int dump_lock(struct dlm_lock *lock, int list_type, char *buf, int len)
#define DEBUG_LOCK_VERSION 1
spin_lock(&lock->spinlock);
- out = snprintf(buf, len, "LOCK:%d,%d,%d,%d,%d,%d:%lld,%d,%d,%d,%d,%d,"
+ out = snprintf(buf, len, "LOCK:%d,%d,%d,%d,%d,%d:%lld,%d,%d,%d,%d,"
"%d,%d,%d,%d\n",
DEBUG_LOCK_VERSION,
list_type, lock->ml.type, lock->ml.convert_type,
@@ -512,7 +511,7 @@ static int dump_lock(struct dlm_lock *lock, int list_type, char *buf, int len)
!list_empty(&lock->ast_list),
!list_empty(&lock->bast_list),
lock->ast_pending, lock->bast_pending,
- lock->convert_pending, lock->lock_pending,
+ lock->lock_pending,
lock->cancel_pending, lock->unlock_pending,
atomic_read(&lock->lock_refs.refcount));
spin_unlock(&lock->spinlock);
diff --git a/fs/ocfs2/dlm/dlmlock.c b/fs/ocfs2/dlm/dlmlock.c
index 66c2a49..857dd15 100644
--- a/fs/ocfs2/dlm/dlmlock.c
+++ b/fs/ocfs2/dlm/dlmlock.c
@@ -411,7 +411,6 @@ static void dlm_init_lock(struct dlm_lock *newlock, int type,
newlock->ml.cookie = cpu_to_be64(cookie);
newlock->ast_pending = 0;
newlock->bast_pending = 0;
- newlock->convert_pending = 0;
newlock->lock_pending = 0;
newlock->unlock_pending = 0;
newlock->cancel_pending = 0;
diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
index 3d90ad7..2402ef7 100644
--- a/fs/ocfs2/dlm/dlmrecovery.c
+++ b/fs/ocfs2/dlm/dlmrecovery.c
@@ -2062,15 +2062,7 @@ void dlm_move_lockres_to_recovery_list(struct dlm_ctxt *dlm,
queue = dlm_list_idx_to_ptr(res, i);
list_for_each_entry_safe(lock, next, queue, list) {
dlm_lock_get(lock);
- if (lock->convert_pending) {
- /* move converting lock back to granted */
- BUG_ON(i != DLM_CONVERTING_LIST);
- mlog(0, "node died with convert pending "
- "on %.*s. move back to granted list.\n",
- res->lockname.len, res->lockname.name);
- dlm_revert_pending_convert(res, lock);
- lock->convert_pending = 0;
- } else if (lock->lock_pending) {
+ if (lock->lock_pending) {
/* remove pending lock requests completely */
BUG_ON(i != DLM_BLOCKED_LIST);
mlog(0, "node died with lock pending "
--
1.8.4.3
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