diff options
| author | Wengang Wang <wen.gang.wang@oracle.com> | 2010-07-16 23:13:33 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-08-26 16:43:18 -0700 |
| commit | ea156ca43e1daf741590124281f9ba9c7ee61c79 (patch) | |
| tree | 5e5d8c3a71b66120851a8f274d2e12aa66942b4c /fs | |
| parent | 9c03fdacc7f541bc3dd67af0955f8e90eadc8c6e (diff) | |
ocfs2/dlm: fix a dead lock
commit 6d98c3ccb52f692f1a60339dde7c700686a5568b upstream.
When we have to take both dlm->master_lock and lockres->spinlock,
take them in order
lockres->spinlock and then dlm->master_lock.
The patch fixes a violation of the rule.
We can simply move taking dlm->master_lock to where we have dropped res->spinlock
since when we access res->state and free mle memory we don't need master_lock's
protection.
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ocfs2/dlm/dlmmaster.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c index 9289b4357d27..91bd48aad118 100644 --- a/fs/ocfs2/dlm/dlmmaster.c +++ b/fs/ocfs2/dlm/dlmmaster.c @@ -3044,8 +3044,6 @@ int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data, /* check for pre-existing lock */ spin_lock(&dlm->spinlock); res = __dlm_lookup_lockres(dlm, name, namelen, hash); - spin_lock(&dlm->master_lock); - if (res) { spin_lock(&res->spinlock); if (res->state & DLM_LOCK_RES_RECOVERING) { @@ -3063,14 +3061,15 @@ int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data, spin_unlock(&res->spinlock); } + spin_lock(&dlm->master_lock); /* ignore status. only nonzero status would BUG. */ ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name, namelen, migrate->new_master, migrate->master); -unlock: spin_unlock(&dlm->master_lock); +unlock: spin_unlock(&dlm->spinlock); if (oldmle) { |