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-rw-r--r--fs/ocfs2/dlm/dlmcommon.h1
-rw-r--r--fs/ocfs2/dlm/dlmrecovery.c40
2 files changed, 35 insertions, 6 deletions
diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index 1f939631ab7..dc8ea666efd 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -176,6 +176,7 @@ struct dlm_mig_lockres_priv
{
struct dlm_lock_resource *lockres;
u8 real_master;
+ u8 extra_ref;
};
struct dlm_assert_master_priv
diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
index db17727594a..f9468355242 100644
--- a/fs/ocfs2/dlm/dlmrecovery.c
+++ b/fs/ocfs2/dlm/dlmrecovery.c
@@ -1327,6 +1327,7 @@ int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
(struct dlm_migratable_lockres *)msg->buf;
int ret = 0;
u8 real_master;
+ u8 extra_refs = 0;
char *buf = NULL;
struct dlm_work_item *item = NULL;
struct dlm_lock_resource *res = NULL;
@@ -1404,16 +1405,28 @@ int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
__dlm_insert_lockres(dlm, res);
spin_unlock(&dlm->spinlock);
+ /* Add an extra ref for this lock-less lockres lest the
+ * dlm_thread purges it before we get the chance to add
+ * locks to it */
+ dlm_lockres_get(res);
+
+ /* There are three refs that need to be put.
+ * 1. Taken above.
+ * 2. kref_init in dlm_new_lockres()->dlm_init_lockres().
+ * 3. dlm_lookup_lockres()
+ * The first one is handled at the end of this function. The
+ * other two are handled in the worker thread after locks have
+ * been attached. Yes, we don't wait for purge time to match
+ * kref_init. The lockres will still have atleast one ref
+ * added because it is in the hash __dlm_insert_lockres() */
+ extra_refs++;
+
/* now that the new lockres is inserted,
* make it usable by other processes */
spin_lock(&res->spinlock);
res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
spin_unlock(&res->spinlock);
wake_up(&res->wq);
-
- /* add an extra ref for just-allocated lockres
- * otherwise the lockres will be purged immediately */
- dlm_lockres_get(res);
}
/* at this point we have allocated everything we need,
@@ -1443,12 +1456,17 @@ int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
dlm_init_work_item(dlm, item, dlm_mig_lockres_worker, buf);
item->u.ml.lockres = res; /* already have a ref */
item->u.ml.real_master = real_master;
+ item->u.ml.extra_ref = extra_refs;
spin_lock(&dlm->work_lock);
list_add_tail(&item->list, &dlm->work_list);
spin_unlock(&dlm->work_lock);
queue_work(dlm->dlm_worker, &dlm->dispatched_work);
leave:
+ /* One extra ref taken needs to be put here */
+ if (extra_refs)
+ dlm_lockres_put(res);
+
dlm_put(dlm);
if (ret < 0) {
if (buf)
@@ -1464,17 +1482,19 @@ leave:
static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data)
{
- struct dlm_ctxt *dlm = data;
+ struct dlm_ctxt *dlm;
struct dlm_migratable_lockres *mres;
int ret = 0;
struct dlm_lock_resource *res;
u8 real_master;
+ u8 extra_ref;
dlm = item->dlm;
mres = (struct dlm_migratable_lockres *)data;
res = item->u.ml.lockres;
real_master = item->u.ml.real_master;
+ extra_ref = item->u.ml.extra_ref;
if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
/* this case is super-rare. only occurs if
@@ -1517,6 +1537,12 @@ again:
}
leave:
+ /* See comment in dlm_mig_lockres_handler() */
+ if (res) {
+ if (extra_ref)
+ dlm_lockres_put(res);
+ dlm_lockres_put(res);
+ }
kfree(data);
mlog_exit(ret);
}
@@ -1644,7 +1670,8 @@ int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data,
/* retry!? */
BUG();
}
- }
+ } else /* put.. incase we are not the master */
+ dlm_lockres_put(res);
spin_unlock(&res->spinlock);
}
spin_unlock(&dlm->spinlock);
@@ -1921,6 +1948,7 @@ void dlm_move_lockres_to_recovery_list(struct dlm_ctxt *dlm,
"Recovering res %s:%.*s, is already on recovery list!\n",
dlm->name, res->lockname.len, res->lockname.name);
list_del_init(&res->recovering);
+ dlm_lockres_put(res);
}
/* We need to hold a reference while on the recovery list */
dlm_lockres_get(res);