md-cluster: convert the completion to wait queue

Previously, we used completion to sync between require dlm lock
and sync_ast, however we will have to expose completion.wait
and completion.done in dlm_lock_sync_interruptible (introduced
later), it is not a common usage for completion, so convert
related things to wait queue.

Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
index b4dc211..c947151 100644 (file)
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -25,7 +25,8 @@ struct dlm_lock_resource {
        struct dlm_lksb lksb;
        char *name; /* lock name. */
        uint32_t flags; /* flags to pass to dlm_lock() */
-       struct completion completion; /* completion for synchronized locking */
+       wait_queue_head_t sync_locking; /* wait queue for synchronized locking */
+       bool sync_locking_done;
        void (*bast)(void *arg, int mode); /* blocking AST function pointer*/
        struct mddev *mddev; /* pointing back to mddev. */
        int mode;
@@ -118,7 +119,8 @@ static void sync_ast(void *arg)
        struct dlm_lock_resource *res;
 
        res = arg;
-       complete(&res->completion);
+       res->sync_locking_done = true;
+       wake_up(&res->sync_locking);
 }
 
 static int dlm_lock_sync(struct dlm_lock_resource *res, int mode)
@@ -130,7 +132,8 @@ static int dlm_lock_sync(struct dlm_lock_resource *res, int mode)
                        0, sync_ast, res, res->bast);
        if (ret)
                return ret;
-       wait_for_completion(&res->completion);
+       wait_event(res->sync_locking, res->sync_locking_done);
+       res->sync_locking_done = false;
        if (res->lksb.sb_status == 0)
                res->mode = mode;
        return res->lksb.sb_status;
@@ -151,7 +154,8 @@ static struct dlm_lock_resource *lockres_init(struct mddev *mddev,
        res = kzalloc(sizeof(struct dlm_lock_resource), GFP_KERNEL);
        if (!res)
                return NULL;
-       init_completion(&res->completion);
+       init_waitqueue_head(&res->sync_locking);
+       res->sync_locking_done = false;
        res->ls = cinfo->lockspace;
        res->mddev = mddev;
        res->mode = DLM_LOCK_IV;
@@ -208,7 +212,7 @@ static void lockres_free(struct dlm_lock_resource *res)
        if (unlikely(ret != 0))
                pr_err("failed to unlock %s return %d\n", res->name, ret);
        else
-               wait_for_completion(&res->completion);
+               wait_event(res->sync_locking, res->sync_locking_done);
 
        kfree(res->name);
        kfree(res->lksb.sb_lvbptr);