block/rq_qos: protect rq_qos apis with a new lock

[linux-2.6-microblaze.git] / block / blk-cgroup.c

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 0ce64dd..1c6716f 100644 (file)
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -748,6 +748,13 @@ int blkg_conf_open_bdev(struct blkg_conf_ctx *ctx)
                return -ENODEV;
        }
 
+       mutex_lock(&bdev->bd_queue->rq_qos_mutex);
+       if (!disk_live(bdev->bd_disk)) {
+               blkdev_put_no_open(bdev);
+               mutex_unlock(&bdev->bd_queue->rq_qos_mutex);
+               return -ENODEV;
+       }
+
        ctx->body = input;
        ctx->bdev = bdev;
        return 0;
@@ -892,6 +899,7 @@ EXPORT_SYMBOL_GPL(blkg_conf_prep);
  */
 void blkg_conf_exit(struct blkg_conf_ctx *ctx)
        __releases(&ctx->bdev->bd_queue->queue_lock)
+       __releases(&ctx->bdev->bd_queue->rq_qos_mutex)
 {
        if (ctx->blkg) {
                spin_unlock_irq(&bdev_get_queue(ctx->bdev)->queue_lock);
@@ -899,6 +907,7 @@ void blkg_conf_exit(struct blkg_conf_ctx *ctx)
        }
 
        if (ctx->bdev) {
+               mutex_unlock(&ctx->bdev->bd_queue->rq_qos_mutex);
                blkdev_put_no_open(ctx->bdev);
                ctx->body = NULL;
                ctx->bdev = NULL;