block: misc updates to blk_get_queue()

* blk_get_queue() is peculiar in that it returns 0 on success and 1 on
  failure instead of 0 / -errno or boolean.  Update it such that it
  returns %true on success and %false on failure.

* Make sure the caller checks for the return value.

* Separate out __blk_get_queue() which doesn't check whether @q is
  dead and put it in blk.h.  This will be used later.

This patch doesn't introduce any functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

4 files changed, 11 insertions, 8 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index af7301581172..fd4749391e17 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -626,14 +626,14 @@ blk_init_allocated_queue_node(struct request_queue *q, request_fn_proc *rfn,
 }
 EXPORT_SYMBOL(blk_init_allocated_queue_node);
 
-int blk_get_queue(struct request_queue *q)
+bool blk_get_queue(struct request_queue *q)
 {
         if (likely(!blk_queue_dead(q))) {
-                kobject_get(&q->kobj);
-                return 0;
+                __blk_get_queue(q);
+                return true;
         }
 
-        return 1;
+        return false;
 }
 EXPORT_SYMBOL(blk_get_queue);
 
diff --git a/block/blk.h b/block/blk.h
index fc3c41b2fd24..8d421156fefb 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -13,6 +13,11 @@ extern struct kmem_cache *blk_requestq_cachep;
 extern struct kobj_type blk_queue_ktype;
 extern struct ida blk_queue_ida;
 
+static inline void __blk_get_queue(struct request_queue *q)
+{
+        kobject_get(&q->kobj);
+}
+
 void init_request_from_bio(struct request *req, struct bio *bio);
 void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
                         struct bio *bio);
diff --git a/block/bsg.c b/block/bsg.c
index 702f1316bb8f..167d586cece6 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -769,12 +769,10 @@ static struct bsg_device *bsg_add_device(struct inode *inode,
                                          struct file *file)
 {
         struct bsg_device *bd;
-        int ret;
 #ifdef BSG_DEBUG
         unsigned char buf[32];
 #endif
-        ret = blk_get_queue(rq);
-        if (ret)
+        if (!blk_get_queue(rq))
                 return ERR_PTR(-ENXIO);
 
         bd = bsg_alloc_device();
diff --git a/block/genhd.c b/block/genhd.c
index 02e9fca80825..c958169d24f0 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -615,7 +615,7 @@ void add_disk(struct gendisk *disk)
          * Take an extra ref on queue which will be put on disk_release()
          * so that it sticks around as long as @disk is there.
          */
-        WARN_ON_ONCE(blk_get_queue(disk->queue));
+        WARN_ON_ONCE(!blk_get_queue(disk->queue));
 
         retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj,
                                    "bdi");