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>

diff --git a/block/blk-core.c b/block/blk-core.c
index af73015811723a37d073b647f7db662de4f47ac0..fd4749391e1757b462a40afd7447536daf2c9bfd 100644 (file)
--- 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 fc3c41b2fd24aa40cf4780a0d2f23a3debcc55c9..8d421156fefbfcab35874d83d84e8e0588559277 100644 (file)
--- 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 702f1316bb8fec6d68fcb7e0fc262c960530fc29..167d586cece6e110ae7a0f39bc475c95643f7dd4 100644 (file)
--- 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 02e9fca808256f762e0af44e8a1055c322b51b40..c958169d24f04c338624e842622955453f62b5ae 100644 (file)
--- 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");

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index b3c6d957fbd8aa587dcd039547eaa82bd67b6476..89da43f73c00ca209b816ecc68b70a95fbfc0888 100644 (file)
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -297,7 +297,7 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
                kfree(sdev);
                goto out;
        }
-       blk_get_queue(sdev->request_queue);
+       WARN_ON_ONCE(!blk_get_queue(sdev->request_queue));
        sdev->request_queue->queuedata = sdev;
        scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
 

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 8c8dbc4738eacc27f1888a253c135d89c21059e4..d1b6f4ed1f962ef1604674c5ec3f2ba4dc21412b 100644 (file)
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -865,7 +865,7 @@ extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatte
 extern void blk_dump_rq_flags(struct request *, char *);
 extern long nr_blockdev_pages(void);
 
-int blk_get_queue(struct request_queue *);
+bool __must_check blk_get_queue(struct request_queue *);
 struct request_queue *blk_alloc_queue(gfp_t);
 struct request_queue *blk_alloc_queue_node(gfp_t, int);
 extern void blk_put_queue(struct request_queue *);