diff options
| author | Tejun Heo <tj@kernel.org> | 2014-09-08 08:03:56 +0900 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2014-09-08 10:00:35 -0600 |
| commit | ff9ea323816dc1c8ac7144afd4eab3ac97704430 (patch) | |
| tree | a865fe69407f8c15d4d877defbc801aebf8d1849 /block | |
| parent | f4da80727cfbc3590d95ff17ef8db96e6f1483a4 (diff) | |
block, bdi: an active gendisk always has a request_queue associated with it
bdev_get_queue() returns the request_queue associated with the
specified block_device. blk_get_backing_dev_info() makes use of
bdev_get_queue() to determine the associated bdi given a block_device.
All the callers of bdev_get_queue() including
blk_get_backing_dev_info() assume that bdev_get_queue() may return
NULL and implement NULL handling; however, bdev_get_queue() requires
the passed in block_device is opened and attached to its gendisk.
Because an active gendisk always has a valid request_queue associated
with it, bdev_get_queue() can never return NULL and neither can
blk_get_backing_dev_info().
Make it clear that neither of the two functions can return NULL and
remove NULL handling from all the callers.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Chris Mason <clm@fb.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-core.c | 10 | ||||
| -rw-r--r-- | block/compat_ioctl.c | 4 | ||||
| -rw-r--r-- | block/ioctl.c | 4 |
3 files changed, 3 insertions, 15 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 93603e6ff479..817446175489 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -83,18 +83,14 @@ void blk_queue_congestion_threshold(struct request_queue *q) * @bdev: device * * Locates the passed device's request queue and returns the address of its - * backing_dev_info - * - * Will return NULL if the request queue cannot be located. + * backing_dev_info. This function can only be called if @bdev is opened + * and the return value is never NULL. */ struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev) { - struct backing_dev_info *ret = NULL; struct request_queue *q = bdev_get_queue(bdev); - if (q) - ret = &q->backing_dev_info; - return ret; + return &q->backing_dev_info; } EXPORT_SYMBOL(blk_get_backing_dev_info); diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c index 18b282ce361e..f678c733df40 100644 --- a/block/compat_ioctl.c +++ b/block/compat_ioctl.c @@ -709,8 +709,6 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg) if (!arg) return -EINVAL; bdi = blk_get_backing_dev_info(bdev); - if (bdi == NULL) - return -ENOTTY; return compat_put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512); case BLKROGET: /* compatible */ @@ -731,8 +729,6 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg) if (!capable(CAP_SYS_ADMIN)) return -EACCES; bdi = blk_get_backing_dev_info(bdev); - if (bdi == NULL) - return -ENOTTY; bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE; return 0; case BLKGETSIZE: diff --git a/block/ioctl.c b/block/ioctl.c index d6cda8147c91..6c7bf903742f 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -356,8 +356,6 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, if (!arg) return -EINVAL; bdi = blk_get_backing_dev_info(bdev); - if (bdi == NULL) - return -ENOTTY; return put_long(arg, (bdi->ra_pages * PAGE_CACHE_SIZE) / 512); case BLKROGET: return put_int(arg, bdev_read_only(bdev) != 0); @@ -386,8 +384,6 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, if(!capable(CAP_SYS_ADMIN)) return -EACCES; bdi = blk_get_backing_dev_info(bdev); - if (bdi == NULL) - return -ENOTTY; bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE; return 0; case BLKBSZSET: |