xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

block, bdi: an active gendisk always has a request_queue associated with it

Browse Source 
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>
This commit is contained in:
Tejun Heo
2014-09-08 08:03:56 +09:00
committed by Jens Axboe
parent f4da80727c
commit ff9ea32381
7 changed files with 5 additions and 21 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
fs/btrfs/disk-io.c
View File

@@ -1694,7 +1694,7 @@ static int btrfs_congested_fn(void *congested_data, int bdi_bits)
if (!device->bdev)
continue;
bdi = blk_get_backing_dev_info(device->bdev);
if (bdi && bdi_congested(bdi, bdi_bits)) {
if (bdi_congested(bdi, bdi_bits)) {
ret = 1;
break;
}