tree be5fbf53681dbe330c4066cf3f1024f8d5fc18d1
parent ec8a6f2643923ee5b74d24fa8d134240379f436b
author Tejun Heo <tj@kernel.org> 1432329222 -0400
committer Jens Axboe <axboe@fb.com> 1433255615 -0600

writeback, blkcg: restructure blk_{set|clear}_queue_congested()

blk_{set|clear}_queue_congested() take @q and set or clear,
respectively, the congestion state of its bdi's root wb.  Because bdi
used to be able to handle congestion state only on the root wb, the
callers of those functions tested whether the congestion is on the
root blkcg and skipped if not.

This is cumbersome and makes implementation of per cgroup
bdi_writeback congestion state propagation difficult.  This patch
renames blk_{set|clear}_queue_congested() to
blk_{set|clear}_congested(), and makes them take request_list instead
of request_queue and test whether the specified request_list is the
root one before updating bdi_writeback congestion state.  This makes
the tests in the callers unnecessary and simplifies them.

As there are no external users of these functions, the definitions are
moved from include/linux/blkdev.h to block/blk-core.c.

This patch doesn't introduce any noticeable behavior difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>