diff options
| author | Tejun Heo <tj@kernel.org> | 2012-03-05 13:15:09 -0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2012-03-06 21:27:22 +0100 |
| commit | 7a4dd281ec66224f802093962d1d903d86b09560 (patch) | |
| tree | c38c5c40464d4d7eb429cc14348a435176832ef2 /block/blk-cgroup.h | |
| parent | 4bfd482e73b30284cb21e10834ce729fa81aa256 (diff) | |
blkcg: kill the mind-bending blkg->dev
blkg->dev is dev_t recording the device number of the block device for
the associated request_queue. It is used to identify the associated
block device when printing out configuration or stats.
This is redundant to begin with. A blkg is an association between a
cgroup and a request_queue and it of course is possible to reach
request_queue from blkg and synchronization conventions are in place
for safe q dereferencing, so this shouldn't be necessary from the
beginning. Furthermore, it's initialized by sscanf()ing the device
name of backing_dev_info. The mind boggles.
Anyways, if blkg is visible under rcu lock, we *know* that the
associated request_queue hasn't gone away yet and its bdi is
registered and alive - blkg can't be created for request_queue which
hasn't been fully initialized and it can't go away before blkg is
removed.
Let stat and conf read functions get device name from
blkg->q->backing_dev_info.dev and pass it down to printing functions
and remove blkg->dev.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-cgroup.h')
| -rw-r--r-- | block/blk-cgroup.h | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 9a5c68d7cc92..7ebecf6ea8f1 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -166,8 +166,6 @@ struct blkio_group { unsigned short blkcg_id; /* Store cgroup path */ char path[128]; - /* The device MKDEV(major, minor), this group has been created for */ - dev_t dev; /* policy which owns this blk group */ enum blkio_policy_id plid; |