blk-throttle: Introduce a helper function to fill in device details

A helper function for the code which is used at 2-3 places. Makes reading
code little easier.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This commit is contained in:
Vivek Goyal 2011-05-19 15:38:25 -04:00 committed by Jens Axboe
parent 29b125892f
commit 269f541555

View File

@ -188,16 +188,34 @@ throtl_add_group_to_td_list(struct throtl_data *td, struct throtl_grp *tg)
td->nr_undestroyed_grps++;
}
static void throtl_init_add_tg_lists(struct throtl_data *td,
struct throtl_grp *tg, struct blkio_cgroup *blkcg)
static void
__throtl_tg_fill_dev_details(struct throtl_data *td, struct throtl_grp *tg)
{
struct backing_dev_info *bdi = &td->queue->backing_dev_info;
unsigned int major, minor;
if (!tg || tg->blkg.dev)
return;
/*
* Fill in device details for a group which might not have been
* filled at group creation time as queue was being instantiated
* and driver had not attached a device yet
*/
if (bdi->dev && dev_name(bdi->dev)) {
sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
tg->blkg.dev = MKDEV(major, minor);
}
}
static void throtl_init_add_tg_lists(struct throtl_data *td,
struct throtl_grp *tg, struct blkio_cgroup *blkcg)
{
__throtl_tg_fill_dev_details(td, tg);
/* Add group onto cgroup list */
sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
blkiocg_add_blkio_group(blkcg, &tg->blkg, (void *)td,
MKDEV(major, minor), BLKIO_POLICY_THROTL);
tg->blkg.dev, BLKIO_POLICY_THROTL);
tg->bps[READ] = blkcg_get_read_bps(blkcg, tg->blkg.dev);
tg->bps[WRITE] = blkcg_get_write_bps(blkcg, tg->blkg.dev);
@ -225,8 +243,6 @@ throtl_grp *throtl_find_tg(struct throtl_data *td, struct blkio_cgroup *blkcg)
{
struct throtl_grp *tg = NULL;
void *key = td;
struct backing_dev_info *bdi = &td->queue->backing_dev_info;
unsigned int major, minor;
/*
* This is the common case when there are no blkio cgroups.
@ -237,12 +253,7 @@ throtl_grp *throtl_find_tg(struct throtl_data *td, struct blkio_cgroup *blkcg)
else
tg = tg_of_blkg(blkiocg_lookup_group(blkcg, key));
/* Fill in device details for root group */
if (tg && !tg->blkg.dev && bdi->dev && dev_name(bdi->dev)) {
sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
tg->blkg.dev = MKDEV(major, minor);
}
__throtl_tg_fill_dev_details(td, tg);
return tg;
}