blkcg: move blkg_for_each_descendant_pre() to block/blk-cgroup.h

blk-throttle hierarchy support will make use of it.  Move
blkg_for_each_descendant_pre() from block/blk-cgroup.c to
block/blk-cgroup.h.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
This commit is contained in:
Tejun Heo 2013-05-14 13:52:30 -07:00
parent 2423c9c3f0
commit dd4a4ffc0a
2 changed files with 22 additions and 22 deletions

View File

@ -32,26 +32,6 @@ EXPORT_SYMBOL_GPL(blkcg_root);
static struct blkcg_policy *blkcg_policy[BLKCG_MAX_POLS];
static struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg,
struct request_queue *q, bool update_hint);
/**
* blkg_for_each_descendant_pre - pre-order walk of a blkg's descendants
* @d_blkg: loop cursor pointing to the current descendant
* @pos_cgrp: used for iteration
* @p_blkg: target blkg to walk descendants of
*
* Walk @c_blkg through the descendants of @p_blkg. Must be used with RCU
* read locked. If called under either blkcg or queue lock, the iteration
* is guaranteed to include all and only online blkgs. The caller may
* update @pos_cgrp by calling cgroup_rightmost_descendant() to skip
* subtree.
*/
#define blkg_for_each_descendant_pre(d_blkg, pos_cgrp, p_blkg) \
cgroup_for_each_descendant_pre((pos_cgrp), (p_blkg)->blkcg->css.cgroup) \
if (((d_blkg) = __blkg_lookup(cgroup_to_blkcg(pos_cgrp), \
(p_blkg)->q, false)))
static bool blkcg_policy_enabled(struct request_queue *q,
const struct blkcg_policy *pol)
{
@ -158,8 +138,8 @@ err_free:
* @q's bypass state. If @update_hint is %true, the caller should be
* holding @q->queue_lock and lookup hint is updated on success.
*/
static struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg,
struct request_queue *q, bool update_hint)
struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg, struct request_queue *q,
bool update_hint)
{
struct blkcg_gq *blkg;

View File

@ -282,6 +282,26 @@ static inline void blkg_put(struct blkcg_gq *blkg)
__blkg_release(blkg);
}
struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg, struct request_queue *q,
bool update_hint);
/**
* blkg_for_each_descendant_pre - pre-order walk of a blkg's descendants
* @d_blkg: loop cursor pointing to the current descendant
* @pos_cgrp: used for iteration
* @p_blkg: target blkg to walk descendants of
*
* Walk @c_blkg through the descendants of @p_blkg. Must be used with RCU
* read locked. If called under either blkcg or queue lock, the iteration
* is guaranteed to include all and only online blkgs. The caller may
* update @pos_cgrp by calling cgroup_rightmost_descendant() to skip
* subtree.
*/
#define blkg_for_each_descendant_pre(d_blkg, pos_cgrp, p_blkg) \
cgroup_for_each_descendant_pre((pos_cgrp), (p_blkg)->blkcg->css.cgroup) \
if (((d_blkg) = __blkg_lookup(cgroup_to_blkcg(pos_cgrp), \
(p_blkg)->q, false)))
/**
* blk_get_rl - get request_list to use
* @q: request_queue of interest