diff options
| author | Tejun Heo <tj@kernel.org> | 2015-07-09 22:39:49 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-07-09 22:41:09 +0200 |
| commit | 7876f930d0e78addc6bbdbba0d6c196a0788d545 (patch) | |
| tree | 3e38c6592038791cff22a9d3dd6b271c04333a58 | |
| parent | blkcg: blkcg_css_alloc() should grab blkcg_pol_mutex while iterating blkcg_po... (diff) | |
| download | linux-7876f930d0e78addc6bbdbba0d6c196a0788d545.tar.xz linux-7876f930d0e78addc6bbdbba0d6c196a0788d545.zip | |
blkcg: implement all_blkcgs list
Add all_blkcgs list goes through blkcg->all_blkcgs_node and is
protected by blkcg_pol_mutex. This will be used to fix
blkcg_policy_data allocation bug.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
| -rw-r--r-- | block/blk-cgroup.c | 17 | ||||
| -rw-r--r-- | include/linux/blk-cgroup.h | 1 |
2 files changed, 13 insertions, 5 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 05b893de516b..42ff436ffaf4 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -46,6 +46,8 @@ struct cgroup_subsys_state * const blkcg_root_css = &blkcg_root.css; static struct blkcg_policy *blkcg_policy[BLKCG_MAX_POLS]; +static LIST_HEAD(all_blkcgs); /* protected by blkcg_pol_mutex */ + static bool blkcg_policy_enabled(struct request_queue *q, const struct blkcg_policy *pol) { @@ -817,6 +819,10 @@ static void blkcg_css_free(struct cgroup_subsys_state *css) { struct blkcg *blkcg = css_to_blkcg(css); + mutex_lock(&blkcg_pol_mutex); + list_del(&blkcg->all_blkcgs_node); + mutex_unlock(&blkcg_pol_mutex); + if (blkcg != &blkcg_root) { int i; @@ -833,6 +839,8 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css) struct cgroup_subsys_state *ret; int i; + mutex_lock(&blkcg_pol_mutex); + if (!parent_css) { blkcg = &blkcg_root; goto done; @@ -844,8 +852,6 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css) goto free_blkcg; } - mutex_lock(&blkcg_pol_mutex); - for (i = 0; i < BLKCG_MAX_POLS ; i++) { struct blkcg_policy *pol = blkcg_policy[i]; struct blkcg_policy_data *cpd; @@ -862,7 +868,6 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css) BUG_ON(blkcg->pd[i]); cpd = kzalloc(pol->cpd_size, GFP_KERNEL); if (!cpd) { - mutex_unlock(&blkcg_pol_mutex); ret = ERR_PTR(-ENOMEM); goto free_pd_blkcg; } @@ -871,7 +876,6 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css) pol->cpd_init_fn(blkcg); } - mutex_unlock(&blkcg_pol_mutex); done: spin_lock_init(&blkcg->lock); INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_ATOMIC); @@ -879,14 +883,17 @@ done: #ifdef CONFIG_CGROUP_WRITEBACK INIT_LIST_HEAD(&blkcg->cgwb_list); #endif + list_add_tail(&blkcg->all_blkcgs_node, &all_blkcgs); + + mutex_unlock(&blkcg_pol_mutex); return &blkcg->css; free_pd_blkcg: for (i--; i >= 0; i--) kfree(blkcg->pd[i]); - free_blkcg: kfree(blkcg); + mutex_unlock(&blkcg_pol_mutex); return ret; } diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 58cfab80dd70..cf3e7bc22ef3 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -47,6 +47,7 @@ struct blkcg { struct blkcg_policy_data *pd[BLKCG_MAX_POLS]; + struct list_head all_blkcgs_node; #ifdef CONFIG_CGROUP_WRITEBACK struct list_head cgwb_list; #endif |