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authorTejun Heo <tj@kernel.org>2015-07-09 23:39:49 +0300
committerJens Axboe <axboe@fb.com>2015-07-09 23:41:09 +0300
commit7876f930d0e78addc6bbdbba0d6c196a0788d545 (patch)
tree3e38c6592038791cff22a9d3dd6b271c04333a58 /block
parent144232b34258c1fc19729e077c6fb161e30da07b (diff)
downloadlinux-7876f930d0e78addc6bbdbba0d6c196a0788d545.tar.xz
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>
Diffstat (limited to 'block')
-rw-r--r--block/blk-cgroup.c17
1 files changed, 12 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;
}