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-rw-r--r--block/blk-cgroup.c92
1 files changed, 81 insertions, 11 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 0ac817b750db..6e43fa355e71 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -9,6 +9,10 @@
*
* Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
* Nauman Rafique <nauman@google.com>
+ *
+ * For policy-specific per-blkcg data:
+ * Copyright (C) 2015 Paolo Valente <paolo.valente@unimore.it>
+ * Arianna Avanzini <avanzini.arianna@gmail.com>
*/
#include <linux/ioprio.h>
#include <linux/kdev_t.h>
@@ -26,8 +30,7 @@
static DEFINE_MUTEX(blkcg_pol_mutex);
-struct blkcg blkcg_root = { .cfq_weight = 2 * CFQ_WEIGHT_DEFAULT,
- .cfq_leaf_weight = 2 * CFQ_WEIGHT_DEFAULT, };
+struct blkcg blkcg_root;
EXPORT_SYMBOL_GPL(blkcg_root);
static struct blkcg_policy *blkcg_policy[BLKCG_MAX_POLS];
@@ -823,6 +826,8 @@ static struct cgroup_subsys_state *
blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
{
struct blkcg *blkcg;
+ struct cgroup_subsys_state *ret;
+ int i;
if (!parent_css) {
blkcg = &blkcg_root;
@@ -830,17 +835,49 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
}
blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL);
- if (!blkcg)
- return ERR_PTR(-ENOMEM);
+ if (!blkcg) {
+ ret = ERR_PTR(-ENOMEM);
+ goto free_blkcg;
+ }
+
+ for (i = 0; i < BLKCG_MAX_POLS ; i++) {
+ struct blkcg_policy *pol = blkcg_policy[i];
+ struct blkcg_policy_data *cpd;
+
+ /*
+ * If the policy hasn't been attached yet, wait for it
+ * to be attached before doing anything else. Otherwise,
+ * check if the policy requires any specific per-cgroup
+ * data: if it does, allocate and initialize it.
+ */
+ if (!pol || !pol->cpd_size)
+ continue;
+
+ BUG_ON(blkcg->pd[i]);
+ cpd = kzalloc(pol->cpd_size, GFP_KERNEL);
+ if (!cpd) {
+ ret = ERR_PTR(-ENOMEM);
+ goto free_pd_blkcg;
+ }
+ blkcg->pd[i] = cpd;
+ cpd->plid = i;
+ pol->cpd_init_fn(blkcg);
+ }
- blkcg->cfq_weight = CFQ_WEIGHT_DEFAULT;
- blkcg->cfq_leaf_weight = CFQ_WEIGHT_DEFAULT;
done:
spin_lock_init(&blkcg->lock);
INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_ATOMIC);
INIT_HLIST_HEAD(&blkcg->blkg_list);
return &blkcg->css;
+
+free_pd_blkcg:
+ for (i--; i >= 0; i--)
+ kfree(blkcg->pd[i]);
+
+free_blkcg:
+ kfree(blkcg);
+ return ret;
}
/**
@@ -958,8 +995,10 @@ int blkcg_activate_policy(struct request_queue *q,
const struct blkcg_policy *pol)
{
LIST_HEAD(pds);
+ LIST_HEAD(cpds);
struct blkcg_gq *blkg, *new_blkg;
- struct blkg_policy_data *pd, *n;
+ struct blkg_policy_data *pd, *nd;
+ struct blkcg_policy_data *cpd, *cnd;
int cnt = 0, ret;
bool preloaded;
@@ -1003,7 +1042,10 @@ int blkcg_activate_policy(struct request_queue *q,
spin_unlock_irq(q->queue_lock);
- /* allocate policy_data for all existing blkgs */
+ /*
+ * Allocate per-blkg and per-blkcg policy data
+ * for all existing blkgs.
+ */
while (cnt--) {
pd = kzalloc_node(pol->pd_size, GFP_KERNEL, q->node);
if (!pd) {
@@ -1011,26 +1053,50 @@ int blkcg_activate_policy(struct request_queue *q,
goto out_free;
}
list_add_tail(&pd->alloc_node, &pds);
+
+ if (!pol->cpd_size)
+ continue;
+ cpd = kzalloc_node(pol->cpd_size, GFP_KERNEL, q->node);
+ if (!cpd) {
+ ret = -ENOMEM;
+ goto out_free;
+ }
+ list_add_tail(&cpd->alloc_node, &cpds);
}
/*
- * Install the allocated pds. With @q bypassing, no new blkg
+ * Install the allocated pds and cpds. With @q bypassing, no new blkg
* should have been created while the queue lock was dropped.
*/
spin_lock_irq(q->queue_lock);
list_for_each_entry(blkg, &q->blkg_list, q_node) {
- if (WARN_ON(list_empty(&pds))) {
+ if (WARN_ON(list_empty(&pds)) ||
+ WARN_ON(pol->cpd_size && list_empty(&cpds))) {
/* umm... this shouldn't happen, just abort */
ret = -ENOMEM;
goto out_unlock;
}
+ cpd = list_first_entry(&cpds, struct blkcg_policy_data,
+ alloc_node);
+ list_del_init(&cpd->alloc_node);
pd = list_first_entry(&pds, struct blkg_policy_data, alloc_node);
list_del_init(&pd->alloc_node);
/* grab blkcg lock too while installing @pd on @blkg */
spin_lock(&blkg->blkcg->lock);
+ if (!pol->cpd_size)
+ goto no_cpd;
+ if (!blkg->blkcg->pd[pol->plid]) {
+ /* Per-policy per-blkcg data */
+ blkg->blkcg->pd[pol->plid] = cpd;
+ cpd->plid = pol->plid;
+ pol->cpd_init_fn(blkg->blkcg);
+ } else { /* must free it as it has already been extracted */
+ kfree(cpd);
+ }
+no_cpd:
blkg->pd[pol->plid] = pd;
pd->blkg = blkg;
pd->plid = pol->plid;
@@ -1045,8 +1111,10 @@ out_unlock:
spin_unlock_irq(q->queue_lock);
out_free:
blk_queue_bypass_end(q);
- list_for_each_entry_safe(pd, n, &pds, alloc_node)
+ list_for_each_entry_safe(pd, nd, &pds, alloc_node)
kfree(pd);
+ list_for_each_entry_safe(cpd, cnd, &cpds, alloc_node)
+ kfree(cpd);
return ret;
}
EXPORT_SYMBOL_GPL(blkcg_activate_policy);
@@ -1087,6 +1155,8 @@ void blkcg_deactivate_policy(struct request_queue *q,
kfree(blkg->pd[pol->plid]);
blkg->pd[pol->plid] = NULL;
+ kfree(blkg->blkcg->pd[pol->plid]);
+ blkg->blkcg->pd[pol->plid] = NULL;
spin_unlock(&blkg->blkcg->lock);
}