#include <linux/err.h>
#include <linux/blkdev.h>
#include <linux/slab.h>
-#include "blk-cgroup.h"
#include <linux/genhd.h>
+#include <linux/delay.h>
+#include <linux/atomic.h>
+#include "blk-cgroup.h"
+#include "blk.h"
#define MAX_KEY_LEN 100
static DEFINE_SPINLOCK(blkio_list_lock);
static LIST_HEAD(blkio_list);
+static DEFINE_MUTEX(all_q_mutex);
+static LIST_HEAD(all_q_list);
+
+/* List of groups pending per cpu stats allocation */
+static DEFINE_SPINLOCK(alloc_list_lock);
+static LIST_HEAD(alloc_list);
+
+static void blkio_stat_alloc_fn(struct work_struct *);
+static DECLARE_DELAYED_WORK(blkio_stat_alloc_work, blkio_stat_alloc_fn);
+
struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT };
EXPORT_SYMBOL_GPL(blkio_root_cgroup);
+static struct blkio_policy_type *blkio_policy[BLKIO_NR_POLICIES];
+
static struct cgroup_subsys_state *blkiocg_create(struct cgroup_subsys *,
struct cgroup *);
static int blkiocg_can_attach(struct cgroup_subsys *, struct cgroup *,
struct cgroup_taskset *);
static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *,
struct cgroup_taskset *);
+static int blkiocg_pre_destroy(struct cgroup_subsys *, struct cgroup *);
static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *);
static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *);
.create = blkiocg_create,
.can_attach = blkiocg_can_attach,
.attach = blkiocg_attach,
+ .pre_destroy = blkiocg_pre_destroy,
.destroy = blkiocg_destroy,
.populate = blkiocg_populate,
-#ifdef CONFIG_BLK_CGROUP
- /* note: blkio_subsys_id is otherwise defined in blk-cgroup.h */
.subsys_id = blkio_subsys_id,
-#endif
- .use_id = 1,
.module = THIS_MODULE,
};
EXPORT_SYMBOL_GPL(blkio_subsys);
-static inline void blkio_policy_insert_node(struct blkio_cgroup *blkcg,
- struct blkio_policy_node *pn)
-{
- list_add(&pn->node, &blkcg->policy_list);
-}
-
-static inline bool cftype_blkg_same_policy(struct cftype *cft,
- struct blkio_group *blkg)
-{
- enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
-
- if (blkg->plid == plid)
- return 1;
-
- return 0;
-}
-
-/* Determines if policy node matches cgroup file being accessed */
-static inline bool pn_matches_cftype(struct cftype *cft,
- struct blkio_policy_node *pn)
-{
- enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
- int fileid = BLKIOFILE_ATTR(cft->private);
-
- return (plid == pn->plid && fileid == pn->fileid);
-}
-
-/* Must be called with blkcg->lock held */
-static inline void blkio_policy_delete_node(struct blkio_policy_node *pn)
-{
- list_del(&pn->node);
-}
-
-/* Must be called with blkcg->lock held */
-static struct blkio_policy_node *
-blkio_policy_search_node(const struct blkio_cgroup *blkcg, dev_t dev,
- enum blkio_policy_id plid, int fileid)
-{
- struct blkio_policy_node *pn;
-
- list_for_each_entry(pn, &blkcg->policy_list, node) {
- if (pn->dev == dev && pn->plid == plid && pn->fileid == fileid)
- return pn;
- }
-
- return NULL;
-}
-
struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup)
{
return container_of(cgroup_subsys_state(cgroup, blkio_subsys_id),
}
EXPORT_SYMBOL_GPL(cgroup_to_blkio_cgroup);
-struct blkio_cgroup *task_blkio_cgroup(struct task_struct *tsk)
+static struct blkio_cgroup *task_blkio_cgroup(struct task_struct *tsk)
{
return container_of(task_subsys_state(tsk, blkio_subsys_id),
struct blkio_cgroup, css);
}
-EXPORT_SYMBOL_GPL(task_blkio_cgroup);
-static inline void
-blkio_update_group_weight(struct blkio_group *blkg, unsigned int weight)
+struct blkio_cgroup *bio_blkio_cgroup(struct bio *bio)
+{
+ if (bio && bio->bi_css)
+ return container_of(bio->bi_css, struct blkio_cgroup, css);
+ return task_blkio_cgroup(current);
+}
+EXPORT_SYMBOL_GPL(bio_blkio_cgroup);
+
+static inline void blkio_update_group_weight(struct blkio_group *blkg,
+ int plid, unsigned int weight)
{
struct blkio_policy_type *blkiop;
list_for_each_entry(blkiop, &blkio_list, list) {
/* If this policy does not own the blkg, do not send updates */
- if (blkiop->plid != blkg->plid)
+ if (blkiop->plid != plid)
continue;
if (blkiop->ops.blkio_update_group_weight_fn)
- blkiop->ops.blkio_update_group_weight_fn(blkg->key,
+ blkiop->ops.blkio_update_group_weight_fn(blkg->q,
blkg, weight);
}
}
-static inline void blkio_update_group_bps(struct blkio_group *blkg, u64 bps,
- int fileid)
+static inline void blkio_update_group_bps(struct blkio_group *blkg, int plid,
+ u64 bps, int fileid)
{
struct blkio_policy_type *blkiop;
list_for_each_entry(blkiop, &blkio_list, list) {
/* If this policy does not own the blkg, do not send updates */
- if (blkiop->plid != blkg->plid)
+ if (blkiop->plid != plid)
continue;
if (fileid == BLKIO_THROTL_read_bps_device
&& blkiop->ops.blkio_update_group_read_bps_fn)
- blkiop->ops.blkio_update_group_read_bps_fn(blkg->key,
+ blkiop->ops.blkio_update_group_read_bps_fn(blkg->q,
blkg, bps);
if (fileid == BLKIO_THROTL_write_bps_device
&& blkiop->ops.blkio_update_group_write_bps_fn)
- blkiop->ops.blkio_update_group_write_bps_fn(blkg->key,
+ blkiop->ops.blkio_update_group_write_bps_fn(blkg->q,
blkg, bps);
}
}
static inline void blkio_update_group_iops(struct blkio_group *blkg,
- unsigned int iops, int fileid)
+ int plid, unsigned int iops,
+ int fileid)
{
struct blkio_policy_type *blkiop;
list_for_each_entry(blkiop, &blkio_list, list) {
/* If this policy does not own the blkg, do not send updates */
- if (blkiop->plid != blkg->plid)
+ if (blkiop->plid != plid)
continue;
if (fileid == BLKIO_THROTL_read_iops_device
&& blkiop->ops.blkio_update_group_read_iops_fn)
- blkiop->ops.blkio_update_group_read_iops_fn(blkg->key,
+ blkiop->ops.blkio_update_group_read_iops_fn(blkg->q,
blkg, iops);
if (fileid == BLKIO_THROTL_write_iops_device
&& blkiop->ops.blkio_update_group_write_iops_fn)
- blkiop->ops.blkio_update_group_write_iops_fn(blkg->key,
+ blkiop->ops.blkio_update_group_write_iops_fn(blkg->q,
blkg,iops);
}
}
/*
* Add to the appropriate stat variable depending on the request type.
- * This should be called with the blkg->stats_lock held.
+ * This should be called with queue_lock held.
*/
static void blkio_add_stat(uint64_t *stat, uint64_t add, bool direction,
bool sync)
/*
* Decrements the appropriate stat variable if non-zero depending on the
* request type. Panics on value being zero.
- * This should be called with the blkg->stats_lock held.
+ * This should be called with the queue_lock held.
*/
static void blkio_check_and_dec_stat(uint64_t *stat, bool direction, bool sync)
{
}
#ifdef CONFIG_DEBUG_BLK_CGROUP
-/* This should be called with the blkg->stats_lock held. */
+/* This should be called with the queue_lock held. */
static void blkio_set_start_group_wait_time(struct blkio_group *blkg,
- struct blkio_group *curr_blkg)
+ struct blkio_policy_type *pol,
+ struct blkio_group *curr_blkg)
{
- if (blkio_blkg_waiting(&blkg->stats))
+ struct blkg_policy_data *pd = blkg->pd[pol->plid];
+
+ if (blkio_blkg_waiting(&pd->stats))
return;
if (blkg == curr_blkg)
return;
- blkg->stats.start_group_wait_time = sched_clock();
- blkio_mark_blkg_waiting(&blkg->stats);
+ pd->stats.start_group_wait_time = sched_clock();
+ blkio_mark_blkg_waiting(&pd->stats);
}
-/* This should be called with the blkg->stats_lock held. */
+/* This should be called with the queue_lock held. */
static void blkio_update_group_wait_time(struct blkio_group_stats *stats)
{
unsigned long long now;
blkio_clear_blkg_waiting(stats);
}
-/* This should be called with the blkg->stats_lock held. */
+/* This should be called with the queue_lock held. */
static void blkio_end_empty_time(struct blkio_group_stats *stats)
{
unsigned long long now;
blkio_clear_blkg_empty(stats);
}
-void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
+void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg,
+ struct blkio_policy_type *pol)
{
- unsigned long flags;
+ struct blkio_group_stats *stats = &blkg->pd[pol->plid]->stats;
- spin_lock_irqsave(&blkg->stats_lock, flags);
- BUG_ON(blkio_blkg_idling(&blkg->stats));
- blkg->stats.start_idle_time = sched_clock();
- blkio_mark_blkg_idling(&blkg->stats);
- spin_unlock_irqrestore(&blkg->stats_lock, flags);
+ lockdep_assert_held(blkg->q->queue_lock);
+ BUG_ON(blkio_blkg_idling(stats));
+
+ stats->start_idle_time = sched_clock();
+ blkio_mark_blkg_idling(stats);
}
EXPORT_SYMBOL_GPL(blkiocg_update_set_idle_time_stats);
-void blkiocg_update_idle_time_stats(struct blkio_group *blkg)
+void blkiocg_update_idle_time_stats(struct blkio_group *blkg,
+ struct blkio_policy_type *pol)
{
- unsigned long flags;
- unsigned long long now;
- struct blkio_group_stats *stats;
+ struct blkio_group_stats *stats = &blkg->pd[pol->plid]->stats;
+
+ lockdep_assert_held(blkg->q->queue_lock);
- spin_lock_irqsave(&blkg->stats_lock, flags);
- stats = &blkg->stats;
if (blkio_blkg_idling(stats)) {
- now = sched_clock();
- if (time_after64(now, stats->start_idle_time))
+ unsigned long long now = sched_clock();
+
+ if (time_after64(now, stats->start_idle_time)) {
+ u64_stats_update_begin(&stats->syncp);
stats->idle_time += now - stats->start_idle_time;
+ u64_stats_update_end(&stats->syncp);
+ }
blkio_clear_blkg_idling(stats);
}
- spin_unlock_irqrestore(&blkg->stats_lock, flags);
}
EXPORT_SYMBOL_GPL(blkiocg_update_idle_time_stats);
-void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg)
+void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg,
+ struct blkio_policy_type *pol)
{
- unsigned long flags;
- struct blkio_group_stats *stats;
+ struct blkio_group_stats *stats = &blkg->pd[pol->plid]->stats;
- spin_lock_irqsave(&blkg->stats_lock, flags);
- stats = &blkg->stats;
+ lockdep_assert_held(blkg->q->queue_lock);
+
+ u64_stats_update_begin(&stats->syncp);
stats->avg_queue_size_sum +=
stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_READ] +
stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_WRITE];
stats->avg_queue_size_samples++;
blkio_update_group_wait_time(stats);
- spin_unlock_irqrestore(&blkg->stats_lock, flags);
+ u64_stats_update_end(&stats->syncp);
}
EXPORT_SYMBOL_GPL(blkiocg_update_avg_queue_size_stats);
-void blkiocg_set_start_empty_time(struct blkio_group *blkg)
+void blkiocg_set_start_empty_time(struct blkio_group *blkg,
+ struct blkio_policy_type *pol)
{
- unsigned long flags;
- struct blkio_group_stats *stats;
+ struct blkio_group_stats *stats = &blkg->pd[pol->plid]->stats;
- spin_lock_irqsave(&blkg->stats_lock, flags);
- stats = &blkg->stats;
+ lockdep_assert_held(blkg->q->queue_lock);
if (stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_READ] ||
- stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_WRITE]) {
- spin_unlock_irqrestore(&blkg->stats_lock, flags);
+ stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_WRITE])
return;
- }
/*
* group is already marked empty. This can happen if cfqq got new
* request in parent group and moved to this group while being added
* to service tree. Just ignore the event and move on.
*/
- if(blkio_blkg_empty(stats)) {
- spin_unlock_irqrestore(&blkg->stats_lock, flags);
+ if (blkio_blkg_empty(stats))
return;
- }
stats->start_empty_time = sched_clock();
blkio_mark_blkg_empty(stats);
- spin_unlock_irqrestore(&blkg->stats_lock, flags);
}
EXPORT_SYMBOL_GPL(blkiocg_set_start_empty_time);
void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
- unsigned long dequeue)
+ struct blkio_policy_type *pol,
+ unsigned long dequeue)
{
- blkg->stats.dequeue += dequeue;
+ struct blkg_policy_data *pd = blkg->pd[pol->plid];
+
+ lockdep_assert_held(blkg->q->queue_lock);
+
+ pd->stats.dequeue += dequeue;
}
EXPORT_SYMBOL_GPL(blkiocg_update_dequeue_stats);
#else
static inline void blkio_set_start_group_wait_time(struct blkio_group *blkg,
- struct blkio_group *curr_blkg) {}
-static inline void blkio_end_empty_time(struct blkio_group_stats *stats) {}
+ struct blkio_policy_type *pol,
+ struct blkio_group *curr_blkg) { }
+static inline void blkio_end_empty_time(struct blkio_group_stats *stats) { }
#endif
void blkiocg_update_io_add_stats(struct blkio_group *blkg,
- struct blkio_group *curr_blkg, bool direction,
- bool sync)
+ struct blkio_policy_type *pol,
+ struct blkio_group *curr_blkg, bool direction,
+ bool sync)
{
- unsigned long flags;
+ struct blkio_group_stats *stats = &blkg->pd[pol->plid]->stats;
- spin_lock_irqsave(&blkg->stats_lock, flags);
- blkio_add_stat(blkg->stats.stat_arr[BLKIO_STAT_QUEUED], 1, direction,
- sync);
- blkio_end_empty_time(&blkg->stats);
- blkio_set_start_group_wait_time(blkg, curr_blkg);
- spin_unlock_irqrestore(&blkg->stats_lock, flags);
+ lockdep_assert_held(blkg->q->queue_lock);
+
+ u64_stats_update_begin(&stats->syncp);
+ blkio_add_stat(stats->stat_arr[BLKIO_STAT_QUEUED], 1, direction, sync);
+ blkio_end_empty_time(stats);
+ u64_stats_update_end(&stats->syncp);
+
+ blkio_set_start_group_wait_time(blkg, pol, curr_blkg);
}
EXPORT_SYMBOL_GPL(blkiocg_update_io_add_stats);
void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
- bool direction, bool sync)
+ struct blkio_policy_type *pol,
+ bool direction, bool sync)
{
- unsigned long flags;
+ struct blkio_group_stats *stats = &blkg->pd[pol->plid]->stats;
+
+ lockdep_assert_held(blkg->q->queue_lock);
- spin_lock_irqsave(&blkg->stats_lock, flags);
- blkio_check_and_dec_stat(blkg->stats.stat_arr[BLKIO_STAT_QUEUED],
- direction, sync);
- spin_unlock_irqrestore(&blkg->stats_lock, flags);
+ u64_stats_update_begin(&stats->syncp);
+ blkio_check_and_dec_stat(stats->stat_arr[BLKIO_STAT_QUEUED], direction,
+ sync);
+ u64_stats_update_end(&stats->syncp);
}
EXPORT_SYMBOL_GPL(blkiocg_update_io_remove_stats);
-void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time,
- unsigned long unaccounted_time)
+void blkiocg_update_timeslice_used(struct blkio_group *blkg,
+ struct blkio_policy_type *pol,
+ unsigned long time,
+ unsigned long unaccounted_time)
{
- unsigned long flags;
+ struct blkio_group_stats *stats = &blkg->pd[pol->plid]->stats;
+
+ lockdep_assert_held(blkg->q->queue_lock);
- spin_lock_irqsave(&blkg->stats_lock, flags);
- blkg->stats.time += time;
+ u64_stats_update_begin(&stats->syncp);
+ stats->time += time;
#ifdef CONFIG_DEBUG_BLK_CGROUP
- blkg->stats.unaccounted_time += unaccounted_time;
+ stats->unaccounted_time += unaccounted_time;
#endif
- spin_unlock_irqrestore(&blkg->stats_lock, flags);
+ u64_stats_update_end(&stats->syncp);
}
EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used);
* is valid.
*/
void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
- uint64_t bytes, bool direction, bool sync)
+ struct blkio_policy_type *pol,
+ uint64_t bytes, bool direction, bool sync)
{
+ struct blkg_policy_data *pd = blkg->pd[pol->plid];
struct blkio_group_stats_cpu *stats_cpu;
unsigned long flags;
+ /* If per cpu stats are not allocated yet, don't do any accounting. */
+ if (pd->stats_cpu == NULL)
+ return;
+
/*
* Disabling interrupts to provide mutual exclusion between two
* writes on same cpu. It probably is not needed for 64bit. Not
*/
local_irq_save(flags);
- stats_cpu = this_cpu_ptr(blkg->stats_cpu);
+ stats_cpu = this_cpu_ptr(pd->stats_cpu);
u64_stats_update_begin(&stats_cpu->syncp);
stats_cpu->sectors += bytes >> 9;
EXPORT_SYMBOL_GPL(blkiocg_update_dispatch_stats);
void blkiocg_update_completion_stats(struct blkio_group *blkg,
- uint64_t start_time, uint64_t io_start_time, bool direction, bool sync)
+ struct blkio_policy_type *pol,
+ uint64_t start_time,
+ uint64_t io_start_time, bool direction,
+ bool sync)
{
- struct blkio_group_stats *stats;
- unsigned long flags;
+ struct blkio_group_stats *stats = &blkg->pd[pol->plid]->stats;
unsigned long long now = sched_clock();
- spin_lock_irqsave(&blkg->stats_lock, flags);
- stats = &blkg->stats;
+ lockdep_assert_held(blkg->q->queue_lock);
+
+ u64_stats_update_begin(&stats->syncp);
if (time_after64(now, io_start_time))
blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_TIME],
now - io_start_time, direction, sync);
if (time_after64(io_start_time, start_time))
blkio_add_stat(stats->stat_arr[BLKIO_STAT_WAIT_TIME],
io_start_time - start_time, direction, sync);
- spin_unlock_irqrestore(&blkg->stats_lock, flags);
+ u64_stats_update_end(&stats->syncp);
}
EXPORT_SYMBOL_GPL(blkiocg_update_completion_stats);
/* Merged stats are per cpu. */
-void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
- bool sync)
+void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
+ struct blkio_policy_type *pol,
+ bool direction, bool sync)
{
- struct blkio_group_stats_cpu *stats_cpu;
- unsigned long flags;
+ struct blkio_group_stats *stats = &blkg->pd[pol->plid]->stats;
- /*
- * Disabling interrupts to provide mutual exclusion between two
- * writes on same cpu. It probably is not needed for 64bit. Not
- * optimizing that case yet.
- */
- local_irq_save(flags);
-
- stats_cpu = this_cpu_ptr(blkg->stats_cpu);
+ lockdep_assert_held(blkg->q->queue_lock);
- u64_stats_update_begin(&stats_cpu->syncp);
- blkio_add_stat(stats_cpu->stat_arr_cpu[BLKIO_STAT_CPU_MERGED], 1,
- direction, sync);
- u64_stats_update_end(&stats_cpu->syncp);
- local_irq_restore(flags);
+ u64_stats_update_begin(&stats->syncp);
+ blkio_add_stat(stats->stat_arr[BLKIO_STAT_MERGED], 1, direction, sync);
+ u64_stats_update_end(&stats->syncp);
}
EXPORT_SYMBOL_GPL(blkiocg_update_io_merged_stats);
/*
- * This function allocates the per cpu stats for blkio_group. Should be called
- * from sleepable context as alloc_per_cpu() requires that.
+ * Worker for allocating per cpu stat for blk groups. This is scheduled on
+ * the system_nrt_wq once there are some groups on the alloc_list waiting
+ * for allocation.
*/
-int blkio_alloc_blkg_stats(struct blkio_group *blkg)
+static void blkio_stat_alloc_fn(struct work_struct *work)
{
- /* Allocate memory for per cpu stats */
- blkg->stats_cpu = alloc_percpu(struct blkio_group_stats_cpu);
- if (!blkg->stats_cpu)
- return -ENOMEM;
- return 0;
-}
-EXPORT_SYMBOL_GPL(blkio_alloc_blkg_stats);
+ static void *pcpu_stats[BLKIO_NR_POLICIES];
+ struct delayed_work *dwork = to_delayed_work(work);
+ struct blkio_group *blkg;
+ int i;
+ bool empty = false;
-void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
- struct blkio_group *blkg, void *key, dev_t dev,
- enum blkio_policy_id plid)
-{
- unsigned long flags;
+alloc_stats:
+ for (i = 0; i < BLKIO_NR_POLICIES; i++) {
+ if (pcpu_stats[i] != NULL)
+ continue;
- spin_lock_irqsave(&blkcg->lock, flags);
- spin_lock_init(&blkg->stats_lock);
- rcu_assign_pointer(blkg->key, key);
- blkg->blkcg_id = css_id(&blkcg->css);
- hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list);
- blkg->plid = plid;
- spin_unlock_irqrestore(&blkcg->lock, flags);
- /* Need to take css reference ? */
- cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path));
- blkg->dev = dev;
+ pcpu_stats[i] = alloc_percpu(struct blkio_group_stats_cpu);
+
+ /* Allocation failed. Try again after some time. */
+ if (pcpu_stats[i] == NULL) {
+ queue_delayed_work(system_nrt_wq, dwork,
+ msecs_to_jiffies(10));
+ return;
+ }
+ }
+
+ spin_lock_irq(&blkio_list_lock);
+ spin_lock(&alloc_list_lock);
+
+ /* cgroup got deleted or queue exited. */
+ if (!list_empty(&alloc_list)) {
+ blkg = list_first_entry(&alloc_list, struct blkio_group,
+ alloc_node);
+ for (i = 0; i < BLKIO_NR_POLICIES; i++) {
+ struct blkg_policy_data *pd = blkg->pd[i];
+
+ if (blkio_policy[i] && pd && !pd->stats_cpu)
+ swap(pd->stats_cpu, pcpu_stats[i]);
+ }
+
+ list_del_init(&blkg->alloc_node);
+ }
+
+ empty = list_empty(&alloc_list);
+
+ spin_unlock(&alloc_list_lock);
+ spin_unlock_irq(&blkio_list_lock);
+
+ if (!empty)
+ goto alloc_stats;
}
-EXPORT_SYMBOL_GPL(blkiocg_add_blkio_group);
-static void __blkiocg_del_blkio_group(struct blkio_group *blkg)
+/**
+ * blkg_free - free a blkg
+ * @blkg: blkg to free
+ *
+ * Free @blkg which may be partially allocated.
+ */
+static void blkg_free(struct blkio_group *blkg)
{
- hlist_del_init_rcu(&blkg->blkcg_node);
- blkg->blkcg_id = 0;
+ int i;
+
+ if (!blkg)
+ return;
+
+ for (i = 0; i < BLKIO_NR_POLICIES; i++) {
+ struct blkg_policy_data *pd = blkg->pd[i];
+
+ if (pd) {
+ free_percpu(pd->stats_cpu);
+ kfree(pd);
+ }
+ }
+
+ kfree(blkg);
}
-/*
- * returns 0 if blkio_group was still on cgroup list. Otherwise returns 1
- * indicating that blk_group was unhashed by the time we got to it.
+/**
+ * blkg_alloc - allocate a blkg
+ * @blkcg: block cgroup the new blkg is associated with
+ * @q: request_queue the new blkg is associated with
+ *
+ * Allocate a new blkg assocating @blkcg and @q.
*/
-int blkiocg_del_blkio_group(struct blkio_group *blkg)
+static struct blkio_group *blkg_alloc(struct blkio_cgroup *blkcg,
+ struct request_queue *q)
{
- struct blkio_cgroup *blkcg;
- unsigned long flags;
- struct cgroup_subsys_state *css;
- int ret = 1;
+ struct blkio_group *blkg;
+ int i;
- rcu_read_lock();
- css = css_lookup(&blkio_subsys, blkg->blkcg_id);
- if (css) {
- blkcg = container_of(css, struct blkio_cgroup, css);
- spin_lock_irqsave(&blkcg->lock, flags);
- if (!hlist_unhashed(&blkg->blkcg_node)) {
- __blkiocg_del_blkio_group(blkg);
- ret = 0;
+ /* alloc and init base part */
+ blkg = kzalloc_node(sizeof(*blkg), GFP_ATOMIC, q->node);
+ if (!blkg)
+ return NULL;
+
+ blkg->q = q;
+ INIT_LIST_HEAD(&blkg->q_node);
+ INIT_LIST_HEAD(&blkg->alloc_node);
+ blkg->blkcg = blkcg;
+ blkg->refcnt = 1;
+ cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path));
+
+ for (i = 0; i < BLKIO_NR_POLICIES; i++) {
+ struct blkio_policy_type *pol = blkio_policy[i];
+ struct blkg_policy_data *pd;
+
+ if (!pol)
+ continue;
+
+ /* alloc per-policy data and attach it to blkg */
+ pd = kzalloc_node(sizeof(*pd) + pol->pdata_size, GFP_ATOMIC,
+ q->node);
+ if (!pd) {
+ blkg_free(blkg);
+ return NULL;
}
- spin_unlock_irqrestore(&blkcg->lock, flags);
+
+ blkg->pd[i] = pd;
+ pd->blkg = blkg;
}
- rcu_read_unlock();
- return ret;
+ /* invoke per-policy init */
+ for (i = 0; i < BLKIO_NR_POLICIES; i++) {
+ struct blkio_policy_type *pol = blkio_policy[i];
+
+ if (pol)
+ pol->ops.blkio_init_group_fn(blkg);
+ }
+
+ return blkg;
+}
+
+struct blkio_group *blkg_lookup_create(struct blkio_cgroup *blkcg,
+ struct request_queue *q,
+ enum blkio_policy_id plid,
+ bool for_root)
+ __releases(q->queue_lock) __acquires(q->queue_lock)
+{
+ struct blkio_group *blkg;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+ lockdep_assert_held(q->queue_lock);
+
+ /*
+ * This could be the first entry point of blkcg implementation and
+ * we shouldn't allow anything to go through for a bypassing queue.
+ * The following can be removed if blkg lookup is guaranteed to
+ * fail on a bypassing queue.
+ */
+ if (unlikely(blk_queue_bypass(q)) && !for_root)
+ return ERR_PTR(blk_queue_dead(q) ? -EINVAL : -EBUSY);
+
+ blkg = blkg_lookup(blkcg, q);
+ if (blkg)
+ return blkg;
+
+ /* blkg holds a reference to blkcg */
+ if (!css_tryget(&blkcg->css))
+ return ERR_PTR(-EINVAL);
+
+ /*
+ * Allocate and initialize.
+ */
+ blkg = blkg_alloc(blkcg, q);
+
+ /* did alloc fail? */
+ if (unlikely(!blkg)) {
+ blkg = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+
+ /* insert */
+ spin_lock(&blkcg->lock);
+ hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list);
+ list_add(&blkg->q_node, &q->blkg_list);
+ spin_unlock(&blkcg->lock);
+
+ spin_lock(&alloc_list_lock);
+ list_add(&blkg->alloc_node, &alloc_list);
+ /* Queue per cpu stat allocation from worker thread. */
+ queue_delayed_work(system_nrt_wq, &blkio_stat_alloc_work, 0);
+ spin_unlock(&alloc_list_lock);
+out:
+ return blkg;
}
-EXPORT_SYMBOL_GPL(blkiocg_del_blkio_group);
+EXPORT_SYMBOL_GPL(blkg_lookup_create);
/* called under rcu_read_lock(). */
-struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key)
+struct blkio_group *blkg_lookup(struct blkio_cgroup *blkcg,
+ struct request_queue *q)
{
struct blkio_group *blkg;
struct hlist_node *n;
- void *__key;
- hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) {
- __key = blkg->key;
- if (__key == key)
+ hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node)
+ if (blkg->q == q)
return blkg;
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(blkg_lookup);
+
+static void blkg_destroy(struct blkio_group *blkg)
+{
+ struct request_queue *q = blkg->q;
+ struct blkio_cgroup *blkcg = blkg->blkcg;
+
+ lockdep_assert_held(q->queue_lock);
+ lockdep_assert_held(&blkcg->lock);
+
+ /* Something wrong if we are trying to remove same group twice */
+ WARN_ON_ONCE(list_empty(&blkg->q_node));
+ WARN_ON_ONCE(hlist_unhashed(&blkg->blkcg_node));
+ list_del_init(&blkg->q_node);
+ hlist_del_init_rcu(&blkg->blkcg_node);
+
+ spin_lock(&alloc_list_lock);
+ list_del_init(&blkg->alloc_node);
+ spin_unlock(&alloc_list_lock);
+
+ /*
+ * Put the reference taken at the time of creation so that when all
+ * queues are gone, group can be destroyed.
+ */
+ blkg_put(blkg);
+}
+
+/*
+ * XXX: This updates blkg policy data in-place for root blkg, which is
+ * necessary across elevator switch and policy registration as root blkgs
+ * aren't shot down. This broken and racy implementation is temporary.
+ * Eventually, blkg shoot down will be replaced by proper in-place update.
+ */
+void update_root_blkg_pd(struct request_queue *q, enum blkio_policy_id plid)
+{
+ struct blkio_policy_type *pol = blkio_policy[plid];
+ struct blkio_group *blkg = blkg_lookup(&blkio_root_cgroup, q);
+ struct blkg_policy_data *pd;
+
+ if (!blkg)
+ return;
+
+ kfree(blkg->pd[plid]);
+ blkg->pd[plid] = NULL;
+
+ if (!pol)
+ return;
+
+ pd = kzalloc(sizeof(*pd) + pol->pdata_size, GFP_KERNEL);
+ WARN_ON_ONCE(!pd);
+
+ pd->stats_cpu = alloc_percpu(struct blkio_group_stats_cpu);
+ WARN_ON_ONCE(!pd->stats_cpu);
+
+ blkg->pd[plid] = pd;
+ pd->blkg = blkg;
+ pol->ops.blkio_init_group_fn(blkg);
+}
+EXPORT_SYMBOL_GPL(update_root_blkg_pd);
+
+/**
+ * blkg_destroy_all - destroy all blkgs associated with a request_queue
+ * @q: request_queue of interest
+ * @destroy_root: whether to destroy root blkg or not
+ *
+ * Destroy blkgs associated with @q. If @destroy_root is %true, all are
+ * destroyed; otherwise, root blkg is left alone.
+ */
+void blkg_destroy_all(struct request_queue *q, bool destroy_root)
+{
+ struct blkio_group *blkg, *n;
+
+ spin_lock_irq(q->queue_lock);
+
+ list_for_each_entry_safe(blkg, n, &q->blkg_list, q_node) {
+ struct blkio_cgroup *blkcg = blkg->blkcg;
+
+ /* skip root? */
+ if (!destroy_root && blkg->blkcg == &blkio_root_cgroup)
+ continue;
+
+ spin_lock(&blkcg->lock);
+ blkg_destroy(blkg);
+ spin_unlock(&blkcg->lock);
}
- return NULL;
+ spin_unlock_irq(q->queue_lock);
}
-EXPORT_SYMBOL_GPL(blkiocg_lookup_group);
+EXPORT_SYMBOL_GPL(blkg_destroy_all);
-static void blkio_reset_stats_cpu(struct blkio_group *blkg)
+static void blkg_rcu_free(struct rcu_head *rcu_head)
{
- struct blkio_group_stats_cpu *stats_cpu;
- int i, j, k;
+ blkg_free(container_of(rcu_head, struct blkio_group, rcu_head));
+}
+
+void __blkg_release(struct blkio_group *blkg)
+{
+ /* release the extra blkcg reference this blkg has been holding */
+ css_put(&blkg->blkcg->css);
+
/*
- * Note: On 64 bit arch this should not be an issue. This has the
- * possibility of returning some inconsistent value on 32bit arch
- * as 64bit update on 32bit is non atomic. Taking care of this
- * corner case makes code very complicated, like sending IPIs to
- * cpus, taking care of stats of offline cpus etc.
+ * A group is freed in rcu manner. But having an rcu lock does not
+ * mean that one can access all the fields of blkg and assume these
+ * are valid. For example, don't try to follow throtl_data and
+ * request queue links.
*
- * reset stats is anyway more of a debug feature and this sounds a
- * corner case. So I am not complicating the code yet until and
- * unless this becomes a real issue.
+ * Having a reference to blkg under an rcu allows acess to only
+ * values local to groups like group stats and group rate limits
*/
- for_each_possible_cpu(i) {
- stats_cpu = per_cpu_ptr(blkg->stats_cpu, i);
- stats_cpu->sectors = 0;
- for(j = 0; j < BLKIO_STAT_CPU_NR; j++)
- for (k = 0; k < BLKIO_STAT_TOTAL; k++)
- stats_cpu->stat_arr_cpu[j][k] = 0;
+ call_rcu(&blkg->rcu_head, blkg_rcu_free);
+}
+EXPORT_SYMBOL_GPL(__blkg_release);
+
+static void blkio_reset_stats_cpu(struct blkio_group *blkg, int plid)
+{
+ struct blkg_policy_data *pd = blkg->pd[plid];
+ int cpu;
+
+ if (pd->stats_cpu == NULL)
+ return;
+
+ for_each_possible_cpu(cpu) {
+ struct blkio_group_stats_cpu *sc =
+ per_cpu_ptr(pd->stats_cpu, cpu);
+
+ sc->sectors = 0;
+ memset(sc->stat_arr_cpu, 0, sizeof(sc->stat_arr_cpu));
}
}
static int
blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val)
{
- struct blkio_cgroup *blkcg;
+ struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup);
struct blkio_group *blkg;
- struct blkio_group_stats *stats;
struct hlist_node *n;
- uint64_t queued[BLKIO_STAT_TOTAL];
int i;
-#ifdef CONFIG_DEBUG_BLK_CGROUP
- bool idling, waiting, empty;
- unsigned long long now = sched_clock();
-#endif
- blkcg = cgroup_to_blkio_cgroup(cgroup);
+ spin_lock(&blkio_list_lock);
spin_lock_irq(&blkcg->lock);
+
+ /*
+ * Note that stat reset is racy - it doesn't synchronize against
+ * stat updates. This is a debug feature which shouldn't exist
+ * anyway. If you get hit by a race, retry.
+ */
hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
- spin_lock(&blkg->stats_lock);
- stats = &blkg->stats;
+ struct blkio_policy_type *pol;
+
+ list_for_each_entry(pol, &blkio_list, list) {
+ struct blkg_policy_data *pd = blkg->pd[pol->plid];
+ struct blkio_group_stats *stats = &pd->stats;
+
+ /* queued stats shouldn't be cleared */
+ for (i = 0; i < ARRAY_SIZE(stats->stat_arr); i++)
+ if (i != BLKIO_STAT_QUEUED)
+ memset(stats->stat_arr[i], 0,
+ sizeof(stats->stat_arr[i]));
+ stats->time = 0;
#ifdef CONFIG_DEBUG_BLK_CGROUP
- idling = blkio_blkg_idling(stats);
- waiting = blkio_blkg_waiting(stats);
- empty = blkio_blkg_empty(stats);
+ memset((void *)stats + BLKG_STATS_DEBUG_CLEAR_START, 0,
+ BLKG_STATS_DEBUG_CLEAR_SIZE);
#endif
- for (i = 0; i < BLKIO_STAT_TOTAL; i++)
- queued[i] = stats->stat_arr[BLKIO_STAT_QUEUED][i];
- memset(stats, 0, sizeof(struct blkio_group_stats));
- for (i = 0; i < BLKIO_STAT_TOTAL; i++)
- stats->stat_arr[BLKIO_STAT_QUEUED][i] = queued[i];
-#ifdef CONFIG_DEBUG_BLK_CGROUP
- if (idling) {
- blkio_mark_blkg_idling(stats);
- stats->start_idle_time = now;
- }
- if (waiting) {
- blkio_mark_blkg_waiting(stats);
- stats->start_group_wait_time = now;
- }
- if (empty) {
- blkio_mark_blkg_empty(stats);
- stats->start_empty_time = now;
+ blkio_reset_stats_cpu(blkg, pol->plid);
}
-#endif
- spin_unlock(&blkg->stats_lock);
-
- /* Reset Per cpu stats which don't take blkg->stats_lock */
- blkio_reset_stats_cpu(blkg);
}
spin_unlock_irq(&blkcg->lock);
+ spin_unlock(&blkio_list_lock);
return 0;
}
-static void blkio_get_key_name(enum stat_sub_type type, dev_t dev, char *str,
- int chars_left, bool diskname_only)
+static void blkio_get_key_name(enum stat_sub_type type, const char *dname,
+ char *str, int chars_left, bool diskname_only)
{
- snprintf(str, chars_left, "%d:%d", MAJOR(dev), MINOR(dev));
+ snprintf(str, chars_left, "%s", dname);
chars_left -= strlen(str);
if (chars_left <= 0) {
printk(KERN_WARNING
}
}
-static uint64_t blkio_fill_stat(char *str, int chars_left, uint64_t val,
- struct cgroup_map_cb *cb, dev_t dev)
-{
- blkio_get_key_name(0, dev, str, chars_left, true);
- cb->fill(cb, str, val);
- return val;
-}
-
-
-static uint64_t blkio_read_stat_cpu(struct blkio_group *blkg,
+static uint64_t blkio_read_stat_cpu(struct blkio_group *blkg, int plid,
enum stat_type_cpu type, enum stat_sub_type sub_type)
{
+ struct blkg_policy_data *pd = blkg->pd[plid];
int cpu;
struct blkio_group_stats_cpu *stats_cpu;
u64 val = 0, tval;
+ if (pd->stats_cpu == NULL)
+ return val;
+
for_each_possible_cpu(cpu) {
unsigned int start;
- stats_cpu = per_cpu_ptr(blkg->stats_cpu, cpu);
+ stats_cpu = per_cpu_ptr(pd->stats_cpu, cpu);
do {
start = u64_stats_fetch_begin(&stats_cpu->syncp);
return val;
}
-static uint64_t blkio_get_stat_cpu(struct blkio_group *blkg,
- struct cgroup_map_cb *cb, dev_t dev, enum stat_type_cpu type)
+static uint64_t blkio_get_stat_cpu(struct blkio_group *blkg, int plid,
+ struct cgroup_map_cb *cb, const char *dname,
+ enum stat_type_cpu type)
{
uint64_t disk_total, val;
char key_str[MAX_KEY_LEN];
enum stat_sub_type sub_type;
if (type == BLKIO_STAT_CPU_SECTORS) {
- val = blkio_read_stat_cpu(blkg, type, 0);
- return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, val, cb, dev);
+ val = blkio_read_stat_cpu(blkg, plid, type, 0);
+ blkio_get_key_name(0, dname, key_str, MAX_KEY_LEN, true);
+ cb->fill(cb, key_str, val);
+ return val;
}
for (sub_type = BLKIO_STAT_READ; sub_type < BLKIO_STAT_TOTAL;
sub_type++) {
- blkio_get_key_name(sub_type, dev, key_str, MAX_KEY_LEN, false);
- val = blkio_read_stat_cpu(blkg, type, sub_type);
+ blkio_get_key_name(sub_type, dname, key_str, MAX_KEY_LEN,
+ false);
+ val = blkio_read_stat_cpu(blkg, plid, type, sub_type);
cb->fill(cb, key_str, val);
}
- disk_total = blkio_read_stat_cpu(blkg, type, BLKIO_STAT_READ) +
- blkio_read_stat_cpu(blkg, type, BLKIO_STAT_WRITE);
+ disk_total = blkio_read_stat_cpu(blkg, plid, type, BLKIO_STAT_READ) +
+ blkio_read_stat_cpu(blkg, plid, type, BLKIO_STAT_WRITE);
- blkio_get_key_name(BLKIO_STAT_TOTAL, dev, key_str, MAX_KEY_LEN, false);
+ blkio_get_key_name(BLKIO_STAT_TOTAL, dname, key_str, MAX_KEY_LEN,
+ false);
cb->fill(cb, key_str, disk_total);
return disk_total;
}
-/* This should be called with blkg->stats_lock held */
-static uint64_t blkio_get_stat(struct blkio_group *blkg,
- struct cgroup_map_cb *cb, dev_t dev, enum stat_type type)
+static uint64_t blkio_get_stat(struct blkio_group *blkg, int plid,
+ struct cgroup_map_cb *cb, const char *dname,
+ enum stat_type type)
{
- uint64_t disk_total;
+ struct blkio_group_stats *stats = &blkg->pd[plid]->stats;
+ uint64_t v = 0, disk_total = 0;
char key_str[MAX_KEY_LEN];
- enum stat_sub_type sub_type;
+ unsigned int sync_start;
+ int st;
- if (type == BLKIO_STAT_TIME)
- return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
- blkg->stats.time, cb, dev);
+ if (type >= BLKIO_STAT_ARR_NR) {
+ do {
+ sync_start = u64_stats_fetch_begin(&stats->syncp);
+ switch (type) {
+ case BLKIO_STAT_TIME:
+ v = stats->time;
+ break;
#ifdef CONFIG_DEBUG_BLK_CGROUP
- if (type == BLKIO_STAT_UNACCOUNTED_TIME)
- return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
- blkg->stats.unaccounted_time, cb, dev);
- if (type == BLKIO_STAT_AVG_QUEUE_SIZE) {
- uint64_t sum = blkg->stats.avg_queue_size_sum;
- uint64_t samples = blkg->stats.avg_queue_size_samples;
- if (samples)
- do_div(sum, samples);
- else
- sum = 0;
- return blkio_fill_stat(key_str, MAX_KEY_LEN - 1, sum, cb, dev);
- }
- if (type == BLKIO_STAT_GROUP_WAIT_TIME)
- return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
- blkg->stats.group_wait_time, cb, dev);
- if (type == BLKIO_STAT_IDLE_TIME)
- return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
- blkg->stats.idle_time, cb, dev);
- if (type == BLKIO_STAT_EMPTY_TIME)
- return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
- blkg->stats.empty_time, cb, dev);
- if (type == BLKIO_STAT_DEQUEUE)
- return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
- blkg->stats.dequeue, cb, dev);
+ case BLKIO_STAT_UNACCOUNTED_TIME:
+ v = stats->unaccounted_time;
+ break;
+ case BLKIO_STAT_AVG_QUEUE_SIZE: {
+ uint64_t samples = stats->avg_queue_size_samples;
+
+ if (samples) {
+ v = stats->avg_queue_size_sum;
+ do_div(v, samples);
+ }
+ break;
+ }
+ case BLKIO_STAT_IDLE_TIME:
+ v = stats->idle_time;
+ break;
+ case BLKIO_STAT_EMPTY_TIME:
+ v = stats->empty_time;
+ break;
+ case BLKIO_STAT_DEQUEUE:
+ v = stats->dequeue;
+ break;
+ case BLKIO_STAT_GROUP_WAIT_TIME:
+ v = stats->group_wait_time;
+ break;
#endif
+ default:
+ WARN_ON_ONCE(1);
+ }
+ } while (u64_stats_fetch_retry(&stats->syncp, sync_start));
- for (sub_type = BLKIO_STAT_READ; sub_type < BLKIO_STAT_TOTAL;
- sub_type++) {
- blkio_get_key_name(sub_type, dev, key_str, MAX_KEY_LEN, false);
- cb->fill(cb, key_str, blkg->stats.stat_arr[type][sub_type]);
+ blkio_get_key_name(0, dname, key_str, MAX_KEY_LEN, true);
+ cb->fill(cb, key_str, v);
+ return v;
+ }
+
+ for (st = BLKIO_STAT_READ; st < BLKIO_STAT_TOTAL; st++) {
+ do {
+ sync_start = u64_stats_fetch_begin(&stats->syncp);
+ v = stats->stat_arr[type][st];
+ } while (u64_stats_fetch_retry(&stats->syncp, sync_start));
+
+ blkio_get_key_name(st, dname, key_str, MAX_KEY_LEN, false);
+ cb->fill(cb, key_str, v);
+ if (st == BLKIO_STAT_READ || st == BLKIO_STAT_WRITE)
+ disk_total += v;
}
- disk_total = blkg->stats.stat_arr[type][BLKIO_STAT_READ] +
- blkg->stats.stat_arr[type][BLKIO_STAT_WRITE];
- blkio_get_key_name(BLKIO_STAT_TOTAL, dev, key_str, MAX_KEY_LEN, false);
+
+ blkio_get_key_name(BLKIO_STAT_TOTAL, dname, key_str, MAX_KEY_LEN,
+ false);
cb->fill(cb, key_str, disk_total);
return disk_total;
}
-static int blkio_policy_parse_and_set(char *buf,
- struct blkio_policy_node *newpn, enum blkio_policy_id plid, int fileid)
+static int blkio_policy_parse_and_set(char *buf, enum blkio_policy_id plid,
+ int fileid, struct blkio_cgroup *blkcg)
{
struct gendisk *disk = NULL;
+ struct blkio_group *blkg = NULL;
+ struct blkg_policy_data *pd;
char *s[4], *p, *major_s = NULL, *minor_s = NULL;
unsigned long major, minor;
int i = 0, ret = -EINVAL;
if (strict_strtoull(s[1], 10, &temp))
goto out;
- /* For rule removal, do not check for device presence. */
- if (temp) {
- disk = get_gendisk(dev, &part);
- if (!disk || part) {
- ret = -ENODEV;
- goto out;
- }
+ disk = get_gendisk(dev, &part);
+ if (!disk || part)
+ goto out;
+
+ rcu_read_lock();
+
+ spin_lock_irq(disk->queue->queue_lock);
+ blkg = blkg_lookup_create(blkcg, disk->queue, plid, false);
+ spin_unlock_irq(disk->queue->queue_lock);
+
+ if (IS_ERR(blkg)) {
+ ret = PTR_ERR(blkg);
+ goto out_unlock;
}
- newpn->dev = dev;
+ pd = blkg->pd[plid];
switch (plid) {
case BLKIO_POLICY_PROP:
if ((temp < BLKIO_WEIGHT_MIN && temp > 0) ||
temp > BLKIO_WEIGHT_MAX)
- goto out;
+ goto out_unlock;
- newpn->plid = plid;
- newpn->fileid = fileid;
- newpn->val.weight = temp;
+ pd->conf.weight = temp;
+ blkio_update_group_weight(blkg, plid, temp ?: blkcg->weight);
break;
case BLKIO_POLICY_THROTL:
switch(fileid) {
case BLKIO_THROTL_read_bps_device:
+ pd->conf.bps[READ] = temp;
+ blkio_update_group_bps(blkg, plid, temp ?: -1, fileid);
+ break;
case BLKIO_THROTL_write_bps_device:
- newpn->plid = plid;
- newpn->fileid = fileid;
- newpn->val.bps = temp;
+ pd->conf.bps[WRITE] = temp;
+ blkio_update_group_bps(blkg, plid, temp ?: -1, fileid);
break;
case BLKIO_THROTL_read_iops_device:
+ if (temp > THROTL_IOPS_MAX)
+ goto out_unlock;
+ pd->conf.iops[READ] = temp;
+ blkio_update_group_iops(blkg, plid, temp ?: -1, fileid);
+ break;
case BLKIO_THROTL_write_iops_device:
if (temp > THROTL_IOPS_MAX)
- goto out;
-
- newpn->plid = plid;
- newpn->fileid = fileid;
- newpn->val.iops = (unsigned int)temp;
+ goto out_unlock;
+ pd->conf.iops[WRITE] = temp;
+ blkio_update_group_iops(blkg, plid, temp ?: -1, fileid);
break;
}
break;
BUG();
}
ret = 0;
+out_unlock:
+ rcu_read_unlock();
out:
put_disk(disk);
- return ret;
-}
-
-unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
- dev_t dev)
-{
- struct blkio_policy_node *pn;
- unsigned long flags;
- unsigned int weight;
-
- spin_lock_irqsave(&blkcg->lock, flags);
-
- pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_PROP,
- BLKIO_PROP_weight_device);
- if (pn)
- weight = pn->val.weight;
- else
- weight = blkcg->weight;
-
- spin_unlock_irqrestore(&blkcg->lock, flags);
-
- return weight;
-}
-EXPORT_SYMBOL_GPL(blkcg_get_weight);
-uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg, dev_t dev)
-{
- struct blkio_policy_node *pn;
- unsigned long flags;
- uint64_t bps = -1;
-
- spin_lock_irqsave(&blkcg->lock, flags);
- pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
- BLKIO_THROTL_read_bps_device);
- if (pn)
- bps = pn->val.bps;
- spin_unlock_irqrestore(&blkcg->lock, flags);
-
- return bps;
-}
-
-uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg, dev_t dev)
-{
- struct blkio_policy_node *pn;
- unsigned long flags;
- uint64_t bps = -1;
-
- spin_lock_irqsave(&blkcg->lock, flags);
- pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
- BLKIO_THROTL_write_bps_device);
- if (pn)
- bps = pn->val.bps;
- spin_unlock_irqrestore(&blkcg->lock, flags);
-
- return bps;
-}
-
-unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg, dev_t dev)
-{
- struct blkio_policy_node *pn;
- unsigned long flags;
- unsigned int iops = -1;
-
- spin_lock_irqsave(&blkcg->lock, flags);
- pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
- BLKIO_THROTL_read_iops_device);
- if (pn)
- iops = pn->val.iops;
- spin_unlock_irqrestore(&blkcg->lock, flags);
-
- return iops;
-}
-
-unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg, dev_t dev)
-{
- struct blkio_policy_node *pn;
- unsigned long flags;
- unsigned int iops = -1;
-
- spin_lock_irqsave(&blkcg->lock, flags);
- pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
- BLKIO_THROTL_write_iops_device);
- if (pn)
- iops = pn->val.iops;
- spin_unlock_irqrestore(&blkcg->lock, flags);
-
- return iops;
-}
-
-/* Checks whether user asked for deleting a policy rule */
-static bool blkio_delete_rule_command(struct blkio_policy_node *pn)
-{
- switch(pn->plid) {
- case BLKIO_POLICY_PROP:
- if (pn->val.weight == 0)
- return 1;
- break;
- case BLKIO_POLICY_THROTL:
- switch(pn->fileid) {
- case BLKIO_THROTL_read_bps_device:
- case BLKIO_THROTL_write_bps_device:
- if (pn->val.bps == 0)
- return 1;
- break;
- case BLKIO_THROTL_read_iops_device:
- case BLKIO_THROTL_write_iops_device:
- if (pn->val.iops == 0)
- return 1;
- }
- break;
- default:
- BUG();
- }
-
- return 0;
-}
-
-static void blkio_update_policy_rule(struct blkio_policy_node *oldpn,
- struct blkio_policy_node *newpn)
-{
- switch(oldpn->plid) {
- case BLKIO_POLICY_PROP:
- oldpn->val.weight = newpn->val.weight;
- break;
- case BLKIO_POLICY_THROTL:
- switch(newpn->fileid) {
- case BLKIO_THROTL_read_bps_device:
- case BLKIO_THROTL_write_bps_device:
- oldpn->val.bps = newpn->val.bps;
- break;
- case BLKIO_THROTL_read_iops_device:
- case BLKIO_THROTL_write_iops_device:
- oldpn->val.iops = newpn->val.iops;
- }
- break;
- default:
- BUG();
- }
-}
-
-/*
- * Some rules/values in blkg have changed. Propagate those to respective
- * policies.
- */
-static void blkio_update_blkg_policy(struct blkio_cgroup *blkcg,
- struct blkio_group *blkg, struct blkio_policy_node *pn)
-{
- unsigned int weight, iops;
- u64 bps;
-
- switch(pn->plid) {
- case BLKIO_POLICY_PROP:
- weight = pn->val.weight ? pn->val.weight :
- blkcg->weight;
- blkio_update_group_weight(blkg, weight);
- break;
- case BLKIO_POLICY_THROTL:
- switch(pn->fileid) {
- case BLKIO_THROTL_read_bps_device:
- case BLKIO_THROTL_write_bps_device:
- bps = pn->val.bps ? pn->val.bps : (-1);
- blkio_update_group_bps(blkg, bps, pn->fileid);
- break;
- case BLKIO_THROTL_read_iops_device:
- case BLKIO_THROTL_write_iops_device:
- iops = pn->val.iops ? pn->val.iops : (-1);
- blkio_update_group_iops(blkg, iops, pn->fileid);
- break;
- }
- break;
- default:
- BUG();
- }
-}
-
-/*
- * A policy node rule has been updated. Propagate this update to all the
- * block groups which might be affected by this update.
- */
-static void blkio_update_policy_node_blkg(struct blkio_cgroup *blkcg,
- struct blkio_policy_node *pn)
-{
- struct blkio_group *blkg;
- struct hlist_node *n;
-
- spin_lock(&blkio_list_lock);
- spin_lock_irq(&blkcg->lock);
-
- hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
- if (pn->dev != blkg->dev || pn->plid != blkg->plid)
- continue;
- blkio_update_blkg_policy(blkcg, blkg, pn);
+ /*
+ * If queue was bypassing, we should retry. Do so after a short
+ * msleep(). It isn't strictly necessary but queue can be
+ * bypassing for some time and it's always nice to avoid busy
+ * looping.
+ */
+ if (ret == -EBUSY) {
+ msleep(10);
+ return restart_syscall();
}
-
- spin_unlock_irq(&blkcg->lock);
- spin_unlock(&blkio_list_lock);
+ return ret;
}
static int blkiocg_file_write(struct cgroup *cgrp, struct cftype *cft,
{
int ret = 0;
char *buf;
- struct blkio_policy_node *newpn, *pn;
- struct blkio_cgroup *blkcg;
- int keep_newpn = 0;
+ struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgrp);
enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
int fileid = BLKIOFILE_ATTR(cft->private);
if (!buf)
return -ENOMEM;
- newpn = kzalloc(sizeof(*newpn), GFP_KERNEL);
- if (!newpn) {
- ret = -ENOMEM;
- goto free_buf;
- }
-
- ret = blkio_policy_parse_and_set(buf, newpn, plid, fileid);
- if (ret)
- goto free_newpn;
-
- blkcg = cgroup_to_blkio_cgroup(cgrp);
-
- spin_lock_irq(&blkcg->lock);
-
- pn = blkio_policy_search_node(blkcg, newpn->dev, plid, fileid);
- if (!pn) {
- if (!blkio_delete_rule_command(newpn)) {
- blkio_policy_insert_node(blkcg, newpn);
- keep_newpn = 1;
- }
- spin_unlock_irq(&blkcg->lock);
- goto update_io_group;
- }
-
- if (blkio_delete_rule_command(newpn)) {
- blkio_policy_delete_node(pn);
- kfree(pn);
- spin_unlock_irq(&blkcg->lock);
- goto update_io_group;
- }
- spin_unlock_irq(&blkcg->lock);
-
- blkio_update_policy_rule(pn, newpn);
-
-update_io_group:
- blkio_update_policy_node_blkg(blkcg, newpn);
-
-free_newpn:
- if (!keep_newpn)
- kfree(newpn);
-free_buf:
+ ret = blkio_policy_parse_and_set(buf, plid, fileid, blkcg);
kfree(buf);
return ret;
}
-static void
-blkio_print_policy_node(struct seq_file *m, struct blkio_policy_node *pn)
+static const char *blkg_dev_name(struct blkio_group *blkg)
+{
+ /* some drivers (floppy) instantiate a queue w/o disk registered */
+ if (blkg->q->backing_dev_info.dev)
+ return dev_name(blkg->q->backing_dev_info.dev);
+ return NULL;
+}
+
+static void blkio_print_group_conf(struct cftype *cft, struct blkio_group *blkg,
+ struct seq_file *m)
{
- switch(pn->plid) {
+ int plid = BLKIOFILE_POLICY(cft->private);
+ int fileid = BLKIOFILE_ATTR(cft->private);
+ struct blkg_policy_data *pd = blkg->pd[plid];
+ const char *dname = blkg_dev_name(blkg);
+ int rw = WRITE;
+
+ if (!dname)
+ return;
+
+ switch (plid) {
case BLKIO_POLICY_PROP:
- if (pn->fileid == BLKIO_PROP_weight_device)
- seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev),
- MINOR(pn->dev), pn->val.weight);
+ if (pd->conf.weight)
+ seq_printf(m, "%s\t%u\n",
+ dname, pd->conf.weight);
break;
case BLKIO_POLICY_THROTL:
- switch(pn->fileid) {
+ switch (fileid) {
case BLKIO_THROTL_read_bps_device:
+ rw = READ;
case BLKIO_THROTL_write_bps_device:
- seq_printf(m, "%u:%u\t%llu\n", MAJOR(pn->dev),
- MINOR(pn->dev), pn->val.bps);
+ if (pd->conf.bps[rw])
+ seq_printf(m, "%s\t%llu\n",
+ dname, pd->conf.bps[rw]);
break;
case BLKIO_THROTL_read_iops_device:
+ rw = READ;
case BLKIO_THROTL_write_iops_device:
- seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev),
- MINOR(pn->dev), pn->val.iops);
+ if (pd->conf.iops[rw])
+ seq_printf(m, "%s\t%u\n",
+ dname, pd->conf.iops[rw]);
break;
}
break;
}
/* cgroup files which read their data from policy nodes end up here */
-static void blkio_read_policy_node_files(struct cftype *cft,
- struct blkio_cgroup *blkcg, struct seq_file *m)
+static void blkio_read_conf(struct cftype *cft, struct blkio_cgroup *blkcg,
+ struct seq_file *m)
{
- struct blkio_policy_node *pn;
-
- if (!list_empty(&blkcg->policy_list)) {
- spin_lock_irq(&blkcg->lock);
- list_for_each_entry(pn, &blkcg->policy_list, node) {
- if (!pn_matches_cftype(cft, pn))
- continue;
- blkio_print_policy_node(m, pn);
- }
- spin_unlock_irq(&blkcg->lock);
- }
+ struct blkio_group *blkg;
+ struct hlist_node *n;
+
+ spin_lock_irq(&blkcg->lock);
+ hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node)
+ blkio_print_group_conf(cft, blkg, m);
+ spin_unlock_irq(&blkcg->lock);
}
static int blkiocg_file_read(struct cgroup *cgrp, struct cftype *cft,
case BLKIO_POLICY_PROP:
switch(name) {
case BLKIO_PROP_weight_device:
- blkio_read_policy_node_files(cft, blkcg, m);
+ blkio_read_conf(cft, blkcg, m);
return 0;
default:
BUG();
case BLKIO_THROTL_write_bps_device:
case BLKIO_THROTL_read_iops_device:
case BLKIO_THROTL_write_iops_device:
- blkio_read_policy_node_files(cft, blkcg, m);
+ blkio_read_conf(cft, blkcg, m);
return 0;
default:
BUG();
struct hlist_node *n;
uint64_t cgroup_total = 0;
- rcu_read_lock();
- hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) {
- if (blkg->dev) {
- if (!cftype_blkg_same_policy(cft, blkg))
- continue;
- if (pcpu)
- cgroup_total += blkio_get_stat_cpu(blkg, cb,
- blkg->dev, type);
- else {
- spin_lock_irq(&blkg->stats_lock);
- cgroup_total += blkio_get_stat(blkg, cb,
- blkg->dev, type);
- spin_unlock_irq(&blkg->stats_lock);
- }
- }
+ spin_lock_irq(&blkcg->lock);
+
+ hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
+ const char *dname = blkg_dev_name(blkg);
+ int plid = BLKIOFILE_POLICY(cft->private);
+
+ if (!dname)
+ continue;
+ if (pcpu)
+ cgroup_total += blkio_get_stat_cpu(blkg, plid,
+ cb, dname, type);
+ else
+ cgroup_total += blkio_get_stat(blkg, plid,
+ cb, dname, type);
}
if (show_total)
cb->fill(cb, "Total", cgroup_total);
- rcu_read_unlock();
+
+ spin_unlock_irq(&blkcg->lock);
return 0;
}
BLKIO_STAT_WAIT_TIME, 1, 0);
case BLKIO_PROP_io_merged:
return blkio_read_blkg_stats(blkcg, cft, cb,
- BLKIO_STAT_CPU_MERGED, 1, 1);
+ BLKIO_STAT_MERGED, 1, 0);
case BLKIO_PROP_io_queued:
return blkio_read_blkg_stats(blkcg, cft, cb,
BLKIO_STAT_QUEUED, 1, 0);
return 0;
}
-static int blkio_weight_write(struct blkio_cgroup *blkcg, u64 val)
+static int blkio_weight_write(struct blkio_cgroup *blkcg, int plid, u64 val)
{
struct blkio_group *blkg;
struct hlist_node *n;
- struct blkio_policy_node *pn;
if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX)
return -EINVAL;
blkcg->weight = (unsigned int)val;
hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
- pn = blkio_policy_search_node(blkcg, blkg->dev,
- BLKIO_POLICY_PROP, BLKIO_PROP_weight_device);
- if (pn)
- continue;
+ struct blkg_policy_data *pd = blkg->pd[plid];
- blkio_update_group_weight(blkg, blkcg->weight);
+ if (!pd->conf.weight)
+ blkio_update_group_weight(blkg, plid, blkcg->weight);
}
+
spin_unlock_irq(&blkcg->lock);
spin_unlock(&blkio_list_lock);
return 0;
case BLKIO_POLICY_PROP:
switch(name) {
case BLKIO_PROP_weight:
- return blkio_weight_write(blkcg, val);
+ return blkio_weight_write(blkcg, plid, val);
}
break;
default:
ARRAY_SIZE(blkio_files));
}
-static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup)
+/**
+ * blkiocg_pre_destroy - cgroup pre_destroy callback
+ * @subsys: cgroup subsys
+ * @cgroup: cgroup of interest
+ *
+ * This function is called when @cgroup is about to go away and responsible
+ * for shooting down all blkgs associated with @cgroup. blkgs should be
+ * removed while holding both q and blkcg locks. As blkcg lock is nested
+ * inside q lock, this function performs reverse double lock dancing.
+ *
+ * This is the blkcg counterpart of ioc_release_fn().
+ */
+static int blkiocg_pre_destroy(struct cgroup_subsys *subsys,
+ struct cgroup *cgroup)
{
struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup);
- unsigned long flags;
- struct blkio_group *blkg;
- void *key;
- struct blkio_policy_type *blkiop;
- struct blkio_policy_node *pn, *pntmp;
- rcu_read_lock();
- do {
- spin_lock_irqsave(&blkcg->lock, flags);
+ spin_lock_irq(&blkcg->lock);
- if (hlist_empty(&blkcg->blkg_list)) {
- spin_unlock_irqrestore(&blkcg->lock, flags);
- break;
+ while (!hlist_empty(&blkcg->blkg_list)) {
+ struct blkio_group *blkg = hlist_entry(blkcg->blkg_list.first,
+ struct blkio_group, blkcg_node);
+ struct request_queue *q = blkg->q;
+
+ if (spin_trylock(q->queue_lock)) {
+ blkg_destroy(blkg);
+ spin_unlock(q->queue_lock);
+ } else {
+ spin_unlock_irq(&blkcg->lock);
+ cpu_relax();
+ spin_lock(&blkcg->lock);
}
+ }
- blkg = hlist_entry(blkcg->blkg_list.first, struct blkio_group,
- blkcg_node);
- key = rcu_dereference(blkg->key);
- __blkiocg_del_blkio_group(blkg);
-
- spin_unlock_irqrestore(&blkcg->lock, flags);
-
- /*
- * This blkio_group is being unlinked as associated cgroup is
- * going away. Let all the IO controlling policies know about
- * this event.
- */
- spin_lock(&blkio_list_lock);
- list_for_each_entry(blkiop, &blkio_list, list) {
- if (blkiop->plid != blkg->plid)
- continue;
- blkiop->ops.blkio_unlink_group_fn(key, blkg);
- }
- spin_unlock(&blkio_list_lock);
- } while (1);
+ spin_unlock_irq(&blkcg->lock);
+ return 0;
+}
- list_for_each_entry_safe(pn, pntmp, &blkcg->policy_list, node) {
- blkio_policy_delete_node(pn);
- kfree(pn);
- }
+static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup)
+{
+ struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup);
- free_css_id(&blkio_subsys, &blkcg->css);
- rcu_read_unlock();
if (blkcg != &blkio_root_cgroup)
kfree(blkcg);
}
static struct cgroup_subsys_state *
blkiocg_create(struct cgroup_subsys *subsys, struct cgroup *cgroup)
{
+ static atomic64_t id_seq = ATOMIC64_INIT(0);
struct blkio_cgroup *blkcg;
struct cgroup *parent = cgroup->parent;
return ERR_PTR(-ENOMEM);
blkcg->weight = BLKIO_WEIGHT_DEFAULT;
+ blkcg->id = atomic64_inc_return(&id_seq); /* root is 0, start from 1 */
done:
spin_lock_init(&blkcg->lock);
INIT_HLIST_HEAD(&blkcg->blkg_list);
- INIT_LIST_HEAD(&blkcg->policy_list);
return &blkcg->css;
}
+/**
+ * blkcg_init_queue - initialize blkcg part of request queue
+ * @q: request_queue to initialize
+ *
+ * Called from blk_alloc_queue_node(). Responsible for initializing blkcg
+ * part of new request_queue @q.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int blkcg_init_queue(struct request_queue *q)
+{
+ int ret;
+
+ might_sleep();
+
+ ret = blk_throtl_init(q);
+ if (ret)
+ return ret;
+
+ mutex_lock(&all_q_mutex);
+ INIT_LIST_HEAD(&q->all_q_node);
+ list_add_tail(&q->all_q_node, &all_q_list);
+ mutex_unlock(&all_q_mutex);
+
+ return 0;
+}
+
+/**
+ * blkcg_drain_queue - drain blkcg part of request_queue
+ * @q: request_queue to drain
+ *
+ * Called from blk_drain_queue(). Responsible for draining blkcg part.
+ */
+void blkcg_drain_queue(struct request_queue *q)
+{
+ lockdep_assert_held(q->queue_lock);
+
+ blk_throtl_drain(q);
+}
+
+/**
+ * blkcg_exit_queue - exit and release blkcg part of request_queue
+ * @q: request_queue being released
+ *
+ * Called from blk_release_queue(). Responsible for exiting blkcg part.
+ */
+void blkcg_exit_queue(struct request_queue *q)
+{
+ mutex_lock(&all_q_mutex);
+ list_del_init(&q->all_q_node);
+ mutex_unlock(&all_q_mutex);
+
+ blkg_destroy_all(q, true);
+
+ blk_throtl_exit(q);
+}
+
/*
* We cannot support shared io contexts, as we have no mean to support
* two tasks with the same ioc in two different groups without major rework
ioc = get_task_io_context(task, GFP_ATOMIC, NUMA_NO_NODE);
if (ioc) {
ioc_cgroup_changed(ioc);
- put_io_context(ioc, NULL);
+ put_io_context(ioc);
}
}
}
+static void blkcg_bypass_start(void)
+ __acquires(&all_q_mutex)
+{
+ struct request_queue *q;
+
+ mutex_lock(&all_q_mutex);
+
+ list_for_each_entry(q, &all_q_list, all_q_node) {
+ blk_queue_bypass_start(q);
+ blkg_destroy_all(q, false);
+ }
+}
+
+static void blkcg_bypass_end(void)
+ __releases(&all_q_mutex)
+{
+ struct request_queue *q;
+
+ list_for_each_entry(q, &all_q_list, all_q_node)
+ blk_queue_bypass_end(q);
+
+ mutex_unlock(&all_q_mutex);
+}
+
void blkio_policy_register(struct blkio_policy_type *blkiop)
{
+ struct request_queue *q;
+
+ blkcg_bypass_start();
spin_lock(&blkio_list_lock);
+
+ BUG_ON(blkio_policy[blkiop->plid]);
+ blkio_policy[blkiop->plid] = blkiop;
list_add_tail(&blkiop->list, &blkio_list);
+
spin_unlock(&blkio_list_lock);
+ list_for_each_entry(q, &all_q_list, all_q_node)
+ update_root_blkg_pd(q, blkiop->plid);
+ blkcg_bypass_end();
}
EXPORT_SYMBOL_GPL(blkio_policy_register);
void blkio_policy_unregister(struct blkio_policy_type *blkiop)
{
+ struct request_queue *q;
+
+ blkcg_bypass_start();
spin_lock(&blkio_list_lock);
+
+ BUG_ON(blkio_policy[blkiop->plid] != blkiop);
+ blkio_policy[blkiop->plid] = NULL;
list_del_init(&blkiop->list);
+
spin_unlock(&blkio_list_lock);
+ list_for_each_entry(q, &all_q_list, all_q_node)
+ update_root_blkg_pd(q, blkiop->plid);
+ blkcg_bypass_end();
}
EXPORT_SYMBOL_GPL(blkio_policy_unregister);
-
-static int __init init_cgroup_blkio(void)
-{
- return cgroup_load_subsys(&blkio_subsys);
-}
-
-static void __exit exit_cgroup_blkio(void)
-{
- cgroup_unload_subsys(&blkio_subsys);
-}
-
-module_init(init_cgroup_blkio);
-module_exit(exit_cgroup_blkio);
-MODULE_LICENSE("GPL");
projects / mirror_ubuntu-zesty-kernel.git / blobdiff