mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
1048 lines
27 KiB
C
1048 lines
27 KiB
C
/*
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* Common Block IO controller cgroup interface
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*
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* Based on ideas and code from CFQ, CFS and BFQ:
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* Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
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*
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* Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
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* Paolo Valente <paolo.valente@unimore.it>
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*
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* Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
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* Nauman Rafique <nauman@google.com>
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*/
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#include <linux/ioprio.h>
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#include <linux/seq_file.h>
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#include <linux/kdev_t.h>
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#include <linux/module.h>
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#include <linux/err.h>
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#include <linux/blkdev.h>
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#include <linux/slab.h>
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#include "blk-cgroup.h"
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#include <linux/genhd.h>
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#define MAX_KEY_LEN 100
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static DEFINE_SPINLOCK(blkio_list_lock);
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static LIST_HEAD(blkio_list);
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struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT };
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EXPORT_SYMBOL_GPL(blkio_root_cgroup);
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static struct cgroup_subsys_state *blkiocg_create(struct cgroup_subsys *,
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struct cgroup *);
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static int blkiocg_can_attach(struct cgroup_subsys *, struct cgroup *,
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struct task_struct *, bool);
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static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *,
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struct cgroup *, struct task_struct *, bool);
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static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *);
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static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *);
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struct cgroup_subsys blkio_subsys = {
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.name = "blkio",
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.create = blkiocg_create,
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.can_attach = blkiocg_can_attach,
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.attach = blkiocg_attach,
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.destroy = blkiocg_destroy,
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.populate = blkiocg_populate,
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#ifdef CONFIG_BLK_CGROUP
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/* note: blkio_subsys_id is otherwise defined in blk-cgroup.h */
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.subsys_id = blkio_subsys_id,
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#endif
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.use_id = 1,
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.module = THIS_MODULE,
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};
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EXPORT_SYMBOL_GPL(blkio_subsys);
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static inline void blkio_policy_insert_node(struct blkio_cgroup *blkcg,
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struct blkio_policy_node *pn)
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{
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list_add(&pn->node, &blkcg->policy_list);
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}
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/* Must be called with blkcg->lock held */
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static inline void blkio_policy_delete_node(struct blkio_policy_node *pn)
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{
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list_del(&pn->node);
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}
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/* Must be called with blkcg->lock held */
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static struct blkio_policy_node *
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blkio_policy_search_node(const struct blkio_cgroup *blkcg, dev_t dev)
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{
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struct blkio_policy_node *pn;
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list_for_each_entry(pn, &blkcg->policy_list, node) {
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if (pn->dev == dev)
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return pn;
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}
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return NULL;
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}
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struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup)
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{
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return container_of(cgroup_subsys_state(cgroup, blkio_subsys_id),
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struct blkio_cgroup, css);
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}
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EXPORT_SYMBOL_GPL(cgroup_to_blkio_cgroup);
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/*
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* Add to the appropriate stat variable depending on the request type.
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* This should be called with the blkg->stats_lock held.
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*/
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static void blkio_add_stat(uint64_t *stat, uint64_t add, bool direction,
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bool sync)
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{
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if (direction)
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stat[BLKIO_STAT_WRITE] += add;
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else
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stat[BLKIO_STAT_READ] += add;
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if (sync)
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stat[BLKIO_STAT_SYNC] += add;
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else
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stat[BLKIO_STAT_ASYNC] += add;
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}
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/*
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* Decrements the appropriate stat variable if non-zero depending on the
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* request type. Panics on value being zero.
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* This should be called with the blkg->stats_lock held.
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*/
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static void blkio_check_and_dec_stat(uint64_t *stat, bool direction, bool sync)
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{
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if (direction) {
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BUG_ON(stat[BLKIO_STAT_WRITE] == 0);
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stat[BLKIO_STAT_WRITE]--;
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} else {
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BUG_ON(stat[BLKIO_STAT_READ] == 0);
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stat[BLKIO_STAT_READ]--;
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}
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if (sync) {
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BUG_ON(stat[BLKIO_STAT_SYNC] == 0);
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stat[BLKIO_STAT_SYNC]--;
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} else {
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BUG_ON(stat[BLKIO_STAT_ASYNC] == 0);
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stat[BLKIO_STAT_ASYNC]--;
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}
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}
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#ifdef CONFIG_DEBUG_BLK_CGROUP
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/* This should be called with the blkg->stats_lock held. */
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static void blkio_set_start_group_wait_time(struct blkio_group *blkg,
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struct blkio_group *curr_blkg)
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{
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if (blkio_blkg_waiting(&blkg->stats))
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return;
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if (blkg == curr_blkg)
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return;
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blkg->stats.start_group_wait_time = sched_clock();
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blkio_mark_blkg_waiting(&blkg->stats);
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}
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/* This should be called with the blkg->stats_lock held. */
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static void blkio_update_group_wait_time(struct blkio_group_stats *stats)
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{
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unsigned long long now;
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if (!blkio_blkg_waiting(stats))
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return;
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now = sched_clock();
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if (time_after64(now, stats->start_group_wait_time))
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stats->group_wait_time += now - stats->start_group_wait_time;
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blkio_clear_blkg_waiting(stats);
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}
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/* This should be called with the blkg->stats_lock held. */
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static void blkio_end_empty_time(struct blkio_group_stats *stats)
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{
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unsigned long long now;
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if (!blkio_blkg_empty(stats))
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return;
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now = sched_clock();
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if (time_after64(now, stats->start_empty_time))
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stats->empty_time += now - stats->start_empty_time;
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blkio_clear_blkg_empty(stats);
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}
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void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
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{
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unsigned long flags;
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spin_lock_irqsave(&blkg->stats_lock, flags);
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BUG_ON(blkio_blkg_idling(&blkg->stats));
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blkg->stats.start_idle_time = sched_clock();
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blkio_mark_blkg_idling(&blkg->stats);
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spin_unlock_irqrestore(&blkg->stats_lock, flags);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_set_idle_time_stats);
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void blkiocg_update_idle_time_stats(struct blkio_group *blkg)
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{
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unsigned long flags;
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unsigned long long now;
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struct blkio_group_stats *stats;
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spin_lock_irqsave(&blkg->stats_lock, flags);
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stats = &blkg->stats;
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if (blkio_blkg_idling(stats)) {
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now = sched_clock();
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if (time_after64(now, stats->start_idle_time))
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stats->idle_time += now - stats->start_idle_time;
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blkio_clear_blkg_idling(stats);
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}
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spin_unlock_irqrestore(&blkg->stats_lock, flags);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_idle_time_stats);
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void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg)
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{
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unsigned long flags;
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struct blkio_group_stats *stats;
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spin_lock_irqsave(&blkg->stats_lock, flags);
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stats = &blkg->stats;
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stats->avg_queue_size_sum +=
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stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_READ] +
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stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_WRITE];
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stats->avg_queue_size_samples++;
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blkio_update_group_wait_time(stats);
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spin_unlock_irqrestore(&blkg->stats_lock, flags);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_avg_queue_size_stats);
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void blkiocg_set_start_empty_time(struct blkio_group *blkg)
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{
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unsigned long flags;
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struct blkio_group_stats *stats;
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spin_lock_irqsave(&blkg->stats_lock, flags);
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stats = &blkg->stats;
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if (stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_READ] ||
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stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_WRITE]) {
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spin_unlock_irqrestore(&blkg->stats_lock, flags);
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return;
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}
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/*
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* group is already marked empty. This can happen if cfqq got new
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* request in parent group and moved to this group while being added
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* to service tree. Just ignore the event and move on.
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*/
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if(blkio_blkg_empty(stats)) {
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spin_unlock_irqrestore(&blkg->stats_lock, flags);
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return;
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}
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stats->start_empty_time = sched_clock();
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blkio_mark_blkg_empty(stats);
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spin_unlock_irqrestore(&blkg->stats_lock, flags);
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}
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EXPORT_SYMBOL_GPL(blkiocg_set_start_empty_time);
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void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
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unsigned long dequeue)
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{
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blkg->stats.dequeue += dequeue;
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_dequeue_stats);
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#else
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static inline void blkio_set_start_group_wait_time(struct blkio_group *blkg,
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struct blkio_group *curr_blkg) {}
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static inline void blkio_end_empty_time(struct blkio_group_stats *stats) {}
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#endif
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void blkiocg_update_io_add_stats(struct blkio_group *blkg,
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struct blkio_group *curr_blkg, bool direction,
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bool sync)
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{
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unsigned long flags;
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spin_lock_irqsave(&blkg->stats_lock, flags);
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blkio_add_stat(blkg->stats.stat_arr[BLKIO_STAT_QUEUED], 1, direction,
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sync);
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blkio_end_empty_time(&blkg->stats);
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blkio_set_start_group_wait_time(blkg, curr_blkg);
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spin_unlock_irqrestore(&blkg->stats_lock, flags);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_io_add_stats);
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void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
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bool direction, bool sync)
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{
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unsigned long flags;
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spin_lock_irqsave(&blkg->stats_lock, flags);
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blkio_check_and_dec_stat(blkg->stats.stat_arr[BLKIO_STAT_QUEUED],
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direction, sync);
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spin_unlock_irqrestore(&blkg->stats_lock, flags);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_io_remove_stats);
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void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time)
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{
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unsigned long flags;
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spin_lock_irqsave(&blkg->stats_lock, flags);
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blkg->stats.time += time;
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spin_unlock_irqrestore(&blkg->stats_lock, flags);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used);
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void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
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uint64_t bytes, bool direction, bool sync)
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{
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struct blkio_group_stats *stats;
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unsigned long flags;
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spin_lock_irqsave(&blkg->stats_lock, flags);
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stats = &blkg->stats;
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stats->sectors += bytes >> 9;
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blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICED], 1, direction,
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sync);
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blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_BYTES], bytes,
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direction, sync);
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spin_unlock_irqrestore(&blkg->stats_lock, flags);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_dispatch_stats);
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void blkiocg_update_completion_stats(struct blkio_group *blkg,
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uint64_t start_time, uint64_t io_start_time, bool direction, bool sync)
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{
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struct blkio_group_stats *stats;
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unsigned long flags;
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unsigned long long now = sched_clock();
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spin_lock_irqsave(&blkg->stats_lock, flags);
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stats = &blkg->stats;
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if (time_after64(now, io_start_time))
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blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_TIME],
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now - io_start_time, direction, sync);
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if (time_after64(io_start_time, start_time))
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blkio_add_stat(stats->stat_arr[BLKIO_STAT_WAIT_TIME],
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io_start_time - start_time, direction, sync);
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spin_unlock_irqrestore(&blkg->stats_lock, flags);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_completion_stats);
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void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
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bool sync)
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{
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unsigned long flags;
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spin_lock_irqsave(&blkg->stats_lock, flags);
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blkio_add_stat(blkg->stats.stat_arr[BLKIO_STAT_MERGED], 1, direction,
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sync);
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spin_unlock_irqrestore(&blkg->stats_lock, flags);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_io_merged_stats);
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void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
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struct blkio_group *blkg, void *key, dev_t dev)
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{
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unsigned long flags;
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spin_lock_irqsave(&blkcg->lock, flags);
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spin_lock_init(&blkg->stats_lock);
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rcu_assign_pointer(blkg->key, key);
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blkg->blkcg_id = css_id(&blkcg->css);
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hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list);
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spin_unlock_irqrestore(&blkcg->lock, flags);
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/* Need to take css reference ? */
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cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path));
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blkg->dev = dev;
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}
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EXPORT_SYMBOL_GPL(blkiocg_add_blkio_group);
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static void __blkiocg_del_blkio_group(struct blkio_group *blkg)
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{
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hlist_del_init_rcu(&blkg->blkcg_node);
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blkg->blkcg_id = 0;
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}
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/*
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* returns 0 if blkio_group was still on cgroup list. Otherwise returns 1
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* indicating that blk_group was unhashed by the time we got to it.
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*/
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int blkiocg_del_blkio_group(struct blkio_group *blkg)
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{
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struct blkio_cgroup *blkcg;
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unsigned long flags;
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struct cgroup_subsys_state *css;
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int ret = 1;
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rcu_read_lock();
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css = css_lookup(&blkio_subsys, blkg->blkcg_id);
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if (css) {
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blkcg = container_of(css, struct blkio_cgroup, css);
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spin_lock_irqsave(&blkcg->lock, flags);
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if (!hlist_unhashed(&blkg->blkcg_node)) {
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__blkiocg_del_blkio_group(blkg);
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ret = 0;
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}
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spin_unlock_irqrestore(&blkcg->lock, flags);
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}
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rcu_read_unlock();
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return ret;
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}
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EXPORT_SYMBOL_GPL(blkiocg_del_blkio_group);
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/* called under rcu_read_lock(). */
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struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key)
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{
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struct blkio_group *blkg;
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struct hlist_node *n;
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void *__key;
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hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) {
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__key = blkg->key;
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if (__key == key)
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return blkg;
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}
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return NULL;
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}
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EXPORT_SYMBOL_GPL(blkiocg_lookup_group);
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#define SHOW_FUNCTION(__VAR) \
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static u64 blkiocg_##__VAR##_read(struct cgroup *cgroup, \
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struct cftype *cftype) \
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{ \
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struct blkio_cgroup *blkcg; \
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\
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blkcg = cgroup_to_blkio_cgroup(cgroup); \
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return (u64)blkcg->__VAR; \
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}
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SHOW_FUNCTION(weight);
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#undef SHOW_FUNCTION
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static int
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blkiocg_weight_write(struct cgroup *cgroup, struct cftype *cftype, u64 val)
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{
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struct blkio_cgroup *blkcg;
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struct blkio_group *blkg;
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struct hlist_node *n;
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struct blkio_policy_type *blkiop;
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struct blkio_policy_node *pn;
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if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX)
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return -EINVAL;
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blkcg = cgroup_to_blkio_cgroup(cgroup);
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spin_lock(&blkio_list_lock);
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spin_lock_irq(&blkcg->lock);
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blkcg->weight = (unsigned int)val;
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hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
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pn = blkio_policy_search_node(blkcg, blkg->dev);
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if (pn)
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continue;
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list_for_each_entry(blkiop, &blkio_list, list)
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blkiop->ops.blkio_update_group_weight_fn(blkg,
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blkcg->weight);
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}
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spin_unlock_irq(&blkcg->lock);
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spin_unlock(&blkio_list_lock);
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return 0;
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}
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|
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static int
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blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val)
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{
|
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struct blkio_cgroup *blkcg;
|
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struct blkio_group *blkg;
|
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struct blkio_group_stats *stats;
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struct hlist_node *n;
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uint64_t queued[BLKIO_STAT_TOTAL];
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int i;
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#ifdef CONFIG_DEBUG_BLK_CGROUP
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bool idling, waiting, empty;
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|
unsigned long long now = sched_clock();
|
|
#endif
|
|
|
|
blkcg = cgroup_to_blkio_cgroup(cgroup);
|
|
spin_lock_irq(&blkcg->lock);
|
|
hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
|
|
spin_lock(&blkg->stats_lock);
|
|
stats = &blkg->stats;
|
|
#ifdef CONFIG_DEBUG_BLK_CGROUP
|
|
idling = blkio_blkg_idling(stats);
|
|
waiting = blkio_blkg_waiting(stats);
|
|
empty = blkio_blkg_empty(stats);
|
|
#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;
|
|
}
|
|
#endif
|
|
spin_unlock(&blkg->stats_lock);
|
|
}
|
|
spin_unlock_irq(&blkcg->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)
|
|
{
|
|
snprintf(str, chars_left, "%d:%d", MAJOR(dev), MINOR(dev));
|
|
chars_left -= strlen(str);
|
|
if (chars_left <= 0) {
|
|
printk(KERN_WARNING
|
|
"Possibly incorrect cgroup stat display format");
|
|
return;
|
|
}
|
|
if (diskname_only)
|
|
return;
|
|
switch (type) {
|
|
case BLKIO_STAT_READ:
|
|
strlcat(str, " Read", chars_left);
|
|
break;
|
|
case BLKIO_STAT_WRITE:
|
|
strlcat(str, " Write", chars_left);
|
|
break;
|
|
case BLKIO_STAT_SYNC:
|
|
strlcat(str, " Sync", chars_left);
|
|
break;
|
|
case BLKIO_STAT_ASYNC:
|
|
strlcat(str, " Async", chars_left);
|
|
break;
|
|
case BLKIO_STAT_TOTAL:
|
|
strlcat(str, " Total", chars_left);
|
|
break;
|
|
default:
|
|
strlcat(str, " Invalid", chars_left);
|
|
}
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/* 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)
|
|
{
|
|
uint64_t disk_total;
|
|
char key_str[MAX_KEY_LEN];
|
|
enum stat_sub_type sub_type;
|
|
|
|
if (type == BLKIO_STAT_TIME)
|
|
return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
|
|
blkg->stats.time, cb, dev);
|
|
if (type == BLKIO_STAT_SECTORS)
|
|
return blkio_fill_stat(key_str, MAX_KEY_LEN - 1,
|
|
blkg->stats.sectors, cb, dev);
|
|
#ifdef CONFIG_DEBUG_BLK_CGROUP
|
|
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);
|
|
#endif
|
|
|
|
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]);
|
|
}
|
|
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);
|
|
cb->fill(cb, key_str, disk_total);
|
|
return disk_total;
|
|
}
|
|
|
|
#define SHOW_FUNCTION_PER_GROUP(__VAR, type, show_total) \
|
|
static int blkiocg_##__VAR##_read(struct cgroup *cgroup, \
|
|
struct cftype *cftype, struct cgroup_map_cb *cb) \
|
|
{ \
|
|
struct blkio_cgroup *blkcg; \
|
|
struct blkio_group *blkg; \
|
|
struct hlist_node *n; \
|
|
uint64_t cgroup_total = 0; \
|
|
\
|
|
if (!cgroup_lock_live_group(cgroup)) \
|
|
return -ENODEV; \
|
|
\
|
|
blkcg = cgroup_to_blkio_cgroup(cgroup); \
|
|
rcu_read_lock(); \
|
|
hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) {\
|
|
if (blkg->dev) { \
|
|
spin_lock_irq(&blkg->stats_lock); \
|
|
cgroup_total += blkio_get_stat(blkg, cb, \
|
|
blkg->dev, type); \
|
|
spin_unlock_irq(&blkg->stats_lock); \
|
|
} \
|
|
} \
|
|
if (show_total) \
|
|
cb->fill(cb, "Total", cgroup_total); \
|
|
rcu_read_unlock(); \
|
|
cgroup_unlock(); \
|
|
return 0; \
|
|
}
|
|
|
|
SHOW_FUNCTION_PER_GROUP(time, BLKIO_STAT_TIME, 0);
|
|
SHOW_FUNCTION_PER_GROUP(sectors, BLKIO_STAT_SECTORS, 0);
|
|
SHOW_FUNCTION_PER_GROUP(io_service_bytes, BLKIO_STAT_SERVICE_BYTES, 1);
|
|
SHOW_FUNCTION_PER_GROUP(io_serviced, BLKIO_STAT_SERVICED, 1);
|
|
SHOW_FUNCTION_PER_GROUP(io_service_time, BLKIO_STAT_SERVICE_TIME, 1);
|
|
SHOW_FUNCTION_PER_GROUP(io_wait_time, BLKIO_STAT_WAIT_TIME, 1);
|
|
SHOW_FUNCTION_PER_GROUP(io_merged, BLKIO_STAT_MERGED, 1);
|
|
SHOW_FUNCTION_PER_GROUP(io_queued, BLKIO_STAT_QUEUED, 1);
|
|
#ifdef CONFIG_DEBUG_BLK_CGROUP
|
|
SHOW_FUNCTION_PER_GROUP(dequeue, BLKIO_STAT_DEQUEUE, 0);
|
|
SHOW_FUNCTION_PER_GROUP(avg_queue_size, BLKIO_STAT_AVG_QUEUE_SIZE, 0);
|
|
SHOW_FUNCTION_PER_GROUP(group_wait_time, BLKIO_STAT_GROUP_WAIT_TIME, 0);
|
|
SHOW_FUNCTION_PER_GROUP(idle_time, BLKIO_STAT_IDLE_TIME, 0);
|
|
SHOW_FUNCTION_PER_GROUP(empty_time, BLKIO_STAT_EMPTY_TIME, 0);
|
|
#endif
|
|
#undef SHOW_FUNCTION_PER_GROUP
|
|
|
|
static int blkio_check_dev_num(dev_t dev)
|
|
{
|
|
int part = 0;
|
|
struct gendisk *disk;
|
|
|
|
disk = get_gendisk(dev, &part);
|
|
if (!disk || part)
|
|
return -ENODEV;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int blkio_policy_parse_and_set(char *buf,
|
|
struct blkio_policy_node *newpn)
|
|
{
|
|
char *s[4], *p, *major_s = NULL, *minor_s = NULL;
|
|
int ret;
|
|
unsigned long major, minor, temp;
|
|
int i = 0;
|
|
dev_t dev;
|
|
|
|
memset(s, 0, sizeof(s));
|
|
|
|
while ((p = strsep(&buf, " ")) != NULL) {
|
|
if (!*p)
|
|
continue;
|
|
|
|
s[i++] = p;
|
|
|
|
/* Prevent from inputing too many things */
|
|
if (i == 3)
|
|
break;
|
|
}
|
|
|
|
if (i != 2)
|
|
return -EINVAL;
|
|
|
|
p = strsep(&s[0], ":");
|
|
if (p != NULL)
|
|
major_s = p;
|
|
else
|
|
return -EINVAL;
|
|
|
|
minor_s = s[0];
|
|
if (!minor_s)
|
|
return -EINVAL;
|
|
|
|
ret = strict_strtoul(major_s, 10, &major);
|
|
if (ret)
|
|
return -EINVAL;
|
|
|
|
ret = strict_strtoul(minor_s, 10, &minor);
|
|
if (ret)
|
|
return -EINVAL;
|
|
|
|
dev = MKDEV(major, minor);
|
|
|
|
ret = blkio_check_dev_num(dev);
|
|
if (ret)
|
|
return ret;
|
|
|
|
newpn->dev = dev;
|
|
|
|
if (s[1] == NULL)
|
|
return -EINVAL;
|
|
|
|
ret = strict_strtoul(s[1], 10, &temp);
|
|
if (ret || (temp < BLKIO_WEIGHT_MIN && temp > 0) ||
|
|
temp > BLKIO_WEIGHT_MAX)
|
|
return -EINVAL;
|
|
|
|
newpn->weight = temp;
|
|
|
|
return 0;
|
|
}
|
|
|
|
unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
|
|
dev_t dev)
|
|
{
|
|
struct blkio_policy_node *pn;
|
|
|
|
pn = blkio_policy_search_node(blkcg, dev);
|
|
if (pn)
|
|
return pn->weight;
|
|
else
|
|
return blkcg->weight;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blkcg_get_weight);
|
|
|
|
|
|
static int blkiocg_weight_device_write(struct cgroup *cgrp, struct cftype *cft,
|
|
const char *buffer)
|
|
{
|
|
int ret = 0;
|
|
char *buf;
|
|
struct blkio_policy_node *newpn, *pn;
|
|
struct blkio_cgroup *blkcg;
|
|
struct blkio_group *blkg;
|
|
int keep_newpn = 0;
|
|
struct hlist_node *n;
|
|
struct blkio_policy_type *blkiop;
|
|
|
|
buf = kstrdup(buffer, GFP_KERNEL);
|
|
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);
|
|
if (ret)
|
|
goto free_newpn;
|
|
|
|
blkcg = cgroup_to_blkio_cgroup(cgrp);
|
|
|
|
spin_lock_irq(&blkcg->lock);
|
|
|
|
pn = blkio_policy_search_node(blkcg, newpn->dev);
|
|
if (!pn) {
|
|
if (newpn->weight != 0) {
|
|
blkio_policy_insert_node(blkcg, newpn);
|
|
keep_newpn = 1;
|
|
}
|
|
spin_unlock_irq(&blkcg->lock);
|
|
goto update_io_group;
|
|
}
|
|
|
|
if (newpn->weight == 0) {
|
|
/* weight == 0 means deleteing a specific weight */
|
|
blkio_policy_delete_node(pn);
|
|
spin_unlock_irq(&blkcg->lock);
|
|
goto update_io_group;
|
|
}
|
|
spin_unlock_irq(&blkcg->lock);
|
|
|
|
pn->weight = newpn->weight;
|
|
|
|
update_io_group:
|
|
/* update weight for each cfqg */
|
|
spin_lock(&blkio_list_lock);
|
|
spin_lock_irq(&blkcg->lock);
|
|
|
|
hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
|
|
if (newpn->dev == blkg->dev) {
|
|
list_for_each_entry(blkiop, &blkio_list, list)
|
|
blkiop->ops.blkio_update_group_weight_fn(blkg,
|
|
newpn->weight ?
|
|
newpn->weight :
|
|
blkcg->weight);
|
|
}
|
|
}
|
|
|
|
spin_unlock_irq(&blkcg->lock);
|
|
spin_unlock(&blkio_list_lock);
|
|
|
|
free_newpn:
|
|
if (!keep_newpn)
|
|
kfree(newpn);
|
|
free_buf:
|
|
kfree(buf);
|
|
return ret;
|
|
}
|
|
|
|
static int blkiocg_weight_device_read(struct cgroup *cgrp, struct cftype *cft,
|
|
struct seq_file *m)
|
|
{
|
|
struct blkio_cgroup *blkcg;
|
|
struct blkio_policy_node *pn;
|
|
|
|
seq_printf(m, "dev\tweight\n");
|
|
|
|
blkcg = cgroup_to_blkio_cgroup(cgrp);
|
|
if (!list_empty(&blkcg->policy_list)) {
|
|
spin_lock_irq(&blkcg->lock);
|
|
list_for_each_entry(pn, &blkcg->policy_list, node) {
|
|
seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev),
|
|
MINOR(pn->dev), pn->weight);
|
|
}
|
|
spin_unlock_irq(&blkcg->lock);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct cftype blkio_files[] = {
|
|
{
|
|
.name = "weight_device",
|
|
.read_seq_string = blkiocg_weight_device_read,
|
|
.write_string = blkiocg_weight_device_write,
|
|
.max_write_len = 256,
|
|
},
|
|
{
|
|
.name = "weight",
|
|
.read_u64 = blkiocg_weight_read,
|
|
.write_u64 = blkiocg_weight_write,
|
|
},
|
|
{
|
|
.name = "time",
|
|
.read_map = blkiocg_time_read,
|
|
},
|
|
{
|
|
.name = "sectors",
|
|
.read_map = blkiocg_sectors_read,
|
|
},
|
|
{
|
|
.name = "io_service_bytes",
|
|
.read_map = blkiocg_io_service_bytes_read,
|
|
},
|
|
{
|
|
.name = "io_serviced",
|
|
.read_map = blkiocg_io_serviced_read,
|
|
},
|
|
{
|
|
.name = "io_service_time",
|
|
.read_map = blkiocg_io_service_time_read,
|
|
},
|
|
{
|
|
.name = "io_wait_time",
|
|
.read_map = blkiocg_io_wait_time_read,
|
|
},
|
|
{
|
|
.name = "io_merged",
|
|
.read_map = blkiocg_io_merged_read,
|
|
},
|
|
{
|
|
.name = "io_queued",
|
|
.read_map = blkiocg_io_queued_read,
|
|
},
|
|
{
|
|
.name = "reset_stats",
|
|
.write_u64 = blkiocg_reset_stats,
|
|
},
|
|
#ifdef CONFIG_DEBUG_BLK_CGROUP
|
|
{
|
|
.name = "avg_queue_size",
|
|
.read_map = blkiocg_avg_queue_size_read,
|
|
},
|
|
{
|
|
.name = "group_wait_time",
|
|
.read_map = blkiocg_group_wait_time_read,
|
|
},
|
|
{
|
|
.name = "idle_time",
|
|
.read_map = blkiocg_idle_time_read,
|
|
},
|
|
{
|
|
.name = "empty_time",
|
|
.read_map = blkiocg_empty_time_read,
|
|
},
|
|
{
|
|
.name = "dequeue",
|
|
.read_map = blkiocg_dequeue_read,
|
|
},
|
|
#endif
|
|
};
|
|
|
|
static int blkiocg_populate(struct cgroup_subsys *subsys, struct cgroup *cgroup)
|
|
{
|
|
return cgroup_add_files(cgroup, subsys, blkio_files,
|
|
ARRAY_SIZE(blkio_files));
|
|
}
|
|
|
|
static void blkiocg_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);
|
|
|
|
if (hlist_empty(&blkcg->blkg_list)) {
|
|
spin_unlock_irqrestore(&blkcg->lock, flags);
|
|
break;
|
|
}
|
|
|
|
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. Currently this is static call to one io
|
|
* controlling policy. Once we have more policies in place, we
|
|
* need some dynamic registration of callback function.
|
|
*/
|
|
spin_lock(&blkio_list_lock);
|
|
list_for_each_entry(blkiop, &blkio_list, list)
|
|
blkiop->ops.blkio_unlink_group_fn(key, blkg);
|
|
spin_unlock(&blkio_list_lock);
|
|
} while (1);
|
|
|
|
list_for_each_entry_safe(pn, pntmp, &blkcg->policy_list, node) {
|
|
blkio_policy_delete_node(pn);
|
|
kfree(pn);
|
|
}
|
|
|
|
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)
|
|
{
|
|
struct blkio_cgroup *blkcg;
|
|
struct cgroup *parent = cgroup->parent;
|
|
|
|
if (!parent) {
|
|
blkcg = &blkio_root_cgroup;
|
|
goto done;
|
|
}
|
|
|
|
/* Currently we do not support hierarchy deeper than two level (0,1) */
|
|
if (parent != cgroup->top_cgroup)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL);
|
|
if (!blkcg)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
blkcg->weight = BLKIO_WEIGHT_DEFAULT;
|
|
done:
|
|
spin_lock_init(&blkcg->lock);
|
|
INIT_HLIST_HEAD(&blkcg->blkg_list);
|
|
|
|
INIT_LIST_HEAD(&blkcg->policy_list);
|
|
return &blkcg->css;
|
|
}
|
|
|
|
/*
|
|
* 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
|
|
* of the main cic data structures. For now we allow a task to change
|
|
* its cgroup only if it's the only owner of its ioc.
|
|
*/
|
|
static int blkiocg_can_attach(struct cgroup_subsys *subsys,
|
|
struct cgroup *cgroup, struct task_struct *tsk,
|
|
bool threadgroup)
|
|
{
|
|
struct io_context *ioc;
|
|
int ret = 0;
|
|
|
|
/* task_lock() is needed to avoid races with exit_io_context() */
|
|
task_lock(tsk);
|
|
ioc = tsk->io_context;
|
|
if (ioc && atomic_read(&ioc->nr_tasks) > 1)
|
|
ret = -EINVAL;
|
|
task_unlock(tsk);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void blkiocg_attach(struct cgroup_subsys *subsys, struct cgroup *cgroup,
|
|
struct cgroup *prev, struct task_struct *tsk,
|
|
bool threadgroup)
|
|
{
|
|
struct io_context *ioc;
|
|
|
|
task_lock(tsk);
|
|
ioc = tsk->io_context;
|
|
if (ioc)
|
|
ioc->cgroup_changed = 1;
|
|
task_unlock(tsk);
|
|
}
|
|
|
|
void blkio_policy_register(struct blkio_policy_type *blkiop)
|
|
{
|
|
spin_lock(&blkio_list_lock);
|
|
list_add_tail(&blkiop->list, &blkio_list);
|
|
spin_unlock(&blkio_list_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blkio_policy_register);
|
|
|
|
void blkio_policy_unregister(struct blkio_policy_type *blkiop)
|
|
{
|
|
spin_lock(&blkio_list_lock);
|
|
list_del_init(&blkiop->list);
|
|
spin_unlock(&blkio_list_lock);
|
|
}
|
|
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");
|