zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/block/blk-cgroup.c b/ap/os/linux/linux-3.4.x/block/blk-cgroup.c
new file mode 100644
index 0000000..ea84a23
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/block/blk-cgroup.c
@@ -0,0 +1,1689 @@
+/*
+ * Common Block IO controller cgroup interface
+ *
+ * Based on ideas and code from CFQ, CFS and BFQ:
+ * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
+ *
+ * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
+ * Paolo Valente <paolo.valente@unimore.it>
+ *
+ * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
+ * Nauman Rafique <nauman@google.com>
+ */
+#include <linux/ioprio.h>
+#include <linux/seq_file.h>
+#include <linux/kdev_t.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/blkdev.h>
+#include <linux/slab.h>
+#include "blk-cgroup.h"
+#include <linux/genhd.h>
+
+#define MAX_KEY_LEN 100
+
+static DEFINE_SPINLOCK(blkio_list_lock);
+static LIST_HEAD(blkio_list);
+
+struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT };
+EXPORT_SYMBOL_GPL(blkio_root_cgroup);
+
+static struct cgroup_subsys_state *blkiocg_create(struct cgroup *);
+static int blkiocg_can_attach(struct cgroup *, struct cgroup_taskset *);
+static void blkiocg_attach(struct cgroup *, struct cgroup_taskset *);
+static void blkiocg_destroy(struct cgroup *);
+static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *);
+
+/* for encoding cft->private value on file */
+#define BLKIOFILE_PRIVATE(x, val) (((x) << 16) | (val))
+/* What policy owns the file, proportional or throttle */
+#define BLKIOFILE_POLICY(val) (((val) >> 16) & 0xffff)
+#define BLKIOFILE_ATTR(val) ((val) & 0xffff)
+
+struct cgroup_subsys blkio_subsys = {
+ .name = "blkio",
+ .create = blkiocg_create,
+ .can_attach = blkiocg_can_attach,
+ .attach = blkiocg_attach,
+ .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),
+ struct blkio_cgroup, css);
+}
+EXPORT_SYMBOL_GPL(cgroup_to_blkio_cgroup);
+
+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_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)
+ continue;
+ if (blkiop->ops.blkio_update_group_weight_fn)
+ blkiop->ops.blkio_update_group_weight_fn(blkg->key,
+ blkg, weight);
+ }
+}
+
+static inline void blkio_update_group_bps(struct blkio_group *blkg, 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)
+ 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,
+ 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,
+ blkg, bps);
+ }
+}
+
+static inline void blkio_update_group_iops(struct blkio_group *blkg,
+ 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)
+ 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,
+ 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,
+ blkg,iops);
+ }
+}
+
+/*
+ * Add to the appropriate stat variable depending on the request type.
+ * This should be called with the blkg->stats_lock held.
+ */
+static void blkio_add_stat(uint64_t *stat, uint64_t add, bool direction,
+ bool sync)
+{
+ if (direction)
+ stat[BLKIO_STAT_WRITE] += add;
+ else
+ stat[BLKIO_STAT_READ] += add;
+ if (sync)
+ stat[BLKIO_STAT_SYNC] += add;
+ else
+ stat[BLKIO_STAT_ASYNC] += add;
+}
+
+/*
+ * 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.
+ */
+static void blkio_check_and_dec_stat(uint64_t *stat, bool direction, bool sync)
+{
+ if (direction) {
+ BUG_ON(stat[BLKIO_STAT_WRITE] == 0);
+ stat[BLKIO_STAT_WRITE]--;
+ } else {
+ BUG_ON(stat[BLKIO_STAT_READ] == 0);
+ stat[BLKIO_STAT_READ]--;
+ }
+ if (sync) {
+ BUG_ON(stat[BLKIO_STAT_SYNC] == 0);
+ stat[BLKIO_STAT_SYNC]--;
+ } else {
+ BUG_ON(stat[BLKIO_STAT_ASYNC] == 0);
+ stat[BLKIO_STAT_ASYNC]--;
+ }
+}
+
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+/* This should be called with the blkg->stats_lock held. */
+static void blkio_set_start_group_wait_time(struct blkio_group *blkg,
+ struct blkio_group *curr_blkg)
+{
+ if (blkio_blkg_waiting(&blkg->stats))
+ return;
+ if (blkg == curr_blkg)
+ return;
+ blkg->stats.start_group_wait_time = sched_clock();
+ blkio_mark_blkg_waiting(&blkg->stats);
+}
+
+/* This should be called with the blkg->stats_lock held. */
+static void blkio_update_group_wait_time(struct blkio_group_stats *stats)
+{
+ unsigned long long now;
+
+ if (!blkio_blkg_waiting(stats))
+ return;
+
+ now = sched_clock();
+ if (time_after64(now, stats->start_group_wait_time))
+ stats->group_wait_time += now - stats->start_group_wait_time;
+ blkio_clear_blkg_waiting(stats);
+}
+
+/* This should be called with the blkg->stats_lock held. */
+static void blkio_end_empty_time(struct blkio_group_stats *stats)
+{
+ unsigned long long now;
+
+ if (!blkio_blkg_empty(stats))
+ return;
+
+ now = sched_clock();
+ if (time_after64(now, stats->start_empty_time))
+ stats->empty_time += now - stats->start_empty_time;
+ blkio_clear_blkg_empty(stats);
+}
+
+void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
+{
+ unsigned long flags;
+
+ 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);
+}
+EXPORT_SYMBOL_GPL(blkiocg_update_set_idle_time_stats);
+
+void blkiocg_update_idle_time_stats(struct blkio_group *blkg)
+{
+ unsigned long flags;
+ unsigned long long now;
+ struct blkio_group_stats *stats;
+
+ 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))
+ stats->idle_time += now - stats->start_idle_time;
+ 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)
+{
+ unsigned long flags;
+ struct blkio_group_stats *stats;
+
+ spin_lock_irqsave(&blkg->stats_lock, flags);
+ stats = &blkg->stats;
+ 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);
+}
+EXPORT_SYMBOL_GPL(blkiocg_update_avg_queue_size_stats);
+
+void blkiocg_set_start_empty_time(struct blkio_group *blkg)
+{
+ unsigned long flags;
+ struct blkio_group_stats *stats;
+
+ spin_lock_irqsave(&blkg->stats_lock, flags);
+ stats = &blkg->stats;
+
+ 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);
+ 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);
+ 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)
+{
+ blkg->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) {}
+#endif
+
+void blkiocg_update_io_add_stats(struct blkio_group *blkg,
+ struct blkio_group *curr_blkg, bool direction,
+ bool sync)
+{
+ unsigned long flags;
+
+ 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);
+}
+EXPORT_SYMBOL_GPL(blkiocg_update_io_add_stats);
+
+void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
+ bool direction, bool sync)
+{
+ unsigned long flags;
+
+ 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);
+}
+EXPORT_SYMBOL_GPL(blkiocg_update_io_remove_stats);
+
+void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time,
+ unsigned long unaccounted_time)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&blkg->stats_lock, flags);
+ blkg->stats.time += time;
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+ blkg->stats.unaccounted_time += unaccounted_time;
+#endif
+ spin_unlock_irqrestore(&blkg->stats_lock, flags);
+}
+EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used);
+
+/*
+ * should be called under rcu read lock or queue lock to make sure blkg pointer
+ * is valid.
+ */
+void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
+ uint64_t bytes, bool direction, bool sync)
+{
+ struct blkio_group_stats_cpu *stats_cpu;
+ unsigned long flags;
+
+ /*
+ * 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);
+
+ u64_stats_update_begin(&stats_cpu->syncp);
+ stats_cpu->sectors += bytes >> 9;
+ blkio_add_stat(stats_cpu->stat_arr_cpu[BLKIO_STAT_CPU_SERVICED],
+ 1, direction, sync);
+ blkio_add_stat(stats_cpu->stat_arr_cpu[BLKIO_STAT_CPU_SERVICE_BYTES],
+ bytes, direction, sync);
+ u64_stats_update_end(&stats_cpu->syncp);
+ local_irq_restore(flags);
+}
+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_group_stats *stats;
+ unsigned long flags;
+ unsigned long long now = sched_clock();
+
+ spin_lock_irqsave(&blkg->stats_lock, flags);
+ stats = &blkg->stats;
+ 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);
+}
+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)
+{
+ struct blkio_group_stats_cpu *stats_cpu;
+ unsigned long flags;
+
+ /*
+ * 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);
+
+ 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);
+}
+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.
+ */
+int blkio_alloc_blkg_stats(struct blkio_group *blkg)
+{
+ /* 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);
+
+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;
+
+ 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;
+}
+EXPORT_SYMBOL_GPL(blkiocg_add_blkio_group);
+
+static void __blkiocg_del_blkio_group(struct blkio_group *blkg)
+{
+ hlist_del_init_rcu(&blkg->blkcg_node);
+ blkg->blkcg_id = 0;
+}
+
+/*
+ * 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.
+ */
+int blkiocg_del_blkio_group(struct blkio_group *blkg)
+{
+ struct blkio_cgroup *blkcg;
+ unsigned long flags;
+ struct cgroup_subsys_state *css;
+ int ret = 1;
+
+ 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;
+ }
+ spin_unlock_irqrestore(&blkcg->lock, flags);
+ }
+
+ rcu_read_unlock();
+ return ret;
+}
+EXPORT_SYMBOL_GPL(blkiocg_del_blkio_group);
+
+/* called under rcu_read_lock(). */
+struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key)
+{
+ 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)
+ return blkg;
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(blkiocg_lookup_group);
+
+static void blkio_reset_stats_cpu(struct blkio_group *blkg)
+{
+ struct blkio_group_stats_cpu *stats_cpu;
+ int i, j, k;
+ /*
+ * 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.
+ *
+ * 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.
+ */
+ 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;
+ }
+}
+
+static int
+blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val)
+{
+ struct blkio_cgroup *blkcg;
+ 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_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);
+
+ /* Reset Per cpu stats which don't take blkg->stats_lock */
+ blkio_reset_stats_cpu(blkg);
+ }
+
+ 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;
+}
+
+
+static uint64_t blkio_read_stat_cpu(struct blkio_group *blkg,
+ enum stat_type_cpu type, enum stat_sub_type sub_type)
+{
+ int cpu;
+ struct blkio_group_stats_cpu *stats_cpu;
+ u64 val = 0, tval;
+
+ for_each_possible_cpu(cpu) {
+ unsigned int start;
+ stats_cpu = per_cpu_ptr(blkg->stats_cpu, cpu);
+
+ do {
+ start = u64_stats_fetch_begin(&stats_cpu->syncp);
+ if (type == BLKIO_STAT_CPU_SECTORS)
+ tval = stats_cpu->sectors;
+ else
+ tval = stats_cpu->stat_arr_cpu[type][sub_type];
+ } while(u64_stats_fetch_retry(&stats_cpu->syncp, start));
+
+ val += tval;
+ }
+
+ 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)
+{
+ 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);
+ }
+
+ 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);
+ 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);
+
+ blkio_get_key_name(BLKIO_STAT_TOTAL, dev, 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)
+{
+ 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);
+#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);
+#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;
+}
+
+static int blkio_policy_parse_and_set(char *buf,
+ struct blkio_policy_node *newpn, enum blkio_policy_id plid, int fileid)
+{
+ struct gendisk *disk = NULL;
+ char *s[4], *p, *major_s = NULL, *minor_s = NULL;
+ unsigned long major, minor;
+ int i = 0, ret = -EINVAL;
+ int part;
+ dev_t dev;
+ u64 temp;
+
+ 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)
+ goto out;
+
+ p = strsep(&s[0], ":");
+ if (p != NULL)
+ major_s = p;
+ else
+ goto out;
+
+ minor_s = s[0];
+ if (!minor_s)
+ goto out;
+
+ if (strict_strtoul(major_s, 10, &major))
+ goto out;
+
+ if (strict_strtoul(minor_s, 10, &minor))
+ goto out;
+
+ dev = MKDEV(major, minor);
+
+ 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;
+ }
+ }
+
+ newpn->dev = dev;
+
+ switch (plid) {
+ case BLKIO_POLICY_PROP:
+ if ((temp < BLKIO_WEIGHT_MIN && temp > 0) ||
+ temp > BLKIO_WEIGHT_MAX)
+ goto out;
+
+ newpn->plid = plid;
+ newpn->fileid = fileid;
+ newpn->val.weight = temp;
+ break;
+ case BLKIO_POLICY_THROTL:
+ switch(fileid) {
+ case BLKIO_THROTL_read_bps_device:
+ case BLKIO_THROTL_write_bps_device:
+ newpn->plid = plid;
+ newpn->fileid = fileid;
+ newpn->val.bps = temp;
+ break;
+ case BLKIO_THROTL_read_iops_device:
+ 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;
+ break;
+ }
+ break;
+ default:
+ BUG();
+ }
+ ret = 0;
+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);
+ }
+
+ spin_unlock_irq(&blkcg->lock);
+ spin_unlock(&blkio_list_lock);
+}
+
+static int blkiocg_file_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;
+ int keep_newpn = 0;
+ enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
+ int fileid = BLKIOFILE_ATTR(cft->private);
+
+ 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, 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:
+ kfree(buf);
+ return ret;
+}
+
+static void
+blkio_print_policy_node(struct seq_file *m, struct blkio_policy_node *pn)
+{
+ switch(pn->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);
+ break;
+ case BLKIO_POLICY_THROTL:
+ switch(pn->fileid) {
+ case BLKIO_THROTL_read_bps_device:
+ case BLKIO_THROTL_write_bps_device:
+ seq_printf(m, "%u:%u\t%llu\n", MAJOR(pn->dev),
+ MINOR(pn->dev), pn->val.bps);
+ break;
+ case BLKIO_THROTL_read_iops_device:
+ case BLKIO_THROTL_write_iops_device:
+ seq_printf(m, "%u:%u\t%u\n", MAJOR(pn->dev),
+ MINOR(pn->dev), pn->val.iops);
+ break;
+ }
+ break;
+ default:
+ BUG();
+ }
+}
+
+/* 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)
+{
+ 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);
+ }
+}
+
+static int blkiocg_file_read(struct cgroup *cgrp, struct cftype *cft,
+ struct seq_file *m)
+{
+ struct blkio_cgroup *blkcg;
+ enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
+ int name = BLKIOFILE_ATTR(cft->private);
+
+ blkcg = cgroup_to_blkio_cgroup(cgrp);
+
+ switch(plid) {
+ case BLKIO_POLICY_PROP:
+ switch(name) {
+ case BLKIO_PROP_weight_device:
+ blkio_read_policy_node_files(cft, blkcg, m);
+ return 0;
+ default:
+ BUG();
+ }
+ break;
+ case BLKIO_POLICY_THROTL:
+ switch(name){
+ case BLKIO_THROTL_read_bps_device:
+ 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);
+ return 0;
+ default:
+ BUG();
+ }
+ break;
+ default:
+ BUG();
+ }
+
+ return 0;
+}
+
+static int blkio_read_blkg_stats(struct blkio_cgroup *blkcg,
+ struct cftype *cft, struct cgroup_map_cb *cb,
+ enum stat_type type, bool show_total, bool pcpu)
+{
+ struct blkio_group *blkg;
+ 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);
+ }
+ }
+ }
+ if (show_total)
+ cb->fill(cb, "Total", cgroup_total);
+ rcu_read_unlock();
+ return 0;
+}
+
+/* All map kind of cgroup file get serviced by this function */
+static int blkiocg_file_read_map(struct cgroup *cgrp, struct cftype *cft,
+ struct cgroup_map_cb *cb)
+{
+ struct blkio_cgroup *blkcg;
+ enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
+ int name = BLKIOFILE_ATTR(cft->private);
+
+ blkcg = cgroup_to_blkio_cgroup(cgrp);
+
+ switch(plid) {
+ case BLKIO_POLICY_PROP:
+ switch(name) {
+ case BLKIO_PROP_time:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_TIME, 0, 0);
+ case BLKIO_PROP_sectors:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_CPU_SECTORS, 0, 1);
+ case BLKIO_PROP_io_service_bytes:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_CPU_SERVICE_BYTES, 1, 1);
+ case BLKIO_PROP_io_serviced:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_CPU_SERVICED, 1, 1);
+ case BLKIO_PROP_io_service_time:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_SERVICE_TIME, 1, 0);
+ case BLKIO_PROP_io_wait_time:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ 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);
+ case BLKIO_PROP_io_queued:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_QUEUED, 1, 0);
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+ case BLKIO_PROP_unaccounted_time:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_UNACCOUNTED_TIME, 0, 0);
+ case BLKIO_PROP_dequeue:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_DEQUEUE, 0, 0);
+ case BLKIO_PROP_avg_queue_size:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_AVG_QUEUE_SIZE, 0, 0);
+ case BLKIO_PROP_group_wait_time:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_GROUP_WAIT_TIME, 0, 0);
+ case BLKIO_PROP_idle_time:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_IDLE_TIME, 0, 0);
+ case BLKIO_PROP_empty_time:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_EMPTY_TIME, 0, 0);
+#endif
+ default:
+ BUG();
+ }
+ break;
+ case BLKIO_POLICY_THROTL:
+ switch(name){
+ case BLKIO_THROTL_io_service_bytes:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_CPU_SERVICE_BYTES, 1, 1);
+ case BLKIO_THROTL_io_serviced:
+ return blkio_read_blkg_stats(blkcg, cft, cb,
+ BLKIO_STAT_CPU_SERVICED, 1, 1);
+ default:
+ BUG();
+ }
+ break;
+ default:
+ BUG();
+ }
+
+ return 0;
+}
+
+static int blkio_weight_write(struct blkio_cgroup *blkcg, 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;
+
+ spin_lock(&blkio_list_lock);
+ spin_lock_irq(&blkcg->lock);
+ 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;
+
+ blkio_update_group_weight(blkg, blkcg->weight);
+ }
+ spin_unlock_irq(&blkcg->lock);
+ spin_unlock(&blkio_list_lock);
+ return 0;
+}
+
+static u64 blkiocg_file_read_u64 (struct cgroup *cgrp, struct cftype *cft) {
+ struct blkio_cgroup *blkcg;
+ enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
+ int name = BLKIOFILE_ATTR(cft->private);
+
+ blkcg = cgroup_to_blkio_cgroup(cgrp);
+
+ switch(plid) {
+ case BLKIO_POLICY_PROP:
+ switch(name) {
+ case BLKIO_PROP_weight:
+ return (u64)blkcg->weight;
+ }
+ break;
+ default:
+ BUG();
+ }
+ return 0;
+}
+
+static int
+blkiocg_file_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val)
+{
+ struct blkio_cgroup *blkcg;
+ enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
+ int name = BLKIOFILE_ATTR(cft->private);
+
+ blkcg = cgroup_to_blkio_cgroup(cgrp);
+
+ switch(plid) {
+ case BLKIO_POLICY_PROP:
+ switch(name) {
+ case BLKIO_PROP_weight:
+ return blkio_weight_write(blkcg, val);
+ }
+ break;
+ default:
+ BUG();
+ }
+
+ return 0;
+}
+
+struct cftype blkio_files[] = {
+ {
+ .name = "weight_device",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_weight_device),
+ .read_seq_string = blkiocg_file_read,
+ .write_string = blkiocg_file_write,
+ .max_write_len = 256,
+ },
+ {
+ .name = "weight",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_weight),
+ .read_u64 = blkiocg_file_read_u64,
+ .write_u64 = blkiocg_file_write_u64,
+ },
+ {
+ .name = "time",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_time),
+ .read_map = blkiocg_file_read_map,
+ },
+ {
+ .name = "sectors",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_sectors),
+ .read_map = blkiocg_file_read_map,
+ },
+ {
+ .name = "io_service_bytes",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_io_service_bytes),
+ .read_map = blkiocg_file_read_map,
+ },
+ {
+ .name = "io_serviced",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_io_serviced),
+ .read_map = blkiocg_file_read_map,
+ },
+ {
+ .name = "io_service_time",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_io_service_time),
+ .read_map = blkiocg_file_read_map,
+ },
+ {
+ .name = "io_wait_time",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_io_wait_time),
+ .read_map = blkiocg_file_read_map,
+ },
+ {
+ .name = "io_merged",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_io_merged),
+ .read_map = blkiocg_file_read_map,
+ },
+ {
+ .name = "io_queued",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_io_queued),
+ .read_map = blkiocg_file_read_map,
+ },
+ {
+ .name = "reset_stats",
+ .write_u64 = blkiocg_reset_stats,
+ },
+#ifdef CONFIG_BLK_DEV_THROTTLING
+ {
+ .name = "throttle.read_bps_device",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
+ BLKIO_THROTL_read_bps_device),
+ .read_seq_string = blkiocg_file_read,
+ .write_string = blkiocg_file_write,
+ .max_write_len = 256,
+ },
+
+ {
+ .name = "throttle.write_bps_device",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
+ BLKIO_THROTL_write_bps_device),
+ .read_seq_string = blkiocg_file_read,
+ .write_string = blkiocg_file_write,
+ .max_write_len = 256,
+ },
+
+ {
+ .name = "throttle.read_iops_device",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
+ BLKIO_THROTL_read_iops_device),
+ .read_seq_string = blkiocg_file_read,
+ .write_string = blkiocg_file_write,
+ .max_write_len = 256,
+ },
+
+ {
+ .name = "throttle.write_iops_device",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
+ BLKIO_THROTL_write_iops_device),
+ .read_seq_string = blkiocg_file_read,
+ .write_string = blkiocg_file_write,
+ .max_write_len = 256,
+ },
+ {
+ .name = "throttle.io_service_bytes",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
+ BLKIO_THROTL_io_service_bytes),
+ .read_map = blkiocg_file_read_map,
+ },
+ {
+ .name = "throttle.io_serviced",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_THROTL,
+ BLKIO_THROTL_io_serviced),
+ .read_map = blkiocg_file_read_map,
+ },
+#endif /* CONFIG_BLK_DEV_THROTTLING */
+
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+ {
+ .name = "avg_queue_size",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_avg_queue_size),
+ .read_map = blkiocg_file_read_map,
+ },
+ {
+ .name = "group_wait_time",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_group_wait_time),
+ .read_map = blkiocg_file_read_map,
+ },
+ {
+ .name = "idle_time",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_idle_time),
+ .read_map = blkiocg_file_read_map,
+ },
+ {
+ .name = "empty_time",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_empty_time),
+ .read_map = blkiocg_file_read_map,
+ },
+ {
+ .name = "dequeue",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_dequeue),
+ .read_map = blkiocg_file_read_map,
+ },
+ {
+ .name = "unaccounted_time",
+ .private = BLKIOFILE_PRIVATE(BLKIO_POLICY_PROP,
+ BLKIO_PROP_unaccounted_time),
+ .read_map = blkiocg_file_read_map,
+ },
+#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 *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.
+ */
+ 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);
+
+ 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 *cgroup)
+{
+ struct blkio_cgroup *blkcg;
+ struct cgroup *parent = cgroup->parent;
+
+ if (!parent) {
+ blkcg = &blkio_root_cgroup;
+ goto done;
+ }
+
+ 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 *cgrp, struct cgroup_taskset *tset)
+{
+ struct task_struct *task;
+ struct io_context *ioc;
+ int ret = 0;
+
+ /* task_lock() is needed to avoid races with exit_io_context() */
+ cgroup_taskset_for_each(task, cgrp, tset) {
+ task_lock(task);
+ ioc = task->io_context;
+ if (ioc && atomic_read(&ioc->nr_tasks) > 1)
+ ret = -EINVAL;
+ task_unlock(task);
+ if (ret)
+ break;
+ }
+ return ret;
+}
+
+static void blkiocg_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
+{
+ struct task_struct *task;
+ struct io_context *ioc;
+
+ cgroup_taskset_for_each(task, cgrp, tset) {
+ /* we don't lose anything even if ioc allocation fails */
+ ioc = get_task_io_context(task, GFP_ATOMIC, NUMA_NO_NODE);
+ if (ioc) {
+ ioc_cgroup_changed(ioc);
+ put_io_context(ioc);
+ }
+ }
+}
+
+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");