+
+ hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
+ pn = blkio_policy_search_node(blkcg, blkg->dev);
+
+ if (pn)
+ continue;
+
+ list_for_each_entry(blkiop, &blkio_list, list)
+ blkiop->ops.blkio_update_group_weight_fn(blkg,
+ blkcg->weight);
+ }
+ spin_unlock_irq(&blkcg->lock);
+ spin_unlock(&blkio_list_lock);
+ return 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);
+ }
+ 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);
+ }
+