* 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 "blk-cgroup.h"
+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_subsys *,
+ struct cgroup *);
+static int blkiocg_can_attach(struct cgroup_subsys *, struct cgroup *,
+ struct task_struct *, bool);
+static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *,
+ struct cgroup *, struct task_struct *, bool);
+static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *);
+static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *);
+
+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);
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);
+
+/*
+ * Add to the appropriate stat variable depending on the request type.
+ * This should be called with the blkg->stats_lock held.
+ */
+void io_add_stat(uint64_t *stat, uint64_t add, unsigned int flags)
+{
+ if (flags & REQ_RW)
+ stat[IO_WRITE] += add;
+ else
+ stat[IO_READ] += add;
+ /*
+ * Everywhere in the block layer, an IO is treated as sync if it is a
+ * read or a SYNC write. We follow the same norm.
+ */
+ if (!(flags & REQ_RW) || flags & REQ_RW_SYNC)
+ stat[IO_SYNC] += add;
+ else
+ stat[IO_ASYNC] += add;
+}
+
+void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&blkg->stats_lock, flags);
+ blkg->stats.time += time;
+ spin_unlock_irqrestore(&blkg->stats_lock, flags);
+}
+EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used);
+
+void blkiocg_update_request_dispatch_stats(struct blkio_group *blkg,
+ struct request *rq)
+{
+ struct blkio_group_stats *stats;
+ unsigned long flags;
+
+ spin_lock_irqsave(&blkg->stats_lock, flags);
+ stats = &blkg->stats;
+ stats->sectors += blk_rq_sectors(rq);
+ io_add_stat(stats->io_serviced, 1, rq->cmd_flags);
+ io_add_stat(stats->io_service_bytes, blk_rq_sectors(rq) << 9,
+ rq->cmd_flags);
+ spin_unlock_irqrestore(&blkg->stats_lock, flags);
+}
+
+void blkiocg_update_request_completion_stats(struct blkio_group *blkg,
+ struct request *rq)
+{
+ 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, rq->io_start_time_ns))
+ io_add_stat(stats->io_service_time, now - rq->io_start_time_ns,
+ rq->cmd_flags);
+ if (time_after64(rq->io_start_time_ns, rq->start_time_ns))
+ io_add_stat(stats->io_wait_time,
+ rq->io_start_time_ns - rq->start_time_ns,
+ rq->cmd_flags);
+ spin_unlock_irqrestore(&blkg->stats_lock, flags);
+}
+EXPORT_SYMBOL_GPL(blkiocg_update_request_completion_stats);
void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
- struct blkio_group *blkg, void *key)
+ struct blkio_group *blkg, void *key, dev_t dev)
{
unsigned long flags;
spin_lock_irqsave(&blkcg->lock, flags);
rcu_assign_pointer(blkg->key, key);
+ blkg->blkcg_id = css_id(&blkcg->css);
hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list);
spin_unlock_irqrestore(&blkcg->lock, flags);
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+ /* Need to take css reference ? */
+ cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path));
+#endif
+ 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)
{
- /* Implemented later */
- return 0;
+ 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)
+ goto out;
+
+ 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);
+out:
+ 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)
return NULL;
}
+EXPORT_SYMBOL_GPL(blkiocg_lookup_group);
#define SHOW_FUNCTION(__VAR) \
static u64 blkiocg_##__VAR##_read(struct cgroup *cgroup, \
blkiocg_weight_write(struct cgroup *cgroup, struct cftype *cftype, u64 val)
{
struct blkio_cgroup *blkcg;
+ struct blkio_group *blkg;
+ struct hlist_node *n;
+ struct blkio_policy_type *blkiop;
if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX)
return -EINVAL;
blkcg = cgroup_to_blkio_cgroup(cgroup);
+ 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) {
+ 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_write(struct cgroup *cgroup, struct cftype *cftype, u64 val)
+{
+ struct blkio_cgroup *blkcg;
+ struct blkio_group *blkg;
+ struct hlist_node *n;
+ struct blkio_group_stats *stats;
+
+ 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;
+ memset(stats, 0, sizeof(struct blkio_group_stats));
+ spin_unlock(&blkg->stats_lock);
+ }
+ spin_unlock_irq(&blkcg->lock);
return 0;
}
+void get_key_name(int type, char *disk_id, char *str, int chars_left)
+{
+ strlcpy(str, disk_id, chars_left);
+ chars_left -= strlen(str);
+ if (chars_left <= 0) {
+ printk(KERN_WARNING
+ "Possibly incorrect cgroup stat display format");
+ return;
+ }
+ switch (type) {
+ case IO_READ:
+ strlcat(str, " Read", chars_left);
+ break;
+ case IO_WRITE:
+ strlcat(str, " Write", chars_left);
+ break;
+ case IO_SYNC:
+ strlcat(str, " Sync", chars_left);
+ break;
+ case IO_ASYNC:
+ strlcat(str, " Async", chars_left);
+ break;
+ case IO_TYPE_MAX:
+ strlcat(str, " Total", chars_left);
+ break;
+ default:
+ strlcat(str, " Invalid", chars_left);
+ }
+}
+
+typedef uint64_t (get_var) (struct blkio_group *, int);
+
+#define MAX_KEY_LEN 100
+uint64_t get_typed_stat(struct blkio_group *blkg, struct cgroup_map_cb *cb,
+ get_var *getvar, char *disk_id)
+{
+ uint64_t disk_total;
+ char key_str[MAX_KEY_LEN];
+ int type;
+
+ for (type = 0; type < IO_TYPE_MAX; type++) {
+ get_key_name(type, disk_id, key_str, MAX_KEY_LEN);
+ cb->fill(cb, key_str, getvar(blkg, type));
+ }
+ disk_total = getvar(blkg, IO_READ) + getvar(blkg, IO_WRITE);
+ get_key_name(IO_TYPE_MAX, disk_id, key_str, MAX_KEY_LEN);
+ cb->fill(cb, key_str, disk_total);
+ return disk_total;
+}
+
+uint64_t get_stat(struct blkio_group *blkg, struct cgroup_map_cb *cb,
+ get_var *getvar, char *disk_id)
+{
+ uint64_t var = getvar(blkg, 0);
+ cb->fill(cb, disk_id, var);
+ return var;
+}
+
+#define GET_STAT_INDEXED(__VAR) \
+uint64_t get_##__VAR##_stat(struct blkio_group *blkg, int type) \
+{ \
+ return blkg->stats.__VAR[type]; \
+} \
+
+GET_STAT_INDEXED(io_service_bytes);
+GET_STAT_INDEXED(io_serviced);
+GET_STAT_INDEXED(io_service_time);
+GET_STAT_INDEXED(io_wait_time);
+#undef GET_STAT_INDEXED
+
+#define GET_STAT(__VAR, __CONV) \
+uint64_t get_##__VAR##_stat(struct blkio_group *blkg, int dummy) \
+{ \
+ uint64_t data = blkg->stats.__VAR; \
+ if (__CONV) \
+ data = (uint64_t)jiffies_to_msecs(data) * NSEC_PER_MSEC;\
+ return data; \
+}
+
+GET_STAT(time, 1);
+GET_STAT(sectors, 0);
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+GET_STAT(dequeue, 0);
+#endif
+#undef GET_STAT
+
+#define SHOW_FUNCTION_PER_GROUP(__VAR, get_stats, getvar, 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; \
+ char disk_id[10]; \
+ \
+ 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); \
+ snprintf(disk_id, 10, "%u:%u", MAJOR(blkg->dev),\
+ MINOR(blkg->dev)); \
+ cgroup_total += get_stats(blkg, cb, getvar, \
+ disk_id); \
+ 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, get_stat, get_time_stat, 0);
+SHOW_FUNCTION_PER_GROUP(sectors, get_stat, get_sectors_stat, 0);
+SHOW_FUNCTION_PER_GROUP(io_service_bytes, get_typed_stat,
+ get_io_service_bytes_stat, 1);
+SHOW_FUNCTION_PER_GROUP(io_serviced, get_typed_stat, get_io_serviced_stat, 1);
+SHOW_FUNCTION_PER_GROUP(io_service_time, get_typed_stat,
+ get_io_service_time_stat, 1);
+SHOW_FUNCTION_PER_GROUP(io_wait_time, get_typed_stat, get_io_wait_time_stat, 1);
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+SHOW_FUNCTION_PER_GROUP(dequeue, get_stat, get_dequeue_stat, 0);
+#endif
+#undef SHOW_FUNCTION_PER_GROUP
+
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
+ unsigned long dequeue)
+{
+ blkg->stats.dequeue += dequeue;
+}
+EXPORT_SYMBOL_GPL(blkiocg_update_dequeue_stats);
+#endif
+
struct cftype blkio_files[] = {
{
.name = "weight",
.read_u64 = blkiocg_weight_read,
.write_u64 = blkiocg_weight_write,
},
+ {
+ .name = "time",
+ .read_map = blkiocg_time_read,
+ .write_u64 = blkiocg_reset_write,
+ },
+ {
+ .name = "sectors",
+ .read_map = blkiocg_sectors_read,
+ .write_u64 = blkiocg_reset_write,
+ },
+ {
+ .name = "io_service_bytes",
+ .read_map = blkiocg_io_service_bytes_read,
+ .write_u64 = blkiocg_reset_write,
+ },
+ {
+ .name = "io_serviced",
+ .read_map = blkiocg_io_serviced_read,
+ .write_u64 = blkiocg_reset_write,
+ },
+ {
+ .name = "io_service_time",
+ .read_map = blkiocg_io_service_time_read,
+ .write_u64 = blkiocg_reset_write,
+ },
+ {
+ .name = "io_wait_time",
+ .read_map = blkiocg_io_wait_time_read,
+ .write_u64 = blkiocg_reset_write,
+ },
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+ {
+ .name = "dequeue",
+ .read_map = blkiocg_dequeue_read,
+ },
+#endif
};
static int blkiocg_populate(struct cgroup_subsys *subsys, struct cgroup *cgroup)
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;
+
+ rcu_read_lock();
+remove_entry:
+ spin_lock_irqsave(&blkcg->lock, flags);
+
+ if (hlist_empty(&blkcg->blkg_list)) {
+ spin_unlock_irqrestore(&blkcg->lock, flags);
+ goto done;
+ }
+
+ 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);
+ goto remove_entry;
+done:
free_css_id(&blkio_subsys, &blkcg->css);
- kfree(blkcg);
+ rcu_read_unlock();
+ if (blkcg != &blkio_root_cgroup)
+ kfree(blkcg);
}
static struct cgroup_subsys_state *
task_unlock(tsk);
}
-struct cgroup_subsys blkio_subsys = {
- .name = "blkio",
- .create = blkiocg_create,
- .can_attach = blkiocg_can_attach,
- .attach = blkiocg_attach,
- .destroy = blkiocg_destroy,
- .populate = blkiocg_populate,
- .subsys_id = blkio_subsys_id,
- .use_id = 1,
-};
+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");