diff options
| -rw-r--r-- | block/blk-cgroup.c | 34 | ||||
| -rw-r--r-- | block/blk-cgroup.h | 5 | ||||
| -rw-r--r-- | block/blk-throttle.c | 27 | ||||
| -rw-r--r-- | block/cfq-iosched.c | 20 | ||||
| -rw-r--r-- | block/elevator.c | 3 |
5 files changed, 84 insertions, 5 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 970a717a056f..159aef59589f 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -17,8 +17,9 @@ #include <linux/err.h> #include <linux/blkdev.h> #include <linux/slab.h> -#include "blk-cgroup.h" #include <linux/genhd.h> +#include <linux/delay.h> +#include "blk-cgroup.h" #define MAX_KEY_LEN 100 @@ -546,6 +547,37 @@ struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) } EXPORT_SYMBOL_GPL(blkiocg_lookup_group); +void blkg_destroy_all(struct request_queue *q) +{ + struct blkio_policy_type *pol; + + while (true) { + bool done = true; + + spin_lock(&blkio_list_lock); + spin_lock_irq(q->queue_lock); + + /* + * clear_queue_fn() might return with non-empty group list + * if it raced cgroup removal and lost. cgroup removal is + * guaranteed to make forward progress and retrying after a + * while is enough. This ugliness is scheduled to be + * removed after locking update. + */ + list_for_each_entry(pol, &blkio_list, list) + if (!pol->ops.blkio_clear_queue_fn(q)) + done = false; + + spin_unlock_irq(q->queue_lock); + spin_unlock(&blkio_list_lock); + + if (done) + break; + + msleep(10); /* just some random duration I like */ + } +} + static void blkio_reset_stats_cpu(struct blkio_group *blkg) { struct blkio_group_stats_cpu *stats_cpu; diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 355168772f51..e5cfcbd4d2f4 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -203,7 +203,7 @@ extern unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg, dev_t dev); typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg); - +typedef bool (blkio_clear_queue_fn)(struct request_queue *q); typedef void (blkio_update_group_weight_fn) (void *key, struct blkio_group *blkg, unsigned int weight); typedef void (blkio_update_group_read_bps_fn) (void * key, @@ -217,6 +217,7 @@ typedef void (blkio_update_group_write_iops_fn) (void *key, struct blkio_policy_ops { blkio_unlink_group_fn *blkio_unlink_group_fn; + blkio_clear_queue_fn *blkio_clear_queue_fn; blkio_update_group_weight_fn *blkio_update_group_weight_fn; blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn; blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn; @@ -233,6 +234,7 @@ struct blkio_policy_type { /* Blkio controller policy registration */ extern void blkio_policy_register(struct blkio_policy_type *); extern void blkio_policy_unregister(struct blkio_policy_type *); +extern void blkg_destroy_all(struct request_queue *q); static inline char *blkg_path(struct blkio_group *blkg) { @@ -249,6 +251,7 @@ struct blkio_policy_type { static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { } static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { } +static inline void blkg_destroy_all(struct request_queue *q) { } static inline char *blkg_path(struct blkio_group *blkg) { return NULL; } diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 702c0e64e09f..3699ab40d494 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -989,12 +989,17 @@ throtl_destroy_tg(struct throtl_data *td, struct throtl_grp *tg) td->nr_undestroyed_grps--; } -static void throtl_release_tgs(struct throtl_data *td) +static bool throtl_release_tgs(struct throtl_data *td, bool release_root) { struct hlist_node *pos, *n; struct throtl_grp *tg; + bool empty = true; hlist_for_each_entry_safe(tg, pos, n, &td->tg_list, tg_node) { + /* skip root? */ + if (!release_root && tg == td->root_tg) + continue; + /* * If cgroup removal path got to blk_group first and removed * it from cgroup list, then it will take care of destroying @@ -1002,7 +1007,10 @@ static void throtl_release_tgs(struct throtl_data *td) */ if (!blkiocg_del_blkio_group(&tg->blkg)) throtl_destroy_tg(td, tg); + else + empty = false; } + return empty; } /* @@ -1029,6 +1037,20 @@ void throtl_unlink_blkio_group(void *key, struct blkio_group *blkg) spin_unlock_irqrestore(td->queue->queue_lock, flags); } +static bool throtl_clear_queue(struct request_queue *q) +{ + lockdep_assert_held(q->queue_lock); + + /* + * Clear tgs but leave the root one alone. This is necessary + * because root_tg is expected to be persistent and safe because + * blk-throtl can never be disabled while @q is alive. This is a + * kludge to prepare for unified blkg. This whole function will be + * removed soon. + */ + return throtl_release_tgs(q->td, false); +} + static void throtl_update_blkio_group_common(struct throtl_data *td, struct throtl_grp *tg) { @@ -1097,6 +1119,7 @@ static void throtl_shutdown_wq(struct request_queue *q) static struct blkio_policy_type blkio_policy_throtl = { .ops = { .blkio_unlink_group_fn = throtl_unlink_blkio_group, + .blkio_clear_queue_fn = throtl_clear_queue, .blkio_update_group_read_bps_fn = throtl_update_blkio_group_read_bps, .blkio_update_group_write_bps_fn = @@ -1282,7 +1305,7 @@ void blk_throtl_exit(struct request_queue *q) throtl_shutdown_wq(q); spin_lock_irq(q->queue_lock); - throtl_release_tgs(td); + throtl_release_tgs(td, true); /* If there are other groups */ if (td->nr_undestroyed_grps > 0) diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 72680a6715fc..61693d3404d0 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1225,10 +1225,11 @@ static void cfq_destroy_cfqg(struct cfq_data *cfqd, struct cfq_group *cfqg) cfq_put_cfqg(cfqg); } -static void cfq_release_cfq_groups(struct cfq_data *cfqd) +static bool cfq_release_cfq_groups(struct cfq_data *cfqd) { struct hlist_node *pos, *n; struct cfq_group *cfqg; + bool empty = true; hlist_for_each_entry_safe(cfqg, pos, n, &cfqd->cfqg_list, cfqd_node) { /* @@ -1238,7 +1239,10 @@ static void cfq_release_cfq_groups(struct cfq_data *cfqd) */ if (!cfq_blkiocg_del_blkio_group(&cfqg->blkg)) cfq_destroy_cfqg(cfqd, cfqg); + else + empty = false; } + return empty; } /* @@ -1265,6 +1269,19 @@ static void cfq_unlink_blkio_group(void *key, struct blkio_group *blkg) spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); } +static struct elevator_type iosched_cfq; + +static bool cfq_clear_queue(struct request_queue *q) +{ + lockdep_assert_held(q->queue_lock); + + /* shoot down blkgs iff the current elevator is cfq */ + if (!q->elevator || q->elevator->type != &iosched_cfq) + return true; + + return cfq_release_cfq_groups(q->elevator->elevator_data); +} + #else /* GROUP_IOSCHED */ static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd) { @@ -3875,6 +3892,7 @@ static struct elevator_type iosched_cfq = { static struct blkio_policy_type blkio_policy_cfq = { .ops = { .blkio_unlink_group_fn = cfq_unlink_blkio_group, + .blkio_clear_queue_fn = cfq_clear_queue, .blkio_update_group_weight_fn = cfq_update_blkio_group_weight, }, .plid = BLKIO_POLICY_PROP, diff --git a/block/elevator.c b/block/elevator.c index 0bdea0ed03a3..8c7561fd2c79 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -38,6 +38,7 @@ #include <trace/events/block.h> #include "blk.h" +#include "blk-cgroup.h" static DEFINE_SPINLOCK(elv_list_lock); static LIST_HEAD(elv_list); @@ -894,6 +895,8 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e) ioc_clear_queue(q); spin_unlock_irq(q->queue_lock); + blkg_destroy_all(q); + /* allocate, init and register new elevator */ err = -ENOMEM; q->elevator = elevator_alloc(q, new_e); |