From: Tejun Heo Date: Mon, 5 Mar 2012 21:15:03 +0000 (-0800) Subject: blkcg: use q and plid instead of opaque void * for blkio_group association X-Git-Tag: firefly_0821_release~3680^2~2720^2~83 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=ca32aefc7f2539ed88d42763330d54ee3e61769a;p=firefly-linux-kernel-4.4.55.git blkcg: use q and plid instead of opaque void * for blkio_group association blkgio_group is association between a block cgroup and a queue for a given policy. Using opaque void * for association makes things confusing and hinders factoring of common code. Use request_queue * and, if necessary, policy id instead. This will help block cgroup API cleanup. Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe --- diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 159aef59589f..5e50ca1f5b47 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -129,7 +129,7 @@ blkio_update_group_weight(struct blkio_group *blkg, unsigned int weight) if (blkiop->plid != blkg->plid) continue; if (blkiop->ops.blkio_update_group_weight_fn) - blkiop->ops.blkio_update_group_weight_fn(blkg->key, + blkiop->ops.blkio_update_group_weight_fn(blkg->q, blkg, weight); } } @@ -147,12 +147,12 @@ static inline void blkio_update_group_bps(struct blkio_group *blkg, u64 bps, 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, + blkiop->ops.blkio_update_group_read_bps_fn(blkg->q, 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, + blkiop->ops.blkio_update_group_write_bps_fn(blkg->q, blkg, bps); } } @@ -170,12 +170,12 @@ static inline void blkio_update_group_iops(struct blkio_group *blkg, 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, + blkiop->ops.blkio_update_group_read_iops_fn(blkg->q, 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, + blkiop->ops.blkio_update_group_write_iops_fn(blkg->q, blkg,iops); } } @@ -478,14 +478,14 @@ int blkio_alloc_blkg_stats(struct blkio_group *blkg) 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, + struct blkio_group *blkg, struct request_queue *q, 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); + rcu_assign_pointer(blkg->q, q); blkg->blkcg_id = css_id(&blkcg->css); hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list); blkg->plid = plid; @@ -531,18 +531,16 @@ int blkiocg_del_blkio_group(struct blkio_group *blkg) 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 *blkiocg_lookup_group(struct blkio_cgroup *blkcg, + struct request_queue *q, + enum blkio_policy_id plid) { 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) + hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) + if (blkg->q == q && blkg->plid == plid) return blkg; - } - return NULL; } EXPORT_SYMBOL_GPL(blkiocg_lookup_group); @@ -1582,7 +1580,7 @@ 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 request_queue *q; struct blkio_policy_type *blkiop; struct blkio_policy_node *pn, *pntmp; @@ -1597,7 +1595,7 @@ static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) blkg = hlist_entry(blkcg->blkg_list.first, struct blkio_group, blkcg_node); - key = rcu_dereference(blkg->key); + q = rcu_dereference(blkg->q); __blkiocg_del_blkio_group(blkg); spin_unlock_irqrestore(&blkcg->lock, flags); @@ -1611,7 +1609,7 @@ static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) list_for_each_entry(blkiop, &blkio_list, list) { if (blkiop->plid != blkg->plid) continue; - blkiop->ops.blkio_unlink_group_fn(key, blkg); + blkiop->ops.blkio_unlink_group_fn(q, blkg); } spin_unlock(&blkio_list_lock); } while (1); diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index e5cfcbd4d2f4..41c960b99c57 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -153,8 +153,8 @@ struct blkio_group_stats_cpu { }; struct blkio_group { - /* An rcu protected unique identifier for the group */ - void *key; + /* Pointer to the associated request_queue, RCU protected */ + struct request_queue __rcu *q; struct hlist_node blkcg_node; unsigned short blkcg_id; /* Store cgroup path */ @@ -202,17 +202,18 @@ extern unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg, 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 void (blkio_unlink_group_fn)(struct request_queue *q, + struct blkio_group *blkg); typedef bool (blkio_clear_queue_fn)(struct request_queue *q); -typedef void (blkio_update_group_weight_fn) (void *key, +typedef void (blkio_update_group_weight_fn)(struct request_queue *q, struct blkio_group *blkg, unsigned int weight); -typedef void (blkio_update_group_read_bps_fn) (void * key, +typedef void (blkio_update_group_read_bps_fn)(struct request_queue *q, struct blkio_group *blkg, u64 read_bps); -typedef void (blkio_update_group_write_bps_fn) (void *key, +typedef void (blkio_update_group_write_bps_fn)(struct request_queue *q, struct blkio_group *blkg, u64 write_bps); -typedef void (blkio_update_group_read_iops_fn) (void *key, +typedef void (blkio_update_group_read_iops_fn)(struct request_queue *q, struct blkio_group *blkg, unsigned int read_iops); -typedef void (blkio_update_group_write_iops_fn) (void *key, +typedef void (blkio_update_group_write_iops_fn)(struct request_queue *q, struct blkio_group *blkg, unsigned int write_iops); struct blkio_policy_ops { @@ -305,12 +306,13 @@ extern struct blkio_cgroup blkio_root_cgroup; extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup); extern struct blkio_cgroup *task_blkio_cgroup(struct task_struct *tsk); extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg, - struct blkio_group *blkg, void *key, dev_t dev, + struct blkio_group *blkg, struct request_queue *q, dev_t dev, enum blkio_policy_id plid); extern int blkio_alloc_blkg_stats(struct blkio_group *blkg); extern int blkiocg_del_blkio_group(struct blkio_group *blkg); extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, - void *key); + struct request_queue *q, + enum blkio_policy_id plid); void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time, unsigned long unaccounted_time); diff --git a/block/blk-throttle.c b/block/blk-throttle.c index c252df9169db..6613de78e364 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -252,7 +252,7 @@ static void throtl_init_add_tg_lists(struct throtl_data *td, __throtl_tg_fill_dev_details(td, tg); /* Add group onto cgroup list */ - blkiocg_add_blkio_group(blkcg, &tg->blkg, (void *)td, + blkiocg_add_blkio_group(blkcg, &tg->blkg, td->queue, tg->blkg.dev, BLKIO_POLICY_THROTL); tg->bps[READ] = blkcg_get_read_bps(blkcg, tg->blkg.dev); @@ -288,7 +288,6 @@ static struct throtl_grp *throtl_find_tg(struct throtl_data *td, struct blkio_cgroup *blkcg) { struct throtl_grp *tg = NULL; - void *key = td; /* * This is the common case when there are no blkio cgroups. @@ -297,7 +296,8 @@ throtl_grp *throtl_find_tg(struct throtl_data *td, struct blkio_cgroup *blkcg) if (blkcg == &blkio_root_cgroup) tg = td->root_tg; else - tg = tg_of_blkg(blkiocg_lookup_group(blkcg, key)); + tg = tg_of_blkg(blkiocg_lookup_group(blkcg, td->queue, + BLKIO_POLICY_THROTL)); __throtl_tg_fill_dev_details(td, tg); return tg; @@ -1012,22 +1012,22 @@ static bool throtl_release_tgs(struct throtl_data *td, bool release_root) * no new IO will come in this group. So get rid of this group as soon as * any pending IO in the group is finished. * - * This function is called under rcu_read_lock(). key is the rcu protected - * pointer. That means "key" is a valid throtl_data pointer as long as we are - * rcu read lock. + * This function is called under rcu_read_lock(). @q is the rcu protected + * pointer. That means @q is a valid request_queue pointer as long as we + * are rcu read lock. * - * "key" was fetched from blkio_group under blkio_cgroup->lock. That means + * @q was fetched from blkio_group under blkio_cgroup->lock. That means * it should not be NULL as even if queue was going away, cgroup deltion * path got to it first. */ -void throtl_unlink_blkio_group(void *key, struct blkio_group *blkg) +void throtl_unlink_blkio_group(struct request_queue *q, + struct blkio_group *blkg) { unsigned long flags; - struct throtl_data *td = key; - spin_lock_irqsave(td->queue->queue_lock, flags); - throtl_destroy_tg(td, tg_of_blkg(blkg)); - spin_unlock_irqrestore(td->queue->queue_lock, flags); + spin_lock_irqsave(q->queue_lock, flags); + throtl_destroy_tg(q->td, tg_of_blkg(blkg)); + spin_unlock_irqrestore(q->queue_lock, flags); } static bool throtl_clear_queue(struct request_queue *q) @@ -1054,52 +1054,48 @@ static void throtl_update_blkio_group_common(struct throtl_data *td, } /* - * For all update functions, key should be a valid pointer because these + * For all update functions, @q should be a valid pointer because these * update functions are called under blkcg_lock, that means, blkg is - * valid and in turn key is valid. queue exit path can not race because + * valid and in turn @q is valid. queue exit path can not race because * of blkcg_lock * * Can not take queue lock in update functions as queue lock under blkcg_lock * is not allowed. Under other paths we take blkcg_lock under queue_lock. */ -static void throtl_update_blkio_group_read_bps(void *key, +static void throtl_update_blkio_group_read_bps(struct request_queue *q, struct blkio_group *blkg, u64 read_bps) { - struct throtl_data *td = key; struct throtl_grp *tg = tg_of_blkg(blkg); tg->bps[READ] = read_bps; - throtl_update_blkio_group_common(td, tg); + throtl_update_blkio_group_common(q->td, tg); } -static void throtl_update_blkio_group_write_bps(void *key, +static void throtl_update_blkio_group_write_bps(struct request_queue *q, struct blkio_group *blkg, u64 write_bps) { - struct throtl_data *td = key; struct throtl_grp *tg = tg_of_blkg(blkg); tg->bps[WRITE] = write_bps; - throtl_update_blkio_group_common(td, tg); + throtl_update_blkio_group_common(q->td, tg); } -static void throtl_update_blkio_group_read_iops(void *key, +static void throtl_update_blkio_group_read_iops(struct request_queue *q, struct blkio_group *blkg, unsigned int read_iops) { - struct throtl_data *td = key; struct throtl_grp *tg = tg_of_blkg(blkg); tg->iops[READ] = read_iops; - throtl_update_blkio_group_common(td, tg); + throtl_update_blkio_group_common(q->td, tg); } -static void throtl_update_blkio_group_write_iops(void *key, +static void throtl_update_blkio_group_write_iops(struct request_queue *q, struct blkio_group *blkg, unsigned int write_iops) { - struct throtl_data *td = key; struct throtl_grp *tg = tg_of_blkg(blkg); tg->iops[WRITE] = write_iops; - throtl_update_blkio_group_common(td, tg); + throtl_update_blkio_group_common(q->td, tg); } static void throtl_shutdown_wq(struct request_queue *q) @@ -1306,7 +1302,7 @@ void blk_throtl_exit(struct request_queue *q) spin_unlock_irq(q->queue_lock); /* - * Wait for tg->blkg->key accessors to exit their grace periods. + * Wait for tg->blkg->q accessors to exit their grace periods. * Do this wait only if there are other undestroyed groups out * there (other than root group). This can happen if cgroup deletion * path claimed the responsibility of cleaning up a group before diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 0f7a81fc7c73..37e2da9cbb09 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1020,7 +1020,8 @@ static inline struct cfq_group *cfqg_of_blkg(struct blkio_group *blkg) return NULL; } -static void cfq_update_blkio_group_weight(void *key, struct blkio_group *blkg, +static void cfq_update_blkio_group_weight(struct request_queue *q, + struct blkio_group *blkg, unsigned int weight) { struct cfq_group *cfqg = cfqg_of_blkg(blkg); @@ -1043,10 +1044,10 @@ static void cfq_init_add_cfqg_lists(struct cfq_data *cfqd, if (bdi->dev) { sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor); cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg, - (void *)cfqd, MKDEV(major, minor)); + cfqd->queue, MKDEV(major, minor)); } else cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg, - (void *)cfqd, 0); + cfqd->queue, 0); cfqd->nr_blkcg_linked_grps++; cfqg->weight = blkcg_get_weight(blkcg, cfqg->blkg.dev); @@ -1097,7 +1098,6 @@ static struct cfq_group * cfq_find_cfqg(struct cfq_data *cfqd, struct blkio_cgroup *blkcg) { struct cfq_group *cfqg = NULL; - void *key = cfqd; struct backing_dev_info *bdi = &cfqd->queue->backing_dev_info; unsigned int major, minor; @@ -1108,7 +1108,8 @@ cfq_find_cfqg(struct cfq_data *cfqd, struct blkio_cgroup *blkcg) if (blkcg == &blkio_root_cgroup) cfqg = &cfqd->root_group; else - cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key)); + cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, cfqd->queue, + BLKIO_POLICY_PROP)); if (cfqg && !cfqg->blkg.dev && bdi->dev && dev_name(bdi->dev)) { sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor); @@ -1247,21 +1248,22 @@ static bool cfq_release_cfq_groups(struct cfq_data *cfqd) * any pending IO in the group is finished. * * This function is called under rcu_read_lock(). key is the rcu protected - * pointer. That means "key" is a valid cfq_data pointer as long as we are rcu - * read lock. + * pointer. That means @q is a valid request_queue pointer as long as we + * are rcu read lock. * - * "key" was fetched from blkio_group under blkio_cgroup->lock. That means + * @q was fetched from blkio_group under blkio_cgroup->lock. That means * it should not be NULL as even if elevator was exiting, cgroup deltion * path got to it first. */ -static void cfq_unlink_blkio_group(void *key, struct blkio_group *blkg) +static void cfq_unlink_blkio_group(struct request_queue *q, + struct blkio_group *blkg) { - unsigned long flags; - struct cfq_data *cfqd = key; + struct cfq_data *cfqd = q->elevator->elevator_data; + unsigned long flags; - spin_lock_irqsave(cfqd->queue->queue_lock, flags); + spin_lock_irqsave(q->queue_lock, flags); cfq_destroy_cfqg(cfqd, cfqg_of_blkg(blkg)); - spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); + spin_unlock_irqrestore(q->queue_lock, flags); } static struct elevator_type iosched_cfq; @@ -3718,7 +3720,7 @@ static int cfq_init_queue(struct request_queue *q) rcu_read_lock(); cfq_blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg, - (void *)cfqd, 0); + cfqd->queue, 0); rcu_read_unlock(); cfqd->nr_blkcg_linked_grps++; diff --git a/block/cfq.h b/block/cfq.h index 2a155927e37c..343b78a61df3 100644 --- a/block/cfq.h +++ b/block/cfq.h @@ -68,8 +68,9 @@ static inline void cfq_blkiocg_update_completion_stats(struct blkio_group *blkg, } static inline void cfq_blkiocg_add_blkio_group(struct blkio_cgroup *blkcg, - struct blkio_group *blkg, void *key, dev_t dev) { - blkiocg_add_blkio_group(blkcg, blkg, key, dev, BLKIO_POLICY_PROP); + struct blkio_group *blkg, struct request_queue *q, dev_t dev) +{ + blkiocg_add_blkio_group(blkcg, blkg, q, dev, BLKIO_POLICY_PROP); } static inline int cfq_blkiocg_del_blkio_group(struct blkio_group *blkg) @@ -105,7 +106,7 @@ static inline void cfq_blkiocg_update_dispatch_stats(struct blkio_group *blkg, static inline void cfq_blkiocg_update_completion_stats(struct blkio_group *blkg, uint64_t start_time, uint64_t io_start_time, bool direction, bool sync) {} static inline void cfq_blkiocg_add_blkio_group(struct blkio_cgroup *blkcg, - struct blkio_group *blkg, void *key, dev_t dev) {} + struct blkio_group *blkg, struct request_queue *q, dev_t dev) {} static inline int cfq_blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0;