diff options
Diffstat (limited to 'drivers/md/dm-delay.c')
-rw-r--r-- | drivers/md/dm-delay.c | 112 |
1 files changed, 52 insertions, 60 deletions
diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c index efd510984e25..5eabdb06c649 100644 --- a/drivers/md/dm-delay.c +++ b/drivers/md/dm-delay.c @@ -33,7 +33,7 @@ struct delay_c { struct work_struct flush_expired_bios; struct list_head delayed_bios; struct task_struct *worker; - atomic_t may_delay; + bool may_delay; struct delay_class read; struct delay_class write; @@ -73,39 +73,6 @@ static inline bool delay_is_fast(struct delay_c *dc) return !!dc->worker; } -static void flush_delayed_bios_fast(struct delay_c *dc, bool flush_all) -{ - struct dm_delay_info *delayed, *next; - - mutex_lock(&delayed_bios_lock); - list_for_each_entry_safe(delayed, next, &dc->delayed_bios, list) { - if (flush_all || time_after_eq(jiffies, delayed->expires)) { - struct bio *bio = dm_bio_from_per_bio_data(delayed, - sizeof(struct dm_delay_info)); - list_del(&delayed->list); - dm_submit_bio_remap(bio, NULL); - delayed->class->ops--; - } - } - mutex_unlock(&delayed_bios_lock); -} - -static int flush_worker_fn(void *data) -{ - struct delay_c *dc = data; - - while (1) { - flush_delayed_bios_fast(dc, false); - if (unlikely(list_empty(&dc->delayed_bios))) { - set_current_state(TASK_INTERRUPTIBLE); - schedule(); - } else - cond_resched(); - } - - return 0; -} - static void flush_bios(struct bio *bio) { struct bio *n; @@ -118,36 +85,61 @@ static void flush_bios(struct bio *bio) } } -static struct bio *flush_delayed_bios(struct delay_c *dc, bool flush_all) +static void flush_delayed_bios(struct delay_c *dc, bool flush_all) { struct dm_delay_info *delayed, *next; + struct bio_list flush_bio_list; unsigned long next_expires = 0; - unsigned long start_timer = 0; - struct bio_list flush_bios = { }; + bool start_timer = false; + bio_list_init(&flush_bio_list); mutex_lock(&delayed_bios_lock); list_for_each_entry_safe(delayed, next, &dc->delayed_bios, list) { + cond_resched(); if (flush_all || time_after_eq(jiffies, delayed->expires)) { struct bio *bio = dm_bio_from_per_bio_data(delayed, sizeof(struct dm_delay_info)); list_del(&delayed->list); - bio_list_add(&flush_bios, bio); + bio_list_add(&flush_bio_list, bio); delayed->class->ops--; continue; } - if (!start_timer) { - start_timer = 1; - next_expires = delayed->expires; - } else - next_expires = min(next_expires, delayed->expires); + if (!delay_is_fast(dc)) { + if (!start_timer) { + start_timer = true; + next_expires = delayed->expires; + } else { + next_expires = min(next_expires, delayed->expires); + } + } } mutex_unlock(&delayed_bios_lock); if (start_timer) queue_timeout(dc, next_expires); - return bio_list_get(&flush_bios); + flush_bios(bio_list_get(&flush_bio_list)); +} + +static int flush_worker_fn(void *data) +{ + struct delay_c *dc = data; + + while (!kthread_should_stop()) { + flush_delayed_bios(dc, false); + mutex_lock(&delayed_bios_lock); + if (unlikely(list_empty(&dc->delayed_bios))) { + set_current_state(TASK_INTERRUPTIBLE); + mutex_unlock(&delayed_bios_lock); + schedule(); + } else { + mutex_unlock(&delayed_bios_lock); + cond_resched(); + } + } + + return 0; } static void flush_expired_bios(struct work_struct *work) @@ -155,10 +147,7 @@ static void flush_expired_bios(struct work_struct *work) struct delay_c *dc; dc = container_of(work, struct delay_c, flush_expired_bios); - if (delay_is_fast(dc)) - flush_delayed_bios_fast(dc, false); - else - flush_bios(flush_delayed_bios(dc, false)); + flush_delayed_bios(dc, false); } static void delay_dtr(struct dm_target *ti) @@ -177,8 +166,7 @@ static void delay_dtr(struct dm_target *ti) if (dc->worker) kthread_stop(dc->worker); - if (!delay_is_fast(dc)) - mutex_destroy(&dc->timer_lock); + mutex_destroy(&dc->timer_lock); kfree(dc); } @@ -236,7 +224,8 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv) ti->private = dc; INIT_LIST_HEAD(&dc->delayed_bios); - atomic_set(&dc->may_delay, 1); + mutex_init(&dc->timer_lock); + dc->may_delay = true; dc->argc = argc; ret = delay_class_ctr(ti, &dc->read, argv); @@ -282,12 +271,12 @@ out: "dm-delay-flush-worker"); if (IS_ERR(dc->worker)) { ret = PTR_ERR(dc->worker); + dc->worker = NULL; goto bad; } } else { timer_setup(&dc->delay_timer, handle_delayed_timer, 0); INIT_WORK(&dc->flush_expired_bios, flush_expired_bios); - mutex_init(&dc->timer_lock); dc->kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0); if (!dc->kdelayd_wq) { ret = -EINVAL; @@ -312,7 +301,7 @@ static int delay_bio(struct delay_c *dc, struct delay_class *c, struct bio *bio) struct dm_delay_info *delayed; unsigned long expires = 0; - if (!c->delay || !atomic_read(&dc->may_delay)) + if (!c->delay) return DM_MAPIO_REMAPPED; delayed = dm_per_bio_data(bio, sizeof(struct dm_delay_info)); @@ -321,6 +310,10 @@ static int delay_bio(struct delay_c *dc, struct delay_class *c, struct bio *bio) delayed->expires = expires = jiffies + msecs_to_jiffies(c->delay); mutex_lock(&delayed_bios_lock); + if (unlikely(!dc->may_delay)) { + mutex_unlock(&delayed_bios_lock); + return DM_MAPIO_REMAPPED; + } c->ops++; list_add_tail(&delayed->list, &dc->delayed_bios); mutex_unlock(&delayed_bios_lock); @@ -337,21 +330,20 @@ static void delay_presuspend(struct dm_target *ti) { struct delay_c *dc = ti->private; - atomic_set(&dc->may_delay, 0); + mutex_lock(&delayed_bios_lock); + dc->may_delay = false; + mutex_unlock(&delayed_bios_lock); - if (delay_is_fast(dc)) - flush_delayed_bios_fast(dc, true); - else { + if (!delay_is_fast(dc)) del_timer_sync(&dc->delay_timer); - flush_bios(flush_delayed_bios(dc, true)); - } + flush_delayed_bios(dc, true); } static void delay_resume(struct dm_target *ti) { struct delay_c *dc = ti->private; - atomic_set(&dc->may_delay, 1); + dc->may_delay = true; } static int delay_map(struct dm_target *ti, struct bio *bio) |