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author | Mikulas Patocka <mpatocka@redhat.com> | 2018-04-17 00:33:13 +0200 |
---|---|---|
committer | Mike Snitzer <snitzer@redhat.com> | 2018-07-27 15:24:19 -0400 |
commit | 3876ac76f02ac2a7b3d96f813c0ee1070e7a8c8e (patch) | |
tree | 6bc385ee1e0f3dcdfd2cee8e4374718a4337b716 /drivers | |
parent | af9313c32c0fa2a0ac3b113669273833d60cc9de (diff) | |
download | linux-stable-3876ac76f02ac2a7b3d96f813c0ee1070e7a8c8e.tar.gz linux-stable-3876ac76f02ac2a7b3d96f813c0ee1070e7a8c8e.tar.bz2 linux-stable-3876ac76f02ac2a7b3d96f813c0ee1070e7a8c8e.zip |
dm delay: refactor repetitive code
dm-delay has a lot of code that is repeated for delaying read and write
bios. Repetitive code is generally bad; refactor out the repetitive
code in preperation for adding another delay class for flush bios.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/md/dm-delay.c | 223 |
1 files changed, 103 insertions, 120 deletions
diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c index 1783d80c9cad..c5ebe56bc28b 100644 --- a/drivers/md/dm-delay.c +++ b/drivers/md/dm-delay.c @@ -17,6 +17,13 @@ #define DM_MSG_PREFIX "delay" +struct delay_class { + struct dm_dev *dev; + sector_t start; + unsigned delay; + unsigned ops; +}; + struct delay_c { struct timer_list delay_timer; struct mutex timer_lock; @@ -25,19 +32,15 @@ struct delay_c { struct list_head delayed_bios; atomic_t may_delay; - struct dm_dev *dev_read; - sector_t start_read; - unsigned read_delay; - unsigned reads; + struct delay_class read; + struct delay_class write; - struct dm_dev *dev_write; - sector_t start_write; - unsigned write_delay; - unsigned writes; + int argc; }; struct dm_delay_info { struct delay_c *context; + struct delay_class *class; struct list_head list; unsigned long expires; }; @@ -77,7 +80,7 @@ static struct bio *flush_delayed_bios(struct delay_c *dc, int flush_all) { struct dm_delay_info *delayed, *next; unsigned long next_expires = 0; - int start_timer = 0; + unsigned long start_timer = 0; struct bio_list flush_bios = { }; mutex_lock(&delayed_bios_lock); @@ -87,10 +90,7 @@ static struct bio *flush_delayed_bios(struct delay_c *dc, int flush_all) sizeof(struct dm_delay_info)); list_del(&delayed->list); bio_list_add(&flush_bios, bio); - if ((bio_data_dir(bio) == WRITE)) - delayed->context->writes--; - else - delayed->context->reads--; + delayed->class->ops--; continue; } @@ -100,7 +100,6 @@ static struct bio *flush_delayed_bios(struct delay_c *dc, int flush_all) } else next_expires = min(next_expires, delayed->expires); } - mutex_unlock(&delayed_bios_lock); if (start_timer) @@ -117,6 +116,48 @@ static void flush_expired_bios(struct work_struct *work) flush_bios(flush_delayed_bios(dc, 0)); } +static void delay_dtr(struct dm_target *ti) +{ + struct delay_c *dc = ti->private; + + destroy_workqueue(dc->kdelayd_wq); + + if (dc->read.dev) + dm_put_device(ti, dc->read.dev); + if (dc->write.dev) + dm_put_device(ti, dc->write.dev); + + mutex_destroy(&dc->timer_lock); + + kfree(dc); +} + +static int delay_class_ctr(struct dm_target *ti, struct delay_class *c, char **argv) +{ + int ret; + unsigned long long tmpll; + char dummy; + + if (sscanf(argv[1], "%llu%c", &tmpll, &dummy) != 1) { + ti->error = "Invalid device sector"; + return -EINVAL; + } + c->start = tmpll; + + if (sscanf(argv[2], "%u%c", &c->delay, &dummy) != 1) { + ti->error = "Invalid delay"; + return -EINVAL; + } + + ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &c->dev); + if (ret) { + ti->error = "Device lookup failed"; + return ret; + } + + return 0; +} + /* * Mapping parameters: * <device> <offset> <delay> [<write_device> <write_offset> <write_delay>] @@ -128,8 +169,6 @@ static void flush_expired_bios(struct work_struct *work) static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv) { struct delay_c *dc; - unsigned long long tmpll; - char dummy; int ret; if (argc != 3 && argc != 6) { @@ -137,125 +176,69 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv) return -EINVAL; } - dc = kmalloc(sizeof(*dc), GFP_KERNEL); + dc = kzalloc(sizeof(*dc), GFP_KERNEL); if (!dc) { ti->error = "Cannot allocate context"; return -ENOMEM; } - dc->reads = dc->writes = 0; - - ret = -EINVAL; - if (sscanf(argv[1], "%llu%c", &tmpll, &dummy) != 1) { - ti->error = "Invalid device sector"; - goto bad; - } - dc->start_read = tmpll; - - if (sscanf(argv[2], "%u%c", &dc->read_delay, &dummy) != 1) { - ti->error = "Invalid delay"; - goto bad; - } + ti->private = dc; + timer_setup(&dc->delay_timer, handle_delayed_timer, 0); + INIT_WORK(&dc->flush_expired_bios, flush_expired_bios); + INIT_LIST_HEAD(&dc->delayed_bios); + mutex_init(&dc->timer_lock); + atomic_set(&dc->may_delay, 1); + dc->argc = argc; - ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), - &dc->dev_read); - if (ret) { - ti->error = "Device lookup failed"; + ret = delay_class_ctr(ti, &dc->read, argv); + if (ret) goto bad; - } - ret = -EINVAL; - dc->dev_write = NULL; - if (argc == 3) + if (argc == 3) { + ret = delay_class_ctr(ti, &dc->write, argv); + if (ret) + goto bad; goto out; - - if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) { - ti->error = "Invalid write device sector"; - goto bad_dev_read; } - dc->start_write = tmpll; - if (sscanf(argv[5], "%u%c", &dc->write_delay, &dummy) != 1) { - ti->error = "Invalid write delay"; - goto bad_dev_read; - } - - ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), - &dc->dev_write); - if (ret) { - ti->error = "Write device lookup failed"; - goto bad_dev_read; - } + ret = delay_class_ctr(ti, &dc->write, argv + 3); + if (ret) + goto bad; out: - ret = -EINVAL; dc->kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0); if (!dc->kdelayd_wq) { + ret = -EINVAL; DMERR("Couldn't start kdelayd"); - goto bad_queue; + goto bad; } - timer_setup(&dc->delay_timer, handle_delayed_timer, 0); - - INIT_WORK(&dc->flush_expired_bios, flush_expired_bios); - INIT_LIST_HEAD(&dc->delayed_bios); - mutex_init(&dc->timer_lock); - atomic_set(&dc->may_delay, 1); - ti->num_flush_bios = 1; ti->num_discard_bios = 1; ti->per_io_data_size = sizeof(struct dm_delay_info); - ti->private = dc; return 0; -bad_queue: - if (dc->dev_write) - dm_put_device(ti, dc->dev_write); -bad_dev_read: - dm_put_device(ti, dc->dev_read); bad: - kfree(dc); + delay_dtr(ti); return ret; } -static void delay_dtr(struct dm_target *ti) -{ - struct delay_c *dc = ti->private; - - destroy_workqueue(dc->kdelayd_wq); - - dm_put_device(ti, dc->dev_read); - - if (dc->dev_write) - dm_put_device(ti, dc->dev_write); - - mutex_destroy(&dc->timer_lock); - - kfree(dc); -} - -static int delay_bio(struct delay_c *dc, int delay, struct bio *bio) +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 (!delay || !atomic_read(&dc->may_delay)) + if (!c->delay || !atomic_read(&dc->may_delay)) return DM_MAPIO_REMAPPED; delayed = dm_per_bio_data(bio, sizeof(struct dm_delay_info)); delayed->context = dc; - delayed->expires = expires = jiffies + msecs_to_jiffies(delay); + delayed->expires = expires = jiffies + msecs_to_jiffies(c->delay); mutex_lock(&delayed_bios_lock); - - if (bio_data_dir(bio) == WRITE) - dc->writes++; - else - dc->reads++; - + c->ops++; list_add_tail(&delayed->list, &dc->delayed_bios); - mutex_unlock(&delayed_bios_lock); queue_timeout(dc, expires); @@ -282,23 +265,25 @@ static void delay_resume(struct dm_target *ti) static int delay_map(struct dm_target *ti, struct bio *bio) { struct delay_c *dc = ti->private; + struct delay_class *c; + struct dm_delay_info *delayed = dm_per_bio_data(bio, sizeof(struct dm_delay_info)); - if ((bio_data_dir(bio) == WRITE) && (dc->dev_write)) { - bio_set_dev(bio, dc->dev_write->bdev); - if (bio_sectors(bio)) - bio->bi_iter.bi_sector = dc->start_write + - dm_target_offset(ti, bio->bi_iter.bi_sector); - - return delay_bio(dc, dc->write_delay, bio); + if (bio_data_dir(bio) == WRITE) { + c = &dc->write; + } else { + c = &dc->read; } + delayed->class = c; + bio_set_dev(bio, c->dev->bdev); + if (bio_sectors(bio)) + bio->bi_iter.bi_sector = c->start + dm_target_offset(ti, bio->bi_iter.bi_sector); - bio_set_dev(bio, dc->dev_read->bdev); - bio->bi_iter.bi_sector = dc->start_read + - dm_target_offset(ti, bio->bi_iter.bi_sector); - - return delay_bio(dc, dc->read_delay, bio); + return delay_bio(dc, c, bio); } +#define DMEMIT_DELAY_CLASS(c) \ + DMEMIT("%s %llu %u", (c)->dev->name, (unsigned long long)(c)->start, (c)->delay) + static void delay_status(struct dm_target *ti, status_type_t type, unsigned status_flags, char *result, unsigned maxlen) { @@ -307,17 +292,15 @@ static void delay_status(struct dm_target *ti, status_type_t type, switch (type) { case STATUSTYPE_INFO: - DMEMIT("%u %u", dc->reads, dc->writes); + DMEMIT("%u %u", dc->read.ops, dc->write.ops); break; case STATUSTYPE_TABLE: - DMEMIT("%s %llu %u", dc->dev_read->name, - (unsigned long long) dc->start_read, - dc->read_delay); - if (dc->dev_write) - DMEMIT(" %s %llu %u", dc->dev_write->name, - (unsigned long long) dc->start_write, - dc->write_delay); + DMEMIT_DELAY_CLASS(&dc->read); + if (dc->argc >= 6) { + DMEMIT(" "); + DMEMIT_DELAY_CLASS(&dc->write); + } break; } } @@ -328,12 +311,12 @@ static int delay_iterate_devices(struct dm_target *ti, struct delay_c *dc = ti->private; int ret = 0; - ret = fn(ti, dc->dev_read, dc->start_read, ti->len, data); + ret = fn(ti, dc->read.dev, dc->read.start, ti->len, data); + if (ret) + goto out; + ret = fn(ti, dc->write.dev, dc->write.start, ti->len, data); if (ret) goto out; - - if (dc->dev_write) - ret = fn(ti, dc->dev_write, dc->start_write, ti->len, data); out: return ret; |