diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/md/dm-delay.c')
| -rw-r--r-- | ANDROID_3.4.5/drivers/md/dm-delay.c | 397 |
1 files changed, 0 insertions, 397 deletions
diff --git a/ANDROID_3.4.5/drivers/md/dm-delay.c b/ANDROID_3.4.5/drivers/md/dm-delay.c deleted file mode 100644 index 2dc22ddd..00000000 --- a/ANDROID_3.4.5/drivers/md/dm-delay.c +++ /dev/null @@ -1,397 +0,0 @@ -/* - * Copyright (C) 2005-2007 Red Hat GmbH - * - * A target that delays reads and/or writes and can send - * them to different devices. - * - * This file is released under the GPL. - */ - -#include <linux/module.h> -#include <linux/init.h> -#include <linux/blkdev.h> -#include <linux/bio.h> -#include <linux/slab.h> - -#include <linux/device-mapper.h> - -#define DM_MSG_PREFIX "delay" - -struct delay_c { - struct timer_list delay_timer; - struct mutex timer_lock; - struct work_struct flush_expired_bios; - struct list_head delayed_bios; - atomic_t may_delay; - mempool_t *delayed_pool; - - struct dm_dev *dev_read; - sector_t start_read; - unsigned read_delay; - unsigned reads; - - struct dm_dev *dev_write; - sector_t start_write; - unsigned write_delay; - unsigned writes; -}; - -struct dm_delay_info { - struct delay_c *context; - struct list_head list; - struct bio *bio; - unsigned long expires; -}; - -static DEFINE_MUTEX(delayed_bios_lock); - -static struct workqueue_struct *kdelayd_wq; -static struct kmem_cache *delayed_cache; - -static void handle_delayed_timer(unsigned long data) -{ - struct delay_c *dc = (struct delay_c *)data; - - queue_work(kdelayd_wq, &dc->flush_expired_bios); -} - -static void queue_timeout(struct delay_c *dc, unsigned long expires) -{ - mutex_lock(&dc->timer_lock); - - if (!timer_pending(&dc->delay_timer) || expires < dc->delay_timer.expires) - mod_timer(&dc->delay_timer, expires); - - mutex_unlock(&dc->timer_lock); -} - -static void flush_bios(struct bio *bio) -{ - struct bio *n; - - while (bio) { - n = bio->bi_next; - bio->bi_next = NULL; - generic_make_request(bio); - bio = n; - } -} - -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; - struct bio_list flush_bios = { }; - - 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)) { - list_del(&delayed->list); - bio_list_add(&flush_bios, delayed->bio); - if ((bio_data_dir(delayed->bio) == WRITE)) - delayed->context->writes--; - else - delayed->context->reads--; - mempool_free(delayed, dc->delayed_pool); - continue; - } - - if (!start_timer) { - start_timer = 1; - 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); -} - -static void flush_expired_bios(struct work_struct *work) -{ - struct delay_c *dc; - - dc = container_of(work, struct delay_c, flush_expired_bios); - flush_bios(flush_delayed_bios(dc, 0)); -} - -/* - * Mapping parameters: - * <device> <offset> <delay> [<write_device> <write_offset> <write_delay>] - * - * With separate write parameters, the first set is only used for reads. - * Delays are specified in milliseconds. - */ -static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv) -{ - struct delay_c *dc; - unsigned long long tmpll; - char dummy; - - if (argc != 3 && argc != 6) { - ti->error = "requires exactly 3 or 6 arguments"; - return -EINVAL; - } - - dc = kmalloc(sizeof(*dc), GFP_KERNEL); - if (!dc) { - ti->error = "Cannot allocate context"; - return -ENOMEM; - } - - dc->reads = dc->writes = 0; - - 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; - } - - if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), - &dc->dev_read)) { - ti->error = "Device lookup failed"; - goto bad; - } - - dc->dev_write = NULL; - if (argc == 3) - 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; - } - - if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), - &dc->dev_write)) { - ti->error = "Write device lookup failed"; - goto bad_dev_read; - } - -out: - dc->delayed_pool = mempool_create_slab_pool(128, delayed_cache); - if (!dc->delayed_pool) { - DMERR("Couldn't create delayed bio pool."); - goto bad_dev_write; - } - - setup_timer(&dc->delay_timer, handle_delayed_timer, (unsigned long)dc); - - 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_requests = 1; - ti->num_discard_requests = 1; - ti->private = dc; - return 0; - -bad_dev_write: - if (dc->dev_write) - dm_put_device(ti, dc->dev_write); -bad_dev_read: - dm_put_device(ti, dc->dev_read); -bad: - kfree(dc); - return -EINVAL; -} - -static void delay_dtr(struct dm_target *ti) -{ - struct delay_c *dc = ti->private; - - flush_workqueue(kdelayd_wq); - - dm_put_device(ti, dc->dev_read); - - if (dc->dev_write) - dm_put_device(ti, dc->dev_write); - - mempool_destroy(dc->delayed_pool); - kfree(dc); -} - -static int delay_bio(struct delay_c *dc, int delay, struct bio *bio) -{ - struct dm_delay_info *delayed; - unsigned long expires = 0; - - if (!delay || !atomic_read(&dc->may_delay)) - return 1; - - delayed = mempool_alloc(dc->delayed_pool, GFP_NOIO); - - delayed->context = dc; - delayed->bio = bio; - delayed->expires = expires = jiffies + (delay * HZ / 1000); - - mutex_lock(&delayed_bios_lock); - - if (bio_data_dir(bio) == WRITE) - dc->writes++; - else - dc->reads++; - - list_add_tail(&delayed->list, &dc->delayed_bios); - - mutex_unlock(&delayed_bios_lock); - - queue_timeout(dc, expires); - - return 0; -} - -static void delay_presuspend(struct dm_target *ti) -{ - struct delay_c *dc = ti->private; - - atomic_set(&dc->may_delay, 0); - del_timer_sync(&dc->delay_timer); - flush_bios(flush_delayed_bios(dc, 1)); -} - -static void delay_resume(struct dm_target *ti) -{ - struct delay_c *dc = ti->private; - - atomic_set(&dc->may_delay, 1); -} - -static int delay_map(struct dm_target *ti, struct bio *bio, - union map_info *map_context) -{ - struct delay_c *dc = ti->private; - - if ((bio_data_dir(bio) == WRITE) && (dc->dev_write)) { - bio->bi_bdev = dc->dev_write->bdev; - if (bio_sectors(bio)) - bio->bi_sector = dc->start_write + - dm_target_offset(ti, bio->bi_sector); - - return delay_bio(dc, dc->write_delay, bio); - } - - bio->bi_bdev = dc->dev_read->bdev; - bio->bi_sector = dc->start_read + dm_target_offset(ti, bio->bi_sector); - - return delay_bio(dc, dc->read_delay, bio); -} - -static int delay_status(struct dm_target *ti, status_type_t type, - char *result, unsigned maxlen) -{ - struct delay_c *dc = ti->private; - int sz = 0; - - switch (type) { - case STATUSTYPE_INFO: - DMEMIT("%u %u", dc->reads, dc->writes); - 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); - break; - } - - return 0; -} - -static int delay_iterate_devices(struct dm_target *ti, - iterate_devices_callout_fn fn, void *data) -{ - struct delay_c *dc = ti->private; - int ret = 0; - - ret = fn(ti, dc->dev_read, dc->start_read, 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; -} - -static struct target_type delay_target = { - .name = "delay", - .version = {1, 1, 0}, - .module = THIS_MODULE, - .ctr = delay_ctr, - .dtr = delay_dtr, - .map = delay_map, - .presuspend = delay_presuspend, - .resume = delay_resume, - .status = delay_status, - .iterate_devices = delay_iterate_devices, -}; - -static int __init dm_delay_init(void) -{ - int r = -ENOMEM; - - kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0); - if (!kdelayd_wq) { - DMERR("Couldn't start kdelayd"); - goto bad_queue; - } - - delayed_cache = KMEM_CACHE(dm_delay_info, 0); - if (!delayed_cache) { - DMERR("Couldn't create delayed bio cache."); - goto bad_memcache; - } - - r = dm_register_target(&delay_target); - if (r < 0) { - DMERR("register failed %d", r); - goto bad_register; - } - - return 0; - -bad_register: - kmem_cache_destroy(delayed_cache); -bad_memcache: - destroy_workqueue(kdelayd_wq); -bad_queue: - return r; -} - -static void __exit dm_delay_exit(void) -{ - dm_unregister_target(&delay_target); - kmem_cache_destroy(delayed_cache); - destroy_workqueue(kdelayd_wq); -} - -/* Module hooks */ -module_init(dm_delay_init); -module_exit(dm_delay_exit); - -MODULE_DESCRIPTION(DM_NAME " delay target"); -MODULE_AUTHOR("Heinz Mauelshagen <mauelshagen@redhat.com>"); -MODULE_LICENSE("GPL"); |