diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/md/dm-region-hash.c')
| -rw-r--r-- | ANDROID_3.4.5/drivers/md/dm-region-hash.c | 720 |
1 files changed, 0 insertions, 720 deletions
diff --git a/ANDROID_3.4.5/drivers/md/dm-region-hash.c b/ANDROID_3.4.5/drivers/md/dm-region-hash.c deleted file mode 100644 index 7771ed21..00000000 --- a/ANDROID_3.4.5/drivers/md/dm-region-hash.c +++ /dev/null @@ -1,720 +0,0 @@ -/* - * Copyright (C) 2003 Sistina Software Limited. - * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. - * - * This file is released under the GPL. - */ - -#include <linux/dm-dirty-log.h> -#include <linux/dm-region-hash.h> - -#include <linux/ctype.h> -#include <linux/init.h> -#include <linux/module.h> -#include <linux/slab.h> -#include <linux/vmalloc.h> - -#include "dm.h" - -#define DM_MSG_PREFIX "region hash" - -/*----------------------------------------------------------------- - * Region hash - * - * The mirror splits itself up into discrete regions. Each - * region can be in one of three states: clean, dirty, - * nosync. There is no need to put clean regions in the hash. - * - * In addition to being present in the hash table a region _may_ - * be present on one of three lists. - * - * clean_regions: Regions on this list have no io pending to - * them, they are in sync, we are no longer interested in them, - * they are dull. dm_rh_update_states() will remove them from the - * hash table. - * - * quiesced_regions: These regions have been spun down, ready - * for recovery. rh_recovery_start() will remove regions from - * this list and hand them to kmirrord, which will schedule the - * recovery io with kcopyd. - * - * recovered_regions: Regions that kcopyd has successfully - * recovered. dm_rh_update_states() will now schedule any delayed - * io, up the recovery_count, and remove the region from the - * hash. - * - * There are 2 locks: - * A rw spin lock 'hash_lock' protects just the hash table, - * this is never held in write mode from interrupt context, - * which I believe means that we only have to disable irqs when - * doing a write lock. - * - * An ordinary spin lock 'region_lock' that protects the three - * lists in the region_hash, with the 'state', 'list' and - * 'delayed_bios' fields of the regions. This is used from irq - * context, so all other uses will have to suspend local irqs. - *---------------------------------------------------------------*/ -struct dm_region_hash { - uint32_t region_size; - unsigned region_shift; - - /* holds persistent region state */ - struct dm_dirty_log *log; - - /* hash table */ - rwlock_t hash_lock; - mempool_t *region_pool; - unsigned mask; - unsigned nr_buckets; - unsigned prime; - unsigned shift; - struct list_head *buckets; - - unsigned max_recovery; /* Max # of regions to recover in parallel */ - - spinlock_t region_lock; - atomic_t recovery_in_flight; - struct semaphore recovery_count; - struct list_head clean_regions; - struct list_head quiesced_regions; - struct list_head recovered_regions; - struct list_head failed_recovered_regions; - - /* - * If there was a flush failure no regions can be marked clean. - */ - int flush_failure; - - void *context; - sector_t target_begin; - - /* Callback function to schedule bios writes */ - void (*dispatch_bios)(void *context, struct bio_list *bios); - - /* Callback function to wakeup callers worker thread. */ - void (*wakeup_workers)(void *context); - - /* Callback function to wakeup callers recovery waiters. */ - void (*wakeup_all_recovery_waiters)(void *context); -}; - -struct dm_region { - struct dm_region_hash *rh; /* FIXME: can we get rid of this ? */ - region_t key; - int state; - - struct list_head hash_list; - struct list_head list; - - atomic_t pending; - struct bio_list delayed_bios; -}; - -/* - * Conversion fns - */ -static region_t dm_rh_sector_to_region(struct dm_region_hash *rh, sector_t sector) -{ - return sector >> rh->region_shift; -} - -sector_t dm_rh_region_to_sector(struct dm_region_hash *rh, region_t region) -{ - return region << rh->region_shift; -} -EXPORT_SYMBOL_GPL(dm_rh_region_to_sector); - -region_t dm_rh_bio_to_region(struct dm_region_hash *rh, struct bio *bio) -{ - return dm_rh_sector_to_region(rh, bio->bi_sector - rh->target_begin); -} -EXPORT_SYMBOL_GPL(dm_rh_bio_to_region); - -void *dm_rh_region_context(struct dm_region *reg) -{ - return reg->rh->context; -} -EXPORT_SYMBOL_GPL(dm_rh_region_context); - -region_t dm_rh_get_region_key(struct dm_region *reg) -{ - return reg->key; -} -EXPORT_SYMBOL_GPL(dm_rh_get_region_key); - -sector_t dm_rh_get_region_size(struct dm_region_hash *rh) -{ - return rh->region_size; -} -EXPORT_SYMBOL_GPL(dm_rh_get_region_size); - -/* - * FIXME: shall we pass in a structure instead of all these args to - * dm_region_hash_create()???? - */ -#define RH_HASH_MULT 2654435387U -#define RH_HASH_SHIFT 12 - -#define MIN_REGIONS 64 -struct dm_region_hash *dm_region_hash_create( - void *context, void (*dispatch_bios)(void *context, - struct bio_list *bios), - void (*wakeup_workers)(void *context), - void (*wakeup_all_recovery_waiters)(void *context), - sector_t target_begin, unsigned max_recovery, - struct dm_dirty_log *log, uint32_t region_size, - region_t nr_regions) -{ - struct dm_region_hash *rh; - unsigned nr_buckets, max_buckets; - size_t i; - - /* - * Calculate a suitable number of buckets for our hash - * table. - */ - max_buckets = nr_regions >> 6; - for (nr_buckets = 128u; nr_buckets < max_buckets; nr_buckets <<= 1) - ; - nr_buckets >>= 1; - - rh = kmalloc(sizeof(*rh), GFP_KERNEL); - if (!rh) { - DMERR("unable to allocate region hash memory"); - return ERR_PTR(-ENOMEM); - } - - rh->context = context; - rh->dispatch_bios = dispatch_bios; - rh->wakeup_workers = wakeup_workers; - rh->wakeup_all_recovery_waiters = wakeup_all_recovery_waiters; - rh->target_begin = target_begin; - rh->max_recovery = max_recovery; - rh->log = log; - rh->region_size = region_size; - rh->region_shift = ffs(region_size) - 1; - rwlock_init(&rh->hash_lock); - rh->mask = nr_buckets - 1; - rh->nr_buckets = nr_buckets; - - rh->shift = RH_HASH_SHIFT; - rh->prime = RH_HASH_MULT; - - rh->buckets = vmalloc(nr_buckets * sizeof(*rh->buckets)); - if (!rh->buckets) { - DMERR("unable to allocate region hash bucket memory"); - kfree(rh); - return ERR_PTR(-ENOMEM); - } - - for (i = 0; i < nr_buckets; i++) - INIT_LIST_HEAD(rh->buckets + i); - - spin_lock_init(&rh->region_lock); - sema_init(&rh->recovery_count, 0); - atomic_set(&rh->recovery_in_flight, 0); - INIT_LIST_HEAD(&rh->clean_regions); - INIT_LIST_HEAD(&rh->quiesced_regions); - INIT_LIST_HEAD(&rh->recovered_regions); - INIT_LIST_HEAD(&rh->failed_recovered_regions); - rh->flush_failure = 0; - - rh->region_pool = mempool_create_kmalloc_pool(MIN_REGIONS, - sizeof(struct dm_region)); - if (!rh->region_pool) { - vfree(rh->buckets); - kfree(rh); - rh = ERR_PTR(-ENOMEM); - } - - return rh; -} -EXPORT_SYMBOL_GPL(dm_region_hash_create); - -void dm_region_hash_destroy(struct dm_region_hash *rh) -{ - unsigned h; - struct dm_region *reg, *nreg; - - BUG_ON(!list_empty(&rh->quiesced_regions)); - for (h = 0; h < rh->nr_buckets; h++) { - list_for_each_entry_safe(reg, nreg, rh->buckets + h, - hash_list) { - BUG_ON(atomic_read(®->pending)); - mempool_free(reg, rh->region_pool); - } - } - - if (rh->log) - dm_dirty_log_destroy(rh->log); - - if (rh->region_pool) - mempool_destroy(rh->region_pool); - - vfree(rh->buckets); - kfree(rh); -} -EXPORT_SYMBOL_GPL(dm_region_hash_destroy); - -struct dm_dirty_log *dm_rh_dirty_log(struct dm_region_hash *rh) -{ - return rh->log; -} -EXPORT_SYMBOL_GPL(dm_rh_dirty_log); - -static unsigned rh_hash(struct dm_region_hash *rh, region_t region) -{ - return (unsigned) ((region * rh->prime) >> rh->shift) & rh->mask; -} - -static struct dm_region *__rh_lookup(struct dm_region_hash *rh, region_t region) -{ - struct dm_region *reg; - struct list_head *bucket = rh->buckets + rh_hash(rh, region); - - list_for_each_entry(reg, bucket, hash_list) - if (reg->key == region) - return reg; - - return NULL; -} - -static void __rh_insert(struct dm_region_hash *rh, struct dm_region *reg) -{ - list_add(®->hash_list, rh->buckets + rh_hash(rh, reg->key)); -} - -static struct dm_region *__rh_alloc(struct dm_region_hash *rh, region_t region) -{ - struct dm_region *reg, *nreg; - - nreg = mempool_alloc(rh->region_pool, GFP_ATOMIC); - if (unlikely(!nreg)) - nreg = kmalloc(sizeof(*nreg), GFP_NOIO | __GFP_NOFAIL); - - nreg->state = rh->log->type->in_sync(rh->log, region, 1) ? - DM_RH_CLEAN : DM_RH_NOSYNC; - nreg->rh = rh; - nreg->key = region; - INIT_LIST_HEAD(&nreg->list); - atomic_set(&nreg->pending, 0); - bio_list_init(&nreg->delayed_bios); - - write_lock_irq(&rh->hash_lock); - reg = __rh_lookup(rh, region); - if (reg) - /* We lost the race. */ - mempool_free(nreg, rh->region_pool); - else { - __rh_insert(rh, nreg); - if (nreg->state == DM_RH_CLEAN) { - spin_lock(&rh->region_lock); - list_add(&nreg->list, &rh->clean_regions); - spin_unlock(&rh->region_lock); - } - - reg = nreg; - } - write_unlock_irq(&rh->hash_lock); - - return reg; -} - -static struct dm_region *__rh_find(struct dm_region_hash *rh, region_t region) -{ - struct dm_region *reg; - - reg = __rh_lookup(rh, region); - if (!reg) { - read_unlock(&rh->hash_lock); - reg = __rh_alloc(rh, region); - read_lock(&rh->hash_lock); - } - - return reg; -} - -int dm_rh_get_state(struct dm_region_hash *rh, region_t region, int may_block) -{ - int r; - struct dm_region *reg; - - read_lock(&rh->hash_lock); - reg = __rh_lookup(rh, region); - read_unlock(&rh->hash_lock); - - if (reg) - return reg->state; - - /* - * The region wasn't in the hash, so we fall back to the - * dirty log. - */ - r = rh->log->type->in_sync(rh->log, region, may_block); - - /* - * Any error from the dirty log (eg. -EWOULDBLOCK) gets - * taken as a DM_RH_NOSYNC - */ - return r == 1 ? DM_RH_CLEAN : DM_RH_NOSYNC; -} -EXPORT_SYMBOL_GPL(dm_rh_get_state); - -static void complete_resync_work(struct dm_region *reg, int success) -{ - struct dm_region_hash *rh = reg->rh; - - rh->log->type->set_region_sync(rh->log, reg->key, success); - - /* - * Dispatch the bios before we call 'wake_up_all'. - * This is important because if we are suspending, - * we want to know that recovery is complete and - * the work queue is flushed. If we wake_up_all - * before we dispatch_bios (queue bios and call wake()), - * then we risk suspending before the work queue - * has been properly flushed. - */ - rh->dispatch_bios(rh->context, ®->delayed_bios); - if (atomic_dec_and_test(&rh->recovery_in_flight)) - rh->wakeup_all_recovery_waiters(rh->context); - up(&rh->recovery_count); -} - -/* dm_rh_mark_nosync - * @ms - * @bio - * - * The bio was written on some mirror(s) but failed on other mirror(s). - * We can successfully endio the bio but should avoid the region being - * marked clean by setting the state DM_RH_NOSYNC. - * - * This function is _not_ safe in interrupt context! - */ -void dm_rh_mark_nosync(struct dm_region_hash *rh, struct bio *bio) -{ - unsigned long flags; - struct dm_dirty_log *log = rh->log; - struct dm_region *reg; - region_t region = dm_rh_bio_to_region(rh, bio); - int recovering = 0; - - if (bio->bi_rw & REQ_FLUSH) { - rh->flush_failure = 1; - return; - } - - /* We must inform the log that the sync count has changed. */ - log->type->set_region_sync(log, region, 0); - - read_lock(&rh->hash_lock); - reg = __rh_find(rh, region); - read_unlock(&rh->hash_lock); - - /* region hash entry should exist because write was in-flight */ - BUG_ON(!reg); - BUG_ON(!list_empty(®->list)); - - spin_lock_irqsave(&rh->region_lock, flags); - /* - * Possible cases: - * 1) DM_RH_DIRTY - * 2) DM_RH_NOSYNC: was dirty, other preceding writes failed - * 3) DM_RH_RECOVERING: flushing pending writes - * Either case, the region should have not been connected to list. - */ - recovering = (reg->state == DM_RH_RECOVERING); - reg->state = DM_RH_NOSYNC; - BUG_ON(!list_empty(®->list)); - spin_unlock_irqrestore(&rh->region_lock, flags); - - if (recovering) - complete_resync_work(reg, 0); -} -EXPORT_SYMBOL_GPL(dm_rh_mark_nosync); - -void dm_rh_update_states(struct dm_region_hash *rh, int errors_handled) -{ - struct dm_region *reg, *next; - - LIST_HEAD(clean); - LIST_HEAD(recovered); - LIST_HEAD(failed_recovered); - - /* - * Quickly grab the lists. - */ - write_lock_irq(&rh->hash_lock); - spin_lock(&rh->region_lock); - if (!list_empty(&rh->clean_regions)) { - list_splice_init(&rh->clean_regions, &clean); - - list_for_each_entry(reg, &clean, list) - list_del(®->hash_list); - } - - if (!list_empty(&rh->recovered_regions)) { - list_splice_init(&rh->recovered_regions, &recovered); - - list_for_each_entry(reg, &recovered, list) - list_del(®->hash_list); - } - - if (!list_empty(&rh->failed_recovered_regions)) { - list_splice_init(&rh->failed_recovered_regions, - &failed_recovered); - - list_for_each_entry(reg, &failed_recovered, list) - list_del(®->hash_list); - } - - spin_unlock(&rh->region_lock); - write_unlock_irq(&rh->hash_lock); - - /* - * All the regions on the recovered and clean lists have - * now been pulled out of the system, so no need to do - * any more locking. - */ - list_for_each_entry_safe(reg, next, &recovered, list) { - rh->log->type->clear_region(rh->log, reg->key); - complete_resync_work(reg, 1); - mempool_free(reg, rh->region_pool); - } - - list_for_each_entry_safe(reg, next, &failed_recovered, list) { - complete_resync_work(reg, errors_handled ? 0 : 1); - mempool_free(reg, rh->region_pool); - } - - list_for_each_entry_safe(reg, next, &clean, list) { - rh->log->type->clear_region(rh->log, reg->key); - mempool_free(reg, rh->region_pool); - } - - rh->log->type->flush(rh->log); -} -EXPORT_SYMBOL_GPL(dm_rh_update_states); - -static void rh_inc(struct dm_region_hash *rh, region_t region) -{ - struct dm_region *reg; - - read_lock(&rh->hash_lock); - reg = __rh_find(rh, region); - - spin_lock_irq(&rh->region_lock); - atomic_inc(®->pending); - - if (reg->state == DM_RH_CLEAN) { - reg->state = DM_RH_DIRTY; - list_del_init(®->list); /* take off the clean list */ - spin_unlock_irq(&rh->region_lock); - - rh->log->type->mark_region(rh->log, reg->key); - } else - spin_unlock_irq(&rh->region_lock); - - - read_unlock(&rh->hash_lock); -} - -void dm_rh_inc_pending(struct dm_region_hash *rh, struct bio_list *bios) -{ - struct bio *bio; - - for (bio = bios->head; bio; bio = bio->bi_next) { - if (bio->bi_rw & REQ_FLUSH) - continue; - rh_inc(rh, dm_rh_bio_to_region(rh, bio)); - } -} -EXPORT_SYMBOL_GPL(dm_rh_inc_pending); - -void dm_rh_dec(struct dm_region_hash *rh, region_t region) -{ - unsigned long flags; - struct dm_region *reg; - int should_wake = 0; - - read_lock(&rh->hash_lock); - reg = __rh_lookup(rh, region); - read_unlock(&rh->hash_lock); - - spin_lock_irqsave(&rh->region_lock, flags); - if (atomic_dec_and_test(®->pending)) { - /* - * There is no pending I/O for this region. - * We can move the region to corresponding list for next action. - * At this point, the region is not yet connected to any list. - * - * If the state is DM_RH_NOSYNC, the region should be kept off - * from clean list. - * The hash entry for DM_RH_NOSYNC will remain in memory - * until the region is recovered or the map is reloaded. - */ - - /* do nothing for DM_RH_NOSYNC */ - if (unlikely(rh->flush_failure)) { - /* - * If a write flush failed some time ago, we - * don't know whether or not this write made it - * to the disk, so we must resync the device. - */ - reg->state = DM_RH_NOSYNC; - } else if (reg->state == DM_RH_RECOVERING) { - list_add_tail(®->list, &rh->quiesced_regions); - } else if (reg->state == DM_RH_DIRTY) { - reg->state = DM_RH_CLEAN; - list_add(®->list, &rh->clean_regions); - } - should_wake = 1; - } - spin_unlock_irqrestore(&rh->region_lock, flags); - - if (should_wake) - rh->wakeup_workers(rh->context); -} -EXPORT_SYMBOL_GPL(dm_rh_dec); - -/* - * Starts quiescing a region in preparation for recovery. - */ -static int __rh_recovery_prepare(struct dm_region_hash *rh) -{ - int r; - region_t region; - struct dm_region *reg; - - /* - * Ask the dirty log what's next. - */ - r = rh->log->type->get_resync_work(rh->log, ®ion); - if (r <= 0) - return r; - - /* - * Get this region, and start it quiescing by setting the - * recovering flag. - */ - read_lock(&rh->hash_lock); - reg = __rh_find(rh, region); - read_unlock(&rh->hash_lock); - - spin_lock_irq(&rh->region_lock); - reg->state = DM_RH_RECOVERING; - - /* Already quiesced ? */ - if (atomic_read(®->pending)) - list_del_init(®->list); - else - list_move(®->list, &rh->quiesced_regions); - - spin_unlock_irq(&rh->region_lock); - - return 1; -} - -void dm_rh_recovery_prepare(struct dm_region_hash *rh) -{ - /* Extra reference to avoid race with dm_rh_stop_recovery */ - atomic_inc(&rh->recovery_in_flight); - - while (!down_trylock(&rh->recovery_count)) { - atomic_inc(&rh->recovery_in_flight); - if (__rh_recovery_prepare(rh) <= 0) { - atomic_dec(&rh->recovery_in_flight); - up(&rh->recovery_count); - break; - } - } - - /* Drop the extra reference */ - if (atomic_dec_and_test(&rh->recovery_in_flight)) - rh->wakeup_all_recovery_waiters(rh->context); -} -EXPORT_SYMBOL_GPL(dm_rh_recovery_prepare); - -/* - * Returns any quiesced regions. - */ -struct dm_region *dm_rh_recovery_start(struct dm_region_hash *rh) -{ - struct dm_region *reg = NULL; - - spin_lock_irq(&rh->region_lock); - if (!list_empty(&rh->quiesced_regions)) { - reg = list_entry(rh->quiesced_regions.next, - struct dm_region, list); - list_del_init(®->list); /* remove from the quiesced list */ - } - spin_unlock_irq(&rh->region_lock); - - return reg; -} -EXPORT_SYMBOL_GPL(dm_rh_recovery_start); - -void dm_rh_recovery_end(struct dm_region *reg, int success) -{ - struct dm_region_hash *rh = reg->rh; - - spin_lock_irq(&rh->region_lock); - if (success) - list_add(®->list, ®->rh->recovered_regions); - else - list_add(®->list, ®->rh->failed_recovered_regions); - - spin_unlock_irq(&rh->region_lock); - - rh->wakeup_workers(rh->context); -} -EXPORT_SYMBOL_GPL(dm_rh_recovery_end); - -/* Return recovery in flight count. */ -int dm_rh_recovery_in_flight(struct dm_region_hash *rh) -{ - return atomic_read(&rh->recovery_in_flight); -} -EXPORT_SYMBOL_GPL(dm_rh_recovery_in_flight); - -int dm_rh_flush(struct dm_region_hash *rh) -{ - return rh->log->type->flush(rh->log); -} -EXPORT_SYMBOL_GPL(dm_rh_flush); - -void dm_rh_delay(struct dm_region_hash *rh, struct bio *bio) -{ - struct dm_region *reg; - - read_lock(&rh->hash_lock); - reg = __rh_find(rh, dm_rh_bio_to_region(rh, bio)); - bio_list_add(®->delayed_bios, bio); - read_unlock(&rh->hash_lock); -} -EXPORT_SYMBOL_GPL(dm_rh_delay); - -void dm_rh_stop_recovery(struct dm_region_hash *rh) -{ - int i; - - /* wait for any recovering regions */ - for (i = 0; i < rh->max_recovery; i++) - down(&rh->recovery_count); -} -EXPORT_SYMBOL_GPL(dm_rh_stop_recovery); - -void dm_rh_start_recovery(struct dm_region_hash *rh) -{ - int i; - - for (i = 0; i < rh->max_recovery; i++) - up(&rh->recovery_count); - - rh->wakeup_workers(rh->context); -} -EXPORT_SYMBOL_GPL(dm_rh_start_recovery); - -MODULE_DESCRIPTION(DM_NAME " region hash"); -MODULE_AUTHOR("Joe Thornber/Heinz Mauelshagen <dm-devel@redhat.com>"); -MODULE_LICENSE("GPL"); |