From 066dbaa386c751164c39ab025e5e8803b4a4d691 Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Fri, 15 May 2015 15:18:01 +0100 Subject: [PATCH] dm cache: track IO to the origin device using io_tracker Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer --- drivers/md/dm-cache-target.c | 56 +++++++++++++++++++++++++++++++----- 1 file changed, 49 insertions(+), 7 deletions(-) diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 6f9bdd1bf7c4..940c7b2b5ab4 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -355,6 +355,8 @@ struct cache { */ spinlock_t invalidation_lock; struct list_head invalidation_requests; + + struct io_tracker origin_tracker; }; struct per_bio_data { @@ -362,6 +364,7 @@ struct per_bio_data { unsigned req_nr:2; struct dm_deferred_entry *all_io_entry; struct dm_hook_info hook_info; + sector_t len; /* * writethrough fields. These MUST remain at the end of this @@ -768,6 +771,7 @@ static struct per_bio_data *init_per_bio_data(struct bio *bio, size_t data_size) pb->tick = false; pb->req_nr = dm_bio_get_target_bio_nr(bio); pb->all_io_entry = NULL; + pb->len = 0; return pb; } @@ -865,12 +869,43 @@ static void inc_ds(struct cache *cache, struct bio *bio, pb->all_io_entry = dm_deferred_entry_inc(cache->all_io_ds); } +static bool accountable_bio(struct cache *cache, struct bio *bio) +{ + return ((bio->bi_bdev == cache->origin_dev->bdev) && + !(bio->bi_rw & REQ_DISCARD)); +} + +static void accounted_begin(struct cache *cache, struct bio *bio) +{ + size_t pb_data_size = get_per_bio_data_size(cache); + struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); + + if (accountable_bio(cache, bio)) { + pb->len = bio_sectors(bio); + iot_io_begin(&cache->origin_tracker, pb->len); + } +} + +static void accounted_complete(struct cache *cache, struct bio *bio) +{ + size_t pb_data_size = get_per_bio_data_size(cache); + struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); + + iot_io_end(&cache->origin_tracker, pb->len); +} + +static void accounted_request(struct cache *cache, struct bio *bio) +{ + accounted_begin(cache, bio); + generic_make_request(bio); +} + static void issue(struct cache *cache, struct bio *bio) { unsigned long flags; if (!bio_triggers_commit(cache, bio)) { - generic_make_request(bio); + accounted_request(cache, bio); return; } @@ -1166,7 +1201,7 @@ static void issue_overwrite(struct dm_cache_migration *mg, struct bio *bio) * No need to inc_ds() here, since the cell will be held for the * duration of the io. */ - generic_make_request(bio); + accounted_request(mg->cache, bio); } static bool bio_writes_complete_block(struct cache *cache, struct bio *bio) @@ -1722,7 +1757,7 @@ static void process_deferred_flush_bios(struct cache *cache, bool submit_bios) * These bios have already been through inc_ds() */ while ((bio = bio_list_pop(&bios))) - submit_bios ? generic_make_request(bio) : bio_io_error(bio); + submit_bios ? accounted_request(cache, bio) : bio_io_error(bio); } static void process_deferred_writethrough_bios(struct cache *cache) @@ -1742,7 +1777,7 @@ static void process_deferred_writethrough_bios(struct cache *cache) * These bios have already been through inc_ds() */ while ((bio = bio_list_pop(&bios))) - generic_make_request(bio); + accounted_request(cache, bio); } static void writeback_some_dirty_blocks(struct cache *cache) @@ -2602,6 +2637,8 @@ static int cache_create(struct cache_args *ca, struct cache **result) spin_lock_init(&cache->invalidation_lock); INIT_LIST_HEAD(&cache->invalidation_requests); + iot_init(&cache->origin_tracker); + *result = cache; return 0; @@ -2791,9 +2828,13 @@ static int cache_map(struct dm_target *ti, struct bio *bio) struct cache *cache = ti->private; r = __cache_map(cache, bio, &cell); - if (r == DM_MAPIO_REMAPPED && cell) { - inc_ds(cache, bio, cell); - cell_defer(cache, cell, false); + if (r == DM_MAPIO_REMAPPED) { + accounted_begin(cache, bio); + + if (cell) { + inc_ds(cache, bio, cell); + cell_defer(cache, cell, false); + } } return r; @@ -2815,6 +2856,7 @@ static int cache_end_io(struct dm_target *ti, struct bio *bio, int error) } check_for_quiesced_migrations(cache, pb); + accounted_complete(cache, bio); return 0; }