diff options
| -rw-r--r-- | drivers/md/dm-cache-target.c | 86 |
1 files changed, 53 insertions, 33 deletions
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 8785134c9f1f..0b7edfd0b454 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -1201,6 +1201,18 @@ static void background_work_end(struct cache *cache) /*----------------------------------------------------------------*/ +static bool bio_writes_complete_block(struct cache *cache, struct bio *bio) +{ + return (bio_data_dir(bio) == WRITE) && + (bio->bi_iter.bi_size == (cache->sectors_per_block << SECTOR_SHIFT)); +} + +static bool optimisable_bio(struct cache *cache, struct bio *bio, dm_oblock_t block) +{ + return writeback_mode(&cache->features) && + (is_discarded_oblock(cache, block) || bio_writes_complete_block(cache, bio)); +} + static void quiesce(struct dm_cache_migration *mg, void (*continuation)(struct work_struct *)) { @@ -1474,13 +1486,51 @@ static void mg_upgrade_lock(struct work_struct *ws) } } +static void mg_full_copy(struct work_struct *ws) +{ + struct dm_cache_migration *mg = ws_to_mg(ws); + struct cache *cache = mg->cache; + struct policy_work *op = mg->op; + bool is_policy_promote = (op->op == POLICY_PROMOTE); + + if ((!is_policy_promote && !is_dirty(cache, op->cblock)) || + is_discarded_oblock(cache, op->oblock)) { + mg_upgrade_lock(ws); + return; + } + + init_continuation(&mg->k, mg_upgrade_lock); + + if (copy(mg, is_policy_promote)) { + DMERR_LIMIT("%s: migration copy failed", cache_device_name(cache)); + mg->k.input = BLK_STS_IOERR; + mg_complete(mg, false); + } +} + static void mg_copy(struct work_struct *ws) { - int r; struct dm_cache_migration *mg = ws_to_mg(ws); if (mg->overwrite_bio) { /* + * No exclusive lock was held when we last checked if the bio + * was optimisable. So we have to check again in case things + * have changed (eg, the block may no longer be discarded). + */ + if (!optimisable_bio(mg->cache, mg->overwrite_bio, mg->op->oblock)) { + /* + * Fallback to a real full copy after doing some tidying up. + */ + bool rb = bio_detain_shared(mg->cache, mg->op->oblock, mg->overwrite_bio); + BUG_ON(rb); /* An exclussive lock must _not_ be held for this block */ + mg->overwrite_bio = NULL; + inc_io_migrations(mg->cache); + mg_full_copy(ws); + return; + } + + /* * It's safe to do this here, even though it's new data * because all IO has been locked out of the block. * @@ -1489,26 +1539,8 @@ static void mg_copy(struct work_struct *ws) */ overwrite(mg, mg_update_metadata_after_copy); - } else { - struct cache *cache = mg->cache; - struct policy_work *op = mg->op; - bool is_policy_promote = (op->op == POLICY_PROMOTE); - - if ((!is_policy_promote && !is_dirty(cache, op->cblock)) || - is_discarded_oblock(cache, op->oblock)) { - mg_upgrade_lock(ws); - return; - } - - init_continuation(&mg->k, mg_upgrade_lock); - - r = copy(mg, is_policy_promote); - if (r) { - DMERR_LIMIT("%s: migration copy failed", cache_device_name(cache)); - mg->k.input = BLK_STS_IOERR; - mg_complete(mg, false); - } - } + } else + mg_full_copy(ws); } static int mg_lock_writes(struct dm_cache_migration *mg) @@ -1748,18 +1780,6 @@ static void inc_miss_counter(struct cache *cache, struct bio *bio) /*----------------------------------------------------------------*/ -static bool bio_writes_complete_block(struct cache *cache, struct bio *bio) -{ - return (bio_data_dir(bio) == WRITE) && - (bio->bi_iter.bi_size == (cache->sectors_per_block << SECTOR_SHIFT)); -} - -static bool optimisable_bio(struct cache *cache, struct bio *bio, dm_oblock_t block) -{ - return writeback_mode(&cache->features) && - (is_discarded_oblock(cache, block) || bio_writes_complete_block(cache, bio)); -} - static int map_bio(struct cache *cache, struct bio *bio, dm_oblock_t block, bool *commit_needed) { |