diff options
Diffstat (limited to 'drivers/md')
-rw-r--r-- | drivers/md/dm-cache-target.c | 6 | ||||
-rw-r--r-- | drivers/md/dm-stats.c | 1 | ||||
-rw-r--r-- | drivers/md/dm.c | 55 | ||||
-rw-r--r-- | drivers/md/linear.c | 39 | ||||
-rw-r--r-- | drivers/md/linear.h | 1 |
5 files changed, 94 insertions, 8 deletions
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 515f83e7d9ab..b59615ddf6ba 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -251,7 +251,7 @@ struct cache { /* * Fields for converting from sectors to blocks. */ - uint32_t sectors_per_block; + sector_t sectors_per_block; int sectors_per_block_shift; spinlock_t lock; @@ -3547,11 +3547,11 @@ static void cache_status(struct dm_target *ti, status_type_t type, residency = policy_residency(cache->policy); - DMEMIT("%u %llu/%llu %u %llu/%llu %u %u %u %u %u %u %lu ", + DMEMIT("%u %llu/%llu %llu %llu/%llu %u %u %u %u %u %u %lu ", (unsigned)DM_CACHE_METADATA_BLOCK_SIZE, (unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata), (unsigned long long)nr_blocks_metadata, - cache->sectors_per_block, + (unsigned long long)cache->sectors_per_block, (unsigned long long) from_cblock(residency), (unsigned long long) from_cblock(cache->cache_size), (unsigned) atomic_read(&cache->stats.read_hit), diff --git a/drivers/md/dm-stats.c b/drivers/md/dm-stats.c index 8289804ccd99..d5ea9f28ae70 100644 --- a/drivers/md/dm-stats.c +++ b/drivers/md/dm-stats.c @@ -175,6 +175,7 @@ static void dm_stat_free(struct rcu_head *head) int cpu; struct dm_stat *s = container_of(head, struct dm_stat, rcu_head); + kfree(s->histogram_boundaries); kfree(s->program_id); kfree(s->aux_data); for_each_possible_cpu(cpu) { diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 3384a3eef917..397f0454100b 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1467,11 +1467,62 @@ void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors) } EXPORT_SYMBOL_GPL(dm_accept_partial_bio); +/* + * Flush current->bio_list when the target map method blocks. + * This fixes deadlocks in snapshot and possibly in other targets. + */ +struct dm_offload { + struct blk_plug plug; + struct blk_plug_cb cb; +}; + +static void flush_current_bio_list(struct blk_plug_cb *cb, bool from_schedule) +{ + struct dm_offload *o = container_of(cb, struct dm_offload, cb); + struct bio_list list; + struct bio *bio; + + INIT_LIST_HEAD(&o->cb.list); + + if (unlikely(!current->bio_list)) + return; + + list = *current->bio_list; + bio_list_init(current->bio_list); + + while ((bio = bio_list_pop(&list))) { + struct bio_set *bs = bio->bi_pool; + if (unlikely(!bs) || bs == fs_bio_set) { + bio_list_add(current->bio_list, bio); + continue; + } + + spin_lock(&bs->rescue_lock); + bio_list_add(&bs->rescue_list, bio); + queue_work(bs->rescue_workqueue, &bs->rescue_work); + spin_unlock(&bs->rescue_lock); + } +} + +static void dm_offload_start(struct dm_offload *o) +{ + blk_start_plug(&o->plug); + o->cb.callback = flush_current_bio_list; + list_add(&o->cb.list, ¤t->plug->cb_list); +} + +static void dm_offload_end(struct dm_offload *o) +{ + list_del(&o->cb.list); + blk_finish_plug(&o->plug); +} + static void __map_bio(struct dm_target_io *tio) { int r; sector_t sector; struct mapped_device *md; + struct dm_offload o; struct bio *clone = &tio->clone; struct dm_target *ti = tio->ti; @@ -1484,7 +1535,11 @@ static void __map_bio(struct dm_target_io *tio) */ atomic_inc(&tio->io->io_count); sector = clone->bi_iter.bi_sector; + + dm_offload_start(&o); r = ti->type->map(ti, clone); + dm_offload_end(&o); + if (r == DM_MAPIO_REMAPPED) { /* the bio has been remapped so dispatch it */ diff --git a/drivers/md/linear.c b/drivers/md/linear.c index b7fe7e9fc777..6ba3227e29b2 100644 --- a/drivers/md/linear.c +++ b/drivers/md/linear.c @@ -52,18 +52,26 @@ static inline struct dev_info *which_dev(struct mddev *mddev, sector_t sector) return conf->disks + lo; } +/* + * In linear_congested() conf->raid_disks is used as a copy of + * mddev->raid_disks to iterate conf->disks[], because conf->raid_disks + * and conf->disks[] are created in linear_conf(), they are always + * consitent with each other, but mddev->raid_disks does not. + */ static int linear_congested(struct mddev *mddev, int bits) { struct linear_conf *conf; int i, ret = 0; - conf = mddev->private; + rcu_read_lock(); + conf = rcu_dereference(mddev->private); - for (i = 0; i < mddev->raid_disks && !ret ; i++) { + for (i = 0; i < conf->raid_disks && !ret ; i++) { struct request_queue *q = bdev_get_queue(conf->disks[i].rdev->bdev); ret |= bdi_congested(&q->backing_dev_info, bits); } + rcu_read_unlock(); return ret; } @@ -143,6 +151,19 @@ static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks) conf->disks[i-1].end_sector + conf->disks[i].rdev->sectors; + /* + * conf->raid_disks is copy of mddev->raid_disks. The reason to + * keep a copy of mddev->raid_disks in struct linear_conf is, + * mddev->raid_disks may not be consistent with pointers number of + * conf->disks[] when it is updated in linear_add() and used to + * iterate old conf->disks[] earray in linear_congested(). + * Here conf->raid_disks is always consitent with number of + * pointers in conf->disks[] array, and mddev->private is updated + * with rcu_assign_pointer() in linear_addr(), such race can be + * avoided. + */ + conf->raid_disks = raid_disks; + return conf; out: @@ -195,15 +216,23 @@ static int linear_add(struct mddev *mddev, struct md_rdev *rdev) if (!newconf) return -ENOMEM; + /* newconf->raid_disks already keeps a copy of * the increased + * value of mddev->raid_disks, WARN_ONCE() is just used to make + * sure of this. It is possible that oldconf is still referenced + * in linear_congested(), therefore kfree_rcu() is used to free + * oldconf until no one uses it anymore. + */ mddev_suspend(mddev); - oldconf = mddev->private; + oldconf = rcu_dereference(mddev->private); mddev->raid_disks++; - mddev->private = newconf; + WARN_ONCE(mddev->raid_disks != newconf->raid_disks, + "copied raid_disks doesn't match mddev->raid_disks"); + rcu_assign_pointer(mddev->private, newconf); md_set_array_sectors(mddev, linear_size(mddev, 0, 0)); set_capacity(mddev->gendisk, mddev->array_sectors); mddev_resume(mddev); revalidate_disk(mddev->gendisk); - kfree(oldconf); + kfree_rcu(oldconf, rcu); return 0; } diff --git a/drivers/md/linear.h b/drivers/md/linear.h index b685ddd7d7f7..8d392e6098b3 100644 --- a/drivers/md/linear.h +++ b/drivers/md/linear.h @@ -10,6 +10,7 @@ struct linear_conf { struct rcu_head rcu; sector_t array_sectors; + int raid_disks; /* a copy of mddev->raid_disks */ struct dev_info disks[0]; }; #endif |