Merge tag 'for-7.3/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mikulas Patocka:

 - fix a dm-crypt race condition that could make errors not being reported

 - dm-cache:
    - fix rwsem being locked and unlocked from different processes
    - fix demotion statistics

 - dm-integrity:
    - set the 'stable writes' flag
    - fix a buffer overflow introduced in this merge window
    - fix an infinite loop if tag size is greater than 64

 - fix NULL pointer dereference in dm-integrity data-recovery mode

 - remove a bogus restriction on the dm-ebs starting sector offset

* tag 'for-7.3/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm-ebs: fix incorrect device offset check in ebs_ctr()
  dm-integrity: fix NULL pointer dereference when the 'R' flag is used
  dm cache: fix demotion stats in passthrough mode
  dm-integrity: fix infinite loop on discard with large tag size
  dm-integrity: fix buffer overflow with keyed discard
  dm-integrity: require stable writes for internal hash modes
  dm cache: fix issue with background work locking
  dm-crypt: fix a tiny race condition in crypt_dec_pending

4 files changed, 44 insertions, 34 deletions

diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 33dbc71b730f..1a5072425c4a 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -340,8 +340,6 @@ struct cache {
 	struct list_head invalidation_requests;
 
 	sector_t migration_threshold;
-	wait_queue_head_t migration_wait;
-	atomic_t nr_allocated_migrations;
 
 	/*
 	 * The number of in flight migrations that are performing
@@ -397,7 +395,11 @@ struct cache {
 	bool loaded_mappings:1;
 	bool loaded_discards:1;
 
-	struct rw_semaphore background_work_lock;
+	/* background work management */
+	bool background_work_allowed;
+	unsigned background_work_nr;
+	spinlock_t background_work_lock;
+	wait_queue_head_t background_work_wait;
 
 	struct batcher committer;
 	struct work_struct commit_ws;
@@ -488,19 +490,13 @@ static struct dm_cache_migration *alloc_migration(struct cache *cache)
 	memset(mg, 0, sizeof(*mg));
 
 	mg->cache = cache;
-	atomic_inc(&cache->nr_allocated_migrations);
 
 	return mg;
 }
 
 static void free_migration(struct dm_cache_migration *mg)
 {
-	struct cache *cache = mg->cache;
-
-	if (atomic_dec_and_test(&cache->nr_allocated_migrations))
-		wake_up(&cache->migration_wait);
-
-	mempool_free(mg, &cache->migration_pool);
+	mempool_free(mg, &mg->cache->migration_pool);
 }
 
 /*----------------------------------------------------------------*/
@@ -1030,34 +1026,39 @@ static void calc_discard_block_range(struct cache *cache, struct bio *bio,
 
 static void prevent_background_work(struct cache *cache)
 {
-	lockdep_off();
-	down_write(&cache->background_work_lock);
-	lockdep_on();
+	spin_lock_irq(&cache->background_work_lock);
+	cache->background_work_allowed = false;
+	wait_event_lock_irq(cache->background_work_wait,
+			    cache->background_work_nr == 0,
+			    cache->background_work_lock);
+	spin_unlock_irq(&cache->background_work_lock);
 }
 
 static void allow_background_work(struct cache *cache)
 {
-	lockdep_off();
-	up_write(&cache->background_work_lock);
-	lockdep_on();
+	spin_lock_irq(&cache->background_work_lock);
+	cache->background_work_allowed = true;
+	spin_unlock_irq(&cache->background_work_lock);
 }
 
 static bool background_work_begin(struct cache *cache)
 {
 	bool r;
 
-	lockdep_off();
-	r = down_read_trylock(&cache->background_work_lock);
-	lockdep_on();
-
+	spin_lock_irq(&cache->background_work_lock);
+	r = cache->background_work_allowed;
+	if (r)
+		cache->background_work_nr++;
+	spin_unlock_irq(&cache->background_work_lock);
 	return r;
 }
 
 static void background_work_end(struct cache *cache)
 {
-	lockdep_off();
-	up_read(&cache->background_work_lock);
-	lockdep_on();
+	spin_lock_irq(&cache->background_work_lock);
+	if (--cache->background_work_nr == 0)
+		wake_up(&cache->background_work_wait);
+	spin_unlock_irq(&cache->background_work_lock);
 }
 
 /*----------------------------------------------------------------*/
@@ -1462,6 +1463,9 @@ static void invalidate_complete(struct dm_cache_migration *mg, bool success)
 	struct bio_list bios;
 	struct cache *cache = mg->cache;
 
+	if (success)
+		atomic_inc(&cache->stats.demotion);
+
 	bio_list_init(&bios);
 	if (mg->cell) {
 		if (dm_cell_unlock_v2(cache->prison, mg->cell, &bios))
@@ -1733,7 +1737,6 @@ static int map_bio(struct cache *cache, struct bio *bio, dm_oblock_t block,
 		if (passthrough_mode(cache)) {
 			if (bio_data_dir(bio) == WRITE) {
 				bio_drop_shared_lock(cache, bio);
-				atomic_inc(&cache->stats.demotion);
 				invalidate_start(cache, cblock, block, bio);
 				return DM_MAPIO_SUBMITTED;
 			} else
@@ -2507,9 +2510,7 @@ static int cache_create(struct cache_args *ca, struct cache **result)
 
 	spin_lock_init(&cache->lock);
 	bio_list_init(&cache->deferred_bios);
-	atomic_set(&cache->nr_allocated_migrations, 0);
 	atomic_set(&cache->nr_io_migrations, 0);
-	init_waitqueue_head(&cache->migration_wait);
 
 	r = -ENOMEM;
 	atomic_set(&cache->nr_dirty, 0);
@@ -2592,8 +2593,10 @@ static int cache_create(struct cache_args *ca, struct cache **result)
 		     issue_op, cache, cache->wq);
 	dm_iot_init(&cache->tracker);
 
-	init_rwsem(&cache->background_work_lock);
-	prevent_background_work(cache);
+	init_waitqueue_head(&cache->background_work_wait);
+	spin_lock_init(&cache->background_work_lock);
+	cache->background_work_allowed = false;
+	cache->background_work_nr = 0;
 
 	*result = cache;
 	return 0;
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 608b617fb817..9e170de50ad3 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1745,7 +1745,6 @@ static void crypt_dec_pending(struct dm_crypt_io *io)
 {
 	struct crypt_config *cc = io->cc;
 	struct bio *base_bio = io->base_bio;
-	blk_status_t error = io->error;
 
 	if (!atomic_dec_and_test(&io->io_pending))
 		return;
@@ -1767,7 +1766,7 @@ static void crypt_dec_pending(struct dm_crypt_io *io)
 	else
 		kfree(io->integrity_metadata);
 
-	base_bio->bi_status = error;
+	base_bio->bi_status = io->error;
 
 	bio_endio(base_bio);
 }
diff --git a/drivers/md/dm-ebs-target.c b/drivers/md/dm-ebs-target.c
index 1e52bde48b91..5d67c6c19d4b 100644
--- a/drivers/md/dm-ebs-target.c
+++ b/drivers/md/dm-ebs-target.c
@@ -265,8 +265,7 @@ static int ebs_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
 	r = -EINVAL;
 	if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1 ||
-	    tmp != (sector_t)tmp ||
-	    (sector_t)tmp >= ti->len) {
+	    tmp != (sector_t)tmp) {
 		ti->error = "Invalid device offset sector";
 		goto bad;
 	}
diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index c50feaa98bf9..92970e12267a 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -1979,8 +1979,8 @@ static void integrity_metadata(struct work_struct *w)
 
 		if (unlikely(dio->op == REQ_OP_DISCARD)) {
 			unsigned int bi_size = dio->bio_details.bi_iter.bi_size;
-			unsigned int max_size = likely(checksums != checksums_onstack) ? PAGE_SIZE : HASH_MAX_DIGESTSIZE;
-			unsigned int max_blocks = max_size / ic->tag_size;
+			unsigned int max_size = likely(checksums != checksums_onstack) ? PAGE_SIZE : sizeof(checksums_onstack);
+			unsigned int max_blocks = (max_size - extra_space) / ic->tag_size;
 			sector_t sector = dio->range.logical_sector;
 
 			if (!ic->discard_keyed)
@@ -3875,6 +3875,10 @@ static void dm_integrity_resume(struct dm_target *ti)
 	r = sync_rw_sb(ic, REQ_OP_READ);
 	if (r)
 		dm_integrity_io_error(ic, "reading superblock", r);
+
+	if (ic->mode == 'R')
+		goto skip_writes;
+
 	if ((ic->sb->flags & flags) != flags) {
 		ic->sb->flags |= flags;
 		r = sync_rw_sb(ic, REQ_OP_WRITE | REQ_FUA);
@@ -3984,6 +3988,7 @@ static void dm_integrity_resume(struct dm_target *ti)
 		}
 	}
 
+skip_writes:
 	ic->reboot_notifier.notifier_call = dm_integrity_reboot;
 	ic->reboot_notifier.next = NULL;
 	ic->reboot_notifier.priority = INT_MAX - 1;	/* be notified after md and before hardware drivers */
@@ -4130,6 +4135,10 @@ static void dm_integrity_io_hints(struct dm_target *ti, struct queue_limits *lim
 	limits->dma_alignment = limits->logical_block_size - 1;
 	limits->discard_granularity = ic->sectors_per_block << SECTOR_SHIFT;
 
+	if (ic->internal_hash &&
+	    (ic->mode == 'D' || ic->mode == 'B' || ic->mode == 'I'))
+		limits->features |= BLK_FEAT_STABLE_WRITES;
+
 	if (!ic->internal_hash) {
 		struct blk_integrity *bi = &limits->integrity;