Merge tag 'for-5.0/dm-fixes-3' of...

Merge tag 'for-5.0/dm-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - Fix bug in DM crypt's sizing of its block integrity tag space,
   resulting in less memory use when DM crypt layers on DM integrity.

 - Fix a long-standing DM thinp crash consistency bug that was due to
   improper handling of FUA. This issue is specific to writes that fill
   an entire thinp block which needs to be allocated.

* tag 'for-5.0/dm-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm thin: fix bug where bio that overwrites thin block ignores FUA
  dm crypt: don't overallocate the integrity tag space

drivers/md/dm-crypt.c

@@ -932,7 +932,7 @@ static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio)
 	if (IS_ERR(bip))
 		return PTR_ERR(bip);
 
-	tag_len = io->cc->on_disk_tag_size * bio_sectors(bio);
+	tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift);
 
 	bip->bip_iter.bi_size = tag_len;
 	bip->bip_iter.bi_sector = io->cc->start + io->sector;

drivers/md/dm-thin.c

@@ -257,6 +257,7 @@ struct pool {
 
 	spinlock_t lock;
 	struct bio_list deferred_flush_bios;
+	struct bio_list deferred_flush_completions;
 	struct list_head prepared_mappings;
 	struct list_head prepared_discards;
 	struct list_head prepared_discards_pt2;
@@ -956,6 +957,39 @@ static void process_prepared_mapping_fail(struct dm_thin_new_mapping *m)
 	mempool_free(m, &m->tc->pool->mapping_pool);
 }
 
+static void complete_overwrite_bio(struct thin_c *tc, struct bio *bio)
+{
+	struct pool *pool = tc->pool;
+	unsigned long flags;
+
+	/*
+	 * If the bio has the REQ_FUA flag set we must commit the metadata
+	 * before signaling its completion.
+	 */
+	if (!bio_triggers_commit(tc, bio)) {
+		bio_endio(bio);
+		return;
+	}
+
+	/*
+	 * Complete bio with an error if earlier I/O caused changes to the
+	 * metadata that can't be committed, e.g, due to I/O errors on the
+	 * metadata device.
+	 */
+	if (dm_thin_aborted_changes(tc->td)) {
+		bio_io_error(bio);
+		return;
+	}
+
+	/*
+	 * Batch together any bios that trigger commits and then issue a
+	 * single commit for them in process_deferred_bios().
+	 */
+	spin_lock_irqsave(&pool->lock, flags);
+	bio_list_add(&pool->deferred_flush_completions, bio);
+	spin_unlock_irqrestore(&pool->lock, flags);
+}
+
 static void process_prepared_mapping(struct dm_thin_new_mapping *m)
 {
 	struct thin_c *tc = m->tc;
@@ -988,7 +1022,7 @@ static void process_prepared_mapping(struct dm_thin_new_mapping *m)
 	 */
 	if (bio) {
 		inc_remap_and_issue_cell(tc, m->cell, m->data_block);
-		bio_endio(bio);
+		complete_overwrite_bio(tc, bio);
 	} else {
 		inc_all_io_entry(tc->pool, m->cell->holder);
 		remap_and_issue(tc, m->cell->holder, m->data_block);
@@ -2317,7 +2351,7 @@ static void process_deferred_bios(struct pool *pool)
 {
 	unsigned long flags;
 	struct bio *bio;
-	struct bio_list bios;
+	struct bio_list bios, bio_completions;
 	struct thin_c *tc;
 
 	tc = get_first_thin(pool);
@@ -2328,26 +2362,36 @@ static void process_deferred_bios(struct pool *pool)
 	}
 
 	/*
-	 * If there are any deferred flush bios, we must commit
-	 * the metadata before issuing them.
+	 * If there are any deferred flush bios, we must commit the metadata
+	 * before issuing them or signaling their completion.
 	 */
 	bio_list_init(&bios);
+	bio_list_init(&bio_completions);
+
 	spin_lock_irqsave(&pool->lock, flags);
 	bio_list_merge(&bios, &pool->deferred_flush_bios);
 	bio_list_init(&pool->deferred_flush_bios);
+
+	bio_list_merge(&bio_completions, &pool->deferred_flush_completions);
+	bio_list_init(&pool->deferred_flush_completions);
 	spin_unlock_irqrestore(&pool->lock, flags);
 
-	if (bio_list_empty(&bios) &&
+	if (bio_list_empty(&bios) && bio_list_empty(&bio_completions) &&
 	    !(dm_pool_changed_this_transaction(pool->pmd) && need_commit_due_to_time(pool)))
 		return;
 
 	if (commit(pool)) {
+		bio_list_merge(&bios, &bio_completions);
+
 		while ((bio = bio_list_pop(&bios)))
 			bio_io_error(bio);
 		return;
 	}
 	pool->last_commit_jiffies = jiffies;
 
+	while ((bio = bio_list_pop(&bio_completions)))
+		bio_endio(bio);
+
 	while ((bio = bio_list_pop(&bios)))
 		generic_make_request(bio);
 }
@@ -2954,6 +2998,7 @@ static struct pool *pool_create(struct mapped_device *pool_md,
 	INIT_DELAYED_WORK(&pool->no_space_timeout, do_no_space_timeout);
 	spin_lock_init(&pool->lock);
 	bio_list_init(&pool->deferred_flush_bios);
+	bio_list_init(&pool->deferred_flush_completions);
 	INIT_LIST_HEAD(&pool->prepared_mappings);
 	INIT_LIST_HEAD(&pool->prepared_discards);
 	INIT_LIST_HEAD(&pool->prepared_discards_pt2);