- a revert of a DM mirror commit that has proven to make the code prone

to crash
 
 - a DM io reference count fix that resolves a NULL pointer seen when
   issuing discards to a DM mirror target's device whose mirror legs do
   not all support discards
 
 - a couple DM integrity fixes
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Merge tag 'for-4.12/dm-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - a revert of a DM mirror commit that has proven to make the code prone
   to crash

 - a DM io reference count fix that resolves a NULL pointer seen when
   issuing discards to a DM mirror target's device whose mirror legs do
   not all support discards

 - a couple DM integrity fixes

* tag 'for-4.12/dm-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm io: fix duplicate bio completion due to missing ref count
  dm integrity: fix to not disable/enable interrupts from interrupt context
  Revert "dm mirror: use all available legs on multiple failures"
  dm integrity: reject mappings too large for device

drivers/md/dm-integrity.c

@@ -1105,10 +1105,13 @@ static void schedule_autocommit(struct dm_integrity_c *ic)
 static void submit_flush_bio(struct dm_integrity_c *ic, struct dm_integrity_io *dio)
 {
 	struct bio *bio;
-	spin_lock_irq(&ic->endio_wait.lock);
+	unsigned long flags;
+
+	spin_lock_irqsave(&ic->endio_wait.lock, flags);
 	bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
 	bio_list_add(&ic->flush_bio_list, bio);
-	spin_unlock_irq(&ic->endio_wait.lock);
+	spin_unlock_irqrestore(&ic->endio_wait.lock, flags);
+
 	queue_work(ic->commit_wq, &ic->commit_work);
 }
 
@@ -3040,6 +3043,11 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
 		ti->error = "The device is too small";
 		goto bad;
 	}
+	if (ti->len > ic->provided_data_sectors) {
+		r = -EINVAL;
+		ti->error = "Not enough provided sectors for requested mapping size";
+		goto bad;
+	}
 
 	if (!buffer_sectors)
 		buffer_sectors = 1;

drivers/md/dm-io.c

@@ -317,8 +317,8 @@ static void do_region(int op, int op_flags, unsigned region,
 	else if (op == REQ_OP_WRITE_SAME)
 		special_cmd_max_sectors = q->limits.max_write_same_sectors;
 	if ((op == REQ_OP_DISCARD || op == REQ_OP_WRITE_ZEROES ||
-	     op == REQ_OP_WRITE_SAME)  &&
-	    special_cmd_max_sectors == 0) {
+	     op == REQ_OP_WRITE_SAME) && special_cmd_max_sectors == 0) {
+		atomic_inc(&io->count);
 		dec_count(io, region, -EOPNOTSUPP);
 		return;
 	}

drivers/md/dm-raid1.c

@@ -145,6 +145,7 @@ static void dispatch_bios(void *context, struct bio_list *bio_list)
 
 struct dm_raid1_bio_record {
 	struct mirror *m;
+	/* if details->bi_bdev == NULL, details were not saved */
 	struct dm_bio_details details;
 	region_t write_region;
 };
@@ -1198,6 +1199,8 @@ static int mirror_map(struct dm_target *ti, struct bio *bio)
 	struct dm_raid1_bio_record *bio_record =
 	  dm_per_bio_data(bio, sizeof(struct dm_raid1_bio_record));
 
+	bio_record->details.bi_bdev = NULL;
+
 	if (rw == WRITE) {
 		/* Save region for mirror_end_io() handler */
 		bio_record->write_region = dm_rh_bio_to_region(ms->rh, bio);
@@ -1256,12 +1259,22 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio, int error)
 	}
 
 	if (error == -EOPNOTSUPP)
-		return error;
+		goto out;
 
 	if ((error == -EWOULDBLOCK) && (bio->bi_opf & REQ_RAHEAD))
-		return error;
+		goto out;
 
 	if (unlikely(error)) {
+		if (!bio_record->details.bi_bdev) {
+			/*
+			 * There wasn't enough memory to record necessary
+			 * information for a retry or there was no other
+			 * mirror in-sync.
+			 */
+			DMERR_LIMIT("Mirror read failed.");
+			return -EIO;
+		}
+
 		m = bio_record->m;
 
 		DMERR("Mirror read failed from %s. Trying alternative device.",
@@ -1277,6 +1290,7 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio, int error)
 			bd = &bio_record->details;
 
 			dm_bio_restore(bd, bio);
+			bio_record->details.bi_bdev = NULL;
 			bio->bi_error = 0;
 
 			queue_bio(ms, bio, rw);
@@ -1285,6 +1299,9 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio, int error)
 		DMERR("All replicated volumes dead, failing I/O");
 	}
 
+out:
+	bio_record->details.bi_bdev = NULL;
+
 	return error;
 }