Merge tag 'md-3.5-fixes' of git://neil.brown.name/md

Pull three md bugfixes from NeilBrown:
 "One of the bugs was introduced in 3.5-rc1.  Others have been there for
  longer."

* tag 'md-3.5-fixes' of git://neil.brown.name/md:
  md/raid1: close some possible races on write errors during resync
  md: avoid crash when stopping md array races with closing other open fds.
  md: fix bug in handling of new_data_offset

drivers/md/md.c

@@ -2931,6 +2931,7 @@ offset_store(struct md_rdev *rdev, const char *buf, size_t len)
 		 * can be sane */
 		return -EBUSY;
 	rdev->data_offset = offset;
+	rdev->new_data_offset = offset;
 	return len;
 }
 
@@ -3926,8 +3927,8 @@ array_state_show(struct mddev *mddev, char *page)
 	return sprintf(page, "%s\n", array_states[st]);
 }
 
-static int do_md_stop(struct mddev * mddev, int ro, int is_open);
-static int md_set_readonly(struct mddev * mddev, int is_open);
+static int do_md_stop(struct mddev * mddev, int ro, struct block_device *bdev);
+static int md_set_readonly(struct mddev * mddev, struct block_device *bdev);
 static int do_md_run(struct mddev * mddev);
 static int restart_array(struct mddev *mddev);
 
@@ -3943,22 +3944,22 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
 		/* stopping an active array */
 		if (atomic_read(&mddev->openers) > 0)
 			return -EBUSY;
-		err = do_md_stop(mddev, 0, 0);
+		err = do_md_stop(mddev, 0, NULL);
 		break;
 	case inactive:
 		/* stopping an active array */
 		if (mddev->pers) {
 			if (atomic_read(&mddev->openers) > 0)
 				return -EBUSY;
-			err = do_md_stop(mddev, 2, 0);
+			err = do_md_stop(mddev, 2, NULL);
 		} else
 			err = 0; /* already inactive */
 		break;
 	case suspended:
 		break; /* not supported yet */
 	case readonly:
 		if (mddev->pers)
-			err = md_set_readonly(mddev, 0);
+			err = md_set_readonly(mddev, NULL);
 		else {
 			mddev->ro = 1;
 			set_disk_ro(mddev->gendisk, 1);
@@ -3968,7 +3969,7 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
 	case read_auto:
 		if (mddev->pers) {
 			if (mddev->ro == 0)
-				err = md_set_readonly(mddev, 0);
+				err = md_set_readonly(mddev, NULL);
 			else if (mddev->ro == 1)
 				err = restart_array(mddev);
 			if (err == 0) {
@@ -5351,15 +5352,17 @@ void md_stop(struct mddev *mddev)
 }
 EXPORT_SYMBOL_GPL(md_stop);
 
-static int md_set_readonly(struct mddev *mddev, int is_open)
+static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
 {
 	int err = 0;
 	mutex_lock(&mddev->open_mutex);
-	if (atomic_read(&mddev->openers) > is_open) {
+	if (atomic_read(&mddev->openers) > !!bdev) {
 		printk("md: %s still in use.\n",mdname(mddev));
 		err = -EBUSY;
 		goto out;
 	}
+	if (bdev)
+		sync_blockdev(bdev);
 	if (mddev->pers) {
 		__md_stop_writes(mddev);
 
@@ -5381,18 +5384,26 @@ static int md_set_readonly(struct mddev *mddev, int is_open)
  *   0 - completely stop and dis-assemble array
  *   2 - stop but do not disassemble array
  */
-static int do_md_stop(struct mddev * mddev, int mode, int is_open)
+static int do_md_stop(struct mddev * mddev, int mode,
+		      struct block_device *bdev)
 {
 	struct gendisk *disk = mddev->gendisk;
 	struct md_rdev *rdev;
 
 	mutex_lock(&mddev->open_mutex);
-	if (atomic_read(&mddev->openers) > is_open ||
+	if (atomic_read(&mddev->openers) > !!bdev ||
 	    mddev->sysfs_active) {
 		printk("md: %s still in use.\n",mdname(mddev));
 		mutex_unlock(&mddev->open_mutex);
 		return -EBUSY;
 	}
+	if (bdev)
+		/* It is possible IO was issued on some other
+		 * open file which was closed before we took ->open_mutex.
+		 * As that was not the last close __blkdev_put will not
+		 * have called sync_blockdev, so we must.
+		 */
+		sync_blockdev(bdev);
 
 	if (mddev->pers) {
 		if (mddev->ro)
@@ -5466,7 +5477,7 @@ static void autorun_array(struct mddev *mddev)
 	err = do_md_run(mddev);
 	if (err) {
 		printk(KERN_WARNING "md: do_md_run() returned %d\n", err);
-		do_md_stop(mddev, 0, 0);
+		do_md_stop(mddev, 0, NULL);
 	}
 }
 
@@ -6481,11 +6492,11 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
 			goto done_unlock;
 
 		case STOP_ARRAY:
-			err = do_md_stop(mddev, 0, 1);
+			err = do_md_stop(mddev, 0, bdev);
 			goto done_unlock;
 
 		case STOP_ARRAY_RO:
-			err = md_set_readonly(mddev, 1);
+			err = md_set_readonly(mddev, bdev);
 			goto done_unlock;
 
 		case BLKROSET:

drivers/md/raid1.c

@@ -1818,8 +1818,14 @@ static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
 
 	if (atomic_dec_and_test(&r1_bio->remaining)) {
 		/* if we're here, all write(s) have completed, so clean up */
-		md_done_sync(mddev, r1_bio->sectors, 1);
-		put_buf(r1_bio);
+		int s = r1_bio->sectors;
+		if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
+		    test_bit(R1BIO_WriteError, &r1_bio->state))
+			reschedule_retry(r1_bio);
+		else {
+			put_buf(r1_bio);
+			md_done_sync(mddev, s, 1);
+		}
 	}
 }