- if (!mutex_trylock(&bdev->bd_mutex))
- return -EBUSY;
- res = rescan_partitions(disk, bdev);
+
+ lockdep_assert_held(&bdev->bd_mutex);
+
+ return rescan_partitions(disk, bdev);
+}
+EXPORT_SYMBOL(__blkdev_reread_part);
+
+/*
+ * This is an exported API for the block driver, and will
+ * try to acquire bd_mutex. If bd_mutex has been held already
+ * in current context, please call __blkdev_reread_part().
+ *
+ * Make sure the held locks in current context aren't required
+ * in open()/close() handler and I/O path for avoiding ABBA deadlock:
+ * - bd_mutex is held before calling block driver's open/close
+ * handler
+ * - reading partition table may submit I/O to the block device
+ */
+int blkdev_reread_part(struct block_device *bdev)
+{
+ int res;
+
+ mutex_lock(&bdev->bd_mutex);
+ res = __blkdev_reread_part(bdev);