[PATCH 02/14] block: cleanup partition scanning in register_disk

Christoph Hellwig
2020-09-21T07:20:04Z

Use blkdev_get_by_dev instead of open coding it using bdget_disk +
blkdev_get, and split the code to read the partition table into a
separate helper to make it a little more obvious.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/genhd.c | 33 ++++++++++++++-------------------
1 file changed, 14 insertions(+), 19 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index 7b56203c90a303..05fb27cbb66784 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -673,11 +673,23 @@ static int exact_lock(dev_t devt, void *data)
return 0;
}

+static void disk_scan_partitions(struct gendisk *disk)
+{
+ struct block_device *bdev;
+
+ if (!get_capacity(disk) || !disk_part_scan_enabled(disk))
+ return;
+
+ set_bit(GD_NEED_PART_SCAN, &disk->state);
+ bdev = blkdev_get_by_dev(disk_devt(disk), FMODE_READ, NULL);
+ if (!IS_ERR(bdev))
+ blkdev_put(bdev, FMODE_READ);
+}
+
static void register_disk(struct device *parent, struct gendisk *disk,
const struct attribute_group **groups)
{
struct device *ddev = disk_to_dev(disk);
- struct block_device *bdev;
struct disk_part_iter piter;
struct hd_struct *part;
int err;
@@ -719,25 +731,8 @@ static void register_disk(struct device *parent, struct gendisk *disk,
return;
}

- /* No minors to use for partitions */
- if (!disk_part_scan_enabled(disk))
- goto exit;
-
- /* No such device (e.g., media were just removed) */
- if (!get_capacity(disk))
- goto exit;
-
- bdev = bdget_disk(disk, 0);
- if (!bdev)
- goto exit;
-
- set_bit(GD_NEED_PART_SCAN, &disk->state);
- err = blkdev_get(bdev, FMODE_READ, NULL);
- if (err < 0)
- goto exit;
- blkdev_put(bdev, FMODE_READ);
+ disk_scan_partitions(disk);

-exit:
/* announce disk after possible partitions are created */
dev_set_uevent_suppress(ddev, 0);
kobject_uevent(&ddev->kobj, KOBJ_ADD);
--
2.28.0