[PATCH 02/15] genhd: Return error from register_disk()

Fam Zheng
2016-08-17T07:15:02Z

Several operations in register_disk can fail, but the caller currently
cannot check for error due to missing return code. Change the function
return type and return -errno if any error happens.

Also add some documentation.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
block/genhd.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index fcd6d4f..3dcecaa 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -506,7 +506,15 @@ static int exact_lock(dev_t devt, void *data)
return 0;
}

-static void register_disk(struct device *parent, struct gendisk *disk)
+/**
+ * register_disk - register a gendisk to a parent device
+ * @parent: parent device for the disk
+ * @disk: per-device partitioning information
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+static int register_disk(struct device *parent, struct gendisk *disk)
{
struct device *ddev = disk_to_dev(disk);
struct block_device *bdev;
@@ -521,14 +529,16 @@ static void register_disk(struct device *parent, struct gendisk *disk)
/* delay uevents, until we scanned partition table */
dev_set_uevent_suppress(ddev, 1);

- if (device_add(ddev))
- return;
+ err = device_add(ddev);
+ if (err)
+ return err;
+
if (!sysfs_deprecated) {
err = sysfs_create_link(block_depr, &ddev->kobj,
kobject_name(&ddev->kobj));
if (err) {
device_del(ddev);
- return;
+ return err;
}
}

@@ -547,12 +557,16 @@ static void register_disk(struct device *parent, struct gendisk *disk)
goto exit;

/* No such device (e.g., media were just removed) */
- if (!get_capacity(disk))
+ if (!get_capacity(disk)) {
+ err = -ENOMEDIUM;
goto exit;
+ }

bdev = bdget_disk(disk, 0);
- if (!bdev)
+ if (!bdev) {
+ err = -ENOMEDIUM;
goto exit;
+ }

bdev->bd_invalidated = 1;
err = blkdev_get(bdev, FMODE_READ, NULL);
@@ -570,6 +584,7 @@ exit:
while ((part = disk_part_iter_next(&piter)))
kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
disk_part_iter_exit(&piter);
+ return err;
}

/**
--
2.7.4