um/drivers/ubd_kern: add error handling support for add_disk()

We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.

ubd_disk_register() never returned an error, so just fix
that now and let the caller handle the error condition.

Reviewed-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20211015233028.2167651-8-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index fefd343..69d2d00 100644 (file)
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -855,8 +855,8 @@ static const struct attribute_group *ubd_attr_groups[] = {
        NULL,
 };
 
-static void ubd_disk_register(int major, u64 size, int unit,
-                             struct gendisk *disk)
+static int ubd_disk_register(int major, u64 size, int unit,
+                            struct gendisk *disk)
 {
        disk->major = major;
        disk->first_minor = unit << UBD_SHIFT;
@@ -873,7 +873,7 @@ static void ubd_disk_register(int major, u64 size, int unit,
 
        disk->private_data = &ubd_devs[unit];
        disk->queue = ubd_devs[unit].queue;
-       device_add_disk(&ubd_devs[unit].pdev.dev, disk, ubd_attr_groups);
+       return device_add_disk(&ubd_devs[unit].pdev.dev, disk, ubd_attr_groups);
 }
 
 #define ROUND_BLOCK(n) ((n + (SECTOR_SIZE - 1)) & (-SECTOR_SIZE))
@@ -920,10 +920,15 @@ static int ubd_add(int n, char **error_out)
        blk_queue_write_cache(ubd_dev->queue, true, false);
        blk_queue_max_segments(ubd_dev->queue, MAX_SG);
        blk_queue_segment_boundary(ubd_dev->queue, PAGE_SIZE - 1);
-       ubd_disk_register(UBD_MAJOR, ubd_dev->size, n, disk);
+       err = ubd_disk_register(UBD_MAJOR, ubd_dev->size, n, disk);
+       if (err)
+               goto out_cleanup_disk;
+
        ubd_gendisk[n] = disk;
        return 0;
 
+out_cleanup_disk:
+       blk_cleanup_disk(disk);
 out_cleanup_tags:
        blk_mq_free_tag_set(&ubd_dev->tag_set);
 out: