Enable partitions for lguest block device

The lguest block device only requests one minor, which means
partitions don't work (eg "root=/dev/lgba1").

Let's follow the crowd and ask for 16.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/block/lguest_blk.c b/drivers/block/lguest_blk.c
index 93e3c4001bf5..160cf14431ac 100644
--- a/drivers/block/lguest_blk.c
+++ b/drivers/block/lguest_blk.c
@@ -308,9 +308,12 @@ static int lguestblk_probe(struct lguest_device *lgdev)
         }
 
         /* This allocates a "struct gendisk" where we pack all the information
-         * about the disk which the rest of Linux sees.  We ask for one minor
-         * number; I do wonder if we should be asking for more. */
-        bd->disk = alloc_disk(1);
+         * about the disk which the rest of Linux sees.  The argument is the
+         * number of minor devices desired: we need one minor for the main
+         * disk, and one for each partition.  Of course, we can't possibly know
+         * how many partitions are on the disk (add_disk does that).
+         */
+        bd->disk = alloc_disk(16);
         if (!bd->disk) {
                 err = -ENOMEM;
                 goto out_unregister_blkdev;