block: do_mounts - accept root=<non-existant partition>

Some devices, like md, may create partitions only at first access,
so allow root= to be set to a valid non-existant partition of an
existing disk. This applies only to non-initramfs root mounting.

This fixes a regression from 2.6.24 which did allow this to happen and
broke some users machines :(

Acked-by: Neil Brown <neilb@suse.de>
Tested-by: Joao Luis Meloni Assirati <assirati@nonada.if.usp.br>
Cc: stable <stable@kernel.org>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index e9874e7fcdf9..ae7aec3cabee 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -525,7 +525,7 @@ struct unixware_disklabel {
 #define ADDPART_FLAG_RAID       1
 #define ADDPART_FLAG_WHOLEDISK  2
 
-extern dev_t blk_lookup_devt(const char *name);
+extern dev_t blk_lookup_devt(const char *name, int part);
 extern char *disk_name (struct gendisk *hd, int part, char *buf);
 
 extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
@@ -553,7 +553,7 @@ static inline struct block_device *bdget_disk(struct gendisk *disk, int index)
 
 static inline void printk_all_partitions(void) { }
 
-static inline dev_t blk_lookup_devt(const char *name)
+static inline dev_t blk_lookup_devt(const char *name, int part)
 {
         dev_t devt = MKDEV(0, 0);
         return devt;