[RFC] do_mounts: Allow mtd names for non-flash block filesystems

[Karl Beldan]

Edit for my off-by-one typo:

On Wed, Oct 6, 2010 at 11:02 PM, Karl Beldan <karl.beldan at gmail.com> wrote:
> Hi,
>
> I have been using this tweak for some time now, and I am getting tired of
> having to resort to it so often.
> It allows to pass such cmdline root as:
>  "root=mtdb:ubivolx rootfstype=squashfs"
> I am pretty sure many people use squashfs/cramfs filesystems on top of nand,
> for example, and I thought that this might initiate discussion.
>
> --
> Karl
>
> Signed-off-by: Karl Beldan <karl.beldan at gmail.com>
> ---
>  init/do_mounts.c |   15 +++++++++++++--
>  1 files changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/init/do_mounts.c b/init/do_mounts.c
> index 02e3ca4..20d9380 100644
> --- a/init/do_mounts.c
> +++ b/init/do_mounts.c
> @@ -20,6 +20,7 @@
>  #include <linux/nfs_fs.h>
>  #include <linux/nfs_fs_sb.h>
>  #include <linux/nfs_mount.h>
> +#include <linux/mtd/mtd.h>
>
>  #include "do_mounts.h"
>
> @@ -386,8 +387,18 @@ void __init prepare_namespace(void)
>
>        if (saved_root_name[0]) {
>                root_device_name = saved_root_name;
> -               if (!strncmp(root_device_name, "mtd", 3) ||
> -                   !strncmp(root_device_name, "ubi", 3)) {
> +               if (!strncmp(root_device_name, "mtdb:", 4)) {
Here, it is 5 not 4

> +                       struct mtd_info *mtd = get_mtd_device_nm(root_device_name + 4);
same here

> +                       if (!IS_ERR(mtd))
> +                               sprintf(root_device_name, "/dev/mtdblock%d", mtd->index);
> +                       else {
> +                               printk(KERN_ERR "VFS: Unable to find mtd \"%s\"\n", root_device_name + 4);
and here

> +                               printk("List of all partitions:\n");
> +                               printk_all_partitions();
> +                               panic("VFS: Unable to mount root fs");
> +                       }
> +               } else if (!strncmp(root_device_name, "mtd", 3) ||
> +                          !strncmp(root_device_name, "ubi", 3)) {
>                        mount_block_root(root_device_name, root_mountflags);
>                        goto out;
>                }
> --
> 1.7.1.422.g049e9
>

-- 
Karl