[PATCH] remove compat code for old devfs naming scheme

[PATCH] remove compat code for old devfs naming scheme

[Christoph Hellwig]

Hi Richard,

current init/do_mounts.c contains the devfs_make_root/convert_name
functions which provide compatiblility for the old, pre kernel-merge
devfs naming scheme in the root= kernel command line.

As this was never present in official kernels there is really no need
in keeping it - it just bloats the kernel.

Could you please forward this patch to Linus and maybe Marcelo with
your next devfs update?

	Christoph

--
--- 1.14/init/do_mounts.c	Sun May  5 18:35:44 2002
+++ edited/init/do_mounts.c	Sat May 11 18:32:17 2002
@@ -636,63 +636,6 @@
 	return rd_load_image("/dev/root");
 }
 
-#ifdef CONFIG_DEVFS_FS
-
-static void __init convert_name(char *prefix, char *name, char *p, int part)
-{
-	int host, bus, target, lun;
-	char dest[64];
-	char src[64];
-	char *base = p - 1;
-
-	/*  Decode "c#b#t#u#"  */
-	if (*p++ != 'c')
-		return;
-	host = simple_strtol(p, &p, 10);
-	if (*p++ != 'b')
-		return;
-	bus = simple_strtol(p, &p, 10);
-	if (*p++ != 't')
-		return;
-	target = simple_strtol(p, &p, 10);
-	if (*p++ != 'u')
-		return;
-	lun = simple_strtol(p, &p, 10);
-	if (!part)
-		sprintf(dest, "%s/host%d/bus%d/target%d/lun%d",
-				prefix, host, bus, target, lun);
-	else if (*p++ == 'p')
-		sprintf(dest, "%s/host%d/bus%d/target%d/lun%d/part%s",
-				prefix, host, bus, target, lun, p);
-	else
-		sprintf(dest, "%s/host%d/bus%d/target%d/lun%d/disc",
-				prefix, host, bus, target, lun);
-	*base = '\0';
-	sprintf(src, "/dev/%s", name);
-	sys_mkdir(src, 0755);
-	*base = '/';
-	sprintf(src, "/dev/%s", name);
-	sys_symlink(dest, src);
-}
-
-static void __init devfs_make_root(char *name)
-{
-
-	if (!strncmp(name, "sd/", 3))
-		convert_name("../scsi", name, name+3, 1);
-	else if (!strncmp(name, "sr/", 3))
-		convert_name("../scsi", name, name+3, 0);
-	else if (!strncmp(name, "ide/hd/", 7))
-		convert_name("..", name, name + 7, 1);
-	else if (!strncmp(name, "ide/cd/", 7))
-		convert_name("..", name, name + 7, 0);
-}
-#else
-static void __init devfs_make_root(char *name)
-{
-}
-#endif
-
 static void __init mount_root(void)
 {
 #ifdef CONFIG_ROOT_NFS
@@ -707,7 +650,6 @@
 		ROOT_DEV = mk_kdev(FLOPPY_MAJOR, 0);
 	}
 #endif
-	devfs_make_root(root_device_name);
 	create_dev("/dev/root", ROOT_DEV, root_device_name);
 #ifdef CONFIG_BLK_DEV_FD
 	if (major(ROOT_DEV) == FLOPPY_MAJOR) {

Re: [PATCH] remove compat code for old devfs naming scheme

[Richard Gooch]

Christoph Hellwig writes:
> Hi Richard,
> 
> current init/do_mounts.c contains the devfs_make_root/convert_name
> functions which provide compatiblility for the old, pre kernel-merge
> devfs naming scheme in the root= kernel command line.
> 
> As this was never present in official kernels there is really no need
> in keeping it - it just bloats the kernel.
> 
> Could you please forward this patch to Linus and maybe Marcelo with
> your next devfs update?

What on earth are you talking about? This code has been in the kernel
since 2.3.46. It's just lived in a different place: fs/devfs/util.c.

And FYI: 2.5.x kernels *are* official!

				Regards,

					Richard....
Permanent: rgooch@atnf.csiro.au
Current:   rgooch@ras.ucalgary.ca

Re: [PATCH] remove compat code for old devfs naming scheme

[Christoph Hellwig]

On Tue, May 14, 2002 at 08:35:03AM -0600, Richard Gooch wrote:
> > As this was never present in official kernels there is really no need
> > in keeping it - it just bloats the kernel.
> > 
> > Could you please forward this patch to Linus and maybe Marcelo with
> > your next devfs update?
> 
> What on earth are you talking about? This code has been in the kernel
> since 2.3.46. It's just lived in a different place: fs/devfs/util.c.
> 

Of course this code was present, otherwise it would be rather hard to
remove it..

But the old devfs naming scheme was obsolete before devfs was merged in
2.3.46 so there is no valid reason to support it for root=.

Re: [PATCH] remove compat code for old devfs naming scheme

[Richard Gooch]

Christoph Hellwig writes:
> On Tue, May 14, 2002 at 08:35:03AM -0600, Richard Gooch wrote:
> > > As this was never present in official kernels there is really no need
> > > in keeping it - it just bloats the kernel.
> > > 
> > > Could you please forward this patch to Linus and maybe Marcelo with
> > > your next devfs update?
> > 
> > What on earth are you talking about? This code has been in the kernel
> > since 2.3.46. It's just lived in a different place: fs/devfs/util.c.
> 
> Of course this code was present, otherwise it would be rather hard
> to remove it..
> 
> But the old devfs naming scheme was obsolete before devfs was merged
> in 2.3.46 so there is no valid reason to support it for root=.

The reason to support it is because lots of people are depending on
it. A lot of systems would break for no real gain. This code is in the
init section, so the memory will be freed before init(8) starts.

The code should stay. In 2.5, I can move it into the mini devfsd that
will go into the initial rootfs.

				Regards,

					Richard....
Permanent: rgooch@atnf.csiro.au
Current:   rgooch@ras.ucalgary.ca

Re: [PATCH] remove compat code for old devfs naming scheme

[Christoph Hellwig]

On Tue, May 14, 2002 at 08:59:41AM -0600, Richard Gooch wrote:
> The reason to support it is because lots of people are depending on
> it. A lot of systems would break for no real gain. This code is in the
> init section, so the memory will be freed before init(8) starts.
> 
> The code should stay. In 2.5, I can move it into the mini devfsd that
> will go into the initial rootfs.

Exactly how many system exist which

  a) still use the two or three year old devfs naming scheme for
     their root= command line
  b) use current 2.5 kernels

and

  c) have users not capable of translating that syntax to either
     the new devfs or traditional Linux syntax?

I don't think there are more then about ten, and no I _absolutely_
do not consider that a reason to bloat the kernel, even if it is just
source and image bloat.

Re: [PATCH] remove compat code for old devfs naming scheme

[Richard Gooch]

Christoph Hellwig writes:
> On Tue, May 14, 2002 at 08:59:41AM -0600, Richard Gooch wrote:
> > The reason to support it is because lots of people are depending on
> > it. A lot of systems would break for no real gain. This code is in the
> > init section, so the memory will be freed before init(8) starts.
> > 
> > The code should stay. In 2.5, I can move it into the mini devfsd that
> > will go into the initial rootfs.
> 
> Exactly how many system exist which
> 
>   a) still use the two or three year old devfs naming scheme for
>      their root= command line
>   b) use current 2.5 kernels

Those names are not really "old", but convenient shorthand. And it's
more systems than you think.

> and
> 
>   c) have users not capable of translating that syntax to either
>      the new devfs or traditional Linux syntax?
> 
> I don't think there are more then about ten, and no I _absolutely_
> do not consider that a reason to bloat the kernel, even if it is just
> source and image bloat.

A lot more people are using devfs than you realise. Removing the code
would screw them over. Leave it alone.

				Regards,

					Richard....
Permanent: rgooch@atnf.csiro.au
Current:   rgooch@ras.ucalgary.ca