2.5.7{,-rmk1}: jffs2 on root patch

2.5.7{,-rmk1}: jffs2 on root patch

[Christopher Hoover]

2.5.7-rmk1 (and apparently any 2.5.7 kernel, hence the cross-posting)
requires the following patch, if you wish to use a jffs2 file system
as your root.  Without the patch, mount_block_root() won't attempt to
use jffs2.

-ch

mailto:ch@murgatroid.com
mailto:ch@hpl.hp.com

--- linux-2.5.7-rmk1/fs/jffs2/super.c	Mon Apr  1 13:25:41 2002
+++ linux-2.5.7-rmk1-ch1/fs/jffs2/super.c	Tue Apr  2 13:20:01 2002
@@ -300,7 +300,8 @@ static struct file_system_type jffs2_fs_
 	owner:		THIS_MODULE,
 	name:		"jffs2",
 	get_sb:		jffs2_get_sb,
-	kill_sb:	generic_shutdown_super
+	kill_sb:	generic_shutdown_super,
+	fs_flags:	FS_REQUIRES_DEV,
 };
 
 

Re: 2.5.7{,-rmk1}: jffs2 on root patch

[David Woodhouse]

ch@hpl.hp.com said:
>  2.5.7-rmk1 (and apparently any 2.5.7 kernel, hence the cross-posting)
> requires the following patch, if you wish to use a jffs2 file system
> as your root.  Without the patch, mount_block_root() won't attempt to
> use jffs2.

I don't like it. We don't require a block device, and I'd rather see the
mechanism fixed to pass the 'root=' argument to the file system, so we can
use the new mount-by-name functionality on the rootfs.

--
dwmw2

RE: 2.5.7{,-rmk1}: jffs2 on root patch

[Christopher Hoover]

I discovered that with vanilla 2.5.7, the kernel will indeed mount a
jffs root, if you do:

  root=/dev/mtdblockX rootfstype=jffs2

[ 

as opposed to simply:

  root=/dev/mtdblockX 

which work just fined prior to 2.5.7

]

The "rootfstype=jffs2" part is *mandatory*, because
do_mounts.c:get_fs_names(), which computes which filesystems should be
attempted for the root partitition, skips any filesystem, such as jffs2,
that is "nodev."

-ch


> -----Original Message-----
> From: linux-mtd-admin@lists.infradead.org 
> [mailto:linux-mtd-admin@lists.infradead.org] On Behalf Of 
> David Woodhouse
> Sent: Tuesday, April 02, 2002 5:29 PM
> To: Christopher Hoover
> Cc: linux-arm-kernel@lists.arm.linux.org.uk; 
> linux-mtd@lists.infradead.org
> Subject: Re: 2.5.7{,-rmk1}: jffs2 on root patch 
> 
> 
> 
> ch@hpl.hp.com said:
> >  2.5.7-rmk1 (and apparently any 2.5.7 kernel, hence the 
> cross-posting) 
> > requires the following patch, if you wish to use a jffs2 
> file system 
> > as your root.  Without the patch, mount_block_root() won't 
> attempt to 
> > use jffs2.
> 
> I don't like it. We don't require a block device, and I'd 
> rather see the mechanism fixed to pass the 'root=' argument 
> to the file system, so we can use the new mount-by-name 
> functionality on the rootfs.
> 
> --
> dwmw2
> 
> 
> 
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