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    SubjectRe: [PATCH] init: fix name of root device in /proc/mounts
    On Mon, Feb 04, 2013 at 06:54:32PM -0800, H. Peter Anvin wrote:
    > The difference is that it used to be customary to have a /dev/root symlink; iirc udev created one. Devtmpfs does not (for largely valid reasons, but it does break some userspaces.)

    Correct. The /dev/root symlink is not created any longer. If you boot
    with an initramfs this path does not show up in /proc/mounts. If you
    boot without one, however, it does.

    This patch just makes the /dev/root path not show up at all in
    /proc/mounts, regardless of whether an initramfs is used.

    Thanks,

    William

    > Rob Landley <rob@landley.net> wrote:
    >
    > >On 01/31/2013 05:22:09 PM, H. Peter Anvin wrote:
    > >> On 01/31/2013 02:51 PM, William Hubbs wrote:
    > >> > On a system that does not use an initramfs, /dev/root was always
    > >> > listed in /proc/mounts. This breaks software which scans
    > >> /proc/mounts to
    > >> > determine which file systems are mounted since /dev/root is not a
    > >> valid
    > >> > device name.
    > >> >
    > >> > This changes that processing so that "/dev/root" is only added to
    > >> > /proc/mounts if a root device is not specified with the root=
    > >> option on
    > >> > the kernel command line.
    > >> >
    > >> > Signed-off-by: William Hubbs <w.d.hubbs@gmail.com>
    > >>
    > >> Let me also point out that most of the time, the kernel actually has
    > >a
    > >> udev device name for an actual device...
    > >
    > >So your software is broken by overmounts? /dev/root is just one example
    > >
    > >of this. (And you can specify a root= on the kernel command line and
    > >have that be parsed by initramfs. I vaguely recall klibc does this...)
    > >
    > >For an example of how to parse this stuff, how about:
    > >
    > > http://landley.net/hg/toybox/file/4ffb735aea59/toys/posix/df.c
    > >
    > >I.E. parse from the end of the list (most recent match is the
    > >overmount), and eliminate synthetic filesystems. Note that code is from
    > >
    > >2006, other people have managed to cope all this time...
    > >
    > >Rob
    >
    > --
    > Sent from my mobile phone. Please excuse brevity and lack of formatting.
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