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 <[email protected]> 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 <[email protected]> > >> > >> 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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