On Fri, Jun 19, 2009 at 01:54:09AM -0500, Rob Landley wrote: > On Thursday 18 June 2009 19:09:26 Colin Watson wrote: > > When FEATURE_MOUNT_HELPERS is enabled, mount should support the -i > > option, which prevents calling the helper function. This is used by > > FUSE: it installs fusermount as a helper, and if it's configured to > > update /etc/mtab then it does so by calling 'mount -i -f' (i.e. don't > > call helper, fake the system call, but do update mtab). > > There's something that still uses mtab? Wow. > > So Ubuntu doesn't support per-process namespaces?
Probably not very well unless you change /etc/mtab to be a symlink, no, not yet. > > I believe this is a fairly standard thing for mount helpers to want > > to do (why should they include code to update mtab when mount can do > > it for them?) > > Why should they have an /etc/mtab when it should be a symlink to > /proc/self/mounts? I'm not sure why I need to justify this here - you have mtab as a configuration option in busybox and so surely that configuration should work. But anyway ... Historically /etc/mtab couldn't be made a symlink because some information was missing from /proc/mounts, which was particularly relevant for the handling of loop devices. It's only relatively recently (Linux 2.6.26) that /proc/mounts has been useful. I think there may even still be some problems with this: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=531371 has some more information. We probably will move to /etc/mtab as a symlink (cf. http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=494001) but we won't do it just because of a busybox bug. When you have production systems depending on existing behaviour, a certain amount of caution and trying to ensure that you've covered all the bases is appropriate. -- Colin Watson [[email protected]] _______________________________________________ busybox mailing list [email protected] http://lists.busybox.net/mailman/listinfo/busybox
