tags 593516 + fixed-upstream pending thanks On Thu, Aug 19, 2010 at 08:54:38PM -0400, Greg Price wrote: > On Thu, Aug 19, 2010 at 3:21 PM, Roger Leigh <[email protected]> wrote: > >> Currently I'm working around the issue with a flock around the body of > >> do_umount_all(). That's easy and is enough to address the problem > >> when no other umounts are happening on the system. > > > > If you would like this fix including, I'll be happy to accept a > > patch implementing this. Are you doing this in the shell script? > > If it's possible to directly lock /proc/mounts with fcntl this could > > be addressed directly in schroot-listmounts using sbuild::file_lock, > > which wraps fcntl. > > Sure, patch copied below. It's not possible for userspace to directly > lock /proc/mounts; the best we can do is an advisory lock that we > ourselves respect. So I placed a flock around the invocations of both > schroot-listmounts and umount, which are the only such invocations in > the schroot source tree.
This is ideal, and I've included your patch on the schroot-1.4 branch http://git.debian.org/?p=buildd-tools/schroot.git;a=commitdiff;h=806466870c810332fc6a5e932598e339029992bf http://git.debian.org/?p=buildd-tools/schroot.git;a=commitdiff;h=8a65a3426da512bba036f4ac02ee588765e1bcc4 I've just altered the patch to add a comment about the purpose of the lock. I've also altered the lock name to /var/log/schroot-umount to prevent conflicts with others since it's in our namespace. > > Has a bug report been filed against the Linux kernel or on the > > kernel mailing list? A fix in the kernel would be ideal, and they > > should probably also be notified. > > I haven't filed such a bug. I'm debating whether to send a message to > the LKML. Honestly, I suspect this will follow many other well-loved > quirks in that it is difficult to fix, and the best solution to hope > for may be for more people to be aware of it and handle it with > strategies like the separate-namespace approach you suggest. Maybe > I'll mail the LKML with a strawman patch, and see if someone can prove > me wrong. =) In the meantime I duplicated this bug as #593883 and assigned it to linux-2.6. At least the Debian kernel team will be aware of it. Thanks, Roger -- .''`. Roger Leigh : :' : Debian GNU/Linux http://people.debian.org/~rleigh/ `. `' Printing on GNU/Linux? http://gutenprint.sourceforge.net/ `- GPG Public Key: 0x25BFB848 Please GPG sign your mail.
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