Bug#645240: race-condition: background tasks run from postinst scripts cause lb_chroot_devpts to fail
Package: live-build
Version: 2.0.12-2
Severity: normal
Tags: squeeze
Hi live team,
I'm building quite large live systems which I employ in daily production use,
so they are BIG (around 4GB). Recently I added the package dwww, which causes
the build to fail occasionally. I was able to track down the issue to the
dwww.postinst script, which does some index creation - in background (squeeze's
dwww.postinst:67-71 to be exact).
Depending on the load situation on my system (CPU vs. I/O), the build fails, if
the index creation is still running, when "lb_chroot_devpts remove" is invoked
by live-build: since the index creation has some open file handles in
[...]/chroot/dev/pts, the umount command fails.
I think this is a conceptual issue, so I didn't file this bug against dwww but
live-build.
Currently, I'm circumventing this issue by invoking a "debug shell" just prior
to the umount invocation in lb_chroot_devpts in order to manually assert dwww
really has finished and the umount would succeed.
Like I said: I'm using live-build for production systems, so I only tried this
with live-build 2, not 3. Did anything change at that place or would this issue
persist in 3? ...just hoping this bug report is justified :-)
I'd be glad to provide additional information if needed.
Thx, cheers
Daniel
-- Package-specific info:
-- System Information:
Debian Release: 6.0.3
APT prefers stable
APT policy: (990, 'stable'), (500, 'stable-updates')
Architecture: amd64 (x86_64)
Kernel: Linux 2.6.32-5-dhr-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Versions of packages live-build depends on:
ii cdebootstrap 0.5.7 Bootstrap a Debian system
ii debootstrap 1.0.26+squeeze1 Bootstrap a basic Debian system
Versions of packages live-build recommends:
ii cpio 2.11-4 GNU cpio -- a program to manage ar
ii gnu-fdisk 1.2.4-3+b1 Linux fdisk replacement based on l
Versions of packages live-build suggests:
ii dosfstools 3.0.9-1 utilities for making and checking
ii fakeroot 1.14.4-1 Gives a fake root environment
ii genisoimage 9:1.1.11-1 Creates ISO-9660 CD-ROM filesystem
ii grub 0.97-64 GRand Unified Bootloader (dummy pa
ii memtest86+ 4.10-1.1 thorough real-mode memory tester
ii mtools 4.0.12-1 Tools for manipulating MSDOS files
ii parted 2.3-5 The GNU Parted disk partition resi
ii squashfs-tools 1:4.0-8 Tool to create and append to squas
ii sudo 1.7.4p4-2.squeeze.2 Provide limited super user privile
ii syslinux 2:4.03+dfsg-12 collection of boot loaders
ii uuid-runtime 2.17.2-9 runtime components for the Univers
pn win32-loader <none> (no description available)
-- no debconf information
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