On Tue, Sep 09, 2008 at 05:55:31PM -0400, Theodore Tso wrote: > > > Unfortunately this is one of those bugs that I can't find a way to > > > reproduce except by randomly breaking one fs after another. This > > > happens with ext3 and ext4, but so far I haven't seen it happen > > > with ext2. > > > > > > > > > *** seed 270, ext3, 2.6.27-rc3 *** > > > *** seed 451, ext4, 2.6.27-rc5 *** > > Given these seed numbers, I assume this was generating using some tool > like fsfuzzer? Would it be possible to generate a filesystem image > *before* that triggers the problem case, before trying to execute the > rm -rf? > > That would be the fastest way to try to track the problem down. Yes, I can generate those filesystems. However the problem seems to be elusive in that I haven't yet been able to reproduce it twice with the same filesystem (and even with random filesystems, it every occurs once in a while). I'll do some more testing and try to figure out if it can be reproduced more easily. Still I can give you some filesystems that crashed once, if you wish. They are typically something like 600 KiB compressed, and I guess that could be made less by zeroing all regular files in the pristine fs before doing the fuzzing. Here's a script I use to do the testing ($1 is the initial seed). The filesystem is a 10 MiB pristine ext[34] image with a copy of my workstation's /dev and a partial copy of /usr/share/doc (I tried to be diverse in what I put there). ------------------------------------------------------------ #!/bin/sh if [ "`hostname`" != "fstest" ]; then echo "This is a dangerous script." echo "Set your hostname to \`fstest\' if you want to use it." exit 1 fi umount /dev/hdb umount /dev/hdc /etc/init.d/sysklogd stop /etc/init.d/klogd stop /etc/init.d/cron stop mount /dev/hda / -t ext3 -o remount,ro || exit 1 #ulimit -t 20 for ((s=$1; s<1000000000; s++)); do umount /mnt echo '***** zzuffing *****' seed $s zzuf -r 0:0.03 -s $s </dev/hdc >/dev/hdb || exit mount /dev/hdb /mnt -t ext2 -o errors=continue || continue cd /mnt || continue timeout 30 cp -r doc doc2 >&/dev/null timeout 30 find -xdev >&/dev/null timeout 30 find -xdev -print0 2>/dev/null |xargs -0 touch -- 2>/dev/null timeout 30 mkdir tmp >&/dev/null timeout 30 echo whoah >tmp/filu 2>/dev/null timeout 30 rm -rf /mnt/* >&/dev/null cd / done ------------------------------------------------------------ Sami -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
