On Fri, May 31, 2013 at 06:45:18AM +0200, Patrik Lundin wrote:
>
> I am currently testing this patch, I will report back once I have
> some results.
>
So have have tried to stress test the patch, and while it seems to
superficially work it doesnt really seem stable.
I have written a rather silly script cycling /usr/src between read/write
and read-only while extracting and clearing the 5.3 src.tar.gz, and
while a non-softdep fs has been able to complete all the runs, the
softdep version seems to halt after a random amount of cycles.
It always freezes at the same place, after clearing out /usr/src and
attempting to mount the now empty partition read-only again. The machine
is still responding but there exists a process looking like this:
===
root 8678 0.0 0.0 344 184 p0 D+ 8:23PM 0:00.05
/sbin/mount_ffs -o nodev -o nosuid -o softdep -o update -o ro /dev/wd0i /usr/src
===
Attempting to attach to it with gdb yields this:
===
# gdb /sbin/mount_ffs 8678
GNU gdb 6.3
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "amd64-unknown-openbsd5.3"...(no debugging symbols
found)
Attaching to program: /sbin/mount_ffs, process 8678
===
ktrace doesnt have much to say either:
===
# kdump
8678 mount_ffs EMUL "native"
===
I'm not used to debugging kernel level freezes, so I am not sure what to do.
Also i must add that the test is performed in a pretty strange setup where
OpenBSD is running as a virtualbox guest on top of Win7 and the disk image is
accessed via an OpenBSD-hosted samba share. But this is what i can test right
now and at least the normal non-softdep operation seems to work as expected.
This is the test script:
===
#!/bin/sh --
COUNTER=0
mount | grep /usr/src
while [ COUNTER -lt 1000 ]; do
echo ""
echo "COUNTER: $COUNTER"
echo ""
echo "Mounting filesystem read/write"
mount -uw /usr/src
if [ $? -ne 0 ]; then
echo "mount -uw failed (1)"
exit 1
fi
mount | grep /usr/src
echo ""
echo "Extracting src.tar.gz"
tar -zxf /root/src.tar.gz -C /usr/src
if [ $? -ne 0 ]; then
echo "tar -zxf failed"
exit 1
fi
echo ""
echo "Mounting filesysytem read-only"
mount -ur /usr/src
if [ $? -ne 0 ]; then
echo "mount -ur failed (1)"
exit 1
fi
mount | grep /usr/src
echo ""
echo "Mounting filesystem read/write"
mount -uw /usr/src
if [ $? -ne 0 ]; then
echo "mount -uw failed (2)"
exit 1
fi
mount | grep /usr/src
echo ""
echo "Clearing filesystem"
rm -r /usr/src/*
if [ $? -ne 0 ]; then
echo "rm -r failed"
exit 1
fi
echo ""
echo "Mounting filesystem read-only"
mount -ur /usr/src
if [ $? -ne 0 ]; then
echo "mount -ur failed (2)"
exit 1
fi
mount | grep /usr/src
let COUNTER=COUNTER+1
done
===
... and when the script decides to stop, it is always at:
===
Mounting filesystem read/write
/dev/wd0i on /usr/src type ffs (local, nodev, nosuid, softdep)
Clearing filesystem
Mounting filesystem read-only
===
Regards,
Patrik Lundin
