panic: snapacct_ufs2: bad block

[Johannes Totz]

Hi!

Just got a panic on my 8-stable box:

panic: snapacct_ufs2: bad block
cpuid = 0
KDB: stack backtrace:
#0 0xffffffff805fd350 at kdb_backtrace+0x60
#1 0xffffffff805cb194 at panic+0x1b4
#2 0xffffffff807eed0e at snapacct_ufs2+0xfe
#3 0xffffffff807ee55f at indiracct_ufs2+0x2ff
#4 0xffffffff807ee4f7 at indiracct_ufs2+0x297
#5 0xffffffff807ef0ce at expunge_ufs2+0x30e
#6 0xffffffff807f2f79 at ffs_snapshot+0x1e59
#7 0xffffffff80802e38 at ffs_mount+0x1628
#8 0xffffffff80654f1c at vfs_donmount+0xf9c
#9 0xffffffff80655903 at nmount+0x73
#10 0xffffffff8060a17e at syscallenter+0x2fe
#11 0xffffffff808bcd31 at syscall+0x41
#12 0xffffffff808a52f2 at Xfast_syscall+0xe2

This box is running:
FreeBSD XXX 8.2-STABLE FreeBSD 8.2-STABLE #0 r224227: Wed Jul 20
16:55:23 BST 2011     root at XXX:/usr/obj/usr/src/sys/GENERIC  amd64

The crash happened during automated backup with dump(8) on the root file
system. There was plenty of free space left.
I have deleted all remaining snapshot files now.

Either dump or savecore didnt work, so that's the only info i have
(interestingly the above backtrace ended up in the logs anyway).

This panic has happened before (twice or so) with older versions of
fbsd. Would it be prudent to newfs and restore from backup, just to make
sure there are no remaining glitches?



Johannes