panic in ufs_lookup (6.2-STABLE)

[Andrew N. Below]

Hi all,

freebsd box connected to Eonstor RAID with 5-6 exported
partitions (each one has ~950Gb size, fs is UFS2)

every night we have a lot of running rsyncs (rsnapshots)
on these partitions

this happens 2-4 times per month

db> bt
Tracing pid 70595 tid 100178 td 0xc95fa600
kdb_enter(c0634690) at kdb_enter+0x2b
panic(c0640603,da7e1200,e8c99a58,c05b591e,cb8cc18c,...) at panic+0x127
ufs_dirbad(cb8cc18c,200,c06405bd,c95fa600,0,...) at ufs_dirbad+0x3a
ufs_lookup(e8c99a7c) at ufs_lookup+0x36a
VOP_CACHEDLOOKUP_APV(c066ae00,e8c99a7c) at VOP_CACHEDLOOKUP_APV+0x38
vfs_cache_lookup(e8c99b18) at vfs_cache_lookup+0xb2
VOP_LOOKUP_APV(c066ae00,e8c99b18) at VOP_LOOKUP_APV+0x43
lookup(e8c99ba0) at lookup+0x4c1
namei(e8c99ba0) at namei+0x39a
kern_lstat(c95fa600,bfbfd870,0,e8c99c74) at kern_lstat+0x47
lstat(c95fa600,e8c99d04) at lstat+0x1b
syscall(809003b,bfbf003b,bfbf003b,8132a5f,bfbfd790,...) at syscall+0x2bf
Xint0x80_syscall() at Xint0x80_syscall+0x1f
--- syscall (190, FreeBSD ELF32, lstat), eip = 0x35dd3427, esp = 0xbfbfcd7c,
ebp = 0xbfbfce08 ---
db> show proc
Process 70595 (rsync) at 0xc95f6648:
  state: NORMAL
  uid: 0  gids: 0, 0, 5
  parent: pid 70594 at 0xc83a5648
  ABI: FreeBSD ELF32
  arguments: /usr/local/bin/rsync
  threads: 1
100178                   Run     CPU 2               rsync

what is exactly wrong?

--
WBR,
Andrew