freebsd crash under I/O - got error messages part 4

[Wojciech Puchar]

even without UFS_DIRHASH there are still errors under heavier I/O load.



lock order reversal:
  1st 0xfffff800182c9068 ufs (ufs) @ kern/vfs_subr.c:2137
  2nd 0xfffffe00612443d0 bufwait (bufwait) @ ufs/ffs/ffs_vnops.c:262
  3rd 0xfffff8004a877418 ufs (ufs) @ kern/vfs_subr.c:2137
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 
0xfffffe007870ae20
kdb_backtrace() at kdb_backtrace+0x39/frame 0xfffffe007870aed0
witness_checkorder() at witness_checkorder+0xdc2/frame 0xfffffe007870af60
__lockmgr_args() at __lockmgr_args+0x9ea/frame 0xfffffe007870b0a0
ffs_lock() at ffs_lock+0x84/frame 0xfffffe007870b0f0
VOP_LOCK1_APV() at VOP_LOCK1_APV+0xd9/frame 0xfffffe007870b120
_vn_lock() at _vn_lock+0xaa/frame 0xfffffe007870b190
vget() at vget+0x67/frame 0xfffffe007870b1d0
vfs_hash_get() at vfs_hash_get+0xe1/frame 0xfffffe007870b220
ffs_vgetf() at ffs_vgetf+0x40/frame 0xfffffe007870b2b0
softdep_sync_buf() at softdep_sync_buf+0x3b3/frame 0xfffffe007870b390
ffs_syncvnode() at ffs_syncvnode+0x286/frame 0xfffffe007870b410
ffs_truncate() at ffs_truncate+0x614/frame 0xfffffe007870b600
ufs_direnter() at ufs_direnter+0x722/frame 0xfffffe007870b6c0
ufs_mkdir() at ufs_mkdir+0x4d0/frame 0xfffffe007870b850
VOP_MKDIR_APV() at VOP_MKDIR_APV+0xd1/frame 0xfffffe007870b880
kern_mkdirat() at kern_mkdirat+0x1be/frame 0xfffffe007870baa0
amd64_syscall() at amd64_syscall+0x216/frame 0xfffffe007870bbb0
Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfffffe007870bbb0
--- syscall (136, FreeBSD ELF64, sys_mkdir), rip = 0x800c0e93a, rsp = 
0x7fffffffd3f8, rbp = 0x7fffffffd520 ---