LOR RELENG_8 unlink/dirhash

Two more...

lock order reversal:
 1st 0xd85c60e0 bufwait (bufwait) _at_ /.../src/sys/kern/vfs_bio.c:2559
 2nd 0xc8553800 dirhash (dirhash) _at_ /.../src/sys/ufs/ufs/ufs_dirhash.c:285
KDB: stack backtrace:
db_trace_self_wrapper(c0c75d72,e6f59a74,c08c1375,c08b20fb,c0c78d15,...)
at db_trace_self_wrapper+0x26
kdb_backtrace(c08b20fb,c0c78d15,c452bfc8,c452f6a0,e6f59ad0,...) at
kdb_backtrace+0x29
_witness_debugger(c0c78d15,c8553800,c0c9aa71,c452f6a0,c0c9a6fa,...) at
_witness_debugger+0x25
witness_checkorder(c8553800,9,c0c9a6fa,11d,0,...) at witness_checkorder+0x839
_sx_xlock(c8553800,0,c0c9a6fa,11d,db205018,...) at _sx_xlock+0x85
ufsdirhash_acquire(0,e,c4756800,d85c6080,db205018,...) at
ufsdirhash_acquire+0x35
ufsdirhash_remove(c6ef7a6c,db205018,18,e6f59b60,e6f59b5c,...) at
ufsdirhash_remove+0x14
ufs_dirremove(ccbb0324,c6ef7bc8,500800c,0,ccbb0324,...) at ufs_dirremove+0xe5
ufs_remove(e6f59c34,0,0,0,cb198218,...) at ufs_remove+0x6e
VOP_REMOVE_APV(c0d7a580,e6f59c34,cb198218,e6f59c0c,28216238,...) at
VOP_REMOVE_APV+0xa5
kern_unlinkat(c636db40,ffffff9c,28216238,0,e6f59c80,...) at kern_unlinkat+0x181
kern_unlink(c636db40,28216238,0,e6f59d2c,c0bb0a63,...) at kern_unlink+0x27
unlink(c636db40,e6f59cf8,4,c0c94eac,c0d58db8,...) at unlink+0x22
syscall(e6f59d38) at syscall+0x2a3
Xint0x80_syscall() at Xint0x80_syscall+0x20
--- syscall (10, FreeBSD ELF32, unlink), eip = 0x28168e7f, esp =
0xbfbfea4c, ebp = 0xbfbfea78 ---

lock order reversal:
 1st 0xd84e6460 bufwait (bufwait) _at_ /.../src/sys/kern/vfs_bio.c:2559
 2nd 0xc4a4f200 dirhash (dirhash) _at_ /.../src/sys/ufs/ufs/ufs_dirhash.c:285
KDB: stack backtrace:
db_trace_self_wrapper(c0c75d72,e6f13a74,c08c1365,c08b20eb,c0c78d15,...)
at db_trace_self_wrapper+0x26
kdb_backtrace(c08b20eb,c0c78d15,c452bfc8,c452f6a0,e6f13ad0,...) at
kdb_backtrace+0x29
_witness_debugger(c0c78d15,c4a4f200,c0c9aa71,c452f6a0,c0c9a6fa,...) at
_witness_debugger+0x25
witness_checkorder(c4a4f200,9,c0c9a6fa,11d,0,...) at witness_checkorder+0x839
_sx_xlock(c4a4f200,0,c0c9a6fa,11d,d874d6ec,...) at _sx_xlock+0x85
ufsdirhash_acquire(0,e,c4756800,d84e6400,d874d6ec,...) at
ufsdirhash_acquire+0x35
ufsdirhash_remove(c4aacd24,d874d6ec,6ec,e6f13b60,e6f13b5c,...) at
ufsdirhash_remove+0x14
ufs_dirremove(c483e648,c4ae9910,500800c,0,c483e648,...) at ufs_dirremove+0xe5
ufs_remove(e6f13c34,0,0,0,c4ae1b84,...) at ufs_remove+0x6e
VOP_REMOVE_APV(c0d7a580,e6f13c34,c4ae1b84,e6f13c0c,804c2e8,...) at
VOP_REMOVE_APV+0xa5
kern_unlinkat(c5fc76c0,ffffff9c,804c2e8,0,e6f13c80,...) at kern_unlinkat+0x181
kern_unlink(c5fc76c0,804c2e8,0,e6f13d2c,c0bb0a53,...) at kern_unlink+0x27
unlink(c5fc76c0,e6f13cf8,4,c0c599ce,c0d58db8,...) at unlink+0x22
syscall(e6f13d38) at syscall+0x2a3
Xint0x80_syscall() at Xint0x80_syscall+0x20
--- syscall (10, FreeBSD ELF32, unlink), eip = 0x28169dbf, esp =
0xbfbfe64c, ebp = 0xbfbfe6b8 ---