Bug 154814

lock order reversal:
 1st 0xc1a87a54 bufwait (bufwait) @ /data/src/freebsd/src/sys/kern/vfs_bio.c:2658
 2nd 0xc1c2d800 dirhash (dirhash) @ /data/src/freebsd/src/sys/ufs/ufs/ufs_dirhash.c:284
KDB: stack backtrace:
db_trace_self_wrapper(c0744e28,72732f64,79732f63,66752f73,66752f73,...) at db_trace_self_wrapper+0x26
kdb_backtrace(c054790b,c0747ead,c1c11878,c1c13b68,c6f7f894,...) at kdb_backtrace+0x2a
_witness_debugger(c0747ead,c1c2d800,c076061b,c1c13b68,c0760293,...) at _witness_debugger+0x25
witness_checkorder(c1c2d800,9,c0760293,11c,0,...) at witness_checkorder+0x839
_sx_xlock(c1c2d800,0,c0760293,11c,c2092414,...) at _sx_xlock+0x85
ufsdirhash_acquire(c1a879f4,c84a4800,200,c84a481c,c6f7f964,...) at ufsdirhash_acquire+0x35
ufsdirhash_add(c2092414,c6f7f9ec,81c,c6f7f950,c6f7f954,...) at ufsdirhash_add+0x13
ufs_direnter(c209c220,c20e3990,c6f7f9ec,c6f7fbd0,c1a8eed4,...) at ufs_direnter+0x6f9
ufs_mkdir(c6f7fbf8,c6f7fc0c,0,0,c6f7fb3c,...) at ufs_mkdir+0x85f
VOP_MKDIR_APV(c07a3340,c6f7fbf8,c6f7fbd0,c6f7fb3c,0,...) at VOP_MKDIR_APV+0xa5
kern_mkdirat(c1e2f5c0,ffffff9c,80513e0,0,1c0,...) at kern_mkdirat+0x235
kern_mkdir(c1e2f5c0,80513e0,0,1c0,c6f7fc7c,...) at kern_mkdir+0x2e
mkdir(c1e2f5c0,c6f7fcec,c6f7fd28,c07467b3,0,...) at mkdir+0x29
syscallenter(c1e2f5c0,c6f7fce4,c6f7fce4,0,51,...) at syscallenter+0x263
syscall(c6f7fd28) at syscall+0x34
Xint0x80_syscall() at Xint0x80_syscall+0x21
--- syscall (136, FreeBSD ELF32, mkdir), eip = 0x28182a53, esp = 0xbfbfe92c, ebp = 0xbfbfe9b8 ---

Fix: 

n/a
How-To-Repeat: n/a