i386/163885: lock order reversal

[Roar Pettersen]

>Number:         163885
>Category:       i386
>Synopsis:       lock order reversal
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-i386
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Jan 07 11:20:06 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator:     Roar Pettersen
>Release:        9.0-STABLE
>Organization:
>Environment:
FreeBSD 9.0-STABLE FreeBSD 9.0-STABLE #0: Sat Jan  7 11:33:10 CET 2012     root at machine:/usr/obj/usr/src/sys/I386  i386
>Description:
lock order reversal:
 1st 0xddf0c8c8 bufwait (bufwait) @ /usr/src/sys/kern/vfs_bio.c:2658
 2nd 0xc4cba000 dirhash (dirhash) @ /usr/src/sys/ufs/ufs/ufs_dirhash.c:284
KDB: stack backtrace:
db_trace_self_wrapper(c0a1c0ac,7366752f,7366752f,7269645f,68736168,...) at db_trace_self_wrapper+0x26
kdb_backtrace(c075847b,c0a1fa73,c45452a0,c4548f90,de2ad898,...) at kdb_backtrace+0x2a
_witness_debugger(c0a1fa73,c4cba000,c0a45212,c4548f90,c0a44e97,...) at _witness_debugger+0x25
witness_checkorder(c4cba000,9,c0a44e97,11c,0,...) at witness_checkorder+0x839
_sx_xlock(c4cba000,0,c0a44e97,11c,c4cc9e80,...) at _sx_xlock+0x85
ufsdirhash_acquire(ddf0c868,c4cc9e80,de2ad9f4,deb48a70,de2ad968,...) at ufsdirhash_acquire+0x35
ufsdirhash_add(c4cc9e80,de2ad9f4,a70,de2ad954,de2ad958,...) at ufsdirhash_add+0x13
ufs_direnter(c4cc0cc0,c4cc0bb0,de2ad9f4,de2adb84,ddf0cc64,...) at ufs_direnter+0x739
ufs_mkdir(de2adc14,de2adc28,0,0,de2adbac,...) at ufs_mkdir+0x8ef
VOP_MKDIR_APV(c0ab2ee0,de2adc14,de2adb84,de2adbac,0,...) at VOP_MKDIR_APV+0xa5
kern_mkdirat(c4cabb80,ffffff9c,28404020,0,1c0,...) at kern_mkdirat+0x2a1
kern_mkdir(c4cabb80,28404020,0,1c0,de2add1c,...) at kern_mkdir+0x2e
sys_mkdir(c4cabb80,de2adcec,c0a58d56,c0a20682,202,...) at sys_mkdir+0x29
syscall(de2add28) at syscall+0x284
Xint0x80_syscall() at Xint0x80_syscall+0x21
--- syscall (136, FreeBSD ELF32, sys_mkdir), eip = 0x28172c93, esp = 0xbfbfe8cc, ebp = 0xbfbfed78 ---
>How-To-Repeat:

>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: