kern/131784: triple LOR after hard reboot

[Dirk Meyer]

>Number:         131784
>Category:       kern
>Synopsis:       triple LOR after hard reboot
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Feb 17 19:40:00 UTC 2009
>Closed-Date:
>Last-Modified:
>Originator:     Dirk Meyer
>Release:        FreeBSD 8.0-STABLE i386
>Organization:
>Environment:
System: FreeBSD book64.dinoex.sub.de 8.0-CURRENT FreeBSD 8.0-CURRENT #5: Tue Feb 17 06:39:57 CET 2009     root at book64.dinoex.sub.de:/usr/obj/usr/src/sys/GENERIC  amd64

>Description:

 lock order reversal:
 1st 0xffffff0003a2d7f8 ufs (ufs) @ /usr/src/sys/ufs/ffs/ffs_snapshot.c:424
 2nd 0xfffffffe53e58bc8 bufwait (bufwait) @ /usr/src/sys/kern/vfs_bio.c:2443
 3rd 0xffffff00034fc7f8 ufs (ufs) @ /usr/src/sys/ufs/ffs/ffs_snapshot.c:545
 KDB: stack backtrace:
 db_trace_self_wrapper() at db_trace_self_wrapper+0x2a
 _witness_debugger() at _witness_debugger+0x2e
 witness_checkorder() at witness_checkorder+0x81e
 __lockmgr_args() at __lockmgr_args+0xc2a
 ffs_lock() at ffs_lock+0x8c
 VOP_LOCK1_APV() at VOP_LOCK1_APV+0x9b
 _vn_lock() at _vn_lock+0x47
 ffs_snapshot() at ffs_snapshot+0x1c09
 ffs_mount() at ffs_mount+0x666
 vfs_donmount() at vfs_donmount+0xe31
 nmount() at nmount+0xa6
 syscall() at syscall+0x1bf
 Xfast_syscall() at Xfast_syscall+0xab

 --- syscall (378, FreeBSD ELF64, nmount), rip = 0x8007a6cec, rsp = 0x7fffffffea48, rbp = 0x800a02530 ---
 lock order reversal:
 1st 0xfffffffe53e58bc8 bufwait (bufwait) @ /usr/src/sys/kern/vfs_bio.c:2443
 2nd 0xffffff0003892330 snaplk (snaplk) @ /usr/src/sys/ufs/ffs/ffs_snapshot.c:794
 KDB: stack backtrace:
 db_trace_self_wrapper() at db_trace_self_wrapper+0x2a
 _witness_debugger() at _witness_debugger+0x2e
 witness_checkorder() at witness_checkorder+0x81e
 __lockmgr_args() at __lockmgr_args+0xc2a
 ffs_lock() at ffs_lock+0x8c
 VOP_LOCK1_APV() at VOP_LOCK1_APV+0x9b
 _vn_lock() at _vn_lock+0x47
 ffs_snapshot() at ffs_snapshot+0x1ad6
 ffs_mount() at ffs_mount+0x666
 vfs_donmount() at vfs_donmount+0xe31
 nmount() at nmount+0xa6
 syscall() at syscall+0x1bf
 Xfast_syscall() at Xfast_syscall+0xab
 --- syscall (378, FreeBSD ELF64, nmount), rip = 0x8007a6cec, rsp = 0x7fffffffea48, rbp = 0x800a02530 ---

 lock order reversal:
 1st 0xffffff0003892330 snaplk (snaplk) @ /usr/src/sys/kern/vfs_vnops.c:293
 2nd 0xffffff0003a2d7f8 ufs (ufs) @ /usr/src/sys/ufs/ffs/ffs_snapshot.c:1588
 KDB: stack backtrace:
 db_trace_self_wrapper() at db_trace_self_wrapper+0x2a
 _witness_debugger() at _witness_debugger+0x2e
 witness_checkorder() at witness_checkorder+0x81e
 __lockmgr_args() at __lockmgr_args+0xc2a
 ffs_snapremove() at ffs_snapremove+0xe7
 softdep_releasefile() at softdep_releasefile+0x139
 ufs_inactive() at ufs_inactive+0x1a7
 vinactive() at vinactive+0x72
 vput() at vput+0x22c
 vn_close() at vn_close+0xb9
 vn_closefile() at vn_closefile+0x7d
 _fdrop() at _fdrop+0x23
 closef() at closef+0x4d
 kern_close() at kern_close+0x10d
 syscall() at syscall+0x1bf
 Xfast_syscall() at Xfast_syscall+0xab
 --- syscall (6, FreeBSD ELF64, close), rip = 0x80083cf8c, rsp = 0x7fffffffea48, rbp = 0 ---

>How-To-Repeat:

	kernel crashes while loading snd_hda, no crashdump can be written.
 	on reboot ffsck runs (and backroung fsck) which tiggered this LOR.

>Fix:

	unknown

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