>Number:         35556
>Category:       kern
>Synopsis:       panic: lockmgr: locking aginst myself
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Feb 06 22:00:00 +0000 2007
>Originator:     Phil Nelson
>Release:        NetBSD-4.0 Beta2
>Organization:
Western Washington University
>Environment:
NetBSD wb26 4.0_BETA2 NetBSD 4.0_BETA2 (GENERIC) #0: Sun Jan 14 05:18:29 GMT 2007  riz@ADMIN:/usr/obj.i386/sys/arch/i386/compile/GENERIC i386

>Description:
panic: lockmgr: locking aginst myself
Stopped in pid 7247.1 (sh) at  netbsd:cpu_Debugger+0x4:    popl  %ebp
db> bt
...
lockmgr(d10edc48,10002,d10edbd4,0,0) at netbsd:lockmgr_0xa1d
genfs_lock(cc3f2a10,c2253bf0,c0f221b8,c0749e80,d10edbd4) at netbsd:genfs_lock+0x25
VOP_LOCK(d10edbd4,10002,cc3f2a9c,c04d165e,cb78b130) at netbsd:VOP_LOCK+0x25
vn_lock(d10edbd4,20002,400,cc3f2bd0,0) at netbsd:vn_lock+0x87
namei(cc3f2bb8,cc89b800,400,0,3) at netbsd:namei+0xd7
vn_open(cc3f2bb8,5,0,c041797f,cdb8e3b0) at netbsd:vn_open+0x21e
sys_open(cc75c81c,cc3f2c48,cc3f2c68,cc3f2c60,c04cf6d4) at netbsd_sys_open+0xb6
syscall_plain() at netbsd:syscall_plain+0x149
--- syscall (number 5) ---
0xbbae3beb:
db>

This back trace from a machine using lft for /.  No other partitions
or filesystems in use.

Same panic happened on a machine using same kernel, but having
3 FFS partitions, /, /usr, and /home.


>How-To-Repeat:
This problem happened consistently on a build cluster building
netbsd-4 and netbsd-3.  When doing the build for the mac68k it
would progress to the point where it did:

Calculated size of `miniroot.fs.tmp': 4194304 bytes, 257 inodes
Extent size set to 4096
miniroot.fs.tmp: 4.0MB (8192 sectors) block size 4096, fragment size 512
        using 1 cylinder groups of 4.00MB, 1024 blks, 352 inodes.
super-block backups (for fsck -b #) at:
 32,
Populating `miniroot.fs.tmp'
Image `miniroot.fs.tmp' complete
all ===> etc/mac68k
all ===> etc/mac68k/instkernel
all ===> etc/mac68k/instkernel/ramdisk
Run "make -f ramdiskbin.mk objs exe" to build crunched binary.

And it would consistently crash at this point.  I can easily
get a machine to db with this crash.
>Fix:
not know.