Re: kern/37925 (more locking problems with unionfs)

[Andrew Doran <ad%NetBSD.org@localhost>]

The following reply was made to PR kern/37925; it has been noted by GNATS.

From: Andrew Doran <ad%NetBSD.org@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: kern/37925 (more locking problems with unionfs)
Date: Thu, 31 Jan 2008 12:01:03 +0000

 I can reproduce this with the new vnode locks:
 
 Reader / writer lock error: lockdebug_unlocked: not held by current LWP
 
 lock address : 0x00000000d2845acc type     :     sleep/adaptive
 shared holds :                  0 exclusive:                  1
 shares wanted:                  0 exclusive:                  0
 current cpu  :                  1 last held:                  0
 current lwp  : 0x00000000d71e8a00 last held: 0x00000000d724fd20
 last locked  : 0x00000000c02f2c0e unlocked : 0x00000000c02f2ca2
 initialized  : 0x00000000c02f3f43
 owner/count  : 0x00000000d724fd20 flags    : 0x000000000000000c
 
 Turnstile chain at 0xc04eb5e0.
 => No active turnstile for this lock.
 
 panic: LOCKDEBUG
 Stopped in pid 22322.1 (cc1) at netbsd:breakpoint+0x4:  popl    %ebp
 db{1}> bt
 breakpoint(d7329958,100,d732998c,c02be4fd,c0470a63) at netbsd:breakpoint+0x4
 cpu_Debugger(c0470a63,d7329998,0,c02be940,0) at netbsd:cpu_Debugger+0xb
 panic(c0470a65,c046dc0d,c0430b46,c0470afd,c04f5b40) at netbsd:panic+0xc1
 lockdebug_abort1(c0470afd,1,2,d724fd2c,d71e8a00) at 
netbsd:lockdebug_abort1+0x62
 lockdebug_unlocked(d2845acc,c02f2ca2,0,5,c04ec120) at 
netbsd:lockdebug_unlocked+0x143
 rw_vector_exit(d2845acc,c04f5b80,d7329a3c,c02fd728,0) at 
netbsd:rw_vector_exit+0x5c
 vlockmgr(d2845acc,6,0,cdaa18b4,d2845a40) at netbsd:vlockmgr+0x138
 ffs_unlock(d7329a7c,c0300f02,0,c0302136,1) at netbsd:ffs_unlock+0x7c
 VOP_UNLOCK(d2845a40,0,d7329afc,cdaa18b4,cdaa18b4) at netbsd:VOP_UNLOCK+0x7b
 union_unlock(d7329acc,d71e8a00,0,18,20) at netbsd:union_unlock+0x93
 VOP_UNLOCK(cdaa18b4,0,d717a00a,cdaa18b4,d7329c90) at netbsd:VOP_UNLOCK+0x47
 vput(cdaa18b4,20002,400,d7329c84,c04f6cb0) at netbsd:vput+0x45
 namei(d7329c68,c04f5b40,d7329bcc,c02b7e99,0) at netbsd:namei+0x2fe
 vn_open(d7329c68,5,1a4,d71e8a0c,d71e8a00) at netbsd:vn_open+0x82
 sys_open(d71e8a00,d7329d08,d7329d00,bb99f000,bb99f000) at netbsd:sys_open+0xb4
 syscall(d7329d48,b3,ab,1f,1f) at netbsd:syscall+0x114