kern/45481: panic: kernel diagnostic assertion "(ap->a_flags & FSYNC_WAIT) == 0" failed

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         45481
>Category:       kern
>Synopsis:       panic: kernel diagnostic assertion "(ap->a_flags & FSYNC_WAIT) 
>== 0" failed
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Oct 17 20:25:00 +0000 2011
>Originator:     Andreas Gustafsson
>Release:        NetBSD-current 2011.10.06.22.25.00, 2011.10.16.21.31.15
>Organization:
>Environment:
System: NetBSD
Architecture: i386
Machine: i386
>Description:

The qemu virtual machine running automated tests on guesthouse.gson.org
has paniced twice in the last few weeks, with similar error messages.

Testing sources from CVS date 2011.10.06.22.25.00:

    bin/resize_ffs/t_grow (420/466): 4 test cases
        grow_16M_v0_8192: Oct  7 03:15:01  postfix/sendmail[6985]: fatal: 
unable to use my own hostname
    panic: kernel diagnostic assertion "(ap->a_flags & FSYNC_WAIT) == 0" 
failed: file 
"/bracket/i386/work/2011.10.06.22.25.00/src/sys/fs/puffs/puffs_vnops.c", line 
1366 
    cpu0: Begin traceback...
    
kern_assert(c0b4a794,c0b4a7d5,c0bc0d28,c0bc0ca4,556,c4092c70,200,c4ed0740,6,0) 
at netbsd:kern_assert+0x23
    puffs_vnop_fsync(c4271c04,0,0,c4e8e580,1,0,c4092aa0,0,c0b39728,c4e8e580) at 
netbsd:puffs_vnop_fsync+0xc8
    VOP_FSYNC(c4e8e580,ffffffff,5,0,0,0,0,c089a4f0,0,3) at netbsd:VOP_FSYNC+0x68
    vinvalbuf(c4e8e580,1,ffffffff,c4092aa0,0,0,c4271cdc,c08b5e25,c4edbf28,0) at 
netbsd:vinvalbuf+0x13c
    
vclean(c4e8e580,8,c408ed40,c408df00,c0c8b880,c4092aa0,691,c4092aa0,c4092aa0,c08b6761)
 at netbsd:vclean+0x1ed
    
cleanvnode(c0c8b880,c0c8b880,64,c4092aa0,c08b6761,0,0,c0100321,c4092aa0,e4d000) 
at netbsd:cleanvnode+0xd7
    vdrain_thread(c4092aa0,e4d000,e56000,0,c0100307,0,0,0,0,0) at 
netbsd:vdrain_thread+0x63
    cpu0: End traceback...

    dumping to dev 0,1 offset 1984
    dump pmap_kenter_pa: mapping already present
    pmap_kenter_pa: mapping already present
    pmap_kenter_pa: mapping already present
    pmap_kenter_pa: mapping already present
    (lots more of these)

Testing sources from CVS date 2011.10.16.21.31.15:

    sbin/resize_ffs/t_shrink (425/470): 4 test cases
        shrink_24M_16M_v0_32768: Oct 17 03:15:02  postfix/sendmail[12064]: 
fatal: unable to use my own hostname
    panic: kernel diagnostic assertion "(ap->a_flags & FSYNC_WAIT) == 0" 
failed: file 
"/bracket/i386/work/2011.10.16.21.31.15/src/sys/fs/puffs/puffs_vnops.c", line 
1366 
    cpu0: Begin traceback...
    
kern_assert(c0b4a5bc,c0b4a5fd,c0bc0af8,c0bc0a74,556,c4092c70,200,c408d480,c10ba9c0,0)
 at netbsd:kern_assert+0x23
    puffs_vnop_fsync(c4271c04,0,0,c4e6a380,1,0,c4092aa0,0,c0b39548,c4e6a380) at 
netbsd:puffs_vnop_fsync+0xc8
    VOP_FSYNC(c4e6a380,ffffffff,5,0,0,0,0,c078e675,0,3) at netbsd:VOP_FSYNC+0x68
    vinvalbuf(c4e6a380,1,ffffffff,c4092aa0,0,0,c4271cdc,c08b5c15,c4e302c4,0) at 
netbsd:vinvalbuf+0x13c
    
vclean(c4e6a380,8,c408fd40,c408ebc0,c4092aa0,c4271d28,c052ecd5,c4092aa0,c4092aa0,c08b6551)
 at netbsd:vclean+0x1ed
    
cleanvnode(c0c8c580,c0c8c580,64,c4092aa0,c08b6551,0,0,c0100321,c4092aa0,e4e000) 
at netbsd:cleanvnode+0xd7
    vdrain_thread(c4092aa0,e4e000,e57000,0,c0100307,0,0,0,0,0) at 
netbsd:vdrain_thread+0x63
    cpu0: End traceback...

    dumping to dev 0,1 offset 1984
    dump pmap_kenter_pa: mapping already present
    pmap_kenter_pa: mapping already present
    pmap_kenter_pa: mapping already present
    pmap_kenter_pa: mapping already present
    (lots more of these)

>How-To-Repeat:

Run the ATF tests on -current lots of times.

>Fix: