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On Mon, Mar 03, 2008 at 05:41:33AM +0300, pluknet wrote:
> On 20/02/2008, pluknet wrote:
> [snip]
> > Unread portion of the kernel message buffer:
> > panic: mutex Giant owned at
> > /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_syscalls.c:556
> > KDB: enter: panic
> > exclusive sleep mutex nfsd_mtx r =3D 0 (0xc41d1660) locked @
> > /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_syscalls.c:501
> > exclusive sleep mutex Giant r =3D 0 (0xc07e6410) locked @
> > /usr/src/sys/kern/vfs_lookup.c:663
> > ...
> > #9 0xc053959d in panic (fmt=3D0xc076181d "mutex %s owned at %s:%d")
> > at /usr/src/sys/kern/kern_shutdown.c:555
> > #10 0xc052adf7 in _mtx_assert (m=3D0xc07e6410, what=3D0,
> > file=3D0xc41cb7b2
> > "/usr/src/sys/modules/nfsserver/../../nfsserver/nfs_syscalls.c",
> > line=3D556) at /usr/src/sys/kern/kern_mutex.c:652
> > #11 0xc41c9e82 in nfssvc (td=3D0xc2e68000, uap=3D0xd600dcfc)
> > at /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_syscalls.c:556
> > #12 0xc0727903 in syscall (frame=3D0xd600dd38)
> > at /usr/src/sys/i386/i386/trap.c:1034
> > #13 0xc0711630 in Xint0x80_syscall () at /usr/src/sys/i386/i386/except=

ion.s:203
> > ---Type to continue, or q to quit---
> > #14 0x00000033 in ?? ()

>=20
> [Some new info probably not related to the thread.]
> Today I got two new panics while performing /etc/rc.d/nfsd stop:
>=20
> System call nfssvc returning with the following locks held:
> exclusive sleep mutex Giant r =3D 2 (0xc07e6410) locked @
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_srvsubs.c:1106
> panic: witness_warn
> ...
> #9 0xc053959d in panic (fmt=3D0xc076791b "witness_warn")
> at /usr/src/sys/kern/kern_shutdown.c:555
> #10 0xc056ff99 in witness_warn (flags=3D2, lock=3D0x0,
> fmt=3D0xc0789975 "System call %s returning")
> at /usr/src/sys/kern/subr_witness.c:1396
> #11 0xc0727a56 in syscall (frame=3D0xd5f9ed38)
> at /usr/src/sys/i386/i386/trap.c:1083
> #12 0xc0711630 in Xint0x80_syscall () at /usr/src/sys/i386/i386/exception=

..s:203
> #13 0x00000033 in ?? ()
>=20
> The second is different only in place where Giant is acquired.
> System call nfssvc returning with the following locks held:
> exclusive sleep mutex Giant r =3D 0 (0xc07e6410) locked @
> /usr/src/sys/kern/vfs_lookup.c:663
> panic: witness_warn
>=20
>=20
> On 21/02/2008, Kris Kennaway wrote:
> > Hopefully it should be a straightforward fix to track down which code
> > path is missing the VFS_UNLOCK_GIANT() to reach the above stack trace,
> > or to reproduce.

>=20
> I've marked VFS_[UN]LOCK_GIANT() in nfs_(serv|srvsubs).c with
> appropriate printf()'s:
> $ rm 123vfslocked lock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_srvsubs.c, 1106
> vfslocked unlock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_serv.c, 253
>=20
> vfslocked lock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_srvsubs.c, 1106
> vfslocked unlock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_serv.c, 253
> vfslocked lock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_srvsubs.c, 1106
> vfslocked lock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_srvsubs.c, 673
> vfslocked unlock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_srvsubs.c, 916
> vfslocked unlock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_serv.c, 648
> vfslocked lock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_srvsubs.c, 1106
> vfslocked lock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_srvsubs.c, 673
> vfslocked unlock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_srvsubs.c, 916
> vfslocked unlock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_serv.c, 648
> vfslocked lock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_serv.c, 2161
> vfslocked lock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_srvsubs.c, 1106
> vfslocked lock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_srvsubs.c, 673
> vfslocked unlock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_srvsubs.c, 916
> vfslocked unlock in
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_serv.c, 2234
> panic: mutex Giant owned at
> /usr/src/sys/modules/nfsserver/../../nfsserver/nfs_syscalls.c:556
>=20
> So, Giant is acquired in nfs_srvsubs.c:1106 and is not released in
> nfs_serv.c:648
> Btw, I cannot reproduce it with module compiled via
> cd /sys/modules/nfsserver; make all && make install
>=20
> On 23/02/2008, Kostik Belousov wrote:
> > Assert itself only catches the missed Giant unlock somewhere during
> > the execution of an nfs requtest.
> > Unfortunately, it seems that the error is in nfsserver that missed
> > Giant unlock (most likely, on some error path). Helpful would be
> > the tcpdump raw trace file of the communication between nfs server and
> > client immediately before the panic.

>=20
> Here it is (with -xvvn). [I can reproduce the panic only when I try to
> delete a file on nfs.]


I mean the raw dump that can be loaded in wireshark, for instance.
I prefer to not do the manual RPC decoding.

>=20
> 03:07:59.342714 IP (tos 0x0, ttl 128, id 39253, offset 0, flags
> [none], proto UDP (17), length 136) 192.168.200.185.1968921799 >
> 192.168.200.137.2049: 108 access [|nfs]
> 0x0000: 4500 0088 9955 0000 8011 8e7b c0a8 c8b9
> 0x0010: c0a8 c889 03f8 0801 0074 3c9e 755b 5cc7
> 0x0020: 0000 0000 0000 0002 0001 86a3 0000 0003
> 0x0030: 0000 0004 0000 0001 0000 0020 0000 0000
> 0x0040: 0000 0000 0000 03e9 0000 03e9 0000 0003
> 0x0050: 0000
> 03:07:59.343818 IP (tos 0x0, ttl 128, id 30823, offset 0, flags
> [none], proto UDP (17), length 148) 192.168.200.137.2049 >
> 192.168.200.185.1968921799: reply ok 120 access attr: REG 755 ids
> 1001/0 [|nfs]
> 0x0000: 4500 0094 7867 0000 8011 af5d c0a8 c889
> 0x0010: c0a8 c8b9 0801 03f8 0080 1bda 755b 5cc7
> 0x0020: 0000 0001 0000 0000 0000 0000 0000 0000
> 0x0030: 0000 0000 0000 0000 0000 0001 0000 0001
> 0x0040: 0000 01ed 0000 0001 0000 03e9 0000 0000
> 0x0050: 0000
> 03:07:59.344297 IP (tos 0x0, ttl 128, id 20293, offset 0, flags
> [none], proto UDP (17), length 140) 192.168.200.185.1968921800 >
> 192.168.200.137.2049: 112 lookup [|nfs]
> 0x0000: 4500 008c 4f45 0000 8011 d887 c0a8 c8b9
> 0x0010: c0a8 c889 03f8 0801 0078 58a1 755b 5cc8
> 0x0020: 0000 0000 0000 0002 0001 86a3 0000 0003
> 0x0030: 0000 0003 0000 0001 0000 0020 0000 0000
> 0x0040: 0000 0000 0000 03e9 0000 03e9 0000 0003
> 0x0050: 0000
> 03:07:59.344782 IP (tos 0x0, ttl 128, id 64063, offset 0, flags
> [none], proto UDP (17), length 264) 192.168.200.137.2049 >
> 192.168.200.185.1968921800: reply ok 236 lookup [|nfs]
> 0x0000: 4500 0108 fa3f 0000 8011 2d11 c0a8 c889
> 0x0010: c0a8 c8b9 0801 03f8 00f4 feb1 755b 5cc8
> 0x0020: 0000 0001 0000 0000 0000 0000 0000 0000
> 0x0030: 0000 0000 0000 0000 0000 001c 5100 0000
> 0x0040: 0400 0000 0c00 0000 4dc9 1000 8001 0000
> 0x0050: 0000
> 03:07:59.345530 IP (tos 0x0, ttl 128, id 32619, offset 0, flags
> [none], proto UDP (17), length 140) 192.168.200.185.1968921801 >
> 192.168.200.137.2049: 112 lookup [|nfs]
> 0x0000: 4500 008c 7f6b 0000 8011 a861 c0a8 c8b9
> 0x0010: c0a8 c889 03f8 0801 0078 58a0 755b 5cc9
> 0x0020: 0000 0000 0000 0002 0001 86a3 0000 0003
> 0x0030: 0000 0003 0000 0001 0000 0020 0000 0000
> 0x0040: 0000 0000 0000 03e9 0000 03e9 0000 0003
> 0x0050: 0000
> 03:07:59.346752 IP (tos 0x0, ttl 128, id 50548, offset 0, flags
> [none], proto UDP (17), length 264) 192.168.200.137.2049 >
> 192.168.200.185.1968921801: reply ok 236 lookup [|nfs]
> 0x0000: 4500 0108 c574 0000 8011 61dc c0a8 c889
> 0x0010: c0a8 c8b9 0801 03f8 00f4 feb0 755b 5cc9
> 0x0020: 0000 0001 0000 0000 0000 0000 0000 0000
> 0x0030: 0000 0000 0000 0000 0000 001c 5100 0000
> 0x0040: 0400 0000 0c00 0000 4dc9 1000 8001 0000
> 0x0050: 0000
> 03:07:59.347265 IP (tos 0x0, ttl 128, id 52799, offset 0, flags
> [none], proto UDP (17), length 140) 192.168.200.185.1968921802 >
> 192.168.200.137.2049: 112 remove [|nfs]
> 0x0000: 4500 008c ce3f 0000 8011 598d c0a8 c8b9
> 0x0010: c0a8 c889 03f8 0801 0078 5896 755b 5cca
> 0x0020: 0000 0000 0000 0002 0001 86a3 0000 0003
> 0x0030: 0000 000c 0000 0001 0000 0020 0000 0000
> 0x0040: 0000 0000 0000 03e9 0000 03e9 0000 0003
> 0x0050: 0000
> 03:07:59.348654 IP (tos 0x0, ttl 128, id 55143, offset 0, flags
> [none], proto UDP (17), length 172) 192.168.200.137.2049 >
> 192.168.200.185.1968921802: reply ok 144 remove PRE: [|nfs]
> 0x0000: 4500 00ac d767 0000 8011 5045 c0a8 c889
> 0x0010: c0a8 c8b9 0801 03f8 0098 1757 755b 5cca
> 0x0020: 0000 0001 0000 0000 0000 0000 0000 0000
> 0x0030: 0000 0000 0000 0000 0000 0001 0000 0000
> 0x0040: 0000 4000 4099 2bf4 0000 0000 4099 2bf4
> 0x0050: 0000
>=20
> wbr,
> pluknet


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