Oops in vn_revalidate with XFS 2.4.4

[Keith Owens <kaos@xxxxxxxxxx>]

XFS 2.4.4 CVS as of Sun May 27 02:00 UTC.  SMP, compiled with gcc
version 2.96 20000731 (Red Hat Linux 7.1 2.96-81).  Redhat claim that
this version of gcc is OK to compile the kernel, there is no kgcc in
Redhat 7.1.  Running rsync from a second machine to this machine.

Reboot came up fine (and fast :).  Rerunning rsync worked the second
time but a later rsync failed at the same place.  Just before the
failure it said

  xfs_iget_core: ambiguous vns: vp/0xc2d9e508, invp/0xc73dbd08

[0]kdb> rd
eax = 0x00000000 ebx = 0xc73dbd08 ecx = 0xc7a6c800 edx = 0xc2d9d9c4
esi = 0xc73dbd08 edi = 0x00000084 esp = 0xc27f3d24 eip = 0xc88a5b0e
ebp = 0xc78db334 xss = 0x00000018 xcs = 0x00000010 eflags = 0x00010286
xds = 0xc2d90018 xes = 0x00000018 origeax = 0xffffffff &regs = 0xc27f3cf0
[0]kdb> bt
    EBP       EIP         Function(args)
0xc78db334 0xc88a5b0e [xfs]vn_revalidate+0x1e (0xc73dbd08, 0x84, 0x0, 
0xc12f70c0, 0xa007f5)
                               xfs .text 0xc8849060 0xc88a5af0 0xc88a5c00
           0xc887d4f1 [xfs]xfs_iget_core+0x611 (0xc73dbd08, 0xc7a6c800, 0x0, 
0xa007f5, 0x0)
                               xfs .text 0xc8849060 0xc887cee0 0xc887d510
           0xc887d615 [xfs]xfs_iget+0x105 (0xc7a6c800, 0x0, 0xa007f5, 0x0, 0x0)
                               xfs .text 0xc8849060 0xc887d510 0xc887d650
           0xc88930f7 [xfs]xfs_dir_lookup_int+0x127 (0x0, 0xc2d9dbb0, 0x5, 
0xc3faed20, 0xc27f3eec)
                               xfs .text 0xc8849060 0xc8892fd0 0xc8893290
           0xc8897a17 [xfs]xfs_lookup+0x97 (0xc2d9dbb0, 0xc3faed20, 0xc27f3ed8, 
0xc27f3eec, 0x0)
                               xfs .text 0xc8849060 0xc8897980 0xc8897a90
           0xc88a05f8 [xfs]linvfs_lookup+0x68 (0xc2d9e5e0, 0xc3faecc0)
                               xfs .text 0xc8849060 0xc88a0590 0xc88a0650
           0xc013fc23 real_lookup+0x73 (0xc3657960, 0xc27f3f54, 0x0, 0x1, 0x8)
                               kernel .text 0xc0100000 0xc013fbb0 0xc013fcc0
           0xc01404f4 path_walk+0x6b4 (0xc6749000, 0xc27f3f9c)
                               kernel .text 0xc0100000 0xc013fe40 0xc0140790
           0xc0140c7a __user_walk+0x3a (0xbfff9878, 0x8, 0xc27f3f9c, 
0xc3657960, 0xc13f0860)
                               kernel .text 0xc0100000 0xc0140c40 0xc0140ca0
           0xc013d623 sys_lstat64+0x13 (0xbfff9878, 0xbfffa888, 0x4014e9e4, 
0xbfffa888, 0xbfff9878)
                               kernel .text 0xc0100000 0xc013d610 0xc013d680
           0xc0106e2b system_call+0x33
                               kernel .text 0xc0100000 0xc0106df8 0xc0106e30
[0]kdb> mds 0xc73dbd08
0xc73dbd08 00010000  ....  __u32 v_flag
0xc73dbd0c 00000002  ....  enum vtype v_type
0xc73dbd10 c7f42860  `(ôÇ  struct vfs *v_vfsp
0xc73dbd14 00026052  R`..  vnumber_t v_number
0xc73dbd18 00000000  ....
0xc73dbd1c 00000000  ....  bhv_head_t v_bh
0xc73dbd20 00000001  ....  spinlock_t v_lock
0xc73dbd24 c73dbc00  .¼=Ç  struct inode *v_inode

inode 0xc73dbc00
struct inode at  0xc73dbc00
 i_ino = 10487797 i_count = 1 i_dev = 0x814 i_size 0
 i_mode = 0x0  i_nlink = 1  i_rdev = 0x0
 i_hash.nxt = 0xc037a5e0 i_hash.prv = 0xc12f70c0
 i_list.nxt = 0xc2d9e5e8 i_list.prv = 0xc02c9288
 i_dentry.nxt = 0xc73dbc10 i_dentry.prv = 0xc73dbc10
 i_dirty_buffers.nxt = 0xc73dbc18 i_dirty_buffers.prv = 0xc73dbc18
 i_sb = 0xc78de800 i_op = 0xc03231e0 i_data = 0xc73dbca4 nrpages = 0
 i_mapping = 0xc73dbca4
 i_flags 0x0 i_state 0x48 [I_LOCK I_NEW]  fs specific info @ 0xc73dbd08

[0]kdb> id vn_revalidate
0xc88a5af0 vn_revalidate push   %edi
0xc88a5af1 vn_revalidate+0x1 push   %esi
0xc88a5af2 vn_revalidate+0x2 push   %ebx
0xc88a5af3 vn_revalidate+0x3 sub    $0x70,%esp
0xc88a5af6 vn_revalidate+0x6 mov    0x80(%esp,1),%ebx           struct vnode *vp
0xc88a5afd vn_revalidate+0xd movl   $0x14003fff,(%esp,1)
0xc88a5b04 vn_revalidate+0x14 mov    0x84(%esp,1),%edi
0xc88a5b0b vn_revalidate+0x1b mov    0x14(%ebx),%eax            vp->v_bh == NULL
0xc88a5b0e vn_revalidate+0x1e mov    0x8(%eax),%edx             
vp->v_bh->bd_ops, oops
0xc88a5b11 vn_revalidate+0x21 push   $0x0
0xc88a5b13 vn_revalidate+0x23 mov    %edi,%eax
0xc88a5b15 vn_revalidate+0x25 and    $0x80,%eax
0xc88a5b1a vn_revalidate+0x2a push   %eax
0xc88a5b1b vn_revalidate+0x2b lea    0x8(%esp,1),%eax
0xc88a5b1f vn_revalidate+0x2f push   %eax
0xc88a5b20 vn_revalidate+0x30 mov    0x14(%ebx),%esi

Why is vp->v_bh NULL?

[0]kdb> mds c7f42860 (struct vfs)
0xc7f42860 00001020   ...
0xc7f42864 00000814  ....
0xc7f42868 00000001  ....
0xc7f4286c c7f4286c  l(ôÇ
0xc7f42870 c7f4286c  l(ôÇ
0xc7f42874 00000001  ....
0xc7f42878 00001000  ....
0xc7f4287c 00000000  ....
0xc7f42880 8b51c640  @ÆQ.
0xc7f42884 266bb554  Tµk&
0xc7f42888 c7a6ca18  .ʦÇ
0xc7f4288c c7a6c800  .ȦÇ
0xc7f42890 c78de800  .è.Ç
0xc7f42894 00000000  ....
0xc7f42898 00000000  ....
0xc7f4289c 00000000  ....
0xc7f428a0 00000002  ....
0xc7f428a4 00048000  ....
0xc7f428a8 6f616b30  0kao
0xc7f428ac 00000073  s...
0xc7f428b0 40000c83  ...@
0xc7f428b4 736f616b  kaos
0xc7f428b8 736e692d  -ins
0xc7f428bc 6c6c6174  tall
0xc7f428c0 8a000000  ....
0xc7f428c4 00000000  ....
0xc7f428c8 00000001  ....
0xc7f428cc 00000001  ....
0xc7f428d0 00000000  ....
0xc7f428d4 00000000  ....
0xc7f428d8 00000000  ....
0xc7f428dc 00000000  ....
0xc7f428e0 c7e93d20   =éÇ
0xc7f428e4 c7e93ea0   >éÇ
0xc7f428e8 00000000  ....
0xc7f428ec c78de000  .à.Ç
0xc7f428f0 00000008  ....
0xc7f428f4 ffffffff  ÿÿÿÿ
0xc7f428f8 00000001  ....
0xc7f428fc 00000002  ....