Re: panic due to lost vnode flag

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Thu, Oct 29, 2009 at 09:23:27PM +0100, Matthias Drochner wrote:
> 
> bouyer%antioche.eu.org@localhost said:
> > Could you print the vnode when this happens again ?
> 
> Just got hit:
> The backtrace is as usual:
> [...]
> The vnode is:
> (gdb) print *vp
> $1 = {v_uobj = {vmobjlock = {u = {mtxa_owner = 0x0}}, pgops = 0xc0673928, memq
> = {
>       tqh_first = 0xc1a80590, tqh_last = 0xc1a86154}, uo_npages = 0x6, uo_refs
> = 0x4, rb_tree = {
>       rbt_root = 0xc1a883d8, rbt_ops = 0xc0673780, rbt_minmax = {0xc1a80590,
> 0xc1a86140}}},
>   v_cv = {cv_opaque = {0x0, 0xcc55be8c, 0xc06e8dc2}}, v_size = 0x6c1c,
> v_writesize = 0x6c1c,
>   v_iflag = 0x0, v_vflag = 0x30, v_uflag = 0x0, v_numoutput = 0x0,
> v_writecount = 0x0,
>   v_holdcnt = 0x1, v_synclist_slot = 0x0, v_mount = 0xcc234004, v_op =
> 0xcb30e0d4, v_freelist = {
>     tqe_next = 0xe8f5f00c, tqe_prev = 0xcb8cb628}, v_freelisthd = 0x0,
> v_mntvnodes = {
>     tqe_next = 0xcc55bdac, tqe_prev = 0xcc54f1e4}, v_cleanblkhd = {lh_first =
> 0x0},
>   v_dirtyblkhd = {lh_first = 0x0}, v_synclist = {tqe_next = 0x0, tqe_prev =
> 0x0}, v_dnclist = {
>     lh_first = 0x0}, v_nclist = {lh_first = 0xe873c100}, v_un =
> {vu_mountedhere = 0xcc5357d0,
>     vu_socket = 0xcc5357d0, vu_specnode = 0xcc5357d0, vu_fifoinfo = 
> 0xcc5357d0,
>     vu_ractx = 0xcc5357d0}, v_type = VREG, v_tag = VT_UFS, v_lock = {vl_lock =
> {rw_owner = 0x0},
>     vl_canrecurse = 0x0, vl_recursecnt = 0x0}, v_vnlock = 0xcc55bf04, v_data =
> 0xcc55ce8c,
>   v_klist = {slh_first = 0x0}}

The vnode is not clean, it has 4 references and is not on a free list.
All is well, except it has lost its v_iflag.

hopefully 0xcc55ce8c is a pointer to a struct inode, could you try to
print it as a struct inode and see what the inode number refers to in
the filesystem ? You may need to look at the v_mount structure to see from
which filesystem it's from.

-- 
Manuel Bouyer, LIP6, Universite Paris VI.           
Manuel.Bouyer%lip6.fr@localhost
     NetBSD: 26 ans d'experience feront toujours la difference
--