Re: list of mandatory hooks in file system module implementation

On 2008-08-24 at 18:50:11 [+0200], Salvatore Benedetto <[email protected]> =

wrote:
> 2008/8/24 J=E9r=F4me Duval <[email protected]>:
> > Hi,
> >
> > Salvatore Benedetto wrote:
> >> Hi there,
> >>
> >> while working on udf, from time to time I get panics on page fault
> >> with an eip =3D 0x0.
> >> This is clearly due to the fact that I forgot to add a certain hook,
> >> probably to the fs_vnode_ops
> >> structure.
> >>
> >> I looked around in vfs.cpp for all the FS_CALL call used
> >> unconditionally (that is, without calling
> >> HAS_FS_CALL first), and I thought I implemented all of them (is
> >> remove_vnode necessary btw?),
> >> but it seems I'm still missing something. Here is the most important
> >> part of a panic I just got
> >>
> >>
> > Maybe try to change FS_CALL() to something like:
> >
> > #define FS_CALL(vnode, op, params...) \
> >                     if (vnode->ops->op)  \
> >                          vnode->ops->op(vnode->mount->
> > volume, vnode,
> > params);  \
> >                     else \
> >                           panic("FS_CALL is NULL for " #op "\n");
> >
> > It should panic on a NULL op.
> =

> Nice! I think that should actually be added to the trunk. It's better
> then having a
> page fault on eip 0x0. What do you think?

Mmh well, it adds quite a bit of code where not necessary -- the =

non-mandatory hooks are checked anyway. Maybe only when KDEBUG is enabled t=
he =

macro could do the check. It would have to look a bit different though, sin=
ce =

the hooks have return values.

CU, Ingo

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