svn commit: r348421 - head/sys/kern

[Benjamin Kaduk]

On Thu, May 30, 2019 at 8:04 AM Konstantin Belousov <kib at freebsd.org> wrote:

> Author: kib
> Date: Thu May 30 15:04:09 2019
> New Revision: 348421
> URL: https://svnweb.freebsd.org/changeset/base/348421
>
> Log:
>   Silence witness warning about duplicated mutex type.
>
>   The order is correct, it is nullfs vnode interlock -> lower vnode
>   interlock.  vop_stdadd_writecount() is called from nullfs
>   VOP_ADD_WRITECOUNT() and both take interlocks.
>
>   Requested by: markj
>   Sponsored by: The FreeBSD Foundation
>   MFC after:    2 weeks
>
> Modified:
>   head/sys/kern/vfs_default.c
>
> Modified: head/sys/kern/vfs_default.c
>
> ==============================================================================
> --- head/sys/kern/vfs_default.c Thu May 30 14:40:23 2019        (r348420)
> +++ head/sys/kern/vfs_default.c Thu May 30 15:04:09 2019        (r348421)
> @@ -1113,7 +1113,7 @@ vop_stdadd_writecount(struct vop_add_writecount_args
> *
>         int error;
>
>         vp = ap->a_vp;
> -       VI_LOCK(vp);
> +       VI_LOCK_FLAGS(vp, MTX_DUPOK);
>         if (vp->v_writecount < 0) {
>                 error = ETXTBSY;
>         } else {
>
>
Does this merit a comment justifying the use of DUPOK?

-Ben