static int
null_accessx(struct vop_accessx_args *ap)
{
struct vnode *vp = ap->a_vp;
accmode_t accmode = ap->a_accmode;
/*
* Disallow write attempts on read-only layers;
* unless the file is a socket, fifo, or a block or
* character device resident on the filesystem.
*/
if (accmode & VWRITE) {
switch (vp->v_type) {
case VDIR:
case VLNK:
case VREG:
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return (EROFS);
break;
default:
break;
}
}
return (null_bypass((struct vop_generic_args *)ap));
}
/*
* We handle this to eliminate null FS to lower FS
* file moving. Don't know why we don't allow this,
* possibly we should.
*/
static int
null_rename(struct vop_rename_args *ap)
{
struct vnode *tdvp = ap->a_tdvp;
struct vnode *fvp = ap->a_fvp;
struct vnode *fdvp = ap->a_fdvp;
struct vnode *tvp = ap->a_tvp;
struct null_node *tnn;
/* Check for cross-device rename. */
if ((fvp->v_mount != tdvp->v_mount) ||
(tvp && (fvp->v_mount != tvp->v_mount))) {
if (tdvp == tvp)
vrele(tdvp);
else
vput(tdvp);
if (tvp)
vput(tvp);
vrele(fdvp);
vrele(fvp);
return (EXDEV);
}
if (tvp != NULL) {
tnn = VTONULL(tvp);
tnn->null_flags |= NULLV_DROP;
}
return (null_bypass((struct vop_generic_args *)ap));
}
static int
null_rmdir(struct vop_rmdir_args *ap)
{
VTONULL(ap->a_vp)->null_flags |= NULLV_DROP;
return (null_bypass(&ap->a_gen));
}
/*
* We handle getattr only to change the fsid.
*/
static int
null_getattr(struct vop_getattr_args *ap)
{
int error;
if ((error = null_bypass((struct vop_generic_args *)ap)) != 0)
return (error);
ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
return (0);
}
static int
null_open(struct vop_open_args *ap)
{
int retval;
struct vnode *vp, *ldvp;
vp = ap->a_vp;
ldvp = NULLVPTOLOWERVP(vp);
retval = null_bypass(&ap->a_gen);
if (retval == 0)
vp->v_object = ldvp->v_object;
return (retval);
}
/*
* Increasing refcount of lower vnode is needed at least for the case
* when lower FS is NFS to do sillyrename if the file is in use.
* Unfortunately v_usecount is incremented in many places in
* the kernel and, as such, there may be races that result in
* the NFS client doing an extraneous silly rename, but that seems
* preferable to not doing a silly rename when it is needed.
*/
static int
null_remove(struct vop_remove_args *ap)
{
int retval, vreleit;
struct vnode *lvp;
if (vrefcnt(ap->a_vp) > 1) {
lvp = NULLVPTOLOWERVP(ap->a_vp);
VREF(lvp);
vreleit = 1;
} else
vreleit = 0;
retval = null_bypass(&ap->a_gen);
if (vreleit != 0)
vrele(lvp);
return (retval);
}
/*
* Setattr call. Disallow write attempts if the layer is mounted read-only.
*/
static int
null_setattr(struct vop_setattr_args *ap)
{
struct vnode *vp = ap->a_vp;
struct vattr *vap = ap->a_vap;
if ((vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL) &&
(vp->v_mount->mnt_flag & MNT_RDONLY))
return (EROFS);
if (vap->va_size != VNOVAL) {
switch (vp->v_type) {
case VDIR:
return (EISDIR);
case VCHR:
case VBLK:
case VSOCK:
case VFIFO:
if (vap->va_flags != VNOVAL)
return (EOPNOTSUPP);
return (0);
case VREG:
case VLNK:
default:
/*
* Disallow write attempts if the filesystem is
* mounted read-only.
*/
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return (EROFS);
}
}
return (null_bypass((struct vop_generic_args *)ap));
}