void
vnode_pager_update_writecount(vm_object_t object, vm_offset_t start,
vm_offset_t end)
{
struct vnode *vp;
vm_ooffset_t old_wm;
VM_OBJECT_WLOCK(object);
if (object->type != OBJT_VNODE) {
VM_OBJECT_WUNLOCK(object);
return;
}
old_wm = object->un_pager.vnp.writemappings;
object->un_pager.vnp.writemappings += (vm_ooffset_t)end - start;
vp = object->handle;
if (old_wm == 0 && object->un_pager.vnp.writemappings != 0) {
ASSERT_VOP_ELOCKED(vp, "v_writecount inc");
VOP_ADD_WRITECOUNT(vp, 1);
CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
__func__, vp, vp->v_writecount);
} else if (old_wm != 0 && object->un_pager.vnp.writemappings == 0) {
ASSERT_VOP_ELOCKED(vp, "v_writecount dec");
VOP_ADD_WRITECOUNT(vp, -1);
CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
__func__, vp, vp->v_writecount);
}
VM_OBJECT_WUNLOCK(object);
}
/*
* The object must be locked.
*/
static void
vnode_pager_dealloc(vm_object_t object)
{
struct vnode *vp;
int refs;
vp = object->handle;
if (vp == NULL)
panic("vnode_pager_dealloc: pager already dealloced");
VM_OBJECT_ASSERT_WLOCKED(object);
vm_object_pip_wait(object, "vnpdea");
refs = object->ref_count;
object->handle = NULL;
object->type = OBJT_DEAD;
if (object->flags & OBJ_DISCONNECTWNT) {
vm_object_clear_flag(object, OBJ_DISCONNECTWNT);
wakeup(object);
}
ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc");
if (object->un_pager.vnp.writemappings > 0) {
object->un_pager.vnp.writemappings = 0;
VOP_ADD_WRITECOUNT(vp, -1);
CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
__func__, vp, vp->v_writecount);
}
vp->v_object = NULL;
VOP_UNSET_TEXT(vp);
VM_OBJECT_WUNLOCK(object);
while (refs-- > 0)
vunref(vp);
VM_OBJECT_WLOCK(object);
}
/*
* Enable an EA using the passed filesystem, backing vnode, attribute name,
* namespace, and proc. Will perform a VOP_OPEN() on the vp, so expects vp
* to be locked when passed in. The vnode will be returned unlocked,
* regardless of success/failure of the function. As a result, the caller
* will always need to vrele(), but not vput().
*/
static int
ufs_extattr_enable_with_open(struct ufsmount *ump, struct vnode *vp,
int attrnamespace, const char *attrname, struct thread *td)
{
int error;
error = VOP_OPEN(vp, FREAD|FWRITE, td->td_ucred, td, NULL);
if (error) {
printf("ufs_extattr_enable_with_open.VOP_OPEN(): failed "
"with %d\n", error);
VOP_UNLOCK(vp, 0);
return (error);
}
error = VOP_ADD_WRITECOUNT(vp, 1);
if (error != 0) {
VOP_CLOSE(vp, FREAD | FWRITE, td->td_ucred, td);
VOP_UNLOCK(vp, 0);
return (error);
}
CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", __func__, vp,
vp->v_writecount);
vref(vp);
VOP_UNLOCK(vp, 0);
error = ufs_extattr_enable(ump, attrnamespace, attrname, vp, td);
if (error != 0)
vn_close(vp, FREAD|FWRITE, td->td_ucred, td);
return (error);
}
static int
null_add_writecount(struct vop_add_writecount_args *ap)
{
struct vnode *lvp, *vp;
int error;
vp = ap->a_vp;
lvp = NULLVPTOLOWERVP(vp);
KASSERT(vp->v_writecount + ap->a_inc >= 0, ("wrong writecount inc"));
if (vp->v_writecount > 0 && vp->v_writecount + ap->a_inc == 0)
error = VOP_ADD_WRITECOUNT(lvp, -1);
else if (vp->v_writecount == 0 && vp->v_writecount + ap->a_inc > 0)
error = VOP_ADD_WRITECOUNT(lvp, 1);
else
error = 0;
if (error == 0)
vp->v_writecount += ap->a_inc;
return (error);
}