C++ VM_OBJECT_WLOCK函数代码示例

/*
 *	Allocates a region from the kernel address map and physically
 *	contiguous pages within the specified address range to the kernel
 *	object.  Creates a wired mapping from this region to these pages, and
 *	returns the region's starting virtual address.  If M_ZERO is specified
 *	through the given flags, then the pages are zeroed before they are
 *	mapped.
 */
vm_offset_t
kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low,
    vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
    vm_memattr_t memattr)
{
	vmem_t *vmem;
	vm_object_t object = kernel_object;
	vm_offset_t addr, offset, tmp;
	vm_page_t end_m, m;
	u_long npages;
	int pflags, tries;
 
	size = round_page(size);
	vmem = vm_dom[domain].vmd_kernel_arena;
	if (vmem_alloc(vmem, size, flags | M_BESTFIT, &addr))
		return (0);
	offset = addr - VM_MIN_KERNEL_ADDRESS;
	pflags = malloc2vm_flags(flags) | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED;
	pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
	pflags |= VM_ALLOC_NOWAIT;
	npages = atop(size);
	VM_OBJECT_WLOCK(object);
	tries = 0;
retry:
	m = vm_page_alloc_contig_domain(object, atop(offset), domain, pflags,
	    npages, low, high, alignment, boundary, memattr);
	if (m == NULL) {
		VM_OBJECT_WUNLOCK(object);
		if (tries < ((flags & M_NOWAIT) != 0 ? 1 : 3)) {
			if (!vm_page_reclaim_contig_domain(domain, pflags,
			    npages, low, high, alignment, boundary) &&
			    (flags & M_WAITOK) != 0)
				vm_wait_domain(domain);
			VM_OBJECT_WLOCK(object);
			tries++;
			goto retry;
		}
		vmem_free(vmem, addr, size);
		return (0);
	}
	KASSERT(vm_phys_domain(m) == domain,
	    ("kmem_alloc_contig_domain: Domain mismatch %d != %d",
	    vm_phys_domain(m), domain));
	end_m = m + npages;
	tmp = addr;
	for (; m < end_m; m++) {
		if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
			pmap_zero_page(m);
		m->valid = VM_PAGE_BITS_ALL;
		pmap_enter(kernel_pmap, tmp, m, VM_PROT_ALL,
		    VM_PROT_ALL | PMAP_ENTER_WIRED, 0);
		tmp += PAGE_SIZE;
	}
	VM_OBJECT_WUNLOCK(object);
	return (addr);
}

/*
 * Helper routines to allow the backing object of a shared memory file
 * descriptor to be mapped in the kernel.
 */
int
shm_map(struct file *fp, size_t size, off_t offset, void **memp)
{
	struct shmfd *shmfd;
	vm_offset_t kva, ofs;
	vm_object_t obj;
	int rv;

	if (fp->f_type != DTYPE_SHM)
		return (EINVAL);
	shmfd = fp->f_data;
	obj = shmfd->shm_object;
	VM_OBJECT_WLOCK(obj);
	/*
	 * XXXRW: This validation is probably insufficient, and subject to
	 * sign errors.  It should be fixed.
	 */
	if (offset >= shmfd->shm_size ||
	    offset + size > round_page(shmfd->shm_size)) {
		VM_OBJECT_WUNLOCK(obj);
		return (EINVAL);
	}

	shmfd->shm_kmappings++;
	vm_object_reference_locked(obj);
	VM_OBJECT_WUNLOCK(obj);

	/* Map the object into the kernel_map and wire it. */
	kva = vm_map_min(kernel_map);
	ofs = offset & PAGE_MASK;
	offset = trunc_page(offset);
	size = round_page(size + ofs);
	rv = vm_map_find(kernel_map, obj, offset, &kva, size, 0,
	    VMFS_OPTIMAL_SPACE, VM_PROT_READ | VM_PROT_WRITE,
	    VM_PROT_READ | VM_PROT_WRITE, 0);
	if (rv == KERN_SUCCESS) {
		rv = vm_map_wire(kernel_map, kva, kva + size,
		    VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES);
		if (rv == KERN_SUCCESS) {
			*memp = (void *)(kva + ofs);
			return (0);
		}
		vm_map_remove(kernel_map, kva, kva + size);
	} else
		vm_object_deallocate(obj);

	/* On failure, drop our mapping reference. */
	VM_OBJECT_WLOCK(obj);
	shmfd->shm_kmappings--;
	VM_OBJECT_WUNLOCK(obj);

	return (vm_mmap_to_errno(rv));
}

/*
 *	Allocates a region from the kernel address map and physical pages
 *	within the specified address range to the kernel object.  Creates a
 *	wired mapping from this region to these pages, and returns the
 *	region's starting virtual address.  The allocated pages are not
 *	necessarily physically contiguous.  If M_ZERO is specified through the
 *	given flags, then the pages are zeroed before they are mapped.
 */
vm_offset_t
kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low,
    vm_paddr_t high, vm_memattr_t memattr)
{
	vmem_t *vmem;
	vm_object_t object = kernel_object;
	vm_offset_t addr, i, offset;
	vm_page_t m;
	int pflags, tries;

	size = round_page(size);
	vmem = vm_dom[domain].vmd_kernel_arena;
	if (vmem_alloc(vmem, size, M_BESTFIT | flags, &addr))
		return (0);
	offset = addr - VM_MIN_KERNEL_ADDRESS;
	pflags = malloc2vm_flags(flags) | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED;
	pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
	pflags |= VM_ALLOC_NOWAIT;
	VM_OBJECT_WLOCK(object);
	for (i = 0; i < size; i += PAGE_SIZE) {
		tries = 0;
retry:
		m = vm_page_alloc_contig_domain(object, atop(offset + i),
		    domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr);
		if (m == NULL) {
			VM_OBJECT_WUNLOCK(object);
			if (tries < ((flags & M_NOWAIT) != 0 ? 1 : 3)) {
				if (!vm_page_reclaim_contig_domain(domain,
				    pflags, 1, low, high, PAGE_SIZE, 0) &&
				    (flags & M_WAITOK) != 0)
					vm_wait_domain(domain);
				VM_OBJECT_WLOCK(object);
				tries++;
				goto retry;
			}
			kmem_unback(object, addr, i);
			vmem_free(vmem, addr, size);
			return (0);
		}
		KASSERT(vm_phys_domain(m) == domain,
		    ("kmem_alloc_attr_domain: Domain mismatch %d != %d",
		    vm_phys_domain(m), domain));
		if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
			pmap_zero_page(m);
		m->valid = VM_PAGE_BITS_ALL;
		pmap_enter(kernel_pmap, addr + i, m, VM_PROT_ALL,
		    VM_PROT_ALL | PMAP_ENTER_WIRED, 0);
	}
	VM_OBJECT_WUNLOCK(object);
	return (addr);
}

/*
 *	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);
}

/*
 *	kmem_unback:
 *
 *	Unmap and free the physical pages underlying the specified virtual
 *	address range.
 *
 *	A physical page must exist within the specified object at each index
 *	that is being unmapped.
 */
static int
_kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
{
	vm_page_t m, next;
	vm_offset_t end, offset;
	int domain;

	KASSERT(object == kernel_object,
	    ("kmem_unback: only supports kernel object."));

	if (size == 0)
		return (0);
	pmap_remove(kernel_pmap, addr, addr + size);
	offset = addr - VM_MIN_KERNEL_ADDRESS;
	end = offset + size;
	VM_OBJECT_WLOCK(object);
	m = vm_page_lookup(object, atop(offset)); 
	domain = vm_phys_domain(m);
	for (; offset < end; offset += PAGE_SIZE, m = next) {
		next = vm_page_next(m);
		vm_page_unwire(m, PQ_NONE);
		vm_page_free(m);
	}
	VM_OBJECT_WUNLOCK(object);

	return (domain);
}

void
vnode_destroy_vobject(struct vnode *vp)
{
	struct vm_object *obj;

	obj = vp->v_object;
	if (obj == NULL)
		return;
	ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject");
	VM_OBJECT_WLOCK(obj);
	if (obj->ref_count == 0) {
		/*
		 * don't double-terminate the object
		 */
		if ((obj->flags & OBJ_DEAD) == 0)
			vm_object_terminate(obj);
		else
			VM_OBJECT_WUNLOCK(obj);
	} else {
		/*
		 * Woe to the process that tries to page now :-).
		 */
		vm_pager_deallocate(obj);
		VM_OBJECT_WUNLOCK(obj);
	}
	vp->v_object = NULL;
}

/*
 * shmfd object management including creation and reference counting
 * routines.
 */
static struct shmfd *
shm_alloc(struct ucred *ucred, mode_t mode)
{
	struct shmfd *shmfd;

	shmfd = malloc(sizeof(*shmfd), M_SHMFD, M_WAITOK | M_ZERO);
	shmfd->shm_size = 0;
	shmfd->shm_uid = ucred->cr_uid;
	shmfd->shm_gid = ucred->cr_gid;
	shmfd->shm_mode = mode;
	shmfd->shm_object = vm_pager_allocate(OBJT_DEFAULT, NULL,
	    shmfd->shm_size, VM_PROT_DEFAULT, 0, ucred);
	KASSERT(shmfd->shm_object != NULL, ("shm_create: vm_pager_allocate"));
	VM_OBJECT_WLOCK(shmfd->shm_object);
	vm_object_clear_flag(shmfd->shm_object, OBJ_ONEMAPPING);
	vm_object_set_flag(shmfd->shm_object, OBJ_NOSPLIT);
	VM_OBJECT_WUNLOCK(shmfd->shm_object);
	vfs_timestamp(&shmfd->shm_birthtime);
	shmfd->shm_atime = shmfd->shm_mtime = shmfd->shm_ctime =
	    shmfd->shm_birthtime;
	refcount_init(&shmfd->shm_refs, 1);
	mtx_init(&shmfd->shm_mtx, "shmrl", NULL, MTX_DEF);
	rangelock_init(&shmfd->shm_rl);
#ifdef MAC
	mac_posixshm_init(shmfd);
	mac_posixshm_create(ucred, shmfd);
#endif

	return (shmfd);
}

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);
}

/*
 * old style vnode pager input routine
 */
static int
vnode_pager_input_old(vm_object_t object, vm_page_t m)
{
	struct uio auio;
	struct iovec aiov;
	int error;
	int size;
	struct sf_buf *sf;
	struct vnode *vp;

	VM_OBJECT_ASSERT_WLOCKED(object);
	error = 0;

	/*
	 * Return failure if beyond current EOF
	 */
	if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) {
		return VM_PAGER_BAD;
	} else {
		size = PAGE_SIZE;
		if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size)
			size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex);
		vp = object->handle;
		VM_OBJECT_WUNLOCK(object);

		/*
		 * Allocate a kernel virtual address and initialize so that
		 * we can use VOP_READ/WRITE routines.
		 */
		sf = sf_buf_alloc(m, 0);

		aiov.iov_base = (caddr_t)sf_buf_kva(sf);
		aiov.iov_len = size;
		auio.uio_iov = &aiov;
		auio.uio_iovcnt = 1;
		auio.uio_offset = IDX_TO_OFF(m->pindex);
		auio.uio_segflg = UIO_SYSSPACE;
		auio.uio_rw = UIO_READ;
		auio.uio_resid = size;
		auio.uio_td = curthread;

		error = VOP_READ(vp, &auio, 0, curthread->td_ucred);
		if (!error) {
			int count = size - auio.uio_resid;

			if (count == 0)
				error = EINVAL;
			else if (count != PAGE_SIZE)
				bzero((caddr_t)sf_buf_kva(sf) + count,
				    PAGE_SIZE - count);
		}
		sf_buf_free(sf);

		VM_OBJECT_WLOCK(object);
	}
	KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m));
	if (!error)
		m->valid = VM_PAGE_BITS_ALL;
	return error ? VM_PAGER_ERROR : VM_PAGER_OK;
}

/*
 * EOPNOTSUPP is no longer legal.  For local media VFS's that do not
 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to
 * vnode_pager_generic_putpages() to implement the previous behaviour.
 *
 * All other FS's should use the bypass to get to the local media
 * backing vp's VOP_PUTPAGES.
 */
static void
vnode_pager_putpages(vm_object_t object, vm_page_t *m, int count,
    int flags, int *rtvals)
{
	int rtval;
	struct vnode *vp;
	int bytes = count * PAGE_SIZE;

	/*
	 * Force synchronous operation if we are extremely low on memory
	 * to prevent a low-memory deadlock.  VOP operations often need to
	 * allocate more memory to initiate the I/O ( i.e. do a BMAP
	 * operation ).  The swapper handles the case by limiting the amount
	 * of asynchronous I/O, but that sort of solution doesn't scale well
	 * for the vnode pager without a lot of work.
	 *
	 * Also, the backing vnode's iodone routine may not wake the pageout
	 * daemon up.  This should be probably be addressed XXX.
	 */

	if (vm_cnt.v_free_count < vm_cnt.v_pageout_free_min)
		flags |= VM_PAGER_PUT_SYNC;

	/*
	 * Call device-specific putpages function
	 */
	vp = object->handle;
	VM_OBJECT_WUNLOCK(object);
	rtval = VOP_PUTPAGES(vp, m, bytes, flags, rtvals);
	KASSERT(rtval != EOPNOTSUPP, 
	    ("vnode_pager: stale FS putpages\n"));
	VM_OBJECT_WLOCK(object);
}

void
ttm_bo_release_mmap(struct ttm_buffer_object *bo)
{
	vm_object_t vm_obj;
	vm_page_t m;
	int i;

	vm_obj = cdev_pager_lookup(bo);
	if (vm_obj == NULL)
		return;

	VM_OBJECT_WLOCK(vm_obj);
retry:
	for (i = 0; i < bo->num_pages; i++) {
		m = vm_page_lookup(vm_obj, i);
		if (m == NULL)
			continue;
		if (vm_page_sleep_if_busy(m, "ttm_unm"))
			goto retry;
		cdev_pager_free_page(vm_obj, m);
	}
	VM_OBJECT_WUNLOCK(vm_obj);

	vm_object_deallocate(vm_obj);
}

/* Create the VM system backing object for this vnode */
int
vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td)
{
	vm_object_t object;
	vm_ooffset_t size = isize;
	struct vattr va;

	if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE)
		return (0);

	while ((object = vp->v_object) != NULL) {
		VM_OBJECT_WLOCK(object);
		if (!(object->flags & OBJ_DEAD)) {
			VM_OBJECT_WUNLOCK(object);
			return (0);
		}
		VOP_UNLOCK(vp, 0);
		vm_object_set_flag(object, OBJ_DISCONNECTWNT);
		VM_OBJECT_SLEEP(object, object, PDROP | PVM, "vodead", 0);
		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
	}

	if (size == 0) {
		if (vn_isdisk(vp, NULL)) {
			size = IDX_TO_OFF(INT_MAX);
		} else {
			if (VOP_GETATTR(vp, &va, td->td_ucred))
				return (0);
			size = va.va_size;
		}
	}

	object = vnode_pager_alloc(vp, size, 0, 0, td->td_ucred);
	/*
	 * Dereference the reference we just created.  This assumes
	 * that the object is associated with the vp.
	 */
	VM_OBJECT_WLOCK(object);
	object->ref_count--;
	VM_OBJECT_WUNLOCK(object);
	vrele(vp);

	KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object"));

	return (0);
}

/*
 * Allocate (or lookup) pager for a vnode.
 * Handle is a vnode pointer.
 *
 * MPSAFE
 */
vm_object_t
vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
    vm_ooffset_t offset, struct ucred *cred)
{
	vm_object_t object;
	struct vnode *vp;

	/*
	 * Pageout to vnode, no can do yet.
	 */
	if (handle == NULL)
		return (NULL);

	vp = (struct vnode *) handle;

	/*
	 * If the object is being terminated, wait for it to
	 * go away.
	 */
retry:
	while ((object = vp->v_object) != NULL) {
		VM_OBJECT_WLOCK(object);
		if ((object->flags & OBJ_DEAD) == 0)
			break;
		vm_object_set_flag(object, OBJ_DISCONNECTWNT);
		VM_OBJECT_SLEEP(object, object, PDROP | PVM, "vadead", 0);
	}

	KASSERT(vp->v_usecount != 0, ("vnode_pager_alloc: no vnode reference"));

	if (object == NULL) {
		/*
		 * Add an object of the appropriate size
		 */
		object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size)));

		object->un_pager.vnp.vnp_size = size;
		object->un_pager.vnp.writemappings = 0;

		object->handle = handle;
		VI_LOCK(vp);
		if (vp->v_object != NULL) {
			/*
			 * Object has been created while we were sleeping
			 */
			VI_UNLOCK(vp);
			vm_object_destroy(object);
			goto retry;
		}
		vp->v_object = object;
		VI_UNLOCK(vp);
	} else {
		object->ref_count++;
		VM_OBJECT_WUNLOCK(object);
	}
	vref(vp);
	return (object);
}

/*
 * Flush and invalidate all dirty buffers. If another process is already
 * doing the flush, just wait for completion.
 */
int
fuse_io_invalbuf(struct vnode *vp, struct thread *td)
{
	struct fuse_vnode_data *fvdat = VTOFUD(vp);
	int error = 0;

	if (vp->v_iflag & VI_DOOMED)
		return 0;

	ASSERT_VOP_ELOCKED(vp, "fuse_io_invalbuf");

	while (fvdat->flag & FN_FLUSHINPROG) {
		struct proc *p = td->td_proc;

		if (vp->v_mount->mnt_kern_flag & MNTK_UNMOUNTF)
			return EIO;
		fvdat->flag |= FN_FLUSHWANT;
		tsleep(&fvdat->flag, PRIBIO + 2, "fusevinv", 2 * hz);
		error = 0;
		if (p != NULL) {
			PROC_LOCK(p);
			if (SIGNOTEMPTY(p->p_siglist) ||
			    SIGNOTEMPTY(td->td_siglist))
				error = EINTR;
			PROC_UNLOCK(p);
		}
		if (error == EINTR)
			return EINTR;
	}
	fvdat->flag |= FN_FLUSHINPROG;

	if (vp->v_bufobj.bo_object != NULL) {
		VM_OBJECT_WLOCK(vp->v_bufobj.bo_object);
		vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC);
		VM_OBJECT_WUNLOCK(vp->v_bufobj.bo_object);
	}
	error = vinvalbuf(vp, V_SAVE, PCATCH, 0);
	while (error) {
		if (error == ERESTART || error == EINTR) {
			fvdat->flag &= ~FN_FLUSHINPROG;
			if (fvdat->flag & FN_FLUSHWANT) {
				fvdat->flag &= ~FN_FLUSHWANT;
				wakeup(&fvdat->flag);
			}
			return EINTR;
		}
		error = vinvalbuf(vp, V_SAVE, PCATCH, 0);
	}
	fvdat->flag &= ~FN_FLUSHINPROG;
	if (fvdat->flag & FN_FLUSHWANT) {
		fvdat->flag &= ~FN_FLUSHWANT;
		wakeup(&fvdat->flag);
	}
	return (error);
}

/*
 *	kmem_back:
 *
 *	Allocate physical pages for the specified virtual address range.
 */
int
kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr,
    vm_size_t size, int flags)
{
	vm_offset_t offset, i;
	vm_page_t m, mpred;
	int pflags;

	KASSERT(object == kernel_object,
	    ("kmem_back_domain: only supports kernel object."));

	offset = addr - VM_MIN_KERNEL_ADDRESS;
	pflags = malloc2vm_flags(flags) | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED;
	pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
	if (flags & M_WAITOK)
		pflags |= VM_ALLOC_WAITFAIL;

	i = 0;
	VM_OBJECT_WLOCK(object);
retry:
	mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i));
	for (; i < size; i += PAGE_SIZE, mpred = m) {
		m = vm_page_alloc_domain_after(object, atop(offset + i),
		    domain, pflags, mpred);

		/*
		 * Ran out of space, free everything up and return. Don't need
		 * to lock page queues here as we know that the pages we got
		 * aren't on any queues.
		 */
		if (m == NULL) {
			if ((flags & M_NOWAIT) == 0)
				goto retry;
			VM_OBJECT_WUNLOCK(object);
			kmem_unback(object, addr, i);
			return (KERN_NO_SPACE);
		}
		KASSERT(vm_phys_domain(m) == domain,
		    ("kmem_back_domain: Domain mismatch %d != %d",
		    vm_phys_domain(m), domain));
		if (flags & M_ZERO && (m->flags & PG_ZERO) == 0)
			pmap_zero_page(m);
		KASSERT((m->oflags & VPO_UNMANAGED) != 0,
		    ("kmem_malloc: page %p is managed", m));
		m->valid = VM_PAGE_BITS_ALL;
		pmap_enter(kernel_pmap, addr + i, m, VM_PROT_ALL,
		    VM_PROT_ALL | PMAP_ENTER_WIRED, 0);
	}
	VM_OBJECT_WUNLOCK(object);

	return (KERN_SUCCESS);
}