Example #1
0
/* --------------------------------------------------------------------- */
static int
tmpfs_nocacheread(vm_object_t tobj, vm_pindex_t idx,
    vm_offset_t offset, size_t tlen, struct uio *uio)
{
	vm_page_t	m;
	int		error, rv;

	VM_OBJECT_LOCK(tobj);
	m = vm_page_grab(tobj, idx, VM_ALLOC_WIRED |
	    VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
	if (m->valid != VM_PAGE_BITS_ALL) {
		if (vm_pager_has_page(tobj, idx, NULL, NULL)) {
			rv = vm_pager_get_pages(tobj, &m, 1, 0);
			if (rv != VM_PAGER_OK) {
				vm_page_lock(m);
				vm_page_free(m);
				vm_page_unlock(m);
				VM_OBJECT_UNLOCK(tobj);
				return (EIO);
			}
		} else
			vm_page_zero_invalid(m, TRUE);
	}
	VM_OBJECT_UNLOCK(tobj);
	error = uiomove_fromphys(&m, offset, tlen, uio);
	VM_OBJECT_LOCK(tobj);
	vm_page_lock(m);
	vm_page_unwire(m, TRUE);
	vm_page_unlock(m);
	vm_page_wakeup(m);
	VM_OBJECT_UNLOCK(tobj);

	return (error);
}
Example #2
0
/* --------------------------------------------------------------------- */
static int
tmpfs_nocacheread(vm_object_t tobj, vm_pindex_t idx,
    vm_offset_t offset, size_t tlen, struct uio *uio)
{
	vm_page_t	m;
	int		error;

	VM_OBJECT_LOCK(tobj);
	vm_object_pip_add(tobj, 1);
	m = vm_page_grab(tobj, idx, VM_ALLOC_WIRED |
	    VM_ALLOC_ZERO | VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
	if (m->valid != VM_PAGE_BITS_ALL) {
		if (vm_pager_has_page(tobj, idx, NULL, NULL)) {
			error = vm_pager_get_pages(tobj, &m, 1, 0);
			if (error != 0) {
				printf("tmpfs get pages from pager error [read]\n");
				goto out;
			}
		} else
			vm_page_zero_invalid(m, TRUE);
	}
	VM_OBJECT_UNLOCK(tobj);
	error = uiomove_fromphys(&m, offset, tlen, uio);
	VM_OBJECT_LOCK(tobj);
out:
	vm_page_lock(m);
	vm_page_unwire(m, TRUE);
	vm_page_unlock(m);
	vm_page_wakeup(m);
	vm_object_pip_subtract(tobj, 1);
	VM_OBJECT_UNLOCK(tobj);

	return (error);
}
Example #3
0
/*
 * vm_fault_prefault provides a quick way of clustering
 * pagefaults into a processes address space.  It is a "cousin"
 * of vm_map_pmap_enter, except it runs at page fault time instead
 * of mmap time.
 */
static void
vm_fault_prefault(pmap_t pmap, vm_offset_t addra, vm_map_entry_t entry)
{
	int i;
	vm_offset_t addr, starta;
	vm_pindex_t pindex;
	vm_page_t m;
	vm_object_t object;

	if (pmap != vmspace_pmap(curthread->td_proc->p_vmspace))
		return;

	object = entry->object.vm_object;

	starta = addra - PFBAK * PAGE_SIZE;
	if (starta < entry->start) {
		starta = entry->start;
	} else if (starta > addra) {
		starta = 0;
	}

	for (i = 0; i < PAGEORDER_SIZE; i++) {
		vm_object_t backing_object, lobject;

		addr = addra + prefault_pageorder[i];
		if (addr > addra + (PFFOR * PAGE_SIZE))
			addr = 0;

		if (addr < starta || addr >= entry->end)
			continue;

		if (!pmap_is_prefaultable(pmap, addr))
			continue;

		pindex = ((addr - entry->start) + entry->offset) >> PAGE_SHIFT;
		lobject = object;
		VM_OBJECT_LOCK(lobject);
		while ((m = vm_page_lookup(lobject, pindex)) == NULL &&
		    lobject->type == OBJT_DEFAULT &&
		    (backing_object = lobject->backing_object) != NULL) {
			KASSERT((lobject->backing_object_offset & PAGE_MASK) ==
			    0, ("vm_fault_prefault: unaligned object offset"));
			pindex += lobject->backing_object_offset >> PAGE_SHIFT;
			VM_OBJECT_LOCK(backing_object);
			VM_OBJECT_UNLOCK(lobject);
			lobject = backing_object;
		}
		/*
		 * give-up when a page is not in memory
		 */
		if (m == NULL) {
			VM_OBJECT_UNLOCK(lobject);
			break;
		}
		if (m->valid == VM_PAGE_BITS_ALL &&
		    (m->flags & PG_FICTITIOUS) == 0)
			pmap_enter_quick(pmap, addr, m, entry->protection);
		VM_OBJECT_UNLOCK(lobject);
	}
}
Example #4
0
/*
 * 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_LOCK(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_UNLOCK(obj);
		return (EINVAL);
	}

	shmfd->shm_kmappings++;
	vm_object_reference_locked(obj);
	VM_OBJECT_UNLOCK(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,
	    VMFS_ALIGNED_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_LOCK(obj);
	shmfd->shm_kmappings--;
	VM_OBJECT_UNLOCK(obj);

	return (vm_mmap_to_errno(rv));
}
static vm_page_t rtR0MemObjFreeBSDContigPhysAllocHelper(vm_object_t pObject, vm_pindex_t iPIndex,
                                                        u_long cPages, vm_paddr_t VmPhysAddrHigh,
                                                        u_long uAlignment, bool fWire)
{
    vm_page_t pPages;
    int cTries = 0;

#if __FreeBSD_version > 1000000
    int fFlags = VM_ALLOC_INTERRUPT | VM_ALLOC_NOBUSY;
    if (fWire)
        fFlags |= VM_ALLOC_WIRED;

    while (cTries <= 1)
    {
        VM_OBJECT_LOCK(pObject);
        pPages = vm_page_alloc_contig(pObject, iPIndex, fFlags, cPages, 0,
                                      VmPhysAddrHigh, uAlignment, 0, VM_MEMATTR_DEFAULT);
        VM_OBJECT_UNLOCK(pObject);
        if (pPages)
            break;
        vm_pageout_grow_cache(cTries, 0, VmPhysAddrHigh);
        cTries++;
    }

    return pPages;
#else
    while (cTries <= 1)
    {
        pPages = vm_phys_alloc_contig(cPages, 0, VmPhysAddrHigh, uAlignment, 0);
        if (pPages)
            break;
        vm_contig_grow_cache(cTries, 0, VmPhysAddrHigh);
        cTries++;
    }

    if (!pPages)
        return pPages;
    VM_OBJECT_LOCK(pObject);
    for (vm_pindex_t iPage = 0; iPage < cPages; iPage++)
    {
        vm_page_t pPage = pPages + iPage;
        vm_page_insert(pPage, pObject, iPIndex + iPage);
        pPage->valid = VM_PAGE_BITS_ALL;
        if (fWire)
        {
            pPage->wire_count = 1;
            atomic_add_int(&cnt.v_wire_count, 1);
        }
    }
    VM_OBJECT_UNLOCK(pObject);
    return pPages;
#endif
}
Example #6
0
/*
 * Speed up the reclamation of up to "distance" pages that precede the
 * faulting pindex within the first object of the shadow chain.
 */
static void
vm_fault_cache_behind(const struct faultstate *fs, int distance)
{
	vm_object_t first_object, object;
	vm_page_t m, m_prev;
	vm_pindex_t pindex;

	object = fs->object;
	VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
	first_object = fs->first_object;
	if (first_object != object) {
		if (!VM_OBJECT_TRYLOCK(first_object)) {
			VM_OBJECT_UNLOCK(object);
			VM_OBJECT_LOCK(first_object);
			VM_OBJECT_LOCK(object);
		}
	}
	if (first_object->type != OBJT_DEVICE &&
	    first_object->type != OBJT_PHYS && first_object->type != OBJT_SG) {
		if (fs->first_pindex < distance)
			pindex = 0;
		else
			pindex = fs->first_pindex - distance;
		if (pindex < OFF_TO_IDX(fs->entry->offset))
			pindex = OFF_TO_IDX(fs->entry->offset);
		m = first_object != object ? fs->first_m : fs->m;
		KASSERT((m->oflags & VPO_BUSY) != 0,
		    ("vm_fault_cache_behind: page %p is not busy", m));
		m_prev = vm_page_prev(m);
		while ((m = m_prev) != NULL && m->pindex >= pindex &&
		    m->valid == VM_PAGE_BITS_ALL) {
			m_prev = vm_page_prev(m);
			if (m->busy != 0 || (m->oflags & VPO_BUSY) != 0)
				continue;
			vm_page_lock(m);
			if (m->hold_count == 0 && m->wire_count == 0) {
				pmap_remove_all(m);
				vm_page_aflag_clear(m, PGA_REFERENCED);
				if (m->dirty != 0)
					vm_page_deactivate(m);
				else
					vm_page_cache(m);
			}
			vm_page_unlock(m);
		}
	}
	if (first_object != object)
		VM_OBJECT_UNLOCK(first_object);
}
Example #7
0
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_LOCK(obj);
	if (obj->ref_count == 0) {
		/*
		 * vclean() may be called twice. The first time
		 * removes the primary reference to the object,
		 * the second time goes one further and is a
		 * special-case to terminate the object.
		 *
		 * don't double-terminate the object
		 */
		if ((obj->flags & OBJ_DEAD) == 0)
			vm_object_terminate(obj);
		else
			VM_OBJECT_UNLOCK(obj);
	} else {
		/*
		 * Woe to the process that tries to page now :-).
		 */
		vm_pager_deallocate(obj);
		VM_OBJECT_UNLOCK(obj);
	}
	vp->v_object = NULL;
}
static int rtR0MemObjFreeBSDPhysAllocHelper(vm_object_t pObject, u_long cPages,
                                            vm_paddr_t VmPhysAddrHigh, u_long uAlignment,
                                            bool fContiguous, bool fWire, int rcNoMem)
{
    if (fContiguous)
    {
        if (rtR0MemObjFreeBSDContigPhysAllocHelper(pObject, 0, cPages, VmPhysAddrHigh,
                                                   uAlignment, fWire) != NULL)
            return VINF_SUCCESS;
        return rcNoMem;
    }

    for (vm_pindex_t iPage = 0; iPage < cPages; iPage++)
    {
        vm_page_t pPage = rtR0MemObjFreeBSDContigPhysAllocHelper(pObject, iPage, 1, VmPhysAddrHigh,
                                                                 uAlignment, fWire);
        if (!pPage)
        {
            /* Free all allocated pages */
            VM_OBJECT_LOCK(pObject);
            while (iPage-- > 0)
            {
                pPage = vm_page_lookup(pObject, iPage);
                vm_page_lock_queues();
                if (fWire)
                    vm_page_unwire(pPage, 0);
                vm_page_free(pPage);
                vm_page_unlock_queues();
            }
            VM_OBJECT_UNLOCK(pObject);
            return rcNoMem;
        }
    }
    return VINF_SUCCESS;
}
Example #9
0
/*
 * 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_LOCK(shmfd->shm_object);
	vm_object_clear_flag(shmfd->shm_object, OBJ_ONEMAPPING);
	vm_object_set_flag(shmfd->shm_object, OBJ_NOSPLIT);
	VM_OBJECT_UNLOCK(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);
#ifdef MAC
	mac_posixshm_init(shmfd);
	mac_posixshm_create(ucred, shmfd);
#endif

	return (shmfd);
}
Example #10
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_LOCK(object);
		if ((object->flags & OBJ_DEAD) == 0)
			break;
		vm_object_set_flag(object, OBJ_DISCONNECTWNT);
		msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vadead", 0);
	}

	if (vp->v_usecount == 0)
		panic("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_UNLOCK(object);
	}
	vref(vp);
	return (object);
}
Example #11
0
/* 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_LOCK(object);
		if (!(object->flags & OBJ_DEAD)) {
			VM_OBJECT_UNLOCK(object);
			return (0);
		}
		VOP_UNLOCK(vp, 0);
		vm_object_set_flag(object, OBJ_DISCONNECTWNT);
		msleep(object, VM_OBJECT_MTX(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_LOCK(object);
	object->ref_count--;
	VM_OBJECT_UNLOCK(object);
	vrele(vp);

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

	return (0);
}
Example #12
0
/* Try to invalidate pages, for "fs flush" or "fs flushv"; or
 * try to free pages, when deleting a file.
 *
 * Locking:  the vcache entry's lock is held.  It may be dropped and 
 * re-obtained.
 *
 * Since we drop and re-obtain the lock, we can't guarantee that there won't
 * be some pages around when we return, newly created by concurrent activity.
 */
void
osi_VM_TryToSmush(struct vcache *avc, afs_ucred_t *acred, int sync)
{
    struct vnode *vp;
    int tries, code;
    int islocked;

    vp = AFSTOV(avc);

    VI_LOCK(vp);
    if (vp->v_iflag & VI_DOOMED) {
	VI_UNLOCK(vp);
	return;
    }
    VI_UNLOCK(vp);

    islocked = islocked_vnode(vp);
    if (islocked == LK_EXCLOTHER)
	panic("Trying to Smush over someone else's lock");
    else if (islocked == LK_SHARED) {
	afs_warn("Trying to Smush with a shared lock");
	lock_vnode(vp, LK_UPGRADE);
    } else if (!islocked)
	lock_vnode(vp, LK_EXCLUSIVE);

    if (vp->v_bufobj.bo_object != NULL) {
	VM_OBJECT_LOCK(vp->v_bufobj.bo_object);
	/*
	 * Do we really want OBJPC_SYNC?  OBJPC_INVAL would be
	 * faster, if invalidation is really what we are being
	 * asked to do.  (It would make more sense, too, since
	 * otherwise this function is practically identical to
	 * osi_VM_StoreAllSegments().)  -GAW
	 */

	/*
	 * Dunno.  We no longer resemble osi_VM_StoreAllSegments,
	 * though maybe that's wrong, now.  And OBJPC_SYNC is the
	 * common thing in 70 file systems, it seems.  Matt.
	 */

	vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC);
	VM_OBJECT_UNLOCK(vp->v_bufobj.bo_object);
    }

    tries = 5;
    code = osi_vinvalbuf(vp, V_SAVE, PCATCH, 0);
    while (code && (tries > 0)) {
	afs_warn("TryToSmush retrying vinvalbuf");
	code = osi_vinvalbuf(vp, V_SAVE, PCATCH, 0);
	--tries;
    }
    if (islocked == LK_SHARED)
	lock_vnode(vp, LK_DOWNGRADE);
    else if (!islocked)
	unlock_vnode(vp);
}
Example #13
0
/*
 * 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_LOCK(vp->v_bufobj.bo_object);
		vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC);
		VM_OBJECT_UNLOCK(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);
}
Example #14
0
/*
 * MPSAFE
 */
static void
phys_pager_dealloc(vm_object_t object)
{

    if (object->handle != NULL) {
        VM_OBJECT_UNLOCK(object);
        mtx_lock(&phys_pager_mtx);
        TAILQ_REMOVE(&phys_pager_object_list, object, pager_object_list);
        mtx_unlock(&phys_pager_mtx);
        VM_OBJECT_LOCK(object);
    }
}
Example #15
0
/*
 * Identify the physical page mapped at the given kernel virtual
 * address.  Insert this physical page into the given address space at
 * the given virtual address, replacing the physical page, if any,
 * that already exists there.
 */
static int
vm_pgmoveco(vm_map_t mapa, vm_offset_t kaddr, vm_offset_t uaddr)
{
	vm_map_t map = mapa;
	vm_page_t kern_pg, user_pg;
	vm_object_t uobject;
	vm_map_entry_t entry;
	vm_pindex_t upindex;
	vm_prot_t prot;
	boolean_t wired;

	KASSERT((uaddr & PAGE_MASK) == 0,
	    ("vm_pgmoveco: uaddr is not page aligned"));

	/*
	 * Herein the physical page is validated and dirtied.  It is
	 * unwired in sf_buf_mext().
	 */
	kern_pg = PHYS_TO_VM_PAGE(vtophys(kaddr));
	kern_pg->valid = VM_PAGE_BITS_ALL;
	KASSERT(kern_pg->queue == PQ_NONE && kern_pg->wire_count == 1,
	    ("vm_pgmoveco: kern_pg is not correctly wired"));

	if ((vm_map_lookup(&map, uaddr,
			   VM_PROT_WRITE, &entry, &uobject,
			   &upindex, &prot, &wired)) != KERN_SUCCESS) {
		return(EFAULT);
	}
	VM_OBJECT_LOCK(uobject);
retry:
	if ((user_pg = vm_page_lookup(uobject, upindex)) != NULL) {
		if (vm_page_sleep_if_busy(user_pg, TRUE, "vm_pgmoveco"))
			goto retry;
		vm_page_lock_queues();
		pmap_remove_all(user_pg);
		vm_page_free(user_pg);
	} else {
		/*
		 * Even if a physical page does not exist in the
		 * object chain's first object, a physical page from a
		 * backing object may be mapped read only.
		 */
		if (uobject->backing_object != NULL)
			pmap_remove(map->pmap, uaddr, uaddr + PAGE_SIZE);
		vm_page_lock_queues();
	}
	vm_page_insert(kern_pg, uobject, upindex);
	vm_page_dirty(kern_pg);
	vm_page_unlock_queues();
	VM_OBJECT_UNLOCK(uobject);
	vm_map_lookup_done(map, entry);
	return(KERN_SUCCESS);
}
Example #16
0
static int rtR0MemObjFreeBSDAllocPhysPages(PPRTR0MEMOBJINTERNAL ppMem, RTR0MEMOBJTYPE enmType,
                                           size_t cb,
                                           RTHCPHYS PhysHighest, size_t uAlignment,
                                           bool fContiguous, int rcNoMem)
{
    uint32_t   cPages = atop(cb);
    vm_paddr_t VmPhysAddrHigh;

    /* create the object. */
    PRTR0MEMOBJFREEBSD pMemFreeBSD = (PRTR0MEMOBJFREEBSD)rtR0MemObjNew(sizeof(*pMemFreeBSD),
                                                                       enmType, NULL, cb);
    if (!pMemFreeBSD)
        return VERR_NO_MEMORY;

    pMemFreeBSD->pObject = vm_object_allocate(OBJT_PHYS, atop(cb));

    if (PhysHighest != NIL_RTHCPHYS)
        VmPhysAddrHigh = PhysHighest;
    else
        VmPhysAddrHigh = ~(vm_paddr_t)0;

    int rc = rtR0MemObjFreeBSDPhysAllocHelper(pMemFreeBSD->pObject, cPages, VmPhysAddrHigh,
                                              uAlignment, fContiguous, true, rcNoMem);
    if (RT_SUCCESS(rc))
    {
        if (fContiguous)
        {
            Assert(enmType == RTR0MEMOBJTYPE_PHYS);
#if __FreeBSD_version >= 1000030
            VM_OBJECT_WLOCK(pMemFreeBSD->pObject);
#else
            VM_OBJECT_LOCK(pMemFreeBSD->pObject);
#endif
            pMemFreeBSD->Core.u.Phys.PhysBase = VM_PAGE_TO_PHYS(vm_page_find_least(pMemFreeBSD->pObject, 0));
#if __FreeBSD_version >= 1000030
            VM_OBJECT_WUNLOCK(pMemFreeBSD->pObject);
#else
            VM_OBJECT_UNLOCK(pMemFreeBSD->pObject);
#endif
            pMemFreeBSD->Core.u.Phys.fAllocated = true;
        }

        *ppMem = &pMemFreeBSD->Core;
    }
    else
    {
        vm_object_deallocate(pMemFreeBSD->pObject);
        rtR0MemObjDelete(&pMemFreeBSD->Core);
    }

    return rc;
}
Example #17
0
int
ncl_inactive(struct vop_inactive_args *ap)
{
	struct nfsnode *np;
	struct sillyrename *sp;
	struct vnode *vp = ap->a_vp;
	boolean_t retv;

	np = VTONFS(vp);

	if (NFS_ISV4(vp) && vp->v_type == VREG) {
		/*
		 * Since mmap()'d files do I/O after VOP_CLOSE(), the NFSv4
		 * Close operations are delayed until now. Any dirty
		 * buffers/pages must be flushed before the close, so that the
		 * stateid is available for the writes.
		 */
		if (vp->v_object != NULL) {
			VM_OBJECT_LOCK(vp->v_object);
			retv = vm_object_page_clean(vp->v_object, 0, 0,
			    OBJPC_SYNC);
			VM_OBJECT_UNLOCK(vp->v_object);
		} else
			retv = TRUE;
		if (retv == TRUE) {
			(void)ncl_flush(vp, MNT_WAIT, NULL, ap->a_td, 1, 0);
			(void)nfsrpc_close(vp, 1, ap->a_td);
		}
	}

	mtx_lock(&np->n_mtx);
	if (vp->v_type != VDIR) {
		sp = np->n_sillyrename;
		np->n_sillyrename = NULL;
	} else
		sp = NULL;
	if (sp) {
		mtx_unlock(&np->n_mtx);
		(void) ncl_vinvalbuf(vp, 0, ap->a_td, 1);
		/*
		 * Remove the silly file that was rename'd earlier
		 */
		ncl_removeit(sp, vp);
		crfree(sp->s_cred);
		TASK_INIT(&sp->s_task, 0, nfs_freesillyrename, sp);
		taskqueue_enqueue(taskqueue_thread, &sp->s_task);
		mtx_lock(&np->n_mtx);
	}
	np->n_flag &= NMODIFIED;
	mtx_unlock(&np->n_mtx);
	return (0);
}
Example #18
0
int ttm_tt_swapin(struct ttm_tt *ttm)
{
	vm_object_t obj;
	vm_page_t from_page, to_page;
	int i, ret, rv;

	obj = ttm->swap_storage;

	VM_OBJECT_LOCK(obj);
	vm_object_pip_add(obj, 1);
	for (i = 0; i < ttm->num_pages; ++i) {
		from_page = vm_page_grab(obj, i, VM_ALLOC_NORMAL |
						 VM_ALLOC_RETRY);
		if (from_page->valid != VM_PAGE_BITS_ALL) {
			if (vm_pager_has_page(obj, i)) {
				rv = vm_pager_get_page(obj, &from_page, 1);
				if (rv != VM_PAGER_OK) {
					vm_page_free(from_page);
					ret = -EIO;
					goto err_ret;
				}
			} else {
				vm_page_zero_invalid(from_page, TRUE);
			}
		}
		to_page = ttm->pages[i];
		if (unlikely(to_page == NULL)) {
			ret = -ENOMEM;
			vm_page_wakeup(from_page);
			goto err_ret;
		}
		pmap_copy_page(VM_PAGE_TO_PHYS(from_page),
			       VM_PAGE_TO_PHYS(to_page));
		vm_page_wakeup(from_page);
	}
	vm_object_pip_wakeup(obj);
	VM_OBJECT_UNLOCK(obj);

	if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTENT_SWAP))
		vm_object_deallocate(obj);
	ttm->swap_storage = NULL;
	ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
	return (0);

err_ret:
	vm_object_pip_wakeup(obj);
	VM_OBJECT_UNLOCK(obj);
	return (ret);
}
Example #19
0
/* Purge VM for a file when its callback is revoked.
 *
 * Locking:  No lock is held, not even the global lock.
 */
void
osi_VM_FlushPages(struct vcache *avc, afs_ucred_t *credp)
{
    struct vnode *vp;
    struct vm_object *obj;

    vp = AFSTOV(avc);
    ASSERT_VOP_LOCKED(vp, __func__);
    if (VOP_GETVOBJECT(vp, &obj) == 0) {
	VM_OBJECT_LOCK(obj);
	vm_object_page_remove(obj, 0, 0, FALSE);
	VM_OBJECT_UNLOCK(obj);
    }
    osi_vinvalbuf(vp, 0, 0, 0);
}
Example #20
0
int ttm_tt_swapout(struct ttm_tt *ttm, vm_object_t persistent_swap_storage)
{
	vm_object_t obj;
	vm_page_t from_page, to_page;
	int i;

	BUG_ON(ttm->state != tt_unbound && ttm->state != tt_unpopulated);
	BUG_ON(ttm->caching_state != tt_cached);

	if (!persistent_swap_storage) {
		obj = swap_pager_alloc(NULL,
		    IDX_TO_OFF(ttm->num_pages), VM_PROT_DEFAULT, 0);
		if (obj == NULL) {
			pr_err("Failed allocating swap storage\n");
			return (-ENOMEM);
		}
	} else
		obj = persistent_swap_storage;

	VM_OBJECT_LOCK(obj);
	vm_object_pip_add(obj, 1);
	for (i = 0; i < ttm->num_pages; ++i) {
		from_page = ttm->pages[i];
		if (unlikely(from_page == NULL))
			continue;
		to_page = vm_page_grab(obj, i, VM_ALLOC_NORMAL |
					       VM_ALLOC_RETRY);
		pmap_copy_page(VM_PAGE_TO_PHYS(from_page),
					VM_PAGE_TO_PHYS(to_page));
		to_page->valid = VM_PAGE_BITS_ALL;
		vm_page_dirty(to_page);
		vm_page_wakeup(to_page);
	}
	vm_object_pip_wakeup(obj);
	VM_OBJECT_UNLOCK(obj);

	ttm->bdev->driver->ttm_tt_unpopulate(ttm);
	ttm->swap_storage = obj;
	ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
	if (persistent_swap_storage)
		ttm->page_flags |= TTM_PAGE_FLAG_PERSISTENT_SWAP;

	return 0;
}
Example #21
0
/* Try to invalidate pages, for "fs flush" or "fs flushv"; or
 * try to free pages, when deleting a file.
 *
 * Locking:  the vcache entry's lock is held.  It may be dropped and 
 * re-obtained.
 *
 * Since we drop and re-obtain the lock, we can't guarantee that there won't
 * be some pages around when we return, newly created by concurrent activity.
 */
void
osi_VM_TryToSmush(struct vcache *avc, afs_ucred_t *acred, int sync)
{
    struct vnode *vp;
    int tries, code;

    SPLVAR;

    vp = AFSTOV(avc);

    if (vp->v_iflag & VI_DOOMED) {
      USERPRI;
      return;
    }

    if (vp->v_bufobj.bo_object != NULL) {
      VM_OBJECT_LOCK(vp->v_bufobj.bo_object);
      /*
       * Do we really want OBJPC_SYNC?  OBJPC_INVAL would be
       * faster, if invalidation is really what we are being
       * asked to do.  (It would make more sense, too, since
       * otherwise this function is practically identical to
       * osi_VM_StoreAllSegments().)  -GAW
       */

      /*
       * Dunno.  We no longer resemble osi_VM_StoreAllSegments,
       * though maybe that's wrong, now.  And OBJPC_SYNC is the
       * common thing in 70 file systems, it seems.  Matt.
       */

      vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC);
      VM_OBJECT_UNLOCK(vp->v_bufobj.bo_object);
    }

    tries = 5;
    code = osi_vinvalbuf(vp, V_SAVE, PCATCH, 0);
    while (code && (tries > 0)) {
      code = osi_vinvalbuf(vp, V_SAVE, PCATCH, 0);
      --tries;
    }
    USERPRI;
}
Example #22
0
static void
pscnv_gem_pager_dtor(void *handle)
{
	struct drm_gem_object *gem_obj = handle;
	struct pscnv_bo *bo = gem_obj->driver_private;
	struct drm_device *dev = gem_obj->dev;
	vm_object_t devobj;

	DRM_LOCK(dev);
	devobj = cdev_pager_lookup(handle);

	if (devobj != NULL) {
		vm_size_t page_count = OFF_TO_IDX(bo->size);
		vm_page_t m;
		int i;
		VM_OBJECT_LOCK(devobj);
		for (i = 0; i < page_count; i++) {
			m = vm_page_lookup(devobj, i);
			if (!m)
				continue;
			if (pscnv_mem_debug > 0)
				NV_WARN(dev, "Freeing %010llx + %08llx (%p\n", bo->start, i * PAGE_SIZE, m);
			cdev_pager_free_page(devobj, m);
		}
		VM_OBJECT_UNLOCK(devobj);
		vm_object_deallocate(devobj);
	}
	else {
		DRM_UNLOCK(dev);
		NV_ERROR(dev, "Could not find handle %p bo %p\n", handle, bo);
		return;
	}
	if (pscnv_mem_debug > 0)
		NV_WARN(dev, "Freed %010llx (%p)\n", bo->start, bo);
	//kfree(bo->fake_pages);

	if (bo->chan)
		pscnv_chan_unref(bo->chan);
	else
		drm_gem_object_unreference_unlocked(gem_obj);
	DRM_UNLOCK(dev);
}
Example #23
0
/* Try to discard pages, in order to recycle a vcache entry.
 *
 * We also make some sanity checks:  ref count, open count, held locks.
 *
 * We also do some non-VM-related chores, such as releasing the cred pointer
 * (for AIX and Solaris) and releasing the gnode (for AIX).
 *
 * Locking:  afs_xvcache lock is held.  If it is dropped and re-acquired,
 *   *slept should be set to warn the caller.
 *
 * Formerly, afs_xvcache was dropped and re-acquired for Solaris, but now it
 * is not dropped and re-acquired for any platform.  It may be that *slept is
 * therefore obsolescent.
 *
 * OSF/1 Locking:  VN_LOCK has been called.
 * We do not lock the vnode here, but instead require that it be exclusive
 * locked by code calling osi_VM_StoreAllSegments directly, or scheduling it
 * from the bqueue - Matt
 * Maybe better to just call vnode_pager_setsize()?
 */
int
osi_VM_FlushVCache(struct vcache *avc, int *slept)
{
    struct vm_object *obj;
    struct vnode *vp;
    if (VREFCOUNT(avc) > 1)
	return EBUSY;

    if (avc->opens)
	return EBUSY;

    /* if a lock is held, give up */
    if (CheckLock(&avc->lock))
	return EBUSY;

    return(0);

    AFS_GUNLOCK();
    vp = AFSTOV(avc);
#ifndef AFS_FBSD70_ENV
    lock_vnode(vp);
#endif
    if (VOP_GETVOBJECT(vp, &obj) == 0) {
	VM_OBJECT_LOCK(obj);
	vm_object_page_remove(obj, 0, 0, FALSE);
#if 1
	if (obj->ref_count == 0) {
	    simple_lock(&vp->v_interlock);
	    vgonel(vp, curthread);
	    vp->v_tag = VT_AFS;
	    SetAfsVnode(vp);
	}
#endif
	VM_OBJECT_UNLOCK(obj);
    }
#ifndef AFS_FBSD70_ENV
    unlock_vnode(vp);
#endif
    AFS_GLOCK();

    return 0;
}
Example #24
0
/* Try to store pages to cache, in order to store a file back to the server.
 *
 * Locking:  the vcache entry's lock is held.  It will usually be dropped and
 * re-obtained.
 */
void
osi_VM_StoreAllSegments(struct vcache *avc)
{
    struct vnode *vp;
    struct vm_object *obj;
    int anyio, tries;

    ReleaseWriteLock(&avc->lock);
    AFS_GUNLOCK();
    tries = 5;
    vp = AFSTOV(avc);

    /*
     * I don't understand this.  Why not just call vm_object_page_clean()
     * and be done with it?  I particularly don't understand why we're calling
     * vget() here.  Is there some reason to believe that the vnode might
     * be being recycled at this point?  I don't think there's any need for
     * this loop, either -- if we keep the vnode locked all the time,
     * that and the object lock will prevent any new pages from appearing.
     * The loop is what causes the race condition.  -GAW
     */
    do {
	anyio = 0;
	
	obj = vp->v_object;
	if (obj != NULL && obj->flags & OBJ_MIGHTBEDIRTY) {
	    if (!vget(vp, LK_EXCLUSIVE | LK_RETRY, curthread)) {
		    obj = vp->v_object;
		    if (obj != NULL) {
			VM_OBJECT_LOCK(obj);
			vm_object_page_clean(obj, 0, 0, OBJPC_SYNC);
			VM_OBJECT_UNLOCK(obj);
			anyio = 1;
		    }
		    vput(vp);
		}
	    }
    } while (anyio && (--tries > 0));
    AFS_GLOCK();
    ObtainWriteLock(&avc->lock, 94);
}
Example #25
0
/*
 * We require the caller to unmap the entire entry.  This allows us to
 * safely decrement shm_kmappings when a mapping is removed.
 */
int
shm_unmap(struct file *fp, void *mem, size_t size)
{
	struct shmfd *shmfd;
	vm_map_entry_t entry;
	vm_offset_t kva, ofs;
	vm_object_t obj;
	vm_pindex_t pindex;
	vm_prot_t prot;
	boolean_t wired;
	vm_map_t map;
	int rv;

	if (fp->f_type != DTYPE_SHM)
		return (EINVAL);
	shmfd = fp->f_data;
	kva = (vm_offset_t)mem;
	ofs = kva & PAGE_MASK;
	kva = trunc_page(kva);
	size = round_page(size + ofs);
	map = kernel_map;
	rv = vm_map_lookup(&map, kva, VM_PROT_READ | VM_PROT_WRITE, &entry,
	    &obj, &pindex, &prot, &wired);
	if (rv != KERN_SUCCESS)
		return (EINVAL);
	if (entry->start != kva || entry->end != kva + size) {
		vm_map_lookup_done(map, entry);
		return (EINVAL);
	}
	vm_map_lookup_done(map, entry);
	if (obj != shmfd->shm_object)
		return (EINVAL);
	vm_map_remove(map, kva, kva + size);
	VM_OBJECT_LOCK(obj);
	KASSERT(shmfd->shm_kmappings > 0, ("shm_unmap: object not mapped"));
	shmfd->shm_kmappings--;
	VM_OBJECT_UNLOCK(obj);
	return (0);
}
Example #26
0
static void
unlock_and_deallocate(struct faultstate *fs)
{

	vm_object_pip_wakeup(fs->object);
	VM_OBJECT_UNLOCK(fs->object);
	if (fs->object != fs->first_object) {
		VM_OBJECT_LOCK(fs->first_object);
		vm_page_lock(fs->first_m);
		vm_page_free(fs->first_m);
		vm_page_unlock(fs->first_m);
		vm_object_pip_wakeup(fs->first_object);
		VM_OBJECT_UNLOCK(fs->first_object);
		fs->first_m = NULL;
	}
	vm_object_deallocate(fs->first_object);
	unlock_map(fs);	
	if (fs->vp != NULL) { 
		vput(fs->vp);
		fs->vp = NULL;
	}
	VFS_UNLOCK_GIANT(fs->vfslocked);
	fs->vfslocked = 0;
}
Example #27
0
int
vm_fault_hold(vm_map_t map, vm_offset_t vaddr, vm_prot_t fault_type,
    int fault_flags, vm_page_t *m_hold)
{
	vm_prot_t prot;
	long ahead, behind;
	int alloc_req, era, faultcount, nera, reqpage, result;
	boolean_t growstack, is_first_object_locked, wired;
	int map_generation;
	vm_object_t next_object;
	vm_page_t marray[VM_FAULT_READ_MAX];
	int hardfault;
	struct faultstate fs;
	struct vnode *vp;
	int locked, error;

	hardfault = 0;
	growstack = TRUE;
	PCPU_INC(cnt.v_vm_faults);
	fs.vp = NULL;
	fs.vfslocked = 0;
	faultcount = reqpage = 0;

RetryFault:;

	/*
	 * Find the backing store object and offset into it to begin the
	 * search.
	 */
	fs.map = map;
	result = vm_map_lookup(&fs.map, vaddr, fault_type, &fs.entry,
	    &fs.first_object, &fs.first_pindex, &prot, &wired);
	if (result != KERN_SUCCESS) {
		if (growstack && result == KERN_INVALID_ADDRESS &&
		    map != kernel_map) {
			result = vm_map_growstack(curproc, vaddr);
			if (result != KERN_SUCCESS)
				return (KERN_FAILURE);
			growstack = FALSE;
			goto RetryFault;
		}
		return (result);
	}

	map_generation = fs.map->timestamp;

	if (fs.entry->eflags & MAP_ENTRY_NOFAULT) {
		panic("vm_fault: fault on nofault entry, addr: %lx",
		    (u_long)vaddr);
	}

	/*
	 * Make a reference to this object to prevent its disposal while we
	 * are messing with it.  Once we have the reference, the map is free
	 * to be diddled.  Since objects reference their shadows (and copies),
	 * they will stay around as well.
	 *
	 * Bump the paging-in-progress count to prevent size changes (e.g. 
	 * truncation operations) during I/O.  This must be done after
	 * obtaining the vnode lock in order to avoid possible deadlocks.
	 */
	VM_OBJECT_LOCK(fs.first_object);
	vm_object_reference_locked(fs.first_object);
	vm_object_pip_add(fs.first_object, 1);

	fs.lookup_still_valid = TRUE;

	if (wired)
		fault_type = prot | (fault_type & VM_PROT_COPY);

	fs.first_m = NULL;

	/*
	 * Search for the page at object/offset.
	 */
	fs.object = fs.first_object;
	fs.pindex = fs.first_pindex;
	while (TRUE) {
		/*
		 * If the object is dead, we stop here
		 */
		if (fs.object->flags & OBJ_DEAD) {
			unlock_and_deallocate(&fs);
			return (KERN_PROTECTION_FAILURE);
		}

		/*
		 * See if page is resident
		 */
		fs.m = vm_page_lookup(fs.object, fs.pindex);
		if (fs.m != NULL) {
			/* 
			 * check for page-based copy on write.
			 * We check fs.object == fs.first_object so
			 * as to ensure the legacy COW mechanism is
			 * used when the page in question is part of
			 * a shadow object.  Otherwise, vm_page_cowfault()
			 * removes the page from the backing object, 
			 * which is not what we want.
			 */
			vm_page_lock(fs.m);
			if ((fs.m->cow) && 
			    (fault_type & VM_PROT_WRITE) &&
			    (fs.object == fs.first_object)) {
				vm_page_cowfault(fs.m);
				unlock_and_deallocate(&fs);
				goto RetryFault;
			}

			/*
			 * Wait/Retry if the page is busy.  We have to do this
			 * if the page is busy via either VPO_BUSY or 
			 * vm_page_t->busy because the vm_pager may be using
			 * vm_page_t->busy for pageouts ( and even pageins if
			 * it is the vnode pager ), and we could end up trying
			 * to pagein and pageout the same page simultaneously.
			 *
			 * We can theoretically allow the busy case on a read
			 * fault if the page is marked valid, but since such
			 * pages are typically already pmap'd, putting that
			 * special case in might be more effort then it is 
			 * worth.  We cannot under any circumstances mess
			 * around with a vm_page_t->busy page except, perhaps,
			 * to pmap it.
			 */
			if ((fs.m->oflags & VPO_BUSY) || fs.m->busy) {
				/*
				 * Reference the page before unlocking and
				 * sleeping so that the page daemon is less
				 * likely to reclaim it. 
				 */
				vm_page_aflag_set(fs.m, PGA_REFERENCED);
				vm_page_unlock(fs.m);
				if (fs.object != fs.first_object) {
					if (!VM_OBJECT_TRYLOCK(
					    fs.first_object)) {
						VM_OBJECT_UNLOCK(fs.object);
						VM_OBJECT_LOCK(fs.first_object);
						VM_OBJECT_LOCK(fs.object);
					}
					vm_page_lock(fs.first_m);
					vm_page_free(fs.first_m);
					vm_page_unlock(fs.first_m);
					vm_object_pip_wakeup(fs.first_object);
					VM_OBJECT_UNLOCK(fs.first_object);
					fs.first_m = NULL;
				}
				unlock_map(&fs);
				if (fs.m == vm_page_lookup(fs.object,
				    fs.pindex)) {
					vm_page_sleep_if_busy(fs.m, TRUE,
					    "vmpfw");
				}
				vm_object_pip_wakeup(fs.object);
				VM_OBJECT_UNLOCK(fs.object);
				PCPU_INC(cnt.v_intrans);
				vm_object_deallocate(fs.first_object);
				goto RetryFault;
			}
			vm_pageq_remove(fs.m);
			vm_page_unlock(fs.m);

			/*
			 * Mark page busy for other processes, and the 
			 * pagedaemon.  If it still isn't completely valid
			 * (readable), jump to readrest, else break-out ( we
			 * found the page ).
			 */
			vm_page_busy(fs.m);
			if (fs.m->valid != VM_PAGE_BITS_ALL)
				goto readrest;
			break;
		}

		/*
		 * Page is not resident, If this is the search termination
		 * or the pager might contain the page, allocate a new page.
		 */
		if (TRYPAGER || fs.object == fs.first_object) {
			if (fs.pindex >= fs.object->size) {
				unlock_and_deallocate(&fs);
				return (KERN_PROTECTION_FAILURE);
			}

			/*
			 * Allocate a new page for this object/offset pair.
			 *
			 * Unlocked read of the p_flag is harmless. At
			 * worst, the P_KILLED might be not observed
			 * there, and allocation can fail, causing
			 * restart and new reading of the p_flag.
			 */
			fs.m = NULL;
			if (!vm_page_count_severe() || P_KILLED(curproc)) {
#if VM_NRESERVLEVEL > 0
				if ((fs.object->flags & OBJ_COLORED) == 0) {
					fs.object->flags |= OBJ_COLORED;
					fs.object->pg_color = atop(vaddr) -
					    fs.pindex;
				}
#endif
				alloc_req = P_KILLED(curproc) ?
				    VM_ALLOC_SYSTEM : VM_ALLOC_NORMAL;
				if (fs.object->type != OBJT_VNODE &&
				    fs.object->backing_object == NULL)
					alloc_req |= VM_ALLOC_ZERO;
				fs.m = vm_page_alloc(fs.object, fs.pindex,
				    alloc_req);
			}
			if (fs.m == NULL) {
				unlock_and_deallocate(&fs);
				VM_WAITPFAULT;
				goto RetryFault;
			} else if (fs.m->valid == VM_PAGE_BITS_ALL)
				break;
		}

readrest:
		/*
		 * We have found a valid page or we have allocated a new page.
		 * The page thus may not be valid or may not be entirely 
		 * valid.
		 *
		 * Attempt to fault-in the page if there is a chance that the
		 * pager has it, and potentially fault in additional pages
		 * at the same time.
		 */
		if (TRYPAGER) {
			int rv;
			u_char behavior = vm_map_entry_behavior(fs.entry);

			if (behavior == MAP_ENTRY_BEHAV_RANDOM ||
			    P_KILLED(curproc)) {
				behind = 0;
				ahead = 0;
			} else if (behavior == MAP_ENTRY_BEHAV_SEQUENTIAL) {
				behind = 0;
				ahead = atop(fs.entry->end - vaddr) - 1;
				if (ahead > VM_FAULT_READ_AHEAD_MAX)
					ahead = VM_FAULT_READ_AHEAD_MAX;
				if (fs.pindex == fs.entry->next_read)
					vm_fault_cache_behind(&fs,
					    VM_FAULT_READ_MAX);
			} else {
				/*
				 * If this is a sequential page fault, then
				 * arithmetically increase the number of pages
				 * in the read-ahead window.  Otherwise, reset
				 * the read-ahead window to its smallest size.
				 */
				behind = atop(vaddr - fs.entry->start);
				if (behind > VM_FAULT_READ_BEHIND)
					behind = VM_FAULT_READ_BEHIND;
				ahead = atop(fs.entry->end - vaddr) - 1;
				era = fs.entry->read_ahead;
				if (fs.pindex == fs.entry->next_read) {
					nera = era + behind;
					if (nera > VM_FAULT_READ_AHEAD_MAX)
						nera = VM_FAULT_READ_AHEAD_MAX;
					behind = 0;
					if (ahead > nera)
						ahead = nera;
					if (era == VM_FAULT_READ_AHEAD_MAX)
						vm_fault_cache_behind(&fs,
						    VM_FAULT_CACHE_BEHIND);
				} else if (ahead > VM_FAULT_READ_AHEAD_MIN)
					ahead = VM_FAULT_READ_AHEAD_MIN;
				if (era != ahead)
					fs.entry->read_ahead = ahead;
			}

			/*
			 * Call the pager to retrieve the data, if any, after
			 * releasing the lock on the map.  We hold a ref on
			 * fs.object and the pages are VPO_BUSY'd.
			 */
			unlock_map(&fs);

vnode_lock:
			if (fs.object->type == OBJT_VNODE) {
				vp = fs.object->handle;
				if (vp == fs.vp)
					goto vnode_locked;
				else if (fs.vp != NULL) {
					vput(fs.vp);
					fs.vp = NULL;
				}
				locked = VOP_ISLOCKED(vp);

				if (VFS_NEEDSGIANT(vp->v_mount) && !fs.vfslocked) {
					fs.vfslocked = 1;
					if (!mtx_trylock(&Giant)) {
						VM_OBJECT_UNLOCK(fs.object);
						mtx_lock(&Giant);
						VM_OBJECT_LOCK(fs.object);
						goto vnode_lock;
					}
				}
				if (locked != LK_EXCLUSIVE)
					locked = LK_SHARED;
				/* Do not sleep for vnode lock while fs.m is busy */
				error = vget(vp, locked | LK_CANRECURSE |
				    LK_NOWAIT, curthread);
				if (error != 0) {
					int vfslocked;

					vfslocked = fs.vfslocked;
					fs.vfslocked = 0; /* Keep Giant */
					vhold(vp);
					release_page(&fs);
					unlock_and_deallocate(&fs);
					error = vget(vp, locked | LK_RETRY |
					    LK_CANRECURSE, curthread);
					vdrop(vp);
					fs.vp = vp;
					fs.vfslocked = vfslocked;
					KASSERT(error == 0,
					    ("vm_fault: vget failed"));
					goto RetryFault;
				}
				fs.vp = vp;
			}
vnode_locked:
			KASSERT(fs.vp == NULL || !fs.map->system_map,
			    ("vm_fault: vnode-backed object mapped by system map"));

			/*
			 * now we find out if any other pages should be paged
			 * in at this time this routine checks to see if the
			 * pages surrounding this fault reside in the same
			 * object as the page for this fault.  If they do,
			 * then they are faulted in also into the object.  The
			 * array "marray" returned contains an array of
			 * vm_page_t structs where one of them is the
			 * vm_page_t passed to the routine.  The reqpage
			 * return value is the index into the marray for the
			 * vm_page_t passed to the routine.
			 *
			 * fs.m plus the additional pages are VPO_BUSY'd.
			 */
			faultcount = vm_fault_additional_pages(
			    fs.m, behind, ahead, marray, &reqpage);

			rv = faultcount ?
			    vm_pager_get_pages(fs.object, marray, faultcount,
				reqpage) : VM_PAGER_FAIL;

			if (rv == VM_PAGER_OK) {
				/*
				 * Found the page. Leave it busy while we play
				 * with it.
				 */

				/*
				 * Relookup in case pager changed page. Pager
				 * is responsible for disposition of old page
				 * if moved.
				 */
				fs.m = vm_page_lookup(fs.object, fs.pindex);
				if (!fs.m) {
					unlock_and_deallocate(&fs);
					goto RetryFault;
				}

				hardfault++;
				break; /* break to PAGE HAS BEEN FOUND */
			}
			/*
			 * Remove the bogus page (which does not exist at this
			 * object/offset); before doing so, we must get back
			 * our object lock to preserve our invariant.
			 *
			 * Also wake up any other process that may want to bring
			 * in this page.
			 *
			 * If this is the top-level object, we must leave the
			 * busy page to prevent another process from rushing
			 * past us, and inserting the page in that object at
			 * the same time that we are.
			 */
			if (rv == VM_PAGER_ERROR)
				printf("vm_fault: pager read error, pid %d (%s)\n",
				    curproc->p_pid, curproc->p_comm);
			/*
			 * Data outside the range of the pager or an I/O error
			 */
			/*
			 * XXX - the check for kernel_map is a kludge to work
			 * around having the machine panic on a kernel space
			 * fault w/ I/O error.
			 */
			if (((fs.map != kernel_map) && (rv == VM_PAGER_ERROR)) ||
				(rv == VM_PAGER_BAD)) {
				vm_page_lock(fs.m);
				vm_page_free(fs.m);
				vm_page_unlock(fs.m);
				fs.m = NULL;
				unlock_and_deallocate(&fs);
				return ((rv == VM_PAGER_ERROR) ? KERN_FAILURE : KERN_PROTECTION_FAILURE);
			}
			if (fs.object != fs.first_object) {
				vm_page_lock(fs.m);
				vm_page_free(fs.m);
				vm_page_unlock(fs.m);
				fs.m = NULL;
				/*
				 * XXX - we cannot just fall out at this
				 * point, m has been freed and is invalid!
				 */
			}
		}

		/*
		 * We get here if the object has default pager (or unwiring) 
		 * or the pager doesn't have the page.
		 */
		if (fs.object == fs.first_object)
			fs.first_m = fs.m;

		/*
		 * Move on to the next object.  Lock the next object before
		 * unlocking the current one.
		 */
		fs.pindex += OFF_TO_IDX(fs.object->backing_object_offset);
		next_object = fs.object->backing_object;
		if (next_object == NULL) {
			/*
			 * If there's no object left, fill the page in the top
			 * object with zeros.
			 */
			if (fs.object != fs.first_object) {
				vm_object_pip_wakeup(fs.object);
				VM_OBJECT_UNLOCK(fs.object);

				fs.object = fs.first_object;
				fs.pindex = fs.first_pindex;
				fs.m = fs.first_m;
				VM_OBJECT_LOCK(fs.object);
			}
			fs.first_m = NULL;

			/*
			 * Zero the page if necessary and mark it valid.
			 */
			if ((fs.m->flags & PG_ZERO) == 0) {
				pmap_zero_page(fs.m);
			} else {
				PCPU_INC(cnt.v_ozfod);
			}
			PCPU_INC(cnt.v_zfod);
			fs.m->valid = VM_PAGE_BITS_ALL;
			break;	/* break to PAGE HAS BEEN FOUND */
		} else {
			KASSERT(fs.object != next_object,
			    ("object loop %p", next_object));
			VM_OBJECT_LOCK(next_object);
			vm_object_pip_add(next_object, 1);
			if (fs.object != fs.first_object)
				vm_object_pip_wakeup(fs.object);
			VM_OBJECT_UNLOCK(fs.object);
			fs.object = next_object;
		}
	}

	KASSERT((fs.m->oflags & VPO_BUSY) != 0,
	    ("vm_fault: not busy after main loop"));

	/*
	 * PAGE HAS BEEN FOUND. [Loop invariant still holds -- the object lock
	 * is held.]
	 */

	/*
	 * If the page is being written, but isn't already owned by the
	 * top-level object, we have to copy it into a new page owned by the
	 * top-level object.
	 */
	if (fs.object != fs.first_object) {
		/*
		 * We only really need to copy if we want to write it.
		 */
		if ((fault_type & (VM_PROT_COPY | VM_PROT_WRITE)) != 0) {
			/*
			 * This allows pages to be virtually copied from a 
			 * backing_object into the first_object, where the 
			 * backing object has no other refs to it, and cannot
			 * gain any more refs.  Instead of a bcopy, we just 
			 * move the page from the backing object to the 
			 * first object.  Note that we must mark the page 
			 * dirty in the first object so that it will go out 
			 * to swap when needed.
			 */
			is_first_object_locked = FALSE;
			if (
				/*
				 * Only one shadow object
				 */
				(fs.object->shadow_count == 1) &&
				/*
				 * No COW refs, except us
				 */
				(fs.object->ref_count == 1) &&
				/*
				 * No one else can look this object up
				 */
				(fs.object->handle == NULL) &&
				/*
				 * No other ways to look the object up
				 */
				((fs.object->type == OBJT_DEFAULT) ||
				 (fs.object->type == OBJT_SWAP)) &&
			    (is_first_object_locked = VM_OBJECT_TRYLOCK(fs.first_object)) &&
				/*
				 * We don't chase down the shadow chain
				 */
			    fs.object == fs.first_object->backing_object) {
				/*
				 * get rid of the unnecessary page
				 */
				vm_page_lock(fs.first_m);
				vm_page_free(fs.first_m);
				vm_page_unlock(fs.first_m);
				/*
				 * grab the page and put it into the 
				 * process'es object.  The page is 
				 * automatically made dirty.
				 */
				vm_page_lock(fs.m);
				vm_page_rename(fs.m, fs.first_object, fs.first_pindex);
				vm_page_unlock(fs.m);
				vm_page_busy(fs.m);
				fs.first_m = fs.m;
				fs.m = NULL;
				PCPU_INC(cnt.v_cow_optim);
			} else {
				/*
				 * Oh, well, lets copy it.
				 */
				pmap_copy_page(fs.m, fs.first_m);
				fs.first_m->valid = VM_PAGE_BITS_ALL;
				if (wired && (fault_flags &
				    VM_FAULT_CHANGE_WIRING) == 0) {
					vm_page_lock(fs.first_m);
					vm_page_wire(fs.first_m);
					vm_page_unlock(fs.first_m);
					
					vm_page_lock(fs.m);
					vm_page_unwire(fs.m, FALSE);
					vm_page_unlock(fs.m);
				}
				/*
				 * We no longer need the old page or object.
				 */
				release_page(&fs);
			}
			/*
			 * fs.object != fs.first_object due to above 
			 * conditional
			 */
			vm_object_pip_wakeup(fs.object);
			VM_OBJECT_UNLOCK(fs.object);
			/*
			 * Only use the new page below...
			 */
			fs.object = fs.first_object;
			fs.pindex = fs.first_pindex;
			fs.m = fs.first_m;
			if (!is_first_object_locked)
				VM_OBJECT_LOCK(fs.object);
			PCPU_INC(cnt.v_cow_faults);
			curthread->td_cow++;
		} else {
			prot &= ~VM_PROT_WRITE;
		}
	}

	/*
	 * We must verify that the maps have not changed since our last
	 * lookup.
	 */
	if (!fs.lookup_still_valid) {
		vm_object_t retry_object;
		vm_pindex_t retry_pindex;
		vm_prot_t retry_prot;

		if (!vm_map_trylock_read(fs.map)) {
			release_page(&fs);
			unlock_and_deallocate(&fs);
			goto RetryFault;
		}
		fs.lookup_still_valid = TRUE;
		if (fs.map->timestamp != map_generation) {
			result = vm_map_lookup_locked(&fs.map, vaddr, fault_type,
			    &fs.entry, &retry_object, &retry_pindex, &retry_prot, &wired);

			/*
			 * If we don't need the page any longer, put it on the inactive
			 * list (the easiest thing to do here).  If no one needs it,
			 * pageout will grab it eventually.
			 */
			if (result != KERN_SUCCESS) {
				release_page(&fs);
				unlock_and_deallocate(&fs);

				/*
				 * If retry of map lookup would have blocked then
				 * retry fault from start.
				 */
				if (result == KERN_FAILURE)
					goto RetryFault;
				return (result);
			}
			if ((retry_object != fs.first_object) ||
			    (retry_pindex != fs.first_pindex)) {
				release_page(&fs);
				unlock_and_deallocate(&fs);
				goto RetryFault;
			}

			/*
			 * Check whether the protection has changed or the object has
			 * been copied while we left the map unlocked. Changing from
			 * read to write permission is OK - we leave the page
			 * write-protected, and catch the write fault. Changing from
			 * write to read permission means that we can't mark the page
			 * write-enabled after all.
			 */
			prot &= retry_prot;
		}
	}
	/*
	 * If the page was filled by a pager, update the map entry's
	 * last read offset.  Since the pager does not return the
	 * actual set of pages that it read, this update is based on
	 * the requested set.  Typically, the requested and actual
	 * sets are the same.
	 *
	 * XXX The following assignment modifies the map
	 * without holding a write lock on it.
	 */
	if (hardfault)
		fs.entry->next_read = fs.pindex + faultcount - reqpage;

	if ((prot & VM_PROT_WRITE) != 0 ||
	    (fault_flags & VM_FAULT_DIRTY) != 0) {
		vm_object_set_writeable_dirty(fs.object);

		/*
		 * If this is a NOSYNC mmap we do not want to set VPO_NOSYNC
		 * if the page is already dirty to prevent data written with
		 * the expectation of being synced from not being synced.
		 * Likewise if this entry does not request NOSYNC then make
		 * sure the page isn't marked NOSYNC.  Applications sharing
		 * data should use the same flags to avoid ping ponging.
		 */
		if (fs.entry->eflags & MAP_ENTRY_NOSYNC) {
			if (fs.m->dirty == 0)
				fs.m->oflags |= VPO_NOSYNC;
		} else {
			fs.m->oflags &= ~VPO_NOSYNC;
		}

		/*
		 * If the fault is a write, we know that this page is being
		 * written NOW so dirty it explicitly to save on 
		 * pmap_is_modified() calls later.
		 *
		 * Also tell the backing pager, if any, that it should remove
		 * any swap backing since the page is now dirty.
		 */
		if (((fault_type & VM_PROT_WRITE) != 0 &&
		    (fault_flags & VM_FAULT_CHANGE_WIRING) == 0) ||
		    (fault_flags & VM_FAULT_DIRTY) != 0) {
			vm_page_dirty(fs.m);
			vm_pager_page_unswapped(fs.m);
		}
	}

	/*
	 * Page had better still be busy
	 */
	KASSERT(fs.m->oflags & VPO_BUSY,
		("vm_fault: page %p not busy!", fs.m));
	/*
	 * Page must be completely valid or it is not fit to
	 * map into user space.  vm_pager_get_pages() ensures this.
	 */
	KASSERT(fs.m->valid == VM_PAGE_BITS_ALL,
	    ("vm_fault: page %p partially invalid", fs.m));
	VM_OBJECT_UNLOCK(fs.object);

	/*
	 * Put this page into the physical map.  We had to do the unlock above
	 * because pmap_enter() may sleep.  We don't put the page
	 * back on the active queue until later so that the pageout daemon
	 * won't find it (yet).
	 */
	pmap_enter(fs.map->pmap, vaddr, fault_type, fs.m, prot, wired);
	if ((fault_flags & VM_FAULT_CHANGE_WIRING) == 0 && wired == 0)
		vm_fault_prefault(fs.map->pmap, vaddr, fs.entry);
	VM_OBJECT_LOCK(fs.object);
	vm_page_lock(fs.m);

	/*
	 * If the page is not wired down, then put it where the pageout daemon
	 * can find it.
	 */
	if (fault_flags & VM_FAULT_CHANGE_WIRING) {
		if (wired)
			vm_page_wire(fs.m);
		else
			vm_page_unwire(fs.m, 1);
	} else
		vm_page_activate(fs.m);
	if (m_hold != NULL) {
		*m_hold = fs.m;
		vm_page_hold(fs.m);
	}
	vm_page_unlock(fs.m);
	vm_page_wakeup(fs.m);

	/*
	 * Unlock everything, and return
	 */
	unlock_and_deallocate(&fs);
	if (hardfault)
		curthread->td_ru.ru_majflt++;
	else
		curthread->td_ru.ru_minflt++;

	return (KERN_SUCCESS);
}
Example #28
0
/*
 *	Routine:
 *		vm_fault_copy_entry
 *	Function:
 *		Create new shadow object backing dst_entry with private copy of
 *		all underlying pages. When src_entry is equal to dst_entry,
 *		function implements COW for wired-down map entry. Otherwise,
 *		it forks wired entry into dst_map.
 *
 *	In/out conditions:
 *		The source and destination maps must be locked for write.
 *		The source map entry must be wired down (or be a sharing map
 *		entry corresponding to a main map entry that is wired down).
 */
void
vm_fault_copy_entry(vm_map_t dst_map, vm_map_t src_map,
    vm_map_entry_t dst_entry, vm_map_entry_t src_entry,
    vm_ooffset_t *fork_charge)
{
	vm_object_t backing_object, dst_object, object, src_object;
	vm_pindex_t dst_pindex, pindex, src_pindex;
	vm_prot_t access, prot;
	vm_offset_t vaddr;
	vm_page_t dst_m;
	vm_page_t src_m;
	boolean_t src_readonly, upgrade;

#ifdef	lint
	src_map++;
#endif	/* lint */

	upgrade = src_entry == dst_entry;

	src_object = src_entry->object.vm_object;
	src_pindex = OFF_TO_IDX(src_entry->offset);
	src_readonly = (src_entry->protection & VM_PROT_WRITE) == 0;

	/*
	 * Create the top-level object for the destination entry. (Doesn't
	 * actually shadow anything - we copy the pages directly.)
	 */
	dst_object = vm_object_allocate(OBJT_DEFAULT,
	    OFF_TO_IDX(dst_entry->end - dst_entry->start));
#if VM_NRESERVLEVEL > 0
	dst_object->flags |= OBJ_COLORED;
	dst_object->pg_color = atop(dst_entry->start);
#endif

	VM_OBJECT_LOCK(dst_object);
	KASSERT(upgrade || dst_entry->object.vm_object == NULL,
	    ("vm_fault_copy_entry: vm_object not NULL"));
	dst_entry->object.vm_object = dst_object;
	dst_entry->offset = 0;
	dst_object->charge = dst_entry->end - dst_entry->start;
	if (fork_charge != NULL) {
		KASSERT(dst_entry->cred == NULL,
		    ("vm_fault_copy_entry: leaked swp charge"));
		dst_object->cred = curthread->td_ucred;
		crhold(dst_object->cred);
		*fork_charge += dst_object->charge;
	} else {
		dst_object->cred = dst_entry->cred;
		dst_entry->cred = NULL;
	}
	access = prot = dst_entry->protection;
	/*
	 * If not an upgrade, then enter the mappings in the pmap as
	 * read and/or execute accesses.  Otherwise, enter them as
	 * write accesses.
	 *
	 * A writeable large page mapping is only created if all of
	 * the constituent small page mappings are modified. Marking
	 * PTEs as modified on inception allows promotion to happen
	 * without taking potentially large number of soft faults.
	 */
	if (!upgrade)
		access &= ~VM_PROT_WRITE;

	/*
	 * Loop through all of the pages in the entry's range, copying each
	 * one from the source object (it should be there) to the destination
	 * object.
	 */
	for (vaddr = dst_entry->start, dst_pindex = 0;
	    vaddr < dst_entry->end;
	    vaddr += PAGE_SIZE, dst_pindex++) {

		/*
		 * Allocate a page in the destination object.
		 */
		do {
			dst_m = vm_page_alloc(dst_object, dst_pindex,
			    VM_ALLOC_NORMAL);
			if (dst_m == NULL) {
				VM_OBJECT_UNLOCK(dst_object);
				VM_WAIT;
				VM_OBJECT_LOCK(dst_object);
			}
		} while (dst_m == NULL);

		/*
		 * Find the page in the source object, and copy it in.
		 * (Because the source is wired down, the page will be in
		 * memory.)
		 */
		VM_OBJECT_LOCK(src_object);
		object = src_object;
		pindex = src_pindex + dst_pindex;
		while ((src_m = vm_page_lookup(object, pindex)) == NULL &&
		    src_readonly &&
		    (backing_object = object->backing_object) != NULL) {
			/*
			 * Allow fallback to backing objects if we are reading.
			 */
			VM_OBJECT_LOCK(backing_object);
			pindex += OFF_TO_IDX(object->backing_object_offset);
			VM_OBJECT_UNLOCK(object);
			object = backing_object;
		}
		if (src_m == NULL)
			panic("vm_fault_copy_wired: page missing");
		pmap_copy_page(src_m, dst_m);
		VM_OBJECT_UNLOCK(object);
		dst_m->valid = VM_PAGE_BITS_ALL;
		VM_OBJECT_UNLOCK(dst_object);

		/*
		 * Enter it in the pmap. If a wired, copy-on-write
		 * mapping is being replaced by a write-enabled
		 * mapping, then wire that new mapping.
		 */
		pmap_enter(dst_map->pmap, vaddr, access, dst_m, prot, upgrade);

		/*
		 * Mark it no longer busy, and put it on the active list.
		 */
		VM_OBJECT_LOCK(dst_object);
		
		if (upgrade) {
			vm_page_lock(src_m);
			vm_page_unwire(src_m, 0);
			vm_page_unlock(src_m);

			vm_page_lock(dst_m);
			vm_page_wire(dst_m);
			vm_page_unlock(dst_m);
		} else {
			vm_page_lock(dst_m);
			vm_page_activate(dst_m);
			vm_page_unlock(dst_m);
		}
		vm_page_wakeup(dst_m);
	}
	VM_OBJECT_UNLOCK(dst_object);
	if (upgrade) {
		dst_entry->eflags &= ~(MAP_ENTRY_COW | MAP_ENTRY_NEEDS_COPY);
		vm_object_deallocate(src_object);
	}
}
Example #29
0
static int
shm_dotruncate(struct shmfd *shmfd, off_t length)
{
	vm_object_t object;
	vm_page_t m, ma[1];
	vm_pindex_t idx, nobjsize;
	vm_ooffset_t delta;
	int base, rv;

	object = shmfd->shm_object;
	VM_OBJECT_LOCK(object);
	if (length == shmfd->shm_size) {
		VM_OBJECT_UNLOCK(object);
		return (0);
	}
	nobjsize = OFF_TO_IDX(length + PAGE_MASK);

	/* Are we shrinking?  If so, trim the end. */
	if (length < shmfd->shm_size) {
		/*
		 * Disallow any requests to shrink the size if this
		 * object is mapped into the kernel.
		 */
		if (shmfd->shm_kmappings > 0) {
			VM_OBJECT_UNLOCK(object);
			return (EBUSY);
		}

		/*
		 * Zero the truncated part of the last page.
		 */
		base = length & PAGE_MASK;
		if (base != 0) {
			idx = OFF_TO_IDX(length);
retry:
			m = vm_page_lookup(object, idx);
			if (m != NULL) {
				if ((m->oflags & VPO_BUSY) != 0 ||
				    m->busy != 0) {
					vm_page_sleep(m, "shmtrc");
					goto retry;
				}
			} else if (vm_pager_has_page(object, idx, NULL, NULL)) {
				m = vm_page_alloc(object, idx, VM_ALLOC_NORMAL);
				if (m == NULL) {
					VM_OBJECT_UNLOCK(object);
					VM_WAIT;
					VM_OBJECT_LOCK(object);
					goto retry;
				} else if (m->valid != VM_PAGE_BITS_ALL) {
					ma[0] = m;
					rv = vm_pager_get_pages(object, ma, 1,
					    0);
					m = vm_page_lookup(object, idx);
				} else
					/* A cached page was reactivated. */
					rv = VM_PAGER_OK;
				vm_page_lock(m);
				if (rv == VM_PAGER_OK) {
					vm_page_deactivate(m);
					vm_page_unlock(m);
					vm_page_wakeup(m);
				} else {
					vm_page_free(m);
					vm_page_unlock(m);
					VM_OBJECT_UNLOCK(object);
					return (EIO);
				}
			}
			if (m != NULL) {
				pmap_zero_page_area(m, base, PAGE_SIZE - base);
				KASSERT(m->valid == VM_PAGE_BITS_ALL,
				    ("shm_dotruncate: page %p is invalid", m));
				vm_page_dirty(m);
				vm_pager_page_unswapped(m);
			}
		}
		delta = ptoa(object->size - nobjsize);

		/* Toss in memory pages. */
		if (nobjsize < object->size)
			vm_object_page_remove(object, nobjsize, object->size,
			    0);

		/* Toss pages from swap. */
		if (object->type == OBJT_SWAP)
			swap_pager_freespace(object, nobjsize, delta);

		/* Free the swap accounted for shm */
		swap_release_by_cred(delta, object->cred);
		object->charge -= delta;
	} else {
		/* Attempt to reserve the swap */
		delta = ptoa(nobjsize - object->size);
		if (!swap_reserve_by_cred(delta, object->cred)) {
			VM_OBJECT_UNLOCK(object);
			return (ENOMEM);
		}
		object->charge += delta;
	}
	shmfd->shm_size = length;
	mtx_lock(&shm_timestamp_lock);
	vfs_timestamp(&shmfd->shm_ctime);
	shmfd->shm_mtime = shmfd->shm_ctime;
	mtx_unlock(&shm_timestamp_lock);
	object->size = nobjsize;
	VM_OBJECT_UNLOCK(object);
	return (0);
}
Example #30
0
/*
 * If blocks are contiguous on disk, use this to provide clustered
 * read ahead.  We will read as many blocks as possible sequentially
 * and then parcel them up into logical blocks in the buffer hash table.
 */
static struct buf *
cluster_rbuild(struct vnode *vp, u_quad_t filesize, daddr_t lbn,
    daddr_t blkno, long size, int run, int gbflags, struct buf *fbp)
{
	struct bufobj *bo;
	struct buf *bp, *tbp;
	daddr_t bn;
	off_t off;
	long tinc, tsize;
	int i, inc, j, toff;

	KASSERT(size == vp->v_mount->mnt_stat.f_iosize,
	    ("cluster_rbuild: size %ld != filesize %jd\n",
	    size, (intmax_t)vp->v_mount->mnt_stat.f_iosize));

	/*
	 * avoid a division
	 */
	while ((u_quad_t) size * (lbn + run) > filesize) {
		--run;
	}

	if (fbp) {
		tbp = fbp;
		tbp->b_iocmd = BIO_READ; 
	} else {
		tbp = getblk(vp, lbn, size, 0, 0, gbflags);
		if (tbp->b_flags & B_CACHE)
			return tbp;
		tbp->b_flags |= B_ASYNC | B_RAM;
		tbp->b_iocmd = BIO_READ;
	}
	tbp->b_blkno = blkno;
	if( (tbp->b_flags & B_MALLOC) ||
		((tbp->b_flags & B_VMIO) == 0) || (run <= 1) )
		return tbp;

	bp = trypbuf(&cluster_pbuf_freecnt);
	if (bp == 0)
		return tbp;

	/*
	 * We are synthesizing a buffer out of vm_page_t's, but
	 * if the block size is not page aligned then the starting
	 * address may not be either.  Inherit the b_data offset
	 * from the original buffer.
	 */
	bp->b_flags = B_ASYNC | B_CLUSTER | B_VMIO;
	if ((gbflags & GB_UNMAPPED) != 0) {
		bp->b_flags |= B_UNMAPPED;
		bp->b_data = unmapped_buf;
	} else {
		bp->b_data = (char *)((vm_offset_t)bp->b_data |
		    ((vm_offset_t)tbp->b_data & PAGE_MASK));
	}
	bp->b_iocmd = BIO_READ;
	bp->b_iodone = cluster_callback;
	bp->b_blkno = blkno;
	bp->b_lblkno = lbn;
	bp->b_offset = tbp->b_offset;
	KASSERT(bp->b_offset != NOOFFSET, ("cluster_rbuild: no buffer offset"));
	pbgetvp(vp, bp);

	TAILQ_INIT(&bp->b_cluster.cluster_head);

	bp->b_bcount = 0;
	bp->b_bufsize = 0;
	bp->b_npages = 0;

	inc = btodb(size);
	bo = &vp->v_bufobj;
	for (bn = blkno, i = 0; i < run; ++i, bn += inc) {
		if (i != 0) {
			if ((bp->b_npages * PAGE_SIZE) +
			    round_page(size) > vp->v_mount->mnt_iosize_max) {
				break;
			}

			tbp = getblk(vp, lbn + i, size, 0, 0, GB_LOCK_NOWAIT |
			    (gbflags & GB_UNMAPPED));

			/* Don't wait around for locked bufs. */
			if (tbp == NULL)
				break;

			/*
			 * Stop scanning if the buffer is fully valid
			 * (marked B_CACHE), or locked (may be doing a
			 * background write), or if the buffer is not
			 * VMIO backed.  The clustering code can only deal
			 * with VMIO-backed buffers.
			 */
			BO_LOCK(bo);
			if ((tbp->b_vflags & BV_BKGRDINPROG) ||
			    (tbp->b_flags & B_CACHE) ||
			    (tbp->b_flags & B_VMIO) == 0) {
				BO_UNLOCK(bo);
				bqrelse(tbp);
				break;
			}
			BO_UNLOCK(bo);

			/*
			 * The buffer must be completely invalid in order to
			 * take part in the cluster.  If it is partially valid
			 * then we stop.
			 */
			off = tbp->b_offset;
			tsize = size;
			VM_OBJECT_LOCK(tbp->b_bufobj->bo_object);
			for (j = 0; tsize > 0; j++) {
				toff = off & PAGE_MASK;
				tinc = tsize;
				if (toff + tinc > PAGE_SIZE)
					tinc = PAGE_SIZE - toff;
				VM_OBJECT_LOCK_ASSERT(tbp->b_pages[j]->object,
				    MA_OWNED);
				if ((tbp->b_pages[j]->valid &
				    vm_page_bits(toff, tinc)) != 0)
					break;
				off += tinc;
				tsize -= tinc;
			}
			VM_OBJECT_UNLOCK(tbp->b_bufobj->bo_object);
			if (tsize > 0) {
				bqrelse(tbp);
				break;
			}

			/*
			 * Set a read-ahead mark as appropriate
			 */
			if ((fbp && (i == 1)) || (i == (run - 1)))
				tbp->b_flags |= B_RAM;

			/*
			 * Set the buffer up for an async read (XXX should
			 * we do this only if we do not wind up brelse()ing?).
			 * Set the block number if it isn't set, otherwise
			 * if it is make sure it matches the block number we
			 * expect.
			 */
			tbp->b_flags |= B_ASYNC;
			tbp->b_iocmd = BIO_READ;
			if (tbp->b_blkno == tbp->b_lblkno) {
				tbp->b_blkno = bn;
			} else if (tbp->b_blkno != bn) {
				brelse(tbp);
				break;
			}
		}
		/*
		 * XXX fbp from caller may not be B_ASYNC, but we are going
		 * to biodone() it in cluster_callback() anyway
		 */
		BUF_KERNPROC(tbp);
		TAILQ_INSERT_TAIL(&bp->b_cluster.cluster_head,
			tbp, b_cluster.cluster_entry);
		VM_OBJECT_LOCK(tbp->b_bufobj->bo_object);
		for (j = 0; j < tbp->b_npages; j += 1) {
			vm_page_t m;
			m = tbp->b_pages[j];
			vm_page_io_start(m);
			vm_object_pip_add(m->object, 1);
			if ((bp->b_npages == 0) ||
				(bp->b_pages[bp->b_npages-1] != m)) {
				bp->b_pages[bp->b_npages] = m;
				bp->b_npages++;
			}
			if (m->valid == VM_PAGE_BITS_ALL)
				tbp->b_pages[j] = bogus_page;
		}
		VM_OBJECT_UNLOCK(tbp->b_bufobj->bo_object);
		/*
		 * Don't inherit tbp->b_bufsize as it may be larger due to
		 * a non-page-aligned size.  Instead just aggregate using
		 * 'size'.
		 */
		if (tbp->b_bcount != size)
			printf("warning: tbp->b_bcount wrong %ld vs %ld\n", tbp->b_bcount, size);
		if (tbp->b_bufsize != size)
			printf("warning: tbp->b_bufsize wrong %ld vs %ld\n", tbp->b_bufsize, size);
		bp->b_bcount += size;
		bp->b_bufsize += size;
	}

	/*
	 * Fully valid pages in the cluster are already good and do not need
	 * to be re-read from disk.  Replace the page with bogus_page
	 */
	VM_OBJECT_LOCK(bp->b_bufobj->bo_object);
	for (j = 0; j < bp->b_npages; j++) {
		VM_OBJECT_LOCK_ASSERT(bp->b_pages[j]->object, MA_OWNED);
		if (bp->b_pages[j]->valid == VM_PAGE_BITS_ALL)
			bp->b_pages[j] = bogus_page;
	}
	VM_OBJECT_UNLOCK(bp->b_bufobj->bo_object);
	if (bp->b_bufsize > bp->b_kvasize)
		panic("cluster_rbuild: b_bufsize(%ld) > b_kvasize(%d)\n",
		    bp->b_bufsize, bp->b_kvasize);
	bp->b_kvasize = bp->b_bufsize;

	if ((bp->b_flags & B_UNMAPPED) == 0) {
		pmap_qenter(trunc_page((vm_offset_t) bp->b_data),
		    (vm_page_t *)bp->b_pages, bp->b_npages);
	}
	return (bp);
}