2 * Copyright (c) 1990 University of Utah.
3 * Copyright (c) 1991 The Regents of the University of California.
5 * Copyright (c) 1993, 1994 John S. Dyson
6 * Copyright (c) 1995, David Greenman
8 * This code is derived from software contributed to Berkeley by
9 * the Systems Programming Group of the University of Utah Computer
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 * must display the following acknowledgement:
22 * This product includes software developed by the University of
23 * California, Berkeley and its contributors.
24 * 4. Neither the name of the University nor the names of its contributors
25 * may be used to endorse or promote products derived from this software
26 * without specific prior written permission.
28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40 * from: @(#)vnode_pager.c 7.5 (Berkeley) 4/20/91
44 * Page to/from files (vnodes).
49 * Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will
50 * greatly re-simplify the vnode_pager.
53 #include <sys/cdefs.h>
54 __FBSDID("$FreeBSD$");
56 #include <sys/param.h>
57 #include <sys/systm.h>
59 #include <sys/vnode.h>
60 #include <sys/mount.h>
63 #include <sys/vmmeter.h>
64 #include <sys/limits.h>
66 #include <sys/sf_buf.h>
68 #include <machine/atomic.h>
71 #include <vm/vm_object.h>
72 #include <vm/vm_page.h>
73 #include <vm/vm_pager.h>
74 #include <vm/vm_map.h>
75 #include <vm/vnode_pager.h>
76 #include <vm/vm_extern.h>
78 static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address,
79 daddr_t *rtaddress, int *run);
80 static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m);
81 static int vnode_pager_input_old(vm_object_t object, vm_page_t m);
82 static void vnode_pager_dealloc(vm_object_t);
83 static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int);
84 static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, boolean_t, int *);
85 static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *);
86 static vm_object_t vnode_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
87 vm_ooffset_t, struct ucred *cred);
89 struct pagerops vnodepagerops = {
90 .pgo_alloc = vnode_pager_alloc,
91 .pgo_dealloc = vnode_pager_dealloc,
92 .pgo_getpages = vnode_pager_getpages,
93 .pgo_putpages = vnode_pager_putpages,
94 .pgo_haspage = vnode_pager_haspage,
97 int vnode_pbuf_freecnt;
99 /* Create the VM system backing object for this vnode */
101 vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td)
104 vm_ooffset_t size = isize;
107 if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE)
110 while ((object = vp->v_object) != NULL) {
111 VM_OBJECT_LOCK(object);
112 if (!(object->flags & OBJ_DEAD)) {
113 VM_OBJECT_UNLOCK(object);
117 vm_object_set_flag(object, OBJ_DISCONNECTWNT);
118 msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vodead", 0);
119 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
123 if (vn_isdisk(vp, NULL)) {
124 size = IDX_TO_OFF(INT_MAX);
126 if (VOP_GETATTR(vp, &va, td->td_ucred))
132 object = vnode_pager_alloc(vp, size, 0, 0, td->td_ucred);
134 * Dereference the reference we just created. This assumes
135 * that the object is associated with the vp.
137 VM_OBJECT_LOCK(object);
139 VM_OBJECT_UNLOCK(object);
142 KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object"));
148 vnode_destroy_vobject(struct vnode *vp)
150 struct vm_object *obj;
155 ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject");
157 if (obj->ref_count == 0) {
159 * vclean() may be called twice. The first time
160 * removes the primary reference to the object,
161 * the second time goes one further and is a
162 * special-case to terminate the object.
164 * don't double-terminate the object
166 if ((obj->flags & OBJ_DEAD) == 0)
167 vm_object_terminate(obj);
169 VM_OBJECT_UNLOCK(obj);
172 * Woe to the process that tries to page now :-).
174 vm_pager_deallocate(obj);
175 VM_OBJECT_UNLOCK(obj);
182 * Allocate (or lookup) pager for a vnode.
183 * Handle is a vnode pointer.
188 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
189 vm_ooffset_t offset, struct ucred *cred)
195 * Pageout to vnode, no can do yet.
200 vp = (struct vnode *) handle;
203 * If the object is being terminated, wait for it to
207 while ((object = vp->v_object) != NULL) {
208 VM_OBJECT_LOCK(object);
209 if ((object->flags & OBJ_DEAD) == 0)
211 vm_object_set_flag(object, OBJ_DISCONNECTWNT);
212 msleep(object, VM_OBJECT_MTX(object), PDROP | PVM, "vadead", 0);
215 if (vp->v_usecount == 0)
216 panic("vnode_pager_alloc: no vnode reference");
218 if (object == NULL) {
220 * Add an object of the appropriate size
222 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size)));
224 object->un_pager.vnp.vnp_size = size;
225 object->un_pager.vnp.writemappings = 0;
227 object->handle = handle;
229 if (vp->v_object != NULL) {
231 * Object has been created while we were sleeping
234 vm_object_destroy(object);
237 vp->v_object = object;
241 VM_OBJECT_UNLOCK(object);
248 * The object must be locked.
251 vnode_pager_dealloc(object)
259 panic("vnode_pager_dealloc: pager already dealloced");
261 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
262 vm_object_pip_wait(object, "vnpdea");
263 refs = object->ref_count;
265 object->handle = NULL;
266 object->type = OBJT_DEAD;
267 if (object->flags & OBJ_DISCONNECTWNT) {
268 vm_object_clear_flag(object, OBJ_DISCONNECTWNT);
271 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc");
272 if (object->un_pager.vnp.writemappings > 0) {
273 object->un_pager.vnp.writemappings = 0;
277 vp->v_vflag &= ~VV_TEXT;
278 VM_OBJECT_UNLOCK(object);
281 VM_OBJECT_LOCK(object);
285 vnode_pager_haspage(object, pindex, before, after)
291 struct vnode *vp = object->handle;
297 int pagesperblock, blocksperpage;
300 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
302 * If no vp or vp is doomed or marked transparent to VM, we do not
305 if (vp == NULL || vp->v_iflag & VI_DOOMED)
308 * If the offset is beyond end of file we do
311 if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size)
314 bsize = vp->v_mount->mnt_stat.f_iosize;
315 pagesperblock = bsize / PAGE_SIZE;
317 if (pagesperblock > 0) {
318 reqblock = pindex / pagesperblock;
320 blocksperpage = (PAGE_SIZE / bsize);
321 reqblock = pindex * blocksperpage;
323 VM_OBJECT_UNLOCK(object);
324 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
325 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before);
326 VFS_UNLOCK_GIANT(vfslocked);
327 VM_OBJECT_LOCK(object);
332 if (pagesperblock > 0) {
333 poff = pindex - (reqblock * pagesperblock);
335 *before *= pagesperblock;
340 *after *= pagesperblock;
341 numafter = pagesperblock - (poff + 1);
342 if (IDX_TO_OFF(pindex + numafter) >
343 object->un_pager.vnp.vnp_size) {
345 OFF_TO_IDX(object->un_pager.vnp.vnp_size) -
352 *before /= blocksperpage;
356 *after /= blocksperpage;
363 * Lets the VM system know about a change in size for a file.
364 * We adjust our own internal size and flush any cached pages in
365 * the associated object that are affected by the size change.
367 * Note: this routine may be invoked as a result of a pager put
368 * operation (possibly at object termination time), so we must be careful.
371 vnode_pager_setsize(vp, nsize)
377 vm_pindex_t nobjsize;
379 if ((object = vp->v_object) == NULL)
381 /* ASSERT_VOP_ELOCKED(vp, "vnode_pager_setsize and not locked vnode"); */
382 VM_OBJECT_LOCK(object);
383 if (nsize == object->un_pager.vnp.vnp_size) {
385 * Hasn't changed size
387 VM_OBJECT_UNLOCK(object);
390 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK);
391 if (nsize < object->un_pager.vnp.vnp_size) {
393 * File has shrunk. Toss any cached pages beyond the new EOF.
395 if (nobjsize < object->size)
396 vm_object_page_remove(object, nobjsize, object->size,
399 * this gets rid of garbage at the end of a page that is now
400 * only partially backed by the vnode.
402 * XXX for some reason (I don't know yet), if we take a
403 * completely invalid page and mark it partially valid
404 * it can screw up NFS reads, so we don't allow the case.
406 if ((nsize & PAGE_MASK) &&
407 (m = vm_page_lookup(object, OFF_TO_IDX(nsize))) != NULL &&
409 int base = (int)nsize & PAGE_MASK;
410 int size = PAGE_SIZE - base;
413 * Clear out partial-page garbage in case
414 * the page has been mapped.
416 pmap_zero_page_area(m, base, size);
419 * Update the valid bits to reflect the blocks that
420 * have been zeroed. Some of these valid bits may
421 * have already been set.
423 vm_page_set_valid(m, base, size);
426 * Round "base" to the next block boundary so that the
427 * dirty bit for a partially zeroed block is not
430 base = roundup2(base, DEV_BSIZE);
433 * Clear out partial-page dirty bits.
435 * note that we do not clear out the valid
436 * bits. This would prevent bogus_page
437 * replacement from working properly.
439 vm_page_clear_dirty(m, base, PAGE_SIZE - base);
440 } else if ((nsize & PAGE_MASK) &&
441 __predict_false(object->cache != NULL)) {
442 vm_page_cache_free(object, OFF_TO_IDX(nsize),
446 object->un_pager.vnp.vnp_size = nsize;
447 object->size = nobjsize;
448 VM_OBJECT_UNLOCK(object);
452 * calculate the linear (byte) disk address of specified virtual
456 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress,
467 if (vp->v_iflag & VI_DOOMED)
470 bsize = vp->v_mount->mnt_stat.f_iosize;
471 vblock = address / bsize;
472 voffset = address % bsize;
474 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL);
476 if (*rtaddress != -1)
477 *rtaddress += voffset / DEV_BSIZE;
480 *run *= bsize/PAGE_SIZE;
481 *run -= voffset/PAGE_SIZE;
489 * small block filesystem vnode pager input
492 vnode_pager_input_smlfs(object, m)
507 if (vp->v_iflag & VI_DOOMED)
510 bsize = vp->v_mount->mnt_stat.f_iosize;
512 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL);
514 sf = sf_buf_alloc(m, 0);
516 for (i = 0; i < PAGE_SIZE / bsize; i++) {
517 vm_ooffset_t address;
519 bits = vm_page_bits(i * bsize, bsize);
523 address = IDX_TO_OFF(m->pindex) + i * bsize;
524 if (address >= object->un_pager.vnp.vnp_size) {
527 error = vnode_pager_addr(vp, address, &fileaddr, NULL);
531 if (fileaddr != -1) {
532 bp = getpbuf(&vnode_pbuf_freecnt);
534 /* build a minimal buffer header */
535 bp->b_iocmd = BIO_READ;
536 bp->b_iodone = bdone;
537 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred"));
538 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred"));
539 bp->b_rcred = crhold(curthread->td_ucred);
540 bp->b_wcred = crhold(curthread->td_ucred);
541 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize;
542 bp->b_blkno = fileaddr;
545 bp->b_bcount = bsize;
546 bp->b_bufsize = bsize;
547 bp->b_runningbufspace = bp->b_bufsize;
548 atomic_add_long(&runningbufspace, bp->b_runningbufspace);
551 bp->b_iooffset = dbtob(bp->b_blkno);
554 bwait(bp, PVM, "vnsrd");
556 if ((bp->b_ioflags & BIO_ERROR) != 0)
560 * free the buffer header back to the swap buffer pool
564 relpbuf(bp, &vnode_pbuf_freecnt);
568 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize);
569 KASSERT((m->dirty & bits) == 0,
570 ("vnode_pager_input_smlfs: page %p is dirty", m));
571 VM_OBJECT_LOCK(object);
573 VM_OBJECT_UNLOCK(object);
577 return VM_PAGER_ERROR;
583 * old style vnode pager input routine
586 vnode_pager_input_old(object, m)
597 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
601 * Return failure if beyond current EOF
603 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) {
607 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size)
608 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex);
610 VM_OBJECT_UNLOCK(object);
613 * Allocate a kernel virtual address and initialize so that
614 * we can use VOP_READ/WRITE routines.
616 sf = sf_buf_alloc(m, 0);
618 aiov.iov_base = (caddr_t)sf_buf_kva(sf);
620 auio.uio_iov = &aiov;
622 auio.uio_offset = IDX_TO_OFF(m->pindex);
623 auio.uio_segflg = UIO_SYSSPACE;
624 auio.uio_rw = UIO_READ;
625 auio.uio_resid = size;
626 auio.uio_td = curthread;
628 error = VOP_READ(vp, &auio, 0, curthread->td_ucred);
630 int count = size - auio.uio_resid;
634 else if (count != PAGE_SIZE)
635 bzero((caddr_t)sf_buf_kva(sf) + count,
640 VM_OBJECT_LOCK(object);
642 KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m));
644 m->valid = VM_PAGE_BITS_ALL;
645 return error ? VM_PAGER_ERROR : VM_PAGER_OK;
649 * generic vnode pager input routine
653 * Local media VFS's that do not implement their own VOP_GETPAGES
654 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages()
655 * to implement the previous behaviour.
657 * All other FS's should use the bypass to get to the local media
658 * backing vp's VOP_GETPAGES.
661 vnode_pager_getpages(object, m, count, reqpage)
669 int bytes = count * PAGE_SIZE;
673 VM_OBJECT_UNLOCK(object);
674 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
675 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0);
676 KASSERT(rtval != EOPNOTSUPP,
677 ("vnode_pager: FS getpages not implemented\n"));
678 VFS_UNLOCK_GIANT(vfslocked);
679 VM_OBJECT_LOCK(object);
684 * This is now called from local media FS's to operate against their
685 * own vnodes if they fail to implement VOP_GETPAGES.
688 vnode_pager_generic_getpages(vp, m, bytecount, reqpage)
696 off_t foff, tfoff, nextoff;
697 int i, j, size, bsize, first;
698 daddr_t firstaddr, reqblock;
706 object = vp->v_object;
707 count = bytecount / PAGE_SIZE;
709 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK,
710 ("vnode_pager_generic_getpages does not support devices"));
711 if (vp->v_iflag & VI_DOOMED)
714 bsize = vp->v_mount->mnt_stat.f_iosize;
716 /* get the UNDERLYING device for the file with VOP_BMAP() */
719 * originally, we did not check for an error return value -- assuming
720 * an fs always has a bmap entry point -- that assumption is wrong!!!
722 foff = IDX_TO_OFF(m[reqpage]->pindex);
725 * if we can't bmap, use old VOP code
727 error = VOP_BMAP(vp, foff / bsize, &bo, &reqblock, NULL, NULL);
728 if (error == EOPNOTSUPP) {
729 VM_OBJECT_LOCK(object);
731 for (i = 0; i < count; i++)
735 vm_page_unlock(m[i]);
737 PCPU_INC(cnt.v_vnodein);
738 PCPU_INC(cnt.v_vnodepgsin);
739 error = vnode_pager_input_old(object, m[reqpage]);
740 VM_OBJECT_UNLOCK(object);
742 } else if (error != 0) {
743 VM_OBJECT_LOCK(object);
744 for (i = 0; i < count; i++)
748 vm_page_unlock(m[i]);
750 VM_OBJECT_UNLOCK(object);
751 return (VM_PAGER_ERROR);
754 * if the blocksize is smaller than a page size, then use
755 * special small filesystem code. NFS sometimes has a small
756 * blocksize, but it can handle large reads itself.
758 } else if ((PAGE_SIZE / bsize) > 1 &&
759 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) {
760 VM_OBJECT_LOCK(object);
761 for (i = 0; i < count; i++)
765 vm_page_unlock(m[i]);
767 VM_OBJECT_UNLOCK(object);
768 PCPU_INC(cnt.v_vnodein);
769 PCPU_INC(cnt.v_vnodepgsin);
770 return vnode_pager_input_smlfs(object, m[reqpage]);
774 * If we have a completely valid page available to us, we can
775 * clean up and return. Otherwise we have to re-read the
778 VM_OBJECT_LOCK(object);
779 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) {
780 for (i = 0; i < count; i++)
784 vm_page_unlock(m[i]);
786 VM_OBJECT_UNLOCK(object);
788 } else if (reqblock == -1) {
789 pmap_zero_page(m[reqpage]);
790 KASSERT(m[reqpage]->dirty == 0,
791 ("vnode_pager_generic_getpages: page %p is dirty", m));
792 m[reqpage]->valid = VM_PAGE_BITS_ALL;
793 for (i = 0; i < count; i++)
797 vm_page_unlock(m[i]);
799 VM_OBJECT_UNLOCK(object);
800 return (VM_PAGER_OK);
802 m[reqpage]->valid = 0;
803 VM_OBJECT_UNLOCK(object);
806 * here on direct device I/O
811 * calculate the run that includes the required page
813 for (first = 0, i = 0; i < count; i = runend) {
814 if (vnode_pager_addr(vp, IDX_TO_OFF(m[i]->pindex), &firstaddr,
816 VM_OBJECT_LOCK(object);
817 for (; i < count; i++)
821 vm_page_unlock(m[i]);
823 VM_OBJECT_UNLOCK(object);
824 return (VM_PAGER_ERROR);
826 if (firstaddr == -1) {
827 VM_OBJECT_LOCK(object);
828 if (i == reqpage && foff < object->un_pager.vnp.vnp_size) {
829 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %jd, foff: 0x%jx%08jx, vnp_size: 0x%jx%08jx",
830 (intmax_t)firstaddr, (uintmax_t)(foff >> 32),
833 (object->un_pager.vnp.vnp_size >> 32),
834 (uintmax_t)object->un_pager.vnp.vnp_size);
838 vm_page_unlock(m[i]);
839 VM_OBJECT_UNLOCK(object);
845 if (runend <= reqpage) {
846 VM_OBJECT_LOCK(object);
847 for (j = i; j < runend; j++) {
850 vm_page_unlock(m[j]);
852 VM_OBJECT_UNLOCK(object);
854 if (runpg < (count - first)) {
855 VM_OBJECT_LOCK(object);
856 for (i = first + runpg; i < count; i++) {
859 vm_page_unlock(m[i]);
861 VM_OBJECT_UNLOCK(object);
862 count = first + runpg;
870 * the first and last page have been calculated now, move input pages
871 * to be zero based...
880 * calculate the file virtual address for the transfer
882 foff = IDX_TO_OFF(m[0]->pindex);
885 * calculate the size of the transfer
887 size = count * PAGE_SIZE;
888 KASSERT(count > 0, ("zero count"));
889 if ((foff + size) > object->un_pager.vnp.vnp_size)
890 size = object->un_pager.vnp.vnp_size - foff;
891 KASSERT(size > 0, ("zero size"));
894 * round up physical size for real devices.
897 int secmask = bo->bo_bsize - 1;
898 KASSERT(secmask < PAGE_SIZE && secmask > 0,
899 ("vnode_pager_generic_getpages: sector size %d too large",
901 size = (size + secmask) & ~secmask;
904 bp = getpbuf(&vnode_pbuf_freecnt);
905 kva = (vm_offset_t) bp->b_data;
908 * and map the pages to be read into the kva
910 pmap_qenter(kva, m, count);
912 /* build a minimal buffer header */
913 bp->b_iocmd = BIO_READ;
914 bp->b_iodone = bdone;
915 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred"));
916 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred"));
917 bp->b_rcred = crhold(curthread->td_ucred);
918 bp->b_wcred = crhold(curthread->td_ucred);
919 bp->b_blkno = firstaddr;
923 bp->b_bufsize = size;
924 bp->b_runningbufspace = bp->b_bufsize;
925 atomic_add_long(&runningbufspace, bp->b_runningbufspace);
927 PCPU_INC(cnt.v_vnodein);
928 PCPU_ADD(cnt.v_vnodepgsin, count);
931 bp->b_iooffset = dbtob(bp->b_blkno);
934 bwait(bp, PVM, "vnread");
936 if ((bp->b_ioflags & BIO_ERROR) != 0)
940 if (size != count * PAGE_SIZE)
941 bzero((caddr_t) kva + size, PAGE_SIZE * count - size);
943 pmap_qremove(kva, count);
946 * free the buffer header back to the swap buffer pool
950 relpbuf(bp, &vnode_pbuf_freecnt);
952 VM_OBJECT_LOCK(object);
953 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) {
956 nextoff = tfoff + PAGE_SIZE;
959 if (nextoff <= object->un_pager.vnp.vnp_size) {
961 * Read filled up entire page.
963 mt->valid = VM_PAGE_BITS_ALL;
964 KASSERT(mt->dirty == 0,
965 ("vnode_pager_generic_getpages: page %p is dirty",
967 KASSERT(!pmap_page_is_mapped(mt),
968 ("vnode_pager_generic_getpages: page %p is mapped",
972 * Read did not fill up entire page.
974 * Currently we do not set the entire page valid,
975 * we just try to clear the piece that we couldn't
978 vm_page_set_valid(mt, 0,
979 object->un_pager.vnp.vnp_size - tfoff);
980 KASSERT((mt->dirty & vm_page_bits(0,
981 object->un_pager.vnp.vnp_size - tfoff)) == 0,
982 ("vnode_pager_generic_getpages: page %p is dirty",
989 * whether or not to leave the page activated is up in
990 * the air, but we should put the page on a page queue
991 * somewhere. (it already is in the object). Result:
992 * It appears that empirical results show that
993 * deactivating pages is best.
997 * just in case someone was asking for this page we
998 * now tell them that it is ok to use
1001 if (mt->oflags & VPO_WANTED) {
1003 vm_page_activate(mt);
1007 vm_page_deactivate(mt);
1018 VM_OBJECT_UNLOCK(object);
1020 printf("vnode_pager_getpages: I/O read error\n");
1022 return (error ? VM_PAGER_ERROR : VM_PAGER_OK);
1026 * EOPNOTSUPP is no longer legal. For local media VFS's that do not
1027 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to
1028 * vnode_pager_generic_putpages() to implement the previous behaviour.
1030 * All other FS's should use the bypass to get to the local media
1031 * backing vp's VOP_PUTPAGES.
1034 vnode_pager_putpages(object, m, count, sync, rtvals)
1043 int bytes = count * PAGE_SIZE;
1046 * Force synchronous operation if we are extremely low on memory
1047 * to prevent a low-memory deadlock. VOP operations often need to
1048 * allocate more memory to initiate the I/O ( i.e. do a BMAP
1049 * operation ). The swapper handles the case by limiting the amount
1050 * of asynchronous I/O, but that sort of solution doesn't scale well
1051 * for the vnode pager without a lot of work.
1053 * Also, the backing vnode's iodone routine may not wake the pageout
1054 * daemon up. This should be probably be addressed XXX.
1057 if ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min)
1061 * Call device-specific putpages function
1063 vp = object->handle;
1064 VM_OBJECT_UNLOCK(object);
1065 rtval = VOP_PUTPAGES(vp, m, bytes, sync, rtvals, 0);
1066 KASSERT(rtval != EOPNOTSUPP,
1067 ("vnode_pager: stale FS putpages\n"));
1068 VM_OBJECT_LOCK(object);
1073 * This is now called from local media FS's to operate against their
1074 * own vnodes if they fail to implement VOP_PUTPAGES.
1076 * This is typically called indirectly via the pageout daemon and
1077 * clustering has already typically occured, so in general we ask the
1078 * underlying filesystem to write the data out asynchronously rather
1082 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *ma, int bytecount,
1083 int flags, int *rtvals)
1090 int maxsize, ncount;
1091 vm_ooffset_t poffset;
1097 static struct timeval lastfail;
1100 object = vp->v_object;
1101 count = bytecount / PAGE_SIZE;
1103 for (i = 0; i < count; i++)
1104 rtvals[i] = VM_PAGER_ERROR;
1106 if ((int64_t)ma[0]->pindex < 0) {
1107 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%lx)\n",
1108 (long)ma[0]->pindex, (u_long)ma[0]->dirty);
1109 rtvals[0] = VM_PAGER_BAD;
1110 return VM_PAGER_BAD;
1113 maxsize = count * PAGE_SIZE;
1116 poffset = IDX_TO_OFF(ma[0]->pindex);
1119 * If the page-aligned write is larger then the actual file we
1120 * have to invalidate pages occuring beyond the file EOF. However,
1121 * there is an edge case where a file may not be page-aligned where
1122 * the last page is partially invalid. In this case the filesystem
1123 * may not properly clear the dirty bits for the entire page (which
1124 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d).
1125 * With the page locked we are free to fix-up the dirty bits here.
1127 * We do not under any circumstances truncate the valid bits, as
1128 * this will screw up bogus page replacement.
1130 VM_OBJECT_LOCK(object);
1131 if (maxsize + poffset > object->un_pager.vnp.vnp_size) {
1132 if (object->un_pager.vnp.vnp_size > poffset) {
1135 maxsize = object->un_pager.vnp.vnp_size - poffset;
1136 ncount = btoc(maxsize);
1137 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) {
1139 * If the object is locked and the following
1140 * conditions hold, then the page's dirty
1141 * field cannot be concurrently changed by a
1145 KASSERT(m->busy > 0,
1146 ("vnode_pager_generic_putpages: page %p is not busy", m));
1147 KASSERT((m->aflags & PGA_WRITEABLE) == 0,
1148 ("vnode_pager_generic_putpages: page %p is not read-only", m));
1149 vm_page_clear_dirty(m, pgoff, PAGE_SIZE -
1156 if (ncount < count) {
1157 for (i = ncount; i < count; i++) {
1158 rtvals[i] = VM_PAGER_BAD;
1162 VM_OBJECT_UNLOCK(object);
1165 * pageouts are already clustered, use IO_ASYNC t o force a bawrite()
1166 * rather then a bdwrite() to prevent paging I/O from saturating
1167 * the buffer cache. Dummy-up the sequential heuristic to cause
1168 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set,
1169 * the system decides how to cluster.
1172 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL))
1174 else if ((flags & VM_PAGER_CLUSTER_OK) == 0)
1175 ioflags |= IO_ASYNC;
1176 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0;
1177 ioflags |= IO_SEQMAX << IO_SEQSHIFT;
1179 aiov.iov_base = (caddr_t) 0;
1180 aiov.iov_len = maxsize;
1181 auio.uio_iov = &aiov;
1182 auio.uio_iovcnt = 1;
1183 auio.uio_offset = poffset;
1184 auio.uio_segflg = UIO_NOCOPY;
1185 auio.uio_rw = UIO_WRITE;
1186 auio.uio_resid = maxsize;
1187 auio.uio_td = (struct thread *) 0;
1188 error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred);
1189 PCPU_INC(cnt.v_vnodeout);
1190 PCPU_ADD(cnt.v_vnodepgsout, ncount);
1193 if ((ppscheck = ppsratecheck(&lastfail, &curfail, 1)))
1194 printf("vnode_pager_putpages: I/O error %d\n", error);
1196 if (auio.uio_resid) {
1197 if (ppscheck || ppsratecheck(&lastfail, &curfail, 1))
1198 printf("vnode_pager_putpages: residual I/O %zd at %lu\n",
1199 auio.uio_resid, (u_long)ma[0]->pindex);
1201 for (i = 0; i < ncount; i++) {
1202 rtvals[i] = VM_PAGER_OK;
1208 vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written)
1215 obj = ma[0]->object;
1216 VM_OBJECT_LOCK(obj);
1217 for (i = 0, pos = 0; pos < written; i++, pos += PAGE_SIZE) {
1218 if (pos < trunc_page(written)) {
1219 rtvals[i] = VM_PAGER_OK;
1220 vm_page_undirty(ma[i]);
1222 /* Partially written page. */
1223 rtvals[i] = VM_PAGER_AGAIN;
1224 vm_page_clear_dirty(ma[i], 0, written & PAGE_MASK);
1227 VM_OBJECT_UNLOCK(obj);
1231 vnode_pager_update_writecount(vm_object_t object, vm_offset_t start,
1235 vm_ooffset_t old_wm;
1237 VM_OBJECT_LOCK(object);
1238 if (object->type != OBJT_VNODE) {
1239 VM_OBJECT_UNLOCK(object);
1242 old_wm = object->un_pager.vnp.writemappings;
1243 object->un_pager.vnp.writemappings += (vm_ooffset_t)end - start;
1244 vp = object->handle;
1245 if (old_wm == 0 && object->un_pager.vnp.writemappings != 0) {
1246 ASSERT_VOP_ELOCKED(vp, "v_writecount inc");
1248 } else if (old_wm != 0 && object->un_pager.vnp.writemappings == 0) {
1249 ASSERT_VOP_ELOCKED(vp, "v_writecount dec");
1252 VM_OBJECT_UNLOCK(object);
1256 vnode_pager_release_writecount(vm_object_t object, vm_offset_t start,
1264 VM_OBJECT_LOCK(object);
1267 * First, recheck the object type to account for the race when
1268 * the vnode is reclaimed.
1270 if (object->type != OBJT_VNODE) {
1271 VM_OBJECT_UNLOCK(object);
1276 * Optimize for the case when writemappings is not going to
1280 if (object->un_pager.vnp.writemappings != inc) {
1281 object->un_pager.vnp.writemappings -= inc;
1282 VM_OBJECT_UNLOCK(object);
1286 vp = object->handle;
1288 VM_OBJECT_UNLOCK(object);
1289 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
1291 vn_start_write(vp, &mp, V_WAIT);
1292 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1295 * Decrement the object's writemappings, by swapping the start
1296 * and end arguments for vnode_pager_update_writecount(). If
1297 * there was not a race with vnode reclaimation, then the
1298 * vnode's v_writecount is decremented.
1300 vnode_pager_update_writecount(object, end, start);
1304 vn_finished_write(mp);
1305 VFS_UNLOCK_GIANT(vfslocked);