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/rwlock.h>
67 #include <sys/sf_buf.h>
69 #include <machine/atomic.h>
72 #include <vm/vm_param.h>
73 #include <vm/vm_object.h>
74 #include <vm/vm_page.h>
75 #include <vm/vm_pager.h>
76 #include <vm/vm_map.h>
77 #include <vm/vnode_pager.h>
78 #include <vm/vm_extern.h>
80 static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address,
81 daddr_t *rtaddress, int *run);
82 static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m);
83 static int vnode_pager_input_old(vm_object_t object, vm_page_t m);
84 static void vnode_pager_dealloc(vm_object_t);
85 static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int);
86 static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, int, int *);
87 static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *);
88 static vm_object_t vnode_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
89 vm_ooffset_t, struct ucred *cred);
91 struct pagerops vnodepagerops = {
92 .pgo_alloc = vnode_pager_alloc,
93 .pgo_dealloc = vnode_pager_dealloc,
94 .pgo_getpages = vnode_pager_getpages,
95 .pgo_putpages = vnode_pager_putpages,
96 .pgo_haspage = vnode_pager_haspage,
99 int vnode_pbuf_freecnt;
101 /* Create the VM system backing object for this vnode */
103 vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td)
106 vm_ooffset_t size = isize;
109 if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE)
112 while ((object = vp->v_object) != NULL) {
113 VM_OBJECT_WLOCK(object);
114 if (!(object->flags & OBJ_DEAD)) {
115 VM_OBJECT_WUNLOCK(object);
119 vm_object_set_flag(object, OBJ_DISCONNECTWNT);
120 VM_OBJECT_SLEEP(object, object, PDROP | PVM, "vodead", 0);
121 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
125 if (vn_isdisk(vp, NULL)) {
126 size = IDX_TO_OFF(INT_MAX);
128 if (VOP_GETATTR(vp, &va, td->td_ucred))
134 object = vnode_pager_alloc(vp, size, 0, 0, td->td_ucred);
136 * Dereference the reference we just created. This assumes
137 * that the object is associated with the vp.
139 VM_OBJECT_WLOCK(object);
141 VM_OBJECT_WUNLOCK(object);
144 KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object"));
150 vnode_destroy_vobject(struct vnode *vp)
152 struct vm_object *obj;
157 ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject");
158 VM_OBJECT_WLOCK(obj);
159 if (obj->ref_count == 0) {
161 * don't double-terminate the object
163 if ((obj->flags & OBJ_DEAD) == 0)
164 vm_object_terminate(obj);
166 VM_OBJECT_WUNLOCK(obj);
169 * Woe to the process that tries to page now :-).
171 vm_pager_deallocate(obj);
172 VM_OBJECT_WUNLOCK(obj);
179 * Allocate (or lookup) pager for a vnode.
180 * Handle is a vnode pointer.
185 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
186 vm_ooffset_t offset, struct ucred *cred)
192 * Pageout to vnode, no can do yet.
197 vp = (struct vnode *) handle;
200 * If the object is being terminated, wait for it to
204 while ((object = vp->v_object) != NULL) {
205 VM_OBJECT_WLOCK(object);
206 if ((object->flags & OBJ_DEAD) == 0)
208 vm_object_set_flag(object, OBJ_DISCONNECTWNT);
209 VM_OBJECT_SLEEP(object, object, PDROP | PVM, "vadead", 0);
212 KASSERT(vp->v_usecount != 0, ("vnode_pager_alloc: no vnode reference"));
214 if (object == NULL) {
216 * Add an object of the appropriate size
218 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size)));
220 object->un_pager.vnp.vnp_size = size;
221 object->un_pager.vnp.writemappings = 0;
223 object->handle = handle;
225 if (vp->v_object != NULL) {
227 * Object has been created while we were sleeping
230 VM_OBJECT_WLOCK(object);
231 KASSERT(object->ref_count == 1,
232 ("leaked ref %p %d", object, object->ref_count));
233 object->type = OBJT_DEAD;
234 object->ref_count = 0;
235 VM_OBJECT_WUNLOCK(object);
236 vm_object_destroy(object);
239 vp->v_object = object;
243 VM_OBJECT_WUNLOCK(object);
250 * The object must be locked.
253 vnode_pager_dealloc(object)
261 panic("vnode_pager_dealloc: pager already dealloced");
263 VM_OBJECT_ASSERT_WLOCKED(object);
264 vm_object_pip_wait(object, "vnpdea");
265 refs = object->ref_count;
267 object->handle = NULL;
268 object->type = OBJT_DEAD;
269 if (object->flags & OBJ_DISCONNECTWNT) {
270 vm_object_clear_flag(object, OBJ_DISCONNECTWNT);
273 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc");
274 if (object->un_pager.vnp.writemappings > 0) {
275 object->un_pager.vnp.writemappings = 0;
276 VOP_ADD_WRITECOUNT(vp, -1);
277 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
278 __func__, vp, vp->v_writecount);
282 VM_OBJECT_WUNLOCK(object);
285 VM_OBJECT_WLOCK(object);
289 vnode_pager_haspage(object, pindex, before, after)
295 struct vnode *vp = object->handle;
301 int pagesperblock, blocksperpage;
303 VM_OBJECT_ASSERT_WLOCKED(object);
305 * If no vp or vp is doomed or marked transparent to VM, we do not
308 if (vp == NULL || vp->v_iflag & VI_DOOMED)
311 * If the offset is beyond end of file we do
314 if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size)
317 bsize = vp->v_mount->mnt_stat.f_iosize;
318 pagesperblock = bsize / PAGE_SIZE;
320 if (pagesperblock > 0) {
321 reqblock = pindex / pagesperblock;
323 blocksperpage = (PAGE_SIZE / bsize);
324 reqblock = pindex * blocksperpage;
326 VM_OBJECT_WUNLOCK(object);
327 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before);
328 VM_OBJECT_WLOCK(object);
333 if (pagesperblock > 0) {
334 poff = pindex - (reqblock * pagesperblock);
336 *before *= pagesperblock;
341 *after *= pagesperblock;
342 numafter = pagesperblock - (poff + 1);
343 if (IDX_TO_OFF(pindex + numafter) >
344 object->un_pager.vnp.vnp_size) {
346 OFF_TO_IDX(object->un_pager.vnp.vnp_size) -
353 *before /= blocksperpage;
357 *after /= blocksperpage;
364 * Lets the VM system know about a change in size for a file.
365 * We adjust our own internal size and flush any cached pages in
366 * the associated object that are affected by the size change.
368 * Note: this routine may be invoked as a result of a pager put
369 * operation (possibly at object termination time), so we must be careful.
372 vnode_pager_setsize(vp, nsize)
378 vm_pindex_t nobjsize;
380 if ((object = vp->v_object) == NULL)
382 /* ASSERT_VOP_ELOCKED(vp, "vnode_pager_setsize and not locked vnode"); */
383 VM_OBJECT_WLOCK(object);
384 if (object->type == OBJT_DEAD) {
385 VM_OBJECT_WUNLOCK(object);
388 KASSERT(object->type == OBJT_VNODE,
389 ("not vnode-backed object %p", object));
390 if (nsize == object->un_pager.vnp.vnp_size) {
392 * Hasn't changed size
394 VM_OBJECT_WUNLOCK(object);
397 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK);
398 if (nsize < object->un_pager.vnp.vnp_size) {
400 * File has shrunk. Toss any cached pages beyond the new EOF.
402 if (nobjsize < object->size)
403 vm_object_page_remove(object, nobjsize, object->size,
406 * this gets rid of garbage at the end of a page that is now
407 * only partially backed by the vnode.
409 * XXX for some reason (I don't know yet), if we take a
410 * completely invalid page and mark it partially valid
411 * it can screw up NFS reads, so we don't allow the case.
413 if ((nsize & PAGE_MASK) &&
414 (m = vm_page_lookup(object, OFF_TO_IDX(nsize))) != NULL &&
416 int base = (int)nsize & PAGE_MASK;
417 int size = PAGE_SIZE - base;
420 * Clear out partial-page garbage in case
421 * the page has been mapped.
423 pmap_zero_page_area(m, base, size);
426 * Update the valid bits to reflect the blocks that
427 * have been zeroed. Some of these valid bits may
428 * have already been set.
430 vm_page_set_valid_range(m, base, size);
433 * Round "base" to the next block boundary so that the
434 * dirty bit for a partially zeroed block is not
437 base = roundup2(base, DEV_BSIZE);
440 * Clear out partial-page dirty bits.
442 * note that we do not clear out the valid
443 * bits. This would prevent bogus_page
444 * replacement from working properly.
446 vm_page_clear_dirty(m, base, PAGE_SIZE - base);
447 } else if ((nsize & PAGE_MASK) &&
448 vm_page_is_cached(object, OFF_TO_IDX(nsize))) {
449 vm_page_cache_free(object, OFF_TO_IDX(nsize),
453 object->un_pager.vnp.vnp_size = nsize;
454 object->size = nobjsize;
455 VM_OBJECT_WUNLOCK(object);
459 * calculate the linear (byte) disk address of specified virtual
463 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress,
474 if (vp->v_iflag & VI_DOOMED)
477 bsize = vp->v_mount->mnt_stat.f_iosize;
478 vblock = address / bsize;
479 voffset = address % bsize;
481 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL);
483 if (*rtaddress != -1)
484 *rtaddress += voffset / DEV_BSIZE;
487 *run *= bsize/PAGE_SIZE;
488 *run -= voffset/PAGE_SIZE;
496 * small block filesystem vnode pager input
499 vnode_pager_input_smlfs(object, m)
514 if (vp->v_iflag & VI_DOOMED)
517 bsize = vp->v_mount->mnt_stat.f_iosize;
519 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL);
521 sf = sf_buf_alloc(m, 0);
523 for (i = 0; i < PAGE_SIZE / bsize; i++) {
524 vm_ooffset_t address;
526 bits = vm_page_bits(i * bsize, bsize);
530 address = IDX_TO_OFF(m->pindex) + i * bsize;
531 if (address >= object->un_pager.vnp.vnp_size) {
534 error = vnode_pager_addr(vp, address, &fileaddr, NULL);
538 if (fileaddr != -1) {
539 bp = getpbuf(&vnode_pbuf_freecnt);
541 /* build a minimal buffer header */
542 bp->b_iocmd = BIO_READ;
543 bp->b_iodone = bdone;
544 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred"));
545 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred"));
546 bp->b_rcred = crhold(curthread->td_ucred);
547 bp->b_wcred = crhold(curthread->td_ucred);
548 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize;
549 bp->b_blkno = fileaddr;
552 bp->b_bcount = bsize;
553 bp->b_bufsize = bsize;
554 bp->b_runningbufspace = bp->b_bufsize;
555 atomic_add_long(&runningbufspace, bp->b_runningbufspace);
558 bp->b_iooffset = dbtob(bp->b_blkno);
561 bwait(bp, PVM, "vnsrd");
563 if ((bp->b_ioflags & BIO_ERROR) != 0)
567 * free the buffer header back to the swap buffer pool
571 relpbuf(bp, &vnode_pbuf_freecnt);
575 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize);
576 KASSERT((m->dirty & bits) == 0,
577 ("vnode_pager_input_smlfs: page %p is dirty", m));
578 VM_OBJECT_WLOCK(object);
580 VM_OBJECT_WUNLOCK(object);
584 return VM_PAGER_ERROR;
590 * old style vnode pager input routine
593 vnode_pager_input_old(object, m)
604 VM_OBJECT_ASSERT_WLOCKED(object);
608 * Return failure if beyond current EOF
610 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) {
614 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size)
615 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex);
617 VM_OBJECT_WUNLOCK(object);
620 * Allocate a kernel virtual address and initialize so that
621 * we can use VOP_READ/WRITE routines.
623 sf = sf_buf_alloc(m, 0);
625 aiov.iov_base = (caddr_t)sf_buf_kva(sf);
627 auio.uio_iov = &aiov;
629 auio.uio_offset = IDX_TO_OFF(m->pindex);
630 auio.uio_segflg = UIO_SYSSPACE;
631 auio.uio_rw = UIO_READ;
632 auio.uio_resid = size;
633 auio.uio_td = curthread;
635 error = VOP_READ(vp, &auio, 0, curthread->td_ucred);
637 int count = size - auio.uio_resid;
641 else if (count != PAGE_SIZE)
642 bzero((caddr_t)sf_buf_kva(sf) + count,
647 VM_OBJECT_WLOCK(object);
649 KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m));
651 m->valid = VM_PAGE_BITS_ALL;
652 return error ? VM_PAGER_ERROR : VM_PAGER_OK;
656 * generic vnode pager input routine
660 * Local media VFS's that do not implement their own VOP_GETPAGES
661 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages()
662 * to implement the previous behaviour.
664 * All other FS's should use the bypass to get to the local media
665 * backing vp's VOP_GETPAGES.
668 vnode_pager_getpages(object, m, count, reqpage)
676 int bytes = count * PAGE_SIZE;
679 VM_OBJECT_WUNLOCK(object);
680 rtval = VOP_GETPAGES(vp, m, bytes, reqpage, 0);
681 KASSERT(rtval != EOPNOTSUPP,
682 ("vnode_pager: FS getpages not implemented\n"));
683 VM_OBJECT_WLOCK(object);
688 * This is now called from local media FS's to operate against their
689 * own vnodes if they fail to implement VOP_GETPAGES.
692 vnode_pager_generic_getpages(vp, m, bytecount, reqpage)
703 daddr_t firstaddr, reqblock;
704 off_t foff, nextoff, tfoff, pib;
705 int pbefore, pafter, i, size, bsize, first, last;
706 int count, error, before, after, secmask;
708 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK,
709 ("vnode_pager_generic_getpages does not support devices"));
710 if (vp->v_iflag & VI_DOOMED)
711 return (VM_PAGER_BAD);
713 object = vp->v_object;
714 count = bytecount / PAGE_SIZE;
715 bsize = vp->v_mount->mnt_stat.f_iosize;
717 /* get the UNDERLYING device for the file with VOP_BMAP() */
720 * originally, we did not check for an error return value -- assuming
721 * an fs always has a bmap entry point -- that assumption is wrong!!!
723 foff = IDX_TO_OFF(m[reqpage]->pindex);
726 * if we can't bmap, use old VOP code
728 error = VOP_BMAP(vp, IDX_TO_OFF(m[reqpage]->pindex) / bsize, &bo,
729 &reqblock, &after, &before);
730 if (error == EOPNOTSUPP) {
731 VM_OBJECT_WLOCK(object);
733 for (i = 0; i < count; i++)
737 vm_page_unlock(m[i]);
739 PCPU_INC(cnt.v_vnodein);
740 PCPU_INC(cnt.v_vnodepgsin);
741 error = vnode_pager_input_old(object, m[reqpage]);
742 VM_OBJECT_WUNLOCK(object);
744 } else if (error != 0) {
745 VM_OBJECT_WLOCK(object);
746 for (i = 0; i < count; i++)
750 vm_page_unlock(m[i]);
752 VM_OBJECT_WUNLOCK(object);
753 return (VM_PAGER_ERROR);
756 * if the blocksize is smaller than a page size, then use
757 * special small filesystem code. NFS sometimes has a small
758 * blocksize, but it can handle large reads itself.
760 } else if ((PAGE_SIZE / bsize) > 1 &&
761 (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) {
762 VM_OBJECT_WLOCK(object);
763 for (i = 0; i < count; i++)
767 vm_page_unlock(m[i]);
769 VM_OBJECT_WUNLOCK(object);
770 PCPU_INC(cnt.v_vnodein);
771 PCPU_INC(cnt.v_vnodepgsin);
772 return (vnode_pager_input_smlfs(object, m[reqpage]));
776 * If we have a completely valid page available to us, we can
777 * clean up and return. Otherwise we have to re-read the
780 VM_OBJECT_WLOCK(object);
781 if (m[reqpage]->valid == VM_PAGE_BITS_ALL) {
782 for (i = 0; i < count; i++)
786 vm_page_unlock(m[i]);
788 VM_OBJECT_WUNLOCK(object);
790 } else if (reqblock == -1) {
791 pmap_zero_page(m[reqpage]);
792 KASSERT(m[reqpage]->dirty == 0,
793 ("vnode_pager_generic_getpages: page %p is dirty", m));
794 m[reqpage]->valid = VM_PAGE_BITS_ALL;
795 for (i = 0; i < count; i++)
799 vm_page_unlock(m[i]);
801 VM_OBJECT_WUNLOCK(object);
802 return (VM_PAGER_OK);
804 m[reqpage]->valid = 0;
805 VM_OBJECT_WUNLOCK(object);
807 pib = IDX_TO_OFF(m[reqpage]->pindex) % bsize;
808 pbefore = ((daddr_t)before * bsize + pib) / PAGE_SIZE;
809 pafter = ((daddr_t)(after + 1) * bsize - pib) / PAGE_SIZE - 1;
810 first = reqpage < pbefore ? 0 : reqpage - pbefore;
811 last = reqpage + pafter >= count ? count - 1 : reqpage + pafter;
812 if (first > 0 || last + 1 < count) {
813 VM_OBJECT_WLOCK(object);
814 for (i = 0; i < first; i++) {
817 vm_page_unlock(m[i]);
819 for (i = last + 1; i < count; i++) {
822 vm_page_unlock(m[i]);
824 VM_OBJECT_WUNLOCK(object);
828 * here on direct device I/O
830 firstaddr = reqblock;
831 firstaddr += pib / DEV_BSIZE;
832 firstaddr -= IDX_TO_OFF(reqpage - first) / DEV_BSIZE;
835 * The first and last page have been calculated now, move
836 * input pages to be zero based, and adjust the count.
840 count = last - first + 1;
843 * calculate the file virtual address for the transfer
845 foff = IDX_TO_OFF(m[0]->pindex);
848 * calculate the size of the transfer
850 size = count * PAGE_SIZE;
851 KASSERT(count > 0, ("zero count"));
852 if ((foff + size) > object->un_pager.vnp.vnp_size)
853 size = object->un_pager.vnp.vnp_size - foff;
854 KASSERT(size > 0, ("zero size"));
857 * round up physical size for real devices.
859 secmask = bo->bo_bsize - 1;
860 KASSERT(secmask < PAGE_SIZE && secmask > 0,
861 ("vnode_pager_generic_getpages: sector size %d too large",
863 size = (size + secmask) & ~secmask;
865 bp = getpbuf(&vnode_pbuf_freecnt);
866 kva = (vm_offset_t)bp->b_data;
869 * and map the pages to be read into the kva, if the filesystem
870 * requires mapped buffers.
873 if (mp != NULL && (mp->mnt_kern_flag & MNTK_UNMAPPED_BUFS) != 0 &&
874 unmapped_buf_allowed) {
875 bp->b_data = unmapped_buf;
876 bp->b_kvabase = unmapped_buf;
878 bp->b_flags |= B_UNMAPPED;
879 bp->b_npages = count;
880 for (i = 0; i < count; i++)
881 bp->b_pages[i] = m[i];
883 pmap_qenter(kva, m, count);
885 /* build a minimal buffer header */
886 bp->b_iocmd = BIO_READ;
887 bp->b_iodone = bdone;
888 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred"));
889 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred"));
890 bp->b_rcred = crhold(curthread->td_ucred);
891 bp->b_wcred = crhold(curthread->td_ucred);
892 bp->b_blkno = firstaddr;
896 bp->b_bufsize = size;
897 bp->b_runningbufspace = bp->b_bufsize;
898 atomic_add_long(&runningbufspace, bp->b_runningbufspace);
900 PCPU_INC(cnt.v_vnodein);
901 PCPU_ADD(cnt.v_vnodepgsin, count);
904 bp->b_iooffset = dbtob(bp->b_blkno);
907 bwait(bp, PVM, "vnread");
909 if ((bp->b_ioflags & BIO_ERROR) != 0)
912 if (error == 0 && size != count * PAGE_SIZE) {
913 if ((bp->b_flags & B_UNMAPPED) != 0) {
914 bp->b_flags &= ~B_UNMAPPED;
915 pmap_qenter(kva, m, count);
917 bzero((caddr_t)kva + size, PAGE_SIZE * count - size);
919 if ((bp->b_flags & B_UNMAPPED) == 0)
920 pmap_qremove(kva, count);
921 if (mp != NULL && (mp->mnt_kern_flag & MNTK_UNMAPPED_BUFS) != 0) {
922 bp->b_data = (caddr_t)kva;
923 bp->b_kvabase = (caddr_t)kva;
924 bp->b_flags &= ~B_UNMAPPED;
925 for (i = 0; i < count; i++)
926 bp->b_pages[i] = NULL;
930 * free the buffer header back to the swap buffer pool
934 relpbuf(bp, &vnode_pbuf_freecnt);
936 VM_OBJECT_WLOCK(object);
937 for (i = 0, tfoff = foff; i < count; i++, tfoff = nextoff) {
940 nextoff = tfoff + PAGE_SIZE;
943 if (nextoff <= object->un_pager.vnp.vnp_size) {
945 * Read filled up entire page.
947 mt->valid = VM_PAGE_BITS_ALL;
948 KASSERT(mt->dirty == 0,
949 ("vnode_pager_generic_getpages: page %p is dirty",
951 KASSERT(!pmap_page_is_mapped(mt),
952 ("vnode_pager_generic_getpages: page %p is mapped",
956 * Read did not fill up entire page.
958 * Currently we do not set the entire page valid,
959 * we just try to clear the piece that we couldn't
962 vm_page_set_valid_range(mt, 0,
963 object->un_pager.vnp.vnp_size - tfoff);
964 KASSERT((mt->dirty & vm_page_bits(0,
965 object->un_pager.vnp.vnp_size - tfoff)) == 0,
966 ("vnode_pager_generic_getpages: page %p is dirty",
971 vm_page_readahead_finish(mt);
973 VM_OBJECT_WUNLOCK(object);
975 printf("vnode_pager_getpages: I/O read error\n");
977 return (error ? VM_PAGER_ERROR : VM_PAGER_OK);
981 * EOPNOTSUPP is no longer legal. For local media VFS's that do not
982 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to
983 * vnode_pager_generic_putpages() to implement the previous behaviour.
985 * All other FS's should use the bypass to get to the local media
986 * backing vp's VOP_PUTPAGES.
989 vnode_pager_putpages(vm_object_t object, vm_page_t *m, int count,
990 int flags, int *rtvals)
994 int bytes = count * PAGE_SIZE;
997 * Force synchronous operation if we are extremely low on memory
998 * to prevent a low-memory deadlock. VOP operations often need to
999 * allocate more memory to initiate the I/O ( i.e. do a BMAP
1000 * operation ). The swapper handles the case by limiting the amount
1001 * of asynchronous I/O, but that sort of solution doesn't scale well
1002 * for the vnode pager without a lot of work.
1004 * Also, the backing vnode's iodone routine may not wake the pageout
1005 * daemon up. This should be probably be addressed XXX.
1008 if (cnt.v_free_count + cnt.v_cache_count < cnt.v_pageout_free_min)
1009 flags |= VM_PAGER_PUT_SYNC;
1012 * Call device-specific putpages function
1014 vp = object->handle;
1015 VM_OBJECT_WUNLOCK(object);
1016 rtval = VOP_PUTPAGES(vp, m, bytes, flags, rtvals, 0);
1017 KASSERT(rtval != EOPNOTSUPP,
1018 ("vnode_pager: stale FS putpages\n"));
1019 VM_OBJECT_WLOCK(object);
1024 * This is now called from local media FS's to operate against their
1025 * own vnodes if they fail to implement VOP_PUTPAGES.
1027 * This is typically called indirectly via the pageout daemon and
1028 * clustering has already typically occured, so in general we ask the
1029 * underlying filesystem to write the data out asynchronously rather
1033 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *ma, int bytecount,
1034 int flags, int *rtvals)
1041 int maxsize, ncount;
1042 vm_ooffset_t poffset;
1048 static struct timeval lastfail;
1051 object = vp->v_object;
1052 count = bytecount / PAGE_SIZE;
1054 for (i = 0; i < count; i++)
1055 rtvals[i] = VM_PAGER_ERROR;
1057 if ((int64_t)ma[0]->pindex < 0) {
1058 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%lx)\n",
1059 (long)ma[0]->pindex, (u_long)ma[0]->dirty);
1060 rtvals[0] = VM_PAGER_BAD;
1061 return VM_PAGER_BAD;
1064 maxsize = count * PAGE_SIZE;
1067 poffset = IDX_TO_OFF(ma[0]->pindex);
1070 * If the page-aligned write is larger then the actual file we
1071 * have to invalidate pages occuring beyond the file EOF. However,
1072 * there is an edge case where a file may not be page-aligned where
1073 * the last page is partially invalid. In this case the filesystem
1074 * may not properly clear the dirty bits for the entire page (which
1075 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d).
1076 * With the page locked we are free to fix-up the dirty bits here.
1078 * We do not under any circumstances truncate the valid bits, as
1079 * this will screw up bogus page replacement.
1081 VM_OBJECT_WLOCK(object);
1082 if (maxsize + poffset > object->un_pager.vnp.vnp_size) {
1083 if (object->un_pager.vnp.vnp_size > poffset) {
1086 maxsize = object->un_pager.vnp.vnp_size - poffset;
1087 ncount = btoc(maxsize);
1088 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) {
1090 * If the object is locked and the following
1091 * conditions hold, then the page's dirty
1092 * field cannot be concurrently changed by a
1096 vm_page_assert_sbusied(m);
1097 KASSERT(!pmap_page_is_write_mapped(m),
1098 ("vnode_pager_generic_putpages: page %p is not read-only", m));
1099 vm_page_clear_dirty(m, pgoff, PAGE_SIZE -
1106 if (ncount < count) {
1107 for (i = ncount; i < count; i++) {
1108 rtvals[i] = VM_PAGER_BAD;
1112 VM_OBJECT_WUNLOCK(object);
1115 * pageouts are already clustered, use IO_ASYNC to force a bawrite()
1116 * rather then a bdwrite() to prevent paging I/O from saturating
1117 * the buffer cache. Dummy-up the sequential heuristic to cause
1118 * large ranges to cluster. If neither IO_SYNC or IO_ASYNC is set,
1119 * the system decides how to cluster.
1122 if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL))
1124 else if ((flags & VM_PAGER_CLUSTER_OK) == 0)
1125 ioflags |= IO_ASYNC;
1126 ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0;
1127 ioflags |= IO_SEQMAX << IO_SEQSHIFT;
1129 aiov.iov_base = (caddr_t) 0;
1130 aiov.iov_len = maxsize;
1131 auio.uio_iov = &aiov;
1132 auio.uio_iovcnt = 1;
1133 auio.uio_offset = poffset;
1134 auio.uio_segflg = UIO_NOCOPY;
1135 auio.uio_rw = UIO_WRITE;
1136 auio.uio_resid = maxsize;
1137 auio.uio_td = (struct thread *) 0;
1138 error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred);
1139 PCPU_INC(cnt.v_vnodeout);
1140 PCPU_ADD(cnt.v_vnodepgsout, ncount);
1143 if ((ppscheck = ppsratecheck(&lastfail, &curfail, 1)))
1144 printf("vnode_pager_putpages: I/O error %d\n", error);
1146 if (auio.uio_resid) {
1147 if (ppscheck || ppsratecheck(&lastfail, &curfail, 1))
1148 printf("vnode_pager_putpages: residual I/O %zd at %lu\n",
1149 auio.uio_resid, (u_long)ma[0]->pindex);
1151 for (i = 0; i < ncount; i++) {
1152 rtvals[i] = VM_PAGER_OK;
1158 vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written)
1165 obj = ma[0]->object;
1166 VM_OBJECT_WLOCK(obj);
1167 for (i = 0, pos = 0; pos < written; i++, pos += PAGE_SIZE) {
1168 if (pos < trunc_page(written)) {
1169 rtvals[i] = VM_PAGER_OK;
1170 vm_page_undirty(ma[i]);
1172 /* Partially written page. */
1173 rtvals[i] = VM_PAGER_AGAIN;
1174 vm_page_clear_dirty(ma[i], 0, written & PAGE_MASK);
1177 VM_OBJECT_WUNLOCK(obj);
1181 vnode_pager_update_writecount(vm_object_t object, vm_offset_t start,
1185 vm_ooffset_t old_wm;
1187 VM_OBJECT_WLOCK(object);
1188 if (object->type != OBJT_VNODE) {
1189 VM_OBJECT_WUNLOCK(object);
1192 old_wm = object->un_pager.vnp.writemappings;
1193 object->un_pager.vnp.writemappings += (vm_ooffset_t)end - start;
1194 vp = object->handle;
1195 if (old_wm == 0 && object->un_pager.vnp.writemappings != 0) {
1196 ASSERT_VOP_ELOCKED(vp, "v_writecount inc");
1197 VOP_ADD_WRITECOUNT(vp, 1);
1198 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
1199 __func__, vp, vp->v_writecount);
1200 } else if (old_wm != 0 && object->un_pager.vnp.writemappings == 0) {
1201 ASSERT_VOP_ELOCKED(vp, "v_writecount dec");
1202 VOP_ADD_WRITECOUNT(vp, -1);
1203 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
1204 __func__, vp, vp->v_writecount);
1206 VM_OBJECT_WUNLOCK(object);
1210 vnode_pager_release_writecount(vm_object_t object, vm_offset_t start,
1217 VM_OBJECT_WLOCK(object);
1220 * First, recheck the object type to account for the race when
1221 * the vnode is reclaimed.
1223 if (object->type != OBJT_VNODE) {
1224 VM_OBJECT_WUNLOCK(object);
1229 * Optimize for the case when writemappings is not going to
1233 if (object->un_pager.vnp.writemappings != inc) {
1234 object->un_pager.vnp.writemappings -= inc;
1235 VM_OBJECT_WUNLOCK(object);
1239 vp = object->handle;
1241 VM_OBJECT_WUNLOCK(object);
1243 vn_start_write(vp, &mp, V_WAIT);
1244 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1247 * Decrement the object's writemappings, by swapping the start
1248 * and end arguments for vnode_pager_update_writecount(). If
1249 * there was not a race with vnode reclaimation, then the
1250 * vnode's v_writecount is decremented.
1252 vnode_pager_update_writecount(object, end, start);
1256 vn_finished_write(mp);