sys/vm/vnode_pager.c

   1 /*-
   2  * Copyright (c) 1990 University of Utah.
   3  * Copyright (c) 1991 The Regents of the University of California.
   4  * All rights reserved.
   5  * Copyright (c) 1993, 1994 John S. Dyson
   6  * Copyright (c) 1995, David Greenman
   7  *
   8  * This code is derived from software contributed to Berkeley by
   9  * the Systems Programming Group of the University of Utah Computer
  10  * Science Department.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  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.
  27  *
  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
  38  * SUCH DAMAGE.
  39  *
  40  *      from: @(#)vnode_pager.c 7.5 (Berkeley) 4/20/91
  41  */
  42
  43 /*
  44  * Page to/from files (vnodes).
  45  */
  46
  47 /*
  48  * TODO:
  49  *      Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will
  50  *      greatly re-simplify the vnode_pager.
  51  */
  52
  53 #include <sys/cdefs.h>
  54 __FBSDID("$FreeBSD$");
  55
  56 #include <sys/param.h>
  57 #include <sys/systm.h>
  58 #include <sys/proc.h>
  59 #include <sys/vnode.h>
  60 #include <sys/mount.h>
  61 #include <sys/bio.h>
  62 #include <sys/buf.h>
  63 #include <sys/vmmeter.h>
  64 #include <sys/limits.h>
  65 #include <sys/conf.h>
  66 #include <sys/rwlock.h>
  67 #include <sys/sf_buf.h>
  68
  69 #include <machine/atomic.h>
  70
  71 #include <vm/vm.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>
  79
  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_local_getpages0(struct vnode *, vm_page_t *, int, int,
  86     vop_getpages_iodone_t, void *);
  87 static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int);
  88 static int vnode_pager_getpages_async(vm_object_t, vm_page_t *, int, int,
  89     vop_getpages_iodone_t, void *);
  90 static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, int, int *);
  91 static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *);
  92 static vm_object_t vnode_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
  93     vm_ooffset_t, struct ucred *cred);
  94 static int vnode_pager_generic_getpages_done(struct buf *);
  95 static void vnode_pager_generic_getpages_done_async(struct buf *);
  96
  97 struct pagerops vnodepagerops = {
  98         .pgo_alloc =    vnode_pager_alloc,
  99         .pgo_dealloc =  vnode_pager_dealloc,
 100         .pgo_getpages = vnode_pager_getpages,
 101         .pgo_getpages_async = vnode_pager_getpages_async,
 102         .pgo_putpages = vnode_pager_putpages,
 103         .pgo_haspage =  vnode_pager_haspage,
 104 };
 105
 106 int vnode_pbuf_freecnt;
 107
 108 /* Create the VM system backing object for this vnode */
 109 int
 110 vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td)
 111 {
 112         vm_object_t object;
 113         vm_ooffset_t size = isize;
 114         struct vattr va;
 115
 116         if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE)
 117                 return (0);
 118
 119         while ((object = vp->v_object) != NULL) {
 120                 VM_OBJECT_WLOCK(object);
 121                 if (!(object->flags & OBJ_DEAD)) {
 122                         VM_OBJECT_WUNLOCK(object);
 123                         return (0);
 124                 }
 125                 VOP_UNLOCK(vp, 0);
 126                 vm_object_set_flag(object, OBJ_DISCONNECTWNT);
 127                 VM_OBJECT_SLEEP(object, object, PDROP | PVM, "vodead", 0);
 128                 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 129         }
 130
 131         if (size == 0) {
 132                 if (vn_isdisk(vp, NULL)) {
 133                         size = IDX_TO_OFF(INT_MAX);
 134                 } else {
 135                         if (VOP_GETATTR(vp, &va, td->td_ucred))
 136                                 return (0);
 137                         size = va.va_size;
 138                 }
 139         }
 140
 141         object = vnode_pager_alloc(vp, size, 0, 0, td->td_ucred);
 142         /*
 143          * Dereference the reference we just created.  This assumes
 144          * that the object is associated with the vp.
 145          */
 146         VM_OBJECT_WLOCK(object);
 147         object->ref_count--;
 148         VM_OBJECT_WUNLOCK(object);
 149         vrele(vp);
 150
 151         KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object"));
 152
 153         return (0);
 154 }
 155
 156 void
 157 vnode_destroy_vobject(struct vnode *vp)
 158 {
 159         struct vm_object *obj;
 160
 161         obj = vp->v_object;
 162         if (obj == NULL)
 163                 return;
 164         ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject");
 165         VM_OBJECT_WLOCK(obj);
 166         if (obj->ref_count == 0) {
 167                 /*
 168                  * don't double-terminate the object
 169                  */
 170                 if ((obj->flags & OBJ_DEAD) == 0)
 171                         vm_object_terminate(obj);
 172                 else
 173                         VM_OBJECT_WUNLOCK(obj);
 174         } else {
 175                 /*
 176                  * Woe to the process that tries to page now :-).
 177                  */
 178                 vm_pager_deallocate(obj);
 179                 VM_OBJECT_WUNLOCK(obj);
 180         }
 181         vp->v_object = NULL;
 182 }
 183
 184
 185 /*
 186  * Allocate (or lookup) pager for a vnode.
 187  * Handle is a vnode pointer.
 188  *
 189  * MPSAFE
 190  */
 191 vm_object_t
 192 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
 193     vm_ooffset_t offset, struct ucred *cred)
 194 {
 195         vm_object_t object;
 196         struct vnode *vp;
 197
 198         /*
 199          * Pageout to vnode, no can do yet.
 200          */
 201         if (handle == NULL)
 202                 return (NULL);
 203
 204         vp = (struct vnode *) handle;
 205
 206         /*
 207          * If the object is being terminated, wait for it to
 208          * go away.
 209          */
 210 retry:
 211         while ((object = vp->v_object) != NULL) {
 212                 VM_OBJECT_WLOCK(object);
 213                 if ((object->flags & OBJ_DEAD) == 0)
 214                         break;
 215                 vm_object_set_flag(object, OBJ_DISCONNECTWNT);
 216                 VM_OBJECT_SLEEP(object, object, PDROP | PVM, "vadead", 0);
 217         }
 218
 219         KASSERT(vp->v_usecount != 0, ("vnode_pager_alloc: no vnode reference"));
 220
 221         if (object == NULL) {
 222                 /*
 223                  * Add an object of the appropriate size
 224                  */
 225                 object = vm_object_allocate(OBJT_VNODE, OFF_TO_IDX(round_page(size)));
 226
 227                 object->un_pager.vnp.vnp_size = size;
 228                 object->un_pager.vnp.writemappings = 0;
 229
 230                 object->handle = handle;
 231                 VI_LOCK(vp);
 232                 if (vp->v_object != NULL) {
 233                         /*
 234                          * Object has been created while we were sleeping
 235                          */
 236                         VI_UNLOCK(vp);
 237                         vm_object_destroy(object);
 238                         goto retry;
 239                 }
 240                 vp->v_object = object;
 241                 VI_UNLOCK(vp);
 242         } else {
 243                 object->ref_count++;
 244                 VM_OBJECT_WUNLOCK(object);
 245         }
 246         vref(vp);
 247         return (object);
 248 }
 249
 250 /*
 251  *      The object must be locked.
 252  */
 253 static void
 254 vnode_pager_dealloc(vm_object_t object)
 255 {
 256         struct vnode *vp;
 257         int refs;
 258
 259         vp = object->handle;
 260         if (vp == NULL)
 261                 panic("vnode_pager_dealloc: pager already dealloced");
 262
 263         VM_OBJECT_ASSERT_WLOCKED(object);
 264         vm_object_pip_wait(object, "vnpdea");
 265         refs = object->ref_count;
 266
 267         object->handle = NULL;
 268         object->type = OBJT_DEAD;
 269         if (object->flags & OBJ_DISCONNECTWNT) {
 270                 vm_object_clear_flag(object, OBJ_DISCONNECTWNT);
 271                 wakeup(object);
 272         }
 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);
 279         }
 280         vp->v_object = NULL;
 281         VOP_UNSET_TEXT(vp);
 282         VM_OBJECT_WUNLOCK(object);
 283         while (refs-- > 0)
 284                 vunref(vp);
 285         VM_OBJECT_WLOCK(object);
 286 }
 287
 288 static boolean_t
 289 vnode_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
 290     int *after)
 291 {
 292         struct vnode *vp = object->handle;
 293         daddr_t bn;
 294         int err;
 295         daddr_t reqblock;
 296         int poff;
 297         int bsize;
 298         int pagesperblock, blocksperpage;
 299
 300         VM_OBJECT_ASSERT_WLOCKED(object);
 301         /*
 302          * If no vp or vp is doomed or marked transparent to VM, we do not
 303          * have the page.
 304          */
 305         if (vp == NULL || vp->v_iflag & VI_DOOMED)
 306                 return FALSE;
 307         /*
 308          * If the offset is beyond end of file we do
 309          * not have the page.
 310          */
 311         if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size)
 312                 return FALSE;
 313
 314         bsize = vp->v_mount->mnt_stat.f_iosize;
 315         pagesperblock = bsize / PAGE_SIZE;
 316         blocksperpage = 0;
 317         if (pagesperblock > 0) {
 318                 reqblock = pindex / pagesperblock;
 319         } else {
 320                 blocksperpage = (PAGE_SIZE / bsize);
 321                 reqblock = pindex * blocksperpage;
 322         }
 323         VM_OBJECT_WUNLOCK(object);
 324         err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before);
 325         VM_OBJECT_WLOCK(object);
 326         if (err)
 327                 return TRUE;
 328         if (bn == -1)
 329                 return FALSE;
 330         if (pagesperblock > 0) {
 331                 poff = pindex - (reqblock * pagesperblock);
 332                 if (before) {
 333                         *before *= pagesperblock;
 334                         *before += poff;
 335                 }
 336                 if (after) {
 337                         int numafter;
 338                         *after *= pagesperblock;
 339                         numafter = pagesperblock - (poff + 1);
 340                         if (IDX_TO_OFF(pindex + numafter) >
 341                             object->un_pager.vnp.vnp_size) {
 342                                 numafter =
 343                                     OFF_TO_IDX(object->un_pager.vnp.vnp_size) -
 344                                     pindex;
 345                         }
 346                         *after += numafter;
 347                 }
 348         } else {
 349                 if (before) {
 350                         *before /= blocksperpage;
 351                 }
 352
 353                 if (after) {
 354                         *after /= blocksperpage;
 355                 }
 356         }
 357         return TRUE;
 358 }
 359
 360 /*
 361  * Lets the VM system know about a change in size for a file.
 362  * We adjust our own internal size and flush any cached pages in
 363  * the associated object that are affected by the size change.
 364  *
 365  * Note: this routine may be invoked as a result of a pager put
 366  * operation (possibly at object termination time), so we must be careful.
 367  */
 368 void
 369 vnode_pager_setsize(struct vnode *vp, vm_ooffset_t nsize)
 370 {
 371         vm_object_t object;
 372         vm_page_t m;
 373         vm_pindex_t nobjsize;
 374
 375         if ((object = vp->v_object) == NULL)
 376                 return;
 377 /*      ASSERT_VOP_ELOCKED(vp, "vnode_pager_setsize and not locked vnode"); */
 378         VM_OBJECT_WLOCK(object);
 379         if (object->type == OBJT_DEAD) {
 380                 VM_OBJECT_WUNLOCK(object);
 381                 return;
 382         }
 383         KASSERT(object->type == OBJT_VNODE,
 384             ("not vnode-backed object %p", object));
 385         if (nsize == object->un_pager.vnp.vnp_size) {
 386                 /*
 387                  * Hasn't changed size
 388                  */
 389                 VM_OBJECT_WUNLOCK(object);
 390                 return;
 391         }
 392         nobjsize = OFF_TO_IDX(nsize + PAGE_MASK);
 393         if (nsize < object->un_pager.vnp.vnp_size) {
 394                 /*
 395                  * File has shrunk. Toss any cached pages beyond the new EOF.
 396                  */
 397                 if (nobjsize < object->size)
 398                         vm_object_page_remove(object, nobjsize, object->size,
 399                             0);
 400                 /*
 401                  * this gets rid of garbage at the end of a page that is now
 402                  * only partially backed by the vnode.
 403                  *
 404                  * XXX for some reason (I don't know yet), if we take a
 405                  * completely invalid page and mark it partially valid
 406                  * it can screw up NFS reads, so we don't allow the case.
 407                  */
 408                 if ((nsize & PAGE_MASK) &&
 409                     (m = vm_page_lookup(object, OFF_TO_IDX(nsize))) != NULL &&
 410                     m->valid != 0) {
 411                         int base = (int)nsize & PAGE_MASK;
 412                         int size = PAGE_SIZE - base;
 413
 414                         /*
 415                          * Clear out partial-page garbage in case
 416                          * the page has been mapped.
 417                          */
 418                         pmap_zero_page_area(m, base, size);
 419
 420                         /*
 421                          * Update the valid bits to reflect the blocks that
 422                          * have been zeroed.  Some of these valid bits may
 423                          * have already been set.
 424                          */
 425                         vm_page_set_valid_range(m, base, size);
 426
 427                         /*
 428                          * Round "base" to the next block boundary so that the
 429                          * dirty bit for a partially zeroed block is not
 430                          * cleared.
 431                          */
 432                         base = roundup2(base, DEV_BSIZE);
 433
 434                         /*
 435                          * Clear out partial-page dirty bits.
 436                          *
 437                          * note that we do not clear out the valid
 438                          * bits.  This would prevent bogus_page
 439                          * replacement from working properly.
 440                          */
 441                         vm_page_clear_dirty(m, base, PAGE_SIZE - base);
 442                 } else if ((nsize & PAGE_MASK) &&
 443                     vm_page_is_cached(object, OFF_TO_IDX(nsize))) {
 444                         vm_page_cache_free(object, OFF_TO_IDX(nsize),
 445                             nobjsize);
 446                 }
 447         }
 448         object->un_pager.vnp.vnp_size = nsize;
 449         object->size = nobjsize;
 450         VM_OBJECT_WUNLOCK(object);
 451 }
 452
 453 /*
 454  * calculate the linear (byte) disk address of specified virtual
 455  * file address
 456  */
 457 static int
 458 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress,
 459     int *run)
 460 {
 461         int bsize;
 462         int err;
 463         daddr_t vblock;
 464         daddr_t voffset;
 465
 466         if (address < 0)
 467                 return -1;
 468
 469         if (vp->v_iflag & VI_DOOMED)
 470                 return -1;
 471
 472         bsize = vp->v_mount->mnt_stat.f_iosize;
 473         vblock = address / bsize;
 474         voffset = address % bsize;
 475
 476         err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL);
 477         if (err == 0) {
 478                 if (*rtaddress != -1)
 479                         *rtaddress += voffset / DEV_BSIZE;
 480                 if (run) {
 481                         *run += 1;
 482                         *run *= bsize/PAGE_SIZE;
 483                         *run -= voffset/PAGE_SIZE;
 484                 }
 485         }
 486
 487         return (err);
 488 }
 489
 490 /*
 491  * small block filesystem vnode pager input
 492  */
 493 static int
 494 vnode_pager_input_smlfs(vm_object_t object, vm_page_t m)
 495 {
 496         struct vnode *vp;
 497         struct bufobj *bo;
 498         struct buf *bp;
 499         struct sf_buf *sf;
 500         daddr_t fileaddr;
 501         vm_offset_t bsize;
 502         vm_page_bits_t bits;
 503         int error, i;
 504
 505         error = 0;
 506         vp = object->handle;
 507         if (vp->v_iflag & VI_DOOMED)
 508                 return VM_PAGER_BAD;
 509
 510         bsize = vp->v_mount->mnt_stat.f_iosize;
 511
 512         VOP_BMAP(vp, 0, &bo, 0, NULL, NULL);
 513
 514         sf = sf_buf_alloc(m, 0);
 515
 516         for (i = 0; i < PAGE_SIZE / bsize; i++) {
 517                 vm_ooffset_t address;
 518
 519                 bits = vm_page_bits(i * bsize, bsize);
 520                 if (m->valid & bits)
 521                         continue;
 522
 523                 address = IDX_TO_OFF(m->pindex) + i * bsize;
 524                 if (address >= object->un_pager.vnp.vnp_size) {
 525                         fileaddr = -1;
 526                 } else {
 527                         error = vnode_pager_addr(vp, address, &fileaddr, NULL);
 528                         if (error)
 529                                 break;
 530                 }
 531                 if (fileaddr != -1) {
 532                         bp = getpbuf(&vnode_pbuf_freecnt);
 533
 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;
 543                         pbgetbo(bo, bp);
 544                         bp->b_vp = vp;
 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);
 549
 550                         /* do the input */
 551                         bp->b_iooffset = dbtob(bp->b_blkno);
 552                         bstrategy(bp);
 553
 554                         bwait(bp, PVM, "vnsrd");
 555
 556                         if ((bp->b_ioflags & BIO_ERROR) != 0)
 557                                 error = EIO;
 558
 559                         /*
 560                          * free the buffer header back to the swap buffer pool
 561                          */
 562                         bp->b_vp = NULL;
 563                         pbrelbo(bp);
 564                         relpbuf(bp, &vnode_pbuf_freecnt);
 565                         if (error)
 566                                 break;
 567                 } else
 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_WLOCK(object);
 572                 m->valid |= bits;
 573                 VM_OBJECT_WUNLOCK(object);
 574         }
 575         sf_buf_free(sf);
 576         if (error) {
 577                 return VM_PAGER_ERROR;
 578         }
 579         return VM_PAGER_OK;
 580 }
 581
 582 /*
 583  * old style vnode pager input routine
 584  */
 585 static int
 586 vnode_pager_input_old(vm_object_t object, vm_page_t m)
 587 {
 588         struct uio auio;
 589         struct iovec aiov;
 590         int error;
 591         int size;
 592         struct sf_buf *sf;
 593         struct vnode *vp;
 594
 595         VM_OBJECT_ASSERT_WLOCKED(object);
 596         error = 0;
 597
 598         /*
 599          * Return failure if beyond current EOF
 600          */
 601         if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) {
 602                 return VM_PAGER_BAD;
 603         } else {
 604                 size = PAGE_SIZE;
 605                 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size)
 606                         size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex);
 607                 vp = object->handle;
 608                 VM_OBJECT_WUNLOCK(object);
 609
 610                 /*
 611                  * Allocate a kernel virtual address and initialize so that
 612                  * we can use VOP_READ/WRITE routines.
 613                  */
 614                 sf = sf_buf_alloc(m, 0);
 615
 616                 aiov.iov_base = (caddr_t)sf_buf_kva(sf);
 617                 aiov.iov_len = size;
 618                 auio.uio_iov = &aiov;
 619                 auio.uio_iovcnt = 1;
 620                 auio.uio_offset = IDX_TO_OFF(m->pindex);
 621                 auio.uio_segflg = UIO_SYSSPACE;
 622                 auio.uio_rw = UIO_READ;
 623                 auio.uio_resid = size;
 624                 auio.uio_td = curthread;
 625
 626                 error = VOP_READ(vp, &auio, 0, curthread->td_ucred);
 627                 if (!error) {
 628                         int count = size - auio.uio_resid;
 629
 630                         if (count == 0)
 631                                 error = EINVAL;
 632                         else if (count != PAGE_SIZE)
 633                                 bzero((caddr_t)sf_buf_kva(sf) + count,
 634                                     PAGE_SIZE - count);
 635                 }
 636                 sf_buf_free(sf);
 637
 638                 VM_OBJECT_WLOCK(object);
 639         }
 640         KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m));
 641         if (!error)
 642                 m->valid = VM_PAGE_BITS_ALL;
 643         return error ? VM_PAGER_ERROR : VM_PAGER_OK;
 644 }
 645
 646 /*
 647  * generic vnode pager input routine
 648  */
 649
 650 /*
 651  * Local media VFS's that do not implement their own VOP_GETPAGES
 652  * should have their VOP_GETPAGES call to vnode_pager_generic_getpages()
 653  * to implement the previous behaviour.
 654  *
 655  * All other FS's should use the bypass to get to the local media
 656  * backing vp's VOP_GETPAGES.
 657  */
 658 static int
 659 vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
 660 {
 661         int rtval;
 662         struct vnode *vp;
 663         int bytes = count * PAGE_SIZE;
 664
 665         vp = object->handle;
 666         VM_OBJECT_WUNLOCK(object);
 667         rtval = VOP_GETPAGES(vp, m, bytes, reqpage);
 668         KASSERT(rtval != EOPNOTSUPP,
 669             ("vnode_pager: FS getpages not implemented\n"));
 670         VM_OBJECT_WLOCK(object);
 671         return rtval;
 672 }
 673
 674 static int
 675 vnode_pager_getpages_async(vm_object_t object, vm_page_t *m, int count,
 676     int reqpage, vop_getpages_iodone_t iodone, void *arg)
 677 {
 678         struct vnode *vp;
 679         int rtval;
 680
 681         vp = object->handle;
 682         VM_OBJECT_WUNLOCK(object);
 683         rtval = VOP_GETPAGES_ASYNC(vp, m, count * PAGE_SIZE, reqpage, 0,
 684             iodone, arg);
 685         KASSERT(rtval != EOPNOTSUPP,
 686             ("vnode_pager: FS getpages_async not implemented\n"));
 687         VM_OBJECT_WLOCK(object);
 688         return (rtval);
 689 }
 690
 691 /*
 692  * The implementation of VOP_GETPAGES() and VOP_GETPAGES_ASYNC() for
 693  * local filesystems, where partially valid pages can only occur at
 694  * the end of file.
 695  */
 696 int
 697 vnode_pager_local_getpages(struct vop_getpages_args *ap)
 698 {
 699
 700         return (vnode_pager_local_getpages0(ap->a_vp, ap->a_m, ap->a_count,
 701             ap->a_reqpage, NULL, NULL));
 702 }
 703
 704 int
 705 vnode_pager_local_getpages_async(struct vop_getpages_async_args *ap)
 706 {
 707
 708         return (vnode_pager_local_getpages0(ap->a_vp, ap->a_m, ap->a_count,
 709             ap->a_reqpage, ap->a_iodone, ap->a_arg));
 710 }
 711
 712 static int
 713 vnode_pager_local_getpages0(struct vnode *vp, vm_page_t *m, int bytecount,
 714     int reqpage, vop_getpages_iodone_t iodone, void *arg)
 715 {
 716         vm_page_t mreq;
 717
 718         mreq = m[reqpage];
 719
 720         /*
 721          * Since the caller has busied the requested page, that page's valid
 722          * field will not be changed by other threads.
 723          */
 724         vm_page_assert_xbusied(mreq);
 725
 726         /*
 727          * The requested page has valid blocks.  Invalid part can only
 728          * exist at the end of file, and the page is made fully valid
 729          * by zeroing in vm_pager_getpages().  Free non-requested
 730          * pages, since no i/o is done to read its content.
 731          */
 732         if (mreq->valid != 0) {
 733                 vm_pager_free_nonreq(mreq->object, m, reqpage,
 734                     round_page(bytecount) / PAGE_SIZE);
 735                 if (iodone != NULL)
 736                         iodone(arg, m, reqpage, 0);
 737                 return (VM_PAGER_OK);
 738         }
 739
 740         return (vnode_pager_generic_getpages(vp, m, bytecount, reqpage,
 741             iodone, arg));
 742 }
 743
 744 /*
 745  * This is now called from local media FS's to operate against their
 746  * own vnodes if they fail to implement VOP_GETPAGES.
 747  */
 748 int
 749 vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int bytecount,
 750     int reqpage, vop_getpages_iodone_t iodone, void *arg)
 751 {
 752         vm_object_t object;
 753         off_t foff;
 754         int i, j, size, bsize, first;
 755         daddr_t firstaddr, reqblock;
 756         struct bufobj *bo;
 757         int runpg;
 758         int runend;
 759         struct buf *bp;
 760         int count;
 761         int error;
 762
 763         object = vp->v_object;
 764         count = bytecount / PAGE_SIZE;
 765
 766         KASSERT(vp->v_type != VCHR && vp->v_type != VBLK,
 767             ("vnode_pager_generic_getpages does not support devices"));
 768         if (vp->v_iflag & VI_DOOMED)
 769                 return VM_PAGER_BAD;
 770
 771         bsize = vp->v_mount->mnt_stat.f_iosize;
 772         foff = IDX_TO_OFF(m[reqpage]->pindex);
 773
 774         /*
 775          * Get the underlying device blocks for the file with VOP_BMAP().
 776          * If the file system doesn't support VOP_BMAP, use old way of
 777          * getting pages via VOP_READ.
 778          */
 779         error = VOP_BMAP(vp, foff / bsize, &bo, &reqblock, NULL, NULL);
 780         if (error == EOPNOTSUPP) {
 781                 VM_OBJECT_WLOCK(object);
 782
 783                 for (i = 0; i < count; i++)
 784                         if (i != reqpage) {
 785                                 vm_page_lock(m[i]);
 786                                 vm_page_free(m[i]);
 787                                 vm_page_unlock(m[i]);
 788                         }
 789                 PCPU_INC(cnt.v_vnodein);
 790                 PCPU_INC(cnt.v_vnodepgsin);
 791                 error = vnode_pager_input_old(object, m[reqpage]);
 792                 VM_OBJECT_WUNLOCK(object);
 793                 return (error);
 794         } else if (error != 0) {
 795                 vm_pager_free_nonreq(object, m, reqpage, count);
 796                 return (VM_PAGER_ERROR);
 797
 798                 /*
 799                  * if the blocksize is smaller than a page size, then use
 800                  * special small filesystem code.  NFS sometimes has a small
 801                  * blocksize, but it can handle large reads itself.
 802                  */
 803         } else if ((PAGE_SIZE / bsize) > 1 &&
 804             (vp->v_mount->mnt_stat.f_type != nfs_mount_type)) {
 805                 vm_pager_free_nonreq(object, m, reqpage, count);
 806                 PCPU_INC(cnt.v_vnodein);
 807                 PCPU_INC(cnt.v_vnodepgsin);
 808                 return vnode_pager_input_smlfs(object, m[reqpage]);
 809         }
 810
 811         /*
 812          * Since the caller has busied the requested page, that page's valid
 813          * field will not be changed by other threads.
 814          */
 815         vm_page_assert_xbusied(m[reqpage]);
 816
 817         /*
 818          * If we have a completely valid page available to us, we can
 819          * clean up and return.  Otherwise we have to re-read the
 820          * media.
 821          */
 822         if (m[reqpage]->valid == VM_PAGE_BITS_ALL) {
 823                 vm_pager_free_nonreq(object, m, reqpage, count);
 824                 return (VM_PAGER_OK);
 825         } else if (reqblock == -1) {
 826                 pmap_zero_page(m[reqpage]);
 827                 KASSERT(m[reqpage]->dirty == 0,
 828                     ("vnode_pager_generic_getpages: page %p is dirty", m));
 829                 VM_OBJECT_WLOCK(object);
 830                 m[reqpage]->valid = VM_PAGE_BITS_ALL;
 831                 for (i = 0; i < count; i++)
 832                         if (i != reqpage) {
 833                                 vm_page_lock(m[i]);
 834                                 vm_page_free(m[i]);
 835                                 vm_page_unlock(m[i]);
 836                         }
 837                 VM_OBJECT_WUNLOCK(object);
 838                 return (VM_PAGER_OK);
 839         } else if (m[reqpage]->valid != 0) {
 840                 VM_OBJECT_WLOCK(object);
 841                 m[reqpage]->valid = 0;
 842                 VM_OBJECT_WUNLOCK(object);
 843         }
 844
 845         /*
 846          * here on direct device I/O
 847          */
 848         firstaddr = -1;
 849
 850         /*
 851          * calculate the run that includes the required page
 852          */
 853         for (first = 0, i = 0; i < count; i = runend) {
 854                 if (vnode_pager_addr(vp, IDX_TO_OFF(m[i]->pindex), &firstaddr,
 855                     &runpg) != 0) {
 856                         VM_OBJECT_WLOCK(object);
 857                         for (; i < count; i++)
 858                                 if (i != reqpage) {
 859                                         vm_page_lock(m[i]);
 860                                         vm_page_free(m[i]);
 861                                         vm_page_unlock(m[i]);
 862                                 }
 863                         VM_OBJECT_WUNLOCK(object);
 864                         return (VM_PAGER_ERROR);
 865                 }
 866                 if (firstaddr == -1) {
 867                         VM_OBJECT_WLOCK(object);
 868                         if (i == reqpage && foff < object->un_pager.vnp.vnp_size) {
 869                                 panic("vnode_pager_getpages: unexpected missing page: firstaddr: %jd, foff: 0x%jx%08jx, vnp_size: 0x%jx%08jx",
 870                                     (intmax_t)firstaddr, (uintmax_t)(foff >> 32),
 871                                     (uintmax_t)foff,
 872                                     (uintmax_t)
 873                                     (object->un_pager.vnp.vnp_size >> 32),
 874                                     (uintmax_t)object->un_pager.vnp.vnp_size);
 875                         }
 876                         vm_page_lock(m[i]);
 877                         vm_page_free(m[i]);
 878                         vm_page_unlock(m[i]);
 879                         VM_OBJECT_WUNLOCK(object);
 880                         runend = i + 1;
 881                         first = runend;
 882                         continue;
 883                 }
 884                 runend = i + runpg;
 885                 if (runend <= reqpage) {
 886                         VM_OBJECT_WLOCK(object);
 887                         for (j = i; j < runend; j++) {
 888                                 vm_page_lock(m[j]);
 889                                 vm_page_free(m[j]);
 890                                 vm_page_unlock(m[j]);
 891                         }
 892                         VM_OBJECT_WUNLOCK(object);
 893                 } else {
 894                         if (runpg < (count - first)) {
 895                                 VM_OBJECT_WLOCK(object);
 896                                 for (i = first + runpg; i < count; i++) {
 897                                         vm_page_lock(m[i]);
 898                                         vm_page_free(m[i]);
 899                                         vm_page_unlock(m[i]);
 900                                 }
 901                                 VM_OBJECT_WUNLOCK(object);
 902                                 count = first + runpg;
 903                         }
 904                         break;
 905                 }
 906                 first = runend;
 907         }
 908
 909         /*
 910          * the first and last page have been calculated now, move input pages
 911          * to be zero based...
 912          */
 913         if (first != 0) {
 914                 m += first;
 915                 count -= first;
 916                 reqpage -= first;
 917         }
 918
 919         /*
 920          * calculate the file virtual address for the transfer
 921          */
 922         foff = IDX_TO_OFF(m[0]->pindex);
 923
 924         /*
 925          * calculate the size of the transfer
 926          */
 927         size = count * PAGE_SIZE;
 928         KASSERT(count > 0, ("zero count"));
 929         if ((foff + size) > object->un_pager.vnp.vnp_size)
 930                 size = object->un_pager.vnp.vnp_size - foff;
 931         KASSERT(size > 0, ("zero size"));
 932
 933         /*
 934          * round up physical size for real devices.
 935          */
 936         if (1) {
 937                 int secmask = bo->bo_bsize - 1;
 938                 KASSERT(secmask < PAGE_SIZE && secmask > 0,
 939                     ("vnode_pager_generic_getpages: sector size %d too large",
 940                     secmask + 1));
 941                 size = (size + secmask) & ~secmask;
 942         }
 943
 944         bp = getpbuf(&vnode_pbuf_freecnt);
 945         bp->b_kvaalloc = bp->b_data;
 946
 947         /*
 948          * and map the pages to be read into the kva, if the filesystem
 949          * requires mapped buffers.
 950          */
 951         if ((vp->v_mount->mnt_kern_flag & MNTK_UNMAPPED_BUFS) != 0 &&
 952             unmapped_buf_allowed) {
 953                 bp->b_data = unmapped_buf;
 954                 bp->b_kvabase = unmapped_buf;
 955                 bp->b_offset = 0;
 956                 bp->b_flags |= B_UNMAPPED;
 957         } else
 958                 pmap_qenter((vm_offset_t)bp->b_kvaalloc, m, count);
 959
 960         /* build a minimal buffer header */
 961         bp->b_iocmd = BIO_READ;
 962         KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred"));
 963         KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred"));
 964         bp->b_rcred = crhold(curthread->td_ucred);
 965         bp->b_wcred = crhold(curthread->td_ucred);
 966         bp->b_blkno = firstaddr;
 967         pbgetbo(bo, bp);
 968         bp->b_vp = vp;
 969         bp->b_bcount = size;
 970         bp->b_bufsize = size;
 971         bp->b_runningbufspace = bp->b_bufsize;
 972         for (i = 0; i < count; i++)
 973                 bp->b_pages[i] = m[i];
 974         bp->b_npages = count;
 975         bp->b_pager.pg_reqpage = reqpage;
 976         atomic_add_long(&runningbufspace, bp->b_runningbufspace);
 977
 978         PCPU_INC(cnt.v_vnodein);
 979         PCPU_ADD(cnt.v_vnodepgsin, count);
 980
 981         /* do the input */
 982         bp->b_iooffset = dbtob(bp->b_blkno);
 983
 984         if (iodone != NULL) { /* async */
 985                 bp->b_pager.pg_iodone = iodone;
 986                 bp->b_caller1 = arg;
 987                 bp->b_iodone = vnode_pager_generic_getpages_done_async;
 988                 bp->b_flags |= B_ASYNC;
 989                 BUF_KERNPROC(bp);
 990                 bstrategy(bp);
 991                 /* Good bye! */
 992         } else {
 993                 bp->b_iodone = bdone;
 994                 bstrategy(bp);
 995                 bwait(bp, PVM, "vnread");
 996                 error = vnode_pager_generic_getpages_done(bp);
 997                 for (i = 0; i < bp->b_npages; i++)
 998                         bp->b_pages[i] = NULL;
 999                 bp->b_vp = NULL;
1000                 pbrelbo(bp);
1001                 relpbuf(bp, &vnode_pbuf_freecnt);
1002         }
1003
1004         return (error != 0 ? VM_PAGER_ERROR : VM_PAGER_OK);
1005 }
1006
1007 static void
1008 vnode_pager_generic_getpages_done_async(struct buf *bp)
1009 {
1010         int error;
1011
1012         error = vnode_pager_generic_getpages_done(bp);
1013         bp->b_pager.pg_iodone(bp->b_caller1, bp->b_pages,
1014           bp->b_pager.pg_reqpage, error);
1015         for (int i = 0; i < bp->b_npages; i++)
1016                 bp->b_pages[i] = NULL;
1017         bp->b_vp = NULL;
1018         pbrelbo(bp);
1019         relpbuf(bp, &vnode_pbuf_freecnt);
1020 }
1021
1022 static int
1023 vnode_pager_generic_getpages_done(struct buf *bp)
1024 {
1025         vm_object_t object;
1026         off_t tfoff, nextoff;
1027         int i, error;
1028
1029         error = (bp->b_ioflags & BIO_ERROR) != 0 ? EIO : 0;
1030         object = bp->b_vp->v_object;
1031
1032         if (error == 0 && bp->b_bcount != bp->b_npages * PAGE_SIZE) {
1033                 if ((bp->b_flags & B_UNMAPPED) != 0) {
1034                         bp->b_flags &= ~B_UNMAPPED;
1035                         pmap_qenter((vm_offset_t)bp->b_kvaalloc, bp->b_pages,
1036                             bp->b_npages);
1037                 }
1038                 bzero(bp->b_kvaalloc + bp->b_bcount,
1039                     PAGE_SIZE * bp->b_npages - bp->b_bcount);
1040         }
1041         if ((bp->b_flags & B_UNMAPPED) == 0)
1042                 pmap_qremove((vm_offset_t)bp->b_kvaalloc, bp->b_npages);
1043         if ((bp->b_vp->v_mount->mnt_kern_flag & MNTK_UNMAPPED_BUFS) != 0) {
1044                 bp->b_data = bp->b_kvaalloc;
1045                 bp->b_kvabase = bp->b_kvaalloc;
1046                 bp->b_flags &= ~B_UNMAPPED;
1047         }
1048
1049         VM_OBJECT_WLOCK(object);
1050         for (i = 0, tfoff = IDX_TO_OFF(bp->b_pages[0]->pindex);
1051             i < bp->b_npages; i++, tfoff = nextoff) {
1052                 vm_page_t mt;
1053
1054                 nextoff = tfoff + PAGE_SIZE;
1055                 mt = bp->b_pages[i];
1056
1057                 if (nextoff <= object->un_pager.vnp.vnp_size) {
1058                         /*
1059                          * Read filled up entire page.
1060                          */
1061                         mt->valid = VM_PAGE_BITS_ALL;
1062                         KASSERT(mt->dirty == 0,
1063                             ("%s: page %p is dirty", __func__, mt));
1064                         KASSERT(!pmap_page_is_mapped(mt),
1065                             ("%s: page %p is mapped", __func__, mt));
1066                 } else {
1067                         /*
1068                          * Read did not fill up entire page.
1069                          *
1070                          * Currently we do not set the entire page valid,
1071                          * we just try to clear the piece that we couldn't
1072                          * read.
1073                          */
1074                         vm_page_set_valid_range(mt, 0,
1075                             object->un_pager.vnp.vnp_size - tfoff);
1076                         KASSERT((mt->dirty & vm_page_bits(0,
1077                             object->un_pager.vnp.vnp_size - tfoff)) == 0,
1078                             ("%s: page %p is dirty", __func__, mt));
1079                 }
1080
1081                 if (i != bp->b_pager.pg_reqpage)
1082                         vm_page_readahead_finish(mt);
1083         }
1084         VM_OBJECT_WUNLOCK(object);
1085         if (error != 0)
1086                 printf("%s: I/O read error %d\n", __func__, error);
1087
1088         return (error);
1089 }
1090
1091 /*
1092  * EOPNOTSUPP is no longer legal.  For local media VFS's that do not
1093  * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to
1094  * vnode_pager_generic_putpages() to implement the previous behaviour.
1095  *
1096  * All other FS's should use the bypass to get to the local media
1097  * backing vp's VOP_PUTPAGES.
1098  */
1099 static void
1100 vnode_pager_putpages(vm_object_t object, vm_page_t *m, int count,
1101     int flags, int *rtvals)
1102 {
1103         int rtval;
1104         struct vnode *vp;
1105         int bytes = count * PAGE_SIZE;
1106
1107         /*
1108          * Force synchronous operation if we are extremely low on memory
1109          * to prevent a low-memory deadlock.  VOP operations often need to
1110          * allocate more memory to initiate the I/O ( i.e. do a BMAP
1111          * operation ).  The swapper handles the case by limiting the amount
1112          * of asynchronous I/O, but that sort of solution doesn't scale well
1113          * for the vnode pager without a lot of work.
1114          *
1115          * Also, the backing vnode's iodone routine may not wake the pageout
1116          * daemon up.  This should be probably be addressed XXX.
1117          */
1118
1119         if (vm_cnt.v_free_count + vm_cnt.v_cache_count <
1120             vm_cnt.v_pageout_free_min)
1121                 flags |= VM_PAGER_PUT_SYNC;
1122
1123         /*
1124          * Call device-specific putpages function
1125          */
1126         vp = object->handle;
1127         VM_OBJECT_WUNLOCK(object);
1128         rtval = VOP_PUTPAGES(vp, m, bytes, flags, rtvals);
1129         KASSERT(rtval != EOPNOTSUPP,
1130             ("vnode_pager: stale FS putpages\n"));
1131         VM_OBJECT_WLOCK(object);
1132 }
1133
1134
1135 /*
1136  * This is now called from local media FS's to operate against their
1137  * own vnodes if they fail to implement VOP_PUTPAGES.
1138  *
1139  * This is typically called indirectly via the pageout daemon and
1140  * clustering has already typically occured, so in general we ask the
1141  * underlying filesystem to write the data out asynchronously rather
1142  * then delayed.
1143  */
1144 int
1145 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *ma, int bytecount,
1146     int flags, int *rtvals)
1147 {
1148         int i;
1149         vm_object_t object;
1150         vm_page_t m;
1151         int count;
1152
1153         int maxsize, ncount;
1154         vm_ooffset_t poffset;
1155         struct uio auio;
1156         struct iovec aiov;
1157         int error;
1158         int ioflags;
1159         int ppscheck = 0;
1160         static struct timeval lastfail;
1161         static int curfail;
1162
1163         object = vp->v_object;
1164         count = bytecount / PAGE_SIZE;
1165
1166         for (i = 0; i < count; i++)
1167                 rtvals[i] = VM_PAGER_ERROR;
1168
1169         if ((int64_t)ma[0]->pindex < 0) {
1170                 printf("vnode_pager_putpages: attempt to write meta-data!!! -- 0x%lx(%lx)\n",
1171                     (long)ma[0]->pindex, (u_long)ma[0]->dirty);
1172                 rtvals[0] = VM_PAGER_BAD;
1173                 return VM_PAGER_BAD;
1174         }
1175
1176         maxsize = count * PAGE_SIZE;
1177         ncount = count;
1178
1179         poffset = IDX_TO_OFF(ma[0]->pindex);
1180
1181         /*
1182          * If the page-aligned write is larger then the actual file we
1183          * have to invalidate pages occuring beyond the file EOF.  However,
1184          * there is an edge case where a file may not be page-aligned where
1185          * the last page is partially invalid.  In this case the filesystem
1186          * may not properly clear the dirty bits for the entire page (which
1187          * could be VM_PAGE_BITS_ALL due to the page having been mmap()d).
1188          * With the page locked we are free to fix-up the dirty bits here.
1189          *
1190          * We do not under any circumstances truncate the valid bits, as
1191          * this will screw up bogus page replacement.
1192          */
1193         VM_OBJECT_WLOCK(object);
1194         if (maxsize + poffset > object->un_pager.vnp.vnp_size) {
1195                 if (object->un_pager.vnp.vnp_size > poffset) {
1196                         int pgoff;
1197
1198                         maxsize = object->un_pager.vnp.vnp_size - poffset;
1199                         ncount = btoc(maxsize);
1200                         if ((pgoff = (int)maxsize & PAGE_MASK) != 0) {
1201                                 /*
1202                                  * If the object is locked and the following
1203                                  * conditions hold, then the page's dirty
1204                                  * field cannot be concurrently changed by a
1205                                  * pmap operation.
1206                                  */
1207                                 m = ma[ncount - 1];
1208                                 vm_page_assert_sbusied(m);
1209                                 KASSERT(!pmap_page_is_write_mapped(m),
1210                 ("vnode_pager_generic_putpages: page %p is not read-only", m));
1211                                 vm_page_clear_dirty(m, pgoff, PAGE_SIZE -
1212                                     pgoff);
1213                         }
1214                 } else {
1215                         maxsize = 0;
1216                         ncount = 0;
1217                 }
1218                 if (ncount < count) {
1219                         for (i = ncount; i < count; i++) {
1220                                 rtvals[i] = VM_PAGER_BAD;
1221                         }
1222                 }
1223         }
1224         VM_OBJECT_WUNLOCK(object);
1225
1226         /*
1227          * pageouts are already clustered, use IO_ASYNC to force a bawrite()
1228          * rather then a bdwrite() to prevent paging I/O from saturating
1229          * the buffer cache.  Dummy-up the sequential heuristic to cause
1230          * large ranges to cluster.  If neither IO_SYNC or IO_ASYNC is set,
1231          * the system decides how to cluster.
1232          */
1233         ioflags = IO_VMIO;
1234         if (flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL))
1235                 ioflags |= IO_SYNC;
1236         else if ((flags & VM_PAGER_CLUSTER_OK) == 0)
1237                 ioflags |= IO_ASYNC;
1238         ioflags |= (flags & VM_PAGER_PUT_INVAL) ? IO_INVAL: 0;
1239         ioflags |= IO_SEQMAX << IO_SEQSHIFT;
1240
1241         aiov.iov_base = (caddr_t) 0;
1242         aiov.iov_len = maxsize;
1243         auio.uio_iov = &aiov;
1244         auio.uio_iovcnt = 1;
1245         auio.uio_offset = poffset;
1246         auio.uio_segflg = UIO_NOCOPY;
1247         auio.uio_rw = UIO_WRITE;
1248         auio.uio_resid = maxsize;
1249         auio.uio_td = (struct thread *) 0;
1250         error = VOP_WRITE(vp, &auio, ioflags, curthread->td_ucred);
1251         PCPU_INC(cnt.v_vnodeout);
1252         PCPU_ADD(cnt.v_vnodepgsout, ncount);
1253
1254         if (error) {
1255                 if ((ppscheck = ppsratecheck(&lastfail, &curfail, 1)))
1256                         printf("vnode_pager_putpages: I/O error %d\n", error);
1257         }
1258         if (auio.uio_resid) {
1259                 if (ppscheck || ppsratecheck(&lastfail, &curfail, 1))
1260                         printf("vnode_pager_putpages: residual I/O %zd at %lu\n",
1261                             auio.uio_resid, (u_long)ma[0]->pindex);
1262         }
1263         for (i = 0; i < ncount; i++) {
1264                 rtvals[i] = VM_PAGER_OK;
1265         }
1266         return rtvals[0];
1267 }
1268
1269 void
1270 vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written)
1271 {
1272         vm_object_t obj;
1273         int i, pos;
1274
1275         if (written == 0)
1276                 return;
1277         obj = ma[0]->object;
1278         VM_OBJECT_WLOCK(obj);
1279         for (i = 0, pos = 0; pos < written; i++, pos += PAGE_SIZE) {
1280                 if (pos < trunc_page(written)) {
1281                         rtvals[i] = VM_PAGER_OK;
1282                         vm_page_undirty(ma[i]);
1283                 } else {
1284                         /* Partially written page. */
1285                         rtvals[i] = VM_PAGER_AGAIN;
1286                         vm_page_clear_dirty(ma[i], 0, written & PAGE_MASK);
1287                 }
1288         }
1289         VM_OBJECT_WUNLOCK(obj);
1290 }
1291
1292 void
1293 vnode_pager_update_writecount(vm_object_t object, vm_offset_t start,
1294     vm_offset_t end)
1295 {
1296         struct vnode *vp;
1297         vm_ooffset_t old_wm;
1298
1299         VM_OBJECT_WLOCK(object);
1300         if (object->type != OBJT_VNODE) {
1301                 VM_OBJECT_WUNLOCK(object);
1302                 return;
1303         }
1304         old_wm = object->un_pager.vnp.writemappings;
1305         object->un_pager.vnp.writemappings += (vm_ooffset_t)end - start;
1306         vp = object->handle;
1307         if (old_wm == 0 && object->un_pager.vnp.writemappings != 0) {
1308                 ASSERT_VOP_ELOCKED(vp, "v_writecount inc");
1309                 VOP_ADD_WRITECOUNT(vp, 1);
1310                 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
1311                     __func__, vp, vp->v_writecount);
1312         } else if (old_wm != 0 && object->un_pager.vnp.writemappings == 0) {
1313                 ASSERT_VOP_ELOCKED(vp, "v_writecount dec");
1314                 VOP_ADD_WRITECOUNT(vp, -1);
1315                 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
1316                     __func__, vp, vp->v_writecount);
1317         }
1318         VM_OBJECT_WUNLOCK(object);
1319 }
1320
1321 void
1322 vnode_pager_release_writecount(vm_object_t object, vm_offset_t start,
1323     vm_offset_t end)
1324 {
1325         struct vnode *vp;
1326         struct mount *mp;
1327         vm_offset_t inc;
1328
1329         VM_OBJECT_WLOCK(object);
1330
1331         /*
1332          * First, recheck the object type to account for the race when
1333          * the vnode is reclaimed.
1334          */
1335         if (object->type != OBJT_VNODE) {
1336                 VM_OBJECT_WUNLOCK(object);
1337                 return;
1338         }
1339
1340         /*
1341          * Optimize for the case when writemappings is not going to
1342          * zero.
1343          */
1344         inc = end - start;
1345         if (object->un_pager.vnp.writemappings != inc) {
1346                 object->un_pager.vnp.writemappings -= inc;
1347                 VM_OBJECT_WUNLOCK(object);
1348                 return;
1349         }
1350
1351         vp = object->handle;
1352         vhold(vp);
1353         VM_OBJECT_WUNLOCK(object);
1354         mp = NULL;
1355         vn_start_write(vp, &mp, V_WAIT);
1356         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1357
1358         /*
1359          * Decrement the object's writemappings, by swapping the start
1360          * and end arguments for vnode_pager_update_writecount().  If
1361          * there was not a race with vnode reclaimation, then the
1362          * vnode's v_writecount is decremented.
1363          */
1364         vnode_pager_update_writecount(object, end, start);
1365         VOP_UNLOCK(vp, 0);
1366         vdrop(vp);
1367         if (mp != NULL)
1368                 vn_finished_write(mp);
1369 }