1 /*- 2 * Copyright (c) 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)ufs_readwrite.c 8.11 (Berkeley) 5/8/95 34 * $FreeBSD: src/sys/ufs/ufs/ufs_readwrite.c,v 1.65.2.14 2003/04/04 22:21:29 tegge Exp $ 35 * $DragonFly: src/sys/vfs/ufs/ufs_readwrite.c,v 1.9 2003/07/26 22:04:27 rob Exp $ 36 */ 37 38 #define BLKSIZE(a, b, c) blksize(a, b, c) 39 #define FS struct fs 40 #define I_FS i_fs 41 42 #include <vm/vm.h> 43 #include <vm/vm_object.h> 44 #include <vm/vm_pager.h> 45 #include <vm/vm_map.h> 46 #include <vm/vnode_pager.h> 47 #include <sys/event.h> 48 #include <sys/vmmeter.h> 49 #include <vm/vm_page2.h> 50 51 #include "opt_directio.h" 52 53 #define VN_KNOTE(vp, b) \ 54 KNOTE((struct klist *)&vp->v_pollinfo.vpi_selinfo.si_note, (b)) 55 56 #ifdef DIRECTIO 57 extern int ffs_rawread(struct vnode *vp, struct uio *uio, int *workdone); 58 #endif 59 60 /* 61 * Vnode op for reading. 62 */ 63 /* ARGSUSED */ 64 int 65 ffs_read(ap) 66 struct vop_read_args /* { 67 struct vnode *a_vp; 68 struct uio *a_uio; 69 int a_ioflag; 70 struct ucred *a_cred; 71 } */ *ap; 72 { 73 struct vnode *vp; 74 struct inode *ip; 75 struct uio *uio; 76 FS *fs; 77 struct buf *bp; 78 ufs_daddr_t lbn, nextlbn; 79 off_t bytesinfile; 80 long size, xfersize, blkoffset; 81 int error, orig_resid; 82 u_short mode; 83 int seqcount; 84 int ioflag; 85 vm_object_t object; 86 87 vp = ap->a_vp; 88 seqcount = ap->a_ioflag >> 16; 89 ip = VTOI(vp); 90 mode = ip->i_mode; 91 uio = ap->a_uio; 92 ioflag = ap->a_ioflag; 93 #ifdef DIRECTIO 94 if ((ioflag & IO_DIRECT) != 0) { 95 int workdone; 96 97 error = ffs_rawread(vp, uio, &workdone); 98 if (error || workdone) 99 return error; 100 } 101 #endif 102 103 #ifdef DIAGNOSTIC 104 if (uio->uio_rw != UIO_READ) 105 panic("ffs_read: mode"); 106 107 if (vp->v_type == VLNK) { 108 if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen) 109 panic("ffs_read: short symlink"); 110 } else if (vp->v_type != VREG && vp->v_type != VDIR) 111 panic("ffs_read: type %d", vp->v_type); 112 #endif 113 fs = ip->I_FS; 114 if ((u_int64_t)uio->uio_offset > fs->fs_maxfilesize) 115 return (EFBIG); 116 117 orig_resid = uio->uio_resid; 118 if (orig_resid <= 0) 119 return (0); 120 121 object = vp->v_object; 122 123 bytesinfile = ip->i_size - uio->uio_offset; 124 if (bytesinfile <= 0) { 125 if ((vp->v_mount->mnt_flag & MNT_NOATIME) == 0) 126 ip->i_flag |= IN_ACCESS; 127 return 0; 128 } 129 130 if (object) 131 vm_object_reference(object); 132 133 #ifdef ENABLE_VFS_IOOPT 134 /* 135 * If IO optimisation is turned on, 136 * and we are NOT a VM based IO request, 137 * (i.e. not headed for the buffer cache) 138 * but there IS a vm object associated with it. 139 */ 140 if ((ioflag & IO_VMIO) == 0 && (vfs_ioopt > 1) && object) { 141 int nread, toread; 142 143 toread = uio->uio_resid; 144 if (toread > bytesinfile) 145 toread = bytesinfile; 146 if (toread >= PAGE_SIZE) { 147 /* 148 * Then if it's at least a page in size, try 149 * get the data from the object using vm tricks 150 */ 151 error = uioread(toread, uio, object, &nread); 152 if ((uio->uio_resid == 0) || (error != 0)) { 153 /* 154 * If we finished or there was an error 155 * then finish up (the reference previously 156 * obtained on object must be released). 157 */ 158 if ((error == 0 || 159 uio->uio_resid != orig_resid) && 160 (vp->v_mount->mnt_flag & MNT_NOATIME) == 0) 161 ip->i_flag |= IN_ACCESS; 162 163 if (object) 164 vm_object_vndeallocate(object); 165 return error; 166 } 167 } 168 } 169 #endif 170 171 /* 172 * Ok so we couldn't do it all in one vm trick... 173 * so cycle around trying smaller bites.. 174 */ 175 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 176 if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0) 177 break; 178 #ifdef ENABLE_VFS_IOOPT 179 if ((ioflag & IO_VMIO) == 0 && (vfs_ioopt > 1) && object) { 180 /* 181 * Obviously we didn't finish above, but we 182 * didn't get an error either. Try the same trick again. 183 * but this time we are looping. 184 */ 185 int nread, toread; 186 toread = uio->uio_resid; 187 if (toread > bytesinfile) 188 toread = bytesinfile; 189 190 /* 191 * Once again, if there isn't enough for a 192 * whole page, don't try optimising. 193 */ 194 if (toread >= PAGE_SIZE) { 195 error = uioread(toread, uio, object, &nread); 196 if ((uio->uio_resid == 0) || (error != 0)) { 197 /* 198 * If we finished or there was an 199 * error then finish up (the reference 200 * previously obtained on object must 201 * be released). 202 */ 203 if ((error == 0 || 204 uio->uio_resid != orig_resid) && 205 (vp->v_mount->mnt_flag & 206 MNT_NOATIME) == 0) 207 ip->i_flag |= IN_ACCESS; 208 if (object) 209 vm_object_vndeallocate(object); 210 return error; 211 } 212 /* 213 * To get here we didnt't finish or err. 214 * If we did get some data, 215 * loop to try another bite. 216 */ 217 if (nread > 0) { 218 continue; 219 } 220 } 221 } 222 #endif 223 224 lbn = lblkno(fs, uio->uio_offset); 225 nextlbn = lbn + 1; 226 227 /* 228 * size of buffer. The buffer representing the 229 * end of the file is rounded up to the size of 230 * the block type ( fragment or full block, 231 * depending ). 232 */ 233 size = BLKSIZE(fs, ip, lbn); 234 blkoffset = blkoff(fs, uio->uio_offset); 235 236 /* 237 * The amount we want to transfer in this iteration is 238 * one FS block less the amount of the data before 239 * our startpoint (duh!) 240 */ 241 xfersize = fs->fs_bsize - blkoffset; 242 243 /* 244 * But if we actually want less than the block, 245 * or the file doesn't have a whole block more of data, 246 * then use the lesser number. 247 */ 248 if (uio->uio_resid < xfersize) 249 xfersize = uio->uio_resid; 250 if (bytesinfile < xfersize) 251 xfersize = bytesinfile; 252 253 if (lblktosize(fs, nextlbn) >= ip->i_size) { 254 /* 255 * Don't do readahead if this is the end of the file. 256 */ 257 error = bread(vp, lbn, size, &bp); 258 } else if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) { 259 /* 260 * Otherwise if we are allowed to cluster, 261 * grab as much as we can. 262 * 263 * XXX This may not be a win if we are not 264 * doing sequential access. 265 */ 266 error = cluster_read(vp, ip->i_size, lbn, 267 size, uio->uio_resid, seqcount, &bp); 268 } else if (seqcount > 1) { 269 /* 270 * If we are NOT allowed to cluster, then 271 * if we appear to be acting sequentially, 272 * fire off a request for a readahead 273 * as well as a read. Note that the 4th and 5th 274 * arguments point to arrays of the size specified in 275 * the 6th argument. 276 */ 277 int nextsize = BLKSIZE(fs, ip, nextlbn); 278 error = breadn(vp, lbn, 279 size, &nextlbn, &nextsize, 1, &bp); 280 } else { 281 /* 282 * Failing all of the above, just read what the 283 * user asked for. Interestingly, the same as 284 * the first option above. 285 */ 286 error = bread(vp, lbn, size, &bp); 287 } 288 if (error) { 289 brelse(bp); 290 bp = NULL; 291 break; 292 } 293 294 /* 295 * If IO_DIRECT then set B_DIRECT for the buffer. This 296 * will cause us to attempt to release the buffer later on 297 * and will cause the buffer cache to attempt to free the 298 * underlying pages. 299 */ 300 if (ioflag & IO_DIRECT) 301 bp->b_flags |= B_DIRECT; 302 303 /* 304 * We should only get non-zero b_resid when an I/O error 305 * has occurred, which should cause us to break above. 306 * However, if the short read did not cause an error, 307 * then we want to ensure that we do not uiomove bad 308 * or uninitialized data. 309 * 310 * XXX b_resid is only valid when an actual I/O has occured 311 * and may be incorrect if the buffer is B_CACHE or if the 312 * last op on the buffer was a failed write. This KASSERT 313 * is a precursor to removing it from the UFS code. 314 */ 315 KASSERT(bp->b_resid == 0, ("bp->b_resid != 0")); 316 size -= bp->b_resid; 317 if (size < xfersize) { 318 if (size == 0) 319 break; 320 xfersize = size; 321 } 322 323 #ifdef ENABLE_VFS_IOOPT 324 if (vfs_ioopt && object && 325 (bp->b_flags & B_VMIO) && 326 ((blkoffset & PAGE_MASK) == 0) && 327 ((xfersize & PAGE_MASK) == 0)) { 328 /* 329 * If VFS IO optimisation is turned on, 330 * and it's an exact page multiple 331 * And a normal VM based op, 332 * then use uiomiveco() 333 */ 334 error = 335 uiomoveco((char *)bp->b_data + blkoffset, 336 (int)xfersize, uio, object); 337 } else 338 #endif 339 { 340 /* 341 * otherwise use the general form 342 */ 343 error = 344 uiomove((char *)bp->b_data + blkoffset, 345 (int)xfersize, uio); 346 } 347 348 if (error) 349 break; 350 351 if ((ioflag & (IO_VMIO|IO_DIRECT)) && 352 (LIST_FIRST(&bp->b_dep) == NULL)) { 353 /* 354 * If there are no dependencies, and it's VMIO, 355 * then we don't need the buf, mark it available 356 * for freeing. The VM has the data. 357 */ 358 bp->b_flags |= B_RELBUF; 359 brelse(bp); 360 } else { 361 /* 362 * Otherwise let whoever 363 * made the request take care of 364 * freeing it. We just queue 365 * it onto another list. 366 */ 367 bqrelse(bp); 368 } 369 } 370 371 /* 372 * This can only happen in the case of an error 373 * because the loop above resets bp to NULL on each iteration 374 * and on normal completion has not set a new value into it. 375 * so it must have come from a 'break' statement 376 */ 377 if (bp != NULL) { 378 if ((ioflag & (IO_VMIO|IO_DIRECT)) && 379 (LIST_FIRST(&bp->b_dep) == NULL)) { 380 bp->b_flags |= B_RELBUF; 381 brelse(bp); 382 } else { 383 bqrelse(bp); 384 } 385 } 386 387 if (object) 388 vm_object_vndeallocate(object); 389 if ((error == 0 || uio->uio_resid != orig_resid) && 390 (vp->v_mount->mnt_flag & MNT_NOATIME) == 0) 391 ip->i_flag |= IN_ACCESS; 392 return (error); 393 } 394 395 /* 396 * Vnode op for writing. 397 */ 398 int 399 ffs_write(ap) 400 struct vop_write_args /* { 401 struct vnode *a_vp; 402 struct uio *a_uio; 403 int a_ioflag; 404 struct ucred *a_cred; 405 } */ *ap; 406 { 407 struct vnode *vp; 408 struct uio *uio; 409 struct inode *ip; 410 FS *fs; 411 struct buf *bp; 412 ufs_daddr_t lbn; 413 off_t osize; 414 int seqcount; 415 int blkoffset, error, extended, flags, ioflag, resid, size, xfersize; 416 vm_object_t object; 417 struct thread *td; 418 419 extended = 0; 420 seqcount = ap->a_ioflag >> 16; 421 ioflag = ap->a_ioflag; 422 uio = ap->a_uio; 423 vp = ap->a_vp; 424 ip = VTOI(vp); 425 426 object = vp->v_object; 427 if (object) 428 vm_object_reference(object); 429 430 #ifdef DIAGNOSTIC 431 if (uio->uio_rw != UIO_WRITE) 432 panic("ffs_write: mode"); 433 #endif 434 435 switch (vp->v_type) { 436 case VREG: 437 if (ioflag & IO_APPEND) 438 uio->uio_offset = ip->i_size; 439 if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size) { 440 if (object) 441 vm_object_vndeallocate(object); 442 return (EPERM); 443 } 444 /* FALLTHROUGH */ 445 case VLNK: 446 break; 447 case VDIR: 448 panic("ffs_write: dir write"); 449 break; 450 default: 451 panic("ffs_write: type %p %d (%d,%d)", vp, (int)vp->v_type, 452 (int)uio->uio_offset, 453 (int)uio->uio_resid 454 ); 455 } 456 457 fs = ip->I_FS; 458 if (uio->uio_offset < 0 || 459 (u_int64_t)uio->uio_offset + uio->uio_resid > fs->fs_maxfilesize) { 460 if (object) 461 vm_object_vndeallocate(object); 462 return (EFBIG); 463 } 464 /* 465 * Maybe this should be above the vnode op call, but so long as 466 * file servers have no limits, I don't think it matters. 467 */ 468 td = uio->uio_td; 469 if (vp->v_type == VREG && td && td->td_proc && 470 uio->uio_offset + uio->uio_resid > 471 td->td_proc->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 472 psignal(td->td_proc, SIGXFSZ); 473 if (object) 474 vm_object_vndeallocate(object); 475 return (EFBIG); 476 } 477 478 resid = uio->uio_resid; 479 osize = ip->i_size; 480 481 /* 482 * NOTE! These B_ flags are actually balloc-only flags, not buffer 483 * flags. They are similar to the BA_ flags in -current. 484 */ 485 if (seqcount > B_SEQMAX) 486 flags = B_SEQMAX << B_SEQSHIFT; 487 else 488 flags = seqcount << B_SEQSHIFT; 489 if ((ioflag & IO_SYNC) && !DOINGASYNC(vp)) 490 flags |= B_SYNC; 491 492 if (object && (object->flags & OBJ_OPT)) { 493 vm_freeze_copyopts(object, 494 OFF_TO_IDX(uio->uio_offset), 495 OFF_TO_IDX(uio->uio_offset + uio->uio_resid + PAGE_MASK)); 496 } 497 498 for (error = 0; uio->uio_resid > 0;) { 499 lbn = lblkno(fs, uio->uio_offset); 500 blkoffset = blkoff(fs, uio->uio_offset); 501 xfersize = fs->fs_bsize - blkoffset; 502 if (uio->uio_resid < xfersize) 503 xfersize = uio->uio_resid; 504 505 if (uio->uio_offset + xfersize > ip->i_size) 506 vnode_pager_setsize(vp, uio->uio_offset + xfersize); 507 508 /* 509 * We must perform a read-before-write if the transfer 510 * size does not cover the entire buffer. 511 */ 512 if (fs->fs_bsize > xfersize) 513 flags |= B_CLRBUF; 514 else 515 flags &= ~B_CLRBUF; 516 /* XXX is uio->uio_offset the right thing here? */ 517 error = VOP_BALLOC(vp, uio->uio_offset, xfersize, 518 ap->a_cred, flags, &bp); 519 if (error != 0) 520 break; 521 /* 522 * If the buffer is not valid and we did not clear garbage 523 * out above, we have to do so here even though the write 524 * covers the entire buffer in order to avoid a mmap()/write 525 * race where another process may see the garbage prior to 526 * the uiomove() for a write replacing it. 527 */ 528 if ((bp->b_flags & B_CACHE) == 0 && fs->fs_bsize <= xfersize) 529 vfs_bio_clrbuf(bp); 530 if (ioflag & IO_DIRECT) 531 bp->b_flags |= B_DIRECT; 532 if (ioflag & IO_NOWDRAIN) 533 bp->b_flags |= B_NOWDRAIN; 534 535 if (uio->uio_offset + xfersize > ip->i_size) { 536 ip->i_size = uio->uio_offset + xfersize; 537 extended = 1; 538 } 539 540 size = BLKSIZE(fs, ip, lbn) - bp->b_resid; 541 if (size < xfersize) 542 xfersize = size; 543 544 error = 545 uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio); 546 if ((ioflag & (IO_VMIO|IO_DIRECT)) && 547 (LIST_FIRST(&bp->b_dep) == NULL)) { 548 bp->b_flags |= B_RELBUF; 549 } 550 551 /* 552 * If IO_SYNC each buffer is written synchronously. Otherwise 553 * if we have a severe page deficiency write the buffer 554 * asynchronously. Otherwise try to cluster, and if that 555 * doesn't do it then either do an async write (if O_DIRECT), 556 * or a delayed write (if not). 557 */ 558 559 if (ioflag & IO_SYNC) { 560 (void)bwrite(bp); 561 } else if (vm_page_count_severe() || 562 buf_dirty_count_severe() || 563 (ioflag & IO_ASYNC)) { 564 bp->b_flags |= B_CLUSTEROK; 565 bawrite(bp); 566 } else if (xfersize + blkoffset == fs->fs_bsize) { 567 if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) { 568 bp->b_flags |= B_CLUSTEROK; 569 cluster_write(bp, ip->i_size, seqcount); 570 } else { 571 bawrite(bp); 572 } 573 } else if (ioflag & IO_DIRECT) { 574 bp->b_flags |= B_CLUSTEROK; 575 bawrite(bp); 576 } else { 577 bp->b_flags |= B_CLUSTEROK; 578 bdwrite(bp); 579 } 580 if (error || xfersize == 0) 581 break; 582 ip->i_flag |= IN_CHANGE | IN_UPDATE; 583 } 584 /* 585 * If we successfully wrote any data, and we are not the superuser 586 * we clear the setuid and setgid bits as a precaution against 587 * tampering. 588 */ 589 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0) 590 ip->i_mode &= ~(ISUID | ISGID); 591 if (resid > uio->uio_resid) 592 VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0)); 593 if (error) { 594 if (ioflag & IO_UNIT) { 595 (void)UFS_TRUNCATE(vp, osize, 596 ioflag & IO_SYNC, ap->a_cred, uio->uio_td); 597 uio->uio_offset -= resid - uio->uio_resid; 598 uio->uio_resid = resid; 599 } 600 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) 601 error = UFS_UPDATE(vp, 1); 602 603 if (object) 604 vm_object_vndeallocate(object); 605 606 return (error); 607 } 608 609 610 /* 611 * get page routine 612 */ 613 int 614 ffs_getpages(ap) 615 struct vop_getpages_args *ap; 616 { 617 off_t foff, physoffset; 618 int i, size, bsize; 619 struct vnode *dp, *vp; 620 vm_object_t obj; 621 vm_pindex_t pindex, firstindex; 622 vm_page_t mreq; 623 int bbackwards, bforwards; 624 int pbackwards, pforwards; 625 int firstpage; 626 int reqlblkno; 627 daddr_t reqblkno; 628 int poff; 629 int pcount; 630 int rtval; 631 int pagesperblock; 632 633 634 pcount = round_page(ap->a_count) / PAGE_SIZE; 635 mreq = ap->a_m[ap->a_reqpage]; 636 firstindex = ap->a_m[0]->pindex; 637 638 /* 639 * if ANY DEV_BSIZE blocks are valid on a large filesystem block, 640 * then the entire page is valid. Since the page may be mapped, 641 * user programs might reference data beyond the actual end of file 642 * occuring within the page. We have to zero that data. 643 */ 644 if (mreq->valid) { 645 if (mreq->valid != VM_PAGE_BITS_ALL) 646 vm_page_zero_invalid(mreq, TRUE); 647 for (i = 0; i < pcount; i++) { 648 if (i != ap->a_reqpage) { 649 vm_page_free(ap->a_m[i]); 650 } 651 } 652 return VM_PAGER_OK; 653 } 654 655 vp = ap->a_vp; 656 obj = vp->v_object; 657 bsize = vp->v_mount->mnt_stat.f_iosize; 658 pindex = mreq->pindex; 659 foff = IDX_TO_OFF(pindex) /* + ap->a_offset should be zero */; 660 661 if (bsize < PAGE_SIZE) 662 return vnode_pager_generic_getpages(ap->a_vp, ap->a_m, 663 ap->a_count, 664 ap->a_reqpage); 665 666 /* 667 * foff is the file offset of the required page 668 * reqlblkno is the logical block that contains the page 669 * poff is the index of the page into the logical block 670 */ 671 reqlblkno = foff / bsize; 672 poff = (foff % bsize) / PAGE_SIZE; 673 674 if ( VOP_BMAP( vp, reqlblkno, &dp, &reqblkno, 675 &bforwards, &bbackwards) || (reqblkno == -1)) { 676 for(i = 0; i < pcount; i++) { 677 if (i != ap->a_reqpage) 678 vm_page_free(ap->a_m[i]); 679 } 680 if (reqblkno == -1) { 681 if ((mreq->flags & PG_ZERO) == 0) 682 vm_page_zero_fill(mreq); 683 vm_page_undirty(mreq); 684 mreq->valid = VM_PAGE_BITS_ALL; 685 return VM_PAGER_OK; 686 } else { 687 return VM_PAGER_ERROR; 688 } 689 } 690 691 physoffset = (off_t)reqblkno * DEV_BSIZE + poff * PAGE_SIZE; 692 pagesperblock = bsize / PAGE_SIZE; 693 /* 694 * find the first page that is contiguous... 695 * note that pbackwards is the number of pages that are contiguous 696 * backwards. 697 */ 698 firstpage = 0; 699 if (ap->a_count) { 700 pbackwards = poff + bbackwards * pagesperblock; 701 if (ap->a_reqpage > pbackwards) { 702 firstpage = ap->a_reqpage - pbackwards; 703 for(i=0;i<firstpage;i++) 704 vm_page_free(ap->a_m[i]); 705 } 706 707 /* 708 * pforwards is the number of pages that are contiguous 709 * after the current page. 710 */ 711 pforwards = (pagesperblock - (poff + 1)) + 712 bforwards * pagesperblock; 713 if (pforwards < (pcount - (ap->a_reqpage + 1))) { 714 for( i = ap->a_reqpage + pforwards + 1; i < pcount; i++) 715 vm_page_free(ap->a_m[i]); 716 pcount = ap->a_reqpage + pforwards + 1; 717 } 718 719 /* 720 * number of pages for I/O corrected for the non-contig pages at 721 * the beginning of the array. 722 */ 723 pcount -= firstpage; 724 } 725 726 /* 727 * calculate the size of the transfer 728 */ 729 730 size = pcount * PAGE_SIZE; 731 732 if ((IDX_TO_OFF(ap->a_m[firstpage]->pindex) + size) > 733 obj->un_pager.vnp.vnp_size) 734 size = obj->un_pager.vnp.vnp_size - 735 IDX_TO_OFF(ap->a_m[firstpage]->pindex); 736 737 physoffset -= foff; 738 rtval = VOP_GETPAGES(dp, &ap->a_m[firstpage], size, 739 (ap->a_reqpage - firstpage), physoffset); 740 741 return (rtval); 742 } 743 744 /* 745 * put page routine 746 * 747 * XXX By default, wimp out... note that a_offset is ignored (and always 748 * XXX has been). 749 */ 750 int 751 ffs_putpages(ap) 752 struct vop_putpages_args *ap; 753 { 754 return vnode_pager_generic_putpages(ap->a_vp, ap->a_m, ap->a_count, 755 ap->a_sync, ap->a_rtvals); 756 } 757