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 1.21 2007/02/22 15:50:50 corecode 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 * ffs_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, 64 * struct ucred *a_cred) 65 */ 66 /* ARGSUSED */ 67 int 68 ffs_read(struct vop_read_args *ap) 69 { 70 struct vnode *vp; 71 struct inode *ip; 72 struct uio *uio; 73 FS *fs; 74 struct buf *bp; 75 off_t bytesinfile; 76 int xfersize, blkoffset; 77 int error, orig_resid; 78 u_short mode; 79 int seqcount; 80 int ioflag; 81 82 vp = ap->a_vp; 83 seqcount = ap->a_ioflag >> 16; 84 ip = VTOI(vp); 85 mode = ip->i_mode; 86 uio = ap->a_uio; 87 ioflag = ap->a_ioflag; 88 #ifdef DIRECTIO 89 if ((ioflag & IO_DIRECT) != 0) { 90 int workdone; 91 92 error = ffs_rawread(vp, uio, &workdone); 93 if (error || workdone) 94 return error; 95 } 96 #endif 97 98 #ifdef DIAGNOSTIC 99 if (uio->uio_rw != UIO_READ) 100 panic("ffs_read: mode"); 101 102 if (vp->v_type == VLNK) { 103 if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen) 104 panic("ffs_read: short symlink"); 105 } else if (vp->v_type != VREG && vp->v_type != VDIR) 106 panic("ffs_read: type %d", vp->v_type); 107 #endif 108 fs = ip->I_FS; 109 if ((uint64_t)uio->uio_offset > fs->fs_maxfilesize) 110 return (EFBIG); 111 112 orig_resid = uio->uio_resid; 113 if (orig_resid <= 0) 114 return (0); 115 116 bytesinfile = ip->i_size - uio->uio_offset; 117 if (bytesinfile <= 0) { 118 if ((vp->v_mount->mnt_flag & MNT_NOATIME) == 0) 119 ip->i_flag |= IN_ACCESS; 120 return 0; 121 } 122 123 /* 124 * Ok so we couldn't do it all in one vm trick... 125 * so cycle around trying smaller bites.. 126 */ 127 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { 128 if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0) 129 break; 130 131 error = ffs_blkatoff_ra(vp, uio->uio_offset, NULL, 132 &bp, seqcount); 133 if (error) 134 break; 135 136 /* 137 * If IO_DIRECT then set B_DIRECT for the buffer. This 138 * will cause us to attempt to release the buffer later on 139 * and will cause the buffer cache to attempt to free the 140 * underlying pages. 141 */ 142 if (ioflag & IO_DIRECT) 143 bp->b_flags |= B_DIRECT; 144 145 /* 146 * We should only get non-zero b_resid when an I/O error 147 * has occurred, which should cause us to break above. 148 * However, if the short read did not cause an error, 149 * then we want to ensure that we do not uiomove bad 150 * or uninitialized data. 151 * 152 * XXX b_resid is only valid when an actual I/O has occured 153 * and may be incorrect if the buffer is B_CACHE or if the 154 * last op on the buffer was a failed write. This KASSERT 155 * is a precursor to removing it from the UFS code. 156 */ 157 KASSERT(bp->b_resid == 0, ("bp->b_resid != 0")); 158 159 /* 160 * Calculate how much data we can copy 161 */ 162 blkoffset = blkoff(fs, uio->uio_offset); 163 xfersize = bp->b_bufsize - blkoffset; 164 if (xfersize > uio->uio_resid) 165 xfersize = uio->uio_resid; 166 if (xfersize > bytesinfile) 167 xfersize = bytesinfile; 168 if (xfersize <= 0) { 169 panic("ufs_readwrite: impossible xfersize: %d", 170 xfersize); 171 } 172 173 /* 174 * otherwise use the general form 175 */ 176 error = uiomove((char *)bp->b_data + blkoffset, 177 (int)xfersize, uio); 178 179 if (error) 180 break; 181 182 if ((ioflag & (IO_VMIO|IO_DIRECT)) && 183 (LIST_FIRST(&bp->b_dep) == NULL)) { 184 /* 185 * If there are no dependencies, and it's VMIO, 186 * then we don't need the buf, mark it available 187 * for freeing. The VM has the data. 188 */ 189 bp->b_flags |= B_RELBUF; 190 brelse(bp); 191 } else { 192 /* 193 * Otherwise let whoever 194 * made the request take care of 195 * freeing it. We just queue 196 * it onto another list. 197 */ 198 bqrelse(bp); 199 } 200 } 201 202 /* 203 * This can only happen in the case of an error 204 * because the loop above resets bp to NULL on each iteration 205 * and on normal completion has not set a new value into it. 206 * so it must have come from a 'break' statement 207 */ 208 if (bp != NULL) { 209 if ((ioflag & (IO_VMIO|IO_DIRECT)) && 210 (LIST_FIRST(&bp->b_dep) == NULL)) { 211 bp->b_flags |= B_RELBUF; 212 brelse(bp); 213 } else { 214 bqrelse(bp); 215 } 216 } 217 218 if ((error == 0 || uio->uio_resid != orig_resid) && 219 (vp->v_mount->mnt_flag & MNT_NOATIME) == 0) 220 ip->i_flag |= IN_ACCESS; 221 return (error); 222 } 223 224 /* 225 * Vnode op for writing. 226 * 227 * ffs_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, 228 * struct ucred *a_cred) 229 */ 230 int 231 ffs_write(struct vop_write_args *ap) 232 { 233 struct vnode *vp; 234 struct uio *uio; 235 struct inode *ip; 236 FS *fs; 237 struct buf *bp; 238 ufs_daddr_t lbn; 239 off_t osize; 240 int seqcount; 241 int blkoffset, error, extended, flags, ioflag, resid, size, xfersize; 242 struct thread *td; 243 244 extended = 0; 245 seqcount = ap->a_ioflag >> 16; 246 ioflag = ap->a_ioflag; 247 uio = ap->a_uio; 248 vp = ap->a_vp; 249 ip = VTOI(vp); 250 251 #ifdef DIAGNOSTIC 252 if (uio->uio_rw != UIO_WRITE) 253 panic("ffs_write: mode"); 254 #endif 255 256 switch (vp->v_type) { 257 case VREG: 258 if (ioflag & IO_APPEND) 259 uio->uio_offset = ip->i_size; 260 if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size) 261 return (EPERM); 262 /* FALLTHROUGH */ 263 case VLNK: 264 break; 265 case VDIR: 266 panic("ffs_write: dir write"); 267 break; 268 default: 269 panic("ffs_write: type %p %d (%d,%d)", vp, (int)vp->v_type, 270 (int)uio->uio_offset, 271 (int)uio->uio_resid 272 ); 273 } 274 275 fs = ip->I_FS; 276 if (uio->uio_offset < 0 || 277 (uint64_t)uio->uio_offset + uio->uio_resid > fs->fs_maxfilesize) { 278 return (EFBIG); 279 } 280 /* 281 * Maybe this should be above the vnode op call, but so long as 282 * file servers have no limits, I don't think it matters. 283 */ 284 td = uio->uio_td; 285 if (vp->v_type == VREG && td && td->td_proc && 286 uio->uio_offset + uio->uio_resid > 287 td->td_proc->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 288 lwpsignal(td->td_proc, td->td_lwp, SIGXFSZ); 289 return (EFBIG); 290 } 291 292 resid = uio->uio_resid; 293 osize = ip->i_size; 294 295 /* 296 * NOTE! These B_ flags are actually balloc-only flags, not buffer 297 * flags. They are similar to the BA_ flags in fbsd. 298 */ 299 if (seqcount > B_SEQMAX) 300 flags = B_SEQMAX << B_SEQSHIFT; 301 else 302 flags = seqcount << B_SEQSHIFT; 303 if ((ioflag & IO_SYNC) && !DOINGASYNC(vp)) 304 flags |= B_SYNC; 305 306 for (error = 0; uio->uio_resid > 0;) { 307 lbn = lblkno(fs, uio->uio_offset); 308 blkoffset = blkoff(fs, uio->uio_offset); 309 xfersize = fs->fs_bsize - blkoffset; 310 if (uio->uio_resid < xfersize) 311 xfersize = uio->uio_resid; 312 313 if (uio->uio_offset + xfersize > ip->i_size) 314 vnode_pager_setsize(vp, uio->uio_offset + xfersize); 315 316 /* 317 * We must perform a read-before-write if the transfer 318 * size does not cover the entire buffer. 319 */ 320 if (fs->fs_bsize > xfersize) 321 flags |= B_CLRBUF; 322 else 323 flags &= ~B_CLRBUF; 324 /* XXX is uio->uio_offset the right thing here? */ 325 error = VOP_BALLOC(vp, uio->uio_offset, xfersize, 326 ap->a_cred, flags, &bp); 327 if (error != 0) 328 break; 329 /* 330 * If the buffer is not valid and we did not clear garbage 331 * out above, we have to do so here even though the write 332 * covers the entire buffer in order to avoid a mmap()/write 333 * race where another process may see the garbage prior to 334 * the uiomove() for a write replacing it. 335 */ 336 if ((bp->b_flags & B_CACHE) == 0 && fs->fs_bsize <= xfersize) 337 vfs_bio_clrbuf(bp); 338 if (ioflag & IO_DIRECT) 339 bp->b_flags |= B_DIRECT; 340 if (ioflag & IO_NOWDRAIN) 341 bp->b_flags |= B_NOWDRAIN; 342 if ((ioflag & (IO_SYNC|IO_INVAL)) == (IO_SYNC|IO_INVAL)) 343 bp->b_flags |= B_NOCACHE; 344 345 if (uio->uio_offset + xfersize > ip->i_size) { 346 ip->i_size = uio->uio_offset + xfersize; 347 extended = 1; 348 } 349 350 size = BLKSIZE(fs, ip, lbn) - bp->b_resid; 351 if (size < xfersize) 352 xfersize = size; 353 354 error = 355 uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio); 356 if ((ioflag & (IO_VMIO|IO_DIRECT)) && 357 (LIST_FIRST(&bp->b_dep) == NULL)) { 358 bp->b_flags |= B_RELBUF; 359 } 360 361 /* 362 * If IO_SYNC each buffer is written synchronously. Otherwise 363 * if we have a severe page deficiency write the buffer 364 * asynchronously. Otherwise try to cluster, and if that 365 * doesn't do it then either do an async write (if O_DIRECT), 366 * or a delayed write (if not). 367 */ 368 369 if (ioflag & IO_SYNC) { 370 (void)bwrite(bp); 371 } else if (vm_page_count_severe() || 372 buf_dirty_count_severe() || 373 (ioflag & IO_ASYNC)) { 374 bp->b_flags |= B_CLUSTEROK; 375 bawrite(bp); 376 } else if (xfersize + blkoffset == fs->fs_bsize) { 377 if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) { 378 bp->b_flags |= B_CLUSTEROK; 379 cluster_write(bp, (off_t)ip->i_size, seqcount); 380 } else { 381 bawrite(bp); 382 } 383 } else if (ioflag & IO_DIRECT) { 384 bp->b_flags |= B_CLUSTEROK; 385 bawrite(bp); 386 } else { 387 bp->b_flags |= B_CLUSTEROK; 388 bdwrite(bp); 389 } 390 if (error || xfersize == 0) 391 break; 392 ip->i_flag |= IN_CHANGE | IN_UPDATE; 393 } 394 /* 395 * If we successfully wrote any data, and we are not the superuser 396 * we clear the setuid and setgid bits as a precaution against 397 * tampering. 398 */ 399 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0) 400 ip->i_mode &= ~(ISUID | ISGID); 401 if (resid > uio->uio_resid) 402 VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0)); 403 if (error) { 404 if (ioflag & IO_UNIT) { 405 (void)ffs_truncate(vp, osize, ioflag & IO_SYNC, 406 ap->a_cred); 407 uio->uio_offset -= resid - uio->uio_resid; 408 uio->uio_resid = resid; 409 } 410 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) { 411 error = ffs_update(vp, 1); 412 } 413 414 return (error); 415 } 416 417 418 /* 419 * get page routine 420 */ 421 int 422 ffs_getpages(struct vop_getpages_args *ap) 423 { 424 off_t foff, physoffset; 425 int i, size, bsize; 426 struct vnode *dp, *vp; 427 vm_object_t obj; 428 vm_pindex_t pindex, firstindex; 429 vm_page_t mreq; 430 int bbackwards, bforwards; 431 int pbackwards, pforwards; 432 int firstpage; 433 off_t reqoffset; 434 off_t doffset; 435 int poff; 436 int pcount; 437 int rtval; 438 int pagesperblock; 439 440 441 pcount = round_page(ap->a_count) / PAGE_SIZE; 442 mreq = ap->a_m[ap->a_reqpage]; 443 firstindex = ap->a_m[0]->pindex; 444 445 /* 446 * if ANY DEV_BSIZE blocks are valid on a large filesystem block, 447 * then the entire page is valid. Since the page may be mapped, 448 * user programs might reference data beyond the actual end of file 449 * occuring within the page. We have to zero that data. 450 */ 451 if (mreq->valid) { 452 if (mreq->valid != VM_PAGE_BITS_ALL) 453 vm_page_zero_invalid(mreq, TRUE); 454 for (i = 0; i < pcount; i++) { 455 if (i != ap->a_reqpage) { 456 vm_page_free(ap->a_m[i]); 457 } 458 } 459 return VM_PAGER_OK; 460 } 461 462 vp = ap->a_vp; 463 obj = vp->v_object; 464 bsize = vp->v_mount->mnt_stat.f_iosize; 465 pindex = mreq->pindex; 466 foff = IDX_TO_OFF(pindex) /* + ap->a_offset should be zero */; 467 468 if (bsize < PAGE_SIZE) 469 return vnode_pager_generic_getpages(ap->a_vp, ap->a_m, 470 ap->a_count, 471 ap->a_reqpage); 472 473 /* 474 * foff is the file offset of the required page 475 * reqlblkno is the logical block that contains the page 476 * poff is the bytes offset of the page in the logical block 477 */ 478 poff = (int)(foff % bsize); 479 reqoffset = foff - poff; 480 481 if (VOP_BMAP(vp, reqoffset, &dp, &doffset, 482 &bforwards, &bbackwards) || (doffset == NOOFFSET) 483 ) { 484 for (i = 0; i < pcount; i++) { 485 if (i != ap->a_reqpage) 486 vm_page_free(ap->a_m[i]); 487 } 488 if (doffset == NOOFFSET) { 489 if ((mreq->flags & PG_ZERO) == 0) 490 vm_page_zero_fill(mreq); 491 vm_page_undirty(mreq); 492 mreq->valid = VM_PAGE_BITS_ALL; 493 return VM_PAGER_OK; 494 } else { 495 return VM_PAGER_ERROR; 496 } 497 } 498 499 physoffset = doffset + poff; 500 pagesperblock = bsize / PAGE_SIZE; 501 502 /* 503 * find the first page that is contiguous. 504 * 505 * bforwards and bbackwards are the number of contiguous bytes 506 * available before and after the block offset. poff is the page 507 * offset, in bytes, relative to the block offset. 508 * 509 * pforwards and pbackwards are the number of contiguous pages 510 * relative to the requested page, non-inclusive of the requested 511 * page (so a pbackwards and pforwards of 0 indicates just the 512 * requested page). 513 */ 514 firstpage = 0; 515 if (ap->a_count) { 516 /* 517 * Calculate pbackwards and clean up any requested 518 * pages that are too far back. 519 */ 520 pbackwards = (poff + bbackwards) >> PAGE_SHIFT; 521 if (ap->a_reqpage > pbackwards) { 522 firstpage = ap->a_reqpage - pbackwards; 523 for (i = 0; i < firstpage; i++) 524 vm_page_free(ap->a_m[i]); 525 } 526 527 /* 528 * Calculate pforwards 529 */ 530 pforwards = (bforwards - poff - PAGE_SIZE) >> PAGE_SHIFT; 531 if (pforwards < 0) 532 pforwards = 0; 533 if (pforwards < (pcount - (ap->a_reqpage + 1))) { 534 for(i = ap->a_reqpage + pforwards + 1; i < pcount; i++) 535 vm_page_free(ap->a_m[i]); 536 pcount = ap->a_reqpage + pforwards + 1; 537 } 538 539 /* 540 * Adjust pcount to be relative to firstpage. All pages prior 541 * to firstpage in the array have been cleaned up. 542 */ 543 pcount -= firstpage; 544 } 545 546 /* 547 * calculate the size of the transfer 548 */ 549 size = pcount * PAGE_SIZE; 550 551 if ((IDX_TO_OFF(ap->a_m[firstpage]->pindex) + size) > vp->v_filesize) { 552 size = vp->v_filesize - IDX_TO_OFF(ap->a_m[firstpage]->pindex); 553 } 554 555 physoffset -= foff; 556 rtval = VOP_GETPAGES(dp, &ap->a_m[firstpage], size, 557 (ap->a_reqpage - firstpage), physoffset); 558 559 return (rtval); 560 } 561 562 /* 563 * put page routine 564 * 565 * XXX By default, wimp out... note that a_offset is ignored (and always 566 * XXX has been). 567 */ 568 int 569 ffs_putpages(struct vop_putpages_args *ap) 570 { 571 return vnode_pager_generic_putpages(ap->a_vp, ap->a_m, ap->a_count, 572 ap->a_sync, ap->a_rtvals); 573 } 574