Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
FreeBSD/Linux Kernel Cross Reference
sys/nfsclient/nfs_bio.c
Version:
- FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
SearchContext: - none - 3 - 10
1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Rick Macklem at The University of Guelph. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)nfs_bio.c 8.9 (Berkeley) 3/30/95 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD: releng/5.1/sys/nfsclient/nfs_bio.c 115041 2003-05-15 21:12:08Z rwatson $"); 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/bio.h> 45 #include <sys/buf.h> 46 #include <sys/kernel.h> 47 #include <sys/mount.h> 48 #include <sys/proc.h> 49 #include <sys/resourcevar.h> 50 #include <sys/signalvar.h> 51 #include <sys/vmmeter.h> 52 #include <sys/vnode.h> 53 54 #include <vm/vm.h> 55 #include <vm/vm_extern.h> 56 #include <vm/vm_page.h> 57 #include <vm/vm_object.h> 58 #include <vm/vm_pager.h> 59 #include <vm/vnode_pager.h> 60 61 #include <nfs/rpcv2.h> 62 #include <nfs/nfsproto.h> 63 #include <nfsclient/nfs.h> 64 #include <nfsclient/nfsmount.h> 65 #include <nfsclient/nfsnode.h> 66 67 /* 68 * Just call nfs_writebp() with the force argument set to 1. 69 * 70 * NOTE: B_DONE may or may not be set in a_bp on call. 71 */ 72 static int 73 nfs_bwrite(struct buf *bp) 74 { 75 76 return (nfs_writebp(bp, 1, curthread)); 77 } 78 79 struct buf_ops buf_ops_nfs = { 80 "buf_ops_nfs", 81 nfs_bwrite 82 }; 83 84 static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, 85 struct thread *td); 86 87 /* 88 * Vnode op for VM getpages. 89 */ 90 int 91 nfs_getpages(struct vop_getpages_args *ap) 92 { 93 int i, error, nextoff, size, toff, count, npages; 94 struct uio uio; 95 struct iovec iov; 96 vm_offset_t kva; 97 struct buf *bp; 98 struct vnode *vp; 99 struct thread *td; 100 struct ucred *cred; 101 struct nfsmount *nmp; 102 vm_page_t *pages; 103 104 GIANT_REQUIRED; 105 106 vp = ap->a_vp; 107 td = curthread; /* XXX */ 108 cred = curthread->td_ucred; /* XXX */ 109 nmp = VFSTONFS(vp->v_mount); 110 pages = ap->a_m; 111 count = ap->a_count; 112 113 if (vp->v_object == NULL) { 114 printf("nfs_getpages: called with non-merged cache vnode??\n"); 115 return VM_PAGER_ERROR; 116 } 117 118 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 119 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 120 (void)nfs_fsinfo(nmp, vp, cred, td); 121 } 122 123 npages = btoc(count); 124 125 /* 126 * If the requested page is partially valid, just return it and 127 * allow the pager to zero-out the blanks. Partially valid pages 128 * can only occur at the file EOF. 129 */ 130 131 { 132 vm_page_t m = pages[ap->a_reqpage]; 133 134 vm_page_lock_queues(); 135 if (m->valid != 0) { 136 /* handled by vm_fault now */ 137 /* vm_page_zero_invalid(m, TRUE); */ 138 for (i = 0; i < npages; ++i) { 139 if (i != ap->a_reqpage) 140 vm_page_free(pages[i]); 141 } 142 vm_page_unlock_queues(); 143 return(0); 144 } 145 vm_page_unlock_queues(); 146 } 147 148 /* 149 * We use only the kva address for the buffer, but this is extremely 150 * convienient and fast. 151 */ 152 bp = getpbuf(&nfs_pbuf_freecnt); 153 154 kva = (vm_offset_t) bp->b_data; 155 pmap_qenter(kva, pages, npages); 156 cnt.v_vnodein++; 157 cnt.v_vnodepgsin += npages; 158 159 iov.iov_base = (caddr_t) kva; 160 iov.iov_len = count; 161 uio.uio_iov = &iov; 162 uio.uio_iovcnt = 1; 163 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex); 164 uio.uio_resid = count; 165 uio.uio_segflg = UIO_SYSSPACE; 166 uio.uio_rw = UIO_READ; 167 uio.uio_td = td; 168 169 error = nfs_readrpc(vp, &uio, cred); 170 pmap_qremove(kva, npages); 171 172 relpbuf(bp, &nfs_pbuf_freecnt); 173 174 if (error && (uio.uio_resid == count)) { 175 printf("nfs_getpages: error %d\n", error); 176 vm_page_lock_queues(); 177 for (i = 0; i < npages; ++i) { 178 if (i != ap->a_reqpage) 179 vm_page_free(pages[i]); 180 } 181 vm_page_unlock_queues(); 182 return VM_PAGER_ERROR; 183 } 184 185 /* 186 * Calculate the number of bytes read and validate only that number 187 * of bytes. Note that due to pending writes, size may be 0. This 188 * does not mean that the remaining data is invalid! 189 */ 190 191 size = count - uio.uio_resid; 192 vm_page_lock_queues(); 193 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) { 194 vm_page_t m; 195 nextoff = toff + PAGE_SIZE; 196 m = pages[i]; 197 198 m->flags &= ~PG_ZERO; 199 200 if (nextoff <= size) { 201 /* 202 * Read operation filled an entire page 203 */ 204 m->valid = VM_PAGE_BITS_ALL; 205 vm_page_undirty(m); 206 } else if (size > toff) { 207 /* 208 * Read operation filled a partial page. 209 */ 210 m->valid = 0; 211 vm_page_set_validclean(m, 0, size - toff); 212 /* handled by vm_fault now */ 213 /* vm_page_zero_invalid(m, TRUE); */ 214 } else { 215 /* 216 * Read operation was short. If no error occured 217 * we may have hit a zero-fill section. We simply 218 * leave valid set to 0. 219 */ 220 ; 221 } 222 if (i != ap->a_reqpage) { 223 /* 224 * Whether or not to leave the page activated is up in 225 * the air, but we should put the page on a page queue 226 * somewhere (it already is in the object). Result: 227 * It appears that emperical results show that 228 * deactivating pages is best. 229 */ 230 231 /* 232 * Just in case someone was asking for this page we 233 * now tell them that it is ok to use. 234 */ 235 if (!error) { 236 if (m->flags & PG_WANTED) 237 vm_page_activate(m); 238 else 239 vm_page_deactivate(m); 240 vm_page_wakeup(m); 241 } else { 242 vm_page_free(m); 243 } 244 } 245 } 246 vm_page_unlock_queues(); 247 return 0; 248 } 249 250 /* 251 * Vnode op for VM putpages. 252 */ 253 int 254 nfs_putpages(struct vop_putpages_args *ap) 255 { 256 struct uio uio; 257 struct iovec iov; 258 vm_offset_t kva; 259 struct buf *bp; 260 int iomode, must_commit, i, error, npages, count; 261 off_t offset; 262 int *rtvals; 263 struct vnode *vp; 264 struct thread *td; 265 struct ucred *cred; 266 struct nfsmount *nmp; 267 struct nfsnode *np; 268 vm_page_t *pages; 269 270 GIANT_REQUIRED; 271 272 vp = ap->a_vp; 273 np = VTONFS(vp); 274 td = curthread; /* XXX */ 275 cred = curthread->td_ucred; /* XXX */ 276 nmp = VFSTONFS(vp->v_mount); 277 pages = ap->a_m; 278 count = ap->a_count; 279 rtvals = ap->a_rtvals; 280 npages = btoc(count); 281 offset = IDX_TO_OFF(pages[0]->pindex); 282 283 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 284 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 285 (void)nfs_fsinfo(nmp, vp, cred, td); 286 } 287 288 for (i = 0; i < npages; i++) 289 rtvals[i] = VM_PAGER_AGAIN; 290 291 /* 292 * When putting pages, do not extend file past EOF. 293 */ 294 295 if (offset + count > np->n_size) { 296 count = np->n_size - offset; 297 if (count < 0) 298 count = 0; 299 } 300 301 /* 302 * We use only the kva address for the buffer, but this is extremely 303 * convienient and fast. 304 */ 305 bp = getpbuf(&nfs_pbuf_freecnt); 306 307 kva = (vm_offset_t) bp->b_data; 308 pmap_qenter(kva, pages, npages); 309 cnt.v_vnodeout++; 310 cnt.v_vnodepgsout += count; 311 312 iov.iov_base = (caddr_t) kva; 313 iov.iov_len = count; 314 uio.uio_iov = &iov; 315 uio.uio_iovcnt = 1; 316 uio.uio_offset = offset; 317 uio.uio_resid = count; 318 uio.uio_segflg = UIO_SYSSPACE; 319 uio.uio_rw = UIO_WRITE; 320 uio.uio_td = td; 321 322 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0) 323 iomode = NFSV3WRITE_UNSTABLE; 324 else 325 iomode = NFSV3WRITE_FILESYNC; 326 327 error = nfs_writerpc(vp, &uio, cred, &iomode, &must_commit); 328 329 pmap_qremove(kva, npages); 330 relpbuf(bp, &nfs_pbuf_freecnt); 331 332 if (!error) { 333 int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE; 334 for (i = 0; i < nwritten; i++) { 335 rtvals[i] = VM_PAGER_OK; 336 vm_page_undirty(pages[i]); 337 } 338 if (must_commit) { 339 nfs_clearcommit(vp->v_mount); 340 } 341 } 342 return rtvals[0]; 343 } 344 345 /* 346 * Vnode op for read using bio 347 */ 348 int 349 nfs_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred) 350 { 351 struct nfsnode *np = VTONFS(vp); 352 int biosize, i; 353 struct buf *bp = 0, *rabp; 354 struct vattr vattr; 355 struct thread *td; 356 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 357 daddr_t lbn, rabn; 358 int bcount; 359 int seqcount; 360 int nra, error = 0, n = 0, on = 0; 361 362 #ifdef DIAGNOSTIC 363 if (uio->uio_rw != UIO_READ) 364 panic("nfs_read mode"); 365 #endif 366 if (uio->uio_resid == 0) 367 return (0); 368 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */ 369 return (EINVAL); 370 td = uio->uio_td; 371 372 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 373 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 374 (void)nfs_fsinfo(nmp, vp, cred, td); 375 if (vp->v_type != VDIR && 376 (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 377 return (EFBIG); 378 biosize = vp->v_mount->mnt_stat.f_iosize; 379 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE); 380 /* 381 * For nfs, cache consistency can only be maintained approximately. 382 * Although RFC1094 does not specify the criteria, the following is 383 * believed to be compatible with the reference port. 384 * For nfs: 385 * If the file's modify time on the server has changed since the 386 * last read rpc or you have written to the file, 387 * you may have lost data cache consistency with the 388 * server, so flush all of the file's data out of the cache. 389 * Then force a getattr rpc to ensure that you have up to date 390 * attributes. 391 * NB: This implies that cache data can be read when up to 392 * NFS_ATTRTIMEO seconds out of date. If you find that you need current 393 * attributes this could be forced by setting n_attrstamp to 0 before 394 * the VOP_GETATTR() call. 395 */ 396 if (np->n_flag & NMODIFIED) { 397 if (vp->v_type != VREG) { 398 if (vp->v_type != VDIR) 399 panic("nfs: bioread, not dir"); 400 nfs_invaldir(vp); 401 error = nfs_vinvalbuf(vp, V_SAVE, cred, td, 1); 402 if (error) 403 return (error); 404 } 405 np->n_attrstamp = 0; 406 error = VOP_GETATTR(vp, &vattr, cred, td); 407 if (error) 408 return (error); 409 np->n_mtime = vattr.va_mtime.tv_sec; 410 } else { 411 error = VOP_GETATTR(vp, &vattr, cred, td); 412 if (error) 413 return (error); 414 if (np->n_mtime != vattr.va_mtime.tv_sec) { 415 if (vp->v_type == VDIR) 416 nfs_invaldir(vp); 417 error = nfs_vinvalbuf(vp, V_SAVE, cred, td, 1); 418 if (error) 419 return (error); 420 np->n_mtime = vattr.va_mtime.tv_sec; 421 } 422 } 423 do { 424 switch (vp->v_type) { 425 case VREG: 426 nfsstats.biocache_reads++; 427 lbn = uio->uio_offset / biosize; 428 on = uio->uio_offset & (biosize - 1); 429 430 /* 431 * Start the read ahead(s), as required. 432 */ 433 if (nmp->nm_readahead > 0) { 434 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && 435 (off_t)(lbn + 1 + nra) * biosize < np->n_size; nra++) { 436 rabn = lbn + 1 + nra; 437 if (incore(vp, rabn) == NULL) { 438 rabp = nfs_getcacheblk(vp, rabn, biosize, td); 439 if (!rabp) 440 return (EINTR); 441 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 442 rabp->b_flags |= B_ASYNC; 443 rabp->b_iocmd = BIO_READ; 444 vfs_busy_pages(rabp, 0); 445 if (nfs_asyncio(rabp, cred, td)) { 446 rabp->b_flags |= B_INVAL; 447 rabp->b_ioflags |= BIO_ERROR; 448 vfs_unbusy_pages(rabp); 449 brelse(rabp); 450 break; 451 } 452 } else { 453 brelse(rabp); 454 } 455 } 456 } 457 } 458 459 /* 460 * Obtain the buffer cache block. Figure out the buffer size 461 * when we are at EOF. If we are modifying the size of the 462 * buffer based on an EOF condition we need to hold 463 * nfs_rslock() through obtaining the buffer to prevent 464 * a potential writer-appender from messing with n_size. 465 * Otherwise we may accidently truncate the buffer and 466 * lose dirty data. 467 * 468 * Note that bcount is *not* DEV_BSIZE aligned. 469 */ 470 471 again: 472 bcount = biosize; 473 if ((off_t)lbn * biosize >= np->n_size) { 474 bcount = 0; 475 } else if ((off_t)(lbn + 1) * biosize > np->n_size) { 476 bcount = np->n_size - (off_t)lbn * biosize; 477 } 478 if (bcount != biosize) { 479 switch(nfs_rslock(np, td)) { 480 case ENOLCK: 481 goto again; 482 /* not reached */ 483 case EINTR: 484 case ERESTART: 485 return(EINTR); 486 /* not reached */ 487 default: 488 break; 489 } 490 } 491 492 bp = nfs_getcacheblk(vp, lbn, bcount, td); 493 494 if (bcount != biosize) 495 nfs_rsunlock(np, td); 496 if (!bp) 497 return (EINTR); 498 499 /* 500 * If B_CACHE is not set, we must issue the read. If this 501 * fails, we return an error. 502 */ 503 504 if ((bp->b_flags & B_CACHE) == 0) { 505 bp->b_iocmd = BIO_READ; 506 vfs_busy_pages(bp, 0); 507 error = nfs_doio(bp, cred, td); 508 if (error) { 509 brelse(bp); 510 return (error); 511 } 512 } 513 514 /* 515 * on is the offset into the current bp. Figure out how many 516 * bytes we can copy out of the bp. Note that bcount is 517 * NOT DEV_BSIZE aligned. 518 * 519 * Then figure out how many bytes we can copy into the uio. 520 */ 521 522 n = 0; 523 if (on < bcount) 524 n = min((unsigned)(bcount - on), uio->uio_resid); 525 break; 526 case VLNK: 527 nfsstats.biocache_readlinks++; 528 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td); 529 if (!bp) 530 return (EINTR); 531 if ((bp->b_flags & B_CACHE) == 0) { 532 bp->b_iocmd = BIO_READ; 533 vfs_busy_pages(bp, 0); 534 error = nfs_doio(bp, cred, td); 535 if (error) { 536 bp->b_ioflags |= BIO_ERROR; 537 brelse(bp); 538 return (error); 539 } 540 } 541 n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); 542 on = 0; 543 break; 544 case VDIR: 545 nfsstats.biocache_readdirs++; 546 if (np->n_direofoffset 547 && uio->uio_offset >= np->n_direofoffset) { 548 return (0); 549 } 550 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; 551 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); 552 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td); 553 if (!bp) 554 return (EINTR); 555 if ((bp->b_flags & B_CACHE) == 0) { 556 bp->b_iocmd = BIO_READ; 557 vfs_busy_pages(bp, 0); 558 error = nfs_doio(bp, cred, td); 559 if (error) { 560 brelse(bp); 561 } 562 while (error == NFSERR_BAD_COOKIE) { 563 printf("got bad cookie vp %p bp %p\n", vp, bp); 564 nfs_invaldir(vp); 565 error = nfs_vinvalbuf(vp, 0, cred, td, 1); 566 /* 567 * Yuck! The directory has been modified on the 568 * server. The only way to get the block is by 569 * reading from the beginning to get all the 570 * offset cookies. 571 * 572 * Leave the last bp intact unless there is an error. 573 * Loop back up to the while if the error is another 574 * NFSERR_BAD_COOKIE (double yuch!). 575 */ 576 for (i = 0; i <= lbn && !error; i++) { 577 if (np->n_direofoffset 578 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) 579 return (0); 580 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td); 581 if (!bp) 582 return (EINTR); 583 if ((bp->b_flags & B_CACHE) == 0) { 584 bp->b_iocmd = BIO_READ; 585 vfs_busy_pages(bp, 0); 586 error = nfs_doio(bp, cred, td); 587 /* 588 * no error + B_INVAL == directory EOF, 589 * use the block. 590 */ 591 if (error == 0 && (bp->b_flags & B_INVAL)) 592 break; 593 } 594 /* 595 * An error will throw away the block and the 596 * for loop will break out. If no error and this 597 * is not the block we want, we throw away the 598 * block and go for the next one via the for loop. 599 */ 600 if (error || i < lbn) 601 brelse(bp); 602 } 603 } 604 /* 605 * The above while is repeated if we hit another cookie 606 * error. If we hit an error and it wasn't a cookie error, 607 * we give up. 608 */ 609 if (error) 610 return (error); 611 } 612 613 /* 614 * If not eof and read aheads are enabled, start one. 615 * (You need the current block first, so that you have the 616 * directory offset cookie of the next block.) 617 */ 618 if (nmp->nm_readahead > 0 && 619 (bp->b_flags & B_INVAL) == 0 && 620 (np->n_direofoffset == 0 || 621 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) && 622 incore(vp, lbn + 1) == NULL) { 623 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td); 624 if (rabp) { 625 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 626 rabp->b_flags |= B_ASYNC; 627 rabp->b_iocmd = BIO_READ; 628 vfs_busy_pages(rabp, 0); 629 if (nfs_asyncio(rabp, cred, td)) { 630 rabp->b_flags |= B_INVAL; 631 rabp->b_ioflags |= BIO_ERROR; 632 vfs_unbusy_pages(rabp); 633 brelse(rabp); 634 } 635 } else { 636 brelse(rabp); 637 } 638 } 639 } 640 /* 641 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is 642 * chopped for the EOF condition, we cannot tell how large 643 * NFS directories are going to be until we hit EOF. So 644 * an NFS directory buffer is *not* chopped to its EOF. Now, 645 * it just so happens that b_resid will effectively chop it 646 * to EOF. *BUT* this information is lost if the buffer goes 647 * away and is reconstituted into a B_CACHE state ( due to 648 * being VMIO ) later. So we keep track of the directory eof 649 * in np->n_direofoffset and chop it off as an extra step 650 * right here. 651 */ 652 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on); 653 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset) 654 n = np->n_direofoffset - uio->uio_offset; 655 break; 656 default: 657 printf(" nfs_bioread: type %x unexpected\n", vp->v_type); 658 break; 659 }; 660 661 if (n > 0) { 662 error = uiomove(bp->b_data + on, (int)n, uio); 663 } 664 switch (vp->v_type) { 665 case VREG: 666 break; 667 case VLNK: 668 n = 0; 669 break; 670 case VDIR: 671 break; 672 default: 673 printf(" nfs_bioread: type %x unexpected\n", vp->v_type); 674 } 675 brelse(bp); 676 } while (error == 0 && uio->uio_resid > 0 && n > 0); 677 return (error); 678 } 679 680 /* 681 * Vnode op for write using bio 682 */ 683 int 684 nfs_write(struct vop_write_args *ap) 685 { 686 int biosize; 687 struct uio *uio = ap->a_uio; 688 struct thread *td = uio->uio_td; 689 struct vnode *vp = ap->a_vp; 690 struct nfsnode *np = VTONFS(vp); 691 struct ucred *cred = ap->a_cred; 692 int ioflag = ap->a_ioflag; 693 struct buf *bp; 694 struct vattr vattr; 695 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 696 daddr_t lbn; 697 int bcount; 698 int n, on, error = 0; 699 int haverslock = 0; 700 struct proc *p = td?td->td_proc:NULL; 701 702 GIANT_REQUIRED; 703 704 #ifdef DIAGNOSTIC 705 if (uio->uio_rw != UIO_WRITE) 706 panic("nfs_write mode"); 707 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_td != curthread) 708 panic("nfs_write proc"); 709 #endif 710 if (vp->v_type != VREG) 711 return (EIO); 712 if (np->n_flag & NWRITEERR) { 713 np->n_flag &= ~NWRITEERR; 714 return (np->n_error); 715 } 716 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 717 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 718 (void)nfs_fsinfo(nmp, vp, cred, td); 719 720 /* 721 * Synchronously flush pending buffers if we are in synchronous 722 * mode or if we are appending. 723 */ 724 if (ioflag & (IO_APPEND | IO_SYNC)) { 725 if (np->n_flag & NMODIFIED) { 726 np->n_attrstamp = 0; 727 error = nfs_vinvalbuf(vp, V_SAVE, cred, td, 1); 728 if (error) 729 return (error); 730 } 731 } 732 733 /* 734 * If IO_APPEND then load uio_offset. We restart here if we cannot 735 * get the append lock. 736 */ 737 restart: 738 if (ioflag & IO_APPEND) { 739 np->n_attrstamp = 0; 740 error = VOP_GETATTR(vp, &vattr, cred, td); 741 if (error) 742 return (error); 743 uio->uio_offset = np->n_size; 744 } 745 746 if (uio->uio_offset < 0) 747 return (EINVAL); 748 if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 749 return (EFBIG); 750 if (uio->uio_resid == 0) 751 return (0); 752 753 /* 754 * We need to obtain the rslock if we intend to modify np->n_size 755 * in order to guarentee the append point with multiple contending 756 * writers, to guarentee that no other appenders modify n_size 757 * while we are trying to obtain a truncated buffer (i.e. to avoid 758 * accidently truncating data written by another appender due to 759 * the race), and to ensure that the buffer is populated prior to 760 * our extending of the file. We hold rslock through the entire 761 * operation. 762 * 763 * Note that we do not synchronize the case where someone truncates 764 * the file while we are appending to it because attempting to lock 765 * this case may deadlock other parts of the system unexpectedly. 766 */ 767 if ((ioflag & IO_APPEND) || 768 uio->uio_offset + uio->uio_resid > np->n_size) { 769 switch(nfs_rslock(np, td)) { 770 case ENOLCK: 771 goto restart; 772 /* not reached */ 773 case EINTR: 774 case ERESTART: 775 return(EINTR); 776 /* not reached */ 777 default: 778 break; 779 } 780 haverslock = 1; 781 } 782 783 /* 784 * Maybe this should be above the vnode op call, but so long as 785 * file servers have no limits, i don't think it matters 786 */ 787 if (p && uio->uio_offset + uio->uio_resid > 788 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 789 PROC_LOCK(p); 790 psignal(p, SIGXFSZ); 791 PROC_UNLOCK(p); 792 if (haverslock) 793 nfs_rsunlock(np, td); 794 return (EFBIG); 795 } 796 797 biosize = vp->v_mount->mnt_stat.f_iosize; 798 799 do { 800 nfsstats.biocache_writes++; 801 lbn = uio->uio_offset / biosize; 802 on = uio->uio_offset & (biosize-1); 803 n = min((unsigned)(biosize - on), uio->uio_resid); 804 again: 805 /* 806 * Handle direct append and file extension cases, calculate 807 * unaligned buffer size. 808 */ 809 810 if (uio->uio_offset == np->n_size && n) { 811 /* 812 * Get the buffer (in its pre-append state to maintain 813 * B_CACHE if it was previously set). Resize the 814 * nfsnode after we have locked the buffer to prevent 815 * readers from reading garbage. 816 */ 817 bcount = on; 818 bp = nfs_getcacheblk(vp, lbn, bcount, td); 819 820 if (bp != NULL) { 821 long save; 822 823 np->n_size = uio->uio_offset + n; 824 np->n_flag |= NMODIFIED; 825 vnode_pager_setsize(vp, np->n_size); 826 827 save = bp->b_flags & B_CACHE; 828 bcount += n; 829 allocbuf(bp, bcount); 830 bp->b_flags |= save; 831 bp->b_magic = B_MAGIC_NFS; 832 bp->b_op = &buf_ops_nfs; 833 } 834 } else { 835 /* 836 * Obtain the locked cache block first, and then 837 * adjust the file's size as appropriate. 838 */ 839 bcount = on + n; 840 if ((off_t)lbn * biosize + bcount < np->n_size) { 841 if ((off_t)(lbn + 1) * biosize < np->n_size) 842 bcount = biosize; 843 else 844 bcount = np->n_size - (off_t)lbn * biosize; 845 } 846 bp = nfs_getcacheblk(vp, lbn, bcount, td); 847 if (uio->uio_offset + n > np->n_size) { 848 np->n_size = uio->uio_offset + n; 849 np->n_flag |= NMODIFIED; 850 vnode_pager_setsize(vp, np->n_size); 851 } 852 } 853 854 if (!bp) { 855 error = EINTR; 856 break; 857 } 858 859 /* 860 * Issue a READ if B_CACHE is not set. In special-append 861 * mode, B_CACHE is based on the buffer prior to the write 862 * op and is typically set, avoiding the read. If a read 863 * is required in special append mode, the server will 864 * probably send us a short-read since we extended the file 865 * on our end, resulting in b_resid == 0 and, thusly, 866 * B_CACHE getting set. 867 * 868 * We can also avoid issuing the read if the write covers 869 * the entire buffer. We have to make sure the buffer state 870 * is reasonable in this case since we will not be initiating 871 * I/O. See the comments in kern/vfs_bio.c's getblk() for 872 * more information. 873 * 874 * B_CACHE may also be set due to the buffer being cached 875 * normally. 876 */ 877 878 if (on == 0 && n == bcount) { 879 bp->b_flags |= B_CACHE; 880 bp->b_flags &= ~B_INVAL; 881 bp->b_ioflags &= ~BIO_ERROR; 882 } 883 884 if ((bp->b_flags & B_CACHE) == 0) { 885 bp->b_iocmd = BIO_READ; 886 vfs_busy_pages(bp, 0); 887 error = nfs_doio(bp, cred, td); 888 if (error) { 889 brelse(bp); 890 break; 891 } 892 } 893 if (!bp) { 894 error = EINTR; 895 break; 896 } 897 if (bp->b_wcred == NOCRED) 898 bp->b_wcred = crhold(cred); 899 np->n_flag |= NMODIFIED; 900 901 /* 902 * If dirtyend exceeds file size, chop it down. This should 903 * not normally occur but there is an append race where it 904 * might occur XXX, so we log it. 905 * 906 * If the chopping creates a reverse-indexed or degenerate 907 * situation with dirtyoff/end, we 0 both of them. 908 */ 909 910 if (bp->b_dirtyend > bcount) { 911 printf("NFS append race @%lx:%d\n", 912 (long)bp->b_blkno * DEV_BSIZE, 913 bp->b_dirtyend - bcount); 914 bp->b_dirtyend = bcount; 915 } 916 917 if (bp->b_dirtyoff >= bp->b_dirtyend) 918 bp->b_dirtyoff = bp->b_dirtyend = 0; 919 920 /* 921 * If the new write will leave a contiguous dirty 922 * area, just update the b_dirtyoff and b_dirtyend, 923 * otherwise force a write rpc of the old dirty area. 924 * 925 * While it is possible to merge discontiguous writes due to 926 * our having a B_CACHE buffer ( and thus valid read data 927 * for the hole), we don't because it could lead to 928 * significant cache coherency problems with multiple clients, 929 * especially if locking is implemented later on. 930 * 931 * as an optimization we could theoretically maintain 932 * a linked list of discontinuous areas, but we would still 933 * have to commit them separately so there isn't much 934 * advantage to it except perhaps a bit of asynchronization. 935 */ 936 937 if (bp->b_dirtyend > 0 && 938 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { 939 if (BUF_WRITE(bp) == EINTR) { 940 error = EINTR; 941 break; 942 } 943 goto again; 944 } 945 946 error = uiomove((char *)bp->b_data + on, n, uio); 947 948 /* 949 * Since this block is being modified, it must be written 950 * again and not just committed. Since write clustering does 951 * not work for the stage 1 data write, only the stage 2 952 * commit rpc, we have to clear B_CLUSTEROK as well. 953 */ 954 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 955 956 if (error) { 957 bp->b_ioflags |= BIO_ERROR; 958 brelse(bp); 959 break; 960 } 961 962 /* 963 * Only update dirtyoff/dirtyend if not a degenerate 964 * condition. 965 */ 966 if (n) { 967 if (bp->b_dirtyend > 0) { 968 bp->b_dirtyoff = min(on, bp->b_dirtyoff); 969 bp->b_dirtyend = max((on + n), bp->b_dirtyend); 970 } else { 971 bp->b_dirtyoff = on; 972 bp->b_dirtyend = on + n; 973 } 974 vfs_bio_set_validclean(bp, on, n); 975 } 976 /* 977 * If IO_NOWDRAIN then set B_NOWDRAIN (nfs-backed MD 978 * filesystem) 979 */ 980 if (ioflag & IO_NOWDRAIN) 981 bp->b_flags |= B_NOWDRAIN; 982 983 /* 984 * If IO_SYNC do bwrite(). 985 * 986 * IO_INVAL appears to be unused. The idea appears to be 987 * to turn off caching in this case. Very odd. XXX 988 */ 989 if ((ioflag & IO_SYNC)) { 990 if (ioflag & IO_INVAL) 991 bp->b_flags |= B_NOCACHE; 992 error = BUF_WRITE(bp); 993 if (error) 994 break; 995 } else if ((n + on) == biosize) { 996 bp->b_flags |= B_ASYNC; 997 (void)nfs_writebp(bp, 0, 0); 998 } else { 999 bdwrite(bp); 1000 } 1001 } while (uio->uio_resid > 0 && n > 0); 1002 1003 if (haverslock) 1004 nfs_rsunlock(np, td); 1005 1006 return (error); 1007 } 1008 1009 /* 1010 * Get an nfs cache block. 1011 * 1012 * Allocate a new one if the block isn't currently in the cache 1013 * and return the block marked busy. If the calling process is 1014 * interrupted by a signal for an interruptible mount point, return 1015 * NULL. 1016 * 1017 * The caller must carefully deal with the possible B_INVAL state of 1018 * the buffer. nfs_doio() clears B_INVAL (and nfs_asyncio() clears it 1019 * indirectly), so synchronous reads can be issued without worrying about 1020 * the B_INVAL state. We have to be a little more careful when dealing 1021 * with writes (see comments in nfs_write()) when extending a file past 1022 * its EOF. 1023 */ 1024 static struct buf * 1025 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td) 1026 { 1027 struct buf *bp; 1028 struct mount *mp; 1029 struct nfsmount *nmp; 1030 1031 mp = vp->v_mount; 1032 nmp = VFSTONFS(mp); 1033 1034 if (nmp->nm_flag & NFSMNT_INT) { 1035 bp = getblk(vp, bn, size, PCATCH, 0, 0); 1036 while (bp == NULL) { 1037 if (nfs_sigintr(nmp, NULL, td)) 1038 return (NULL); 1039 bp = getblk(vp, bn, size, 0, 2 * hz, 0); 1040 } 1041 } else { 1042 bp = getblk(vp, bn, size, 0, 0, 0); 1043 } 1044 1045 if (vp->v_type == VREG) { 1046 int biosize; 1047 1048 biosize = mp->mnt_stat.f_iosize; 1049 bp->b_blkno = bn * (biosize / DEV_BSIZE); 1050 } 1051 return (bp); 1052 } 1053 1054 /* 1055 * Flush and invalidate all dirty buffers. If another process is already 1056 * doing the flush, just wait for completion. 1057 */ 1058 int 1059 nfs_vinvalbuf(struct vnode *vp, int flags, struct ucred *cred, 1060 struct thread *td, int intrflg) 1061 { 1062 struct nfsnode *np = VTONFS(vp); 1063 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 1064 int error = 0, slpflag, slptimeo; 1065 1066 ASSERT_VOP_LOCKED(vp, "nfs_vinvalbuf"); 1067 1068 VI_LOCK(vp); 1069 if (vp->v_iflag & VI_XLOCK) { 1070 /* XXX Should we wait here? */ 1071 VI_UNLOCK(vp); 1072 return (0); 1073 } 1074 VI_UNLOCK(vp); 1075 1076 if ((nmp->nm_flag & NFSMNT_INT) == 0) 1077 intrflg = 0; 1078 if (intrflg) { 1079 slpflag = PCATCH; 1080 slptimeo = 2 * hz; 1081 } else { 1082 slpflag = 0; 1083 slptimeo = 0; 1084 } 1085 /* 1086 * First wait for any other process doing a flush to complete. 1087 */ 1088 while (np->n_flag & NFLUSHINPROG) { 1089 np->n_flag |= NFLUSHWANT; 1090 error = tsleep(&np->n_flag, PRIBIO + 2, "nfsvinval", 1091 slptimeo); 1092 if (error && intrflg && 1093 nfs_sigintr(nmp, NULL, td)) 1094 return (EINTR); 1095 } 1096 1097 /* 1098 * Now, flush as required. 1099 */ 1100 np->n_flag |= NFLUSHINPROG; 1101 error = vinvalbuf(vp, flags, cred, td, slpflag, 0); 1102 while (error) { 1103 if (intrflg && 1104 nfs_sigintr(nmp, NULL, td)) { 1105 np->n_flag &= ~NFLUSHINPROG; 1106 if (np->n_flag & NFLUSHWANT) { 1107 np->n_flag &= ~NFLUSHWANT; 1108 wakeup(&np->n_flag); 1109 } 1110 return (EINTR); 1111 } 1112 error = vinvalbuf(vp, flags, cred, td, 0, slptimeo); 1113 } 1114 np->n_flag &= ~(NMODIFIED | NFLUSHINPROG); 1115 if (np->n_flag & NFLUSHWANT) { 1116 np->n_flag &= ~NFLUSHWANT; 1117 wakeup(&np->n_flag); 1118 } 1119 return (0); 1120 } 1121 1122 /* 1123 * Initiate asynchronous I/O. Return an error if no nfsiods are available. 1124 * This is mainly to avoid queueing async I/O requests when the nfsiods 1125 * are all hung on a dead server. 1126 * 1127 * Note: nfs_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp 1128 * is eventually dequeued by the async daemon, nfs_doio() *will*. 1129 */ 1130 int 1131 nfs_asyncio(struct buf *bp, struct ucred *cred, struct thread *td) 1132 { 1133 struct nfsmount *nmp; 1134 int iod; 1135 int gotiod; 1136 int slpflag = 0; 1137 int slptimeo = 0; 1138 int error; 1139 1140 nmp = VFSTONFS(bp->b_vp->v_mount); 1141 1142 /* 1143 * Commits are usually short and sweet so lets save some cpu and 1144 * leave the async daemons for more important rpc's (such as reads 1145 * and writes). 1146 */ 1147 if (bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) && 1148 (nmp->nm_bufqiods > nfs_numasync / 2)) { 1149 return(EIO); 1150 } 1151 1152 again: 1153 if (nmp->nm_flag & NFSMNT_INT) 1154 slpflag = PCATCH; 1155 gotiod = FALSE; 1156 1157 /* 1158 * Find a free iod to process this request. 1159 */ 1160 for (iod = 0; iod < nfs_numasync; iod++) 1161 if (nfs_iodwant[iod]) { 1162 gotiod = TRUE; 1163 break; 1164 } 1165 1166 /* 1167 * Try to create one if none are free. 1168 */ 1169 if (!gotiod) { 1170 iod = nfs_nfsiodnew(); 1171 if (iod != -1) 1172 gotiod = TRUE; 1173 } 1174 1175 if (gotiod) { 1176 /* 1177 * Found one, so wake it up and tell it which 1178 * mount to process. 1179 */ 1180 NFS_DPF(ASYNCIO, ("nfs_asyncio: waking iod %d for mount %p\n", 1181 iod, nmp)); 1182 nfs_iodwant[iod] = NULL; 1183 nfs_iodmount[iod] = nmp; 1184 nmp->nm_bufqiods++; 1185 wakeup(&nfs_iodwant[iod]); 1186 } 1187 1188 /* 1189 * If none are free, we may already have an iod working on this mount 1190 * point. If so, it will process our request. 1191 */ 1192 if (!gotiod) { 1193 if (nmp->nm_bufqiods > 0) { 1194 NFS_DPF(ASYNCIO, 1195 ("nfs_asyncio: %d iods are already processing mount %p\n", 1196 nmp->nm_bufqiods, nmp)); 1197 gotiod = TRUE; 1198 } 1199 } 1200 1201 /* 1202 * If we have an iod which can process the request, then queue 1203 * the buffer. 1204 */ 1205 if (gotiod) { 1206 /* 1207 * Ensure that the queue never grows too large. We still want 1208 * to asynchronize so we block rather then return EIO. 1209 */ 1210 while (nmp->nm_bufqlen >= 2*nfs_numasync) { 1211 NFS_DPF(ASYNCIO, 1212 ("nfs_asyncio: waiting for mount %p queue to drain\n", nmp)); 1213 nmp->nm_bufqwant = TRUE; 1214 error = tsleep(&nmp->nm_bufq, slpflag | PRIBIO, 1215 "nfsaio", slptimeo); 1216 if (error) { 1217 if (nfs_sigintr(nmp, NULL, td)) 1218 return (EINTR); 1219 if (slpflag == PCATCH) { 1220 slpflag = 0; 1221 slptimeo = 2 * hz; 1222 } 1223 } 1224 /* 1225 * We might have lost our iod while sleeping, 1226 * so check and loop if nescessary. 1227 */ 1228 if (nmp->nm_bufqiods == 0) { 1229 NFS_DPF(ASYNCIO, 1230 ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); 1231 goto again; 1232 } 1233 } 1234 1235 if (bp->b_iocmd == BIO_READ) { 1236 if (bp->b_rcred == NOCRED && cred != NOCRED) 1237 bp->b_rcred = crhold(cred); 1238 } else { 1239 bp->b_flags |= B_WRITEINPROG; 1240 if (bp->b_wcred == NOCRED && cred != NOCRED) 1241 bp->b_wcred = crhold(cred); 1242 } 1243 1244 BUF_KERNPROC(bp); 1245 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist); 1246 nmp->nm_bufqlen++; 1247 return (0); 1248 } 1249 1250 /* 1251 * All the iods are busy on other mounts, so return EIO to 1252 * force the caller to process the i/o synchronously. 1253 */ 1254 NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n")); 1255 return (EIO); 1256 } 1257 1258 /* 1259 * Do an I/O operation to/from a cache block. This may be called 1260 * synchronously or from an nfsiod. 1261 */ 1262 int 1263 nfs_doio(struct buf *bp, struct ucred *cr, struct thread *td) 1264 { 1265 struct uio *uiop; 1266 struct vnode *vp; 1267 struct nfsnode *np; 1268 struct nfsmount *nmp; 1269 int error = 0, iomode, must_commit = 0; 1270 struct uio uio; 1271 struct iovec io; 1272 struct proc *p = td ? td->td_proc : NULL; 1273 1274 vp = bp->b_vp; 1275 np = VTONFS(vp); 1276 nmp = VFSTONFS(vp->v_mount); 1277 uiop = &uio; 1278 uiop->uio_iov = &io; 1279 uiop->uio_iovcnt = 1; 1280 uiop->uio_segflg = UIO_SYSSPACE; 1281 uiop->uio_td = td; 1282 1283 /* 1284 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We 1285 * do this here so we do not have to do it in all the code that 1286 * calls us. 1287 */ 1288 bp->b_flags &= ~B_INVAL; 1289 bp->b_ioflags &= ~BIO_ERROR; 1290 1291 KASSERT(!(bp->b_flags & B_DONE), ("nfs_doio: bp %p already marked done", bp)); 1292 1293 /* 1294 * Historically, paging was done with physio, but no more. 1295 */ 1296 if (bp->b_flags & B_PHYS) { 1297 /* 1298 * ...though reading /dev/drum still gets us here. 1299 */ 1300 io.iov_len = uiop->uio_resid = bp->b_bcount; 1301 /* mapping was done by vmapbuf() */ 1302 io.iov_base = bp->b_data; 1303 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE; 1304 if (bp->b_iocmd == BIO_READ) { 1305 uiop->uio_rw = UIO_READ; 1306 nfsstats.read_physios++; 1307 error = nfs_readrpc(vp, uiop, cr); 1308 } else { 1309 int com; 1310 1311 iomode = NFSV3WRITE_DATASYNC; 1312 uiop->uio_rw = UIO_WRITE; 1313 nfsstats.write_physios++; 1314 error = nfs_writerpc(vp, uiop, cr, &iomode, &com); 1315 } 1316 if (error) { 1317 bp->b_ioflags |= BIO_ERROR; 1318 bp->b_error = error; 1319 } 1320 } else if (bp->b_iocmd == BIO_READ) { 1321 io.iov_len = uiop->uio_resid = bp->b_bcount; 1322 io.iov_base = bp->b_data; 1323 uiop->uio_rw = UIO_READ; 1324 1325 switch (vp->v_type) { 1326 case VREG: 1327 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE; 1328 nfsstats.read_bios++; 1329 error = nfs_readrpc(vp, uiop, cr); 1330 1331 if (!error) { 1332 if (uiop->uio_resid) { 1333 /* 1334 * If we had a short read with no error, we must have 1335 * hit a file hole. We should zero-fill the remainder. 1336 * This can also occur if the server hits the file EOF. 1337 * 1338 * Holes used to be able to occur due to pending 1339 * writes, but that is not possible any longer. 1340 */ 1341 int nread = bp->b_bcount - uiop->uio_resid; 1342 int left = uiop->uio_resid; 1343 1344 if (left > 0) 1345 bzero((char *)bp->b_data + nread, left); 1346 uiop->uio_resid = 0; 1347 } 1348 } 1349 /* ASSERT_VOP_LOCKED(vp, "nfs_doio"); */ 1350 if (p && (vp->v_vflag & VV_TEXT) && 1351 (np->n_mtime != np->n_vattr.va_mtime.tv_sec)) { 1352 uprintf("Process killed due to text file modification\n"); 1353 PROC_LOCK(p); 1354 psignal(p, SIGKILL); 1355 _PHOLD(p); 1356 PROC_UNLOCK(p); 1357 } 1358 break; 1359 case VLNK: 1360 uiop->uio_offset = (off_t)0; 1361 nfsstats.readlink_bios++; 1362 error = nfs_readlinkrpc(vp, uiop, cr); 1363 break; 1364 case VDIR: 1365 nfsstats.readdir_bios++; 1366 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ; 1367 if (nmp->nm_flag & NFSMNT_RDIRPLUS) { 1368 error = nfs_readdirplusrpc(vp, uiop, cr); 1369 if (error == NFSERR_NOTSUPP) 1370 nmp->nm_flag &= ~NFSMNT_RDIRPLUS; 1371 } 1372 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) 1373 error = nfs_readdirrpc(vp, uiop, cr); 1374 /* 1375 * end-of-directory sets B_INVAL but does not generate an 1376 * error. 1377 */ 1378 if (error == 0 && uiop->uio_resid == bp->b_bcount) 1379 bp->b_flags |= B_INVAL; 1380 break; 1381 default: 1382 printf("nfs_doio: type %x unexpected\n", vp->v_type); 1383 break; 1384 }; 1385 if (error) { 1386 bp->b_ioflags |= BIO_ERROR; 1387 bp->b_error = error; 1388 } 1389 } else { 1390 /* 1391 * If we only need to commit, try to commit 1392 */ 1393 if (bp->b_flags & B_NEEDCOMMIT) { 1394 int retv; 1395 off_t off; 1396 1397 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff; 1398 bp->b_flags |= B_WRITEINPROG; 1399 retv = nfs_commit( 1400 bp->b_vp, off, bp->b_dirtyend-bp->b_dirtyoff, 1401 bp->b_wcred, td); 1402 bp->b_flags &= ~B_WRITEINPROG; 1403 if (retv == 0) { 1404 bp->b_dirtyoff = bp->b_dirtyend = 0; 1405 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1406 bp->b_resid = 0; 1407 bufdone(bp); 1408 return (0); 1409 } 1410 if (retv == NFSERR_STALEWRITEVERF) { 1411 nfs_clearcommit(bp->b_vp->v_mount); 1412 } 1413 } 1414 1415 /* 1416 * Setup for actual write 1417 */ 1418 1419 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size) 1420 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE; 1421 1422 if (bp->b_dirtyend > bp->b_dirtyoff) { 1423 io.iov_len = uiop->uio_resid = bp->b_dirtyend 1424 - bp->b_dirtyoff; 1425 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE 1426 + bp->b_dirtyoff; 1427 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; 1428 uiop->uio_rw = UIO_WRITE; 1429 nfsstats.write_bios++; 1430 1431 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC) 1432 iomode = NFSV3WRITE_UNSTABLE; 1433 else 1434 iomode = NFSV3WRITE_FILESYNC; 1435 1436 bp->b_flags |= B_WRITEINPROG; 1437 error = nfs_writerpc(vp, uiop, cr, &iomode, &must_commit); 1438 1439 /* 1440 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try 1441 * to cluster the buffers needing commit. This will allow 1442 * the system to submit a single commit rpc for the whole 1443 * cluster. We can do this even if the buffer is not 100% 1444 * dirty (relative to the NFS blocksize), so we optimize the 1445 * append-to-file-case. 1446 * 1447 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be 1448 * cleared because write clustering only works for commit 1449 * rpc's, not for the data portion of the write). 1450 */ 1451 1452 if (!error && iomode == NFSV3WRITE_UNSTABLE) { 1453 bp->b_flags |= B_NEEDCOMMIT; 1454 if (bp->b_dirtyoff == 0 1455 && bp->b_dirtyend == bp->b_bcount) 1456 bp->b_flags |= B_CLUSTEROK; 1457 } else { 1458 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1459 } 1460 bp->b_flags &= ~B_WRITEINPROG; 1461 1462 /* 1463 * For an interrupted write, the buffer is still valid 1464 * and the write hasn't been pushed to the server yet, 1465 * so we can't set BIO_ERROR and report the interruption 1466 * by setting B_EINTR. For the B_ASYNC case, B_EINTR 1467 * is not relevant, so the rpc attempt is essentially 1468 * a noop. For the case of a V3 write rpc not being 1469 * committed to stable storage, the block is still 1470 * dirty and requires either a commit rpc or another 1471 * write rpc with iomode == NFSV3WRITE_FILESYNC before 1472 * the block is reused. This is indicated by setting 1473 * the B_DELWRI and B_NEEDCOMMIT flags. 1474 * 1475 * If the buffer is marked B_PAGING, it does not reside on 1476 * the vp's paging queues so we cannot call bdirty(). The 1477 * bp in this case is not an NFS cache block so we should 1478 * be safe. XXX 1479 */ 1480 if (error == EINTR 1481 || (!error && (bp->b_flags & B_NEEDCOMMIT))) { 1482 int s; 1483 1484 s = splbio(); 1485 bp->b_flags &= ~(B_INVAL|B_NOCACHE); 1486 if ((bp->b_flags & B_PAGING) == 0) { 1487 bdirty(bp); 1488 bp->b_flags &= ~B_DONE; 1489 } 1490 if (error && (bp->b_flags & B_ASYNC) == 0) 1491 bp->b_flags |= B_EINTR; 1492 splx(s); 1493 } else { 1494 if (error) { 1495 bp->b_ioflags |= BIO_ERROR; 1496 bp->b_error = np->n_error = error; 1497 np->n_flag |= NWRITEERR; 1498 } 1499 bp->b_dirtyoff = bp->b_dirtyend = 0; 1500 } 1501 } else { 1502 bp->b_resid = 0; 1503 bufdone(bp); 1504 return (0); 1505 } 1506 } 1507 bp->b_resid = uiop->uio_resid; 1508 if (must_commit) 1509 nfs_clearcommit(vp->v_mount); 1510 bufdone(bp); 1511 return (error); 1512 } 1513 1514 /* 1515 * Used to aid in handling ftruncate() operations on the NFS client side. 1516 * Truncation creates a number of special problems for NFS. We have to 1517 * throw away VM pages and buffer cache buffers that are beyond EOF, and 1518 * we have to properly handle VM pages or (potentially dirty) buffers 1519 * that straddle the truncation point. 1520 */ 1521 1522 int 1523 nfs_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize) 1524 { 1525 struct nfsnode *np = VTONFS(vp); 1526 u_quad_t tsize = np->n_size; 1527 int biosize = vp->v_mount->mnt_stat.f_iosize; 1528 int error = 0; 1529 1530 np->n_size = nsize; 1531 1532 if (np->n_size < tsize) { 1533 struct buf *bp; 1534 daddr_t lbn; 1535 int bufsize; 1536 1537 /* 1538 * vtruncbuf() doesn't get the buffer overlapping the 1539 * truncation point. We may have a B_DELWRI and/or B_CACHE 1540 * buffer that now needs to be truncated. 1541 */ 1542 error = vtruncbuf(vp, cred, td, nsize, biosize); 1543 lbn = nsize / biosize; 1544 bufsize = nsize & (biosize - 1); 1545 bp = nfs_getcacheblk(vp, lbn, bufsize, td); 1546 if (bp->b_dirtyoff > bp->b_bcount) 1547 bp->b_dirtyoff = bp->b_bcount; 1548 if (bp->b_dirtyend > bp->b_bcount) 1549 bp->b_dirtyend = bp->b_bcount; 1550 bp->b_flags |= B_RELBUF; /* don't leave garbage around */ 1551 brelse(bp); 1552 } else { 1553 vnode_pager_setsize(vp, nsize); 1554 } 1555 return(error); 1556 } 1557
Cache object: cac6ed202d97cd10f5affd7fb1fe1fbe
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]