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/nfs/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 * $FreeBSD$ 38 */ 39 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/resourcevar.h> 44 #include <sys/signalvar.h> 45 #include <sys/proc.h> 46 #include <sys/buf.h> 47 #include <sys/vnode.h> 48 #include <sys/mount.h> 49 #include <sys/kernel.h> 50 51 #include <vm/vm.h> 52 #include <vm/vm_extern.h> 53 #include <vm/vm_page.h> 54 #include <vm/vm_object.h> 55 #include <vm/vm_pager.h> 56 #include <vm/vnode_pager.h> 57 58 #include <nfs/rpcv2.h> 59 #include <nfs/nfsproto.h> 60 #include <nfs/nfs.h> 61 #include <nfs/nfsmount.h> 62 #include <nfs/nqnfs.h> 63 #include <nfs/nfsnode.h> 64 65 static struct buf *nfs_getcacheblk __P((struct vnode *vp, daddr_t bn, int size, 66 struct proc *p)); 67 68 extern int nfs_numasync; 69 extern int nfs_pbuf_freecnt; 70 extern struct nfsstats nfsstats; 71 72 /* 73 * Vnode op for VM getpages. 74 */ 75 int 76 nfs_getpages(ap) 77 struct vop_getpages_args /* { 78 struct vnode *a_vp; 79 vm_page_t *a_m; 80 int a_count; 81 int a_reqpage; 82 vm_ooffset_t a_offset; 83 } */ *ap; 84 { 85 int i, error, nextoff, size, toff, count, npages; 86 struct uio uio; 87 struct iovec iov; 88 vm_offset_t kva; 89 struct buf *bp; 90 struct vnode *vp; 91 struct proc *p; 92 struct ucred *cred; 93 struct nfsmount *nmp; 94 vm_page_t *pages; 95 96 vp = ap->a_vp; 97 p = curproc; /* XXX */ 98 cred = curproc->p_ucred; /* XXX */ 99 nmp = VFSTONFS(vp->v_mount); 100 pages = ap->a_m; 101 count = ap->a_count; 102 103 if (vp->v_object == NULL) { 104 printf("nfs_getpages: called with non-merged cache vnode??\n"); 105 return VM_PAGER_ERROR; 106 } 107 108 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 109 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 110 (void)nfs_fsinfo(nmp, vp, cred, p); 111 112 npages = btoc(count); 113 114 /* 115 * If the requested page is partially valid, just return it and 116 * allow the pager to zero-out the blanks. Partially valid pages 117 * can only occur at the file EOF. 118 */ 119 120 { 121 vm_page_t m = pages[ap->a_reqpage]; 122 123 if (m->valid != 0) { 124 /* handled by vm_fault now */ 125 /* vm_page_zero_invalid(m, TRUE); */ 126 for (i = 0; i < npages; ++i) { 127 if (i != ap->a_reqpage) 128 vnode_pager_freepage(pages[i]); 129 } 130 return(0); 131 } 132 } 133 134 /* 135 * We use only the kva address for the buffer, but this is extremely 136 * convienient and fast. 137 */ 138 bp = getpbuf(&nfs_pbuf_freecnt); 139 140 kva = (vm_offset_t) bp->b_data; 141 pmap_qenter(kva, pages, npages); 142 143 iov.iov_base = (caddr_t) kva; 144 iov.iov_len = count; 145 uio.uio_iov = &iov; 146 uio.uio_iovcnt = 1; 147 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex); 148 uio.uio_resid = count; 149 uio.uio_segflg = UIO_SYSSPACE; 150 uio.uio_rw = UIO_READ; 151 uio.uio_procp = p; 152 153 error = nfs_readrpc(vp, &uio, cred); 154 pmap_qremove(kva, npages); 155 156 relpbuf(bp, &nfs_pbuf_freecnt); 157 158 if (error && (uio.uio_resid == count)) { 159 printf("nfs_getpages: error %d\n", error); 160 for (i = 0; i < npages; ++i) { 161 if (i != ap->a_reqpage) 162 vnode_pager_freepage(pages[i]); 163 } 164 return VM_PAGER_ERROR; 165 } 166 167 /* 168 * Calculate the number of bytes read and validate only that number 169 * of bytes. Note that due to pending writes, size may be 0. This 170 * does not mean that the remaining data is invalid! 171 */ 172 173 size = count - uio.uio_resid; 174 175 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) { 176 vm_page_t m; 177 nextoff = toff + PAGE_SIZE; 178 m = pages[i]; 179 180 m->flags &= ~PG_ZERO; 181 182 if (nextoff <= size) { 183 /* 184 * Read operation filled an entire page 185 */ 186 m->valid = VM_PAGE_BITS_ALL; 187 vm_page_undirty(m); 188 } else if (size > toff) { 189 /* 190 * Read operation filled a partial page. 191 */ 192 m->valid = 0; 193 vm_page_set_validclean(m, 0, size - toff); 194 /* handled by vm_fault now */ 195 /* vm_page_zero_invalid(m, TRUE); */ 196 } else { 197 /* 198 * Read operation was short. If no error occured 199 * we may have hit a zero-fill section. We simply 200 * leave valid set to 0. 201 */ 202 ; 203 } 204 if (i != ap->a_reqpage) { 205 /* 206 * Whether or not to leave the page activated is up in 207 * the air, but we should put the page on a page queue 208 * somewhere (it already is in the object). Result: 209 * It appears that emperical results show that 210 * deactivating pages is best. 211 */ 212 213 /* 214 * Just in case someone was asking for this page we 215 * now tell them that it is ok to use. 216 */ 217 if (!error) { 218 if (m->flags & PG_WANTED) 219 vm_page_activate(m); 220 else 221 vm_page_deactivate(m); 222 vm_page_wakeup(m); 223 } else { 224 vnode_pager_freepage(m); 225 } 226 } 227 } 228 return 0; 229 } 230 231 /* 232 * Vnode op for VM putpages. 233 */ 234 int 235 nfs_putpages(ap) 236 struct vop_putpages_args /* { 237 struct vnode *a_vp; 238 vm_page_t *a_m; 239 int a_count; 240 int a_sync; 241 int *a_rtvals; 242 vm_ooffset_t a_offset; 243 } */ *ap; 244 { 245 struct uio uio; 246 struct iovec iov; 247 vm_offset_t kva; 248 struct buf *bp; 249 int iomode, must_commit, i, error, npages, count; 250 off_t offset; 251 int *rtvals; 252 struct vnode *vp; 253 struct proc *p; 254 struct ucred *cred; 255 struct nfsmount *nmp; 256 struct nfsnode *np; 257 vm_page_t *pages; 258 259 vp = ap->a_vp; 260 np = VTONFS(vp); 261 p = curproc; /* XXX */ 262 cred = curproc->p_ucred; /* XXX */ 263 nmp = VFSTONFS(vp->v_mount); 264 pages = ap->a_m; 265 count = ap->a_count; 266 rtvals = ap->a_rtvals; 267 npages = btoc(count); 268 offset = IDX_TO_OFF(pages[0]->pindex); 269 270 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 271 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 272 (void)nfs_fsinfo(nmp, vp, cred, p); 273 274 for (i = 0; i < npages; i++) { 275 rtvals[i] = VM_PAGER_AGAIN; 276 } 277 278 /* 279 * When putting pages, do not extend file past EOF. 280 */ 281 282 if (offset + count > np->n_size) { 283 count = np->n_size - offset; 284 if (count < 0) 285 count = 0; 286 } 287 288 /* 289 * We use only the kva address for the buffer, but this is extremely 290 * convienient and fast. 291 */ 292 bp = getpbuf(&nfs_pbuf_freecnt); 293 294 kva = (vm_offset_t) bp->b_data; 295 pmap_qenter(kva, pages, npages); 296 297 iov.iov_base = (caddr_t) kva; 298 iov.iov_len = count; 299 uio.uio_iov = &iov; 300 uio.uio_iovcnt = 1; 301 uio.uio_offset = offset; 302 uio.uio_resid = count; 303 uio.uio_segflg = UIO_SYSSPACE; 304 uio.uio_rw = UIO_WRITE; 305 uio.uio_procp = p; 306 307 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0) 308 iomode = NFSV3WRITE_UNSTABLE; 309 else 310 iomode = NFSV3WRITE_FILESYNC; 311 312 error = nfs_writerpc(vp, &uio, cred, &iomode, &must_commit); 313 314 pmap_qremove(kva, npages); 315 relpbuf(bp, &nfs_pbuf_freecnt); 316 317 if (!error) { 318 int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE; 319 for (i = 0; i < nwritten; i++) { 320 rtvals[i] = VM_PAGER_OK; 321 vm_page_undirty(pages[i]); 322 } 323 if (must_commit) 324 nfs_clearcommit(vp->v_mount); 325 } 326 return rtvals[0]; 327 } 328 329 /* 330 * Vnode op for read using bio 331 */ 332 int 333 nfs_bioread(vp, uio, ioflag, cred) 334 register struct vnode *vp; 335 register struct uio *uio; 336 int ioflag; 337 struct ucred *cred; 338 { 339 register struct nfsnode *np = VTONFS(vp); 340 register int biosize, i; 341 struct buf *bp = 0, *rabp; 342 struct vattr vattr; 343 struct proc *p; 344 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 345 daddr_t lbn, rabn; 346 int bcount; 347 int seqcount; 348 int nra, error = 0, n = 0, on = 0; 349 350 #ifdef DIAGNOSTIC 351 if (uio->uio_rw != UIO_READ) 352 panic("nfs_read mode"); 353 #endif 354 if (uio->uio_resid == 0) 355 return (0); 356 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */ 357 return (EINVAL); 358 p = uio->uio_procp; 359 360 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 361 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 362 (void)nfs_fsinfo(nmp, vp, cred, p); 363 if (vp->v_type != VDIR && 364 (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 365 return (EFBIG); 366 biosize = vp->v_mount->mnt_stat.f_iosize; 367 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE); 368 /* 369 * For nfs, cache consistency can only be maintained approximately. 370 * Although RFC1094 does not specify the criteria, the following is 371 * believed to be compatible with the reference port. 372 * For nqnfs, full cache consistency is maintained within the loop. 373 * For nfs: 374 * If the file's modify time on the server has changed since the 375 * last read rpc or you have written to the file, 376 * you may have lost data cache consistency with the 377 * server, so flush all of the file's data out of the cache. 378 * Then force a getattr rpc to ensure that you have up to date 379 * attributes. 380 * NB: This implies that cache data can be read when up to 381 * NFS_ATTRTIMEO seconds out of date. If you find that you need current 382 * attributes this could be forced by setting n_attrstamp to 0 before 383 * the VOP_GETATTR() call. 384 */ 385 if ((nmp->nm_flag & NFSMNT_NQNFS) == 0) { 386 if (np->n_flag & NMODIFIED) { 387 if (vp->v_type != VREG) { 388 if (vp->v_type != VDIR) 389 panic("nfs: bioread, not dir"); 390 nfs_invaldir(vp); 391 error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); 392 if (error) 393 return (error); 394 } 395 np->n_attrstamp = 0; 396 error = VOP_GETATTR(vp, &vattr, cred, p); 397 if (error) 398 return (error); 399 np->n_mtime = vattr.va_mtime.tv_sec; 400 } else { 401 error = VOP_GETATTR(vp, &vattr, cred, p); 402 if (error) 403 return (error); 404 if ((np->n_flag & NSIZECHANGED) 405 || np->n_mtime != vattr.va_mtime.tv_sec) { 406 if (vp->v_type == VDIR) 407 nfs_invaldir(vp); 408 error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); 409 if (error) 410 return (error); 411 np->n_mtime = vattr.va_mtime.tv_sec; 412 np->n_flag &= ~NSIZECHANGED; 413 } 414 } 415 } 416 do { 417 418 /* 419 * Get a valid lease. If cached data is stale, flush it. 420 */ 421 if (nmp->nm_flag & NFSMNT_NQNFS) { 422 if (NQNFS_CKINVALID(vp, np, ND_READ)) { 423 do { 424 error = nqnfs_getlease(vp, ND_READ, cred, p); 425 } while (error == NQNFS_EXPIRED); 426 if (error) 427 return (error); 428 if (np->n_lrev != np->n_brev || 429 (np->n_flag & NQNFSNONCACHE) || 430 ((np->n_flag & NMODIFIED) && vp->v_type == VDIR)) { 431 if (vp->v_type == VDIR) 432 nfs_invaldir(vp); 433 error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); 434 if (error) 435 return (error); 436 np->n_brev = np->n_lrev; 437 } 438 } else if (vp->v_type == VDIR && (np->n_flag & NMODIFIED)) { 439 nfs_invaldir(vp); 440 error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); 441 if (error) 442 return (error); 443 } 444 } 445 if (np->n_flag & NQNFSNONCACHE) { 446 switch (vp->v_type) { 447 case VREG: 448 return (nfs_readrpc(vp, uio, cred)); 449 case VLNK: 450 return (nfs_readlinkrpc(vp, uio, cred)); 451 case VDIR: 452 break; 453 default: 454 printf(" NQNFSNONCACHE: type %x unexpected\n", 455 vp->v_type); 456 }; 457 } 458 switch (vp->v_type) { 459 case VREG: 460 nfsstats.biocache_reads++; 461 lbn = uio->uio_offset / biosize; 462 on = uio->uio_offset & (biosize - 1); 463 464 /* 465 * Start the read ahead(s), as required. 466 */ 467 if (nfs_numasync > 0 && nmp->nm_readahead > 0) { 468 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && 469 (off_t)(lbn + 1 + nra) * biosize < np->n_size; nra++) { 470 rabn = lbn + 1 + nra; 471 if (!incore(vp, rabn)) { 472 rabp = nfs_getcacheblk(vp, rabn, biosize, p); 473 if (!rabp) 474 return (EINTR); 475 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 476 rabp->b_flags |= (B_READ | B_ASYNC); 477 vfs_busy_pages(rabp, 0); 478 if (nfs_asyncio(rabp, cred, p)) { 479 rabp->b_flags |= B_INVAL|B_ERROR; 480 vfs_unbusy_pages(rabp); 481 brelse(rabp); 482 break; 483 } 484 } else { 485 brelse(rabp); 486 } 487 } 488 } 489 } 490 491 /* 492 * Obtain the buffer cache block. Figure out the buffer size 493 * when we are at EOF. If we are modifying the size of the 494 * buffer based on an EOF condition we need to hold 495 * nfs_rslock() through obtaining the buffer to prevent 496 * a potential writer-appender from messing with n_size. 497 * Otherwise we may accidently truncate the buffer and 498 * lose dirty data. 499 * 500 * Note that bcount is *not* DEV_BSIZE aligned. 501 */ 502 503 again: 504 bcount = biosize; 505 if ((off_t)lbn * biosize >= np->n_size) { 506 bcount = 0; 507 } else if ((off_t)(lbn + 1) * biosize > np->n_size) { 508 bcount = np->n_size - (off_t)lbn * biosize; 509 } 510 if (bcount != biosize) { 511 switch(nfs_rslock(np, p)) { 512 case ENOLCK: 513 goto again; 514 /* not reached */ 515 case EINTR: 516 case ERESTART: 517 return(EINTR); 518 /* not reached */ 519 default: 520 break; 521 } 522 } 523 524 bp = nfs_getcacheblk(vp, lbn, bcount, p); 525 526 if (bcount != biosize) 527 nfs_rsunlock(np, p); 528 if (!bp) 529 return (EINTR); 530 531 /* 532 * If B_CACHE is not set, we must issue the read. If this 533 * fails, we return an error. 534 */ 535 536 if ((bp->b_flags & B_CACHE) == 0) { 537 bp->b_flags |= B_READ; 538 vfs_busy_pages(bp, 0); 539 error = nfs_doio(bp, cred, p); 540 if (error) { 541 brelse(bp); 542 return (error); 543 } 544 } 545 546 /* 547 * on is the offset into the current bp. Figure out how many 548 * bytes we can copy out of the bp. Note that bcount is 549 * NOT DEV_BSIZE aligned. 550 * 551 * Then figure out how many bytes we can copy into the uio. 552 */ 553 554 n = 0; 555 if (on < bcount) 556 n = min((unsigned)(bcount - on), uio->uio_resid); 557 break; 558 case VLNK: 559 nfsstats.biocache_readlinks++; 560 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, p); 561 if (!bp) 562 return (EINTR); 563 if ((bp->b_flags & B_CACHE) == 0) { 564 bp->b_flags |= B_READ; 565 vfs_busy_pages(bp, 0); 566 error = nfs_doio(bp, cred, p); 567 if (error) { 568 bp->b_flags |= B_ERROR; 569 brelse(bp); 570 return (error); 571 } 572 } 573 n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); 574 on = 0; 575 break; 576 case VDIR: 577 nfsstats.biocache_readdirs++; 578 if (np->n_direofoffset 579 && uio->uio_offset >= np->n_direofoffset) { 580 return (0); 581 } 582 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; 583 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); 584 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, p); 585 if (!bp) 586 return (EINTR); 587 if ((bp->b_flags & B_CACHE) == 0) { 588 bp->b_flags |= B_READ; 589 vfs_busy_pages(bp, 0); 590 error = nfs_doio(bp, cred, p); 591 if (error) { 592 brelse(bp); 593 } 594 while (error == NFSERR_BAD_COOKIE) { 595 printf("got bad cookie vp %p bp %p\n", vp, bp); 596 nfs_invaldir(vp); 597 error = nfs_vinvalbuf(vp, 0, cred, p, 1); 598 /* 599 * Yuck! The directory has been modified on the 600 * server. The only way to get the block is by 601 * reading from the beginning to get all the 602 * offset cookies. 603 * 604 * Leave the last bp intact unless there is an error. 605 * Loop back up to the while if the error is another 606 * NFSERR_BAD_COOKIE (double yuch!). 607 */ 608 for (i = 0; i <= lbn && !error; i++) { 609 if (np->n_direofoffset 610 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) 611 return (0); 612 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, p); 613 if (!bp) 614 return (EINTR); 615 if ((bp->b_flags & B_CACHE) == 0) { 616 bp->b_flags |= B_READ; 617 vfs_busy_pages(bp, 0); 618 error = nfs_doio(bp, cred, p); 619 /* 620 * no error + B_INVAL == directory EOF, 621 * use the block. 622 */ 623 if (error == 0 && (bp->b_flags & B_INVAL)) 624 break; 625 } 626 /* 627 * An error will throw away the block and the 628 * for loop will break out. If no error and this 629 * is not the block we want, we throw away the 630 * block and go for the next one via the for loop. 631 */ 632 if (error || i < lbn) 633 brelse(bp); 634 } 635 } 636 /* 637 * The above while is repeated if we hit another cookie 638 * error. If we hit an error and it wasn't a cookie error, 639 * we give up. 640 */ 641 if (error) 642 return (error); 643 } 644 645 /* 646 * If not eof and read aheads are enabled, start one. 647 * (You need the current block first, so that you have the 648 * directory offset cookie of the next block.) 649 */ 650 if (nfs_numasync > 0 && nmp->nm_readahead > 0 && 651 (bp->b_flags & B_INVAL) == 0 && 652 (np->n_direofoffset == 0 || 653 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) && 654 !(np->n_flag & NQNFSNONCACHE) && 655 !incore(vp, lbn + 1)) { 656 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, p); 657 if (rabp) { 658 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 659 rabp->b_flags |= (B_READ | B_ASYNC); 660 vfs_busy_pages(rabp, 0); 661 if (nfs_asyncio(rabp, cred, p)) { 662 rabp->b_flags |= B_INVAL|B_ERROR; 663 vfs_unbusy_pages(rabp); 664 brelse(rabp); 665 } 666 } else { 667 brelse(rabp); 668 } 669 } 670 } 671 /* 672 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is 673 * chopped for the EOF condition, we cannot tell how large 674 * NFS directories are going to be until we hit EOF. So 675 * an NFS directory buffer is *not* chopped to its EOF. Now, 676 * it just so happens that b_resid will effectively chop it 677 * to EOF. *BUT* this information is lost if the buffer goes 678 * away and is reconstituted into a B_CACHE state ( due to 679 * being VMIO ) later. So we keep track of the directory eof 680 * in np->n_direofoffset and chop it off as an extra step 681 * right here. 682 */ 683 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on); 684 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset) 685 n = np->n_direofoffset - uio->uio_offset; 686 break; 687 default: 688 printf(" nfs_bioread: type %x unexpected\n",vp->v_type); 689 break; 690 }; 691 692 if (n > 0) { 693 error = uiomove(bp->b_data + on, (int)n, uio); 694 } 695 switch (vp->v_type) { 696 case VREG: 697 break; 698 case VLNK: 699 n = 0; 700 break; 701 case VDIR: 702 /* 703 * Invalidate buffer if caching is disabled, forcing a 704 * re-read from the remote later. 705 */ 706 if (np->n_flag & NQNFSNONCACHE) 707 bp->b_flags |= B_INVAL; 708 break; 709 default: 710 printf(" nfs_bioread: type %x unexpected\n",vp->v_type); 711 } 712 brelse(bp); 713 } while (error == 0 && uio->uio_resid > 0 && n > 0); 714 return (error); 715 } 716 717 /* 718 * Vnode op for write using bio 719 */ 720 int 721 nfs_write(ap) 722 struct vop_write_args /* { 723 struct vnode *a_vp; 724 struct uio *a_uio; 725 int a_ioflag; 726 struct ucred *a_cred; 727 } */ *ap; 728 { 729 int biosize; 730 struct uio *uio = ap->a_uio; 731 struct proc *p = uio->uio_procp; 732 struct vnode *vp = ap->a_vp; 733 struct nfsnode *np = VTONFS(vp); 734 struct ucred *cred = ap->a_cred; 735 int ioflag = ap->a_ioflag; 736 struct buf *bp; 737 struct vattr vattr; 738 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 739 daddr_t lbn; 740 int bcount; 741 int n, on, error = 0, iomode, must_commit; 742 int haverslock = 0; 743 744 #ifdef DIAGNOSTIC 745 if (uio->uio_rw != UIO_WRITE) 746 panic("nfs_write mode"); 747 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 748 panic("nfs_write proc"); 749 #endif 750 if (vp->v_type != VREG) 751 return (EIO); 752 if (np->n_flag & NWRITEERR) { 753 np->n_flag &= ~NWRITEERR; 754 return (np->n_error); 755 } 756 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 757 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 758 (void)nfs_fsinfo(nmp, vp, cred, p); 759 760 /* 761 * Synchronously flush pending buffers if we are in synchronous 762 * mode or if we are appending. 763 */ 764 if (ioflag & (IO_APPEND | IO_SYNC)) { 765 if (np->n_flag & NMODIFIED) { 766 np->n_attrstamp = 0; 767 error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); 768 if (error) 769 return (error); 770 } 771 } 772 773 /* 774 * If IO_APPEND then load uio_offset. We restart here if we cannot 775 * get the append lock. 776 */ 777 restart: 778 if (ioflag & IO_APPEND) { 779 np->n_attrstamp = 0; 780 error = VOP_GETATTR(vp, &vattr, cred, p); 781 if (error) 782 return (error); 783 uio->uio_offset = np->n_size; 784 } 785 786 if (uio->uio_offset < 0) 787 return (EINVAL); 788 if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 789 return (EFBIG); 790 if (uio->uio_resid == 0) 791 return (0); 792 793 /* 794 * We need to obtain the rslock if we intend to modify np->n_size 795 * in order to guarentee the append point with multiple contending 796 * writers, to guarentee that no other appenders modify n_size 797 * while we are trying to obtain a truncated buffer (i.e. to avoid 798 * accidently truncating data written by another appender due to 799 * the race), and to ensure that the buffer is populated prior to 800 * our extending of the file. We hold rslock through the entire 801 * operation. 802 * 803 * Note that we do not synchronize the case where someone truncates 804 * the file while we are appending to it because attempting to lock 805 * this case may deadlock other parts of the system unexpectedly. 806 */ 807 if ((ioflag & IO_APPEND) || 808 uio->uio_offset + uio->uio_resid > np->n_size) { 809 switch(nfs_rslock(np, p)) { 810 case ENOLCK: 811 goto restart; 812 /* not reached */ 813 case EINTR: 814 case ERESTART: 815 return(EINTR); 816 /* not reached */ 817 default: 818 break; 819 } 820 haverslock = 1; 821 } 822 823 /* 824 * Maybe this should be above the vnode op call, but so long as 825 * file servers have no limits, i don't think it matters 826 */ 827 if (p && uio->uio_offset + uio->uio_resid > 828 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 829 psignal(p, SIGXFSZ); 830 if (haverslock) 831 nfs_rsunlock(np, p); 832 return (EFBIG); 833 } 834 835 biosize = vp->v_mount->mnt_stat.f_iosize; 836 837 do { 838 /* 839 * Check for a valid write lease. 840 */ 841 if ((nmp->nm_flag & NFSMNT_NQNFS) && 842 NQNFS_CKINVALID(vp, np, ND_WRITE)) { 843 do { 844 error = nqnfs_getlease(vp, ND_WRITE, cred, p); 845 } while (error == NQNFS_EXPIRED); 846 if (error) 847 break; 848 if (np->n_lrev != np->n_brev || 849 (np->n_flag & NQNFSNONCACHE)) { 850 error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); 851 if (error) 852 break; 853 np->n_brev = np->n_lrev; 854 } 855 } 856 if ((np->n_flag & NQNFSNONCACHE) && uio->uio_iovcnt == 1) { 857 iomode = NFSV3WRITE_FILESYNC; 858 error = nfs_writerpc(vp, uio, cred, &iomode, &must_commit); 859 if (must_commit) 860 nfs_clearcommit(vp->v_mount); 861 break; 862 } 863 nfsstats.biocache_writes++; 864 lbn = uio->uio_offset / biosize; 865 on = uio->uio_offset & (biosize-1); 866 n = min((unsigned)(biosize - on), uio->uio_resid); 867 again: 868 /* 869 * Handle direct append and file extension cases, calculate 870 * unaligned buffer size. 871 */ 872 873 if (uio->uio_offset == np->n_size && n) { 874 /* 875 * Get the buffer (in its pre-append state to maintain 876 * B_CACHE if it was previously set). Resize the 877 * nfsnode after we have locked the buffer to prevent 878 * readers from reading garbage. 879 */ 880 bcount = on; 881 bp = nfs_getcacheblk(vp, lbn, bcount, p); 882 883 if (bp != NULL) { 884 long save; 885 886 np->n_size = uio->uio_offset + n; 887 np->n_flag |= NMODIFIED; 888 vnode_pager_setsize(vp, np->n_size); 889 890 save = bp->b_flags & B_CACHE; 891 bcount += n; 892 allocbuf(bp, bcount); 893 bp->b_flags |= save; 894 } 895 } else { 896 /* 897 * Obtain the locked cache block first, and then 898 * adjust the file's size as appropriate. 899 */ 900 bcount = on + n; 901 if ((off_t)lbn * biosize + bcount < np->n_size) { 902 if ((off_t)(lbn + 1) * biosize < np->n_size) 903 bcount = biosize; 904 else 905 bcount = np->n_size - (off_t)lbn * biosize; 906 } 907 bp = nfs_getcacheblk(vp, lbn, bcount, p); 908 if (uio->uio_offset + n > np->n_size) { 909 np->n_size = uio->uio_offset + n; 910 np->n_flag |= NMODIFIED; 911 vnode_pager_setsize(vp, np->n_size); 912 } 913 } 914 915 if (!bp) { 916 error = EINTR; 917 break; 918 } 919 920 /* 921 * Issue a READ if B_CACHE is not set. In special-append 922 * mode, B_CACHE is based on the buffer prior to the write 923 * op and is typically set, avoiding the read. If a read 924 * is required in special append mode, the server will 925 * probably send us a short-read since we extended the file 926 * on our end, resulting in b_resid == 0 and, thusly, 927 * B_CACHE getting set. 928 * 929 * We can also avoid issuing the read if the write covers 930 * the entire buffer. We have to make sure the buffer state 931 * is reasonable in this case since we will not be initiating 932 * I/O. See the comments in kern/vfs_bio.c's getblk() for 933 * more information. 934 * 935 * B_CACHE may also be set due to the buffer being cached 936 * normally. 937 */ 938 939 if (on == 0 && n == bcount) { 940 bp->b_flags |= B_CACHE; 941 bp->b_flags &= ~(B_ERROR | B_INVAL); 942 } 943 944 if ((bp->b_flags & B_CACHE) == 0) { 945 bp->b_flags |= B_READ; 946 vfs_busy_pages(bp, 0); 947 error = nfs_doio(bp, cred, p); 948 if (error) { 949 brelse(bp); 950 break; 951 } 952 } 953 if (!bp) { 954 error = EINTR; 955 break; 956 } 957 if (bp->b_wcred == NOCRED) { 958 crhold(cred); 959 bp->b_wcred = cred; 960 } 961 np->n_flag |= NMODIFIED; 962 963 /* 964 * If dirtyend exceeds file size, chop it down. This should 965 * not normally occur but there is an append race where it 966 * might occur XXX, so we log it. 967 * 968 * If the chopping creates a reverse-indexed or degenerate 969 * situation with dirtyoff/end, we 0 both of them. 970 */ 971 972 if (bp->b_dirtyend > bcount) { 973 printf("NFS append race @%lx:%d\n", 974 (long)bp->b_blkno * DEV_BSIZE, 975 bp->b_dirtyend - bcount); 976 bp->b_dirtyend = bcount; 977 } 978 979 if (bp->b_dirtyoff >= bp->b_dirtyend) 980 bp->b_dirtyoff = bp->b_dirtyend = 0; 981 982 /* 983 * If the new write will leave a contiguous dirty 984 * area, just update the b_dirtyoff and b_dirtyend, 985 * otherwise force a write rpc of the old dirty area. 986 * 987 * While it is possible to merge discontiguous writes due to 988 * our having a B_CACHE buffer ( and thus valid read data 989 * for the hole), we don't because it could lead to 990 * significant cache coherency problems with multiple clients, 991 * especially if locking is implemented later on. 992 * 993 * as an optimization we could theoretically maintain 994 * a linked list of discontinuous areas, but we would still 995 * have to commit them separately so there isn't much 996 * advantage to it except perhaps a bit of asynchronization. 997 */ 998 999 if (bp->b_dirtyend > 0 && 1000 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { 1001 if (VOP_BWRITE(bp->b_vp, bp) == EINTR) { 1002 error = EINTR; 1003 break; 1004 } 1005 goto again; 1006 } 1007 1008 /* 1009 * Check for valid write lease and get one as required. 1010 * In case getblk() and/or bwrite() delayed us. 1011 */ 1012 if ((nmp->nm_flag & NFSMNT_NQNFS) && 1013 NQNFS_CKINVALID(vp, np, ND_WRITE)) { 1014 do { 1015 error = nqnfs_getlease(vp, ND_WRITE, cred, p); 1016 } while (error == NQNFS_EXPIRED); 1017 if (error) { 1018 brelse(bp); 1019 break; 1020 } 1021 if (np->n_lrev != np->n_brev || 1022 (np->n_flag & NQNFSNONCACHE)) { 1023 brelse(bp); 1024 error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); 1025 if (error) 1026 break; 1027 np->n_brev = np->n_lrev; 1028 goto again; 1029 } 1030 } 1031 1032 error = uiomove((char *)bp->b_data + on, n, uio); 1033 1034 /* 1035 * Since this block is being modified, it must be written 1036 * again and not just committed. Since write clustering does 1037 * not work for the stage 1 data write, only the stage 2 1038 * commit rpc, we have to clear B_CLUSTEROK as well. 1039 */ 1040 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1041 1042 if (error) { 1043 bp->b_flags |= B_ERROR; 1044 brelse(bp); 1045 break; 1046 } 1047 1048 /* 1049 * Only update dirtyoff/dirtyend if not a degenerate 1050 * condition. 1051 */ 1052 if (n) { 1053 if (bp->b_dirtyend > 0) { 1054 bp->b_dirtyoff = min(on, bp->b_dirtyoff); 1055 bp->b_dirtyend = max((on + n), bp->b_dirtyend); 1056 } else { 1057 bp->b_dirtyoff = on; 1058 bp->b_dirtyend = on + n; 1059 } 1060 vfs_bio_set_validclean(bp, on, n); 1061 } 1062 /* 1063 * If IO_NOWDRAIN then set B_NOWDRAIN (e.g. nfs-backed VN 1064 * filesystem). XXX also use for loopback NFS mounts. 1065 */ 1066 if (ioflag & IO_NOWDRAIN) 1067 bp->b_flags |= B_NOWDRAIN; 1068 1069 /* 1070 * If the lease is non-cachable or IO_SYNC do bwrite(). 1071 * 1072 * IO_INVAL appears to be unused. The idea appears to be 1073 * to turn off caching in this case. Very odd. XXX 1074 */ 1075 if ((np->n_flag & NQNFSNONCACHE) || (ioflag & IO_SYNC)) { 1076 if (ioflag & IO_INVAL) 1077 bp->b_flags |= B_NOCACHE; 1078 error = VOP_BWRITE(bp->b_vp, bp); 1079 if (error) 1080 break; 1081 if (np->n_flag & NQNFSNONCACHE) { 1082 error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); 1083 if (error) 1084 break; 1085 } 1086 } else if ((n + on) == biosize && 1087 (nmp->nm_flag & NFSMNT_NQNFS) == 0) { 1088 bp->b_flags |= B_ASYNC; 1089 (void)nfs_writebp(bp, 0, 0); 1090 } else { 1091 bdwrite(bp); 1092 } 1093 } while (uio->uio_resid > 0 && n > 0); 1094 1095 if (haverslock) 1096 nfs_rsunlock(np, p); 1097 1098 return (error); 1099 } 1100 1101 /* 1102 * Get an nfs cache block. 1103 * 1104 * Allocate a new one if the block isn't currently in the cache 1105 * and return the block marked busy. If the calling process is 1106 * interrupted by a signal for an interruptible mount point, return 1107 * NULL. 1108 * 1109 * The caller must carefully deal with the possible B_INVAL state of 1110 * the buffer. nfs_doio() clears B_INVAL (and nfs_asyncio() clears it 1111 * indirectly), so synchronous reads can be issued without worrying about 1112 * the B_INVAL state. We have to be a little more careful when dealing 1113 * with writes (see comments in nfs_write()) when extending a file past 1114 * its EOF. 1115 */ 1116 static struct buf * 1117 nfs_getcacheblk(vp, bn, size, p) 1118 struct vnode *vp; 1119 daddr_t bn; 1120 int size; 1121 struct proc *p; 1122 { 1123 register struct buf *bp; 1124 struct mount *mp; 1125 struct nfsmount *nmp; 1126 1127 mp = vp->v_mount; 1128 nmp = VFSTONFS(mp); 1129 1130 if (nmp->nm_flag & NFSMNT_INT) { 1131 bp = getblk(vp, bn, size, PCATCH, 0); 1132 while (bp == (struct buf *)0) { 1133 if (nfs_sigintr(nmp, (struct nfsreq *)0, p)) 1134 return ((struct buf *)0); 1135 bp = getblk(vp, bn, size, 0, 2 * hz); 1136 } 1137 } else { 1138 bp = getblk(vp, bn, size, 0, 0); 1139 } 1140 1141 if (vp->v_type == VREG) { 1142 int biosize; 1143 1144 biosize = mp->mnt_stat.f_iosize; 1145 bp->b_blkno = bn * (biosize / DEV_BSIZE); 1146 } 1147 return (bp); 1148 } 1149 1150 /* 1151 * Flush and invalidate all dirty buffers. If another process is already 1152 * doing the flush, just wait for completion. 1153 */ 1154 int 1155 nfs_vinvalbuf(vp, flags, cred, p, intrflg) 1156 struct vnode *vp; 1157 int flags; 1158 struct ucred *cred; 1159 struct proc *p; 1160 int intrflg; 1161 { 1162 register struct nfsnode *np = VTONFS(vp); 1163 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 1164 int error = 0, slpflag, slptimeo; 1165 1166 if (vp->v_flag & VXLOCK) { 1167 return (0); 1168 } 1169 1170 if ((nmp->nm_flag & NFSMNT_INT) == 0) 1171 intrflg = 0; 1172 if (intrflg) { 1173 slpflag = PCATCH; 1174 slptimeo = 2 * hz; 1175 } else { 1176 slpflag = 0; 1177 slptimeo = 0; 1178 } 1179 /* 1180 * First wait for any other process doing a flush to complete. 1181 */ 1182 while (np->n_flag & NFLUSHINPROG) { 1183 np->n_flag |= NFLUSHWANT; 1184 error = tsleep((caddr_t)&np->n_flag, PRIBIO + 2, "nfsvinval", 1185 slptimeo); 1186 if (error && intrflg && nfs_sigintr(nmp, (struct nfsreq *)0, p)) 1187 return (EINTR); 1188 } 1189 1190 /* 1191 * Now, flush as required. 1192 */ 1193 np->n_flag |= NFLUSHINPROG; 1194 error = vinvalbuf(vp, flags, cred, p, slpflag, 0); 1195 while (error) { 1196 if (intrflg && nfs_sigintr(nmp, (struct nfsreq *)0, p)) { 1197 np->n_flag &= ~NFLUSHINPROG; 1198 if (np->n_flag & NFLUSHWANT) { 1199 np->n_flag &= ~NFLUSHWANT; 1200 wakeup((caddr_t)&np->n_flag); 1201 } 1202 return (EINTR); 1203 } 1204 error = vinvalbuf(vp, flags, cred, p, 0, slptimeo); 1205 } 1206 np->n_flag &= ~(NMODIFIED | NFLUSHINPROG); 1207 if (np->n_flag & NFLUSHWANT) { 1208 np->n_flag &= ~NFLUSHWANT; 1209 wakeup((caddr_t)&np->n_flag); 1210 } 1211 return (0); 1212 } 1213 1214 /* 1215 * Initiate asynchronous I/O. Return an error if no nfsiods are available. 1216 * This is mainly to avoid queueing async I/O requests when the nfsiods 1217 * are all hung on a dead server. 1218 * 1219 * Note: nfs_asyncio() does not clear (B_ERROR|B_INVAL) but when the bp 1220 * is eventually dequeued by the async daemon, nfs_doio() *will*. 1221 */ 1222 int 1223 nfs_asyncio(bp, cred, procp) 1224 register struct buf *bp; 1225 struct ucred *cred; 1226 struct proc *procp; 1227 { 1228 struct nfsmount *nmp; 1229 int i; 1230 int gotiod; 1231 int slpflag = 0; 1232 int slptimeo = 0; 1233 int error; 1234 1235 /* 1236 * If no async daemons then return EIO to force caller to run the rpc 1237 * synchronously. 1238 */ 1239 if (nfs_numasync == 0) 1240 return (EIO); 1241 1242 nmp = VFSTONFS(bp->b_vp->v_mount); 1243 1244 /* 1245 * Commits are usually short and sweet so lets save some cpu and 1246 * leave the async daemons for more important rpc's (such as reads 1247 * and writes). 1248 */ 1249 if ((bp->b_flags & (B_READ|B_NEEDCOMMIT)) == B_NEEDCOMMIT && 1250 (nmp->nm_bufqiods > nfs_numasync / 2)) { 1251 return(EIO); 1252 } 1253 1254 again: 1255 if (nmp->nm_flag & NFSMNT_INT) 1256 slpflag = PCATCH; 1257 gotiod = FALSE; 1258 1259 /* 1260 * Find a free iod to process this request. 1261 */ 1262 for (i = 0; i < NFS_MAXASYNCDAEMON; i++) 1263 if (nfs_iodwant[i]) { 1264 /* 1265 * Found one, so wake it up and tell it which 1266 * mount to process. 1267 */ 1268 NFS_DPF(ASYNCIO, 1269 ("nfs_asyncio: waking iod %d for mount %p\n", 1270 i, nmp)); 1271 nfs_iodwant[i] = (struct proc *)0; 1272 nfs_iodmount[i] = nmp; 1273 nmp->nm_bufqiods++; 1274 wakeup((caddr_t)&nfs_iodwant[i]); 1275 gotiod = TRUE; 1276 break; 1277 } 1278 1279 /* 1280 * If none are free, we may already have an iod working on this mount 1281 * point. If so, it will process our request. 1282 */ 1283 if (!gotiod) { 1284 if (nmp->nm_bufqiods > 0) { 1285 NFS_DPF(ASYNCIO, 1286 ("nfs_asyncio: %d iods are already processing mount %p\n", 1287 nmp->nm_bufqiods, nmp)); 1288 gotiod = TRUE; 1289 } 1290 } 1291 1292 /* 1293 * If we have an iod which can process the request, then queue 1294 * the buffer. 1295 */ 1296 if (gotiod) { 1297 /* 1298 * Ensure that the queue never grows too large. We still want 1299 * to asynchronize so we block rather then return EIO. 1300 */ 1301 while (nmp->nm_bufqlen >= 2*nfs_numasync) { 1302 NFS_DPF(ASYNCIO, 1303 ("nfs_asyncio: waiting for mount %p queue to drain\n", nmp)); 1304 nmp->nm_bufqwant = TRUE; 1305 error = tsleep(&nmp->nm_bufq, slpflag | PRIBIO, 1306 "nfsaio", slptimeo); 1307 if (error) { 1308 if (nfs_sigintr(nmp, NULL, procp)) 1309 return (EINTR); 1310 if (slpflag == PCATCH) { 1311 slpflag = 0; 1312 slptimeo = 2 * hz; 1313 } 1314 } 1315 /* 1316 * We might have lost our iod while sleeping, 1317 * so check and loop if nescessary. 1318 */ 1319 if (nmp->nm_bufqiods == 0) { 1320 NFS_DPF(ASYNCIO, 1321 ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); 1322 goto again; 1323 } 1324 } 1325 1326 if (bp->b_flags & B_READ) { 1327 if (bp->b_rcred == NOCRED && cred != NOCRED) { 1328 crhold(cred); 1329 bp->b_rcred = cred; 1330 } 1331 } else { 1332 bp->b_flags |= B_WRITEINPROG; 1333 if (bp->b_wcred == NOCRED && cred != NOCRED) { 1334 crhold(cred); 1335 bp->b_wcred = cred; 1336 } 1337 } 1338 1339 BUF_KERNPROC(bp); 1340 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist); 1341 nmp->nm_bufqlen++; 1342 return (0); 1343 } 1344 1345 /* 1346 * All the iods are busy on other mounts, so return EIO to 1347 * force the caller to process the i/o synchronously. 1348 */ 1349 NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n")); 1350 return (EIO); 1351 } 1352 1353 /* 1354 * Do an I/O operation to/from a cache block. This may be called 1355 * synchronously or from an nfsiod. 1356 */ 1357 int 1358 nfs_doio(bp, cr, p) 1359 struct buf *bp; 1360 struct ucred *cr; 1361 struct proc *p; 1362 { 1363 struct uio *uiop; 1364 struct vnode *vp; 1365 struct nfsnode *np; 1366 struct nfsmount *nmp; 1367 int error = 0, iomode, must_commit = 0; 1368 struct uio uio; 1369 struct iovec io; 1370 1371 vp = bp->b_vp; 1372 np = VTONFS(vp); 1373 nmp = VFSTONFS(vp->v_mount); 1374 uiop = &uio; 1375 uiop->uio_iov = &io; 1376 uiop->uio_iovcnt = 1; 1377 uiop->uio_segflg = UIO_SYSSPACE; 1378 uiop->uio_procp = p; 1379 1380 /* 1381 * clear B_ERROR and B_INVAL state prior to initiating the I/O. We 1382 * do this here so we do not have to do it in all the code that 1383 * calls us. 1384 */ 1385 bp->b_flags &= ~(B_ERROR | B_INVAL); 1386 1387 KASSERT(!(bp->b_flags & B_DONE), ("nfs_doio: bp %p already marked done", bp)); 1388 1389 /* 1390 * Historically, paging was done with physio, but no more. 1391 */ 1392 if (bp->b_flags & B_PHYS) { 1393 /* 1394 * ...though reading /dev/drum still gets us here. 1395 */ 1396 io.iov_len = uiop->uio_resid = bp->b_bcount; 1397 /* mapping was done by vmapbuf() */ 1398 io.iov_base = bp->b_data; 1399 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE; 1400 if (bp->b_flags & B_READ) { 1401 uiop->uio_rw = UIO_READ; 1402 nfsstats.read_physios++; 1403 error = nfs_readrpc(vp, uiop, cr); 1404 } else { 1405 int com; 1406 1407 iomode = NFSV3WRITE_DATASYNC; 1408 uiop->uio_rw = UIO_WRITE; 1409 nfsstats.write_physios++; 1410 error = nfs_writerpc(vp, uiop, cr, &iomode, &com); 1411 } 1412 if (error) { 1413 bp->b_flags |= B_ERROR; 1414 bp->b_error = error; 1415 } 1416 } else if (bp->b_flags & B_READ) { 1417 io.iov_len = uiop->uio_resid = bp->b_bcount; 1418 io.iov_base = bp->b_data; 1419 uiop->uio_rw = UIO_READ; 1420 1421 switch (vp->v_type) { 1422 case VREG: 1423 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE; 1424 nfsstats.read_bios++; 1425 error = nfs_readrpc(vp, uiop, cr); 1426 1427 if (!error) { 1428 if (uiop->uio_resid) { 1429 /* 1430 * If we had a short read with no error, we must have 1431 * hit a file hole. We should zero-fill the remainder. 1432 * This can also occur if the server hits the file EOF. 1433 * 1434 * Holes used to be able to occur due to pending 1435 * writes, but that is not possible any longer. 1436 */ 1437 int nread = bp->b_bcount - uiop->uio_resid; 1438 int left = uiop->uio_resid; 1439 1440 if (left > 0) 1441 bzero((char *)bp->b_data + nread, left); 1442 uiop->uio_resid = 0; 1443 } 1444 } 1445 if (p && (vp->v_flag & VTEXT) && 1446 (((nmp->nm_flag & NFSMNT_NQNFS) && 1447 NQNFS_CKINVALID(vp, np, ND_READ) && 1448 np->n_lrev != np->n_brev) || 1449 (!(nmp->nm_flag & NFSMNT_NQNFS) && 1450 np->n_mtime != np->n_vattr.va_mtime.tv_sec))) { 1451 uprintf("Process killed due to text file modification\n"); 1452 psignal(p, SIGKILL); 1453 PHOLD(p); 1454 } 1455 break; 1456 case VLNK: 1457 uiop->uio_offset = (off_t)0; 1458 nfsstats.readlink_bios++; 1459 error = nfs_readlinkrpc(vp, uiop, cr); 1460 break; 1461 case VDIR: 1462 nfsstats.readdir_bios++; 1463 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ; 1464 if (nmp->nm_flag & NFSMNT_RDIRPLUS) { 1465 error = nfs_readdirplusrpc(vp, uiop, cr); 1466 if (error == NFSERR_NOTSUPP) 1467 nmp->nm_flag &= ~NFSMNT_RDIRPLUS; 1468 } 1469 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) 1470 error = nfs_readdirrpc(vp, uiop, cr); 1471 /* 1472 * end-of-directory sets B_INVAL but does not generate an 1473 * error. 1474 */ 1475 if (error == 0 && uiop->uio_resid == bp->b_bcount) 1476 bp->b_flags |= B_INVAL; 1477 break; 1478 default: 1479 printf("nfs_doio: type %x unexpected\n",vp->v_type); 1480 break; 1481 }; 1482 if (error) { 1483 bp->b_flags |= B_ERROR; 1484 bp->b_error = error; 1485 } 1486 } else { 1487 /* 1488 * If we only need to commit, try to commit 1489 */ 1490 if (bp->b_flags & B_NEEDCOMMIT) { 1491 int retv; 1492 off_t off; 1493 1494 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff; 1495 bp->b_flags |= B_WRITEINPROG; 1496 retv = nfs_commit( 1497 bp->b_vp, off, bp->b_dirtyend-bp->b_dirtyoff, 1498 bp->b_wcred, p); 1499 bp->b_flags &= ~B_WRITEINPROG; 1500 if (retv == 0) { 1501 bp->b_dirtyoff = bp->b_dirtyend = 0; 1502 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1503 bp->b_resid = 0; 1504 biodone(bp); 1505 return (0); 1506 } 1507 if (retv == NFSERR_STALEWRITEVERF) { 1508 nfs_clearcommit(bp->b_vp->v_mount); 1509 } 1510 } 1511 1512 /* 1513 * Setup for actual write 1514 */ 1515 1516 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size) 1517 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE; 1518 1519 if (bp->b_dirtyend > bp->b_dirtyoff) { 1520 io.iov_len = uiop->uio_resid = bp->b_dirtyend 1521 - bp->b_dirtyoff; 1522 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE 1523 + bp->b_dirtyoff; 1524 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; 1525 uiop->uio_rw = UIO_WRITE; 1526 nfsstats.write_bios++; 1527 1528 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC) 1529 iomode = NFSV3WRITE_UNSTABLE; 1530 else 1531 iomode = NFSV3WRITE_FILESYNC; 1532 1533 bp->b_flags |= B_WRITEINPROG; 1534 error = nfs_writerpc(vp, uiop, cr, &iomode, &must_commit); 1535 1536 /* 1537 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try 1538 * to cluster the buffers needing commit. This will allow 1539 * the system to submit a single commit rpc for the whole 1540 * cluster. We can do this even if the buffer is not 100% 1541 * dirty (relative to the NFS blocksize), so we optimize the 1542 * append-to-file-case. 1543 * 1544 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be 1545 * cleared because write clustering only works for commit 1546 * rpc's, not for the data portion of the write). 1547 */ 1548 1549 if (!error && iomode == NFSV3WRITE_UNSTABLE) { 1550 bp->b_flags |= B_NEEDCOMMIT; 1551 if (bp->b_dirtyoff == 0 1552 && bp->b_dirtyend == bp->b_bcount) 1553 bp->b_flags |= B_CLUSTEROK; 1554 } else { 1555 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1556 } 1557 bp->b_flags &= ~B_WRITEINPROG; 1558 1559 /* 1560 * For an interrupted write, the buffer is still valid 1561 * and the write hasn't been pushed to the server yet, 1562 * so we can't set B_ERROR and report the interruption 1563 * by setting B_EINTR. For the B_ASYNC case, B_EINTR 1564 * is not relevant, so the rpc attempt is essentially 1565 * a noop. For the case of a V3 write rpc not being 1566 * committed to stable storage, the block is still 1567 * dirty and requires either a commit rpc or another 1568 * write rpc with iomode == NFSV3WRITE_FILESYNC before 1569 * the block is reused. This is indicated by setting 1570 * the B_DELWRI and B_NEEDCOMMIT flags. 1571 * 1572 * If the buffer is marked B_PAGING, it does not reside on 1573 * the vp's paging queues so we cannot call bdirty(). The 1574 * bp in this case is not an NFS cache block so we should 1575 * be safe. XXX 1576 */ 1577 if (error == EINTR 1578 || (!error && (bp->b_flags & B_NEEDCOMMIT))) { 1579 int s; 1580 1581 s = splbio(); 1582 bp->b_flags &= ~(B_INVAL|B_NOCACHE); 1583 if ((bp->b_flags & B_PAGING) == 0) { 1584 bdirty(bp); 1585 bp->b_flags &= ~B_DONE; 1586 } 1587 if (error && (bp->b_flags & B_ASYNC) == 0) 1588 bp->b_flags |= B_EINTR; 1589 splx(s); 1590 } else { 1591 if (error) { 1592 bp->b_flags |= B_ERROR; 1593 bp->b_error = np->n_error = error; 1594 np->n_flag |= NWRITEERR; 1595 } 1596 bp->b_dirtyoff = bp->b_dirtyend = 0; 1597 } 1598 } else { 1599 bp->b_resid = 0; 1600 biodone(bp); 1601 return (0); 1602 } 1603 } 1604 bp->b_resid = uiop->uio_resid; 1605 if (must_commit) 1606 nfs_clearcommit(vp->v_mount); 1607 biodone(bp); 1608 return (error); 1609 } 1610 1611 /* 1612 * Used to aid in handling ftruncate() operations on the NFS client side. 1613 * Truncation creates a number of special problems for NFS. We have to 1614 * throw away VM pages and buffer cache buffers that are beyond EOF, and 1615 * we have to properly handle VM pages or (potentially dirty) buffers 1616 * that straddle the truncation point. 1617 */ 1618 1619 int 1620 nfs_meta_setsize(struct vnode *vp, struct ucred *cred, struct proc *p, u_quad_t nsize) 1621 { 1622 struct nfsnode *np = VTONFS(vp); 1623 u_quad_t tsize = np->n_size; 1624 int biosize = vp->v_mount->mnt_stat.f_iosize; 1625 int error = 0; 1626 1627 np->n_size = nsize; 1628 1629 if (np->n_size < tsize) { 1630 struct buf *bp; 1631 daddr_t lbn; 1632 int bufsize; 1633 1634 /* 1635 * vtruncbuf() doesn't get the buffer overlapping the 1636 * truncation point. We may have a B_DELWRI and/or B_CACHE 1637 * buffer that now needs to be truncated. 1638 */ 1639 error = vtruncbuf(vp, cred, p, nsize, biosize); 1640 lbn = nsize / biosize; 1641 bufsize = nsize & (biosize - 1); 1642 bp = nfs_getcacheblk(vp, lbn, bufsize, p); 1643 if (bp->b_dirtyoff > bp->b_bcount) 1644 bp->b_dirtyoff = bp->b_bcount; 1645 if (bp->b_dirtyend > bp->b_bcount) 1646 bp->b_dirtyend = bp->b_bcount; 1647 bp->b_flags |= B_RELBUF; /* don't leave garbage around */ 1648 brelse(bp); 1649 } else { 1650 vnode_pager_setsize(vp, nsize); 1651 } 1652 return(error); 1653 } 1654
Cache object: f90a15c872d517485541660472cd4e9f
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]