nfs_bio.c revision 59249
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: head/sys/nfsclient/nfs_bio.c 59249 2000-04-15 05:54:02Z phk $ 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 65static struct buf *nfs_getcacheblk __P((struct vnode *vp, daddr_t bn, int size, 66 struct proc *p)); 67 68extern int nfs_numasync; 69extern int nfs_pbuf_freecnt; 70extern struct nfsstats nfsstats; 71 72/* 73 * Vnode op for VM getpages. 74 */ 75int 76nfs_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 } 197 198 if (i != ap->a_reqpage) { 199 /* 200 * Whether or not to leave the page activated is up in 201 * the air, but we should put the page on a page queue 202 * somewhere (it already is in the object). Result: 203 * It appears that emperical results show that 204 * deactivating pages is best. 205 */ 206 207 /* 208 * Just in case someone was asking for this page we 209 * now tell them that it is ok to use. 210 */ 211 if (!error) { 212 if (m->flags & PG_WANTED) 213 vm_page_activate(m); 214 else 215 vm_page_deactivate(m); 216 vm_page_wakeup(m); 217 } else { 218 vnode_pager_freepage(m); 219 } 220 } 221 } 222 return 0; 223} 224 225/* 226 * Vnode op for VM putpages. 227 */ 228int 229nfs_putpages(ap) 230 struct vop_putpages_args /* { 231 struct vnode *a_vp; 232 vm_page_t *a_m; 233 int a_count; 234 int a_sync; 235 int *a_rtvals; 236 vm_ooffset_t a_offset; 237 } */ *ap; 238{ 239 struct uio uio; 240 struct iovec iov; 241 vm_offset_t kva; 242 struct buf *bp; 243 int iomode, must_commit, i, error, npages, count; 244 off_t offset; 245 int *rtvals; 246 struct vnode *vp; 247 struct proc *p; 248 struct ucred *cred; 249 struct nfsmount *nmp; 250 struct nfsnode *np; 251 vm_page_t *pages; 252 253 vp = ap->a_vp; 254 np = VTONFS(vp); 255 p = curproc; /* XXX */ 256 cred = curproc->p_ucred; /* XXX */ 257 nmp = VFSTONFS(vp->v_mount); 258 pages = ap->a_m; 259 count = ap->a_count; 260 rtvals = ap->a_rtvals; 261 npages = btoc(count); 262 offset = IDX_TO_OFF(pages[0]->pindex); 263 264 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 265 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 266 (void)nfs_fsinfo(nmp, vp, cred, p); 267 268 for (i = 0; i < npages; i++) { 269 rtvals[i] = VM_PAGER_AGAIN; 270 } 271 272 /* 273 * When putting pages, do not extend file past EOF. 274 */ 275 276 if (offset + count > np->n_size) { 277 count = np->n_size - offset; 278 if (count < 0) 279 count = 0; 280 } 281 282 /* 283 * We use only the kva address for the buffer, but this is extremely 284 * convienient and fast. 285 */ 286 bp = getpbuf(&nfs_pbuf_freecnt); 287 288 kva = (vm_offset_t) bp->b_data; 289 pmap_qenter(kva, pages, npages); 290 291 iov.iov_base = (caddr_t) kva; 292 iov.iov_len = count; 293 uio.uio_iov = &iov; 294 uio.uio_iovcnt = 1; 295 uio.uio_offset = offset; 296 uio.uio_resid = count; 297 uio.uio_segflg = UIO_SYSSPACE; 298 uio.uio_rw = UIO_WRITE; 299 uio.uio_procp = p; 300 301 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0) 302 iomode = NFSV3WRITE_UNSTABLE; 303 else 304 iomode = NFSV3WRITE_FILESYNC; 305 306 error = nfs_writerpc(vp, &uio, cred, &iomode, &must_commit); 307 308 pmap_qremove(kva, npages); 309 relpbuf(bp, &nfs_pbuf_freecnt); 310 311 if (!error) { 312 int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE; 313 for (i = 0; i < nwritten; i++) { 314 rtvals[i] = VM_PAGER_OK; 315 vm_page_undirty(pages[i]); 316 } 317 if (must_commit) 318 nfs_clearcommit(vp->v_mount); 319 } 320 return rtvals[0]; 321} 322 323/* 324 * Vnode op for read using bio 325 */ 326int 327nfs_bioread(vp, uio, ioflag, cred) 328 register struct vnode *vp; 329 register struct uio *uio; 330 int ioflag; 331 struct ucred *cred; 332{ 333 register struct nfsnode *np = VTONFS(vp); 334 register int biosize, i; 335 struct buf *bp = 0, *rabp; 336 struct vattr vattr; 337 struct proc *p; 338 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 339 daddr_t lbn, rabn; 340 int bcount; 341 int seqcount; 342 int nra, error = 0, n = 0, on = 0; 343 344#ifdef DIAGNOSTIC 345 if (uio->uio_rw != UIO_READ) 346 panic("nfs_read mode"); 347#endif 348 if (uio->uio_resid == 0) 349 return (0); 350 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */ 351 return (EINVAL); 352 p = uio->uio_procp; 353 354 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 355 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 356 (void)nfs_fsinfo(nmp, vp, cred, p); 357 if (vp->v_type != VDIR && 358 (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 359 return (EFBIG); 360 biosize = vp->v_mount->mnt_stat.f_iosize; 361 seqcount = (int)((off_t)(ioflag >> 16) * biosize / BKVASIZE); 362 /* 363 * For nfs, cache consistency can only be maintained approximately. 364 * Although RFC1094 does not specify the criteria, the following is 365 * believed to be compatible with the reference port. 366 * For nqnfs, full cache consistency is maintained within the loop. 367 * For nfs: 368 * If the file's modify time on the server has changed since the 369 * last read rpc or you have written to the file, 370 * you may have lost data cache consistency with the 371 * server, so flush all of the file's data out of the cache. 372 * Then force a getattr rpc to ensure that you have up to date 373 * attributes. 374 * NB: This implies that cache data can be read when up to 375 * NFS_ATTRTIMEO seconds out of date. If you find that you need current 376 * attributes this could be forced by setting n_attrstamp to 0 before 377 * the VOP_GETATTR() call. 378 */ 379 if ((nmp->nm_flag & NFSMNT_NQNFS) == 0) { 380 if (np->n_flag & NMODIFIED) { 381 if (vp->v_type != VREG) { 382 if (vp->v_type != VDIR) 383 panic("nfs: bioread, not dir"); 384 nfs_invaldir(vp); 385 error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); 386 if (error) 387 return (error); 388 } 389 np->n_attrstamp = 0; 390 error = VOP_GETATTR(vp, &vattr, cred, p); 391 if (error) 392 return (error); 393 np->n_mtime = vattr.va_mtime.tv_sec; 394 } else { 395 error = VOP_GETATTR(vp, &vattr, cred, p); 396 if (error) 397 return (error); 398 if (np->n_mtime != vattr.va_mtime.tv_sec) { 399 if (vp->v_type == VDIR) 400 nfs_invaldir(vp); 401 error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); 402 if (error) 403 return (error); 404 np->n_mtime = vattr.va_mtime.tv_sec; 405 } 406 } 407 } 408 do { 409 410 /* 411 * Get a valid lease. If cached data is stale, flush it. 412 */ 413 if (nmp->nm_flag & NFSMNT_NQNFS) { 414 if (NQNFS_CKINVALID(vp, np, ND_READ)) { 415 do { 416 error = nqnfs_getlease(vp, ND_READ, cred, p); 417 } while (error == NQNFS_EXPIRED); 418 if (error) 419 return (error); 420 if (np->n_lrev != np->n_brev || 421 (np->n_flag & NQNFSNONCACHE) || 422 ((np->n_flag & NMODIFIED) && vp->v_type == VDIR)) { 423 if (vp->v_type == VDIR) 424 nfs_invaldir(vp); 425 error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); 426 if (error) 427 return (error); 428 np->n_brev = np->n_lrev; 429 } 430 } else if (vp->v_type == VDIR && (np->n_flag & NMODIFIED)) { 431 nfs_invaldir(vp); 432 error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); 433 if (error) 434 return (error); 435 } 436 } 437 if (np->n_flag & NQNFSNONCACHE) { 438 switch (vp->v_type) { 439 case VREG: 440 return (nfs_readrpc(vp, uio, cred)); 441 case VLNK: 442 return (nfs_readlinkrpc(vp, uio, cred)); 443 case VDIR: 444 break; 445 default: 446 printf(" NQNFSNONCACHE: type %x unexpected\n", 447 vp->v_type); 448 }; 449 } 450 switch (vp->v_type) { 451 case VREG: 452 nfsstats.biocache_reads++; 453 lbn = uio->uio_offset / biosize; 454 on = uio->uio_offset & (biosize - 1); 455 456 /* 457 * Start the read ahead(s), as required. 458 */ 459 if (nfs_numasync > 0 && nmp->nm_readahead > 0) { 460 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && 461 (off_t)(lbn + 1 + nra) * biosize < np->n_size; nra++) { 462 rabn = lbn + 1 + nra; 463 if (!incore(vp, rabn)) { 464 rabp = nfs_getcacheblk(vp, rabn, biosize, p); 465 if (!rabp) 466 return (EINTR); 467 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 468 rabp->b_flags |= B_ASYNC; 469 rabp->b_iocmd = BIO_READ; 470 vfs_busy_pages(rabp, 0); 471 if (nfs_asyncio(rabp, cred, p)) { 472 rabp->b_flags |= B_INVAL; 473 rabp->b_ioflags |= BIO_ERROR; 474 vfs_unbusy_pages(rabp); 475 brelse(rabp); 476 break; 477 } 478 } else { 479 brelse(rabp); 480 } 481 } 482 } 483 } 484 485 /* 486 * Obtain the buffer cache block. Figure out the buffer size 487 * when we are at EOF. If we are modifying the size of the 488 * buffer based on an EOF condition we need to hold 489 * nfs_rslock() through obtaining the buffer to prevent 490 * a potential writer-appender from messing with n_size. 491 * Otherwise we may accidently truncate the buffer and 492 * lose dirty data. 493 * 494 * Note that bcount is *not* DEV_BSIZE aligned. 495 */ 496 497again: 498 bcount = biosize; 499 if ((off_t)lbn * biosize >= np->n_size) { 500 bcount = 0; 501 } else if ((off_t)(lbn + 1) * biosize > np->n_size) { 502 bcount = np->n_size - (off_t)lbn * biosize; 503 } 504 if (bcount != biosize) { 505 switch(nfs_rslock(np, p)) { 506 case ENOLCK: 507 goto again; 508 /* not reached */ 509 case EINTR: 510 case ERESTART: 511 return(EINTR); 512 /* not reached */ 513 default: 514 break; 515 } 516 } 517 518 bp = nfs_getcacheblk(vp, lbn, bcount, p); 519 520 if (bcount != biosize) 521 nfs_rsunlock(np, p); 522 if (!bp) 523 return (EINTR); 524 525 /* 526 * If B_CACHE is not set, we must issue the read. If this 527 * fails, we return an error. 528 */ 529 530 if ((bp->b_flags & B_CACHE) == 0) { 531 bp->b_iocmd = BIO_READ; 532 vfs_busy_pages(bp, 0); 533 error = nfs_doio(bp, cred, p); 534 if (error) { 535 brelse(bp); 536 return (error); 537 } 538 } 539 540 /* 541 * on is the offset into the current bp. Figure out how many 542 * bytes we can copy out of the bp. Note that bcount is 543 * NOT DEV_BSIZE aligned. 544 * 545 * Then figure out how many bytes we can copy into the uio. 546 */ 547 548 n = 0; 549 if (on < bcount) 550 n = min((unsigned)(bcount - on), uio->uio_resid); 551 break; 552 case VLNK: 553 nfsstats.biocache_readlinks++; 554 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, p); 555 if (!bp) 556 return (EINTR); 557 if ((bp->b_flags & B_CACHE) == 0) { 558 bp->b_iocmd = BIO_READ; 559 vfs_busy_pages(bp, 0); 560 error = nfs_doio(bp, cred, p); 561 if (error) { 562 bp->b_ioflags |= BIO_ERROR; 563 brelse(bp); 564 return (error); 565 } 566 } 567 n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); 568 on = 0; 569 break; 570 case VDIR: 571 nfsstats.biocache_readdirs++; 572 if (np->n_direofoffset 573 && uio->uio_offset >= np->n_direofoffset) { 574 return (0); 575 } 576 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; 577 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); 578 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, p); 579 if (!bp) 580 return (EINTR); 581 if ((bp->b_flags & B_CACHE) == 0) { 582 bp->b_iocmd = BIO_READ; 583 vfs_busy_pages(bp, 0); 584 error = nfs_doio(bp, cred, p); 585 if (error) { 586 brelse(bp); 587 } 588 while (error == NFSERR_BAD_COOKIE) { 589 printf("got bad cookie vp %p bp %p\n", vp, bp); 590 nfs_invaldir(vp); 591 error = nfs_vinvalbuf(vp, 0, cred, p, 1); 592 /* 593 * Yuck! The directory has been modified on the 594 * server. The only way to get the block is by 595 * reading from the beginning to get all the 596 * offset cookies. 597 * 598 * Leave the last bp intact unless there is an error. 599 * Loop back up to the while if the error is another 600 * NFSERR_BAD_COOKIE (double yuch!). 601 */ 602 for (i = 0; i <= lbn && !error; i++) { 603 if (np->n_direofoffset 604 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) 605 return (0); 606 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, p); 607 if (!bp) 608 return (EINTR); 609 if ((bp->b_flags & B_CACHE) == 0) { 610 bp->b_iocmd = BIO_READ; 611 vfs_busy_pages(bp, 0); 612 error = nfs_doio(bp, cred, p); 613 /* 614 * no error + B_INVAL == directory EOF, 615 * use the block. 616 */ 617 if (error == 0 && (bp->b_flags & B_INVAL)) 618 break; 619 } 620 /* 621 * An error will throw away the block and the 622 * for loop will break out. If no error and this 623 * is not the block we want, we throw away the 624 * block and go for the next one via the for loop. 625 */ 626 if (error || i < lbn) 627 brelse(bp); 628 } 629 } 630 /* 631 * The above while is repeated if we hit another cookie 632 * error. If we hit an error and it wasn't a cookie error, 633 * we give up. 634 */ 635 if (error) 636 return (error); 637 } 638 639 /* 640 * If not eof and read aheads are enabled, start one. 641 * (You need the current block first, so that you have the 642 * directory offset cookie of the next block.) 643 */ 644 if (nfs_numasync > 0 && nmp->nm_readahead > 0 && 645 (bp->b_flags & B_INVAL) == 0 && 646 (np->n_direofoffset == 0 || 647 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) && 648 !(np->n_flag & NQNFSNONCACHE) && 649 !incore(vp, lbn + 1)) { 650 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, p); 651 if (rabp) { 652 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 653 rabp->b_flags |= B_ASYNC; 654 rabp->b_iocmd = BIO_READ; 655 vfs_busy_pages(rabp, 0); 656 if (nfs_asyncio(rabp, cred, p)) { 657 rabp->b_flags |= B_INVAL; 658 rabp->b_ioflags |= BIO_ERROR; 659 vfs_unbusy_pages(rabp); 660 brelse(rabp); 661 } 662 } else { 663 brelse(rabp); 664 } 665 } 666 } 667 /* 668 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is 669 * chopped for the EOF condition, we cannot tell how large 670 * NFS directories are going to be until we hit EOF. So 671 * an NFS directory buffer is *not* chopped to its EOF. Now, 672 * it just so happens that b_resid will effectively chop it 673 * to EOF. *BUT* this information is lost if the buffer goes 674 * away and is reconstituted into a B_CACHE state ( due to 675 * being VMIO ) later. So we keep track of the directory eof 676 * in np->n_direofoffset and chop it off as an extra step 677 * right here. 678 */ 679 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on); 680 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset) 681 n = np->n_direofoffset - uio->uio_offset; 682 break; 683 default: 684 printf(" nfs_bioread: type %x unexpected\n",vp->v_type); 685 break; 686 }; 687 688 if (n > 0) { 689 error = uiomove(bp->b_data + on, (int)n, uio); 690 } 691 switch (vp->v_type) { 692 case VREG: 693 break; 694 case VLNK: 695 n = 0; 696 break; 697 case VDIR: 698 /* 699 * Invalidate buffer if caching is disabled, forcing a 700 * re-read from the remote later. 701 */ 702 if (np->n_flag & NQNFSNONCACHE) 703 bp->b_flags |= B_INVAL; 704 break; 705 default: 706 printf(" nfs_bioread: type %x unexpected\n",vp->v_type); 707 } 708 brelse(bp); 709 } while (error == 0 && uio->uio_resid > 0 && n > 0); 710 return (error); 711} 712 713/* 714 * Vnode op for write using bio 715 */ 716int 717nfs_write(ap) 718 struct vop_write_args /* { 719 struct vnode *a_vp; 720 struct uio *a_uio; 721 int a_ioflag; 722 struct ucred *a_cred; 723 } */ *ap; 724{ 725 int biosize; 726 struct uio *uio = ap->a_uio; 727 struct proc *p = uio->uio_procp; 728 struct vnode *vp = ap->a_vp; 729 struct nfsnode *np = VTONFS(vp); 730 struct ucred *cred = ap->a_cred; 731 int ioflag = ap->a_ioflag; 732 struct buf *bp; 733 struct vattr vattr; 734 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 735 daddr_t lbn; 736 int bcount; 737 int n, on, error = 0, iomode, must_commit; 738 int haverslock = 0; 739 740#ifdef DIAGNOSTIC 741 if (uio->uio_rw != UIO_WRITE) 742 panic("nfs_write mode"); 743 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 744 panic("nfs_write proc"); 745#endif 746 if (vp->v_type != VREG) 747 return (EIO); 748 if (np->n_flag & NWRITEERR) { 749 np->n_flag &= ~NWRITEERR; 750 return (np->n_error); 751 } 752 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 753 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 754 (void)nfs_fsinfo(nmp, vp, cred, p); 755 756 /* 757 * Synchronously flush pending buffers if we are in synchronous 758 * mode or if we are appending. 759 */ 760 if (ioflag & (IO_APPEND | IO_SYNC)) { 761 if (np->n_flag & NMODIFIED) { 762 np->n_attrstamp = 0; 763 error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); 764 if (error) 765 return (error); 766 } 767 } 768 769 /* 770 * If IO_APPEND then load uio_offset. We restart here if we cannot 771 * get the append lock. 772 */ 773restart: 774 if (ioflag & IO_APPEND) { 775 np->n_attrstamp = 0; 776 error = VOP_GETATTR(vp, &vattr, cred, p); 777 if (error) 778 return (error); 779 uio->uio_offset = np->n_size; 780 } 781 782 if (uio->uio_offset < 0) 783 return (EINVAL); 784 if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 785 return (EFBIG); 786 if (uio->uio_resid == 0) 787 return (0); 788 789 /* 790 * We need to obtain the rslock if we intend to modify np->n_size 791 * in order to guarentee the append point with multiple contending 792 * writers, to guarentee that no other appenders modify n_size 793 * while we are trying to obtain a truncated buffer (i.e. to avoid 794 * accidently truncating data written by another appender due to 795 * the race), and to ensure that the buffer is populated prior to 796 * our extending of the file. We hold rslock through the entire 797 * operation. 798 * 799 * Note that we do not synchronize the case where someone truncates 800 * the file while we are appending to it because attempting to lock 801 * this case may deadlock other parts of the system unexpectedly. 802 */ 803 if ((ioflag & IO_APPEND) || 804 uio->uio_offset + uio->uio_resid > np->n_size) { 805 switch(nfs_rslock(np, p)) { 806 case ENOLCK: 807 goto restart; 808 /* not reached */ 809 case EINTR: 810 case ERESTART: 811 return(EINTR); 812 /* not reached */ 813 default: 814 break; 815 } 816 haverslock = 1; 817 } 818 819 /* 820 * Maybe this should be above the vnode op call, but so long as 821 * file servers have no limits, i don't think it matters 822 */ 823 if (p && uio->uio_offset + uio->uio_resid > 824 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 825 psignal(p, SIGXFSZ); 826 if (haverslock) 827 nfs_rsunlock(np, p); 828 return (EFBIG); 829 } 830 831 biosize = vp->v_mount->mnt_stat.f_iosize; 832 833 do { 834 /* 835 * Check for a valid write lease. 836 */ 837 if ((nmp->nm_flag & NFSMNT_NQNFS) && 838 NQNFS_CKINVALID(vp, np, ND_WRITE)) { 839 do { 840 error = nqnfs_getlease(vp, ND_WRITE, cred, p); 841 } while (error == NQNFS_EXPIRED); 842 if (error) 843 break; 844 if (np->n_lrev != np->n_brev || 845 (np->n_flag & NQNFSNONCACHE)) { 846 error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); 847 if (error) 848 break; 849 np->n_brev = np->n_lrev; 850 } 851 } 852 if ((np->n_flag & NQNFSNONCACHE) && uio->uio_iovcnt == 1) { 853 iomode = NFSV3WRITE_FILESYNC; 854 error = nfs_writerpc(vp, uio, cred, &iomode, &must_commit); 855 if (must_commit) 856 nfs_clearcommit(vp->v_mount); 857 break; 858 } 859 nfsstats.biocache_writes++; 860 lbn = uio->uio_offset / biosize; 861 on = uio->uio_offset & (biosize-1); 862 n = min((unsigned)(biosize - on), uio->uio_resid); 863again: 864 /* 865 * Handle direct append and file extension cases, calculate 866 * unaligned buffer size. 867 */ 868 869 if (uio->uio_offset == np->n_size && n) { 870 /* 871 * Get the buffer (in its pre-append state to maintain 872 * B_CACHE if it was previously set). Resize the 873 * nfsnode after we have locked the buffer to prevent 874 * readers from reading garbage. 875 */ 876 bcount = on; 877 bp = nfs_getcacheblk(vp, lbn, bcount, p); 878 879 if (bp != NULL) { 880 long save; 881 882 np->n_size = uio->uio_offset + n; 883 np->n_flag |= NMODIFIED; 884 vnode_pager_setsize(vp, np->n_size); 885 886 save = bp->b_flags & B_CACHE; 887 bcount += n; 888 allocbuf(bp, bcount); 889 bp->b_flags |= save; 890 } 891 } else { 892 /* 893 * Obtain the locked cache block first, and then 894 * adjust the file's size as appropriate. 895 */ 896 bcount = on + n; 897 if ((off_t)lbn * biosize + bcount < np->n_size) { 898 if ((off_t)(lbn + 1) * biosize < np->n_size) 899 bcount = biosize; 900 else 901 bcount = np->n_size - (off_t)lbn * biosize; 902 } 903 904 bp = nfs_getcacheblk(vp, lbn, bcount, p); 905 906 if (uio->uio_offset + n > np->n_size) { 907 np->n_size = uio->uio_offset + n; 908 np->n_flag |= NMODIFIED; 909 vnode_pager_setsize(vp, np->n_size); 910 } 911 } 912 913 if (!bp) { 914 error = EINTR; 915 break; 916 } 917 918 /* 919 * Issue a READ if B_CACHE is not set. In special-append 920 * mode, B_CACHE is based on the buffer prior to the write 921 * op and is typically set, avoiding the read. If a read 922 * is required in special append mode, the server will 923 * probably send us a short-read since we extended the file 924 * on our end, resulting in b_resid == 0 and, thusly, 925 * B_CACHE getting set. 926 * 927 * We can also avoid issuing the read if the write covers 928 * the entire buffer. We have to make sure the buffer state 929 * is reasonable in this case since we will not be initiating 930 * I/O. See the comments in kern/vfs_bio.c's getblk() for 931 * more information. 932 * 933 * B_CACHE may also be set due to the buffer being cached 934 * normally. 935 */ 936 937 if (on == 0 && n == bcount) { 938 bp->b_flags |= B_CACHE; 939 bp->b_flags &= ~B_INVAL; 940 bp->b_ioflags &= ~BIO_ERROR; 941 } 942 943 if ((bp->b_flags & B_CACHE) == 0) { 944 bp->b_iocmd = BIO_READ; 945 vfs_busy_pages(bp, 0); 946 error = nfs_doio(bp, cred, p); 947 if (error) { 948 brelse(bp); 949 break; 950 } 951 } 952 if (!bp) { 953 error = EINTR; 954 break; 955 } 956 if (bp->b_wcred == NOCRED) { 957 crhold(cred); 958 bp->b_wcred = cred; 959 } 960 np->n_flag |= NMODIFIED; 961 962 /* 963 * If dirtyend exceeds file size, chop it down. This should 964 * not normally occur but there is an append race where it 965 * might occur XXX, so we log it. 966 * 967 * If the chopping creates a reverse-indexed or degenerate 968 * situation with dirtyoff/end, we 0 both of them. 969 */ 970 971 if (bp->b_dirtyend > bcount) { 972 printf("NFS append race @%lx:%d\n", 973 (long)bp->b_blkno * DEV_BSIZE, 974 bp->b_dirtyend - bcount); 975 bp->b_dirtyend = bcount; 976 } 977 978 if (bp->b_dirtyoff >= bp->b_dirtyend) 979 bp->b_dirtyoff = bp->b_dirtyend = 0; 980 981 /* 982 * If the new write will leave a contiguous dirty 983 * area, just update the b_dirtyoff and b_dirtyend, 984 * otherwise force a write rpc of the old dirty area. 985 * 986 * While it is possible to merge discontiguous writes due to 987 * our having a B_CACHE buffer ( and thus valid read data 988 * for the hole), we don't because it could lead to 989 * significant cache coherency problems with multiple clients, 990 * especially if locking is implemented later on. 991 * 992 * as an optimization we could theoretically maintain 993 * a linked list of discontinuous areas, but we would still 994 * have to commit them separately so there isn't much 995 * advantage to it except perhaps a bit of asynchronization. 996 */ 997 998 if (bp->b_dirtyend > 0 && 999 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { 1000 if (BUF_WRITE(bp) == EINTR) 1001 return (EINTR); 1002 goto again; 1003 } 1004 1005 /* 1006 * Check for valid write lease and get one as required. 1007 * In case getblk() and/or bwrite() delayed us. 1008 */ 1009 if ((nmp->nm_flag & NFSMNT_NQNFS) && 1010 NQNFS_CKINVALID(vp, np, ND_WRITE)) { 1011 do { 1012 error = nqnfs_getlease(vp, ND_WRITE, cred, p); 1013 } while (error == NQNFS_EXPIRED); 1014 if (error) { 1015 brelse(bp); 1016 break; 1017 } 1018 if (np->n_lrev != np->n_brev || 1019 (np->n_flag & NQNFSNONCACHE)) { 1020 brelse(bp); 1021 error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); 1022 if (error) 1023 break; 1024 np->n_brev = np->n_lrev; 1025 goto again; 1026 } 1027 } 1028 1029 error = uiomove((char *)bp->b_data + on, n, uio); 1030 1031 /* 1032 * Since this block is being modified, it must be written 1033 * again and not just committed. Since write clustering does 1034 * not work for the stage 1 data write, only the stage 2 1035 * commit rpc, we have to clear B_CLUSTEROK as well. 1036 */ 1037 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1038 1039 if (error) { 1040 bp->b_ioflags |= BIO_ERROR; 1041 brelse(bp); 1042 break; 1043 } 1044 1045 /* 1046 * Only update dirtyoff/dirtyend if not a degenerate 1047 * condition. 1048 */ 1049 if (n) { 1050 if (bp->b_dirtyend > 0) { 1051 bp->b_dirtyoff = min(on, bp->b_dirtyoff); 1052 bp->b_dirtyend = max((on + n), bp->b_dirtyend); 1053 } else { 1054 bp->b_dirtyoff = on; 1055 bp->b_dirtyend = on + n; 1056 } 1057 vfs_bio_set_validclean(bp, on, n); 1058 } 1059 1060 /* 1061 * If the lease is non-cachable or IO_SYNC do bwrite(). 1062 * 1063 * IO_INVAL appears to be unused. The idea appears to be 1064 * to turn off caching in this case. Very odd. XXX 1065 */ 1066 if ((np->n_flag & NQNFSNONCACHE) || (ioflag & IO_SYNC)) { 1067 if (ioflag & IO_INVAL) 1068 bp->b_flags |= B_NOCACHE; 1069 error = BUF_WRITE(bp); 1070 if (error) 1071 break; 1072 if (np->n_flag & NQNFSNONCACHE) { 1073 error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); 1074 if (error) 1075 break; 1076 } 1077 } else if ((n + on) == biosize && 1078 (nmp->nm_flag & NFSMNT_NQNFS) == 0) { 1079 bp->b_flags |= B_ASYNC; 1080 (void)nfs_writebp(bp, 0, 0); 1081 } else { 1082 bdwrite(bp); 1083 } 1084 } while (uio->uio_resid > 0 && n > 0); 1085 1086 if (haverslock) 1087 nfs_rsunlock(np, p); 1088 1089 return (error); 1090} 1091 1092/* 1093 * Get an nfs cache block. 1094 * 1095 * Allocate a new one if the block isn't currently in the cache 1096 * and return the block marked busy. If the calling process is 1097 * interrupted by a signal for an interruptible mount point, return 1098 * NULL. 1099 * 1100 * The caller must carefully deal with the possible B_INVAL state of 1101 * the buffer. nfs_doio() clears B_INVAL (and nfs_asyncio() clears it 1102 * indirectly), so synchronous reads can be issued without worrying about 1103 * the B_INVAL state. We have to be a little more careful when dealing 1104 * with writes (see comments in nfs_write()) when extending a file past 1105 * its EOF. 1106 */ 1107static struct buf * 1108nfs_getcacheblk(vp, bn, size, p) 1109 struct vnode *vp; 1110 daddr_t bn; 1111 int size; 1112 struct proc *p; 1113{ 1114 register struct buf *bp; 1115 struct mount *mp; 1116 struct nfsmount *nmp; 1117 1118 mp = vp->v_mount; 1119 nmp = VFSTONFS(mp); 1120 1121 if (nmp->nm_flag & NFSMNT_INT) { 1122 bp = getblk(vp, bn, size, PCATCH, 0); 1123 while (bp == (struct buf *)0) { 1124 if (nfs_sigintr(nmp, (struct nfsreq *)0, p)) 1125 return ((struct buf *)0); 1126 bp = getblk(vp, bn, size, 0, 2 * hz); 1127 } 1128 } else { 1129 bp = getblk(vp, bn, size, 0, 0); 1130 } 1131 1132 if (vp->v_type == VREG) { 1133 int biosize; 1134 1135 biosize = mp->mnt_stat.f_iosize; 1136 bp->b_blkno = bn * (biosize / DEV_BSIZE); 1137 } 1138 return (bp); 1139} 1140 1141/* 1142 * Flush and invalidate all dirty buffers. If another process is already 1143 * doing the flush, just wait for completion. 1144 */ 1145int 1146nfs_vinvalbuf(vp, flags, cred, p, intrflg) 1147 struct vnode *vp; 1148 int flags; 1149 struct ucred *cred; 1150 struct proc *p; 1151 int intrflg; 1152{ 1153 register struct nfsnode *np = VTONFS(vp); 1154 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 1155 int error = 0, slpflag, slptimeo; 1156 1157 if (vp->v_flag & VXLOCK) { 1158 return (0); 1159 } 1160 1161 if ((nmp->nm_flag & NFSMNT_INT) == 0) 1162 intrflg = 0; 1163 if (intrflg) { 1164 slpflag = PCATCH; 1165 slptimeo = 2 * hz; 1166 } else { 1167 slpflag = 0; 1168 slptimeo = 0; 1169 } 1170 /* 1171 * First wait for any other process doing a flush to complete. 1172 */ 1173 while (np->n_flag & NFLUSHINPROG) { 1174 np->n_flag |= NFLUSHWANT; 1175 error = tsleep((caddr_t)&np->n_flag, PRIBIO + 2, "nfsvinval", 1176 slptimeo); 1177 if (error && intrflg && nfs_sigintr(nmp, (struct nfsreq *)0, p)) 1178 return (EINTR); 1179 } 1180 1181 /* 1182 * Now, flush as required. 1183 */ 1184 np->n_flag |= NFLUSHINPROG; 1185 error = vinvalbuf(vp, flags, cred, p, slpflag, 0); 1186 while (error) { 1187 if (intrflg && nfs_sigintr(nmp, (struct nfsreq *)0, p)) { 1188 np->n_flag &= ~NFLUSHINPROG; 1189 if (np->n_flag & NFLUSHWANT) { 1190 np->n_flag &= ~NFLUSHWANT; 1191 wakeup((caddr_t)&np->n_flag); 1192 } 1193 return (EINTR); 1194 } 1195 error = vinvalbuf(vp, flags, cred, p, 0, slptimeo); 1196 } 1197 np->n_flag &= ~(NMODIFIED | NFLUSHINPROG); 1198 if (np->n_flag & NFLUSHWANT) { 1199 np->n_flag &= ~NFLUSHWANT; 1200 wakeup((caddr_t)&np->n_flag); 1201 } 1202 return (0); 1203} 1204 1205/* 1206 * Initiate asynchronous I/O. Return an error if no nfsiods are available. 1207 * This is mainly to avoid queueing async I/O requests when the nfsiods 1208 * are all hung on a dead server. 1209 * 1210 * Note: nfs_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp 1211 * is eventually dequeued by the async daemon, nfs_doio() *will*. 1212 */ 1213int 1214nfs_asyncio(bp, cred, procp) 1215 register struct buf *bp; 1216 struct ucred *cred; 1217 struct proc *procp; 1218{ 1219 struct nfsmount *nmp; 1220 int i; 1221 int gotiod; 1222 int slpflag = 0; 1223 int slptimeo = 0; 1224 int error; 1225 1226 /* 1227 * If no async daemons then return EIO to force caller to run the rpc 1228 * synchronously. 1229 */ 1230 if (nfs_numasync == 0) 1231 return (EIO); 1232 1233 nmp = VFSTONFS(bp->b_vp->v_mount); 1234 1235 /* 1236 * Commits are usually short and sweet so lets save some cpu and 1237 * leave the async daemons for more important rpc's (such as reads 1238 * and writes). 1239 */ 1240 if (bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) && 1241 (nmp->nm_bufqiods > nfs_numasync / 2)) { 1242 return(EIO); 1243 } 1244 1245again: 1246 if (nmp->nm_flag & NFSMNT_INT) 1247 slpflag = PCATCH; 1248 gotiod = FALSE; 1249 1250 /* 1251 * Find a free iod to process this request. 1252 */ 1253 for (i = 0; i < NFS_MAXASYNCDAEMON; i++) 1254 if (nfs_iodwant[i]) { 1255 /* 1256 * Found one, so wake it up and tell it which 1257 * mount to process. 1258 */ 1259 NFS_DPF(ASYNCIO, 1260 ("nfs_asyncio: waking iod %d for mount %p\n", 1261 i, nmp)); 1262 nfs_iodwant[i] = (struct proc *)0; 1263 nfs_iodmount[i] = nmp; 1264 nmp->nm_bufqiods++; 1265 wakeup((caddr_t)&nfs_iodwant[i]); 1266 gotiod = TRUE; 1267 break; 1268 } 1269 1270 /* 1271 * If none are free, we may already have an iod working on this mount 1272 * point. If so, it will process our request. 1273 */ 1274 if (!gotiod) { 1275 if (nmp->nm_bufqiods > 0) { 1276 NFS_DPF(ASYNCIO, 1277 ("nfs_asyncio: %d iods are already processing mount %p\n", 1278 nmp->nm_bufqiods, nmp)); 1279 gotiod = TRUE; 1280 } 1281 } 1282 1283 /* 1284 * If we have an iod which can process the request, then queue 1285 * the buffer. 1286 */ 1287 if (gotiod) { 1288 /* 1289 * Ensure that the queue never grows too large. We still want 1290 * to asynchronize so we block rather then return EIO. 1291 */ 1292 while (nmp->nm_bufqlen >= 2*nfs_numasync) { 1293 NFS_DPF(ASYNCIO, 1294 ("nfs_asyncio: waiting for mount %p queue to drain\n", nmp)); 1295 nmp->nm_bufqwant = TRUE; 1296 error = tsleep(&nmp->nm_bufq, slpflag | PRIBIO, 1297 "nfsaio", slptimeo); 1298 if (error) { 1299 if (nfs_sigintr(nmp, NULL, procp)) 1300 return (EINTR); 1301 if (slpflag == PCATCH) { 1302 slpflag = 0; 1303 slptimeo = 2 * hz; 1304 } 1305 } 1306 /* 1307 * We might have lost our iod while sleeping, 1308 * so check and loop if nescessary. 1309 */ 1310 if (nmp->nm_bufqiods == 0) { 1311 NFS_DPF(ASYNCIO, 1312 ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); 1313 goto again; 1314 } 1315 } 1316 1317 if (bp->b_iocmd == BIO_READ) { 1318 if (bp->b_rcred == NOCRED && cred != NOCRED) { 1319 crhold(cred); 1320 bp->b_rcred = cred; 1321 } 1322 } else { 1323 bp->b_flags |= B_WRITEINPROG; 1324 if (bp->b_wcred == NOCRED && cred != NOCRED) { 1325 crhold(cred); 1326 bp->b_wcred = cred; 1327 } 1328 } 1329 1330 BUF_KERNPROC(bp); 1331 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist); 1332 nmp->nm_bufqlen++; 1333 return (0); 1334 } 1335 1336 /* 1337 * All the iods are busy on other mounts, so return EIO to 1338 * force the caller to process the i/o synchronously. 1339 */ 1340 NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n")); 1341 return (EIO); 1342} 1343 1344/* 1345 * Do an I/O operation to/from a cache block. This may be called 1346 * synchronously or from an nfsiod. 1347 */ 1348int 1349nfs_doio(bp, cr, p) 1350 struct buf *bp; 1351 struct ucred *cr; 1352 struct proc *p; 1353{ 1354 struct uio *uiop; 1355 struct vnode *vp; 1356 struct nfsnode *np; 1357 struct nfsmount *nmp; 1358 int error = 0, iomode, must_commit = 0; 1359 struct uio uio; 1360 struct iovec io; 1361 1362 vp = bp->b_vp; 1363 np = VTONFS(vp); 1364 nmp = VFSTONFS(vp->v_mount); 1365 uiop = &uio; 1366 uiop->uio_iov = &io; 1367 uiop->uio_iovcnt = 1; 1368 uiop->uio_segflg = UIO_SYSSPACE; 1369 uiop->uio_procp = p; 1370 1371 /* 1372 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We 1373 * do this here so we do not have to do it in all the code that 1374 * calls us. 1375 */ 1376 bp->b_flags &= ~B_INVAL; 1377 bp->b_ioflags &= ~BIO_ERROR; 1378 1379 KASSERT(!(bp->b_flags & B_DONE), ("nfs_doio: bp %p already marked done", bp)); 1380 1381 /* 1382 * Historically, paging was done with physio, but no more. 1383 */ 1384 if (bp->b_flags & B_PHYS) { 1385 /* 1386 * ...though reading /dev/drum still gets us here. 1387 */ 1388 io.iov_len = uiop->uio_resid = bp->b_bcount; 1389 /* mapping was done by vmapbuf() */ 1390 io.iov_base = bp->b_data; 1391 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE; 1392 if (bp->b_iocmd == BIO_READ) { 1393 uiop->uio_rw = UIO_READ; 1394 nfsstats.read_physios++; 1395 error = nfs_readrpc(vp, uiop, cr); 1396 } else { 1397 int com; 1398 1399 iomode = NFSV3WRITE_DATASYNC; 1400 uiop->uio_rw = UIO_WRITE; 1401 nfsstats.write_physios++; 1402 error = nfs_writerpc(vp, uiop, cr, &iomode, &com); 1403 } 1404 if (error) { 1405 bp->b_ioflags |= BIO_ERROR; 1406 bp->b_error = error; 1407 } 1408 } else if (bp->b_iocmd == BIO_READ) { 1409 io.iov_len = uiop->uio_resid = bp->b_bcount; 1410 io.iov_base = bp->b_data; 1411 uiop->uio_rw = UIO_READ; 1412 switch (vp->v_type) { 1413 case VREG: 1414 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE; 1415 nfsstats.read_bios++; 1416 error = nfs_readrpc(vp, uiop, cr); 1417 if (!error) { 1418 if (uiop->uio_resid) { 1419 /* 1420 * If we had a short read with no error, we must have 1421 * hit a file hole. We should zero-fill the remainder. 1422 * This can also occur if the server hits the file EOF. 1423 * 1424 * Holes used to be able to occur due to pending 1425 * writes, but that is not possible any longer. 1426 */ 1427 int nread = bp->b_bcount - uiop->uio_resid; 1428 int left = bp->b_bcount - nread; 1429 1430 if (left > 0) 1431 bzero((char *)bp->b_data + nread, left); 1432 uiop->uio_resid = 0; 1433 } 1434 } 1435 if (p && (vp->v_flag & VTEXT) && 1436 (((nmp->nm_flag & NFSMNT_NQNFS) && 1437 NQNFS_CKINVALID(vp, np, ND_READ) && 1438 np->n_lrev != np->n_brev) || 1439 (!(nmp->nm_flag & NFSMNT_NQNFS) && 1440 np->n_mtime != np->n_vattr.va_mtime.tv_sec))) { 1441 uprintf("Process killed due to text file modification\n"); 1442 psignal(p, SIGKILL); 1443 PHOLD(p); 1444 } 1445 break; 1446 case VLNK: 1447 uiop->uio_offset = (off_t)0; 1448 nfsstats.readlink_bios++; 1449 error = nfs_readlinkrpc(vp, uiop, cr); 1450 break; 1451 case VDIR: 1452 nfsstats.readdir_bios++; 1453 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ; 1454 if (nmp->nm_flag & NFSMNT_RDIRPLUS) { 1455 error = nfs_readdirplusrpc(vp, uiop, cr); 1456 if (error == NFSERR_NOTSUPP) 1457 nmp->nm_flag &= ~NFSMNT_RDIRPLUS; 1458 } 1459 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) 1460 error = nfs_readdirrpc(vp, uiop, cr); 1461 /* 1462 * end-of-directory sets B_INVAL but does not generate an 1463 * error. 1464 */ 1465 if (error == 0 && uiop->uio_resid == bp->b_bcount) 1466 bp->b_flags |= B_INVAL; 1467 break; 1468 default: 1469 printf("nfs_doio: type %x unexpected\n",vp->v_type); 1470 break; 1471 }; 1472 if (error) { 1473 bp->b_ioflags |= BIO_ERROR; 1474 bp->b_error = error; 1475 } 1476 } else { 1477 /* 1478 * If we only need to commit, try to commit 1479 */ 1480 if (bp->b_flags & B_NEEDCOMMIT) { 1481 int retv; 1482 off_t off; 1483 1484 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff; 1485 bp->b_flags |= B_WRITEINPROG; 1486 retv = nfs_commit( 1487 bp->b_vp, off, bp->b_dirtyend-bp->b_dirtyoff, 1488 bp->b_wcred, p); 1489 bp->b_flags &= ~B_WRITEINPROG; 1490 if (retv == 0) { 1491 bp->b_dirtyoff = bp->b_dirtyend = 0; 1492 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1493 bp->b_resid = 0; 1494 bufdone(bp); 1495 return (0); 1496 } 1497 if (retv == NFSERR_STALEWRITEVERF) { 1498 nfs_clearcommit(bp->b_vp->v_mount); 1499 } 1500 } 1501 1502 /* 1503 * Setup for actual write 1504 */ 1505 1506 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size) 1507 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE; 1508 1509 if (bp->b_dirtyend > bp->b_dirtyoff) { 1510 io.iov_len = uiop->uio_resid = bp->b_dirtyend 1511 - bp->b_dirtyoff; 1512 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE 1513 + bp->b_dirtyoff; 1514 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; 1515 uiop->uio_rw = UIO_WRITE; 1516 nfsstats.write_bios++; 1517 1518 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC) 1519 iomode = NFSV3WRITE_UNSTABLE; 1520 else 1521 iomode = NFSV3WRITE_FILESYNC; 1522 1523 bp->b_flags |= B_WRITEINPROG; 1524 error = nfs_writerpc(vp, uiop, cr, &iomode, &must_commit); 1525 1526 /* 1527 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try 1528 * to cluster the buffers needing commit. This will allow 1529 * the system to submit a single commit rpc for the whole 1530 * cluster. We can do this even if the buffer is not 100% 1531 * dirty (relative to the NFS blocksize), so we optimize the 1532 * append-to-file-case. 1533 * 1534 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be 1535 * cleared because write clustering only works for commit 1536 * rpc's, not for the data portion of the write). 1537 */ 1538 1539 if (!error && iomode == NFSV3WRITE_UNSTABLE) { 1540 bp->b_flags |= B_NEEDCOMMIT; 1541 if (bp->b_dirtyoff == 0 1542 && bp->b_dirtyend == bp->b_bcount) 1543 bp->b_flags |= B_CLUSTEROK; 1544 } else { 1545 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1546 } 1547 bp->b_flags &= ~B_WRITEINPROG; 1548 1549 /* 1550 * For an interrupted write, the buffer is still valid 1551 * and the write hasn't been pushed to the server yet, 1552 * so we can't set BIO_ERROR and report the interruption 1553 * by setting B_EINTR. For the B_ASYNC case, B_EINTR 1554 * is not relevant, so the rpc attempt is essentially 1555 * a noop. For the case of a V3 write rpc not being 1556 * committed to stable storage, the block is still 1557 * dirty and requires either a commit rpc or another 1558 * write rpc with iomode == NFSV3WRITE_FILESYNC before 1559 * the block is reused. This is indicated by setting 1560 * the B_DELWRI and B_NEEDCOMMIT flags. 1561 * 1562 * If the buffer is marked B_PAGING, it does not reside on 1563 * the vp's paging queues so we cannot call bdirty(). The 1564 * bp in this case is not an NFS cache block so we should 1565 * be safe. XXX 1566 */ 1567 if (error == EINTR 1568 || (!error && (bp->b_flags & B_NEEDCOMMIT))) { 1569 int s; 1570 1571 s = splbio(); 1572 bp->b_flags &= ~(B_INVAL|B_NOCACHE); 1573 if ((bp->b_flags & B_PAGING) == 0) { 1574 bdirty(bp); 1575 bp->b_flags &= ~B_DONE; 1576 } 1577 if (error && (bp->b_flags & B_ASYNC) == 0) 1578 bp->b_flags |= B_EINTR; 1579 splx(s); 1580 } else { 1581 if (error) { 1582 bp->b_ioflags |= BIO_ERROR; 1583 bp->b_error = np->n_error = error; 1584 np->n_flag |= NWRITEERR; 1585 } 1586 bp->b_dirtyoff = bp->b_dirtyend = 0; 1587 } 1588 } else { 1589 bp->b_resid = 0; 1590 bufdone(bp); 1591 return (0); 1592 } 1593 } 1594 bp->b_resid = uiop->uio_resid; 1595 if (must_commit) 1596 nfs_clearcommit(vp->v_mount); 1597 bufdone(bp); 1598 return (error); 1599} 1600