Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/nfsclient/nfs_bio.c
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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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)nfs_bio.c 8.9 (Berkeley) 3/30/95 33 */ 34 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD: src/sys/nfsclient/nfs_bio.c,v 1.133.2.3 2005/06/26 23:55:50 green Exp $"); 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/bio.h> 41 #include <sys/buf.h> 42 #include <sys/kernel.h> 43 #include <sys/mount.h> 44 #include <sys/proc.h> 45 #include <sys/resourcevar.h> 46 #include <sys/signalvar.h> 47 #include <sys/vmmeter.h> 48 #include <sys/vnode.h> 49 50 #include <vm/vm.h> 51 #include <vm/vm_extern.h> 52 #include <vm/vm_page.h> 53 #include <vm/vm_object.h> 54 #include <vm/vm_pager.h> 55 #include <vm/vnode_pager.h> 56 57 #include <rpc/rpcclnt.h> 58 59 #include <nfs/rpcv2.h> 60 #include <nfs/nfsproto.h> 61 #include <nfsclient/nfs.h> 62 #include <nfsclient/nfsmount.h> 63 #include <nfsclient/nfsnode.h> 64 65 #include <nfs4client/nfs4.h> 66 67 /* 68 * Just call nfs_writebp() with the force argument set to 1. 69 * 70 * NOTE: B_DONE may or may not be set in a_bp on call. 71 */ 72 static int 73 nfs4_bwrite(struct buf *bp) 74 { 75 76 return (nfs4_writebp(bp, 1, curthread)); 77 } 78 79 static int 80 nfs_bwrite(struct buf *bp) 81 { 82 83 return (nfs_writebp(bp, 1, curthread)); 84 } 85 86 struct buf_ops buf_ops_nfs4 = { 87 "buf_ops_nfs4", 88 nfs4_bwrite 89 }; 90 91 struct buf_ops buf_ops_nfs = { 92 "buf_ops_nfs", 93 nfs_bwrite 94 }; 95 96 static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, 97 struct thread *td); 98 99 /* 100 * Vnode op for VM getpages. 101 */ 102 int 103 nfs_getpages(struct vop_getpages_args *ap) 104 { 105 int i, error, nextoff, size, toff, count, npages; 106 struct uio uio; 107 struct iovec iov; 108 vm_offset_t kva; 109 struct buf *bp; 110 struct vnode *vp; 111 struct thread *td; 112 struct ucred *cred; 113 struct nfsmount *nmp; 114 vm_object_t object; 115 vm_page_t *pages; 116 117 GIANT_REQUIRED; 118 119 vp = ap->a_vp; 120 td = curthread; /* XXX */ 121 cred = curthread->td_ucred; /* XXX */ 122 nmp = VFSTONFS(vp->v_mount); 123 pages = ap->a_m; 124 count = ap->a_count; 125 126 if ((object = vp->v_object) == NULL) { 127 printf("nfs_getpages: called with non-merged cache vnode??\n"); 128 return VM_PAGER_ERROR; 129 } 130 131 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 132 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 133 /* We'll never get here for v4, because we always have fsinfo */ 134 (void)nfs_fsinfo(nmp, vp, cred, td); 135 } 136 137 npages = btoc(count); 138 139 /* 140 * If the requested page is partially valid, just return it and 141 * allow the pager to zero-out the blanks. Partially valid pages 142 * can only occur at the file EOF. 143 */ 144 145 { 146 vm_page_t m = pages[ap->a_reqpage]; 147 148 VM_OBJECT_LOCK(object); 149 vm_page_lock_queues(); 150 if (m->valid != 0) { 151 /* handled by vm_fault now */ 152 /* vm_page_zero_invalid(m, TRUE); */ 153 for (i = 0; i < npages; ++i) { 154 if (i != ap->a_reqpage) 155 vm_page_free(pages[i]); 156 } 157 vm_page_unlock_queues(); 158 VM_OBJECT_UNLOCK(object); 159 return(0); 160 } 161 vm_page_unlock_queues(); 162 VM_OBJECT_UNLOCK(object); 163 } 164 165 /* 166 * We use only the kva address for the buffer, but this is extremely 167 * convienient and fast. 168 */ 169 bp = getpbuf(&nfs_pbuf_freecnt); 170 171 kva = (vm_offset_t) bp->b_data; 172 pmap_qenter(kva, pages, npages); 173 cnt.v_vnodein++; 174 cnt.v_vnodepgsin += npages; 175 176 iov.iov_base = (caddr_t) kva; 177 iov.iov_len = count; 178 uio.uio_iov = &iov; 179 uio.uio_iovcnt = 1; 180 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex); 181 uio.uio_resid = count; 182 uio.uio_segflg = UIO_SYSSPACE; 183 uio.uio_rw = UIO_READ; 184 uio.uio_td = td; 185 186 error = (nmp->nm_rpcops->nr_readrpc)(vp, &uio, cred); 187 pmap_qremove(kva, npages); 188 189 relpbuf(bp, &nfs_pbuf_freecnt); 190 191 if (error && (uio.uio_resid == count)) { 192 printf("nfs_getpages: error %d\n", error); 193 VM_OBJECT_LOCK(object); 194 vm_page_lock_queues(); 195 for (i = 0; i < npages; ++i) { 196 if (i != ap->a_reqpage) 197 vm_page_free(pages[i]); 198 } 199 vm_page_unlock_queues(); 200 VM_OBJECT_UNLOCK(object); 201 return VM_PAGER_ERROR; 202 } 203 204 /* 205 * Calculate the number of bytes read and validate only that number 206 * of bytes. Note that due to pending writes, size may be 0. This 207 * does not mean that the remaining data is invalid! 208 */ 209 210 size = count - uio.uio_resid; 211 VM_OBJECT_LOCK(object); 212 vm_page_lock_queues(); 213 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) { 214 vm_page_t m; 215 nextoff = toff + PAGE_SIZE; 216 m = pages[i]; 217 218 if (nextoff <= size) { 219 /* 220 * Read operation filled an entire page 221 */ 222 m->valid = VM_PAGE_BITS_ALL; 223 vm_page_undirty(m); 224 } else if (size > toff) { 225 /* 226 * Read operation filled a partial page. 227 */ 228 m->valid = 0; 229 vm_page_set_validclean(m, 0, size - toff); 230 /* handled by vm_fault now */ 231 /* vm_page_zero_invalid(m, TRUE); */ 232 } else { 233 /* 234 * Read operation was short. If no error occured 235 * we may have hit a zero-fill section. We simply 236 * leave valid set to 0. 237 */ 238 ; 239 } 240 if (i != ap->a_reqpage) { 241 /* 242 * Whether or not to leave the page activated is up in 243 * the air, but we should put the page on a page queue 244 * somewhere (it already is in the object). Result: 245 * It appears that emperical results show that 246 * deactivating pages is best. 247 */ 248 249 /* 250 * Just in case someone was asking for this page we 251 * now tell them that it is ok to use. 252 */ 253 if (!error) { 254 if (m->flags & PG_WANTED) 255 vm_page_activate(m); 256 else 257 vm_page_deactivate(m); 258 vm_page_wakeup(m); 259 } else { 260 vm_page_free(m); 261 } 262 } 263 } 264 vm_page_unlock_queues(); 265 VM_OBJECT_UNLOCK(object); 266 return 0; 267 } 268 269 /* 270 * Vnode op for VM putpages. 271 */ 272 int 273 nfs_putpages(struct vop_putpages_args *ap) 274 { 275 struct uio uio; 276 struct iovec iov; 277 vm_offset_t kva; 278 struct buf *bp; 279 int iomode, must_commit, i, error, npages, count; 280 off_t offset; 281 int *rtvals; 282 struct vnode *vp; 283 struct thread *td; 284 struct ucred *cred; 285 struct nfsmount *nmp; 286 struct nfsnode *np; 287 vm_page_t *pages; 288 289 GIANT_REQUIRED; 290 291 vp = ap->a_vp; 292 np = VTONFS(vp); 293 td = curthread; /* XXX */ 294 cred = curthread->td_ucred; /* XXX */ 295 nmp = VFSTONFS(vp->v_mount); 296 pages = ap->a_m; 297 count = ap->a_count; 298 rtvals = ap->a_rtvals; 299 npages = btoc(count); 300 offset = IDX_TO_OFF(pages[0]->pindex); 301 302 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 303 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 304 (void)nfs_fsinfo(nmp, vp, cred, td); 305 } 306 307 for (i = 0; i < npages; i++) 308 rtvals[i] = VM_PAGER_AGAIN; 309 310 /* 311 * When putting pages, do not extend file past EOF. 312 */ 313 314 if (offset + count > np->n_size) { 315 count = np->n_size - offset; 316 if (count < 0) 317 count = 0; 318 } 319 320 /* 321 * We use only the kva address for the buffer, but this is extremely 322 * convienient and fast. 323 */ 324 bp = getpbuf(&nfs_pbuf_freecnt); 325 326 kva = (vm_offset_t) bp->b_data; 327 pmap_qenter(kva, pages, npages); 328 cnt.v_vnodeout++; 329 cnt.v_vnodepgsout += count; 330 331 iov.iov_base = (caddr_t) kva; 332 iov.iov_len = count; 333 uio.uio_iov = &iov; 334 uio.uio_iovcnt = 1; 335 uio.uio_offset = offset; 336 uio.uio_resid = count; 337 uio.uio_segflg = UIO_SYSSPACE; 338 uio.uio_rw = UIO_WRITE; 339 uio.uio_td = td; 340 341 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0) 342 iomode = NFSV3WRITE_UNSTABLE; 343 else 344 iomode = NFSV3WRITE_FILESYNC; 345 346 error = (nmp->nm_rpcops->nr_writerpc)(vp, &uio, cred, &iomode, &must_commit); 347 348 pmap_qremove(kva, npages); 349 relpbuf(bp, &nfs_pbuf_freecnt); 350 351 if (!error) { 352 int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE; 353 for (i = 0; i < nwritten; i++) { 354 rtvals[i] = VM_PAGER_OK; 355 vm_page_undirty(pages[i]); 356 } 357 if (must_commit) { 358 nfs_clearcommit(vp->v_mount); 359 } 360 } 361 return rtvals[0]; 362 } 363 364 /* 365 * Vnode op for read using bio 366 */ 367 int 368 nfs_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred) 369 { 370 struct nfsnode *np = VTONFS(vp); 371 int biosize, i; 372 struct buf *bp = 0, *rabp; 373 struct vattr vattr; 374 struct thread *td; 375 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 376 daddr_t lbn, rabn; 377 int bcount; 378 int seqcount; 379 int nra, error = 0, n = 0, on = 0; 380 381 #ifdef DIAGNOSTIC 382 if (uio->uio_rw != UIO_READ) 383 panic("nfs_read mode"); 384 #endif 385 if (uio->uio_resid == 0) 386 return (0); 387 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */ 388 return (EINVAL); 389 td = uio->uio_td; 390 391 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 392 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 393 (void)nfs_fsinfo(nmp, vp, cred, td); 394 if (vp->v_type != VDIR && 395 (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 396 return (EFBIG); 397 biosize = vp->v_mount->mnt_stat.f_iosize; 398 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE); 399 /* 400 * For nfs, cache consistency can only be maintained approximately. 401 * Although RFC1094 does not specify the criteria, the following is 402 * believed to be compatible with the reference port. 403 * For nfs: 404 * If the file's modify time on the server has changed since the 405 * last read rpc or you have written to the file, 406 * you may have lost data cache consistency with the 407 * server, so flush all of the file's data out of the cache. 408 * Then force a getattr rpc to ensure that you have up to date 409 * attributes. 410 * NB: This implies that cache data can be read when up to 411 * NFS_ATTRTIMEO seconds out of date. If you find that you need current 412 * attributes this could be forced by setting n_attrstamp to 0 before 413 * the VOP_GETATTR() call. 414 */ 415 if (np->n_flag & NMODIFIED) { 416 if (vp->v_type != VREG) { 417 if (vp->v_type != VDIR) 418 panic("nfs: bioread, not dir"); 419 (nmp->nm_rpcops->nr_invaldir)(vp); 420 error = nfs_vinvalbuf(vp, V_SAVE, cred, td, 1); 421 if (error) 422 return (error); 423 } 424 np->n_attrstamp = 0; 425 error = VOP_GETATTR(vp, &vattr, cred, td); 426 if (error) 427 return (error); 428 np->n_mtime = vattr.va_mtime.tv_sec; 429 } else { 430 error = VOP_GETATTR(vp, &vattr, cred, td); 431 if (error) 432 return (error); 433 if ((np->n_flag & NSIZECHANGED) 434 || (np->n_mtime != vattr.va_mtime.tv_sec)) { 435 if (vp->v_type == VDIR) 436 (nmp->nm_rpcops->nr_invaldir)(vp); 437 error = nfs_vinvalbuf(vp, V_SAVE, cred, td, 1); 438 if (error) 439 return (error); 440 np->n_mtime = vattr.va_mtime.tv_sec; 441 np->n_flag &= ~NSIZECHANGED; 442 } 443 } 444 do { 445 switch (vp->v_type) { 446 case VREG: 447 nfsstats.biocache_reads++; 448 lbn = uio->uio_offset / biosize; 449 on = uio->uio_offset & (biosize - 1); 450 451 /* 452 * Start the read ahead(s), as required. 453 */ 454 if (nmp->nm_readahead > 0) { 455 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && 456 (off_t)(lbn + 1 + nra) * biosize < np->n_size; nra++) { 457 rabn = lbn + 1 + nra; 458 if (incore(vp, rabn) == NULL) { 459 rabp = nfs_getcacheblk(vp, rabn, biosize, td); 460 if (!rabp) { 461 error = nfs_sigintr(nmp, NULL, td); 462 return (error ? error : EINTR); 463 } 464 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 465 rabp->b_flags |= B_ASYNC; 466 rabp->b_iocmd = BIO_READ; 467 vfs_busy_pages(rabp, 0); 468 if (nfs_asyncio(rabp, cred, td)) { 469 rabp->b_flags |= B_INVAL; 470 rabp->b_ioflags |= BIO_ERROR; 471 vfs_unbusy_pages(rabp); 472 brelse(rabp); 473 break; 474 } 475 } else { 476 brelse(rabp); 477 } 478 } 479 } 480 } 481 482 /* 483 * Obtain the buffer cache block. Figure out the buffer size 484 * when we are at EOF. If we are modifying the size of the 485 * buffer based on an EOF condition we need to hold 486 * nfs_rslock() through obtaining the buffer to prevent 487 * a potential writer-appender from messing with n_size. 488 * Otherwise we may accidently truncate the buffer and 489 * lose dirty data. 490 * 491 * Note that bcount is *not* DEV_BSIZE aligned. 492 */ 493 494 again: 495 bcount = biosize; 496 if ((off_t)lbn * biosize >= np->n_size) { 497 bcount = 0; 498 } else if ((off_t)(lbn + 1) * biosize > np->n_size) { 499 bcount = np->n_size - (off_t)lbn * biosize; 500 } 501 if (bcount != biosize) { 502 switch(nfs_rslock(np, td)) { 503 case ENOLCK: 504 goto again; 505 /* not reached */ 506 case EIO: 507 return (EIO); 508 case EINTR: 509 case ERESTART: 510 return(EINTR); 511 /* not reached */ 512 default: 513 break; 514 } 515 } 516 517 bp = nfs_getcacheblk(vp, lbn, bcount, td); 518 519 if (bcount != biosize) 520 nfs_rsunlock(np, td); 521 if (!bp) { 522 error = nfs_sigintr(nmp, NULL, td); 523 return (error ? error : EINTR); 524 } 525 526 /* 527 * If B_CACHE is not set, we must issue the read. If this 528 * fails, we return an error. 529 */ 530 531 if ((bp->b_flags & B_CACHE) == 0) { 532 bp->b_iocmd = BIO_READ; 533 vfs_busy_pages(bp, 0); 534 error = nfs_doio(bp, cred, td); 535 if (error) { 536 brelse(bp); 537 return (error); 538 } 539 } 540 541 /* 542 * on is the offset into the current bp. Figure out how many 543 * bytes we can copy out of the bp. Note that bcount is 544 * NOT DEV_BSIZE aligned. 545 * 546 * Then figure out how many bytes we can copy into the uio. 547 */ 548 549 n = 0; 550 if (on < bcount) 551 n = min((unsigned)(bcount - on), uio->uio_resid); 552 break; 553 case VLNK: 554 nfsstats.biocache_readlinks++; 555 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td); 556 if (!bp) { 557 error = nfs_sigintr(nmp, NULL, td); 558 return (error ? error : EINTR); 559 } 560 if ((bp->b_flags & B_CACHE) == 0) { 561 bp->b_iocmd = BIO_READ; 562 vfs_busy_pages(bp, 0); 563 error = nfs_doio(bp, cred, td); 564 if (error) { 565 bp->b_ioflags |= BIO_ERROR; 566 brelse(bp); 567 return (error); 568 } 569 } 570 n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); 571 on = 0; 572 break; 573 case VDIR: 574 nfsstats.biocache_readdirs++; 575 if (np->n_direofoffset 576 && uio->uio_offset >= np->n_direofoffset) { 577 return (0); 578 } 579 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; 580 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); 581 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td); 582 if (!bp) { 583 error = nfs_sigintr(nmp, NULL, td); 584 return (error ? error : EINTR); 585 } 586 if ((bp->b_flags & B_CACHE) == 0) { 587 bp->b_iocmd = BIO_READ; 588 vfs_busy_pages(bp, 0); 589 error = nfs_doio(bp, cred, td); 590 if (error) { 591 brelse(bp); 592 } 593 while (error == NFSERR_BAD_COOKIE) { 594 (nmp->nm_rpcops->nr_invaldir)(vp); 595 error = nfs_vinvalbuf(vp, 0, cred, td, 1); 596 /* 597 * Yuck! The directory has been modified on the 598 * server. The only way to get the block is by 599 * reading from the beginning to get all the 600 * offset cookies. 601 * 602 * Leave the last bp intact unless there is an error. 603 * Loop back up to the while if the error is another 604 * NFSERR_BAD_COOKIE (double yuch!). 605 */ 606 for (i = 0; i <= lbn && !error; i++) { 607 if (np->n_direofoffset 608 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) 609 return (0); 610 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td); 611 if (!bp) { 612 error = nfs_sigintr(nmp, NULL, td); 613 return (error ? error : EINTR); 614 } 615 if ((bp->b_flags & B_CACHE) == 0) { 616 bp->b_iocmd = BIO_READ; 617 vfs_busy_pages(bp, 0); 618 error = nfs_doio(bp, cred, td); 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 (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 incore(vp, lbn + 1) == NULL) { 655 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td); 656 if (rabp) { 657 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 658 rabp->b_flags |= B_ASYNC; 659 rabp->b_iocmd = BIO_READ; 660 vfs_busy_pages(rabp, 0); 661 if (nfs_asyncio(rabp, cred, td)) { 662 rabp->b_flags |= B_INVAL; 663 rabp->b_ioflags |= BIO_ERROR; 664 vfs_unbusy_pages(rabp); 665 brelse(rabp); 666 } 667 } else { 668 brelse(rabp); 669 } 670 } 671 } 672 /* 673 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is 674 * chopped for the EOF condition, we cannot tell how large 675 * NFS directories are going to be until we hit EOF. So 676 * an NFS directory buffer is *not* chopped to its EOF. Now, 677 * it just so happens that b_resid will effectively chop it 678 * to EOF. *BUT* this information is lost if the buffer goes 679 * away and is reconstituted into a B_CACHE state ( due to 680 * being VMIO ) later. So we keep track of the directory eof 681 * in np->n_direofoffset and chop it off as an extra step 682 * right here. 683 */ 684 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on); 685 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset) 686 n = np->n_direofoffset - uio->uio_offset; 687 break; 688 default: 689 printf(" nfs_bioread: type %x unexpected\n", vp->v_type); 690 break; 691 }; 692 693 if (n > 0) { 694 error = uiomove(bp->b_data + on, (int)n, uio); 695 } 696 switch (vp->v_type) { 697 case VREG: 698 break; 699 case VLNK: 700 n = 0; 701 break; 702 case VDIR: 703 break; 704 default: 705 printf(" nfs_bioread: type %x unexpected\n", vp->v_type); 706 } 707 brelse(bp); 708 } while (error == 0 && uio->uio_resid > 0 && n > 0); 709 return (error); 710 } 711 712 /* 713 * Vnode op for write using bio 714 */ 715 int 716 nfs_write(struct vop_write_args *ap) 717 { 718 int biosize; 719 struct uio *uio = ap->a_uio; 720 struct thread *td = uio->uio_td; 721 struct vnode *vp = ap->a_vp; 722 struct nfsnode *np = VTONFS(vp); 723 struct ucred *cred = ap->a_cred; 724 int ioflag = ap->a_ioflag; 725 struct buf *bp; 726 struct vattr vattr; 727 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 728 daddr_t lbn; 729 int bcount; 730 int n, on, error = 0; 731 int haverslock = 0; 732 struct proc *p = td?td->td_proc:NULL; 733 734 GIANT_REQUIRED; 735 736 #ifdef DIAGNOSTIC 737 if (uio->uio_rw != UIO_WRITE) 738 panic("nfs_write mode"); 739 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_td != curthread) 740 panic("nfs_write proc"); 741 #endif 742 if (vp->v_type != VREG) 743 return (EIO); 744 if (np->n_flag & NWRITEERR) { 745 np->n_flag &= ~NWRITEERR; 746 return (np->n_error); 747 } 748 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 749 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 750 (void)nfs_fsinfo(nmp, vp, cred, td); 751 752 /* 753 * Synchronously flush pending buffers if we are in synchronous 754 * mode or if we are appending. 755 */ 756 if (ioflag & (IO_APPEND | IO_SYNC)) { 757 if (np->n_flag & NMODIFIED) { 758 #ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */ 759 /* 760 * Require non-blocking, synchronous writes to 761 * dirty files to inform the program it needs 762 * to fsync(2) explicitly. 763 */ 764 if (ioflag & IO_NDELAY) 765 return (EAGAIN); 766 #endif 767 flush_and_restart: 768 np->n_attrstamp = 0; 769 error = nfs_vinvalbuf(vp, V_SAVE, cred, td, 1); 770 if (error) 771 return (error); 772 } 773 } 774 775 /* 776 * If IO_APPEND then load uio_offset. We restart here if we cannot 777 * get the append lock. 778 */ 779 restart: 780 if (ioflag & IO_APPEND) { 781 np->n_attrstamp = 0; 782 error = VOP_GETATTR(vp, &vattr, cred, td); 783 if (error) 784 return (error); 785 uio->uio_offset = np->n_size; 786 } 787 788 if (uio->uio_offset < 0) 789 return (EINVAL); 790 if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 791 return (EFBIG); 792 if (uio->uio_resid == 0) 793 return (0); 794 795 /* 796 * We need to obtain the rslock if we intend to modify np->n_size 797 * in order to guarentee the append point with multiple contending 798 * writers, to guarentee that no other appenders modify n_size 799 * while we are trying to obtain a truncated buffer (i.e. to avoid 800 * accidently truncating data written by another appender due to 801 * the race), and to ensure that the buffer is populated prior to 802 * our extending of the file. We hold rslock through the entire 803 * operation. 804 * 805 * Note that we do not synchronize the case where someone truncates 806 * the file while we are appending to it because attempting to lock 807 * this case may deadlock other parts of the system unexpectedly. 808 */ 809 if ((ioflag & IO_APPEND) || 810 uio->uio_offset + uio->uio_resid > np->n_size) { 811 switch(nfs_rslock(np, td)) { 812 case ENOLCK: 813 goto restart; 814 /* not reached */ 815 case EIO: 816 return (EIO); 817 case EINTR: 818 case ERESTART: 819 return(EINTR); 820 /* not reached */ 821 default: 822 break; 823 } 824 haverslock = 1; 825 } 826 827 /* 828 * Maybe this should be above the vnode op call, but so long as 829 * file servers have no limits, i don't think it matters 830 */ 831 if (p != NULL) { 832 PROC_LOCK(p); 833 if (uio->uio_offset + uio->uio_resid > 834 lim_cur(p, RLIMIT_FSIZE)) { 835 psignal(p, SIGXFSZ); 836 PROC_UNLOCK(p); 837 if (haverslock) 838 nfs_rsunlock(np, td); 839 return (EFBIG); 840 } 841 PROC_UNLOCK(p); 842 } 843 844 biosize = vp->v_mount->mnt_stat.f_iosize; 845 /* 846 * Find all of this file's B_NEEDCOMMIT buffers. If our writes 847 * would exceed the local maximum per-file write commit size when 848 * combined with those, we must decide whether to flush, 849 * go synchronous, or return error. 850 */ 851 if (!(ioflag & IO_SYNC)) { 852 int needrestart = 0; 853 if (nmp->nm_wcommitsize < uio->uio_resid) { 854 /* 855 * If this request could not possibly be completed 856 * without exceeding the maximum outstanding write 857 * commit size, see if we can convert it into a 858 * synchronous write operation. 859 */ 860 if (ioflag & IO_NDELAY) 861 return (EAGAIN); 862 ioflag |= IO_SYNC; 863 if (np->n_flag & NMODIFIED) 864 needrestart = 1; 865 } else if (np->n_flag & NMODIFIED) { 866 int wouldcommit = 0; 867 VI_LOCK(vp); 868 TAILQ_FOREACH(bp, &vp->v_dirtyblkhd, b_vnbufs) { 869 if (bp->b_flags & B_NEEDCOMMIT) 870 wouldcommit += bp->b_bcount; 871 } 872 VI_UNLOCK(vp); 873 /* 874 * Since we're not operating synchronously and 875 * bypassing the buffer cache, we are in a commit 876 * and holding all of these buffers whether 877 * transmitted or not. If not limited, this 878 * will lead to the buffer cache deadlocking, 879 * as no one else can flush our uncommitted buffers. 880 */ 881 wouldcommit += uio->uio_resid; 882 /* 883 * If we would initially exceed the maximum 884 * outstanding write commit size, flush and restart. 885 */ 886 if (wouldcommit > nmp->nm_wcommitsize) 887 needrestart = 1; 888 } 889 if (needrestart) { 890 if (haverslock) { 891 nfs_rsunlock(np, td); 892 haverslock = 0; 893 } 894 goto flush_and_restart; 895 } 896 } 897 898 do { 899 nfsstats.biocache_writes++; 900 lbn = uio->uio_offset / biosize; 901 on = uio->uio_offset & (biosize-1); 902 n = min((unsigned)(biosize - on), uio->uio_resid); 903 again: 904 /* 905 * Handle direct append and file extension cases, calculate 906 * unaligned buffer size. 907 */ 908 909 if (uio->uio_offset == np->n_size && n) { 910 /* 911 * Get the buffer (in its pre-append state to maintain 912 * B_CACHE if it was previously set). Resize the 913 * nfsnode after we have locked the buffer to prevent 914 * readers from reading garbage. 915 */ 916 bcount = on; 917 bp = nfs_getcacheblk(vp, lbn, bcount, td); 918 919 if (bp != NULL) { 920 long save; 921 922 np->n_size = uio->uio_offset + n; 923 np->n_flag |= NMODIFIED; 924 vnode_pager_setsize(vp, np->n_size); 925 926 save = bp->b_flags & B_CACHE; 927 bcount += n; 928 allocbuf(bp, bcount); 929 bp->b_flags |= save; 930 bp->b_magic = B_MAGIC_NFS; 931 if ((nmp->nm_flag & NFSMNT_NFSV4) != 0) 932 bp->b_op = &buf_ops_nfs4; 933 else 934 bp->b_op = &buf_ops_nfs; 935 } 936 } else { 937 /* 938 * Obtain the locked cache block first, and then 939 * adjust the file's size as appropriate. 940 */ 941 bcount = on + n; 942 if ((off_t)lbn * biosize + bcount < np->n_size) { 943 if ((off_t)(lbn + 1) * biosize < np->n_size) 944 bcount = biosize; 945 else 946 bcount = np->n_size - (off_t)lbn * biosize; 947 } 948 bp = nfs_getcacheblk(vp, lbn, bcount, td); 949 if (uio->uio_offset + n > np->n_size) { 950 np->n_size = uio->uio_offset + n; 951 np->n_flag |= NMODIFIED; 952 vnode_pager_setsize(vp, np->n_size); 953 } 954 } 955 956 if (!bp) { 957 error = nfs_sigintr(nmp, NULL, td); 958 if (!error) 959 error = EINTR; 960 break; 961 } 962 963 /* 964 * Issue a READ if B_CACHE is not set. In special-append 965 * mode, B_CACHE is based on the buffer prior to the write 966 * op and is typically set, avoiding the read. If a read 967 * is required in special append mode, the server will 968 * probably send us a short-read since we extended the file 969 * on our end, resulting in b_resid == 0 and, thusly, 970 * B_CACHE getting set. 971 * 972 * We can also avoid issuing the read if the write covers 973 * the entire buffer. We have to make sure the buffer state 974 * is reasonable in this case since we will not be initiating 975 * I/O. See the comments in kern/vfs_bio.c's getblk() for 976 * more information. 977 * 978 * B_CACHE may also be set due to the buffer being cached 979 * normally. 980 */ 981 982 if (on == 0 && n == bcount) { 983 bp->b_flags |= B_CACHE; 984 bp->b_flags &= ~B_INVAL; 985 bp->b_ioflags &= ~BIO_ERROR; 986 } 987 988 if ((bp->b_flags & B_CACHE) == 0) { 989 bp->b_iocmd = BIO_READ; 990 vfs_busy_pages(bp, 0); 991 error = nfs_doio(bp, cred, td); 992 if (error) { 993 brelse(bp); 994 break; 995 } 996 } 997 if (bp->b_wcred == NOCRED) 998 bp->b_wcred = crhold(cred); 999 np->n_flag |= NMODIFIED; 1000 1001 /* 1002 * If dirtyend exceeds file size, chop it down. This should 1003 * not normally occur but there is an append race where it 1004 * might occur XXX, so we log it. 1005 * 1006 * If the chopping creates a reverse-indexed or degenerate 1007 * situation with dirtyoff/end, we 0 both of them. 1008 */ 1009 1010 if (bp->b_dirtyend > bcount) { 1011 printf("NFS append race @%lx:%d\n", 1012 (long)bp->b_blkno * DEV_BSIZE, 1013 bp->b_dirtyend - bcount); 1014 bp->b_dirtyend = bcount; 1015 } 1016 1017 if (bp->b_dirtyoff >= bp->b_dirtyend) 1018 bp->b_dirtyoff = bp->b_dirtyend = 0; 1019 1020 /* 1021 * If the new write will leave a contiguous dirty 1022 * area, just update the b_dirtyoff and b_dirtyend, 1023 * otherwise force a write rpc of the old dirty area. 1024 * 1025 * While it is possible to merge discontiguous writes due to 1026 * our having a B_CACHE buffer ( and thus valid read data 1027 * for the hole), we don't because it could lead to 1028 * significant cache coherency problems with multiple clients, 1029 * especially if locking is implemented later on. 1030 * 1031 * as an optimization we could theoretically maintain 1032 * a linked list of discontinuous areas, but we would still 1033 * have to commit them separately so there isn't much 1034 * advantage to it except perhaps a bit of asynchronization. 1035 */ 1036 1037 if (bp->b_dirtyend > 0 && 1038 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { 1039 if (bwrite(bp) == EINTR) { 1040 error = EINTR; 1041 break; 1042 } 1043 goto again; 1044 } 1045 1046 error = uiomove((char *)bp->b_data + on, n, uio); 1047 1048 /* 1049 * Since this block is being modified, it must be written 1050 * again and not just committed. Since write clustering does 1051 * not work for the stage 1 data write, only the stage 2 1052 * commit rpc, we have to clear B_CLUSTEROK as well. 1053 */ 1054 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1055 1056 if (error) { 1057 bp->b_ioflags |= BIO_ERROR; 1058 brelse(bp); 1059 break; 1060 } 1061 1062 /* 1063 * Only update dirtyoff/dirtyend if not a degenerate 1064 * condition. 1065 */ 1066 if (n) { 1067 if (bp->b_dirtyend > 0) { 1068 bp->b_dirtyoff = min(on, bp->b_dirtyoff); 1069 bp->b_dirtyend = max((on + n), bp->b_dirtyend); 1070 } else { 1071 bp->b_dirtyoff = on; 1072 bp->b_dirtyend = on + n; 1073 } 1074 vfs_bio_set_validclean(bp, on, n); 1075 } 1076 1077 /* 1078 * If IO_SYNC do bwrite(). 1079 * 1080 * IO_INVAL appears to be unused. The idea appears to be 1081 * to turn off caching in this case. Very odd. XXX 1082 */ 1083 if ((ioflag & IO_SYNC)) { 1084 if (ioflag & IO_INVAL) 1085 bp->b_flags |= B_NOCACHE; 1086 error = bwrite(bp); 1087 if (error) 1088 break; 1089 } else if ((n + on) == biosize) { 1090 bp->b_flags |= B_ASYNC; 1091 (void) (nmp->nm_rpcops->nr_writebp)(bp, 0, 0); 1092 } else { 1093 bdwrite(bp); 1094 } 1095 } while (uio->uio_resid > 0 && n > 0); 1096 1097 if (haverslock) 1098 nfs_rsunlock(np, td); 1099 1100 return (error); 1101 } 1102 1103 /* 1104 * Get an nfs cache block. 1105 * 1106 * Allocate a new one if the block isn't currently in the cache 1107 * and return the block marked busy. If the calling process is 1108 * interrupted by a signal for an interruptible mount point, return 1109 * NULL. 1110 * 1111 * The caller must carefully deal with the possible B_INVAL state of 1112 * the buffer. nfs_doio() clears B_INVAL (and nfs_asyncio() clears it 1113 * indirectly), so synchronous reads can be issued without worrying about 1114 * the B_INVAL state. We have to be a little more careful when dealing 1115 * with writes (see comments in nfs_write()) when extending a file past 1116 * its EOF. 1117 */ 1118 static struct buf * 1119 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td) 1120 { 1121 struct buf *bp; 1122 struct mount *mp; 1123 struct nfsmount *nmp; 1124 1125 mp = vp->v_mount; 1126 nmp = VFSTONFS(mp); 1127 1128 if (nmp->nm_flag & NFSMNT_INT) { 1129 bp = getblk(vp, bn, size, PCATCH, 0, 0); 1130 while (bp == NULL) { 1131 if (nfs_sigintr(nmp, NULL, td)) 1132 return (NULL); 1133 bp = getblk(vp, bn, size, 0, 2 * hz, 0); 1134 } 1135 } else { 1136 bp = getblk(vp, bn, size, 0, 0, 0); 1137 } 1138 1139 if (vp->v_type == VREG) { 1140 int biosize; 1141 1142 biosize = mp->mnt_stat.f_iosize; 1143 bp->b_blkno = bn * (biosize / DEV_BSIZE); 1144 } 1145 return (bp); 1146 } 1147 1148 /* 1149 * Flush and invalidate all dirty buffers. If another process is already 1150 * doing the flush, just wait for completion. 1151 */ 1152 int 1153 nfs_vinvalbuf(struct vnode *vp, int flags, struct ucred *cred, 1154 struct thread *td, int intrflg) 1155 { 1156 struct nfsnode *np = VTONFS(vp); 1157 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 1158 int error = 0, slpflag, slptimeo; 1159 1160 ASSERT_VOP_LOCKED(vp, "nfs_vinvalbuf"); 1161 1162 /* 1163 * XXX This check stops us from needlessly doing a vinvalbuf when 1164 * being called through vclean(). It is not clear that this is 1165 * unsafe. 1166 */ 1167 if (vp->v_iflag & VI_XLOCK) 1168 return (0); 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(&np->n_flag, PRIBIO + 2, "nfsvinval", 1185 slptimeo); 1186 if (error && intrflg && 1187 nfs_sigintr(nmp, NULL, td)) 1188 return (EINTR); 1189 } 1190 1191 /* 1192 * Now, flush as required. 1193 */ 1194 np->n_flag |= NFLUSHINPROG; 1195 error = vinvalbuf(vp, flags, cred, td, slpflag, 0); 1196 while (error) { 1197 if (intrflg && (error = nfs_sigintr(nmp, NULL, td))) { 1198 np->n_flag &= ~NFLUSHINPROG; 1199 if (np->n_flag & NFLUSHWANT) { 1200 np->n_flag &= ~NFLUSHWANT; 1201 wakeup(&np->n_flag); 1202 } 1203 return (error); 1204 } 1205 error = vinvalbuf(vp, flags, cred, td, 0, slptimeo); 1206 } 1207 np->n_flag &= ~(NMODIFIED | NFLUSHINPROG); 1208 if (np->n_flag & NFLUSHWANT) { 1209 np->n_flag &= ~NFLUSHWANT; 1210 wakeup(&np->n_flag); 1211 } 1212 return (0); 1213 } 1214 1215 /* 1216 * Initiate asynchronous I/O. Return an error if no nfsiods are available. 1217 * This is mainly to avoid queueing async I/O requests when the nfsiods 1218 * are all hung on a dead server. 1219 * 1220 * Note: nfs_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp 1221 * is eventually dequeued by the async daemon, nfs_doio() *will*. 1222 */ 1223 int 1224 nfs_asyncio(struct buf *bp, struct ucred *cred, struct thread *td) 1225 { 1226 struct nfsmount *nmp; 1227 int iod; 1228 int gotiod; 1229 int slpflag = 0; 1230 int slptimeo = 0; 1231 int error, error2; 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 1245 again: 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 (iod = 0; iod < nfs_numasync; iod++) 1254 if (nfs_iodwant[iod]) { 1255 gotiod = TRUE; 1256 break; 1257 } 1258 1259 /* 1260 * Try to create one if none are free. 1261 */ 1262 if (!gotiod) { 1263 iod = nfs_nfsiodnew(); 1264 if (iod != -1) 1265 gotiod = TRUE; 1266 } 1267 1268 if (gotiod) { 1269 /* 1270 * Found one, so wake it up and tell it which 1271 * mount to process. 1272 */ 1273 NFS_DPF(ASYNCIO, ("nfs_asyncio: waking iod %d for mount %p\n", 1274 iod, nmp)); 1275 nfs_iodwant[iod] = NULL; 1276 nfs_iodmount[iod] = nmp; 1277 nmp->nm_bufqiods++; 1278 wakeup(&nfs_iodwant[iod]); 1279 } 1280 1281 /* 1282 * If none are free, we may already have an iod working on this mount 1283 * point. If so, it will process our request. 1284 */ 1285 if (!gotiod) { 1286 if (nmp->nm_bufqiods > 0) { 1287 NFS_DPF(ASYNCIO, 1288 ("nfs_asyncio: %d iods are already processing mount %p\n", 1289 nmp->nm_bufqiods, nmp)); 1290 gotiod = TRUE; 1291 } 1292 } 1293 1294 /* 1295 * If we have an iod which can process the request, then queue 1296 * the buffer. 1297 */ 1298 if (gotiod) { 1299 /* 1300 * Ensure that the queue never grows too large. We still want 1301 * to asynchronize so we block rather then return EIO. 1302 */ 1303 while (nmp->nm_bufqlen >= 2*nfs_numasync) { 1304 NFS_DPF(ASYNCIO, 1305 ("nfs_asyncio: waiting for mount %p queue to drain\n", nmp)); 1306 nmp->nm_bufqwant = TRUE; 1307 error = tsleep(&nmp->nm_bufq, slpflag | PRIBIO, 1308 "nfsaio", slptimeo); 1309 if (error) { 1310 error2 = nfs_sigintr(nmp, NULL, td); 1311 if (error2) 1312 return (error2); 1313 if (slpflag == PCATCH) { 1314 slpflag = 0; 1315 slptimeo = 2 * hz; 1316 } 1317 } 1318 /* 1319 * We might have lost our iod while sleeping, 1320 * so check and loop if nescessary. 1321 */ 1322 if (nmp->nm_bufqiods == 0) { 1323 NFS_DPF(ASYNCIO, 1324 ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); 1325 goto again; 1326 } 1327 } 1328 1329 if (bp->b_iocmd == BIO_READ) { 1330 if (bp->b_rcred == NOCRED && cred != NOCRED) 1331 bp->b_rcred = crhold(cred); 1332 } else { 1333 bp->b_flags |= B_WRITEINPROG; 1334 if (bp->b_wcred == NOCRED && cred != NOCRED) 1335 bp->b_wcred = crhold(cred); 1336 } 1337 1338 BUF_KERNPROC(bp); 1339 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist); 1340 nmp->nm_bufqlen++; 1341 return (0); 1342 } 1343 1344 /* 1345 * All the iods are busy on other mounts, so return EIO to 1346 * force the caller to process the i/o synchronously. 1347 */ 1348 NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n")); 1349 return (EIO); 1350 } 1351 1352 /* 1353 * Do an I/O operation to/from a cache block. This may be called 1354 * synchronously or from an nfsiod. 1355 */ 1356 int 1357 nfs_doio(struct buf *bp, struct ucred *cr, struct thread *td) 1358 { 1359 struct uio *uiop; 1360 struct vnode *vp; 1361 struct nfsnode *np; 1362 struct nfsmount *nmp; 1363 int error = 0, iomode, must_commit = 0; 1364 struct uio uio; 1365 struct iovec io; 1366 struct proc *p = td ? td->td_proc : NULL; 1367 1368 vp = bp->b_vp; 1369 np = VTONFS(vp); 1370 nmp = VFSTONFS(vp->v_mount); 1371 uiop = &uio; 1372 uiop->uio_iov = &io; 1373 uiop->uio_iovcnt = 1; 1374 uiop->uio_segflg = UIO_SYSSPACE; 1375 uiop->uio_td = td; 1376 1377 /* 1378 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We 1379 * do this here so we do not have to do it in all the code that 1380 * calls us. 1381 */ 1382 bp->b_flags &= ~B_INVAL; 1383 bp->b_ioflags &= ~BIO_ERROR; 1384 1385 KASSERT(!(bp->b_flags & B_DONE), ("nfs_doio: bp %p already marked done", bp)); 1386 1387 if (bp->b_iocmd == BIO_READ) { 1388 io.iov_len = uiop->uio_resid = bp->b_bcount; 1389 io.iov_base = bp->b_data; 1390 uiop->uio_rw = UIO_READ; 1391 1392 switch (vp->v_type) { 1393 case VREG: 1394 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE; 1395 nfsstats.read_bios++; 1396 error = (nmp->nm_rpcops->nr_readrpc)(vp, uiop, cr); 1397 1398 if (!error) { 1399 if (uiop->uio_resid) { 1400 /* 1401 * If we had a short read with no error, we must have 1402 * hit a file hole. We should zero-fill the remainder. 1403 * This can also occur if the server hits the file EOF. 1404 * 1405 * Holes used to be able to occur due to pending 1406 * writes, but that is not possible any longer. 1407 */ 1408 int nread = bp->b_bcount - uiop->uio_resid; 1409 int left = uiop->uio_resid; 1410 1411 if (left > 0) 1412 bzero((char *)bp->b_data + nread, left); 1413 uiop->uio_resid = 0; 1414 } 1415 } 1416 /* ASSERT_VOP_LOCKED(vp, "nfs_doio"); */ 1417 if (p && (vp->v_vflag & VV_TEXT) && 1418 (np->n_mtime != np->n_vattr.va_mtime.tv_sec)) { 1419 PROC_LOCK(p); 1420 killproc(p, "text file modification"); 1421 PROC_UNLOCK(p); 1422 } 1423 break; 1424 case VLNK: 1425 uiop->uio_offset = (off_t)0; 1426 nfsstats.readlink_bios++; 1427 error = (nmp->nm_rpcops->nr_readlinkrpc)(vp, uiop, cr); 1428 break; 1429 case VDIR: 1430 nfsstats.readdir_bios++; 1431 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ; 1432 if ((nmp->nm_flag & NFSMNT_NFSV4) != 0) 1433 error = nfs4_readdirrpc(vp, uiop, cr); 1434 else { 1435 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) { 1436 error = nfs_readdirplusrpc(vp, uiop, cr); 1437 if (error == NFSERR_NOTSUPP) 1438 nmp->nm_flag &= ~NFSMNT_RDIRPLUS; 1439 } 1440 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) 1441 error = nfs_readdirrpc(vp, uiop, cr); 1442 } 1443 /* 1444 * end-of-directory sets B_INVAL but does not generate an 1445 * error. 1446 */ 1447 if (error == 0 && uiop->uio_resid == bp->b_bcount) 1448 bp->b_flags |= B_INVAL; 1449 break; 1450 default: 1451 printf("nfs_doio: type %x unexpected\n", vp->v_type); 1452 break; 1453 }; 1454 if (error) { 1455 bp->b_ioflags |= BIO_ERROR; 1456 bp->b_error = error; 1457 } 1458 } else { 1459 /* 1460 * If we only need to commit, try to commit 1461 */ 1462 if (bp->b_flags & B_NEEDCOMMIT) { 1463 int retv; 1464 off_t off; 1465 1466 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff; 1467 bp->b_flags |= B_WRITEINPROG; 1468 retv = (nmp->nm_rpcops->nr_commit)( 1469 bp->b_vp, off, bp->b_dirtyend-bp->b_dirtyoff, 1470 bp->b_wcred, td); 1471 bp->b_flags &= ~B_WRITEINPROG; 1472 if (retv == 0) { 1473 bp->b_dirtyoff = bp->b_dirtyend = 0; 1474 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1475 bp->b_resid = 0; 1476 bufdone(bp); 1477 return (0); 1478 } 1479 if (retv == NFSERR_STALEWRITEVERF) { 1480 nfs_clearcommit(bp->b_vp->v_mount); 1481 } 1482 } 1483 1484 /* 1485 * Setup for actual write 1486 */ 1487 1488 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size) 1489 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE; 1490 1491 if (bp->b_dirtyend > bp->b_dirtyoff) { 1492 io.iov_len = uiop->uio_resid = bp->b_dirtyend 1493 - bp->b_dirtyoff; 1494 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE 1495 + bp->b_dirtyoff; 1496 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; 1497 uiop->uio_rw = UIO_WRITE; 1498 nfsstats.write_bios++; 1499 1500 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC) 1501 iomode = NFSV3WRITE_UNSTABLE; 1502 else 1503 iomode = NFSV3WRITE_FILESYNC; 1504 1505 bp->b_flags |= B_WRITEINPROG; 1506 error = (nmp->nm_rpcops->nr_writerpc)(vp, uiop, cr, &iomode, &must_commit); 1507 1508 /* 1509 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try 1510 * to cluster the buffers needing commit. This will allow 1511 * the system to submit a single commit rpc for the whole 1512 * cluster. We can do this even if the buffer is not 100% 1513 * dirty (relative to the NFS blocksize), so we optimize the 1514 * append-to-file-case. 1515 * 1516 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be 1517 * cleared because write clustering only works for commit 1518 * rpc's, not for the data portion of the write). 1519 */ 1520 1521 if (!error && iomode == NFSV3WRITE_UNSTABLE) { 1522 bp->b_flags |= B_NEEDCOMMIT; 1523 if (bp->b_dirtyoff == 0 1524 && bp->b_dirtyend == bp->b_bcount) 1525 bp->b_flags |= B_CLUSTEROK; 1526 } else { 1527 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1528 } 1529 bp->b_flags &= ~B_WRITEINPROG; 1530 1531 /* 1532 * For an interrupted write, the buffer is still valid 1533 * and the write hasn't been pushed to the server yet, 1534 * so we can't set BIO_ERROR and report the interruption 1535 * by setting B_EINTR. For the B_ASYNC case, B_EINTR 1536 * is not relevant, so the rpc attempt is essentially 1537 * a noop. For the case of a V3 write rpc not being 1538 * committed to stable storage, the block is still 1539 * dirty and requires either a commit rpc or another 1540 * write rpc with iomode == NFSV3WRITE_FILESYNC before 1541 * the block is reused. This is indicated by setting 1542 * the B_DELWRI and B_NEEDCOMMIT flags. 1543 * 1544 * If the buffer is marked B_PAGING, it does not reside on 1545 * the vp's paging queues so we cannot call bdirty(). The 1546 * bp in this case is not an NFS cache block so we should 1547 * be safe. XXX 1548 */ 1549 if (error == EINTR || error == EIO 1550 || (!error && (bp->b_flags & B_NEEDCOMMIT))) { 1551 int s; 1552 1553 s = splbio(); 1554 bp->b_flags &= ~(B_INVAL|B_NOCACHE); 1555 if ((bp->b_flags & B_PAGING) == 0) { 1556 bdirty(bp); 1557 bp->b_flags &= ~B_DONE; 1558 } 1559 if (error && (bp->b_flags & B_ASYNC) == 0) 1560 bp->b_flags |= B_EINTR; 1561 splx(s); 1562 } else { 1563 if (error) { 1564 bp->b_ioflags |= BIO_ERROR; 1565 bp->b_error = np->n_error = error; 1566 np->n_flag |= NWRITEERR; 1567 } 1568 bp->b_dirtyoff = bp->b_dirtyend = 0; 1569 } 1570 } else { 1571 bp->b_resid = 0; 1572 bufdone(bp); 1573 return (0); 1574 } 1575 } 1576 bp->b_resid = uiop->uio_resid; 1577 if (must_commit) 1578 nfs_clearcommit(vp->v_mount); 1579 bufdone(bp); 1580 return (error); 1581 } 1582 1583 /* 1584 * Used to aid in handling ftruncate() operations on the NFS client side. 1585 * Truncation creates a number of special problems for NFS. We have to 1586 * throw away VM pages and buffer cache buffers that are beyond EOF, and 1587 * we have to properly handle VM pages or (potentially dirty) buffers 1588 * that straddle the truncation point. 1589 */ 1590 1591 int 1592 nfs_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize) 1593 { 1594 struct nfsnode *np = VTONFS(vp); 1595 u_quad_t tsize = np->n_size; 1596 int biosize = vp->v_mount->mnt_stat.f_iosize; 1597 int error = 0; 1598 1599 np->n_size = nsize; 1600 1601 if (np->n_size < tsize) { 1602 struct buf *bp; 1603 daddr_t lbn; 1604 int bufsize; 1605 1606 /* 1607 * vtruncbuf() doesn't get the buffer overlapping the 1608 * truncation point. We may have a B_DELWRI and/or B_CACHE 1609 * buffer that now needs to be truncated. 1610 */ 1611 error = vtruncbuf(vp, cred, td, nsize, biosize); 1612 lbn = nsize / biosize; 1613 bufsize = nsize & (biosize - 1); 1614 bp = nfs_getcacheblk(vp, lbn, bufsize, td); 1615 if (bp->b_dirtyoff > bp->b_bcount) 1616 bp->b_dirtyoff = bp->b_bcount; 1617 if (bp->b_dirtyend > bp->b_bcount) 1618 bp->b_dirtyend = bp->b_bcount; 1619 bp->b_flags |= B_RELBUF; /* don't leave garbage around */ 1620 brelse(bp); 1621 } else { 1622 vnode_pager_setsize(vp, nsize); 1623 } 1624 return(error); 1625 } 1626
Cache object: fb713aa03965e13a721119c5661fef45
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