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: releng/6.0/sys/nfsclient/nfs_bio.c 147420 2005-06-16 15:43:17Z green $"); 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 static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, 68 struct thread *td); 69 static int nfs_directio_write(struct vnode *vp, struct uio *uiop, 70 struct ucred *cred, int ioflag); 71 72 extern int nfs_directio_enable; 73 extern int nfs_directio_allow_mmap; 74 /* 75 * Vnode op for VM getpages. 76 */ 77 int 78 nfs_getpages(struct vop_getpages_args *ap) 79 { 80 int i, error, nextoff, size, toff, count, npages; 81 struct uio uio; 82 struct iovec iov; 83 vm_offset_t kva; 84 struct buf *bp; 85 struct vnode *vp; 86 struct thread *td; 87 struct ucred *cred; 88 struct nfsmount *nmp; 89 vm_object_t object; 90 vm_page_t *pages; 91 struct nfsnode *np; 92 93 GIANT_REQUIRED; 94 95 vp = ap->a_vp; 96 np = VTONFS(vp); 97 td = curthread; /* XXX */ 98 cred = curthread->td_ucred; /* XXX */ 99 nmp = VFSTONFS(vp->v_mount); 100 pages = ap->a_m; 101 count = ap->a_count; 102 103 if ((object = vp->v_object) == NULL) { 104 printf("nfs_getpages: called with non-merged cache vnode??\n"); 105 return VM_PAGER_ERROR; 106 } 107 108 if (!nfs_directio_allow_mmap && (np->n_flag & NNONCACHE) && 109 (vp->v_type == VREG)) { 110 printf("nfs_getpages: called on non-cacheable vnode??\n"); 111 return VM_PAGER_ERROR; 112 } 113 114 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 115 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 116 /* We'll never get here for v4, because we always have fsinfo */ 117 (void)nfs_fsinfo(nmp, vp, cred, td); 118 } 119 120 npages = btoc(count); 121 122 /* 123 * If the requested page is partially valid, just return it and 124 * allow the pager to zero-out the blanks. Partially valid pages 125 * can only occur at the file EOF. 126 */ 127 128 { 129 vm_page_t m = pages[ap->a_reqpage]; 130 131 VM_OBJECT_LOCK(object); 132 vm_page_lock_queues(); 133 if (m->valid != 0) { 134 /* handled by vm_fault now */ 135 /* vm_page_zero_invalid(m, TRUE); */ 136 for (i = 0; i < npages; ++i) { 137 if (i != ap->a_reqpage) 138 vm_page_free(pages[i]); 139 } 140 vm_page_unlock_queues(); 141 VM_OBJECT_UNLOCK(object); 142 return(0); 143 } 144 vm_page_unlock_queues(); 145 VM_OBJECT_UNLOCK(object); 146 } 147 148 /* 149 * We use only the kva address for the buffer, but this is extremely 150 * convienient and fast. 151 */ 152 bp = getpbuf(&nfs_pbuf_freecnt); 153 154 kva = (vm_offset_t) bp->b_data; 155 pmap_qenter(kva, pages, npages); 156 cnt.v_vnodein++; 157 cnt.v_vnodepgsin += npages; 158 159 iov.iov_base = (caddr_t) kva; 160 iov.iov_len = count; 161 uio.uio_iov = &iov; 162 uio.uio_iovcnt = 1; 163 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex); 164 uio.uio_resid = count; 165 uio.uio_segflg = UIO_SYSSPACE; 166 uio.uio_rw = UIO_READ; 167 uio.uio_td = td; 168 169 error = (nmp->nm_rpcops->nr_readrpc)(vp, &uio, cred); 170 pmap_qremove(kva, npages); 171 172 relpbuf(bp, &nfs_pbuf_freecnt); 173 174 if (error && (uio.uio_resid == count)) { 175 printf("nfs_getpages: error %d\n", error); 176 VM_OBJECT_LOCK(object); 177 vm_page_lock_queues(); 178 for (i = 0; i < npages; ++i) { 179 if (i != ap->a_reqpage) 180 vm_page_free(pages[i]); 181 } 182 vm_page_unlock_queues(); 183 VM_OBJECT_UNLOCK(object); 184 return VM_PAGER_ERROR; 185 } 186 187 /* 188 * Calculate the number of bytes read and validate only that number 189 * of bytes. Note that due to pending writes, size may be 0. This 190 * does not mean that the remaining data is invalid! 191 */ 192 193 size = count - uio.uio_resid; 194 VM_OBJECT_LOCK(object); 195 vm_page_lock_queues(); 196 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) { 197 vm_page_t m; 198 nextoff = toff + PAGE_SIZE; 199 m = pages[i]; 200 201 if (nextoff <= size) { 202 /* 203 * Read operation filled an entire page 204 */ 205 m->valid = VM_PAGE_BITS_ALL; 206 vm_page_undirty(m); 207 } else if (size > toff) { 208 /* 209 * Read operation filled a partial page. 210 */ 211 m->valid = 0; 212 vm_page_set_validclean(m, 0, size - toff); 213 /* handled by vm_fault now */ 214 /* vm_page_zero_invalid(m, TRUE); */ 215 } else { 216 /* 217 * Read operation was short. If no error occured 218 * we may have hit a zero-fill section. We simply 219 * leave valid set to 0. 220 */ 221 ; 222 } 223 if (i != ap->a_reqpage) { 224 /* 225 * Whether or not to leave the page activated is up in 226 * the air, but we should put the page on a page queue 227 * somewhere (it already is in the object). Result: 228 * It appears that emperical results show that 229 * deactivating pages is best. 230 */ 231 232 /* 233 * Just in case someone was asking for this page we 234 * now tell them that it is ok to use. 235 */ 236 if (!error) { 237 if (m->flags & PG_WANTED) 238 vm_page_activate(m); 239 else 240 vm_page_deactivate(m); 241 vm_page_wakeup(m); 242 } else { 243 vm_page_free(m); 244 } 245 } 246 } 247 vm_page_unlock_queues(); 248 VM_OBJECT_UNLOCK(object); 249 return 0; 250 } 251 252 /* 253 * Vnode op for VM putpages. 254 */ 255 int 256 nfs_putpages(struct vop_putpages_args *ap) 257 { 258 struct uio uio; 259 struct iovec iov; 260 vm_offset_t kva; 261 struct buf *bp; 262 int iomode, must_commit, i, error, npages, count; 263 off_t offset; 264 int *rtvals; 265 struct vnode *vp; 266 struct thread *td; 267 struct ucred *cred; 268 struct nfsmount *nmp; 269 struct nfsnode *np; 270 vm_page_t *pages; 271 272 GIANT_REQUIRED; 273 274 vp = ap->a_vp; 275 np = VTONFS(vp); 276 td = curthread; /* XXX */ 277 cred = curthread->td_ucred; /* XXX */ 278 nmp = VFSTONFS(vp->v_mount); 279 pages = ap->a_m; 280 count = ap->a_count; 281 rtvals = ap->a_rtvals; 282 npages = btoc(count); 283 offset = IDX_TO_OFF(pages[0]->pindex); 284 285 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 286 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 287 (void)nfs_fsinfo(nmp, vp, cred, td); 288 } 289 290 if (!nfs_directio_allow_mmap && (np->n_flag & NNONCACHE) && 291 (vp->v_type == VREG)) 292 printf("nfs_putpages: called on noncache-able vnode??\n"); 293 294 for (i = 0; i < npages; i++) 295 rtvals[i] = VM_PAGER_AGAIN; 296 297 /* 298 * When putting pages, do not extend file past EOF. 299 */ 300 301 if (offset + count > np->n_size) { 302 count = np->n_size - offset; 303 if (count < 0) 304 count = 0; 305 } 306 307 /* 308 * We use only the kva address for the buffer, but this is extremely 309 * convienient and fast. 310 */ 311 bp = getpbuf(&nfs_pbuf_freecnt); 312 313 kva = (vm_offset_t) bp->b_data; 314 pmap_qenter(kva, pages, npages); 315 cnt.v_vnodeout++; 316 cnt.v_vnodepgsout += count; 317 318 iov.iov_base = (caddr_t) kva; 319 iov.iov_len = count; 320 uio.uio_iov = &iov; 321 uio.uio_iovcnt = 1; 322 uio.uio_offset = offset; 323 uio.uio_resid = count; 324 uio.uio_segflg = UIO_SYSSPACE; 325 uio.uio_rw = UIO_WRITE; 326 uio.uio_td = td; 327 328 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0) 329 iomode = NFSV3WRITE_UNSTABLE; 330 else 331 iomode = NFSV3WRITE_FILESYNC; 332 333 error = (nmp->nm_rpcops->nr_writerpc)(vp, &uio, cred, &iomode, &must_commit); 334 335 pmap_qremove(kva, npages); 336 relpbuf(bp, &nfs_pbuf_freecnt); 337 338 if (!error) { 339 int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE; 340 for (i = 0; i < nwritten; i++) { 341 rtvals[i] = VM_PAGER_OK; 342 vm_page_undirty(pages[i]); 343 } 344 if (must_commit) { 345 nfs_clearcommit(vp->v_mount); 346 } 347 } 348 return rtvals[0]; 349 } 350 351 /* 352 * Vnode op for read using bio 353 */ 354 int 355 nfs_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred) 356 { 357 struct nfsnode *np = VTONFS(vp); 358 int biosize, i; 359 struct buf *bp, *rabp; 360 struct vattr vattr; 361 struct thread *td; 362 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 363 daddr_t lbn, rabn; 364 int bcount; 365 int seqcount; 366 int nra, error = 0, n = 0, on = 0; 367 368 #ifdef DIAGNOSTIC 369 if (uio->uio_rw != UIO_READ) 370 panic("nfs_read mode"); 371 #endif 372 if (uio->uio_resid == 0) 373 return (0); 374 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */ 375 return (EINVAL); 376 td = uio->uio_td; 377 378 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 379 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 380 (void)nfs_fsinfo(nmp, vp, cred, td); 381 if (vp->v_type != VDIR && 382 (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 383 return (EFBIG); 384 385 if (nfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG)) 386 /* No caching/ no readaheads. Just read data into the user buffer */ 387 return nfs_readrpc(vp, uio, cred); 388 389 biosize = vp->v_mount->mnt_stat.f_iosize; 390 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE); 391 /* 392 * For nfs, cache consistency can only be maintained approximately. 393 * Although RFC1094 does not specify the criteria, the following is 394 * believed to be compatible with the reference port. 395 * For nfs: 396 * If the file's modify time on the server has changed since the 397 * last read rpc or you have written to the file, 398 * you may have lost data cache consistency with the 399 * server, so flush all of the file's data out of the cache. 400 * Then force a getattr rpc to ensure that you have up to date 401 * attributes. 402 * NB: This implies that cache data can be read when up to 403 * NFS_ATTRTIMEO seconds out of date. If you find that you need current 404 * attributes this could be forced by setting n_attrstamp to 0 before 405 * the VOP_GETATTR() call. 406 */ 407 if (np->n_flag & NMODIFIED) { 408 if (vp->v_type != VREG) { 409 if (vp->v_type != VDIR) 410 panic("nfs: bioread, not dir"); 411 (nmp->nm_rpcops->nr_invaldir)(vp); 412 error = nfs_vinvalbuf(vp, V_SAVE, td, 1); 413 if (error) 414 return (error); 415 } 416 np->n_attrstamp = 0; 417 error = VOP_GETATTR(vp, &vattr, cred, td); 418 if (error) 419 return (error); 420 np->n_mtime = vattr.va_mtime; 421 } else { 422 error = VOP_GETATTR(vp, &vattr, cred, td); 423 if (error) 424 return (error); 425 if ((np->n_flag & NSIZECHANGED) 426 || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) { 427 if (vp->v_type == VDIR) 428 (nmp->nm_rpcops->nr_invaldir)(vp); 429 error = nfs_vinvalbuf(vp, V_SAVE, td, 1); 430 if (error) 431 return (error); 432 np->n_mtime = vattr.va_mtime; 433 np->n_flag &= ~NSIZECHANGED; 434 } 435 } 436 do { 437 switch (vp->v_type) { 438 case VREG: 439 nfsstats.biocache_reads++; 440 lbn = uio->uio_offset / biosize; 441 on = uio->uio_offset & (biosize - 1); 442 443 /* 444 * Start the read ahead(s), as required. 445 * The readahead is kicked off only if sequential access 446 * is detected, based on the readahead hint (ra_expect_lbn). 447 */ 448 if (nmp->nm_readahead > 0 && np->ra_expect_lbn == lbn) { 449 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && 450 (off_t)(lbn + 1 + nra) * biosize < np->n_size; nra++) { 451 rabn = lbn + 1 + nra; 452 if (incore(&vp->v_bufobj, rabn) == NULL) { 453 rabp = nfs_getcacheblk(vp, rabn, biosize, td); 454 if (!rabp) { 455 error = nfs_sigintr(nmp, NULL, td); 456 return (error ? error : EINTR); 457 } 458 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 459 rabp->b_flags |= B_ASYNC; 460 rabp->b_iocmd = BIO_READ; 461 vfs_busy_pages(rabp, 0); 462 if (nfs_asyncio(nmp, rabp, cred, td)) { 463 rabp->b_flags |= B_INVAL; 464 rabp->b_ioflags |= BIO_ERROR; 465 vfs_unbusy_pages(rabp); 466 brelse(rabp); 467 break; 468 } 469 } else { 470 brelse(rabp); 471 } 472 } 473 } 474 np->ra_expect_lbn = lbn + 1; 475 } 476 477 /* 478 * Obtain the buffer cache block. Figure out the buffer size 479 * when we are at EOF. If we are modifying the size of the 480 * buffer based on an EOF condition we need to hold 481 * nfs_rslock() through obtaining the buffer to prevent 482 * a potential writer-appender from messing with n_size. 483 * Otherwise we may accidently truncate the buffer and 484 * lose dirty data. 485 * 486 * Note that bcount is *not* DEV_BSIZE aligned. 487 */ 488 489 again: 490 bcount = biosize; 491 if ((off_t)lbn * biosize >= np->n_size) { 492 bcount = 0; 493 } else if ((off_t)(lbn + 1) * biosize > np->n_size) { 494 bcount = np->n_size - (off_t)lbn * biosize; 495 } 496 if (bcount != biosize) { 497 switch(nfs_rslock(np, td)) { 498 case ENOLCK: 499 goto again; 500 /* not reached */ 501 case EIO: 502 return (EIO); 503 case EINTR: 504 case ERESTART: 505 return(EINTR); 506 /* not reached */ 507 default: 508 break; 509 } 510 } 511 512 bp = nfs_getcacheblk(vp, lbn, bcount, td); 513 514 if (bcount != biosize) 515 nfs_rsunlock(np, td); 516 if (!bp) { 517 error = nfs_sigintr(nmp, NULL, td); 518 return (error ? error : EINTR); 519 } 520 521 /* 522 * If B_CACHE is not set, we must issue the read. If this 523 * fails, we return an error. 524 */ 525 526 if ((bp->b_flags & B_CACHE) == 0) { 527 bp->b_iocmd = BIO_READ; 528 vfs_busy_pages(bp, 0); 529 error = nfs_doio(vp, bp, cred, td); 530 if (error) { 531 brelse(bp); 532 return (error); 533 } 534 } 535 536 /* 537 * on is the offset into the current bp. Figure out how many 538 * bytes we can copy out of the bp. Note that bcount is 539 * NOT DEV_BSIZE aligned. 540 * 541 * Then figure out how many bytes we can copy into the uio. 542 */ 543 544 n = 0; 545 if (on < bcount) 546 n = min((unsigned)(bcount - on), uio->uio_resid); 547 break; 548 case VLNK: 549 nfsstats.biocache_readlinks++; 550 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td); 551 if (!bp) { 552 error = nfs_sigintr(nmp, NULL, td); 553 return (error ? error : EINTR); 554 } 555 if ((bp->b_flags & B_CACHE) == 0) { 556 bp->b_iocmd = BIO_READ; 557 vfs_busy_pages(bp, 0); 558 error = nfs_doio(vp, bp, cred, td); 559 if (error) { 560 bp->b_ioflags |= BIO_ERROR; 561 brelse(bp); 562 return (error); 563 } 564 } 565 n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); 566 on = 0; 567 break; 568 case VDIR: 569 nfsstats.biocache_readdirs++; 570 if (np->n_direofoffset 571 && uio->uio_offset >= np->n_direofoffset) { 572 return (0); 573 } 574 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; 575 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); 576 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td); 577 if (!bp) { 578 error = nfs_sigintr(nmp, NULL, td); 579 return (error ? error : EINTR); 580 } 581 if ((bp->b_flags & B_CACHE) == 0) { 582 bp->b_iocmd = BIO_READ; 583 vfs_busy_pages(bp, 0); 584 error = nfs_doio(vp, bp, cred, td); 585 if (error) { 586 brelse(bp); 587 } 588 while (error == NFSERR_BAD_COOKIE) { 589 (nmp->nm_rpcops->nr_invaldir)(vp); 590 error = nfs_vinvalbuf(vp, 0, td, 1); 591 /* 592 * Yuck! The directory has been modified on the 593 * server. The only way to get the block is by 594 * reading from the beginning to get all the 595 * offset cookies. 596 * 597 * Leave the last bp intact unless there is an error. 598 * Loop back up to the while if the error is another 599 * NFSERR_BAD_COOKIE (double yuch!). 600 */ 601 for (i = 0; i <= lbn && !error; i++) { 602 if (np->n_direofoffset 603 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) 604 return (0); 605 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td); 606 if (!bp) { 607 error = nfs_sigintr(nmp, NULL, td); 608 return (error ? error : EINTR); 609 } 610 if ((bp->b_flags & B_CACHE) == 0) { 611 bp->b_iocmd = BIO_READ; 612 vfs_busy_pages(bp, 0); 613 error = nfs_doio(vp, bp, cred, td); 614 /* 615 * no error + B_INVAL == directory EOF, 616 * use the block. 617 */ 618 if (error == 0 && (bp->b_flags & B_INVAL)) 619 break; 620 } 621 /* 622 * An error will throw away the block and the 623 * for loop will break out. If no error and this 624 * is not the block we want, we throw away the 625 * block and go for the next one via the for loop. 626 */ 627 if (error || i < lbn) 628 brelse(bp); 629 } 630 } 631 /* 632 * The above while is repeated if we hit another cookie 633 * error. If we hit an error and it wasn't a cookie error, 634 * we give up. 635 */ 636 if (error) 637 return (error); 638 } 639 640 /* 641 * If not eof and read aheads are enabled, start one. 642 * (You need the current block first, so that you have the 643 * directory offset cookie of the next block.) 644 */ 645 if (nmp->nm_readahead > 0 && 646 (bp->b_flags & B_INVAL) == 0 && 647 (np->n_direofoffset == 0 || 648 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) && 649 incore(&vp->v_bufobj, lbn + 1) == NULL) { 650 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td); 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(nmp, rabp, cred, td)) { 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 bp = NULL; 686 break; 687 }; 688 689 if (n > 0) { 690 error = uiomove(bp->b_data + on, (int)n, uio); 691 } 692 if (vp->v_type == VLNK) 693 n = 0; 694 if (bp != NULL) 695 brelse(bp); 696 } while (error == 0 && uio->uio_resid > 0 && n > 0); 697 return (error); 698 } 699 700 /* 701 * The NFS write path cannot handle iovecs with len > 1. So we need to 702 * break up iovecs accordingly (restricting them to wsize). 703 * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf). 704 * For the ASYNC case, 2 copies are needed. The first a copy from the 705 * user buffer to a staging buffer and then a second copy from the staging 706 * buffer to mbufs. This can be optimized by copying from the user buffer 707 * directly into mbufs and passing the chain down, but that requires a 708 * fair amount of re-working of the relevant codepaths (and can be done 709 * later). 710 */ 711 static int 712 nfs_directio_write(vp, uiop, cred, ioflag) 713 struct vnode *vp; 714 struct uio *uiop; 715 struct ucred *cred; 716 int ioflag; 717 { 718 int error; 719 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 720 struct thread *td = uiop->uio_td; 721 int size; 722 723 if (ioflag & IO_SYNC) { 724 int iomode, must_commit; 725 struct uio uio; 726 struct iovec iov; 727 do_sync: 728 while (uiop->uio_resid > 0) { 729 size = min(uiop->uio_resid, nmp->nm_wsize); 730 size = min(uiop->uio_iov->iov_len, size); 731 iov.iov_base = uiop->uio_iov->iov_base; 732 iov.iov_len = size; 733 uio.uio_iov = &iov; 734 uio.uio_iovcnt = 1; 735 uio.uio_offset = uiop->uio_offset; 736 uio.uio_resid = size; 737 uio.uio_segflg = UIO_USERSPACE; 738 uio.uio_rw = UIO_WRITE; 739 uio.uio_td = td; 740 iomode = NFSV3WRITE_FILESYNC; 741 error = (nmp->nm_rpcops->nr_writerpc)(vp, &uio, cred, 742 &iomode, &must_commit); 743 KASSERT((must_commit == 0), 744 ("nfs_directio_write: Did not commit write")); 745 if (error) 746 return (error); 747 uiop->uio_offset += size; 748 uiop->uio_resid -= size; 749 if (uiop->uio_iov->iov_len <= size) { 750 uiop->uio_iovcnt--; 751 uiop->uio_iov++; 752 } else { 753 uiop->uio_iov->iov_base = 754 (char *)uiop->uio_iov->iov_base + size; 755 uiop->uio_iov->iov_len -= size; 756 } 757 } 758 } else { 759 struct uio *t_uio; 760 struct iovec *t_iov; 761 struct buf *bp; 762 763 /* 764 * Break up the write into blocksize chunks and hand these 765 * over to nfsiod's for write back. 766 * Unfortunately, this incurs a copy of the data. Since 767 * the user could modify the buffer before the write is 768 * initiated. 769 * 770 * The obvious optimization here is that one of the 2 copies 771 * in the async write path can be eliminated by copying the 772 * data here directly into mbufs and passing the mbuf chain 773 * down. But that will require a fair amount of re-working 774 * of the code and can be done if there's enough interest 775 * in NFS directio access. 776 */ 777 while (uiop->uio_resid > 0) { 778 size = min(uiop->uio_resid, nmp->nm_wsize); 779 size = min(uiop->uio_iov->iov_len, size); 780 bp = getpbuf(&nfs_pbuf_freecnt); 781 t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK); 782 t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK); 783 t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK); 784 t_iov->iov_len = size; 785 t_uio->uio_iov = t_iov; 786 t_uio->uio_iovcnt = 1; 787 t_uio->uio_offset = uiop->uio_offset; 788 t_uio->uio_resid = size; 789 t_uio->uio_segflg = UIO_SYSSPACE; 790 t_uio->uio_rw = UIO_WRITE; 791 t_uio->uio_td = td; 792 bcopy(uiop->uio_iov->iov_base, t_iov->iov_base, size); 793 bp->b_flags |= B_DIRECT; 794 bp->b_iocmd = BIO_WRITE; 795 if (cred != NOCRED) { 796 crhold(cred); 797 bp->b_wcred = cred; 798 } else 799 bp->b_wcred = NOCRED; 800 bp->b_caller1 = (void *)t_uio; 801 bp->b_vp = vp; 802 vhold(vp); 803 error = nfs_asyncio(nmp, bp, NOCRED, td); 804 if (error) { 805 free(t_iov->iov_base, M_NFSDIRECTIO); 806 free(t_iov, M_NFSDIRECTIO); 807 free(t_uio, M_NFSDIRECTIO); 808 vdrop(bp->b_vp); 809 bp->b_vp = NULL; 810 relpbuf(bp, &nfs_pbuf_freecnt); 811 if (error == EINTR) 812 return (error); 813 goto do_sync; 814 } 815 uiop->uio_offset += size; 816 uiop->uio_resid -= size; 817 if (uiop->uio_iov->iov_len <= size) { 818 uiop->uio_iovcnt--; 819 uiop->uio_iov++; 820 } else { 821 uiop->uio_iov->iov_base = 822 (char *)uiop->uio_iov->iov_base + size; 823 uiop->uio_iov->iov_len -= size; 824 } 825 } 826 } 827 return (0); 828 } 829 830 /* 831 * Vnode op for write using bio 832 */ 833 int 834 nfs_write(struct vop_write_args *ap) 835 { 836 int biosize; 837 struct uio *uio = ap->a_uio; 838 struct thread *td = uio->uio_td; 839 struct vnode *vp = ap->a_vp; 840 struct nfsnode *np = VTONFS(vp); 841 struct ucred *cred = ap->a_cred; 842 int ioflag = ap->a_ioflag; 843 struct buf *bp; 844 struct vattr vattr; 845 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 846 daddr_t lbn; 847 int bcount; 848 int n, on, error = 0; 849 int haverslock = 0; 850 struct proc *p = td?td->td_proc:NULL; 851 852 GIANT_REQUIRED; 853 854 #ifdef DIAGNOSTIC 855 if (uio->uio_rw != UIO_WRITE) 856 panic("nfs_write mode"); 857 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_td != curthread) 858 panic("nfs_write proc"); 859 #endif 860 if (vp->v_type != VREG) 861 return (EIO); 862 if (np->n_flag & NWRITEERR) { 863 np->n_flag &= ~NWRITEERR; 864 return (np->n_error); 865 } 866 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 867 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 868 (void)nfs_fsinfo(nmp, vp, cred, td); 869 870 /* 871 * Synchronously flush pending buffers if we are in synchronous 872 * mode or if we are appending. 873 */ 874 if (ioflag & (IO_APPEND | IO_SYNC)) { 875 if (np->n_flag & NMODIFIED) { 876 #ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */ 877 /* 878 * Require non-blocking, synchronous writes to 879 * dirty files to inform the program it needs 880 * to fsync(2) explicitly. 881 */ 882 if (ioflag & IO_NDELAY) 883 return (EAGAIN); 884 #endif 885 flush_and_restart: 886 np->n_attrstamp = 0; 887 error = nfs_vinvalbuf(vp, V_SAVE, td, 1); 888 if (error) 889 return (error); 890 } 891 } 892 893 /* 894 * If IO_APPEND then load uio_offset. We restart here if we cannot 895 * get the append lock. 896 */ 897 restart: 898 if (ioflag & IO_APPEND) { 899 np->n_attrstamp = 0; 900 error = VOP_GETATTR(vp, &vattr, cred, td); 901 if (error) 902 return (error); 903 uio->uio_offset = np->n_size; 904 } 905 906 if (uio->uio_offset < 0) 907 return (EINVAL); 908 if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 909 return (EFBIG); 910 if (uio->uio_resid == 0) 911 return (0); 912 913 if (nfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG) 914 return nfs_directio_write(vp, uio, cred, ioflag); 915 916 /* 917 * We need to obtain the rslock if we intend to modify np->n_size 918 * in order to guarentee the append point with multiple contending 919 * writers, to guarentee that no other appenders modify n_size 920 * while we are trying to obtain a truncated buffer (i.e. to avoid 921 * accidently truncating data written by another appender due to 922 * the race), and to ensure that the buffer is populated prior to 923 * our extending of the file. We hold rslock through the entire 924 * operation. 925 * 926 * Note that we do not synchronize the case where someone truncates 927 * the file while we are appending to it because attempting to lock 928 * this case may deadlock other parts of the system unexpectedly. 929 */ 930 if ((ioflag & IO_APPEND) || 931 uio->uio_offset + uio->uio_resid > np->n_size) { 932 switch(nfs_rslock(np, td)) { 933 case ENOLCK: 934 goto restart; 935 /* not reached */ 936 case EIO: 937 return (EIO); 938 case EINTR: 939 case ERESTART: 940 return(EINTR); 941 /* not reached */ 942 default: 943 break; 944 } 945 haverslock = 1; 946 } 947 948 /* 949 * Maybe this should be above the vnode op call, but so long as 950 * file servers have no limits, i don't think it matters 951 */ 952 if (p != NULL) { 953 PROC_LOCK(p); 954 if (uio->uio_offset + uio->uio_resid > 955 lim_cur(p, RLIMIT_FSIZE)) { 956 psignal(p, SIGXFSZ); 957 PROC_UNLOCK(p); 958 if (haverslock) 959 nfs_rsunlock(np, td); 960 return (EFBIG); 961 } 962 PROC_UNLOCK(p); 963 } 964 965 biosize = vp->v_mount->mnt_stat.f_iosize; 966 /* 967 * Find all of this file's B_NEEDCOMMIT buffers. If our writes 968 * would exceed the local maximum per-file write commit size when 969 * combined with those, we must decide whether to flush, 970 * go synchronous, or return error. We don't bother checking 971 * IO_UNIT -- we just make all writes atomic anyway, as there's 972 * no point optimizing for something that really won't ever happen. 973 */ 974 if (!(ioflag & IO_SYNC)) { 975 int needrestart = 0; 976 if (nmp->nm_wcommitsize < uio->uio_resid) { 977 /* 978 * If this request could not possibly be completed 979 * without exceeding the maximum outstanding write 980 * commit size, see if we can convert it into a 981 * synchronous write operation. 982 */ 983 if (ioflag & IO_NDELAY) 984 return (EAGAIN); 985 ioflag |= IO_SYNC; 986 if (np->n_flag & NMODIFIED) 987 needrestart = 1; 988 } else if (np->n_flag & NMODIFIED) { 989 int wouldcommit = 0; 990 BO_LOCK(&vp->v_bufobj); 991 if (vp->v_bufobj.bo_dirty.bv_cnt != 0) { 992 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd, 993 b_bobufs) { 994 if (bp->b_flags & B_NEEDCOMMIT) 995 wouldcommit += bp->b_bcount; 996 } 997 } 998 BO_UNLOCK(&vp->v_bufobj); 999 /* 1000 * Since we're not operating synchronously and 1001 * bypassing the buffer cache, we are in a commit 1002 * and holding all of these buffers whether 1003 * transmitted or not. If not limited, this 1004 * will lead to the buffer cache deadlocking, 1005 * as no one else can flush our uncommitted buffers. 1006 */ 1007 wouldcommit += uio->uio_resid; 1008 /* 1009 * If we would initially exceed the maximum 1010 * outstanding write commit size, flush and restart. 1011 */ 1012 if (wouldcommit > nmp->nm_wcommitsize) 1013 needrestart = 1; 1014 } 1015 if (needrestart) { 1016 if (haverslock) { 1017 nfs_rsunlock(np, td); 1018 haverslock = 0; 1019 } 1020 goto flush_and_restart; 1021 } 1022 } 1023 1024 do { 1025 nfsstats.biocache_writes++; 1026 lbn = uio->uio_offset / biosize; 1027 on = uio->uio_offset & (biosize-1); 1028 n = min((unsigned)(biosize - on), uio->uio_resid); 1029 again: 1030 /* 1031 * Handle direct append and file extension cases, calculate 1032 * unaligned buffer size. 1033 */ 1034 1035 if (uio->uio_offset == np->n_size && n) { 1036 /* 1037 * Get the buffer (in its pre-append state to maintain 1038 * B_CACHE if it was previously set). Resize the 1039 * nfsnode after we have locked the buffer to prevent 1040 * readers from reading garbage. 1041 */ 1042 bcount = on; 1043 bp = nfs_getcacheblk(vp, lbn, bcount, td); 1044 1045 if (bp != NULL) { 1046 long save; 1047 1048 np->n_size = uio->uio_offset + n; 1049 np->n_flag |= NMODIFIED; 1050 vnode_pager_setsize(vp, np->n_size); 1051 1052 save = bp->b_flags & B_CACHE; 1053 bcount += n; 1054 allocbuf(bp, bcount); 1055 bp->b_flags |= save; 1056 } 1057 } else { 1058 /* 1059 * Obtain the locked cache block first, and then 1060 * adjust the file's size as appropriate. 1061 */ 1062 bcount = on + n; 1063 if ((off_t)lbn * biosize + bcount < np->n_size) { 1064 if ((off_t)(lbn + 1) * biosize < np->n_size) 1065 bcount = biosize; 1066 else 1067 bcount = np->n_size - (off_t)lbn * biosize; 1068 } 1069 bp = nfs_getcacheblk(vp, lbn, bcount, td); 1070 if (uio->uio_offset + n > np->n_size) { 1071 np->n_size = uio->uio_offset + n; 1072 np->n_flag |= NMODIFIED; 1073 vnode_pager_setsize(vp, np->n_size); 1074 } 1075 } 1076 1077 if (!bp) { 1078 error = nfs_sigintr(nmp, NULL, td); 1079 if (!error) 1080 error = EINTR; 1081 break; 1082 } 1083 1084 /* 1085 * Issue a READ if B_CACHE is not set. In special-append 1086 * mode, B_CACHE is based on the buffer prior to the write 1087 * op and is typically set, avoiding the read. If a read 1088 * is required in special append mode, the server will 1089 * probably send us a short-read since we extended the file 1090 * on our end, resulting in b_resid == 0 and, thusly, 1091 * B_CACHE getting set. 1092 * 1093 * We can also avoid issuing the read if the write covers 1094 * the entire buffer. We have to make sure the buffer state 1095 * is reasonable in this case since we will not be initiating 1096 * I/O. See the comments in kern/vfs_bio.c's getblk() for 1097 * more information. 1098 * 1099 * B_CACHE may also be set due to the buffer being cached 1100 * normally. 1101 */ 1102 1103 if (on == 0 && n == bcount) { 1104 bp->b_flags |= B_CACHE; 1105 bp->b_flags &= ~B_INVAL; 1106 bp->b_ioflags &= ~BIO_ERROR; 1107 } 1108 1109 if ((bp->b_flags & B_CACHE) == 0) { 1110 bp->b_iocmd = BIO_READ; 1111 vfs_busy_pages(bp, 0); 1112 error = nfs_doio(vp, bp, cred, td); 1113 if (error) { 1114 brelse(bp); 1115 break; 1116 } 1117 } 1118 if (bp->b_wcred == NOCRED) 1119 bp->b_wcred = crhold(cred); 1120 np->n_flag |= NMODIFIED; 1121 1122 /* 1123 * If dirtyend exceeds file size, chop it down. This should 1124 * not normally occur but there is an append race where it 1125 * might occur XXX, so we log it. 1126 * 1127 * If the chopping creates a reverse-indexed or degenerate 1128 * situation with dirtyoff/end, we 0 both of them. 1129 */ 1130 1131 if (bp->b_dirtyend > bcount) { 1132 printf("NFS append race @%lx:%d\n", 1133 (long)bp->b_blkno * DEV_BSIZE, 1134 bp->b_dirtyend - bcount); 1135 bp->b_dirtyend = bcount; 1136 } 1137 1138 if (bp->b_dirtyoff >= bp->b_dirtyend) 1139 bp->b_dirtyoff = bp->b_dirtyend = 0; 1140 1141 /* 1142 * If the new write will leave a contiguous dirty 1143 * area, just update the b_dirtyoff and b_dirtyend, 1144 * otherwise force a write rpc of the old dirty area. 1145 * 1146 * While it is possible to merge discontiguous writes due to 1147 * our having a B_CACHE buffer ( and thus valid read data 1148 * for the hole), we don't because it could lead to 1149 * significant cache coherency problems with multiple clients, 1150 * especially if locking is implemented later on. 1151 * 1152 * as an optimization we could theoretically maintain 1153 * a linked list of discontinuous areas, but we would still 1154 * have to commit them separately so there isn't much 1155 * advantage to it except perhaps a bit of asynchronization. 1156 */ 1157 1158 if (bp->b_dirtyend > 0 && 1159 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { 1160 if (bwrite(bp) == EINTR) { 1161 error = EINTR; 1162 break; 1163 } 1164 goto again; 1165 } 1166 1167 error = uiomove((char *)bp->b_data + on, n, uio); 1168 1169 /* 1170 * Since this block is being modified, it must be written 1171 * again and not just committed. Since write clustering does 1172 * not work for the stage 1 data write, only the stage 2 1173 * commit rpc, we have to clear B_CLUSTEROK as well. 1174 */ 1175 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1176 1177 if (error) { 1178 bp->b_ioflags |= BIO_ERROR; 1179 brelse(bp); 1180 break; 1181 } 1182 1183 /* 1184 * Only update dirtyoff/dirtyend if not a degenerate 1185 * condition. 1186 */ 1187 if (n) { 1188 if (bp->b_dirtyend > 0) { 1189 bp->b_dirtyoff = min(on, bp->b_dirtyoff); 1190 bp->b_dirtyend = max((on + n), bp->b_dirtyend); 1191 } else { 1192 bp->b_dirtyoff = on; 1193 bp->b_dirtyend = on + n; 1194 } 1195 vfs_bio_set_validclean(bp, on, n); 1196 } 1197 1198 /* 1199 * If IO_SYNC do bwrite(). 1200 * 1201 * IO_INVAL appears to be unused. The idea appears to be 1202 * to turn off caching in this case. Very odd. XXX 1203 */ 1204 if ((ioflag & IO_SYNC)) { 1205 if (ioflag & IO_INVAL) 1206 bp->b_flags |= B_NOCACHE; 1207 error = bwrite(bp); 1208 if (error) 1209 break; 1210 } else if ((n + on) == biosize) { 1211 bp->b_flags |= B_ASYNC; 1212 (void) (nmp->nm_rpcops->nr_writebp)(bp, 0, 0); 1213 } else { 1214 bdwrite(bp); 1215 } 1216 } while (uio->uio_resid > 0 && n > 0); 1217 1218 if (haverslock) 1219 nfs_rsunlock(np, td); 1220 1221 return (error); 1222 } 1223 1224 /* 1225 * Get an nfs cache block. 1226 * 1227 * Allocate a new one if the block isn't currently in the cache 1228 * and return the block marked busy. If the calling process is 1229 * interrupted by a signal for an interruptible mount point, return 1230 * NULL. 1231 * 1232 * The caller must carefully deal with the possible B_INVAL state of 1233 * the buffer. nfs_doio() clears B_INVAL (and nfs_asyncio() clears it 1234 * indirectly), so synchronous reads can be issued without worrying about 1235 * the B_INVAL state. We have to be a little more careful when dealing 1236 * with writes (see comments in nfs_write()) when extending a file past 1237 * its EOF. 1238 */ 1239 static struct buf * 1240 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td) 1241 { 1242 struct buf *bp; 1243 struct mount *mp; 1244 struct nfsmount *nmp; 1245 1246 mp = vp->v_mount; 1247 nmp = VFSTONFS(mp); 1248 1249 if (nmp->nm_flag & NFSMNT_INT) { 1250 sigset_t oldset; 1251 1252 nfs_set_sigmask(td, &oldset); 1253 bp = getblk(vp, bn, size, PCATCH, 0, 0); 1254 nfs_restore_sigmask(td, &oldset); 1255 while (bp == NULL) { 1256 if (nfs_sigintr(nmp, NULL, td)) 1257 return (NULL); 1258 bp = getblk(vp, bn, size, 0, 2 * hz, 0); 1259 } 1260 } else { 1261 bp = getblk(vp, bn, size, 0, 0, 0); 1262 } 1263 1264 if (vp->v_type == VREG) { 1265 int biosize; 1266 1267 biosize = mp->mnt_stat.f_iosize; 1268 bp->b_blkno = bn * (biosize / DEV_BSIZE); 1269 } 1270 return (bp); 1271 } 1272 1273 /* 1274 * Flush and invalidate all dirty buffers. If another process is already 1275 * doing the flush, just wait for completion. 1276 */ 1277 int 1278 nfs_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg) 1279 { 1280 struct nfsnode *np = VTONFS(vp); 1281 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 1282 int error = 0, slpflag, slptimeo; 1283 int old_lock = 0; 1284 1285 ASSERT_VOP_LOCKED(vp, "nfs_vinvalbuf"); 1286 1287 /* 1288 * XXX This check stops us from needlessly doing a vinvalbuf when 1289 * being called through vclean(). It is not clear that this is 1290 * unsafe. 1291 */ 1292 if (vp->v_iflag & VI_DOOMED) 1293 return (0); 1294 1295 if ((nmp->nm_flag & NFSMNT_INT) == 0) 1296 intrflg = 0; 1297 if (intrflg) { 1298 slpflag = PCATCH; 1299 slptimeo = 2 * hz; 1300 } else { 1301 slpflag = 0; 1302 slptimeo = 0; 1303 } 1304 1305 if ((old_lock = VOP_ISLOCKED(vp, td)) != LK_EXCLUSIVE) { 1306 if (old_lock == LK_SHARED) { 1307 /* Upgrade to exclusive lock, this might block */ 1308 vn_lock(vp, LK_UPGRADE | LK_RETRY, td); 1309 } else { 1310 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1311 } 1312 } 1313 1314 /* 1315 * Now, flush as required. 1316 */ 1317 error = vinvalbuf(vp, flags, td, slpflag, 0); 1318 while (error) { 1319 if (intrflg && (error = nfs_sigintr(nmp, NULL, td))) 1320 goto out; 1321 error = vinvalbuf(vp, flags, td, 0, slptimeo); 1322 } 1323 np->n_flag &= ~NMODIFIED; 1324 out: 1325 if (old_lock != LK_EXCLUSIVE) { 1326 if (old_lock == LK_SHARED) { 1327 /* Downgrade from exclusive lock, this might block */ 1328 vn_lock(vp, LK_DOWNGRADE, td); 1329 } else { 1330 VOP_UNLOCK(vp, 0, td); 1331 } 1332 } 1333 return error; 1334 } 1335 1336 /* 1337 * Initiate asynchronous I/O. Return an error if no nfsiods are available. 1338 * This is mainly to avoid queueing async I/O requests when the nfsiods 1339 * are all hung on a dead server. 1340 * 1341 * Note: nfs_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp 1342 * is eventually dequeued by the async daemon, nfs_doio() *will*. 1343 */ 1344 int 1345 nfs_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td) 1346 { 1347 int iod; 1348 int gotiod; 1349 int slpflag = 0; 1350 int slptimeo = 0; 1351 int error, error2; 1352 1353 /* 1354 * Commits are usually short and sweet so lets save some cpu and 1355 * leave the async daemons for more important rpc's (such as reads 1356 * and writes). 1357 */ 1358 if (bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) && 1359 (nmp->nm_bufqiods > nfs_numasync / 2)) { 1360 return(EIO); 1361 } 1362 1363 again: 1364 if (nmp->nm_flag & NFSMNT_INT) 1365 slpflag = PCATCH; 1366 gotiod = FALSE; 1367 1368 /* 1369 * Find a free iod to process this request. 1370 */ 1371 for (iod = 0; iod < nfs_numasync; iod++) 1372 if (nfs_iodwant[iod]) { 1373 gotiod = TRUE; 1374 break; 1375 } 1376 1377 /* 1378 * Try to create one if none are free. 1379 */ 1380 if (!gotiod) { 1381 iod = nfs_nfsiodnew(); 1382 if (iod != -1) 1383 gotiod = TRUE; 1384 } 1385 1386 if (gotiod) { 1387 /* 1388 * Found one, so wake it up and tell it which 1389 * mount to process. 1390 */ 1391 NFS_DPF(ASYNCIO, ("nfs_asyncio: waking iod %d for mount %p\n", 1392 iod, nmp)); 1393 nfs_iodwant[iod] = NULL; 1394 nfs_iodmount[iod] = nmp; 1395 nmp->nm_bufqiods++; 1396 wakeup(&nfs_iodwant[iod]); 1397 } 1398 1399 /* 1400 * If none are free, we may already have an iod working on this mount 1401 * point. If so, it will process our request. 1402 */ 1403 if (!gotiod) { 1404 if (nmp->nm_bufqiods > 0) { 1405 NFS_DPF(ASYNCIO, 1406 ("nfs_asyncio: %d iods are already processing mount %p\n", 1407 nmp->nm_bufqiods, nmp)); 1408 gotiod = TRUE; 1409 } 1410 } 1411 1412 /* 1413 * If we have an iod which can process the request, then queue 1414 * the buffer. 1415 */ 1416 if (gotiod) { 1417 /* 1418 * Ensure that the queue never grows too large. We still want 1419 * to asynchronize so we block rather then return EIO. 1420 */ 1421 while (nmp->nm_bufqlen >= 2*nfs_numasync) { 1422 NFS_DPF(ASYNCIO, 1423 ("nfs_asyncio: waiting for mount %p queue to drain\n", nmp)); 1424 nmp->nm_bufqwant = TRUE; 1425 error = nfs_tsleep(td, &nmp->nm_bufq, slpflag | PRIBIO, 1426 "nfsaio", slptimeo); 1427 if (error) { 1428 error2 = nfs_sigintr(nmp, NULL, td); 1429 if (error2) 1430 return (error2); 1431 if (slpflag == PCATCH) { 1432 slpflag = 0; 1433 slptimeo = 2 * hz; 1434 } 1435 } 1436 /* 1437 * We might have lost our iod while sleeping, 1438 * so check and loop if nescessary. 1439 */ 1440 if (nmp->nm_bufqiods == 0) { 1441 NFS_DPF(ASYNCIO, 1442 ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); 1443 goto again; 1444 } 1445 } 1446 1447 if (bp->b_iocmd == BIO_READ) { 1448 if (bp->b_rcred == NOCRED && cred != NOCRED) 1449 bp->b_rcred = crhold(cred); 1450 } else { 1451 if (bp->b_wcred == NOCRED && cred != NOCRED) 1452 bp->b_wcred = crhold(cred); 1453 } 1454 1455 if (bp->b_flags & B_REMFREE) 1456 bremfreef(bp); 1457 BUF_KERNPROC(bp); 1458 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist); 1459 nmp->nm_bufqlen++; 1460 return (0); 1461 } 1462 1463 /* 1464 * All the iods are busy on other mounts, so return EIO to 1465 * force the caller to process the i/o synchronously. 1466 */ 1467 NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n")); 1468 return (EIO); 1469 } 1470 1471 void 1472 nfs_doio_directwrite(struct buf *bp) 1473 { 1474 int iomode, must_commit; 1475 struct uio *uiop = (struct uio *)bp->b_caller1; 1476 char *iov_base = uiop->uio_iov->iov_base; 1477 struct nfsmount *nmp = VFSTONFS(bp->b_vp->v_mount); 1478 1479 iomode = NFSV3WRITE_FILESYNC; 1480 uiop->uio_td = NULL; /* NULL since we're in nfsiod */ 1481 (nmp->nm_rpcops->nr_writerpc)(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit); 1482 KASSERT((must_commit == 0), ("nfs_doio_directwrite: Did not commit write")); 1483 free(iov_base, M_NFSDIRECTIO); 1484 free(uiop->uio_iov, M_NFSDIRECTIO); 1485 free(uiop, M_NFSDIRECTIO); 1486 vdrop(bp->b_vp); 1487 bp->b_vp = NULL; 1488 relpbuf(bp, &nfs_pbuf_freecnt); 1489 } 1490 1491 /* 1492 * Do an I/O operation to/from a cache block. This may be called 1493 * synchronously or from an nfsiod. 1494 */ 1495 int 1496 nfs_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td) 1497 { 1498 struct uio *uiop; 1499 struct nfsnode *np; 1500 struct nfsmount *nmp; 1501 int error = 0, iomode, must_commit = 0; 1502 struct uio uio; 1503 struct iovec io; 1504 struct proc *p = td ? td->td_proc : NULL; 1505 1506 np = VTONFS(vp); 1507 nmp = VFSTONFS(vp->v_mount); 1508 uiop = &uio; 1509 uiop->uio_iov = &io; 1510 uiop->uio_iovcnt = 1; 1511 uiop->uio_segflg = UIO_SYSSPACE; 1512 uiop->uio_td = td; 1513 1514 /* 1515 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We 1516 * do this here so we do not have to do it in all the code that 1517 * calls us. 1518 */ 1519 bp->b_flags &= ~B_INVAL; 1520 bp->b_ioflags &= ~BIO_ERROR; 1521 1522 KASSERT(!(bp->b_flags & B_DONE), ("nfs_doio: bp %p already marked done", bp)); 1523 1524 if (bp->b_iocmd == BIO_READ) { 1525 io.iov_len = uiop->uio_resid = bp->b_bcount; 1526 io.iov_base = bp->b_data; 1527 uiop->uio_rw = UIO_READ; 1528 1529 switch (vp->v_type) { 1530 case VREG: 1531 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE; 1532 nfsstats.read_bios++; 1533 error = (nmp->nm_rpcops->nr_readrpc)(vp, uiop, cr); 1534 1535 if (!error) { 1536 if (uiop->uio_resid) { 1537 /* 1538 * If we had a short read with no error, we must have 1539 * hit a file hole. We should zero-fill the remainder. 1540 * This can also occur if the server hits the file EOF. 1541 * 1542 * Holes used to be able to occur due to pending 1543 * writes, but that is not possible any longer. 1544 */ 1545 int nread = bp->b_bcount - uiop->uio_resid; 1546 int left = uiop->uio_resid; 1547 1548 if (left > 0) 1549 bzero((char *)bp->b_data + nread, left); 1550 uiop->uio_resid = 0; 1551 } 1552 } 1553 /* ASSERT_VOP_LOCKED(vp, "nfs_doio"); */ 1554 if (p && (vp->v_vflag & VV_TEXT) && 1555 (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.va_mtime))) { 1556 PROC_LOCK(p); 1557 killproc(p, "text file modification"); 1558 PROC_UNLOCK(p); 1559 } 1560 break; 1561 case VLNK: 1562 uiop->uio_offset = (off_t)0; 1563 nfsstats.readlink_bios++; 1564 error = (nmp->nm_rpcops->nr_readlinkrpc)(vp, uiop, cr); 1565 break; 1566 case VDIR: 1567 nfsstats.readdir_bios++; 1568 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ; 1569 if ((nmp->nm_flag & NFSMNT_NFSV4) != 0) 1570 error = nfs4_readdirrpc(vp, uiop, cr); 1571 else { 1572 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) { 1573 error = nfs_readdirplusrpc(vp, uiop, cr); 1574 if (error == NFSERR_NOTSUPP) 1575 nmp->nm_flag &= ~NFSMNT_RDIRPLUS; 1576 } 1577 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) 1578 error = nfs_readdirrpc(vp, uiop, cr); 1579 } 1580 /* 1581 * end-of-directory sets B_INVAL but does not generate an 1582 * error. 1583 */ 1584 if (error == 0 && uiop->uio_resid == bp->b_bcount) 1585 bp->b_flags |= B_INVAL; 1586 break; 1587 default: 1588 printf("nfs_doio: type %x unexpected\n", vp->v_type); 1589 break; 1590 }; 1591 if (error) { 1592 bp->b_ioflags |= BIO_ERROR; 1593 bp->b_error = error; 1594 } 1595 } else { 1596 /* 1597 * If we only need to commit, try to commit 1598 */ 1599 if (bp->b_flags & B_NEEDCOMMIT) { 1600 int retv; 1601 off_t off; 1602 1603 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff; 1604 retv = (nmp->nm_rpcops->nr_commit)( 1605 vp, off, bp->b_dirtyend-bp->b_dirtyoff, 1606 bp->b_wcred, td); 1607 if (retv == 0) { 1608 bp->b_dirtyoff = bp->b_dirtyend = 0; 1609 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1610 bp->b_resid = 0; 1611 bufdone(bp); 1612 return (0); 1613 } 1614 if (retv == NFSERR_STALEWRITEVERF) { 1615 nfs_clearcommit(vp->v_mount); 1616 } 1617 } 1618 1619 /* 1620 * Setup for actual write 1621 */ 1622 1623 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size) 1624 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE; 1625 1626 if (bp->b_dirtyend > bp->b_dirtyoff) { 1627 io.iov_len = uiop->uio_resid = bp->b_dirtyend 1628 - bp->b_dirtyoff; 1629 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE 1630 + bp->b_dirtyoff; 1631 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; 1632 uiop->uio_rw = UIO_WRITE; 1633 nfsstats.write_bios++; 1634 1635 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC) 1636 iomode = NFSV3WRITE_UNSTABLE; 1637 else 1638 iomode = NFSV3WRITE_FILESYNC; 1639 1640 error = (nmp->nm_rpcops->nr_writerpc)(vp, uiop, cr, &iomode, &must_commit); 1641 1642 /* 1643 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try 1644 * to cluster the buffers needing commit. This will allow 1645 * the system to submit a single commit rpc for the whole 1646 * cluster. We can do this even if the buffer is not 100% 1647 * dirty (relative to the NFS blocksize), so we optimize the 1648 * append-to-file-case. 1649 * 1650 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be 1651 * cleared because write clustering only works for commit 1652 * rpc's, not for the data portion of the write). 1653 */ 1654 1655 if (!error && iomode == NFSV3WRITE_UNSTABLE) { 1656 bp->b_flags |= B_NEEDCOMMIT; 1657 if (bp->b_dirtyoff == 0 1658 && bp->b_dirtyend == bp->b_bcount) 1659 bp->b_flags |= B_CLUSTEROK; 1660 } else { 1661 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1662 } 1663 1664 /* 1665 * For an interrupted write, the buffer is still valid 1666 * and the write hasn't been pushed to the server yet, 1667 * so we can't set BIO_ERROR and report the interruption 1668 * by setting B_EINTR. For the B_ASYNC case, B_EINTR 1669 * is not relevant, so the rpc attempt is essentially 1670 * a noop. For the case of a V3 write rpc not being 1671 * committed to stable storage, the block is still 1672 * dirty and requires either a commit rpc or another 1673 * write rpc with iomode == NFSV3WRITE_FILESYNC before 1674 * the block is reused. This is indicated by setting 1675 * the B_DELWRI and B_NEEDCOMMIT flags. 1676 * 1677 * If the buffer is marked B_PAGING, it does not reside on 1678 * the vp's paging queues so we cannot call bdirty(). The 1679 * bp in this case is not an NFS cache block so we should 1680 * be safe. XXX 1681 */ 1682 if (error == EINTR || error == EIO 1683 || (!error && (bp->b_flags & B_NEEDCOMMIT))) { 1684 int s; 1685 1686 s = splbio(); 1687 bp->b_flags &= ~(B_INVAL|B_NOCACHE); 1688 if ((bp->b_flags & B_PAGING) == 0) { 1689 bdirty(bp); 1690 bp->b_flags &= ~B_DONE; 1691 } 1692 if (error && (bp->b_flags & B_ASYNC) == 0) 1693 bp->b_flags |= B_EINTR; 1694 splx(s); 1695 } else { 1696 if (error) { 1697 bp->b_ioflags |= BIO_ERROR; 1698 bp->b_error = np->n_error = error; 1699 np->n_flag |= NWRITEERR; 1700 } 1701 bp->b_dirtyoff = bp->b_dirtyend = 0; 1702 } 1703 } else { 1704 bp->b_resid = 0; 1705 bufdone(bp); 1706 return (0); 1707 } 1708 } 1709 bp->b_resid = uiop->uio_resid; 1710 if (must_commit) 1711 nfs_clearcommit(vp->v_mount); 1712 bufdone(bp); 1713 return (error); 1714 } 1715 1716 /* 1717 * Used to aid in handling ftruncate() operations on the NFS client side. 1718 * Truncation creates a number of special problems for NFS. We have to 1719 * throw away VM pages and buffer cache buffers that are beyond EOF, and 1720 * we have to properly handle VM pages or (potentially dirty) buffers 1721 * that straddle the truncation point. 1722 */ 1723 1724 int 1725 nfs_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize) 1726 { 1727 struct nfsnode *np = VTONFS(vp); 1728 u_quad_t tsize = np->n_size; 1729 int biosize = vp->v_mount->mnt_stat.f_iosize; 1730 int error = 0; 1731 1732 np->n_size = nsize; 1733 1734 if (np->n_size < tsize) { 1735 struct buf *bp; 1736 daddr_t lbn; 1737 int bufsize; 1738 1739 /* 1740 * vtruncbuf() doesn't get the buffer overlapping the 1741 * truncation point. We may have a B_DELWRI and/or B_CACHE 1742 * buffer that now needs to be truncated. 1743 */ 1744 error = vtruncbuf(vp, cred, td, nsize, biosize); 1745 lbn = nsize / biosize; 1746 bufsize = nsize & (biosize - 1); 1747 bp = nfs_getcacheblk(vp, lbn, bufsize, td); 1748 if (!bp) 1749 return EINTR; 1750 if (bp->b_dirtyoff > bp->b_bcount) 1751 bp->b_dirtyoff = bp->b_bcount; 1752 if (bp->b_dirtyend > bp->b_bcount) 1753 bp->b_dirtyend = bp->b_bcount; 1754 bp->b_flags |= B_RELBUF; /* don't leave garbage around */ 1755 brelse(bp); 1756 } else { 1757 vnode_pager_setsize(vp, nsize); 1758 } 1759 return(error); 1760 } 1761
Cache object: 1fe38f1d339e5451810389e929c3abb0
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