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/6.3/sys/nfsclient/nfs_bio.c 171478 2007-07-17 21:02:08Z jhb $"); 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_enable && !nfs_directio_allow_mmap && 109 (np->n_flag & NNONCACHE) && 110 (vp->v_type == VREG)) { 111 printf("nfs_getpages: called on non-cacheable vnode??\n"); 112 return VM_PAGER_ERROR; 113 } 114 115 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 116 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 117 /* We'll never get here for v4, because we always have fsinfo */ 118 (void)nfs_fsinfo(nmp, vp, cred, td); 119 } 120 121 npages = btoc(count); 122 123 /* 124 * If the requested page is partially valid, just return it and 125 * allow the pager to zero-out the blanks. Partially valid pages 126 * can only occur at the file EOF. 127 */ 128 129 { 130 vm_page_t m = pages[ap->a_reqpage]; 131 132 VM_OBJECT_LOCK(object); 133 vm_page_lock_queues(); 134 if (m->valid != 0) { 135 /* handled by vm_fault now */ 136 /* vm_page_zero_invalid(m, TRUE); */ 137 for (i = 0; i < npages; ++i) { 138 if (i != ap->a_reqpage) 139 vm_page_free(pages[i]); 140 } 141 vm_page_unlock_queues(); 142 VM_OBJECT_UNLOCK(object); 143 return(0); 144 } 145 vm_page_unlock_queues(); 146 VM_OBJECT_UNLOCK(object); 147 } 148 149 /* 150 * We use only the kva address for the buffer, but this is extremely 151 * convienient and fast. 152 */ 153 bp = getpbuf(&nfs_pbuf_freecnt); 154 155 kva = (vm_offset_t) bp->b_data; 156 pmap_qenter(kva, pages, npages); 157 cnt.v_vnodein++; 158 cnt.v_vnodepgsin += npages; 159 160 iov.iov_base = (caddr_t) kva; 161 iov.iov_len = count; 162 uio.uio_iov = &iov; 163 uio.uio_iovcnt = 1; 164 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex); 165 uio.uio_resid = count; 166 uio.uio_segflg = UIO_SYSSPACE; 167 uio.uio_rw = UIO_READ; 168 uio.uio_td = td; 169 170 error = (nmp->nm_rpcops->nr_readrpc)(vp, &uio, cred); 171 pmap_qremove(kva, npages); 172 173 relpbuf(bp, &nfs_pbuf_freecnt); 174 175 if (error && (uio.uio_resid == count)) { 176 printf("nfs_getpages: error %d\n", error); 177 VM_OBJECT_LOCK(object); 178 vm_page_lock_queues(); 179 for (i = 0; i < npages; ++i) { 180 if (i != ap->a_reqpage) 181 vm_page_free(pages[i]); 182 } 183 vm_page_unlock_queues(); 184 VM_OBJECT_UNLOCK(object); 185 return VM_PAGER_ERROR; 186 } 187 188 /* 189 * Calculate the number of bytes read and validate only that number 190 * of bytes. Note that due to pending writes, size may be 0. This 191 * does not mean that the remaining data is invalid! 192 */ 193 194 size = count - uio.uio_resid; 195 VM_OBJECT_LOCK(object); 196 vm_page_lock_queues(); 197 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) { 198 vm_page_t m; 199 nextoff = toff + PAGE_SIZE; 200 m = pages[i]; 201 202 if (nextoff <= size) { 203 /* 204 * Read operation filled an entire page 205 */ 206 m->valid = VM_PAGE_BITS_ALL; 207 vm_page_undirty(m); 208 } else if (size > toff) { 209 /* 210 * Read operation filled a partial page. 211 */ 212 m->valid = 0; 213 vm_page_set_validclean(m, 0, size - toff); 214 /* handled by vm_fault now */ 215 /* vm_page_zero_invalid(m, TRUE); */ 216 } else { 217 /* 218 * Read operation was short. If no error occured 219 * we may have hit a zero-fill section. We simply 220 * leave valid set to 0. 221 */ 222 ; 223 } 224 if (i != ap->a_reqpage) { 225 /* 226 * Whether or not to leave the page activated is up in 227 * the air, but we should put the page on a page queue 228 * somewhere (it already is in the object). Result: 229 * It appears that emperical results show that 230 * deactivating pages is best. 231 */ 232 233 /* 234 * Just in case someone was asking for this page we 235 * now tell them that it is ok to use. 236 */ 237 if (!error) { 238 if (m->flags & PG_WANTED) 239 vm_page_activate(m); 240 else 241 vm_page_deactivate(m); 242 vm_page_wakeup(m); 243 } else { 244 vm_page_free(m); 245 } 246 } 247 } 248 vm_page_unlock_queues(); 249 VM_OBJECT_UNLOCK(object); 250 return 0; 251 } 252 253 /* 254 * Vnode op for VM putpages. 255 */ 256 int 257 nfs_putpages(struct vop_putpages_args *ap) 258 { 259 struct uio uio; 260 struct iovec iov; 261 vm_offset_t kva; 262 struct buf *bp; 263 int iomode, must_commit, i, error, npages, count; 264 off_t offset; 265 int *rtvals; 266 struct vnode *vp; 267 struct thread *td; 268 struct ucred *cred; 269 struct nfsmount *nmp; 270 struct nfsnode *np; 271 vm_page_t *pages; 272 273 GIANT_REQUIRED; 274 275 vp = ap->a_vp; 276 np = VTONFS(vp); 277 td = curthread; /* XXX */ 278 cred = curthread->td_ucred; /* XXX */ 279 nmp = VFSTONFS(vp->v_mount); 280 pages = ap->a_m; 281 count = ap->a_count; 282 rtvals = ap->a_rtvals; 283 npages = btoc(count); 284 offset = IDX_TO_OFF(pages[0]->pindex); 285 286 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 287 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 288 (void)nfs_fsinfo(nmp, vp, cred, td); 289 } 290 291 if (nfs_directio_enable && !nfs_directio_allow_mmap && 292 (np->n_flag & NNONCACHE) && (vp->v_type == VREG)) 293 printf("nfs_putpages: called on noncache-able vnode??\n"); 294 295 for (i = 0; i < npages; i++) 296 rtvals[i] = VM_PAGER_AGAIN; 297 298 /* 299 * When putting pages, do not extend file past EOF. 300 */ 301 302 if (offset + count > np->n_size) { 303 count = np->n_size - offset; 304 if (count < 0) 305 count = 0; 306 } 307 308 /* 309 * We use only the kva address for the buffer, but this is extremely 310 * convienient and fast. 311 */ 312 bp = getpbuf(&nfs_pbuf_freecnt); 313 314 kva = (vm_offset_t) bp->b_data; 315 pmap_qenter(kva, pages, npages); 316 cnt.v_vnodeout++; 317 cnt.v_vnodepgsout += count; 318 319 iov.iov_base = (caddr_t) kva; 320 iov.iov_len = count; 321 uio.uio_iov = &iov; 322 uio.uio_iovcnt = 1; 323 uio.uio_offset = offset; 324 uio.uio_resid = count; 325 uio.uio_segflg = UIO_SYSSPACE; 326 uio.uio_rw = UIO_WRITE; 327 uio.uio_td = td; 328 329 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0) 330 iomode = NFSV3WRITE_UNSTABLE; 331 else 332 iomode = NFSV3WRITE_FILESYNC; 333 334 error = (nmp->nm_rpcops->nr_writerpc)(vp, &uio, cred, &iomode, &must_commit); 335 336 pmap_qremove(kva, npages); 337 relpbuf(bp, &nfs_pbuf_freecnt); 338 339 if (!error) { 340 int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE; 341 for (i = 0; i < nwritten; i++) { 342 rtvals[i] = VM_PAGER_OK; 343 vm_page_undirty(pages[i]); 344 } 345 if (must_commit) { 346 nfs_clearcommit(vp->v_mount); 347 } 348 } 349 return rtvals[0]; 350 } 351 352 /* 353 * Vnode op for read using bio 354 */ 355 int 356 nfs_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred) 357 { 358 struct nfsnode *np = VTONFS(vp); 359 int biosize, i; 360 struct buf *bp, *rabp; 361 struct vattr vattr; 362 struct thread *td; 363 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 364 daddr_t lbn, rabn; 365 int bcount; 366 int seqcount; 367 int nra, error = 0, n = 0, on = 0; 368 369 #ifdef DIAGNOSTIC 370 if (uio->uio_rw != UIO_READ) 371 panic("nfs_read mode"); 372 #endif 373 if (uio->uio_resid == 0) 374 return (0); 375 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */ 376 return (EINVAL); 377 td = uio->uio_td; 378 379 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 380 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 381 (void)nfs_fsinfo(nmp, vp, cred, td); 382 if (vp->v_type != VDIR && 383 (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 384 return (EFBIG); 385 386 if (nfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG)) 387 /* No caching/ no readaheads. Just read data into the user buffer */ 388 return nfs_readrpc(vp, uio, cred); 389 390 biosize = vp->v_mount->mnt_stat.f_iosize; 391 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE); 392 /* 393 * For nfs, cache consistency can only be maintained approximately. 394 * Although RFC1094 does not specify the criteria, the following is 395 * believed to be compatible with the reference port. 396 * For nfs: 397 * If the file's modify time on the server has changed since the 398 * last read rpc or you have written to the file, 399 * you may have lost data cache consistency with the 400 * server, so flush all of the file's data out of the cache. 401 * Then force a getattr rpc to ensure that you have up to date 402 * attributes. 403 * NB: This implies that cache data can be read when up to 404 * NFS_ATTRTIMEO seconds out of date. If you find that you need current 405 * attributes this could be forced by setting n_attrstamp to 0 before 406 * the VOP_GETATTR() call. 407 */ 408 if (np->n_flag & NMODIFIED) { 409 if (vp->v_type != VREG) { 410 if (vp->v_type != VDIR) 411 panic("nfs: bioread, not dir"); 412 (nmp->nm_rpcops->nr_invaldir)(vp); 413 error = nfs_vinvalbuf(vp, V_SAVE, td, 1); 414 if (error) 415 return (error); 416 } 417 np->n_attrstamp = 0; 418 error = VOP_GETATTR(vp, &vattr, cred, td); 419 if (error) 420 return (error); 421 np->n_mtime = vattr.va_mtime; 422 } else { 423 error = VOP_GETATTR(vp, &vattr, cred, td); 424 if (error) 425 return (error); 426 if ((np->n_flag & NSIZECHANGED) 427 || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) { 428 if (vp->v_type == VDIR) 429 (nmp->nm_rpcops->nr_invaldir)(vp); 430 error = nfs_vinvalbuf(vp, V_SAVE, td, 1); 431 if (error) 432 return (error); 433 np->n_mtime = vattr.va_mtime; 434 np->n_flag &= ~NSIZECHANGED; 435 } 436 } 437 do { 438 switch (vp->v_type) { 439 case VREG: 440 nfsstats.biocache_reads++; 441 lbn = uio->uio_offset / biosize; 442 on = uio->uio_offset & (biosize - 1); 443 444 /* 445 * Start the read ahead(s), as required. 446 * The readahead is kicked off only if sequential access 447 * is detected, based on the readahead hint (ra_expect_lbn). 448 */ 449 if (nmp->nm_readahead > 0 && np->ra_expect_lbn == lbn) { 450 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && 451 (off_t)(lbn + 1 + nra) * biosize < np->n_size; nra++) { 452 rabn = lbn + 1 + nra; 453 if (incore(&vp->v_bufobj, rabn) == NULL) { 454 rabp = nfs_getcacheblk(vp, rabn, biosize, td); 455 if (!rabp) { 456 error = nfs_sigintr(nmp, NULL, td); 457 return (error ? error : EINTR); 458 } 459 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 460 rabp->b_flags |= B_ASYNC; 461 rabp->b_iocmd = BIO_READ; 462 vfs_busy_pages(rabp, 0); 463 if (nfs_asyncio(nmp, rabp, cred, td)) { 464 rabp->b_flags |= B_INVAL; 465 rabp->b_ioflags |= BIO_ERROR; 466 vfs_unbusy_pages(rabp); 467 brelse(rabp); 468 break; 469 } 470 } else { 471 brelse(rabp); 472 } 473 } 474 } 475 np->ra_expect_lbn = lbn + 1; 476 } 477 478 /* 479 * Obtain the buffer cache block. Figure out the buffer size 480 * when we are at EOF. If we are modifying the size of the 481 * buffer based on an EOF condition we need to hold 482 * nfs_rslock() through obtaining the buffer to prevent 483 * a potential writer-appender from messing with n_size. 484 * Otherwise we may accidently truncate the buffer and 485 * lose dirty data. 486 * 487 * Note that bcount is *not* DEV_BSIZE aligned. 488 */ 489 490 again: 491 bcount = biosize; 492 if ((off_t)lbn * biosize >= np->n_size) { 493 bcount = 0; 494 } else if ((off_t)(lbn + 1) * biosize > np->n_size) { 495 bcount = np->n_size - (off_t)lbn * biosize; 496 } 497 if (bcount != biosize) { 498 switch(nfs_rslock(np, td)) { 499 case ENOLCK: 500 goto again; 501 /* not reached */ 502 case EIO: 503 return (EIO); 504 case EINTR: 505 case ERESTART: 506 return(EINTR); 507 /* not reached */ 508 default: 509 break; 510 } 511 } 512 513 bp = nfs_getcacheblk(vp, lbn, bcount, td); 514 515 if (bcount != biosize) 516 nfs_rsunlock(np, td); 517 if (!bp) { 518 error = nfs_sigintr(nmp, NULL, td); 519 return (error ? error : EINTR); 520 } 521 522 /* 523 * If B_CACHE is not set, we must issue the read. If this 524 * fails, we return an error. 525 */ 526 527 if ((bp->b_flags & B_CACHE) == 0) { 528 bp->b_iocmd = BIO_READ; 529 vfs_busy_pages(bp, 0); 530 error = nfs_doio(vp, bp, cred, td); 531 if (error) { 532 brelse(bp); 533 return (error); 534 } 535 } 536 537 /* 538 * on is the offset into the current bp. Figure out how many 539 * bytes we can copy out of the bp. Note that bcount is 540 * NOT DEV_BSIZE aligned. 541 * 542 * Then figure out how many bytes we can copy into the uio. 543 */ 544 545 n = 0; 546 if (on < bcount) 547 n = min((unsigned)(bcount - on), uio->uio_resid); 548 break; 549 case VLNK: 550 nfsstats.biocache_readlinks++; 551 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td); 552 if (!bp) { 553 error = nfs_sigintr(nmp, NULL, td); 554 return (error ? error : EINTR); 555 } 556 if ((bp->b_flags & B_CACHE) == 0) { 557 bp->b_iocmd = BIO_READ; 558 vfs_busy_pages(bp, 0); 559 error = nfs_doio(vp, bp, cred, td); 560 if (error) { 561 bp->b_ioflags |= BIO_ERROR; 562 brelse(bp); 563 return (error); 564 } 565 } 566 n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); 567 on = 0; 568 break; 569 case VDIR: 570 nfsstats.biocache_readdirs++; 571 if (np->n_direofoffset 572 && uio->uio_offset >= np->n_direofoffset) { 573 return (0); 574 } 575 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; 576 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); 577 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td); 578 if (!bp) { 579 error = nfs_sigintr(nmp, NULL, td); 580 return (error ? error : EINTR); 581 } 582 if ((bp->b_flags & B_CACHE) == 0) { 583 bp->b_iocmd = BIO_READ; 584 vfs_busy_pages(bp, 0); 585 error = nfs_doio(vp, bp, cred, td); 586 if (error) { 587 brelse(bp); 588 } 589 while (error == NFSERR_BAD_COOKIE) { 590 (nmp->nm_rpcops->nr_invaldir)(vp); 591 error = nfs_vinvalbuf(vp, 0, td, 1); 592 /* 593 * Yuck! The directory has been modified on the 594 * server. The only way to get the block is by 595 * reading from the beginning to get all the 596 * offset cookies. 597 * 598 * Leave the last bp intact unless there is an error. 599 * Loop back up to the while if the error is another 600 * NFSERR_BAD_COOKIE (double yuch!). 601 */ 602 for (i = 0; i <= lbn && !error; i++) { 603 if (np->n_direofoffset 604 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) 605 return (0); 606 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td); 607 if (!bp) { 608 error = nfs_sigintr(nmp, NULL, td); 609 return (error ? error : EINTR); 610 } 611 if ((bp->b_flags & B_CACHE) == 0) { 612 bp->b_iocmd = BIO_READ; 613 vfs_busy_pages(bp, 0); 614 error = nfs_doio(vp, bp, cred, td); 615 /* 616 * no error + B_INVAL == directory EOF, 617 * use the block. 618 */ 619 if (error == 0 && (bp->b_flags & B_INVAL)) 620 break; 621 } 622 /* 623 * An error will throw away the block and the 624 * for loop will break out. If no error and this 625 * is not the block we want, we throw away the 626 * block and go for the next one via the for loop. 627 */ 628 if (error || i < lbn) 629 brelse(bp); 630 } 631 } 632 /* 633 * The above while is repeated if we hit another cookie 634 * error. If we hit an error and it wasn't a cookie error, 635 * we give up. 636 */ 637 if (error) 638 return (error); 639 } 640 641 /* 642 * If not eof and read aheads are enabled, start one. 643 * (You need the current block first, so that you have the 644 * directory offset cookie of the next block.) 645 */ 646 if (nmp->nm_readahead > 0 && 647 (bp->b_flags & B_INVAL) == 0 && 648 (np->n_direofoffset == 0 || 649 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) && 650 incore(&vp->v_bufobj, lbn + 1) == NULL) { 651 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td); 652 if (rabp) { 653 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 654 rabp->b_flags |= B_ASYNC; 655 rabp->b_iocmd = BIO_READ; 656 vfs_busy_pages(rabp, 0); 657 if (nfs_asyncio(nmp, rabp, cred, td)) { 658 rabp->b_flags |= B_INVAL; 659 rabp->b_ioflags |= BIO_ERROR; 660 vfs_unbusy_pages(rabp); 661 brelse(rabp); 662 } 663 } else { 664 brelse(rabp); 665 } 666 } 667 } 668 /* 669 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is 670 * chopped for the EOF condition, we cannot tell how large 671 * NFS directories are going to be until we hit EOF. So 672 * an NFS directory buffer is *not* chopped to its EOF. Now, 673 * it just so happens that b_resid will effectively chop it 674 * to EOF. *BUT* this information is lost if the buffer goes 675 * away and is reconstituted into a B_CACHE state ( due to 676 * being VMIO ) later. So we keep track of the directory eof 677 * in np->n_direofoffset and chop it off as an extra step 678 * right here. 679 */ 680 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on); 681 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset) 682 n = np->n_direofoffset - uio->uio_offset; 683 break; 684 default: 685 printf(" nfs_bioread: type %x unexpected\n", vp->v_type); 686 bp = NULL; 687 break; 688 }; 689 690 if (n > 0) { 691 error = uiomove(bp->b_data + on, (int)n, uio); 692 } 693 if (vp->v_type == VLNK) 694 n = 0; 695 if (bp != NULL) 696 brelse(bp); 697 } while (error == 0 && uio->uio_resid > 0 && n > 0); 698 return (error); 699 } 700 701 /* 702 * The NFS write path cannot handle iovecs with len > 1. So we need to 703 * break up iovecs accordingly (restricting them to wsize). 704 * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf). 705 * For the ASYNC case, 2 copies are needed. The first a copy from the 706 * user buffer to a staging buffer and then a second copy from the staging 707 * buffer to mbufs. This can be optimized by copying from the user buffer 708 * directly into mbufs and passing the chain down, but that requires a 709 * fair amount of re-working of the relevant codepaths (and can be done 710 * later). 711 */ 712 static int 713 nfs_directio_write(vp, uiop, cred, ioflag) 714 struct vnode *vp; 715 struct uio *uiop; 716 struct ucred *cred; 717 int ioflag; 718 { 719 int error; 720 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 721 struct thread *td = uiop->uio_td; 722 int size; 723 724 if (ioflag & IO_SYNC) { 725 int iomode, must_commit; 726 struct uio uio; 727 struct iovec iov; 728 do_sync: 729 while (uiop->uio_resid > 0) { 730 size = min(uiop->uio_resid, nmp->nm_wsize); 731 size = min(uiop->uio_iov->iov_len, size); 732 iov.iov_base = uiop->uio_iov->iov_base; 733 iov.iov_len = size; 734 uio.uio_iov = &iov; 735 uio.uio_iovcnt = 1; 736 uio.uio_offset = uiop->uio_offset; 737 uio.uio_resid = size; 738 uio.uio_segflg = UIO_USERSPACE; 739 uio.uio_rw = UIO_WRITE; 740 uio.uio_td = td; 741 iomode = NFSV3WRITE_FILESYNC; 742 error = (nmp->nm_rpcops->nr_writerpc)(vp, &uio, cred, 743 &iomode, &must_commit); 744 KASSERT((must_commit == 0), 745 ("nfs_directio_write: Did not commit write")); 746 if (error) 747 return (error); 748 uiop->uio_offset += size; 749 uiop->uio_resid -= size; 750 if (uiop->uio_iov->iov_len <= size) { 751 uiop->uio_iovcnt--; 752 uiop->uio_iov++; 753 } else { 754 uiop->uio_iov->iov_base = 755 (char *)uiop->uio_iov->iov_base + size; 756 uiop->uio_iov->iov_len -= size; 757 } 758 } 759 } else { 760 struct uio *t_uio; 761 struct iovec *t_iov; 762 struct buf *bp; 763 764 /* 765 * Break up the write into blocksize chunks and hand these 766 * over to nfsiod's for write back. 767 * Unfortunately, this incurs a copy of the data. Since 768 * the user could modify the buffer before the write is 769 * initiated. 770 * 771 * The obvious optimization here is that one of the 2 copies 772 * in the async write path can be eliminated by copying the 773 * data here directly into mbufs and passing the mbuf chain 774 * down. But that will require a fair amount of re-working 775 * of the code and can be done if there's enough interest 776 * in NFS directio access. 777 */ 778 while (uiop->uio_resid > 0) { 779 size = min(uiop->uio_resid, nmp->nm_wsize); 780 size = min(uiop->uio_iov->iov_len, size); 781 bp = getpbuf(&nfs_pbuf_freecnt); 782 t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK); 783 t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK); 784 t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK); 785 t_iov->iov_len = size; 786 t_uio->uio_iov = t_iov; 787 t_uio->uio_iovcnt = 1; 788 t_uio->uio_offset = uiop->uio_offset; 789 t_uio->uio_resid = size; 790 t_uio->uio_segflg = UIO_SYSSPACE; 791 t_uio->uio_rw = UIO_WRITE; 792 t_uio->uio_td = td; 793 bcopy(uiop->uio_iov->iov_base, t_iov->iov_base, size); 794 bp->b_flags |= B_DIRECT; 795 bp->b_iocmd = BIO_WRITE; 796 if (cred != NOCRED) { 797 crhold(cred); 798 bp->b_wcred = cred; 799 } else 800 bp->b_wcred = NOCRED; 801 bp->b_caller1 = (void *)t_uio; 802 bp->b_vp = 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 bp->b_vp = NULL; 809 relpbuf(bp, &nfs_pbuf_freecnt); 810 if (error == EINTR) 811 return (error); 812 goto do_sync; 813 } 814 uiop->uio_offset += size; 815 uiop->uio_resid -= size; 816 if (uiop->uio_iov->iov_len <= size) { 817 uiop->uio_iovcnt--; 818 uiop->uio_iov++; 819 } else { 820 uiop->uio_iov->iov_base = 821 (char *)uiop->uio_iov->iov_base + size; 822 uiop->uio_iov->iov_len -= size; 823 } 824 } 825 } 826 return (0); 827 } 828 829 /* 830 * Vnode op for write using bio 831 */ 832 int 833 nfs_write(struct vop_write_args *ap) 834 { 835 int biosize; 836 struct uio *uio = ap->a_uio; 837 struct thread *td = uio->uio_td; 838 struct vnode *vp = ap->a_vp; 839 struct nfsnode *np = VTONFS(vp); 840 struct ucred *cred = ap->a_cred; 841 int ioflag = ap->a_ioflag; 842 struct buf *bp; 843 struct vattr vattr; 844 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 845 daddr_t lbn; 846 int bcount; 847 int n, on, error = 0; 848 int haverslock = 0; 849 struct proc *p = td?td->td_proc:NULL; 850 851 GIANT_REQUIRED; 852 853 #ifdef DIAGNOSTIC 854 if (uio->uio_rw != UIO_WRITE) 855 panic("nfs_write mode"); 856 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_td != curthread) 857 panic("nfs_write proc"); 858 #endif 859 if (vp->v_type != VREG) 860 return (EIO); 861 if (np->n_flag & NWRITEERR) { 862 np->n_flag &= ~NWRITEERR; 863 return (np->n_error); 864 } 865 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 866 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 867 (void)nfs_fsinfo(nmp, vp, cred, td); 868 869 /* 870 * Synchronously flush pending buffers if we are in synchronous 871 * mode or if we are appending. 872 */ 873 if (ioflag & (IO_APPEND | IO_SYNC)) { 874 if (np->n_flag & NMODIFIED) { 875 #ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */ 876 /* 877 * Require non-blocking, synchronous writes to 878 * dirty files to inform the program it needs 879 * to fsync(2) explicitly. 880 */ 881 if (ioflag & IO_NDELAY) 882 return (EAGAIN); 883 #endif 884 flush_and_restart: 885 np->n_attrstamp = 0; 886 error = nfs_vinvalbuf(vp, V_SAVE, td, 1); 887 if (error) 888 return (error); 889 } 890 } 891 892 /* 893 * If IO_APPEND then load uio_offset. We restart here if we cannot 894 * get the append lock. 895 */ 896 restart: 897 if (ioflag & IO_APPEND) { 898 np->n_attrstamp = 0; 899 error = VOP_GETATTR(vp, &vattr, cred, td); 900 if (error) 901 return (error); 902 uio->uio_offset = np->n_size; 903 } 904 905 if (uio->uio_offset < 0) 906 return (EINVAL); 907 if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 908 return (EFBIG); 909 if (uio->uio_resid == 0) 910 return (0); 911 912 if (nfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG) 913 return nfs_directio_write(vp, uio, cred, ioflag); 914 915 /* 916 * We need to obtain the rslock if we intend to modify np->n_size 917 * in order to guarentee the append point with multiple contending 918 * writers, to guarentee that no other appenders modify n_size 919 * while we are trying to obtain a truncated buffer (i.e. to avoid 920 * accidently truncating data written by another appender due to 921 * the race), and to ensure that the buffer is populated prior to 922 * our extending of the file. We hold rslock through the entire 923 * operation. 924 * 925 * Note that we do not synchronize the case where someone truncates 926 * the file while we are appending to it because attempting to lock 927 * this case may deadlock other parts of the system unexpectedly. 928 */ 929 if ((ioflag & IO_APPEND) || 930 uio->uio_offset + uio->uio_resid > np->n_size) { 931 switch(nfs_rslock(np, td)) { 932 case ENOLCK: 933 goto restart; 934 /* not reached */ 935 case EIO: 936 return (EIO); 937 case EINTR: 938 case ERESTART: 939 return(EINTR); 940 /* not reached */ 941 default: 942 break; 943 } 944 haverslock = 1; 945 } 946 947 /* 948 * Maybe this should be above the vnode op call, but so long as 949 * file servers have no limits, i don't think it matters 950 */ 951 if (p != NULL) { 952 PROC_LOCK(p); 953 if (uio->uio_offset + uio->uio_resid > 954 lim_cur(p, RLIMIT_FSIZE)) { 955 psignal(p, SIGXFSZ); 956 PROC_UNLOCK(p); 957 if (haverslock) 958 nfs_rsunlock(np, td); 959 return (EFBIG); 960 } 961 PROC_UNLOCK(p); 962 } 963 964 biosize = vp->v_mount->mnt_stat.f_iosize; 965 /* 966 * Find all of this file's B_NEEDCOMMIT buffers. If our writes 967 * would exceed the local maximum per-file write commit size when 968 * combined with those, we must decide whether to flush, 969 * go synchronous, or return error. We don't bother checking 970 * IO_UNIT -- we just make all writes atomic anyway, as there's 971 * no point optimizing for something that really won't ever happen. 972 */ 973 if (!(ioflag & IO_SYNC)) { 974 int needrestart = 0; 975 if (nmp->nm_wcommitsize < uio->uio_resid) { 976 /* 977 * If this request could not possibly be completed 978 * without exceeding the maximum outstanding write 979 * commit size, see if we can convert it into a 980 * synchronous write operation. 981 */ 982 if (ioflag & IO_NDELAY) 983 return (EAGAIN); 984 ioflag |= IO_SYNC; 985 if (np->n_flag & NMODIFIED) 986 needrestart = 1; 987 } else if (np->n_flag & NMODIFIED) { 988 int wouldcommit = 0; 989 BO_LOCK(&vp->v_bufobj); 990 if (vp->v_bufobj.bo_dirty.bv_cnt != 0) { 991 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd, 992 b_bobufs) { 993 if (bp->b_flags & B_NEEDCOMMIT) 994 wouldcommit += bp->b_bcount; 995 } 996 } 997 BO_UNLOCK(&vp->v_bufobj); 998 /* 999 * Since we're not operating synchronously and 1000 * bypassing the buffer cache, we are in a commit 1001 * and holding all of these buffers whether 1002 * transmitted or not. If not limited, this 1003 * will lead to the buffer cache deadlocking, 1004 * as no one else can flush our uncommitted buffers. 1005 */ 1006 wouldcommit += uio->uio_resid; 1007 /* 1008 * If we would initially exceed the maximum 1009 * outstanding write commit size, flush and restart. 1010 */ 1011 if (wouldcommit > nmp->nm_wcommitsize) 1012 needrestart = 1; 1013 } 1014 if (needrestart) { 1015 if (haverslock) { 1016 nfs_rsunlock(np, td); 1017 haverslock = 0; 1018 } 1019 goto flush_and_restart; 1020 } 1021 } 1022 1023 do { 1024 nfsstats.biocache_writes++; 1025 lbn = uio->uio_offset / biosize; 1026 on = uio->uio_offset & (biosize-1); 1027 n = min((unsigned)(biosize - on), uio->uio_resid); 1028 again: 1029 /* 1030 * Handle direct append and file extension cases, calculate 1031 * unaligned buffer size. 1032 */ 1033 1034 if (uio->uio_offset == np->n_size && n) { 1035 /* 1036 * Get the buffer (in its pre-append state to maintain 1037 * B_CACHE if it was previously set). Resize the 1038 * nfsnode after we have locked the buffer to prevent 1039 * readers from reading garbage. 1040 */ 1041 bcount = on; 1042 bp = nfs_getcacheblk(vp, lbn, bcount, td); 1043 1044 if (bp != NULL) { 1045 long save; 1046 1047 np->n_size = uio->uio_offset + n; 1048 np->n_flag |= NMODIFIED; 1049 vnode_pager_setsize(vp, np->n_size); 1050 1051 save = bp->b_flags & B_CACHE; 1052 bcount += n; 1053 allocbuf(bp, bcount); 1054 bp->b_flags |= save; 1055 } 1056 } else { 1057 /* 1058 * Obtain the locked cache block first, and then 1059 * adjust the file's size as appropriate. 1060 */ 1061 bcount = on + n; 1062 if ((off_t)lbn * biosize + bcount < np->n_size) { 1063 if ((off_t)(lbn + 1) * biosize < np->n_size) 1064 bcount = biosize; 1065 else 1066 bcount = np->n_size - (off_t)lbn * biosize; 1067 } 1068 bp = nfs_getcacheblk(vp, lbn, bcount, td); 1069 if (uio->uio_offset + n > np->n_size) { 1070 np->n_size = uio->uio_offset + n; 1071 np->n_flag |= NMODIFIED; 1072 vnode_pager_setsize(vp, np->n_size); 1073 } 1074 } 1075 1076 if (!bp) { 1077 error = nfs_sigintr(nmp, NULL, td); 1078 if (!error) 1079 error = EINTR; 1080 break; 1081 } 1082 1083 /* 1084 * Issue a READ if B_CACHE is not set. In special-append 1085 * mode, B_CACHE is based on the buffer prior to the write 1086 * op and is typically set, avoiding the read. If a read 1087 * is required in special append mode, the server will 1088 * probably send us a short-read since we extended the file 1089 * on our end, resulting in b_resid == 0 and, thusly, 1090 * B_CACHE getting set. 1091 * 1092 * We can also avoid issuing the read if the write covers 1093 * the entire buffer. We have to make sure the buffer state 1094 * is reasonable in this case since we will not be initiating 1095 * I/O. See the comments in kern/vfs_bio.c's getblk() for 1096 * more information. 1097 * 1098 * B_CACHE may also be set due to the buffer being cached 1099 * normally. 1100 */ 1101 1102 if (on == 0 && n == bcount) { 1103 bp->b_flags |= B_CACHE; 1104 bp->b_flags &= ~B_INVAL; 1105 bp->b_ioflags &= ~BIO_ERROR; 1106 } 1107 1108 if ((bp->b_flags & B_CACHE) == 0) { 1109 bp->b_iocmd = BIO_READ; 1110 vfs_busy_pages(bp, 0); 1111 error = nfs_doio(vp, bp, cred, td); 1112 if (error) { 1113 brelse(bp); 1114 break; 1115 } 1116 } 1117 if (bp->b_wcred == NOCRED) 1118 bp->b_wcred = crhold(cred); 1119 np->n_flag |= NMODIFIED; 1120 1121 /* 1122 * If dirtyend exceeds file size, chop it down. This should 1123 * not normally occur but there is an append race where it 1124 * might occur XXX, so we log it. 1125 * 1126 * If the chopping creates a reverse-indexed or degenerate 1127 * situation with dirtyoff/end, we 0 both of them. 1128 */ 1129 1130 if (bp->b_dirtyend > bcount) { 1131 printf("NFS append race @%lx:%d\n", 1132 (long)bp->b_blkno * DEV_BSIZE, 1133 bp->b_dirtyend - bcount); 1134 bp->b_dirtyend = bcount; 1135 } 1136 1137 if (bp->b_dirtyoff >= bp->b_dirtyend) 1138 bp->b_dirtyoff = bp->b_dirtyend = 0; 1139 1140 /* 1141 * If the new write will leave a contiguous dirty 1142 * area, just update the b_dirtyoff and b_dirtyend, 1143 * otherwise force a write rpc of the old dirty area. 1144 * 1145 * While it is possible to merge discontiguous writes due to 1146 * our having a B_CACHE buffer ( and thus valid read data 1147 * for the hole), we don't because it could lead to 1148 * significant cache coherency problems with multiple clients, 1149 * especially if locking is implemented later on. 1150 * 1151 * as an optimization we could theoretically maintain 1152 * a linked list of discontinuous areas, but we would still 1153 * have to commit them separately so there isn't much 1154 * advantage to it except perhaps a bit of asynchronization. 1155 */ 1156 1157 if (bp->b_dirtyend > 0 && 1158 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { 1159 if (bwrite(bp) == EINTR) { 1160 error = EINTR; 1161 break; 1162 } 1163 goto again; 1164 } 1165 1166 error = uiomove((char *)bp->b_data + on, n, uio); 1167 1168 /* 1169 * Since this block is being modified, it must be written 1170 * again and not just committed. Since write clustering does 1171 * not work for the stage 1 data write, only the stage 2 1172 * commit rpc, we have to clear B_CLUSTEROK as well. 1173 */ 1174 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1175 1176 if (error) { 1177 bp->b_ioflags |= BIO_ERROR; 1178 brelse(bp); 1179 break; 1180 } 1181 1182 /* 1183 * Only update dirtyoff/dirtyend if not a degenerate 1184 * condition. 1185 */ 1186 if (n) { 1187 if (bp->b_dirtyend > 0) { 1188 bp->b_dirtyoff = min(on, bp->b_dirtyoff); 1189 bp->b_dirtyend = max((on + n), bp->b_dirtyend); 1190 } else { 1191 bp->b_dirtyoff = on; 1192 bp->b_dirtyend = on + n; 1193 } 1194 vfs_bio_set_validclean(bp, on, n); 1195 } 1196 1197 /* 1198 * If IO_SYNC do bwrite(). 1199 * 1200 * IO_INVAL appears to be unused. The idea appears to be 1201 * to turn off caching in this case. Very odd. XXX 1202 */ 1203 if ((ioflag & IO_SYNC)) { 1204 if (ioflag & IO_INVAL) 1205 bp->b_flags |= B_NOCACHE; 1206 error = bwrite(bp); 1207 if (error) 1208 break; 1209 } else if ((n + on) == biosize) { 1210 bp->b_flags |= B_ASYNC; 1211 (void) (nmp->nm_rpcops->nr_writebp)(bp, 0, 0); 1212 } else { 1213 bdwrite(bp); 1214 } 1215 } while (uio->uio_resid > 0 && n > 0); 1216 1217 if (haverslock) 1218 nfs_rsunlock(np, td); 1219 1220 return (error); 1221 } 1222 1223 /* 1224 * Get an nfs cache block. 1225 * 1226 * Allocate a new one if the block isn't currently in the cache 1227 * and return the block marked busy. If the calling process is 1228 * interrupted by a signal for an interruptible mount point, return 1229 * NULL. 1230 * 1231 * The caller must carefully deal with the possible B_INVAL state of 1232 * the buffer. nfs_doio() clears B_INVAL (and nfs_asyncio() clears it 1233 * indirectly), so synchronous reads can be issued without worrying about 1234 * the B_INVAL state. We have to be a little more careful when dealing 1235 * with writes (see comments in nfs_write()) when extending a file past 1236 * its EOF. 1237 */ 1238 static struct buf * 1239 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td) 1240 { 1241 struct buf *bp; 1242 struct mount *mp; 1243 struct nfsmount *nmp; 1244 1245 mp = vp->v_mount; 1246 nmp = VFSTONFS(mp); 1247 1248 if (nmp->nm_flag & NFSMNT_INT) { 1249 sigset_t oldset; 1250 1251 nfs_set_sigmask(td, &oldset); 1252 bp = getblk(vp, bn, size, PCATCH, 0, 0); 1253 nfs_restore_sigmask(td, &oldset); 1254 while (bp == NULL) { 1255 if (nfs_sigintr(nmp, NULL, td)) 1256 return (NULL); 1257 bp = getblk(vp, bn, size, 0, 2 * hz, 0); 1258 } 1259 } else { 1260 bp = getblk(vp, bn, size, 0, 0, 0); 1261 } 1262 1263 if (vp->v_type == VREG) { 1264 int biosize; 1265 1266 biosize = mp->mnt_stat.f_iosize; 1267 bp->b_blkno = bn * (biosize / DEV_BSIZE); 1268 } 1269 return (bp); 1270 } 1271 1272 /* 1273 * Flush and invalidate all dirty buffers. If another process is already 1274 * doing the flush, just wait for completion. 1275 */ 1276 int 1277 nfs_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg) 1278 { 1279 struct nfsnode *np = VTONFS(vp); 1280 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 1281 int error = 0, slpflag, slptimeo; 1282 int old_lock = 0; 1283 1284 ASSERT_VOP_LOCKED(vp, "nfs_vinvalbuf"); 1285 1286 /* 1287 * XXX This check stops us from needlessly doing a vinvalbuf when 1288 * being called through vclean(). It is not clear that this is 1289 * unsafe. 1290 */ 1291 if (vp->v_iflag & VI_DOOMED) 1292 return (0); 1293 1294 if ((nmp->nm_flag & NFSMNT_INT) == 0) 1295 intrflg = 0; 1296 if (intrflg) { 1297 slpflag = PCATCH; 1298 slptimeo = 2 * hz; 1299 } else { 1300 slpflag = 0; 1301 slptimeo = 0; 1302 } 1303 1304 if ((old_lock = VOP_ISLOCKED(vp, td)) != LK_EXCLUSIVE) { 1305 if (old_lock == LK_SHARED) { 1306 /* Upgrade to exclusive lock, this might block */ 1307 vn_lock(vp, LK_UPGRADE | LK_RETRY, td); 1308 } else { 1309 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 1310 } 1311 } 1312 1313 /* 1314 * Now, flush as required. 1315 */ 1316 if ((flags & V_SAVE) && (vp->v_bufobj.bo_object != NULL)) { 1317 VM_OBJECT_LOCK(vp->v_bufobj.bo_object); 1318 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC); 1319 VM_OBJECT_UNLOCK(vp->v_bufobj.bo_object); 1320 /* 1321 * If the page clean was interrupted, fail the invalidation. 1322 * Not doing so, we run the risk of losing dirty pages in the 1323 * vinvalbuf() call below. 1324 */ 1325 if (intrflg && (error = nfs_sigintr(nmp, NULL, td))) 1326 goto out; 1327 } 1328 1329 error = vinvalbuf(vp, flags, td, slpflag, 0); 1330 while (error) { 1331 if (intrflg && (error = nfs_sigintr(nmp, NULL, td))) 1332 goto out; 1333 error = vinvalbuf(vp, flags, td, 0, slptimeo); 1334 } 1335 if (np->n_directio_asyncwr == 0) 1336 np->n_flag &= ~NMODIFIED; 1337 out: 1338 if (old_lock != LK_EXCLUSIVE) { 1339 if (old_lock == LK_SHARED) { 1340 /* Downgrade from exclusive lock, this might block */ 1341 vn_lock(vp, LK_DOWNGRADE, td); 1342 } else { 1343 VOP_UNLOCK(vp, 0, td); 1344 } 1345 } 1346 return error; 1347 } 1348 1349 /* 1350 * Initiate asynchronous I/O. Return an error if no nfsiods are available. 1351 * This is mainly to avoid queueing async I/O requests when the nfsiods 1352 * are all hung on a dead server. 1353 * 1354 * Note: nfs_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp 1355 * is eventually dequeued by the async daemon, nfs_doio() *will*. 1356 */ 1357 int 1358 nfs_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td) 1359 { 1360 int iod; 1361 int gotiod; 1362 int slpflag = 0; 1363 int slptimeo = 0; 1364 int error, error2; 1365 1366 /* 1367 * Commits are usually short and sweet so lets save some cpu and 1368 * leave the async daemons for more important rpc's (such as reads 1369 * and writes). 1370 */ 1371 if (bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) && 1372 (nmp->nm_bufqiods > nfs_numasync / 2)) { 1373 return(EIO); 1374 } 1375 1376 again: 1377 if (nmp->nm_flag & NFSMNT_INT) 1378 slpflag = PCATCH; 1379 gotiod = FALSE; 1380 1381 /* 1382 * Find a free iod to process this request. 1383 */ 1384 for (iod = 0; iod < nfs_numasync; iod++) 1385 if (nfs_iodwant[iod]) { 1386 gotiod = TRUE; 1387 break; 1388 } 1389 1390 /* 1391 * Try to create one if none are free. 1392 */ 1393 if (!gotiod) { 1394 iod = nfs_nfsiodnew(); 1395 if (iod != -1) 1396 gotiod = TRUE; 1397 } 1398 1399 if (gotiod) { 1400 /* 1401 * Found one, so wake it up and tell it which 1402 * mount to process. 1403 */ 1404 NFS_DPF(ASYNCIO, ("nfs_asyncio: waking iod %d for mount %p\n", 1405 iod, nmp)); 1406 nfs_iodwant[iod] = NULL; 1407 nfs_iodmount[iod] = nmp; 1408 nmp->nm_bufqiods++; 1409 wakeup(&nfs_iodwant[iod]); 1410 } 1411 1412 /* 1413 * If none are free, we may already have an iod working on this mount 1414 * point. If so, it will process our request. 1415 */ 1416 if (!gotiod) { 1417 if (nmp->nm_bufqiods > 0) { 1418 NFS_DPF(ASYNCIO, 1419 ("nfs_asyncio: %d iods are already processing mount %p\n", 1420 nmp->nm_bufqiods, nmp)); 1421 gotiod = TRUE; 1422 } 1423 } 1424 1425 /* 1426 * If we have an iod which can process the request, then queue 1427 * the buffer. 1428 */ 1429 if (gotiod) { 1430 /* 1431 * Ensure that the queue never grows too large. We still want 1432 * to asynchronize so we block rather then return EIO. 1433 */ 1434 while (nmp->nm_bufqlen >= 2*nfs_numasync) { 1435 NFS_DPF(ASYNCIO, 1436 ("nfs_asyncio: waiting for mount %p queue to drain\n", nmp)); 1437 nmp->nm_bufqwant = TRUE; 1438 error = nfs_tsleep(td, &nmp->nm_bufq, slpflag | PRIBIO, 1439 "nfsaio", slptimeo); 1440 if (error) { 1441 error2 = nfs_sigintr(nmp, NULL, td); 1442 if (error2) 1443 return (error2); 1444 if (slpflag == PCATCH) { 1445 slpflag = 0; 1446 slptimeo = 2 * hz; 1447 } 1448 } 1449 /* 1450 * We might have lost our iod while sleeping, 1451 * so check and loop if nescessary. 1452 */ 1453 if (nmp->nm_bufqiods == 0) { 1454 NFS_DPF(ASYNCIO, 1455 ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); 1456 goto again; 1457 } 1458 } 1459 1460 if (bp->b_iocmd == BIO_READ) { 1461 if (bp->b_rcred == NOCRED && cred != NOCRED) 1462 bp->b_rcred = crhold(cred); 1463 } else { 1464 if (bp->b_wcred == NOCRED && cred != NOCRED) 1465 bp->b_wcred = crhold(cred); 1466 } 1467 1468 if (bp->b_flags & B_REMFREE) 1469 bremfreef(bp); 1470 BUF_KERNPROC(bp); 1471 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist); 1472 nmp->nm_bufqlen++; 1473 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) { 1474 VTONFS(bp->b_vp)->n_flag |= NMODIFIED; 1475 VTONFS(bp->b_vp)->n_directio_asyncwr++; 1476 } 1477 return (0); 1478 } 1479 1480 /* 1481 * All the iods are busy on other mounts, so return EIO to 1482 * force the caller to process the i/o synchronously. 1483 */ 1484 NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n")); 1485 return (EIO); 1486 } 1487 1488 void 1489 nfs_doio_directwrite(struct buf *bp) 1490 { 1491 int iomode, must_commit; 1492 struct uio *uiop = (struct uio *)bp->b_caller1; 1493 char *iov_base = uiop->uio_iov->iov_base; 1494 struct nfsmount *nmp = VFSTONFS(bp->b_vp->v_mount); 1495 1496 iomode = NFSV3WRITE_FILESYNC; 1497 uiop->uio_td = NULL; /* NULL since we're in nfsiod */ 1498 (nmp->nm_rpcops->nr_writerpc)(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit); 1499 KASSERT((must_commit == 0), ("nfs_doio_directwrite: Did not commit write")); 1500 free(iov_base, M_NFSDIRECTIO); 1501 free(uiop->uio_iov, M_NFSDIRECTIO); 1502 free(uiop, M_NFSDIRECTIO); 1503 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) { 1504 struct nfsnode *np = VTONFS(bp->b_vp); 1505 1506 np->n_directio_asyncwr--; 1507 if (np->n_directio_asyncwr == 0) { 1508 VTONFS(bp->b_vp)->n_flag &= ~NMODIFIED; 1509 if ((np->n_flag & NFSYNCWAIT)) { 1510 np->n_flag &= ~NFSYNCWAIT; 1511 wakeup((caddr_t)&np->n_directio_asyncwr); 1512 } 1513 } 1514 } 1515 bp->b_vp = NULL; 1516 relpbuf(bp, &nfs_pbuf_freecnt); 1517 } 1518 1519 /* 1520 * Do an I/O operation to/from a cache block. This may be called 1521 * synchronously or from an nfsiod. 1522 */ 1523 int 1524 nfs_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td) 1525 { 1526 struct uio *uiop; 1527 struct nfsnode *np; 1528 struct nfsmount *nmp; 1529 int error = 0, iomode, must_commit = 0; 1530 struct uio uio; 1531 struct iovec io; 1532 struct proc *p = td ? td->td_proc : NULL; 1533 1534 np = VTONFS(vp); 1535 nmp = VFSTONFS(vp->v_mount); 1536 uiop = &uio; 1537 uiop->uio_iov = &io; 1538 uiop->uio_iovcnt = 1; 1539 uiop->uio_segflg = UIO_SYSSPACE; 1540 uiop->uio_td = td; 1541 1542 /* 1543 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We 1544 * do this here so we do not have to do it in all the code that 1545 * calls us. 1546 */ 1547 bp->b_flags &= ~B_INVAL; 1548 bp->b_ioflags &= ~BIO_ERROR; 1549 1550 KASSERT(!(bp->b_flags & B_DONE), ("nfs_doio: bp %p already marked done", bp)); 1551 1552 if (bp->b_iocmd == BIO_READ) { 1553 io.iov_len = uiop->uio_resid = bp->b_bcount; 1554 io.iov_base = bp->b_data; 1555 uiop->uio_rw = UIO_READ; 1556 1557 switch (vp->v_type) { 1558 case VREG: 1559 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE; 1560 nfsstats.read_bios++; 1561 error = (nmp->nm_rpcops->nr_readrpc)(vp, uiop, cr); 1562 1563 if (!error) { 1564 if (uiop->uio_resid) { 1565 /* 1566 * If we had a short read with no error, we must have 1567 * hit a file hole. We should zero-fill the remainder. 1568 * This can also occur if the server hits the file EOF. 1569 * 1570 * Holes used to be able to occur due to pending 1571 * writes, but that is not possible any longer. 1572 */ 1573 int nread = bp->b_bcount - uiop->uio_resid; 1574 int left = uiop->uio_resid; 1575 1576 if (left > 0) 1577 bzero((char *)bp->b_data + nread, left); 1578 uiop->uio_resid = 0; 1579 } 1580 } 1581 /* ASSERT_VOP_LOCKED(vp, "nfs_doio"); */ 1582 if (p && (vp->v_vflag & VV_TEXT) && 1583 (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.va_mtime))) { 1584 PROC_LOCK(p); 1585 killproc(p, "text file modification"); 1586 PROC_UNLOCK(p); 1587 } 1588 break; 1589 case VLNK: 1590 uiop->uio_offset = (off_t)0; 1591 nfsstats.readlink_bios++; 1592 error = (nmp->nm_rpcops->nr_readlinkrpc)(vp, uiop, cr); 1593 break; 1594 case VDIR: 1595 nfsstats.readdir_bios++; 1596 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ; 1597 if ((nmp->nm_flag & NFSMNT_NFSV4) != 0) 1598 error = nfs4_readdirrpc(vp, uiop, cr); 1599 else { 1600 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) { 1601 error = nfs_readdirplusrpc(vp, uiop, cr); 1602 if (error == NFSERR_NOTSUPP) 1603 nmp->nm_flag &= ~NFSMNT_RDIRPLUS; 1604 } 1605 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) 1606 error = nfs_readdirrpc(vp, uiop, cr); 1607 } 1608 /* 1609 * end-of-directory sets B_INVAL but does not generate an 1610 * error. 1611 */ 1612 if (error == 0 && uiop->uio_resid == bp->b_bcount) 1613 bp->b_flags |= B_INVAL; 1614 break; 1615 default: 1616 printf("nfs_doio: type %x unexpected\n", vp->v_type); 1617 break; 1618 }; 1619 if (error) { 1620 bp->b_ioflags |= BIO_ERROR; 1621 bp->b_error = error; 1622 } 1623 } else { 1624 /* 1625 * If we only need to commit, try to commit 1626 */ 1627 if (bp->b_flags & B_NEEDCOMMIT) { 1628 int retv; 1629 off_t off; 1630 1631 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff; 1632 retv = (nmp->nm_rpcops->nr_commit)( 1633 vp, off, bp->b_dirtyend-bp->b_dirtyoff, 1634 bp->b_wcred, td); 1635 if (retv == 0) { 1636 bp->b_dirtyoff = bp->b_dirtyend = 0; 1637 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1638 bp->b_resid = 0; 1639 bufdone(bp); 1640 return (0); 1641 } 1642 if (retv == NFSERR_STALEWRITEVERF) { 1643 nfs_clearcommit(vp->v_mount); 1644 } 1645 } 1646 1647 /* 1648 * Setup for actual write 1649 */ 1650 1651 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size) 1652 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE; 1653 1654 if (bp->b_dirtyend > bp->b_dirtyoff) { 1655 io.iov_len = uiop->uio_resid = bp->b_dirtyend 1656 - bp->b_dirtyoff; 1657 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE 1658 + bp->b_dirtyoff; 1659 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; 1660 uiop->uio_rw = UIO_WRITE; 1661 nfsstats.write_bios++; 1662 1663 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC) 1664 iomode = NFSV3WRITE_UNSTABLE; 1665 else 1666 iomode = NFSV3WRITE_FILESYNC; 1667 1668 error = (nmp->nm_rpcops->nr_writerpc)(vp, uiop, cr, &iomode, &must_commit); 1669 1670 /* 1671 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try 1672 * to cluster the buffers needing commit. This will allow 1673 * the system to submit a single commit rpc for the whole 1674 * cluster. We can do this even if the buffer is not 100% 1675 * dirty (relative to the NFS blocksize), so we optimize the 1676 * append-to-file-case. 1677 * 1678 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be 1679 * cleared because write clustering only works for commit 1680 * rpc's, not for the data portion of the write). 1681 */ 1682 1683 if (!error && iomode == NFSV3WRITE_UNSTABLE) { 1684 bp->b_flags |= B_NEEDCOMMIT; 1685 if (bp->b_dirtyoff == 0 1686 && bp->b_dirtyend == bp->b_bcount) 1687 bp->b_flags |= B_CLUSTEROK; 1688 } else { 1689 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1690 } 1691 1692 /* 1693 * For an interrupted write, the buffer is still valid 1694 * and the write hasn't been pushed to the server yet, 1695 * so we can't set BIO_ERROR and report the interruption 1696 * by setting B_EINTR. For the B_ASYNC case, B_EINTR 1697 * is not relevant, so the rpc attempt is essentially 1698 * a noop. For the case of a V3 write rpc not being 1699 * committed to stable storage, the block is still 1700 * dirty and requires either a commit rpc or another 1701 * write rpc with iomode == NFSV3WRITE_FILESYNC before 1702 * the block is reused. This is indicated by setting 1703 * the B_DELWRI and B_NEEDCOMMIT flags. 1704 * 1705 * If the buffer is marked B_PAGING, it does not reside on 1706 * the vp's paging queues so we cannot call bdirty(). The 1707 * bp in this case is not an NFS cache block so we should 1708 * be safe. XXX 1709 * 1710 * The logic below breaks up errors into recoverable and 1711 * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE 1712 * and keep the buffer around for potential write retries. 1713 * For the latter (eg ESTALE), we toss the buffer away (B_INVAL) 1714 * and save the error in the nfsnode. This is less than ideal 1715 * but necessary. Keeping such buffers around could potentially 1716 * cause buffer exhaustion eventually (they can never be written 1717 * out, so will get constantly be re-dirtied). It also causes 1718 * all sorts of vfs panics. For non-recoverable write errors, 1719 * also invalidate the attrcache, so we'll be forced to go over 1720 * the wire for this object, returning an error to user on next 1721 * call (most of the time). 1722 */ 1723 if (error == EINTR || error == EIO || error == ETIMEDOUT 1724 || (!error && (bp->b_flags & B_NEEDCOMMIT))) { 1725 int s; 1726 1727 s = splbio(); 1728 bp->b_flags &= ~(B_INVAL|B_NOCACHE); 1729 if ((bp->b_flags & B_PAGING) == 0) { 1730 bdirty(bp); 1731 bp->b_flags &= ~B_DONE; 1732 } 1733 if (error && (bp->b_flags & B_ASYNC) == 0) 1734 bp->b_flags |= B_EINTR; 1735 splx(s); 1736 } else { 1737 if (error) { 1738 bp->b_ioflags |= BIO_ERROR; 1739 bp->b_flags |= B_INVAL; 1740 bp->b_error = np->n_error = error; 1741 np->n_flag |= NWRITEERR; 1742 np->n_attrstamp = 0; 1743 } 1744 bp->b_dirtyoff = bp->b_dirtyend = 0; 1745 } 1746 } else { 1747 bp->b_resid = 0; 1748 bufdone(bp); 1749 return (0); 1750 } 1751 } 1752 bp->b_resid = uiop->uio_resid; 1753 if (must_commit) 1754 nfs_clearcommit(vp->v_mount); 1755 bufdone(bp); 1756 return (error); 1757 } 1758 1759 /* 1760 * Used to aid in handling ftruncate() operations on the NFS client side. 1761 * Truncation creates a number of special problems for NFS. We have to 1762 * throw away VM pages and buffer cache buffers that are beyond EOF, and 1763 * we have to properly handle VM pages or (potentially dirty) buffers 1764 * that straddle the truncation point. 1765 */ 1766 1767 int 1768 nfs_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize) 1769 { 1770 struct nfsnode *np = VTONFS(vp); 1771 u_quad_t tsize = np->n_size; 1772 int biosize = vp->v_mount->mnt_stat.f_iosize; 1773 int error = 0; 1774 1775 np->n_size = nsize; 1776 1777 if (np->n_size < tsize) { 1778 struct buf *bp; 1779 daddr_t lbn; 1780 int bufsize; 1781 1782 /* 1783 * vtruncbuf() doesn't get the buffer overlapping the 1784 * truncation point. We may have a B_DELWRI and/or B_CACHE 1785 * buffer that now needs to be truncated. 1786 */ 1787 error = vtruncbuf(vp, cred, td, nsize, biosize); 1788 lbn = nsize / biosize; 1789 bufsize = nsize & (biosize - 1); 1790 bp = nfs_getcacheblk(vp, lbn, bufsize, td); 1791 if (!bp) 1792 return EINTR; 1793 if (bp->b_dirtyoff > bp->b_bcount) 1794 bp->b_dirtyoff = bp->b_bcount; 1795 if (bp->b_dirtyend > bp->b_bcount) 1796 bp->b_dirtyend = bp->b_bcount; 1797 bp->b_flags |= B_RELBUF; /* don't leave garbage around */ 1798 brelse(bp); 1799 } else { 1800 vnode_pager_setsize(vp, nsize); 1801 } 1802 return(error); 1803 } 1804
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