1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Rick Macklem at The University of Guelph. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)nfs_bio.c 8.9 (Berkeley) 3/30/95 37 * $FreeBSD: /repoman/r/ncvs/src/sys/nfsclient/nfs_bio.c,v 1.130 2004/04/14 23:23:55 peadar Exp $ 38 * $DragonFly: src/sys/vfs/nfs/nfs_bio.c,v 1.45 2008/07/18 00:09:39 dillon Exp $ 39 */ 40 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/resourcevar.h> 45 #include <sys/signalvar.h> 46 #include <sys/proc.h> 47 #include <sys/buf.h> 48 #include <sys/vnode.h> 49 #include <sys/mount.h> 50 #include <sys/kernel.h> 51 #include <sys/buf2.h> 52 #include <sys/msfbuf.h> 53 54 #include <vm/vm.h> 55 #include <vm/vm_extern.h> 56 #include <vm/vm_page.h> 57 #include <vm/vm_object.h> 58 #include <vm/vm_pager.h> 59 #include <vm/vnode_pager.h> 60 61 #include <sys/thread2.h> 62 63 #include "rpcv2.h" 64 #include "nfsproto.h" 65 #include "nfs.h" 66 #include "nfsmount.h" 67 #include "nfsnode.h" 68 69 static struct buf *nfs_getcacheblk(struct vnode *vp, off_t loffset, 70 int size, struct thread *td); 71 static int nfs_check_dirent(struct nfs_dirent *dp, int maxlen); 72 73 extern int nfs_numasync; 74 extern int nfs_pbuf_freecnt; 75 extern struct nfsstats nfsstats; 76 77 /* 78 * Vnode op for VM getpages. 79 * 80 * nfs_getpages(struct vnode *a_vp, vm_page_t *a_m, int a_count, 81 * int a_reqpage, vm_ooffset_t a_offset) 82 */ 83 int 84 nfs_getpages(struct vop_getpages_args *ap) 85 { 86 struct thread *td = curthread; /* XXX */ 87 int i, error, nextoff, size, toff, count, npages; 88 struct uio uio; 89 struct iovec iov; 90 char *kva; 91 struct vnode *vp; 92 struct nfsmount *nmp; 93 vm_page_t *pages; 94 vm_page_t m; 95 struct msf_buf *msf; 96 97 vp = ap->a_vp; 98 nmp = VFSTONFS(vp->v_mount); 99 pages = ap->a_m; 100 count = ap->a_count; 101 102 if (vp->v_object == NULL) { 103 kprintf("nfs_getpages: called with non-merged cache vnode??\n"); 104 return VM_PAGER_ERROR; 105 } 106 107 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 108 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 109 (void)nfs_fsinfo(nmp, vp, td); 110 111 npages = btoc(count); 112 113 /* 114 * NOTE that partially valid pages may occur in cases other 115 * then file EOF, such as when a file is partially written and 116 * ftruncate()-extended to a larger size. It is also possible 117 * for the valid bits to be set on garbage beyond the file EOF and 118 * clear in the area before EOF (e.g. m->valid == 0xfc), which can 119 * occur due to vtruncbuf() and the buffer cache's handling of 120 * pages which 'straddle' buffers or when b_bufsize is not a 121 * multiple of PAGE_SIZE.... the buffer cache cannot normally 122 * clear the extra bits. This kind of situation occurs when you 123 * make a small write() (m->valid == 0x03) and then mmap() and 124 * fault in the buffer(m->valid = 0xFF). When NFS flushes the 125 * buffer (vinvalbuf() m->valid = 0xFC) we are left with a mess. 126 * 127 * This is combined with the possibility that the pages are partially 128 * dirty or that there is a buffer backing the pages that is dirty 129 * (even if m->dirty is 0). 130 * 131 * To solve this problem several hacks have been made: (1) NFS 132 * guarentees that the IO block size is a multiple of PAGE_SIZE and 133 * (2) The buffer cache, when invalidating an NFS buffer, will 134 * disregard the buffer's fragmentory b_bufsize and invalidate 135 * the whole page rather then just the piece the buffer owns. 136 * 137 * This allows us to assume that a partially valid page found here 138 * is fully valid (vm_fault will zero'd out areas of the page not 139 * marked as valid). 140 */ 141 m = pages[ap->a_reqpage]; 142 if (m->valid != 0) { 143 for (i = 0; i < npages; ++i) { 144 if (i != ap->a_reqpage) 145 vnode_pager_freepage(pages[i]); 146 } 147 return(0); 148 } 149 150 /* 151 * Use an MSF_BUF as a medium to retrieve data from the pages. 152 */ 153 msf_map_pagelist(&msf, pages, npages, 0); 154 KKASSERT(msf); 155 kva = msf_buf_kva(msf); 156 157 iov.iov_base = kva; 158 iov.iov_len = count; 159 uio.uio_iov = &iov; 160 uio.uio_iovcnt = 1; 161 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex); 162 uio.uio_resid = count; 163 uio.uio_segflg = UIO_SYSSPACE; 164 uio.uio_rw = UIO_READ; 165 uio.uio_td = td; 166 167 error = nfs_readrpc(vp, &uio); 168 msf_buf_free(msf); 169 170 if (error && (uio.uio_resid == count)) { 171 kprintf("nfs_getpages: error %d\n", error); 172 for (i = 0; i < npages; ++i) { 173 if (i != ap->a_reqpage) 174 vnode_pager_freepage(pages[i]); 175 } 176 return VM_PAGER_ERROR; 177 } 178 179 /* 180 * Calculate the number of bytes read and validate only that number 181 * of bytes. Note that due to pending writes, size may be 0. This 182 * does not mean that the remaining data is invalid! 183 */ 184 185 size = count - uio.uio_resid; 186 187 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) { 188 nextoff = toff + PAGE_SIZE; 189 m = pages[i]; 190 191 m->flags &= ~PG_ZERO; 192 193 if (nextoff <= size) { 194 /* 195 * Read operation filled an entire page 196 */ 197 m->valid = VM_PAGE_BITS_ALL; 198 vm_page_undirty(m); 199 } else if (size > toff) { 200 /* 201 * Read operation filled a partial page. 202 */ 203 m->valid = 0; 204 vm_page_set_validclean(m, 0, size - toff); 205 /* handled by vm_fault now */ 206 /* vm_page_zero_invalid(m, TRUE); */ 207 } else { 208 /* 209 * Read operation was short. If no error occured 210 * we may have hit a zero-fill section. We simply 211 * leave valid set to 0. 212 */ 213 ; 214 } 215 if (i != ap->a_reqpage) { 216 /* 217 * Whether or not to leave the page activated is up in 218 * the air, but we should put the page on a page queue 219 * somewhere (it already is in the object). Result: 220 * It appears that emperical results show that 221 * deactivating pages is best. 222 */ 223 224 /* 225 * Just in case someone was asking for this page we 226 * now tell them that it is ok to use. 227 */ 228 if (!error) { 229 if (m->flags & PG_WANTED) 230 vm_page_activate(m); 231 else 232 vm_page_deactivate(m); 233 vm_page_wakeup(m); 234 } else { 235 vnode_pager_freepage(m); 236 } 237 } 238 } 239 return 0; 240 } 241 242 /* 243 * Vnode op for VM putpages. 244 * 245 * nfs_putpages(struct vnode *a_vp, vm_page_t *a_m, int a_count, int a_sync, 246 * int *a_rtvals, vm_ooffset_t a_offset) 247 */ 248 int 249 nfs_putpages(struct vop_putpages_args *ap) 250 { 251 struct thread *td = curthread; 252 struct uio uio; 253 struct iovec iov; 254 char *kva; 255 int iomode, must_commit, i, error, npages, count; 256 off_t offset; 257 int *rtvals; 258 struct vnode *vp; 259 struct nfsmount *nmp; 260 struct nfsnode *np; 261 vm_page_t *pages; 262 struct msf_buf *msf; 263 264 vp = ap->a_vp; 265 np = VTONFS(vp); 266 nmp = VFSTONFS(vp->v_mount); 267 pages = ap->a_m; 268 count = ap->a_count; 269 rtvals = ap->a_rtvals; 270 npages = btoc(count); 271 offset = IDX_TO_OFF(pages[0]->pindex); 272 273 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 274 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 275 (void)nfs_fsinfo(nmp, vp, td); 276 277 for (i = 0; i < npages; i++) { 278 rtvals[i] = VM_PAGER_AGAIN; 279 } 280 281 /* 282 * When putting pages, do not extend file past EOF. 283 */ 284 285 if (offset + count > np->n_size) { 286 count = np->n_size - offset; 287 if (count < 0) 288 count = 0; 289 } 290 291 /* 292 * Use an MSF_BUF as a medium to retrieve data from the pages. 293 */ 294 msf_map_pagelist(&msf, pages, npages, 0); 295 KKASSERT(msf); 296 kva = msf_buf_kva(msf); 297 298 iov.iov_base = kva; 299 iov.iov_len = count; 300 uio.uio_iov = &iov; 301 uio.uio_iovcnt = 1; 302 uio.uio_offset = offset; 303 uio.uio_resid = count; 304 uio.uio_segflg = UIO_SYSSPACE; 305 uio.uio_rw = UIO_WRITE; 306 uio.uio_td = td; 307 308 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0) 309 iomode = NFSV3WRITE_UNSTABLE; 310 else 311 iomode = NFSV3WRITE_FILESYNC; 312 313 error = nfs_writerpc(vp, &uio, &iomode, &must_commit); 314 315 msf_buf_free(msf); 316 317 if (!error) { 318 int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE; 319 for (i = 0; i < nwritten; i++) { 320 rtvals[i] = VM_PAGER_OK; 321 vm_page_undirty(pages[i]); 322 } 323 if (must_commit) 324 nfs_clearcommit(vp->v_mount); 325 } 326 return rtvals[0]; 327 } 328 329 /* 330 * Vnode op for read using bio 331 */ 332 int 333 nfs_bioread(struct vnode *vp, struct uio *uio, int ioflag) 334 { 335 struct nfsnode *np = VTONFS(vp); 336 int biosize, i; 337 struct buf *bp = 0, *rabp; 338 struct vattr vattr; 339 struct thread *td; 340 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 341 daddr_t lbn, rabn; 342 off_t raoffset; 343 off_t loffset; 344 int bcount; 345 int seqcount; 346 int nra, error = 0, n = 0, on = 0; 347 348 #ifdef DIAGNOSTIC 349 if (uio->uio_rw != UIO_READ) 350 panic("nfs_read mode"); 351 #endif 352 if (uio->uio_resid == 0) 353 return (0); 354 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */ 355 return (EINVAL); 356 td = uio->uio_td; 357 358 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 359 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 360 (void)nfs_fsinfo(nmp, vp, td); 361 if (vp->v_type != VDIR && 362 (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 363 return (EFBIG); 364 biosize = vp->v_mount->mnt_stat.f_iosize; 365 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE); 366 367 /* 368 * For nfs, cache consistency can only be maintained approximately. 369 * Although RFC1094 does not specify the criteria, the following is 370 * believed to be compatible with the reference port. 371 * 372 * NFS: If local changes have been made and this is a 373 * directory, the directory must be invalidated and 374 * the attribute cache must be cleared. 375 * 376 * GETATTR is called to synchronize the file size. 377 * 378 * If remote changes are detected local data is flushed 379 * and the cache is invalidated. 380 * 381 * NOTE: In the normal case the attribute cache is not 382 * cleared which means GETATTR may use cached data and 383 * not immediately detect changes made on the server. 384 */ 385 if ((np->n_flag & NLMODIFIED) && vp->v_type == VDIR) { 386 nfs_invaldir(vp); 387 error = nfs_vinvalbuf(vp, V_SAVE, 1); 388 if (error) 389 return (error); 390 np->n_attrstamp = 0; 391 } 392 error = VOP_GETATTR(vp, &vattr); 393 if (error) 394 return (error); 395 if (np->n_flag & NRMODIFIED) { 396 if (vp->v_type == VDIR) 397 nfs_invaldir(vp); 398 error = nfs_vinvalbuf(vp, V_SAVE, 1); 399 if (error) 400 return (error); 401 np->n_flag &= ~NRMODIFIED; 402 } 403 do { 404 if (np->n_flag & NDONTCACHE) { 405 switch (vp->v_type) { 406 case VREG: 407 return (nfs_readrpc(vp, uio)); 408 case VLNK: 409 return (nfs_readlinkrpc(vp, uio)); 410 case VDIR: 411 break; 412 default: 413 kprintf(" NDONTCACHE: type %x unexpected\n", vp->v_type); 414 break; 415 }; 416 } 417 switch (vp->v_type) { 418 case VREG: 419 nfsstats.biocache_reads++; 420 lbn = uio->uio_offset / biosize; 421 on = uio->uio_offset & (biosize - 1); 422 loffset = (off_t)lbn * biosize; 423 424 /* 425 * Start the read ahead(s), as required. 426 */ 427 if (nfs_numasync > 0 && nmp->nm_readahead > 0) { 428 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && 429 (off_t)(lbn + 1 + nra) * biosize < np->n_size; nra++) { 430 rabn = lbn + 1 + nra; 431 raoffset = (off_t)rabn * biosize; 432 if (findblk(vp, raoffset, FINDBLK_TEST) == NULL) { 433 rabp = nfs_getcacheblk(vp, raoffset, biosize, td); 434 if (!rabp) 435 return (EINTR); 436 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 437 rabp->b_flags |= B_ASYNC; 438 rabp->b_cmd = BUF_CMD_READ; 439 vfs_busy_pages(vp, rabp); 440 if (nfs_asyncio(vp, &rabp->b_bio2, td)) { 441 rabp->b_flags |= B_INVAL|B_ERROR; 442 vfs_unbusy_pages(rabp); 443 brelse(rabp); 444 break; 445 } 446 } else { 447 brelse(rabp); 448 } 449 } 450 } 451 } 452 453 /* 454 * Obtain the buffer cache block. Figure out the buffer size 455 * when we are at EOF. If we are modifying the size of the 456 * buffer based on an EOF condition we need to hold 457 * nfs_rslock() through obtaining the buffer to prevent 458 * a potential writer-appender from messing with n_size. 459 * Otherwise we may accidently truncate the buffer and 460 * lose dirty data. 461 * 462 * Note that bcount is *not* DEV_BSIZE aligned. 463 */ 464 465 again: 466 bcount = biosize; 467 if (loffset >= np->n_size) { 468 bcount = 0; 469 } else if (loffset + biosize > np->n_size) { 470 bcount = np->n_size - loffset; 471 } 472 if (bcount != biosize) { 473 switch(nfs_rslock(np)) { 474 case ENOLCK: 475 goto again; 476 /* not reached */ 477 case EINTR: 478 case ERESTART: 479 return(EINTR); 480 /* not reached */ 481 default: 482 break; 483 } 484 } 485 486 bp = nfs_getcacheblk(vp, loffset, bcount, td); 487 488 if (bcount != biosize) 489 nfs_rsunlock(np); 490 if (!bp) 491 return (EINTR); 492 493 /* 494 * If B_CACHE is not set, we must issue the read. If this 495 * fails, we return an error. 496 */ 497 498 if ((bp->b_flags & B_CACHE) == 0) { 499 bp->b_cmd = BUF_CMD_READ; 500 vfs_busy_pages(vp, bp); 501 error = nfs_doio(vp, &bp->b_bio2, td); 502 if (error) { 503 brelse(bp); 504 return (error); 505 } 506 } 507 508 /* 509 * on is the offset into the current bp. Figure out how many 510 * bytes we can copy out of the bp. Note that bcount is 511 * NOT DEV_BSIZE aligned. 512 * 513 * Then figure out how many bytes we can copy into the uio. 514 */ 515 516 n = 0; 517 if (on < bcount) 518 n = min((unsigned)(bcount - on), uio->uio_resid); 519 break; 520 case VLNK: 521 biosize = min(NFS_MAXPATHLEN, np->n_size); 522 nfsstats.biocache_readlinks++; 523 bp = nfs_getcacheblk(vp, (off_t)0, biosize, td); 524 if (bp == NULL) 525 return (EINTR); 526 if ((bp->b_flags & B_CACHE) == 0) { 527 bp->b_cmd = BUF_CMD_READ; 528 vfs_busy_pages(vp, bp); 529 error = nfs_doio(vp, &bp->b_bio2, td); 530 if (error) { 531 bp->b_flags |= B_ERROR | B_INVAL; 532 brelse(bp); 533 return (error); 534 } 535 } 536 n = min(uio->uio_resid, bp->b_bcount - bp->b_resid); 537 on = 0; 538 break; 539 case VDIR: 540 nfsstats.biocache_readdirs++; 541 if (np->n_direofoffset 542 && uio->uio_offset >= np->n_direofoffset) { 543 return (0); 544 } 545 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; 546 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); 547 loffset = uio->uio_offset - on; 548 bp = nfs_getcacheblk(vp, loffset, NFS_DIRBLKSIZ, td); 549 if (bp == NULL) 550 return (EINTR); 551 552 if ((bp->b_flags & B_CACHE) == 0) { 553 bp->b_cmd = BUF_CMD_READ; 554 vfs_busy_pages(vp, bp); 555 error = nfs_doio(vp, &bp->b_bio2, td); 556 if (error) { 557 brelse(bp); 558 } 559 while (error == NFSERR_BAD_COOKIE) { 560 kprintf("got bad cookie vp %p bp %p\n", vp, bp); 561 nfs_invaldir(vp); 562 error = nfs_vinvalbuf(vp, 0, 1); 563 /* 564 * Yuck! The directory has been modified on the 565 * server. The only way to get the block is by 566 * reading from the beginning to get all the 567 * offset cookies. 568 * 569 * Leave the last bp intact unless there is an error. 570 * Loop back up to the while if the error is another 571 * NFSERR_BAD_COOKIE (double yuch!). 572 */ 573 for (i = 0; i <= lbn && !error; i++) { 574 if (np->n_direofoffset 575 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) 576 return (0); 577 bp = nfs_getcacheblk(vp, (off_t)i * NFS_DIRBLKSIZ, 578 NFS_DIRBLKSIZ, td); 579 if (!bp) 580 return (EINTR); 581 if ((bp->b_flags & B_CACHE) == 0) { 582 bp->b_cmd = BUF_CMD_READ; 583 vfs_busy_pages(vp, bp); 584 error = nfs_doio(vp, &bp->b_bio2, td); 585 /* 586 * no error + B_INVAL == directory EOF, 587 * use the block. 588 */ 589 if (error == 0 && (bp->b_flags & B_INVAL)) 590 break; 591 } 592 /* 593 * An error will throw away the block and the 594 * for loop will break out. If no error and this 595 * is not the block we want, we throw away the 596 * block and go for the next one via the for loop. 597 */ 598 if (error || i < lbn) 599 brelse(bp); 600 } 601 } 602 /* 603 * The above while is repeated if we hit another cookie 604 * error. If we hit an error and it wasn't a cookie error, 605 * we give up. 606 */ 607 if (error) 608 return (error); 609 } 610 611 /* 612 * If not eof and read aheads are enabled, start one. 613 * (You need the current block first, so that you have the 614 * directory offset cookie of the next block.) 615 */ 616 if (nfs_numasync > 0 && nmp->nm_readahead > 0 && 617 (bp->b_flags & B_INVAL) == 0 && 618 (np->n_direofoffset == 0 || 619 loffset + NFS_DIRBLKSIZ < np->n_direofoffset) && 620 (np->n_flag & NDONTCACHE) == 0 && 621 findblk(vp, loffset + NFS_DIRBLKSIZ, FINDBLK_TEST) == NULL 622 ) { 623 rabp = nfs_getcacheblk(vp, loffset + NFS_DIRBLKSIZ, 624 NFS_DIRBLKSIZ, td); 625 if (rabp) { 626 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 627 rabp->b_flags |= B_ASYNC; 628 rabp->b_cmd = BUF_CMD_READ; 629 vfs_busy_pages(vp, rabp); 630 if (nfs_asyncio(vp, &rabp->b_bio2, td)) { 631 rabp->b_flags |= B_INVAL|B_ERROR; 632 vfs_unbusy_pages(rabp); 633 brelse(rabp); 634 } 635 } else { 636 brelse(rabp); 637 } 638 } 639 } 640 /* 641 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is 642 * chopped for the EOF condition, we cannot tell how large 643 * NFS directories are going to be until we hit EOF. So 644 * an NFS directory buffer is *not* chopped to its EOF. Now, 645 * it just so happens that b_resid will effectively chop it 646 * to EOF. *BUT* this information is lost if the buffer goes 647 * away and is reconstituted into a B_CACHE state ( due to 648 * being VMIO ) later. So we keep track of the directory eof 649 * in np->n_direofoffset and chop it off as an extra step 650 * right here. 651 */ 652 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on); 653 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset) 654 n = np->n_direofoffset - uio->uio_offset; 655 break; 656 default: 657 kprintf(" nfs_bioread: type %x unexpected\n",vp->v_type); 658 break; 659 }; 660 661 switch (vp->v_type) { 662 case VREG: 663 if (n > 0) 664 error = uiomove(bp->b_data + on, (int)n, uio); 665 break; 666 case VLNK: 667 if (n > 0) 668 error = uiomove(bp->b_data + on, (int)n, uio); 669 n = 0; 670 break; 671 case VDIR: 672 if (n > 0) { 673 off_t old_off = uio->uio_offset; 674 caddr_t cpos, epos; 675 struct nfs_dirent *dp; 676 677 /* 678 * We are casting cpos to nfs_dirent, it must be 679 * int-aligned. 680 */ 681 if (on & 3) { 682 error = EINVAL; 683 break; 684 } 685 686 cpos = bp->b_data + on; 687 epos = bp->b_data + on + n; 688 while (cpos < epos && error == 0 && uio->uio_resid > 0) { 689 dp = (struct nfs_dirent *)cpos; 690 error = nfs_check_dirent(dp, (int)(epos - cpos)); 691 if (error) 692 break; 693 if (vop_write_dirent(&error, uio, dp->nfs_ino, 694 dp->nfs_type, dp->nfs_namlen, dp->nfs_name)) { 695 break; 696 } 697 cpos += dp->nfs_reclen; 698 } 699 n = 0; 700 if (error == 0) 701 uio->uio_offset = old_off + cpos - bp->b_data - on; 702 } 703 /* 704 * Invalidate buffer if caching is disabled, forcing a 705 * re-read from the remote later. 706 */ 707 if (np->n_flag & NDONTCACHE) 708 bp->b_flags |= B_INVAL; 709 break; 710 default: 711 kprintf(" nfs_bioread: type %x unexpected\n",vp->v_type); 712 } 713 brelse(bp); 714 } while (error == 0 && uio->uio_resid > 0 && n > 0); 715 return (error); 716 } 717 718 /* 719 * Userland can supply any 'seek' offset when reading a NFS directory. 720 * Validate the structure so we don't panic the kernel. Note that 721 * the element name is nul terminated and the nul is not included 722 * in nfs_namlen. 723 */ 724 static 725 int 726 nfs_check_dirent(struct nfs_dirent *dp, int maxlen) 727 { 728 int nfs_name_off = offsetof(struct nfs_dirent, nfs_name[0]); 729 730 if (nfs_name_off >= maxlen) 731 return (EINVAL); 732 if (dp->nfs_reclen < nfs_name_off || dp->nfs_reclen > maxlen) 733 return (EINVAL); 734 if (nfs_name_off + dp->nfs_namlen >= dp->nfs_reclen) 735 return (EINVAL); 736 if (dp->nfs_reclen & 3) 737 return (EINVAL); 738 return (0); 739 } 740 741 /* 742 * Vnode op for write using bio 743 * 744 * nfs_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, 745 * struct ucred *a_cred) 746 */ 747 int 748 nfs_write(struct vop_write_args *ap) 749 { 750 struct uio *uio = ap->a_uio; 751 struct thread *td = uio->uio_td; 752 struct vnode *vp = ap->a_vp; 753 struct nfsnode *np = VTONFS(vp); 754 int ioflag = ap->a_ioflag; 755 struct buf *bp; 756 struct vattr vattr; 757 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 758 daddr_t lbn; 759 off_t loffset; 760 int n, on, error = 0, iomode, must_commit; 761 int haverslock = 0; 762 int bcount; 763 int biosize; 764 765 #ifdef DIAGNOSTIC 766 if (uio->uio_rw != UIO_WRITE) 767 panic("nfs_write mode"); 768 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_td != curthread) 769 panic("nfs_write proc"); 770 #endif 771 if (vp->v_type != VREG) 772 return (EIO); 773 if (np->n_flag & NWRITEERR) { 774 np->n_flag &= ~NWRITEERR; 775 return (np->n_error); 776 } 777 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 778 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 779 (void)nfs_fsinfo(nmp, vp, td); 780 781 /* 782 * Synchronously flush pending buffers if we are in synchronous 783 * mode or if we are appending. 784 */ 785 if (ioflag & (IO_APPEND | IO_SYNC)) { 786 if (np->n_flag & NLMODIFIED) { 787 np->n_attrstamp = 0; 788 error = nfs_flush(vp, MNT_WAIT, td, 0); 789 /* error = nfs_vinvalbuf(vp, V_SAVE, 1); */ 790 if (error) 791 return (error); 792 } 793 } 794 795 /* 796 * If IO_APPEND then load uio_offset. We restart here if we cannot 797 * get the append lock. 798 */ 799 restart: 800 if (ioflag & IO_APPEND) { 801 np->n_attrstamp = 0; 802 error = VOP_GETATTR(vp, &vattr); 803 if (error) 804 return (error); 805 uio->uio_offset = np->n_size; 806 } 807 808 if (uio->uio_offset < 0) 809 return (EINVAL); 810 if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 811 return (EFBIG); 812 if (uio->uio_resid == 0) 813 return (0); 814 815 /* 816 * We need to obtain the rslock if we intend to modify np->n_size 817 * in order to guarentee the append point with multiple contending 818 * writers, to guarentee that no other appenders modify n_size 819 * while we are trying to obtain a truncated buffer (i.e. to avoid 820 * accidently truncating data written by another appender due to 821 * the race), and to ensure that the buffer is populated prior to 822 * our extending of the file. We hold rslock through the entire 823 * operation. 824 * 825 * Note that we do not synchronize the case where someone truncates 826 * the file while we are appending to it because attempting to lock 827 * this case may deadlock other parts of the system unexpectedly. 828 */ 829 if ((ioflag & IO_APPEND) || 830 uio->uio_offset + uio->uio_resid > np->n_size) { 831 switch(nfs_rslock(np)) { 832 case ENOLCK: 833 goto restart; 834 /* not reached */ 835 case EINTR: 836 case ERESTART: 837 return(EINTR); 838 /* not reached */ 839 default: 840 break; 841 } 842 haverslock = 1; 843 } 844 845 /* 846 * Maybe this should be above the vnode op call, but so long as 847 * file servers have no limits, i don't think it matters 848 */ 849 if (td->td_proc && uio->uio_offset + uio->uio_resid > 850 td->td_proc->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 851 lwpsignal(td->td_proc, td->td_lwp, SIGXFSZ); 852 if (haverslock) 853 nfs_rsunlock(np); 854 return (EFBIG); 855 } 856 857 biosize = vp->v_mount->mnt_stat.f_iosize; 858 859 do { 860 if ((np->n_flag & NDONTCACHE) && uio->uio_iovcnt == 1) { 861 iomode = NFSV3WRITE_FILESYNC; 862 error = nfs_writerpc(vp, uio, &iomode, &must_commit); 863 if (must_commit) 864 nfs_clearcommit(vp->v_mount); 865 break; 866 } 867 nfsstats.biocache_writes++; 868 lbn = uio->uio_offset / biosize; 869 on = uio->uio_offset & (biosize-1); 870 loffset = uio->uio_offset - on; 871 n = min((unsigned)(biosize - on), uio->uio_resid); 872 again: 873 /* 874 * Handle direct append and file extension cases, calculate 875 * unaligned buffer size. 876 */ 877 878 if (uio->uio_offset == np->n_size && n) { 879 /* 880 * Get the buffer (in its pre-append state to maintain 881 * B_CACHE if it was previously set). Resize the 882 * nfsnode after we have locked the buffer to prevent 883 * readers from reading garbage. 884 */ 885 bcount = on; 886 bp = nfs_getcacheblk(vp, loffset, bcount, td); 887 888 if (bp != NULL) { 889 long save; 890 891 np->n_size = uio->uio_offset + n; 892 np->n_flag |= NLMODIFIED; 893 vnode_pager_setsize(vp, np->n_size); 894 895 save = bp->b_flags & B_CACHE; 896 bcount += n; 897 allocbuf(bp, bcount); 898 bp->b_flags |= save; 899 } 900 } else { 901 /* 902 * Obtain the locked cache block first, and then 903 * adjust the file's size as appropriate. 904 */ 905 bcount = on + n; 906 if (loffset + bcount < np->n_size) { 907 if (loffset + biosize < np->n_size) 908 bcount = biosize; 909 else 910 bcount = np->n_size - loffset; 911 } 912 bp = nfs_getcacheblk(vp, loffset, bcount, td); 913 if (uio->uio_offset + n > np->n_size) { 914 np->n_size = uio->uio_offset + n; 915 np->n_flag |= NLMODIFIED; 916 vnode_pager_setsize(vp, np->n_size); 917 } 918 } 919 920 if (bp == NULL) { 921 error = EINTR; 922 break; 923 } 924 925 /* 926 * Issue a READ if B_CACHE is not set. In special-append 927 * mode, B_CACHE is based on the buffer prior to the write 928 * op and is typically set, avoiding the read. If a read 929 * is required in special append mode, the server will 930 * probably send us a short-read since we extended the file 931 * on our end, resulting in b_resid == 0 and, thusly, 932 * B_CACHE getting set. 933 * 934 * We can also avoid issuing the read if the write covers 935 * the entire buffer. We have to make sure the buffer state 936 * is reasonable in this case since we will not be initiating 937 * I/O. See the comments in kern/vfs_bio.c's getblk() for 938 * more information. 939 * 940 * B_CACHE may also be set due to the buffer being cached 941 * normally. 942 * 943 * When doing a UIO_NOCOPY write the buffer is not 944 * overwritten and we cannot just set B_CACHE unconditionally 945 * for full-block writes. 946 */ 947 948 if (on == 0 && n == bcount && uio->uio_segflg != UIO_NOCOPY) { 949 bp->b_flags |= B_CACHE; 950 bp->b_flags &= ~(B_ERROR | B_INVAL); 951 } 952 953 if ((bp->b_flags & B_CACHE) == 0) { 954 bp->b_cmd = BUF_CMD_READ; 955 vfs_busy_pages(vp, bp); 956 error = nfs_doio(vp, &bp->b_bio2, td); 957 if (error) { 958 brelse(bp); 959 break; 960 } 961 } 962 if (!bp) { 963 error = EINTR; 964 break; 965 } 966 np->n_flag |= NLMODIFIED; 967 968 /* 969 * If dirtyend exceeds file size, chop it down. This should 970 * not normally occur but there is an append race where it 971 * might occur XXX, so we log it. 972 * 973 * If the chopping creates a reverse-indexed or degenerate 974 * situation with dirtyoff/end, we 0 both of them. 975 */ 976 977 if (bp->b_dirtyend > bcount) { 978 kprintf("NFS append race @%08llx:%d\n", 979 (long long)bp->b_bio2.bio_offset, 980 bp->b_dirtyend - bcount); 981 bp->b_dirtyend = bcount; 982 } 983 984 if (bp->b_dirtyoff >= bp->b_dirtyend) 985 bp->b_dirtyoff = bp->b_dirtyend = 0; 986 987 /* 988 * If the new write will leave a contiguous dirty 989 * area, just update the b_dirtyoff and b_dirtyend, 990 * otherwise force a write rpc of the old dirty area. 991 * 992 * While it is possible to merge discontiguous writes due to 993 * our having a B_CACHE buffer ( and thus valid read data 994 * for the hole), we don't because it could lead to 995 * significant cache coherency problems with multiple clients, 996 * especially if locking is implemented later on. 997 * 998 * as an optimization we could theoretically maintain 999 * a linked list of discontinuous areas, but we would still 1000 * have to commit them separately so there isn't much 1001 * advantage to it except perhaps a bit of asynchronization. 1002 */ 1003 1004 if (bp->b_dirtyend > 0 && 1005 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { 1006 if (bwrite(bp) == EINTR) { 1007 error = EINTR; 1008 break; 1009 } 1010 goto again; 1011 } 1012 1013 error = uiomove((char *)bp->b_data + on, n, uio); 1014 1015 /* 1016 * Since this block is being modified, it must be written 1017 * again and not just committed. Since write clustering does 1018 * not work for the stage 1 data write, only the stage 2 1019 * commit rpc, we have to clear B_CLUSTEROK as well. 1020 */ 1021 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1022 1023 if (error) { 1024 bp->b_flags |= B_ERROR; 1025 brelse(bp); 1026 break; 1027 } 1028 1029 /* 1030 * Only update dirtyoff/dirtyend if not a degenerate 1031 * condition. 1032 */ 1033 if (n) { 1034 if (bp->b_dirtyend > 0) { 1035 bp->b_dirtyoff = min(on, bp->b_dirtyoff); 1036 bp->b_dirtyend = max((on + n), bp->b_dirtyend); 1037 } else { 1038 bp->b_dirtyoff = on; 1039 bp->b_dirtyend = on + n; 1040 } 1041 vfs_bio_set_validclean(bp, on, n); 1042 } 1043 1044 /* 1045 * If the lease is non-cachable or IO_SYNC do bwrite(). 1046 * 1047 * IO_INVAL appears to be unused. The idea appears to be 1048 * to turn off caching in this case. Very odd. XXX 1049 * 1050 * If nfs_async is set bawrite() will use an unstable write 1051 * (build dirty bufs on the server), so we might as well 1052 * push it out with bawrite(). If nfs_async is not set we 1053 * use bdwrite() to cache dirty bufs on the client. 1054 */ 1055 if ((np->n_flag & NDONTCACHE) || (ioflag & IO_SYNC)) { 1056 if (ioflag & IO_INVAL) 1057 bp->b_flags |= B_NOCACHE; 1058 error = bwrite(bp); 1059 if (error) 1060 break; 1061 if (np->n_flag & NDONTCACHE) { 1062 error = nfs_vinvalbuf(vp, V_SAVE, 1); 1063 if (error) 1064 break; 1065 } 1066 } else if ((n + on) == biosize && nfs_async) { 1067 bawrite(bp); 1068 } else { 1069 bdwrite(bp); 1070 } 1071 } while (uio->uio_resid > 0 && n > 0); 1072 1073 if (haverslock) 1074 nfs_rsunlock(np); 1075 1076 return (error); 1077 } 1078 1079 /* 1080 * Get an nfs cache block. 1081 * 1082 * Allocate a new one if the block isn't currently in the cache 1083 * and return the block marked busy. If the calling process is 1084 * interrupted by a signal for an interruptible mount point, return 1085 * NULL. 1086 * 1087 * The caller must carefully deal with the possible B_INVAL state of 1088 * the buffer. nfs_doio() clears B_INVAL (and nfs_asyncio() clears it 1089 * indirectly), so synchronous reads can be issued without worrying about 1090 * the B_INVAL state. We have to be a little more careful when dealing 1091 * with writes (see comments in nfs_write()) when extending a file past 1092 * its EOF. 1093 */ 1094 static struct buf * 1095 nfs_getcacheblk(struct vnode *vp, off_t loffset, int size, struct thread *td) 1096 { 1097 struct buf *bp; 1098 struct mount *mp; 1099 struct nfsmount *nmp; 1100 1101 mp = vp->v_mount; 1102 nmp = VFSTONFS(mp); 1103 1104 if (nmp->nm_flag & NFSMNT_INT) { 1105 bp = getblk(vp, loffset, size, GETBLK_PCATCH, 0); 1106 while (bp == NULL) { 1107 if (nfs_sigintr(nmp, NULL, td)) 1108 return (NULL); 1109 bp = getblk(vp, loffset, size, 0, 2 * hz); 1110 } 1111 } else { 1112 bp = getblk(vp, loffset, size, 0, 0); 1113 } 1114 1115 /* 1116 * bio2, the 'device' layer. Since BIOs use 64 bit byte offsets 1117 * now, no translation is necessary. 1118 */ 1119 bp->b_bio2.bio_offset = loffset; 1120 return (bp); 1121 } 1122 1123 /* 1124 * Flush and invalidate all dirty buffers. If another process is already 1125 * doing the flush, just wait for completion. 1126 */ 1127 int 1128 nfs_vinvalbuf(struct vnode *vp, int flags, int intrflg) 1129 { 1130 struct nfsnode *np = VTONFS(vp); 1131 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 1132 int error = 0, slpflag, slptimeo; 1133 thread_t td = curthread; 1134 1135 if (vp->v_flag & VRECLAIMED) 1136 return (0); 1137 1138 if ((nmp->nm_flag & NFSMNT_INT) == 0) 1139 intrflg = 0; 1140 if (intrflg) { 1141 slpflag = PCATCH; 1142 slptimeo = 2 * hz; 1143 } else { 1144 slpflag = 0; 1145 slptimeo = 0; 1146 } 1147 /* 1148 * First wait for any other process doing a flush to complete. 1149 */ 1150 while (np->n_flag & NFLUSHINPROG) { 1151 np->n_flag |= NFLUSHWANT; 1152 error = tsleep((caddr_t)&np->n_flag, 0, "nfsvinval", slptimeo); 1153 if (error && intrflg && nfs_sigintr(nmp, NULL, td)) 1154 return (EINTR); 1155 } 1156 1157 /* 1158 * Now, flush as required. 1159 */ 1160 np->n_flag |= NFLUSHINPROG; 1161 error = vinvalbuf(vp, flags, slpflag, 0); 1162 while (error) { 1163 if (intrflg && nfs_sigintr(nmp, NULL, td)) { 1164 np->n_flag &= ~NFLUSHINPROG; 1165 if (np->n_flag & NFLUSHWANT) { 1166 np->n_flag &= ~NFLUSHWANT; 1167 wakeup((caddr_t)&np->n_flag); 1168 } 1169 return (EINTR); 1170 } 1171 error = vinvalbuf(vp, flags, 0, slptimeo); 1172 } 1173 np->n_flag &= ~(NLMODIFIED | NFLUSHINPROG); 1174 if (np->n_flag & NFLUSHWANT) { 1175 np->n_flag &= ~NFLUSHWANT; 1176 wakeup((caddr_t)&np->n_flag); 1177 } 1178 return (0); 1179 } 1180 1181 /* 1182 * Initiate asynchronous I/O. Return an error if no nfsiods are available. 1183 * This is mainly to avoid queueing async I/O requests when the nfsiods 1184 * are all hung on a dead server. 1185 * 1186 * Note: nfs_asyncio() does not clear (B_ERROR|B_INVAL) but when the bp 1187 * is eventually dequeued by the async daemon, nfs_doio() *will*. 1188 */ 1189 int 1190 nfs_asyncio(struct vnode *vp, struct bio *bio, struct thread *td) 1191 { 1192 struct buf *bp = bio->bio_buf; 1193 struct nfsmount *nmp; 1194 int i; 1195 int gotiod; 1196 int slpflag = 0; 1197 int slptimeo = 0; 1198 int error; 1199 1200 /* 1201 * If no async daemons then return EIO to force caller to run the rpc 1202 * synchronously. 1203 */ 1204 if (nfs_numasync == 0) 1205 return (EIO); 1206 1207 KKASSERT(vp->v_tag == VT_NFS); 1208 nmp = VFSTONFS(vp->v_mount); 1209 1210 /* 1211 * Commits are usually short and sweet so lets save some cpu and 1212 * leave the async daemons for more important rpc's (such as reads 1213 * and writes). 1214 */ 1215 if (bp->b_cmd == BUF_CMD_WRITE && (bp->b_flags & B_NEEDCOMMIT) && 1216 (nmp->nm_bioqiods > nfs_numasync / 2)) { 1217 return(EIO); 1218 } 1219 1220 again: 1221 if (nmp->nm_flag & NFSMNT_INT) 1222 slpflag = PCATCH; 1223 gotiod = FALSE; 1224 1225 /* 1226 * Find a free iod to process this request. 1227 */ 1228 for (i = 0; i < NFS_MAXASYNCDAEMON; i++) 1229 if (nfs_iodwant[i]) { 1230 /* 1231 * Found one, so wake it up and tell it which 1232 * mount to process. 1233 */ 1234 NFS_DPF(ASYNCIO, 1235 ("nfs_asyncio: waking iod %d for mount %p\n", 1236 i, nmp)); 1237 nfs_iodwant[i] = NULL; 1238 nfs_iodmount[i] = nmp; 1239 nmp->nm_bioqiods++; 1240 wakeup((caddr_t)&nfs_iodwant[i]); 1241 gotiod = TRUE; 1242 break; 1243 } 1244 1245 /* 1246 * If none are free, we may already have an iod working on this mount 1247 * point. If so, it will process our request. 1248 */ 1249 if (!gotiod) { 1250 if (nmp->nm_bioqiods > 0) { 1251 NFS_DPF(ASYNCIO, 1252 ("nfs_asyncio: %d iods are already processing mount %p\n", 1253 nmp->nm_bioqiods, nmp)); 1254 gotiod = TRUE; 1255 } 1256 } 1257 1258 /* 1259 * If we have an iod which can process the request, then queue 1260 * the buffer. 1261 */ 1262 if (gotiod) { 1263 /* 1264 * Ensure that the queue never grows too large. We still want 1265 * to asynchronize so we block rather then return EIO. 1266 */ 1267 while (nmp->nm_bioqlen >= 2*nfs_numasync) { 1268 NFS_DPF(ASYNCIO, 1269 ("nfs_asyncio: waiting for mount %p queue to drain\n", nmp)); 1270 nmp->nm_bioqwant = TRUE; 1271 error = tsleep(&nmp->nm_bioq, slpflag, 1272 "nfsaio", slptimeo); 1273 if (error) { 1274 if (nfs_sigintr(nmp, NULL, td)) 1275 return (EINTR); 1276 if (slpflag == PCATCH) { 1277 slpflag = 0; 1278 slptimeo = 2 * hz; 1279 } 1280 } 1281 /* 1282 * We might have lost our iod while sleeping, 1283 * so check and loop if nescessary. 1284 */ 1285 if (nmp->nm_bioqiods == 0) { 1286 NFS_DPF(ASYNCIO, 1287 ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); 1288 goto again; 1289 } 1290 } 1291 BUF_KERNPROC(bp); 1292 1293 /* 1294 * The passed bio's buffer is not necessary associated with 1295 * the NFS vnode it is being written to. Store the NFS vnode 1296 * in the BIO driver info. 1297 */ 1298 bio->bio_driver_info = vp; 1299 TAILQ_INSERT_TAIL(&nmp->nm_bioq, bio, bio_act); 1300 nmp->nm_bioqlen++; 1301 return (0); 1302 } 1303 1304 /* 1305 * All the iods are busy on other mounts, so return EIO to 1306 * force the caller to process the i/o synchronously. 1307 */ 1308 NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n")); 1309 return (EIO); 1310 } 1311 1312 /* 1313 * Do an I/O operation to/from a cache block. This may be called 1314 * synchronously or from an nfsiod. The BIO is normalized for DEV_BSIZE. 1315 * 1316 * NOTE! TD MIGHT BE NULL 1317 */ 1318 int 1319 nfs_doio(struct vnode *vp, struct bio *bio, struct thread *td) 1320 { 1321 struct buf *bp = bio->bio_buf; 1322 struct uio *uiop; 1323 struct nfsnode *np; 1324 struct nfsmount *nmp; 1325 int error = 0, iomode, must_commit = 0; 1326 struct uio uio; 1327 struct iovec io; 1328 1329 KKASSERT(vp->v_tag == VT_NFS); 1330 np = VTONFS(vp); 1331 nmp = VFSTONFS(vp->v_mount); 1332 uiop = &uio; 1333 uiop->uio_iov = &io; 1334 uiop->uio_iovcnt = 1; 1335 uiop->uio_segflg = UIO_SYSSPACE; 1336 uiop->uio_td = td; 1337 1338 /* 1339 * clear B_ERROR and B_INVAL state prior to initiating the I/O. We 1340 * do this here so we do not have to do it in all the code that 1341 * calls us. 1342 */ 1343 bp->b_flags &= ~(B_ERROR | B_INVAL); 1344 1345 1346 KASSERT(bp->b_cmd != BUF_CMD_DONE, 1347 ("nfs_doio: bp %p already marked done!", bp)); 1348 1349 if (bp->b_cmd == BUF_CMD_READ) { 1350 io.iov_len = uiop->uio_resid = bp->b_bcount; 1351 io.iov_base = bp->b_data; 1352 uiop->uio_rw = UIO_READ; 1353 1354 switch (vp->v_type) { 1355 case VREG: 1356 uiop->uio_offset = bio->bio_offset; 1357 nfsstats.read_bios++; 1358 error = nfs_readrpc(vp, uiop); 1359 1360 if (!error) { 1361 if (uiop->uio_resid) { 1362 /* 1363 * If we had a short read with no error, we must have 1364 * hit a file hole. We should zero-fill the remainder. 1365 * This can also occur if the server hits the file EOF. 1366 * 1367 * Holes used to be able to occur due to pending 1368 * writes, but that is not possible any longer. 1369 */ 1370 int nread = bp->b_bcount - uiop->uio_resid; 1371 int left = uiop->uio_resid; 1372 1373 if (left > 0) 1374 bzero((char *)bp->b_data + nread, left); 1375 uiop->uio_resid = 0; 1376 } 1377 } 1378 if (td && td->td_proc && (vp->v_flag & VTEXT) && 1379 np->n_mtime != np->n_vattr.va_mtime.tv_sec) { 1380 uprintf("Process killed due to text file modification\n"); 1381 ksignal(td->td_proc, SIGKILL); 1382 } 1383 break; 1384 case VLNK: 1385 uiop->uio_offset = 0; 1386 nfsstats.readlink_bios++; 1387 error = nfs_readlinkrpc(vp, uiop); 1388 break; 1389 case VDIR: 1390 nfsstats.readdir_bios++; 1391 uiop->uio_offset = bio->bio_offset; 1392 if (nmp->nm_flag & NFSMNT_RDIRPLUS) { 1393 error = nfs_readdirplusrpc(vp, uiop); 1394 if (error == NFSERR_NOTSUPP) 1395 nmp->nm_flag &= ~NFSMNT_RDIRPLUS; 1396 } 1397 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) 1398 error = nfs_readdirrpc(vp, uiop); 1399 /* 1400 * end-of-directory sets B_INVAL but does not generate an 1401 * error. 1402 */ 1403 if (error == 0 && uiop->uio_resid == bp->b_bcount) 1404 bp->b_flags |= B_INVAL; 1405 break; 1406 default: 1407 kprintf("nfs_doio: type %x unexpected\n",vp->v_type); 1408 break; 1409 }; 1410 if (error) { 1411 bp->b_flags |= B_ERROR; 1412 bp->b_error = error; 1413 } 1414 } else { 1415 /* 1416 * If we only need to commit, try to commit 1417 */ 1418 KKASSERT(bp->b_cmd == BUF_CMD_WRITE); 1419 if (bp->b_flags & B_NEEDCOMMIT) { 1420 int retv; 1421 off_t off; 1422 1423 off = bio->bio_offset + bp->b_dirtyoff; 1424 retv = nfs_commit(vp, off, 1425 bp->b_dirtyend - bp->b_dirtyoff, td); 1426 if (retv == 0) { 1427 bp->b_dirtyoff = bp->b_dirtyend = 0; 1428 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1429 bp->b_resid = 0; 1430 biodone(bio); 1431 return (0); 1432 } 1433 if (retv == NFSERR_STALEWRITEVERF) { 1434 nfs_clearcommit(vp->v_mount); 1435 } 1436 } 1437 1438 /* 1439 * Setup for actual write 1440 */ 1441 1442 if (bio->bio_offset + bp->b_dirtyend > np->n_size) 1443 bp->b_dirtyend = np->n_size - bio->bio_offset; 1444 1445 if (bp->b_dirtyend > bp->b_dirtyoff) { 1446 io.iov_len = uiop->uio_resid = bp->b_dirtyend 1447 - bp->b_dirtyoff; 1448 uiop->uio_offset = bio->bio_offset + bp->b_dirtyoff; 1449 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; 1450 uiop->uio_rw = UIO_WRITE; 1451 nfsstats.write_bios++; 1452 1453 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC) 1454 iomode = NFSV3WRITE_UNSTABLE; 1455 else 1456 iomode = NFSV3WRITE_FILESYNC; 1457 1458 error = nfs_writerpc(vp, uiop, &iomode, &must_commit); 1459 1460 /* 1461 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try 1462 * to cluster the buffers needing commit. This will allow 1463 * the system to submit a single commit rpc for the whole 1464 * cluster. We can do this even if the buffer is not 100% 1465 * dirty (relative to the NFS blocksize), so we optimize the 1466 * append-to-file-case. 1467 * 1468 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be 1469 * cleared because write clustering only works for commit 1470 * rpc's, not for the data portion of the write). 1471 */ 1472 1473 if (!error && iomode == NFSV3WRITE_UNSTABLE) { 1474 bp->b_flags |= B_NEEDCOMMIT; 1475 if (bp->b_dirtyoff == 0 1476 && bp->b_dirtyend == bp->b_bcount) 1477 bp->b_flags |= B_CLUSTEROK; 1478 } else { 1479 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1480 } 1481 1482 /* 1483 * For an interrupted write, the buffer is still valid 1484 * and the write hasn't been pushed to the server yet, 1485 * so we can't set B_ERROR and report the interruption 1486 * by setting B_EINTR. For the B_ASYNC case, B_EINTR 1487 * is not relevant, so the rpc attempt is essentially 1488 * a noop. For the case of a V3 write rpc not being 1489 * committed to stable storage, the block is still 1490 * dirty and requires either a commit rpc or another 1491 * write rpc with iomode == NFSV3WRITE_FILESYNC before 1492 * the block is reused. This is indicated by setting 1493 * the B_DELWRI and B_NEEDCOMMIT flags. 1494 * 1495 * If the buffer is marked B_PAGING, it does not reside on 1496 * the vp's paging queues so we cannot call bdirty(). The 1497 * bp in this case is not an NFS cache block so we should 1498 * be safe. XXX 1499 */ 1500 if (error == EINTR 1501 || (!error && (bp->b_flags & B_NEEDCOMMIT))) { 1502 crit_enter(); 1503 bp->b_flags &= ~(B_INVAL|B_NOCACHE); 1504 if ((bp->b_flags & B_PAGING) == 0) 1505 bdirty(bp); 1506 if (error && (bp->b_flags & B_ASYNC) == 0) 1507 bp->b_flags |= B_EINTR; 1508 crit_exit(); 1509 } else { 1510 if (error) { 1511 bp->b_flags |= B_ERROR; 1512 bp->b_error = np->n_error = error; 1513 np->n_flag |= NWRITEERR; 1514 } 1515 bp->b_dirtyoff = bp->b_dirtyend = 0; 1516 } 1517 } else { 1518 bp->b_resid = 0; 1519 biodone(bio); 1520 return (0); 1521 } 1522 } 1523 bp->b_resid = uiop->uio_resid; 1524 if (must_commit) 1525 nfs_clearcommit(vp->v_mount); 1526 biodone(bio); 1527 return (error); 1528 } 1529 1530 /* 1531 * Used to aid in handling ftruncate() operations on the NFS client side. 1532 * Truncation creates a number of special problems for NFS. We have to 1533 * throw away VM pages and buffer cache buffers that are beyond EOF, and 1534 * we have to properly handle VM pages or (potentially dirty) buffers 1535 * that straddle the truncation point. 1536 */ 1537 1538 int 1539 nfs_meta_setsize(struct vnode *vp, struct thread *td, u_quad_t nsize) 1540 { 1541 struct nfsnode *np = VTONFS(vp); 1542 u_quad_t tsize = np->n_size; 1543 int biosize = vp->v_mount->mnt_stat.f_iosize; 1544 int error = 0; 1545 1546 np->n_size = nsize; 1547 1548 if (np->n_size < tsize) { 1549 struct buf *bp; 1550 daddr_t lbn; 1551 off_t loffset; 1552 int bufsize; 1553 1554 /* 1555 * vtruncbuf() doesn't get the buffer overlapping the 1556 * truncation point. We may have a B_DELWRI and/or B_CACHE 1557 * buffer that now needs to be truncated. 1558 */ 1559 error = vtruncbuf(vp, nsize, biosize); 1560 lbn = nsize / biosize; 1561 bufsize = nsize & (biosize - 1); 1562 loffset = nsize - bufsize; 1563 bp = nfs_getcacheblk(vp, loffset, bufsize, td); 1564 if (bp->b_dirtyoff > bp->b_bcount) 1565 bp->b_dirtyoff = bp->b_bcount; 1566 if (bp->b_dirtyend > bp->b_bcount) 1567 bp->b_dirtyend = bp->b_bcount; 1568 bp->b_flags |= B_RELBUF; /* don't leave garbage around */ 1569 brelse(bp); 1570 } else { 1571 vnode_pager_setsize(vp, nsize); 1572 } 1573 return(error); 1574 } 1575 1576