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 static void nfsiodone_sync(struct bio *bio); 73 74 extern int nfs_numasync; 75 extern int nfs_pbuf_freecnt; 76 extern struct nfsstats nfsstats; 77 78 /* 79 * Vnode op for VM getpages. 80 * 81 * nfs_getpages(struct vnode *a_vp, vm_page_t *a_m, int a_count, 82 * int a_reqpage, vm_ooffset_t a_offset) 83 */ 84 int 85 nfs_getpages(struct vop_getpages_args *ap) 86 { 87 struct thread *td = curthread; /* XXX */ 88 int i, error, nextoff, size, toff, count, npages; 89 struct uio uio; 90 struct iovec iov; 91 char *kva; 92 struct vnode *vp; 93 struct nfsmount *nmp; 94 vm_page_t *pages; 95 vm_page_t m; 96 struct msf_buf *msf; 97 98 vp = ap->a_vp; 99 nmp = VFSTONFS(vp->v_mount); 100 pages = ap->a_m; 101 count = ap->a_count; 102 103 if (vp->v_object == NULL) { 104 kprintf("nfs_getpages: called with non-merged cache vnode??\n"); 105 return VM_PAGER_ERROR; 106 } 107 108 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 109 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 110 (void)nfs_fsinfo(nmp, vp, td); 111 112 npages = btoc(count); 113 114 /* 115 * NOTE that partially valid pages may occur in cases other 116 * then file EOF, such as when a file is partially written and 117 * ftruncate()-extended to a larger size. It is also possible 118 * for the valid bits to be set on garbage beyond the file EOF and 119 * clear in the area before EOF (e.g. m->valid == 0xfc), which can 120 * occur due to vtruncbuf() and the buffer cache's handling of 121 * pages which 'straddle' buffers or when b_bufsize is not a 122 * multiple of PAGE_SIZE.... the buffer cache cannot normally 123 * clear the extra bits. This kind of situation occurs when you 124 * make a small write() (m->valid == 0x03) and then mmap() and 125 * fault in the buffer(m->valid = 0xFF). When NFS flushes the 126 * buffer (vinvalbuf() m->valid = 0xFC) we are left with a mess. 127 * 128 * This is combined with the possibility that the pages are partially 129 * dirty or that there is a buffer backing the pages that is dirty 130 * (even if m->dirty is 0). 131 * 132 * To solve this problem several hacks have been made: (1) NFS 133 * guarentees that the IO block size is a multiple of PAGE_SIZE and 134 * (2) The buffer cache, when invalidating an NFS buffer, will 135 * disregard the buffer's fragmentory b_bufsize and invalidate 136 * the whole page rather then just the piece the buffer owns. 137 * 138 * This allows us to assume that a partially valid page found here 139 * is fully valid (vm_fault will zero'd out areas of the page not 140 * marked as valid). 141 */ 142 m = pages[ap->a_reqpage]; 143 if (m->valid != 0) { 144 for (i = 0; i < npages; ++i) { 145 if (i != ap->a_reqpage) 146 vnode_pager_freepage(pages[i]); 147 } 148 return(0); 149 } 150 151 /* 152 * Use an MSF_BUF as a medium to retrieve data from the pages. 153 */ 154 msf_map_pagelist(&msf, pages, npages, 0); 155 KKASSERT(msf); 156 kva = msf_buf_kva(msf); 157 158 iov.iov_base = kva; 159 iov.iov_len = count; 160 uio.uio_iov = &iov; 161 uio.uio_iovcnt = 1; 162 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex); 163 uio.uio_resid = count; 164 uio.uio_segflg = UIO_SYSSPACE; 165 uio.uio_rw = UIO_READ; 166 uio.uio_td = td; 167 168 error = nfs_readrpc(vp, &uio); 169 msf_buf_free(msf); 170 171 if (error && (uio.uio_resid == count)) { 172 kprintf("nfs_getpages: error %d\n", error); 173 for (i = 0; i < npages; ++i) { 174 if (i != ap->a_reqpage) 175 vnode_pager_freepage(pages[i]); 176 } 177 return VM_PAGER_ERROR; 178 } 179 180 /* 181 * Calculate the number of bytes read and validate only that number 182 * of bytes. Note that due to pending writes, size may be 0. This 183 * does not mean that the remaining data is invalid! 184 */ 185 186 size = count - uio.uio_resid; 187 188 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) { 189 nextoff = toff + PAGE_SIZE; 190 m = pages[i]; 191 192 m->flags &= ~PG_ZERO; 193 194 if (nextoff <= size) { 195 /* 196 * Read operation filled an entire page 197 */ 198 m->valid = VM_PAGE_BITS_ALL; 199 vm_page_undirty(m); 200 } else if (size > toff) { 201 /* 202 * Read operation filled a partial page. 203 */ 204 m->valid = 0; 205 vm_page_set_validclean(m, 0, size - toff); 206 /* handled by vm_fault now */ 207 /* vm_page_zero_invalid(m, TRUE); */ 208 } else { 209 /* 210 * Read operation was short. If no error occured 211 * we may have hit a zero-fill section. We simply 212 * leave valid set to 0. 213 */ 214 ; 215 } 216 if (i != ap->a_reqpage) { 217 /* 218 * Whether or not to leave the page activated is up in 219 * the air, but we should put the page on a page queue 220 * somewhere (it already is in the object). Result: 221 * It appears that emperical results show that 222 * deactivating pages is best. 223 */ 224 225 /* 226 * Just in case someone was asking for this page we 227 * now tell them that it is ok to use. 228 */ 229 if (!error) { 230 if (m->flags & PG_WANTED) 231 vm_page_activate(m); 232 else 233 vm_page_deactivate(m); 234 vm_page_wakeup(m); 235 } else { 236 vnode_pager_freepage(m); 237 } 238 } 239 } 240 return 0; 241 } 242 243 /* 244 * Vnode op for VM putpages. 245 * 246 * nfs_putpages(struct vnode *a_vp, vm_page_t *a_m, int a_count, int a_sync, 247 * int *a_rtvals, vm_ooffset_t a_offset) 248 */ 249 int 250 nfs_putpages(struct vop_putpages_args *ap) 251 { 252 struct thread *td = curthread; 253 struct uio uio; 254 struct iovec iov; 255 char *kva; 256 int iomode, must_commit, i, error, npages, count; 257 off_t offset; 258 int *rtvals; 259 struct vnode *vp; 260 struct nfsmount *nmp; 261 struct nfsnode *np; 262 vm_page_t *pages; 263 struct msf_buf *msf; 264 265 vp = ap->a_vp; 266 np = VTONFS(vp); 267 nmp = VFSTONFS(vp->v_mount); 268 pages = ap->a_m; 269 count = ap->a_count; 270 rtvals = ap->a_rtvals; 271 npages = btoc(count); 272 offset = IDX_TO_OFF(pages[0]->pindex); 273 274 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 275 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 276 (void)nfs_fsinfo(nmp, vp, td); 277 278 for (i = 0; i < npages; i++) { 279 rtvals[i] = VM_PAGER_AGAIN; 280 } 281 282 /* 283 * When putting pages, do not extend file past EOF. 284 */ 285 286 if (offset + count > np->n_size) { 287 count = np->n_size - offset; 288 if (count < 0) 289 count = 0; 290 } 291 292 /* 293 * Use an MSF_BUF as a medium to retrieve data from the pages. 294 */ 295 msf_map_pagelist(&msf, pages, npages, 0); 296 KKASSERT(msf); 297 kva = msf_buf_kva(msf); 298 299 iov.iov_base = kva; 300 iov.iov_len = count; 301 uio.uio_iov = &iov; 302 uio.uio_iovcnt = 1; 303 uio.uio_offset = offset; 304 uio.uio_resid = count; 305 uio.uio_segflg = UIO_SYSSPACE; 306 uio.uio_rw = UIO_WRITE; 307 uio.uio_td = td; 308 309 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0) 310 iomode = NFSV3WRITE_UNSTABLE; 311 else 312 iomode = NFSV3WRITE_FILESYNC; 313 314 error = nfs_writerpc(vp, &uio, &iomode, &must_commit); 315 316 msf_buf_free(msf); 317 318 if (!error) { 319 int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE; 320 for (i = 0; i < nwritten; i++) { 321 rtvals[i] = VM_PAGER_OK; 322 vm_page_undirty(pages[i]); 323 } 324 if (must_commit) 325 nfs_clearcommit(vp->v_mount); 326 } 327 return rtvals[0]; 328 } 329 330 /* 331 * Vnode op for read using bio 332 */ 333 int 334 nfs_bioread(struct vnode *vp, struct uio *uio, int ioflag) 335 { 336 struct nfsnode *np = VTONFS(vp); 337 int biosize, i; 338 struct buf *bp = 0, *rabp; 339 struct vattr vattr; 340 struct thread *td; 341 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 342 daddr_t lbn, rabn; 343 off_t raoffset; 344 off_t loffset; 345 int bcount; 346 int seqcount; 347 int nra, error = 0, n = 0, on = 0; 348 349 #ifdef DIAGNOSTIC 350 if (uio->uio_rw != UIO_READ) 351 panic("nfs_read mode"); 352 #endif 353 if (uio->uio_resid == 0) 354 return (0); 355 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */ 356 return (EINVAL); 357 td = uio->uio_td; 358 359 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 360 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 361 (void)nfs_fsinfo(nmp, vp, td); 362 if (vp->v_type != VDIR && 363 (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 364 return (EFBIG); 365 biosize = vp->v_mount->mnt_stat.f_iosize; 366 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE); 367 368 /* 369 * For nfs, cache consistency can only be maintained approximately. 370 * Although RFC1094 does not specify the criteria, the following is 371 * believed to be compatible with the reference port. 372 * 373 * NFS: If local changes have been made and this is a 374 * directory, the directory must be invalidated and 375 * the attribute cache must be cleared. 376 * 377 * GETATTR is called to synchronize the file size. 378 * 379 * If remote changes are detected local data is flushed 380 * and the cache is invalidated. 381 * 382 * NOTE: In the normal case the attribute cache is not 383 * cleared which means GETATTR may use cached data and 384 * not immediately detect changes made on the server. 385 */ 386 if ((np->n_flag & NLMODIFIED) && vp->v_type == VDIR) { 387 nfs_invaldir(vp); 388 error = nfs_vinvalbuf(vp, V_SAVE, 1); 389 if (error) 390 return (error); 391 np->n_attrstamp = 0; 392 } 393 error = VOP_GETATTR(vp, &vattr); 394 if (error) 395 return (error); 396 if (np->n_flag & NRMODIFIED) { 397 if (vp->v_type == VDIR) 398 nfs_invaldir(vp); 399 error = nfs_vinvalbuf(vp, V_SAVE, 1); 400 if (error) 401 return (error); 402 np->n_flag &= ~NRMODIFIED; 403 } 404 do { 405 if (np->n_flag & NDONTCACHE) { 406 switch (vp->v_type) { 407 case VREG: 408 return (nfs_readrpc(vp, uio)); 409 case VLNK: 410 return (nfs_readlinkrpc(vp, uio)); 411 case VDIR: 412 break; 413 default: 414 kprintf(" NDONTCACHE: type %x unexpected\n", vp->v_type); 415 break; 416 }; 417 } 418 switch (vp->v_type) { 419 case VREG: 420 nfsstats.biocache_reads++; 421 lbn = uio->uio_offset / biosize; 422 on = uio->uio_offset & (biosize - 1); 423 loffset = (off_t)lbn * biosize; 424 425 /* 426 * Start the read ahead(s), as required. 427 */ 428 if (nfs_numasync > 0 && nmp->nm_readahead > 0) { 429 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && 430 (off_t)(lbn + 1 + nra) * biosize < np->n_size; nra++) { 431 rabn = lbn + 1 + nra; 432 raoffset = (off_t)rabn * biosize; 433 if (findblk(vp, raoffset, FINDBLK_TEST) == NULL) { 434 rabp = nfs_getcacheblk(vp, raoffset, biosize, td); 435 if (!rabp) 436 return (EINTR); 437 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 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 bp->b_bio2.bio_done = nfsiodone_sync; 501 bp->b_bio2.bio_flags |= BIO_SYNC; 502 vfs_busy_pages(vp, bp); 503 error = nfs_doio(vp, &bp->b_bio2, td); 504 if (error) { 505 brelse(bp); 506 return (error); 507 } 508 } 509 510 /* 511 * on is the offset into the current bp. Figure out how many 512 * bytes we can copy out of the bp. Note that bcount is 513 * NOT DEV_BSIZE aligned. 514 * 515 * Then figure out how many bytes we can copy into the uio. 516 */ 517 518 n = 0; 519 if (on < bcount) 520 n = min((unsigned)(bcount - on), uio->uio_resid); 521 break; 522 case VLNK: 523 biosize = min(NFS_MAXPATHLEN, np->n_size); 524 nfsstats.biocache_readlinks++; 525 bp = nfs_getcacheblk(vp, (off_t)0, biosize, td); 526 if (bp == NULL) 527 return (EINTR); 528 if ((bp->b_flags & B_CACHE) == 0) { 529 bp->b_cmd = BUF_CMD_READ; 530 bp->b_bio2.bio_done = nfsiodone_sync; 531 bp->b_bio2.bio_flags |= BIO_SYNC; 532 vfs_busy_pages(vp, bp); 533 error = nfs_doio(vp, &bp->b_bio2, td); 534 if (error) { 535 bp->b_flags |= B_ERROR | B_INVAL; 536 brelse(bp); 537 return (error); 538 } 539 } 540 n = min(uio->uio_resid, bp->b_bcount - bp->b_resid); 541 on = 0; 542 break; 543 case VDIR: 544 nfsstats.biocache_readdirs++; 545 if (np->n_direofoffset 546 && uio->uio_offset >= np->n_direofoffset) { 547 return (0); 548 } 549 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; 550 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); 551 loffset = uio->uio_offset - on; 552 bp = nfs_getcacheblk(vp, loffset, NFS_DIRBLKSIZ, td); 553 if (bp == NULL) 554 return (EINTR); 555 556 if ((bp->b_flags & B_CACHE) == 0) { 557 bp->b_cmd = BUF_CMD_READ; 558 bp->b_bio2.bio_done = nfsiodone_sync; 559 bp->b_bio2.bio_flags |= BIO_SYNC; 560 vfs_busy_pages(vp, bp); 561 error = nfs_doio(vp, &bp->b_bio2, td); 562 if (error) { 563 brelse(bp); 564 } 565 while (error == NFSERR_BAD_COOKIE) { 566 kprintf("got bad cookie vp %p bp %p\n", vp, bp); 567 nfs_invaldir(vp); 568 error = nfs_vinvalbuf(vp, 0, 1); 569 /* 570 * Yuck! The directory has been modified on the 571 * server. The only way to get the block is by 572 * reading from the beginning to get all the 573 * offset cookies. 574 * 575 * Leave the last bp intact unless there is an error. 576 * Loop back up to the while if the error is another 577 * NFSERR_BAD_COOKIE (double yuch!). 578 */ 579 for (i = 0; i <= lbn && !error; i++) { 580 if (np->n_direofoffset 581 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) 582 return (0); 583 bp = nfs_getcacheblk(vp, (off_t)i * NFS_DIRBLKSIZ, 584 NFS_DIRBLKSIZ, td); 585 if (!bp) 586 return (EINTR); 587 if ((bp->b_flags & B_CACHE) == 0) { 588 bp->b_cmd = BUF_CMD_READ; 589 bp->b_bio2.bio_done = nfsiodone_sync; 590 bp->b_bio2.bio_flags |= BIO_SYNC; 591 vfs_busy_pages(vp, bp); 592 error = nfs_doio(vp, &bp->b_bio2, td); 593 /* 594 * no error + B_INVAL == directory EOF, 595 * use the block. 596 */ 597 if (error == 0 && (bp->b_flags & B_INVAL)) 598 break; 599 } 600 /* 601 * An error will throw away the block and the 602 * for loop will break out. If no error and this 603 * is not the block we want, we throw away the 604 * block and go for the next one via the for loop. 605 */ 606 if (error || i < lbn) 607 brelse(bp); 608 } 609 } 610 /* 611 * The above while is repeated if we hit another cookie 612 * error. If we hit an error and it wasn't a cookie error, 613 * we give up. 614 */ 615 if (error) 616 return (error); 617 } 618 619 /* 620 * If not eof and read aheads are enabled, start one. 621 * (You need the current block first, so that you have the 622 * directory offset cookie of the next block.) 623 */ 624 if (nfs_numasync > 0 && nmp->nm_readahead > 0 && 625 (bp->b_flags & B_INVAL) == 0 && 626 (np->n_direofoffset == 0 || 627 loffset + NFS_DIRBLKSIZ < np->n_direofoffset) && 628 (np->n_flag & NDONTCACHE) == 0 && 629 findblk(vp, loffset + NFS_DIRBLKSIZ, FINDBLK_TEST) == NULL 630 ) { 631 rabp = nfs_getcacheblk(vp, loffset + NFS_DIRBLKSIZ, 632 NFS_DIRBLKSIZ, td); 633 if (rabp) { 634 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 635 rabp->b_cmd = BUF_CMD_READ; 636 vfs_busy_pages(vp, rabp); 637 if (nfs_asyncio(vp, &rabp->b_bio2, td)) { 638 rabp->b_flags |= B_INVAL|B_ERROR; 639 vfs_unbusy_pages(rabp); 640 brelse(rabp); 641 } 642 } else { 643 brelse(rabp); 644 } 645 } 646 } 647 /* 648 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is 649 * chopped for the EOF condition, we cannot tell how large 650 * NFS directories are going to be until we hit EOF. So 651 * an NFS directory buffer is *not* chopped to its EOF. Now, 652 * it just so happens that b_resid will effectively chop it 653 * to EOF. *BUT* this information is lost if the buffer goes 654 * away and is reconstituted into a B_CACHE state ( due to 655 * being VMIO ) later. So we keep track of the directory eof 656 * in np->n_direofoffset and chop it off as an extra step 657 * right here. 658 */ 659 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on); 660 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset) 661 n = np->n_direofoffset - uio->uio_offset; 662 break; 663 default: 664 kprintf(" nfs_bioread: type %x unexpected\n",vp->v_type); 665 break; 666 }; 667 668 switch (vp->v_type) { 669 case VREG: 670 if (n > 0) 671 error = uiomove(bp->b_data + on, (int)n, uio); 672 break; 673 case VLNK: 674 if (n > 0) 675 error = uiomove(bp->b_data + on, (int)n, uio); 676 n = 0; 677 break; 678 case VDIR: 679 if (n > 0) { 680 off_t old_off = uio->uio_offset; 681 caddr_t cpos, epos; 682 struct nfs_dirent *dp; 683 684 /* 685 * We are casting cpos to nfs_dirent, it must be 686 * int-aligned. 687 */ 688 if (on & 3) { 689 error = EINVAL; 690 break; 691 } 692 693 cpos = bp->b_data + on; 694 epos = bp->b_data + on + n; 695 while (cpos < epos && error == 0 && uio->uio_resid > 0) { 696 dp = (struct nfs_dirent *)cpos; 697 error = nfs_check_dirent(dp, (int)(epos - cpos)); 698 if (error) 699 break; 700 if (vop_write_dirent(&error, uio, dp->nfs_ino, 701 dp->nfs_type, dp->nfs_namlen, dp->nfs_name)) { 702 break; 703 } 704 cpos += dp->nfs_reclen; 705 } 706 n = 0; 707 if (error == 0) 708 uio->uio_offset = old_off + cpos - bp->b_data - on; 709 } 710 /* 711 * Invalidate buffer if caching is disabled, forcing a 712 * re-read from the remote later. 713 */ 714 if (np->n_flag & NDONTCACHE) 715 bp->b_flags |= B_INVAL; 716 break; 717 default: 718 kprintf(" nfs_bioread: type %x unexpected\n",vp->v_type); 719 } 720 brelse(bp); 721 } while (error == 0 && uio->uio_resid > 0 && n > 0); 722 return (error); 723 } 724 725 /* 726 * Userland can supply any 'seek' offset when reading a NFS directory. 727 * Validate the structure so we don't panic the kernel. Note that 728 * the element name is nul terminated and the nul is not included 729 * in nfs_namlen. 730 */ 731 static 732 int 733 nfs_check_dirent(struct nfs_dirent *dp, int maxlen) 734 { 735 int nfs_name_off = offsetof(struct nfs_dirent, nfs_name[0]); 736 737 if (nfs_name_off >= maxlen) 738 return (EINVAL); 739 if (dp->nfs_reclen < nfs_name_off || dp->nfs_reclen > maxlen) 740 return (EINVAL); 741 if (nfs_name_off + dp->nfs_namlen >= dp->nfs_reclen) 742 return (EINVAL); 743 if (dp->nfs_reclen & 3) 744 return (EINVAL); 745 return (0); 746 } 747 748 /* 749 * Vnode op for write using bio 750 * 751 * nfs_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, 752 * struct ucred *a_cred) 753 */ 754 int 755 nfs_write(struct vop_write_args *ap) 756 { 757 struct uio *uio = ap->a_uio; 758 struct thread *td = uio->uio_td; 759 struct vnode *vp = ap->a_vp; 760 struct nfsnode *np = VTONFS(vp); 761 int ioflag = ap->a_ioflag; 762 struct buf *bp; 763 struct vattr vattr; 764 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 765 daddr_t lbn; 766 off_t loffset; 767 int n, on, error = 0, iomode, must_commit; 768 int haverslock = 0; 769 int bcount; 770 int biosize; 771 772 #ifdef DIAGNOSTIC 773 if (uio->uio_rw != UIO_WRITE) 774 panic("nfs_write mode"); 775 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_td != curthread) 776 panic("nfs_write proc"); 777 #endif 778 if (vp->v_type != VREG) 779 return (EIO); 780 if (np->n_flag & NWRITEERR) { 781 np->n_flag &= ~NWRITEERR; 782 return (np->n_error); 783 } 784 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 785 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) 786 (void)nfs_fsinfo(nmp, vp, td); 787 788 /* 789 * Synchronously flush pending buffers if we are in synchronous 790 * mode or if we are appending. 791 */ 792 if (ioflag & (IO_APPEND | IO_SYNC)) { 793 if (np->n_flag & NLMODIFIED) { 794 np->n_attrstamp = 0; 795 error = nfs_flush(vp, MNT_WAIT, td, 0); 796 /* error = nfs_vinvalbuf(vp, V_SAVE, 1); */ 797 if (error) 798 return (error); 799 } 800 } 801 802 /* 803 * If IO_APPEND then load uio_offset. We restart here if we cannot 804 * get the append lock. 805 */ 806 restart: 807 if (ioflag & IO_APPEND) { 808 np->n_attrstamp = 0; 809 error = VOP_GETATTR(vp, &vattr); 810 if (error) 811 return (error); 812 uio->uio_offset = np->n_size; 813 } 814 815 if (uio->uio_offset < 0) 816 return (EINVAL); 817 if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 818 return (EFBIG); 819 if (uio->uio_resid == 0) 820 return (0); 821 822 /* 823 * We need to obtain the rslock if we intend to modify np->n_size 824 * in order to guarentee the append point with multiple contending 825 * writers, to guarentee that no other appenders modify n_size 826 * while we are trying to obtain a truncated buffer (i.e. to avoid 827 * accidently truncating data written by another appender due to 828 * the race), and to ensure that the buffer is populated prior to 829 * our extending of the file. We hold rslock through the entire 830 * operation. 831 * 832 * Note that we do not synchronize the case where someone truncates 833 * the file while we are appending to it because attempting to lock 834 * this case may deadlock other parts of the system unexpectedly. 835 */ 836 if ((ioflag & IO_APPEND) || 837 uio->uio_offset + uio->uio_resid > np->n_size) { 838 switch(nfs_rslock(np)) { 839 case ENOLCK: 840 goto restart; 841 /* not reached */ 842 case EINTR: 843 case ERESTART: 844 return(EINTR); 845 /* not reached */ 846 default: 847 break; 848 } 849 haverslock = 1; 850 } 851 852 /* 853 * Maybe this should be above the vnode op call, but so long as 854 * file servers have no limits, i don't think it matters 855 */ 856 if (td->td_proc && uio->uio_offset + uio->uio_resid > 857 td->td_proc->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 858 lwpsignal(td->td_proc, td->td_lwp, SIGXFSZ); 859 if (haverslock) 860 nfs_rsunlock(np); 861 return (EFBIG); 862 } 863 864 biosize = vp->v_mount->mnt_stat.f_iosize; 865 866 do { 867 if ((np->n_flag & NDONTCACHE) && uio->uio_iovcnt == 1) { 868 iomode = NFSV3WRITE_FILESYNC; 869 error = nfs_writerpc(vp, uio, &iomode, &must_commit); 870 if (must_commit) 871 nfs_clearcommit(vp->v_mount); 872 break; 873 } 874 nfsstats.biocache_writes++; 875 lbn = uio->uio_offset / biosize; 876 on = uio->uio_offset & (biosize-1); 877 loffset = uio->uio_offset - on; 878 n = min((unsigned)(biosize - on), uio->uio_resid); 879 again: 880 /* 881 * Handle direct append and file extension cases, calculate 882 * unaligned buffer size. 883 */ 884 885 if (uio->uio_offset == np->n_size && n) { 886 /* 887 * Get the buffer (in its pre-append state to maintain 888 * B_CACHE if it was previously set). Resize the 889 * nfsnode after we have locked the buffer to prevent 890 * readers from reading garbage. 891 */ 892 bcount = on; 893 bp = nfs_getcacheblk(vp, loffset, bcount, td); 894 895 if (bp != NULL) { 896 long save; 897 898 np->n_size = uio->uio_offset + n; 899 np->n_flag |= NLMODIFIED; 900 vnode_pager_setsize(vp, np->n_size); 901 902 save = bp->b_flags & B_CACHE; 903 bcount += n; 904 allocbuf(bp, bcount); 905 bp->b_flags |= save; 906 } 907 } else { 908 /* 909 * Obtain the locked cache block first, and then 910 * adjust the file's size as appropriate. 911 */ 912 bcount = on + n; 913 if (loffset + bcount < np->n_size) { 914 if (loffset + biosize < np->n_size) 915 bcount = biosize; 916 else 917 bcount = np->n_size - loffset; 918 } 919 bp = nfs_getcacheblk(vp, loffset, bcount, td); 920 if (uio->uio_offset + n > np->n_size) { 921 np->n_size = uio->uio_offset + n; 922 np->n_flag |= NLMODIFIED; 923 vnode_pager_setsize(vp, np->n_size); 924 } 925 } 926 927 if (bp == NULL) { 928 error = EINTR; 929 break; 930 } 931 932 /* 933 * Issue a READ if B_CACHE is not set. In special-append 934 * mode, B_CACHE is based on the buffer prior to the write 935 * op and is typically set, avoiding the read. If a read 936 * is required in special append mode, the server will 937 * probably send us a short-read since we extended the file 938 * on our end, resulting in b_resid == 0 and, thusly, 939 * B_CACHE getting set. 940 * 941 * We can also avoid issuing the read if the write covers 942 * the entire buffer. We have to make sure the buffer state 943 * is reasonable in this case since we will not be initiating 944 * I/O. See the comments in kern/vfs_bio.c's getblk() for 945 * more information. 946 * 947 * B_CACHE may also be set due to the buffer being cached 948 * normally. 949 * 950 * When doing a UIO_NOCOPY write the buffer is not 951 * overwritten and we cannot just set B_CACHE unconditionally 952 * for full-block writes. 953 */ 954 955 if (on == 0 && n == bcount && uio->uio_segflg != UIO_NOCOPY) { 956 bp->b_flags |= B_CACHE; 957 bp->b_flags &= ~(B_ERROR | B_INVAL); 958 } 959 960 if ((bp->b_flags & B_CACHE) == 0) { 961 bp->b_cmd = BUF_CMD_READ; 962 bp->b_bio2.bio_done = nfsiodone_sync; 963 bp->b_bio2.bio_flags |= BIO_SYNC; 964 vfs_busy_pages(vp, bp); 965 error = nfs_doio(vp, &bp->b_bio2, td); 966 if (error) { 967 brelse(bp); 968 break; 969 } 970 } 971 if (!bp) { 972 error = EINTR; 973 break; 974 } 975 np->n_flag |= NLMODIFIED; 976 977 /* 978 * If dirtyend exceeds file size, chop it down. This should 979 * not normally occur but there is an append race where it 980 * might occur XXX, so we log it. 981 * 982 * If the chopping creates a reverse-indexed or degenerate 983 * situation with dirtyoff/end, we 0 both of them. 984 */ 985 986 if (bp->b_dirtyend > bcount) { 987 kprintf("NFS append race @%08llx:%d\n", 988 (long long)bp->b_bio2.bio_offset, 989 bp->b_dirtyend - bcount); 990 bp->b_dirtyend = bcount; 991 } 992 993 if (bp->b_dirtyoff >= bp->b_dirtyend) 994 bp->b_dirtyoff = bp->b_dirtyend = 0; 995 996 /* 997 * If the new write will leave a contiguous dirty 998 * area, just update the b_dirtyoff and b_dirtyend, 999 * otherwise force a write rpc of the old dirty area. 1000 * 1001 * While it is possible to merge discontiguous writes due to 1002 * our having a B_CACHE buffer ( and thus valid read data 1003 * for the hole), we don't because it could lead to 1004 * significant cache coherency problems with multiple clients, 1005 * especially if locking is implemented later on. 1006 * 1007 * as an optimization we could theoretically maintain 1008 * a linked list of discontinuous areas, but we would still 1009 * have to commit them separately so there isn't much 1010 * advantage to it except perhaps a bit of asynchronization. 1011 */ 1012 1013 if (bp->b_dirtyend > 0 && 1014 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { 1015 if (bwrite(bp) == EINTR) { 1016 error = EINTR; 1017 break; 1018 } 1019 goto again; 1020 } 1021 1022 error = uiomove((char *)bp->b_data + on, n, uio); 1023 1024 /* 1025 * Since this block is being modified, it must be written 1026 * again and not just committed. Since write clustering does 1027 * not work for the stage 1 data write, only the stage 2 1028 * commit rpc, we have to clear B_CLUSTEROK as well. 1029 */ 1030 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1031 1032 if (error) { 1033 bp->b_flags |= B_ERROR; 1034 brelse(bp); 1035 break; 1036 } 1037 1038 /* 1039 * Only update dirtyoff/dirtyend if not a degenerate 1040 * condition. 1041 */ 1042 if (n) { 1043 if (bp->b_dirtyend > 0) { 1044 bp->b_dirtyoff = min(on, bp->b_dirtyoff); 1045 bp->b_dirtyend = max((on + n), bp->b_dirtyend); 1046 } else { 1047 bp->b_dirtyoff = on; 1048 bp->b_dirtyend = on + n; 1049 } 1050 vfs_bio_set_validclean(bp, on, n); 1051 } 1052 1053 /* 1054 * If the lease is non-cachable or IO_SYNC do bwrite(). 1055 * 1056 * IO_INVAL appears to be unused. The idea appears to be 1057 * to turn off caching in this case. Very odd. XXX 1058 * 1059 * If nfs_async is set bawrite() will use an unstable write 1060 * (build dirty bufs on the server), so we might as well 1061 * push it out with bawrite(). If nfs_async is not set we 1062 * use bdwrite() to cache dirty bufs on the client. 1063 */ 1064 if ((np->n_flag & NDONTCACHE) || (ioflag & IO_SYNC)) { 1065 if (ioflag & IO_INVAL) 1066 bp->b_flags |= B_NOCACHE; 1067 error = bwrite(bp); 1068 if (error) 1069 break; 1070 if (np->n_flag & NDONTCACHE) { 1071 error = nfs_vinvalbuf(vp, V_SAVE, 1); 1072 if (error) 1073 break; 1074 } 1075 } else if ((n + on) == biosize && nfs_async) { 1076 bawrite(bp); 1077 } else { 1078 bdwrite(bp); 1079 } 1080 } while (uio->uio_resid > 0 && n > 0); 1081 1082 if (haverslock) 1083 nfs_rsunlock(np); 1084 1085 return (error); 1086 } 1087 1088 /* 1089 * Get an nfs cache block. 1090 * 1091 * Allocate a new one if the block isn't currently in the cache 1092 * and return the block marked busy. If the calling process is 1093 * interrupted by a signal for an interruptible mount point, return 1094 * NULL. 1095 * 1096 * The caller must carefully deal with the possible B_INVAL state of 1097 * the buffer. nfs_doio() clears B_INVAL (and nfs_asyncio() clears it 1098 * indirectly), so synchronous reads can be issued without worrying about 1099 * the B_INVAL state. We have to be a little more careful when dealing 1100 * with writes (see comments in nfs_write()) when extending a file past 1101 * its EOF. 1102 */ 1103 static struct buf * 1104 nfs_getcacheblk(struct vnode *vp, off_t loffset, int size, struct thread *td) 1105 { 1106 struct buf *bp; 1107 struct mount *mp; 1108 struct nfsmount *nmp; 1109 1110 mp = vp->v_mount; 1111 nmp = VFSTONFS(mp); 1112 1113 if (nmp->nm_flag & NFSMNT_INT) { 1114 bp = getblk(vp, loffset, size, GETBLK_PCATCH, 0); 1115 while (bp == NULL) { 1116 if (nfs_sigintr(nmp, NULL, td)) 1117 return (NULL); 1118 bp = getblk(vp, loffset, size, 0, 2 * hz); 1119 } 1120 } else { 1121 bp = getblk(vp, loffset, size, 0, 0); 1122 } 1123 1124 /* 1125 * bio2, the 'device' layer. Since BIOs use 64 bit byte offsets 1126 * now, no translation is necessary. 1127 */ 1128 bp->b_bio2.bio_offset = loffset; 1129 return (bp); 1130 } 1131 1132 /* 1133 * Flush and invalidate all dirty buffers. If another process is already 1134 * doing the flush, just wait for completion. 1135 */ 1136 int 1137 nfs_vinvalbuf(struct vnode *vp, int flags, int intrflg) 1138 { 1139 struct nfsnode *np = VTONFS(vp); 1140 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 1141 int error = 0, slpflag, slptimeo; 1142 thread_t td = curthread; 1143 1144 if (vp->v_flag & VRECLAIMED) 1145 return (0); 1146 1147 if ((nmp->nm_flag & NFSMNT_INT) == 0) 1148 intrflg = 0; 1149 if (intrflg) { 1150 slpflag = PCATCH; 1151 slptimeo = 2 * hz; 1152 } else { 1153 slpflag = 0; 1154 slptimeo = 0; 1155 } 1156 /* 1157 * First wait for any other process doing a flush to complete. 1158 */ 1159 while (np->n_flag & NFLUSHINPROG) { 1160 np->n_flag |= NFLUSHWANT; 1161 error = tsleep((caddr_t)&np->n_flag, 0, "nfsvinval", slptimeo); 1162 if (error && intrflg && nfs_sigintr(nmp, NULL, td)) 1163 return (EINTR); 1164 } 1165 1166 /* 1167 * Now, flush as required. 1168 */ 1169 np->n_flag |= NFLUSHINPROG; 1170 error = vinvalbuf(vp, flags, slpflag, 0); 1171 while (error) { 1172 if (intrflg && nfs_sigintr(nmp, NULL, td)) { 1173 np->n_flag &= ~NFLUSHINPROG; 1174 if (np->n_flag & NFLUSHWANT) { 1175 np->n_flag &= ~NFLUSHWANT; 1176 wakeup((caddr_t)&np->n_flag); 1177 } 1178 return (EINTR); 1179 } 1180 error = vinvalbuf(vp, flags, 0, slptimeo); 1181 } 1182 np->n_flag &= ~(NLMODIFIED | NFLUSHINPROG); 1183 if (np->n_flag & NFLUSHWANT) { 1184 np->n_flag &= ~NFLUSHWANT; 1185 wakeup((caddr_t)&np->n_flag); 1186 } 1187 return (0); 1188 } 1189 1190 /* 1191 * Initiate asynchronous I/O. Return an error if no nfsiods are available. 1192 * This is mainly to avoid queueing async I/O requests when the nfsiods 1193 * are all hung on a dead server. 1194 * 1195 * Note: nfs_asyncio() does not clear (B_ERROR|B_INVAL) but when the bp 1196 * is eventually dequeued by the async daemon, nfs_doio() *will*. 1197 */ 1198 int 1199 nfs_asyncio(struct vnode *vp, struct bio *bio, struct thread *td) 1200 { 1201 struct buf *bp = bio->bio_buf; 1202 struct nfsmount *nmp; 1203 int i; 1204 int gotiod; 1205 int slpflag = 0; 1206 int slptimeo = 0; 1207 int error; 1208 1209 /* 1210 * If no async daemons then return EIO to force caller to run the rpc 1211 * synchronously. 1212 */ 1213 if (nfs_numasync == 0) 1214 return (EIO); 1215 1216 KKASSERT(vp->v_tag == VT_NFS); 1217 nmp = VFSTONFS(vp->v_mount); 1218 1219 /* 1220 * Commits are usually short and sweet so lets save some cpu and 1221 * leave the async daemons for more important rpc's (such as reads 1222 * and writes). 1223 */ 1224 if (bp->b_cmd == BUF_CMD_WRITE && (bp->b_flags & B_NEEDCOMMIT) && 1225 (nmp->nm_bioqiods > nfs_numasync / 2)) { 1226 return(EIO); 1227 } 1228 1229 again: 1230 if (nmp->nm_flag & NFSMNT_INT) 1231 slpflag = PCATCH; 1232 gotiod = FALSE; 1233 1234 /* 1235 * Find a free iod to process this request. 1236 */ 1237 for (i = 0; i < NFS_MAXASYNCDAEMON; i++) 1238 if (nfs_iodwant[i]) { 1239 /* 1240 * Found one, so wake it up and tell it which 1241 * mount to process. 1242 */ 1243 NFS_DPF(ASYNCIO, 1244 ("nfs_asyncio: waking iod %d for mount %p\n", 1245 i, nmp)); 1246 nfs_iodwant[i] = NULL; 1247 nfs_iodmount[i] = nmp; 1248 nmp->nm_bioqiods++; 1249 wakeup((caddr_t)&nfs_iodwant[i]); 1250 gotiod = TRUE; 1251 break; 1252 } 1253 1254 /* 1255 * If none are free, we may already have an iod working on this mount 1256 * point. If so, it will process our request. 1257 */ 1258 if (!gotiod) { 1259 if (nmp->nm_bioqiods > 0) { 1260 NFS_DPF(ASYNCIO, 1261 ("nfs_asyncio: %d iods are already processing mount %p\n", 1262 nmp->nm_bioqiods, nmp)); 1263 gotiod = TRUE; 1264 } 1265 } 1266 1267 /* 1268 * If we have an iod which can process the request, then queue 1269 * the buffer. 1270 */ 1271 if (gotiod) { 1272 /* 1273 * Ensure that the queue never grows too large. We still want 1274 * to asynchronize so we block rather then return EIO. 1275 */ 1276 while (nmp->nm_bioqlen >= 2*nfs_numasync) { 1277 NFS_DPF(ASYNCIO, 1278 ("nfs_asyncio: waiting for mount %p queue to drain\n", nmp)); 1279 nmp->nm_bioqwant = TRUE; 1280 error = tsleep(&nmp->nm_bioq, slpflag, 1281 "nfsaio", slptimeo); 1282 if (error) { 1283 if (nfs_sigintr(nmp, NULL, td)) 1284 return (EINTR); 1285 if (slpflag == PCATCH) { 1286 slpflag = 0; 1287 slptimeo = 2 * hz; 1288 } 1289 } 1290 /* 1291 * We might have lost our iod while sleeping, 1292 * so check and loop if nescessary. 1293 */ 1294 if (nmp->nm_bioqiods == 0) { 1295 NFS_DPF(ASYNCIO, 1296 ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); 1297 goto again; 1298 } 1299 } 1300 BUF_KERNPROC(bp); 1301 1302 /* 1303 * The passed bio's buffer is not necessary associated with 1304 * the NFS vnode it is being written to. Store the NFS vnode 1305 * in the BIO driver info. 1306 */ 1307 bio->bio_driver_info = vp; 1308 TAILQ_INSERT_TAIL(&nmp->nm_bioq, bio, bio_act); 1309 nmp->nm_bioqlen++; 1310 return (0); 1311 } 1312 1313 /* 1314 * All the iods are busy on other mounts, so return EIO to 1315 * force the caller to process the i/o synchronously. 1316 */ 1317 NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n")); 1318 return (EIO); 1319 } 1320 1321 /* 1322 * Do an I/O operation to/from a cache block. This may be called 1323 * synchronously or from an nfsiod. The BIO is normalized for DEV_BSIZE. 1324 * 1325 * A locked, completed I/O is returned and the caller is responsible for 1326 * brelse()'ing it. 1327 * 1328 * NOTE! TD MIGHT BE NULL 1329 */ 1330 int 1331 nfs_doio(struct vnode *vp, struct bio *bio, struct thread *td) 1332 { 1333 struct buf *bp = bio->bio_buf; 1334 struct uio *uiop; 1335 struct nfsnode *np; 1336 struct nfsmount *nmp; 1337 int error = 0, iomode, must_commit = 0; 1338 struct uio uio; 1339 struct iovec io; 1340 1341 KKASSERT(vp->v_tag == VT_NFS); 1342 np = VTONFS(vp); 1343 nmp = VFSTONFS(vp->v_mount); 1344 uiop = &uio; 1345 uiop->uio_iov = &io; 1346 uiop->uio_iovcnt = 1; 1347 uiop->uio_segflg = UIO_SYSSPACE; 1348 uiop->uio_td = td; 1349 1350 /* 1351 * clear B_ERROR and B_INVAL state prior to initiating the I/O. We 1352 * do this here so we do not have to do it in all the code that 1353 * calls us. 1354 */ 1355 bp->b_flags &= ~(B_ERROR | B_INVAL); 1356 1357 1358 KASSERT(bp->b_cmd != BUF_CMD_DONE, 1359 ("nfs_doio: bp %p already marked done!", bp)); 1360 1361 if (bp->b_cmd == BUF_CMD_READ) { 1362 io.iov_len = uiop->uio_resid = bp->b_bcount; 1363 io.iov_base = bp->b_data; 1364 uiop->uio_rw = UIO_READ; 1365 1366 switch (vp->v_type) { 1367 case VREG: 1368 uiop->uio_offset = bio->bio_offset; 1369 nfsstats.read_bios++; 1370 error = nfs_readrpc(vp, uiop); 1371 1372 if (!error) { 1373 if (uiop->uio_resid) { 1374 /* 1375 * If we had a short read with no error, we must have 1376 * hit a file hole. We should zero-fill the remainder. 1377 * This can also occur if the server hits the file EOF. 1378 * 1379 * Holes used to be able to occur due to pending 1380 * writes, but that is not possible any longer. 1381 */ 1382 int nread = bp->b_bcount - uiop->uio_resid; 1383 int left = uiop->uio_resid; 1384 1385 if (left > 0) 1386 bzero((char *)bp->b_data + nread, left); 1387 uiop->uio_resid = 0; 1388 } 1389 } 1390 if (td && td->td_proc && (vp->v_flag & VTEXT) && 1391 np->n_mtime != np->n_vattr.va_mtime.tv_sec) { 1392 uprintf("Process killed due to text file modification\n"); 1393 ksignal(td->td_proc, SIGKILL); 1394 } 1395 break; 1396 case VLNK: 1397 uiop->uio_offset = 0; 1398 nfsstats.readlink_bios++; 1399 error = nfs_readlinkrpc(vp, uiop); 1400 break; 1401 case VDIR: 1402 nfsstats.readdir_bios++; 1403 uiop->uio_offset = bio->bio_offset; 1404 if (nmp->nm_flag & NFSMNT_RDIRPLUS) { 1405 error = nfs_readdirplusrpc(vp, uiop); 1406 if (error == NFSERR_NOTSUPP) 1407 nmp->nm_flag &= ~NFSMNT_RDIRPLUS; 1408 } 1409 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) 1410 error = nfs_readdirrpc(vp, uiop); 1411 /* 1412 * end-of-directory sets B_INVAL but does not generate an 1413 * error. 1414 */ 1415 if (error == 0 && uiop->uio_resid == bp->b_bcount) 1416 bp->b_flags |= B_INVAL; 1417 break; 1418 default: 1419 kprintf("nfs_doio: type %x unexpected\n",vp->v_type); 1420 break; 1421 }; 1422 if (error) { 1423 bp->b_flags |= B_ERROR; 1424 bp->b_error = error; 1425 } 1426 } else { 1427 /* 1428 * If we only need to commit, try to commit 1429 */ 1430 KKASSERT(bp->b_cmd == BUF_CMD_WRITE); 1431 if (bp->b_flags & B_NEEDCOMMIT) { 1432 int retv; 1433 off_t off; 1434 1435 off = bio->bio_offset + bp->b_dirtyoff; 1436 retv = nfs_commit(vp, off, 1437 bp->b_dirtyend - bp->b_dirtyoff, td); 1438 if (retv == 0) { 1439 bp->b_dirtyoff = bp->b_dirtyend = 0; 1440 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1441 bp->b_resid = 0; 1442 biodone(bio); 1443 return (0); 1444 } 1445 if (retv == NFSERR_STALEWRITEVERF) { 1446 nfs_clearcommit(vp->v_mount); 1447 } 1448 } 1449 1450 /* 1451 * Setup for actual write 1452 */ 1453 1454 if (bio->bio_offset + bp->b_dirtyend > np->n_size) 1455 bp->b_dirtyend = np->n_size - bio->bio_offset; 1456 1457 if (bp->b_dirtyend > bp->b_dirtyoff) { 1458 io.iov_len = uiop->uio_resid = bp->b_dirtyend 1459 - bp->b_dirtyoff; 1460 uiop->uio_offset = bio->bio_offset + bp->b_dirtyoff; 1461 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; 1462 uiop->uio_rw = UIO_WRITE; 1463 nfsstats.write_bios++; 1464 1465 if ((bp->b_flags & (B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == 0) 1466 iomode = NFSV3WRITE_UNSTABLE; 1467 else 1468 iomode = NFSV3WRITE_FILESYNC; 1469 1470 error = nfs_writerpc(vp, uiop, &iomode, &must_commit); 1471 1472 /* 1473 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try 1474 * to cluster the buffers needing commit. This will allow 1475 * the system to submit a single commit rpc for the whole 1476 * cluster. We can do this even if the buffer is not 100% 1477 * dirty (relative to the NFS blocksize), so we optimize the 1478 * append-to-file-case. 1479 * 1480 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be 1481 * cleared because write clustering only works for commit 1482 * rpc's, not for the data portion of the write). 1483 */ 1484 1485 if (!error && iomode == NFSV3WRITE_UNSTABLE) { 1486 bp->b_flags |= B_NEEDCOMMIT; 1487 if (bp->b_dirtyoff == 0 1488 && bp->b_dirtyend == bp->b_bcount) 1489 bp->b_flags |= B_CLUSTEROK; 1490 } else { 1491 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1492 } 1493 1494 /* 1495 * For an interrupted write, the buffer is still valid 1496 * and the write hasn't been pushed to the server yet, 1497 * so we can't set B_ERROR and report the interruption 1498 * by setting B_EINTR. For the async case, B_EINTR 1499 * is not relevant, so the rpc attempt is essentially 1500 * a noop. For the case of a V3 write rpc not being 1501 * committed to stable storage, the block is still 1502 * dirty and requires either a commit rpc or another 1503 * write rpc with iomode == NFSV3WRITE_FILESYNC before 1504 * the block is reused. This is indicated by setting 1505 * the B_DELWRI and B_NEEDCOMMIT flags. 1506 * 1507 * If the buffer is marked B_PAGING, it does not reside on 1508 * the vp's paging queues so we cannot call bdirty(). The 1509 * bp in this case is not an NFS cache block so we should 1510 * be safe. XXX 1511 */ 1512 if (error == EINTR 1513 || (!error && (bp->b_flags & B_NEEDCOMMIT))) { 1514 crit_enter(); 1515 bp->b_flags &= ~(B_INVAL|B_NOCACHE); 1516 if ((bp->b_flags & B_PAGING) == 0) 1517 bdirty(bp); 1518 if (error) 1519 bp->b_flags |= B_EINTR; 1520 crit_exit(); 1521 } else { 1522 if (error) { 1523 bp->b_flags |= B_ERROR; 1524 bp->b_error = np->n_error = error; 1525 np->n_flag |= NWRITEERR; 1526 } 1527 bp->b_dirtyoff = bp->b_dirtyend = 0; 1528 } 1529 } else { 1530 bp->b_resid = 0; 1531 biodone(bio); 1532 return (0); 1533 } 1534 } 1535 bp->b_resid = uiop->uio_resid; 1536 if (must_commit) 1537 nfs_clearcommit(vp->v_mount); 1538 biodone(bio); 1539 return (error); 1540 } 1541 1542 /* 1543 * Used to aid in handling ftruncate() operations on the NFS client side. 1544 * Truncation creates a number of special problems for NFS. We have to 1545 * throw away VM pages and buffer cache buffers that are beyond EOF, and 1546 * we have to properly handle VM pages or (potentially dirty) buffers 1547 * that straddle the truncation point. 1548 */ 1549 1550 int 1551 nfs_meta_setsize(struct vnode *vp, struct thread *td, u_quad_t nsize) 1552 { 1553 struct nfsnode *np = VTONFS(vp); 1554 u_quad_t tsize = np->n_size; 1555 int biosize = vp->v_mount->mnt_stat.f_iosize; 1556 int error = 0; 1557 1558 np->n_size = nsize; 1559 1560 if (np->n_size < tsize) { 1561 struct buf *bp; 1562 daddr_t lbn; 1563 off_t loffset; 1564 int bufsize; 1565 1566 /* 1567 * vtruncbuf() doesn't get the buffer overlapping the 1568 * truncation point. We may have a B_DELWRI and/or B_CACHE 1569 * buffer that now needs to be truncated. 1570 */ 1571 error = vtruncbuf(vp, nsize, biosize); 1572 lbn = nsize / biosize; 1573 bufsize = nsize & (biosize - 1); 1574 loffset = nsize - bufsize; 1575 bp = nfs_getcacheblk(vp, loffset, bufsize, td); 1576 if (bp->b_dirtyoff > bp->b_bcount) 1577 bp->b_dirtyoff = bp->b_bcount; 1578 if (bp->b_dirtyend > bp->b_bcount) 1579 bp->b_dirtyend = bp->b_bcount; 1580 bp->b_flags |= B_RELBUF; /* don't leave garbage around */ 1581 brelse(bp); 1582 } else { 1583 vnode_pager_setsize(vp, nsize); 1584 } 1585 return(error); 1586 } 1587 1588 /* 1589 * Synchronous completion for nfs_doio. Call bpdone() with elseit=FALSE. 1590 * Caller is responsible for brelse()'ing the bp. 1591 */ 1592 static void 1593 nfsiodone_sync(struct bio *bio) 1594 { 1595 bio->bio_flags = 0; 1596 bpdone(bio->bio_buf, 0); 1597 } 1598