1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Rick Macklem at The University of Guelph. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)nfs_bio.c 8.9 (Berkeley) 3/30/95 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/bio.h> 43 #include <sys/buf.h> 44 #include <sys/kernel.h> 45 #include <sys/mount.h> 46 #include <sys/rwlock.h> 47 #include <sys/vmmeter.h> 48 #include <sys/vnode.h> 49 50 #include <vm/vm.h> 51 #include <vm/vm_param.h> 52 #include <vm/vm_extern.h> 53 #include <vm/vm_page.h> 54 #include <vm/vm_object.h> 55 #include <vm/vm_pager.h> 56 #include <vm/vnode_pager.h> 57 58 #include <fs/nfs/nfsport.h> 59 #include <fs/nfsclient/nfsmount.h> 60 #include <fs/nfsclient/nfs.h> 61 #include <fs/nfsclient/nfsnode.h> 62 #include <fs/nfsclient/nfs_kdtrace.h> 63 64 extern int newnfs_directio_allow_mmap; 65 extern struct nfsstatsv1 nfsstatsv1; 66 extern struct mtx ncl_iod_mutex; 67 extern int ncl_numasync; 68 extern enum nfsiod_state ncl_iodwant[NFS_MAXASYNCDAEMON]; 69 extern struct nfsmount *ncl_iodmount[NFS_MAXASYNCDAEMON]; 70 extern int newnfs_directio_enable; 71 extern int nfs_keep_dirty_on_error; 72 73 uma_zone_t ncl_pbuf_zone; 74 75 static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, 76 struct thread *td); 77 static int nfs_directio_write(struct vnode *vp, struct uio *uiop, 78 struct ucred *cred, int ioflag); 79 80 /* 81 * Vnode op for VM getpages. 82 */ 83 SYSCTL_DECL(_vfs_nfs); 84 static int use_buf_pager = 1; 85 SYSCTL_INT(_vfs_nfs, OID_AUTO, use_buf_pager, CTLFLAG_RWTUN, 86 &use_buf_pager, 0, 87 "Use buffer pager instead of direct readrpc call"); 88 89 static daddr_t 90 ncl_gbp_getblkno(struct vnode *vp, vm_ooffset_t off) 91 { 92 93 return (off / vp->v_bufobj.bo_bsize); 94 } 95 96 static int 97 ncl_gbp_getblksz(struct vnode *vp, daddr_t lbn) 98 { 99 struct nfsnode *np; 100 u_quad_t nsize; 101 int biosize, bcount; 102 103 np = VTONFS(vp); 104 NFSLOCKNODE(np); 105 nsize = np->n_size; 106 NFSUNLOCKNODE(np); 107 108 biosize = vp->v_bufobj.bo_bsize; 109 bcount = biosize; 110 if ((off_t)lbn * biosize >= nsize) 111 bcount = 0; 112 else if ((off_t)(lbn + 1) * biosize > nsize) 113 bcount = nsize - (off_t)lbn * biosize; 114 return (bcount); 115 } 116 117 int 118 ncl_getpages(struct vop_getpages_args *ap) 119 { 120 int i, error, nextoff, size, toff, count, npages; 121 struct uio uio; 122 struct iovec iov; 123 vm_offset_t kva; 124 struct buf *bp; 125 struct vnode *vp; 126 struct thread *td; 127 struct ucred *cred; 128 struct nfsmount *nmp; 129 vm_object_t object; 130 vm_page_t *pages; 131 struct nfsnode *np; 132 133 vp = ap->a_vp; 134 np = VTONFS(vp); 135 td = curthread; 136 cred = curthread->td_ucred; 137 nmp = VFSTONFS(vp->v_mount); 138 pages = ap->a_m; 139 npages = ap->a_count; 140 141 if ((object = vp->v_object) == NULL) { 142 printf("ncl_getpages: called with non-merged cache vnode\n"); 143 return (VM_PAGER_ERROR); 144 } 145 146 if (newnfs_directio_enable && !newnfs_directio_allow_mmap) { 147 NFSLOCKNODE(np); 148 if ((np->n_flag & NNONCACHE) && (vp->v_type == VREG)) { 149 NFSUNLOCKNODE(np); 150 printf("ncl_getpages: called on non-cacheable vnode\n"); 151 return (VM_PAGER_ERROR); 152 } else 153 NFSUNLOCKNODE(np); 154 } 155 156 mtx_lock(&nmp->nm_mtx); 157 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 158 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 159 mtx_unlock(&nmp->nm_mtx); 160 /* We'll never get here for v4, because we always have fsinfo */ 161 (void)ncl_fsinfo(nmp, vp, cred, td); 162 } else 163 mtx_unlock(&nmp->nm_mtx); 164 165 if (use_buf_pager) 166 return (vfs_bio_getpages(vp, pages, npages, ap->a_rbehind, 167 ap->a_rahead, ncl_gbp_getblkno, ncl_gbp_getblksz)); 168 169 /* 170 * If the requested page is partially valid, just return it and 171 * allow the pager to zero-out the blanks. Partially valid pages 172 * can only occur at the file EOF. 173 * 174 * XXXGL: is that true for NFS, where short read can occur??? 175 */ 176 VM_OBJECT_WLOCK(object); 177 if (!vm_page_none_valid(pages[npages - 1]) && --npages == 0) 178 goto out; 179 VM_OBJECT_WUNLOCK(object); 180 181 /* 182 * We use only the kva address for the buffer, but this is extremely 183 * convenient and fast. 184 */ 185 bp = uma_zalloc(ncl_pbuf_zone, M_WAITOK); 186 187 kva = (vm_offset_t) bp->b_data; 188 pmap_qenter(kva, pages, npages); 189 VM_CNT_INC(v_vnodein); 190 VM_CNT_ADD(v_vnodepgsin, npages); 191 192 count = npages << PAGE_SHIFT; 193 iov.iov_base = (caddr_t) kva; 194 iov.iov_len = count; 195 uio.uio_iov = &iov; 196 uio.uio_iovcnt = 1; 197 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex); 198 uio.uio_resid = count; 199 uio.uio_segflg = UIO_SYSSPACE; 200 uio.uio_rw = UIO_READ; 201 uio.uio_td = td; 202 203 error = ncl_readrpc(vp, &uio, cred); 204 pmap_qremove(kva, npages); 205 206 uma_zfree(ncl_pbuf_zone, bp); 207 208 if (error && (uio.uio_resid == count)) { 209 printf("ncl_getpages: error %d\n", error); 210 return (VM_PAGER_ERROR); 211 } 212 213 /* 214 * Calculate the number of bytes read and validate only that number 215 * of bytes. Note that due to pending writes, size may be 0. This 216 * does not mean that the remaining data is invalid! 217 */ 218 219 size = count - uio.uio_resid; 220 VM_OBJECT_WLOCK(object); 221 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) { 222 vm_page_t m; 223 nextoff = toff + PAGE_SIZE; 224 m = pages[i]; 225 226 if (nextoff <= size) { 227 /* 228 * Read operation filled an entire page 229 */ 230 vm_page_valid(m); 231 KASSERT(m->dirty == 0, 232 ("nfs_getpages: page %p is dirty", m)); 233 } else if (size > toff) { 234 /* 235 * Read operation filled a partial page. 236 */ 237 vm_page_invalid(m); 238 vm_page_set_valid_range(m, 0, size - toff); 239 KASSERT(m->dirty == 0, 240 ("nfs_getpages: page %p is dirty", m)); 241 } else { 242 /* 243 * Read operation was short. If no error 244 * occurred we may have hit a zero-fill 245 * section. We leave valid set to 0, and page 246 * is freed by vm_page_readahead_finish() if 247 * its index is not equal to requested, or 248 * page is zeroed and set valid by 249 * vm_pager_get_pages() for requested page. 250 */ 251 ; 252 } 253 } 254 out: 255 VM_OBJECT_WUNLOCK(object); 256 if (ap->a_rbehind) 257 *ap->a_rbehind = 0; 258 if (ap->a_rahead) 259 *ap->a_rahead = 0; 260 return (VM_PAGER_OK); 261 } 262 263 /* 264 * Vnode op for VM putpages. 265 */ 266 int 267 ncl_putpages(struct vop_putpages_args *ap) 268 { 269 struct uio uio; 270 struct iovec iov; 271 int i, error, npages, count; 272 off_t offset; 273 int *rtvals; 274 struct vnode *vp; 275 struct thread *td; 276 struct ucred *cred; 277 struct nfsmount *nmp; 278 struct nfsnode *np; 279 vm_page_t *pages; 280 281 vp = ap->a_vp; 282 np = VTONFS(vp); 283 td = curthread; /* XXX */ 284 /* Set the cred to n_writecred for the write rpcs. */ 285 if (np->n_writecred != NULL) 286 cred = crhold(np->n_writecred); 287 else 288 cred = crhold(curthread->td_ucred); /* XXX */ 289 nmp = VFSTONFS(vp->v_mount); 290 pages = ap->a_m; 291 count = ap->a_count; 292 rtvals = ap->a_rtvals; 293 npages = btoc(count); 294 offset = IDX_TO_OFF(pages[0]->pindex); 295 296 mtx_lock(&nmp->nm_mtx); 297 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 298 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 299 mtx_unlock(&nmp->nm_mtx); 300 (void)ncl_fsinfo(nmp, vp, cred, td); 301 } else 302 mtx_unlock(&nmp->nm_mtx); 303 304 NFSLOCKNODE(np); 305 if (newnfs_directio_enable && !newnfs_directio_allow_mmap && 306 (np->n_flag & NNONCACHE) && (vp->v_type == VREG)) { 307 NFSUNLOCKNODE(np); 308 printf("ncl_putpages: called on noncache-able vnode\n"); 309 NFSLOCKNODE(np); 310 } 311 /* 312 * When putting pages, do not extend file past EOF. 313 */ 314 if (offset + count > np->n_size) { 315 count = np->n_size - offset; 316 if (count < 0) 317 count = 0; 318 } 319 NFSUNLOCKNODE(np); 320 321 for (i = 0; i < npages; i++) 322 rtvals[i] = VM_PAGER_ERROR; 323 324 VM_CNT_INC(v_vnodeout); 325 VM_CNT_ADD(v_vnodepgsout, count); 326 327 iov.iov_base = unmapped_buf; 328 iov.iov_len = count; 329 uio.uio_iov = &iov; 330 uio.uio_iovcnt = 1; 331 uio.uio_offset = offset; 332 uio.uio_resid = count; 333 uio.uio_segflg = UIO_NOCOPY; 334 uio.uio_rw = UIO_WRITE; 335 uio.uio_td = td; 336 337 error = VOP_WRITE(vp, &uio, vnode_pager_putpages_ioflags(ap->a_sync), 338 cred); 339 crfree(cred); 340 341 if (error == 0 || !nfs_keep_dirty_on_error) { 342 vnode_pager_undirty_pages(pages, rtvals, count - uio.uio_resid, 343 np->n_size - offset, npages * PAGE_SIZE); 344 } 345 return (rtvals[0]); 346 } 347 348 /* 349 * For nfs, cache consistency can only be maintained approximately. 350 * Although RFC1094 does not specify the criteria, the following is 351 * believed to be compatible with the reference port. 352 * For nfs: 353 * If the file's modify time on the server has changed since the 354 * last read rpc or you have written to the file, 355 * you may have lost data cache consistency with the 356 * server, so flush all of the file's data out of the cache. 357 * Then force a getattr rpc to ensure that you have up to date 358 * attributes. 359 * NB: This implies that cache data can be read when up to 360 * NFS_ATTRTIMEO seconds out of date. If you find that you need current 361 * attributes this could be forced by setting n_attrstamp to 0 before 362 * the VOP_GETATTR() call. 363 */ 364 static inline int 365 nfs_bioread_check_cons(struct vnode *vp, struct thread *td, struct ucred *cred) 366 { 367 int error = 0; 368 struct vattr vattr; 369 struct nfsnode *np = VTONFS(vp); 370 bool old_lock; 371 372 /* 373 * Ensure the exclusove access to the node before checking 374 * whether the cache is consistent. 375 */ 376 old_lock = ncl_excl_start(vp); 377 NFSLOCKNODE(np); 378 if (np->n_flag & NMODIFIED) { 379 NFSUNLOCKNODE(np); 380 if (vp->v_type != VREG) { 381 if (vp->v_type != VDIR) 382 panic("nfs: bioread, not dir"); 383 ncl_invaldir(vp); 384 error = ncl_vinvalbuf(vp, V_SAVE | V_ALLOWCLEAN, td, 1); 385 if (error != 0) 386 goto out; 387 } 388 np->n_attrstamp = 0; 389 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 390 error = VOP_GETATTR(vp, &vattr, cred); 391 if (error) 392 goto out; 393 NFSLOCKNODE(np); 394 np->n_mtime = vattr.va_mtime; 395 NFSUNLOCKNODE(np); 396 } else { 397 NFSUNLOCKNODE(np); 398 error = VOP_GETATTR(vp, &vattr, cred); 399 if (error) 400 goto out; 401 NFSLOCKNODE(np); 402 if ((np->n_flag & NSIZECHANGED) 403 || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) { 404 NFSUNLOCKNODE(np); 405 if (vp->v_type == VDIR) 406 ncl_invaldir(vp); 407 error = ncl_vinvalbuf(vp, V_SAVE | V_ALLOWCLEAN, td, 1); 408 if (error != 0) 409 goto out; 410 NFSLOCKNODE(np); 411 np->n_mtime = vattr.va_mtime; 412 np->n_flag &= ~NSIZECHANGED; 413 } 414 NFSUNLOCKNODE(np); 415 } 416 out: 417 ncl_excl_finish(vp, old_lock); 418 return (error); 419 } 420 421 /* 422 * Vnode op for read using bio 423 */ 424 int 425 ncl_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred) 426 { 427 struct nfsnode *np = VTONFS(vp); 428 struct buf *bp, *rabp; 429 struct thread *td; 430 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 431 daddr_t lbn, rabn; 432 int biosize, bcount, error, i, n, nra, on, save2, seqcount; 433 off_t tmp_off; 434 435 KASSERT(uio->uio_rw == UIO_READ, ("ncl_read mode")); 436 if (uio->uio_resid == 0) 437 return (0); 438 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */ 439 return (EINVAL); 440 td = uio->uio_td; 441 442 mtx_lock(&nmp->nm_mtx); 443 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 444 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 445 mtx_unlock(&nmp->nm_mtx); 446 (void)ncl_fsinfo(nmp, vp, cred, td); 447 mtx_lock(&nmp->nm_mtx); 448 } 449 if (nmp->nm_rsize == 0 || nmp->nm_readdirsize == 0) 450 (void) newnfs_iosize(nmp); 451 452 tmp_off = uio->uio_offset + uio->uio_resid; 453 if (vp->v_type != VDIR && 454 (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)) { 455 mtx_unlock(&nmp->nm_mtx); 456 return (EFBIG); 457 } 458 mtx_unlock(&nmp->nm_mtx); 459 460 if (newnfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG)) 461 /* No caching/ no readaheads. Just read data into the user buffer */ 462 return ncl_readrpc(vp, uio, cred); 463 464 n = 0; 465 on = 0; 466 biosize = vp->v_bufobj.bo_bsize; 467 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE); 468 469 error = nfs_bioread_check_cons(vp, td, cred); 470 if (error) 471 return error; 472 473 save2 = curthread_pflags2_set(TDP2_SBPAGES); 474 do { 475 u_quad_t nsize; 476 477 NFSLOCKNODE(np); 478 nsize = np->n_size; 479 NFSUNLOCKNODE(np); 480 481 switch (vp->v_type) { 482 case VREG: 483 NFSINCRGLOBAL(nfsstatsv1.biocache_reads); 484 lbn = uio->uio_offset / biosize; 485 on = uio->uio_offset - (lbn * biosize); 486 487 /* 488 * Start the read ahead(s), as required. 489 */ 490 if (nmp->nm_readahead > 0) { 491 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && 492 (off_t)(lbn + 1 + nra) * biosize < nsize; nra++) { 493 rabn = lbn + 1 + nra; 494 if (incore(&vp->v_bufobj, rabn) == NULL) { 495 rabp = nfs_getcacheblk(vp, rabn, biosize, td); 496 if (!rabp) { 497 error = newnfs_sigintr(nmp, td); 498 if (error == 0) 499 error = EINTR; 500 goto out; 501 } 502 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 503 rabp->b_flags |= B_ASYNC; 504 rabp->b_iocmd = BIO_READ; 505 vfs_busy_pages(rabp, 0); 506 if (ncl_asyncio(nmp, rabp, cred, td)) { 507 rabp->b_flags |= B_INVAL; 508 rabp->b_ioflags |= BIO_ERROR; 509 vfs_unbusy_pages(rabp); 510 brelse(rabp); 511 break; 512 } 513 } else { 514 brelse(rabp); 515 } 516 } 517 } 518 } 519 520 /* Note that bcount is *not* DEV_BSIZE aligned. */ 521 bcount = biosize; 522 if ((off_t)lbn * biosize >= nsize) { 523 bcount = 0; 524 } else if ((off_t)(lbn + 1) * biosize > nsize) { 525 bcount = nsize - (off_t)lbn * biosize; 526 } 527 bp = nfs_getcacheblk(vp, lbn, bcount, td); 528 529 if (!bp) { 530 error = newnfs_sigintr(nmp, td); 531 if (error == 0) 532 error = EINTR; 533 goto out; 534 } 535 536 /* 537 * If B_CACHE is not set, we must issue the read. If this 538 * fails, we return an error. 539 */ 540 541 if ((bp->b_flags & B_CACHE) == 0) { 542 bp->b_iocmd = BIO_READ; 543 vfs_busy_pages(bp, 0); 544 error = ncl_doio(vp, bp, cred, td, 0); 545 if (error) { 546 brelse(bp); 547 goto out; 548 } 549 } 550 551 /* 552 * on is the offset into the current bp. Figure out how many 553 * bytes we can copy out of the bp. Note that bcount is 554 * NOT DEV_BSIZE aligned. 555 * 556 * Then figure out how many bytes we can copy into the uio. 557 */ 558 559 n = 0; 560 if (on < bcount) 561 n = MIN((unsigned)(bcount - on), uio->uio_resid); 562 break; 563 case VLNK: 564 NFSINCRGLOBAL(nfsstatsv1.biocache_readlinks); 565 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td); 566 if (!bp) { 567 error = newnfs_sigintr(nmp, td); 568 if (error == 0) 569 error = EINTR; 570 goto out; 571 } 572 if ((bp->b_flags & B_CACHE) == 0) { 573 bp->b_iocmd = BIO_READ; 574 vfs_busy_pages(bp, 0); 575 error = ncl_doio(vp, bp, cred, td, 0); 576 if (error) { 577 bp->b_ioflags |= BIO_ERROR; 578 brelse(bp); 579 goto out; 580 } 581 } 582 n = MIN(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); 583 on = 0; 584 break; 585 case VDIR: 586 NFSINCRGLOBAL(nfsstatsv1.biocache_readdirs); 587 if (np->n_direofoffset 588 && uio->uio_offset >= np->n_direofoffset) { 589 error = 0; 590 goto out; 591 } 592 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; 593 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); 594 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td); 595 if (!bp) { 596 error = newnfs_sigintr(nmp, td); 597 if (error == 0) 598 error = EINTR; 599 goto out; 600 } 601 if ((bp->b_flags & B_CACHE) == 0) { 602 bp->b_iocmd = BIO_READ; 603 vfs_busy_pages(bp, 0); 604 error = ncl_doio(vp, bp, cred, td, 0); 605 if (error) { 606 brelse(bp); 607 } 608 while (error == NFSERR_BAD_COOKIE) { 609 ncl_invaldir(vp); 610 error = ncl_vinvalbuf(vp, 0, td, 1); 611 612 /* 613 * Yuck! The directory has been modified on the 614 * server. The only way to get the block is by 615 * reading from the beginning to get all the 616 * offset cookies. 617 * 618 * Leave the last bp intact unless there is an error. 619 * Loop back up to the while if the error is another 620 * NFSERR_BAD_COOKIE (double yuch!). 621 */ 622 for (i = 0; i <= lbn && !error; i++) { 623 if (np->n_direofoffset 624 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) { 625 error = 0; 626 goto out; 627 } 628 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td); 629 if (!bp) { 630 error = newnfs_sigintr(nmp, td); 631 if (error == 0) 632 error = EINTR; 633 goto out; 634 } 635 if ((bp->b_flags & B_CACHE) == 0) { 636 bp->b_iocmd = BIO_READ; 637 vfs_busy_pages(bp, 0); 638 error = ncl_doio(vp, bp, cred, td, 0); 639 /* 640 * no error + B_INVAL == directory EOF, 641 * use the block. 642 */ 643 if (error == 0 && (bp->b_flags & B_INVAL)) 644 break; 645 } 646 /* 647 * An error will throw away the block and the 648 * for loop will break out. If no error and this 649 * is not the block we want, we throw away the 650 * block and go for the next one via the for loop. 651 */ 652 if (error || i < lbn) 653 brelse(bp); 654 } 655 } 656 /* 657 * The above while is repeated if we hit another cookie 658 * error. If we hit an error and it wasn't a cookie error, 659 * we give up. 660 */ 661 if (error) 662 goto out; 663 } 664 665 /* 666 * If not eof and read aheads are enabled, start one. 667 * (You need the current block first, so that you have the 668 * directory offset cookie of the next block.) 669 */ 670 if (nmp->nm_readahead > 0 && 671 (bp->b_flags & B_INVAL) == 0 && 672 (np->n_direofoffset == 0 || 673 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) && 674 incore(&vp->v_bufobj, lbn + 1) == NULL) { 675 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td); 676 if (rabp) { 677 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 678 rabp->b_flags |= B_ASYNC; 679 rabp->b_iocmd = BIO_READ; 680 vfs_busy_pages(rabp, 0); 681 if (ncl_asyncio(nmp, rabp, cred, td)) { 682 rabp->b_flags |= B_INVAL; 683 rabp->b_ioflags |= BIO_ERROR; 684 vfs_unbusy_pages(rabp); 685 brelse(rabp); 686 } 687 } else { 688 brelse(rabp); 689 } 690 } 691 } 692 /* 693 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is 694 * chopped for the EOF condition, we cannot tell how large 695 * NFS directories are going to be until we hit EOF. So 696 * an NFS directory buffer is *not* chopped to its EOF. Now, 697 * it just so happens that b_resid will effectively chop it 698 * to EOF. *BUT* this information is lost if the buffer goes 699 * away and is reconstituted into a B_CACHE state ( due to 700 * being VMIO ) later. So we keep track of the directory eof 701 * in np->n_direofoffset and chop it off as an extra step 702 * right here. 703 */ 704 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on); 705 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset) 706 n = np->n_direofoffset - uio->uio_offset; 707 break; 708 default: 709 printf(" ncl_bioread: type %x unexpected\n", vp->v_type); 710 bp = NULL; 711 break; 712 } 713 714 if (n > 0) { 715 error = vn_io_fault_uiomove(bp->b_data + on, (int)n, uio); 716 } 717 if (vp->v_type == VLNK) 718 n = 0; 719 if (bp != NULL) 720 brelse(bp); 721 } while (error == 0 && uio->uio_resid > 0 && n > 0); 722 out: 723 curthread_pflags2_restore(save2); 724 if ((curthread->td_pflags2 & TDP2_SBPAGES) == 0) { 725 NFSLOCKNODE(np); 726 ncl_pager_setsize(vp, NULL); 727 } 728 return (error); 729 } 730 731 /* 732 * The NFS write path cannot handle iovecs with len > 1. So we need to 733 * break up iovecs accordingly (restricting them to wsize). 734 * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf). 735 * For the ASYNC case, 2 copies are needed. The first a copy from the 736 * user buffer to a staging buffer and then a second copy from the staging 737 * buffer to mbufs. This can be optimized by copying from the user buffer 738 * directly into mbufs and passing the chain down, but that requires a 739 * fair amount of re-working of the relevant codepaths (and can be done 740 * later). 741 */ 742 static int 743 nfs_directio_write(vp, uiop, cred, ioflag) 744 struct vnode *vp; 745 struct uio *uiop; 746 struct ucred *cred; 747 int ioflag; 748 { 749 int error; 750 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 751 struct thread *td = uiop->uio_td; 752 int size; 753 int wsize; 754 755 mtx_lock(&nmp->nm_mtx); 756 wsize = nmp->nm_wsize; 757 mtx_unlock(&nmp->nm_mtx); 758 if (ioflag & IO_SYNC) { 759 int iomode, must_commit; 760 struct uio uio; 761 struct iovec iov; 762 do_sync: 763 while (uiop->uio_resid > 0) { 764 size = MIN(uiop->uio_resid, wsize); 765 size = MIN(uiop->uio_iov->iov_len, size); 766 iov.iov_base = uiop->uio_iov->iov_base; 767 iov.iov_len = size; 768 uio.uio_iov = &iov; 769 uio.uio_iovcnt = 1; 770 uio.uio_offset = uiop->uio_offset; 771 uio.uio_resid = size; 772 uio.uio_segflg = UIO_USERSPACE; 773 uio.uio_rw = UIO_WRITE; 774 uio.uio_td = td; 775 iomode = NFSWRITE_FILESYNC; 776 error = ncl_writerpc(vp, &uio, cred, &iomode, 777 &must_commit, 0); 778 KASSERT((must_commit == 0), 779 ("ncl_directio_write: Did not commit write")); 780 if (error) 781 return (error); 782 uiop->uio_offset += size; 783 uiop->uio_resid -= size; 784 if (uiop->uio_iov->iov_len <= size) { 785 uiop->uio_iovcnt--; 786 uiop->uio_iov++; 787 } else { 788 uiop->uio_iov->iov_base = 789 (char *)uiop->uio_iov->iov_base + size; 790 uiop->uio_iov->iov_len -= size; 791 } 792 } 793 } else { 794 struct uio *t_uio; 795 struct iovec *t_iov; 796 struct buf *bp; 797 798 /* 799 * Break up the write into blocksize chunks and hand these 800 * over to nfsiod's for write back. 801 * Unfortunately, this incurs a copy of the data. Since 802 * the user could modify the buffer before the write is 803 * initiated. 804 * 805 * The obvious optimization here is that one of the 2 copies 806 * in the async write path can be eliminated by copying the 807 * data here directly into mbufs and passing the mbuf chain 808 * down. But that will require a fair amount of re-working 809 * of the code and can be done if there's enough interest 810 * in NFS directio access. 811 */ 812 while (uiop->uio_resid > 0) { 813 size = MIN(uiop->uio_resid, wsize); 814 size = MIN(uiop->uio_iov->iov_len, size); 815 bp = uma_zalloc(ncl_pbuf_zone, M_WAITOK); 816 t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK); 817 t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK); 818 t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK); 819 t_iov->iov_len = size; 820 t_uio->uio_iov = t_iov; 821 t_uio->uio_iovcnt = 1; 822 t_uio->uio_offset = uiop->uio_offset; 823 t_uio->uio_resid = size; 824 t_uio->uio_segflg = UIO_SYSSPACE; 825 t_uio->uio_rw = UIO_WRITE; 826 t_uio->uio_td = td; 827 KASSERT(uiop->uio_segflg == UIO_USERSPACE || 828 uiop->uio_segflg == UIO_SYSSPACE, 829 ("nfs_directio_write: Bad uio_segflg")); 830 if (uiop->uio_segflg == UIO_USERSPACE) { 831 error = copyin(uiop->uio_iov->iov_base, 832 t_iov->iov_base, size); 833 if (error != 0) 834 goto err_free; 835 } else 836 /* 837 * UIO_SYSSPACE may never happen, but handle 838 * it just in case it does. 839 */ 840 bcopy(uiop->uio_iov->iov_base, t_iov->iov_base, 841 size); 842 bp->b_flags |= B_DIRECT; 843 bp->b_iocmd = BIO_WRITE; 844 if (cred != NOCRED) { 845 crhold(cred); 846 bp->b_wcred = cred; 847 } else 848 bp->b_wcred = NOCRED; 849 bp->b_caller1 = (void *)t_uio; 850 bp->b_vp = vp; 851 error = ncl_asyncio(nmp, bp, NOCRED, td); 852 err_free: 853 if (error) { 854 free(t_iov->iov_base, M_NFSDIRECTIO); 855 free(t_iov, M_NFSDIRECTIO); 856 free(t_uio, M_NFSDIRECTIO); 857 bp->b_vp = NULL; 858 uma_zfree(ncl_pbuf_zone, bp); 859 if (error == EINTR) 860 return (error); 861 goto do_sync; 862 } 863 uiop->uio_offset += size; 864 uiop->uio_resid -= size; 865 if (uiop->uio_iov->iov_len <= size) { 866 uiop->uio_iovcnt--; 867 uiop->uio_iov++; 868 } else { 869 uiop->uio_iov->iov_base = 870 (char *)uiop->uio_iov->iov_base + size; 871 uiop->uio_iov->iov_len -= size; 872 } 873 } 874 } 875 return (0); 876 } 877 878 /* 879 * Vnode op for write using bio 880 */ 881 int 882 ncl_write(struct vop_write_args *ap) 883 { 884 int biosize; 885 struct uio *uio = ap->a_uio; 886 struct thread *td = uio->uio_td; 887 struct vnode *vp = ap->a_vp; 888 struct nfsnode *np = VTONFS(vp); 889 struct ucred *cred = ap->a_cred; 890 int ioflag = ap->a_ioflag; 891 struct buf *bp; 892 struct vattr vattr; 893 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 894 daddr_t lbn; 895 int bcount, noncontig_write, obcount; 896 int bp_cached, n, on, error = 0, error1, save2, wouldcommit; 897 size_t orig_resid, local_resid; 898 off_t orig_size, tmp_off; 899 900 KASSERT(uio->uio_rw == UIO_WRITE, ("ncl_write mode")); 901 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, 902 ("ncl_write proc")); 903 if (vp->v_type != VREG) 904 return (EIO); 905 NFSLOCKNODE(np); 906 if (np->n_flag & NWRITEERR) { 907 np->n_flag &= ~NWRITEERR; 908 NFSUNLOCKNODE(np); 909 return (np->n_error); 910 } else 911 NFSUNLOCKNODE(np); 912 mtx_lock(&nmp->nm_mtx); 913 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 914 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 915 mtx_unlock(&nmp->nm_mtx); 916 (void)ncl_fsinfo(nmp, vp, cred, td); 917 mtx_lock(&nmp->nm_mtx); 918 } 919 if (nmp->nm_wsize == 0) 920 (void) newnfs_iosize(nmp); 921 mtx_unlock(&nmp->nm_mtx); 922 923 /* 924 * Synchronously flush pending buffers if we are in synchronous 925 * mode or if we are appending. 926 */ 927 if (ioflag & (IO_APPEND | IO_SYNC)) { 928 NFSLOCKNODE(np); 929 if (np->n_flag & NMODIFIED) { 930 NFSUNLOCKNODE(np); 931 #ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */ 932 /* 933 * Require non-blocking, synchronous writes to 934 * dirty files to inform the program it needs 935 * to fsync(2) explicitly. 936 */ 937 if (ioflag & IO_NDELAY) 938 return (EAGAIN); 939 #endif 940 np->n_attrstamp = 0; 941 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 942 error = ncl_vinvalbuf(vp, V_SAVE | ((ioflag & 943 IO_VMIO) != 0 ? V_VMIO : 0), td, 1); 944 if (error != 0) 945 return (error); 946 } else 947 NFSUNLOCKNODE(np); 948 } 949 950 orig_resid = uio->uio_resid; 951 NFSLOCKNODE(np); 952 orig_size = np->n_size; 953 NFSUNLOCKNODE(np); 954 955 /* 956 * If IO_APPEND then load uio_offset. We restart here if we cannot 957 * get the append lock. 958 */ 959 if (ioflag & IO_APPEND) { 960 np->n_attrstamp = 0; 961 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 962 error = VOP_GETATTR(vp, &vattr, cred); 963 if (error) 964 return (error); 965 NFSLOCKNODE(np); 966 uio->uio_offset = np->n_size; 967 NFSUNLOCKNODE(np); 968 } 969 970 if (uio->uio_offset < 0) 971 return (EINVAL); 972 tmp_off = uio->uio_offset + uio->uio_resid; 973 if (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset) 974 return (EFBIG); 975 if (uio->uio_resid == 0) 976 return (0); 977 978 if (newnfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG) 979 return nfs_directio_write(vp, uio, cred, ioflag); 980 981 /* 982 * Maybe this should be above the vnode op call, but so long as 983 * file servers have no limits, i don't think it matters 984 */ 985 if (vn_rlimit_fsize(vp, uio, td)) 986 return (EFBIG); 987 988 save2 = curthread_pflags2_set(TDP2_SBPAGES); 989 biosize = vp->v_bufobj.bo_bsize; 990 /* 991 * Find all of this file's B_NEEDCOMMIT buffers. If our writes 992 * would exceed the local maximum per-file write commit size when 993 * combined with those, we must decide whether to flush, 994 * go synchronous, or return error. We don't bother checking 995 * IO_UNIT -- we just make all writes atomic anyway, as there's 996 * no point optimizing for something that really won't ever happen. 997 */ 998 wouldcommit = 0; 999 if (!(ioflag & IO_SYNC)) { 1000 int nflag; 1001 1002 NFSLOCKNODE(np); 1003 nflag = np->n_flag; 1004 NFSUNLOCKNODE(np); 1005 if (nflag & NMODIFIED) { 1006 BO_LOCK(&vp->v_bufobj); 1007 if (vp->v_bufobj.bo_dirty.bv_cnt != 0) { 1008 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd, 1009 b_bobufs) { 1010 if (bp->b_flags & B_NEEDCOMMIT) 1011 wouldcommit += bp->b_bcount; 1012 } 1013 } 1014 BO_UNLOCK(&vp->v_bufobj); 1015 } 1016 } 1017 1018 do { 1019 if (!(ioflag & IO_SYNC)) { 1020 wouldcommit += biosize; 1021 if (wouldcommit > nmp->nm_wcommitsize) { 1022 np->n_attrstamp = 0; 1023 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 1024 error = ncl_vinvalbuf(vp, V_SAVE | ((ioflag & 1025 IO_VMIO) != 0 ? V_VMIO : 0), td, 1); 1026 if (error != 0) 1027 goto out; 1028 wouldcommit = biosize; 1029 } 1030 } 1031 1032 NFSINCRGLOBAL(nfsstatsv1.biocache_writes); 1033 lbn = uio->uio_offset / biosize; 1034 on = uio->uio_offset - (lbn * biosize); 1035 n = MIN((unsigned)(biosize - on), uio->uio_resid); 1036 again: 1037 /* 1038 * Handle direct append and file extension cases, calculate 1039 * unaligned buffer size. 1040 */ 1041 NFSLOCKNODE(np); 1042 if ((np->n_flag & NHASBEENLOCKED) == 0 && 1043 (nmp->nm_flag & NFSMNT_NONCONTIGWR) != 0) 1044 noncontig_write = 1; 1045 else 1046 noncontig_write = 0; 1047 if ((uio->uio_offset == np->n_size || 1048 (noncontig_write != 0 && 1049 lbn == (np->n_size / biosize) && 1050 uio->uio_offset + n > np->n_size)) && n) { 1051 NFSUNLOCKNODE(np); 1052 /* 1053 * Get the buffer (in its pre-append state to maintain 1054 * B_CACHE if it was previously set). Resize the 1055 * nfsnode after we have locked the buffer to prevent 1056 * readers from reading garbage. 1057 */ 1058 obcount = np->n_size - (lbn * biosize); 1059 bp = nfs_getcacheblk(vp, lbn, obcount, td); 1060 1061 if (bp != NULL) { 1062 long save; 1063 1064 NFSLOCKNODE(np); 1065 np->n_size = uio->uio_offset + n; 1066 np->n_flag |= NMODIFIED; 1067 np->n_flag &= ~NVNSETSZSKIP; 1068 vnode_pager_setsize(vp, np->n_size); 1069 NFSUNLOCKNODE(np); 1070 1071 save = bp->b_flags & B_CACHE; 1072 bcount = on + n; 1073 allocbuf(bp, bcount); 1074 bp->b_flags |= save; 1075 if (noncontig_write != 0 && on > obcount) 1076 vfs_bio_bzero_buf(bp, obcount, on - 1077 obcount); 1078 } 1079 } else { 1080 /* 1081 * Obtain the locked cache block first, and then 1082 * adjust the file's size as appropriate. 1083 */ 1084 bcount = on + n; 1085 if ((off_t)lbn * biosize + bcount < np->n_size) { 1086 if ((off_t)(lbn + 1) * biosize < np->n_size) 1087 bcount = biosize; 1088 else 1089 bcount = np->n_size - (off_t)lbn * biosize; 1090 } 1091 NFSUNLOCKNODE(np); 1092 bp = nfs_getcacheblk(vp, lbn, bcount, td); 1093 NFSLOCKNODE(np); 1094 if (uio->uio_offset + n > np->n_size) { 1095 np->n_size = uio->uio_offset + n; 1096 np->n_flag |= NMODIFIED; 1097 np->n_flag &= ~NVNSETSZSKIP; 1098 vnode_pager_setsize(vp, np->n_size); 1099 } 1100 NFSUNLOCKNODE(np); 1101 } 1102 1103 if (!bp) { 1104 error = newnfs_sigintr(nmp, td); 1105 if (!error) 1106 error = EINTR; 1107 break; 1108 } 1109 1110 /* 1111 * Issue a READ if B_CACHE is not set. In special-append 1112 * mode, B_CACHE is based on the buffer prior to the write 1113 * op and is typically set, avoiding the read. If a read 1114 * is required in special append mode, the server will 1115 * probably send us a short-read since we extended the file 1116 * on our end, resulting in b_resid == 0 and, thusly, 1117 * B_CACHE getting set. 1118 * 1119 * We can also avoid issuing the read if the write covers 1120 * the entire buffer. We have to make sure the buffer state 1121 * is reasonable in this case since we will not be initiating 1122 * I/O. See the comments in kern/vfs_bio.c's getblk() for 1123 * more information. 1124 * 1125 * B_CACHE may also be set due to the buffer being cached 1126 * normally. 1127 */ 1128 1129 bp_cached = 1; 1130 if (on == 0 && n == bcount) { 1131 if ((bp->b_flags & B_CACHE) == 0) 1132 bp_cached = 0; 1133 bp->b_flags |= B_CACHE; 1134 bp->b_flags &= ~B_INVAL; 1135 bp->b_ioflags &= ~BIO_ERROR; 1136 } 1137 1138 if ((bp->b_flags & B_CACHE) == 0) { 1139 bp->b_iocmd = BIO_READ; 1140 vfs_busy_pages(bp, 0); 1141 error = ncl_doio(vp, bp, cred, td, 0); 1142 if (error) { 1143 brelse(bp); 1144 break; 1145 } 1146 } 1147 if (bp->b_wcred == NOCRED) 1148 bp->b_wcred = crhold(cred); 1149 NFSLOCKNODE(np); 1150 np->n_flag |= NMODIFIED; 1151 NFSUNLOCKNODE(np); 1152 1153 /* 1154 * If dirtyend exceeds file size, chop it down. This should 1155 * not normally occur but there is an append race where it 1156 * might occur XXX, so we log it. 1157 * 1158 * If the chopping creates a reverse-indexed or degenerate 1159 * situation with dirtyoff/end, we 0 both of them. 1160 */ 1161 1162 if (bp->b_dirtyend > bcount) { 1163 printf("NFS append race @%lx:%d\n", 1164 (long)bp->b_blkno * DEV_BSIZE, 1165 bp->b_dirtyend - bcount); 1166 bp->b_dirtyend = bcount; 1167 } 1168 1169 if (bp->b_dirtyoff >= bp->b_dirtyend) 1170 bp->b_dirtyoff = bp->b_dirtyend = 0; 1171 1172 /* 1173 * If the new write will leave a contiguous dirty 1174 * area, just update the b_dirtyoff and b_dirtyend, 1175 * otherwise force a write rpc of the old dirty area. 1176 * 1177 * If there has been a file lock applied to this file 1178 * or vfs.nfs.old_noncontig_writing is set, do the following: 1179 * While it is possible to merge discontiguous writes due to 1180 * our having a B_CACHE buffer ( and thus valid read data 1181 * for the hole), we don't because it could lead to 1182 * significant cache coherency problems with multiple clients, 1183 * especially if locking is implemented later on. 1184 * 1185 * If vfs.nfs.old_noncontig_writing is not set and there has 1186 * not been file locking done on this file: 1187 * Relax coherency a bit for the sake of performance and 1188 * expand the current dirty region to contain the new 1189 * write even if it means we mark some non-dirty data as 1190 * dirty. 1191 */ 1192 1193 if (noncontig_write == 0 && bp->b_dirtyend > 0 && 1194 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { 1195 if (bwrite(bp) == EINTR) { 1196 error = EINTR; 1197 break; 1198 } 1199 goto again; 1200 } 1201 1202 local_resid = uio->uio_resid; 1203 error = vn_io_fault_uiomove((char *)bp->b_data + on, n, uio); 1204 1205 if (error != 0 && !bp_cached) { 1206 /* 1207 * This block has no other content then what 1208 * possibly was written by the faulty uiomove. 1209 * Release it, forgetting the data pages, to 1210 * prevent the leak of uninitialized data to 1211 * usermode. 1212 */ 1213 bp->b_ioflags |= BIO_ERROR; 1214 brelse(bp); 1215 uio->uio_offset -= local_resid - uio->uio_resid; 1216 uio->uio_resid = local_resid; 1217 break; 1218 } 1219 1220 /* 1221 * Since this block is being modified, it must be written 1222 * again and not just committed. Since write clustering does 1223 * not work for the stage 1 data write, only the stage 2 1224 * commit rpc, we have to clear B_CLUSTEROK as well. 1225 */ 1226 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1227 1228 /* 1229 * Get the partial update on the progress made from 1230 * uiomove, if an error occurred. 1231 */ 1232 if (error != 0) 1233 n = local_resid - uio->uio_resid; 1234 1235 /* 1236 * Only update dirtyoff/dirtyend if not a degenerate 1237 * condition. 1238 */ 1239 if (n > 0) { 1240 if (bp->b_dirtyend > 0) { 1241 bp->b_dirtyoff = min(on, bp->b_dirtyoff); 1242 bp->b_dirtyend = max((on + n), bp->b_dirtyend); 1243 } else { 1244 bp->b_dirtyoff = on; 1245 bp->b_dirtyend = on + n; 1246 } 1247 vfs_bio_set_valid(bp, on, n); 1248 } 1249 1250 /* 1251 * If IO_SYNC do bwrite(). 1252 * 1253 * IO_INVAL appears to be unused. The idea appears to be 1254 * to turn off caching in this case. Very odd. XXX 1255 */ 1256 if ((ioflag & IO_SYNC)) { 1257 if (ioflag & IO_INVAL) 1258 bp->b_flags |= B_NOCACHE; 1259 error1 = bwrite(bp); 1260 if (error1 != 0) { 1261 if (error == 0) 1262 error = error1; 1263 break; 1264 } 1265 } else if ((n + on) == biosize || (ioflag & IO_ASYNC) != 0) { 1266 bp->b_flags |= B_ASYNC; 1267 (void) ncl_writebp(bp, 0, NULL); 1268 } else { 1269 bdwrite(bp); 1270 } 1271 1272 if (error != 0) 1273 break; 1274 } while (uio->uio_resid > 0 && n > 0); 1275 1276 if (error != 0) { 1277 if (ioflag & IO_UNIT) { 1278 VATTR_NULL(&vattr); 1279 vattr.va_size = orig_size; 1280 /* IO_SYNC is handled implicitely */ 1281 (void)VOP_SETATTR(vp, &vattr, cred); 1282 uio->uio_offset -= orig_resid - uio->uio_resid; 1283 uio->uio_resid = orig_resid; 1284 } 1285 } 1286 1287 out: 1288 curthread_pflags2_restore(save2); 1289 return (error); 1290 } 1291 1292 /* 1293 * Get an nfs cache block. 1294 * 1295 * Allocate a new one if the block isn't currently in the cache 1296 * and return the block marked busy. If the calling process is 1297 * interrupted by a signal for an interruptible mount point, return 1298 * NULL. 1299 * 1300 * The caller must carefully deal with the possible B_INVAL state of 1301 * the buffer. ncl_doio() clears B_INVAL (and ncl_asyncio() clears it 1302 * indirectly), so synchronous reads can be issued without worrying about 1303 * the B_INVAL state. We have to be a little more careful when dealing 1304 * with writes (see comments in nfs_write()) when extending a file past 1305 * its EOF. 1306 */ 1307 static struct buf * 1308 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td) 1309 { 1310 struct buf *bp; 1311 struct mount *mp; 1312 struct nfsmount *nmp; 1313 1314 mp = vp->v_mount; 1315 nmp = VFSTONFS(mp); 1316 1317 if (nmp->nm_flag & NFSMNT_INT) { 1318 sigset_t oldset; 1319 1320 newnfs_set_sigmask(td, &oldset); 1321 bp = getblk(vp, bn, size, PCATCH, 0, 0); 1322 newnfs_restore_sigmask(td, &oldset); 1323 while (bp == NULL) { 1324 if (newnfs_sigintr(nmp, td)) 1325 return (NULL); 1326 bp = getblk(vp, bn, size, 0, 2 * hz, 0); 1327 } 1328 } else { 1329 bp = getblk(vp, bn, size, 0, 0, 0); 1330 } 1331 1332 if (vp->v_type == VREG) 1333 bp->b_blkno = bn * (vp->v_bufobj.bo_bsize / DEV_BSIZE); 1334 return (bp); 1335 } 1336 1337 /* 1338 * Flush and invalidate all dirty buffers. If another process is already 1339 * doing the flush, just wait for completion. 1340 */ 1341 int 1342 ncl_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg) 1343 { 1344 struct nfsnode *np = VTONFS(vp); 1345 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 1346 int error = 0, slpflag, slptimeo; 1347 bool old_lock; 1348 1349 ASSERT_VOP_LOCKED(vp, "ncl_vinvalbuf"); 1350 1351 if ((nmp->nm_flag & NFSMNT_INT) == 0) 1352 intrflg = 0; 1353 if (NFSCL_FORCEDISM(nmp->nm_mountp)) 1354 intrflg = 1; 1355 if (intrflg) { 1356 slpflag = PCATCH; 1357 slptimeo = 2 * hz; 1358 } else { 1359 slpflag = 0; 1360 slptimeo = 0; 1361 } 1362 1363 old_lock = ncl_excl_start(vp); 1364 if (old_lock) 1365 flags |= V_ALLOWCLEAN; 1366 1367 /* 1368 * Now, flush as required. 1369 */ 1370 if ((flags & (V_SAVE | V_VMIO)) == V_SAVE && 1371 vp->v_bufobj.bo_object != NULL) { 1372 VM_OBJECT_WLOCK(vp->v_bufobj.bo_object); 1373 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC); 1374 VM_OBJECT_WUNLOCK(vp->v_bufobj.bo_object); 1375 /* 1376 * If the page clean was interrupted, fail the invalidation. 1377 * Not doing so, we run the risk of losing dirty pages in the 1378 * vinvalbuf() call below. 1379 */ 1380 if (intrflg && (error = newnfs_sigintr(nmp, td))) 1381 goto out; 1382 } 1383 1384 error = vinvalbuf(vp, flags, slpflag, 0); 1385 while (error) { 1386 if (intrflg && (error = newnfs_sigintr(nmp, td))) 1387 goto out; 1388 error = vinvalbuf(vp, flags, 0, slptimeo); 1389 } 1390 if (NFSHASPNFS(nmp)) { 1391 nfscl_layoutcommit(vp, td); 1392 /* 1393 * Invalidate the attribute cache, since writes to a DS 1394 * won't update the size attribute. 1395 */ 1396 NFSLOCKNODE(np); 1397 np->n_attrstamp = 0; 1398 } else 1399 NFSLOCKNODE(np); 1400 if (np->n_directio_asyncwr == 0) 1401 np->n_flag &= ~NMODIFIED; 1402 NFSUNLOCKNODE(np); 1403 out: 1404 ncl_excl_finish(vp, old_lock); 1405 return error; 1406 } 1407 1408 /* 1409 * Initiate asynchronous I/O. Return an error if no nfsiods are available. 1410 * This is mainly to avoid queueing async I/O requests when the nfsiods 1411 * are all hung on a dead server. 1412 * 1413 * Note: ncl_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp 1414 * is eventually dequeued by the async daemon, ncl_doio() *will*. 1415 */ 1416 int 1417 ncl_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td) 1418 { 1419 int iod; 1420 int gotiod; 1421 int slpflag = 0; 1422 int slptimeo = 0; 1423 int error, error2; 1424 1425 /* 1426 * Commits are usually short and sweet so lets save some cpu and 1427 * leave the async daemons for more important rpc's (such as reads 1428 * and writes). 1429 * 1430 * Readdirplus RPCs do vget()s to acquire the vnodes for entries 1431 * in the directory in order to update attributes. This can deadlock 1432 * with another thread that is waiting for async I/O to be done by 1433 * an nfsiod thread while holding a lock on one of these vnodes. 1434 * To avoid this deadlock, don't allow the async nfsiod threads to 1435 * perform Readdirplus RPCs. 1436 */ 1437 NFSLOCKIOD(); 1438 if ((bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) && 1439 (nmp->nm_bufqiods > ncl_numasync / 2)) || 1440 (bp->b_vp->v_type == VDIR && (nmp->nm_flag & NFSMNT_RDIRPLUS))) { 1441 NFSUNLOCKIOD(); 1442 return(EIO); 1443 } 1444 again: 1445 if (nmp->nm_flag & NFSMNT_INT) 1446 slpflag = PCATCH; 1447 gotiod = FALSE; 1448 1449 /* 1450 * Find a free iod to process this request. 1451 */ 1452 for (iod = 0; iod < ncl_numasync; iod++) 1453 if (ncl_iodwant[iod] == NFSIOD_AVAILABLE) { 1454 gotiod = TRUE; 1455 break; 1456 } 1457 1458 /* 1459 * Try to create one if none are free. 1460 */ 1461 if (!gotiod) 1462 ncl_nfsiodnew(); 1463 else { 1464 /* 1465 * Found one, so wake it up and tell it which 1466 * mount to process. 1467 */ 1468 NFS_DPF(ASYNCIO, ("ncl_asyncio: waking iod %d for mount %p\n", 1469 iod, nmp)); 1470 ncl_iodwant[iod] = NFSIOD_NOT_AVAILABLE; 1471 ncl_iodmount[iod] = nmp; 1472 nmp->nm_bufqiods++; 1473 wakeup(&ncl_iodwant[iod]); 1474 } 1475 1476 /* 1477 * If none are free, we may already have an iod working on this mount 1478 * point. If so, it will process our request. 1479 */ 1480 if (!gotiod) { 1481 if (nmp->nm_bufqiods > 0) { 1482 NFS_DPF(ASYNCIO, 1483 ("ncl_asyncio: %d iods are already processing mount %p\n", 1484 nmp->nm_bufqiods, nmp)); 1485 gotiod = TRUE; 1486 } 1487 } 1488 1489 /* 1490 * If we have an iod which can process the request, then queue 1491 * the buffer. 1492 */ 1493 if (gotiod) { 1494 /* 1495 * Ensure that the queue never grows too large. We still want 1496 * to asynchronize so we block rather then return EIO. 1497 */ 1498 while (nmp->nm_bufqlen >= 2*ncl_numasync) { 1499 NFS_DPF(ASYNCIO, 1500 ("ncl_asyncio: waiting for mount %p queue to drain\n", nmp)); 1501 nmp->nm_bufqwant = TRUE; 1502 error = newnfs_msleep(td, &nmp->nm_bufq, 1503 &ncl_iod_mutex, slpflag | PRIBIO, "nfsaio", 1504 slptimeo); 1505 if (error) { 1506 error2 = newnfs_sigintr(nmp, td); 1507 if (error2) { 1508 NFSUNLOCKIOD(); 1509 return (error2); 1510 } 1511 if (slpflag == PCATCH) { 1512 slpflag = 0; 1513 slptimeo = 2 * hz; 1514 } 1515 } 1516 /* 1517 * We might have lost our iod while sleeping, 1518 * so check and loop if necessary. 1519 */ 1520 goto again; 1521 } 1522 1523 /* We might have lost our nfsiod */ 1524 if (nmp->nm_bufqiods == 0) { 1525 NFS_DPF(ASYNCIO, 1526 ("ncl_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); 1527 goto again; 1528 } 1529 1530 if (bp->b_iocmd == BIO_READ) { 1531 if (bp->b_rcred == NOCRED && cred != NOCRED) 1532 bp->b_rcred = crhold(cred); 1533 } else { 1534 if (bp->b_wcred == NOCRED && cred != NOCRED) 1535 bp->b_wcred = crhold(cred); 1536 } 1537 1538 if (bp->b_flags & B_REMFREE) 1539 bremfreef(bp); 1540 BUF_KERNPROC(bp); 1541 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist); 1542 nmp->nm_bufqlen++; 1543 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) { 1544 NFSLOCKNODE(VTONFS(bp->b_vp)); 1545 VTONFS(bp->b_vp)->n_flag |= NMODIFIED; 1546 VTONFS(bp->b_vp)->n_directio_asyncwr++; 1547 NFSUNLOCKNODE(VTONFS(bp->b_vp)); 1548 } 1549 NFSUNLOCKIOD(); 1550 return (0); 1551 } 1552 1553 NFSUNLOCKIOD(); 1554 1555 /* 1556 * All the iods are busy on other mounts, so return EIO to 1557 * force the caller to process the i/o synchronously. 1558 */ 1559 NFS_DPF(ASYNCIO, ("ncl_asyncio: no iods available, i/o is synchronous\n")); 1560 return (EIO); 1561 } 1562 1563 void 1564 ncl_doio_directwrite(struct buf *bp) 1565 { 1566 int iomode, must_commit; 1567 struct uio *uiop = (struct uio *)bp->b_caller1; 1568 char *iov_base = uiop->uio_iov->iov_base; 1569 1570 iomode = NFSWRITE_FILESYNC; 1571 uiop->uio_td = NULL; /* NULL since we're in nfsiod */ 1572 ncl_writerpc(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit, 0); 1573 KASSERT((must_commit == 0), ("ncl_doio_directwrite: Did not commit write")); 1574 free(iov_base, M_NFSDIRECTIO); 1575 free(uiop->uio_iov, M_NFSDIRECTIO); 1576 free(uiop, M_NFSDIRECTIO); 1577 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) { 1578 struct nfsnode *np = VTONFS(bp->b_vp); 1579 NFSLOCKNODE(np); 1580 if (NFSHASPNFS(VFSTONFS(bp->b_vp->v_mount))) { 1581 /* 1582 * Invalidate the attribute cache, since writes to a DS 1583 * won't update the size attribute. 1584 */ 1585 np->n_attrstamp = 0; 1586 } 1587 np->n_directio_asyncwr--; 1588 if (np->n_directio_asyncwr == 0) { 1589 np->n_flag &= ~NMODIFIED; 1590 if ((np->n_flag & NFSYNCWAIT)) { 1591 np->n_flag &= ~NFSYNCWAIT; 1592 wakeup((caddr_t)&np->n_directio_asyncwr); 1593 } 1594 } 1595 NFSUNLOCKNODE(np); 1596 } 1597 bp->b_vp = NULL; 1598 uma_zfree(ncl_pbuf_zone, bp); 1599 } 1600 1601 /* 1602 * Do an I/O operation to/from a cache block. This may be called 1603 * synchronously or from an nfsiod. 1604 */ 1605 int 1606 ncl_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td, 1607 int called_from_strategy) 1608 { 1609 struct uio *uiop; 1610 struct nfsnode *np; 1611 struct nfsmount *nmp; 1612 int error = 0, iomode, must_commit = 0; 1613 struct uio uio; 1614 struct iovec io; 1615 struct proc *p = td ? td->td_proc : NULL; 1616 uint8_t iocmd; 1617 1618 np = VTONFS(vp); 1619 nmp = VFSTONFS(vp->v_mount); 1620 uiop = &uio; 1621 uiop->uio_iov = &io; 1622 uiop->uio_iovcnt = 1; 1623 uiop->uio_segflg = UIO_SYSSPACE; 1624 uiop->uio_td = td; 1625 1626 /* 1627 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We 1628 * do this here so we do not have to do it in all the code that 1629 * calls us. 1630 */ 1631 bp->b_flags &= ~B_INVAL; 1632 bp->b_ioflags &= ~BIO_ERROR; 1633 1634 KASSERT(!(bp->b_flags & B_DONE), ("ncl_doio: bp %p already marked done", bp)); 1635 iocmd = bp->b_iocmd; 1636 if (iocmd == BIO_READ) { 1637 io.iov_len = uiop->uio_resid = bp->b_bcount; 1638 io.iov_base = bp->b_data; 1639 uiop->uio_rw = UIO_READ; 1640 1641 switch (vp->v_type) { 1642 case VREG: 1643 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE; 1644 NFSINCRGLOBAL(nfsstatsv1.read_bios); 1645 error = ncl_readrpc(vp, uiop, cr); 1646 1647 if (!error) { 1648 if (uiop->uio_resid) { 1649 /* 1650 * If we had a short read with no error, we must have 1651 * hit a file hole. We should zero-fill the remainder. 1652 * This can also occur if the server hits the file EOF. 1653 * 1654 * Holes used to be able to occur due to pending 1655 * writes, but that is not possible any longer. 1656 */ 1657 int nread = bp->b_bcount - uiop->uio_resid; 1658 ssize_t left = uiop->uio_resid; 1659 1660 if (left > 0) 1661 bzero((char *)bp->b_data + nread, left); 1662 uiop->uio_resid = 0; 1663 } 1664 } 1665 /* ASSERT_VOP_LOCKED(vp, "ncl_doio"); */ 1666 if (p && vp->v_writecount <= -1) { 1667 NFSLOCKNODE(np); 1668 if (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.na_mtime)) { 1669 NFSUNLOCKNODE(np); 1670 PROC_LOCK(p); 1671 killproc(p, "text file modification"); 1672 PROC_UNLOCK(p); 1673 } else 1674 NFSUNLOCKNODE(np); 1675 } 1676 break; 1677 case VLNK: 1678 uiop->uio_offset = (off_t)0; 1679 NFSINCRGLOBAL(nfsstatsv1.readlink_bios); 1680 error = ncl_readlinkrpc(vp, uiop, cr); 1681 break; 1682 case VDIR: 1683 NFSINCRGLOBAL(nfsstatsv1.readdir_bios); 1684 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ; 1685 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) { 1686 error = ncl_readdirplusrpc(vp, uiop, cr, td); 1687 if (error == NFSERR_NOTSUPP) 1688 nmp->nm_flag &= ~NFSMNT_RDIRPLUS; 1689 } 1690 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) 1691 error = ncl_readdirrpc(vp, uiop, cr, td); 1692 /* 1693 * end-of-directory sets B_INVAL but does not generate an 1694 * error. 1695 */ 1696 if (error == 0 && uiop->uio_resid == bp->b_bcount) 1697 bp->b_flags |= B_INVAL; 1698 break; 1699 default: 1700 printf("ncl_doio: type %x unexpected\n", vp->v_type); 1701 break; 1702 } 1703 if (error) { 1704 bp->b_ioflags |= BIO_ERROR; 1705 bp->b_error = error; 1706 } 1707 } else { 1708 /* 1709 * If we only need to commit, try to commit 1710 */ 1711 if (bp->b_flags & B_NEEDCOMMIT) { 1712 int retv; 1713 off_t off; 1714 1715 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff; 1716 retv = ncl_commit(vp, off, bp->b_dirtyend-bp->b_dirtyoff, 1717 bp->b_wcred, td); 1718 if (retv == 0) { 1719 bp->b_dirtyoff = bp->b_dirtyend = 0; 1720 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1721 bp->b_resid = 0; 1722 bufdone(bp); 1723 return (0); 1724 } 1725 if (retv == NFSERR_STALEWRITEVERF) { 1726 ncl_clearcommit(vp->v_mount); 1727 } 1728 } 1729 1730 /* 1731 * Setup for actual write 1732 */ 1733 NFSLOCKNODE(np); 1734 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size) 1735 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE; 1736 NFSUNLOCKNODE(np); 1737 1738 if (bp->b_dirtyend > bp->b_dirtyoff) { 1739 io.iov_len = uiop->uio_resid = bp->b_dirtyend 1740 - bp->b_dirtyoff; 1741 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE 1742 + bp->b_dirtyoff; 1743 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; 1744 uiop->uio_rw = UIO_WRITE; 1745 NFSINCRGLOBAL(nfsstatsv1.write_bios); 1746 1747 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC) 1748 iomode = NFSWRITE_UNSTABLE; 1749 else 1750 iomode = NFSWRITE_FILESYNC; 1751 1752 error = ncl_writerpc(vp, uiop, cr, &iomode, &must_commit, 1753 called_from_strategy); 1754 1755 /* 1756 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try 1757 * to cluster the buffers needing commit. This will allow 1758 * the system to submit a single commit rpc for the whole 1759 * cluster. We can do this even if the buffer is not 100% 1760 * dirty (relative to the NFS blocksize), so we optimize the 1761 * append-to-file-case. 1762 * 1763 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be 1764 * cleared because write clustering only works for commit 1765 * rpc's, not for the data portion of the write). 1766 */ 1767 1768 if (!error && iomode == NFSWRITE_UNSTABLE) { 1769 bp->b_flags |= B_NEEDCOMMIT; 1770 if (bp->b_dirtyoff == 0 1771 && bp->b_dirtyend == bp->b_bcount) 1772 bp->b_flags |= B_CLUSTEROK; 1773 } else { 1774 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1775 } 1776 1777 /* 1778 * For an interrupted write, the buffer is still valid 1779 * and the write hasn't been pushed to the server yet, 1780 * so we can't set BIO_ERROR and report the interruption 1781 * by setting B_EINTR. For the B_ASYNC case, B_EINTR 1782 * is not relevant, so the rpc attempt is essentially 1783 * a noop. For the case of a V3 write rpc not being 1784 * committed to stable storage, the block is still 1785 * dirty and requires either a commit rpc or another 1786 * write rpc with iomode == NFSV3WRITE_FILESYNC before 1787 * the block is reused. This is indicated by setting 1788 * the B_DELWRI and B_NEEDCOMMIT flags. 1789 * 1790 * EIO is returned by ncl_writerpc() to indicate a recoverable 1791 * write error and is handled as above, except that 1792 * B_EINTR isn't set. One cause of this is a stale stateid 1793 * error for the RPC that indicates recovery is required, 1794 * when called with called_from_strategy != 0. 1795 * 1796 * If the buffer is marked B_PAGING, it does not reside on 1797 * the vp's paging queues so we cannot call bdirty(). The 1798 * bp in this case is not an NFS cache block so we should 1799 * be safe. XXX 1800 * 1801 * The logic below breaks up errors into recoverable and 1802 * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE 1803 * and keep the buffer around for potential write retries. 1804 * For the latter (eg ESTALE), we toss the buffer away (B_INVAL) 1805 * and save the error in the nfsnode. This is less than ideal 1806 * but necessary. Keeping such buffers around could potentially 1807 * cause buffer exhaustion eventually (they can never be written 1808 * out, so will get constantly be re-dirtied). It also causes 1809 * all sorts of vfs panics. For non-recoverable write errors, 1810 * also invalidate the attrcache, so we'll be forced to go over 1811 * the wire for this object, returning an error to user on next 1812 * call (most of the time). 1813 */ 1814 if (error == EINTR || error == EIO || error == ETIMEDOUT 1815 || (!error && (bp->b_flags & B_NEEDCOMMIT))) { 1816 bp->b_flags &= ~(B_INVAL|B_NOCACHE); 1817 if ((bp->b_flags & B_PAGING) == 0) { 1818 bdirty(bp); 1819 bp->b_flags &= ~B_DONE; 1820 } 1821 if ((error == EINTR || error == ETIMEDOUT) && 1822 (bp->b_flags & B_ASYNC) == 0) 1823 bp->b_flags |= B_EINTR; 1824 } else { 1825 if (error) { 1826 bp->b_ioflags |= BIO_ERROR; 1827 bp->b_flags |= B_INVAL; 1828 bp->b_error = np->n_error = error; 1829 NFSLOCKNODE(np); 1830 np->n_flag |= NWRITEERR; 1831 np->n_attrstamp = 0; 1832 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 1833 NFSUNLOCKNODE(np); 1834 } 1835 bp->b_dirtyoff = bp->b_dirtyend = 0; 1836 } 1837 } else { 1838 bp->b_resid = 0; 1839 bufdone(bp); 1840 return (0); 1841 } 1842 } 1843 bp->b_resid = uiop->uio_resid; 1844 if (must_commit) 1845 ncl_clearcommit(vp->v_mount); 1846 bufdone(bp); 1847 return (error); 1848 } 1849 1850 /* 1851 * Used to aid in handling ftruncate() operations on the NFS client side. 1852 * Truncation creates a number of special problems for NFS. We have to 1853 * throw away VM pages and buffer cache buffers that are beyond EOF, and 1854 * we have to properly handle VM pages or (potentially dirty) buffers 1855 * that straddle the truncation point. 1856 */ 1857 1858 int 1859 ncl_meta_setsize(struct vnode *vp, struct thread *td, u_quad_t nsize) 1860 { 1861 struct nfsnode *np = VTONFS(vp); 1862 u_quad_t tsize; 1863 int biosize = vp->v_bufobj.bo_bsize; 1864 int error = 0; 1865 1866 NFSLOCKNODE(np); 1867 tsize = np->n_size; 1868 np->n_size = nsize; 1869 NFSUNLOCKNODE(np); 1870 1871 if (nsize < tsize) { 1872 struct buf *bp; 1873 daddr_t lbn; 1874 int bufsize; 1875 1876 /* 1877 * vtruncbuf() doesn't get the buffer overlapping the 1878 * truncation point. We may have a B_DELWRI and/or B_CACHE 1879 * buffer that now needs to be truncated. 1880 */ 1881 error = vtruncbuf(vp, nsize, biosize); 1882 lbn = nsize / biosize; 1883 bufsize = nsize - (lbn * biosize); 1884 bp = nfs_getcacheblk(vp, lbn, bufsize, td); 1885 if (!bp) 1886 return EINTR; 1887 if (bp->b_dirtyoff > bp->b_bcount) 1888 bp->b_dirtyoff = bp->b_bcount; 1889 if (bp->b_dirtyend > bp->b_bcount) 1890 bp->b_dirtyend = bp->b_bcount; 1891 bp->b_flags |= B_RELBUF; /* don't leave garbage around */ 1892 brelse(bp); 1893 } else { 1894 vnode_pager_setsize(vp, nsize); 1895 } 1896 return(error); 1897 } 1898