1/*- 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Rick Macklem at The University of Guelph. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)nfs_bio.c 8.9 (Berkeley) 3/30/95 33 */ 34 35#include <sys/cdefs.h> 36__FBSDID("$FreeBSD: stable/11/sys/fs/nfsclient/nfs_clbio.c 349308 2019-06-23 14:49:30Z asomers $"); 37 38#include <sys/param.h> 39#include <sys/systm.h> 40#include <sys/bio.h> 41#include <sys/buf.h> 42#include <sys/kernel.h> 43#include <sys/mount.h> 44#include <sys/rwlock.h> 45#include <sys/vmmeter.h> 46#include <sys/vnode.h> 47 48#include <vm/vm.h> 49#include <vm/vm_param.h> 50#include <vm/vm_extern.h> 51#include <vm/vm_page.h> 52#include <vm/vm_object.h> 53#include <vm/vm_pager.h> 54#include <vm/vnode_pager.h> 55 56#include <fs/nfs/nfsport.h> 57#include <fs/nfsclient/nfsmount.h> 58#include <fs/nfsclient/nfs.h> 59#include <fs/nfsclient/nfsnode.h> 60#include <fs/nfsclient/nfs_kdtrace.h> 61 62extern int newnfs_directio_allow_mmap; 63extern struct nfsstatsv1 nfsstatsv1; 64extern struct mtx ncl_iod_mutex; 65extern int ncl_numasync; 66extern enum nfsiod_state ncl_iodwant[NFS_MAXASYNCDAEMON]; 67extern struct nfsmount *ncl_iodmount[NFS_MAXASYNCDAEMON]; 68extern int newnfs_directio_enable; 69extern int nfs_keep_dirty_on_error; 70 71int ncl_pbuf_freecnt = -1; /* start out unlimited */ 72 73static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, 74 struct thread *td); 75static int nfs_directio_write(struct vnode *vp, struct uio *uiop, 76 struct ucred *cred, int ioflag); 77 78/* 79 * Vnode op for VM getpages. 80 */ 81SYSCTL_DECL(_vfs_nfs); 82static int use_buf_pager = 0; 83SYSCTL_INT(_vfs_nfs, OID_AUTO, use_buf_pager, CTLFLAG_RWTUN, 84 &use_buf_pager, 0, 85 "Use buffer pager instead of direct readrpc call"); 86 87static daddr_t 88ncl_gbp_getblkno(struct vnode *vp, vm_ooffset_t off) 89{ 90 91 return (off / vp->v_bufobj.bo_bsize); 92} 93 94static int 95ncl_gbp_getblksz(struct vnode *vp, daddr_t lbn) 96{ 97 struct nfsnode *np; 98 u_quad_t nsize; 99 int biosize, bcount; 100 101 np = VTONFS(vp); 102 mtx_lock(&np->n_mtx); 103 nsize = np->n_size; 104 mtx_unlock(&np->n_mtx); 105 106 biosize = vp->v_bufobj.bo_bsize; 107 bcount = biosize; 108 if ((off_t)lbn * biosize >= nsize) 109 bcount = 0; 110 else if ((off_t)(lbn + 1) * biosize > nsize) 111 bcount = nsize - (off_t)lbn * biosize; 112 return (bcount); 113} 114 115int 116ncl_getpages(struct vop_getpages_args *ap) 117{ 118 int i, error, nextoff, size, toff, count, npages; 119 struct uio uio; 120 struct iovec iov; 121 vm_offset_t kva; 122 struct buf *bp; 123 struct vnode *vp; 124 struct thread *td; 125 struct ucred *cred; 126 struct nfsmount *nmp; 127 vm_object_t object; 128 vm_page_t *pages; 129 struct nfsnode *np; 130 131 vp = ap->a_vp; 132 np = VTONFS(vp); 133 td = curthread; 134 cred = curthread->td_ucred; 135 nmp = VFSTONFS(vp->v_mount); 136 pages = ap->a_m; 137 npages = ap->a_count; 138 139 if ((object = vp->v_object) == NULL) { 140 printf("ncl_getpages: called with non-merged cache vnode\n"); 141 return (VM_PAGER_ERROR); 142 } 143 144 if (newnfs_directio_enable && !newnfs_directio_allow_mmap) { 145 mtx_lock(&np->n_mtx); 146 if ((np->n_flag & NNONCACHE) && (vp->v_type == VREG)) { 147 mtx_unlock(&np->n_mtx); 148 printf("ncl_getpages: called on non-cacheable vnode\n"); 149 return (VM_PAGER_ERROR); 150 } else 151 mtx_unlock(&np->n_mtx); 152 } 153 154 mtx_lock(&nmp->nm_mtx); 155 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 156 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 157 mtx_unlock(&nmp->nm_mtx); 158 /* We'll never get here for v4, because we always have fsinfo */ 159 (void)ncl_fsinfo(nmp, vp, cred, td); 160 } else 161 mtx_unlock(&nmp->nm_mtx); 162 163 if (use_buf_pager) 164 return (vfs_bio_getpages(vp, pages, npages, ap->a_rbehind, 165 ap->a_rahead, ncl_gbp_getblkno, ncl_gbp_getblksz)); 166 167 /* 168 * If the requested page is partially valid, just return it and 169 * allow the pager to zero-out the blanks. Partially valid pages 170 * can only occur at the file EOF. 171 * 172 * XXXGL: is that true for NFS, where short read can occur??? 173 */ 174 VM_OBJECT_WLOCK(object); 175 if (pages[npages - 1]->valid != 0 && --npages == 0) 176 goto out; 177 VM_OBJECT_WUNLOCK(object); 178 179 /* 180 * We use only the kva address for the buffer, but this is extremely 181 * convenient and fast. 182 */ 183 bp = getpbuf(&ncl_pbuf_freecnt); 184 185 kva = (vm_offset_t) bp->b_data; 186 pmap_qenter(kva, pages, npages); 187 PCPU_INC(cnt.v_vnodein); 188 PCPU_ADD(cnt.v_vnodepgsin, npages); 189 190 count = npages << PAGE_SHIFT; 191 iov.iov_base = (caddr_t) kva; 192 iov.iov_len = count; 193 uio.uio_iov = &iov; 194 uio.uio_iovcnt = 1; 195 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex); 196 uio.uio_resid = count; 197 uio.uio_segflg = UIO_SYSSPACE; 198 uio.uio_rw = UIO_READ; 199 uio.uio_td = td; 200 201 error = ncl_readrpc(vp, &uio, cred); 202 pmap_qremove(kva, npages); 203 204 relpbuf(bp, &ncl_pbuf_freecnt); 205 206 if (error && (uio.uio_resid == count)) { 207 printf("ncl_getpages: error %d\n", error); 208 return (VM_PAGER_ERROR); 209 } 210 211 /* 212 * Calculate the number of bytes read and validate only that number 213 * of bytes. Note that due to pending writes, size may be 0. This 214 * does not mean that the remaining data is invalid! 215 */ 216 217 size = count - uio.uio_resid; 218 VM_OBJECT_WLOCK(object); 219 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) { 220 vm_page_t m; 221 nextoff = toff + PAGE_SIZE; 222 m = pages[i]; 223 224 if (nextoff <= size) { 225 /* 226 * Read operation filled an entire page 227 */ 228 m->valid = VM_PAGE_BITS_ALL; 229 KASSERT(m->dirty == 0, 230 ("nfs_getpages: page %p is dirty", m)); 231 } else if (size > toff) { 232 /* 233 * Read operation filled a partial page. 234 */ 235 m->valid = 0; 236 vm_page_set_valid_range(m, 0, size - toff); 237 KASSERT(m->dirty == 0, 238 ("nfs_getpages: page %p is dirty", m)); 239 } else { 240 /* 241 * Read operation was short. If no error 242 * occurred we may have hit a zero-fill 243 * section. We leave valid set to 0, and page 244 * is freed by vm_page_readahead_finish() if 245 * its index is not equal to requested, or 246 * page is zeroed and set valid by 247 * vm_pager_get_pages() for requested page. 248 */ 249 ; 250 } 251 } 252out: 253 VM_OBJECT_WUNLOCK(object); 254 if (ap->a_rbehind) 255 *ap->a_rbehind = 0; 256 if (ap->a_rahead) 257 *ap->a_rahead = 0; 258 return (VM_PAGER_OK); 259} 260 261/* 262 * Vnode op for VM putpages. 263 */ 264int 265ncl_putpages(struct vop_putpages_args *ap) 266{ 267 struct uio uio; 268 struct iovec iov; 269 int i, error, npages, count; 270 off_t offset; 271 int *rtvals; 272 struct vnode *vp; 273 struct thread *td; 274 struct ucred *cred; 275 struct nfsmount *nmp; 276 struct nfsnode *np; 277 vm_page_t *pages; 278 279 vp = ap->a_vp; 280 np = VTONFS(vp); 281 td = curthread; /* XXX */ 282 /* Set the cred to n_writecred for the write rpcs. */ 283 if (np->n_writecred != NULL) 284 cred = crhold(np->n_writecred); 285 else 286 cred = crhold(curthread->td_ucred); /* XXX */ 287 nmp = VFSTONFS(vp->v_mount); 288 pages = ap->a_m; 289 count = ap->a_count; 290 rtvals = ap->a_rtvals; 291 npages = btoc(count); 292 offset = IDX_TO_OFF(pages[0]->pindex); 293 294 mtx_lock(&nmp->nm_mtx); 295 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 296 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 297 mtx_unlock(&nmp->nm_mtx); 298 (void)ncl_fsinfo(nmp, vp, cred, td); 299 } else 300 mtx_unlock(&nmp->nm_mtx); 301 302 mtx_lock(&np->n_mtx); 303 if (newnfs_directio_enable && !newnfs_directio_allow_mmap && 304 (np->n_flag & NNONCACHE) && (vp->v_type == VREG)) { 305 mtx_unlock(&np->n_mtx); 306 printf("ncl_putpages: called on noncache-able vnode\n"); 307 mtx_lock(&np->n_mtx); 308 } 309 /* 310 * When putting pages, do not extend file past EOF. 311 */ 312 if (offset + count > np->n_size) { 313 count = np->n_size - offset; 314 if (count < 0) 315 count = 0; 316 } 317 mtx_unlock(&np->n_mtx); 318 319 for (i = 0; i < npages; i++) 320 rtvals[i] = VM_PAGER_ERROR; 321 322 PCPU_INC(cnt.v_vnodeout); 323 PCPU_ADD(cnt.v_vnodepgsout, count); 324 325 iov.iov_base = unmapped_buf; 326 iov.iov_len = count; 327 uio.uio_iov = &iov; 328 uio.uio_iovcnt = 1; 329 uio.uio_offset = offset; 330 uio.uio_resid = count; 331 uio.uio_segflg = UIO_NOCOPY; 332 uio.uio_rw = UIO_WRITE; 333 uio.uio_td = td; 334 335 error = VOP_WRITE(vp, &uio, vnode_pager_putpages_ioflags(ap->a_sync), 336 cred); 337 crfree(cred); 338 339 if (error == 0 || !nfs_keep_dirty_on_error) { 340 vnode_pager_undirty_pages(pages, rtvals, count - uio.uio_resid, 341 np->n_size - offset, npages * PAGE_SIZE); 342 } 343 return (rtvals[0]); 344} 345 346/* 347 * For nfs, cache consistency can only be maintained approximately. 348 * Although RFC1094 does not specify the criteria, the following is 349 * believed to be compatible with the reference port. 350 * For nfs: 351 * If the file's modify time on the server has changed since the 352 * last read rpc or you have written to the file, 353 * you may have lost data cache consistency with the 354 * server, so flush all of the file's data out of the cache. 355 * Then force a getattr rpc to ensure that you have up to date 356 * attributes. 357 * NB: This implies that cache data can be read when up to 358 * NFS_ATTRTIMEO seconds out of date. If you find that you need current 359 * attributes this could be forced by setting n_attrstamp to 0 before 360 * the VOP_GETATTR() call. 361 */ 362static inline int 363nfs_bioread_check_cons(struct vnode *vp, struct thread *td, struct ucred *cred) 364{ 365 int error = 0; 366 struct vattr vattr; 367 struct nfsnode *np = VTONFS(vp); 368 bool old_lock; 369 370 /* 371 * Ensure the exclusove access to the node before checking 372 * whether the cache is consistent. 373 */ 374 old_lock = ncl_excl_start(vp); 375 mtx_lock(&np->n_mtx); 376 if (np->n_flag & NMODIFIED) { 377 mtx_unlock(&np->n_mtx); 378 if (vp->v_type != VREG) { 379 if (vp->v_type != VDIR) 380 panic("nfs: bioread, not dir"); 381 ncl_invaldir(vp); 382 error = ncl_vinvalbuf(vp, V_SAVE | V_ALLOWCLEAN, td, 1); 383 if (error != 0) 384 goto out; 385 } 386 np->n_attrstamp = 0; 387 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 388 error = VOP_GETATTR(vp, &vattr, cred); 389 if (error) 390 goto out; 391 mtx_lock(&np->n_mtx); 392 np->n_mtime = vattr.va_mtime; 393 mtx_unlock(&np->n_mtx); 394 } else { 395 mtx_unlock(&np->n_mtx); 396 error = VOP_GETATTR(vp, &vattr, cred); 397 if (error) 398 goto out; 399 mtx_lock(&np->n_mtx); 400 if ((np->n_flag & NSIZECHANGED) 401 || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) { 402 mtx_unlock(&np->n_mtx); 403 if (vp->v_type == VDIR) 404 ncl_invaldir(vp); 405 error = ncl_vinvalbuf(vp, V_SAVE | V_ALLOWCLEAN, td, 1); 406 if (error != 0) 407 goto out; 408 mtx_lock(&np->n_mtx); 409 np->n_mtime = vattr.va_mtime; 410 np->n_flag &= ~NSIZECHANGED; 411 } 412 mtx_unlock(&np->n_mtx); 413 } 414out: 415 ncl_excl_finish(vp, old_lock); 416 return (error); 417} 418 419/* 420 * Vnode op for read using bio 421 */ 422int 423ncl_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred) 424{ 425 struct nfsnode *np = VTONFS(vp); 426 int biosize, i; 427 struct buf *bp, *rabp; 428 struct thread *td; 429 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 430 daddr_t lbn, rabn; 431 int bcount; 432 int seqcount; 433 int nra, error = 0, n = 0, on = 0; 434 off_t tmp_off; 435 436 KASSERT(uio->uio_rw == UIO_READ, ("ncl_read mode")); 437 if (uio->uio_resid == 0) 438 return (0); 439 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */ 440 return (EINVAL); 441 td = uio->uio_td; 442 443 mtx_lock(&nmp->nm_mtx); 444 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 445 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 446 mtx_unlock(&nmp->nm_mtx); 447 (void)ncl_fsinfo(nmp, vp, cred, td); 448 mtx_lock(&nmp->nm_mtx); 449 } 450 if (nmp->nm_rsize == 0 || nmp->nm_readdirsize == 0) 451 (void) newnfs_iosize(nmp); 452 453 tmp_off = uio->uio_offset + uio->uio_resid; 454 if (vp->v_type != VDIR && 455 (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)) { 456 mtx_unlock(&nmp->nm_mtx); 457 return (EFBIG); 458 } 459 mtx_unlock(&nmp->nm_mtx); 460 461 if (newnfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG)) 462 /* No caching/ no readaheads. Just read data into the user buffer */ 463 return ncl_readrpc(vp, uio, cred); 464 465 biosize = vp->v_bufobj.bo_bsize; 466 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE); 467 468 error = nfs_bioread_check_cons(vp, td, cred); 469 if (error) 470 return error; 471 472 do { 473 u_quad_t nsize; 474 475 mtx_lock(&np->n_mtx); 476 nsize = np->n_size; 477 mtx_unlock(&np->n_mtx); 478 479 switch (vp->v_type) { 480 case VREG: 481 NFSINCRGLOBAL(nfsstatsv1.biocache_reads); 482 lbn = uio->uio_offset / biosize; 483 on = uio->uio_offset - (lbn * biosize); 484 485 /* 486 * Start the read ahead(s), as required. 487 */ 488 if (nmp->nm_readahead > 0) { 489 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && 490 (off_t)(lbn + 1 + nra) * biosize < nsize; nra++) { 491 rabn = lbn + 1 + nra; 492 if (incore(&vp->v_bufobj, rabn) == NULL) { 493 rabp = nfs_getcacheblk(vp, rabn, biosize, td); 494 if (!rabp) { 495 error = newnfs_sigintr(nmp, td); 496 return (error ? error : EINTR); 497 } 498 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 499 rabp->b_flags |= B_ASYNC; 500 rabp->b_iocmd = BIO_READ; 501 vfs_busy_pages(rabp, 0); 502 if (ncl_asyncio(nmp, rabp, cred, td)) { 503 rabp->b_flags |= B_INVAL; 504 rabp->b_ioflags |= BIO_ERROR; 505 vfs_unbusy_pages(rabp); 506 brelse(rabp); 507 break; 508 } 509 } else { 510 brelse(rabp); 511 } 512 } 513 } 514 } 515 516 /* Note that bcount is *not* DEV_BSIZE aligned. */ 517 bcount = biosize; 518 if ((off_t)lbn * biosize >= nsize) { 519 bcount = 0; 520 } else if ((off_t)(lbn + 1) * biosize > nsize) { 521 bcount = nsize - (off_t)lbn * biosize; 522 } 523 bp = nfs_getcacheblk(vp, lbn, bcount, td); 524 525 if (!bp) { 526 error = newnfs_sigintr(nmp, td); 527 return (error ? error : EINTR); 528 } 529 530 /* 531 * If B_CACHE is not set, we must issue the read. If this 532 * fails, we return an error. 533 */ 534 535 if ((bp->b_flags & B_CACHE) == 0) { 536 bp->b_iocmd = BIO_READ; 537 vfs_busy_pages(bp, 0); 538 error = ncl_doio(vp, bp, cred, td, 0); 539 if (error) { 540 brelse(bp); 541 return (error); 542 } 543 } 544 545 /* 546 * on is the offset into the current bp. Figure out how many 547 * bytes we can copy out of the bp. Note that bcount is 548 * NOT DEV_BSIZE aligned. 549 * 550 * Then figure out how many bytes we can copy into the uio. 551 */ 552 553 n = 0; 554 if (on < bcount) 555 n = MIN((unsigned)(bcount - on), uio->uio_resid); 556 break; 557 case VLNK: 558 NFSINCRGLOBAL(nfsstatsv1.biocache_readlinks); 559 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td); 560 if (!bp) { 561 error = newnfs_sigintr(nmp, td); 562 return (error ? error : EINTR); 563 } 564 if ((bp->b_flags & B_CACHE) == 0) { 565 bp->b_iocmd = BIO_READ; 566 vfs_busy_pages(bp, 0); 567 error = ncl_doio(vp, bp, cred, td, 0); 568 if (error) { 569 bp->b_ioflags |= BIO_ERROR; 570 brelse(bp); 571 return (error); 572 } 573 } 574 n = MIN(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); 575 on = 0; 576 break; 577 case VDIR: 578 NFSINCRGLOBAL(nfsstatsv1.biocache_readdirs); 579 if (np->n_direofoffset 580 && uio->uio_offset >= np->n_direofoffset) { 581 return (0); 582 } 583 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; 584 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); 585 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td); 586 if (!bp) { 587 error = newnfs_sigintr(nmp, td); 588 return (error ? error : EINTR); 589 } 590 if ((bp->b_flags & B_CACHE) == 0) { 591 bp->b_iocmd = BIO_READ; 592 vfs_busy_pages(bp, 0); 593 error = ncl_doio(vp, bp, cred, td, 0); 594 if (error) { 595 brelse(bp); 596 } 597 while (error == NFSERR_BAD_COOKIE) { 598 ncl_invaldir(vp); 599 error = ncl_vinvalbuf(vp, 0, td, 1); 600 601 /* 602 * Yuck! The directory has been modified on the 603 * server. The only way to get the block is by 604 * reading from the beginning to get all the 605 * offset cookies. 606 * 607 * Leave the last bp intact unless there is an error. 608 * Loop back up to the while if the error is another 609 * NFSERR_BAD_COOKIE (double yuch!). 610 */ 611 for (i = 0; i <= lbn && !error; i++) { 612 if (np->n_direofoffset 613 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) 614 return (0); 615 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td); 616 if (!bp) { 617 error = newnfs_sigintr(nmp, td); 618 return (error ? error : EINTR); 619 } 620 if ((bp->b_flags & B_CACHE) == 0) { 621 bp->b_iocmd = BIO_READ; 622 vfs_busy_pages(bp, 0); 623 error = ncl_doio(vp, bp, cred, td, 0); 624 /* 625 * no error + B_INVAL == directory EOF, 626 * use the block. 627 */ 628 if (error == 0 && (bp->b_flags & B_INVAL)) 629 break; 630 } 631 /* 632 * An error will throw away the block and the 633 * for loop will break out. If no error and this 634 * is not the block we want, we throw away the 635 * block and go for the next one via the for loop. 636 */ 637 if (error || i < lbn) 638 brelse(bp); 639 } 640 } 641 /* 642 * The above while is repeated if we hit another cookie 643 * error. If we hit an error and it wasn't a cookie error, 644 * we give up. 645 */ 646 if (error) 647 return (error); 648 } 649 650 /* 651 * If not eof and read aheads are enabled, start one. 652 * (You need the current block first, so that you have the 653 * directory offset cookie of the next block.) 654 */ 655 if (nmp->nm_readahead > 0 && 656 (bp->b_flags & B_INVAL) == 0 && 657 (np->n_direofoffset == 0 || 658 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) && 659 incore(&vp->v_bufobj, lbn + 1) == NULL) { 660 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td); 661 if (rabp) { 662 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 663 rabp->b_flags |= B_ASYNC; 664 rabp->b_iocmd = BIO_READ; 665 vfs_busy_pages(rabp, 0); 666 if (ncl_asyncio(nmp, rabp, cred, td)) { 667 rabp->b_flags |= B_INVAL; 668 rabp->b_ioflags |= BIO_ERROR; 669 vfs_unbusy_pages(rabp); 670 brelse(rabp); 671 } 672 } else { 673 brelse(rabp); 674 } 675 } 676 } 677 /* 678 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is 679 * chopped for the EOF condition, we cannot tell how large 680 * NFS directories are going to be until we hit EOF. So 681 * an NFS directory buffer is *not* chopped to its EOF. Now, 682 * it just so happens that b_resid will effectively chop it 683 * to EOF. *BUT* this information is lost if the buffer goes 684 * away and is reconstituted into a B_CACHE state ( due to 685 * being VMIO ) later. So we keep track of the directory eof 686 * in np->n_direofoffset and chop it off as an extra step 687 * right here. 688 */ 689 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on); 690 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset) 691 n = np->n_direofoffset - uio->uio_offset; 692 break; 693 default: 694 printf(" ncl_bioread: type %x unexpected\n", vp->v_type); 695 bp = NULL; 696 break; 697 } 698 699 if (n > 0) { 700 error = vn_io_fault_uiomove(bp->b_data + on, (int)n, uio); 701 } 702 if (vp->v_type == VLNK) 703 n = 0; 704 if (bp != NULL) 705 brelse(bp); 706 } while (error == 0 && uio->uio_resid > 0 && n > 0); 707 return (error); 708} 709 710/* 711 * The NFS write path cannot handle iovecs with len > 1. So we need to 712 * break up iovecs accordingly (restricting them to wsize). 713 * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf). 714 * For the ASYNC case, 2 copies are needed. The first a copy from the 715 * user buffer to a staging buffer and then a second copy from the staging 716 * buffer to mbufs. This can be optimized by copying from the user buffer 717 * directly into mbufs and passing the chain down, but that requires a 718 * fair amount of re-working of the relevant codepaths (and can be done 719 * later). 720 */ 721static int 722nfs_directio_write(vp, uiop, cred, ioflag) 723 struct vnode *vp; 724 struct uio *uiop; 725 struct ucred *cred; 726 int ioflag; 727{ 728 int error; 729 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 730 struct thread *td = uiop->uio_td; 731 int size; 732 int wsize; 733 734 mtx_lock(&nmp->nm_mtx); 735 wsize = nmp->nm_wsize; 736 mtx_unlock(&nmp->nm_mtx); 737 if (ioflag & IO_SYNC) { 738 int iomode, must_commit; 739 struct uio uio; 740 struct iovec iov; 741do_sync: 742 while (uiop->uio_resid > 0) { 743 size = MIN(uiop->uio_resid, wsize); 744 size = MIN(uiop->uio_iov->iov_len, size); 745 iov.iov_base = uiop->uio_iov->iov_base; 746 iov.iov_len = size; 747 uio.uio_iov = &iov; 748 uio.uio_iovcnt = 1; 749 uio.uio_offset = uiop->uio_offset; 750 uio.uio_resid = size; 751 uio.uio_segflg = UIO_USERSPACE; 752 uio.uio_rw = UIO_WRITE; 753 uio.uio_td = td; 754 iomode = NFSWRITE_FILESYNC; 755 error = ncl_writerpc(vp, &uio, cred, &iomode, 756 &must_commit, 0); 757 KASSERT((must_commit == 0), 758 ("ncl_directio_write: Did not commit write")); 759 if (error) 760 return (error); 761 uiop->uio_offset += size; 762 uiop->uio_resid -= size; 763 if (uiop->uio_iov->iov_len <= size) { 764 uiop->uio_iovcnt--; 765 uiop->uio_iov++; 766 } else { 767 uiop->uio_iov->iov_base = 768 (char *)uiop->uio_iov->iov_base + size; 769 uiop->uio_iov->iov_len -= size; 770 } 771 } 772 } else { 773 struct uio *t_uio; 774 struct iovec *t_iov; 775 struct buf *bp; 776 777 /* 778 * Break up the write into blocksize chunks and hand these 779 * over to nfsiod's for write back. 780 * Unfortunately, this incurs a copy of the data. Since 781 * the user could modify the buffer before the write is 782 * initiated. 783 * 784 * The obvious optimization here is that one of the 2 copies 785 * in the async write path can be eliminated by copying the 786 * data here directly into mbufs and passing the mbuf chain 787 * down. But that will require a fair amount of re-working 788 * of the code and can be done if there's enough interest 789 * in NFS directio access. 790 */ 791 while (uiop->uio_resid > 0) { 792 size = MIN(uiop->uio_resid, wsize); 793 size = MIN(uiop->uio_iov->iov_len, size); 794 bp = getpbuf(&ncl_pbuf_freecnt); 795 t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK); 796 t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK); 797 t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK); 798 t_iov->iov_len = size; 799 t_uio->uio_iov = t_iov; 800 t_uio->uio_iovcnt = 1; 801 t_uio->uio_offset = uiop->uio_offset; 802 t_uio->uio_resid = size; 803 t_uio->uio_segflg = UIO_SYSSPACE; 804 t_uio->uio_rw = UIO_WRITE; 805 t_uio->uio_td = td; 806 KASSERT(uiop->uio_segflg == UIO_USERSPACE || 807 uiop->uio_segflg == UIO_SYSSPACE, 808 ("nfs_directio_write: Bad uio_segflg")); 809 if (uiop->uio_segflg == UIO_USERSPACE) { 810 error = copyin(uiop->uio_iov->iov_base, 811 t_iov->iov_base, size); 812 if (error != 0) 813 goto err_free; 814 } else 815 /* 816 * UIO_SYSSPACE may never happen, but handle 817 * it just in case it does. 818 */ 819 bcopy(uiop->uio_iov->iov_base, t_iov->iov_base, 820 size); 821 bp->b_flags |= B_DIRECT; 822 bp->b_iocmd = BIO_WRITE; 823 if (cred != NOCRED) { 824 crhold(cred); 825 bp->b_wcred = cred; 826 } else 827 bp->b_wcred = NOCRED; 828 bp->b_caller1 = (void *)t_uio; 829 bp->b_vp = vp; 830 error = ncl_asyncio(nmp, bp, NOCRED, td); 831err_free: 832 if (error) { 833 free(t_iov->iov_base, M_NFSDIRECTIO); 834 free(t_iov, M_NFSDIRECTIO); 835 free(t_uio, M_NFSDIRECTIO); 836 bp->b_vp = NULL; 837 relpbuf(bp, &ncl_pbuf_freecnt); 838 if (error == EINTR) 839 return (error); 840 goto do_sync; 841 } 842 uiop->uio_offset += size; 843 uiop->uio_resid -= size; 844 if (uiop->uio_iov->iov_len <= size) { 845 uiop->uio_iovcnt--; 846 uiop->uio_iov++; 847 } else { 848 uiop->uio_iov->iov_base = 849 (char *)uiop->uio_iov->iov_base + size; 850 uiop->uio_iov->iov_len -= size; 851 } 852 } 853 } 854 return (0); 855} 856 857/* 858 * Vnode op for write using bio 859 */ 860int 861ncl_write(struct vop_write_args *ap) 862{ 863 int biosize; 864 struct uio *uio = ap->a_uio; 865 struct thread *td = uio->uio_td; 866 struct vnode *vp = ap->a_vp; 867 struct nfsnode *np = VTONFS(vp); 868 struct ucred *cred = ap->a_cred; 869 int ioflag = ap->a_ioflag; 870 struct buf *bp; 871 struct vattr vattr; 872 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 873 daddr_t lbn; 874 int bcount, noncontig_write, obcount; 875 int bp_cached, n, on, error = 0, error1, wouldcommit; 876 size_t orig_resid, local_resid; 877 off_t orig_size, tmp_off; 878 879 KASSERT(uio->uio_rw == UIO_WRITE, ("ncl_write mode")); 880 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, 881 ("ncl_write proc")); 882 if (vp->v_type != VREG) 883 return (EIO); 884 mtx_lock(&np->n_mtx); 885 if (np->n_flag & NWRITEERR) { 886 np->n_flag &= ~NWRITEERR; 887 mtx_unlock(&np->n_mtx); 888 return (np->n_error); 889 } else 890 mtx_unlock(&np->n_mtx); 891 mtx_lock(&nmp->nm_mtx); 892 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 893 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 894 mtx_unlock(&nmp->nm_mtx); 895 (void)ncl_fsinfo(nmp, vp, cred, td); 896 mtx_lock(&nmp->nm_mtx); 897 } 898 if (nmp->nm_wsize == 0) 899 (void) newnfs_iosize(nmp); 900 mtx_unlock(&nmp->nm_mtx); 901 902 /* 903 * Synchronously flush pending buffers if we are in synchronous 904 * mode or if we are appending. 905 */ 906 if (ioflag & (IO_APPEND | IO_SYNC)) { 907 mtx_lock(&np->n_mtx); 908 if (np->n_flag & NMODIFIED) { 909 mtx_unlock(&np->n_mtx); 910#ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */ 911 /* 912 * Require non-blocking, synchronous writes to 913 * dirty files to inform the program it needs 914 * to fsync(2) explicitly. 915 */ 916 if (ioflag & IO_NDELAY) 917 return (EAGAIN); 918#endif 919 np->n_attrstamp = 0; 920 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 921 error = ncl_vinvalbuf(vp, V_SAVE | ((ioflag & 922 IO_VMIO) != 0 ? V_VMIO : 0), td, 1); 923 if (error != 0) 924 return (error); 925 } else 926 mtx_unlock(&np->n_mtx); 927 } 928 929 orig_resid = uio->uio_resid; 930 mtx_lock(&np->n_mtx); 931 orig_size = np->n_size; 932 mtx_unlock(&np->n_mtx); 933 934 /* 935 * If IO_APPEND then load uio_offset. We restart here if we cannot 936 * get the append lock. 937 */ 938 if (ioflag & IO_APPEND) { 939 np->n_attrstamp = 0; 940 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 941 error = VOP_GETATTR(vp, &vattr, cred); 942 if (error) 943 return (error); 944 mtx_lock(&np->n_mtx); 945 uio->uio_offset = np->n_size; 946 mtx_unlock(&np->n_mtx); 947 } 948 949 if (uio->uio_offset < 0) 950 return (EINVAL); 951 tmp_off = uio->uio_offset + uio->uio_resid; 952 if (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset) 953 return (EFBIG); 954 if (uio->uio_resid == 0) 955 return (0); 956 957 if (newnfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG) 958 return nfs_directio_write(vp, uio, cred, ioflag); 959 960 /* 961 * Maybe this should be above the vnode op call, but so long as 962 * file servers have no limits, i don't think it matters 963 */ 964 if (vn_rlimit_fsize(vp, uio, td)) 965 return (EFBIG); 966 967 biosize = vp->v_bufobj.bo_bsize; 968 /* 969 * Find all of this file's B_NEEDCOMMIT buffers. If our writes 970 * would exceed the local maximum per-file write commit size when 971 * combined with those, we must decide whether to flush, 972 * go synchronous, or return error. We don't bother checking 973 * IO_UNIT -- we just make all writes atomic anyway, as there's 974 * no point optimizing for something that really won't ever happen. 975 */ 976 wouldcommit = 0; 977 if (!(ioflag & IO_SYNC)) { 978 int nflag; 979 980 mtx_lock(&np->n_mtx); 981 nflag = np->n_flag; 982 mtx_unlock(&np->n_mtx); 983 if (nflag & NMODIFIED) { 984 BO_LOCK(&vp->v_bufobj); 985 if (vp->v_bufobj.bo_dirty.bv_cnt != 0) { 986 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd, 987 b_bobufs) { 988 if (bp->b_flags & B_NEEDCOMMIT) 989 wouldcommit += bp->b_bcount; 990 } 991 } 992 BO_UNLOCK(&vp->v_bufobj); 993 } 994 } 995 996 do { 997 if (!(ioflag & IO_SYNC)) { 998 wouldcommit += biosize; 999 if (wouldcommit > nmp->nm_wcommitsize) { 1000 np->n_attrstamp = 0; 1001 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 1002 error = ncl_vinvalbuf(vp, V_SAVE | ((ioflag & 1003 IO_VMIO) != 0 ? V_VMIO : 0), td, 1); 1004 if (error != 0) 1005 return (error); 1006 wouldcommit = biosize; 1007 } 1008 } 1009 1010 NFSINCRGLOBAL(nfsstatsv1.biocache_writes); 1011 lbn = uio->uio_offset / biosize; 1012 on = uio->uio_offset - (lbn * biosize); 1013 n = MIN((unsigned)(biosize - on), uio->uio_resid); 1014again: 1015 /* 1016 * Handle direct append and file extension cases, calculate 1017 * unaligned buffer size. 1018 */ 1019 mtx_lock(&np->n_mtx); 1020 if ((np->n_flag & NHASBEENLOCKED) == 0 && 1021 (nmp->nm_flag & NFSMNT_NONCONTIGWR) != 0) 1022 noncontig_write = 1; 1023 else 1024 noncontig_write = 0; 1025 if ((uio->uio_offset == np->n_size || 1026 (noncontig_write != 0 && 1027 lbn == (np->n_size / biosize) && 1028 uio->uio_offset + n > np->n_size)) && n) { 1029 mtx_unlock(&np->n_mtx); 1030 /* 1031 * Get the buffer (in its pre-append state to maintain 1032 * B_CACHE if it was previously set). Resize the 1033 * nfsnode after we have locked the buffer to prevent 1034 * readers from reading garbage. 1035 */ 1036 obcount = np->n_size - (lbn * biosize); 1037 bp = nfs_getcacheblk(vp, lbn, obcount, td); 1038 1039 if (bp != NULL) { 1040 long save; 1041 1042 mtx_lock(&np->n_mtx); 1043 np->n_size = uio->uio_offset + n; 1044 np->n_flag |= NMODIFIED; 1045 vnode_pager_setsize(vp, np->n_size); 1046 mtx_unlock(&np->n_mtx); 1047 1048 save = bp->b_flags & B_CACHE; 1049 bcount = on + n; 1050 allocbuf(bp, bcount); 1051 bp->b_flags |= save; 1052 if (noncontig_write != 0 && on > obcount) 1053 vfs_bio_bzero_buf(bp, obcount, on - 1054 obcount); 1055 } 1056 } else { 1057 /* 1058 * Obtain the locked cache block first, and then 1059 * adjust the file's size as appropriate. 1060 */ 1061 bcount = on + n; 1062 if ((off_t)lbn * biosize + bcount < np->n_size) { 1063 if ((off_t)(lbn + 1) * biosize < np->n_size) 1064 bcount = biosize; 1065 else 1066 bcount = np->n_size - (off_t)lbn * biosize; 1067 } 1068 mtx_unlock(&np->n_mtx); 1069 bp = nfs_getcacheblk(vp, lbn, bcount, td); 1070 mtx_lock(&np->n_mtx); 1071 if (uio->uio_offset + n > np->n_size) { 1072 np->n_size = uio->uio_offset + n; 1073 np->n_flag |= NMODIFIED; 1074 vnode_pager_setsize(vp, np->n_size); 1075 } 1076 mtx_unlock(&np->n_mtx); 1077 } 1078 1079 if (!bp) { 1080 error = newnfs_sigintr(nmp, td); 1081 if (!error) 1082 error = EINTR; 1083 break; 1084 } 1085 1086 /* 1087 * Issue a READ if B_CACHE is not set. In special-append 1088 * mode, B_CACHE is based on the buffer prior to the write 1089 * op and is typically set, avoiding the read. If a read 1090 * is required in special append mode, the server will 1091 * probably send us a short-read since we extended the file 1092 * on our end, resulting in b_resid == 0 and, thusly, 1093 * B_CACHE getting set. 1094 * 1095 * We can also avoid issuing the read if the write covers 1096 * the entire buffer. We have to make sure the buffer state 1097 * is reasonable in this case since we will not be initiating 1098 * I/O. See the comments in kern/vfs_bio.c's getblk() for 1099 * more information. 1100 * 1101 * B_CACHE may also be set due to the buffer being cached 1102 * normally. 1103 */ 1104 1105 bp_cached = 1; 1106 if (on == 0 && n == bcount) { 1107 if ((bp->b_flags & B_CACHE) == 0) 1108 bp_cached = 0; 1109 bp->b_flags |= B_CACHE; 1110 bp->b_flags &= ~B_INVAL; 1111 bp->b_ioflags &= ~BIO_ERROR; 1112 } 1113 1114 if ((bp->b_flags & B_CACHE) == 0) { 1115 bp->b_iocmd = BIO_READ; 1116 vfs_busy_pages(bp, 0); 1117 error = ncl_doio(vp, bp, cred, td, 0); 1118 if (error) { 1119 brelse(bp); 1120 break; 1121 } 1122 } 1123 if (bp->b_wcred == NOCRED) 1124 bp->b_wcred = crhold(cred); 1125 mtx_lock(&np->n_mtx); 1126 np->n_flag |= NMODIFIED; 1127 mtx_unlock(&np->n_mtx); 1128 1129 /* 1130 * If dirtyend exceeds file size, chop it down. This should 1131 * not normally occur but there is an append race where it 1132 * might occur XXX, so we log it. 1133 * 1134 * If the chopping creates a reverse-indexed or degenerate 1135 * situation with dirtyoff/end, we 0 both of them. 1136 */ 1137 1138 if (bp->b_dirtyend > bcount) { 1139 printf("NFS append race @%lx:%d\n", 1140 (long)bp->b_blkno * DEV_BSIZE, 1141 bp->b_dirtyend - bcount); 1142 bp->b_dirtyend = bcount; 1143 } 1144 1145 if (bp->b_dirtyoff >= bp->b_dirtyend) 1146 bp->b_dirtyoff = bp->b_dirtyend = 0; 1147 1148 /* 1149 * If the new write will leave a contiguous dirty 1150 * area, just update the b_dirtyoff and b_dirtyend, 1151 * otherwise force a write rpc of the old dirty area. 1152 * 1153 * If there has been a file lock applied to this file 1154 * or vfs.nfs.old_noncontig_writing is set, do the following: 1155 * While it is possible to merge discontiguous writes due to 1156 * our having a B_CACHE buffer ( and thus valid read data 1157 * for the hole), we don't because it could lead to 1158 * significant cache coherency problems with multiple clients, 1159 * especially if locking is implemented later on. 1160 * 1161 * If vfs.nfs.old_noncontig_writing is not set and there has 1162 * not been file locking done on this file: 1163 * Relax coherency a bit for the sake of performance and 1164 * expand the current dirty region to contain the new 1165 * write even if it means we mark some non-dirty data as 1166 * dirty. 1167 */ 1168 1169 if (noncontig_write == 0 && bp->b_dirtyend > 0 && 1170 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { 1171 if (bwrite(bp) == EINTR) { 1172 error = EINTR; 1173 break; 1174 } 1175 goto again; 1176 } 1177 1178 local_resid = uio->uio_resid; 1179 error = vn_io_fault_uiomove((char *)bp->b_data + on, n, uio); 1180 1181 if (error != 0 && !bp_cached) { 1182 /* 1183 * This block has no other content then what 1184 * possibly was written by the faulty uiomove. 1185 * Release it, forgetting the data pages, to 1186 * prevent the leak of uninitialized data to 1187 * usermode. 1188 */ 1189 bp->b_ioflags |= BIO_ERROR; 1190 brelse(bp); 1191 uio->uio_offset -= local_resid - uio->uio_resid; 1192 uio->uio_resid = local_resid; 1193 break; 1194 } 1195 1196 /* 1197 * Since this block is being modified, it must be written 1198 * again and not just committed. Since write clustering does 1199 * not work for the stage 1 data write, only the stage 2 1200 * commit rpc, we have to clear B_CLUSTEROK as well. 1201 */ 1202 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1203 1204 /* 1205 * Get the partial update on the progress made from 1206 * uiomove, if an error occurred. 1207 */ 1208 if (error != 0) 1209 n = local_resid - uio->uio_resid; 1210 1211 /* 1212 * Only update dirtyoff/dirtyend if not a degenerate 1213 * condition. 1214 */ 1215 if (n > 0) { 1216 if (bp->b_dirtyend > 0) { 1217 bp->b_dirtyoff = min(on, bp->b_dirtyoff); 1218 bp->b_dirtyend = max((on + n), bp->b_dirtyend); 1219 } else { 1220 bp->b_dirtyoff = on; 1221 bp->b_dirtyend = on + n; 1222 } 1223 vfs_bio_set_valid(bp, on, n); 1224 } 1225 1226 /* 1227 * If IO_SYNC do bwrite(). 1228 * 1229 * IO_INVAL appears to be unused. The idea appears to be 1230 * to turn off caching in this case. Very odd. XXX 1231 */ 1232 if ((ioflag & IO_SYNC)) { 1233 if (ioflag & IO_INVAL) 1234 bp->b_flags |= B_NOCACHE; 1235 error1 = bwrite(bp); 1236 if (error1 != 0) { 1237 if (error == 0) 1238 error = error1; 1239 break; 1240 } 1241 } else if ((n + on) == biosize || (ioflag & IO_ASYNC) != 0) { 1242 bp->b_flags |= B_ASYNC; 1243 (void) ncl_writebp(bp, 0, NULL); 1244 } else { 1245 bdwrite(bp); 1246 } 1247 1248 if (error != 0) 1249 break; 1250 } while (uio->uio_resid > 0 && n > 0); 1251 1252 if (error != 0) { 1253 if (ioflag & IO_UNIT) { 1254 VATTR_NULL(&vattr); 1255 vattr.va_size = orig_size; 1256 /* IO_SYNC is handled implicitely */ 1257 (void)VOP_SETATTR(vp, &vattr, cred); 1258 uio->uio_offset -= orig_resid - uio->uio_resid; 1259 uio->uio_resid = orig_resid; 1260 } 1261 } 1262 1263 return (error); 1264} 1265 1266/* 1267 * Get an nfs cache block. 1268 * 1269 * Allocate a new one if the block isn't currently in the cache 1270 * and return the block marked busy. If the calling process is 1271 * interrupted by a signal for an interruptible mount point, return 1272 * NULL. 1273 * 1274 * The caller must carefully deal with the possible B_INVAL state of 1275 * the buffer. ncl_doio() clears B_INVAL (and ncl_asyncio() clears it 1276 * indirectly), so synchronous reads can be issued without worrying about 1277 * the B_INVAL state. We have to be a little more careful when dealing 1278 * with writes (see comments in nfs_write()) when extending a file past 1279 * its EOF. 1280 */ 1281static struct buf * 1282nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td) 1283{ 1284 struct buf *bp; 1285 struct mount *mp; 1286 struct nfsmount *nmp; 1287 1288 mp = vp->v_mount; 1289 nmp = VFSTONFS(mp); 1290 1291 if (nmp->nm_flag & NFSMNT_INT) { 1292 sigset_t oldset; 1293 1294 newnfs_set_sigmask(td, &oldset); 1295 bp = getblk(vp, bn, size, PCATCH, 0, 0); 1296 newnfs_restore_sigmask(td, &oldset); 1297 while (bp == NULL) { 1298 if (newnfs_sigintr(nmp, td)) 1299 return (NULL); 1300 bp = getblk(vp, bn, size, 0, 2 * hz, 0); 1301 } 1302 } else { 1303 bp = getblk(vp, bn, size, 0, 0, 0); 1304 } 1305 1306 if (vp->v_type == VREG) 1307 bp->b_blkno = bn * (vp->v_bufobj.bo_bsize / DEV_BSIZE); 1308 return (bp); 1309} 1310 1311/* 1312 * Flush and invalidate all dirty buffers. If another process is already 1313 * doing the flush, just wait for completion. 1314 */ 1315int 1316ncl_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg) 1317{ 1318 struct nfsnode *np = VTONFS(vp); 1319 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 1320 int error = 0, slpflag, slptimeo; 1321 bool old_lock; 1322 1323 ASSERT_VOP_LOCKED(vp, "ncl_vinvalbuf"); 1324 1325 if ((nmp->nm_flag & NFSMNT_INT) == 0) 1326 intrflg = 0; 1327 if (NFSCL_FORCEDISM(nmp->nm_mountp)) 1328 intrflg = 1; 1329 if (intrflg) { 1330 slpflag = PCATCH; 1331 slptimeo = 2 * hz; 1332 } else { 1333 slpflag = 0; 1334 slptimeo = 0; 1335 } 1336 1337 old_lock = ncl_excl_start(vp); 1338 if (old_lock) 1339 flags |= V_ALLOWCLEAN; 1340 1341 /* 1342 * Now, flush as required. 1343 */ 1344 if ((flags & (V_SAVE | V_VMIO)) == V_SAVE && 1345 vp->v_bufobj.bo_object != NULL) { 1346 VM_OBJECT_WLOCK(vp->v_bufobj.bo_object); 1347 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC); 1348 VM_OBJECT_WUNLOCK(vp->v_bufobj.bo_object); 1349 /* 1350 * If the page clean was interrupted, fail the invalidation. 1351 * Not doing so, we run the risk of losing dirty pages in the 1352 * vinvalbuf() call below. 1353 */ 1354 if (intrflg && (error = newnfs_sigintr(nmp, td))) 1355 goto out; 1356 } 1357 1358 error = vinvalbuf(vp, flags, slpflag, 0); 1359 while (error) { 1360 if (intrflg && (error = newnfs_sigintr(nmp, td))) 1361 goto out; 1362 error = vinvalbuf(vp, flags, 0, slptimeo); 1363 } 1364 if (NFSHASPNFS(nmp)) { 1365 nfscl_layoutcommit(vp, td); 1366 /* 1367 * Invalidate the attribute cache, since writes to a DS 1368 * won't update the size attribute. 1369 */ 1370 mtx_lock(&np->n_mtx); 1371 np->n_attrstamp = 0; 1372 } else 1373 mtx_lock(&np->n_mtx); 1374 if (np->n_directio_asyncwr == 0) 1375 np->n_flag &= ~NMODIFIED; 1376 mtx_unlock(&np->n_mtx); 1377out: 1378 ncl_excl_finish(vp, old_lock); 1379 return error; 1380} 1381 1382/* 1383 * Initiate asynchronous I/O. Return an error if no nfsiods are available. 1384 * This is mainly to avoid queueing async I/O requests when the nfsiods 1385 * are all hung on a dead server. 1386 * 1387 * Note: ncl_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp 1388 * is eventually dequeued by the async daemon, ncl_doio() *will*. 1389 */ 1390int 1391ncl_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td) 1392{ 1393 int iod; 1394 int gotiod; 1395 int slpflag = 0; 1396 int slptimeo = 0; 1397 int error, error2; 1398 1399 /* 1400 * Commits are usually short and sweet so lets save some cpu and 1401 * leave the async daemons for more important rpc's (such as reads 1402 * and writes). 1403 * 1404 * Readdirplus RPCs do vget()s to acquire the vnodes for entries 1405 * in the directory in order to update attributes. This can deadlock 1406 * with another thread that is waiting for async I/O to be done by 1407 * an nfsiod thread while holding a lock on one of these vnodes. 1408 * To avoid this deadlock, don't allow the async nfsiod threads to 1409 * perform Readdirplus RPCs. 1410 */ 1411 mtx_lock(&ncl_iod_mutex); 1412 if ((bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) && 1413 (nmp->nm_bufqiods > ncl_numasync / 2)) || 1414 (bp->b_vp->v_type == VDIR && (nmp->nm_flag & NFSMNT_RDIRPLUS))) { 1415 mtx_unlock(&ncl_iod_mutex); 1416 return(EIO); 1417 } 1418again: 1419 if (nmp->nm_flag & NFSMNT_INT) 1420 slpflag = PCATCH; 1421 gotiod = FALSE; 1422 1423 /* 1424 * Find a free iod to process this request. 1425 */ 1426 for (iod = 0; iod < ncl_numasync; iod++) 1427 if (ncl_iodwant[iod] == NFSIOD_AVAILABLE) { 1428 gotiod = TRUE; 1429 break; 1430 } 1431 1432 /* 1433 * Try to create one if none are free. 1434 */ 1435 if (!gotiod) 1436 ncl_nfsiodnew(); 1437 else { 1438 /* 1439 * Found one, so wake it up and tell it which 1440 * mount to process. 1441 */ 1442 NFS_DPF(ASYNCIO, ("ncl_asyncio: waking iod %d for mount %p\n", 1443 iod, nmp)); 1444 ncl_iodwant[iod] = NFSIOD_NOT_AVAILABLE; 1445 ncl_iodmount[iod] = nmp; 1446 nmp->nm_bufqiods++; 1447 wakeup(&ncl_iodwant[iod]); 1448 } 1449 1450 /* 1451 * If none are free, we may already have an iod working on this mount 1452 * point. If so, it will process our request. 1453 */ 1454 if (!gotiod) { 1455 if (nmp->nm_bufqiods > 0) { 1456 NFS_DPF(ASYNCIO, 1457 ("ncl_asyncio: %d iods are already processing mount %p\n", 1458 nmp->nm_bufqiods, nmp)); 1459 gotiod = TRUE; 1460 } 1461 } 1462 1463 /* 1464 * If we have an iod which can process the request, then queue 1465 * the buffer. 1466 */ 1467 if (gotiod) { 1468 /* 1469 * Ensure that the queue never grows too large. We still want 1470 * to asynchronize so we block rather then return EIO. 1471 */ 1472 while (nmp->nm_bufqlen >= 2*ncl_numasync) { 1473 NFS_DPF(ASYNCIO, 1474 ("ncl_asyncio: waiting for mount %p queue to drain\n", nmp)); 1475 nmp->nm_bufqwant = TRUE; 1476 error = newnfs_msleep(td, &nmp->nm_bufq, 1477 &ncl_iod_mutex, slpflag | PRIBIO, "nfsaio", 1478 slptimeo); 1479 if (error) { 1480 error2 = newnfs_sigintr(nmp, td); 1481 if (error2) { 1482 mtx_unlock(&ncl_iod_mutex); 1483 return (error2); 1484 } 1485 if (slpflag == PCATCH) { 1486 slpflag = 0; 1487 slptimeo = 2 * hz; 1488 } 1489 } 1490 /* 1491 * We might have lost our iod while sleeping, 1492 * so check and loop if necessary. 1493 */ 1494 goto again; 1495 } 1496 1497 /* We might have lost our nfsiod */ 1498 if (nmp->nm_bufqiods == 0) { 1499 NFS_DPF(ASYNCIO, 1500 ("ncl_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); 1501 goto again; 1502 } 1503 1504 if (bp->b_iocmd == BIO_READ) { 1505 if (bp->b_rcred == NOCRED && cred != NOCRED) 1506 bp->b_rcred = crhold(cred); 1507 } else { 1508 if (bp->b_wcred == NOCRED && cred != NOCRED) 1509 bp->b_wcred = crhold(cred); 1510 } 1511 1512 if (bp->b_flags & B_REMFREE) 1513 bremfreef(bp); 1514 BUF_KERNPROC(bp); 1515 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist); 1516 nmp->nm_bufqlen++; 1517 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) { 1518 mtx_lock(&(VTONFS(bp->b_vp))->n_mtx); 1519 VTONFS(bp->b_vp)->n_flag |= NMODIFIED; 1520 VTONFS(bp->b_vp)->n_directio_asyncwr++; 1521 mtx_unlock(&(VTONFS(bp->b_vp))->n_mtx); 1522 } 1523 mtx_unlock(&ncl_iod_mutex); 1524 return (0); 1525 } 1526 1527 mtx_unlock(&ncl_iod_mutex); 1528 1529 /* 1530 * All the iods are busy on other mounts, so return EIO to 1531 * force the caller to process the i/o synchronously. 1532 */ 1533 NFS_DPF(ASYNCIO, ("ncl_asyncio: no iods available, i/o is synchronous\n")); 1534 return (EIO); 1535} 1536 1537void 1538ncl_doio_directwrite(struct buf *bp) 1539{ 1540 int iomode, must_commit; 1541 struct uio *uiop = (struct uio *)bp->b_caller1; 1542 char *iov_base = uiop->uio_iov->iov_base; 1543 1544 iomode = NFSWRITE_FILESYNC; 1545 uiop->uio_td = NULL; /* NULL since we're in nfsiod */ 1546 ncl_writerpc(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit, 0); 1547 KASSERT((must_commit == 0), ("ncl_doio_directwrite: Did not commit write")); 1548 free(iov_base, M_NFSDIRECTIO); 1549 free(uiop->uio_iov, M_NFSDIRECTIO); 1550 free(uiop, M_NFSDIRECTIO); 1551 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) { 1552 struct nfsnode *np = VTONFS(bp->b_vp); 1553 mtx_lock(&np->n_mtx); 1554 if (NFSHASPNFS(VFSTONFS(vnode_mount(bp->b_vp)))) { 1555 /* 1556 * Invalidate the attribute cache, since writes to a DS 1557 * won't update the size attribute. 1558 */ 1559 np->n_attrstamp = 0; 1560 } 1561 np->n_directio_asyncwr--; 1562 if (np->n_directio_asyncwr == 0) { 1563 np->n_flag &= ~NMODIFIED; 1564 if ((np->n_flag & NFSYNCWAIT)) { 1565 np->n_flag &= ~NFSYNCWAIT; 1566 wakeup((caddr_t)&np->n_directio_asyncwr); 1567 } 1568 } 1569 mtx_unlock(&np->n_mtx); 1570 } 1571 bp->b_vp = NULL; 1572 relpbuf(bp, &ncl_pbuf_freecnt); 1573} 1574 1575/* 1576 * Do an I/O operation to/from a cache block. This may be called 1577 * synchronously or from an nfsiod. 1578 */ 1579int 1580ncl_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td, 1581 int called_from_strategy) 1582{ 1583 struct uio *uiop; 1584 struct nfsnode *np; 1585 struct nfsmount *nmp; 1586 int error = 0, iomode, must_commit = 0; 1587 struct uio uio; 1588 struct iovec io; 1589 struct proc *p = td ? td->td_proc : NULL; 1590 uint8_t iocmd; 1591 1592 np = VTONFS(vp); 1593 nmp = VFSTONFS(vp->v_mount); 1594 uiop = &uio; 1595 uiop->uio_iov = &io; 1596 uiop->uio_iovcnt = 1; 1597 uiop->uio_segflg = UIO_SYSSPACE; 1598 uiop->uio_td = td; 1599 1600 /* 1601 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We 1602 * do this here so we do not have to do it in all the code that 1603 * calls us. 1604 */ 1605 bp->b_flags &= ~B_INVAL; 1606 bp->b_ioflags &= ~BIO_ERROR; 1607 1608 KASSERT(!(bp->b_flags & B_DONE), ("ncl_doio: bp %p already marked done", bp)); 1609 iocmd = bp->b_iocmd; 1610 if (iocmd == BIO_READ) { 1611 io.iov_len = uiop->uio_resid = bp->b_bcount; 1612 io.iov_base = bp->b_data; 1613 uiop->uio_rw = UIO_READ; 1614 1615 switch (vp->v_type) { 1616 case VREG: 1617 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE; 1618 NFSINCRGLOBAL(nfsstatsv1.read_bios); 1619 error = ncl_readrpc(vp, uiop, cr); 1620 1621 if (!error) { 1622 if (uiop->uio_resid) { 1623 /* 1624 * If we had a short read with no error, we must have 1625 * hit a file hole. We should zero-fill the remainder. 1626 * This can also occur if the server hits the file EOF. 1627 * 1628 * Holes used to be able to occur due to pending 1629 * writes, but that is not possible any longer. 1630 */ 1631 int nread = bp->b_bcount - uiop->uio_resid; 1632 ssize_t left = uiop->uio_resid; 1633 1634 if (left > 0) 1635 bzero((char *)bp->b_data + nread, left); 1636 uiop->uio_resid = 0; 1637 } 1638 } 1639 /* ASSERT_VOP_LOCKED(vp, "ncl_doio"); */ 1640 if (p && (vp->v_vflag & VV_TEXT)) { 1641 mtx_lock(&np->n_mtx); 1642 if (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.na_mtime)) { 1643 mtx_unlock(&np->n_mtx); 1644 PROC_LOCK(p); 1645 killproc(p, "text file modification"); 1646 PROC_UNLOCK(p); 1647 } else 1648 mtx_unlock(&np->n_mtx); 1649 } 1650 break; 1651 case VLNK: 1652 uiop->uio_offset = (off_t)0; 1653 NFSINCRGLOBAL(nfsstatsv1.readlink_bios); 1654 error = ncl_readlinkrpc(vp, uiop, cr); 1655 break; 1656 case VDIR: 1657 NFSINCRGLOBAL(nfsstatsv1.readdir_bios); 1658 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ; 1659 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) { 1660 error = ncl_readdirplusrpc(vp, uiop, cr, td); 1661 if (error == NFSERR_NOTSUPP) 1662 nmp->nm_flag &= ~NFSMNT_RDIRPLUS; 1663 } 1664 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) 1665 error = ncl_readdirrpc(vp, uiop, cr, td); 1666 /* 1667 * end-of-directory sets B_INVAL but does not generate an 1668 * error. 1669 */ 1670 if (error == 0 && uiop->uio_resid == bp->b_bcount) 1671 bp->b_flags |= B_INVAL; 1672 break; 1673 default: 1674 printf("ncl_doio: type %x unexpected\n", vp->v_type); 1675 break; 1676 } 1677 if (error) { 1678 bp->b_ioflags |= BIO_ERROR; 1679 bp->b_error = error; 1680 } 1681 } else { 1682 /* 1683 * If we only need to commit, try to commit 1684 */ 1685 if (bp->b_flags & B_NEEDCOMMIT) { 1686 int retv; 1687 off_t off; 1688 1689 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff; 1690 retv = ncl_commit(vp, off, bp->b_dirtyend-bp->b_dirtyoff, 1691 bp->b_wcred, td); 1692 if (retv == 0) { 1693 bp->b_dirtyoff = bp->b_dirtyend = 0; 1694 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1695 bp->b_resid = 0; 1696 bufdone(bp); 1697 return (0); 1698 } 1699 if (retv == NFSERR_STALEWRITEVERF) { 1700 ncl_clearcommit(vp->v_mount); 1701 } 1702 } 1703 1704 /* 1705 * Setup for actual write 1706 */ 1707 mtx_lock(&np->n_mtx); 1708 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size) 1709 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE; 1710 mtx_unlock(&np->n_mtx); 1711 1712 if (bp->b_dirtyend > bp->b_dirtyoff) { 1713 io.iov_len = uiop->uio_resid = bp->b_dirtyend 1714 - bp->b_dirtyoff; 1715 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE 1716 + bp->b_dirtyoff; 1717 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; 1718 uiop->uio_rw = UIO_WRITE; 1719 NFSINCRGLOBAL(nfsstatsv1.write_bios); 1720 1721 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC) 1722 iomode = NFSWRITE_UNSTABLE; 1723 else 1724 iomode = NFSWRITE_FILESYNC; 1725 1726 error = ncl_writerpc(vp, uiop, cr, &iomode, &must_commit, 1727 called_from_strategy); 1728 1729 /* 1730 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try 1731 * to cluster the buffers needing commit. This will allow 1732 * the system to submit a single commit rpc for the whole 1733 * cluster. We can do this even if the buffer is not 100% 1734 * dirty (relative to the NFS blocksize), so we optimize the 1735 * append-to-file-case. 1736 * 1737 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be 1738 * cleared because write clustering only works for commit 1739 * rpc's, not for the data portion of the write). 1740 */ 1741 1742 if (!error && iomode == NFSWRITE_UNSTABLE) { 1743 bp->b_flags |= B_NEEDCOMMIT; 1744 if (bp->b_dirtyoff == 0 1745 && bp->b_dirtyend == bp->b_bcount) 1746 bp->b_flags |= B_CLUSTEROK; 1747 } else { 1748 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1749 } 1750 1751 /* 1752 * For an interrupted write, the buffer is still valid 1753 * and the write hasn't been pushed to the server yet, 1754 * so we can't set BIO_ERROR and report the interruption 1755 * by setting B_EINTR. For the B_ASYNC case, B_EINTR 1756 * is not relevant, so the rpc attempt is essentially 1757 * a noop. For the case of a V3 write rpc not being 1758 * committed to stable storage, the block is still 1759 * dirty and requires either a commit rpc or another 1760 * write rpc with iomode == NFSV3WRITE_FILESYNC before 1761 * the block is reused. This is indicated by setting 1762 * the B_DELWRI and B_NEEDCOMMIT flags. 1763 * 1764 * EIO is returned by ncl_writerpc() to indicate a recoverable 1765 * write error and is handled as above, except that 1766 * B_EINTR isn't set. One cause of this is a stale stateid 1767 * error for the RPC that indicates recovery is required, 1768 * when called with called_from_strategy != 0. 1769 * 1770 * If the buffer is marked B_PAGING, it does not reside on 1771 * the vp's paging queues so we cannot call bdirty(). The 1772 * bp in this case is not an NFS cache block so we should 1773 * be safe. XXX 1774 * 1775 * The logic below breaks up errors into recoverable and 1776 * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE 1777 * and keep the buffer around for potential write retries. 1778 * For the latter (eg ESTALE), we toss the buffer away (B_INVAL) 1779 * and save the error in the nfsnode. This is less than ideal 1780 * but necessary. Keeping such buffers around could potentially 1781 * cause buffer exhaustion eventually (they can never be written 1782 * out, so will get constantly be re-dirtied). It also causes 1783 * all sorts of vfs panics. For non-recoverable write errors, 1784 * also invalidate the attrcache, so we'll be forced to go over 1785 * the wire for this object, returning an error to user on next 1786 * call (most of the time). 1787 */ 1788 if (error == EINTR || error == EIO || error == ETIMEDOUT 1789 || (!error && (bp->b_flags & B_NEEDCOMMIT))) { 1790 bp->b_flags &= ~(B_INVAL|B_NOCACHE); 1791 if ((bp->b_flags & B_PAGING) == 0) { 1792 bdirty(bp); 1793 bp->b_flags &= ~B_DONE; 1794 } 1795 if ((error == EINTR || error == ETIMEDOUT) && 1796 (bp->b_flags & B_ASYNC) == 0) 1797 bp->b_flags |= B_EINTR; 1798 } else { 1799 if (error) { 1800 bp->b_ioflags |= BIO_ERROR; 1801 bp->b_flags |= B_INVAL; 1802 bp->b_error = np->n_error = error; 1803 mtx_lock(&np->n_mtx); 1804 np->n_flag |= NWRITEERR; 1805 np->n_attrstamp = 0; 1806 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 1807 mtx_unlock(&np->n_mtx); 1808 } 1809 bp->b_dirtyoff = bp->b_dirtyend = 0; 1810 } 1811 } else { 1812 bp->b_resid = 0; 1813 bufdone(bp); 1814 return (0); 1815 } 1816 } 1817 bp->b_resid = uiop->uio_resid; 1818 if (must_commit) 1819 ncl_clearcommit(vp->v_mount); 1820 bufdone(bp); 1821 return (error); 1822} 1823 1824/* 1825 * Used to aid in handling ftruncate() operations on the NFS client side. 1826 * Truncation creates a number of special problems for NFS. We have to 1827 * throw away VM pages and buffer cache buffers that are beyond EOF, and 1828 * we have to properly handle VM pages or (potentially dirty) buffers 1829 * that straddle the truncation point. 1830 */ 1831 1832int 1833ncl_meta_setsize(struct vnode *vp, struct thread *td, u_quad_t nsize) 1834{ 1835 struct nfsnode *np = VTONFS(vp); 1836 u_quad_t tsize; 1837 int biosize = vp->v_bufobj.bo_bsize; 1838 int error = 0; 1839 1840 mtx_lock(&np->n_mtx); 1841 tsize = np->n_size; 1842 np->n_size = nsize; 1843 mtx_unlock(&np->n_mtx); 1844 1845 if (nsize < tsize) { 1846 struct buf *bp; 1847 daddr_t lbn; 1848 int bufsize; 1849 1850 /* 1851 * vtruncbuf() doesn't get the buffer overlapping the 1852 * truncation point. We may have a B_DELWRI and/or B_CACHE 1853 * buffer that now needs to be truncated. 1854 */ 1855 error = vtruncbuf(vp, nsize, biosize); 1856 lbn = nsize / biosize; 1857 bufsize = nsize - (lbn * biosize); 1858 bp = nfs_getcacheblk(vp, lbn, bufsize, td); 1859 if (!bp) 1860 return EINTR; 1861 if (bp->b_dirtyoff > bp->b_bcount) 1862 bp->b_dirtyoff = bp->b_bcount; 1863 if (bp->b_dirtyend > bp->b_bcount) 1864 bp->b_dirtyend = bp->b_bcount; 1865 bp->b_flags |= B_RELBUF; /* don't leave garbage around */ 1866 brelse(bp); 1867 } else { 1868 vnode_pager_setsize(vp, nsize); 1869 } 1870 return(error); 1871} 1872 1873