nfs_clbio.c revision 306663
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/10/sys/fs/nfsclient/nfs_clbio.c 306663 2016-10-03 23:17:57Z rmacklem $"); 37 38#include "opt_kdtrace.h" 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 64extern int newnfs_directio_allow_mmap; 65extern struct nfsstats newnfsstats; 66extern struct mtx ncl_iod_mutex; 67extern int ncl_numasync; 68extern enum nfsiod_state ncl_iodwant[NFS_MAXASYNCDAEMON]; 69extern struct nfsmount *ncl_iodmount[NFS_MAXASYNCDAEMON]; 70extern int newnfs_directio_enable; 71extern int nfs_keep_dirty_on_error; 72 73int ncl_pbuf_freecnt = -1; /* start out unlimited */ 74 75static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, 76 struct thread *td); 77static 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 */ 83int 84ncl_getpages(struct vop_getpages_args *ap) 85{ 86 int i, error, nextoff, size, toff, count, npages; 87 struct uio uio; 88 struct iovec iov; 89 vm_offset_t kva; 90 struct buf *bp; 91 struct vnode *vp; 92 struct thread *td; 93 struct ucred *cred; 94 struct nfsmount *nmp; 95 vm_object_t object; 96 vm_page_t *pages; 97 struct nfsnode *np; 98 99 vp = ap->a_vp; 100 np = VTONFS(vp); 101 td = curthread; /* XXX */ 102 cred = curthread->td_ucred; /* XXX */ 103 nmp = VFSTONFS(vp->v_mount); 104 pages = ap->a_m; 105 count = ap->a_count; 106 107 if ((object = vp->v_object) == NULL) { 108 printf("ncl_getpages: called with non-merged cache vnode\n"); 109 return (VM_PAGER_ERROR); 110 } 111 112 if (newnfs_directio_enable && !newnfs_directio_allow_mmap) { 113 mtx_lock(&np->n_mtx); 114 if ((np->n_flag & NNONCACHE) && (vp->v_type == VREG)) { 115 mtx_unlock(&np->n_mtx); 116 printf("ncl_getpages: called on non-cacheable vnode\n"); 117 return (VM_PAGER_ERROR); 118 } else 119 mtx_unlock(&np->n_mtx); 120 } 121 122 mtx_lock(&nmp->nm_mtx); 123 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 124 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 125 mtx_unlock(&nmp->nm_mtx); 126 /* We'll never get here for v4, because we always have fsinfo */ 127 (void)ncl_fsinfo(nmp, vp, cred, td); 128 } else 129 mtx_unlock(&nmp->nm_mtx); 130 131 npages = btoc(count); 132 133 /* 134 * If the requested page is partially valid, just return it and 135 * allow the pager to zero-out the blanks. Partially valid pages 136 * can only occur at the file EOF. 137 */ 138 VM_OBJECT_WLOCK(object); 139 if (pages[ap->a_reqpage]->valid != 0) { 140 for (i = 0; i < npages; ++i) { 141 if (i != ap->a_reqpage) { 142 vm_page_lock(pages[i]); 143 vm_page_free(pages[i]); 144 vm_page_unlock(pages[i]); 145 } 146 } 147 VM_OBJECT_WUNLOCK(object); 148 return (0); 149 } 150 VM_OBJECT_WUNLOCK(object); 151 152 /* 153 * We use only the kva address for the buffer, but this is extremely 154 * convienient and fast. 155 */ 156 bp = getpbuf(&ncl_pbuf_freecnt); 157 158 kva = (vm_offset_t) bp->b_data; 159 pmap_qenter(kva, pages, npages); 160 PCPU_INC(cnt.v_vnodein); 161 PCPU_ADD(cnt.v_vnodepgsin, npages); 162 163 iov.iov_base = (caddr_t) kva; 164 iov.iov_len = count; 165 uio.uio_iov = &iov; 166 uio.uio_iovcnt = 1; 167 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex); 168 uio.uio_resid = count; 169 uio.uio_segflg = UIO_SYSSPACE; 170 uio.uio_rw = UIO_READ; 171 uio.uio_td = td; 172 173 error = ncl_readrpc(vp, &uio, cred); 174 pmap_qremove(kva, npages); 175 176 relpbuf(bp, &ncl_pbuf_freecnt); 177 178 if (error && (uio.uio_resid == count)) { 179 printf("ncl_getpages: error %d\n", error); 180 VM_OBJECT_WLOCK(object); 181 for (i = 0; i < npages; ++i) { 182 if (i != ap->a_reqpage) { 183 vm_page_lock(pages[i]); 184 vm_page_free(pages[i]); 185 vm_page_unlock(pages[i]); 186 } 187 } 188 VM_OBJECT_WUNLOCK(object); 189 return (VM_PAGER_ERROR); 190 } 191 192 /* 193 * Calculate the number of bytes read and validate only that number 194 * of bytes. Note that due to pending writes, size may be 0. This 195 * does not mean that the remaining data is invalid! 196 */ 197 198 size = count - uio.uio_resid; 199 VM_OBJECT_WLOCK(object); 200 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) { 201 vm_page_t m; 202 nextoff = toff + PAGE_SIZE; 203 m = pages[i]; 204 205 if (nextoff <= size) { 206 /* 207 * Read operation filled an entire page 208 */ 209 m->valid = VM_PAGE_BITS_ALL; 210 KASSERT(m->dirty == 0, 211 ("nfs_getpages: page %p is dirty", m)); 212 } else if (size > toff) { 213 /* 214 * Read operation filled a partial page. 215 */ 216 m->valid = 0; 217 vm_page_set_valid_range(m, 0, size - toff); 218 KASSERT(m->dirty == 0, 219 ("nfs_getpages: page %p is dirty", m)); 220 } else { 221 /* 222 * Read operation was short. If no error 223 * occured we may have hit a zero-fill 224 * section. We leave valid set to 0, and page 225 * is freed by vm_page_readahead_finish() if 226 * its index is not equal to requested, or 227 * page is zeroed and set valid by 228 * vm_pager_get_pages() for requested page. 229 */ 230 ; 231 } 232 if (i != ap->a_reqpage) 233 vm_page_readahead_finish(m); 234 } 235 VM_OBJECT_WUNLOCK(object); 236 return (0); 237} 238 239/* 240 * Vnode op for VM putpages. 241 */ 242int 243ncl_putpages(struct vop_putpages_args *ap) 244{ 245 struct uio uio; 246 struct iovec iov; 247 vm_offset_t kva; 248 struct buf *bp; 249 int iomode, must_commit, i, error, npages, count; 250 off_t offset; 251 int *rtvals; 252 struct vnode *vp; 253 struct thread *td; 254 struct ucred *cred; 255 struct nfsmount *nmp; 256 struct nfsnode *np; 257 vm_page_t *pages; 258 259 vp = ap->a_vp; 260 np = VTONFS(vp); 261 td = curthread; /* XXX */ 262 /* Set the cred to n_writecred for the write rpcs. */ 263 if (np->n_writecred != NULL) 264 cred = crhold(np->n_writecred); 265 else 266 cred = crhold(curthread->td_ucred); /* XXX */ 267 nmp = VFSTONFS(vp->v_mount); 268 pages = ap->a_m; 269 count = ap->a_count; 270 rtvals = ap->a_rtvals; 271 npages = btoc(count); 272 offset = IDX_TO_OFF(pages[0]->pindex); 273 274 mtx_lock(&nmp->nm_mtx); 275 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 276 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 277 mtx_unlock(&nmp->nm_mtx); 278 (void)ncl_fsinfo(nmp, vp, cred, td); 279 } else 280 mtx_unlock(&nmp->nm_mtx); 281 282 mtx_lock(&np->n_mtx); 283 if (newnfs_directio_enable && !newnfs_directio_allow_mmap && 284 (np->n_flag & NNONCACHE) && (vp->v_type == VREG)) { 285 mtx_unlock(&np->n_mtx); 286 printf("ncl_putpages: called on noncache-able vnode\n"); 287 mtx_lock(&np->n_mtx); 288 } 289 290 for (i = 0; i < npages; i++) 291 rtvals[i] = VM_PAGER_ERROR; 292 293 /* 294 * When putting pages, do not extend file past EOF. 295 */ 296 if (offset + count > np->n_size) { 297 count = np->n_size - offset; 298 if (count < 0) 299 count = 0; 300 } 301 mtx_unlock(&np->n_mtx); 302 303 /* 304 * We use only the kva address for the buffer, but this is extremely 305 * convienient and fast. 306 */ 307 bp = getpbuf(&ncl_pbuf_freecnt); 308 309 kva = (vm_offset_t) bp->b_data; 310 pmap_qenter(kva, pages, npages); 311 PCPU_INC(cnt.v_vnodeout); 312 PCPU_ADD(cnt.v_vnodepgsout, count); 313 314 iov.iov_base = (caddr_t) kva; 315 iov.iov_len = count; 316 uio.uio_iov = &iov; 317 uio.uio_iovcnt = 1; 318 uio.uio_offset = offset; 319 uio.uio_resid = count; 320 uio.uio_segflg = UIO_SYSSPACE; 321 uio.uio_rw = UIO_WRITE; 322 uio.uio_td = td; 323 324 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0) 325 iomode = NFSWRITE_UNSTABLE; 326 else 327 iomode = NFSWRITE_FILESYNC; 328 329 error = ncl_writerpc(vp, &uio, cred, &iomode, &must_commit, 0); 330 crfree(cred); 331 332 pmap_qremove(kva, npages); 333 relpbuf(bp, &ncl_pbuf_freecnt); 334 335 if (error == 0 || !nfs_keep_dirty_on_error) { 336 vnode_pager_undirty_pages(pages, rtvals, count - uio.uio_resid); 337 if (must_commit) 338 ncl_clearcommit(vp->v_mount); 339 } 340 return rtvals[0]; 341} 342 343/* 344 * For nfs, cache consistency can only be maintained approximately. 345 * Although RFC1094 does not specify the criteria, the following is 346 * believed to be compatible with the reference port. 347 * For nfs: 348 * If the file's modify time on the server has changed since the 349 * last read rpc or you have written to the file, 350 * you may have lost data cache consistency with the 351 * server, so flush all of the file's data out of the cache. 352 * Then force a getattr rpc to ensure that you have up to date 353 * attributes. 354 * NB: This implies that cache data can be read when up to 355 * NFS_ATTRTIMEO seconds out of date. If you find that you need current 356 * attributes this could be forced by setting n_attrstamp to 0 before 357 * the VOP_GETATTR() call. 358 */ 359static inline int 360nfs_bioread_check_cons(struct vnode *vp, struct thread *td, struct ucred *cred) 361{ 362 int error = 0; 363 struct vattr vattr; 364 struct nfsnode *np = VTONFS(vp); 365 int old_lock; 366 367 /* 368 * Grab the exclusive lock before checking whether the cache is 369 * consistent. 370 * XXX - We can make this cheaper later (by acquiring cheaper locks). 371 * But for now, this suffices. 372 */ 373 old_lock = ncl_upgrade_vnlock(vp); 374 if (vp->v_iflag & VI_DOOMED) { 375 ncl_downgrade_vnlock(vp, old_lock); 376 return (EBADF); 377 } 378 379 mtx_lock(&np->n_mtx); 380 if (np->n_flag & NMODIFIED) { 381 mtx_unlock(&np->n_mtx); 382 if (vp->v_type != VREG) { 383 if (vp->v_type != VDIR) 384 panic("nfs: bioread, not dir"); 385 ncl_invaldir(vp); 386 error = ncl_vinvalbuf(vp, V_SAVE, td, 1); 387 if (error) 388 goto out; 389 } 390 np->n_attrstamp = 0; 391 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 392 error = VOP_GETATTR(vp, &vattr, cred); 393 if (error) 394 goto out; 395 mtx_lock(&np->n_mtx); 396 np->n_mtime = vattr.va_mtime; 397 mtx_unlock(&np->n_mtx); 398 } else { 399 mtx_unlock(&np->n_mtx); 400 error = VOP_GETATTR(vp, &vattr, cred); 401 if (error) 402 return (error); 403 mtx_lock(&np->n_mtx); 404 if ((np->n_flag & NSIZECHANGED) 405 || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) { 406 mtx_unlock(&np->n_mtx); 407 if (vp->v_type == VDIR) 408 ncl_invaldir(vp); 409 error = ncl_vinvalbuf(vp, V_SAVE, td, 1); 410 if (error) 411 goto out; 412 mtx_lock(&np->n_mtx); 413 np->n_mtime = vattr.va_mtime; 414 np->n_flag &= ~NSIZECHANGED; 415 } 416 mtx_unlock(&np->n_mtx); 417 } 418out: 419 ncl_downgrade_vnlock(vp, old_lock); 420 return error; 421} 422 423/* 424 * Vnode op for read using bio 425 */ 426int 427ncl_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred) 428{ 429 struct nfsnode *np = VTONFS(vp); 430 int biosize, i; 431 struct buf *bp, *rabp; 432 struct thread *td; 433 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 434 daddr_t lbn, rabn; 435 int bcount; 436 int seqcount; 437 int nra, error = 0, n = 0, on = 0; 438 off_t tmp_off; 439 440 KASSERT(uio->uio_rw == UIO_READ, ("ncl_read mode")); 441 if (uio->uio_resid == 0) 442 return (0); 443 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */ 444 return (EINVAL); 445 td = uio->uio_td; 446 447 mtx_lock(&nmp->nm_mtx); 448 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 449 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 450 mtx_unlock(&nmp->nm_mtx); 451 (void)ncl_fsinfo(nmp, vp, cred, td); 452 mtx_lock(&nmp->nm_mtx); 453 } 454 if (nmp->nm_rsize == 0 || nmp->nm_readdirsize == 0) 455 (void) newnfs_iosize(nmp); 456 457 tmp_off = uio->uio_offset + uio->uio_resid; 458 if (vp->v_type != VDIR && 459 (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)) { 460 mtx_unlock(&nmp->nm_mtx); 461 return (EFBIG); 462 } 463 mtx_unlock(&nmp->nm_mtx); 464 465 if (newnfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG)) 466 /* No caching/ no readaheads. Just read data into the user buffer */ 467 return ncl_readrpc(vp, uio, cred); 468 469 biosize = vp->v_bufobj.bo_bsize; 470 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE); 471 472 error = nfs_bioread_check_cons(vp, td, cred); 473 if (error) 474 return error; 475 476 do { 477 u_quad_t nsize; 478 479 mtx_lock(&np->n_mtx); 480 nsize = np->n_size; 481 mtx_unlock(&np->n_mtx); 482 483 switch (vp->v_type) { 484 case VREG: 485 NFSINCRGLOBAL(newnfsstats.biocache_reads); 486 lbn = uio->uio_offset / biosize; 487 on = uio->uio_offset - (lbn * biosize); 488 489 /* 490 * Start the read ahead(s), as required. 491 */ 492 if (nmp->nm_readahead > 0) { 493 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && 494 (off_t)(lbn + 1 + nra) * biosize < nsize; nra++) { 495 rabn = lbn + 1 + nra; 496 if (incore(&vp->v_bufobj, rabn) == NULL) { 497 rabp = nfs_getcacheblk(vp, rabn, biosize, td); 498 if (!rabp) { 499 error = newnfs_sigintr(nmp, td); 500 return (error ? error : EINTR); 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 return (error ? error : EINTR); 532 } 533 534 /* 535 * If B_CACHE is not set, we must issue the read. If this 536 * fails, we return an error. 537 */ 538 539 if ((bp->b_flags & B_CACHE) == 0) { 540 bp->b_iocmd = BIO_READ; 541 vfs_busy_pages(bp, 0); 542 error = ncl_doio(vp, bp, cred, td, 0); 543 if (error) { 544 brelse(bp); 545 return (error); 546 } 547 } 548 549 /* 550 * on is the offset into the current bp. Figure out how many 551 * bytes we can copy out of the bp. Note that bcount is 552 * NOT DEV_BSIZE aligned. 553 * 554 * Then figure out how many bytes we can copy into the uio. 555 */ 556 557 n = 0; 558 if (on < bcount) 559 n = MIN((unsigned)(bcount - on), uio->uio_resid); 560 break; 561 case VLNK: 562 NFSINCRGLOBAL(newnfsstats.biocache_readlinks); 563 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td); 564 if (!bp) { 565 error = newnfs_sigintr(nmp, td); 566 return (error ? error : EINTR); 567 } 568 if ((bp->b_flags & B_CACHE) == 0) { 569 bp->b_iocmd = BIO_READ; 570 vfs_busy_pages(bp, 0); 571 error = ncl_doio(vp, bp, cred, td, 0); 572 if (error) { 573 bp->b_ioflags |= BIO_ERROR; 574 brelse(bp); 575 return (error); 576 } 577 } 578 n = MIN(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); 579 on = 0; 580 break; 581 case VDIR: 582 NFSINCRGLOBAL(newnfsstats.biocache_readdirs); 583 if (np->n_direofoffset 584 && uio->uio_offset >= np->n_direofoffset) { 585 return (0); 586 } 587 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; 588 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); 589 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td); 590 if (!bp) { 591 error = newnfs_sigintr(nmp, td); 592 return (error ? error : EINTR); 593 } 594 if ((bp->b_flags & B_CACHE) == 0) { 595 bp->b_iocmd = BIO_READ; 596 vfs_busy_pages(bp, 0); 597 error = ncl_doio(vp, bp, cred, td, 0); 598 if (error) { 599 brelse(bp); 600 } 601 while (error == NFSERR_BAD_COOKIE) { 602 ncl_invaldir(vp); 603 error = ncl_vinvalbuf(vp, 0, td, 1); 604 /* 605 * Yuck! The directory has been modified on the 606 * server. The only way to get the block is by 607 * reading from the beginning to get all the 608 * offset cookies. 609 * 610 * Leave the last bp intact unless there is an error. 611 * Loop back up to the while if the error is another 612 * NFSERR_BAD_COOKIE (double yuch!). 613 */ 614 for (i = 0; i <= lbn && !error; i++) { 615 if (np->n_direofoffset 616 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) 617 return (0); 618 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td); 619 if (!bp) { 620 error = newnfs_sigintr(nmp, td); 621 return (error ? error : EINTR); 622 } 623 if ((bp->b_flags & B_CACHE) == 0) { 624 bp->b_iocmd = BIO_READ; 625 vfs_busy_pages(bp, 0); 626 error = ncl_doio(vp, bp, cred, td, 0); 627 /* 628 * no error + B_INVAL == directory EOF, 629 * use the block. 630 */ 631 if (error == 0 && (bp->b_flags & B_INVAL)) 632 break; 633 } 634 /* 635 * An error will throw away the block and the 636 * for loop will break out. If no error and this 637 * is not the block we want, we throw away the 638 * block and go for the next one via the for loop. 639 */ 640 if (error || i < lbn) 641 brelse(bp); 642 } 643 } 644 /* 645 * The above while is repeated if we hit another cookie 646 * error. If we hit an error and it wasn't a cookie error, 647 * we give up. 648 */ 649 if (error) 650 return (error); 651 } 652 653 /* 654 * If not eof and read aheads are enabled, start one. 655 * (You need the current block first, so that you have the 656 * directory offset cookie of the next block.) 657 */ 658 if (nmp->nm_readahead > 0 && 659 (bp->b_flags & B_INVAL) == 0 && 660 (np->n_direofoffset == 0 || 661 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) && 662 incore(&vp->v_bufobj, lbn + 1) == NULL) { 663 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td); 664 if (rabp) { 665 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 666 rabp->b_flags |= B_ASYNC; 667 rabp->b_iocmd = BIO_READ; 668 vfs_busy_pages(rabp, 0); 669 if (ncl_asyncio(nmp, rabp, cred, td)) { 670 rabp->b_flags |= B_INVAL; 671 rabp->b_ioflags |= BIO_ERROR; 672 vfs_unbusy_pages(rabp); 673 brelse(rabp); 674 } 675 } else { 676 brelse(rabp); 677 } 678 } 679 } 680 /* 681 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is 682 * chopped for the EOF condition, we cannot tell how large 683 * NFS directories are going to be until we hit EOF. So 684 * an NFS directory buffer is *not* chopped to its EOF. Now, 685 * it just so happens that b_resid will effectively chop it 686 * to EOF. *BUT* this information is lost if the buffer goes 687 * away and is reconstituted into a B_CACHE state ( due to 688 * being VMIO ) later. So we keep track of the directory eof 689 * in np->n_direofoffset and chop it off as an extra step 690 * right here. 691 */ 692 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on); 693 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset) 694 n = np->n_direofoffset - uio->uio_offset; 695 break; 696 default: 697 printf(" ncl_bioread: type %x unexpected\n", vp->v_type); 698 bp = NULL; 699 break; 700 }; 701 702 if (n > 0) { 703 error = vn_io_fault_uiomove(bp->b_data + on, (int)n, uio); 704 } 705 if (vp->v_type == VLNK) 706 n = 0; 707 if (bp != NULL) 708 brelse(bp); 709 } while (error == 0 && uio->uio_resid > 0 && n > 0); 710 return (error); 711} 712 713/* 714 * The NFS write path cannot handle iovecs with len > 1. So we need to 715 * break up iovecs accordingly (restricting them to wsize). 716 * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf). 717 * For the ASYNC case, 2 copies are needed. The first a copy from the 718 * user buffer to a staging buffer and then a second copy from the staging 719 * buffer to mbufs. This can be optimized by copying from the user buffer 720 * directly into mbufs and passing the chain down, but that requires a 721 * fair amount of re-working of the relevant codepaths (and can be done 722 * later). 723 */ 724static int 725nfs_directio_write(vp, uiop, cred, ioflag) 726 struct vnode *vp; 727 struct uio *uiop; 728 struct ucred *cred; 729 int ioflag; 730{ 731 int error; 732 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 733 struct thread *td = uiop->uio_td; 734 int size; 735 int wsize; 736 737 mtx_lock(&nmp->nm_mtx); 738 wsize = nmp->nm_wsize; 739 mtx_unlock(&nmp->nm_mtx); 740 if (ioflag & IO_SYNC) { 741 int iomode, must_commit; 742 struct uio uio; 743 struct iovec iov; 744do_sync: 745 while (uiop->uio_resid > 0) { 746 size = MIN(uiop->uio_resid, wsize); 747 size = MIN(uiop->uio_iov->iov_len, size); 748 iov.iov_base = uiop->uio_iov->iov_base; 749 iov.iov_len = size; 750 uio.uio_iov = &iov; 751 uio.uio_iovcnt = 1; 752 uio.uio_offset = uiop->uio_offset; 753 uio.uio_resid = size; 754 uio.uio_segflg = UIO_USERSPACE; 755 uio.uio_rw = UIO_WRITE; 756 uio.uio_td = td; 757 iomode = NFSWRITE_FILESYNC; 758 error = ncl_writerpc(vp, &uio, cred, &iomode, 759 &must_commit, 0); 760 KASSERT((must_commit == 0), 761 ("ncl_directio_write: Did not commit write")); 762 if (error) 763 return (error); 764 uiop->uio_offset += size; 765 uiop->uio_resid -= size; 766 if (uiop->uio_iov->iov_len <= size) { 767 uiop->uio_iovcnt--; 768 uiop->uio_iov++; 769 } else { 770 uiop->uio_iov->iov_base = 771 (char *)uiop->uio_iov->iov_base + size; 772 uiop->uio_iov->iov_len -= size; 773 } 774 } 775 } else { 776 struct uio *t_uio; 777 struct iovec *t_iov; 778 struct buf *bp; 779 780 /* 781 * Break up the write into blocksize chunks and hand these 782 * over to nfsiod's for write back. 783 * Unfortunately, this incurs a copy of the data. Since 784 * the user could modify the buffer before the write is 785 * initiated. 786 * 787 * The obvious optimization here is that one of the 2 copies 788 * in the async write path can be eliminated by copying the 789 * data here directly into mbufs and passing the mbuf chain 790 * down. But that will require a fair amount of re-working 791 * of the code and can be done if there's enough interest 792 * in NFS directio access. 793 */ 794 while (uiop->uio_resid > 0) { 795 size = MIN(uiop->uio_resid, wsize); 796 size = MIN(uiop->uio_iov->iov_len, size); 797 bp = getpbuf(&ncl_pbuf_freecnt); 798 t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK); 799 t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK); 800 t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK); 801 t_iov->iov_len = size; 802 t_uio->uio_iov = t_iov; 803 t_uio->uio_iovcnt = 1; 804 t_uio->uio_offset = uiop->uio_offset; 805 t_uio->uio_resid = size; 806 t_uio->uio_segflg = UIO_SYSSPACE; 807 t_uio->uio_rw = UIO_WRITE; 808 t_uio->uio_td = td; 809 KASSERT(uiop->uio_segflg == UIO_USERSPACE || 810 uiop->uio_segflg == UIO_SYSSPACE, 811 ("nfs_directio_write: Bad uio_segflg")); 812 if (uiop->uio_segflg == UIO_USERSPACE) { 813 error = copyin(uiop->uio_iov->iov_base, 814 t_iov->iov_base, size); 815 if (error != 0) 816 goto err_free; 817 } else 818 /* 819 * UIO_SYSSPACE may never happen, but handle 820 * it just in case it does. 821 */ 822 bcopy(uiop->uio_iov->iov_base, t_iov->iov_base, 823 size); 824 bp->b_flags |= B_DIRECT; 825 bp->b_iocmd = BIO_WRITE; 826 if (cred != NOCRED) { 827 crhold(cred); 828 bp->b_wcred = cred; 829 } else 830 bp->b_wcred = NOCRED; 831 bp->b_caller1 = (void *)t_uio; 832 bp->b_vp = vp; 833 error = ncl_asyncio(nmp, bp, NOCRED, td); 834err_free: 835 if (error) { 836 free(t_iov->iov_base, M_NFSDIRECTIO); 837 free(t_iov, M_NFSDIRECTIO); 838 free(t_uio, M_NFSDIRECTIO); 839 bp->b_vp = NULL; 840 relpbuf(bp, &ncl_pbuf_freecnt); 841 if (error == EINTR) 842 return (error); 843 goto do_sync; 844 } 845 uiop->uio_offset += size; 846 uiop->uio_resid -= size; 847 if (uiop->uio_iov->iov_len <= size) { 848 uiop->uio_iovcnt--; 849 uiop->uio_iov++; 850 } else { 851 uiop->uio_iov->iov_base = 852 (char *)uiop->uio_iov->iov_base + size; 853 uiop->uio_iov->iov_len -= size; 854 } 855 } 856 } 857 return (0); 858} 859 860/* 861 * Vnode op for write using bio 862 */ 863int 864ncl_write(struct vop_write_args *ap) 865{ 866 int biosize; 867 struct uio *uio = ap->a_uio; 868 struct thread *td = uio->uio_td; 869 struct vnode *vp = ap->a_vp; 870 struct nfsnode *np = VTONFS(vp); 871 struct ucred *cred = ap->a_cred; 872 int ioflag = ap->a_ioflag; 873 struct buf *bp; 874 struct vattr vattr; 875 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 876 daddr_t lbn; 877 int bcount, noncontig_write, obcount; 878 int bp_cached, n, on, error = 0, error1, wouldcommit; 879 size_t orig_resid, local_resid; 880 off_t orig_size, tmp_off; 881 882 KASSERT(uio->uio_rw == UIO_WRITE, ("ncl_write mode")); 883 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, 884 ("ncl_write proc")); 885 if (vp->v_type != VREG) 886 return (EIO); 887 mtx_lock(&np->n_mtx); 888 if (np->n_flag & NWRITEERR) { 889 np->n_flag &= ~NWRITEERR; 890 mtx_unlock(&np->n_mtx); 891 return (np->n_error); 892 } else 893 mtx_unlock(&np->n_mtx); 894 mtx_lock(&nmp->nm_mtx); 895 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 896 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 897 mtx_unlock(&nmp->nm_mtx); 898 (void)ncl_fsinfo(nmp, vp, cred, td); 899 mtx_lock(&nmp->nm_mtx); 900 } 901 if (nmp->nm_wsize == 0) 902 (void) newnfs_iosize(nmp); 903 mtx_unlock(&nmp->nm_mtx); 904 905 /* 906 * Synchronously flush pending buffers if we are in synchronous 907 * mode or if we are appending. 908 */ 909 if (ioflag & (IO_APPEND | IO_SYNC)) { 910 mtx_lock(&np->n_mtx); 911 if (np->n_flag & NMODIFIED) { 912 mtx_unlock(&np->n_mtx); 913#ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */ 914 /* 915 * Require non-blocking, synchronous writes to 916 * dirty files to inform the program it needs 917 * to fsync(2) explicitly. 918 */ 919 if (ioflag & IO_NDELAY) 920 return (EAGAIN); 921#endif 922 np->n_attrstamp = 0; 923 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 924 error = ncl_vinvalbuf(vp, V_SAVE, td, 1); 925 if (error) 926 return (error); 927 } else 928 mtx_unlock(&np->n_mtx); 929 } 930 931 orig_resid = uio->uio_resid; 932 mtx_lock(&np->n_mtx); 933 orig_size = np->n_size; 934 mtx_unlock(&np->n_mtx); 935 936 /* 937 * If IO_APPEND then load uio_offset. We restart here if we cannot 938 * get the append lock. 939 */ 940 if (ioflag & IO_APPEND) { 941 np->n_attrstamp = 0; 942 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 943 error = VOP_GETATTR(vp, &vattr, cred); 944 if (error) 945 return (error); 946 mtx_lock(&np->n_mtx); 947 uio->uio_offset = np->n_size; 948 mtx_unlock(&np->n_mtx); 949 } 950 951 if (uio->uio_offset < 0) 952 return (EINVAL); 953 tmp_off = uio->uio_offset + uio->uio_resid; 954 if (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset) 955 return (EFBIG); 956 if (uio->uio_resid == 0) 957 return (0); 958 959 if (newnfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG) 960 return nfs_directio_write(vp, uio, cred, ioflag); 961 962 /* 963 * Maybe this should be above the vnode op call, but so long as 964 * file servers have no limits, i don't think it matters 965 */ 966 if (vn_rlimit_fsize(vp, uio, td)) 967 return (EFBIG); 968 969 biosize = vp->v_bufobj.bo_bsize; 970 /* 971 * Find all of this file's B_NEEDCOMMIT buffers. If our writes 972 * would exceed the local maximum per-file write commit size when 973 * combined with those, we must decide whether to flush, 974 * go synchronous, or return error. We don't bother checking 975 * IO_UNIT -- we just make all writes atomic anyway, as there's 976 * no point optimizing for something that really won't ever happen. 977 */ 978 wouldcommit = 0; 979 if (!(ioflag & IO_SYNC)) { 980 int nflag; 981 982 mtx_lock(&np->n_mtx); 983 nflag = np->n_flag; 984 mtx_unlock(&np->n_mtx); 985 if (nflag & NMODIFIED) { 986 BO_LOCK(&vp->v_bufobj); 987 if (vp->v_bufobj.bo_dirty.bv_cnt != 0) { 988 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd, 989 b_bobufs) { 990 if (bp->b_flags & B_NEEDCOMMIT) 991 wouldcommit += bp->b_bcount; 992 } 993 } 994 BO_UNLOCK(&vp->v_bufobj); 995 } 996 } 997 998 do { 999 if (!(ioflag & IO_SYNC)) { 1000 wouldcommit += biosize; 1001 if (wouldcommit > nmp->nm_wcommitsize) { 1002 np->n_attrstamp = 0; 1003 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 1004 error = ncl_vinvalbuf(vp, V_SAVE, td, 1); 1005 if (error) 1006 return (error); 1007 wouldcommit = biosize; 1008 } 1009 } 1010 1011 NFSINCRGLOBAL(newnfsstats.biocache_writes); 1012 lbn = uio->uio_offset / biosize; 1013 on = uio->uio_offset - (lbn * biosize); 1014 n = MIN((unsigned)(biosize - on), uio->uio_resid); 1015again: 1016 /* 1017 * Handle direct append and file extension cases, calculate 1018 * unaligned buffer size. 1019 */ 1020 mtx_lock(&np->n_mtx); 1021 if ((np->n_flag & NHASBEENLOCKED) == 0 && 1022 (nmp->nm_flag & NFSMNT_NONCONTIGWR) != 0) 1023 noncontig_write = 1; 1024 else 1025 noncontig_write = 0; 1026 if ((uio->uio_offset == np->n_size || 1027 (noncontig_write != 0 && 1028 lbn == (np->n_size / biosize) && 1029 uio->uio_offset + n > np->n_size)) && n) { 1030 mtx_unlock(&np->n_mtx); 1031 /* 1032 * Get the buffer (in its pre-append state to maintain 1033 * B_CACHE if it was previously set). Resize the 1034 * nfsnode after we have locked the buffer to prevent 1035 * readers from reading garbage. 1036 */ 1037 obcount = np->n_size - (lbn * biosize); 1038 bp = nfs_getcacheblk(vp, lbn, obcount, td); 1039 1040 if (bp != NULL) { 1041 long save; 1042 1043 mtx_lock(&np->n_mtx); 1044 np->n_size = uio->uio_offset + n; 1045 np->n_flag |= NMODIFIED; 1046 vnode_pager_setsize(vp, np->n_size); 1047 mtx_unlock(&np->n_mtx); 1048 1049 save = bp->b_flags & B_CACHE; 1050 bcount = on + n; 1051 allocbuf(bp, bcount); 1052 bp->b_flags |= save; 1053 if (noncontig_write != 0 && on > obcount) 1054 vfs_bio_bzero_buf(bp, obcount, on - 1055 obcount); 1056 } 1057 } else { 1058 /* 1059 * Obtain the locked cache block first, and then 1060 * adjust the file's size as appropriate. 1061 */ 1062 bcount = on + n; 1063 if ((off_t)lbn * biosize + bcount < np->n_size) { 1064 if ((off_t)(lbn + 1) * biosize < np->n_size) 1065 bcount = biosize; 1066 else 1067 bcount = np->n_size - (off_t)lbn * biosize; 1068 } 1069 mtx_unlock(&np->n_mtx); 1070 bp = nfs_getcacheblk(vp, lbn, bcount, td); 1071 mtx_lock(&np->n_mtx); 1072 if (uio->uio_offset + n > np->n_size) { 1073 np->n_size = uio->uio_offset + n; 1074 np->n_flag |= NMODIFIED; 1075 vnode_pager_setsize(vp, np->n_size); 1076 } 1077 mtx_unlock(&np->n_mtx); 1078 } 1079 1080 if (!bp) { 1081 error = newnfs_sigintr(nmp, td); 1082 if (!error) 1083 error = EINTR; 1084 break; 1085 } 1086 1087 /* 1088 * Issue a READ if B_CACHE is not set. In special-append 1089 * mode, B_CACHE is based on the buffer prior to the write 1090 * op and is typically set, avoiding the read. If a read 1091 * is required in special append mode, the server will 1092 * probably send us a short-read since we extended the file 1093 * on our end, resulting in b_resid == 0 and, thusly, 1094 * B_CACHE getting set. 1095 * 1096 * We can also avoid issuing the read if the write covers 1097 * the entire buffer. We have to make sure the buffer state 1098 * is reasonable in this case since we will not be initiating 1099 * I/O. See the comments in kern/vfs_bio.c's getblk() for 1100 * more information. 1101 * 1102 * B_CACHE may also be set due to the buffer being cached 1103 * normally. 1104 */ 1105 1106 bp_cached = 1; 1107 if (on == 0 && n == bcount) { 1108 if ((bp->b_flags & B_CACHE) == 0) 1109 bp_cached = 0; 1110 bp->b_flags |= B_CACHE; 1111 bp->b_flags &= ~B_INVAL; 1112 bp->b_ioflags &= ~BIO_ERROR; 1113 } 1114 1115 if ((bp->b_flags & B_CACHE) == 0) { 1116 bp->b_iocmd = BIO_READ; 1117 vfs_busy_pages(bp, 0); 1118 error = ncl_doio(vp, bp, cred, td, 0); 1119 if (error) { 1120 brelse(bp); 1121 break; 1122 } 1123 } 1124 if (bp->b_wcred == NOCRED) 1125 bp->b_wcred = crhold(cred); 1126 mtx_lock(&np->n_mtx); 1127 np->n_flag |= NMODIFIED; 1128 mtx_unlock(&np->n_mtx); 1129 1130 /* 1131 * If dirtyend exceeds file size, chop it down. This should 1132 * not normally occur but there is an append race where it 1133 * might occur XXX, so we log it. 1134 * 1135 * If the chopping creates a reverse-indexed or degenerate 1136 * situation with dirtyoff/end, we 0 both of them. 1137 */ 1138 1139 if (bp->b_dirtyend > bcount) { 1140 printf("NFS append race @%lx:%d\n", 1141 (long)bp->b_blkno * DEV_BSIZE, 1142 bp->b_dirtyend - bcount); 1143 bp->b_dirtyend = bcount; 1144 } 1145 1146 if (bp->b_dirtyoff >= bp->b_dirtyend) 1147 bp->b_dirtyoff = bp->b_dirtyend = 0; 1148 1149 /* 1150 * If the new write will leave a contiguous dirty 1151 * area, just update the b_dirtyoff and b_dirtyend, 1152 * otherwise force a write rpc of the old dirty area. 1153 * 1154 * If there has been a file lock applied to this file 1155 * or vfs.nfs.old_noncontig_writing is set, do the following: 1156 * While it is possible to merge discontiguous writes due to 1157 * our having a B_CACHE buffer ( and thus valid read data 1158 * for the hole), we don't because it could lead to 1159 * significant cache coherency problems with multiple clients, 1160 * especially if locking is implemented later on. 1161 * 1162 * If vfs.nfs.old_noncontig_writing is not set and there has 1163 * not been file locking done on this file: 1164 * Relax coherency a bit for the sake of performance and 1165 * expand the current dirty region to contain the new 1166 * write even if it means we mark some non-dirty data as 1167 * dirty. 1168 */ 1169 1170 if (noncontig_write == 0 && bp->b_dirtyend > 0 && 1171 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { 1172 if (bwrite(bp) == EINTR) { 1173 error = EINTR; 1174 break; 1175 } 1176 goto again; 1177 } 1178 1179 local_resid = uio->uio_resid; 1180 error = vn_io_fault_uiomove((char *)bp->b_data + on, n, uio); 1181 1182 if (error != 0 && !bp_cached) { 1183 /* 1184 * This block has no other content then what 1185 * possibly was written by the faulty uiomove. 1186 * Release it, forgetting the data pages, to 1187 * prevent the leak of uninitialized data to 1188 * usermode. 1189 */ 1190 bp->b_ioflags |= BIO_ERROR; 1191 brelse(bp); 1192 uio->uio_offset -= local_resid - uio->uio_resid; 1193 uio->uio_resid = local_resid; 1194 break; 1195 } 1196 1197 /* 1198 * Since this block is being modified, it must be written 1199 * again and not just committed. Since write clustering does 1200 * not work for the stage 1 data write, only the stage 2 1201 * commit rpc, we have to clear B_CLUSTEROK as well. 1202 */ 1203 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1204 1205 /* 1206 * Get the partial update on the progress made from 1207 * uiomove, if an error occured. 1208 */ 1209 if (error != 0) 1210 n = local_resid - uio->uio_resid; 1211 1212 /* 1213 * Only update dirtyoff/dirtyend if not a degenerate 1214 * condition. 1215 */ 1216 if (n > 0) { 1217 if (bp->b_dirtyend > 0) { 1218 bp->b_dirtyoff = min(on, bp->b_dirtyoff); 1219 bp->b_dirtyend = max((on + n), bp->b_dirtyend); 1220 } else { 1221 bp->b_dirtyoff = on; 1222 bp->b_dirtyend = on + n; 1223 } 1224 vfs_bio_set_valid(bp, on, n); 1225 } 1226 1227 /* 1228 * If IO_SYNC do bwrite(). 1229 * 1230 * IO_INVAL appears to be unused. The idea appears to be 1231 * to turn off caching in this case. Very odd. XXX 1232 */ 1233 if ((ioflag & IO_SYNC)) { 1234 if (ioflag & IO_INVAL) 1235 bp->b_flags |= B_NOCACHE; 1236 error1 = bwrite(bp); 1237 if (error1 != 0) { 1238 if (error == 0) 1239 error = error1; 1240 break; 1241 } 1242 } else if ((n + on) == biosize) { 1243 bp->b_flags |= B_ASYNC; 1244 (void) ncl_writebp(bp, 0, NULL); 1245 } else { 1246 bdwrite(bp); 1247 } 1248 1249 if (error != 0) 1250 break; 1251 } while (uio->uio_resid > 0 && n > 0); 1252 1253 if (error != 0) { 1254 if (ioflag & IO_UNIT) { 1255 VATTR_NULL(&vattr); 1256 vattr.va_size = orig_size; 1257 /* IO_SYNC is handled implicitely */ 1258 (void)VOP_SETATTR(vp, &vattr, cred); 1259 uio->uio_offset -= orig_resid - uio->uio_resid; 1260 uio->uio_resid = orig_resid; 1261 } 1262 } 1263 1264 return (error); 1265} 1266 1267/* 1268 * Get an nfs cache block. 1269 * 1270 * Allocate a new one if the block isn't currently in the cache 1271 * and return the block marked busy. If the calling process is 1272 * interrupted by a signal for an interruptible mount point, return 1273 * NULL. 1274 * 1275 * The caller must carefully deal with the possible B_INVAL state of 1276 * the buffer. ncl_doio() clears B_INVAL (and ncl_asyncio() clears it 1277 * indirectly), so synchronous reads can be issued without worrying about 1278 * the B_INVAL state. We have to be a little more careful when dealing 1279 * with writes (see comments in nfs_write()) when extending a file past 1280 * its EOF. 1281 */ 1282static struct buf * 1283nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td) 1284{ 1285 struct buf *bp; 1286 struct mount *mp; 1287 struct nfsmount *nmp; 1288 1289 mp = vp->v_mount; 1290 nmp = VFSTONFS(mp); 1291 1292 if (nmp->nm_flag & NFSMNT_INT) { 1293 sigset_t oldset; 1294 1295 newnfs_set_sigmask(td, &oldset); 1296 bp = getblk(vp, bn, size, PCATCH, 0, 0); 1297 newnfs_restore_sigmask(td, &oldset); 1298 while (bp == NULL) { 1299 if (newnfs_sigintr(nmp, td)) 1300 return (NULL); 1301 bp = getblk(vp, bn, size, 0, 2 * hz, 0); 1302 } 1303 } else { 1304 bp = getblk(vp, bn, size, 0, 0, 0); 1305 } 1306 1307 if (vp->v_type == VREG) 1308 bp->b_blkno = bn * (vp->v_bufobj.bo_bsize / DEV_BSIZE); 1309 return (bp); 1310} 1311 1312/* 1313 * Flush and invalidate all dirty buffers. If another process is already 1314 * doing the flush, just wait for completion. 1315 */ 1316int 1317ncl_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg) 1318{ 1319 struct nfsnode *np = VTONFS(vp); 1320 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 1321 int error = 0, slpflag, slptimeo; 1322 int old_lock = 0; 1323 1324 ASSERT_VOP_LOCKED(vp, "ncl_vinvalbuf"); 1325 1326 if ((nmp->nm_flag & NFSMNT_INT) == 0) 1327 intrflg = 0; 1328 if ((nmp->nm_mountp->mnt_kern_flag & MNTK_UNMOUNTF)) 1329 intrflg = 1; 1330 if (intrflg) { 1331 slpflag = PCATCH; 1332 slptimeo = 2 * hz; 1333 } else { 1334 slpflag = 0; 1335 slptimeo = 0; 1336 } 1337 1338 old_lock = ncl_upgrade_vnlock(vp); 1339 if (vp->v_iflag & VI_DOOMED) { 1340 /* 1341 * Since vgonel() uses the generic vinvalbuf() to flush 1342 * dirty buffers and it does not call this function, it 1343 * is safe to just return OK when VI_DOOMED is set. 1344 */ 1345 ncl_downgrade_vnlock(vp, old_lock); 1346 return (0); 1347 } 1348 1349 /* 1350 * Now, flush as required. 1351 */ 1352 if ((flags & V_SAVE) && (vp->v_bufobj.bo_object != NULL)) { 1353 VM_OBJECT_WLOCK(vp->v_bufobj.bo_object); 1354 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC); 1355 VM_OBJECT_WUNLOCK(vp->v_bufobj.bo_object); 1356 /* 1357 * If the page clean was interrupted, fail the invalidation. 1358 * Not doing so, we run the risk of losing dirty pages in the 1359 * vinvalbuf() call below. 1360 */ 1361 if (intrflg && (error = newnfs_sigintr(nmp, td))) 1362 goto out; 1363 } 1364 1365 error = vinvalbuf(vp, flags, slpflag, 0); 1366 while (error) { 1367 if (intrflg && (error = newnfs_sigintr(nmp, td))) 1368 goto out; 1369 error = vinvalbuf(vp, flags, 0, slptimeo); 1370 } 1371 if (NFSHASPNFS(nmp)) { 1372 nfscl_layoutcommit(vp, td); 1373 /* 1374 * Invalidate the attribute cache, since writes to a DS 1375 * won't update the size attribute. 1376 */ 1377 mtx_lock(&np->n_mtx); 1378 np->n_attrstamp = 0; 1379 } else 1380 mtx_lock(&np->n_mtx); 1381 if (np->n_directio_asyncwr == 0) 1382 np->n_flag &= ~NMODIFIED; 1383 mtx_unlock(&np->n_mtx); 1384out: 1385 ncl_downgrade_vnlock(vp, old_lock); 1386 return error; 1387} 1388 1389/* 1390 * Initiate asynchronous I/O. Return an error if no nfsiods are available. 1391 * This is mainly to avoid queueing async I/O requests when the nfsiods 1392 * are all hung on a dead server. 1393 * 1394 * Note: ncl_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp 1395 * is eventually dequeued by the async daemon, ncl_doio() *will*. 1396 */ 1397int 1398ncl_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td) 1399{ 1400 int iod; 1401 int gotiod; 1402 int slpflag = 0; 1403 int slptimeo = 0; 1404 int error, error2; 1405 1406 /* 1407 * Commits are usually short and sweet so lets save some cpu and 1408 * leave the async daemons for more important rpc's (such as reads 1409 * and writes). 1410 * 1411 * Readdirplus RPCs do vget()s to acquire the vnodes for entries 1412 * in the directory in order to update attributes. This can deadlock 1413 * with another thread that is waiting for async I/O to be done by 1414 * an nfsiod thread while holding a lock on one of these vnodes. 1415 * To avoid this deadlock, don't allow the async nfsiod threads to 1416 * perform Readdirplus RPCs. 1417 */ 1418 mtx_lock(&ncl_iod_mutex); 1419 if ((bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) && 1420 (nmp->nm_bufqiods > ncl_numasync / 2)) || 1421 (bp->b_vp->v_type == VDIR && (nmp->nm_flag & NFSMNT_RDIRPLUS))) { 1422 mtx_unlock(&ncl_iod_mutex); 1423 return(EIO); 1424 } 1425again: 1426 if (nmp->nm_flag & NFSMNT_INT) 1427 slpflag = PCATCH; 1428 gotiod = FALSE; 1429 1430 /* 1431 * Find a free iod to process this request. 1432 */ 1433 for (iod = 0; iod < ncl_numasync; iod++) 1434 if (ncl_iodwant[iod] == NFSIOD_AVAILABLE) { 1435 gotiod = TRUE; 1436 break; 1437 } 1438 1439 /* 1440 * Try to create one if none are free. 1441 */ 1442 if (!gotiod) 1443 ncl_nfsiodnew(); 1444 else { 1445 /* 1446 * Found one, so wake it up and tell it which 1447 * mount to process. 1448 */ 1449 NFS_DPF(ASYNCIO, ("ncl_asyncio: waking iod %d for mount %p\n", 1450 iod, nmp)); 1451 ncl_iodwant[iod] = NFSIOD_NOT_AVAILABLE; 1452 ncl_iodmount[iod] = nmp; 1453 nmp->nm_bufqiods++; 1454 wakeup(&ncl_iodwant[iod]); 1455 } 1456 1457 /* 1458 * If none are free, we may already have an iod working on this mount 1459 * point. If so, it will process our request. 1460 */ 1461 if (!gotiod) { 1462 if (nmp->nm_bufqiods > 0) { 1463 NFS_DPF(ASYNCIO, 1464 ("ncl_asyncio: %d iods are already processing mount %p\n", 1465 nmp->nm_bufqiods, nmp)); 1466 gotiod = TRUE; 1467 } 1468 } 1469 1470 /* 1471 * If we have an iod which can process the request, then queue 1472 * the buffer. 1473 */ 1474 if (gotiod) { 1475 /* 1476 * Ensure that the queue never grows too large. We still want 1477 * to asynchronize so we block rather then return EIO. 1478 */ 1479 while (nmp->nm_bufqlen >= 2*ncl_numasync) { 1480 NFS_DPF(ASYNCIO, 1481 ("ncl_asyncio: waiting for mount %p queue to drain\n", nmp)); 1482 nmp->nm_bufqwant = TRUE; 1483 error = newnfs_msleep(td, &nmp->nm_bufq, 1484 &ncl_iod_mutex, slpflag | PRIBIO, "nfsaio", 1485 slptimeo); 1486 if (error) { 1487 error2 = newnfs_sigintr(nmp, td); 1488 if (error2) { 1489 mtx_unlock(&ncl_iod_mutex); 1490 return (error2); 1491 } 1492 if (slpflag == PCATCH) { 1493 slpflag = 0; 1494 slptimeo = 2 * hz; 1495 } 1496 } 1497 /* 1498 * We might have lost our iod while sleeping, 1499 * so check and loop if nescessary. 1500 */ 1501 goto again; 1502 } 1503 1504 /* We might have lost our nfsiod */ 1505 if (nmp->nm_bufqiods == 0) { 1506 NFS_DPF(ASYNCIO, 1507 ("ncl_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); 1508 goto again; 1509 } 1510 1511 if (bp->b_iocmd == BIO_READ) { 1512 if (bp->b_rcred == NOCRED && cred != NOCRED) 1513 bp->b_rcred = crhold(cred); 1514 } else { 1515 if (bp->b_wcred == NOCRED && cred != NOCRED) 1516 bp->b_wcred = crhold(cred); 1517 } 1518 1519 if (bp->b_flags & B_REMFREE) 1520 bremfreef(bp); 1521 BUF_KERNPROC(bp); 1522 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist); 1523 nmp->nm_bufqlen++; 1524 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) { 1525 mtx_lock(&(VTONFS(bp->b_vp))->n_mtx); 1526 VTONFS(bp->b_vp)->n_flag |= NMODIFIED; 1527 VTONFS(bp->b_vp)->n_directio_asyncwr++; 1528 mtx_unlock(&(VTONFS(bp->b_vp))->n_mtx); 1529 } 1530 mtx_unlock(&ncl_iod_mutex); 1531 return (0); 1532 } 1533 1534 mtx_unlock(&ncl_iod_mutex); 1535 1536 /* 1537 * All the iods are busy on other mounts, so return EIO to 1538 * force the caller to process the i/o synchronously. 1539 */ 1540 NFS_DPF(ASYNCIO, ("ncl_asyncio: no iods available, i/o is synchronous\n")); 1541 return (EIO); 1542} 1543 1544void 1545ncl_doio_directwrite(struct buf *bp) 1546{ 1547 int iomode, must_commit; 1548 struct uio *uiop = (struct uio *)bp->b_caller1; 1549 char *iov_base = uiop->uio_iov->iov_base; 1550 1551 iomode = NFSWRITE_FILESYNC; 1552 uiop->uio_td = NULL; /* NULL since we're in nfsiod */ 1553 ncl_writerpc(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit, 0); 1554 KASSERT((must_commit == 0), ("ncl_doio_directwrite: Did not commit write")); 1555 free(iov_base, M_NFSDIRECTIO); 1556 free(uiop->uio_iov, M_NFSDIRECTIO); 1557 free(uiop, M_NFSDIRECTIO); 1558 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) { 1559 struct nfsnode *np = VTONFS(bp->b_vp); 1560 mtx_lock(&np->n_mtx); 1561 if (NFSHASPNFS(VFSTONFS(vnode_mount(bp->b_vp)))) { 1562 /* 1563 * Invalidate the attribute cache, since writes to a DS 1564 * won't update the size attribute. 1565 */ 1566 np->n_attrstamp = 0; 1567 } 1568 np->n_directio_asyncwr--; 1569 if (np->n_directio_asyncwr == 0) { 1570 np->n_flag &= ~NMODIFIED; 1571 if ((np->n_flag & NFSYNCWAIT)) { 1572 np->n_flag &= ~NFSYNCWAIT; 1573 wakeup((caddr_t)&np->n_directio_asyncwr); 1574 } 1575 } 1576 mtx_unlock(&np->n_mtx); 1577 } 1578 bp->b_vp = NULL; 1579 relpbuf(bp, &ncl_pbuf_freecnt); 1580} 1581 1582/* 1583 * Do an I/O operation to/from a cache block. This may be called 1584 * synchronously or from an nfsiod. 1585 */ 1586int 1587ncl_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td, 1588 int called_from_strategy) 1589{ 1590 struct uio *uiop; 1591 struct nfsnode *np; 1592 struct nfsmount *nmp; 1593 int error = 0, iomode, must_commit = 0; 1594 struct uio uio; 1595 struct iovec io; 1596 struct proc *p = td ? td->td_proc : NULL; 1597 uint8_t iocmd; 1598 1599 np = VTONFS(vp); 1600 nmp = VFSTONFS(vp->v_mount); 1601 uiop = &uio; 1602 uiop->uio_iov = &io; 1603 uiop->uio_iovcnt = 1; 1604 uiop->uio_segflg = UIO_SYSSPACE; 1605 uiop->uio_td = td; 1606 1607 /* 1608 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We 1609 * do this here so we do not have to do it in all the code that 1610 * calls us. 1611 */ 1612 bp->b_flags &= ~B_INVAL; 1613 bp->b_ioflags &= ~BIO_ERROR; 1614 1615 KASSERT(!(bp->b_flags & B_DONE), ("ncl_doio: bp %p already marked done", bp)); 1616 iocmd = bp->b_iocmd; 1617 if (iocmd == BIO_READ) { 1618 io.iov_len = uiop->uio_resid = bp->b_bcount; 1619 io.iov_base = bp->b_data; 1620 uiop->uio_rw = UIO_READ; 1621 1622 switch (vp->v_type) { 1623 case VREG: 1624 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE; 1625 NFSINCRGLOBAL(newnfsstats.read_bios); 1626 error = ncl_readrpc(vp, uiop, cr); 1627 1628 if (!error) { 1629 if (uiop->uio_resid) { 1630 /* 1631 * If we had a short read with no error, we must have 1632 * hit a file hole. We should zero-fill the remainder. 1633 * This can also occur if the server hits the file EOF. 1634 * 1635 * Holes used to be able to occur due to pending 1636 * writes, but that is not possible any longer. 1637 */ 1638 int nread = bp->b_bcount - uiop->uio_resid; 1639 ssize_t left = uiop->uio_resid; 1640 1641 if (left > 0) 1642 bzero((char *)bp->b_data + nread, left); 1643 uiop->uio_resid = 0; 1644 } 1645 } 1646 /* ASSERT_VOP_LOCKED(vp, "ncl_doio"); */ 1647 if (p && (vp->v_vflag & VV_TEXT)) { 1648 mtx_lock(&np->n_mtx); 1649 if (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.na_mtime)) { 1650 mtx_unlock(&np->n_mtx); 1651 PROC_LOCK(p); 1652 killproc(p, "text file modification"); 1653 PROC_UNLOCK(p); 1654 } else 1655 mtx_unlock(&np->n_mtx); 1656 } 1657 break; 1658 case VLNK: 1659 uiop->uio_offset = (off_t)0; 1660 NFSINCRGLOBAL(newnfsstats.readlink_bios); 1661 error = ncl_readlinkrpc(vp, uiop, cr); 1662 break; 1663 case VDIR: 1664 NFSINCRGLOBAL(newnfsstats.readdir_bios); 1665 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ; 1666 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) { 1667 error = ncl_readdirplusrpc(vp, uiop, cr, td); 1668 if (error == NFSERR_NOTSUPP) 1669 nmp->nm_flag &= ~NFSMNT_RDIRPLUS; 1670 } 1671 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) 1672 error = ncl_readdirrpc(vp, uiop, cr, td); 1673 /* 1674 * end-of-directory sets B_INVAL but does not generate an 1675 * error. 1676 */ 1677 if (error == 0 && uiop->uio_resid == bp->b_bcount) 1678 bp->b_flags |= B_INVAL; 1679 break; 1680 default: 1681 printf("ncl_doio: type %x unexpected\n", vp->v_type); 1682 break; 1683 }; 1684 if (error) { 1685 bp->b_ioflags |= BIO_ERROR; 1686 bp->b_error = error; 1687 } 1688 } else { 1689 /* 1690 * If we only need to commit, try to commit 1691 */ 1692 if (bp->b_flags & B_NEEDCOMMIT) { 1693 int retv; 1694 off_t off; 1695 1696 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff; 1697 retv = ncl_commit(vp, off, bp->b_dirtyend-bp->b_dirtyoff, 1698 bp->b_wcred, td); 1699 if (retv == 0) { 1700 bp->b_dirtyoff = bp->b_dirtyend = 0; 1701 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1702 bp->b_resid = 0; 1703 bufdone(bp); 1704 return (0); 1705 } 1706 if (retv == NFSERR_STALEWRITEVERF) { 1707 ncl_clearcommit(vp->v_mount); 1708 } 1709 } 1710 1711 /* 1712 * Setup for actual write 1713 */ 1714 mtx_lock(&np->n_mtx); 1715 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size) 1716 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE; 1717 mtx_unlock(&np->n_mtx); 1718 1719 if (bp->b_dirtyend > bp->b_dirtyoff) { 1720 io.iov_len = uiop->uio_resid = bp->b_dirtyend 1721 - bp->b_dirtyoff; 1722 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE 1723 + bp->b_dirtyoff; 1724 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; 1725 uiop->uio_rw = UIO_WRITE; 1726 NFSINCRGLOBAL(newnfsstats.write_bios); 1727 1728 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC) 1729 iomode = NFSWRITE_UNSTABLE; 1730 else 1731 iomode = NFSWRITE_FILESYNC; 1732 1733 error = ncl_writerpc(vp, uiop, cr, &iomode, &must_commit, 1734 called_from_strategy); 1735 1736 /* 1737 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try 1738 * to cluster the buffers needing commit. This will allow 1739 * the system to submit a single commit rpc for the whole 1740 * cluster. We can do this even if the buffer is not 100% 1741 * dirty (relative to the NFS blocksize), so we optimize the 1742 * append-to-file-case. 1743 * 1744 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be 1745 * cleared because write clustering only works for commit 1746 * rpc's, not for the data portion of the write). 1747 */ 1748 1749 if (!error && iomode == NFSWRITE_UNSTABLE) { 1750 bp->b_flags |= B_NEEDCOMMIT; 1751 if (bp->b_dirtyoff == 0 1752 && bp->b_dirtyend == bp->b_bcount) 1753 bp->b_flags |= B_CLUSTEROK; 1754 } else { 1755 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1756 } 1757 1758 /* 1759 * For an interrupted write, the buffer is still valid 1760 * and the write hasn't been pushed to the server yet, 1761 * so we can't set BIO_ERROR and report the interruption 1762 * by setting B_EINTR. For the B_ASYNC case, B_EINTR 1763 * is not relevant, so the rpc attempt is essentially 1764 * a noop. For the case of a V3 write rpc not being 1765 * committed to stable storage, the block is still 1766 * dirty and requires either a commit rpc or another 1767 * write rpc with iomode == NFSV3WRITE_FILESYNC before 1768 * the block is reused. This is indicated by setting 1769 * the B_DELWRI and B_NEEDCOMMIT flags. 1770 * 1771 * EIO is returned by ncl_writerpc() to indicate a recoverable 1772 * write error and is handled as above, except that 1773 * B_EINTR isn't set. One cause of this is a stale stateid 1774 * error for the RPC that indicates recovery is required, 1775 * when called with called_from_strategy != 0. 1776 * 1777 * If the buffer is marked B_PAGING, it does not reside on 1778 * the vp's paging queues so we cannot call bdirty(). The 1779 * bp in this case is not an NFS cache block so we should 1780 * be safe. XXX 1781 * 1782 * The logic below breaks up errors into recoverable and 1783 * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE 1784 * and keep the buffer around for potential write retries. 1785 * For the latter (eg ESTALE), we toss the buffer away (B_INVAL) 1786 * and save the error in the nfsnode. This is less than ideal 1787 * but necessary. Keeping such buffers around could potentially 1788 * cause buffer exhaustion eventually (they can never be written 1789 * out, so will get constantly be re-dirtied). It also causes 1790 * all sorts of vfs panics. For non-recoverable write errors, 1791 * also invalidate the attrcache, so we'll be forced to go over 1792 * the wire for this object, returning an error to user on next 1793 * call (most of the time). 1794 */ 1795 if (error == EINTR || error == EIO || error == ETIMEDOUT 1796 || (!error && (bp->b_flags & B_NEEDCOMMIT))) { 1797 int s; 1798 1799 s = splbio(); 1800 bp->b_flags &= ~(B_INVAL|B_NOCACHE); 1801 if ((bp->b_flags & B_PAGING) == 0) { 1802 bdirty(bp); 1803 bp->b_flags &= ~B_DONE; 1804 } 1805 if ((error == EINTR || error == ETIMEDOUT) && 1806 (bp->b_flags & B_ASYNC) == 0) 1807 bp->b_flags |= B_EINTR; 1808 splx(s); 1809 } else { 1810 if (error) { 1811 bp->b_ioflags |= BIO_ERROR; 1812 bp->b_flags |= B_INVAL; 1813 bp->b_error = np->n_error = error; 1814 mtx_lock(&np->n_mtx); 1815 np->n_flag |= NWRITEERR; 1816 np->n_attrstamp = 0; 1817 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 1818 mtx_unlock(&np->n_mtx); 1819 } 1820 bp->b_dirtyoff = bp->b_dirtyend = 0; 1821 } 1822 } else { 1823 bp->b_resid = 0; 1824 bufdone(bp); 1825 return (0); 1826 } 1827 } 1828 bp->b_resid = uiop->uio_resid; 1829 if (must_commit) 1830 ncl_clearcommit(vp->v_mount); 1831 bufdone(bp); 1832 return (error); 1833} 1834 1835/* 1836 * Used to aid in handling ftruncate() operations on the NFS client side. 1837 * Truncation creates a number of special problems for NFS. We have to 1838 * throw away VM pages and buffer cache buffers that are beyond EOF, and 1839 * we have to properly handle VM pages or (potentially dirty) buffers 1840 * that straddle the truncation point. 1841 */ 1842 1843int 1844ncl_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize) 1845{ 1846 struct nfsnode *np = VTONFS(vp); 1847 u_quad_t tsize; 1848 int biosize = vp->v_bufobj.bo_bsize; 1849 int error = 0; 1850 1851 mtx_lock(&np->n_mtx); 1852 tsize = np->n_size; 1853 np->n_size = nsize; 1854 mtx_unlock(&np->n_mtx); 1855 1856 if (nsize < tsize) { 1857 struct buf *bp; 1858 daddr_t lbn; 1859 int bufsize; 1860 1861 /* 1862 * vtruncbuf() doesn't get the buffer overlapping the 1863 * truncation point. We may have a B_DELWRI and/or B_CACHE 1864 * buffer that now needs to be truncated. 1865 */ 1866 error = vtruncbuf(vp, cred, nsize, biosize); 1867 lbn = nsize / biosize; 1868 bufsize = nsize - (lbn * biosize); 1869 bp = nfs_getcacheblk(vp, lbn, bufsize, td); 1870 if (!bp) 1871 return EINTR; 1872 if (bp->b_dirtyoff > bp->b_bcount) 1873 bp->b_dirtyoff = bp->b_bcount; 1874 if (bp->b_dirtyend > bp->b_bcount) 1875 bp->b_dirtyend = bp->b_bcount; 1876 bp->b_flags |= B_RELBUF; /* don't leave garbage around */ 1877 brelse(bp); 1878 } else { 1879 vnode_pager_setsize(vp, nsize); 1880 } 1881 return(error); 1882} 1883 1884