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