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