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 * 3. 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 SYSCTL_DECL(_vfs_nfs); 82 static int use_buf_pager = 1; 83 SYSCTL_INT(_vfs_nfs, OID_AUTO, use_buf_pager, CTLFLAG_RWTUN, 84 &use_buf_pager, 0, 85 "Use buffer pager instead of direct readrpc call"); 86 87 static daddr_t 88 ncl_gbp_getblkno(struct vnode *vp, vm_ooffset_t off) 89 { 90 91 return (off / vp->v_bufobj.bo_bsize); 92 } 93 94 static int 95 ncl_gbp_getblksz(struct vnode *vp, daddr_t lbn) 96 { 97 struct nfsnode *np; 98 u_quad_t nsize; 99 int biosize, bcount; 100 101 np = VTONFS(vp); 102 mtx_lock(&np->n_mtx); 103 nsize = np->n_size; 104 mtx_unlock(&np->n_mtx); 105 106 biosize = vp->v_bufobj.bo_bsize; 107 bcount = biosize; 108 if ((off_t)lbn * biosize >= nsize) 109 bcount = 0; 110 else if ((off_t)(lbn + 1) * biosize > nsize) 111 bcount = nsize - (off_t)lbn * biosize; 112 return (bcount); 113 } 114 115 int 116 ncl_getpages(struct vop_getpages_args *ap) 117 { 118 int i, error, nextoff, size, toff, count, npages; 119 struct uio uio; 120 struct iovec iov; 121 vm_offset_t kva; 122 struct buf *bp; 123 struct vnode *vp; 124 struct thread *td; 125 struct ucred *cred; 126 struct nfsmount *nmp; 127 vm_object_t object; 128 vm_page_t *pages; 129 struct nfsnode *np; 130 131 vp = ap->a_vp; 132 np = VTONFS(vp); 133 td = curthread; 134 cred = curthread->td_ucred; 135 nmp = VFSTONFS(vp->v_mount); 136 pages = ap->a_m; 137 npages = ap->a_count; 138 139 if ((object = vp->v_object) == NULL) { 140 printf("ncl_getpages: called with non-merged cache vnode\n"); 141 return (VM_PAGER_ERROR); 142 } 143 144 if (newnfs_directio_enable && !newnfs_directio_allow_mmap) { 145 mtx_lock(&np->n_mtx); 146 if ((np->n_flag & NNONCACHE) && (vp->v_type == VREG)) { 147 mtx_unlock(&np->n_mtx); 148 printf("ncl_getpages: called on non-cacheable vnode\n"); 149 return (VM_PAGER_ERROR); 150 } else 151 mtx_unlock(&np->n_mtx); 152 } 153 154 mtx_lock(&nmp->nm_mtx); 155 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 156 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 157 mtx_unlock(&nmp->nm_mtx); 158 /* We'll never get here for v4, because we always have fsinfo */ 159 (void)ncl_fsinfo(nmp, vp, cred, td); 160 } else 161 mtx_unlock(&nmp->nm_mtx); 162 163 if (use_buf_pager) 164 return (vfs_bio_getpages(vp, pages, npages, ap->a_rbehind, 165 ap->a_rahead, ncl_gbp_getblkno, ncl_gbp_getblksz)); 166 167 /* 168 * If the requested page is partially valid, just return it and 169 * allow the pager to zero-out the blanks. Partially valid pages 170 * can only occur at the file EOF. 171 * 172 * XXXGL: is that true for NFS, where short read can occur??? 173 */ 174 VM_OBJECT_WLOCK(object); 175 if (pages[npages - 1]->valid != 0 && --npages == 0) 176 goto out; 177 VM_OBJECT_WUNLOCK(object); 178 179 /* 180 * We use only the kva address for the buffer, but this is extremely 181 * convenient and fast. 182 */ 183 bp = getpbuf(&ncl_pbuf_freecnt); 184 185 kva = (vm_offset_t) bp->b_data; 186 pmap_qenter(kva, pages, npages); 187 PCPU_INC(cnt.v_vnodein); 188 PCPU_ADD(cnt.v_vnodepgsin, npages); 189 190 count = npages << PAGE_SHIFT; 191 iov.iov_base = (caddr_t) kva; 192 iov.iov_len = count; 193 uio.uio_iov = &iov; 194 uio.uio_iovcnt = 1; 195 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex); 196 uio.uio_resid = count; 197 uio.uio_segflg = UIO_SYSSPACE; 198 uio.uio_rw = UIO_READ; 199 uio.uio_td = td; 200 201 error = ncl_readrpc(vp, &uio, cred); 202 pmap_qremove(kva, npages); 203 204 relpbuf(bp, &ncl_pbuf_freecnt); 205 206 if (error && (uio.uio_resid == count)) { 207 printf("ncl_getpages: error %d\n", error); 208 return (VM_PAGER_ERROR); 209 } 210 211 /* 212 * Calculate the number of bytes read and validate only that number 213 * of bytes. Note that due to pending writes, size may be 0. This 214 * does not mean that the remaining data is invalid! 215 */ 216 217 size = count - uio.uio_resid; 218 VM_OBJECT_WLOCK(object); 219 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) { 220 vm_page_t m; 221 nextoff = toff + PAGE_SIZE; 222 m = pages[i]; 223 224 if (nextoff <= size) { 225 /* 226 * Read operation filled an entire page 227 */ 228 m->valid = VM_PAGE_BITS_ALL; 229 KASSERT(m->dirty == 0, 230 ("nfs_getpages: page %p is dirty", m)); 231 } else if (size > toff) { 232 /* 233 * Read operation filled a partial page. 234 */ 235 m->valid = 0; 236 vm_page_set_valid_range(m, 0, size - toff); 237 KASSERT(m->dirty == 0, 238 ("nfs_getpages: page %p is dirty", m)); 239 } else { 240 /* 241 * Read operation was short. If no error 242 * occurred we may have hit a zero-fill 243 * section. We leave valid set to 0, and page 244 * is freed by vm_page_readahead_finish() if 245 * its index is not equal to requested, or 246 * page is zeroed and set valid by 247 * vm_pager_get_pages() for requested page. 248 */ 249 ; 250 } 251 } 252 out: 253 VM_OBJECT_WUNLOCK(object); 254 if (ap->a_rbehind) 255 *ap->a_rbehind = 0; 256 if (ap->a_rahead) 257 *ap->a_rahead = 0; 258 return (VM_PAGER_OK); 259 } 260 261 /* 262 * Vnode op for VM putpages. 263 */ 264 int 265 ncl_putpages(struct vop_putpages_args *ap) 266 { 267 struct uio uio; 268 struct iovec iov; 269 vm_offset_t kva; 270 struct buf *bp; 271 int iomode, must_commit, i, error, npages, count; 272 off_t offset; 273 int *rtvals; 274 struct vnode *vp; 275 struct thread *td; 276 struct ucred *cred; 277 struct nfsmount *nmp; 278 struct nfsnode *np; 279 vm_page_t *pages; 280 281 vp = ap->a_vp; 282 np = VTONFS(vp); 283 td = curthread; /* XXX */ 284 /* Set the cred to n_writecred for the write rpcs. */ 285 if (np->n_writecred != NULL) 286 cred = crhold(np->n_writecred); 287 else 288 cred = crhold(curthread->td_ucred); /* XXX */ 289 nmp = VFSTONFS(vp->v_mount); 290 pages = ap->a_m; 291 count = ap->a_count; 292 rtvals = ap->a_rtvals; 293 npages = btoc(count); 294 offset = IDX_TO_OFF(pages[0]->pindex); 295 296 mtx_lock(&nmp->nm_mtx); 297 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 298 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 299 mtx_unlock(&nmp->nm_mtx); 300 (void)ncl_fsinfo(nmp, vp, cred, td); 301 } else 302 mtx_unlock(&nmp->nm_mtx); 303 304 mtx_lock(&np->n_mtx); 305 if (newnfs_directio_enable && !newnfs_directio_allow_mmap && 306 (np->n_flag & NNONCACHE) && (vp->v_type == VREG)) { 307 mtx_unlock(&np->n_mtx); 308 printf("ncl_putpages: called on noncache-able vnode\n"); 309 mtx_lock(&np->n_mtx); 310 } 311 312 for (i = 0; i < npages; i++) 313 rtvals[i] = VM_PAGER_ERROR; 314 315 /* 316 * When putting pages, do not extend file past EOF. 317 */ 318 if (offset + count > np->n_size) { 319 count = np->n_size - offset; 320 if (count < 0) 321 count = 0; 322 } 323 mtx_unlock(&np->n_mtx); 324 325 /* 326 * We use only the kva address for the buffer, but this is extremely 327 * convenient and fast. 328 */ 329 bp = getpbuf(&ncl_pbuf_freecnt); 330 331 kva = (vm_offset_t) bp->b_data; 332 pmap_qenter(kva, pages, npages); 333 PCPU_INC(cnt.v_vnodeout); 334 PCPU_ADD(cnt.v_vnodepgsout, count); 335 336 iov.iov_base = (caddr_t) kva; 337 iov.iov_len = count; 338 uio.uio_iov = &iov; 339 uio.uio_iovcnt = 1; 340 uio.uio_offset = offset; 341 uio.uio_resid = count; 342 uio.uio_segflg = UIO_SYSSPACE; 343 uio.uio_rw = UIO_WRITE; 344 uio.uio_td = td; 345 346 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0) 347 iomode = NFSWRITE_UNSTABLE; 348 else 349 iomode = NFSWRITE_FILESYNC; 350 351 error = ncl_writerpc(vp, &uio, cred, &iomode, &must_commit, 0); 352 crfree(cred); 353 354 pmap_qremove(kva, npages); 355 relpbuf(bp, &ncl_pbuf_freecnt); 356 357 if (error == 0 || !nfs_keep_dirty_on_error) { 358 vnode_pager_undirty_pages(pages, rtvals, count - uio.uio_resid); 359 if (must_commit) 360 ncl_clearcommit(vp->v_mount); 361 } 362 return rtvals[0]; 363 } 364 365 /* 366 * For nfs, cache consistency can only be maintained approximately. 367 * Although RFC1094 does not specify the criteria, the following is 368 * believed to be compatible with the reference port. 369 * For nfs: 370 * If the file's modify time on the server has changed since the 371 * last read rpc or you have written to the file, 372 * you may have lost data cache consistency with the 373 * server, so flush all of the file's data out of the cache. 374 * Then force a getattr rpc to ensure that you have up to date 375 * attributes. 376 * NB: This implies that cache data can be read when up to 377 * NFS_ATTRTIMEO seconds out of date. If you find that you need current 378 * attributes this could be forced by setting n_attrstamp to 0 before 379 * the VOP_GETATTR() call. 380 */ 381 static inline int 382 nfs_bioread_check_cons(struct vnode *vp, struct thread *td, struct ucred *cred) 383 { 384 int error = 0; 385 struct vattr vattr; 386 struct nfsnode *np = VTONFS(vp); 387 int old_lock; 388 389 /* 390 * Grab the exclusive lock before checking whether the cache is 391 * consistent. 392 * XXX - We can make this cheaper later (by acquiring cheaper locks). 393 * But for now, this suffices. 394 */ 395 old_lock = ncl_upgrade_vnlock(vp); 396 if (vp->v_iflag & VI_DOOMED) { 397 ncl_downgrade_vnlock(vp, old_lock); 398 return (EBADF); 399 } 400 401 mtx_lock(&np->n_mtx); 402 if (np->n_flag & NMODIFIED) { 403 mtx_unlock(&np->n_mtx); 404 if (vp->v_type != VREG) { 405 if (vp->v_type != VDIR) 406 panic("nfs: bioread, not dir"); 407 ncl_invaldir(vp); 408 error = ncl_vinvalbuf(vp, V_SAVE, td, 1); 409 if (error) 410 goto out; 411 } 412 np->n_attrstamp = 0; 413 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 414 error = VOP_GETATTR(vp, &vattr, cred); 415 if (error) 416 goto out; 417 mtx_lock(&np->n_mtx); 418 np->n_mtime = vattr.va_mtime; 419 mtx_unlock(&np->n_mtx); 420 } else { 421 mtx_unlock(&np->n_mtx); 422 error = VOP_GETATTR(vp, &vattr, cred); 423 if (error) 424 return (error); 425 mtx_lock(&np->n_mtx); 426 if ((np->n_flag & NSIZECHANGED) 427 || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) { 428 mtx_unlock(&np->n_mtx); 429 if (vp->v_type == VDIR) 430 ncl_invaldir(vp); 431 error = ncl_vinvalbuf(vp, V_SAVE, td, 1); 432 if (error) 433 goto out; 434 mtx_lock(&np->n_mtx); 435 np->n_mtime = vattr.va_mtime; 436 np->n_flag &= ~NSIZECHANGED; 437 } 438 mtx_unlock(&np->n_mtx); 439 } 440 out: 441 ncl_downgrade_vnlock(vp, old_lock); 442 return error; 443 } 444 445 /* 446 * Vnode op for read using bio 447 */ 448 int 449 ncl_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred) 450 { 451 struct nfsnode *np = VTONFS(vp); 452 int biosize, i; 453 struct buf *bp, *rabp; 454 struct thread *td; 455 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 456 daddr_t lbn, rabn; 457 int bcount; 458 int seqcount; 459 int nra, error = 0, n = 0, on = 0; 460 off_t tmp_off; 461 462 KASSERT(uio->uio_rw == UIO_READ, ("ncl_read mode")); 463 if (uio->uio_resid == 0) 464 return (0); 465 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */ 466 return (EINVAL); 467 td = uio->uio_td; 468 469 mtx_lock(&nmp->nm_mtx); 470 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 471 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 472 mtx_unlock(&nmp->nm_mtx); 473 (void)ncl_fsinfo(nmp, vp, cred, td); 474 mtx_lock(&nmp->nm_mtx); 475 } 476 if (nmp->nm_rsize == 0 || nmp->nm_readdirsize == 0) 477 (void) newnfs_iosize(nmp); 478 479 tmp_off = uio->uio_offset + uio->uio_resid; 480 if (vp->v_type != VDIR && 481 (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)) { 482 mtx_unlock(&nmp->nm_mtx); 483 return (EFBIG); 484 } 485 mtx_unlock(&nmp->nm_mtx); 486 487 if (newnfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG)) 488 /* No caching/ no readaheads. Just read data into the user buffer */ 489 return ncl_readrpc(vp, uio, cred); 490 491 biosize = vp->v_bufobj.bo_bsize; 492 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE); 493 494 error = nfs_bioread_check_cons(vp, td, cred); 495 if (error) 496 return error; 497 498 do { 499 u_quad_t nsize; 500 501 mtx_lock(&np->n_mtx); 502 nsize = np->n_size; 503 mtx_unlock(&np->n_mtx); 504 505 switch (vp->v_type) { 506 case VREG: 507 NFSINCRGLOBAL(nfsstatsv1.biocache_reads); 508 lbn = uio->uio_offset / biosize; 509 on = uio->uio_offset - (lbn * biosize); 510 511 /* 512 * Start the read ahead(s), as required. 513 */ 514 if (nmp->nm_readahead > 0) { 515 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && 516 (off_t)(lbn + 1 + nra) * biosize < nsize; nra++) { 517 rabn = lbn + 1 + nra; 518 if (incore(&vp->v_bufobj, rabn) == NULL) { 519 rabp = nfs_getcacheblk(vp, rabn, biosize, td); 520 if (!rabp) { 521 error = newnfs_sigintr(nmp, td); 522 return (error ? error : EINTR); 523 } 524 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 525 rabp->b_flags |= B_ASYNC; 526 rabp->b_iocmd = BIO_READ; 527 vfs_busy_pages(rabp, 0); 528 if (ncl_asyncio(nmp, rabp, cred, td)) { 529 rabp->b_flags |= B_INVAL; 530 rabp->b_ioflags |= BIO_ERROR; 531 vfs_unbusy_pages(rabp); 532 brelse(rabp); 533 break; 534 } 535 } else { 536 brelse(rabp); 537 } 538 } 539 } 540 } 541 542 /* Note that bcount is *not* DEV_BSIZE aligned. */ 543 bcount = biosize; 544 if ((off_t)lbn * biosize >= nsize) { 545 bcount = 0; 546 } else if ((off_t)(lbn + 1) * biosize > nsize) { 547 bcount = nsize - (off_t)lbn * biosize; 548 } 549 bp = nfs_getcacheblk(vp, lbn, bcount, td); 550 551 if (!bp) { 552 error = newnfs_sigintr(nmp, td); 553 return (error ? error : EINTR); 554 } 555 556 /* 557 * If B_CACHE is not set, we must issue the read. If this 558 * fails, we return an error. 559 */ 560 561 if ((bp->b_flags & B_CACHE) == 0) { 562 bp->b_iocmd = BIO_READ; 563 vfs_busy_pages(bp, 0); 564 error = ncl_doio(vp, bp, cred, td, 0); 565 if (error) { 566 brelse(bp); 567 return (error); 568 } 569 } 570 571 /* 572 * on is the offset into the current bp. Figure out how many 573 * bytes we can copy out of the bp. Note that bcount is 574 * NOT DEV_BSIZE aligned. 575 * 576 * Then figure out how many bytes we can copy into the uio. 577 */ 578 579 n = 0; 580 if (on < bcount) 581 n = MIN((unsigned)(bcount - on), uio->uio_resid); 582 break; 583 case VLNK: 584 NFSINCRGLOBAL(nfsstatsv1.biocache_readlinks); 585 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td); 586 if (!bp) { 587 error = newnfs_sigintr(nmp, td); 588 return (error ? error : EINTR); 589 } 590 if ((bp->b_flags & B_CACHE) == 0) { 591 bp->b_iocmd = BIO_READ; 592 vfs_busy_pages(bp, 0); 593 error = ncl_doio(vp, bp, cred, td, 0); 594 if (error) { 595 bp->b_ioflags |= BIO_ERROR; 596 brelse(bp); 597 return (error); 598 } 599 } 600 n = MIN(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); 601 on = 0; 602 break; 603 case VDIR: 604 NFSINCRGLOBAL(nfsstatsv1.biocache_readdirs); 605 if (np->n_direofoffset 606 && uio->uio_offset >= np->n_direofoffset) { 607 return (0); 608 } 609 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; 610 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); 611 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td); 612 if (!bp) { 613 error = newnfs_sigintr(nmp, td); 614 return (error ? error : EINTR); 615 } 616 if ((bp->b_flags & B_CACHE) == 0) { 617 bp->b_iocmd = BIO_READ; 618 vfs_busy_pages(bp, 0); 619 error = ncl_doio(vp, bp, cred, td, 0); 620 if (error) { 621 brelse(bp); 622 } 623 while (error == NFSERR_BAD_COOKIE) { 624 ncl_invaldir(vp); 625 error = ncl_vinvalbuf(vp, 0, td, 1); 626 /* 627 * Yuck! The directory has been modified on the 628 * server. The only way to get the block is by 629 * reading from the beginning to get all the 630 * offset cookies. 631 * 632 * Leave the last bp intact unless there is an error. 633 * Loop back up to the while if the error is another 634 * NFSERR_BAD_COOKIE (double yuch!). 635 */ 636 for (i = 0; i <= lbn && !error; i++) { 637 if (np->n_direofoffset 638 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) 639 return (0); 640 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td); 641 if (!bp) { 642 error = newnfs_sigintr(nmp, td); 643 return (error ? error : EINTR); 644 } 645 if ((bp->b_flags & B_CACHE) == 0) { 646 bp->b_iocmd = BIO_READ; 647 vfs_busy_pages(bp, 0); 648 error = ncl_doio(vp, bp, cred, td, 0); 649 /* 650 * no error + B_INVAL == directory EOF, 651 * use the block. 652 */ 653 if (error == 0 && (bp->b_flags & B_INVAL)) 654 break; 655 } 656 /* 657 * An error will throw away the block and the 658 * for loop will break out. If no error and this 659 * is not the block we want, we throw away the 660 * block and go for the next one via the for loop. 661 */ 662 if (error || i < lbn) 663 brelse(bp); 664 } 665 } 666 /* 667 * The above while is repeated if we hit another cookie 668 * error. If we hit an error and it wasn't a cookie error, 669 * we give up. 670 */ 671 if (error) 672 return (error); 673 } 674 675 /* 676 * If not eof and read aheads are enabled, start one. 677 * (You need the current block first, so that you have the 678 * directory offset cookie of the next block.) 679 */ 680 if (nmp->nm_readahead > 0 && 681 (bp->b_flags & B_INVAL) == 0 && 682 (np->n_direofoffset == 0 || 683 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) && 684 incore(&vp->v_bufobj, lbn + 1) == NULL) { 685 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td); 686 if (rabp) { 687 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 688 rabp->b_flags |= B_ASYNC; 689 rabp->b_iocmd = BIO_READ; 690 vfs_busy_pages(rabp, 0); 691 if (ncl_asyncio(nmp, rabp, cred, td)) { 692 rabp->b_flags |= B_INVAL; 693 rabp->b_ioflags |= BIO_ERROR; 694 vfs_unbusy_pages(rabp); 695 brelse(rabp); 696 } 697 } else { 698 brelse(rabp); 699 } 700 } 701 } 702 /* 703 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is 704 * chopped for the EOF condition, we cannot tell how large 705 * NFS directories are going to be until we hit EOF. So 706 * an NFS directory buffer is *not* chopped to its EOF. Now, 707 * it just so happens that b_resid will effectively chop it 708 * to EOF. *BUT* this information is lost if the buffer goes 709 * away and is reconstituted into a B_CACHE state ( due to 710 * being VMIO ) later. So we keep track of the directory eof 711 * in np->n_direofoffset and chop it off as an extra step 712 * right here. 713 */ 714 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on); 715 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset) 716 n = np->n_direofoffset - uio->uio_offset; 717 break; 718 default: 719 printf(" ncl_bioread: type %x unexpected\n", vp->v_type); 720 bp = NULL; 721 break; 722 } 723 724 if (n > 0) { 725 error = vn_io_fault_uiomove(bp->b_data + on, (int)n, uio); 726 } 727 if (vp->v_type == VLNK) 728 n = 0; 729 if (bp != NULL) 730 brelse(bp); 731 } while (error == 0 && uio->uio_resid > 0 && n > 0); 732 return (error); 733 } 734 735 /* 736 * The NFS write path cannot handle iovecs with len > 1. So we need to 737 * break up iovecs accordingly (restricting them to wsize). 738 * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf). 739 * For the ASYNC case, 2 copies are needed. The first a copy from the 740 * user buffer to a staging buffer and then a second copy from the staging 741 * buffer to mbufs. This can be optimized by copying from the user buffer 742 * directly into mbufs and passing the chain down, but that requires a 743 * fair amount of re-working of the relevant codepaths (and can be done 744 * later). 745 */ 746 static int 747 nfs_directio_write(vp, uiop, cred, ioflag) 748 struct vnode *vp; 749 struct uio *uiop; 750 struct ucred *cred; 751 int ioflag; 752 { 753 int error; 754 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 755 struct thread *td = uiop->uio_td; 756 int size; 757 int wsize; 758 759 mtx_lock(&nmp->nm_mtx); 760 wsize = nmp->nm_wsize; 761 mtx_unlock(&nmp->nm_mtx); 762 if (ioflag & IO_SYNC) { 763 int iomode, must_commit; 764 struct uio uio; 765 struct iovec iov; 766 do_sync: 767 while (uiop->uio_resid > 0) { 768 size = MIN(uiop->uio_resid, wsize); 769 size = MIN(uiop->uio_iov->iov_len, size); 770 iov.iov_base = uiop->uio_iov->iov_base; 771 iov.iov_len = size; 772 uio.uio_iov = &iov; 773 uio.uio_iovcnt = 1; 774 uio.uio_offset = uiop->uio_offset; 775 uio.uio_resid = size; 776 uio.uio_segflg = UIO_USERSPACE; 777 uio.uio_rw = UIO_WRITE; 778 uio.uio_td = td; 779 iomode = NFSWRITE_FILESYNC; 780 error = ncl_writerpc(vp, &uio, cred, &iomode, 781 &must_commit, 0); 782 KASSERT((must_commit == 0), 783 ("ncl_directio_write: Did not commit write")); 784 if (error) 785 return (error); 786 uiop->uio_offset += size; 787 uiop->uio_resid -= size; 788 if (uiop->uio_iov->iov_len <= size) { 789 uiop->uio_iovcnt--; 790 uiop->uio_iov++; 791 } else { 792 uiop->uio_iov->iov_base = 793 (char *)uiop->uio_iov->iov_base + size; 794 uiop->uio_iov->iov_len -= size; 795 } 796 } 797 } else { 798 struct uio *t_uio; 799 struct iovec *t_iov; 800 struct buf *bp; 801 802 /* 803 * Break up the write into blocksize chunks and hand these 804 * over to nfsiod's for write back. 805 * Unfortunately, this incurs a copy of the data. Since 806 * the user could modify the buffer before the write is 807 * initiated. 808 * 809 * The obvious optimization here is that one of the 2 copies 810 * in the async write path can be eliminated by copying the 811 * data here directly into mbufs and passing the mbuf chain 812 * down. But that will require a fair amount of re-working 813 * of the code and can be done if there's enough interest 814 * in NFS directio access. 815 */ 816 while (uiop->uio_resid > 0) { 817 size = MIN(uiop->uio_resid, wsize); 818 size = MIN(uiop->uio_iov->iov_len, size); 819 bp = getpbuf(&ncl_pbuf_freecnt); 820 t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK); 821 t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK); 822 t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK); 823 t_iov->iov_len = size; 824 t_uio->uio_iov = t_iov; 825 t_uio->uio_iovcnt = 1; 826 t_uio->uio_offset = uiop->uio_offset; 827 t_uio->uio_resid = size; 828 t_uio->uio_segflg = UIO_SYSSPACE; 829 t_uio->uio_rw = UIO_WRITE; 830 t_uio->uio_td = td; 831 KASSERT(uiop->uio_segflg == UIO_USERSPACE || 832 uiop->uio_segflg == UIO_SYSSPACE, 833 ("nfs_directio_write: Bad uio_segflg")); 834 if (uiop->uio_segflg == UIO_USERSPACE) { 835 error = copyin(uiop->uio_iov->iov_base, 836 t_iov->iov_base, size); 837 if (error != 0) 838 goto err_free; 839 } else 840 /* 841 * UIO_SYSSPACE may never happen, but handle 842 * it just in case it does. 843 */ 844 bcopy(uiop->uio_iov->iov_base, t_iov->iov_base, 845 size); 846 bp->b_flags |= B_DIRECT; 847 bp->b_iocmd = BIO_WRITE; 848 if (cred != NOCRED) { 849 crhold(cred); 850 bp->b_wcred = cred; 851 } else 852 bp->b_wcred = NOCRED; 853 bp->b_caller1 = (void *)t_uio; 854 bp->b_vp = vp; 855 error = ncl_asyncio(nmp, bp, NOCRED, td); 856 err_free: 857 if (error) { 858 free(t_iov->iov_base, M_NFSDIRECTIO); 859 free(t_iov, M_NFSDIRECTIO); 860 free(t_uio, M_NFSDIRECTIO); 861 bp->b_vp = NULL; 862 relpbuf(bp, &ncl_pbuf_freecnt); 863 if (error == EINTR) 864 return (error); 865 goto do_sync; 866 } 867 uiop->uio_offset += size; 868 uiop->uio_resid -= size; 869 if (uiop->uio_iov->iov_len <= size) { 870 uiop->uio_iovcnt--; 871 uiop->uio_iov++; 872 } else { 873 uiop->uio_iov->iov_base = 874 (char *)uiop->uio_iov->iov_base + size; 875 uiop->uio_iov->iov_len -= size; 876 } 877 } 878 } 879 return (0); 880 } 881 882 /* 883 * Vnode op for write using bio 884 */ 885 int 886 ncl_write(struct vop_write_args *ap) 887 { 888 int biosize; 889 struct uio *uio = ap->a_uio; 890 struct thread *td = uio->uio_td; 891 struct vnode *vp = ap->a_vp; 892 struct nfsnode *np = VTONFS(vp); 893 struct ucred *cred = ap->a_cred; 894 int ioflag = ap->a_ioflag; 895 struct buf *bp; 896 struct vattr vattr; 897 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 898 daddr_t lbn; 899 int bcount, noncontig_write, obcount; 900 int bp_cached, n, on, error = 0, error1, wouldcommit; 901 size_t orig_resid, local_resid; 902 off_t orig_size, tmp_off; 903 904 KASSERT(uio->uio_rw == UIO_WRITE, ("ncl_write mode")); 905 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, 906 ("ncl_write proc")); 907 if (vp->v_type != VREG) 908 return (EIO); 909 mtx_lock(&np->n_mtx); 910 if (np->n_flag & NWRITEERR) { 911 np->n_flag &= ~NWRITEERR; 912 mtx_unlock(&np->n_mtx); 913 return (np->n_error); 914 } else 915 mtx_unlock(&np->n_mtx); 916 mtx_lock(&nmp->nm_mtx); 917 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 918 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 919 mtx_unlock(&nmp->nm_mtx); 920 (void)ncl_fsinfo(nmp, vp, cred, td); 921 mtx_lock(&nmp->nm_mtx); 922 } 923 if (nmp->nm_wsize == 0) 924 (void) newnfs_iosize(nmp); 925 mtx_unlock(&nmp->nm_mtx); 926 927 /* 928 * Synchronously flush pending buffers if we are in synchronous 929 * mode or if we are appending. 930 */ 931 if (ioflag & (IO_APPEND | IO_SYNC)) { 932 mtx_lock(&np->n_mtx); 933 if (np->n_flag & NMODIFIED) { 934 mtx_unlock(&np->n_mtx); 935 #ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */ 936 /* 937 * Require non-blocking, synchronous writes to 938 * dirty files to inform the program it needs 939 * to fsync(2) explicitly. 940 */ 941 if (ioflag & IO_NDELAY) 942 return (EAGAIN); 943 #endif 944 np->n_attrstamp = 0; 945 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 946 error = ncl_vinvalbuf(vp, V_SAVE, td, 1); 947 if (error) 948 return (error); 949 } else 950 mtx_unlock(&np->n_mtx); 951 } 952 953 orig_resid = uio->uio_resid; 954 mtx_lock(&np->n_mtx); 955 orig_size = np->n_size; 956 mtx_unlock(&np->n_mtx); 957 958 /* 959 * If IO_APPEND then load uio_offset. We restart here if we cannot 960 * get the append lock. 961 */ 962 if (ioflag & IO_APPEND) { 963 np->n_attrstamp = 0; 964 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 965 error = VOP_GETATTR(vp, &vattr, cred); 966 if (error) 967 return (error); 968 mtx_lock(&np->n_mtx); 969 uio->uio_offset = np->n_size; 970 mtx_unlock(&np->n_mtx); 971 } 972 973 if (uio->uio_offset < 0) 974 return (EINVAL); 975 tmp_off = uio->uio_offset + uio->uio_resid; 976 if (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset) 977 return (EFBIG); 978 if (uio->uio_resid == 0) 979 return (0); 980 981 if (newnfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG) 982 return nfs_directio_write(vp, uio, cred, ioflag); 983 984 /* 985 * Maybe this should be above the vnode op call, but so long as 986 * file servers have no limits, i don't think it matters 987 */ 988 if (vn_rlimit_fsize(vp, uio, td)) 989 return (EFBIG); 990 991 biosize = vp->v_bufobj.bo_bsize; 992 /* 993 * Find all of this file's B_NEEDCOMMIT buffers. If our writes 994 * would exceed the local maximum per-file write commit size when 995 * combined with those, we must decide whether to flush, 996 * go synchronous, or return error. We don't bother checking 997 * IO_UNIT -- we just make all writes atomic anyway, as there's 998 * no point optimizing for something that really won't ever happen. 999 */ 1000 wouldcommit = 0; 1001 if (!(ioflag & IO_SYNC)) { 1002 int nflag; 1003 1004 mtx_lock(&np->n_mtx); 1005 nflag = np->n_flag; 1006 mtx_unlock(&np->n_mtx); 1007 if (nflag & NMODIFIED) { 1008 BO_LOCK(&vp->v_bufobj); 1009 if (vp->v_bufobj.bo_dirty.bv_cnt != 0) { 1010 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd, 1011 b_bobufs) { 1012 if (bp->b_flags & B_NEEDCOMMIT) 1013 wouldcommit += bp->b_bcount; 1014 } 1015 } 1016 BO_UNLOCK(&vp->v_bufobj); 1017 } 1018 } 1019 1020 do { 1021 if (!(ioflag & IO_SYNC)) { 1022 wouldcommit += biosize; 1023 if (wouldcommit > nmp->nm_wcommitsize) { 1024 np->n_attrstamp = 0; 1025 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 1026 error = ncl_vinvalbuf(vp, V_SAVE, td, 1); 1027 if (error) 1028 return (error); 1029 wouldcommit = biosize; 1030 } 1031 } 1032 1033 NFSINCRGLOBAL(nfsstatsv1.biocache_writes); 1034 lbn = uio->uio_offset / biosize; 1035 on = uio->uio_offset - (lbn * biosize); 1036 n = MIN((unsigned)(biosize - on), uio->uio_resid); 1037 again: 1038 /* 1039 * Handle direct append and file extension cases, calculate 1040 * unaligned buffer size. 1041 */ 1042 mtx_lock(&np->n_mtx); 1043 if ((np->n_flag & NHASBEENLOCKED) == 0 && 1044 (nmp->nm_flag & NFSMNT_NONCONTIGWR) != 0) 1045 noncontig_write = 1; 1046 else 1047 noncontig_write = 0; 1048 if ((uio->uio_offset == np->n_size || 1049 (noncontig_write != 0 && 1050 lbn == (np->n_size / biosize) && 1051 uio->uio_offset + n > np->n_size)) && n) { 1052 mtx_unlock(&np->n_mtx); 1053 /* 1054 * Get the buffer (in its pre-append state to maintain 1055 * B_CACHE if it was previously set). Resize the 1056 * nfsnode after we have locked the buffer to prevent 1057 * readers from reading garbage. 1058 */ 1059 obcount = np->n_size - (lbn * biosize); 1060 bp = nfs_getcacheblk(vp, lbn, obcount, td); 1061 1062 if (bp != NULL) { 1063 long save; 1064 1065 mtx_lock(&np->n_mtx); 1066 np->n_size = uio->uio_offset + n; 1067 np->n_flag |= NMODIFIED; 1068 vnode_pager_setsize(vp, np->n_size); 1069 mtx_unlock(&np->n_mtx); 1070 1071 save = bp->b_flags & B_CACHE; 1072 bcount = on + n; 1073 allocbuf(bp, bcount); 1074 bp->b_flags |= save; 1075 if (noncontig_write != 0 && on > obcount) 1076 vfs_bio_bzero_buf(bp, obcount, on - 1077 obcount); 1078 } 1079 } else { 1080 /* 1081 * Obtain the locked cache block first, and then 1082 * adjust the file's size as appropriate. 1083 */ 1084 bcount = on + n; 1085 if ((off_t)lbn * biosize + bcount < np->n_size) { 1086 if ((off_t)(lbn + 1) * biosize < np->n_size) 1087 bcount = biosize; 1088 else 1089 bcount = np->n_size - (off_t)lbn * biosize; 1090 } 1091 mtx_unlock(&np->n_mtx); 1092 bp = nfs_getcacheblk(vp, lbn, bcount, td); 1093 mtx_lock(&np->n_mtx); 1094 if (uio->uio_offset + n > np->n_size) { 1095 np->n_size = uio->uio_offset + n; 1096 np->n_flag |= NMODIFIED; 1097 vnode_pager_setsize(vp, np->n_size); 1098 } 1099 mtx_unlock(&np->n_mtx); 1100 } 1101 1102 if (!bp) { 1103 error = newnfs_sigintr(nmp, td); 1104 if (!error) 1105 error = EINTR; 1106 break; 1107 } 1108 1109 /* 1110 * Issue a READ if B_CACHE is not set. In special-append 1111 * mode, B_CACHE is based on the buffer prior to the write 1112 * op and is typically set, avoiding the read. If a read 1113 * is required in special append mode, the server will 1114 * probably send us a short-read since we extended the file 1115 * on our end, resulting in b_resid == 0 and, thusly, 1116 * B_CACHE getting set. 1117 * 1118 * We can also avoid issuing the read if the write covers 1119 * the entire buffer. We have to make sure the buffer state 1120 * is reasonable in this case since we will not be initiating 1121 * I/O. See the comments in kern/vfs_bio.c's getblk() for 1122 * more information. 1123 * 1124 * B_CACHE may also be set due to the buffer being cached 1125 * normally. 1126 */ 1127 1128 bp_cached = 1; 1129 if (on == 0 && n == bcount) { 1130 if ((bp->b_flags & B_CACHE) == 0) 1131 bp_cached = 0; 1132 bp->b_flags |= B_CACHE; 1133 bp->b_flags &= ~B_INVAL; 1134 bp->b_ioflags &= ~BIO_ERROR; 1135 } 1136 1137 if ((bp->b_flags & B_CACHE) == 0) { 1138 bp->b_iocmd = BIO_READ; 1139 vfs_busy_pages(bp, 0); 1140 error = ncl_doio(vp, bp, cred, td, 0); 1141 if (error) { 1142 brelse(bp); 1143 break; 1144 } 1145 } 1146 if (bp->b_wcred == NOCRED) 1147 bp->b_wcred = crhold(cred); 1148 mtx_lock(&np->n_mtx); 1149 np->n_flag |= NMODIFIED; 1150 mtx_unlock(&np->n_mtx); 1151 1152 /* 1153 * If dirtyend exceeds file size, chop it down. This should 1154 * not normally occur but there is an append race where it 1155 * might occur XXX, so we log it. 1156 * 1157 * If the chopping creates a reverse-indexed or degenerate 1158 * situation with dirtyoff/end, we 0 both of them. 1159 */ 1160 1161 if (bp->b_dirtyend > bcount) { 1162 printf("NFS append race @%lx:%d\n", 1163 (long)bp->b_blkno * DEV_BSIZE, 1164 bp->b_dirtyend - bcount); 1165 bp->b_dirtyend = bcount; 1166 } 1167 1168 if (bp->b_dirtyoff >= bp->b_dirtyend) 1169 bp->b_dirtyoff = bp->b_dirtyend = 0; 1170 1171 /* 1172 * If the new write will leave a contiguous dirty 1173 * area, just update the b_dirtyoff and b_dirtyend, 1174 * otherwise force a write rpc of the old dirty area. 1175 * 1176 * If there has been a file lock applied to this file 1177 * or vfs.nfs.old_noncontig_writing is set, do the following: 1178 * While it is possible to merge discontiguous writes due to 1179 * our having a B_CACHE buffer ( and thus valid read data 1180 * for the hole), we don't because it could lead to 1181 * significant cache coherency problems with multiple clients, 1182 * especially if locking is implemented later on. 1183 * 1184 * If vfs.nfs.old_noncontig_writing is not set and there has 1185 * not been file locking done on this file: 1186 * Relax coherency a bit for the sake of performance and 1187 * expand the current dirty region to contain the new 1188 * write even if it means we mark some non-dirty data as 1189 * dirty. 1190 */ 1191 1192 if (noncontig_write == 0 && bp->b_dirtyend > 0 && 1193 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { 1194 if (bwrite(bp) == EINTR) { 1195 error = EINTR; 1196 break; 1197 } 1198 goto again; 1199 } 1200 1201 local_resid = uio->uio_resid; 1202 error = vn_io_fault_uiomove((char *)bp->b_data + on, n, uio); 1203 1204 if (error != 0 && !bp_cached) { 1205 /* 1206 * This block has no other content then what 1207 * possibly was written by the faulty uiomove. 1208 * Release it, forgetting the data pages, to 1209 * prevent the leak of uninitialized data to 1210 * usermode. 1211 */ 1212 bp->b_ioflags |= BIO_ERROR; 1213 brelse(bp); 1214 uio->uio_offset -= local_resid - uio->uio_resid; 1215 uio->uio_resid = local_resid; 1216 break; 1217 } 1218 1219 /* 1220 * Since this block is being modified, it must be written 1221 * again and not just committed. Since write clustering does 1222 * not work for the stage 1 data write, only the stage 2 1223 * commit rpc, we have to clear B_CLUSTEROK as well. 1224 */ 1225 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1226 1227 /* 1228 * Get the partial update on the progress made from 1229 * uiomove, if an error occurred. 1230 */ 1231 if (error != 0) 1232 n = local_resid - uio->uio_resid; 1233 1234 /* 1235 * Only update dirtyoff/dirtyend if not a degenerate 1236 * condition. 1237 */ 1238 if (n > 0) { 1239 if (bp->b_dirtyend > 0) { 1240 bp->b_dirtyoff = min(on, bp->b_dirtyoff); 1241 bp->b_dirtyend = max((on + n), bp->b_dirtyend); 1242 } else { 1243 bp->b_dirtyoff = on; 1244 bp->b_dirtyend = on + n; 1245 } 1246 vfs_bio_set_valid(bp, on, n); 1247 } 1248 1249 /* 1250 * If IO_SYNC do bwrite(). 1251 * 1252 * IO_INVAL appears to be unused. The idea appears to be 1253 * to turn off caching in this case. Very odd. XXX 1254 */ 1255 if ((ioflag & IO_SYNC)) { 1256 if (ioflag & IO_INVAL) 1257 bp->b_flags |= B_NOCACHE; 1258 error1 = bwrite(bp); 1259 if (error1 != 0) { 1260 if (error == 0) 1261 error = error1; 1262 break; 1263 } 1264 } else if ((n + on) == biosize) { 1265 bp->b_flags |= B_ASYNC; 1266 (void) ncl_writebp(bp, 0, NULL); 1267 } else { 1268 bdwrite(bp); 1269 } 1270 1271 if (error != 0) 1272 break; 1273 } while (uio->uio_resid > 0 && n > 0); 1274 1275 if (error != 0) { 1276 if (ioflag & IO_UNIT) { 1277 VATTR_NULL(&vattr); 1278 vattr.va_size = orig_size; 1279 /* IO_SYNC is handled implicitely */ 1280 (void)VOP_SETATTR(vp, &vattr, cred); 1281 uio->uio_offset -= orig_resid - uio->uio_resid; 1282 uio->uio_resid = orig_resid; 1283 } 1284 } 1285 1286 return (error); 1287 } 1288 1289 /* 1290 * Get an nfs cache block. 1291 * 1292 * Allocate a new one if the block isn't currently in the cache 1293 * and return the block marked busy. If the calling process is 1294 * interrupted by a signal for an interruptible mount point, return 1295 * NULL. 1296 * 1297 * The caller must carefully deal with the possible B_INVAL state of 1298 * the buffer. ncl_doio() clears B_INVAL (and ncl_asyncio() clears it 1299 * indirectly), so synchronous reads can be issued without worrying about 1300 * the B_INVAL state. We have to be a little more careful when dealing 1301 * with writes (see comments in nfs_write()) when extending a file past 1302 * its EOF. 1303 */ 1304 static struct buf * 1305 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td) 1306 { 1307 struct buf *bp; 1308 struct mount *mp; 1309 struct nfsmount *nmp; 1310 1311 mp = vp->v_mount; 1312 nmp = VFSTONFS(mp); 1313 1314 if (nmp->nm_flag & NFSMNT_INT) { 1315 sigset_t oldset; 1316 1317 newnfs_set_sigmask(td, &oldset); 1318 bp = getblk(vp, bn, size, PCATCH, 0, 0); 1319 newnfs_restore_sigmask(td, &oldset); 1320 while (bp == NULL) { 1321 if (newnfs_sigintr(nmp, td)) 1322 return (NULL); 1323 bp = getblk(vp, bn, size, 0, 2 * hz, 0); 1324 } 1325 } else { 1326 bp = getblk(vp, bn, size, 0, 0, 0); 1327 } 1328 1329 if (vp->v_type == VREG) 1330 bp->b_blkno = bn * (vp->v_bufobj.bo_bsize / DEV_BSIZE); 1331 return (bp); 1332 } 1333 1334 /* 1335 * Flush and invalidate all dirty buffers. If another process is already 1336 * doing the flush, just wait for completion. 1337 */ 1338 int 1339 ncl_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg) 1340 { 1341 struct nfsnode *np = VTONFS(vp); 1342 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 1343 int error = 0, slpflag, slptimeo; 1344 int old_lock = 0; 1345 1346 ASSERT_VOP_LOCKED(vp, "ncl_vinvalbuf"); 1347 1348 if ((nmp->nm_flag & NFSMNT_INT) == 0) 1349 intrflg = 0; 1350 if ((nmp->nm_mountp->mnt_kern_flag & MNTK_UNMOUNTF)) 1351 intrflg = 1; 1352 if (intrflg) { 1353 slpflag = PCATCH; 1354 slptimeo = 2 * hz; 1355 } else { 1356 slpflag = 0; 1357 slptimeo = 0; 1358 } 1359 1360 old_lock = ncl_upgrade_vnlock(vp); 1361 if (vp->v_iflag & VI_DOOMED) { 1362 /* 1363 * Since vgonel() uses the generic vinvalbuf() to flush 1364 * dirty buffers and it does not call this function, it 1365 * is safe to just return OK when VI_DOOMED is set. 1366 */ 1367 ncl_downgrade_vnlock(vp, old_lock); 1368 return (0); 1369 } 1370 1371 /* 1372 * Now, flush as required. 1373 */ 1374 if ((flags & V_SAVE) && (vp->v_bufobj.bo_object != NULL)) { 1375 VM_OBJECT_WLOCK(vp->v_bufobj.bo_object); 1376 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC); 1377 VM_OBJECT_WUNLOCK(vp->v_bufobj.bo_object); 1378 /* 1379 * If the page clean was interrupted, fail the invalidation. 1380 * Not doing so, we run the risk of losing dirty pages in the 1381 * vinvalbuf() call below. 1382 */ 1383 if (intrflg && (error = newnfs_sigintr(nmp, td))) 1384 goto out; 1385 } 1386 1387 error = vinvalbuf(vp, flags, slpflag, 0); 1388 while (error) { 1389 if (intrflg && (error = newnfs_sigintr(nmp, td))) 1390 goto out; 1391 error = vinvalbuf(vp, flags, 0, slptimeo); 1392 } 1393 if (NFSHASPNFS(nmp)) { 1394 nfscl_layoutcommit(vp, td); 1395 /* 1396 * Invalidate the attribute cache, since writes to a DS 1397 * won't update the size attribute. 1398 */ 1399 mtx_lock(&np->n_mtx); 1400 np->n_attrstamp = 0; 1401 } else 1402 mtx_lock(&np->n_mtx); 1403 if (np->n_directio_asyncwr == 0) 1404 np->n_flag &= ~NMODIFIED; 1405 mtx_unlock(&np->n_mtx); 1406 out: 1407 ncl_downgrade_vnlock(vp, old_lock); 1408 return error; 1409 } 1410 1411 /* 1412 * Initiate asynchronous I/O. Return an error if no nfsiods are available. 1413 * This is mainly to avoid queueing async I/O requests when the nfsiods 1414 * are all hung on a dead server. 1415 * 1416 * Note: ncl_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp 1417 * is eventually dequeued by the async daemon, ncl_doio() *will*. 1418 */ 1419 int 1420 ncl_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td) 1421 { 1422 int iod; 1423 int gotiod; 1424 int slpflag = 0; 1425 int slptimeo = 0; 1426 int error, error2; 1427 1428 /* 1429 * Commits are usually short and sweet so lets save some cpu and 1430 * leave the async daemons for more important rpc's (such as reads 1431 * and writes). 1432 * 1433 * Readdirplus RPCs do vget()s to acquire the vnodes for entries 1434 * in the directory in order to update attributes. This can deadlock 1435 * with another thread that is waiting for async I/O to be done by 1436 * an nfsiod thread while holding a lock on one of these vnodes. 1437 * To avoid this deadlock, don't allow the async nfsiod threads to 1438 * perform Readdirplus RPCs. 1439 */ 1440 mtx_lock(&ncl_iod_mutex); 1441 if ((bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) && 1442 (nmp->nm_bufqiods > ncl_numasync / 2)) || 1443 (bp->b_vp->v_type == VDIR && (nmp->nm_flag & NFSMNT_RDIRPLUS))) { 1444 mtx_unlock(&ncl_iod_mutex); 1445 return(EIO); 1446 } 1447 again: 1448 if (nmp->nm_flag & NFSMNT_INT) 1449 slpflag = PCATCH; 1450 gotiod = FALSE; 1451 1452 /* 1453 * Find a free iod to process this request. 1454 */ 1455 for (iod = 0; iod < ncl_numasync; iod++) 1456 if (ncl_iodwant[iod] == NFSIOD_AVAILABLE) { 1457 gotiod = TRUE; 1458 break; 1459 } 1460 1461 /* 1462 * Try to create one if none are free. 1463 */ 1464 if (!gotiod) 1465 ncl_nfsiodnew(); 1466 else { 1467 /* 1468 * Found one, so wake it up and tell it which 1469 * mount to process. 1470 */ 1471 NFS_DPF(ASYNCIO, ("ncl_asyncio: waking iod %d for mount %p\n", 1472 iod, nmp)); 1473 ncl_iodwant[iod] = NFSIOD_NOT_AVAILABLE; 1474 ncl_iodmount[iod] = nmp; 1475 nmp->nm_bufqiods++; 1476 wakeup(&ncl_iodwant[iod]); 1477 } 1478 1479 /* 1480 * If none are free, we may already have an iod working on this mount 1481 * point. If so, it will process our request. 1482 */ 1483 if (!gotiod) { 1484 if (nmp->nm_bufqiods > 0) { 1485 NFS_DPF(ASYNCIO, 1486 ("ncl_asyncio: %d iods are already processing mount %p\n", 1487 nmp->nm_bufqiods, nmp)); 1488 gotiod = TRUE; 1489 } 1490 } 1491 1492 /* 1493 * If we have an iod which can process the request, then queue 1494 * the buffer. 1495 */ 1496 if (gotiod) { 1497 /* 1498 * Ensure that the queue never grows too large. We still want 1499 * to asynchronize so we block rather then return EIO. 1500 */ 1501 while (nmp->nm_bufqlen >= 2*ncl_numasync) { 1502 NFS_DPF(ASYNCIO, 1503 ("ncl_asyncio: waiting for mount %p queue to drain\n", nmp)); 1504 nmp->nm_bufqwant = TRUE; 1505 error = newnfs_msleep(td, &nmp->nm_bufq, 1506 &ncl_iod_mutex, slpflag | PRIBIO, "nfsaio", 1507 slptimeo); 1508 if (error) { 1509 error2 = newnfs_sigintr(nmp, td); 1510 if (error2) { 1511 mtx_unlock(&ncl_iod_mutex); 1512 return (error2); 1513 } 1514 if (slpflag == PCATCH) { 1515 slpflag = 0; 1516 slptimeo = 2 * hz; 1517 } 1518 } 1519 /* 1520 * We might have lost our iod while sleeping, 1521 * so check and loop if necessary. 1522 */ 1523 goto again; 1524 } 1525 1526 /* We might have lost our nfsiod */ 1527 if (nmp->nm_bufqiods == 0) { 1528 NFS_DPF(ASYNCIO, 1529 ("ncl_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); 1530 goto again; 1531 } 1532 1533 if (bp->b_iocmd == BIO_READ) { 1534 if (bp->b_rcred == NOCRED && cred != NOCRED) 1535 bp->b_rcred = crhold(cred); 1536 } else { 1537 if (bp->b_wcred == NOCRED && cred != NOCRED) 1538 bp->b_wcred = crhold(cred); 1539 } 1540 1541 if (bp->b_flags & B_REMFREE) 1542 bremfreef(bp); 1543 BUF_KERNPROC(bp); 1544 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist); 1545 nmp->nm_bufqlen++; 1546 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) { 1547 mtx_lock(&(VTONFS(bp->b_vp))->n_mtx); 1548 VTONFS(bp->b_vp)->n_flag |= NMODIFIED; 1549 VTONFS(bp->b_vp)->n_directio_asyncwr++; 1550 mtx_unlock(&(VTONFS(bp->b_vp))->n_mtx); 1551 } 1552 mtx_unlock(&ncl_iod_mutex); 1553 return (0); 1554 } 1555 1556 mtx_unlock(&ncl_iod_mutex); 1557 1558 /* 1559 * All the iods are busy on other mounts, so return EIO to 1560 * force the caller to process the i/o synchronously. 1561 */ 1562 NFS_DPF(ASYNCIO, ("ncl_asyncio: no iods available, i/o is synchronous\n")); 1563 return (EIO); 1564 } 1565 1566 void 1567 ncl_doio_directwrite(struct buf *bp) 1568 { 1569 int iomode, must_commit; 1570 struct uio *uiop = (struct uio *)bp->b_caller1; 1571 char *iov_base = uiop->uio_iov->iov_base; 1572 1573 iomode = NFSWRITE_FILESYNC; 1574 uiop->uio_td = NULL; /* NULL since we're in nfsiod */ 1575 ncl_writerpc(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit, 0); 1576 KASSERT((must_commit == 0), ("ncl_doio_directwrite: Did not commit write")); 1577 free(iov_base, M_NFSDIRECTIO); 1578 free(uiop->uio_iov, M_NFSDIRECTIO); 1579 free(uiop, M_NFSDIRECTIO); 1580 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) { 1581 struct nfsnode *np = VTONFS(bp->b_vp); 1582 mtx_lock(&np->n_mtx); 1583 if (NFSHASPNFS(VFSTONFS(vnode_mount(bp->b_vp)))) { 1584 /* 1585 * Invalidate the attribute cache, since writes to a DS 1586 * won't update the size attribute. 1587 */ 1588 np->n_attrstamp = 0; 1589 } 1590 np->n_directio_asyncwr--; 1591 if (np->n_directio_asyncwr == 0) { 1592 np->n_flag &= ~NMODIFIED; 1593 if ((np->n_flag & NFSYNCWAIT)) { 1594 np->n_flag &= ~NFSYNCWAIT; 1595 wakeup((caddr_t)&np->n_directio_asyncwr); 1596 } 1597 } 1598 mtx_unlock(&np->n_mtx); 1599 } 1600 bp->b_vp = NULL; 1601 relpbuf(bp, &ncl_pbuf_freecnt); 1602 } 1603 1604 /* 1605 * Do an I/O operation to/from a cache block. This may be called 1606 * synchronously or from an nfsiod. 1607 */ 1608 int 1609 ncl_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td, 1610 int called_from_strategy) 1611 { 1612 struct uio *uiop; 1613 struct nfsnode *np; 1614 struct nfsmount *nmp; 1615 int error = 0, iomode, must_commit = 0; 1616 struct uio uio; 1617 struct iovec io; 1618 struct proc *p = td ? td->td_proc : NULL; 1619 uint8_t iocmd; 1620 1621 np = VTONFS(vp); 1622 nmp = VFSTONFS(vp->v_mount); 1623 uiop = &uio; 1624 uiop->uio_iov = &io; 1625 uiop->uio_iovcnt = 1; 1626 uiop->uio_segflg = UIO_SYSSPACE; 1627 uiop->uio_td = td; 1628 1629 /* 1630 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We 1631 * do this here so we do not have to do it in all the code that 1632 * calls us. 1633 */ 1634 bp->b_flags &= ~B_INVAL; 1635 bp->b_ioflags &= ~BIO_ERROR; 1636 1637 KASSERT(!(bp->b_flags & B_DONE), ("ncl_doio: bp %p already marked done", bp)); 1638 iocmd = bp->b_iocmd; 1639 if (iocmd == BIO_READ) { 1640 io.iov_len = uiop->uio_resid = bp->b_bcount; 1641 io.iov_base = bp->b_data; 1642 uiop->uio_rw = UIO_READ; 1643 1644 switch (vp->v_type) { 1645 case VREG: 1646 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE; 1647 NFSINCRGLOBAL(nfsstatsv1.read_bios); 1648 error = ncl_readrpc(vp, uiop, cr); 1649 1650 if (!error) { 1651 if (uiop->uio_resid) { 1652 /* 1653 * If we had a short read with no error, we must have 1654 * hit a file hole. We should zero-fill the remainder. 1655 * This can also occur if the server hits the file EOF. 1656 * 1657 * Holes used to be able to occur due to pending 1658 * writes, but that is not possible any longer. 1659 */ 1660 int nread = bp->b_bcount - uiop->uio_resid; 1661 ssize_t left = uiop->uio_resid; 1662 1663 if (left > 0) 1664 bzero((char *)bp->b_data + nread, left); 1665 uiop->uio_resid = 0; 1666 } 1667 } 1668 /* ASSERT_VOP_LOCKED(vp, "ncl_doio"); */ 1669 if (p && (vp->v_vflag & VV_TEXT)) { 1670 mtx_lock(&np->n_mtx); 1671 if (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.na_mtime)) { 1672 mtx_unlock(&np->n_mtx); 1673 PROC_LOCK(p); 1674 killproc(p, "text file modification"); 1675 PROC_UNLOCK(p); 1676 } else 1677 mtx_unlock(&np->n_mtx); 1678 } 1679 break; 1680 case VLNK: 1681 uiop->uio_offset = (off_t)0; 1682 NFSINCRGLOBAL(nfsstatsv1.readlink_bios); 1683 error = ncl_readlinkrpc(vp, uiop, cr); 1684 break; 1685 case VDIR: 1686 NFSINCRGLOBAL(nfsstatsv1.readdir_bios); 1687 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ; 1688 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) { 1689 error = ncl_readdirplusrpc(vp, uiop, cr, td); 1690 if (error == NFSERR_NOTSUPP) 1691 nmp->nm_flag &= ~NFSMNT_RDIRPLUS; 1692 } 1693 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) 1694 error = ncl_readdirrpc(vp, uiop, cr, td); 1695 /* 1696 * end-of-directory sets B_INVAL but does not generate an 1697 * error. 1698 */ 1699 if (error == 0 && uiop->uio_resid == bp->b_bcount) 1700 bp->b_flags |= B_INVAL; 1701 break; 1702 default: 1703 printf("ncl_doio: type %x unexpected\n", vp->v_type); 1704 break; 1705 } 1706 if (error) { 1707 bp->b_ioflags |= BIO_ERROR; 1708 bp->b_error = error; 1709 } 1710 } else { 1711 /* 1712 * If we only need to commit, try to commit 1713 */ 1714 if (bp->b_flags & B_NEEDCOMMIT) { 1715 int retv; 1716 off_t off; 1717 1718 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff; 1719 retv = ncl_commit(vp, off, bp->b_dirtyend-bp->b_dirtyoff, 1720 bp->b_wcred, td); 1721 if (retv == 0) { 1722 bp->b_dirtyoff = bp->b_dirtyend = 0; 1723 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1724 bp->b_resid = 0; 1725 bufdone(bp); 1726 return (0); 1727 } 1728 if (retv == NFSERR_STALEWRITEVERF) { 1729 ncl_clearcommit(vp->v_mount); 1730 } 1731 } 1732 1733 /* 1734 * Setup for actual write 1735 */ 1736 mtx_lock(&np->n_mtx); 1737 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size) 1738 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE; 1739 mtx_unlock(&np->n_mtx); 1740 1741 if (bp->b_dirtyend > bp->b_dirtyoff) { 1742 io.iov_len = uiop->uio_resid = bp->b_dirtyend 1743 - bp->b_dirtyoff; 1744 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE 1745 + bp->b_dirtyoff; 1746 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; 1747 uiop->uio_rw = UIO_WRITE; 1748 NFSINCRGLOBAL(nfsstatsv1.write_bios); 1749 1750 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC) 1751 iomode = NFSWRITE_UNSTABLE; 1752 else 1753 iomode = NFSWRITE_FILESYNC; 1754 1755 error = ncl_writerpc(vp, uiop, cr, &iomode, &must_commit, 1756 called_from_strategy); 1757 1758 /* 1759 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try 1760 * to cluster the buffers needing commit. This will allow 1761 * the system to submit a single commit rpc for the whole 1762 * cluster. We can do this even if the buffer is not 100% 1763 * dirty (relative to the NFS blocksize), so we optimize the 1764 * append-to-file-case. 1765 * 1766 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be 1767 * cleared because write clustering only works for commit 1768 * rpc's, not for the data portion of the write). 1769 */ 1770 1771 if (!error && iomode == NFSWRITE_UNSTABLE) { 1772 bp->b_flags |= B_NEEDCOMMIT; 1773 if (bp->b_dirtyoff == 0 1774 && bp->b_dirtyend == bp->b_bcount) 1775 bp->b_flags |= B_CLUSTEROK; 1776 } else { 1777 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1778 } 1779 1780 /* 1781 * For an interrupted write, the buffer is still valid 1782 * and the write hasn't been pushed to the server yet, 1783 * so we can't set BIO_ERROR and report the interruption 1784 * by setting B_EINTR. For the B_ASYNC case, B_EINTR 1785 * is not relevant, so the rpc attempt is essentially 1786 * a noop. For the case of a V3 write rpc not being 1787 * committed to stable storage, the block is still 1788 * dirty and requires either a commit rpc or another 1789 * write rpc with iomode == NFSV3WRITE_FILESYNC before 1790 * the block is reused. This is indicated by setting 1791 * the B_DELWRI and B_NEEDCOMMIT flags. 1792 * 1793 * EIO is returned by ncl_writerpc() to indicate a recoverable 1794 * write error and is handled as above, except that 1795 * B_EINTR isn't set. One cause of this is a stale stateid 1796 * error for the RPC that indicates recovery is required, 1797 * when called with called_from_strategy != 0. 1798 * 1799 * If the buffer is marked B_PAGING, it does not reside on 1800 * the vp's paging queues so we cannot call bdirty(). The 1801 * bp in this case is not an NFS cache block so we should 1802 * be safe. XXX 1803 * 1804 * The logic below breaks up errors into recoverable and 1805 * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE 1806 * and keep the buffer around for potential write retries. 1807 * For the latter (eg ESTALE), we toss the buffer away (B_INVAL) 1808 * and save the error in the nfsnode. This is less than ideal 1809 * but necessary. Keeping such buffers around could potentially 1810 * cause buffer exhaustion eventually (they can never be written 1811 * out, so will get constantly be re-dirtied). It also causes 1812 * all sorts of vfs panics. For non-recoverable write errors, 1813 * also invalidate the attrcache, so we'll be forced to go over 1814 * the wire for this object, returning an error to user on next 1815 * call (most of the time). 1816 */ 1817 if (error == EINTR || error == EIO || error == ETIMEDOUT 1818 || (!error && (bp->b_flags & B_NEEDCOMMIT))) { 1819 int s; 1820 1821 s = splbio(); 1822 bp->b_flags &= ~(B_INVAL|B_NOCACHE); 1823 if ((bp->b_flags & B_PAGING) == 0) { 1824 bdirty(bp); 1825 bp->b_flags &= ~B_DONE; 1826 } 1827 if ((error == EINTR || error == ETIMEDOUT) && 1828 (bp->b_flags & B_ASYNC) == 0) 1829 bp->b_flags |= B_EINTR; 1830 splx(s); 1831 } else { 1832 if (error) { 1833 bp->b_ioflags |= BIO_ERROR; 1834 bp->b_flags |= B_INVAL; 1835 bp->b_error = np->n_error = error; 1836 mtx_lock(&np->n_mtx); 1837 np->n_flag |= NWRITEERR; 1838 np->n_attrstamp = 0; 1839 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 1840 mtx_unlock(&np->n_mtx); 1841 } 1842 bp->b_dirtyoff = bp->b_dirtyend = 0; 1843 } 1844 } else { 1845 bp->b_resid = 0; 1846 bufdone(bp); 1847 return (0); 1848 } 1849 } 1850 bp->b_resid = uiop->uio_resid; 1851 if (must_commit) 1852 ncl_clearcommit(vp->v_mount); 1853 bufdone(bp); 1854 return (error); 1855 } 1856 1857 /* 1858 * Used to aid in handling ftruncate() operations on the NFS client side. 1859 * Truncation creates a number of special problems for NFS. We have to 1860 * throw away VM pages and buffer cache buffers that are beyond EOF, and 1861 * we have to properly handle VM pages or (potentially dirty) buffers 1862 * that straddle the truncation point. 1863 */ 1864 1865 int 1866 ncl_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize) 1867 { 1868 struct nfsnode *np = VTONFS(vp); 1869 u_quad_t tsize; 1870 int biosize = vp->v_bufobj.bo_bsize; 1871 int error = 0; 1872 1873 mtx_lock(&np->n_mtx); 1874 tsize = np->n_size; 1875 np->n_size = nsize; 1876 mtx_unlock(&np->n_mtx); 1877 1878 if (nsize < tsize) { 1879 struct buf *bp; 1880 daddr_t lbn; 1881 int bufsize; 1882 1883 /* 1884 * vtruncbuf() doesn't get the buffer overlapping the 1885 * truncation point. We may have a B_DELWRI and/or B_CACHE 1886 * buffer that now needs to be truncated. 1887 */ 1888 error = vtruncbuf(vp, cred, nsize, biosize); 1889 lbn = nsize / biosize; 1890 bufsize = nsize - (lbn * biosize); 1891 bp = nfs_getcacheblk(vp, lbn, bufsize, td); 1892 if (!bp) 1893 return EINTR; 1894 if (bp->b_dirtyoff > bp->b_bcount) 1895 bp->b_dirtyoff = bp->b_bcount; 1896 if (bp->b_dirtyend > bp->b_bcount) 1897 bp->b_dirtyend = bp->b_bcount; 1898 bp->b_flags |= B_RELBUF; /* don't leave garbage around */ 1899 brelse(bp); 1900 } else { 1901 vnode_pager_setsize(vp, nsize); 1902 } 1903 return(error); 1904 } 1905 1906