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