Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
FreeBSD/Linux Kernel Cross Reference
sys/nfsclient/nfs_bio.c
Version:
- FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
SearchContext: - none - 3 - 10
1 /*- 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Rick Macklem at The University of Guelph. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)nfs_bio.c 8.9 (Berkeley) 3/30/95 33 */ 34 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD: releng/9.1/sys/nfsclient/nfs_bio.c 236096 2012-05-26 13:12:14Z rmacklem $"); 37 38 #include "opt_kdtrace.h" 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/bio.h> 43 #include <sys/buf.h> 44 #include <sys/kernel.h> 45 #include <sys/mbuf.h> 46 #include <sys/mount.h> 47 #include <sys/proc.h> 48 #include <sys/vmmeter.h> 49 #include <sys/vnode.h> 50 51 #include <vm/vm.h> 52 #include <vm/vm_extern.h> 53 #include <vm/vm_page.h> 54 #include <vm/vm_object.h> 55 #include <vm/vm_pager.h> 56 #include <vm/vnode_pager.h> 57 58 #include <nfs/nfsproto.h> 59 #include <nfsclient/nfs.h> 60 #include <nfsclient/nfsmount.h> 61 #include <nfsclient/nfsnode.h> 62 #include <nfs/nfs_kdtrace.h> 63 64 static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, 65 struct thread *td); 66 static int nfs_directio_write(struct vnode *vp, struct uio *uiop, 67 struct ucred *cred, int ioflag); 68 69 extern int nfs_directio_enable; 70 extern int nfs_directio_allow_mmap; 71 72 /* 73 * Vnode op for VM getpages. 74 */ 75 int 76 nfs_getpages(struct vop_getpages_args *ap) 77 { 78 int i, error, nextoff, size, toff, count, npages; 79 struct uio uio; 80 struct iovec iov; 81 vm_offset_t kva; 82 struct buf *bp; 83 struct vnode *vp; 84 struct thread *td; 85 struct ucred *cred; 86 struct nfsmount *nmp; 87 vm_object_t object; 88 vm_page_t *pages; 89 struct nfsnode *np; 90 91 vp = ap->a_vp; 92 np = VTONFS(vp); 93 td = curthread; /* XXX */ 94 cred = curthread->td_ucred; /* XXX */ 95 nmp = VFSTONFS(vp->v_mount); 96 pages = ap->a_m; 97 count = ap->a_count; 98 99 if ((object = vp->v_object) == NULL) { 100 nfs_printf("nfs_getpages: called with non-merged cache vnode??\n"); 101 return (VM_PAGER_ERROR); 102 } 103 104 if (nfs_directio_enable && !nfs_directio_allow_mmap) { 105 mtx_lock(&np->n_mtx); 106 if ((np->n_flag & NNONCACHE) && (vp->v_type == VREG)) { 107 mtx_unlock(&np->n_mtx); 108 nfs_printf("nfs_getpages: called on non-cacheable vnode??\n"); 109 return (VM_PAGER_ERROR); 110 } else 111 mtx_unlock(&np->n_mtx); 112 } 113 114 mtx_lock(&nmp->nm_mtx); 115 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 116 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 117 mtx_unlock(&nmp->nm_mtx); 118 /* We'll never get here for v4, because we always have fsinfo */ 119 (void)nfs_fsinfo(nmp, vp, cred, td); 120 } else 121 mtx_unlock(&nmp->nm_mtx); 122 123 npages = btoc(count); 124 125 /* 126 * If the requested page is partially valid, just return it and 127 * allow the pager to zero-out the blanks. Partially valid pages 128 * can only occur at the file EOF. 129 */ 130 VM_OBJECT_LOCK(object); 131 if (pages[ap->a_reqpage]->valid != 0) { 132 for (i = 0; i < npages; ++i) { 133 if (i != ap->a_reqpage) { 134 vm_page_lock(pages[i]); 135 vm_page_free(pages[i]); 136 vm_page_unlock(pages[i]); 137 } 138 } 139 VM_OBJECT_UNLOCK(object); 140 return (0); 141 } 142 VM_OBJECT_UNLOCK(object); 143 144 /* 145 * We use only the kva address for the buffer, but this is extremely 146 * convienient and fast. 147 */ 148 bp = getpbuf(&nfs_pbuf_freecnt); 149 150 kva = (vm_offset_t) bp->b_data; 151 pmap_qenter(kva, pages, npages); 152 PCPU_INC(cnt.v_vnodein); 153 PCPU_ADD(cnt.v_vnodepgsin, npages); 154 155 iov.iov_base = (caddr_t) kva; 156 iov.iov_len = count; 157 uio.uio_iov = &iov; 158 uio.uio_iovcnt = 1; 159 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex); 160 uio.uio_resid = count; 161 uio.uio_segflg = UIO_SYSSPACE; 162 uio.uio_rw = UIO_READ; 163 uio.uio_td = td; 164 165 error = (nmp->nm_rpcops->nr_readrpc)(vp, &uio, cred); 166 pmap_qremove(kva, npages); 167 168 relpbuf(bp, &nfs_pbuf_freecnt); 169 170 if (error && (uio.uio_resid == count)) { 171 nfs_printf("nfs_getpages: error %d\n", error); 172 VM_OBJECT_LOCK(object); 173 for (i = 0; i < npages; ++i) { 174 if (i != ap->a_reqpage) { 175 vm_page_lock(pages[i]); 176 vm_page_free(pages[i]); 177 vm_page_unlock(pages[i]); 178 } 179 } 180 VM_OBJECT_UNLOCK(object); 181 return (VM_PAGER_ERROR); 182 } 183 184 /* 185 * Calculate the number of bytes read and validate only that number 186 * of bytes. Note that due to pending writes, size may be 0. This 187 * does not mean that the remaining data is invalid! 188 */ 189 190 size = count - uio.uio_resid; 191 VM_OBJECT_LOCK(object); 192 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) { 193 vm_page_t m; 194 nextoff = toff + PAGE_SIZE; 195 m = pages[i]; 196 197 if (nextoff <= size) { 198 /* 199 * Read operation filled an entire page 200 */ 201 m->valid = VM_PAGE_BITS_ALL; 202 KASSERT(m->dirty == 0, 203 ("nfs_getpages: page %p is dirty", m)); 204 } else if (size > toff) { 205 /* 206 * Read operation filled a partial page. 207 */ 208 m->valid = 0; 209 vm_page_set_valid(m, 0, size - toff); 210 KASSERT(m->dirty == 0, 211 ("nfs_getpages: page %p is dirty", m)); 212 } else { 213 /* 214 * Read operation was short. If no error occured 215 * we may have hit a zero-fill section. We simply 216 * leave valid set to 0. 217 */ 218 ; 219 } 220 if (i != ap->a_reqpage) { 221 /* 222 * Whether or not to leave the page activated is up in 223 * the air, but we should put the page on a page queue 224 * somewhere (it already is in the object). Result: 225 * It appears that emperical results show that 226 * deactivating pages is best. 227 */ 228 229 /* 230 * Just in case someone was asking for this page we 231 * now tell them that it is ok to use. 232 */ 233 if (!error) { 234 if (m->oflags & VPO_WANTED) { 235 vm_page_lock(m); 236 vm_page_activate(m); 237 vm_page_unlock(m); 238 } else { 239 vm_page_lock(m); 240 vm_page_deactivate(m); 241 vm_page_unlock(m); 242 } 243 vm_page_wakeup(m); 244 } else { 245 vm_page_lock(m); 246 vm_page_free(m); 247 vm_page_unlock(m); 248 } 249 } 250 } 251 VM_OBJECT_UNLOCK(object); 252 return (0); 253 } 254 255 /* 256 * Vnode op for VM putpages. 257 */ 258 int 259 nfs_putpages(struct vop_putpages_args *ap) 260 { 261 struct uio uio; 262 struct iovec iov; 263 vm_offset_t kva; 264 struct buf *bp; 265 int iomode, must_commit, i, error, npages, count; 266 off_t offset; 267 int *rtvals; 268 struct vnode *vp; 269 struct thread *td; 270 struct ucred *cred; 271 struct nfsmount *nmp; 272 struct nfsnode *np; 273 vm_page_t *pages; 274 275 vp = ap->a_vp; 276 np = VTONFS(vp); 277 td = curthread; /* XXX */ 278 /* Set the cred to n_writecred for the write rpcs. */ 279 if (np->n_writecred != NULL) 280 cred = crhold(np->n_writecred); 281 else 282 cred = crhold(curthread->td_ucred); /* XXX */ 283 nmp = VFSTONFS(vp->v_mount); 284 pages = ap->a_m; 285 count = ap->a_count; 286 rtvals = ap->a_rtvals; 287 npages = btoc(count); 288 offset = IDX_TO_OFF(pages[0]->pindex); 289 290 mtx_lock(&nmp->nm_mtx); 291 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 292 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 293 mtx_unlock(&nmp->nm_mtx); 294 (void)nfs_fsinfo(nmp, vp, cred, td); 295 } else 296 mtx_unlock(&nmp->nm_mtx); 297 298 mtx_lock(&np->n_mtx); 299 if (nfs_directio_enable && !nfs_directio_allow_mmap && 300 (np->n_flag & NNONCACHE) && (vp->v_type == VREG)) { 301 mtx_unlock(&np->n_mtx); 302 nfs_printf("nfs_putpages: called on noncache-able vnode??\n"); 303 mtx_lock(&np->n_mtx); 304 } 305 306 for (i = 0; i < npages; i++) 307 rtvals[i] = VM_PAGER_ERROR; 308 309 /* 310 * When putting pages, do not extend file past EOF. 311 */ 312 if (offset + count > np->n_size) { 313 count = np->n_size - offset; 314 if (count < 0) 315 count = 0; 316 } 317 mtx_unlock(&np->n_mtx); 318 319 /* 320 * We use only the kva address for the buffer, but this is extremely 321 * convienient and fast. 322 */ 323 bp = getpbuf(&nfs_pbuf_freecnt); 324 325 kva = (vm_offset_t) bp->b_data; 326 pmap_qenter(kva, pages, npages); 327 PCPU_INC(cnt.v_vnodeout); 328 PCPU_ADD(cnt.v_vnodepgsout, count); 329 330 iov.iov_base = (caddr_t) kva; 331 iov.iov_len = count; 332 uio.uio_iov = &iov; 333 uio.uio_iovcnt = 1; 334 uio.uio_offset = offset; 335 uio.uio_resid = count; 336 uio.uio_segflg = UIO_SYSSPACE; 337 uio.uio_rw = UIO_WRITE; 338 uio.uio_td = td; 339 340 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0) 341 iomode = NFSV3WRITE_UNSTABLE; 342 else 343 iomode = NFSV3WRITE_FILESYNC; 344 345 error = (nmp->nm_rpcops->nr_writerpc)(vp, &uio, cred, &iomode, &must_commit); 346 crfree(cred); 347 348 pmap_qremove(kva, npages); 349 relpbuf(bp, &nfs_pbuf_freecnt); 350 351 if (!error) { 352 vnode_pager_undirty_pages(pages, rtvals, count - uio.uio_resid); 353 if (must_commit) { 354 nfs_clearcommit(vp->v_mount); 355 } 356 } 357 return rtvals[0]; 358 } 359 360 /* 361 * For nfs, cache consistency can only be maintained approximately. 362 * Although RFC1094 does not specify the criteria, the following is 363 * believed to be compatible with the reference port. 364 * For nfs: 365 * If the file's modify time on the server has changed since the 366 * last read rpc or you have written to the file, 367 * you may have lost data cache consistency with the 368 * server, so flush all of the file's data out of the cache. 369 * Then force a getattr rpc to ensure that you have up to date 370 * attributes. 371 * NB: This implies that cache data can be read when up to 372 * NFS_ATTRTIMEO seconds out of date. If you find that you need current 373 * attributes this could be forced by setting n_attrstamp to 0 before 374 * the VOP_GETATTR() call. 375 */ 376 static inline int 377 nfs_bioread_check_cons(struct vnode *vp, struct thread *td, struct ucred *cred) 378 { 379 int error = 0; 380 struct vattr vattr; 381 struct nfsnode *np = VTONFS(vp); 382 int old_lock; 383 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 384 385 /* 386 * Grab the exclusive lock before checking whether the cache is 387 * consistent. 388 * XXX - We can make this cheaper later (by acquiring cheaper locks). 389 * But for now, this suffices. 390 */ 391 old_lock = nfs_upgrade_vnlock(vp); 392 if (vp->v_iflag & VI_DOOMED) { 393 nfs_downgrade_vnlock(vp, old_lock); 394 return (EBADF); 395 } 396 397 mtx_lock(&np->n_mtx); 398 if (np->n_flag & NMODIFIED) { 399 mtx_unlock(&np->n_mtx); 400 if (vp->v_type != VREG) { 401 if (vp->v_type != VDIR) 402 panic("nfs: bioread, not dir"); 403 (nmp->nm_rpcops->nr_invaldir)(vp); 404 error = nfs_vinvalbuf(vp, V_SAVE, td, 1); 405 if (error) 406 goto out; 407 } 408 np->n_attrstamp = 0; 409 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 410 error = VOP_GETATTR(vp, &vattr, cred); 411 if (error) 412 goto out; 413 mtx_lock(&np->n_mtx); 414 np->n_mtime = vattr.va_mtime; 415 mtx_unlock(&np->n_mtx); 416 } else { 417 mtx_unlock(&np->n_mtx); 418 error = VOP_GETATTR(vp, &vattr, cred); 419 if (error) 420 return (error); 421 mtx_lock(&np->n_mtx); 422 if ((np->n_flag & NSIZECHANGED) 423 || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) { 424 mtx_unlock(&np->n_mtx); 425 if (vp->v_type == VDIR) 426 (nmp->nm_rpcops->nr_invaldir)(vp); 427 error = nfs_vinvalbuf(vp, V_SAVE, td, 1); 428 if (error) 429 goto out; 430 mtx_lock(&np->n_mtx); 431 np->n_mtime = vattr.va_mtime; 432 np->n_flag &= ~NSIZECHANGED; 433 } 434 mtx_unlock(&np->n_mtx); 435 } 436 out: 437 nfs_downgrade_vnlock(vp, old_lock); 438 return error; 439 } 440 441 /* 442 * Vnode op for read using bio 443 */ 444 int 445 nfs_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred) 446 { 447 struct nfsnode *np = VTONFS(vp); 448 int biosize, i; 449 struct buf *bp, *rabp; 450 struct thread *td; 451 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 452 daddr_t lbn, rabn; 453 off_t end; 454 int bcount; 455 int seqcount; 456 int nra, error = 0, n = 0, on = 0; 457 458 KASSERT(uio->uio_rw == UIO_READ, ("nfs_read mode")); 459 if (uio->uio_resid == 0) 460 return (0); 461 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */ 462 return (EINVAL); 463 td = uio->uio_td; 464 465 mtx_lock(&nmp->nm_mtx); 466 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 467 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 468 mtx_unlock(&nmp->nm_mtx); 469 (void)nfs_fsinfo(nmp, vp, cred, td); 470 } else 471 mtx_unlock(&nmp->nm_mtx); 472 473 end = uio->uio_offset + uio->uio_resid; 474 if (vp->v_type != VDIR && 475 (end > nmp->nm_maxfilesize || end < uio->uio_offset)) 476 return (EFBIG); 477 478 if (nfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG)) 479 /* No caching/ no readaheads. Just read data into the user buffer */ 480 return nfs_readrpc(vp, uio, cred); 481 482 biosize = vp->v_bufobj.bo_bsize; 483 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE); 484 485 error = nfs_bioread_check_cons(vp, td, cred); 486 if (error) 487 return error; 488 489 do { 490 u_quad_t nsize; 491 492 mtx_lock(&np->n_mtx); 493 nsize = np->n_size; 494 mtx_unlock(&np->n_mtx); 495 496 switch (vp->v_type) { 497 case VREG: 498 nfsstats.biocache_reads++; 499 lbn = uio->uio_offset / biosize; 500 on = uio->uio_offset & (biosize - 1); 501 502 /* 503 * Start the read ahead(s), as required. 504 */ 505 if (nmp->nm_readahead > 0) { 506 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && 507 (off_t)(lbn + 1 + nra) * biosize < nsize; nra++) { 508 rabn = lbn + 1 + nra; 509 if (incore(&vp->v_bufobj, rabn) == NULL) { 510 rabp = nfs_getcacheblk(vp, rabn, biosize, td); 511 if (!rabp) { 512 error = nfs_sigintr(nmp, td); 513 return (error ? error : EINTR); 514 } 515 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 516 rabp->b_flags |= B_ASYNC; 517 rabp->b_iocmd = BIO_READ; 518 vfs_busy_pages(rabp, 0); 519 if (nfs_asyncio(nmp, rabp, cred, td)) { 520 rabp->b_flags |= B_INVAL; 521 rabp->b_ioflags |= BIO_ERROR; 522 vfs_unbusy_pages(rabp); 523 brelse(rabp); 524 break; 525 } 526 } else { 527 brelse(rabp); 528 } 529 } 530 } 531 } 532 533 /* Note that bcount is *not* DEV_BSIZE aligned. */ 534 bcount = biosize; 535 if ((off_t)lbn * biosize >= nsize) { 536 bcount = 0; 537 } else if ((off_t)(lbn + 1) * biosize > nsize) { 538 bcount = nsize - (off_t)lbn * biosize; 539 } 540 bp = nfs_getcacheblk(vp, lbn, bcount, td); 541 542 if (!bp) { 543 error = nfs_sigintr(nmp, td); 544 return (error ? error : EINTR); 545 } 546 547 /* 548 * If B_CACHE is not set, we must issue the read. If this 549 * fails, we return an error. 550 */ 551 552 if ((bp->b_flags & B_CACHE) == 0) { 553 bp->b_iocmd = BIO_READ; 554 vfs_busy_pages(bp, 0); 555 error = nfs_doio(vp, bp, cred, td); 556 if (error) { 557 brelse(bp); 558 return (error); 559 } 560 } 561 562 /* 563 * on is the offset into the current bp. Figure out how many 564 * bytes we can copy out of the bp. Note that bcount is 565 * NOT DEV_BSIZE aligned. 566 * 567 * Then figure out how many bytes we can copy into the uio. 568 */ 569 570 n = 0; 571 if (on < bcount) 572 n = MIN((unsigned)(bcount - on), uio->uio_resid); 573 break; 574 case VLNK: 575 nfsstats.biocache_readlinks++; 576 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td); 577 if (!bp) { 578 error = nfs_sigintr(nmp, td); 579 return (error ? error : EINTR); 580 } 581 if ((bp->b_flags & B_CACHE) == 0) { 582 bp->b_iocmd = BIO_READ; 583 vfs_busy_pages(bp, 0); 584 error = nfs_doio(vp, bp, cred, td); 585 if (error) { 586 bp->b_ioflags |= BIO_ERROR; 587 brelse(bp); 588 return (error); 589 } 590 } 591 n = MIN(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); 592 on = 0; 593 break; 594 case VDIR: 595 nfsstats.biocache_readdirs++; 596 if (np->n_direofoffset 597 && uio->uio_offset >= np->n_direofoffset) { 598 return (0); 599 } 600 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; 601 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); 602 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td); 603 if (!bp) { 604 error = nfs_sigintr(nmp, td); 605 return (error ? error : EINTR); 606 } 607 if ((bp->b_flags & B_CACHE) == 0) { 608 bp->b_iocmd = BIO_READ; 609 vfs_busy_pages(bp, 0); 610 error = nfs_doio(vp, bp, cred, td); 611 if (error) { 612 brelse(bp); 613 } 614 while (error == NFSERR_BAD_COOKIE) { 615 (nmp->nm_rpcops->nr_invaldir)(vp); 616 error = nfs_vinvalbuf(vp, 0, td, 1); 617 /* 618 * Yuck! The directory has been modified on the 619 * server. The only way to get the block is by 620 * reading from the beginning to get all the 621 * offset cookies. 622 * 623 * Leave the last bp intact unless there is an error. 624 * Loop back up to the while if the error is another 625 * NFSERR_BAD_COOKIE (double yuch!). 626 */ 627 for (i = 0; i <= lbn && !error; i++) { 628 if (np->n_direofoffset 629 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) 630 return (0); 631 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td); 632 if (!bp) { 633 error = nfs_sigintr(nmp, td); 634 return (error ? error : EINTR); 635 } 636 if ((bp->b_flags & B_CACHE) == 0) { 637 bp->b_iocmd = BIO_READ; 638 vfs_busy_pages(bp, 0); 639 error = nfs_doio(vp, bp, cred, td); 640 /* 641 * no error + B_INVAL == directory EOF, 642 * use the block. 643 */ 644 if (error == 0 && (bp->b_flags & B_INVAL)) 645 break; 646 } 647 /* 648 * An error will throw away the block and the 649 * for loop will break out. If no error and this 650 * is not the block we want, we throw away the 651 * block and go for the next one via the for loop. 652 */ 653 if (error || i < lbn) 654 brelse(bp); 655 } 656 } 657 /* 658 * The above while is repeated if we hit another cookie 659 * error. If we hit an error and it wasn't a cookie error, 660 * we give up. 661 */ 662 if (error) 663 return (error); 664 } 665 666 /* 667 * If not eof and read aheads are enabled, start one. 668 * (You need the current block first, so that you have the 669 * directory offset cookie of the next block.) 670 */ 671 if (nmp->nm_readahead > 0 && 672 (bp->b_flags & B_INVAL) == 0 && 673 (np->n_direofoffset == 0 || 674 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) && 675 incore(&vp->v_bufobj, lbn + 1) == NULL) { 676 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td); 677 if (rabp) { 678 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 679 rabp->b_flags |= B_ASYNC; 680 rabp->b_iocmd = BIO_READ; 681 vfs_busy_pages(rabp, 0); 682 if (nfs_asyncio(nmp, rabp, cred, td)) { 683 rabp->b_flags |= B_INVAL; 684 rabp->b_ioflags |= BIO_ERROR; 685 vfs_unbusy_pages(rabp); 686 brelse(rabp); 687 } 688 } else { 689 brelse(rabp); 690 } 691 } 692 } 693 /* 694 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is 695 * chopped for the EOF condition, we cannot tell how large 696 * NFS directories are going to be until we hit EOF. So 697 * an NFS directory buffer is *not* chopped to its EOF. Now, 698 * it just so happens that b_resid will effectively chop it 699 * to EOF. *BUT* this information is lost if the buffer goes 700 * away and is reconstituted into a B_CACHE state ( due to 701 * being VMIO ) later. So we keep track of the directory eof 702 * in np->n_direofoffset and chop it off as an extra step 703 * right here. 704 */ 705 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on); 706 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset) 707 n = np->n_direofoffset - uio->uio_offset; 708 break; 709 default: 710 nfs_printf(" nfs_bioread: type %x unexpected\n", vp->v_type); 711 bp = NULL; 712 break; 713 }; 714 715 if (n > 0) { 716 error = uiomove(bp->b_data + on, (int)n, uio); 717 } 718 if (vp->v_type == VLNK) 719 n = 0; 720 if (bp != NULL) 721 brelse(bp); 722 } while (error == 0 && uio->uio_resid > 0 && n > 0); 723 return (error); 724 } 725 726 /* 727 * The NFS write path cannot handle iovecs with len > 1. So we need to 728 * break up iovecs accordingly (restricting them to wsize). 729 * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf). 730 * For the ASYNC case, 2 copies are needed. The first a copy from the 731 * user buffer to a staging buffer and then a second copy from the staging 732 * buffer to mbufs. This can be optimized by copying from the user buffer 733 * directly into mbufs and passing the chain down, but that requires a 734 * fair amount of re-working of the relevant codepaths (and can be done 735 * later). 736 */ 737 static int 738 nfs_directio_write(vp, uiop, cred, ioflag) 739 struct vnode *vp; 740 struct uio *uiop; 741 struct ucred *cred; 742 int ioflag; 743 { 744 int error; 745 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 746 struct thread *td = uiop->uio_td; 747 int size; 748 int wsize; 749 750 mtx_lock(&nmp->nm_mtx); 751 wsize = nmp->nm_wsize; 752 mtx_unlock(&nmp->nm_mtx); 753 if (ioflag & IO_SYNC) { 754 int iomode, must_commit; 755 struct uio uio; 756 struct iovec iov; 757 do_sync: 758 while (uiop->uio_resid > 0) { 759 size = MIN(uiop->uio_resid, wsize); 760 size = MIN(uiop->uio_iov->iov_len, size); 761 iov.iov_base = uiop->uio_iov->iov_base; 762 iov.iov_len = size; 763 uio.uio_iov = &iov; 764 uio.uio_iovcnt = 1; 765 uio.uio_offset = uiop->uio_offset; 766 uio.uio_resid = size; 767 uio.uio_segflg = UIO_USERSPACE; 768 uio.uio_rw = UIO_WRITE; 769 uio.uio_td = td; 770 iomode = NFSV3WRITE_FILESYNC; 771 error = (nmp->nm_rpcops->nr_writerpc)(vp, &uio, cred, 772 &iomode, &must_commit); 773 KASSERT((must_commit == 0), 774 ("nfs_directio_write: Did not commit write")); 775 if (error) 776 return (error); 777 uiop->uio_offset += size; 778 uiop->uio_resid -= size; 779 if (uiop->uio_iov->iov_len <= size) { 780 uiop->uio_iovcnt--; 781 uiop->uio_iov++; 782 } else { 783 uiop->uio_iov->iov_base = 784 (char *)uiop->uio_iov->iov_base + size; 785 uiop->uio_iov->iov_len -= size; 786 } 787 } 788 } else { 789 struct uio *t_uio; 790 struct iovec *t_iov; 791 struct buf *bp; 792 793 /* 794 * Break up the write into blocksize chunks and hand these 795 * over to nfsiod's for write back. 796 * Unfortunately, this incurs a copy of the data. Since 797 * the user could modify the buffer before the write is 798 * initiated. 799 * 800 * The obvious optimization here is that one of the 2 copies 801 * in the async write path can be eliminated by copying the 802 * data here directly into mbufs and passing the mbuf chain 803 * down. But that will require a fair amount of re-working 804 * of the code and can be done if there's enough interest 805 * in NFS directio access. 806 */ 807 while (uiop->uio_resid > 0) { 808 size = MIN(uiop->uio_resid, wsize); 809 size = MIN(uiop->uio_iov->iov_len, size); 810 bp = getpbuf(&nfs_pbuf_freecnt); 811 t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK); 812 t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK); 813 t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK); 814 t_iov->iov_len = size; 815 t_uio->uio_iov = t_iov; 816 t_uio->uio_iovcnt = 1; 817 t_uio->uio_offset = uiop->uio_offset; 818 t_uio->uio_resid = size; 819 t_uio->uio_segflg = UIO_SYSSPACE; 820 t_uio->uio_rw = UIO_WRITE; 821 t_uio->uio_td = td; 822 KASSERT(uiop->uio_segflg == UIO_USERSPACE || 823 uiop->uio_segflg == UIO_SYSSPACE, 824 ("nfs_directio_write: Bad uio_segflg")); 825 if (uiop->uio_segflg == UIO_USERSPACE) { 826 error = copyin(uiop->uio_iov->iov_base, 827 t_iov->iov_base, size); 828 if (error != 0) 829 goto err_free; 830 } else 831 /* 832 * UIO_SYSSPACE may never happen, but handle 833 * it just in case it does. 834 */ 835 bcopy(uiop->uio_iov->iov_base, t_iov->iov_base, 836 size); 837 bp->b_flags |= B_DIRECT; 838 bp->b_iocmd = BIO_WRITE; 839 if (cred != NOCRED) { 840 crhold(cred); 841 bp->b_wcred = cred; 842 } else 843 bp->b_wcred = NOCRED; 844 bp->b_caller1 = (void *)t_uio; 845 bp->b_vp = vp; 846 error = nfs_asyncio(nmp, bp, NOCRED, td); 847 err_free: 848 if (error) { 849 free(t_iov->iov_base, M_NFSDIRECTIO); 850 free(t_iov, M_NFSDIRECTIO); 851 free(t_uio, M_NFSDIRECTIO); 852 bp->b_vp = NULL; 853 relpbuf(bp, &nfs_pbuf_freecnt); 854 if (error == EINTR) 855 return (error); 856 goto do_sync; 857 } 858 uiop->uio_offset += size; 859 uiop->uio_resid -= size; 860 if (uiop->uio_iov->iov_len <= size) { 861 uiop->uio_iovcnt--; 862 uiop->uio_iov++; 863 } else { 864 uiop->uio_iov->iov_base = 865 (char *)uiop->uio_iov->iov_base + size; 866 uiop->uio_iov->iov_len -= size; 867 } 868 } 869 } 870 return (0); 871 } 872 873 /* 874 * Vnode op for write using bio 875 */ 876 int 877 nfs_write(struct vop_write_args *ap) 878 { 879 int biosize; 880 struct uio *uio = ap->a_uio; 881 struct thread *td = uio->uio_td; 882 struct vnode *vp = ap->a_vp; 883 struct nfsnode *np = VTONFS(vp); 884 struct ucred *cred = ap->a_cred; 885 int ioflag = ap->a_ioflag; 886 struct buf *bp; 887 struct vattr vattr; 888 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 889 daddr_t lbn; 890 off_t end; 891 int bcount; 892 int n, on, error = 0; 893 894 KASSERT(uio->uio_rw == UIO_WRITE, ("nfs_write mode")); 895 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, 896 ("nfs_write proc")); 897 if (vp->v_type != VREG) 898 return (EIO); 899 mtx_lock(&np->n_mtx); 900 if (np->n_flag & NWRITEERR) { 901 np->n_flag &= ~NWRITEERR; 902 mtx_unlock(&np->n_mtx); 903 return (np->n_error); 904 } else 905 mtx_unlock(&np->n_mtx); 906 mtx_lock(&nmp->nm_mtx); 907 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 908 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 909 mtx_unlock(&nmp->nm_mtx); 910 (void)nfs_fsinfo(nmp, vp, cred, td); 911 } else 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 flush_and_restart: 932 np->n_attrstamp = 0; 933 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 934 error = nfs_vinvalbuf(vp, V_SAVE, td, 1); 935 if (error) 936 return (error); 937 } else 938 mtx_unlock(&np->n_mtx); 939 } 940 941 /* 942 * If IO_APPEND then load uio_offset. We restart here if we cannot 943 * get the append lock. 944 */ 945 if (ioflag & IO_APPEND) { 946 np->n_attrstamp = 0; 947 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 948 error = VOP_GETATTR(vp, &vattr, cred); 949 if (error) 950 return (error); 951 mtx_lock(&np->n_mtx); 952 uio->uio_offset = np->n_size; 953 mtx_unlock(&np->n_mtx); 954 } 955 956 if (uio->uio_offset < 0) 957 return (EINVAL); 958 end = uio->uio_offset + uio->uio_resid; 959 if (end > nmp->nm_maxfilesize || end < uio->uio_offset) 960 return (EFBIG); 961 if (uio->uio_resid == 0) 962 return (0); 963 964 if (nfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG) 965 return nfs_directio_write(vp, uio, cred, ioflag); 966 967 /* 968 * Maybe this should be above the vnode op call, but so long as 969 * file servers have no limits, i don't think it matters 970 */ 971 if (vn_rlimit_fsize(vp, uio, td)) 972 return (EFBIG); 973 974 biosize = vp->v_bufobj.bo_bsize; 975 /* 976 * Find all of this file's B_NEEDCOMMIT buffers. If our writes 977 * would exceed the local maximum per-file write commit size when 978 * combined with those, we must decide whether to flush, 979 * go synchronous, or return error. We don't bother checking 980 * IO_UNIT -- we just make all writes atomic anyway, as there's 981 * no point optimizing for something that really won't ever happen. 982 */ 983 if (!(ioflag & IO_SYNC)) { 984 int nflag; 985 986 mtx_lock(&np->n_mtx); 987 nflag = np->n_flag; 988 mtx_unlock(&np->n_mtx); 989 int needrestart = 0; 990 if (nmp->nm_wcommitsize < uio->uio_resid) { 991 /* 992 * If this request could not possibly be completed 993 * without exceeding the maximum outstanding write 994 * commit size, see if we can convert it into a 995 * synchronous write operation. 996 */ 997 if (ioflag & IO_NDELAY) 998 return (EAGAIN); 999 ioflag |= IO_SYNC; 1000 if (nflag & NMODIFIED) 1001 needrestart = 1; 1002 } else if (nflag & NMODIFIED) { 1003 int wouldcommit = 0; 1004 BO_LOCK(&vp->v_bufobj); 1005 if (vp->v_bufobj.bo_dirty.bv_cnt != 0) { 1006 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd, 1007 b_bobufs) { 1008 if (bp->b_flags & B_NEEDCOMMIT) 1009 wouldcommit += bp->b_bcount; 1010 } 1011 } 1012 BO_UNLOCK(&vp->v_bufobj); 1013 /* 1014 * Since we're not operating synchronously and 1015 * bypassing the buffer cache, we are in a commit 1016 * and holding all of these buffers whether 1017 * transmitted or not. If not limited, this 1018 * will lead to the buffer cache deadlocking, 1019 * as no one else can flush our uncommitted buffers. 1020 */ 1021 wouldcommit += uio->uio_resid; 1022 /* 1023 * If we would initially exceed the maximum 1024 * outstanding write commit size, flush and restart. 1025 */ 1026 if (wouldcommit > nmp->nm_wcommitsize) 1027 needrestart = 1; 1028 } 1029 if (needrestart) 1030 goto flush_and_restart; 1031 } 1032 1033 do { 1034 nfsstats.biocache_writes++; 1035 lbn = uio->uio_offset / biosize; 1036 on = uio->uio_offset & (biosize-1); 1037 n = MIN((unsigned)(biosize - on), uio->uio_resid); 1038 again: 1039 /* 1040 * Handle direct append and file extension cases, calculate 1041 * unaligned buffer size. 1042 */ 1043 mtx_lock(&np->n_mtx); 1044 if (uio->uio_offset == np->n_size && n) { 1045 mtx_unlock(&np->n_mtx); 1046 /* 1047 * Get the buffer (in its pre-append state to maintain 1048 * B_CACHE if it was previously set). Resize the 1049 * nfsnode after we have locked the buffer to prevent 1050 * readers from reading garbage. 1051 */ 1052 bcount = on; 1053 bp = nfs_getcacheblk(vp, lbn, bcount, td); 1054 1055 if (bp != NULL) { 1056 long save; 1057 1058 mtx_lock(&np->n_mtx); 1059 np->n_size = uio->uio_offset + n; 1060 np->n_flag |= NMODIFIED; 1061 vnode_pager_setsize(vp, np->n_size); 1062 mtx_unlock(&np->n_mtx); 1063 1064 save = bp->b_flags & B_CACHE; 1065 bcount += n; 1066 allocbuf(bp, bcount); 1067 bp->b_flags |= save; 1068 } 1069 } else { 1070 /* 1071 * Obtain the locked cache block first, and then 1072 * adjust the file's size as appropriate. 1073 */ 1074 bcount = on + n; 1075 if ((off_t)lbn * biosize + bcount < np->n_size) { 1076 if ((off_t)(lbn + 1) * biosize < np->n_size) 1077 bcount = biosize; 1078 else 1079 bcount = np->n_size - (off_t)lbn * biosize; 1080 } 1081 mtx_unlock(&np->n_mtx); 1082 bp = nfs_getcacheblk(vp, lbn, bcount, td); 1083 mtx_lock(&np->n_mtx); 1084 if (uio->uio_offset + n > np->n_size) { 1085 np->n_size = uio->uio_offset + n; 1086 np->n_flag |= NMODIFIED; 1087 vnode_pager_setsize(vp, np->n_size); 1088 } 1089 mtx_unlock(&np->n_mtx); 1090 } 1091 1092 if (!bp) { 1093 error = nfs_sigintr(nmp, td); 1094 if (!error) 1095 error = EINTR; 1096 break; 1097 } 1098 1099 /* 1100 * Issue a READ if B_CACHE is not set. In special-append 1101 * mode, B_CACHE is based on the buffer prior to the write 1102 * op and is typically set, avoiding the read. If a read 1103 * is required in special append mode, the server will 1104 * probably send us a short-read since we extended the file 1105 * on our end, resulting in b_resid == 0 and, thusly, 1106 * B_CACHE getting set. 1107 * 1108 * We can also avoid issuing the read if the write covers 1109 * the entire buffer. We have to make sure the buffer state 1110 * is reasonable in this case since we will not be initiating 1111 * I/O. See the comments in kern/vfs_bio.c's getblk() for 1112 * more information. 1113 * 1114 * B_CACHE may also be set due to the buffer being cached 1115 * normally. 1116 */ 1117 1118 if (on == 0 && n == bcount) { 1119 bp->b_flags |= B_CACHE; 1120 bp->b_flags &= ~B_INVAL; 1121 bp->b_ioflags &= ~BIO_ERROR; 1122 } 1123 1124 if ((bp->b_flags & B_CACHE) == 0) { 1125 bp->b_iocmd = BIO_READ; 1126 vfs_busy_pages(bp, 0); 1127 error = nfs_doio(vp, bp, cred, td); 1128 if (error) { 1129 brelse(bp); 1130 break; 1131 } 1132 } 1133 if (bp->b_wcred == NOCRED) 1134 bp->b_wcred = crhold(cred); 1135 mtx_lock(&np->n_mtx); 1136 np->n_flag |= NMODIFIED; 1137 mtx_unlock(&np->n_mtx); 1138 1139 /* 1140 * If dirtyend exceeds file size, chop it down. This should 1141 * not normally occur but there is an append race where it 1142 * might occur XXX, so we log it. 1143 * 1144 * If the chopping creates a reverse-indexed or degenerate 1145 * situation with dirtyoff/end, we 0 both of them. 1146 */ 1147 1148 if (bp->b_dirtyend > bcount) { 1149 nfs_printf("NFS append race @%lx:%d\n", 1150 (long)bp->b_blkno * DEV_BSIZE, 1151 bp->b_dirtyend - bcount); 1152 bp->b_dirtyend = bcount; 1153 } 1154 1155 if (bp->b_dirtyoff >= bp->b_dirtyend) 1156 bp->b_dirtyoff = bp->b_dirtyend = 0; 1157 1158 /* 1159 * If the new write will leave a contiguous dirty 1160 * area, just update the b_dirtyoff and b_dirtyend, 1161 * otherwise force a write rpc of the old dirty area. 1162 * 1163 * While it is possible to merge discontiguous writes due to 1164 * our having a B_CACHE buffer ( and thus valid read data 1165 * for the hole), we don't because it could lead to 1166 * significant cache coherency problems with multiple clients, 1167 * especially if locking is implemented later on. 1168 * 1169 * as an optimization we could theoretically maintain 1170 * a linked list of discontinuous areas, but we would still 1171 * have to commit them separately so there isn't much 1172 * advantage to it except perhaps a bit of asynchronization. 1173 */ 1174 1175 if (bp->b_dirtyend > 0 && 1176 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { 1177 if (bwrite(bp) == EINTR) { 1178 error = EINTR; 1179 break; 1180 } 1181 goto again; 1182 } 1183 1184 error = uiomove((char *)bp->b_data + on, n, uio); 1185 1186 /* 1187 * Since this block is being modified, it must be written 1188 * again and not just committed. Since write clustering does 1189 * not work for the stage 1 data write, only the stage 2 1190 * commit rpc, we have to clear B_CLUSTEROK as well. 1191 */ 1192 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1193 1194 if (error) { 1195 bp->b_ioflags |= BIO_ERROR; 1196 brelse(bp); 1197 break; 1198 } 1199 1200 /* 1201 * Only update dirtyoff/dirtyend if not a degenerate 1202 * condition. 1203 */ 1204 if (n) { 1205 if (bp->b_dirtyend > 0) { 1206 bp->b_dirtyoff = min(on, bp->b_dirtyoff); 1207 bp->b_dirtyend = max((on + n), bp->b_dirtyend); 1208 } else { 1209 bp->b_dirtyoff = on; 1210 bp->b_dirtyend = on + n; 1211 } 1212 vfs_bio_set_valid(bp, on, n); 1213 } 1214 1215 /* 1216 * If IO_SYNC do bwrite(). 1217 * 1218 * IO_INVAL appears to be unused. The idea appears to be 1219 * to turn off caching in this case. Very odd. XXX 1220 */ 1221 if ((ioflag & IO_SYNC)) { 1222 if (ioflag & IO_INVAL) 1223 bp->b_flags |= B_NOCACHE; 1224 error = bwrite(bp); 1225 if (error) 1226 break; 1227 } else if ((n + on) == biosize) { 1228 bp->b_flags |= B_ASYNC; 1229 (void) (nmp->nm_rpcops->nr_writebp)(bp, 0, NULL); 1230 } else { 1231 bdwrite(bp); 1232 } 1233 } while (uio->uio_resid > 0 && n > 0); 1234 1235 return (error); 1236 } 1237 1238 /* 1239 * Get an nfs cache block. 1240 * 1241 * Allocate a new one if the block isn't currently in the cache 1242 * and return the block marked busy. If the calling process is 1243 * interrupted by a signal for an interruptible mount point, return 1244 * NULL. 1245 * 1246 * The caller must carefully deal with the possible B_INVAL state of 1247 * the buffer. nfs_doio() clears B_INVAL (and nfs_asyncio() clears it 1248 * indirectly), so synchronous reads can be issued without worrying about 1249 * the B_INVAL state. We have to be a little more careful when dealing 1250 * with writes (see comments in nfs_write()) when extending a file past 1251 * its EOF. 1252 */ 1253 static struct buf * 1254 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td) 1255 { 1256 struct buf *bp; 1257 struct mount *mp; 1258 struct nfsmount *nmp; 1259 1260 mp = vp->v_mount; 1261 nmp = VFSTONFS(mp); 1262 1263 if (nmp->nm_flag & NFSMNT_INT) { 1264 sigset_t oldset; 1265 1266 nfs_set_sigmask(td, &oldset); 1267 bp = getblk(vp, bn, size, NFS_PCATCH, 0, 0); 1268 nfs_restore_sigmask(td, &oldset); 1269 while (bp == NULL) { 1270 if (nfs_sigintr(nmp, td)) 1271 return (NULL); 1272 bp = getblk(vp, bn, size, 0, 2 * hz, 0); 1273 } 1274 } else { 1275 bp = getblk(vp, bn, size, 0, 0, 0); 1276 } 1277 1278 if (vp->v_type == VREG) 1279 bp->b_blkno = bn * (vp->v_bufobj.bo_bsize / DEV_BSIZE); 1280 return (bp); 1281 } 1282 1283 /* 1284 * Flush and invalidate all dirty buffers. If another process is already 1285 * doing the flush, just wait for completion. 1286 */ 1287 int 1288 nfs_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg) 1289 { 1290 struct nfsnode *np = VTONFS(vp); 1291 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 1292 int error = 0, slpflag, slptimeo; 1293 int old_lock = 0; 1294 1295 ASSERT_VOP_LOCKED(vp, "nfs_vinvalbuf"); 1296 1297 if ((nmp->nm_flag & NFSMNT_INT) == 0) 1298 intrflg = 0; 1299 if (intrflg) { 1300 slpflag = NFS_PCATCH; 1301 slptimeo = 2 * hz; 1302 } else { 1303 slpflag = 0; 1304 slptimeo = 0; 1305 } 1306 1307 old_lock = nfs_upgrade_vnlock(vp); 1308 if (vp->v_iflag & VI_DOOMED) { 1309 /* 1310 * Since vgonel() uses the generic vinvalbuf() to flush 1311 * dirty buffers and it does not call this function, it 1312 * is safe to just return OK when VI_DOOMED is set. 1313 */ 1314 nfs_downgrade_vnlock(vp, old_lock); 1315 return (0); 1316 } 1317 1318 /* 1319 * Now, flush as required. 1320 */ 1321 if ((flags & V_SAVE) && (vp->v_bufobj.bo_object != NULL)) { 1322 VM_OBJECT_LOCK(vp->v_bufobj.bo_object); 1323 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC); 1324 VM_OBJECT_UNLOCK(vp->v_bufobj.bo_object); 1325 /* 1326 * If the page clean was interrupted, fail the invalidation. 1327 * Not doing so, we run the risk of losing dirty pages in the 1328 * vinvalbuf() call below. 1329 */ 1330 if (intrflg && (error = nfs_sigintr(nmp, td))) 1331 goto out; 1332 } 1333 1334 error = vinvalbuf(vp, flags, slpflag, 0); 1335 while (error) { 1336 if (intrflg && (error = nfs_sigintr(nmp, td))) 1337 goto out; 1338 error = vinvalbuf(vp, flags, 0, slptimeo); 1339 } 1340 mtx_lock(&np->n_mtx); 1341 if (np->n_directio_asyncwr == 0) 1342 np->n_flag &= ~NMODIFIED; 1343 mtx_unlock(&np->n_mtx); 1344 out: 1345 nfs_downgrade_vnlock(vp, old_lock); 1346 return error; 1347 } 1348 1349 /* 1350 * Initiate asynchronous I/O. Return an error if no nfsiods are available. 1351 * This is mainly to avoid queueing async I/O requests when the nfsiods 1352 * are all hung on a dead server. 1353 * 1354 * Note: nfs_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp 1355 * is eventually dequeued by the async daemon, nfs_doio() *will*. 1356 */ 1357 int 1358 nfs_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td) 1359 { 1360 int iod; 1361 int gotiod; 1362 int slpflag = 0; 1363 int slptimeo = 0; 1364 int error, error2; 1365 1366 /* 1367 * Commits are usually short and sweet so lets save some cpu and 1368 * leave the async daemons for more important rpc's (such as reads 1369 * and writes). 1370 */ 1371 mtx_lock(&nfs_iod_mtx); 1372 if (bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) && 1373 (nmp->nm_bufqiods > nfs_numasync / 2)) { 1374 mtx_unlock(&nfs_iod_mtx); 1375 return(EIO); 1376 } 1377 again: 1378 if (nmp->nm_flag & NFSMNT_INT) 1379 slpflag = NFS_PCATCH; 1380 gotiod = FALSE; 1381 1382 /* 1383 * Find a free iod to process this request. 1384 */ 1385 for (iod = 0; iod < nfs_numasync; iod++) 1386 if (nfs_iodwant[iod] == NFSIOD_AVAILABLE) { 1387 gotiod = TRUE; 1388 break; 1389 } 1390 1391 /* 1392 * Try to create one if none are free. 1393 */ 1394 if (!gotiod) 1395 nfs_nfsiodnew(); 1396 else { 1397 /* 1398 * Found one, so wake it up and tell it which 1399 * mount to process. 1400 */ 1401 NFS_DPF(ASYNCIO, ("nfs_asyncio: waking iod %d for mount %p\n", 1402 iod, nmp)); 1403 nfs_iodwant[iod] = NFSIOD_NOT_AVAILABLE; 1404 nfs_iodmount[iod] = nmp; 1405 nmp->nm_bufqiods++; 1406 wakeup(&nfs_iodwant[iod]); 1407 } 1408 1409 /* 1410 * If none are free, we may already have an iod working on this mount 1411 * point. If so, it will process our request. 1412 */ 1413 if (!gotiod) { 1414 if (nmp->nm_bufqiods > 0) { 1415 NFS_DPF(ASYNCIO, 1416 ("nfs_asyncio: %d iods are already processing mount %p\n", 1417 nmp->nm_bufqiods, nmp)); 1418 gotiod = TRUE; 1419 } 1420 } 1421 1422 /* 1423 * If we have an iod which can process the request, then queue 1424 * the buffer. 1425 */ 1426 if (gotiod) { 1427 /* 1428 * Ensure that the queue never grows too large. We still want 1429 * to asynchronize so we block rather then return EIO. 1430 */ 1431 while (nmp->nm_bufqlen >= 2 * nfs_numasync) { 1432 NFS_DPF(ASYNCIO, 1433 ("nfs_asyncio: waiting for mount %p queue to drain\n", nmp)); 1434 nmp->nm_bufqwant = TRUE; 1435 error = nfs_msleep(td, &nmp->nm_bufq, &nfs_iod_mtx, 1436 slpflag | PRIBIO, 1437 "nfsaio", slptimeo); 1438 if (error) { 1439 error2 = nfs_sigintr(nmp, td); 1440 if (error2) { 1441 mtx_unlock(&nfs_iod_mtx); 1442 return (error2); 1443 } 1444 if (slpflag == NFS_PCATCH) { 1445 slpflag = 0; 1446 slptimeo = 2 * hz; 1447 } 1448 } 1449 /* 1450 * We might have lost our iod while sleeping, 1451 * so check and loop if nescessary. 1452 */ 1453 goto again; 1454 } 1455 1456 /* We might have lost our nfsiod */ 1457 if (nmp->nm_bufqiods == 0) { 1458 NFS_DPF(ASYNCIO, 1459 ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); 1460 goto again; 1461 } 1462 1463 if (bp->b_iocmd == BIO_READ) { 1464 if (bp->b_rcred == NOCRED && cred != NOCRED) 1465 bp->b_rcred = crhold(cred); 1466 } else { 1467 if (bp->b_wcred == NOCRED && cred != NOCRED) 1468 bp->b_wcred = crhold(cred); 1469 } 1470 1471 if (bp->b_flags & B_REMFREE) 1472 bremfreef(bp); 1473 BUF_KERNPROC(bp); 1474 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist); 1475 nmp->nm_bufqlen++; 1476 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) { 1477 mtx_lock(&(VTONFS(bp->b_vp))->n_mtx); 1478 VTONFS(bp->b_vp)->n_flag |= NMODIFIED; 1479 VTONFS(bp->b_vp)->n_directio_asyncwr++; 1480 mtx_unlock(&(VTONFS(bp->b_vp))->n_mtx); 1481 } 1482 mtx_unlock(&nfs_iod_mtx); 1483 return (0); 1484 } 1485 1486 mtx_unlock(&nfs_iod_mtx); 1487 1488 /* 1489 * All the iods are busy on other mounts, so return EIO to 1490 * force the caller to process the i/o synchronously. 1491 */ 1492 NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n")); 1493 return (EIO); 1494 } 1495 1496 void 1497 nfs_doio_directwrite(struct buf *bp) 1498 { 1499 int iomode, must_commit; 1500 struct uio *uiop = (struct uio *)bp->b_caller1; 1501 char *iov_base = uiop->uio_iov->iov_base; 1502 struct nfsmount *nmp = VFSTONFS(bp->b_vp->v_mount); 1503 1504 iomode = NFSV3WRITE_FILESYNC; 1505 uiop->uio_td = NULL; /* NULL since we're in nfsiod */ 1506 (nmp->nm_rpcops->nr_writerpc)(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit); 1507 KASSERT((must_commit == 0), ("nfs_doio_directwrite: Did not commit write")); 1508 free(iov_base, M_NFSDIRECTIO); 1509 free(uiop->uio_iov, M_NFSDIRECTIO); 1510 free(uiop, M_NFSDIRECTIO); 1511 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) { 1512 struct nfsnode *np = VTONFS(bp->b_vp); 1513 mtx_lock(&np->n_mtx); 1514 np->n_directio_asyncwr--; 1515 if (np->n_directio_asyncwr == 0) { 1516 VTONFS(bp->b_vp)->n_flag &= ~NMODIFIED; 1517 if ((np->n_flag & NFSYNCWAIT)) { 1518 np->n_flag &= ~NFSYNCWAIT; 1519 wakeup((caddr_t)&np->n_directio_asyncwr); 1520 } 1521 } 1522 mtx_unlock(&np->n_mtx); 1523 } 1524 bp->b_vp = NULL; 1525 relpbuf(bp, &nfs_pbuf_freecnt); 1526 } 1527 1528 /* 1529 * Do an I/O operation to/from a cache block. This may be called 1530 * synchronously or from an nfsiod. 1531 */ 1532 int 1533 nfs_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td) 1534 { 1535 struct uio *uiop; 1536 struct nfsnode *np; 1537 struct nfsmount *nmp; 1538 int error = 0, iomode, must_commit = 0; 1539 struct uio uio; 1540 struct iovec io; 1541 struct proc *p = td ? td->td_proc : NULL; 1542 uint8_t iocmd; 1543 1544 np = VTONFS(vp); 1545 nmp = VFSTONFS(vp->v_mount); 1546 uiop = &uio; 1547 uiop->uio_iov = &io; 1548 uiop->uio_iovcnt = 1; 1549 uiop->uio_segflg = UIO_SYSSPACE; 1550 uiop->uio_td = td; 1551 1552 /* 1553 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We 1554 * do this here so we do not have to do it in all the code that 1555 * calls us. 1556 */ 1557 bp->b_flags &= ~B_INVAL; 1558 bp->b_ioflags &= ~BIO_ERROR; 1559 1560 KASSERT(!(bp->b_flags & B_DONE), ("nfs_doio: bp %p already marked done", bp)); 1561 iocmd = bp->b_iocmd; 1562 if (iocmd == BIO_READ) { 1563 io.iov_len = uiop->uio_resid = bp->b_bcount; 1564 io.iov_base = bp->b_data; 1565 uiop->uio_rw = UIO_READ; 1566 1567 switch (vp->v_type) { 1568 case VREG: 1569 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE; 1570 nfsstats.read_bios++; 1571 error = (nmp->nm_rpcops->nr_readrpc)(vp, uiop, cr); 1572 1573 if (!error) { 1574 if (uiop->uio_resid) { 1575 /* 1576 * If we had a short read with no error, we must have 1577 * hit a file hole. We should zero-fill the remainder. 1578 * This can also occur if the server hits the file EOF. 1579 * 1580 * Holes used to be able to occur due to pending 1581 * writes, but that is not possible any longer. 1582 */ 1583 int nread = bp->b_bcount - uiop->uio_resid; 1584 int left = uiop->uio_resid; 1585 1586 if (left > 0) 1587 bzero((char *)bp->b_data + nread, left); 1588 uiop->uio_resid = 0; 1589 } 1590 } 1591 /* ASSERT_VOP_LOCKED(vp, "nfs_doio"); */ 1592 if (p && (vp->v_vflag & VV_TEXT)) { 1593 mtx_lock(&np->n_mtx); 1594 if (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.va_mtime)) { 1595 mtx_unlock(&np->n_mtx); 1596 PROC_LOCK(p); 1597 killproc(p, "text file modification"); 1598 PROC_UNLOCK(p); 1599 } else 1600 mtx_unlock(&np->n_mtx); 1601 } 1602 break; 1603 case VLNK: 1604 uiop->uio_offset = (off_t)0; 1605 nfsstats.readlink_bios++; 1606 error = (nmp->nm_rpcops->nr_readlinkrpc)(vp, uiop, cr); 1607 break; 1608 case VDIR: 1609 nfsstats.readdir_bios++; 1610 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ; 1611 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) { 1612 error = nfs_readdirplusrpc(vp, uiop, cr); 1613 if (error == NFSERR_NOTSUPP) 1614 nmp->nm_flag &= ~NFSMNT_RDIRPLUS; 1615 } 1616 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) 1617 error = nfs_readdirrpc(vp, uiop, cr); 1618 /* 1619 * end-of-directory sets B_INVAL but does not generate an 1620 * error. 1621 */ 1622 if (error == 0 && uiop->uio_resid == bp->b_bcount) 1623 bp->b_flags |= B_INVAL; 1624 break; 1625 default: 1626 nfs_printf("nfs_doio: type %x unexpected\n", vp->v_type); 1627 break; 1628 }; 1629 if (error) { 1630 bp->b_ioflags |= BIO_ERROR; 1631 bp->b_error = error; 1632 } 1633 } else { 1634 /* 1635 * If we only need to commit, try to commit 1636 */ 1637 if (bp->b_flags & B_NEEDCOMMIT) { 1638 int retv; 1639 off_t off; 1640 1641 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff; 1642 retv = (nmp->nm_rpcops->nr_commit)( 1643 vp, off, bp->b_dirtyend-bp->b_dirtyoff, 1644 bp->b_wcred, td); 1645 if (retv == 0) { 1646 bp->b_dirtyoff = bp->b_dirtyend = 0; 1647 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1648 bp->b_resid = 0; 1649 bufdone(bp); 1650 return (0); 1651 } 1652 if (retv == NFSERR_STALEWRITEVERF) { 1653 nfs_clearcommit(vp->v_mount); 1654 } 1655 } 1656 1657 /* 1658 * Setup for actual write 1659 */ 1660 mtx_lock(&np->n_mtx); 1661 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size) 1662 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE; 1663 mtx_unlock(&np->n_mtx); 1664 1665 if (bp->b_dirtyend > bp->b_dirtyoff) { 1666 io.iov_len = uiop->uio_resid = bp->b_dirtyend 1667 - bp->b_dirtyoff; 1668 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE 1669 + bp->b_dirtyoff; 1670 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; 1671 uiop->uio_rw = UIO_WRITE; 1672 nfsstats.write_bios++; 1673 1674 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC) 1675 iomode = NFSV3WRITE_UNSTABLE; 1676 else 1677 iomode = NFSV3WRITE_FILESYNC; 1678 1679 error = (nmp->nm_rpcops->nr_writerpc)(vp, uiop, cr, &iomode, &must_commit); 1680 1681 /* 1682 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try 1683 * to cluster the buffers needing commit. This will allow 1684 * the system to submit a single commit rpc for the whole 1685 * cluster. We can do this even if the buffer is not 100% 1686 * dirty (relative to the NFS blocksize), so we optimize the 1687 * append-to-file-case. 1688 * 1689 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be 1690 * cleared because write clustering only works for commit 1691 * rpc's, not for the data portion of the write). 1692 */ 1693 1694 if (!error && iomode == NFSV3WRITE_UNSTABLE) { 1695 bp->b_flags |= B_NEEDCOMMIT; 1696 if (bp->b_dirtyoff == 0 1697 && bp->b_dirtyend == bp->b_bcount) 1698 bp->b_flags |= B_CLUSTEROK; 1699 } else { 1700 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1701 } 1702 1703 /* 1704 * For an interrupted write, the buffer is still valid 1705 * and the write hasn't been pushed to the server yet, 1706 * so we can't set BIO_ERROR and report the interruption 1707 * by setting B_EINTR. For the B_ASYNC case, B_EINTR 1708 * is not relevant, so the rpc attempt is essentially 1709 * a noop. For the case of a V3 write rpc not being 1710 * committed to stable storage, the block is still 1711 * dirty and requires either a commit rpc or another 1712 * write rpc with iomode == NFSV3WRITE_FILESYNC before 1713 * the block is reused. This is indicated by setting 1714 * the B_DELWRI and B_NEEDCOMMIT flags. 1715 * 1716 * If the buffer is marked B_PAGING, it does not reside on 1717 * the vp's paging queues so we cannot call bdirty(). The 1718 * bp in this case is not an NFS cache block so we should 1719 * be safe. XXX 1720 * 1721 * The logic below breaks up errors into recoverable and 1722 * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE 1723 * and keep the buffer around for potential write retries. 1724 * For the latter (eg ESTALE), we toss the buffer away (B_INVAL) 1725 * and save the error in the nfsnode. This is less than ideal 1726 * but necessary. Keeping such buffers around could potentially 1727 * cause buffer exhaustion eventually (they can never be written 1728 * out, so will get constantly be re-dirtied). It also causes 1729 * all sorts of vfs panics. For non-recoverable write errors, 1730 * also invalidate the attrcache, so we'll be forced to go over 1731 * the wire for this object, returning an error to user on next 1732 * call (most of the time). 1733 */ 1734 if (error == EINTR || error == EIO || error == ETIMEDOUT 1735 || (!error && (bp->b_flags & B_NEEDCOMMIT))) { 1736 int s; 1737 1738 s = splbio(); 1739 bp->b_flags &= ~(B_INVAL|B_NOCACHE); 1740 if ((bp->b_flags & B_PAGING) == 0) { 1741 bdirty(bp); 1742 bp->b_flags &= ~B_DONE; 1743 } 1744 if (error && (bp->b_flags & B_ASYNC) == 0) 1745 bp->b_flags |= B_EINTR; 1746 splx(s); 1747 } else { 1748 if (error) { 1749 bp->b_ioflags |= BIO_ERROR; 1750 bp->b_flags |= B_INVAL; 1751 bp->b_error = np->n_error = error; 1752 mtx_lock(&np->n_mtx); 1753 np->n_flag |= NWRITEERR; 1754 np->n_attrstamp = 0; 1755 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 1756 mtx_unlock(&np->n_mtx); 1757 } 1758 bp->b_dirtyoff = bp->b_dirtyend = 0; 1759 } 1760 } else { 1761 bp->b_resid = 0; 1762 bufdone(bp); 1763 return (0); 1764 } 1765 } 1766 bp->b_resid = uiop->uio_resid; 1767 if (must_commit) 1768 nfs_clearcommit(vp->v_mount); 1769 bufdone(bp); 1770 return (error); 1771 } 1772 1773 /* 1774 * Used to aid in handling ftruncate() operations on the NFS client side. 1775 * Truncation creates a number of special problems for NFS. We have to 1776 * throw away VM pages and buffer cache buffers that are beyond EOF, and 1777 * we have to properly handle VM pages or (potentially dirty) buffers 1778 * that straddle the truncation point. 1779 */ 1780 1781 int 1782 nfs_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize) 1783 { 1784 struct nfsnode *np = VTONFS(vp); 1785 u_quad_t tsize; 1786 int biosize = vp->v_bufobj.bo_bsize; 1787 int error = 0; 1788 1789 mtx_lock(&np->n_mtx); 1790 tsize = np->n_size; 1791 np->n_size = nsize; 1792 mtx_unlock(&np->n_mtx); 1793 1794 if (nsize < tsize) { 1795 struct buf *bp; 1796 daddr_t lbn; 1797 int bufsize; 1798 1799 /* 1800 * vtruncbuf() doesn't get the buffer overlapping the 1801 * truncation point. We may have a B_DELWRI and/or B_CACHE 1802 * buffer that now needs to be truncated. 1803 */ 1804 error = vtruncbuf(vp, cred, td, nsize, biosize); 1805 lbn = nsize / biosize; 1806 bufsize = nsize & (biosize - 1); 1807 bp = nfs_getcacheblk(vp, lbn, bufsize, td); 1808 if (!bp) 1809 return EINTR; 1810 if (bp->b_dirtyoff > bp->b_bcount) 1811 bp->b_dirtyoff = bp->b_bcount; 1812 if (bp->b_dirtyend > bp->b_bcount) 1813 bp->b_dirtyend = bp->b_bcount; 1814 bp->b_flags |= B_RELBUF; /* don't leave garbage around */ 1815 brelse(bp); 1816 } else { 1817 vnode_pager_setsize(vp, nsize); 1818 } 1819 return(error); 1820 } 1821
Cache object: d0450d2f5afea28b980819ac88e69c5d
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]