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sys/nfsclient/nfs_bio.c
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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/8.2/sys/nfsclient/nfs_bio.c 214977 2010-11-08 10:23:39Z kib $"); 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/resourcevar.h> 49 #include <sys/signalvar.h> 50 #include <sys/vmmeter.h> 51 #include <sys/vnode.h> 52 53 #include <vm/vm.h> 54 #include <vm/vm_extern.h> 55 #include <vm/vm_page.h> 56 #include <vm/vm_object.h> 57 #include <vm/vm_pager.h> 58 #include <vm/vnode_pager.h> 59 60 #include <nfs/nfsproto.h> 61 #include <nfsclient/nfs.h> 62 #include <nfsclient/nfsmount.h> 63 #include <nfsclient/nfsnode.h> 64 #include <nfsclient/nfs_kdtrace.h> 65 66 static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, 67 struct thread *td); 68 static int nfs_directio_write(struct vnode *vp, struct uio *uiop, 69 struct ucred *cred, int ioflag); 70 71 extern int nfs_directio_enable; 72 extern int nfs_directio_allow_mmap; 73 74 /* 75 * Vnode op for VM getpages. 76 */ 77 int 78 nfs_getpages(struct vop_getpages_args *ap) 79 { 80 int i, error, nextoff, size, toff, count, npages; 81 struct uio uio; 82 struct iovec iov; 83 vm_offset_t kva; 84 struct buf *bp; 85 struct vnode *vp; 86 struct thread *td; 87 struct ucred *cred; 88 struct nfsmount *nmp; 89 vm_object_t object; 90 vm_page_t *pages; 91 struct nfsnode *np; 92 93 vp = ap->a_vp; 94 np = VTONFS(vp); 95 td = curthread; /* XXX */ 96 cred = curthread->td_ucred; /* XXX */ 97 nmp = VFSTONFS(vp->v_mount); 98 pages = ap->a_m; 99 count = ap->a_count; 100 101 if ((object = vp->v_object) == NULL) { 102 nfs_printf("nfs_getpages: called with non-merged cache vnode??\n"); 103 return (VM_PAGER_ERROR); 104 } 105 106 if (nfs_directio_enable && !nfs_directio_allow_mmap) { 107 mtx_lock(&np->n_mtx); 108 if ((np->n_flag & NNONCACHE) && (vp->v_type == VREG)) { 109 mtx_unlock(&np->n_mtx); 110 nfs_printf("nfs_getpages: called on non-cacheable vnode??\n"); 111 return (VM_PAGER_ERROR); 112 } else 113 mtx_unlock(&np->n_mtx); 114 } 115 116 mtx_lock(&nmp->nm_mtx); 117 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 118 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 119 mtx_unlock(&nmp->nm_mtx); 120 /* We'll never get here for v4, because we always have fsinfo */ 121 (void)nfs_fsinfo(nmp, vp, cred, td); 122 } else 123 mtx_unlock(&nmp->nm_mtx); 124 125 npages = btoc(count); 126 127 /* 128 * If the requested page is partially valid, just return it and 129 * allow the pager to zero-out the blanks. Partially valid pages 130 * can only occur at the file EOF. 131 */ 132 VM_OBJECT_LOCK(object); 133 if (pages[ap->a_reqpage]->valid != 0) { 134 vm_page_lock_queues(); 135 for (i = 0; i < npages; ++i) { 136 if (i != ap->a_reqpage) 137 vm_page_free(pages[i]); 138 } 139 vm_page_unlock_queues(); 140 VM_OBJECT_UNLOCK(object); 141 return (0); 142 } 143 VM_OBJECT_UNLOCK(object); 144 145 /* 146 * We use only the kva address for the buffer, but this is extremely 147 * convienient and fast. 148 */ 149 bp = getpbuf(&nfs_pbuf_freecnt); 150 151 kva = (vm_offset_t) bp->b_data; 152 pmap_qenter(kva, pages, npages); 153 PCPU_INC(cnt.v_vnodein); 154 PCPU_ADD(cnt.v_vnodepgsin, npages); 155 156 iov.iov_base = (caddr_t) kva; 157 iov.iov_len = count; 158 uio.uio_iov = &iov; 159 uio.uio_iovcnt = 1; 160 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex); 161 uio.uio_resid = count; 162 uio.uio_segflg = UIO_SYSSPACE; 163 uio.uio_rw = UIO_READ; 164 uio.uio_td = td; 165 166 error = (nmp->nm_rpcops->nr_readrpc)(vp, &uio, cred); 167 pmap_qremove(kva, npages); 168 169 relpbuf(bp, &nfs_pbuf_freecnt); 170 171 if (error && (uio.uio_resid == count)) { 172 nfs_printf("nfs_getpages: error %d\n", error); 173 VM_OBJECT_LOCK(object); 174 vm_page_lock_queues(); 175 for (i = 0; i < npages; ++i) { 176 if (i != ap->a_reqpage) 177 vm_page_free(pages[i]); 178 } 179 vm_page_unlock_queues(); 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 vm_page_lock_queues(); 193 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) { 194 vm_page_t m; 195 nextoff = toff + PAGE_SIZE; 196 m = pages[i]; 197 198 if (nextoff <= size) { 199 /* 200 * Read operation filled an entire page 201 */ 202 m->valid = VM_PAGE_BITS_ALL; 203 KASSERT(m->dirty == 0, 204 ("nfs_getpages: page %p is dirty", m)); 205 } else if (size > toff) { 206 /* 207 * Read operation filled a partial page. 208 */ 209 m->valid = 0; 210 vm_page_set_valid(m, 0, size - toff); 211 KASSERT(m->dirty == 0, 212 ("nfs_getpages: page %p is dirty", m)); 213 } else { 214 /* 215 * Read operation was short. If no error occured 216 * we may have hit a zero-fill section. We simply 217 * leave valid set to 0. 218 */ 219 ; 220 } 221 if (i != ap->a_reqpage) { 222 /* 223 * Whether or not to leave the page activated is up in 224 * the air, but we should put the page on a page queue 225 * somewhere (it already is in the object). Result: 226 * It appears that emperical results show that 227 * deactivating pages is best. 228 */ 229 230 /* 231 * Just in case someone was asking for this page we 232 * now tell them that it is ok to use. 233 */ 234 if (!error) { 235 if (m->oflags & VPO_WANTED) 236 vm_page_activate(m); 237 else 238 vm_page_deactivate(m); 239 vm_page_wakeup(m); 240 } else { 241 vm_page_free(m); 242 } 243 } 244 } 245 vm_page_unlock_queues(); 246 VM_OBJECT_UNLOCK(object); 247 return (0); 248 } 249 250 /* 251 * Vnode op for VM putpages. 252 */ 253 int 254 nfs_putpages(struct vop_putpages_args *ap) 255 { 256 struct uio uio; 257 struct iovec iov; 258 vm_offset_t kva; 259 struct buf *bp; 260 int iomode, must_commit, i, error, npages, count; 261 off_t offset; 262 int *rtvals; 263 struct vnode *vp; 264 struct thread *td; 265 struct ucred *cred; 266 struct nfsmount *nmp; 267 struct nfsnode *np; 268 vm_page_t *pages; 269 270 vp = ap->a_vp; 271 np = VTONFS(vp); 272 td = curthread; /* XXX */ 273 cred = curthread->td_ucred; /* XXX */ 274 nmp = VFSTONFS(vp->v_mount); 275 pages = ap->a_m; 276 count = ap->a_count; 277 rtvals = ap->a_rtvals; 278 npages = btoc(count); 279 offset = IDX_TO_OFF(pages[0]->pindex); 280 281 mtx_lock(&nmp->nm_mtx); 282 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 283 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 284 mtx_unlock(&nmp->nm_mtx); 285 (void)nfs_fsinfo(nmp, vp, cred, td); 286 } else 287 mtx_unlock(&nmp->nm_mtx); 288 289 mtx_lock(&np->n_mtx); 290 if (nfs_directio_enable && !nfs_directio_allow_mmap && 291 (np->n_flag & NNONCACHE) && (vp->v_type == VREG)) { 292 mtx_unlock(&np->n_mtx); 293 nfs_printf("nfs_putpages: called on noncache-able vnode??\n"); 294 mtx_lock(&np->n_mtx); 295 } 296 297 for (i = 0; i < npages; i++) 298 rtvals[i] = VM_PAGER_AGAIN; 299 300 /* 301 * When putting pages, do not extend file past EOF. 302 */ 303 if (offset + count > np->n_size) { 304 count = np->n_size - offset; 305 if (count < 0) 306 count = 0; 307 } 308 mtx_unlock(&np->n_mtx); 309 310 /* 311 * We use only the kva address for the buffer, but this is extremely 312 * convienient and fast. 313 */ 314 bp = getpbuf(&nfs_pbuf_freecnt); 315 316 kva = (vm_offset_t) bp->b_data; 317 pmap_qenter(kva, pages, npages); 318 PCPU_INC(cnt.v_vnodeout); 319 PCPU_ADD(cnt.v_vnodepgsout, count); 320 321 iov.iov_base = (caddr_t) kva; 322 iov.iov_len = count; 323 uio.uio_iov = &iov; 324 uio.uio_iovcnt = 1; 325 uio.uio_offset = offset; 326 uio.uio_resid = count; 327 uio.uio_segflg = UIO_SYSSPACE; 328 uio.uio_rw = UIO_WRITE; 329 uio.uio_td = td; 330 331 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0) 332 iomode = NFSV3WRITE_UNSTABLE; 333 else 334 iomode = NFSV3WRITE_FILESYNC; 335 336 error = (nmp->nm_rpcops->nr_writerpc)(vp, &uio, cred, &iomode, &must_commit); 337 338 pmap_qremove(kva, npages); 339 relpbuf(bp, &nfs_pbuf_freecnt); 340 341 if (!error) { 342 int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE; 343 for (i = 0; i < nwritten; i++) { 344 rtvals[i] = VM_PAGER_OK; 345 vm_page_undirty(pages[i]); 346 } 347 if (must_commit) { 348 nfs_clearcommit(vp->v_mount); 349 } 350 } 351 return rtvals[0]; 352 } 353 354 /* 355 * For nfs, cache consistency can only be maintained approximately. 356 * Although RFC1094 does not specify the criteria, the following is 357 * believed to be compatible with the reference port. 358 * For nfs: 359 * If the file's modify time on the server has changed since the 360 * last read rpc or you have written to the file, 361 * you may have lost data cache consistency with the 362 * server, so flush all of the file's data out of the cache. 363 * Then force a getattr rpc to ensure that you have up to date 364 * attributes. 365 * NB: This implies that cache data can be read when up to 366 * NFS_ATTRTIMEO seconds out of date. If you find that you need current 367 * attributes this could be forced by setting n_attrstamp to 0 before 368 * the VOP_GETATTR() call. 369 */ 370 static inline int 371 nfs_bioread_check_cons(struct vnode *vp, struct thread *td, struct ucred *cred) 372 { 373 int error = 0; 374 struct vattr vattr; 375 struct nfsnode *np = VTONFS(vp); 376 int old_lock; 377 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 378 379 /* 380 * Grab the exclusive lock before checking whether the cache is 381 * consistent. 382 * XXX - We can make this cheaper later (by acquiring cheaper locks). 383 * But for now, this suffices. 384 */ 385 old_lock = nfs_upgrade_vnlock(vp); 386 if (vp->v_iflag & VI_DOOMED) { 387 nfs_downgrade_vnlock(vp, old_lock); 388 return (EBADF); 389 } 390 391 mtx_lock(&np->n_mtx); 392 if (np->n_flag & NMODIFIED) { 393 mtx_unlock(&np->n_mtx); 394 if (vp->v_type != VREG) { 395 if (vp->v_type != VDIR) 396 panic("nfs: bioread, not dir"); 397 (nmp->nm_rpcops->nr_invaldir)(vp); 398 error = nfs_vinvalbuf(vp, V_SAVE, td, 1); 399 if (error) 400 goto out; 401 } 402 np->n_attrstamp = 0; 403 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 404 error = VOP_GETATTR(vp, &vattr, cred); 405 if (error) 406 goto out; 407 mtx_lock(&np->n_mtx); 408 np->n_mtime = vattr.va_mtime; 409 mtx_unlock(&np->n_mtx); 410 } else { 411 mtx_unlock(&np->n_mtx); 412 error = VOP_GETATTR(vp, &vattr, cred); 413 if (error) 414 return (error); 415 mtx_lock(&np->n_mtx); 416 if ((np->n_flag & NSIZECHANGED) 417 || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) { 418 mtx_unlock(&np->n_mtx); 419 if (vp->v_type == VDIR) 420 (nmp->nm_rpcops->nr_invaldir)(vp); 421 error = nfs_vinvalbuf(vp, V_SAVE, td, 1); 422 if (error) 423 goto out; 424 mtx_lock(&np->n_mtx); 425 np->n_mtime = vattr.va_mtime; 426 np->n_flag &= ~NSIZECHANGED; 427 } 428 mtx_unlock(&np->n_mtx); 429 } 430 out: 431 nfs_downgrade_vnlock(vp, old_lock); 432 return error; 433 } 434 435 /* 436 * Vnode op for read using bio 437 */ 438 int 439 nfs_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred) 440 { 441 struct nfsnode *np = VTONFS(vp); 442 int biosize, i; 443 struct buf *bp, *rabp; 444 struct thread *td; 445 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 446 daddr_t lbn, rabn; 447 int bcount; 448 int seqcount; 449 int nra, error = 0, n = 0, on = 0; 450 451 KASSERT(uio->uio_rw == UIO_READ, ("nfs_read mode")); 452 if (uio->uio_resid == 0) 453 return (0); 454 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */ 455 return (EINVAL); 456 td = uio->uio_td; 457 458 mtx_lock(&nmp->nm_mtx); 459 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 460 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 461 mtx_unlock(&nmp->nm_mtx); 462 (void)nfs_fsinfo(nmp, vp, cred, td); 463 } else 464 mtx_unlock(&nmp->nm_mtx); 465 466 if (vp->v_type != VDIR && 467 (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 468 return (EFBIG); 469 470 if (nfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG)) 471 /* No caching/ no readaheads. Just read data into the user buffer */ 472 return nfs_readrpc(vp, uio, cred); 473 474 biosize = vp->v_mount->mnt_stat.f_iosize; 475 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE); 476 477 error = nfs_bioread_check_cons(vp, td, cred); 478 if (error) 479 return error; 480 481 do { 482 u_quad_t nsize; 483 484 mtx_lock(&np->n_mtx); 485 nsize = np->n_size; 486 mtx_unlock(&np->n_mtx); 487 488 switch (vp->v_type) { 489 case VREG: 490 nfsstats.biocache_reads++; 491 lbn = uio->uio_offset / biosize; 492 on = uio->uio_offset & (biosize - 1); 493 494 /* 495 * Start the read ahead(s), as required. 496 */ 497 if (nmp->nm_readahead > 0) { 498 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && 499 (off_t)(lbn + 1 + nra) * biosize < nsize; nra++) { 500 rabn = lbn + 1 + nra; 501 if (incore(&vp->v_bufobj, rabn) == NULL) { 502 rabp = nfs_getcacheblk(vp, rabn, biosize, td); 503 if (!rabp) { 504 error = nfs_sigintr(nmp, td); 505 return (error ? error : EINTR); 506 } 507 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 508 rabp->b_flags |= B_ASYNC; 509 rabp->b_iocmd = BIO_READ; 510 vfs_busy_pages(rabp, 0); 511 if (nfs_asyncio(nmp, rabp, cred, td)) { 512 rabp->b_flags |= B_INVAL; 513 rabp->b_ioflags |= BIO_ERROR; 514 vfs_unbusy_pages(rabp); 515 brelse(rabp); 516 break; 517 } 518 } else { 519 brelse(rabp); 520 } 521 } 522 } 523 } 524 525 /* Note that bcount is *not* DEV_BSIZE aligned. */ 526 bcount = biosize; 527 if ((off_t)lbn * biosize >= nsize) { 528 bcount = 0; 529 } else if ((off_t)(lbn + 1) * biosize > nsize) { 530 bcount = nsize - (off_t)lbn * biosize; 531 } 532 bp = nfs_getcacheblk(vp, lbn, bcount, td); 533 534 if (!bp) { 535 error = nfs_sigintr(nmp, td); 536 return (error ? error : EINTR); 537 } 538 539 /* 540 * If B_CACHE is not set, we must issue the read. If this 541 * fails, we return an error. 542 */ 543 544 if ((bp->b_flags & B_CACHE) == 0) { 545 bp->b_iocmd = BIO_READ; 546 vfs_busy_pages(bp, 0); 547 error = nfs_doio(vp, bp, cred, td); 548 if (error) { 549 brelse(bp); 550 return (error); 551 } 552 } 553 554 /* 555 * on is the offset into the current bp. Figure out how many 556 * bytes we can copy out of the bp. Note that bcount is 557 * NOT DEV_BSIZE aligned. 558 * 559 * Then figure out how many bytes we can copy into the uio. 560 */ 561 562 n = 0; 563 if (on < bcount) 564 n = min((unsigned)(bcount - on), uio->uio_resid); 565 break; 566 case VLNK: 567 nfsstats.biocache_readlinks++; 568 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td); 569 if (!bp) { 570 error = nfs_sigintr(nmp, td); 571 return (error ? error : EINTR); 572 } 573 if ((bp->b_flags & B_CACHE) == 0) { 574 bp->b_iocmd = BIO_READ; 575 vfs_busy_pages(bp, 0); 576 error = nfs_doio(vp, bp, cred, td); 577 if (error) { 578 bp->b_ioflags |= BIO_ERROR; 579 brelse(bp); 580 return (error); 581 } 582 } 583 n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); 584 on = 0; 585 break; 586 case VDIR: 587 nfsstats.biocache_readdirs++; 588 if (np->n_direofoffset 589 && uio->uio_offset >= np->n_direofoffset) { 590 return (0); 591 } 592 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; 593 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); 594 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td); 595 if (!bp) { 596 error = nfs_sigintr(nmp, td); 597 return (error ? error : EINTR); 598 } 599 if ((bp->b_flags & B_CACHE) == 0) { 600 bp->b_iocmd = BIO_READ; 601 vfs_busy_pages(bp, 0); 602 error = nfs_doio(vp, bp, cred, td); 603 if (error) { 604 brelse(bp); 605 } 606 while (error == NFSERR_BAD_COOKIE) { 607 (nmp->nm_rpcops->nr_invaldir)(vp); 608 error = nfs_vinvalbuf(vp, 0, td, 1); 609 /* 610 * Yuck! The directory has been modified on the 611 * server. The only way to get the block is by 612 * reading from the beginning to get all the 613 * offset cookies. 614 * 615 * Leave the last bp intact unless there is an error. 616 * Loop back up to the while if the error is another 617 * NFSERR_BAD_COOKIE (double yuch!). 618 */ 619 for (i = 0; i <= lbn && !error; i++) { 620 if (np->n_direofoffset 621 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) 622 return (0); 623 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td); 624 if (!bp) { 625 error = nfs_sigintr(nmp, td); 626 return (error ? error : EINTR); 627 } 628 if ((bp->b_flags & B_CACHE) == 0) { 629 bp->b_iocmd = BIO_READ; 630 vfs_busy_pages(bp, 0); 631 error = nfs_doio(vp, bp, cred, td); 632 /* 633 * no error + B_INVAL == directory EOF, 634 * use the block. 635 */ 636 if (error == 0 && (bp->b_flags & B_INVAL)) 637 break; 638 } 639 /* 640 * An error will throw away the block and the 641 * for loop will break out. If no error and this 642 * is not the block we want, we throw away the 643 * block and go for the next one via the for loop. 644 */ 645 if (error || i < lbn) 646 brelse(bp); 647 } 648 } 649 /* 650 * The above while is repeated if we hit another cookie 651 * error. If we hit an error and it wasn't a cookie error, 652 * we give up. 653 */ 654 if (error) 655 return (error); 656 } 657 658 /* 659 * If not eof and read aheads are enabled, start one. 660 * (You need the current block first, so that you have the 661 * directory offset cookie of the next block.) 662 */ 663 if (nmp->nm_readahead > 0 && 664 (bp->b_flags & B_INVAL) == 0 && 665 (np->n_direofoffset == 0 || 666 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) && 667 incore(&vp->v_bufobj, lbn + 1) == NULL) { 668 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td); 669 if (rabp) { 670 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 671 rabp->b_flags |= B_ASYNC; 672 rabp->b_iocmd = BIO_READ; 673 vfs_busy_pages(rabp, 0); 674 if (nfs_asyncio(nmp, rabp, cred, td)) { 675 rabp->b_flags |= B_INVAL; 676 rabp->b_ioflags |= BIO_ERROR; 677 vfs_unbusy_pages(rabp); 678 brelse(rabp); 679 } 680 } else { 681 brelse(rabp); 682 } 683 } 684 } 685 /* 686 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is 687 * chopped for the EOF condition, we cannot tell how large 688 * NFS directories are going to be until we hit EOF. So 689 * an NFS directory buffer is *not* chopped to its EOF. Now, 690 * it just so happens that b_resid will effectively chop it 691 * to EOF. *BUT* this information is lost if the buffer goes 692 * away and is reconstituted into a B_CACHE state ( due to 693 * being VMIO ) later. So we keep track of the directory eof 694 * in np->n_direofoffset and chop it off as an extra step 695 * right here. 696 */ 697 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on); 698 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset) 699 n = np->n_direofoffset - uio->uio_offset; 700 break; 701 default: 702 nfs_printf(" nfs_bioread: type %x unexpected\n", vp->v_type); 703 bp = NULL; 704 break; 705 }; 706 707 if (n > 0) { 708 error = uiomove(bp->b_data + on, (int)n, uio); 709 } 710 if (vp->v_type == VLNK) 711 n = 0; 712 if (bp != NULL) 713 brelse(bp); 714 } while (error == 0 && uio->uio_resid > 0 && n > 0); 715 return (error); 716 } 717 718 /* 719 * The NFS write path cannot handle iovecs with len > 1. So we need to 720 * break up iovecs accordingly (restricting them to wsize). 721 * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf). 722 * For the ASYNC case, 2 copies are needed. The first a copy from the 723 * user buffer to a staging buffer and then a second copy from the staging 724 * buffer to mbufs. This can be optimized by copying from the user buffer 725 * directly into mbufs and passing the chain down, but that requires a 726 * fair amount of re-working of the relevant codepaths (and can be done 727 * later). 728 */ 729 static int 730 nfs_directio_write(vp, uiop, cred, ioflag) 731 struct vnode *vp; 732 struct uio *uiop; 733 struct ucred *cred; 734 int ioflag; 735 { 736 int error; 737 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 738 struct thread *td = uiop->uio_td; 739 int size; 740 int wsize; 741 742 mtx_lock(&nmp->nm_mtx); 743 wsize = nmp->nm_wsize; 744 mtx_unlock(&nmp->nm_mtx); 745 if (ioflag & IO_SYNC) { 746 int iomode, must_commit; 747 struct uio uio; 748 struct iovec iov; 749 do_sync: 750 while (uiop->uio_resid > 0) { 751 size = min(uiop->uio_resid, wsize); 752 size = min(uiop->uio_iov->iov_len, size); 753 iov.iov_base = uiop->uio_iov->iov_base; 754 iov.iov_len = size; 755 uio.uio_iov = &iov; 756 uio.uio_iovcnt = 1; 757 uio.uio_offset = uiop->uio_offset; 758 uio.uio_resid = size; 759 uio.uio_segflg = UIO_USERSPACE; 760 uio.uio_rw = UIO_WRITE; 761 uio.uio_td = td; 762 iomode = NFSV3WRITE_FILESYNC; 763 error = (nmp->nm_rpcops->nr_writerpc)(vp, &uio, cred, 764 &iomode, &must_commit); 765 KASSERT((must_commit == 0), 766 ("nfs_directio_write: Did not commit write")); 767 if (error) 768 return (error); 769 uiop->uio_offset += size; 770 uiop->uio_resid -= size; 771 if (uiop->uio_iov->iov_len <= size) { 772 uiop->uio_iovcnt--; 773 uiop->uio_iov++; 774 } else { 775 uiop->uio_iov->iov_base = 776 (char *)uiop->uio_iov->iov_base + size; 777 uiop->uio_iov->iov_len -= size; 778 } 779 } 780 } else { 781 struct uio *t_uio; 782 struct iovec *t_iov; 783 struct buf *bp; 784 785 /* 786 * Break up the write into blocksize chunks and hand these 787 * over to nfsiod's for write back. 788 * Unfortunately, this incurs a copy of the data. Since 789 * the user could modify the buffer before the write is 790 * initiated. 791 * 792 * The obvious optimization here is that one of the 2 copies 793 * in the async write path can be eliminated by copying the 794 * data here directly into mbufs and passing the mbuf chain 795 * down. But that will require a fair amount of re-working 796 * of the code and can be done if there's enough interest 797 * in NFS directio access. 798 */ 799 while (uiop->uio_resid > 0) { 800 size = min(uiop->uio_resid, wsize); 801 size = min(uiop->uio_iov->iov_len, size); 802 bp = getpbuf(&nfs_pbuf_freecnt); 803 t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK); 804 t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK); 805 t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK); 806 t_iov->iov_len = size; 807 t_uio->uio_iov = t_iov; 808 t_uio->uio_iovcnt = 1; 809 t_uio->uio_offset = uiop->uio_offset; 810 t_uio->uio_resid = size; 811 t_uio->uio_segflg = UIO_SYSSPACE; 812 t_uio->uio_rw = UIO_WRITE; 813 t_uio->uio_td = td; 814 bcopy(uiop->uio_iov->iov_base, t_iov->iov_base, size); 815 bp->b_flags |= B_DIRECT; 816 bp->b_iocmd = BIO_WRITE; 817 if (cred != NOCRED) { 818 crhold(cred); 819 bp->b_wcred = cred; 820 } else 821 bp->b_wcred = NOCRED; 822 bp->b_caller1 = (void *)t_uio; 823 bp->b_vp = vp; 824 error = nfs_asyncio(nmp, bp, NOCRED, td); 825 if (error) { 826 free(t_iov->iov_base, M_NFSDIRECTIO); 827 free(t_iov, M_NFSDIRECTIO); 828 free(t_uio, M_NFSDIRECTIO); 829 bp->b_vp = NULL; 830 relpbuf(bp, &nfs_pbuf_freecnt); 831 if (error == EINTR) 832 return (error); 833 goto do_sync; 834 } 835 uiop->uio_offset += size; 836 uiop->uio_resid -= size; 837 if (uiop->uio_iov->iov_len <= size) { 838 uiop->uio_iovcnt--; 839 uiop->uio_iov++; 840 } else { 841 uiop->uio_iov->iov_base = 842 (char *)uiop->uio_iov->iov_base + size; 843 uiop->uio_iov->iov_len -= size; 844 } 845 } 846 } 847 return (0); 848 } 849 850 /* 851 * Vnode op for write using bio 852 */ 853 int 854 nfs_write(struct vop_write_args *ap) 855 { 856 int biosize; 857 struct uio *uio = ap->a_uio; 858 struct thread *td = uio->uio_td; 859 struct vnode *vp = ap->a_vp; 860 struct nfsnode *np = VTONFS(vp); 861 struct ucred *cred = ap->a_cred; 862 int ioflag = ap->a_ioflag; 863 struct buf *bp; 864 struct vattr vattr; 865 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 866 daddr_t lbn; 867 int bcount; 868 int n, on, error = 0; 869 struct proc *p = td?td->td_proc:NULL; 870 871 KASSERT(uio->uio_rw == UIO_WRITE, ("nfs_write mode")); 872 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, 873 ("nfs_write proc")); 874 if (vp->v_type != VREG) 875 return (EIO); 876 mtx_lock(&np->n_mtx); 877 if (np->n_flag & NWRITEERR) { 878 np->n_flag &= ~NWRITEERR; 879 mtx_unlock(&np->n_mtx); 880 return (np->n_error); 881 } else 882 mtx_unlock(&np->n_mtx); 883 mtx_lock(&nmp->nm_mtx); 884 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 885 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 886 mtx_unlock(&nmp->nm_mtx); 887 (void)nfs_fsinfo(nmp, vp, cred, td); 888 } else 889 mtx_unlock(&nmp->nm_mtx); 890 891 /* 892 * Synchronously flush pending buffers if we are in synchronous 893 * mode or if we are appending. 894 */ 895 if (ioflag & (IO_APPEND | IO_SYNC)) { 896 mtx_lock(&np->n_mtx); 897 if (np->n_flag & NMODIFIED) { 898 mtx_unlock(&np->n_mtx); 899 #ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */ 900 /* 901 * Require non-blocking, synchronous writes to 902 * dirty files to inform the program it needs 903 * to fsync(2) explicitly. 904 */ 905 if (ioflag & IO_NDELAY) 906 return (EAGAIN); 907 #endif 908 flush_and_restart: 909 np->n_attrstamp = 0; 910 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 911 error = nfs_vinvalbuf(vp, V_SAVE, td, 1); 912 if (error) 913 return (error); 914 } else 915 mtx_unlock(&np->n_mtx); 916 } 917 918 /* 919 * If IO_APPEND then load uio_offset. We restart here if we cannot 920 * get the append lock. 921 */ 922 if (ioflag & IO_APPEND) { 923 np->n_attrstamp = 0; 924 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 925 error = VOP_GETATTR(vp, &vattr, cred); 926 if (error) 927 return (error); 928 mtx_lock(&np->n_mtx); 929 uio->uio_offset = np->n_size; 930 mtx_unlock(&np->n_mtx); 931 } 932 933 if (uio->uio_offset < 0) 934 return (EINVAL); 935 if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 936 return (EFBIG); 937 if (uio->uio_resid == 0) 938 return (0); 939 940 if (nfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG) 941 return nfs_directio_write(vp, uio, cred, ioflag); 942 943 /* 944 * Maybe this should be above the vnode op call, but so long as 945 * file servers have no limits, i don't think it matters 946 */ 947 if (p != NULL) { 948 PROC_LOCK(p); 949 if (uio->uio_offset + uio->uio_resid > 950 lim_cur(p, RLIMIT_FSIZE)) { 951 psignal(p, SIGXFSZ); 952 PROC_UNLOCK(p); 953 return (EFBIG); 954 } 955 PROC_UNLOCK(p); 956 } 957 958 biosize = vp->v_mount->mnt_stat.f_iosize; 959 /* 960 * Find all of this file's B_NEEDCOMMIT buffers. If our writes 961 * would exceed the local maximum per-file write commit size when 962 * combined with those, we must decide whether to flush, 963 * go synchronous, or return error. We don't bother checking 964 * IO_UNIT -- we just make all writes atomic anyway, as there's 965 * no point optimizing for something that really won't ever happen. 966 */ 967 if (!(ioflag & IO_SYNC)) { 968 int nflag; 969 970 mtx_lock(&np->n_mtx); 971 nflag = np->n_flag; 972 mtx_unlock(&np->n_mtx); 973 int needrestart = 0; 974 if (nmp->nm_wcommitsize < uio->uio_resid) { 975 /* 976 * If this request could not possibly be completed 977 * without exceeding the maximum outstanding write 978 * commit size, see if we can convert it into a 979 * synchronous write operation. 980 */ 981 if (ioflag & IO_NDELAY) 982 return (EAGAIN); 983 ioflag |= IO_SYNC; 984 if (nflag & NMODIFIED) 985 needrestart = 1; 986 } else if (nflag & NMODIFIED) { 987 int wouldcommit = 0; 988 BO_LOCK(&vp->v_bufobj); 989 if (vp->v_bufobj.bo_dirty.bv_cnt != 0) { 990 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd, 991 b_bobufs) { 992 if (bp->b_flags & B_NEEDCOMMIT) 993 wouldcommit += bp->b_bcount; 994 } 995 } 996 BO_UNLOCK(&vp->v_bufobj); 997 /* 998 * Since we're not operating synchronously and 999 * bypassing the buffer cache, we are in a commit 1000 * and holding all of these buffers whether 1001 * transmitted or not. If not limited, this 1002 * will lead to the buffer cache deadlocking, 1003 * as no one else can flush our uncommitted buffers. 1004 */ 1005 wouldcommit += uio->uio_resid; 1006 /* 1007 * If we would initially exceed the maximum 1008 * outstanding write commit size, flush and restart. 1009 */ 1010 if (wouldcommit > nmp->nm_wcommitsize) 1011 needrestart = 1; 1012 } 1013 if (needrestart) 1014 goto flush_and_restart; 1015 } 1016 1017 do { 1018 nfsstats.biocache_writes++; 1019 lbn = uio->uio_offset / biosize; 1020 on = uio->uio_offset & (biosize-1); 1021 n = min((unsigned)(biosize - on), uio->uio_resid); 1022 again: 1023 /* 1024 * Handle direct append and file extension cases, calculate 1025 * unaligned buffer size. 1026 */ 1027 mtx_lock(&np->n_mtx); 1028 if (uio->uio_offset == np->n_size && n) { 1029 mtx_unlock(&np->n_mtx); 1030 /* 1031 * Get the buffer (in its pre-append state to maintain 1032 * B_CACHE if it was previously set). Resize the 1033 * nfsnode after we have locked the buffer to prevent 1034 * readers from reading garbage. 1035 */ 1036 bcount = on; 1037 bp = nfs_getcacheblk(vp, lbn, bcount, td); 1038 1039 if (bp != NULL) { 1040 long save; 1041 1042 mtx_lock(&np->n_mtx); 1043 np->n_size = uio->uio_offset + n; 1044 np->n_flag |= NMODIFIED; 1045 vnode_pager_setsize(vp, np->n_size); 1046 mtx_unlock(&np->n_mtx); 1047 1048 save = bp->b_flags & B_CACHE; 1049 bcount += n; 1050 allocbuf(bp, bcount); 1051 bp->b_flags |= save; 1052 } 1053 } else { 1054 /* 1055 * Obtain the locked cache block first, and then 1056 * adjust the file's size as appropriate. 1057 */ 1058 bcount = on + n; 1059 if ((off_t)lbn * biosize + bcount < np->n_size) { 1060 if ((off_t)(lbn + 1) * biosize < np->n_size) 1061 bcount = biosize; 1062 else 1063 bcount = np->n_size - (off_t)lbn * biosize; 1064 } 1065 mtx_unlock(&np->n_mtx); 1066 bp = nfs_getcacheblk(vp, lbn, bcount, td); 1067 mtx_lock(&np->n_mtx); 1068 if (uio->uio_offset + n > np->n_size) { 1069 np->n_size = uio->uio_offset + n; 1070 np->n_flag |= NMODIFIED; 1071 vnode_pager_setsize(vp, np->n_size); 1072 } 1073 mtx_unlock(&np->n_mtx); 1074 } 1075 1076 if (!bp) { 1077 error = nfs_sigintr(nmp, td); 1078 if (!error) 1079 error = EINTR; 1080 break; 1081 } 1082 1083 /* 1084 * Issue a READ if B_CACHE is not set. In special-append 1085 * mode, B_CACHE is based on the buffer prior to the write 1086 * op and is typically set, avoiding the read. If a read 1087 * is required in special append mode, the server will 1088 * probably send us a short-read since we extended the file 1089 * on our end, resulting in b_resid == 0 and, thusly, 1090 * B_CACHE getting set. 1091 * 1092 * We can also avoid issuing the read if the write covers 1093 * the entire buffer. We have to make sure the buffer state 1094 * is reasonable in this case since we will not be initiating 1095 * I/O. See the comments in kern/vfs_bio.c's getblk() for 1096 * more information. 1097 * 1098 * B_CACHE may also be set due to the buffer being cached 1099 * normally. 1100 */ 1101 1102 if (on == 0 && n == bcount) { 1103 bp->b_flags |= B_CACHE; 1104 bp->b_flags &= ~B_INVAL; 1105 bp->b_ioflags &= ~BIO_ERROR; 1106 } 1107 1108 if ((bp->b_flags & B_CACHE) == 0) { 1109 bp->b_iocmd = BIO_READ; 1110 vfs_busy_pages(bp, 0); 1111 error = nfs_doio(vp, bp, cred, td); 1112 if (error) { 1113 brelse(bp); 1114 break; 1115 } 1116 } 1117 if (bp->b_wcred == NOCRED) 1118 bp->b_wcred = crhold(cred); 1119 mtx_lock(&np->n_mtx); 1120 np->n_flag |= NMODIFIED; 1121 mtx_unlock(&np->n_mtx); 1122 1123 /* 1124 * If dirtyend exceeds file size, chop it down. This should 1125 * not normally occur but there is an append race where it 1126 * might occur XXX, so we log it. 1127 * 1128 * If the chopping creates a reverse-indexed or degenerate 1129 * situation with dirtyoff/end, we 0 both of them. 1130 */ 1131 1132 if (bp->b_dirtyend > bcount) { 1133 nfs_printf("NFS append race @%lx:%d\n", 1134 (long)bp->b_blkno * DEV_BSIZE, 1135 bp->b_dirtyend - bcount); 1136 bp->b_dirtyend = bcount; 1137 } 1138 1139 if (bp->b_dirtyoff >= bp->b_dirtyend) 1140 bp->b_dirtyoff = bp->b_dirtyend = 0; 1141 1142 /* 1143 * If the new write will leave a contiguous dirty 1144 * area, just update the b_dirtyoff and b_dirtyend, 1145 * otherwise force a write rpc of the old dirty area. 1146 * 1147 * While it is possible to merge discontiguous writes due to 1148 * our having a B_CACHE buffer ( and thus valid read data 1149 * for the hole), we don't because it could lead to 1150 * significant cache coherency problems with multiple clients, 1151 * especially if locking is implemented later on. 1152 * 1153 * as an optimization we could theoretically maintain 1154 * a linked list of discontinuous areas, but we would still 1155 * have to commit them separately so there isn't much 1156 * advantage to it except perhaps a bit of asynchronization. 1157 */ 1158 1159 if (bp->b_dirtyend > 0 && 1160 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { 1161 if (bwrite(bp) == EINTR) { 1162 error = EINTR; 1163 break; 1164 } 1165 goto again; 1166 } 1167 1168 error = uiomove((char *)bp->b_data + on, n, uio); 1169 1170 /* 1171 * Since this block is being modified, it must be written 1172 * again and not just committed. Since write clustering does 1173 * not work for the stage 1 data write, only the stage 2 1174 * commit rpc, we have to clear B_CLUSTEROK as well. 1175 */ 1176 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1177 1178 if (error) { 1179 bp->b_ioflags |= BIO_ERROR; 1180 brelse(bp); 1181 break; 1182 } 1183 1184 /* 1185 * Only update dirtyoff/dirtyend if not a degenerate 1186 * condition. 1187 */ 1188 if (n) { 1189 if (bp->b_dirtyend > 0) { 1190 bp->b_dirtyoff = min(on, bp->b_dirtyoff); 1191 bp->b_dirtyend = max((on + n), bp->b_dirtyend); 1192 } else { 1193 bp->b_dirtyoff = on; 1194 bp->b_dirtyend = on + n; 1195 } 1196 vfs_bio_set_valid(bp, on, n); 1197 } 1198 1199 /* 1200 * If IO_SYNC do bwrite(). 1201 * 1202 * IO_INVAL appears to be unused. The idea appears to be 1203 * to turn off caching in this case. Very odd. XXX 1204 */ 1205 if ((ioflag & IO_SYNC)) { 1206 if (ioflag & IO_INVAL) 1207 bp->b_flags |= B_NOCACHE; 1208 error = bwrite(bp); 1209 if (error) 1210 break; 1211 } else if ((n + on) == biosize) { 1212 bp->b_flags |= B_ASYNC; 1213 (void) (nmp->nm_rpcops->nr_writebp)(bp, 0, NULL); 1214 } else { 1215 bdwrite(bp); 1216 } 1217 } while (uio->uio_resid > 0 && n > 0); 1218 1219 return (error); 1220 } 1221 1222 /* 1223 * Get an nfs cache block. 1224 * 1225 * Allocate a new one if the block isn't currently in the cache 1226 * and return the block marked busy. If the calling process is 1227 * interrupted by a signal for an interruptible mount point, return 1228 * NULL. 1229 * 1230 * The caller must carefully deal with the possible B_INVAL state of 1231 * the buffer. nfs_doio() clears B_INVAL (and nfs_asyncio() clears it 1232 * indirectly), so synchronous reads can be issued without worrying about 1233 * the B_INVAL state. We have to be a little more careful when dealing 1234 * with writes (see comments in nfs_write()) when extending a file past 1235 * its EOF. 1236 */ 1237 static struct buf * 1238 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td) 1239 { 1240 struct buf *bp; 1241 struct mount *mp; 1242 struct nfsmount *nmp; 1243 1244 mp = vp->v_mount; 1245 nmp = VFSTONFS(mp); 1246 1247 if (nmp->nm_flag & NFSMNT_INT) { 1248 sigset_t oldset; 1249 1250 nfs_set_sigmask(td, &oldset); 1251 bp = getblk(vp, bn, size, NFS_PCATCH, 0, 0); 1252 nfs_restore_sigmask(td, &oldset); 1253 while (bp == NULL) { 1254 if (nfs_sigintr(nmp, td)) 1255 return (NULL); 1256 bp = getblk(vp, bn, size, 0, 2 * hz, 0); 1257 } 1258 } else { 1259 bp = getblk(vp, bn, size, 0, 0, 0); 1260 } 1261 1262 if (vp->v_type == VREG) { 1263 int biosize; 1264 1265 biosize = mp->mnt_stat.f_iosize; 1266 bp->b_blkno = bn * (biosize / DEV_BSIZE); 1267 } 1268 return (bp); 1269 } 1270 1271 /* 1272 * Flush and invalidate all dirty buffers. If another process is already 1273 * doing the flush, just wait for completion. 1274 */ 1275 int 1276 nfs_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg) 1277 { 1278 struct nfsnode *np = VTONFS(vp); 1279 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 1280 int error = 0, slpflag, slptimeo; 1281 int old_lock = 0; 1282 1283 ASSERT_VOP_LOCKED(vp, "nfs_vinvalbuf"); 1284 1285 if ((nmp->nm_flag & NFSMNT_INT) == 0) 1286 intrflg = 0; 1287 if (intrflg) { 1288 slpflag = NFS_PCATCH; 1289 slptimeo = 2 * hz; 1290 } else { 1291 slpflag = 0; 1292 slptimeo = 0; 1293 } 1294 1295 old_lock = nfs_upgrade_vnlock(vp); 1296 if (vp->v_iflag & VI_DOOMED) { 1297 /* 1298 * Since vgonel() uses the generic vinvalbuf() to flush 1299 * dirty buffers and it does not call this function, it 1300 * is safe to just return OK when VI_DOOMED is set. 1301 */ 1302 nfs_downgrade_vnlock(vp, old_lock); 1303 return (0); 1304 } 1305 1306 /* 1307 * Now, flush as required. 1308 */ 1309 if ((flags & V_SAVE) && (vp->v_bufobj.bo_object != NULL)) { 1310 VM_OBJECT_LOCK(vp->v_bufobj.bo_object); 1311 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC); 1312 VM_OBJECT_UNLOCK(vp->v_bufobj.bo_object); 1313 /* 1314 * If the page clean was interrupted, fail the invalidation. 1315 * Not doing so, we run the risk of losing dirty pages in the 1316 * vinvalbuf() call below. 1317 */ 1318 if (intrflg && (error = nfs_sigintr(nmp, td))) 1319 goto out; 1320 } 1321 1322 error = vinvalbuf(vp, flags, slpflag, 0); 1323 while (error) { 1324 if (intrflg && (error = nfs_sigintr(nmp, td))) 1325 goto out; 1326 error = vinvalbuf(vp, flags, 0, slptimeo); 1327 } 1328 mtx_lock(&np->n_mtx); 1329 if (np->n_directio_asyncwr == 0) 1330 np->n_flag &= ~NMODIFIED; 1331 mtx_unlock(&np->n_mtx); 1332 out: 1333 nfs_downgrade_vnlock(vp, old_lock); 1334 return error; 1335 } 1336 1337 /* 1338 * Initiate asynchronous I/O. Return an error if no nfsiods are available. 1339 * This is mainly to avoid queueing async I/O requests when the nfsiods 1340 * are all hung on a dead server. 1341 * 1342 * Note: nfs_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp 1343 * is eventually dequeued by the async daemon, nfs_doio() *will*. 1344 */ 1345 int 1346 nfs_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td) 1347 { 1348 int iod; 1349 int gotiod; 1350 int slpflag = 0; 1351 int slptimeo = 0; 1352 int error, error2; 1353 1354 /* 1355 * Commits are usually short and sweet so lets save some cpu and 1356 * leave the async daemons for more important rpc's (such as reads 1357 * and writes). 1358 */ 1359 mtx_lock(&nfs_iod_mtx); 1360 if (bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) && 1361 (nmp->nm_bufqiods > nfs_numasync / 2)) { 1362 mtx_unlock(&nfs_iod_mtx); 1363 return(EIO); 1364 } 1365 again: 1366 if (nmp->nm_flag & NFSMNT_INT) 1367 slpflag = NFS_PCATCH; 1368 gotiod = FALSE; 1369 1370 /* 1371 * Find a free iod to process this request. 1372 */ 1373 for (iod = 0; iod < nfs_numasync; iod++) 1374 if (nfs_iodwant[iod] == NFSIOD_AVAILABLE) { 1375 gotiod = TRUE; 1376 break; 1377 } 1378 1379 /* 1380 * Try to create one if none are free. 1381 */ 1382 if (!gotiod) 1383 nfs_nfsiodnew(); 1384 else { 1385 /* 1386 * Found one, so wake it up and tell it which 1387 * mount to process. 1388 */ 1389 NFS_DPF(ASYNCIO, ("nfs_asyncio: waking iod %d for mount %p\n", 1390 iod, nmp)); 1391 nfs_iodwant[iod] = NFSIOD_NOT_AVAILABLE; 1392 nfs_iodmount[iod] = nmp; 1393 nmp->nm_bufqiods++; 1394 wakeup(&nfs_iodwant[iod]); 1395 } 1396 1397 /* 1398 * If none are free, we may already have an iod working on this mount 1399 * point. If so, it will process our request. 1400 */ 1401 if (!gotiod) { 1402 if (nmp->nm_bufqiods > 0) { 1403 NFS_DPF(ASYNCIO, 1404 ("nfs_asyncio: %d iods are already processing mount %p\n", 1405 nmp->nm_bufqiods, nmp)); 1406 gotiod = TRUE; 1407 } 1408 } 1409 1410 /* 1411 * If we have an iod which can process the request, then queue 1412 * the buffer. 1413 */ 1414 if (gotiod) { 1415 /* 1416 * Ensure that the queue never grows too large. We still want 1417 * to asynchronize so we block rather then return EIO. 1418 */ 1419 while (nmp->nm_bufqlen >= 2 * nfs_numasync) { 1420 NFS_DPF(ASYNCIO, 1421 ("nfs_asyncio: waiting for mount %p queue to drain\n", nmp)); 1422 nmp->nm_bufqwant = TRUE; 1423 error = nfs_msleep(td, &nmp->nm_bufq, &nfs_iod_mtx, 1424 slpflag | PRIBIO, 1425 "nfsaio", slptimeo); 1426 if (error) { 1427 error2 = nfs_sigintr(nmp, td); 1428 if (error2) { 1429 mtx_unlock(&nfs_iod_mtx); 1430 return (error2); 1431 } 1432 if (slpflag == NFS_PCATCH) { 1433 slpflag = 0; 1434 slptimeo = 2 * hz; 1435 } 1436 } 1437 /* 1438 * We might have lost our iod while sleeping, 1439 * so check and loop if nescessary. 1440 */ 1441 goto again; 1442 } 1443 1444 /* We might have lost our nfsiod */ 1445 if (nmp->nm_bufqiods == 0) { 1446 NFS_DPF(ASYNCIO, 1447 ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); 1448 goto again; 1449 } 1450 1451 if (bp->b_iocmd == BIO_READ) { 1452 if (bp->b_rcred == NOCRED && cred != NOCRED) 1453 bp->b_rcred = crhold(cred); 1454 } else { 1455 if (bp->b_wcred == NOCRED && cred != NOCRED) 1456 bp->b_wcred = crhold(cred); 1457 } 1458 1459 if (bp->b_flags & B_REMFREE) 1460 bremfreef(bp); 1461 BUF_KERNPROC(bp); 1462 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist); 1463 nmp->nm_bufqlen++; 1464 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) { 1465 mtx_lock(&(VTONFS(bp->b_vp))->n_mtx); 1466 VTONFS(bp->b_vp)->n_flag |= NMODIFIED; 1467 VTONFS(bp->b_vp)->n_directio_asyncwr++; 1468 mtx_unlock(&(VTONFS(bp->b_vp))->n_mtx); 1469 } 1470 mtx_unlock(&nfs_iod_mtx); 1471 return (0); 1472 } 1473 1474 mtx_unlock(&nfs_iod_mtx); 1475 1476 /* 1477 * All the iods are busy on other mounts, so return EIO to 1478 * force the caller to process the i/o synchronously. 1479 */ 1480 NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n")); 1481 return (EIO); 1482 } 1483 1484 void 1485 nfs_doio_directwrite(struct buf *bp) 1486 { 1487 int iomode, must_commit; 1488 struct uio *uiop = (struct uio *)bp->b_caller1; 1489 char *iov_base = uiop->uio_iov->iov_base; 1490 struct nfsmount *nmp = VFSTONFS(bp->b_vp->v_mount); 1491 1492 iomode = NFSV3WRITE_FILESYNC; 1493 uiop->uio_td = NULL; /* NULL since we're in nfsiod */ 1494 (nmp->nm_rpcops->nr_writerpc)(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit); 1495 KASSERT((must_commit == 0), ("nfs_doio_directwrite: Did not commit write")); 1496 free(iov_base, M_NFSDIRECTIO); 1497 free(uiop->uio_iov, M_NFSDIRECTIO); 1498 free(uiop, M_NFSDIRECTIO); 1499 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) { 1500 struct nfsnode *np = VTONFS(bp->b_vp); 1501 mtx_lock(&np->n_mtx); 1502 np->n_directio_asyncwr--; 1503 if (np->n_directio_asyncwr == 0) { 1504 VTONFS(bp->b_vp)->n_flag &= ~NMODIFIED; 1505 if ((np->n_flag & NFSYNCWAIT)) { 1506 np->n_flag &= ~NFSYNCWAIT; 1507 wakeup((caddr_t)&np->n_directio_asyncwr); 1508 } 1509 } 1510 mtx_unlock(&np->n_mtx); 1511 } 1512 bp->b_vp = NULL; 1513 relpbuf(bp, &nfs_pbuf_freecnt); 1514 } 1515 1516 /* 1517 * Do an I/O operation to/from a cache block. This may be called 1518 * synchronously or from an nfsiod. 1519 */ 1520 int 1521 nfs_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td) 1522 { 1523 struct uio *uiop; 1524 struct nfsnode *np; 1525 struct nfsmount *nmp; 1526 int error = 0, iomode, must_commit = 0; 1527 struct uio uio; 1528 struct iovec io; 1529 struct proc *p = td ? td->td_proc : NULL; 1530 uint8_t iocmd; 1531 1532 np = VTONFS(vp); 1533 nmp = VFSTONFS(vp->v_mount); 1534 uiop = &uio; 1535 uiop->uio_iov = &io; 1536 uiop->uio_iovcnt = 1; 1537 uiop->uio_segflg = UIO_SYSSPACE; 1538 uiop->uio_td = td; 1539 1540 /* 1541 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We 1542 * do this here so we do not have to do it in all the code that 1543 * calls us. 1544 */ 1545 bp->b_flags &= ~B_INVAL; 1546 bp->b_ioflags &= ~BIO_ERROR; 1547 1548 KASSERT(!(bp->b_flags & B_DONE), ("nfs_doio: bp %p already marked done", bp)); 1549 iocmd = bp->b_iocmd; 1550 if (iocmd == BIO_READ) { 1551 io.iov_len = uiop->uio_resid = bp->b_bcount; 1552 io.iov_base = bp->b_data; 1553 uiop->uio_rw = UIO_READ; 1554 1555 switch (vp->v_type) { 1556 case VREG: 1557 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE; 1558 nfsstats.read_bios++; 1559 error = (nmp->nm_rpcops->nr_readrpc)(vp, uiop, cr); 1560 1561 if (!error) { 1562 if (uiop->uio_resid) { 1563 /* 1564 * If we had a short read with no error, we must have 1565 * hit a file hole. We should zero-fill the remainder. 1566 * This can also occur if the server hits the file EOF. 1567 * 1568 * Holes used to be able to occur due to pending 1569 * writes, but that is not possible any longer. 1570 */ 1571 int nread = bp->b_bcount - uiop->uio_resid; 1572 int left = uiop->uio_resid; 1573 1574 if (left > 0) 1575 bzero((char *)bp->b_data + nread, left); 1576 uiop->uio_resid = 0; 1577 } 1578 } 1579 /* ASSERT_VOP_LOCKED(vp, "nfs_doio"); */ 1580 if (p && (vp->v_vflag & VV_TEXT)) { 1581 mtx_lock(&np->n_mtx); 1582 if (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.va_mtime)) { 1583 mtx_unlock(&np->n_mtx); 1584 PROC_LOCK(p); 1585 killproc(p, "text file modification"); 1586 PROC_UNLOCK(p); 1587 } else 1588 mtx_unlock(&np->n_mtx); 1589 } 1590 break; 1591 case VLNK: 1592 uiop->uio_offset = (off_t)0; 1593 nfsstats.readlink_bios++; 1594 error = (nmp->nm_rpcops->nr_readlinkrpc)(vp, uiop, cr); 1595 break; 1596 case VDIR: 1597 nfsstats.readdir_bios++; 1598 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ; 1599 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) { 1600 error = nfs_readdirplusrpc(vp, uiop, cr); 1601 if (error == NFSERR_NOTSUPP) 1602 nmp->nm_flag &= ~NFSMNT_RDIRPLUS; 1603 } 1604 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) 1605 error = nfs_readdirrpc(vp, uiop, cr); 1606 /* 1607 * end-of-directory sets B_INVAL but does not generate an 1608 * error. 1609 */ 1610 if (error == 0 && uiop->uio_resid == bp->b_bcount) 1611 bp->b_flags |= B_INVAL; 1612 break; 1613 default: 1614 nfs_printf("nfs_doio: type %x unexpected\n", vp->v_type); 1615 break; 1616 }; 1617 if (error) { 1618 bp->b_ioflags |= BIO_ERROR; 1619 bp->b_error = error; 1620 } 1621 } else { 1622 /* 1623 * If we only need to commit, try to commit 1624 */ 1625 if (bp->b_flags & B_NEEDCOMMIT) { 1626 int retv; 1627 off_t off; 1628 1629 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff; 1630 retv = (nmp->nm_rpcops->nr_commit)( 1631 vp, off, bp->b_dirtyend-bp->b_dirtyoff, 1632 bp->b_wcred, td); 1633 if (retv == 0) { 1634 bp->b_dirtyoff = bp->b_dirtyend = 0; 1635 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1636 bp->b_resid = 0; 1637 bufdone(bp); 1638 return (0); 1639 } 1640 if (retv == NFSERR_STALEWRITEVERF) { 1641 nfs_clearcommit(vp->v_mount); 1642 } 1643 } 1644 1645 /* 1646 * Setup for actual write 1647 */ 1648 mtx_lock(&np->n_mtx); 1649 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size) 1650 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE; 1651 mtx_unlock(&np->n_mtx); 1652 1653 if (bp->b_dirtyend > bp->b_dirtyoff) { 1654 io.iov_len = uiop->uio_resid = bp->b_dirtyend 1655 - bp->b_dirtyoff; 1656 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE 1657 + bp->b_dirtyoff; 1658 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; 1659 uiop->uio_rw = UIO_WRITE; 1660 nfsstats.write_bios++; 1661 1662 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC) 1663 iomode = NFSV3WRITE_UNSTABLE; 1664 else 1665 iomode = NFSV3WRITE_FILESYNC; 1666 1667 error = (nmp->nm_rpcops->nr_writerpc)(vp, uiop, cr, &iomode, &must_commit); 1668 1669 /* 1670 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try 1671 * to cluster the buffers needing commit. This will allow 1672 * the system to submit a single commit rpc for the whole 1673 * cluster. We can do this even if the buffer is not 100% 1674 * dirty (relative to the NFS blocksize), so we optimize the 1675 * append-to-file-case. 1676 * 1677 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be 1678 * cleared because write clustering only works for commit 1679 * rpc's, not for the data portion of the write). 1680 */ 1681 1682 if (!error && iomode == NFSV3WRITE_UNSTABLE) { 1683 bp->b_flags |= B_NEEDCOMMIT; 1684 if (bp->b_dirtyoff == 0 1685 && bp->b_dirtyend == bp->b_bcount) 1686 bp->b_flags |= B_CLUSTEROK; 1687 } else { 1688 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1689 } 1690 1691 /* 1692 * For an interrupted write, the buffer is still valid 1693 * and the write hasn't been pushed to the server yet, 1694 * so we can't set BIO_ERROR and report the interruption 1695 * by setting B_EINTR. For the B_ASYNC case, B_EINTR 1696 * is not relevant, so the rpc attempt is essentially 1697 * a noop. For the case of a V3 write rpc not being 1698 * committed to stable storage, the block is still 1699 * dirty and requires either a commit rpc or another 1700 * write rpc with iomode == NFSV3WRITE_FILESYNC before 1701 * the block is reused. This is indicated by setting 1702 * the B_DELWRI and B_NEEDCOMMIT flags. 1703 * 1704 * If the buffer is marked B_PAGING, it does not reside on 1705 * the vp's paging queues so we cannot call bdirty(). The 1706 * bp in this case is not an NFS cache block so we should 1707 * be safe. XXX 1708 * 1709 * The logic below breaks up errors into recoverable and 1710 * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE 1711 * and keep the buffer around for potential write retries. 1712 * For the latter (eg ESTALE), we toss the buffer away (B_INVAL) 1713 * and save the error in the nfsnode. This is less than ideal 1714 * but necessary. Keeping such buffers around could potentially 1715 * cause buffer exhaustion eventually (they can never be written 1716 * out, so will get constantly be re-dirtied). It also causes 1717 * all sorts of vfs panics. For non-recoverable write errors, 1718 * also invalidate the attrcache, so we'll be forced to go over 1719 * the wire for this object, returning an error to user on next 1720 * call (most of the time). 1721 */ 1722 if (error == EINTR || error == EIO || error == ETIMEDOUT 1723 || (!error && (bp->b_flags & B_NEEDCOMMIT))) { 1724 int s; 1725 1726 s = splbio(); 1727 bp->b_flags &= ~(B_INVAL|B_NOCACHE); 1728 if ((bp->b_flags & B_PAGING) == 0) { 1729 bdirty(bp); 1730 bp->b_flags &= ~B_DONE; 1731 } 1732 if (error && (bp->b_flags & B_ASYNC) == 0) 1733 bp->b_flags |= B_EINTR; 1734 splx(s); 1735 } else { 1736 if (error) { 1737 bp->b_ioflags |= BIO_ERROR; 1738 bp->b_flags |= B_INVAL; 1739 bp->b_error = np->n_error = error; 1740 mtx_lock(&np->n_mtx); 1741 np->n_flag |= NWRITEERR; 1742 np->n_attrstamp = 0; 1743 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 1744 mtx_unlock(&np->n_mtx); 1745 } 1746 bp->b_dirtyoff = bp->b_dirtyend = 0; 1747 } 1748 } else { 1749 bp->b_resid = 0; 1750 bufdone(bp); 1751 return (0); 1752 } 1753 } 1754 bp->b_resid = uiop->uio_resid; 1755 if (must_commit) 1756 nfs_clearcommit(vp->v_mount); 1757 bufdone(bp); 1758 return (error); 1759 } 1760 1761 /* 1762 * Used to aid in handling ftruncate() operations on the NFS client side. 1763 * Truncation creates a number of special problems for NFS. We have to 1764 * throw away VM pages and buffer cache buffers that are beyond EOF, and 1765 * we have to properly handle VM pages or (potentially dirty) buffers 1766 * that straddle the truncation point. 1767 */ 1768 1769 int 1770 nfs_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize) 1771 { 1772 struct nfsnode *np = VTONFS(vp); 1773 u_quad_t tsize; 1774 int biosize = vp->v_mount->mnt_stat.f_iosize; 1775 int error = 0; 1776 1777 mtx_lock(&np->n_mtx); 1778 tsize = np->n_size; 1779 np->n_size = nsize; 1780 mtx_unlock(&np->n_mtx); 1781 1782 if (nsize < tsize) { 1783 struct buf *bp; 1784 daddr_t lbn; 1785 int bufsize; 1786 1787 /* 1788 * vtruncbuf() doesn't get the buffer overlapping the 1789 * truncation point. We may have a B_DELWRI and/or B_CACHE 1790 * buffer that now needs to be truncated. 1791 */ 1792 error = vtruncbuf(vp, cred, td, nsize, biosize); 1793 lbn = nsize / biosize; 1794 bufsize = nsize & (biosize - 1); 1795 bp = nfs_getcacheblk(vp, lbn, bufsize, td); 1796 if (!bp) 1797 return EINTR; 1798 if (bp->b_dirtyoff > bp->b_bcount) 1799 bp->b_dirtyoff = bp->b_bcount; 1800 if (bp->b_dirtyend > bp->b_bcount) 1801 bp->b_dirtyend = bp->b_bcount; 1802 bp->b_flags |= B_RELBUF; /* don't leave garbage around */ 1803 brelse(bp); 1804 } else { 1805 vnode_pager_setsize(vp, nsize); 1806 } 1807 return(error); 1808 } 1809
Cache object: cf1cfd2ea8497443b2c63ecf3c4bd97f
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