nfs_bio.c revision 192010
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: head/sys/nfsclient/nfs_bio.c 192010 2009-05-12 05:49:02Z alc $"); 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/mount.h> 46#include <sys/proc.h> 47#include <sys/resourcevar.h> 48#include <sys/signalvar.h> 49#include <sys/vmmeter.h> 50#include <sys/vnode.h> 51 52#include <vm/vm.h> 53#include <vm/vm_extern.h> 54#include <vm/vm_page.h> 55#include <vm/vm_object.h> 56#include <vm/vm_pager.h> 57#include <vm/vnode_pager.h> 58 59#include <rpc/rpcclnt.h> 60 61#include <nfs/rpcv2.h> 62#include <nfs/nfsproto.h> 63#include <nfsclient/nfs.h> 64#include <nfsclient/nfsmount.h> 65#include <nfsclient/nfsnode.h> 66#include <nfsclient/nfs_kdtrace.h> 67 68#include <nfs4client/nfs4.h> 69 70static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, 71 struct thread *td); 72static int nfs_directio_write(struct vnode *vp, struct uio *uiop, 73 struct ucred *cred, int ioflag); 74 75extern int nfs_directio_enable; 76extern int nfs_directio_allow_mmap; 77 78/* 79 * Vnode op for VM getpages. 80 */ 81int 82nfs_getpages(struct vop_getpages_args *ap) 83{ 84 int i, error, nextoff, size, toff, count, npages; 85 struct uio uio; 86 struct iovec iov; 87 vm_offset_t kva; 88 struct buf *bp; 89 struct vnode *vp; 90 struct thread *td; 91 struct ucred *cred; 92 struct nfsmount *nmp; 93 vm_object_t object; 94 vm_page_t *pages; 95 struct nfsnode *np; 96 97 vp = ap->a_vp; 98 np = VTONFS(vp); 99 td = curthread; /* XXX */ 100 cred = curthread->td_ucred; /* XXX */ 101 nmp = VFSTONFS(vp->v_mount); 102 pages = ap->a_m; 103 count = ap->a_count; 104 105 if ((object = vp->v_object) == NULL) { 106 nfs_printf("nfs_getpages: called with non-merged cache vnode??\n"); 107 return VM_PAGER_ERROR; 108 } 109 110 if (nfs_directio_enable && !nfs_directio_allow_mmap) { 111 mtx_lock(&np->n_mtx); 112 if ((np->n_flag & NNONCACHE) && (vp->v_type == VREG)) { 113 mtx_unlock(&np->n_mtx); 114 nfs_printf("nfs_getpages: called on non-cacheable vnode??\n"); 115 return VM_PAGER_ERROR; 116 } else 117 mtx_unlock(&np->n_mtx); 118 } 119 120 mtx_lock(&nmp->nm_mtx); 121 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 122 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 123 mtx_unlock(&nmp->nm_mtx); 124 /* We'll never get here for v4, because we always have fsinfo */ 125 (void)nfs_fsinfo(nmp, vp, cred, td); 126 } else 127 mtx_unlock(&nmp->nm_mtx); 128 129 npages = btoc(count); 130 131 /* 132 * If the requested page is partially valid, just return it and 133 * allow the pager to zero-out the blanks. Partially valid pages 134 * can only occur at the file EOF. 135 */ 136 137 { 138 vm_page_t m = pages[ap->a_reqpage]; 139 140 VM_OBJECT_LOCK(object); 141 if (m->valid != 0) { 142 vm_page_lock_queues(); 143 for (i = 0; i < npages; ++i) { 144 if (i != ap->a_reqpage) 145 vm_page_free(pages[i]); 146 } 147 vm_page_unlock_queues(); 148 VM_OBJECT_UNLOCK(object); 149 return(0); 150 } 151 VM_OBJECT_UNLOCK(object); 152 } 153 154 /* 155 * We use only the kva address for the buffer, but this is extremely 156 * convienient and fast. 157 */ 158 bp = getpbuf(&nfs_pbuf_freecnt); 159 160 kva = (vm_offset_t) bp->b_data; 161 pmap_qenter(kva, pages, npages); 162 PCPU_INC(cnt.v_vnodein); 163 PCPU_ADD(cnt.v_vnodepgsin, npages); 164 165 iov.iov_base = (caddr_t) kva; 166 iov.iov_len = count; 167 uio.uio_iov = &iov; 168 uio.uio_iovcnt = 1; 169 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex); 170 uio.uio_resid = count; 171 uio.uio_segflg = UIO_SYSSPACE; 172 uio.uio_rw = UIO_READ; 173 uio.uio_td = td; 174 175 error = (nmp->nm_rpcops->nr_readrpc)(vp, &uio, cred); 176 pmap_qremove(kva, npages); 177 178 relpbuf(bp, &nfs_pbuf_freecnt); 179 180 if (error && (uio.uio_resid == count)) { 181 nfs_printf("nfs_getpages: error %d\n", error); 182 VM_OBJECT_LOCK(object); 183 vm_page_lock_queues(); 184 for (i = 0; i < npages; ++i) { 185 if (i != ap->a_reqpage) 186 vm_page_free(pages[i]); 187 } 188 vm_page_unlock_queues(); 189 VM_OBJECT_UNLOCK(object); 190 return VM_PAGER_ERROR; 191 } 192 193 /* 194 * Calculate the number of bytes read and validate only that number 195 * of bytes. Note that due to pending writes, size may be 0. This 196 * does not mean that the remaining data is invalid! 197 */ 198 199 size = count - uio.uio_resid; 200 VM_OBJECT_LOCK(object); 201 vm_page_lock_queues(); 202 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) { 203 vm_page_t m; 204 nextoff = toff + PAGE_SIZE; 205 m = pages[i]; 206 207 if (nextoff <= size) { 208 /* 209 * Read operation filled an entire page 210 */ 211 m->valid = VM_PAGE_BITS_ALL; 212 KASSERT(m->dirty == 0, 213 ("nfs_getpages: page %p is dirty", m)); 214 } else if (size > toff) { 215 /* 216 * Read operation filled a partial page. 217 */ 218 m->valid = 0; 219 vm_page_set_validclean(m, 0, size - toff); 220 } else { 221 /* 222 * Read operation was short. If no error occured 223 * we may have hit a zero-fill section. We simply 224 * leave valid set to 0. 225 */ 226 ; 227 } 228 if (i != ap->a_reqpage) { 229 /* 230 * Whether or not to leave the page activated is up in 231 * the air, but we should put the page on a page queue 232 * somewhere (it already is in the object). Result: 233 * It appears that emperical results show that 234 * deactivating pages is best. 235 */ 236 237 /* 238 * Just in case someone was asking for this page we 239 * now tell them that it is ok to use. 240 */ 241 if (!error) { 242 if (m->oflags & VPO_WANTED) 243 vm_page_activate(m); 244 else 245 vm_page_deactivate(m); 246 vm_page_wakeup(m); 247 } else { 248 vm_page_free(m); 249 } 250 } 251 } 252 vm_page_unlock_queues(); 253 VM_OBJECT_UNLOCK(object); 254 return 0; 255} 256 257/* 258 * Vnode op for VM putpages. 259 */ 260int 261nfs_putpages(struct vop_putpages_args *ap) 262{ 263 struct uio uio; 264 struct iovec iov; 265 vm_offset_t kva; 266 struct buf *bp; 267 int iomode, must_commit, i, error, npages, count; 268 off_t offset; 269 int *rtvals; 270 struct vnode *vp; 271 struct thread *td; 272 struct ucred *cred; 273 struct nfsmount *nmp; 274 struct nfsnode *np; 275 vm_page_t *pages; 276 277 vp = ap->a_vp; 278 np = VTONFS(vp); 279 td = curthread; /* XXX */ 280 cred = curthread->td_ucred; /* XXX */ 281 nmp = VFSTONFS(vp->v_mount); 282 pages = ap->a_m; 283 count = ap->a_count; 284 rtvals = ap->a_rtvals; 285 npages = btoc(count); 286 offset = IDX_TO_OFF(pages[0]->pindex); 287 288 mtx_lock(&nmp->nm_mtx); 289 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 290 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 291 mtx_unlock(&nmp->nm_mtx); 292 (void)nfs_fsinfo(nmp, vp, cred, td); 293 } else 294 mtx_unlock(&nmp->nm_mtx); 295 296 mtx_lock(&np->n_mtx); 297 if (nfs_directio_enable && !nfs_directio_allow_mmap && 298 (np->n_flag & NNONCACHE) && (vp->v_type == VREG)) { 299 mtx_unlock(&np->n_mtx); 300 nfs_printf("nfs_putpages: called on noncache-able vnode??\n"); 301 mtx_lock(&np->n_mtx); 302 } 303 304 for (i = 0; i < npages; i++) 305 rtvals[i] = VM_PAGER_AGAIN; 306 307 /* 308 * When putting pages, do not extend file past EOF. 309 */ 310 if (offset + count > np->n_size) { 311 count = np->n_size - offset; 312 if (count < 0) 313 count = 0; 314 } 315 mtx_unlock(&np->n_mtx); 316 317 /* 318 * We use only the kva address for the buffer, but this is extremely 319 * convienient and fast. 320 */ 321 bp = getpbuf(&nfs_pbuf_freecnt); 322 323 kva = (vm_offset_t) bp->b_data; 324 pmap_qenter(kva, pages, npages); 325 PCPU_INC(cnt.v_vnodeout); 326 PCPU_ADD(cnt.v_vnodepgsout, count); 327 328 iov.iov_base = (caddr_t) kva; 329 iov.iov_len = count; 330 uio.uio_iov = &iov; 331 uio.uio_iovcnt = 1; 332 uio.uio_offset = offset; 333 uio.uio_resid = count; 334 uio.uio_segflg = UIO_SYSSPACE; 335 uio.uio_rw = UIO_WRITE; 336 uio.uio_td = td; 337 338 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0) 339 iomode = NFSV3WRITE_UNSTABLE; 340 else 341 iomode = NFSV3WRITE_FILESYNC; 342 343 error = (nmp->nm_rpcops->nr_writerpc)(vp, &uio, cred, &iomode, &must_commit); 344 345 pmap_qremove(kva, npages); 346 relpbuf(bp, &nfs_pbuf_freecnt); 347 348 if (!error) { 349 int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE; 350 for (i = 0; i < nwritten; i++) { 351 rtvals[i] = VM_PAGER_OK; 352 vm_page_undirty(pages[i]); 353 } 354 if (must_commit) { 355 nfs_clearcommit(vp->v_mount); 356 } 357 } 358 return rtvals[0]; 359} 360 361/* 362 * For nfs, cache consistency can only be maintained approximately. 363 * Although RFC1094 does not specify the criteria, the following is 364 * believed to be compatible with the reference port. 365 * For nfs: 366 * If the file's modify time on the server has changed since the 367 * last read rpc or you have written to the file, 368 * you may have lost data cache consistency with the 369 * server, so flush all of the file's data out of the cache. 370 * Then force a getattr rpc to ensure that you have up to date 371 * attributes. 372 * NB: This implies that cache data can be read when up to 373 * NFS_ATTRTIMEO seconds out of date. If you find that you need current 374 * attributes this could be forced by setting n_attrstamp to 0 before 375 * the VOP_GETATTR() call. 376 */ 377static inline int 378nfs_bioread_check_cons(struct vnode *vp, struct thread *td, struct ucred *cred) 379{ 380 int error = 0; 381 struct vattr vattr; 382 struct nfsnode *np = VTONFS(vp); 383 int old_lock; 384 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 385 386 /* 387 * Grab the exclusive lock before checking whether the cache is 388 * consistent. 389 * XXX - We can make this cheaper later (by acquiring cheaper locks). 390 * But for now, this suffices. 391 */ 392 old_lock = nfs_upgrade_vnlock(vp); 393 mtx_lock(&np->n_mtx); 394 if (np->n_flag & NMODIFIED) { 395 mtx_unlock(&np->n_mtx); 396 if (vp->v_type != VREG) { 397 if (vp->v_type != VDIR) 398 panic("nfs: bioread, not dir"); 399 (nmp->nm_rpcops->nr_invaldir)(vp); 400 error = nfs_vinvalbuf(vp, V_SAVE, td, 1); 401 if (error) 402 goto out; 403 } 404 np->n_attrstamp = 0; 405 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 406 error = VOP_GETATTR(vp, &vattr, cred); 407 if (error) 408 goto out; 409 mtx_lock(&np->n_mtx); 410 np->n_mtime = vattr.va_mtime; 411 mtx_unlock(&np->n_mtx); 412 } else { 413 mtx_unlock(&np->n_mtx); 414 error = VOP_GETATTR(vp, &vattr, cred); 415 if (error) 416 return (error); 417 mtx_lock(&np->n_mtx); 418 if ((np->n_flag & NSIZECHANGED) 419 || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) { 420 mtx_unlock(&np->n_mtx); 421 if (vp->v_type == VDIR) 422 (nmp->nm_rpcops->nr_invaldir)(vp); 423 error = nfs_vinvalbuf(vp, V_SAVE, td, 1); 424 if (error) 425 goto out; 426 mtx_lock(&np->n_mtx); 427 np->n_mtime = vattr.va_mtime; 428 np->n_flag &= ~NSIZECHANGED; 429 } 430 mtx_unlock(&np->n_mtx); 431 } 432out: 433 nfs_downgrade_vnlock(vp, old_lock); 434 return error; 435} 436 437/* 438 * Vnode op for read using bio 439 */ 440int 441nfs_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred) 442{ 443 struct nfsnode *np = VTONFS(vp); 444 int biosize, i; 445 struct buf *bp, *rabp; 446 struct thread *td; 447 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 448 daddr_t lbn, rabn; 449 int bcount; 450 int seqcount; 451 int nra, error = 0, n = 0, on = 0; 452 453#ifdef DIAGNOSTIC 454 if (uio->uio_rw != UIO_READ) 455 panic("nfs_read mode"); 456#endif 457 if (uio->uio_resid == 0) 458 return (0); 459 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */ 460 return (EINVAL); 461 td = uio->uio_td; 462 463 mtx_lock(&nmp->nm_mtx); 464 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 465 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 466 mtx_unlock(&nmp->nm_mtx); 467 (void)nfs_fsinfo(nmp, vp, cred, td); 468 } else 469 mtx_unlock(&nmp->nm_mtx); 470 471 if (vp->v_type != VDIR && 472 (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 473 return (EFBIG); 474 475 if (nfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG)) 476 /* No caching/ no readaheads. Just read data into the user buffer */ 477 return nfs_readrpc(vp, uio, cred); 478 479 biosize = vp->v_mount->mnt_stat.f_iosize; 480 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE); 481 482 error = nfs_bioread_check_cons(vp, td, cred); 483 if (error) 484 return error; 485 486 do { 487 u_quad_t nsize; 488 489 mtx_lock(&np->n_mtx); 490 nsize = np->n_size; 491 mtx_unlock(&np->n_mtx); 492 493 switch (vp->v_type) { 494 case VREG: 495 nfsstats.biocache_reads++; 496 lbn = uio->uio_offset / biosize; 497 on = uio->uio_offset & (biosize - 1); 498 499 /* 500 * Start the read ahead(s), as required. 501 */ 502 if (nmp->nm_readahead > 0) { 503 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && 504 (off_t)(lbn + 1 + nra) * biosize < nsize; nra++) { 505 rabn = lbn + 1 + nra; 506 if (incore(&vp->v_bufobj, rabn) == NULL) { 507 rabp = nfs_getcacheblk(vp, rabn, biosize, td); 508 if (!rabp) { 509 error = nfs_sigintr(nmp, NULL, td); 510 return (error ? error : EINTR); 511 } 512 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 513 rabp->b_flags |= B_ASYNC; 514 rabp->b_iocmd = BIO_READ; 515 vfs_busy_pages(rabp, 0); 516 if (nfs_asyncio(nmp, rabp, cred, td)) { 517 rabp->b_flags |= B_INVAL; 518 rabp->b_ioflags |= BIO_ERROR; 519 vfs_unbusy_pages(rabp); 520 brelse(rabp); 521 break; 522 } 523 } else { 524 brelse(rabp); 525 } 526 } 527 } 528 } 529 530 /* Note that bcount is *not* DEV_BSIZE aligned. */ 531 bcount = biosize; 532 if ((off_t)lbn * biosize >= nsize) { 533 bcount = 0; 534 } else if ((off_t)(lbn + 1) * biosize > nsize) { 535 bcount = nsize - (off_t)lbn * biosize; 536 } 537 bp = nfs_getcacheblk(vp, lbn, bcount, td); 538 539 if (!bp) { 540 error = nfs_sigintr(nmp, NULL, td); 541 return (error ? error : EINTR); 542 } 543 544 /* 545 * If B_CACHE is not set, we must issue the read. If this 546 * fails, we return an error. 547 */ 548 549 if ((bp->b_flags & B_CACHE) == 0) { 550 bp->b_iocmd = BIO_READ; 551 vfs_busy_pages(bp, 0); 552 error = nfs_doio(vp, bp, cred, td); 553 if (error) { 554 brelse(bp); 555 return (error); 556 } 557 } 558 559 /* 560 * on is the offset into the current bp. Figure out how many 561 * bytes we can copy out of the bp. Note that bcount is 562 * NOT DEV_BSIZE aligned. 563 * 564 * Then figure out how many bytes we can copy into the uio. 565 */ 566 567 n = 0; 568 if (on < bcount) 569 n = min((unsigned)(bcount - on), uio->uio_resid); 570 break; 571 case VLNK: 572 nfsstats.biocache_readlinks++; 573 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td); 574 if (!bp) { 575 error = nfs_sigintr(nmp, NULL, td); 576 return (error ? error : EINTR); 577 } 578 if ((bp->b_flags & B_CACHE) == 0) { 579 bp->b_iocmd = BIO_READ; 580 vfs_busy_pages(bp, 0); 581 error = nfs_doio(vp, bp, cred, td); 582 if (error) { 583 bp->b_ioflags |= BIO_ERROR; 584 brelse(bp); 585 return (error); 586 } 587 } 588 n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); 589 on = 0; 590 break; 591 case VDIR: 592 nfsstats.biocache_readdirs++; 593 if (np->n_direofoffset 594 && uio->uio_offset >= np->n_direofoffset) { 595 return (0); 596 } 597 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; 598 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); 599 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td); 600 if (!bp) { 601 error = nfs_sigintr(nmp, NULL, td); 602 return (error ? error : EINTR); 603 } 604 if ((bp->b_flags & B_CACHE) == 0) { 605 bp->b_iocmd = BIO_READ; 606 vfs_busy_pages(bp, 0); 607 error = nfs_doio(vp, bp, cred, td); 608 if (error) { 609 brelse(bp); 610 } 611 while (error == NFSERR_BAD_COOKIE) { 612 (nmp->nm_rpcops->nr_invaldir)(vp); 613 error = nfs_vinvalbuf(vp, 0, td, 1); 614 /* 615 * Yuck! The directory has been modified on the 616 * server. The only way to get the block is by 617 * reading from the beginning to get all the 618 * offset cookies. 619 * 620 * Leave the last bp intact unless there is an error. 621 * Loop back up to the while if the error is another 622 * NFSERR_BAD_COOKIE (double yuch!). 623 */ 624 for (i = 0; i <= lbn && !error; i++) { 625 if (np->n_direofoffset 626 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) 627 return (0); 628 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td); 629 if (!bp) { 630 error = nfs_sigintr(nmp, NULL, td); 631 return (error ? error : EINTR); 632 } 633 if ((bp->b_flags & B_CACHE) == 0) { 634 bp->b_iocmd = BIO_READ; 635 vfs_busy_pages(bp, 0); 636 error = nfs_doio(vp, bp, cred, td); 637 /* 638 * no error + B_INVAL == directory EOF, 639 * use the block. 640 */ 641 if (error == 0 && (bp->b_flags & B_INVAL)) 642 break; 643 } 644 /* 645 * An error will throw away the block and the 646 * for loop will break out. If no error and this 647 * is not the block we want, we throw away the 648 * block and go for the next one via the for loop. 649 */ 650 if (error || i < lbn) 651 brelse(bp); 652 } 653 } 654 /* 655 * The above while is repeated if we hit another cookie 656 * error. If we hit an error and it wasn't a cookie error, 657 * we give up. 658 */ 659 if (error) 660 return (error); 661 } 662 663 /* 664 * If not eof and read aheads are enabled, start one. 665 * (You need the current block first, so that you have the 666 * directory offset cookie of the next block.) 667 */ 668 if (nmp->nm_readahead > 0 && 669 (bp->b_flags & B_INVAL) == 0 && 670 (np->n_direofoffset == 0 || 671 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) && 672 incore(&vp->v_bufobj, lbn + 1) == NULL) { 673 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td); 674 if (rabp) { 675 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { 676 rabp->b_flags |= B_ASYNC; 677 rabp->b_iocmd = BIO_READ; 678 vfs_busy_pages(rabp, 0); 679 if (nfs_asyncio(nmp, rabp, cred, td)) { 680 rabp->b_flags |= B_INVAL; 681 rabp->b_ioflags |= BIO_ERROR; 682 vfs_unbusy_pages(rabp); 683 brelse(rabp); 684 } 685 } else { 686 brelse(rabp); 687 } 688 } 689 } 690 /* 691 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is 692 * chopped for the EOF condition, we cannot tell how large 693 * NFS directories are going to be until we hit EOF. So 694 * an NFS directory buffer is *not* chopped to its EOF. Now, 695 * it just so happens that b_resid will effectively chop it 696 * to EOF. *BUT* this information is lost if the buffer goes 697 * away and is reconstituted into a B_CACHE state ( due to 698 * being VMIO ) later. So we keep track of the directory eof 699 * in np->n_direofoffset and chop it off as an extra step 700 * right here. 701 */ 702 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on); 703 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset) 704 n = np->n_direofoffset - uio->uio_offset; 705 break; 706 default: 707 nfs_printf(" nfs_bioread: type %x unexpected\n", vp->v_type); 708 bp = NULL; 709 break; 710 }; 711 712 if (n > 0) { 713 error = uiomove(bp->b_data + on, (int)n, uio); 714 } 715 if (vp->v_type == VLNK) 716 n = 0; 717 if (bp != NULL) 718 brelse(bp); 719 } while (error == 0 && uio->uio_resid > 0 && n > 0); 720 return (error); 721} 722 723/* 724 * The NFS write path cannot handle iovecs with len > 1. So we need to 725 * break up iovecs accordingly (restricting them to wsize). 726 * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf). 727 * For the ASYNC case, 2 copies are needed. The first a copy from the 728 * user buffer to a staging buffer and then a second copy from the staging 729 * buffer to mbufs. This can be optimized by copying from the user buffer 730 * directly into mbufs and passing the chain down, but that requires a 731 * fair amount of re-working of the relevant codepaths (and can be done 732 * later). 733 */ 734static int 735nfs_directio_write(vp, uiop, cred, ioflag) 736 struct vnode *vp; 737 struct uio *uiop; 738 struct ucred *cred; 739 int ioflag; 740{ 741 int error; 742 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 743 struct thread *td = uiop->uio_td; 744 int size; 745 int wsize; 746 747 mtx_lock(&nmp->nm_mtx); 748 wsize = nmp->nm_wsize; 749 mtx_unlock(&nmp->nm_mtx); 750 if (ioflag & IO_SYNC) { 751 int iomode, must_commit; 752 struct uio uio; 753 struct iovec iov; 754do_sync: 755 while (uiop->uio_resid > 0) { 756 size = min(uiop->uio_resid, wsize); 757 size = min(uiop->uio_iov->iov_len, size); 758 iov.iov_base = uiop->uio_iov->iov_base; 759 iov.iov_len = size; 760 uio.uio_iov = &iov; 761 uio.uio_iovcnt = 1; 762 uio.uio_offset = uiop->uio_offset; 763 uio.uio_resid = size; 764 uio.uio_segflg = UIO_USERSPACE; 765 uio.uio_rw = UIO_WRITE; 766 uio.uio_td = td; 767 iomode = NFSV3WRITE_FILESYNC; 768 error = (nmp->nm_rpcops->nr_writerpc)(vp, &uio, cred, 769 &iomode, &must_commit); 770 KASSERT((must_commit == 0), 771 ("nfs_directio_write: Did not commit write")); 772 if (error) 773 return (error); 774 uiop->uio_offset += size; 775 uiop->uio_resid -= size; 776 if (uiop->uio_iov->iov_len <= size) { 777 uiop->uio_iovcnt--; 778 uiop->uio_iov++; 779 } else { 780 uiop->uio_iov->iov_base = 781 (char *)uiop->uio_iov->iov_base + size; 782 uiop->uio_iov->iov_len -= size; 783 } 784 } 785 } else { 786 struct uio *t_uio; 787 struct iovec *t_iov; 788 struct buf *bp; 789 790 /* 791 * Break up the write into blocksize chunks and hand these 792 * over to nfsiod's for write back. 793 * Unfortunately, this incurs a copy of the data. Since 794 * the user could modify the buffer before the write is 795 * initiated. 796 * 797 * The obvious optimization here is that one of the 2 copies 798 * in the async write path can be eliminated by copying the 799 * data here directly into mbufs and passing the mbuf chain 800 * down. But that will require a fair amount of re-working 801 * of the code and can be done if there's enough interest 802 * in NFS directio access. 803 */ 804 while (uiop->uio_resid > 0) { 805 size = min(uiop->uio_resid, wsize); 806 size = min(uiop->uio_iov->iov_len, size); 807 bp = getpbuf(&nfs_pbuf_freecnt); 808 t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK); 809 t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK); 810 t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK); 811 t_iov->iov_len = size; 812 t_uio->uio_iov = t_iov; 813 t_uio->uio_iovcnt = 1; 814 t_uio->uio_offset = uiop->uio_offset; 815 t_uio->uio_resid = size; 816 t_uio->uio_segflg = UIO_SYSSPACE; 817 t_uio->uio_rw = UIO_WRITE; 818 t_uio->uio_td = td; 819 bcopy(uiop->uio_iov->iov_base, t_iov->iov_base, size); 820 bp->b_flags |= B_DIRECT; 821 bp->b_iocmd = BIO_WRITE; 822 if (cred != NOCRED) { 823 crhold(cred); 824 bp->b_wcred = cred; 825 } else 826 bp->b_wcred = NOCRED; 827 bp->b_caller1 = (void *)t_uio; 828 bp->b_vp = vp; 829 error = nfs_asyncio(nmp, bp, NOCRED, td); 830 if (error) { 831 free(t_iov->iov_base, M_NFSDIRECTIO); 832 free(t_iov, M_NFSDIRECTIO); 833 free(t_uio, M_NFSDIRECTIO); 834 bp->b_vp = NULL; 835 relpbuf(bp, &nfs_pbuf_freecnt); 836 if (error == EINTR) 837 return (error); 838 goto do_sync; 839 } 840 uiop->uio_offset += size; 841 uiop->uio_resid -= size; 842 if (uiop->uio_iov->iov_len <= size) { 843 uiop->uio_iovcnt--; 844 uiop->uio_iov++; 845 } else { 846 uiop->uio_iov->iov_base = 847 (char *)uiop->uio_iov->iov_base + size; 848 uiop->uio_iov->iov_len -= size; 849 } 850 } 851 } 852 return (0); 853} 854 855/* 856 * Vnode op for write using bio 857 */ 858int 859nfs_write(struct vop_write_args *ap) 860{ 861 int biosize; 862 struct uio *uio = ap->a_uio; 863 struct thread *td = uio->uio_td; 864 struct vnode *vp = ap->a_vp; 865 struct nfsnode *np = VTONFS(vp); 866 struct ucred *cred = ap->a_cred; 867 int ioflag = ap->a_ioflag; 868 struct buf *bp; 869 struct vattr vattr; 870 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 871 daddr_t lbn; 872 int bcount; 873 int n, on, error = 0; 874 struct proc *p = td?td->td_proc:NULL; 875 876#ifdef DIAGNOSTIC 877 if (uio->uio_rw != UIO_WRITE) 878 panic("nfs_write mode"); 879 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_td != curthread) 880 panic("nfs_write proc"); 881#endif 882 if (vp->v_type != VREG) 883 return (EIO); 884 mtx_lock(&np->n_mtx); 885 if (np->n_flag & NWRITEERR) { 886 np->n_flag &= ~NWRITEERR; 887 mtx_unlock(&np->n_mtx); 888 return (np->n_error); 889 } else 890 mtx_unlock(&np->n_mtx); 891 mtx_lock(&nmp->nm_mtx); 892 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && 893 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { 894 mtx_unlock(&nmp->nm_mtx); 895 (void)nfs_fsinfo(nmp, vp, cred, td); 896 } else 897 mtx_unlock(&nmp->nm_mtx); 898 899 /* 900 * Synchronously flush pending buffers if we are in synchronous 901 * mode or if we are appending. 902 */ 903 if (ioflag & (IO_APPEND | IO_SYNC)) { 904 mtx_lock(&np->n_mtx); 905 if (np->n_flag & NMODIFIED) { 906 mtx_unlock(&np->n_mtx); 907#ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */ 908 /* 909 * Require non-blocking, synchronous writes to 910 * dirty files to inform the program it needs 911 * to fsync(2) explicitly. 912 */ 913 if (ioflag & IO_NDELAY) 914 return (EAGAIN); 915#endif 916flush_and_restart: 917 np->n_attrstamp = 0; 918 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 919 error = nfs_vinvalbuf(vp, V_SAVE, td, 1); 920 if (error) 921 return (error); 922 } else 923 mtx_unlock(&np->n_mtx); 924 } 925 926 /* 927 * If IO_APPEND then load uio_offset. We restart here if we cannot 928 * get the append lock. 929 */ 930 if (ioflag & IO_APPEND) { 931 np->n_attrstamp = 0; 932 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 933 error = VOP_GETATTR(vp, &vattr, cred); 934 if (error) 935 return (error); 936 mtx_lock(&np->n_mtx); 937 uio->uio_offset = np->n_size; 938 mtx_unlock(&np->n_mtx); 939 } 940 941 if (uio->uio_offset < 0) 942 return (EINVAL); 943 if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) 944 return (EFBIG); 945 if (uio->uio_resid == 0) 946 return (0); 947 948 if (nfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG) 949 return nfs_directio_write(vp, uio, cred, ioflag); 950 951 /* 952 * Maybe this should be above the vnode op call, but so long as 953 * file servers have no limits, i don't think it matters 954 */ 955 if (p != NULL) { 956 PROC_LOCK(p); 957 if (uio->uio_offset + uio->uio_resid > 958 lim_cur(p, RLIMIT_FSIZE)) { 959 psignal(p, SIGXFSZ); 960 PROC_UNLOCK(p); 961 return (EFBIG); 962 } 963 PROC_UNLOCK(p); 964 } 965 966 biosize = vp->v_mount->mnt_stat.f_iosize; 967 /* 968 * Find all of this file's B_NEEDCOMMIT buffers. If our writes 969 * would exceed the local maximum per-file write commit size when 970 * combined with those, we must decide whether to flush, 971 * go synchronous, or return error. We don't bother checking 972 * IO_UNIT -- we just make all writes atomic anyway, as there's 973 * no point optimizing for something that really won't ever happen. 974 */ 975 if (!(ioflag & IO_SYNC)) { 976 int nflag; 977 978 mtx_lock(&np->n_mtx); 979 nflag = np->n_flag; 980 mtx_unlock(&np->n_mtx); 981 int needrestart = 0; 982 if (nmp->nm_wcommitsize < uio->uio_resid) { 983 /* 984 * If this request could not possibly be completed 985 * without exceeding the maximum outstanding write 986 * commit size, see if we can convert it into a 987 * synchronous write operation. 988 */ 989 if (ioflag & IO_NDELAY) 990 return (EAGAIN); 991 ioflag |= IO_SYNC; 992 if (nflag & NMODIFIED) 993 needrestart = 1; 994 } else if (nflag & NMODIFIED) { 995 int wouldcommit = 0; 996 BO_LOCK(&vp->v_bufobj); 997 if (vp->v_bufobj.bo_dirty.bv_cnt != 0) { 998 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd, 999 b_bobufs) { 1000 if (bp->b_flags & B_NEEDCOMMIT) 1001 wouldcommit += bp->b_bcount; 1002 } 1003 } 1004 BO_UNLOCK(&vp->v_bufobj); 1005 /* 1006 * Since we're not operating synchronously and 1007 * bypassing the buffer cache, we are in a commit 1008 * and holding all of these buffers whether 1009 * transmitted or not. If not limited, this 1010 * will lead to the buffer cache deadlocking, 1011 * as no one else can flush our uncommitted buffers. 1012 */ 1013 wouldcommit += uio->uio_resid; 1014 /* 1015 * If we would initially exceed the maximum 1016 * outstanding write commit size, flush and restart. 1017 */ 1018 if (wouldcommit > nmp->nm_wcommitsize) 1019 needrestart = 1; 1020 } 1021 if (needrestart) 1022 goto flush_and_restart; 1023 } 1024 1025 do { 1026 nfsstats.biocache_writes++; 1027 lbn = uio->uio_offset / biosize; 1028 on = uio->uio_offset & (biosize-1); 1029 n = min((unsigned)(biosize - on), uio->uio_resid); 1030again: 1031 /* 1032 * Handle direct append and file extension cases, calculate 1033 * unaligned buffer size. 1034 */ 1035 mtx_lock(&np->n_mtx); 1036 if (uio->uio_offset == np->n_size && n) { 1037 mtx_unlock(&np->n_mtx); 1038 /* 1039 * Get the buffer (in its pre-append state to maintain 1040 * B_CACHE if it was previously set). Resize the 1041 * nfsnode after we have locked the buffer to prevent 1042 * readers from reading garbage. 1043 */ 1044 bcount = on; 1045 bp = nfs_getcacheblk(vp, lbn, bcount, td); 1046 1047 if (bp != NULL) { 1048 long save; 1049 1050 mtx_lock(&np->n_mtx); 1051 np->n_size = uio->uio_offset + n; 1052 np->n_flag |= NMODIFIED; 1053 vnode_pager_setsize(vp, np->n_size); 1054 mtx_unlock(&np->n_mtx); 1055 1056 save = bp->b_flags & B_CACHE; 1057 bcount += n; 1058 allocbuf(bp, bcount); 1059 bp->b_flags |= save; 1060 } 1061 } else { 1062 /* 1063 * Obtain the locked cache block first, and then 1064 * adjust the file's size as appropriate. 1065 */ 1066 bcount = on + n; 1067 if ((off_t)lbn * biosize + bcount < np->n_size) { 1068 if ((off_t)(lbn + 1) * biosize < np->n_size) 1069 bcount = biosize; 1070 else 1071 bcount = np->n_size - (off_t)lbn * biosize; 1072 } 1073 mtx_unlock(&np->n_mtx); 1074 bp = nfs_getcacheblk(vp, lbn, bcount, td); 1075 mtx_lock(&np->n_mtx); 1076 if (uio->uio_offset + n > np->n_size) { 1077 np->n_size = uio->uio_offset + n; 1078 np->n_flag |= NMODIFIED; 1079 vnode_pager_setsize(vp, np->n_size); 1080 } 1081 mtx_unlock(&np->n_mtx); 1082 } 1083 1084 if (!bp) { 1085 error = nfs_sigintr(nmp, NULL, td); 1086 if (!error) 1087 error = EINTR; 1088 break; 1089 } 1090 1091 /* 1092 * Issue a READ if B_CACHE is not set. In special-append 1093 * mode, B_CACHE is based on the buffer prior to the write 1094 * op and is typically set, avoiding the read. If a read 1095 * is required in special append mode, the server will 1096 * probably send us a short-read since we extended the file 1097 * on our end, resulting in b_resid == 0 and, thusly, 1098 * B_CACHE getting set. 1099 * 1100 * We can also avoid issuing the read if the write covers 1101 * the entire buffer. We have to make sure the buffer state 1102 * is reasonable in this case since we will not be initiating 1103 * I/O. See the comments in kern/vfs_bio.c's getblk() for 1104 * more information. 1105 * 1106 * B_CACHE may also be set due to the buffer being cached 1107 * normally. 1108 */ 1109 1110 if (on == 0 && n == bcount) { 1111 bp->b_flags |= B_CACHE; 1112 bp->b_flags &= ~B_INVAL; 1113 bp->b_ioflags &= ~BIO_ERROR; 1114 } 1115 1116 if ((bp->b_flags & B_CACHE) == 0) { 1117 bp->b_iocmd = BIO_READ; 1118 vfs_busy_pages(bp, 0); 1119 error = nfs_doio(vp, bp, cred, td); 1120 if (error) { 1121 brelse(bp); 1122 break; 1123 } 1124 } 1125 if (bp->b_wcred == NOCRED) 1126 bp->b_wcred = crhold(cred); 1127 mtx_lock(&np->n_mtx); 1128 np->n_flag |= NMODIFIED; 1129 mtx_unlock(&np->n_mtx); 1130 1131 /* 1132 * If dirtyend exceeds file size, chop it down. This should 1133 * not normally occur but there is an append race where it 1134 * might occur XXX, so we log it. 1135 * 1136 * If the chopping creates a reverse-indexed or degenerate 1137 * situation with dirtyoff/end, we 0 both of them. 1138 */ 1139 1140 if (bp->b_dirtyend > bcount) { 1141 nfs_printf("NFS append race @%lx:%d\n", 1142 (long)bp->b_blkno * DEV_BSIZE, 1143 bp->b_dirtyend - bcount); 1144 bp->b_dirtyend = bcount; 1145 } 1146 1147 if (bp->b_dirtyoff >= bp->b_dirtyend) 1148 bp->b_dirtyoff = bp->b_dirtyend = 0; 1149 1150 /* 1151 * If the new write will leave a contiguous dirty 1152 * area, just update the b_dirtyoff and b_dirtyend, 1153 * otherwise force a write rpc of the old dirty area. 1154 * 1155 * While it is possible to merge discontiguous writes due to 1156 * our having a B_CACHE buffer ( and thus valid read data 1157 * for the hole), we don't because it could lead to 1158 * significant cache coherency problems with multiple clients, 1159 * especially if locking is implemented later on. 1160 * 1161 * as an optimization we could theoretically maintain 1162 * a linked list of discontinuous areas, but we would still 1163 * have to commit them separately so there isn't much 1164 * advantage to it except perhaps a bit of asynchronization. 1165 */ 1166 1167 if (bp->b_dirtyend > 0 && 1168 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { 1169 if (bwrite(bp) == EINTR) { 1170 error = EINTR; 1171 break; 1172 } 1173 goto again; 1174 } 1175 1176 error = uiomove((char *)bp->b_data + on, n, uio); 1177 1178 /* 1179 * Since this block is being modified, it must be written 1180 * again and not just committed. Since write clustering does 1181 * not work for the stage 1 data write, only the stage 2 1182 * commit rpc, we have to clear B_CLUSTEROK as well. 1183 */ 1184 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1185 1186 if (error) { 1187 bp->b_ioflags |= BIO_ERROR; 1188 brelse(bp); 1189 break; 1190 } 1191 1192 /* 1193 * Only update dirtyoff/dirtyend if not a degenerate 1194 * condition. 1195 */ 1196 if (n) { 1197 if (bp->b_dirtyend > 0) { 1198 bp->b_dirtyoff = min(on, bp->b_dirtyoff); 1199 bp->b_dirtyend = max((on + n), bp->b_dirtyend); 1200 } else { 1201 bp->b_dirtyoff = on; 1202 bp->b_dirtyend = on + n; 1203 } 1204 vfs_bio_set_validclean(bp, on, n); 1205 } 1206 1207 /* 1208 * If IO_SYNC do bwrite(). 1209 * 1210 * IO_INVAL appears to be unused. The idea appears to be 1211 * to turn off caching in this case. Very odd. XXX 1212 */ 1213 if ((ioflag & IO_SYNC)) { 1214 if (ioflag & IO_INVAL) 1215 bp->b_flags |= B_NOCACHE; 1216 error = bwrite(bp); 1217 if (error) 1218 break; 1219 } else if ((n + on) == biosize) { 1220 bp->b_flags |= B_ASYNC; 1221 (void) (nmp->nm_rpcops->nr_writebp)(bp, 0, NULL); 1222 } else { 1223 bdwrite(bp); 1224 } 1225 } while (uio->uio_resid > 0 && n > 0); 1226 1227 return (error); 1228} 1229 1230/* 1231 * Get an nfs cache block. 1232 * 1233 * Allocate a new one if the block isn't currently in the cache 1234 * and return the block marked busy. If the calling process is 1235 * interrupted by a signal for an interruptible mount point, return 1236 * NULL. 1237 * 1238 * The caller must carefully deal with the possible B_INVAL state of 1239 * the buffer. nfs_doio() clears B_INVAL (and nfs_asyncio() clears it 1240 * indirectly), so synchronous reads can be issued without worrying about 1241 * the B_INVAL state. We have to be a little more careful when dealing 1242 * with writes (see comments in nfs_write()) when extending a file past 1243 * its EOF. 1244 */ 1245static struct buf * 1246nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td) 1247{ 1248 struct buf *bp; 1249 struct mount *mp; 1250 struct nfsmount *nmp; 1251 1252 mp = vp->v_mount; 1253 nmp = VFSTONFS(mp); 1254 1255 if (nmp->nm_flag & NFSMNT_INT) { 1256 sigset_t oldset; 1257 1258 nfs_set_sigmask(td, &oldset); 1259 bp = getblk(vp, bn, size, PCATCH, 0, 0); 1260 nfs_restore_sigmask(td, &oldset); 1261 while (bp == NULL) { 1262 if (nfs_sigintr(nmp, NULL, td)) 1263 return (NULL); 1264 bp = getblk(vp, bn, size, 0, 2 * hz, 0); 1265 } 1266 } else { 1267 bp = getblk(vp, bn, size, 0, 0, 0); 1268 } 1269 1270 if (vp->v_type == VREG) { 1271 int biosize; 1272 1273 biosize = mp->mnt_stat.f_iosize; 1274 bp->b_blkno = bn * (biosize / DEV_BSIZE); 1275 } 1276 return (bp); 1277} 1278 1279/* 1280 * Flush and invalidate all dirty buffers. If another process is already 1281 * doing the flush, just wait for completion. 1282 */ 1283int 1284nfs_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg) 1285{ 1286 struct nfsnode *np = VTONFS(vp); 1287 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 1288 int error = 0, slpflag, slptimeo; 1289 int old_lock = 0; 1290 1291 ASSERT_VOP_LOCKED(vp, "nfs_vinvalbuf"); 1292 1293 /* 1294 * XXX This check stops us from needlessly doing a vinvalbuf when 1295 * being called through vclean(). It is not clear that this is 1296 * unsafe. 1297 */ 1298 if (vp->v_iflag & VI_DOOMED) 1299 return (0); 1300 1301 if ((nmp->nm_flag & NFSMNT_INT) == 0) 1302 intrflg = 0; 1303 if (intrflg) { 1304 slpflag = PCATCH; 1305 slptimeo = 2 * hz; 1306 } else { 1307 slpflag = 0; 1308 slptimeo = 0; 1309 } 1310 1311 old_lock = nfs_upgrade_vnlock(vp); 1312 /* 1313 * Now, flush as required. 1314 */ 1315 if ((flags & V_SAVE) && (vp->v_bufobj.bo_object != NULL)) { 1316 VM_OBJECT_LOCK(vp->v_bufobj.bo_object); 1317 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC); 1318 VM_OBJECT_UNLOCK(vp->v_bufobj.bo_object); 1319 /* 1320 * If the page clean was interrupted, fail the invalidation. 1321 * Not doing so, we run the risk of losing dirty pages in the 1322 * vinvalbuf() call below. 1323 */ 1324 if (intrflg && (error = nfs_sigintr(nmp, NULL, td))) 1325 goto out; 1326 } 1327 1328 error = vinvalbuf(vp, flags, slpflag, 0); 1329 while (error) { 1330 if (intrflg && (error = nfs_sigintr(nmp, NULL, td))) 1331 goto out; 1332 error = vinvalbuf(vp, flags, 0, slptimeo); 1333 } 1334 mtx_lock(&np->n_mtx); 1335 if (np->n_directio_asyncwr == 0) 1336 np->n_flag &= ~NMODIFIED; 1337 mtx_unlock(&np->n_mtx); 1338out: 1339 nfs_downgrade_vnlock(vp, old_lock); 1340 return error; 1341} 1342 1343/* 1344 * Initiate asynchronous I/O. Return an error if no nfsiods are available. 1345 * This is mainly to avoid queueing async I/O requests when the nfsiods 1346 * are all hung on a dead server. 1347 * 1348 * Note: nfs_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp 1349 * is eventually dequeued by the async daemon, nfs_doio() *will*. 1350 */ 1351int 1352nfs_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td) 1353{ 1354 int iod; 1355 int gotiod; 1356 int slpflag = 0; 1357 int slptimeo = 0; 1358 int error, error2; 1359 1360 /* 1361 * Commits are usually short and sweet so lets save some cpu and 1362 * leave the async daemons for more important rpc's (such as reads 1363 * and writes). 1364 */ 1365 mtx_lock(&nfs_iod_mtx); 1366 if (bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) && 1367 (nmp->nm_bufqiods > nfs_numasync / 2)) { 1368 mtx_unlock(&nfs_iod_mtx); 1369 return(EIO); 1370 } 1371again: 1372 if (nmp->nm_flag & NFSMNT_INT) 1373 slpflag = PCATCH; 1374 gotiod = FALSE; 1375 1376 /* 1377 * Find a free iod to process this request. 1378 */ 1379 for (iod = 0; iod < nfs_numasync; iod++) 1380 if (nfs_iodwant[iod]) { 1381 gotiod = TRUE; 1382 break; 1383 } 1384 1385 /* 1386 * Try to create one if none are free. 1387 */ 1388 if (!gotiod) { 1389 iod = nfs_nfsiodnew(); 1390 if (iod != -1) 1391 gotiod = TRUE; 1392 } 1393 1394 if (gotiod) { 1395 /* 1396 * Found one, so wake it up and tell it which 1397 * mount to process. 1398 */ 1399 NFS_DPF(ASYNCIO, ("nfs_asyncio: waking iod %d for mount %p\n", 1400 iod, nmp)); 1401 nfs_iodwant[iod] = NULL; 1402 nfs_iodmount[iod] = nmp; 1403 nmp->nm_bufqiods++; 1404 wakeup(&nfs_iodwant[iod]); 1405 } 1406 1407 /* 1408 * If none are free, we may already have an iod working on this mount 1409 * point. If so, it will process our request. 1410 */ 1411 if (!gotiod) { 1412 if (nmp->nm_bufqiods > 0) { 1413 NFS_DPF(ASYNCIO, 1414 ("nfs_asyncio: %d iods are already processing mount %p\n", 1415 nmp->nm_bufqiods, nmp)); 1416 gotiod = TRUE; 1417 } 1418 } 1419 1420 /* 1421 * If we have an iod which can process the request, then queue 1422 * the buffer. 1423 */ 1424 if (gotiod) { 1425 /* 1426 * Ensure that the queue never grows too large. We still want 1427 * to asynchronize so we block rather then return EIO. 1428 */ 1429 while (nmp->nm_bufqlen >= 2*nfs_numasync) { 1430 NFS_DPF(ASYNCIO, 1431 ("nfs_asyncio: waiting for mount %p queue to drain\n", nmp)); 1432 nmp->nm_bufqwant = TRUE; 1433 error = nfs_msleep(td, &nmp->nm_bufq, &nfs_iod_mtx, 1434 slpflag | PRIBIO, 1435 "nfsaio", slptimeo); 1436 if (error) { 1437 error2 = nfs_sigintr(nmp, NULL, td); 1438 if (error2) { 1439 mtx_unlock(&nfs_iod_mtx); 1440 return (error2); 1441 } 1442 if (slpflag == PCATCH) { 1443 slpflag = 0; 1444 slptimeo = 2 * hz; 1445 } 1446 } 1447 /* 1448 * We might have lost our iod while sleeping, 1449 * so check and loop if nescessary. 1450 */ 1451 if (nmp->nm_bufqiods == 0) { 1452 NFS_DPF(ASYNCIO, 1453 ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); 1454 goto again; 1455 } 1456 } 1457 1458 /* We might have lost our nfsiod */ 1459 if (nmp->nm_bufqiods == 0) { 1460 NFS_DPF(ASYNCIO, 1461 ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); 1462 goto again; 1463 } 1464 1465 if (bp->b_iocmd == BIO_READ) { 1466 if (bp->b_rcred == NOCRED && cred != NOCRED) 1467 bp->b_rcred = crhold(cred); 1468 } else { 1469 if (bp->b_wcred == NOCRED && cred != NOCRED) 1470 bp->b_wcred = crhold(cred); 1471 } 1472 1473 if (bp->b_flags & B_REMFREE) 1474 bremfreef(bp); 1475 BUF_KERNPROC(bp); 1476 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist); 1477 nmp->nm_bufqlen++; 1478 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) { 1479 mtx_lock(&(VTONFS(bp->b_vp))->n_mtx); 1480 VTONFS(bp->b_vp)->n_flag |= NMODIFIED; 1481 VTONFS(bp->b_vp)->n_directio_asyncwr++; 1482 mtx_unlock(&(VTONFS(bp->b_vp))->n_mtx); 1483 } 1484 mtx_unlock(&nfs_iod_mtx); 1485 return (0); 1486 } 1487 1488 mtx_unlock(&nfs_iod_mtx); 1489 1490 /* 1491 * All the iods are busy on other mounts, so return EIO to 1492 * force the caller to process the i/o synchronously. 1493 */ 1494 NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n")); 1495 return (EIO); 1496} 1497 1498void 1499nfs_doio_directwrite(struct buf *bp) 1500{ 1501 int iomode, must_commit; 1502 struct uio *uiop = (struct uio *)bp->b_caller1; 1503 char *iov_base = uiop->uio_iov->iov_base; 1504 struct nfsmount *nmp = VFSTONFS(bp->b_vp->v_mount); 1505 1506 iomode = NFSV3WRITE_FILESYNC; 1507 uiop->uio_td = NULL; /* NULL since we're in nfsiod */ 1508 (nmp->nm_rpcops->nr_writerpc)(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit); 1509 KASSERT((must_commit == 0), ("nfs_doio_directwrite: Did not commit write")); 1510 free(iov_base, M_NFSDIRECTIO); 1511 free(uiop->uio_iov, M_NFSDIRECTIO); 1512 free(uiop, M_NFSDIRECTIO); 1513 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) { 1514 struct nfsnode *np = VTONFS(bp->b_vp); 1515 mtx_lock(&np->n_mtx); 1516 np->n_directio_asyncwr--; 1517 if (np->n_directio_asyncwr == 0) { 1518 VTONFS(bp->b_vp)->n_flag &= ~NMODIFIED; 1519 if ((np->n_flag & NFSYNCWAIT)) { 1520 np->n_flag &= ~NFSYNCWAIT; 1521 wakeup((caddr_t)&np->n_directio_asyncwr); 1522 } 1523 } 1524 mtx_unlock(&np->n_mtx); 1525 } 1526 bp->b_vp = NULL; 1527 relpbuf(bp, &nfs_pbuf_freecnt); 1528} 1529 1530/* 1531 * Do an I/O operation to/from a cache block. This may be called 1532 * synchronously or from an nfsiod. 1533 */ 1534int 1535nfs_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td) 1536{ 1537 struct uio *uiop; 1538 struct nfsnode *np; 1539 struct nfsmount *nmp; 1540 int error = 0, iomode, must_commit = 0; 1541 struct uio uio; 1542 struct iovec io; 1543 struct proc *p = td ? td->td_proc : NULL; 1544 uint8_t iocmd; 1545 1546 np = VTONFS(vp); 1547 nmp = VFSTONFS(vp->v_mount); 1548 uiop = &uio; 1549 uiop->uio_iov = &io; 1550 uiop->uio_iovcnt = 1; 1551 uiop->uio_segflg = UIO_SYSSPACE; 1552 uiop->uio_td = td; 1553 1554 /* 1555 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We 1556 * do this here so we do not have to do it in all the code that 1557 * calls us. 1558 */ 1559 bp->b_flags &= ~B_INVAL; 1560 bp->b_ioflags &= ~BIO_ERROR; 1561 1562 KASSERT(!(bp->b_flags & B_DONE), ("nfs_doio: bp %p already marked done", bp)); 1563 iocmd = bp->b_iocmd; 1564 if (iocmd == BIO_READ) { 1565 io.iov_len = uiop->uio_resid = bp->b_bcount; 1566 io.iov_base = bp->b_data; 1567 uiop->uio_rw = UIO_READ; 1568 1569 switch (vp->v_type) { 1570 case VREG: 1571 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE; 1572 nfsstats.read_bios++; 1573 error = (nmp->nm_rpcops->nr_readrpc)(vp, uiop, cr); 1574 1575 if (!error) { 1576 if (uiop->uio_resid) { 1577 /* 1578 * If we had a short read with no error, we must have 1579 * hit a file hole. We should zero-fill the remainder. 1580 * This can also occur if the server hits the file EOF. 1581 * 1582 * Holes used to be able to occur due to pending 1583 * writes, but that is not possible any longer. 1584 */ 1585 int nread = bp->b_bcount - uiop->uio_resid; 1586 int left = uiop->uio_resid; 1587 1588 if (left > 0) 1589 bzero((char *)bp->b_data + nread, left); 1590 uiop->uio_resid = 0; 1591 } 1592 } 1593 /* ASSERT_VOP_LOCKED(vp, "nfs_doio"); */ 1594 if (p && (vp->v_vflag & VV_TEXT)) { 1595 mtx_lock(&np->n_mtx); 1596 if (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.va_mtime)) { 1597 mtx_unlock(&np->n_mtx); 1598 PROC_LOCK(p); 1599 killproc(p, "text file modification"); 1600 PROC_UNLOCK(p); 1601 } else 1602 mtx_unlock(&np->n_mtx); 1603 } 1604 break; 1605 case VLNK: 1606 uiop->uio_offset = (off_t)0; 1607 nfsstats.readlink_bios++; 1608 error = (nmp->nm_rpcops->nr_readlinkrpc)(vp, uiop, cr); 1609 break; 1610 case VDIR: 1611 nfsstats.readdir_bios++; 1612 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ; 1613 if ((nmp->nm_flag & NFSMNT_NFSV4) != 0) 1614 error = nfs4_readdirrpc(vp, uiop, cr); 1615 else { 1616 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) { 1617 error = nfs_readdirplusrpc(vp, uiop, cr); 1618 if (error == NFSERR_NOTSUPP) 1619 nmp->nm_flag &= ~NFSMNT_RDIRPLUS; 1620 } 1621 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) 1622 error = nfs_readdirrpc(vp, uiop, cr); 1623 } 1624 /* 1625 * end-of-directory sets B_INVAL but does not generate an 1626 * error. 1627 */ 1628 if (error == 0 && uiop->uio_resid == bp->b_bcount) 1629 bp->b_flags |= B_INVAL; 1630 break; 1631 default: 1632 nfs_printf("nfs_doio: type %x unexpected\n", vp->v_type); 1633 break; 1634 }; 1635 if (error) { 1636 bp->b_ioflags |= BIO_ERROR; 1637 bp->b_error = error; 1638 } 1639 } else { 1640 /* 1641 * If we only need to commit, try to commit 1642 */ 1643 if (bp->b_flags & B_NEEDCOMMIT) { 1644 int retv; 1645 off_t off; 1646 1647 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff; 1648 retv = (nmp->nm_rpcops->nr_commit)( 1649 vp, off, bp->b_dirtyend-bp->b_dirtyoff, 1650 bp->b_wcred, td); 1651 if (retv == 0) { 1652 bp->b_dirtyoff = bp->b_dirtyend = 0; 1653 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1654 bp->b_resid = 0; 1655 bufdone(bp); 1656 return (0); 1657 } 1658 if (retv == NFSERR_STALEWRITEVERF) { 1659 nfs_clearcommit(vp->v_mount); 1660 } 1661 } 1662 1663 /* 1664 * Setup for actual write 1665 */ 1666 mtx_lock(&np->n_mtx); 1667 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size) 1668 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE; 1669 mtx_unlock(&np->n_mtx); 1670 1671 if (bp->b_dirtyend > bp->b_dirtyoff) { 1672 io.iov_len = uiop->uio_resid = bp->b_dirtyend 1673 - bp->b_dirtyoff; 1674 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE 1675 + bp->b_dirtyoff; 1676 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; 1677 uiop->uio_rw = UIO_WRITE; 1678 nfsstats.write_bios++; 1679 1680 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC) 1681 iomode = NFSV3WRITE_UNSTABLE; 1682 else 1683 iomode = NFSV3WRITE_FILESYNC; 1684 1685 error = (nmp->nm_rpcops->nr_writerpc)(vp, uiop, cr, &iomode, &must_commit); 1686 1687 /* 1688 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try 1689 * to cluster the buffers needing commit. This will allow 1690 * the system to submit a single commit rpc for the whole 1691 * cluster. We can do this even if the buffer is not 100% 1692 * dirty (relative to the NFS blocksize), so we optimize the 1693 * append-to-file-case. 1694 * 1695 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be 1696 * cleared because write clustering only works for commit 1697 * rpc's, not for the data portion of the write). 1698 */ 1699 1700 if (!error && iomode == NFSV3WRITE_UNSTABLE) { 1701 bp->b_flags |= B_NEEDCOMMIT; 1702 if (bp->b_dirtyoff == 0 1703 && bp->b_dirtyend == bp->b_bcount) 1704 bp->b_flags |= B_CLUSTEROK; 1705 } else { 1706 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); 1707 } 1708 1709 /* 1710 * For an interrupted write, the buffer is still valid 1711 * and the write hasn't been pushed to the server yet, 1712 * so we can't set BIO_ERROR and report the interruption 1713 * by setting B_EINTR. For the B_ASYNC case, B_EINTR 1714 * is not relevant, so the rpc attempt is essentially 1715 * a noop. For the case of a V3 write rpc not being 1716 * committed to stable storage, the block is still 1717 * dirty and requires either a commit rpc or another 1718 * write rpc with iomode == NFSV3WRITE_FILESYNC before 1719 * the block is reused. This is indicated by setting 1720 * the B_DELWRI and B_NEEDCOMMIT flags. 1721 * 1722 * If the buffer is marked B_PAGING, it does not reside on 1723 * the vp's paging queues so we cannot call bdirty(). The 1724 * bp in this case is not an NFS cache block so we should 1725 * be safe. XXX 1726 * 1727 * The logic below breaks up errors into recoverable and 1728 * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE 1729 * and keep the buffer around for potential write retries. 1730 * For the latter (eg ESTALE), we toss the buffer away (B_INVAL) 1731 * and save the error in the nfsnode. This is less than ideal 1732 * but necessary. Keeping such buffers around could potentially 1733 * cause buffer exhaustion eventually (they can never be written 1734 * out, so will get constantly be re-dirtied). It also causes 1735 * all sorts of vfs panics. For non-recoverable write errors, 1736 * also invalidate the attrcache, so we'll be forced to go over 1737 * the wire for this object, returning an error to user on next 1738 * call (most of the time). 1739 */ 1740 if (error == EINTR || error == EIO || error == ETIMEDOUT 1741 || (!error && (bp->b_flags & B_NEEDCOMMIT))) { 1742 int s; 1743 1744 s = splbio(); 1745 bp->b_flags &= ~(B_INVAL|B_NOCACHE); 1746 if ((bp->b_flags & B_PAGING) == 0) { 1747 bdirty(bp); 1748 bp->b_flags &= ~B_DONE; 1749 } 1750 if (error && (bp->b_flags & B_ASYNC) == 0) 1751 bp->b_flags |= B_EINTR; 1752 splx(s); 1753 } else { 1754 if (error) { 1755 bp->b_ioflags |= BIO_ERROR; 1756 bp->b_flags |= B_INVAL; 1757 bp->b_error = np->n_error = error; 1758 mtx_lock(&np->n_mtx); 1759 np->n_flag |= NWRITEERR; 1760 np->n_attrstamp = 0; 1761 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp); 1762 mtx_unlock(&np->n_mtx); 1763 } 1764 bp->b_dirtyoff = bp->b_dirtyend = 0; 1765 } 1766 } else { 1767 bp->b_resid = 0; 1768 bufdone(bp); 1769 return (0); 1770 } 1771 } 1772 bp->b_resid = uiop->uio_resid; 1773 if (must_commit) 1774 nfs_clearcommit(vp->v_mount); 1775 bufdone(bp); 1776 return (error); 1777} 1778 1779/* 1780 * Used to aid in handling ftruncate() operations on the NFS client side. 1781 * Truncation creates a number of special problems for NFS. We have to 1782 * throw away VM pages and buffer cache buffers that are beyond EOF, and 1783 * we have to properly handle VM pages or (potentially dirty) buffers 1784 * that straddle the truncation point. 1785 */ 1786 1787int 1788nfs_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize) 1789{ 1790 struct nfsnode *np = VTONFS(vp); 1791 u_quad_t tsize; 1792 int biosize = vp->v_mount->mnt_stat.f_iosize; 1793 int error = 0; 1794 1795 mtx_lock(&np->n_mtx); 1796 tsize = np->n_size; 1797 np->n_size = nsize; 1798 mtx_unlock(&np->n_mtx); 1799 1800 if (nsize < tsize) { 1801 struct buf *bp; 1802 daddr_t lbn; 1803 int bufsize; 1804 1805 /* 1806 * vtruncbuf() doesn't get the buffer overlapping the 1807 * truncation point. We may have a B_DELWRI and/or B_CACHE 1808 * buffer that now needs to be truncated. 1809 */ 1810 error = vtruncbuf(vp, cred, td, nsize, biosize); 1811 lbn = nsize / biosize; 1812 bufsize = nsize & (biosize - 1); 1813 bp = nfs_getcacheblk(vp, lbn, bufsize, td); 1814 if (!bp) 1815 return EINTR; 1816 if (bp->b_dirtyoff > bp->b_bcount) 1817 bp->b_dirtyoff = bp->b_bcount; 1818 if (bp->b_dirtyend > bp->b_bcount) 1819 bp->b_dirtyend = bp->b_bcount; 1820 bp->b_flags |= B_RELBUF; /* don't leave garbage around */ 1821 brelse(bp); 1822 } else { 1823 vnode_pager_setsize(vp, nsize); 1824 } 1825 return(error); 1826} 1827 1828