vfs_default.c revision 176320
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 6 * to Berkeley by John Heidemann of the UCLA Ficus project. 7 * 8 * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35#include <sys/cdefs.h> 36__FBSDID("$FreeBSD: head/sys/kern/vfs_default.c 176320 2008-02-15 21:04:36Z attilio $"); 37 38#include <sys/param.h> 39#include <sys/systm.h> 40#include <sys/bio.h> 41#include <sys/buf.h> 42#include <sys/conf.h> 43#include <sys/event.h> 44#include <sys/kernel.h> 45#include <sys/limits.h> 46#include <sys/lock.h> 47#include <sys/malloc.h> 48#include <sys/mount.h> 49#include <sys/mutex.h> 50#include <sys/unistd.h> 51#include <sys/vnode.h> 52#include <sys/poll.h> 53 54#include <vm/vm.h> 55#include <vm/vm_object.h> 56#include <vm/vm_extern.h> 57#include <vm/pmap.h> 58#include <vm/vm_map.h> 59#include <vm/vm_page.h> 60#include <vm/vm_pager.h> 61#include <vm/vnode_pager.h> 62 63static int vop_nolookup(struct vop_lookup_args *); 64static int vop_nostrategy(struct vop_strategy_args *); 65 66/* 67 * This vnode table stores what we want to do if the filesystem doesn't 68 * implement a particular VOP. 69 * 70 * If there is no specific entry here, we will return EOPNOTSUPP. 71 * 72 */ 73 74struct vop_vector default_vnodeops = { 75 .vop_default = NULL, 76 .vop_bypass = VOP_EOPNOTSUPP, 77 78 .vop_advlock = VOP_EINVAL, 79 .vop_bmap = vop_stdbmap, 80 .vop_close = VOP_NULL, 81 .vop_fsync = VOP_NULL, 82 .vop_getpages = vop_stdgetpages, 83 .vop_getwritemount = vop_stdgetwritemount, 84 .vop_inactive = VOP_NULL, 85 .vop_ioctl = VOP_ENOTTY, 86 .vop_kqfilter = vop_stdkqfilter, 87 .vop_islocked = vop_stdislocked, 88 .vop_lease = VOP_NULL, 89 .vop_lock1 = vop_stdlock, 90 .vop_lookup = vop_nolookup, 91 .vop_open = VOP_NULL, 92 .vop_pathconf = VOP_EINVAL, 93 .vop_poll = vop_nopoll, 94 .vop_putpages = vop_stdputpages, 95 .vop_readlink = VOP_EINVAL, 96 .vop_revoke = VOP_PANIC, 97 .vop_strategy = vop_nostrategy, 98 .vop_unlock = vop_stdunlock, 99 .vop_vptofh = vop_stdvptofh, 100}; 101 102/* 103 * Series of placeholder functions for various error returns for 104 * VOPs. 105 */ 106 107int 108vop_eopnotsupp(struct vop_generic_args *ap) 109{ 110 /* 111 printf("vop_notsupp[%s]\n", ap->a_desc->vdesc_name); 112 */ 113 114 return (EOPNOTSUPP); 115} 116 117int 118vop_ebadf(struct vop_generic_args *ap) 119{ 120 121 return (EBADF); 122} 123 124int 125vop_enotty(struct vop_generic_args *ap) 126{ 127 128 return (ENOTTY); 129} 130 131int 132vop_einval(struct vop_generic_args *ap) 133{ 134 135 return (EINVAL); 136} 137 138int 139vop_null(struct vop_generic_args *ap) 140{ 141 142 return (0); 143} 144 145/* 146 * Helper function to panic on some bad VOPs in some filesystems. 147 */ 148int 149vop_panic(struct vop_generic_args *ap) 150{ 151 152 panic("filesystem goof: vop_panic[%s]", ap->a_desc->vdesc_name); 153} 154 155/* 156 * vop_std<something> and vop_no<something> are default functions for use by 157 * filesystems that need the "default reasonable" implementation for a 158 * particular operation. 159 * 160 * The documentation for the operations they implement exists (if it exists) 161 * in the VOP_<SOMETHING>(9) manpage (all uppercase). 162 */ 163 164/* 165 * Default vop for filesystems that do not support name lookup 166 */ 167static int 168vop_nolookup(ap) 169 struct vop_lookup_args /* { 170 struct vnode *a_dvp; 171 struct vnode **a_vpp; 172 struct componentname *a_cnp; 173 } */ *ap; 174{ 175 176 *ap->a_vpp = NULL; 177 return (ENOTDIR); 178} 179 180/* 181 * vop_nostrategy: 182 * 183 * Strategy routine for VFS devices that have none. 184 * 185 * BIO_ERROR and B_INVAL must be cleared prior to calling any strategy 186 * routine. Typically this is done for a BIO_READ strategy call. 187 * Typically B_INVAL is assumed to already be clear prior to a write 188 * and should not be cleared manually unless you just made the buffer 189 * invalid. BIO_ERROR should be cleared either way. 190 */ 191 192static int 193vop_nostrategy (struct vop_strategy_args *ap) 194{ 195 printf("No strategy for buffer at %p\n", ap->a_bp); 196 vprint("vnode", ap->a_vp); 197 ap->a_bp->b_ioflags |= BIO_ERROR; 198 ap->a_bp->b_error = EOPNOTSUPP; 199 bufdone(ap->a_bp); 200 return (EOPNOTSUPP); 201} 202 203/* 204 * vop_stdpathconf: 205 * 206 * Standard implementation of POSIX pathconf, to get information about limits 207 * for a filesystem. 208 * Override per filesystem for the case where the filesystem has smaller 209 * limits. 210 */ 211int 212vop_stdpathconf(ap) 213 struct vop_pathconf_args /* { 214 struct vnode *a_vp; 215 int a_name; 216 int *a_retval; 217 } */ *ap; 218{ 219 220 switch (ap->a_name) { 221 case _PC_NAME_MAX: 222 *ap->a_retval = NAME_MAX; 223 return (0); 224 case _PC_PATH_MAX: 225 *ap->a_retval = PATH_MAX; 226 return (0); 227 case _PC_LINK_MAX: 228 *ap->a_retval = LINK_MAX; 229 return (0); 230 case _PC_MAX_CANON: 231 *ap->a_retval = MAX_CANON; 232 return (0); 233 case _PC_MAX_INPUT: 234 *ap->a_retval = MAX_INPUT; 235 return (0); 236 case _PC_PIPE_BUF: 237 *ap->a_retval = PIPE_BUF; 238 return (0); 239 case _PC_CHOWN_RESTRICTED: 240 *ap->a_retval = 1; 241 return (0); 242 case _PC_VDISABLE: 243 *ap->a_retval = _POSIX_VDISABLE; 244 return (0); 245 default: 246 return (EINVAL); 247 } 248 /* NOTREACHED */ 249} 250 251/* 252 * Standard lock, unlock and islocked functions. 253 */ 254int 255vop_stdlock(ap) 256 struct vop_lock1_args /* { 257 struct vnode *a_vp; 258 int a_flags; 259 struct thread *a_td; 260 char *file; 261 int line; 262 } */ *ap; 263{ 264 struct vnode *vp = ap->a_vp; 265 266 return (_lockmgr_args(vp->v_vnlock, ap->a_flags, VI_MTX(vp), 267 LK_WMESG_DEFAULT, LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, ap->a_file, 268 ap->a_line)); 269} 270 271/* See above. */ 272int 273vop_stdunlock(ap) 274 struct vop_unlock_args /* { 275 struct vnode *a_vp; 276 int a_flags; 277 struct thread *a_td; 278 } */ *ap; 279{ 280 struct vnode *vp = ap->a_vp; 281 282 return (lockmgr(vp->v_vnlock, ap->a_flags | LK_RELEASE, VI_MTX(vp))); 283} 284 285/* See above. */ 286int 287vop_stdislocked(ap) 288 struct vop_islocked_args /* { 289 struct vnode *a_vp; 290 struct thread *a_td; 291 } */ *ap; 292{ 293 294 return (lockstatus(ap->a_vp->v_vnlock, ap->a_td)); 295} 296 297/* 298 * Return true for select/poll. 299 */ 300int 301vop_nopoll(ap) 302 struct vop_poll_args /* { 303 struct vnode *a_vp; 304 int a_events; 305 struct ucred *a_cred; 306 struct thread *a_td; 307 } */ *ap; 308{ 309 /* 310 * Return true for read/write. If the user asked for something 311 * special, return POLLNVAL, so that clients have a way of 312 * determining reliably whether or not the extended 313 * functionality is present without hard-coding knowledge 314 * of specific filesystem implementations. 315 * Stay in sync with kern_conf.c::no_poll(). 316 */ 317 if (ap->a_events & ~POLLSTANDARD) 318 return (POLLNVAL); 319 320 return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 321} 322 323/* 324 * Implement poll for local filesystems that support it. 325 */ 326int 327vop_stdpoll(ap) 328 struct vop_poll_args /* { 329 struct vnode *a_vp; 330 int a_events; 331 struct ucred *a_cred; 332 struct thread *a_td; 333 } */ *ap; 334{ 335 if (ap->a_events & ~POLLSTANDARD) 336 return (vn_pollrecord(ap->a_vp, ap->a_td, ap->a_events)); 337 return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 338} 339 340/* 341 * Return our mount point, as we will take charge of the writes. 342 */ 343int 344vop_stdgetwritemount(ap) 345 struct vop_getwritemount_args /* { 346 struct vnode *a_vp; 347 struct mount **a_mpp; 348 } */ *ap; 349{ 350 struct mount *mp; 351 352 /* 353 * XXX Since this is called unlocked we may be recycled while 354 * attempting to ref the mount. If this is the case or mountpoint 355 * will be set to NULL. We only have to prevent this call from 356 * returning with a ref to an incorrect mountpoint. It is not 357 * harmful to return with a ref to our previous mountpoint. 358 */ 359 mp = ap->a_vp->v_mount; 360 if (mp != NULL) { 361 vfs_ref(mp); 362 if (mp != ap->a_vp->v_mount) { 363 vfs_rel(mp); 364 mp = NULL; 365 } 366 } 367 *(ap->a_mpp) = mp; 368 return (0); 369} 370 371/* XXX Needs good comment and VOP_BMAP(9) manpage */ 372int 373vop_stdbmap(ap) 374 struct vop_bmap_args /* { 375 struct vnode *a_vp; 376 daddr_t a_bn; 377 struct bufobj **a_bop; 378 daddr_t *a_bnp; 379 int *a_runp; 380 int *a_runb; 381 } */ *ap; 382{ 383 384 if (ap->a_bop != NULL) 385 *ap->a_bop = &ap->a_vp->v_bufobj; 386 if (ap->a_bnp != NULL) 387 *ap->a_bnp = ap->a_bn * btodb(ap->a_vp->v_mount->mnt_stat.f_iosize); 388 if (ap->a_runp != NULL) 389 *ap->a_runp = 0; 390 if (ap->a_runb != NULL) 391 *ap->a_runb = 0; 392 return (0); 393} 394 395int 396vop_stdfsync(ap) 397 struct vop_fsync_args /* { 398 struct vnode *a_vp; 399 struct ucred *a_cred; 400 int a_waitfor; 401 struct thread *a_td; 402 } */ *ap; 403{ 404 struct vnode *vp = ap->a_vp; 405 struct buf *bp; 406 struct bufobj *bo; 407 struct buf *nbp; 408 int error = 0; 409 int maxretry = 1000; /* large, arbitrarily chosen */ 410 411 VI_LOCK(vp); 412loop1: 413 /* 414 * MARK/SCAN initialization to avoid infinite loops. 415 */ 416 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd, b_bobufs) { 417 bp->b_vflags &= ~BV_SCANNED; 418 bp->b_error = 0; 419 } 420 421 /* 422 * Flush all dirty buffers associated with a vnode. 423 */ 424loop2: 425 TAILQ_FOREACH_SAFE(bp, &vp->v_bufobj.bo_dirty.bv_hd, b_bobufs, nbp) { 426 if ((bp->b_vflags & BV_SCANNED) != 0) 427 continue; 428 bp->b_vflags |= BV_SCANNED; 429 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) 430 continue; 431 VI_UNLOCK(vp); 432 KASSERT(bp->b_bufobj == &vp->v_bufobj, 433 ("bp %p wrong b_bufobj %p should be %p", 434 bp, bp->b_bufobj, &vp->v_bufobj)); 435 if ((bp->b_flags & B_DELWRI) == 0) 436 panic("fsync: not dirty"); 437 if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) { 438 vfs_bio_awrite(bp); 439 } else { 440 bremfree(bp); 441 bawrite(bp); 442 } 443 VI_LOCK(vp); 444 goto loop2; 445 } 446 447 /* 448 * If synchronous the caller expects us to completely resolve all 449 * dirty buffers in the system. Wait for in-progress I/O to 450 * complete (which could include background bitmap writes), then 451 * retry if dirty blocks still exist. 452 */ 453 if (ap->a_waitfor == MNT_WAIT) { 454 bo = &vp->v_bufobj; 455 bufobj_wwait(bo, 0, 0); 456 if (bo->bo_dirty.bv_cnt > 0) { 457 /* 458 * If we are unable to write any of these buffers 459 * then we fail now rather than trying endlessly 460 * to write them out. 461 */ 462 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) 463 if ((error = bp->b_error) == 0) 464 continue; 465 if (error == 0 && --maxretry >= 0) 466 goto loop1; 467 error = EAGAIN; 468 } 469 } 470 VI_UNLOCK(vp); 471 if (error == EAGAIN) 472 vprint("fsync: giving up on dirty", vp); 473 474 return (error); 475} 476 477/* XXX Needs good comment and more info in the manpage (VOP_GETPAGES(9)). */ 478int 479vop_stdgetpages(ap) 480 struct vop_getpages_args /* { 481 struct vnode *a_vp; 482 vm_page_t *a_m; 483 int a_count; 484 int a_reqpage; 485 vm_ooffset_t a_offset; 486 } */ *ap; 487{ 488 489 return vnode_pager_generic_getpages(ap->a_vp, ap->a_m, 490 ap->a_count, ap->a_reqpage); 491} 492 493int 494vop_stdkqfilter(struct vop_kqfilter_args *ap) 495{ 496 return vfs_kqfilter(ap); 497} 498 499/* XXX Needs good comment and more info in the manpage (VOP_PUTPAGES(9)). */ 500int 501vop_stdputpages(ap) 502 struct vop_putpages_args /* { 503 struct vnode *a_vp; 504 vm_page_t *a_m; 505 int a_count; 506 int a_sync; 507 int *a_rtvals; 508 vm_ooffset_t a_offset; 509 } */ *ap; 510{ 511 512 return vnode_pager_generic_putpages(ap->a_vp, ap->a_m, ap->a_count, 513 ap->a_sync, ap->a_rtvals); 514} 515 516int 517vop_stdvptofh(struct vop_vptofh_args *ap) 518{ 519 return (EOPNOTSUPP); 520} 521 522/* 523 * vfs default ops 524 * used to fill the vfs function table to get reasonable default return values. 525 */ 526int 527vfs_stdroot (mp, flags, vpp, td) 528 struct mount *mp; 529 int flags; 530 struct vnode **vpp; 531 struct thread *td; 532{ 533 534 return (EOPNOTSUPP); 535} 536 537int 538vfs_stdstatfs (mp, sbp, td) 539 struct mount *mp; 540 struct statfs *sbp; 541 struct thread *td; 542{ 543 544 return (EOPNOTSUPP); 545} 546 547int 548vfs_stdquotactl (mp, cmds, uid, arg, td) 549 struct mount *mp; 550 int cmds; 551 uid_t uid; 552 void *arg; 553 struct thread *td; 554{ 555 556 return (EOPNOTSUPP); 557} 558 559int 560vfs_stdsync(mp, waitfor, td) 561 struct mount *mp; 562 int waitfor; 563 struct thread *td; 564{ 565 struct vnode *vp, *mvp; 566 int error, lockreq, allerror = 0; 567 568 lockreq = LK_EXCLUSIVE | LK_INTERLOCK; 569 if (waitfor != MNT_WAIT) 570 lockreq |= LK_NOWAIT; 571 /* 572 * Force stale buffer cache information to be flushed. 573 */ 574 MNT_ILOCK(mp); 575loop: 576 MNT_VNODE_FOREACH(vp, mp, mvp) { 577 578 VI_LOCK(vp); 579 if (vp->v_bufobj.bo_dirty.bv_cnt == 0) { 580 VI_UNLOCK(vp); 581 continue; 582 } 583 MNT_IUNLOCK(mp); 584 585 if ((error = vget(vp, lockreq, td)) != 0) { 586 MNT_ILOCK(mp); 587 if (error == ENOENT) { 588 MNT_VNODE_FOREACH_ABORT_ILOCKED(mp, mvp); 589 goto loop; 590 } 591 continue; 592 } 593 error = VOP_FSYNC(vp, waitfor, td); 594 if (error) 595 allerror = error; 596 597 /* Do not turn this into vput. td is not always curthread. */ 598 VOP_UNLOCK(vp, 0); 599 vrele(vp); 600 MNT_ILOCK(mp); 601 } 602 MNT_IUNLOCK(mp); 603 return (allerror); 604} 605 606int 607vfs_stdnosync (mp, waitfor, td) 608 struct mount *mp; 609 int waitfor; 610 struct thread *td; 611{ 612 613 return (0); 614} 615 616int 617vfs_stdvget (mp, ino, flags, vpp) 618 struct mount *mp; 619 ino_t ino; 620 int flags; 621 struct vnode **vpp; 622{ 623 624 return (EOPNOTSUPP); 625} 626 627int 628vfs_stdfhtovp (mp, fhp, vpp) 629 struct mount *mp; 630 struct fid *fhp; 631 struct vnode **vpp; 632{ 633 634 return (EOPNOTSUPP); 635} 636 637int 638vfs_stdinit (vfsp) 639 struct vfsconf *vfsp; 640{ 641 642 return (0); 643} 644 645int 646vfs_stduninit (vfsp) 647 struct vfsconf *vfsp; 648{ 649 650 return(0); 651} 652 653int 654vfs_stdextattrctl(mp, cmd, filename_vp, attrnamespace, attrname, td) 655 struct mount *mp; 656 int cmd; 657 struct vnode *filename_vp; 658 int attrnamespace; 659 const char *attrname; 660 struct thread *td; 661{ 662 663 if (filename_vp != NULL) 664 VOP_UNLOCK(filename_vp, 0); 665 return (EOPNOTSUPP); 666} 667 668int 669vfs_stdsysctl(mp, op, req) 670 struct mount *mp; 671 fsctlop_t op; 672 struct sysctl_req *req; 673{ 674 675 return (EOPNOTSUPP); 676} 677 678/* end of vfs default ops */ 679