vfs_default.c revision 112067
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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * 39 * $FreeBSD: head/sys/kern/vfs_default.c 112067 2003-03-10 21:55:00Z kan $ 40 */ 41 42#include <sys/param.h> 43#include <sys/systm.h> 44#include <sys/bio.h> 45#include <sys/buf.h> 46#include <sys/conf.h> 47#include <sys/kernel.h> 48#include <sys/lock.h> 49#include <sys/malloc.h> 50#include <sys/mount.h> 51#include <sys/mutex.h> 52#include <sys/unistd.h> 53#include <sys/vnode.h> 54#include <sys/poll.h> 55 56#include <machine/limits.h> 57 58#include <vm/vm.h> 59#include <vm/vm_object.h> 60#include <vm/vm_extern.h> 61#include <vm/pmap.h> 62#include <vm/vm_map.h> 63#include <vm/vm_page.h> 64#include <vm/vm_pager.h> 65#include <vm/vnode_pager.h> 66 67static int vop_nolookup(struct vop_lookup_args *); 68static int vop_nostrategy(struct vop_strategy_args *); 69static int vop_nospecstrategy(struct vop_specstrategy_args *); 70 71/* 72 * This vnode table stores what we want to do if the filesystem doesn't 73 * implement a particular VOP. 74 * 75 * If there is no specific entry here, we will return EOPNOTSUPP. 76 * 77 */ 78 79vop_t **default_vnodeop_p; 80static struct vnodeopv_entry_desc default_vnodeop_entries[] = { 81 { &vop_default_desc, (vop_t *) vop_eopnotsupp }, 82 { &vop_advlock_desc, (vop_t *) vop_einval }, 83 { &vop_bmap_desc, (vop_t *) vop_stdbmap }, 84 { &vop_close_desc, (vop_t *) vop_null }, 85 { &vop_createvobject_desc, (vop_t *) vop_stdcreatevobject }, 86 { &vop_destroyvobject_desc, (vop_t *) vop_stddestroyvobject }, 87 { &vop_fsync_desc, (vop_t *) vop_null }, 88 { &vop_getpages_desc, (vop_t *) vop_stdgetpages }, 89 { &vop_getvobject_desc, (vop_t *) vop_stdgetvobject }, 90 { &vop_inactive_desc, (vop_t *) vop_stdinactive }, 91 { &vop_ioctl_desc, (vop_t *) vop_enotty }, 92 { &vop_islocked_desc, (vop_t *) vop_stdislocked }, 93 { &vop_lease_desc, (vop_t *) vop_null }, 94 { &vop_lock_desc, (vop_t *) vop_stdlock }, 95 { &vop_lookup_desc, (vop_t *) vop_nolookup }, 96 { &vop_open_desc, (vop_t *) vop_null }, 97 { &vop_pathconf_desc, (vop_t *) vop_einval }, 98 { &vop_poll_desc, (vop_t *) vop_nopoll }, 99 { &vop_putpages_desc, (vop_t *) vop_stdputpages }, 100 { &vop_readlink_desc, (vop_t *) vop_einval }, 101 { &vop_revoke_desc, (vop_t *) vop_revoke }, 102 { &vop_specstrategy_desc, (vop_t *) vop_nospecstrategy }, 103 { &vop_strategy_desc, (vop_t *) vop_nostrategy }, 104 { &vop_unlock_desc, (vop_t *) vop_stdunlock }, 105 { NULL, NULL } 106}; 107 108static struct vnodeopv_desc default_vnodeop_opv_desc = 109 { &default_vnodeop_p, default_vnodeop_entries }; 110 111VNODEOP_SET(default_vnodeop_opv_desc); 112 113/* 114 * Series of placeholder functions for various error returns for 115 * VOPs. 116 */ 117 118int 119vop_eopnotsupp(struct vop_generic_args *ap) 120{ 121 /* 122 printf("vop_notsupp[%s]\n", ap->a_desc->vdesc_name); 123 */ 124 125 return (EOPNOTSUPP); 126} 127 128int 129vop_ebadf(struct vop_generic_args *ap) 130{ 131 132 return (EBADF); 133} 134 135int 136vop_enotty(struct vop_generic_args *ap) 137{ 138 139 return (ENOTTY); 140} 141 142int 143vop_einval(struct vop_generic_args *ap) 144{ 145 146 return (EINVAL); 147} 148 149int 150vop_null(struct vop_generic_args *ap) 151{ 152 153 return (0); 154} 155 156/* 157 * Used to make a defined VOP fall back to the default VOP. 158 */ 159int 160vop_defaultop(struct vop_generic_args *ap) 161{ 162 163 return (VOCALL(default_vnodeop_p, ap->a_desc->vdesc_offset, ap)); 164} 165 166/* 167 * Helper function to panic on some bad VOPs in some filesystems. 168 */ 169int 170vop_panic(struct vop_generic_args *ap) 171{ 172 173 panic("filesystem goof: vop_panic[%s]", ap->a_desc->vdesc_name); 174} 175 176/* 177 * vop_std<something> and vop_no<something> are default functions for use by 178 * filesystems that need the "default reasonable" implementation for a 179 * particular operation. 180 * 181 * The documentation for the operations they implement exists (if it exists) 182 * in the VOP_<SOMETHING>(9) manpage (all uppercase). 183 */ 184 185/* 186 * Default vop for filesystems that do not support name lookup 187 */ 188static int 189vop_nolookup(ap) 190 struct vop_lookup_args /* { 191 struct vnode *a_dvp; 192 struct vnode **a_vpp; 193 struct componentname *a_cnp; 194 } */ *ap; 195{ 196 197 *ap->a_vpp = NULL; 198 return (ENOTDIR); 199} 200 201/* 202 * vop_nostrategy: 203 * 204 * Strategy routine for VFS devices that have none. 205 * 206 * BIO_ERROR and B_INVAL must be cleared prior to calling any strategy 207 * routine. Typically this is done for a BIO_READ strategy call. 208 * Typically B_INVAL is assumed to already be clear prior to a write 209 * and should not be cleared manually unless you just made the buffer 210 * invalid. BIO_ERROR should be cleared either way. 211 */ 212 213static int 214vop_nostrategy (struct vop_strategy_args *ap) 215{ 216 printf("No strategy for buffer at %p\n", ap->a_bp); 217 vprint("vnode", ap->a_vp); 218 vprint("device vnode", ap->a_bp->b_vp); 219 ap->a_bp->b_ioflags |= BIO_ERROR; 220 ap->a_bp->b_error = EOPNOTSUPP; 221 bufdone(ap->a_bp); 222 return (EOPNOTSUPP); 223} 224 225/* 226 * vop_nospecstrategy: 227 * 228 * This shouldn't happen. VOP_SPECSTRATEGY should always have a VCHR 229 * argument vnode, and thos have a method for specstrategy over in 230 * specfs, so we only ever get here if somebody botched it. 231 * Pass the call to VOP_STRATEGY() and get on with life. 232 * The first time we print some info useful for debugging. 233 */ 234 235static int 236vop_nospecstrategy (struct vop_specstrategy_args *ap) 237{ 238 static int once; 239 240 if (!once) { 241 vprint("VOP_SPECSTRATEGY on non-VCHR", ap->a_vp); 242 backtrace(); 243 once++; 244 } 245 return VOP_STRATEGY(ap->a_vp, ap->a_bp); 246} 247 248/* 249 * vop_stdpathconf: 250 * 251 * Standard implementation of POSIX pathconf, to get information about limits 252 * for a filesystem. 253 * Override per filesystem for the case where the filesystem has smaller 254 * limits. 255 */ 256int 257vop_stdpathconf(ap) 258 struct vop_pathconf_args /* { 259 struct vnode *a_vp; 260 int a_name; 261 int *a_retval; 262 } */ *ap; 263{ 264 265 switch (ap->a_name) { 266 case _PC_LINK_MAX: 267 *ap->a_retval = LINK_MAX; 268 return (0); 269 case _PC_MAX_CANON: 270 *ap->a_retval = MAX_CANON; 271 return (0); 272 case _PC_MAX_INPUT: 273 *ap->a_retval = MAX_INPUT; 274 return (0); 275 case _PC_PIPE_BUF: 276 *ap->a_retval = PIPE_BUF; 277 return (0); 278 case _PC_CHOWN_RESTRICTED: 279 *ap->a_retval = 1; 280 return (0); 281 case _PC_VDISABLE: 282 *ap->a_retval = _POSIX_VDISABLE; 283 return (0); 284 default: 285 return (EINVAL); 286 } 287 /* NOTREACHED */ 288} 289 290/* 291 * Standard lock, unlock and islocked functions. 292 */ 293int 294vop_stdlock(ap) 295 struct vop_lock_args /* { 296 struct vnode *a_vp; 297 int a_flags; 298 struct thread *a_td; 299 } */ *ap; 300{ 301 struct vnode *vp = ap->a_vp; 302 303#ifndef DEBUG_LOCKS 304 return (lockmgr(vp->v_vnlock, ap->a_flags, VI_MTX(vp), ap->a_td)); 305#else 306 return (debuglockmgr(vp->v_vnlock, ap->a_flags, VI_MTX(vp), 307 ap->a_td, "vop_stdlock", vp->filename, vp->line)); 308#endif 309} 310 311/* See above. */ 312int 313vop_stdunlock(ap) 314 struct vop_unlock_args /* { 315 struct vnode *a_vp; 316 int a_flags; 317 struct thread *a_td; 318 } */ *ap; 319{ 320 struct vnode *vp = ap->a_vp; 321 322 return (lockmgr(vp->v_vnlock, ap->a_flags | LK_RELEASE, VI_MTX(vp), 323 ap->a_td)); 324} 325 326/* See above. */ 327int 328vop_stdislocked(ap) 329 struct vop_islocked_args /* { 330 struct vnode *a_vp; 331 struct thread *a_td; 332 } */ *ap; 333{ 334 335 return (lockstatus(ap->a_vp->v_vnlock, ap->a_td)); 336} 337 338/* Mark the vnode inactive */ 339int 340vop_stdinactive(ap) 341 struct vop_inactive_args /* { 342 struct vnode *a_vp; 343 struct thread *a_td; 344 } */ *ap; 345{ 346 347 VOP_UNLOCK(ap->a_vp, 0, ap->a_td); 348 return (0); 349} 350 351/* 352 * Return true for select/poll. 353 */ 354int 355vop_nopoll(ap) 356 struct vop_poll_args /* { 357 struct vnode *a_vp; 358 int a_events; 359 struct ucred *a_cred; 360 struct thread *a_td; 361 } */ *ap; 362{ 363 /* 364 * Return true for read/write. If the user asked for something 365 * special, return POLLNVAL, so that clients have a way of 366 * determining reliably whether or not the extended 367 * functionality is present without hard-coding knowledge 368 * of specific filesystem implementations. 369 */ 370 if (ap->a_events & ~POLLSTANDARD) 371 return (POLLNVAL); 372 373 return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 374} 375 376/* 377 * Implement poll for local filesystems that support it. 378 */ 379int 380vop_stdpoll(ap) 381 struct vop_poll_args /* { 382 struct vnode *a_vp; 383 int a_events; 384 struct ucred *a_cred; 385 struct thread *a_td; 386 } */ *ap; 387{ 388 if (ap->a_events & ~POLLSTANDARD) 389 return (vn_pollrecord(ap->a_vp, ap->a_td, ap->a_events)); 390 return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 391} 392 393/* 394 * Stubs to use when there is no locking to be done on the underlying object. 395 * A minimal shared lock is necessary to ensure that the underlying object 396 * is not revoked while an operation is in progress. So, an active shared 397 * count is maintained in an auxillary vnode lock structure. 398 */ 399int 400vop_sharedlock(ap) 401 struct vop_lock_args /* { 402 struct vnode *a_vp; 403 int a_flags; 404 struct thread *a_td; 405 } */ *ap; 406{ 407 /* 408 * This code cannot be used until all the non-locking filesystems 409 * (notably NFS) are converted to properly lock and release nodes. 410 * Also, certain vnode operations change the locking state within 411 * the operation (create, mknod, remove, link, rename, mkdir, rmdir, 412 * and symlink). Ideally these operations should not change the 413 * lock state, but should be changed to let the caller of the 414 * function unlock them. Otherwise all intermediate vnode layers 415 * (such as union, umapfs, etc) must catch these functions to do 416 * the necessary locking at their layer. Note that the inactive 417 * and lookup operations also change their lock state, but this 418 * cannot be avoided, so these two operations will always need 419 * to be handled in intermediate layers. 420 */ 421 struct vnode *vp = ap->a_vp; 422 int vnflags, flags = ap->a_flags; 423 424 switch (flags & LK_TYPE_MASK) { 425 case LK_DRAIN: 426 vnflags = LK_DRAIN; 427 break; 428 case LK_EXCLUSIVE: 429#ifdef DEBUG_VFS_LOCKS 430 /* 431 * Normally, we use shared locks here, but that confuses 432 * the locking assertions. 433 */ 434 vnflags = LK_EXCLUSIVE; 435 break; 436#endif 437 case LK_SHARED: 438 vnflags = LK_SHARED; 439 break; 440 case LK_UPGRADE: 441 case LK_EXCLUPGRADE: 442 case LK_DOWNGRADE: 443 return (0); 444 case LK_RELEASE: 445 default: 446 panic("vop_sharedlock: bad operation %d", flags & LK_TYPE_MASK); 447 } 448 vnflags |= flags & (LK_INTERLOCK | LK_EXTFLG_MASK); 449#ifndef DEBUG_LOCKS 450 return (lockmgr(vp->v_vnlock, vnflags, VI_MTX(vp), ap->a_td)); 451#else 452 return (debuglockmgr(vp->v_vnlock, vnflags, VI_MTX(vp), ap->a_td, 453 "vop_sharedlock", vp->filename, vp->line)); 454#endif 455} 456 457/* 458 * Stubs to use when there is no locking to be done on the underlying object. 459 * A minimal shared lock is necessary to ensure that the underlying object 460 * is not revoked while an operation is in progress. So, an active shared 461 * count is maintained in an auxillary vnode lock structure. 462 */ 463int 464vop_nolock(ap) 465 struct vop_lock_args /* { 466 struct vnode *a_vp; 467 int a_flags; 468 struct thread *a_td; 469 } */ *ap; 470{ 471#ifdef notyet 472 /* 473 * This code cannot be used until all the non-locking filesystems 474 * (notably NFS) are converted to properly lock and release nodes. 475 * Also, certain vnode operations change the locking state within 476 * the operation (create, mknod, remove, link, rename, mkdir, rmdir, 477 * and symlink). Ideally these operations should not change the 478 * lock state, but should be changed to let the caller of the 479 * function unlock them. Otherwise all intermediate vnode layers 480 * (such as union, umapfs, etc) must catch these functions to do 481 * the necessary locking at their layer. Note that the inactive 482 * and lookup operations also change their lock state, but this 483 * cannot be avoided, so these two operations will always need 484 * to be handled in intermediate layers. 485 */ 486 struct vnode *vp = ap->a_vp; 487 int vnflags, flags = ap->a_flags; 488 489 switch (flags & LK_TYPE_MASK) { 490 case LK_DRAIN: 491 vnflags = LK_DRAIN; 492 break; 493 case LK_EXCLUSIVE: 494 case LK_SHARED: 495 vnflags = LK_SHARED; 496 break; 497 case LK_UPGRADE: 498 case LK_EXCLUPGRADE: 499 case LK_DOWNGRADE: 500 return (0); 501 case LK_RELEASE: 502 default: 503 panic("vop_nolock: bad operation %d", flags & LK_TYPE_MASK); 504 } 505 vnflags |= flags & (LK_INTERLOCK | LK_EXTFLG_MASK); 506 return(lockmgr(vp->v_vnlock, vnflags, VI_MTX(vp), ap->a_td)); 507#else /* for now */ 508 /* 509 * Since we are not using the lock manager, we must clear 510 * the interlock here. 511 */ 512 if (ap->a_flags & LK_INTERLOCK) 513 VI_UNLOCK(ap->a_vp); 514 return (0); 515#endif 516} 517 518/* 519 * Do the inverse of vop_nolock, handling the interlock in a compatible way. 520 */ 521int 522vop_nounlock(ap) 523 struct vop_unlock_args /* { 524 struct vnode *a_vp; 525 int a_flags; 526 struct thread *a_td; 527 } */ *ap; 528{ 529 530 /* 531 * Since we are not using the lock manager, we must clear 532 * the interlock here. 533 */ 534 if (ap->a_flags & LK_INTERLOCK) 535 VI_UNLOCK(ap->a_vp); 536 return (0); 537} 538 539/* 540 * Return whether or not the node is in use. 541 */ 542int 543vop_noislocked(ap) 544 struct vop_islocked_args /* { 545 struct vnode *a_vp; 546 struct thread *a_td; 547 } */ *ap; 548{ 549 550 return (0); 551} 552 553/* 554 * Return our mount point, as we will take charge of the writes. 555 */ 556int 557vop_stdgetwritemount(ap) 558 struct vop_getwritemount_args /* { 559 struct vnode *a_vp; 560 struct mount **a_mpp; 561 } */ *ap; 562{ 563 564 *(ap->a_mpp) = ap->a_vp->v_mount; 565 return (0); 566} 567 568/* Create the VM system backing object for this vnode */ 569int 570vop_stdcreatevobject(ap) 571 struct vop_createvobject_args /* { 572 struct vnode *vp; 573 struct ucred *cred; 574 struct thread *td; 575 } */ *ap; 576{ 577 struct vnode *vp = ap->a_vp; 578 struct ucred *cred = ap->a_cred; 579 struct thread *td = ap->a_td; 580 struct vattr vat; 581 vm_object_t object; 582 int error = 0; 583 584 GIANT_REQUIRED; 585 586 if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE) 587 return (0); 588 589retry: 590 if ((object = vp->v_object) == NULL) { 591 if (vp->v_type == VREG || vp->v_type == VDIR) { 592 if ((error = VOP_GETATTR(vp, &vat, cred, td)) != 0) 593 goto retn; 594 object = vnode_pager_alloc(vp, vat.va_size, 0, 0); 595 } else if (devsw(vp->v_rdev) != NULL) { 596 /* 597 * This simply allocates the biggest object possible 598 * for a disk vnode. This should be fixed, but doesn't 599 * cause any problems (yet). 600 */ 601 object = vnode_pager_alloc(vp, IDX_TO_OFF(INT_MAX), 0, 0); 602 } else { 603 goto retn; 604 } 605 /* 606 * Dereference the reference we just created. This assumes 607 * that the object is associated with the vp. 608 */ 609 object->ref_count--; 610 vrele(vp); 611 } else { 612 if (object->flags & OBJ_DEAD) { 613 VOP_UNLOCK(vp, 0, td); 614 tsleep(object, PVM, "vodead", 0); 615 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 616 goto retry; 617 } 618 } 619 620 KASSERT(vp->v_object != NULL, ("vfs_object_create: NULL object")); 621 vp->v_vflag |= VV_OBJBUF; 622 623retn: 624 return (error); 625} 626 627/* Destroy the VM system object associated with this vnode */ 628int 629vop_stddestroyvobject(ap) 630 struct vop_destroyvobject_args /* { 631 struct vnode *vp; 632 } */ *ap; 633{ 634 struct vnode *vp = ap->a_vp; 635 vm_object_t obj = vp->v_object; 636 637 GIANT_REQUIRED; 638 639 if (vp->v_object == NULL) 640 return (0); 641 642 if (obj->ref_count == 0) { 643 /* 644 * vclean() may be called twice. The first time 645 * removes the primary reference to the object, 646 * the second time goes one further and is a 647 * special-case to terminate the object. 648 * 649 * don't double-terminate the object 650 */ 651 if ((obj->flags & OBJ_DEAD) == 0) 652 vm_object_terminate(obj); 653 } else { 654 /* 655 * Woe to the process that tries to page now :-). 656 */ 657 vm_pager_deallocate(obj); 658 } 659 return (0); 660} 661 662/* 663 * Return the underlying VM object. This routine may be called with or 664 * without the vnode interlock held. If called without, the returned 665 * object is not guarenteed to be valid. The syncer typically gets the 666 * object without holding the interlock in order to quickly test whether 667 * it might be dirty before going heavy-weight. vm_object's use zalloc 668 * and thus stable-storage, so this is safe. 669 */ 670int 671vop_stdgetvobject(ap) 672 struct vop_getvobject_args /* { 673 struct vnode *vp; 674 struct vm_object **objpp; 675 } */ *ap; 676{ 677 struct vnode *vp = ap->a_vp; 678 struct vm_object **objpp = ap->a_objpp; 679 680 if (objpp) 681 *objpp = vp->v_object; 682 return (vp->v_object ? 0 : EINVAL); 683} 684 685/* XXX Needs good comment and VOP_BMAP(9) manpage */ 686int 687vop_stdbmap(ap) 688 struct vop_bmap_args /* { 689 struct vnode *a_vp; 690 daddr_t a_bn; 691 struct vnode **a_vpp; 692 daddr_t *a_bnp; 693 int *a_runp; 694 int *a_runb; 695 } */ *ap; 696{ 697 698 if (ap->a_vpp != NULL) 699 *ap->a_vpp = ap->a_vp; 700 if (ap->a_bnp != NULL) 701 *ap->a_bnp = ap->a_bn * btodb(ap->a_vp->v_mount->mnt_stat.f_iosize); 702 if (ap->a_runp != NULL) 703 *ap->a_runp = 0; 704 if (ap->a_runb != NULL) 705 *ap->a_runb = 0; 706 return (0); 707} 708 709int 710vop_stdfsync(ap) 711 struct vop_fsync_args /* { 712 struct vnode *a_vp; 713 struct ucred *a_cred; 714 int a_waitfor; 715 struct thread *a_td; 716 } */ *ap; 717{ 718 struct vnode *vp = ap->a_vp; 719 struct buf *bp; 720 struct buf *nbp; 721 int s, error = 0; 722 int maxretry = 100; /* large, arbitrarily chosen */ 723 724 VI_LOCK(vp); 725loop1: 726 /* 727 * MARK/SCAN initialization to avoid infinite loops. 728 */ 729 s = splbio(); 730 TAILQ_FOREACH(bp, &vp->v_dirtyblkhd, b_vnbufs) { 731 bp->b_vflags &= ~BV_SCANNED; 732 bp->b_error = 0; 733 } 734 splx(s); 735 736 /* 737 * Flush all dirty buffers associated with a block device. 738 */ 739loop2: 740 s = splbio(); 741 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp != NULL; bp = nbp) { 742 nbp = TAILQ_NEXT(bp, b_vnbufs); 743 if ((bp->b_vflags & BV_SCANNED) != 0) 744 continue; 745 bp->b_vflags |= BV_SCANNED; 746 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) 747 continue; 748 VI_UNLOCK(vp); 749 if ((bp->b_flags & B_DELWRI) == 0) 750 panic("fsync: not dirty"); 751 if ((vp->v_vflag & VV_OBJBUF) && (bp->b_flags & B_CLUSTEROK)) { 752 BUF_UNLOCK(bp); 753 vfs_bio_awrite(bp); 754 splx(s); 755 } else { 756 bremfree(bp); 757 splx(s); 758 bawrite(bp); 759 } 760 VI_LOCK(vp); 761 goto loop2; 762 } 763 764 /* 765 * If synchronous the caller expects us to completely resolve all 766 * dirty buffers in the system. Wait for in-progress I/O to 767 * complete (which could include background bitmap writes), then 768 * retry if dirty blocks still exist. 769 */ 770 if (ap->a_waitfor == MNT_WAIT) { 771 while (vp->v_numoutput) { 772 vp->v_iflag |= VI_BWAIT; 773 msleep((caddr_t)&vp->v_numoutput, VI_MTX(vp), 774 PRIBIO + 1, "fsync", 0); 775 } 776 if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) { 777 /* 778 * If we are unable to write any of these buffers 779 * then we fail now rather than trying endlessly 780 * to write them out. 781 */ 782 TAILQ_FOREACH(bp, &vp->v_dirtyblkhd, b_vnbufs) 783 if ((error = bp->b_error) == 0) 784 continue; 785 if (error == 0 && --maxretry >= 0) { 786 splx(s); 787 goto loop1; 788 } 789 vprint("fsync: giving up on dirty", vp); 790 error = EAGAIN; 791 } 792 } 793 VI_UNLOCK(vp); 794 splx(s); 795 796 return (error); 797} 798 799/* XXX Needs good comment and more info in the manpage (VOP_GETPAGES(9)). */ 800int 801vop_stdgetpages(ap) 802 struct vop_getpages_args /* { 803 struct vnode *a_vp; 804 vm_page_t *a_m; 805 int a_count; 806 int a_reqpage; 807 vm_ooffset_t a_offset; 808 } */ *ap; 809{ 810 811 return vnode_pager_generic_getpages(ap->a_vp, ap->a_m, 812 ap->a_count, ap->a_reqpage); 813} 814 815/* XXX Needs good comment and more info in the manpage (VOP_PUTPAGES(9)). */ 816int 817vop_stdputpages(ap) 818 struct vop_putpages_args /* { 819 struct vnode *a_vp; 820 vm_page_t *a_m; 821 int a_count; 822 int a_sync; 823 int *a_rtvals; 824 vm_ooffset_t a_offset; 825 } */ *ap; 826{ 827 828 return vnode_pager_generic_putpages(ap->a_vp, ap->a_m, ap->a_count, 829 ap->a_sync, ap->a_rtvals); 830} 831 832/* 833 * vfs default ops 834 * used to fill the vfs function table to get reasonable default return values. 835 */ 836int 837vfs_stdroot (mp, vpp) 838 struct mount *mp; 839 struct vnode **vpp; 840{ 841 return (EOPNOTSUPP); 842} 843 844int 845vfs_stdstatfs (mp, sbp, td) 846 struct mount *mp; 847 struct statfs *sbp; 848 struct thread *td; 849{ 850 return (EOPNOTSUPP); 851} 852 853int 854vfs_stdvptofh (vp, fhp) 855 struct vnode *vp; 856 struct fid *fhp; 857{ 858 return (EOPNOTSUPP); 859} 860 861int 862vfs_stdstart (mp, flags, td) 863 struct mount *mp; 864 int flags; 865 struct thread *td; 866{ 867 return (0); 868} 869 870int 871vfs_stdquotactl (mp, cmds, uid, arg, td) 872 struct mount *mp; 873 int cmds; 874 uid_t uid; 875 caddr_t arg; 876 struct thread *td; 877{ 878 return (EOPNOTSUPP); 879} 880 881int 882vfs_stdsync (mp, waitfor, cred, td) 883 struct mount *mp; 884 int waitfor; 885 struct ucred *cred; 886 struct thread *td; 887{ 888 return (0); 889} 890 891int 892vfs_stdvget (mp, ino, flags, vpp) 893 struct mount *mp; 894 ino_t ino; 895 int flags; 896 struct vnode **vpp; 897{ 898 return (EOPNOTSUPP); 899} 900 901int 902vfs_stdfhtovp (mp, fhp, vpp) 903 struct mount *mp; 904 struct fid *fhp; 905 struct vnode **vpp; 906{ 907 return (EOPNOTSUPP); 908} 909 910int 911vfs_stdinit (vfsp) 912 struct vfsconf *vfsp; 913{ 914 return (0); 915} 916 917int 918vfs_stduninit (vfsp) 919 struct vfsconf *vfsp; 920{ 921 return(0); 922} 923 924int 925vfs_stdextattrctl(mp, cmd, filename_vp, attrnamespace, attrname, td) 926 struct mount *mp; 927 int cmd; 928 struct vnode *filename_vp; 929 int attrnamespace; 930 const char *attrname; 931 struct thread *td; 932{ 933 if (filename_vp != NULL) 934 VOP_UNLOCK(filename_vp, 0, td); 935 return(EOPNOTSUPP); 936} 937 938/* end of vfs default ops */ 939