vfs_export.c revision 7181
1/* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 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 * @(#)vfs_subr.c 8.13 (Berkeley) 4/18/94 39 * $Id: vfs_subr.c,v 1.23 1995/03/16 18:12:49 bde Exp $ 40 */ 41 42/* 43 * External virtual filesystem routines 44 */ 45 46#include <sys/param.h> 47#include <sys/systm.h> 48#include <sys/proc.h> 49#include <sys/mount.h> 50#include <sys/time.h> 51#include <sys/vnode.h> 52#include <sys/stat.h> 53#include <sys/namei.h> 54#include <sys/ucred.h> 55#include <sys/buf.h> 56#include <sys/errno.h> 57#include <sys/malloc.h> 58#include <sys/domain.h> 59#include <sys/mbuf.h> 60 61#include <vm/vm.h> 62#include <sys/sysctl.h> 63 64#include <miscfs/specfs/specdev.h> 65 66void insmntque __P((struct vnode *, struct mount *)); 67 68enum vtype iftovt_tab[16] = { 69 VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON, 70 VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD, 71}; 72int vttoif_tab[9] = { 73 0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 74 S_IFSOCK, S_IFIFO, S_IFMT, 75}; 76 77/* 78 * Insq/Remq for the vnode usage lists. 79 */ 80#define bufinsvn(bp, dp) LIST_INSERT_HEAD(dp, bp, b_vnbufs) 81#define bufremvn(bp) { \ 82 LIST_REMOVE(bp, b_vnbufs); \ 83 (bp)->b_vnbufs.le_next = NOLIST; \ 84} 85 86TAILQ_HEAD(freelst, vnode) vnode_free_list; /* vnode free list */ 87u_long freevnodes = 0; 88 89struct mntlist mountlist; /* mounted filesystem list */ 90 91int desiredvnodes; 92 93/* 94 * Initialize the vnode management data structures. 95 */ 96void 97vntblinit() 98{ 99 desiredvnodes = maxproc + vm_object_cache_max; 100 101 TAILQ_INIT(&vnode_free_list); 102 TAILQ_INIT(&mountlist); 103} 104 105/* 106 * Lock a filesystem. 107 * Used to prevent access to it while mounting and unmounting. 108 */ 109int 110vfs_lock(mp) 111 register struct mount *mp; 112{ 113 114 while (mp->mnt_flag & MNT_MLOCK) { 115 mp->mnt_flag |= MNT_MWAIT; 116 (void) tsleep((caddr_t) mp, PVFS, "vfslck", 0); 117 } 118 mp->mnt_flag |= MNT_MLOCK; 119 return (0); 120} 121 122/* 123 * Unlock a locked filesystem. 124 * Panic if filesystem is not locked. 125 */ 126void 127vfs_unlock(mp) 128 register struct mount *mp; 129{ 130 131 if ((mp->mnt_flag & MNT_MLOCK) == 0) 132 panic("vfs_unlock: not locked"); 133 mp->mnt_flag &= ~MNT_MLOCK; 134 if (mp->mnt_flag & MNT_MWAIT) { 135 mp->mnt_flag &= ~MNT_MWAIT; 136 wakeup((caddr_t) mp); 137 } 138} 139 140/* 141 * Mark a mount point as busy. 142 * Used to synchronize access and to delay unmounting. 143 */ 144int 145vfs_busy(mp) 146 register struct mount *mp; 147{ 148 149 while (mp->mnt_flag & MNT_MPBUSY) { 150 mp->mnt_flag |= MNT_MPWANT; 151 (void) tsleep((caddr_t) &mp->mnt_flag, PVFS, "vfsbsy", 0); 152 } 153 if (mp->mnt_flag & MNT_UNMOUNT) 154 return (1); 155 mp->mnt_flag |= MNT_MPBUSY; 156 return (0); 157} 158 159/* 160 * Free a busy filesystem. 161 * Panic if filesystem is not busy. 162 */ 163void 164vfs_unbusy(mp) 165 register struct mount *mp; 166{ 167 168 if ((mp->mnt_flag & MNT_MPBUSY) == 0) 169 panic("vfs_unbusy: not busy"); 170 mp->mnt_flag &= ~MNT_MPBUSY; 171 if (mp->mnt_flag & MNT_MPWANT) { 172 mp->mnt_flag &= ~MNT_MPWANT; 173 wakeup((caddr_t) &mp->mnt_flag); 174 } 175} 176 177void 178vfs_unmountroot(rootfs) 179 struct mount *rootfs; 180{ 181 struct mount *mp = rootfs; 182 int error; 183 184 if (vfs_busy(mp)) { 185 printf("failed to unmount root\n"); 186 return; 187 } 188 mp->mnt_flag |= MNT_UNMOUNT; 189 if ((error = vfs_lock(mp))) { 190 printf("lock of root filesystem failed (%d)\n", error); 191 return; 192 } 193 vnode_pager_umount(mp); /* release cached vnodes */ 194 cache_purgevfs(mp); /* remove cache entries for this file sys */ 195 196 if ((error = VFS_SYNC(mp, MNT_WAIT, initproc->p_ucred, initproc))) 197 printf("sync of root filesystem failed (%d)\n", error); 198 199 if ((error = VFS_UNMOUNT(mp, MNT_FORCE, initproc))) { 200 printf("unmount of root filesystem failed ("); 201 if (error == EBUSY) 202 printf("BUSY)\n"); 203 else 204 printf("%d)\n", error); 205 } 206 mp->mnt_flag &= ~MNT_UNMOUNT; 207 vfs_unbusy(mp); 208} 209 210/* 211 * Unmount all filesystems. Should only be called by halt(). 212 */ 213void 214vfs_unmountall() 215{ 216 struct mount *mp, *mp_next, *rootfs = NULL; 217 int error; 218 219 /* unmount all but rootfs */ 220 for (mp = mountlist.tqh_first; mp != NULL; mp = mp_next) { 221 mp_next = mp->mnt_list.tqe_next; 222 223 if (mp->mnt_flag & MNT_ROOTFS) { 224 rootfs = mp; 225 continue; 226 } 227 error = dounmount(mp, MNT_FORCE, initproc); 228 if (error) { 229 printf("unmount of %s failed (", mp->mnt_stat.f_mntonname); 230 if (error == EBUSY) 231 printf("BUSY)\n"); 232 else 233 printf("%d)\n", error); 234 } 235 } 236 237 /* and finally... */ 238 if (rootfs) { 239 vfs_unmountroot(rootfs); 240 } else { 241 printf("no root filesystem\n"); 242 } 243} 244 245/* 246 * Lookup a mount point by filesystem identifier. 247 */ 248struct mount * 249getvfs(fsid) 250 fsid_t *fsid; 251{ 252 register struct mount *mp; 253 254 for (mp = mountlist.tqh_first; mp != NULL; mp = mp->mnt_list.tqe_next) { 255 if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] && 256 mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) 257 return (mp); 258 } 259 return ((struct mount *) 0); 260} 261 262/* 263 * Get a new unique fsid 264 */ 265void 266getnewfsid(mp, mtype) 267 struct mount *mp; 268 int mtype; 269{ 270 static u_short xxxfs_mntid; 271 272 fsid_t tfsid; 273 274 mp->mnt_stat.f_fsid.val[0] = makedev(nblkdev + mtype, 0); 275 mp->mnt_stat.f_fsid.val[1] = mtype; 276 if (xxxfs_mntid == 0) 277 ++xxxfs_mntid; 278 tfsid.val[0] = makedev(nblkdev + mtype, xxxfs_mntid); 279 tfsid.val[1] = mtype; 280 if (mountlist.tqh_first != NULL) { 281 while (getvfs(&tfsid)) { 282 tfsid.val[0]++; 283 xxxfs_mntid++; 284 } 285 } 286 mp->mnt_stat.f_fsid.val[0] = tfsid.val[0]; 287} 288 289/* 290 * Set vnode attributes to VNOVAL 291 */ 292void 293vattr_null(vap) 294 register struct vattr *vap; 295{ 296 297 vap->va_type = VNON; 298 vap->va_size = VNOVAL; 299 vap->va_bytes = VNOVAL; 300 vap->va_mode = vap->va_nlink = vap->va_uid = vap->va_gid = 301 vap->va_fsid = vap->va_fileid = 302 vap->va_blocksize = vap->va_rdev = 303 vap->va_atime.ts_sec = vap->va_atime.ts_nsec = 304 vap->va_mtime.ts_sec = vap->va_mtime.ts_nsec = 305 vap->va_ctime.ts_sec = vap->va_ctime.ts_nsec = 306 vap->va_flags = vap->va_gen = VNOVAL; 307 vap->va_vaflags = 0; 308} 309 310/* 311 * Routines having to do with the management of the vnode table. 312 */ 313extern int (**dead_vnodeop_p) (); 314extern void vclean(); 315 316/* 317 * Return the next vnode from the free list. 318 */ 319int 320getnewvnode(tag, mp, vops, vpp) 321 enum vtagtype tag; 322 struct mount *mp; 323 int (**vops) (); 324 struct vnode **vpp; 325{ 326 register struct vnode *vp; 327 328 vp = vnode_free_list.tqh_first; 329 /* 330 * we allocate a new vnode if 331 * 1. we don't have any free 332 * Pretty obvious, we actually used to panic, but that 333 * is a silly thing to do. 334 * 2. we havn't filled our pool yet 335 * We don't want to trash the incore (VM-)vnodecache. 336 * 3. if less that 1/16th of our vnodes are free. 337 * We don't want to trash the namei cache either. 338 */ 339 if (freevnodes < (numvnodes >> 4) || 340 numvnodes < desiredvnodes || 341 vp == NULL) { 342 vp = (struct vnode *) malloc((u_long) sizeof *vp, 343 M_VNODE, M_WAITOK); 344 bzero((char *) vp, sizeof *vp); 345 numvnodes++; 346 } else { 347 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 348 freevnodes--; 349 350 if (vp->v_usecount) 351 panic("free vnode isn't"); 352 353 /* see comment on why 0xdeadb is set at end of vgone (below) */ 354 vp->v_freelist.tqe_prev = (struct vnode **) 0xdeadb; 355 vp->v_lease = NULL; 356 if (vp->v_type != VBAD) 357 vgone(vp); 358#ifdef DIAGNOSTIC 359 { 360 int s; 361 362 if (vp->v_data) 363 panic("cleaned vnode isn't"); 364 s = splbio(); 365 if (vp->v_numoutput) 366 panic("Clean vnode has pending I/O's"); 367 splx(s); 368 } 369#endif 370 vp->v_flag = 0; 371 vp->v_lastr = 0; 372 vp->v_ralen = 0; 373 vp->v_maxra = 0; 374 vp->v_lastw = 0; 375 vp->v_lasta = 0; 376 vp->v_cstart = 0; 377 vp->v_clen = 0; 378 vp->v_socket = 0; 379 vp->v_writecount = 0; /* XXX */ 380 } 381 vp->v_type = VNON; 382 cache_purge(vp); 383 vp->v_tag = tag; 384 vp->v_op = vops; 385 insmntque(vp, mp); 386 *vpp = vp; 387 vp->v_usecount = 1; 388 vp->v_data = 0; 389 return (0); 390} 391 392/* 393 * Move a vnode from one mount queue to another. 394 */ 395void 396insmntque(vp, mp) 397 register struct vnode *vp; 398 register struct mount *mp; 399{ 400 401 /* 402 * Delete from old mount point vnode list, if on one. 403 */ 404 if (vp->v_mount != NULL) 405 LIST_REMOVE(vp, v_mntvnodes); 406 /* 407 * Insert into list of vnodes for the new mount point, if available. 408 */ 409 if ((vp->v_mount = mp) == NULL) 410 return; 411 LIST_INSERT_HEAD(&mp->mnt_vnodelist, vp, v_mntvnodes); 412} 413 414/* 415 * Update outstanding I/O count and do wakeup if requested. 416 */ 417void 418vwakeup(bp) 419 register struct buf *bp; 420{ 421 register struct vnode *vp; 422 423 bp->b_flags &= ~B_WRITEINPROG; 424 if ((vp = bp->b_vp)) { 425 vp->v_numoutput--; 426 if (vp->v_numoutput < 0) 427 panic("vwakeup: neg numoutput"); 428 if ((vp->v_numoutput == 0) && (vp->v_flag & VBWAIT)) { 429 vp->v_flag &= ~VBWAIT; 430 wakeup((caddr_t) &vp->v_numoutput); 431 } 432 } 433} 434 435/* 436 * Flush out and invalidate all buffers associated with a vnode. 437 * Called with the underlying object locked. 438 */ 439int 440vinvalbuf(vp, flags, cred, p, slpflag, slptimeo) 441 register struct vnode *vp; 442 int flags; 443 struct ucred *cred; 444 struct proc *p; 445 int slpflag, slptimeo; 446{ 447 register struct buf *bp; 448 struct buf *nbp, *blist; 449 int s, error; 450 vm_pager_t pager; 451 vm_object_t object; 452 453 if (flags & V_SAVE) { 454 if ((error = VOP_FSYNC(vp, cred, MNT_WAIT, p))) 455 return (error); 456 if (vp->v_dirtyblkhd.lh_first != NULL) 457 panic("vinvalbuf: dirty bufs"); 458 } 459 for (;;) { 460 if ((blist = vp->v_cleanblkhd.lh_first) && (flags & V_SAVEMETA)) 461 while (blist && blist->b_lblkno < 0) 462 blist = blist->b_vnbufs.le_next; 463 if (!blist && (blist = vp->v_dirtyblkhd.lh_first) && 464 (flags & V_SAVEMETA)) 465 while (blist && blist->b_lblkno < 0) 466 blist = blist->b_vnbufs.le_next; 467 if (!blist) 468 break; 469 470 for (bp = blist; bp; bp = nbp) { 471 nbp = bp->b_vnbufs.le_next; 472 if ((flags & V_SAVEMETA) && bp->b_lblkno < 0) 473 continue; 474 s = splbio(); 475 if (bp->b_flags & B_BUSY) { 476 bp->b_flags |= B_WANTED; 477 error = tsleep((caddr_t) bp, 478 slpflag | (PRIBIO + 1), "vinvalbuf", 479 slptimeo); 480 splx(s); 481 if (error) 482 return (error); 483 break; 484 } 485 bremfree(bp); 486 bp->b_flags |= B_BUSY; 487 splx(s); 488 /* 489 * XXX Since there are no node locks for NFS, I 490 * believe there is a slight chance that a delayed 491 * write will occur while sleeping just above, so 492 * check for it. 493 */ 494 if ((bp->b_flags & B_DELWRI) && (flags & V_SAVE)) { 495 (void) VOP_BWRITE(bp); 496 break; 497 } 498 bp->b_flags |= B_INVAL; 499 brelse(bp); 500 } 501 } 502 503 504 s = splbio(); 505 while (vp->v_numoutput > 0) { 506 vp->v_flag |= VBWAIT; 507 tsleep(&vp->v_numoutput, PVM, "vnvlbv", 0); 508 } 509 splx(s); 510 511 /* 512 * Destroy the copy in the VM cache, too. 513 */ 514 if ((flags & V_SAVE) == 0) { 515 pager = NULL; 516 object = (vm_object_t) vp->v_vmdata; 517 if (object != NULL) 518 pager = object->pager; 519 if (pager != NULL) { 520 object = vm_object_lookup(pager); 521 if (object) { 522 vm_object_lock(object); 523 vm_object_page_remove(object, 0, object->size); 524 vm_object_unlock(object); 525 vm_object_deallocate(object); 526 } 527 } 528 } 529 if (!(flags & V_SAVEMETA) && 530 (vp->v_dirtyblkhd.lh_first || vp->v_cleanblkhd.lh_first)) 531 panic("vinvalbuf: flush failed"); 532 return (0); 533} 534 535/* 536 * Associate a buffer with a vnode. 537 */ 538void 539bgetvp(vp, bp) 540 register struct vnode *vp; 541 register struct buf *bp; 542{ 543 int s; 544 545 if (bp->b_vp) 546 panic("bgetvp: not free"); 547 VHOLD(vp); 548 bp->b_vp = vp; 549 if (vp->v_type == VBLK || vp->v_type == VCHR) 550 bp->b_dev = vp->v_rdev; 551 else 552 bp->b_dev = NODEV; 553 /* 554 * Insert onto list for new vnode. 555 */ 556 s = splbio(); 557 bufinsvn(bp, &vp->v_cleanblkhd); 558 splx(s); 559} 560 561/* 562 * Disassociate a buffer from a vnode. 563 */ 564void 565brelvp(bp) 566 register struct buf *bp; 567{ 568 struct vnode *vp; 569 int s; 570 571 if (bp->b_vp == (struct vnode *) 0) 572 panic("brelvp: NULL"); 573 /* 574 * Delete from old vnode list, if on one. 575 */ 576 s = splbio(); 577 if (bp->b_vnbufs.le_next != NOLIST) 578 bufremvn(bp); 579 splx(s); 580 581 vp = bp->b_vp; 582 bp->b_vp = (struct vnode *) 0; 583 HOLDRELE(vp); 584} 585 586/* 587 * Associate a p-buffer with a vnode. 588 */ 589void 590pbgetvp(vp, bp) 591 register struct vnode *vp; 592 register struct buf *bp; 593{ 594 if (bp->b_vp) 595 panic("pbgetvp: not free"); 596 VHOLD(vp); 597 bp->b_vp = vp; 598 if (vp->v_type == VBLK || vp->v_type == VCHR) 599 bp->b_dev = vp->v_rdev; 600 else 601 bp->b_dev = NODEV; 602} 603 604/* 605 * Disassociate a p-buffer from a vnode. 606 */ 607void 608pbrelvp(bp) 609 register struct buf *bp; 610{ 611 struct vnode *vp; 612 613 if (bp->b_vp == (struct vnode *) 0) 614 panic("brelvp: NULL"); 615 616 vp = bp->b_vp; 617 bp->b_vp = (struct vnode *) 0; 618 HOLDRELE(vp); 619} 620 621/* 622 * Reassign a buffer from one vnode to another. 623 * Used to assign file specific control information 624 * (indirect blocks) to the vnode to which they belong. 625 */ 626void 627reassignbuf(bp, newvp) 628 register struct buf *bp; 629 register struct vnode *newvp; 630{ 631 register struct buflists *listheadp; 632 633 if (newvp == NULL) { 634 printf("reassignbuf: NULL"); 635 return; 636 } 637 /* 638 * Delete from old vnode list, if on one. 639 */ 640 if (bp->b_vnbufs.le_next != NOLIST) 641 bufremvn(bp); 642 /* 643 * If dirty, put on list of dirty buffers; otherwise insert onto list 644 * of clean buffers. 645 */ 646 if (bp->b_flags & B_DELWRI) { 647 struct buf *tbp; 648 649 tbp = newvp->v_dirtyblkhd.lh_first; 650 if (!tbp || (tbp->b_lblkno > bp->b_lblkno)) { 651 bufinsvn(bp, &newvp->v_dirtyblkhd); 652 } else { 653 while (tbp->b_vnbufs.le_next && (tbp->b_vnbufs.le_next->b_lblkno < bp->b_lblkno)) { 654 tbp = tbp->b_vnbufs.le_next; 655 } 656 LIST_INSERT_AFTER(tbp, bp, b_vnbufs); 657 } 658 } else { 659 listheadp = &newvp->v_cleanblkhd; 660 bufinsvn(bp, listheadp); 661 } 662} 663 664/* 665 * Create a vnode for a block device. 666 * Used for root filesystem, argdev, and swap areas. 667 * Also used for memory file system special devices. 668 */ 669int 670bdevvp(dev, vpp) 671 dev_t dev; 672 struct vnode **vpp; 673{ 674 register struct vnode *vp; 675 struct vnode *nvp; 676 int error; 677 678 if (dev == NODEV) 679 return (0); 680 error = getnewvnode(VT_NON, (struct mount *) 0, spec_vnodeop_p, &nvp); 681 if (error) { 682 *vpp = 0; 683 return (error); 684 } 685 vp = nvp; 686 vp->v_type = VBLK; 687 if ((nvp = checkalias(vp, dev, (struct mount *) 0))) { 688 vput(vp); 689 vp = nvp; 690 } 691 *vpp = vp; 692 return (0); 693} 694 695/* 696 * Check to see if the new vnode represents a special device 697 * for which we already have a vnode (either because of 698 * bdevvp() or because of a different vnode representing 699 * the same block device). If such an alias exists, deallocate 700 * the existing contents and return the aliased vnode. The 701 * caller is responsible for filling it with its new contents. 702 */ 703struct vnode * 704checkalias(nvp, nvp_rdev, mp) 705 register struct vnode *nvp; 706 dev_t nvp_rdev; 707 struct mount *mp; 708{ 709 register struct vnode *vp; 710 struct vnode **vpp; 711 712 if (nvp->v_type != VBLK && nvp->v_type != VCHR) 713 return (NULLVP); 714 715 vpp = &speclisth[SPECHASH(nvp_rdev)]; 716loop: 717 for (vp = *vpp; vp; vp = vp->v_specnext) { 718 if (nvp_rdev != vp->v_rdev || nvp->v_type != vp->v_type) 719 continue; 720 /* 721 * Alias, but not in use, so flush it out. 722 */ 723 if (vp->v_usecount == 0) { 724 vgone(vp); 725 goto loop; 726 } 727 if (vget(vp, 1)) 728 goto loop; 729 break; 730 } 731 if (vp == NULL || vp->v_tag != VT_NON) { 732 MALLOC(nvp->v_specinfo, struct specinfo *, 733 sizeof(struct specinfo), M_VNODE, M_WAITOK); 734 nvp->v_rdev = nvp_rdev; 735 nvp->v_hashchain = vpp; 736 nvp->v_specnext = *vpp; 737 nvp->v_specflags = 0; 738 *vpp = nvp; 739 if (vp != NULL) { 740 nvp->v_flag |= VALIASED; 741 vp->v_flag |= VALIASED; 742 vput(vp); 743 } 744 return (NULLVP); 745 } 746 VOP_UNLOCK(vp); 747 vclean(vp, 0); 748 vp->v_op = nvp->v_op; 749 vp->v_tag = nvp->v_tag; 750 nvp->v_type = VNON; 751 insmntque(vp, mp); 752 return (vp); 753} 754 755/* 756 * Grab a particular vnode from the free list, increment its 757 * reference count and lock it. The vnode lock bit is set the 758 * vnode is being eliminated in vgone. The process is awakened 759 * when the transition is completed, and an error returned to 760 * indicate that the vnode is no longer usable (possibly having 761 * been changed to a new file system type). 762 */ 763int 764vget(vp, lockflag) 765 register struct vnode *vp; 766 int lockflag; 767{ 768 769 /* 770 * If the vnode is in the process of being cleaned out for another 771 * use, we wait for the cleaning to finish and then return failure. 772 * Cleaning is determined either by checking that the VXLOCK flag is 773 * set, or that the use count is zero with the back pointer set to 774 * show that it has been removed from the free list by getnewvnode. 775 * The VXLOCK flag may not have been set yet because vclean is blocked 776 * in the VOP_LOCK call waiting for the VOP_INACTIVE to complete. 777 */ 778 if ((vp->v_flag & VXLOCK) || 779 (vp->v_usecount == 0 && 780 vp->v_freelist.tqe_prev == (struct vnode **) 0xdeadb)) { 781 vp->v_flag |= VXWANT; 782 (void) tsleep((caddr_t) vp, PINOD, "vget", 0); 783 return (1); 784 } 785 if (vp->v_usecount == 0) { 786 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 787 freevnodes--; 788 } 789 vp->v_usecount++; 790 if (lockflag) 791 VOP_LOCK(vp); 792 return (0); 793} 794 795/* 796 * Vnode reference, just increment the count 797 */ 798void 799vref(vp) 800 struct vnode *vp; 801{ 802 803 if (vp->v_usecount <= 0) 804 panic("vref used where vget required"); 805 vp->v_usecount++; 806} 807 808/* 809 * vput(), just unlock and vrele() 810 */ 811void 812vput(vp) 813 register struct vnode *vp; 814{ 815 816 VOP_UNLOCK(vp); 817 vrele(vp); 818} 819 820/* 821 * Vnode release. 822 * If count drops to zero, call inactive routine and return to freelist. 823 */ 824void 825vrele(vp) 826 register struct vnode *vp; 827{ 828 829#ifdef DIAGNOSTIC 830 if (vp == NULL) 831 panic("vrele: null vp"); 832#endif 833 vp->v_usecount--; 834 if (vp->v_usecount > 0) 835 return; 836#ifdef DIAGNOSTIC 837 if (vp->v_usecount != 0 /* || vp->v_writecount != 0 */ ) { 838 vprint("vrele: bad ref count", vp); 839 panic("vrele: ref cnt"); 840 } 841#endif 842 if (vp->v_flag & VAGE) { 843 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 844 vp->v_flag &= ~VAGE; 845 } else { 846 TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist); 847 } 848 freevnodes++; 849 850 VOP_INACTIVE(vp); 851} 852 853/* 854 * Page or buffer structure gets a reference. 855 */ 856void 857vhold(vp) 858 register struct vnode *vp; 859{ 860 861 vp->v_holdcnt++; 862} 863 864/* 865 * Page or buffer structure frees a reference. 866 */ 867void 868holdrele(vp) 869 register struct vnode *vp; 870{ 871 872 if (vp->v_holdcnt <= 0) 873 panic("holdrele: holdcnt"); 874 vp->v_holdcnt--; 875} 876 877/* 878 * Remove any vnodes in the vnode table belonging to mount point mp. 879 * 880 * If MNT_NOFORCE is specified, there should not be any active ones, 881 * return error if any are found (nb: this is a user error, not a 882 * system error). If MNT_FORCE is specified, detach any active vnodes 883 * that are found. 884 */ 885#ifdef DIAGNOSTIC 886int busyprt = 0; /* print out busy vnodes */ 887struct ctldebug debug1 = {"busyprt", &busyprt}; 888 889#endif 890 891int 892vflush(mp, skipvp, flags) 893 struct mount *mp; 894 struct vnode *skipvp; 895 int flags; 896{ 897 register struct vnode *vp, *nvp; 898 int busy = 0; 899 900 if ((mp->mnt_flag & MNT_MPBUSY) == 0) 901 panic("vflush: not busy"); 902loop: 903 for (vp = mp->mnt_vnodelist.lh_first; vp; vp = nvp) { 904 /* 905 * Make sure this vnode wasn't reclaimed in getnewvnode(). 906 * Start over if it has (it won't be on the list anymore). 907 */ 908 if (vp->v_mount != mp) 909 goto loop; 910 nvp = vp->v_mntvnodes.le_next; 911 /* 912 * Skip over a selected vnode. 913 */ 914 if (vp == skipvp) 915 continue; 916 /* 917 * Skip over a vnodes marked VSYSTEM. 918 */ 919 if ((flags & SKIPSYSTEM) && (vp->v_flag & VSYSTEM)) 920 continue; 921 /* 922 * If WRITECLOSE is set, only flush out regular file vnodes 923 * open for writing. 924 */ 925 if ((flags & WRITECLOSE) && 926 (vp->v_writecount == 0 || vp->v_type != VREG)) 927 continue; 928 /* 929 * With v_usecount == 0, all we need to do is clear out the 930 * vnode data structures and we are done. 931 */ 932 if (vp->v_usecount == 0) { 933 vgone(vp); 934 continue; 935 } 936 /* 937 * If FORCECLOSE is set, forcibly close the vnode. For block 938 * or character devices, revert to an anonymous device. For 939 * all other files, just kill them. 940 */ 941 if (flags & FORCECLOSE) { 942 if (vp->v_type != VBLK && vp->v_type != VCHR) { 943 vgone(vp); 944 } else { 945 vclean(vp, 0); 946 vp->v_op = spec_vnodeop_p; 947 insmntque(vp, (struct mount *) 0); 948 } 949 continue; 950 } 951#ifdef DIAGNOSTIC 952 if (busyprt) 953 vprint("vflush: busy vnode", vp); 954#endif 955 busy++; 956 } 957 if (busy) 958 return (EBUSY); 959 return (0); 960} 961 962/* 963 * Disassociate the underlying file system from a vnode. 964 */ 965void 966vclean(vp, flags) 967 register struct vnode *vp; 968 int flags; 969{ 970 int active; 971 972 /* 973 * Check to see if the vnode is in use. If so we have to reference it 974 * before we clean it out so that its count cannot fall to zero and 975 * generate a race against ourselves to recycle it. 976 */ 977 if ((active = vp->v_usecount)) 978 VREF(vp); 979 /* 980 * Even if the count is zero, the VOP_INACTIVE routine may still have 981 * the object locked while it cleans it out. The VOP_LOCK ensures that 982 * the VOP_INACTIVE routine is done with its work. For active vnodes, 983 * it ensures that no other activity can occur while the underlying 984 * object is being cleaned out. 985 */ 986 VOP_LOCK(vp); 987 /* 988 * Prevent the vnode from being recycled or brought into use while we 989 * clean it out. 990 */ 991 if (vp->v_flag & VXLOCK) 992 panic("vclean: deadlock"); 993 vp->v_flag |= VXLOCK; 994 /* 995 * Clean out any buffers associated with the vnode. 996 */ 997 if (flags & DOCLOSE) 998 vinvalbuf(vp, V_SAVE, NOCRED, NULL, 0, 0); 999 /* 1000 * Any other processes trying to obtain this lock must first wait for 1001 * VXLOCK to clear, then call the new lock operation. 1002 */ 1003 VOP_UNLOCK(vp); 1004 /* 1005 * If purging an active vnode, it must be closed and deactivated 1006 * before being reclaimed. 1007 */ 1008 if (active) { 1009 if (flags & DOCLOSE) 1010 VOP_CLOSE(vp, IO_NDELAY, NOCRED, NULL); 1011 VOP_INACTIVE(vp); 1012 } 1013 /* 1014 * Reclaim the vnode. 1015 */ 1016 if (VOP_RECLAIM(vp)) 1017 panic("vclean: cannot reclaim"); 1018 if (active) 1019 vrele(vp); 1020 1021 /* 1022 * Done with purge, notify sleepers of the grim news. 1023 */ 1024 vp->v_op = dead_vnodeop_p; 1025 vp->v_tag = VT_NON; 1026 vp->v_flag &= ~VXLOCK; 1027 if (vp->v_flag & VXWANT) { 1028 vp->v_flag &= ~VXWANT; 1029 wakeup((caddr_t) vp); 1030 } 1031} 1032 1033/* 1034 * Eliminate all activity associated with the requested vnode 1035 * and with all vnodes aliased to the requested vnode. 1036 */ 1037void 1038vgoneall(vp) 1039 register struct vnode *vp; 1040{ 1041 register struct vnode *vq; 1042 1043 if (vp->v_flag & VALIASED) { 1044 /* 1045 * If a vgone (or vclean) is already in progress, wait until 1046 * it is done and return. 1047 */ 1048 if (vp->v_flag & VXLOCK) { 1049 vp->v_flag |= VXWANT; 1050 (void) tsleep((caddr_t) vp, PINOD, "vgall", 0); 1051 return; 1052 } 1053 /* 1054 * Ensure that vp will not be vgone'd while we are eliminating 1055 * its aliases. 1056 */ 1057 vp->v_flag |= VXLOCK; 1058 while (vp->v_flag & VALIASED) { 1059 for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) { 1060 if (vq->v_rdev != vp->v_rdev || 1061 vq->v_type != vp->v_type || vp == vq) 1062 continue; 1063 vgone(vq); 1064 break; 1065 } 1066 } 1067 /* 1068 * Remove the lock so that vgone below will really eliminate 1069 * the vnode after which time vgone will awaken any sleepers. 1070 */ 1071 vp->v_flag &= ~VXLOCK; 1072 } 1073 vgone(vp); 1074} 1075 1076/* 1077 * Eliminate all activity associated with a vnode 1078 * in preparation for reuse. 1079 */ 1080void 1081vgone(vp) 1082 register struct vnode *vp; 1083{ 1084 register struct vnode *vq; 1085 struct vnode *vx; 1086 1087 /* 1088 * If a vgone (or vclean) is already in progress, wait until it is 1089 * done and return. 1090 */ 1091 if (vp->v_flag & VXLOCK) { 1092 vp->v_flag |= VXWANT; 1093 (void) tsleep((caddr_t) vp, PINOD, "vgone", 0); 1094 return; 1095 } 1096 /* 1097 * Clean out the filesystem specific data. 1098 */ 1099 vclean(vp, DOCLOSE); 1100 /* 1101 * Delete from old mount point vnode list, if on one. 1102 */ 1103 if (vp->v_mount != NULL) { 1104 LIST_REMOVE(vp, v_mntvnodes); 1105 vp->v_mount = NULL; 1106 } 1107 /* 1108 * If special device, remove it from special device alias list. 1109 */ 1110 if (vp->v_type == VBLK || vp->v_type == VCHR) { 1111 if (*vp->v_hashchain == vp) { 1112 *vp->v_hashchain = vp->v_specnext; 1113 } else { 1114 for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) { 1115 if (vq->v_specnext != vp) 1116 continue; 1117 vq->v_specnext = vp->v_specnext; 1118 break; 1119 } 1120 if (vq == NULL) 1121 panic("missing bdev"); 1122 } 1123 if (vp->v_flag & VALIASED) { 1124 vx = NULL; 1125 for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) { 1126 if (vq->v_rdev != vp->v_rdev || 1127 vq->v_type != vp->v_type) 1128 continue; 1129 if (vx) 1130 break; 1131 vx = vq; 1132 } 1133 if (vx == NULL) 1134 panic("missing alias"); 1135 if (vq == NULL) 1136 vx->v_flag &= ~VALIASED; 1137 vp->v_flag &= ~VALIASED; 1138 } 1139 FREE(vp->v_specinfo, M_VNODE); 1140 vp->v_specinfo = NULL; 1141 } 1142 /* 1143 * If it is on the freelist and not already at the head, move it to 1144 * the head of the list. The test of the back pointer and the 1145 * reference count of zero is because it will be removed from the free 1146 * list by getnewvnode, but will not have its reference count 1147 * incremented until after calling vgone. If the reference count were 1148 * incremented first, vgone would (incorrectly) try to close the 1149 * previous instance of the underlying object. So, the back pointer is 1150 * explicitly set to `0xdeadb' in getnewvnode after removing it from 1151 * the freelist to ensure that we do not try to move it here. 1152 */ 1153 if (vp->v_usecount == 0 && 1154 vp->v_freelist.tqe_prev != (struct vnode **) 0xdeadb && 1155 vnode_free_list.tqh_first != vp) { 1156 TAILQ_REMOVE(&vnode_free_list, vp, v_freelist); 1157 TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist); 1158 } 1159 vp->v_type = VBAD; 1160} 1161 1162/* 1163 * Lookup a vnode by device number. 1164 */ 1165int 1166vfinddev(dev, type, vpp) 1167 dev_t dev; 1168 enum vtype type; 1169 struct vnode **vpp; 1170{ 1171 register struct vnode *vp; 1172 1173 for (vp = speclisth[SPECHASH(dev)]; vp; vp = vp->v_specnext) { 1174 if (dev != vp->v_rdev || type != vp->v_type) 1175 continue; 1176 *vpp = vp; 1177 return (1); 1178 } 1179 return (0); 1180} 1181 1182/* 1183 * Calculate the total number of references to a special device. 1184 */ 1185int 1186vcount(vp) 1187 register struct vnode *vp; 1188{ 1189 register struct vnode *vq, *vnext; 1190 int count; 1191 1192loop: 1193 if ((vp->v_flag & VALIASED) == 0) 1194 return (vp->v_usecount); 1195 for (count = 0, vq = *vp->v_hashchain; vq; vq = vnext) { 1196 vnext = vq->v_specnext; 1197 if (vq->v_rdev != vp->v_rdev || vq->v_type != vp->v_type) 1198 continue; 1199 /* 1200 * Alias, but not in use, so flush it out. 1201 */ 1202 if (vq->v_usecount == 0 && vq != vp) { 1203 vgone(vq); 1204 goto loop; 1205 } 1206 count += vq->v_usecount; 1207 } 1208 return (count); 1209} 1210 1211/* 1212 * Print out a description of a vnode. 1213 */ 1214static char *typename[] = 1215{"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"}; 1216 1217void 1218vprint(label, vp) 1219 char *label; 1220 register struct vnode *vp; 1221{ 1222 char buf[64]; 1223 1224 if (label != NULL) 1225 printf("%s: ", label); 1226 printf("type %s, usecount %d, writecount %d, refcount %ld,", 1227 typename[vp->v_type], vp->v_usecount, vp->v_writecount, 1228 vp->v_holdcnt); 1229 buf[0] = '\0'; 1230 if (vp->v_flag & VROOT) 1231 strcat(buf, "|VROOT"); 1232 if (vp->v_flag & VTEXT) 1233 strcat(buf, "|VTEXT"); 1234 if (vp->v_flag & VSYSTEM) 1235 strcat(buf, "|VSYSTEM"); 1236 if (vp->v_flag & VXLOCK) 1237 strcat(buf, "|VXLOCK"); 1238 if (vp->v_flag & VXWANT) 1239 strcat(buf, "|VXWANT"); 1240 if (vp->v_flag & VBWAIT) 1241 strcat(buf, "|VBWAIT"); 1242 if (vp->v_flag & VALIASED) 1243 strcat(buf, "|VALIASED"); 1244 if (buf[0] != '\0') 1245 printf(" flags (%s)", &buf[1]); 1246 if (vp->v_data == NULL) { 1247 printf("\n"); 1248 } else { 1249 printf("\n\t"); 1250 VOP_PRINT(vp); 1251 } 1252} 1253 1254#ifdef DEBUG 1255/* 1256 * List all of the locked vnodes in the system. 1257 * Called when debugging the kernel. 1258 */ 1259void 1260printlockedvnodes() 1261{ 1262 register struct mount *mp; 1263 register struct vnode *vp; 1264 1265 printf("Locked vnodes\n"); 1266 for (mp = mountlist.tqh_first; mp != NULL; mp = mp->mnt_list.tqe_next) { 1267 for (vp = mp->mnt_vnodelist.lh_first; 1268 vp != NULL; 1269 vp = vp->v_mntvnodes.le_next) 1270 if (VOP_ISLOCKED(vp)) 1271 vprint((char *) 0, vp); 1272 } 1273} 1274#endif 1275 1276int kinfo_vdebug = 1; 1277int kinfo_vgetfailed; 1278 1279#define KINFO_VNODESLOP 10 1280/* 1281 * Dump vnode list (via sysctl). 1282 * Copyout address of vnode followed by vnode. 1283 */ 1284/* ARGSUSED */ 1285int 1286sysctl_vnode(where, sizep) 1287 char *where; 1288 size_t *sizep; 1289{ 1290 register struct mount *mp, *nmp; 1291 struct vnode *vp; 1292 register char *bp = where, *savebp; 1293 char *ewhere; 1294 int error; 1295 1296#define VPTRSZ sizeof (struct vnode *) 1297#define VNODESZ sizeof (struct vnode) 1298 if (where == NULL) { 1299 *sizep = (numvnodes + KINFO_VNODESLOP) * (VPTRSZ + VNODESZ); 1300 return (0); 1301 } 1302 ewhere = where + *sizep; 1303 1304 for (mp = mountlist.tqh_first; mp != NULL; mp = nmp) { 1305 nmp = mp->mnt_list.tqe_next; 1306 if (vfs_busy(mp)) 1307 continue; 1308 savebp = bp; 1309again: 1310 for (vp = mp->mnt_vnodelist.lh_first; 1311 vp != NULL; 1312 vp = vp->v_mntvnodes.le_next) { 1313 /* 1314 * Check that the vp is still associated with this 1315 * filesystem. RACE: could have been recycled onto 1316 * the same filesystem. 1317 */ 1318 if (vp->v_mount != mp) { 1319 if (kinfo_vdebug) 1320 printf("kinfo: vp changed\n"); 1321 bp = savebp; 1322 goto again; 1323 } 1324 if (bp + VPTRSZ + VNODESZ > ewhere) { 1325 *sizep = bp - where; 1326 return (ENOMEM); 1327 } 1328 if ((error = copyout((caddr_t) &vp, bp, VPTRSZ)) || 1329 (error = copyout((caddr_t) vp, bp + VPTRSZ, VNODESZ))) 1330 return (error); 1331 bp += VPTRSZ + VNODESZ; 1332 } 1333 vfs_unbusy(mp); 1334 } 1335 1336 *sizep = bp - where; 1337 return (0); 1338} 1339 1340/* 1341 * Check to see if a filesystem is mounted on a block device. 1342 */ 1343int 1344vfs_mountedon(vp) 1345 register struct vnode *vp; 1346{ 1347 register struct vnode *vq; 1348 1349 if (vp->v_specflags & SI_MOUNTEDON) 1350 return (EBUSY); 1351 if (vp->v_flag & VALIASED) { 1352 for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) { 1353 if (vq->v_rdev != vp->v_rdev || 1354 vq->v_type != vp->v_type) 1355 continue; 1356 if (vq->v_specflags & SI_MOUNTEDON) 1357 return (EBUSY); 1358 } 1359 } 1360 return (0); 1361} 1362 1363/* 1364 * Build hash lists of net addresses and hang them off the mount point. 1365 * Called by ufs_mount() to set up the lists of export addresses. 1366 */ 1367static int 1368vfs_hang_addrlist(mp, nep, argp) 1369 struct mount *mp; 1370 struct netexport *nep; 1371 struct export_args *argp; 1372{ 1373 register struct netcred *np; 1374 register struct radix_node_head *rnh; 1375 register int i; 1376 struct radix_node *rn; 1377 struct sockaddr *saddr, *smask = 0; 1378 struct domain *dom; 1379 int error; 1380 1381 if (argp->ex_addrlen == 0) { 1382 if (mp->mnt_flag & MNT_DEFEXPORTED) 1383 return (EPERM); 1384 np = &nep->ne_defexported; 1385 np->netc_exflags = argp->ex_flags; 1386 np->netc_anon = argp->ex_anon; 1387 np->netc_anon.cr_ref = 1; 1388 mp->mnt_flag |= MNT_DEFEXPORTED; 1389 return (0); 1390 } 1391 i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen; 1392 np = (struct netcred *) malloc(i, M_NETADDR, M_WAITOK); 1393 bzero((caddr_t) np, i); 1394 saddr = (struct sockaddr *) (np + 1); 1395 if ((error = copyin(argp->ex_addr, (caddr_t) saddr, argp->ex_addrlen))) 1396 goto out; 1397 if (saddr->sa_len > argp->ex_addrlen) 1398 saddr->sa_len = argp->ex_addrlen; 1399 if (argp->ex_masklen) { 1400 smask = (struct sockaddr *) ((caddr_t) saddr + argp->ex_addrlen); 1401 error = copyin(argp->ex_addr, (caddr_t) smask, argp->ex_masklen); 1402 if (error) 1403 goto out; 1404 if (smask->sa_len > argp->ex_masklen) 1405 smask->sa_len = argp->ex_masklen; 1406 } 1407 i = saddr->sa_family; 1408 if ((rnh = nep->ne_rtable[i]) == 0) { 1409 /* 1410 * Seems silly to initialize every AF when most are not used, 1411 * do so on demand here 1412 */ 1413 for (dom = domains; dom; dom = dom->dom_next) 1414 if (dom->dom_family == i && dom->dom_rtattach) { 1415 dom->dom_rtattach((void **) &nep->ne_rtable[i], 1416 dom->dom_rtoffset); 1417 break; 1418 } 1419 if ((rnh = nep->ne_rtable[i]) == 0) { 1420 error = ENOBUFS; 1421 goto out; 1422 } 1423 } 1424 rn = (*rnh->rnh_addaddr) ((caddr_t) saddr, (caddr_t) smask, rnh, 1425 np->netc_rnodes); 1426 if (rn == 0 || np != (struct netcred *) rn) { /* already exists */ 1427 error = EPERM; 1428 goto out; 1429 } 1430 np->netc_exflags = argp->ex_flags; 1431 np->netc_anon = argp->ex_anon; 1432 np->netc_anon.cr_ref = 1; 1433 return (0); 1434out: 1435 free(np, M_NETADDR); 1436 return (error); 1437} 1438 1439/* ARGSUSED */ 1440static int 1441vfs_free_netcred(rn, w) 1442 struct radix_node *rn; 1443 caddr_t w; 1444{ 1445 register struct radix_node_head *rnh = (struct radix_node_head *) w; 1446 1447 (*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, rnh); 1448 free((caddr_t) rn, M_NETADDR); 1449 return (0); 1450} 1451 1452/* 1453 * Free the net address hash lists that are hanging off the mount points. 1454 */ 1455static void 1456vfs_free_addrlist(nep) 1457 struct netexport *nep; 1458{ 1459 register int i; 1460 register struct radix_node_head *rnh; 1461 1462 for (i = 0; i <= AF_MAX; i++) 1463 if ((rnh = nep->ne_rtable[i])) { 1464 (*rnh->rnh_walktree) (rnh, vfs_free_netcred, 1465 (caddr_t) rnh); 1466 free((caddr_t) rnh, M_RTABLE); 1467 nep->ne_rtable[i] = 0; 1468 } 1469} 1470 1471int 1472vfs_export(mp, nep, argp) 1473 struct mount *mp; 1474 struct netexport *nep; 1475 struct export_args *argp; 1476{ 1477 int error; 1478 1479 if (argp->ex_flags & MNT_DELEXPORT) { 1480 vfs_free_addrlist(nep); 1481 mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED); 1482 } 1483 if (argp->ex_flags & MNT_EXPORTED) { 1484 if ((error = vfs_hang_addrlist(mp, nep, argp))) 1485 return (error); 1486 mp->mnt_flag |= MNT_EXPORTED; 1487 } 1488 return (0); 1489} 1490 1491struct netcred * 1492vfs_export_lookup(mp, nep, nam) 1493 register struct mount *mp; 1494 struct netexport *nep; 1495 struct mbuf *nam; 1496{ 1497 register struct netcred *np; 1498 register struct radix_node_head *rnh; 1499 struct sockaddr *saddr; 1500 1501 np = NULL; 1502 if (mp->mnt_flag & MNT_EXPORTED) { 1503 /* 1504 * Lookup in the export list first. 1505 */ 1506 if (nam != NULL) { 1507 saddr = mtod(nam, struct sockaddr *); 1508 rnh = nep->ne_rtable[saddr->sa_family]; 1509 if (rnh != NULL) { 1510 np = (struct netcred *) 1511 (*rnh->rnh_matchaddr) ((caddr_t) saddr, 1512 rnh); 1513 if (np && np->netc_rnodes->rn_flags & RNF_ROOT) 1514 np = NULL; 1515 } 1516 } 1517 /* 1518 * If no address match, use the default if it exists. 1519 */ 1520 if (np == NULL && mp->mnt_flag & MNT_DEFEXPORTED) 1521 np = &nep->ne_defexported; 1522 } 1523 return (np); 1524} 1525