sys/kern/vfs_syscalls.c

   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_syscalls.c      8.13 (Berkeley) 4/15/94
  39  * $FreeBSD: src/sys/kern/vfs_syscalls.c,v 1.151.2.18 2003/04/04 20:35:58 tegge Exp $
  40  * $DragonFly: src/sys/kern/vfs_syscalls.c,v 1.135 2008/11/11 00:55:49 pavalos Exp $
  41  */
  42
  43 #include <sys/param.h>
  44 #include <sys/systm.h>
  45 #include <sys/buf.h>
  46 #include <sys/conf.h>
  47 #include <sys/sysent.h>
  48 #include <sys/malloc.h>
  49 #include <sys/mount.h>
  50 #include <sys/mountctl.h>
  51 #include <sys/sysproto.h>
  52 #include <sys/filedesc.h>
  53 #include <sys/kernel.h>
  54 #include <sys/fcntl.h>
  55 #include <sys/file.h>
  56 #include <sys/linker.h>
  57 #include <sys/stat.h>
  58 #include <sys/unistd.h>
  59 #include <sys/vnode.h>
  60 #include <sys/proc.h>
  61 #include <sys/priv.h>
  62 #include <sys/jail.h>
  63 #include <sys/namei.h>
  64 #include <sys/nlookup.h>
  65 #include <sys/dirent.h>
  66 #include <sys/extattr.h>
  67 #include <sys/spinlock.h>
  68 #include <sys/kern_syscall.h>
  69 #include <sys/objcache.h>
  70 #include <sys/sysctl.h>
  71
  72 #include <sys/buf2.h>
  73 #include <sys/file2.h>
  74 #include <sys/spinlock2.h>
  75
  76 #include <vm/vm.h>
  77 #include <vm/vm_object.h>
  78 #include <vm/vm_page.h>
  79
  80 #include <machine/limits.h>
  81 #include <machine/stdarg.h>
  82
  83 #include <vfs/union/union.h>
  84
  85 static void mount_warning(struct mount *mp, const char *ctl, ...);
  86 static int mount_path(struct proc *p, struct mount *mp, char **rb, char **fb);
  87 static int checkvp_chdir (struct vnode *vn, struct thread *td);
  88 static void checkdirs (struct nchandle *old_nch, struct nchandle *new_nch);
  89 static int chroot_refuse_vdir_fds (struct filedesc *fdp);
  90 static int chroot_visible_mnt(struct mount *mp, struct proc *p);
  91 static int getutimes (const struct timeval *, struct timespec *);
  92 static int setfown (struct vnode *, uid_t, gid_t);
  93 static int setfmode (struct vnode *, int);
  94 static int setfflags (struct vnode *, int);
  95 static int setutimes (struct vnode *, struct vattr *,
  96                         const struct timespec *, int);
  97 static int      usermount = 0;  /* if 1, non-root can mount fs. */
  98
  99 int (*union_dircheckp) (struct thread *, struct vnode **, struct file *);
 100
 101 SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0, "");
 102
 103 /*
 104  * Virtual File System System Calls
 105  */
 106
 107 /*
 108  * Mount a file system.
 109  */
 110 /*
 111  * mount_args(char *type, char *path, int flags, caddr_t data)
 112  */
 113 /* ARGSUSED */
 114 int
 115 sys_mount(struct mount_args *uap)
 116 {
 117         struct thread *td = curthread;
 118         struct proc *p = td->td_proc;
 119         struct vnode *vp;
 120         struct nchandle nch;
 121         struct mount *mp;
 122         struct vfsconf *vfsp;
 123         int error, flag = 0, flag2 = 0;
 124         int hasmount;
 125         struct vattr va;
 126         struct nlookupdata nd;
 127         char fstypename[MFSNAMELEN];
 128         struct ucred *cred = p->p_ucred;
 129
 130         KKASSERT(p);
 131         if (jailed(cred))
 132                 return (EPERM);
 133         if (usermount == 0 && (error = priv_check(td, PRIV_ROOT)))
 134                 return (error);
 135         /*
 136          * Do not allow NFS export by non-root users.
 137          */
 138         if (uap->flags & MNT_EXPORTED) {
 139                 error = priv_check(td, PRIV_ROOT);
 140                 if (error)
 141                         return (error);
 142         }
 143         /*
 144          * Silently enforce MNT_NOSUID and MNT_NODEV for non-root users
 145          */
 146         if (priv_check(td, PRIV_ROOT))
 147                 uap->flags |= MNT_NOSUID | MNT_NODEV;
 148
 149         /*
 150          * Lookup the requested path and extract the nch and vnode.
 151          */
 152         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
 153         if (error == 0) {
 154                 if ((error = nlookup(&nd)) == 0) {
 155                         if (nd.nl_nch.ncp->nc_vp == NULL)
 156                                 error = ENOENT;
 157                 }
 158         }
 159         if (error) {
 160                 nlookup_done(&nd);
 161                 return (error);
 162         }
 163
 164         /*
 165          * Extract the locked+refd ncp and cleanup the nd structure
 166          */
 167         nch = nd.nl_nch;
 168         cache_zero(&nd.nl_nch);
 169         nlookup_done(&nd);
 170
 171         if ((nch.ncp->nc_flag & NCF_ISMOUNTPT) && cache_findmount(&nch))
 172                 hasmount = 1;
 173         else
 174                 hasmount = 0;
 175
 176
 177         /*
 178          * now we have the locked ref'd nch and unreferenced vnode.
 179          */
 180         vp = nch.ncp->nc_vp;
 181         if ((error = vget(vp, LK_EXCLUSIVE)) != 0) {
 182                 cache_put(&nch);
 183                 return (error);
 184         }
 185         cache_unlock(&nch);
 186
 187         /*
 188          * Now we have an unlocked ref'd nch and a locked ref'd vp
 189          */
 190         if (uap->flags & MNT_UPDATE) {
 191                 if ((vp->v_flag & (VROOT|VPFSROOT)) == 0) {
 192                         cache_drop(&nch);
 193                         vput(vp);
 194                         return (EINVAL);
 195                 }
 196                 mp = vp->v_mount;
 197                 flag = mp->mnt_flag;
 198                 flag2 = mp->mnt_kern_flag;
 199                 /*
 200                  * We only allow the filesystem to be reloaded if it
 201                  * is currently mounted read-only.
 202                  */
 203                 if ((uap->flags & MNT_RELOAD) &&
 204                     ((mp->mnt_flag & MNT_RDONLY) == 0)) {
 205                         cache_drop(&nch);
 206                         vput(vp);
 207                         return (EOPNOTSUPP);    /* Needs translation */
 208                 }
 209                 /*
 210                  * Only root, or the user that did the original mount is
 211                  * permitted to update it.
 212                  */
 213                 if (mp->mnt_stat.f_owner != cred->cr_uid &&
 214                     (error = priv_check(td, PRIV_ROOT))) {
 215                         cache_drop(&nch);
 216                         vput(vp);
 217                         return (error);
 218                 }
 219                 if (vfs_busy(mp, LK_NOWAIT)) {
 220                         cache_drop(&nch);
 221                         vput(vp);
 222                         return (EBUSY);
 223                 }
 224                 if ((vp->v_flag & VMOUNT) != 0 || hasmount) {
 225                         cache_drop(&nch);
 226                         vfs_unbusy(mp);
 227                         vput(vp);
 228                         return (EBUSY);
 229                 }
 230                 vp->v_flag |= VMOUNT;
 231                 mp->mnt_flag |=
 232                     uap->flags & (MNT_RELOAD | MNT_FORCE | MNT_UPDATE);
 233                 vn_unlock(vp);
 234                 goto update;
 235         }
 236         /*
 237          * If the user is not root, ensure that they own the directory
 238          * onto which we are attempting to mount.
 239          */
 240         if ((error = VOP_GETATTR(vp, &va)) ||
 241             (va.va_uid != cred->cr_uid && (error = priv_check(td, PRIV_ROOT)))) {
 242                 cache_drop(&nch);
 243                 vput(vp);
 244                 return (error);
 245         }
 246         if ((error = vinvalbuf(vp, V_SAVE, 0, 0)) != 0) {
 247                 cache_drop(&nch);
 248                 vput(vp);
 249                 return (error);
 250         }
 251         if (vp->v_type != VDIR) {
 252                 cache_drop(&nch);
 253                 vput(vp);
 254                 return (ENOTDIR);
 255         }
 256         if (vp->v_mount->mnt_kern_flag & MNTK_NOSTKMNT) {
 257                 cache_drop(&nch);
 258                 vput(vp);
 259                 return (EPERM);
 260         }
 261         if ((error = copyinstr(uap->type, fstypename, MFSNAMELEN, NULL)) != 0) {
 262                 cache_drop(&nch);
 263                 vput(vp);
 264                 return (error);
 265         }
 266         vfsp = vfsconf_find_by_name(fstypename);
 267         if (vfsp == NULL) {
 268                 linker_file_t lf;
 269
 270                 /* Only load modules for root (very important!) */
 271                 if ((error = priv_check(td, PRIV_ROOT)) != 0) {
 272                         cache_drop(&nch);
 273                         vput(vp);
 274                         return error;
 275                 }
 276                 error = linker_load_file(fstypename, &lf);
 277                 if (error || lf == NULL) {
 278                         cache_drop(&nch);
 279                         vput(vp);
 280                         if (lf == NULL)
 281                                 error = ENODEV;
 282                         return error;
 283                 }
 284                 lf->userrefs++;
 285                 /* lookup again, see if the VFS was loaded */
 286                 vfsp = vfsconf_find_by_name(fstypename);
 287                 if (vfsp == NULL) {
 288                         lf->userrefs--;
 289                         linker_file_unload(lf);
 290                         cache_drop(&nch);
 291                         vput(vp);
 292                         return (ENODEV);
 293                 }
 294         }
 295         if ((vp->v_flag & VMOUNT) != 0 || hasmount) {
 296                 cache_drop(&nch);
 297                 vput(vp);
 298                 return (EBUSY);
 299         }
 300         vp->v_flag |= VMOUNT;
 301
 302         /*
 303          * Allocate and initialize the filesystem.
 304          */
 305         mp = kmalloc(sizeof(struct mount), M_MOUNT, M_ZERO|M_WAITOK);
 306         TAILQ_INIT(&mp->mnt_nvnodelist);
 307         TAILQ_INIT(&mp->mnt_reservedvnlist);
 308         TAILQ_INIT(&mp->mnt_jlist);
 309         mp->mnt_nvnodelistsize = 0;
 310         lockinit(&mp->mnt_lock, "vfslock", 0, 0);
 311         vfs_busy(mp, LK_NOWAIT);
 312         mp->mnt_op = vfsp->vfc_vfsops;
 313         mp->mnt_vfc = vfsp;
 314         vfsp->vfc_refcount++;
 315         mp->mnt_stat.f_type = vfsp->vfc_typenum;
 316         mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
 317         strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
 318         mp->mnt_stat.f_owner = cred->cr_uid;
 319         mp->mnt_iosize_max = DFLTPHYS;
 320         vn_unlock(vp);
 321 update:
 322         /*
 323          * Set the mount level flags.
 324          */
 325         if (uap->flags & MNT_RDONLY)
 326                 mp->mnt_flag |= MNT_RDONLY;
 327         else if (mp->mnt_flag & MNT_RDONLY)
 328                 mp->mnt_kern_flag |= MNTK_WANTRDWR;
 329         mp->mnt_flag &=~ (MNT_NOSUID | MNT_NOEXEC | MNT_NODEV |
 330             MNT_SYNCHRONOUS | MNT_UNION | MNT_ASYNC | MNT_NOATIME |
 331             MNT_NOSYMFOLLOW | MNT_IGNORE |
 332             MNT_NOCLUSTERR | MNT_NOCLUSTERW | MNT_SUIDDIR);
 333         mp->mnt_flag |= uap->flags & (MNT_NOSUID | MNT_NOEXEC |
 334             MNT_NODEV | MNT_SYNCHRONOUS | MNT_UNION | MNT_ASYNC | MNT_FORCE |
 335             MNT_NOSYMFOLLOW | MNT_IGNORE |
 336             MNT_NOATIME | MNT_NOCLUSTERR | MNT_NOCLUSTERW | MNT_SUIDDIR);
 337         /*
 338          * Mount the filesystem.
 339          * XXX The final recipients of VFS_MOUNT just overwrite the ndp they
 340          * get.
 341          */
 342         error = VFS_MOUNT(mp, uap->path, uap->data, cred);
 343         if (mp->mnt_flag & MNT_UPDATE) {
 344                 if (mp->mnt_kern_flag & MNTK_WANTRDWR)
 345                         mp->mnt_flag &= ~MNT_RDONLY;
 346                 mp->mnt_flag &=~ (MNT_UPDATE | MNT_RELOAD | MNT_FORCE);
 347                 mp->mnt_kern_flag &=~ MNTK_WANTRDWR;
 348                 if (error) {
 349                         mp->mnt_flag = flag;
 350                         mp->mnt_kern_flag = flag2;
 351                 }
 352                 vfs_unbusy(mp);
 353                 vp->v_flag &= ~VMOUNT;
 354                 vrele(vp);
 355                 cache_drop(&nch);
 356                 return (error);
 357         }
 358         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 359         /*
 360          * Put the new filesystem on the mount list after root.  The mount
 361          * point gets its own mnt_ncmountpt (unless the VFS already set one
 362          * up) which represents the root of the mount.  The lookup code
 363          * detects the mount point going forward and checks the root of
 364          * the mount going backwards.
 365          *
 366          * It is not necessary to invalidate or purge the vnode underneath
 367          * because elements under the mount will be given their own glue
 368          * namecache record.
 369          */
 370         if (!error) {
 371                 if (mp->mnt_ncmountpt.ncp == NULL) {
 372                         /*
 373                          * allocate, then unlock, but leave the ref intact
 374                          */
 375                         cache_allocroot(&mp->mnt_ncmountpt, mp, NULL);
 376                         cache_unlock(&mp->mnt_ncmountpt);
 377                 }
 378                 mp->mnt_ncmounton = nch;                /* inherits ref */
 379                 nch.ncp->nc_flag |= NCF_ISMOUNTPT;
 380
 381                 /* XXX get the root of the fs and cache_setvp(mnt_ncmountpt...) */
 382                 vp->v_flag &= ~VMOUNT;
 383                 mountlist_insert(mp, MNTINS_LAST);
 384                 vn_unlock(vp);
 385                 checkdirs(&mp->mnt_ncmounton, &mp->mnt_ncmountpt);
 386                 error = vfs_allocate_syncvnode(mp);
 387                 vfs_unbusy(mp);
 388                 error = VFS_START(mp, 0);
 389                 vrele(vp);
 390         } else {
 391                 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_coherency_ops);
 392                 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_journal_ops);
 393                 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_norm_ops);
 394                 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_spec_ops);
 395                 vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_fifo_ops);
 396                 vp->v_flag &= ~VMOUNT;
 397                 mp->mnt_vfc->vfc_refcount--;
 398                 vfs_unbusy(mp);
 399                 kfree(mp, M_MOUNT);
 400                 cache_drop(&nch);
 401                 vput(vp);
 402         }
 403         return (error);
 404 }
 405
 406 /*
 407  * Scan all active processes to see if any of them have a current
 408  * or root directory onto which the new filesystem has just been
 409  * mounted. If so, replace them with the new mount point.
 410  *
 411  * The passed ncp is ref'd and locked (from the mount code) and
 412  * must be associated with the vnode representing the root of the
 413  * mount point.
 414  */
 415 struct checkdirs_info {
 416         struct nchandle old_nch;
 417         struct nchandle new_nch;
 418         struct vnode *old_vp;
 419         struct vnode *new_vp;
 420 };
 421
 422 static int checkdirs_callback(struct proc *p, void *data);
 423
 424 static void
 425 checkdirs(struct nchandle *old_nch, struct nchandle *new_nch)
 426 {
 427         struct checkdirs_info info;
 428         struct vnode *olddp;
 429         struct vnode *newdp;
 430         struct mount *mp;
 431
 432         /*
 433          * If the old mount point's vnode has a usecount of 1, it is not
 434          * being held as a descriptor anywhere.
 435          */
 436         olddp = old_nch->ncp->nc_vp;
 437         if (olddp == NULL || olddp->v_sysref.refcnt == 1)
 438                 return;
 439
 440         /*
 441          * Force the root vnode of the new mount point to be resolved
 442          * so we can update any matching processes.
 443          */
 444         mp = new_nch->mount;
 445         if (VFS_ROOT(mp, &newdp))
 446                 panic("mount: lost mount");
 447         cache_setunresolved(new_nch);
 448         cache_setvp(new_nch, newdp);
 449
 450         /*
 451          * Special handling of the root node
 452          */
 453         if (rootvnode == olddp) {
 454                 vref(newdp);
 455                 vfs_cache_setroot(newdp, cache_hold(new_nch));
 456         }
 457
 458         /*
 459          * Pass newdp separately so the callback does not have to access
 460          * it via new_nch->ncp->nc_vp.
 461          */
 462         info.old_nch = *old_nch;
 463         info.new_nch = *new_nch;
 464         info.new_vp = newdp;
 465         allproc_scan(checkdirs_callback, &info);
 466         vput(newdp);
 467 }
 468
 469 /*
 470  * NOTE: callback is not MP safe because the scanned process's filedesc
 471  * structure can be ripped out from under us, amoung other things.
 472  */
 473 static int
 474 checkdirs_callback(struct proc *p, void *data)
 475 {
 476         struct checkdirs_info *info = data;
 477         struct filedesc *fdp;
 478         struct nchandle ncdrop1;
 479         struct nchandle ncdrop2;
 480         struct vnode *vprele1;
 481         struct vnode *vprele2;
 482
 483         if ((fdp = p->p_fd) != NULL) {
 484                 cache_zero(&ncdrop1);
 485                 cache_zero(&ncdrop2);
 486                 vprele1 = NULL;
 487                 vprele2 = NULL;
 488
 489                 /*
 490                  * MPUNSAFE - XXX fdp can be pulled out from under a
 491                  * foreign process.
 492                  *
 493                  * A shared filedesc is ok, we don't have to copy it
 494                  * because we are making this change globally.
 495                  */
 496                 spin_lock_wr(&fdp->fd_spin);
 497                 if (fdp->fd_ncdir.mount == info->old_nch.mount &&
 498                     fdp->fd_ncdir.ncp == info->old_nch.ncp) {
 499                         vprele1 = fdp->fd_cdir;
 500                         vref(info->new_vp);
 501                         fdp->fd_cdir = info->new_vp;
 502                         ncdrop1 = fdp->fd_ncdir;
 503                         cache_copy(&info->new_nch, &fdp->fd_ncdir);
 504                 }
 505                 if (fdp->fd_nrdir.mount == info->old_nch.mount &&
 506                     fdp->fd_nrdir.ncp == info->old_nch.ncp) {
 507                         vprele2 = fdp->fd_rdir;
 508                         vref(info->new_vp);
 509                         fdp->fd_rdir = info->new_vp;
 510                         ncdrop2 = fdp->fd_nrdir;
 511                         cache_copy(&info->new_nch, &fdp->fd_nrdir);
 512                 }
 513                 spin_unlock_wr(&fdp->fd_spin);
 514                 if (ncdrop1.ncp)
 515                         cache_drop(&ncdrop1);
 516                 if (ncdrop2.ncp)
 517                         cache_drop(&ncdrop2);
 518                 if (vprele1)
 519                         vrele(vprele1);
 520                 if (vprele2)
 521                         vrele(vprele2);
 522         }
 523         return(0);
 524 }
 525
 526 /*
 527  * Unmount a file system.
 528  *
 529  * Note: unmount takes a path to the vnode mounted on as argument,
 530  * not special file (as before).
 531  */
 532 /*
 533  * umount_args(char *path, int flags)
 534  */
 535 /* ARGSUSED */
 536 int
 537 sys_unmount(struct unmount_args *uap)
 538 {
 539         struct thread *td = curthread;
 540         struct proc *p = td->td_proc;
 541         struct mount *mp = NULL;
 542         int error;
 543         struct nlookupdata nd;
 544
 545         KKASSERT(p);
 546         if (p->p_ucred->cr_prison != NULL)
 547                 return (EPERM);
 548         if (usermount == 0 && (error = priv_check(td, PRIV_ROOT)))
 549                 return (error);
 550
 551         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
 552         if (error == 0)
 553                 error = nlookup(&nd);
 554         if (error)
 555                 goto out;
 556
 557         mp = nd.nl_nch.mount;
 558
 559         /*
 560          * Only root, or the user that did the original mount is
 561          * permitted to unmount this filesystem.
 562          */
 563         if ((mp->mnt_stat.f_owner != p->p_ucred->cr_uid) &&
 564             (error = priv_check(td, PRIV_ROOT)))
 565                 goto out;
 566
 567         /*
 568          * Don't allow unmounting the root file system.
 569          */
 570         if (mp->mnt_flag & MNT_ROOTFS) {
 571                 error = EINVAL;
 572                 goto out;
 573         }
 574
 575         /*
 576          * Must be the root of the filesystem
 577          */
 578         if (nd.nl_nch.ncp != mp->mnt_ncmountpt.ncp) {
 579                 error = EINVAL;
 580                 goto out;
 581         }
 582
 583 out:
 584         nlookup_done(&nd);
 585         if (error)
 586                 return (error);
 587         return (dounmount(mp, uap->flags));
 588 }
 589
 590 /*
 591  * Do the actual file system unmount.
 592  */
 593 static int
 594 dounmount_interlock(struct mount *mp)
 595 {
 596         if (mp->mnt_kern_flag & MNTK_UNMOUNT)
 597                 return (EBUSY);
 598         mp->mnt_kern_flag |= MNTK_UNMOUNT;
 599         return(0);
 600 }
 601
 602 int
 603 dounmount(struct mount *mp, int flags)
 604 {
 605         struct namecache *ncp;
 606         struct nchandle nch;
 607         struct vnode *vp;
 608         int error;
 609         int async_flag;
 610         int lflags;
 611         int freeok = 1;
 612
 613         /*
 614          * Exclusive access for unmounting purposes
 615          */
 616         if ((error = mountlist_interlock(dounmount_interlock, mp)) != 0)
 617                 return (error);
 618
 619         /*
 620          * Allow filesystems to detect that a forced unmount is in progress.
 621          */
 622         if (flags & MNT_FORCE)
 623                 mp->mnt_kern_flag |= MNTK_UNMOUNTF;
 624         lflags = LK_EXCLUSIVE | ((flags & MNT_FORCE) ? 0 : LK_NOWAIT);
 625         error = lockmgr(&mp->mnt_lock, lflags);
 626         if (error) {
 627                 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
 628                 if (mp->mnt_kern_flag & MNTK_MWAIT)
 629                         wakeup(mp);
 630                 return (error);
 631         }
 632
 633         if (mp->mnt_flag & MNT_EXPUBLIC)
 634                 vfs_setpublicfs(NULL, NULL, NULL);
 635
 636         vfs_msync(mp, MNT_WAIT);
 637         async_flag = mp->mnt_flag & MNT_ASYNC;
 638         mp->mnt_flag &=~ MNT_ASYNC;
 639
 640         /*
 641          * If this filesystem isn't aliasing other filesystems,
 642          * try to invalidate any remaining namecache entries and
 643          * check the count afterwords.
 644          */
 645         if ((mp->mnt_kern_flag & MNTK_NCALIASED) == 0) {
 646                 cache_lock(&mp->mnt_ncmountpt);
 647                 cache_inval(&mp->mnt_ncmountpt, CINV_DESTROY|CINV_CHILDREN);
 648                 cache_unlock(&mp->mnt_ncmountpt);
 649
 650                 if ((ncp = mp->mnt_ncmountpt.ncp) != NULL &&
 651                     (ncp->nc_refs != 1 || TAILQ_FIRST(&ncp->nc_list))) {
 652
 653                         if ((flags & MNT_FORCE) == 0) {
 654                                 error = EBUSY;
 655                                 mount_warning(mp, "Cannot unmount: "
 656                                                   "%d namecache "
 657                                                   "references still "
 658                                                   "present",
 659                                                   ncp->nc_refs - 1);
 660                         } else {
 661                                 mount_warning(mp, "Forced unmount: "
 662                                                   "%d namecache "
 663                                                   "references still "
 664                                                   "present",
 665                                                   ncp->nc_refs - 1);
 666                                 freeok = 0;
 667                         }
 668                 }
 669         }
 670
 671         /*
 672          * nchandle records ref the mount structure.  Expect a count of 1
 673          * (our mount->mnt_ncmountpt).
 674          */
 675         if (mp->mnt_refs != 1) {
 676                 if ((flags & MNT_FORCE) == 0) {
 677                         mount_warning(mp, "Cannot unmount: "
 678                                           "%d process references still "
 679                                           "present", mp->mnt_refs);
 680                         error = EBUSY;
 681                 } else {
 682                         mount_warning(mp, "Forced unmount: "
 683                                           "%d process references still "
 684                                           "present", mp->mnt_refs);
 685                         freeok = 0;
 686                 }
 687         }
 688
 689         /*
 690          * Decomission our special mnt_syncer vnode.  This also stops
 691          * the vnlru code.  If we are unable to unmount we recommission
 692          * the vnode.
 693          */
 694         if (error == 0) {
 695                 if ((vp = mp->mnt_syncer) != NULL) {
 696                         mp->mnt_syncer = NULL;
 697                         vrele(vp);
 698                 }
 699                 if (((mp->mnt_flag & MNT_RDONLY) ||
 700                      (error = VFS_SYNC(mp, MNT_WAIT)) == 0) ||
 701                     (flags & MNT_FORCE)) {
 702                         error = VFS_UNMOUNT(mp, flags);
 703                 }
 704         }
 705         if (error) {
 706                 if (mp->mnt_syncer == NULL)
 707                         vfs_allocate_syncvnode(mp);
 708                 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
 709                 mp->mnt_flag |= async_flag;
 710                 lockmgr(&mp->mnt_lock, LK_RELEASE);
 711                 if (mp->mnt_kern_flag & MNTK_MWAIT)
 712                         wakeup(mp);
 713                 return (error);
 714         }
 715         /*
 716          * Clean up any journals still associated with the mount after
 717          * filesystem activity has ceased.
 718          */
 719         journal_remove_all_journals(mp,
 720             ((flags & MNT_FORCE) ? MC_JOURNAL_STOP_IMM : 0));
 721
 722         mountlist_remove(mp);
 723
 724         /*
 725          * Remove any installed vnode ops here so the individual VFSs don't
 726          * have to.
 727          */
 728         vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_coherency_ops);
 729         vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_journal_ops);
 730         vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_norm_ops);
 731         vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_spec_ops);
 732         vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_fifo_ops);
 733
 734         if (mp->mnt_ncmountpt.ncp != NULL) {
 735                 nch = mp->mnt_ncmountpt;
 736                 cache_zero(&mp->mnt_ncmountpt);
 737                 cache_clrmountpt(&nch);
 738                 cache_drop(&nch);
 739         }
 740         if (mp->mnt_ncmounton.ncp != NULL) {
 741                 nch = mp->mnt_ncmounton;
 742                 cache_zero(&mp->mnt_ncmounton);
 743                 cache_clrmountpt(&nch);
 744                 cache_drop(&nch);
 745         }
 746
 747         mp->mnt_vfc->vfc_refcount--;
 748         if (!TAILQ_EMPTY(&mp->mnt_nvnodelist))
 749                 panic("unmount: dangling vnode");
 750         lockmgr(&mp->mnt_lock, LK_RELEASE);
 751         if (mp->mnt_kern_flag & MNTK_MWAIT)
 752                 wakeup(mp);
 753         if (freeok)
 754                 kfree(mp, M_MOUNT);
 755         return (0);
 756 }
 757
 758 static
 759 void
 760 mount_warning(struct mount *mp, const char *ctl, ...)
 761 {
 762         char *ptr;
 763         char *buf;
 764         __va_list va;
 765
 766         __va_start(va, ctl);
 767         if (cache_fullpath(NULL, &mp->mnt_ncmounton, &ptr, &buf) == 0) {
 768                 kprintf("unmount(%s): ", ptr);
 769                 kvprintf(ctl, va);
 770                 kprintf("\n");
 771                 kfree(buf, M_TEMP);
 772         } else {
 773                 kprintf("unmount(%p", mp);
 774                 if (mp->mnt_ncmounton.ncp && mp->mnt_ncmounton.ncp->nc_name)
 775                         kprintf(",%s", mp->mnt_ncmounton.ncp->nc_name);
 776                 kprintf("): ");
 777                 kvprintf(ctl, va);
 778                 kprintf("\n");
 779         }
 780         __va_end(va);
 781 }
 782
 783 /*
 784  * Shim cache_fullpath() to handle the case where a process is chrooted into
 785  * a subdirectory of a mount.  In this case if the root mount matches the
 786  * process root directory's mount we have to specify the process's root
 787  * directory instead of the mount point, because the mount point might
 788  * be above the root directory.
 789  */
 790 static
 791 int
 792 mount_path(struct proc *p, struct mount *mp, char **rb, char **fb)
 793 {
 794         struct nchandle *nch;
 795
 796         if (p && p->p_fd->fd_nrdir.mount == mp)
 797                 nch = &p->p_fd->fd_nrdir;
 798         else
 799                 nch = &mp->mnt_ncmountpt;
 800         return(cache_fullpath(p, nch, rb, fb));
 801 }
 802
 803 /*
 804  * Sync each mounted filesystem.
 805  */
 806
 807 #ifdef DEBUG
 808 static int syncprt = 0;
 809 SYSCTL_INT(_debug, OID_AUTO, syncprt, CTLFLAG_RW, &syncprt, 0, "");
 810 #endif /* DEBUG */
 811
 812 static int sync_callback(struct mount *mp, void *data);
 813
 814 /* ARGSUSED */
 815 int
 816 sys_sync(struct sync_args *uap)
 817 {
 818         mountlist_scan(sync_callback, NULL, MNTSCAN_FORWARD);
 819 #ifdef DEBUG
 820         /*
 821          * print out buffer pool stat information on each sync() call.
 822          */
 823         if (syncprt)
 824                 vfs_bufstats();
 825 #endif /* DEBUG */
 826         return (0);
 827 }
 828
 829 static
 830 int
 831 sync_callback(struct mount *mp, void *data __unused)
 832 {
 833         int asyncflag;
 834
 835         if ((mp->mnt_flag & MNT_RDONLY) == 0) {
 836                 asyncflag = mp->mnt_flag & MNT_ASYNC;
 837                 mp->mnt_flag &= ~MNT_ASYNC;
 838                 vfs_msync(mp, MNT_NOWAIT);
 839                 VFS_SYNC(mp, MNT_NOWAIT);
 840                 mp->mnt_flag |= asyncflag;
 841         }
 842         return(0);
 843 }
 844
 845 /* XXX PRISON: could be per prison flag */
 846 static int prison_quotas;
 847 #if 0
 848 SYSCTL_INT(_kern_prison, OID_AUTO, quotas, CTLFLAG_RW, &prison_quotas, 0, "");
 849 #endif
 850
 851 /*
 852  *  quotactl_args(char *path, int fcmd, int uid, caddr_t arg)
 853  *
 854  * Change filesystem quotas.
 855  */
 856 /* ARGSUSED */
 857 int
 858 sys_quotactl(struct quotactl_args *uap)
 859 {
 860         struct nlookupdata nd;
 861         struct thread *td;
 862         struct proc *p;
 863         struct mount *mp;
 864         int error;
 865
 866         td = curthread;
 867         p = td->td_proc;
 868         if (p->p_ucred->cr_prison && !prison_quotas)
 869                 return (EPERM);
 870
 871         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
 872         if (error == 0)
 873                 error = nlookup(&nd);
 874         if (error == 0) {
 875                 mp = nd.nl_nch.mount;
 876                 error = VFS_QUOTACTL(mp, uap->cmd, uap->uid,
 877                                     uap->arg, nd.nl_cred);
 878         }
 879         nlookup_done(&nd);
 880         return (error);
 881 }
 882
 883 /*
 884  * mountctl(char *path, int op, int fd, const void *ctl, int ctllen,
 885  *              void *buf, int buflen)
 886  *
 887  * This function operates on a mount point and executes the specified
 888  * operation using the specified control data, and possibly returns data.
 889  *
 890  * The actual number of bytes stored in the result buffer is returned, 0
 891  * if none, otherwise an error is returned.
 892  */
 893 /* ARGSUSED */
 894 int
 895 sys_mountctl(struct mountctl_args *uap)
 896 {
 897         struct thread *td = curthread;
 898         struct proc *p = td->td_proc;
 899         struct file *fp;
 900         void *ctl = NULL;
 901         void *buf = NULL;
 902         char *path = NULL;
 903         int error;
 904
 905         /*
 906          * Sanity and permissions checks.  We must be root.
 907          */
 908         KKASSERT(p);
 909         if (p->p_ucred->cr_prison != NULL)
 910                 return (EPERM);
 911         if ((error = priv_check(td, PRIV_ROOT)) != 0)
 912                 return (error);
 913
 914         /*
 915          * Argument length checks
 916          */
 917         if (uap->ctllen < 0 || uap->ctllen > 1024)
 918                 return (EINVAL);
 919         if (uap->buflen < 0 || uap->buflen > 16 * 1024)
 920                 return (EINVAL);
 921         if (uap->path == NULL)
 922                 return (EINVAL);
 923
 924         /*
 925          * Allocate the necessary buffers and copyin data
 926          */
 927         path = objcache_get(namei_oc, M_WAITOK);
 928         error = copyinstr(uap->path, path, MAXPATHLEN, NULL);
 929         if (error)
 930                 goto done;
 931
 932         if (uap->ctllen) {
 933                 ctl = kmalloc(uap->ctllen + 1, M_TEMP, M_WAITOK|M_ZERO);
 934                 error = copyin(uap->ctl, ctl, uap->ctllen);
 935                 if (error)
 936                         goto done;
 937         }
 938         if (uap->buflen)
 939                 buf = kmalloc(uap->buflen + 1, M_TEMP, M_WAITOK|M_ZERO);
 940
 941         /*
 942          * Validate the descriptor
 943          */
 944         if (uap->fd >= 0) {
 945                 fp = holdfp(p->p_fd, uap->fd, -1);
 946                 if (fp == NULL) {
 947                         error = EBADF;
 948                         goto done;
 949                 }
 950         } else {
 951                 fp = NULL;
 952         }
 953
 954         /*
 955          * Execute the internal kernel function and clean up.
 956          */
 957         error = kern_mountctl(path, uap->op, fp, ctl, uap->ctllen, buf, uap->buflen, &uap->sysmsg_result);
 958         if (fp)
 959                 fdrop(fp);
 960         if (error == 0 && uap->sysmsg_result > 0)
 961                 error = copyout(buf, uap->buf, uap->sysmsg_result);
 962 done:
 963         if (path)
 964                 objcache_put(namei_oc, path);
 965         if (ctl)
 966                 kfree(ctl, M_TEMP);
 967         if (buf)
 968                 kfree(buf, M_TEMP);
 969         return (error);
 970 }
 971
 972 /*
 973  * Execute a mount control operation by resolving the path to a mount point
 974  * and calling vop_mountctl().
 975  *
 976  * Use the mount point from the nch instead of the vnode so nullfs mounts
 977  * can properly spike the VOP.
 978  */
 979 int
 980 kern_mountctl(const char *path, int op, struct file *fp,
 981                 const void *ctl, int ctllen,
 982                 void *buf, int buflen, int *res)
 983 {
 984         struct vnode *vp;
 985         struct mount *mp;
 986         struct nlookupdata nd;
 987         int error;
 988
 989         *res = 0;
 990         vp = NULL;
 991         error = nlookup_init(&nd, path, UIO_SYSSPACE, NLC_FOLLOW);
 992         if (error == 0)
 993                 error = nlookup(&nd);
 994         if (error == 0)
 995                 error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
 996         mp = nd.nl_nch.mount;
 997         nlookup_done(&nd);
 998         if (error)
 999                 return (error);
1000
1001         /*
1002          * Must be the root of the filesystem
1003          */
1004         if ((vp->v_flag & (VROOT|VPFSROOT)) == 0) {
1005                 vput(vp);
1006                 return (EINVAL);
1007         }
1008         error = vop_mountctl(mp->mnt_vn_use_ops, op, fp, ctl, ctllen,
1009                                 buf, buflen, res);
1010         vput(vp);
1011         return (error);
1012 }
1013
1014 int
1015 kern_statfs(struct nlookupdata *nd, struct statfs *buf)
1016 {
1017         struct thread *td = curthread;
1018         struct proc *p = td->td_proc;
1019         struct mount *mp;
1020         struct statfs *sp;
1021         char *fullpath, *freepath;
1022         int error;
1023
1024         if ((error = nlookup(nd)) != 0)
1025                 return (error);
1026         mp = nd->nl_nch.mount;
1027         sp = &mp->mnt_stat;
1028         if ((error = VFS_STATFS(mp, sp, nd->nl_cred)) != 0)
1029                 return (error);
1030
1031         error = mount_path(p, mp, &fullpath, &freepath);
1032         if (error)
1033                 return(error);
1034         bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
1035         strlcpy(sp->f_mntonname, fullpath, sizeof(sp->f_mntonname));
1036         kfree(freepath, M_TEMP);
1037
1038         sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
1039         bcopy(sp, buf, sizeof(*buf));
1040         /* Only root should have access to the fsid's. */
1041         if (priv_check(td, PRIV_ROOT))
1042                 buf->f_fsid.val[0] = buf->f_fsid.val[1] = 0;
1043         return (0);
1044 }
1045
1046 /*
1047  * statfs_args(char *path, struct statfs *buf)
1048  *
1049  * Get filesystem statistics.
1050  */
1051 int
1052 sys_statfs(struct statfs_args *uap)
1053 {
1054         struct nlookupdata nd;
1055         struct statfs buf;
1056         int error;
1057
1058         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
1059         if (error == 0)
1060                 error = kern_statfs(&nd, &buf);
1061         nlookup_done(&nd);
1062         if (error == 0)
1063                 error = copyout(&buf, uap->buf, sizeof(*uap->buf));
1064         return (error);
1065 }
1066
1067 int
1068 kern_fstatfs(int fd, struct statfs *buf)
1069 {
1070         struct thread *td = curthread;
1071         struct proc *p = td->td_proc;
1072         struct file *fp;
1073         struct mount *mp;
1074         struct statfs *sp;
1075         char *fullpath, *freepath;
1076         int error;
1077
1078         KKASSERT(p);
1079         if ((error = holdvnode(p->p_fd, fd, &fp)) != 0)
1080                 return (error);
1081         mp = ((struct vnode *)fp->f_data)->v_mount;
1082         if (mp == NULL) {
1083                 error = EBADF;
1084                 goto done;
1085         }
1086         if (fp->f_cred == NULL) {
1087                 error = EINVAL;
1088                 goto done;
1089         }
1090         sp = &mp->mnt_stat;
1091         if ((error = VFS_STATFS(mp, sp, fp->f_cred)) != 0)
1092                 goto done;
1093
1094         if ((error = mount_path(p, mp, &fullpath, &freepath)) != 0)
1095                 goto done;
1096         bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
1097         strlcpy(sp->f_mntonname, fullpath, sizeof(sp->f_mntonname));
1098         kfree(freepath, M_TEMP);
1099
1100         sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
1101         bcopy(sp, buf, sizeof(*buf));
1102
1103         /* Only root should have access to the fsid's. */
1104         if (priv_check(td, PRIV_ROOT))
1105                 buf->f_fsid.val[0] = buf->f_fsid.val[1] = 0;
1106         error = 0;
1107 done:
1108         fdrop(fp);
1109         return (error);
1110 }
1111
1112 /*
1113  * fstatfs_args(int fd, struct statfs *buf)
1114  *
1115  * Get filesystem statistics.
1116  */
1117 int
1118 sys_fstatfs(struct fstatfs_args *uap)
1119 {
1120         struct statfs buf;
1121         int error;
1122
1123         error = kern_fstatfs(uap->fd, &buf);
1124
1125         if (error == 0)
1126                 error = copyout(&buf, uap->buf, sizeof(*uap->buf));
1127         return (error);
1128 }
1129
1130 int
1131 kern_statvfs(struct nlookupdata *nd, struct statvfs *buf)
1132 {
1133         struct mount *mp;
1134         struct statvfs *sp;
1135         int error;
1136
1137         if ((error = nlookup(nd)) != 0)
1138                 return (error);
1139         mp = nd->nl_nch.mount;
1140         sp = &mp->mnt_vstat;
1141         if ((error = VFS_STATVFS(mp, sp, nd->nl_cred)) != 0)
1142                 return (error);
1143
1144         sp->f_flag = 0;
1145         if (mp->mnt_flag & MNT_RDONLY)
1146                 sp->f_flag |= ST_RDONLY;
1147         if (mp->mnt_flag & MNT_NOSUID)
1148                 sp->f_flag |= ST_NOSUID;
1149         bcopy(sp, buf, sizeof(*buf));
1150         return (0);
1151 }
1152
1153 /*
1154  * statfs_args(char *path, struct statfs *buf)
1155  *
1156  * Get filesystem statistics.
1157  */
1158 int
1159 sys_statvfs(struct statvfs_args *uap)
1160 {
1161         struct nlookupdata nd;
1162         struct statvfs buf;
1163         int error;
1164
1165         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
1166         if (error == 0)
1167                 error = kern_statvfs(&nd, &buf);
1168         nlookup_done(&nd);
1169         if (error == 0)
1170                 error = copyout(&buf, uap->buf, sizeof(*uap->buf));
1171         return (error);
1172 }
1173
1174 int
1175 kern_fstatvfs(int fd, struct statvfs *buf)
1176 {
1177         struct thread *td = curthread;
1178         struct proc *p = td->td_proc;
1179         struct file *fp;
1180         struct mount *mp;
1181         struct statvfs *sp;
1182         int error;
1183
1184         KKASSERT(p);
1185         if ((error = holdvnode(p->p_fd, fd, &fp)) != 0)
1186                 return (error);
1187         mp = ((struct vnode *)fp->f_data)->v_mount;
1188         if (mp == NULL) {
1189                 error = EBADF;
1190                 goto done;
1191         }
1192         if (fp->f_cred == NULL) {
1193                 error = EINVAL;
1194                 goto done;
1195         }
1196         sp = &mp->mnt_vstat;
1197         if ((error = VFS_STATVFS(mp, sp, fp->f_cred)) != 0)
1198                 goto done;
1199
1200         sp->f_flag = 0;
1201         if (mp->mnt_flag & MNT_RDONLY)
1202                 sp->f_flag |= ST_RDONLY;
1203         if (mp->mnt_flag & MNT_NOSUID)
1204                 sp->f_flag |= ST_NOSUID;
1205
1206         bcopy(sp, buf, sizeof(*buf));
1207         error = 0;
1208 done:
1209         fdrop(fp);
1210         return (error);
1211 }
1212
1213 /*
1214  * fstatfs_args(int fd, struct statfs *buf)
1215  *
1216  * Get filesystem statistics.
1217  */
1218 int
1219 sys_fstatvfs(struct fstatvfs_args *uap)
1220 {
1221         struct statvfs buf;
1222         int error;
1223
1224         error = kern_fstatvfs(uap->fd, &buf);
1225
1226         if (error == 0)
1227                 error = copyout(&buf, uap->buf, sizeof(*uap->buf));
1228         return (error);
1229 }
1230
1231 /*
1232  * getfsstat_args(struct statfs *buf, long bufsize, int flags)
1233  *
1234  * Get statistics on all filesystems.
1235  */
1236
1237 struct getfsstat_info {
1238         struct statfs *sfsp;
1239         long count;
1240         long maxcount;
1241         int error;
1242         int flags;
1243         struct proc *p;
1244 };
1245
1246 static int getfsstat_callback(struct mount *, void *);
1247
1248 /* ARGSUSED */
1249 int
1250 sys_getfsstat(struct getfsstat_args *uap)
1251 {
1252         struct thread *td = curthread;
1253         struct proc *p = td->td_proc;
1254         struct getfsstat_info info;
1255
1256         bzero(&info, sizeof(info));
1257
1258         info.maxcount = uap->bufsize / sizeof(struct statfs);
1259         info.sfsp = uap->buf;
1260         info.count = 0;
1261         info.flags = uap->flags;
1262         info.p = p;
1263
1264         mountlist_scan(getfsstat_callback, &info, MNTSCAN_FORWARD);
1265         if (info.sfsp && info.count > info.maxcount)
1266                 uap->sysmsg_result = info.maxcount;
1267         else
1268                 uap->sysmsg_result = info.count;
1269         return (info.error);
1270 }
1271
1272 static int
1273 getfsstat_callback(struct mount *mp, void *data)
1274 {
1275         struct getfsstat_info *info = data;
1276         struct statfs *sp;
1277         char *freepath;
1278         char *fullpath;
1279         int error;
1280
1281         if (info->sfsp && info->count < info->maxcount) {
1282                 if (info->p && !chroot_visible_mnt(mp, info->p))
1283                         return(0);
1284                 sp = &mp->mnt_stat;
1285
1286                 /*
1287                  * If MNT_NOWAIT or MNT_LAZY is specified, do not
1288                  * refresh the fsstat cache. MNT_NOWAIT or MNT_LAZY
1289                  * overrides MNT_WAIT.
1290                  */
1291                 if (((info->flags & (MNT_LAZY|MNT_NOWAIT)) == 0 ||
1292                     (info->flags & MNT_WAIT)) &&
1293                     (error = VFS_STATFS(mp, sp, info->p->p_ucred))) {
1294                         return(0);
1295                 }
1296                 sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
1297
1298                 error = mount_path(info->p, mp, &fullpath, &freepath);
1299                 if (error) {
1300                         info->error = error;
1301                         return(-1);
1302                 }
1303                 bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
1304                 strlcpy(sp->f_mntonname, fullpath, sizeof(sp->f_mntonname));
1305                 kfree(freepath, M_TEMP);
1306
1307                 error = copyout(sp, info->sfsp, sizeof(*sp));
1308                 if (error) {
1309                         info->error = error;
1310                         return (-1);
1311                 }
1312                 ++info->sfsp;
1313         }
1314         info->count++;
1315         return(0);
1316 }
1317
1318 /*
1319  * getvfsstat_args(struct statfs *buf, struct statvfs *vbuf,
1320                    long bufsize, int flags)
1321  *
1322  * Get statistics on all filesystems.
1323  */
1324
1325 struct getvfsstat_info {
1326         struct statfs *sfsp;
1327         struct statvfs *vsfsp;
1328         long count;
1329         long maxcount;
1330         int error;
1331         int flags;
1332         struct proc *p;
1333 };
1334
1335 static int getvfsstat_callback(struct mount *, void *);
1336
1337 /* ARGSUSED */
1338 int
1339 sys_getvfsstat(struct getvfsstat_args *uap)
1340 {
1341         struct thread *td = curthread;
1342         struct proc *p = td->td_proc;
1343         struct getvfsstat_info info;
1344
1345         bzero(&info, sizeof(info));
1346
1347         info.maxcount = uap->vbufsize / sizeof(struct statvfs);
1348         info.sfsp = uap->buf;
1349         info.vsfsp = uap->vbuf;
1350         info.count = 0;
1351         info.flags = uap->flags;
1352         info.p = p;
1353
1354         mountlist_scan(getvfsstat_callback, &info, MNTSCAN_FORWARD);
1355         if (info.vsfsp && info.count > info.maxcount)
1356                 uap->sysmsg_result = info.maxcount;
1357         else
1358                 uap->sysmsg_result = info.count;
1359         return (info.error);
1360 }
1361
1362 static int
1363 getvfsstat_callback(struct mount *mp, void *data)
1364 {
1365         struct getvfsstat_info *info = data;
1366         struct statfs *sp;
1367         struct statvfs *vsp;
1368         char *freepath;
1369         char *fullpath;
1370         int error;
1371
1372         if (info->vsfsp && info->count < info->maxcount) {
1373                 if (info->p && !chroot_visible_mnt(mp, info->p))
1374                         return(0);
1375                 sp = &mp->mnt_stat;
1376                 vsp = &mp->mnt_vstat;
1377
1378                 /*
1379                  * If MNT_NOWAIT or MNT_LAZY is specified, do not
1380                  * refresh the fsstat cache. MNT_NOWAIT or MNT_LAZY
1381                  * overrides MNT_WAIT.
1382                  */
1383                 if (((info->flags & (MNT_LAZY|MNT_NOWAIT)) == 0 ||
1384                     (info->flags & MNT_WAIT)) &&
1385                     (error = VFS_STATFS(mp, sp, info->p->p_ucred))) {
1386                         return(0);
1387                 }
1388                 sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
1389
1390                 if (((info->flags & (MNT_LAZY|MNT_NOWAIT)) == 0 ||
1391                     (info->flags & MNT_WAIT)) &&
1392                     (error = VFS_STATVFS(mp, vsp, info->p->p_ucred))) {
1393                         return(0);
1394                 }
1395                 vsp->f_flag = 0;
1396                 if (mp->mnt_flag & MNT_RDONLY)
1397                         vsp->f_flag |= ST_RDONLY;
1398                 if (mp->mnt_flag & MNT_NOSUID)
1399                         vsp->f_flag |= ST_NOSUID;
1400
1401                 error = mount_path(info->p, mp, &fullpath, &freepath);
1402                 if (error) {
1403                         info->error = error;
1404                         return(-1);
1405                 }
1406                 bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
1407                 strlcpy(sp->f_mntonname, fullpath, sizeof(sp->f_mntonname));
1408                 kfree(freepath, M_TEMP);
1409
1410                 error = copyout(sp, info->sfsp, sizeof(*sp));
1411                 if (error == 0)
1412                         error = copyout(vsp, info->vsfsp, sizeof(*vsp));
1413                 if (error) {
1414                         info->error = error;
1415                         return (-1);
1416                 }
1417                 ++info->sfsp;
1418                 ++info->vsfsp;
1419         }
1420         info->count++;
1421         return(0);
1422 }
1423
1424
1425 /*
1426  * fchdir_args(int fd)
1427  *
1428  * Change current working directory to a given file descriptor.
1429  */
1430 /* ARGSUSED */
1431 int
1432 sys_fchdir(struct fchdir_args *uap)
1433 {
1434         struct thread *td = curthread;
1435         struct proc *p = td->td_proc;
1436         struct filedesc *fdp = p->p_fd;
1437         struct vnode *vp, *ovp;
1438         struct mount *mp;
1439         struct file *fp;
1440         struct nchandle nch, onch, tnch;
1441         int error;
1442
1443         if ((error = holdvnode(fdp, uap->fd, &fp)) != 0)
1444                 return (error);
1445         vp = (struct vnode *)fp->f_data;
1446         vref(vp);
1447         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1448         if (vp->v_type != VDIR || fp->f_nchandle.ncp == NULL)
1449                 error = ENOTDIR;
1450         else
1451                 error = VOP_ACCESS(vp, VEXEC, p->p_ucred);
1452         if (error) {
1453                 vput(vp);
1454                 fdrop(fp);
1455                 return (error);
1456         }
1457         cache_copy(&fp->f_nchandle, &nch);
1458
1459         /*
1460          * If the ncp has become a mount point, traverse through
1461          * the mount point.
1462          */
1463
1464         while (!error && (nch.ncp->nc_flag & NCF_ISMOUNTPT) &&
1465                (mp = cache_findmount(&nch)) != NULL
1466         ) {
1467                 error = nlookup_mp(mp, &tnch);
1468                 if (error == 0) {
1469                         cache_unlock(&tnch);    /* leave ref intact */
1470                         vput(vp);
1471                         vp = tnch.ncp->nc_vp;
1472                         error = vget(vp, LK_SHARED);
1473                         KKASSERT(error == 0);
1474                         cache_drop(&nch);
1475                         nch = tnch;
1476                 }
1477         }
1478         if (error == 0) {
1479                 ovp = fdp->fd_cdir;
1480                 onch = fdp->fd_ncdir;
1481                 vn_unlock(vp);          /* leave ref intact */
1482                 fdp->fd_cdir = vp;
1483                 fdp->fd_ncdir = nch;
1484                 cache_drop(&onch);
1485                 vrele(ovp);
1486         } else {
1487                 cache_drop(&nch);
1488                 vput(vp);
1489         }
1490         fdrop(fp);
1491         return (error);
1492 }
1493
1494 int
1495 kern_chdir(struct nlookupdata *nd)
1496 {
1497         struct thread *td = curthread;
1498         struct proc *p = td->td_proc;
1499         struct filedesc *fdp = p->p_fd;
1500         struct vnode *vp, *ovp;
1501         struct nchandle onch;
1502         int error;
1503
1504         if ((error = nlookup(nd)) != 0)
1505                 return (error);
1506         if ((vp = nd->nl_nch.ncp->nc_vp) == NULL)
1507                 return (ENOENT);
1508         if ((error = vget(vp, LK_SHARED)) != 0)
1509                 return (error);
1510
1511         error = checkvp_chdir(vp, td);
1512         vn_unlock(vp);
1513         if (error == 0) {
1514                 ovp = fdp->fd_cdir;
1515                 onch = fdp->fd_ncdir;
1516                 cache_unlock(&nd->nl_nch);      /* leave reference intact */
1517                 fdp->fd_ncdir = nd->nl_nch;
1518                 fdp->fd_cdir = vp;
1519                 cache_drop(&onch);
1520                 vrele(ovp);
1521                 cache_zero(&nd->nl_nch);
1522         } else {
1523                 vrele(vp);
1524         }
1525         return (error);
1526 }
1527
1528 /*
1529  * chdir_args(char *path)
1530  *
1531  * Change current working directory (``.'').
1532  */
1533 int
1534 sys_chdir(struct chdir_args *uap)
1535 {
1536         struct nlookupdata nd;
1537         int error;
1538
1539         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
1540         if (error == 0)
1541                 error = kern_chdir(&nd);
1542         nlookup_done(&nd);
1543         return (error);
1544 }
1545
1546 /*
1547  * Helper function for raised chroot(2) security function:  Refuse if
1548  * any filedescriptors are open directories.
1549  */
1550 static int
1551 chroot_refuse_vdir_fds(struct filedesc *fdp)
1552 {
1553         struct vnode *vp;
1554         struct file *fp;
1555         int error;
1556         int fd;
1557
1558         for (fd = 0; fd < fdp->fd_nfiles ; fd++) {
1559                 if ((error = holdvnode(fdp, fd, &fp)) != 0)
1560                         continue;
1561                 vp = (struct vnode *)fp->f_data;
1562                 if (vp->v_type != VDIR) {
1563                         fdrop(fp);
1564                         continue;
1565                 }
1566                 fdrop(fp);
1567                 return(EPERM);
1568         }
1569         return (0);
1570 }
1571
1572 /*
1573  * This sysctl determines if we will allow a process to chroot(2) if it
1574  * has a directory open:
1575  *      0: disallowed for all processes.
1576  *      1: allowed for processes that were not already chroot(2)'ed.
1577  *      2: allowed for all processes.
1578  */
1579
1580 static int chroot_allow_open_directories = 1;
1581
1582 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW,
1583      &chroot_allow_open_directories, 0, "");
1584
1585 /*
1586  * chroot to the specified namecache entry.  We obtain the vp from the
1587  * namecache data.  The passed ncp must be locked and referenced and will
1588  * remain locked and referenced on return.
1589  */
1590 int
1591 kern_chroot(struct nchandle *nch)
1592 {
1593         struct thread *td = curthread;
1594         struct proc *p = td->td_proc;
1595         struct filedesc *fdp = p->p_fd;
1596         struct vnode *vp;
1597         int error;
1598
1599         /*
1600          * Only privileged user can chroot
1601          */
1602         error = priv_check_cred(p->p_ucred, PRIV_VFS_CHROOT, 0);
1603         if (error)
1604                 return (error);
1605
1606         /*
1607          * Disallow open directory descriptors (fchdir() breakouts).
1608          */
1609         if (chroot_allow_open_directories == 0 ||
1610            (chroot_allow_open_directories == 1 && fdp->fd_rdir != rootvnode)) {
1611                 if ((error = chroot_refuse_vdir_fds(fdp)) != 0)
1612                         return (error);
1613         }
1614         if ((vp = nch->ncp->nc_vp) == NULL)
1615                 return (ENOENT);
1616
1617         if ((error = vget(vp, LK_SHARED)) != 0)
1618                 return (error);
1619
1620         /*
1621          * Check the validity of vp as a directory to change to and
1622          * associate it with rdir/jdir.
1623          */
1624         error = checkvp_chdir(vp, td);
1625         vn_unlock(vp);                  /* leave reference intact */
1626         if (error == 0) {
1627                 vrele(fdp->fd_rdir);
1628                 fdp->fd_rdir = vp;      /* reference inherited by fd_rdir */
1629                 cache_drop(&fdp->fd_nrdir);
1630                 cache_copy(nch, &fdp->fd_nrdir);
1631                 if (fdp->fd_jdir == NULL) {
1632                         fdp->fd_jdir = vp;
1633                         vref(fdp->fd_jdir);
1634                         cache_copy(nch, &fdp->fd_njdir);
1635                 }
1636         } else {
1637                 vrele(vp);
1638         }
1639         return (error);
1640 }
1641
1642 /*
1643  * chroot_args(char *path)
1644  *
1645  * Change notion of root (``/'') directory.
1646  */
1647 /* ARGSUSED */
1648 int
1649 sys_chroot(struct chroot_args *uap)
1650 {
1651         struct thread *td = curthread;
1652         struct nlookupdata nd;
1653         int error;
1654
1655         KKASSERT(td->td_proc);
1656         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
1657         if (error) {
1658                 nlookup_done(&nd);
1659                 return(error);
1660         }
1661         nd.nl_flags |= NLC_EXEC;
1662         error = nlookup(&nd);
1663         if (error == 0)
1664                 error = kern_chroot(&nd.nl_nch);
1665         nlookup_done(&nd);
1666         return(error);
1667 }
1668
1669 /*
1670  * Common routine for chroot and chdir.  Given a locked, referenced vnode,
1671  * determine whether it is legal to chdir to the vnode.  The vnode's state
1672  * is not changed by this call.
1673  */
1674 int
1675 checkvp_chdir(struct vnode *vp, struct thread *td)
1676 {
1677         int error;
1678
1679         if (vp->v_type != VDIR)
1680                 error = ENOTDIR;
1681         else
1682                 error = VOP_ACCESS(vp, VEXEC, td->td_proc->p_ucred);
1683         return (error);
1684 }
1685
1686 int
1687 kern_open(struct nlookupdata *nd, int oflags, int mode, int *res)
1688 {
1689         struct thread *td = curthread;
1690         struct proc *p = td->td_proc;
1691         struct lwp *lp = td->td_lwp;
1692         struct filedesc *fdp = p->p_fd;
1693         int cmode, flags;
1694         struct file *nfp;
1695         struct file *fp;
1696         struct vnode *vp;
1697         int type, indx, error;
1698         struct flock lf;
1699
1700         if ((oflags & O_ACCMODE) == O_ACCMODE)
1701                 return (EINVAL);
1702         flags = FFLAGS(oflags);
1703         error = falloc(p, &nfp, NULL);
1704         if (error)
1705                 return (error);
1706         fp = nfp;
1707         cmode = ((mode &~ fdp->fd_cmask) & ALLPERMS) & ~S_ISTXT;
1708
1709         /*
1710          * XXX p_dupfd is a real mess.  It allows a device to return a
1711          * file descriptor to be duplicated rather then doing the open
1712          * itself.
1713          */
1714         lp->lwp_dupfd = -1;
1715
1716         /*
1717          * Call vn_open() to do the lookup and assign the vnode to the
1718          * file pointer.  vn_open() does not change the ref count on fp
1719          * and the vnode, on success, will be inherited by the file pointer
1720          * and unlocked.
1721          */
1722         nd->nl_flags |= NLC_LOCKVP;
1723         error = vn_open(nd, fp, flags, cmode);
1724         nlookup_done(nd);
1725         if (error) {
1726                 /*
1727                  * handle special fdopen() case.  bleh.  dupfdopen() is
1728                  * responsible for dropping the old contents of ofiles[indx]
1729                  * if it succeeds.
1730                  *
1731                  * Note that fsetfd() will add a ref to fp which represents
1732                  * the fd_files[] assignment.  We must still drop our
1733                  * reference.
1734                  */
1735                 if ((error == ENODEV || error == ENXIO) && lp->lwp_dupfd >= 0) {
1736                         if (fdalloc(p, 0, &indx) == 0) {
1737                                 error = dupfdopen(p, indx, lp->lwp_dupfd, flags, error);
1738                                 if (error == 0) {
1739                                         *res = indx;
1740                                         fdrop(fp);      /* our ref */
1741                                         return (0);
1742                                 }
1743                                 fsetfd(p, NULL, indx);
1744                         }
1745                 }
1746                 fdrop(fp);      /* our ref */
1747                 if (error == ERESTART)
1748                         error = EINTR;
1749                 return (error);
1750         }
1751
1752         /*
1753          * ref the vnode for ourselves so it can't be ripped out from under
1754          * is.  XXX need an ND flag to request that the vnode be returned
1755          * anyway.
1756          *
1757          * Reserve a file descriptor but do not assign it until the open
1758          * succeeds.
1759          */
1760         vp = (struct vnode *)fp->f_data;
1761         vref(vp);
1762         if ((error = fdalloc(p, 0, &indx)) != 0) {
1763                 fdrop(fp);
1764                 vrele(vp);
1765                 return (error);
1766         }
1767
1768         /*
1769          * If no error occurs the vp will have been assigned to the file
1770          * pointer.
1771          */
1772         lp->lwp_dupfd = 0;
1773
1774         if (flags & (O_EXLOCK | O_SHLOCK)) {
1775                 lf.l_whence = SEEK_SET;
1776                 lf.l_start = 0;
1777                 lf.l_len = 0;
1778                 if (flags & O_EXLOCK)
1779                         lf.l_type = F_WRLCK;
1780                 else
1781                         lf.l_type = F_RDLCK;
1782                 if (flags & FNONBLOCK)
1783                         type = 0;
1784                 else
1785                         type = F_WAIT;
1786
1787                 if ((error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type)) != 0) {
1788                         /*
1789                          * lock request failed.  Clean up the reserved
1790                          * descriptor.
1791                          */
1792                         vrele(vp);
1793                         fsetfd(p, NULL, indx);
1794                         fdrop(fp);
1795                         return (error);
1796                 }
1797                 fp->f_flag |= FHASLOCK;
1798         }
1799 #if 0
1800         /*
1801          * Assert that all regular file vnodes were created with a object.
1802          */
1803         KASSERT(vp->v_type != VREG || vp->v_object != NULL,
1804                 ("open: regular file has no backing object after vn_open"));
1805 #endif
1806
1807         vrele(vp);
1808
1809         /*
1810          * release our private reference, leaving the one associated with the
1811          * descriptor table intact.
1812          */
1813         fsetfd(p, fp, indx);
1814         fdrop(fp);
1815         *res = indx;
1816         return (0);
1817 }
1818
1819 /*
1820  * open_args(char *path, int flags, int mode)
1821  *
1822  * Check permissions, allocate an open file structure,
1823  * and call the device open routine if any.
1824  */
1825 int
1826 sys_open(struct open_args *uap)
1827 {
1828         struct nlookupdata nd;
1829         int error;
1830
1831         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
1832         if (error == 0) {
1833                 error = kern_open(&nd, uap->flags,
1834                                     uap->mode, &uap->sysmsg_result);
1835         }
1836         nlookup_done(&nd);
1837         return (error);
1838 }
1839
1840 int
1841 kern_mknod(struct nlookupdata *nd, int mode, int rmajor, int rminor)
1842 {
1843         struct thread *td = curthread;
1844         struct proc *p = td->td_proc;
1845         struct vnode *vp;
1846         struct vattr vattr;
1847         int error;
1848         int whiteout = 0;
1849
1850         KKASSERT(p);
1851
1852         VATTR_NULL(&vattr);
1853         vattr.va_mode = (mode & ALLPERMS) &~ p->p_fd->fd_cmask;
1854         vattr.va_rmajor = rmajor;
1855         vattr.va_rminor = rminor;
1856
1857         switch (mode & S_IFMT) {
1858         case S_IFMT:    /* used by badsect to flag bad sectors */
1859                 error = priv_check_cred(p->p_ucred, PRIV_VFS_MKNOD_BAD, 0);
1860                 vattr.va_type = VBAD;
1861                 break;
1862         case S_IFCHR:
1863                 error = priv_check(td, PRIV_VFS_MKNOD_DEV);
1864                 vattr.va_type = VCHR;
1865                 break;
1866         case S_IFBLK:
1867                 error = priv_check(td, PRIV_VFS_MKNOD_DEV);
1868                 vattr.va_type = VBLK;
1869                 break;
1870         case S_IFWHT:
1871                 error = priv_check_cred(p->p_ucred, PRIV_VFS_MKNOD_WHT, 0);
1872                 whiteout = 1;
1873                 break;
1874         case S_IFDIR:   /* special directories support for HAMMER */
1875                 error = priv_check_cred(p->p_ucred, PRIV_VFS_MKNOD_DIR, 0);
1876                 vattr.va_type = VDIR;
1877                 break;
1878         default:
1879                 error = EINVAL;
1880                 break;
1881         }
1882
1883         if (error)
1884                 return (error);
1885
1886         bwillinode(1);
1887         nd->nl_flags |= NLC_CREATE | NLC_REFDVP;
1888         if ((error = nlookup(nd)) != 0)
1889                 return (error);
1890         if (nd->nl_nch.ncp->nc_vp)
1891                 return (EEXIST);
1892         if ((error = ncp_writechk(&nd->nl_nch)) != 0)
1893                 return (error);
1894
1895         if (whiteout) {
1896                 error = VOP_NWHITEOUT(&nd->nl_nch, nd->nl_dvp,
1897                                       nd->nl_cred, NAMEI_CREATE);
1898         } else {
1899                 vp = NULL;
1900                 error = VOP_NMKNOD(&nd->nl_nch, nd->nl_dvp,
1901                                    &vp, nd->nl_cred, &vattr);
1902                 if (error == 0)
1903                         vput(vp);
1904         }
1905         return (error);
1906 }
1907
1908 /*
1909  * mknod_args(char *path, int mode, int dev)
1910  *
1911  * Create a special file.
1912  */
1913 int
1914 sys_mknod(struct mknod_args *uap)
1915 {
1916         struct nlookupdata nd;
1917         int error;
1918
1919         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
1920         if (error == 0) {
1921                 error = kern_mknod(&nd, uap->mode,
1922                                    umajor(uap->dev), uminor(uap->dev));
1923         }
1924         nlookup_done(&nd);
1925         return (error);
1926 }
1927
1928 int
1929 kern_mkfifo(struct nlookupdata *nd, int mode)
1930 {
1931         struct thread *td = curthread;
1932         struct proc *p = td->td_proc;
1933         struct vattr vattr;
1934         struct vnode *vp;
1935         int error;
1936
1937         bwillinode(1);
1938
1939         nd->nl_flags |= NLC_CREATE | NLC_REFDVP;
1940         if ((error = nlookup(nd)) != 0)
1941                 return (error);
1942         if (nd->nl_nch.ncp->nc_vp)
1943                 return (EEXIST);
1944         if ((error = ncp_writechk(&nd->nl_nch)) != 0)
1945                 return (error);
1946
1947         VATTR_NULL(&vattr);
1948         vattr.va_type = VFIFO;
1949         vattr.va_mode = (mode & ALLPERMS) &~ p->p_fd->fd_cmask;
1950         vp = NULL;
1951         error = VOP_NMKNOD(&nd->nl_nch, nd->nl_dvp, &vp, nd->nl_cred, &vattr);
1952         if (error == 0)
1953                 vput(vp);
1954         return (error);
1955 }
1956
1957 /*
1958  * mkfifo_args(char *path, int mode)
1959  *
1960  * Create a named pipe.
1961  */
1962 int
1963 sys_mkfifo(struct mkfifo_args *uap)
1964 {
1965         struct nlookupdata nd;
1966         int error;
1967
1968         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
1969         if (error == 0)
1970                 error = kern_mkfifo(&nd, uap->mode);
1971         nlookup_done(&nd);
1972         return (error);
1973 }
1974
1975 static int hardlink_check_uid = 0;
1976 SYSCTL_INT(_security, OID_AUTO, hardlink_check_uid, CTLFLAG_RW,
1977     &hardlink_check_uid, 0,
1978     "Unprivileged processes cannot create hard links to files owned by other "
1979     "users");
1980 static int hardlink_check_gid = 0;
1981 SYSCTL_INT(_security, OID_AUTO, hardlink_check_gid, CTLFLAG_RW,
1982     &hardlink_check_gid, 0,
1983     "Unprivileged processes cannot create hard links to files owned by other "
1984     "groups");
1985
1986 static int
1987 can_hardlink(struct vnode *vp, struct thread *td, struct ucred *cred)
1988 {
1989         struct vattr va;
1990         int error;
1991
1992         /*
1993          * Shortcut if disabled
1994          */
1995         if (hardlink_check_uid == 0 && hardlink_check_gid == 0)
1996                 return (0);
1997
1998         /*
1999          * Privileged user can always hardlink
2000          */
2001         if (priv_check_cred(cred, PRIV_VFS_LINK, 0) == 0)
2002                 return (0);
2003
2004         /*
2005          * Otherwise only if the originating file is owned by the
2006          * same user or group.  Note that any group is allowed if
2007          * the file is owned by the caller.
2008          */
2009         error = VOP_GETATTR(vp, &va);
2010         if (error != 0)
2011                 return (error);
2012
2013         if (hardlink_check_uid) {
2014                 if (cred->cr_uid != va.va_uid)
2015                         return (EPERM);
2016         }
2017
2018         if (hardlink_check_gid) {
2019                 if (cred->cr_uid != va.va_uid && !groupmember(va.va_gid, cred))
2020                         return (EPERM);
2021         }
2022
2023         return (0);
2024 }
2025
2026 int
2027 kern_link(struct nlookupdata *nd, struct nlookupdata *linknd)
2028 {
2029         struct thread *td = curthread;
2030         struct vnode *vp;
2031         int error;
2032
2033         /*
2034          * Lookup the source and obtained a locked vnode.
2035          *
2036          * You may only hardlink a file which you have write permission
2037          * on or which you own.
2038          *
2039          * XXX relookup on vget failure / race ?
2040          */
2041         bwillinode(1);
2042         nd->nl_flags |= NLC_WRITE | NLC_OWN | NLC_HLINK;
2043         if ((error = nlookup(nd)) != 0)
2044                 return (error);
2045         vp = nd->nl_nch.ncp->nc_vp;
2046         KKASSERT(vp != NULL);
2047         if (vp->v_type == VDIR)
2048                 return (EPERM);         /* POSIX */
2049         if ((error = ncp_writechk(&nd->nl_nch)) != 0)
2050                 return (error);
2051         if ((error = vget(vp, LK_EXCLUSIVE)) != 0)
2052                 return (error);
2053
2054         /*
2055          * Unlock the source so we can lookup the target without deadlocking
2056          * (XXX vp is locked already, possible other deadlock?).  The target
2057          * must not exist.
2058          */
2059         KKASSERT(nd->nl_flags & NLC_NCPISLOCKED);
2060         nd->nl_flags &= ~NLC_NCPISLOCKED;
2061         cache_unlock(&nd->nl_nch);
2062
2063         linknd->nl_flags |= NLC_CREATE | NLC_REFDVP;
2064         if ((error = nlookup(linknd)) != 0) {
2065                 vput(vp);
2066                 return (error);
2067         }
2068         if (linknd->nl_nch.ncp->nc_vp) {
2069                 vput(vp);
2070                 return (EEXIST);
2071         }
2072
2073         /*
2074          * Finally run the new API VOP.
2075          */
2076         error = can_hardlink(vp, td, td->td_proc->p_ucred);
2077         if (error == 0) {
2078                 error = VOP_NLINK(&linknd->nl_nch, linknd->nl_dvp,
2079                                   vp, linknd->nl_cred);
2080         }
2081         vput(vp);
2082         return (error);
2083 }
2084
2085 /*
2086  * link_args(char *path, char *link)
2087  *
2088  * Make a hard file link.
2089  */
2090 int
2091 sys_link(struct link_args *uap)
2092 {
2093         struct nlookupdata nd, linknd;
2094         int error;
2095
2096         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2097         if (error == 0) {
2098                 error = nlookup_init(&linknd, uap->link, UIO_USERSPACE, 0);
2099                 if (error == 0)
2100                         error = kern_link(&nd, &linknd);
2101                 nlookup_done(&linknd);
2102         }
2103         nlookup_done(&nd);
2104         return (error);
2105 }
2106
2107 int
2108 kern_symlink(struct nlookupdata *nd, char *path, int mode)
2109 {
2110         struct vattr vattr;
2111         struct vnode *vp;
2112         struct vnode *dvp;
2113         int error;
2114
2115         bwillinode(1);
2116         nd->nl_flags |= NLC_CREATE | NLC_REFDVP;
2117         if ((error = nlookup(nd)) != 0)
2118                 return (error);
2119         if (nd->nl_nch.ncp->nc_vp)
2120                 return (EEXIST);
2121         if ((error = ncp_writechk(&nd->nl_nch)) != 0)
2122                 return (error);
2123         dvp = nd->nl_dvp;
2124         VATTR_NULL(&vattr);
2125         vattr.va_mode = mode;
2126         error = VOP_NSYMLINK(&nd->nl_nch, dvp, &vp, nd->nl_cred, &vattr, path);
2127         if (error == 0)
2128                 vput(vp);
2129         return (error);
2130 }
2131
2132 /*
2133  * symlink(char *path, char *link)
2134  *
2135  * Make a symbolic link.
2136  */
2137 int
2138 sys_symlink(struct symlink_args *uap)
2139 {
2140         struct thread *td = curthread;
2141         struct nlookupdata nd;
2142         char *path;
2143         int error;
2144         int mode;
2145
2146         path = objcache_get(namei_oc, M_WAITOK);
2147         error = copyinstr(uap->path, path, MAXPATHLEN, NULL);
2148         if (error == 0) {
2149                 error = nlookup_init(&nd, uap->link, UIO_USERSPACE, 0);
2150                 if (error == 0) {
2151                         mode = ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask;
2152                         error = kern_symlink(&nd, path, mode);
2153                 }
2154                 nlookup_done(&nd);
2155         }
2156         objcache_put(namei_oc, path);
2157         return (error);
2158 }
2159
2160 /*
2161  * undelete_args(char *path)
2162  *
2163  * Delete a whiteout from the filesystem.
2164  */
2165 /* ARGSUSED */
2166 int
2167 sys_undelete(struct undelete_args *uap)
2168 {
2169         struct nlookupdata nd;
2170         int error;
2171
2172         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2173         bwillinode(1);
2174         nd.nl_flags |= NLC_DELETE | NLC_REFDVP;
2175         if (error == 0)
2176                 error = nlookup(&nd);
2177         if (error == 0)
2178                 error = ncp_writechk(&nd.nl_nch);
2179         if (error == 0) {
2180                 error = VOP_NWHITEOUT(&nd.nl_nch, nd.nl_dvp, nd.nl_cred,
2181                                       NAMEI_DELETE);
2182         }
2183         nlookup_done(&nd);
2184         return (error);
2185 }
2186
2187 int
2188 kern_unlink(struct nlookupdata *nd)
2189 {
2190         int error;
2191
2192         bwillinode(1);
2193         nd->nl_flags |= NLC_DELETE | NLC_REFDVP;
2194         if ((error = nlookup(nd)) != 0)
2195                 return (error);
2196         if ((error = ncp_writechk(&nd->nl_nch)) != 0)
2197                 return (error);
2198         error = VOP_NREMOVE(&nd->nl_nch, nd->nl_dvp, nd->nl_cred);
2199         return (error);
2200 }
2201
2202 /*
2203  * unlink_args(char *path)
2204  *
2205  * Delete a name from the filesystem.
2206  */
2207 int
2208 sys_unlink(struct unlink_args *uap)
2209 {
2210         struct nlookupdata nd;
2211         int error;
2212
2213         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2214         if (error == 0)
2215                 error = kern_unlink(&nd);
2216         nlookup_done(&nd);
2217         return (error);
2218 }
2219
2220 int
2221 kern_lseek(int fd, off_t offset, int whence, off_t *res)
2222 {
2223         struct thread *td = curthread;
2224         struct proc *p = td->td_proc;
2225         struct file *fp;
2226         struct vnode *vp;
2227         struct vattr vattr;
2228         off_t new_offset;
2229         int error;
2230
2231         fp = holdfp(p->p_fd, fd, -1);
2232         if (fp == NULL)
2233                 return (EBADF);
2234         if (fp->f_type != DTYPE_VNODE) {
2235                 error = ESPIPE;
2236                 goto done;
2237         }
2238         vp = (struct vnode *)fp->f_data;
2239
2240         switch (whence) {
2241         case L_INCR:
2242                 new_offset = fp->f_offset + offset;
2243                 error = 0;
2244                 break;
2245         case L_XTND:
2246                 error = VOP_GETATTR(vp, &vattr);
2247                 new_offset = offset + vattr.va_size;
2248                 break;
2249         case L_SET:
2250                 new_offset = offset;
2251                 error = 0;
2252                 break;
2253         default:
2254                 new_offset = 0;
2255                 error = EINVAL;
2256                 break;
2257         }
2258
2259         /*
2260          * Validate the seek position.  Negative offsets are not allowed
2261          * for regular files or directories.
2262          *
2263          * Normally we would also not want to allow negative offsets for
2264          * character and block-special devices.  However kvm addresses
2265          * on 64 bit architectures might appear to be negative and must
2266          * be allowed.
2267          */
2268         if (error == 0) {
2269                 if (new_offset < 0 &&
2270                     (vp->v_type == VREG || vp->v_type == VDIR)) {
2271                         error = EINVAL;
2272                 } else {
2273                         fp->f_offset = new_offset;
2274                 }
2275         }
2276         *res = fp->f_offset;
2277 done:
2278         fdrop(fp);
2279         return (error);
2280 }
2281
2282 /*
2283  * lseek_args(int fd, int pad, off_t offset, int whence)
2284  *
2285  * Reposition read/write file offset.
2286  */
2287 int
2288 sys_lseek(struct lseek_args *uap)
2289 {
2290         int error;
2291
2292         error = kern_lseek(uap->fd, uap->offset, uap->whence,
2293                            &uap->sysmsg_offset);
2294
2295         return (error);
2296 }
2297
2298 int
2299 kern_access(struct nlookupdata *nd, int aflags)
2300 {
2301         struct vnode *vp;
2302         int error, flags;
2303
2304         if ((error = nlookup(nd)) != 0)
2305                 return (error);
2306 retry:
2307         error = cache_vget(&nd->nl_nch, nd->nl_cred, LK_EXCLUSIVE, &vp);
2308         if (error)
2309                 return (error);
2310
2311         /* Flags == 0 means only check for existence. */
2312         if (aflags) {
2313                 flags = 0;
2314                 if (aflags & R_OK)
2315                         flags |= VREAD;
2316                 if (aflags & W_OK)
2317                         flags |= VWRITE;
2318                 if (aflags & X_OK)
2319                         flags |= VEXEC;
2320                 if ((flags & VWRITE) == 0 ||
2321                     (error = vn_writechk(vp, &nd->nl_nch)) == 0)
2322                         error = VOP_ACCESS(vp, flags, nd->nl_cred);
2323
2324                 /*
2325                  * If the file handle is stale we have to re-resolve the
2326                  * entry.  This is a hack at the moment.
2327                  */
2328                 if (error == ESTALE) {
2329                         vput(vp);
2330                         cache_setunresolved(&nd->nl_nch);
2331                         error = cache_resolve(&nd->nl_nch, nd->nl_cred);
2332                         if (error == 0) {
2333                                 vp = NULL;
2334                                 goto retry;
2335                         }
2336                         return(error);
2337                 }
2338         }
2339         vput(vp);
2340         return (error);
2341 }
2342
2343 /*
2344  * access_args(char *path, int flags)
2345  *
2346  * Check access permissions.
2347  */
2348 int
2349 sys_access(struct access_args *uap)
2350 {
2351         struct nlookupdata nd;
2352         int error;
2353
2354         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2355         if (error == 0)
2356                 error = kern_access(&nd, uap->flags);
2357         nlookup_done(&nd);
2358         return (error);
2359 }
2360
2361 int
2362 kern_stat(struct nlookupdata *nd, struct stat *st)
2363 {
2364         int error;
2365         struct vnode *vp;
2366         thread_t td;
2367
2368         if ((error = nlookup(nd)) != 0)
2369                 return (error);
2370 again:
2371         if ((vp = nd->nl_nch.ncp->nc_vp) == NULL)
2372                 return (ENOENT);
2373
2374         td = curthread;
2375         if ((error = vget(vp, LK_SHARED)) != 0)
2376                 return (error);
2377         error = vn_stat(vp, st, nd->nl_cred);
2378
2379         /*
2380          * If the file handle is stale we have to re-resolve the entry.  This
2381          * is a hack at the moment.
2382          */
2383         if (error == ESTALE) {
2384                 vput(vp);
2385                 cache_setunresolved(&nd->nl_nch);
2386                 error = cache_resolve(&nd->nl_nch, nd->nl_cred);
2387                 if (error == 0)
2388                         goto again;
2389         } else {
2390                 vput(vp);
2391         }
2392         return (error);
2393 }
2394
2395 /*
2396  * stat_args(char *path, struct stat *ub)
2397  *
2398  * Get file status; this version follows links.
2399  */
2400 int
2401 sys_stat(struct stat_args *uap)
2402 {
2403         struct nlookupdata nd;
2404         struct stat st;
2405         int error;
2406
2407         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2408         if (error == 0) {
2409                 error = kern_stat(&nd, &st);
2410                 if (error == 0)
2411                         error = copyout(&st, uap->ub, sizeof(*uap->ub));
2412         }
2413         nlookup_done(&nd);
2414         return (error);
2415 }
2416
2417 /*
2418  * lstat_args(char *path, struct stat *ub)
2419  *
2420  * Get file status; this version does not follow links.
2421  */
2422 int
2423 sys_lstat(struct lstat_args *uap)
2424 {
2425         struct nlookupdata nd;
2426         struct stat st;
2427         int error;
2428
2429         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2430         if (error == 0) {
2431                 error = kern_stat(&nd, &st);
2432                 if (error == 0)
2433                         error = copyout(&st, uap->ub, sizeof(*uap->ub));
2434         }
2435         nlookup_done(&nd);
2436         return (error);
2437 }
2438
2439 /*
2440  * pathconf_Args(char *path, int name)
2441  *
2442  * Get configurable pathname variables.
2443  */
2444 /* ARGSUSED */
2445 int
2446 sys_pathconf(struct pathconf_args *uap)
2447 {
2448         struct nlookupdata nd;
2449         struct vnode *vp;
2450         int error;
2451
2452         vp = NULL;
2453         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2454         if (error == 0)
2455                 error = nlookup(&nd);
2456         if (error == 0)
2457                 error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
2458         nlookup_done(&nd);
2459         if (error == 0) {
2460                 error = VOP_PATHCONF(vp, uap->name, &uap->sysmsg_reg);
2461                 vput(vp);
2462         }
2463         return (error);
2464 }
2465
2466 /*
2467  * XXX: daver
2468  * kern_readlink isn't properly split yet.  There is a copyin burried
2469  * in VOP_READLINK().
2470  */
2471 int
2472 kern_readlink(struct nlookupdata *nd, char *buf, int count, int *res)
2473 {
2474         struct thread *td = curthread;
2475         struct proc *p = td->td_proc;
2476         struct vnode *vp;
2477         struct iovec aiov;
2478         struct uio auio;
2479         int error;
2480
2481         if ((error = nlookup(nd)) != 0)
2482                 return (error);
2483         error = cache_vget(&nd->nl_nch, nd->nl_cred, LK_EXCLUSIVE, &vp);
2484         if (error)
2485                 return (error);
2486         if (vp->v_type != VLNK) {
2487                 error = EINVAL;
2488         } else {
2489                 aiov.iov_base = buf;
2490                 aiov.iov_len = count;
2491                 auio.uio_iov = &aiov;
2492                 auio.uio_iovcnt = 1;
2493                 auio.uio_offset = 0;
2494                 auio.uio_rw = UIO_READ;
2495                 auio.uio_segflg = UIO_USERSPACE;
2496                 auio.uio_td = td;
2497                 auio.uio_resid = count;
2498                 error = VOP_READLINK(vp, &auio, p->p_ucred);
2499         }
2500         vput(vp);
2501         *res = count - auio.uio_resid;
2502         return (error);
2503 }
2504
2505 /*
2506  * readlink_args(char *path, char *buf, int count)
2507  *
2508  * Return target name of a symbolic link.
2509  */
2510 int
2511 sys_readlink(struct readlink_args *uap)
2512 {
2513         struct nlookupdata nd;
2514         int error;
2515
2516         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2517         if (error == 0) {
2518                 error = kern_readlink(&nd, uap->buf, uap->count,
2519                                         &uap->sysmsg_result);
2520         }
2521         nlookup_done(&nd);
2522         return (error);
2523 }
2524
2525 static int
2526 setfflags(struct vnode *vp, int flags)
2527 {
2528         struct thread *td = curthread;
2529         struct proc *p = td->td_proc;
2530         int error;
2531         struct vattr vattr;
2532
2533         /*
2534          * Prevent non-root users from setting flags on devices.  When
2535          * a device is reused, users can retain ownership of the device
2536          * if they are allowed to set flags and programs assume that
2537          * chown can't fail when done as root.
2538          */
2539         if ((vp->v_type == VCHR || vp->v_type == VBLK) &&
2540             ((error = priv_check_cred(p->p_ucred, PRIV_VFS_CHFLAGS_DEV, 0)) != 0))
2541                 return (error);
2542
2543         /*
2544          * note: vget is required for any operation that might mod the vnode
2545          * so VINACTIVE is properly cleared.
2546          */
2547         if ((error = vget(vp, LK_EXCLUSIVE)) == 0) {
2548                 VATTR_NULL(&vattr);
2549                 vattr.va_flags = flags;
2550                 error = VOP_SETATTR(vp, &vattr, p->p_ucred);
2551                 vput(vp);
2552         }
2553         return (error);
2554 }
2555
2556 /*
2557  * chflags(char *path, int flags)
2558  *
2559  * Change flags of a file given a path name.
2560  */
2561 /* ARGSUSED */
2562 int
2563 sys_chflags(struct chflags_args *uap)
2564 {
2565         struct nlookupdata nd;
2566         struct vnode *vp;
2567         int error;
2568
2569         vp = NULL;
2570         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2571         if (error == 0)
2572                 error = nlookup(&nd);
2573         if (error == 0)
2574                 error = ncp_writechk(&nd.nl_nch);
2575         if (error == 0)
2576                 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
2577         nlookup_done(&nd);
2578         if (error == 0) {
2579                 error = setfflags(vp, uap->flags);
2580                 vrele(vp);
2581         }
2582         return (error);
2583 }
2584
2585 /*
2586  * lchflags(char *path, int flags)
2587  *
2588  * Change flags of a file given a path name, but don't follow symlinks.
2589  */
2590 /* ARGSUSED */
2591 int
2592 sys_lchflags(struct lchflags_args *uap)
2593 {
2594         struct nlookupdata nd;
2595         struct vnode *vp;
2596         int error;
2597
2598         vp = NULL;
2599         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2600         if (error == 0)
2601                 error = nlookup(&nd);
2602         if (error == 0)
2603                 error = ncp_writechk(&nd.nl_nch);
2604         if (error == 0)
2605                 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
2606         nlookup_done(&nd);
2607         if (error == 0) {
2608                 error = setfflags(vp, uap->flags);
2609                 vrele(vp);
2610         }
2611         return (error);
2612 }
2613
2614 /*
2615  * fchflags_args(int fd, int flags)
2616  *
2617  * Change flags of a file given a file descriptor.
2618  */
2619 /* ARGSUSED */
2620 int
2621 sys_fchflags(struct fchflags_args *uap)
2622 {
2623         struct thread *td = curthread;
2624         struct proc *p = td->td_proc;
2625         struct file *fp;
2626         int error;
2627
2628         if ((error = holdvnode(p->p_fd, uap->fd, &fp)) != 0)
2629                 return (error);
2630         if (fp->f_nchandle.ncp)
2631                 error = ncp_writechk(&fp->f_nchandle);
2632         if (error == 0)
2633                 error = setfflags((struct vnode *) fp->f_data, uap->flags);
2634         fdrop(fp);
2635         return (error);
2636 }
2637
2638 static int
2639 setfmode(struct vnode *vp, int mode)
2640 {
2641         struct thread *td = curthread;
2642         struct proc *p = td->td_proc;
2643         int error;
2644         struct vattr vattr;
2645
2646         /*
2647          * note: vget is required for any operation that might mod the vnode
2648          * so VINACTIVE is properly cleared.
2649          */
2650         if ((error = vget(vp, LK_EXCLUSIVE)) == 0) {
2651                 VATTR_NULL(&vattr);
2652                 vattr.va_mode = mode & ALLPERMS;
2653                 error = VOP_SETATTR(vp, &vattr, p->p_ucred);
2654                 vput(vp);
2655         }
2656         return error;
2657 }
2658
2659 int
2660 kern_chmod(struct nlookupdata *nd, int mode)
2661 {
2662         struct vnode *vp;
2663         int error;
2664
2665         if ((error = nlookup(nd)) != 0)
2666                 return (error);
2667         if ((error = cache_vref(&nd->nl_nch, nd->nl_cred, &vp)) != 0)
2668                 return (error);
2669         if ((error = ncp_writechk(&nd->nl_nch)) == 0)
2670                 error = setfmode(vp, mode);
2671         vrele(vp);
2672         return (error);
2673 }
2674
2675 /*
2676  * chmod_args(char *path, int mode)
2677  *
2678  * Change mode of a file given path name.
2679  */
2680 /* ARGSUSED */
2681 int
2682 sys_chmod(struct chmod_args *uap)
2683 {
2684         struct nlookupdata nd;
2685         int error;
2686
2687         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2688         if (error == 0)
2689                 error = kern_chmod(&nd, uap->mode);
2690         nlookup_done(&nd);
2691         return (error);
2692 }
2693
2694 /*
2695  * lchmod_args(char *path, int mode)
2696  *
2697  * Change mode of a file given path name (don't follow links.)
2698  */
2699 /* ARGSUSED */
2700 int
2701 sys_lchmod(struct lchmod_args *uap)
2702 {
2703         struct nlookupdata nd;
2704         int error;
2705
2706         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2707         if (error == 0)
2708                 error = kern_chmod(&nd, uap->mode);
2709         nlookup_done(&nd);
2710         return (error);
2711 }
2712
2713 /*
2714  * fchmod_args(int fd, int mode)
2715  *
2716  * Change mode of a file given a file descriptor.
2717  */
2718 /* ARGSUSED */
2719 int
2720 sys_fchmod(struct fchmod_args *uap)
2721 {
2722         struct thread *td = curthread;
2723         struct proc *p = td->td_proc;
2724         struct file *fp;
2725         int error;
2726
2727         if ((error = holdvnode(p->p_fd, uap->fd, &fp)) != 0)
2728                 return (error);
2729         if (fp->f_nchandle.ncp)
2730                 error = ncp_writechk(&fp->f_nchandle);
2731         if (error == 0)
2732                 error = setfmode((struct vnode *)fp->f_data, uap->mode);
2733         fdrop(fp);
2734         return (error);
2735 }
2736
2737 static int
2738 setfown(struct vnode *vp, uid_t uid, gid_t gid)
2739 {
2740         struct thread *td = curthread;
2741         struct proc *p = td->td_proc;
2742         int error;
2743         struct vattr vattr;
2744
2745         /*
2746          * note: vget is required for any operation that might mod the vnode
2747          * so VINACTIVE is properly cleared.
2748          */
2749         if ((error = vget(vp, LK_EXCLUSIVE)) == 0) {
2750                 VATTR_NULL(&vattr);
2751                 vattr.va_uid = uid;
2752                 vattr.va_gid = gid;
2753                 error = VOP_SETATTR(vp, &vattr, p->p_ucred);
2754                 vput(vp);
2755         }
2756         return error;
2757 }
2758
2759 int
2760 kern_chown(struct nlookupdata *nd, int uid, int gid)
2761 {
2762         struct vnode *vp;
2763         int error;
2764
2765         if ((error = nlookup(nd)) != 0)
2766                 return (error);
2767         if ((error = cache_vref(&nd->nl_nch, nd->nl_cred, &vp)) != 0)
2768                 return (error);
2769         if ((error = ncp_writechk(&nd->nl_nch)) == 0)
2770                 error = setfown(vp, uid, gid);
2771         vrele(vp);
2772         return (error);
2773 }
2774
2775 /*
2776  * chown(char *path, int uid, int gid)
2777  *
2778  * Set ownership given a path name.
2779  */
2780 int
2781 sys_chown(struct chown_args *uap)
2782 {
2783         struct nlookupdata nd;
2784         int error;
2785
2786         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2787         if (error == 0)
2788                 error = kern_chown(&nd, uap->uid, uap->gid);
2789         nlookup_done(&nd);
2790         return (error);
2791 }
2792
2793 /*
2794  * lchown_args(char *path, int uid, int gid)
2795  *
2796  * Set ownership given a path name, do not cross symlinks.
2797  */
2798 int
2799 sys_lchown(struct lchown_args *uap)
2800 {
2801         struct nlookupdata nd;
2802         int error;
2803
2804         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2805         if (error == 0)
2806                 error = kern_chown(&nd, uap->uid, uap->gid);
2807         nlookup_done(&nd);
2808         return (error);
2809 }
2810
2811 /*
2812  * fchown_args(int fd, int uid, int gid)
2813  *
2814  * Set ownership given a file descriptor.
2815  */
2816 /* ARGSUSED */
2817 int
2818 sys_fchown(struct fchown_args *uap)
2819 {
2820         struct thread *td = curthread;
2821         struct proc *p = td->td_proc;
2822         struct file *fp;
2823         int error;
2824
2825         if ((error = holdvnode(p->p_fd, uap->fd, &fp)) != 0)
2826                 return (error);
2827         if (fp->f_nchandle.ncp)
2828                 error = ncp_writechk(&fp->f_nchandle);
2829         if (error == 0)
2830                 error = setfown((struct vnode *)fp->f_data, uap->uid, uap->gid);
2831         fdrop(fp);
2832         return (error);
2833 }
2834
2835 static int
2836 getutimes(const struct timeval *tvp, struct timespec *tsp)
2837 {
2838         struct timeval tv[2];
2839
2840         if (tvp == NULL) {
2841                 microtime(&tv[0]);
2842                 TIMEVAL_TO_TIMESPEC(&tv[0], &tsp[0]);
2843                 tsp[1] = tsp[0];
2844         } else {
2845                 TIMEVAL_TO_TIMESPEC(&tvp[0], &tsp[0]);
2846                 TIMEVAL_TO_TIMESPEC(&tvp[1], &tsp[1]);
2847         }
2848         return 0;
2849 }
2850
2851 static int
2852 setutimes(struct vnode *vp, struct vattr *vattr,
2853           const struct timespec *ts, int nullflag)
2854 {
2855         struct thread *td = curthread;
2856         struct proc *p = td->td_proc;
2857         int error;
2858
2859         VATTR_NULL(vattr);
2860         vattr->va_atime = ts[0];
2861         vattr->va_mtime = ts[1];
2862         if (nullflag)
2863                 vattr->va_vaflags |= VA_UTIMES_NULL;
2864         error = VOP_SETATTR(vp, vattr, p->p_ucred);
2865
2866         return error;
2867 }
2868
2869 int
2870 kern_utimes(struct nlookupdata *nd, struct timeval *tptr)
2871 {
2872         struct timespec ts[2];
2873         struct vnode *vp;
2874         struct vattr vattr;
2875         int error;
2876
2877         if ((error = getutimes(tptr, ts)) != 0)
2878                 return (error);
2879
2880         /*
2881          * NOTE: utimes() succeeds for the owner even if the file
2882          * is not user-writable.
2883          */
2884         nd->nl_flags |= NLC_OWN | NLC_WRITE;
2885
2886         if ((error = nlookup(nd)) != 0)
2887                 return (error);
2888         if ((error = ncp_writechk(&nd->nl_nch)) != 0)
2889                 return (error);
2890         if ((error = cache_vref(&nd->nl_nch, nd->nl_cred, &vp)) != 0)
2891                 return (error);
2892
2893         /*
2894          * note: vget is required for any operation that might mod the vnode
2895          * so VINACTIVE is properly cleared.
2896          */
2897         if ((error = vn_writechk(vp, &nd->nl_nch)) == 0) {
2898                 error = vget(vp, LK_EXCLUSIVE);
2899                 if (error == 0) {
2900                         error = setutimes(vp, &vattr, ts, (tptr == NULL));
2901                         vput(vp);
2902                 }
2903         }
2904         vrele(vp);
2905         return (error);
2906 }
2907
2908 /*
2909  * utimes_args(char *path, struct timeval *tptr)
2910  *
2911  * Set the access and modification times of a file.
2912  */
2913 int
2914 sys_utimes(struct utimes_args *uap)
2915 {
2916         struct timeval tv[2];
2917         struct nlookupdata nd;
2918         int error;
2919
2920         if (uap->tptr) {
2921                 error = copyin(uap->tptr, tv, sizeof(tv));
2922                 if (error)
2923                         return (error);
2924         }
2925         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2926         if (error == 0)
2927                 error = kern_utimes(&nd, uap->tptr ? tv : NULL);
2928         nlookup_done(&nd);
2929         return (error);
2930 }
2931
2932 /*
2933  * lutimes_args(char *path, struct timeval *tptr)
2934  *
2935  * Set the access and modification times of a file.
2936  */
2937 int
2938 sys_lutimes(struct lutimes_args *uap)
2939 {
2940         struct timeval tv[2];
2941         struct nlookupdata nd;
2942         int error;
2943
2944         if (uap->tptr) {
2945                 error = copyin(uap->tptr, tv, sizeof(tv));
2946                 if (error)
2947                         return (error);
2948         }
2949         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2950         if (error == 0)
2951                 error = kern_utimes(&nd, uap->tptr ? tv : NULL);
2952         nlookup_done(&nd);
2953         return (error);
2954 }
2955
2956 /*
2957  * Set utimes on a file descriptor.  The creds used to open the
2958  * file are used to determine whether the operation is allowed
2959  * or not.
2960  */
2961 int
2962 kern_futimes(int fd, struct timeval *tptr)
2963 {
2964         struct thread *td = curthread;
2965         struct proc *p = td->td_proc;
2966         struct timespec ts[2];
2967         struct file *fp;
2968         struct vnode *vp;
2969         struct vattr vattr;
2970         int error;
2971
2972         error = getutimes(tptr, ts);
2973         if (error)
2974                 return (error);
2975         if ((error = holdvnode(p->p_fd, fd, &fp)) != 0)
2976                 return (error);
2977         if (fp->f_nchandle.ncp)
2978                 error = ncp_writechk(&fp->f_nchandle);
2979         if (error == 0) {
2980                 vp = fp->f_data;
2981                 error = vget(vp, LK_EXCLUSIVE);
2982                 if (error == 0) {
2983                         error = VOP_GETATTR(vp, &vattr);
2984                         if (error == 0) {
2985                                 error = naccess_va(&vattr, NLC_OWN | NLC_WRITE,
2986                                                    fp->f_cred);
2987                         }
2988                         if (error == 0) {
2989                                 error = setutimes(vp, &vattr, ts,
2990                                                   (tptr == NULL));
2991                         }
2992                         vput(vp);
2993                 }
2994         }
2995         fdrop(fp);
2996         return (error);
2997 }
2998
2999 /*
3000  * futimes_args(int fd, struct timeval *tptr)
3001  *
3002  * Set the access and modification times of a file.
3003  */
3004 int
3005 sys_futimes(struct futimes_args *uap)
3006 {
3007         struct timeval tv[2];
3008         int error;
3009
3010         if (uap->tptr) {
3011                 error = copyin(uap->tptr, tv, sizeof(tv));
3012                 if (error)
3013                         return (error);
3014         }
3015
3016         error = kern_futimes(uap->fd, uap->tptr ? tv : NULL);
3017
3018         return (error);
3019 }
3020
3021 int
3022 kern_truncate(struct nlookupdata *nd, off_t length)
3023 {
3024         struct vnode *vp;
3025         struct vattr vattr;
3026         int error;
3027
3028         if (length < 0)
3029                 return(EINVAL);
3030         nd->nl_flags |= NLC_WRITE | NLC_TRUNCATE;
3031         if ((error = nlookup(nd)) != 0)
3032                 return (error);
3033         if ((error = ncp_writechk(&nd->nl_nch)) != 0)
3034                 return (error);
3035         if ((error = cache_vref(&nd->nl_nch, nd->nl_cred, &vp)) != 0)
3036                 return (error);
3037         if ((error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY)) != 0) {
3038                 vrele(vp);
3039                 return (error);
3040         }
3041         if (vp->v_type == VDIR) {
3042                 error = EISDIR;
3043         } else if ((error = vn_writechk(vp, &nd->nl_nch)) == 0) {
3044                 VATTR_NULL(&vattr);
3045                 vattr.va_size = length;
3046                 error = VOP_SETATTR(vp, &vattr, nd->nl_cred);
3047         }
3048         vput(vp);
3049         return (error);
3050 }
3051
3052 /*
3053  * truncate(char *path, int pad, off_t length)
3054  *
3055  * Truncate a file given its path name.
3056  */
3057 int
3058 sys_truncate(struct truncate_args *uap)
3059 {
3060         struct nlookupdata nd;
3061         int error;
3062
3063         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
3064         if (error == 0)
3065                 error = kern_truncate(&nd, uap->length);
3066         nlookup_done(&nd);
3067         return error;
3068 }
3069
3070 int
3071 kern_ftruncate(int fd, off_t length)
3072 {
3073         struct thread *td = curthread;
3074         struct proc *p = td->td_proc;
3075         struct vattr vattr;
3076         struct vnode *vp;
3077         struct file *fp;
3078         int error;
3079
3080         if (length < 0)
3081                 return(EINVAL);
3082         if ((error = holdvnode(p->p_fd, fd, &fp)) != 0)
3083                 return (error);
3084         if (fp->f_nchandle.ncp) {
3085                 error = ncp_writechk(&fp->f_nchandle);
3086                 if (error)
3087                         goto done;
3088         }
3089         if ((fp->f_flag & FWRITE) == 0) {
3090                 error = EINVAL;
3091                 goto done;
3092         }
3093         if (fp->f_flag & FAPPENDONLY) { /* inode was set s/uapnd */
3094                 error = EINVAL;
3095                 goto done;
3096         }
3097         vp = (struct vnode *)fp->f_data;
3098         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3099         if (vp->v_type == VDIR) {
3100                 error = EISDIR;
3101         } else if ((error = vn_writechk(vp, NULL)) == 0) {
3102                 VATTR_NULL(&vattr);
3103                 vattr.va_size = length;
3104                 error = VOP_SETATTR(vp, &vattr, fp->f_cred);
3105         }
3106         vn_unlock(vp);
3107 done:
3108         fdrop(fp);
3109         return (error);
3110 }
3111
3112 /*
3113  * ftruncate_args(int fd, int pad, off_t length)
3114  *
3115  * Truncate a file given a file descriptor.
3116  */
3117 int
3118 sys_ftruncate(struct ftruncate_args *uap)
3119 {
3120         int error;
3121
3122         error = kern_ftruncate(uap->fd, uap->length);
3123
3124         return (error);
3125 }
3126
3127 /*
3128  * fsync(int fd)
3129  *
3130  * Sync an open file.
3131  */
3132 /* ARGSUSED */
3133 int
3134 sys_fsync(struct fsync_args *uap)
3135 {
3136         struct thread *td = curthread;
3137         struct proc *p = td->td_proc;
3138         struct vnode *vp;
3139         struct file *fp;
3140         vm_object_t obj;
3141         int error;
3142
3143         if ((error = holdvnode(p->p_fd, uap->fd, &fp)) != 0)
3144                 return (error);
3145         vp = (struct vnode *)fp->f_data;
3146         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3147         if ((obj = vp->v_object) != NULL)
3148                 vm_object_page_clean(obj, 0, 0, 0);
3149         if ((error = VOP_FSYNC(vp, MNT_WAIT)) == 0 && vp->v_mount)
3150                 error = buf_fsync(vp);
3151         vn_unlock(vp);
3152         fdrop(fp);
3153         return (error);
3154 }
3155
3156 int
3157 kern_rename(struct nlookupdata *fromnd, struct nlookupdata *tond)
3158 {
3159         struct nchandle fnchd;
3160         struct nchandle tnchd;
3161         struct namecache *ncp;
3162         struct vnode *fdvp;
3163         struct vnode *tdvp;
3164         struct mount *mp;
3165         int error;
3166
3167         bwillinode(1);
3168         fromnd->nl_flags |= NLC_REFDVP | NLC_RENAME_SRC;
3169         if ((error = nlookup(fromnd)) != 0)
3170                 return (error);
3171         if ((fnchd.ncp = fromnd->nl_nch.ncp->nc_parent) == NULL)
3172                 return (ENOENT);
3173         fnchd.mount = fromnd->nl_nch.mount;
3174         cache_hold(&fnchd);
3175
3176         /*
3177          * unlock the source nch so we can lookup the target nch without
3178          * deadlocking.  The target may or may not exist so we do not check
3179          * for a target vp like kern_mkdir() and other creation functions do.
3180          *
3181          * The source and target directories are ref'd and rechecked after
3182          * everything is relocked to determine if the source or target file
3183          * has been renamed.
3184          */
3185         KKASSERT(fromnd->nl_flags & NLC_NCPISLOCKED);
3186         fromnd->nl_flags &= ~NLC_NCPISLOCKED;
3187         cache_unlock(&fromnd->nl_nch);
3188
3189         tond->nl_flags |= NLC_RENAME_DST | NLC_REFDVP;
3190         if ((error = nlookup(tond)) != 0) {
3191                 cache_drop(&fnchd);
3192                 return (error);
3193         }
3194         if ((tnchd.ncp = tond->nl_nch.ncp->nc_parent) == NULL) {
3195                 cache_drop(&fnchd);
3196                 return (ENOENT);
3197         }
3198         tnchd.mount = tond->nl_nch.mount;
3199         cache_hold(&tnchd);
3200
3201         /*
3202          * If the source and target are the same there is nothing to do
3203          */
3204         if (fromnd->nl_nch.ncp == tond->nl_nch.ncp) {
3205                 cache_drop(&fnchd);
3206                 cache_drop(&tnchd);
3207                 return (0);
3208         }
3209
3210         /*
3211          * Mount points cannot be renamed or overwritten
3212          */
3213         if ((fromnd->nl_nch.ncp->nc_flag | tond->nl_nch.ncp->nc_flag) &
3214             NCF_ISMOUNTPT
3215         ) {
3216                 cache_drop(&fnchd);
3217                 cache_drop(&tnchd);
3218                 return (EINVAL);
3219         }
3220
3221         /*
3222          * relock the source ncp.  NOTE AFTER RELOCKING: the source ncp
3223          * may have become invalid while it was unlocked, nc_vp and nc_mount
3224          * could be NULL.
3225          */
3226         if (cache_lock_nonblock(&fromnd->nl_nch) == 0) {
3227                 cache_resolve(&fromnd->nl_nch, fromnd->nl_cred);
3228         } else if (fromnd->nl_nch.ncp > tond->nl_nch.ncp) {
3229                 cache_lock(&fromnd->nl_nch);
3230                 cache_resolve(&fromnd->nl_nch, fromnd->nl_cred);
3231         } else {
3232                 cache_unlock(&tond->nl_nch);
3233                 cache_lock(&fromnd->nl_nch);
3234                 cache_resolve(&fromnd->nl_nch, fromnd->nl_cred);
3235                 cache_lock(&tond->nl_nch);
3236                 cache_resolve(&tond->nl_nch, tond->nl_cred);
3237         }
3238         fromnd->nl_flags |= NLC_NCPISLOCKED;
3239
3240         /*
3241          * make sure the parent directories linkages are the same
3242          */
3243         if (fnchd.ncp != fromnd->nl_nch.ncp->nc_parent ||
3244             tnchd.ncp != tond->nl_nch.ncp->nc_parent) {
3245                 cache_drop(&fnchd);
3246                 cache_drop(&tnchd);
3247                 return (ENOENT);
3248         }
3249
3250         /*
3251          * Both the source and target must be within the same filesystem and
3252          * in the same filesystem as their parent directories within the
3253          * namecache topology.
3254          *
3255          * NOTE: fromnd's nc_mount or nc_vp could be NULL.
3256          */
3257         mp = fnchd.mount;
3258         if (mp != tnchd.mount || mp != fromnd->nl_nch.mount ||
3259             mp != tond->nl_nch.mount) {
3260                 cache_drop(&fnchd);
3261                 cache_drop(&tnchd);
3262                 return (EXDEV);
3263         }
3264
3265         /*
3266          * Make sure the mount point is writable
3267          */
3268         if ((error = ncp_writechk(&tond->nl_nch)) != 0) {
3269                 cache_drop(&fnchd);
3270                 cache_drop(&tnchd);
3271                 return (error);
3272         }
3273
3274         /*
3275          * If the target exists and either the source or target is a directory,
3276          * then both must be directories.
3277          *
3278          * Due to relocking of the source, fromnd->nl_nch.ncp->nc_vp might h
3279          * have become NULL.
3280          */
3281         if (tond->nl_nch.ncp->nc_vp) {
3282                 if (fromnd->nl_nch.ncp->nc_vp == NULL) {
3283                         error = ENOENT;
3284                 } else if (fromnd->nl_nch.ncp->nc_vp->v_type == VDIR) {
3285                         if (tond->nl_nch.ncp->nc_vp->v_type != VDIR)
3286                                 error = ENOTDIR;
3287                 } else if (tond->nl_nch.ncp->nc_vp->v_type == VDIR) {
3288                         error = EISDIR;
3289                 }
3290         }
3291
3292         /*
3293          * You cannot rename a source into itself or a subdirectory of itself.
3294          * We check this by travsersing the target directory upwards looking
3295          * for a match against the source.
3296          */
3297         if (error == 0) {
3298                 for (ncp = tnchd.ncp; ncp; ncp = ncp->nc_parent) {
3299                         if (fromnd->nl_nch.ncp == ncp) {
3300                                 error = EINVAL;
3301                                 break;
3302                         }
3303                 }
3304         }
3305
3306         cache_drop(&fnchd);
3307         cache_drop(&tnchd);
3308
3309         /*
3310          * Even though the namespaces are different, they may still represent
3311          * hardlinks to the same file.  The filesystem might have a hard time
3312          * with this so we issue a NREMOVE of the source instead of a NRENAME
3313          * when we detect the situation.
3314          */
3315         if (error == 0) {
3316                 fdvp = fromnd->nl_dvp;
3317                 tdvp = tond->nl_dvp;
3318                 if (fdvp == NULL || tdvp == NULL) {
3319                         error = EPERM;
3320                 } else if (fromnd->nl_nch.ncp->nc_vp == tond->nl_nch.ncp->nc_vp) {
3321                         error = VOP_NREMOVE(&fromnd->nl_nch, fdvp,
3322                                             fromnd->nl_cred);
3323                 } else {
3324                         error = VOP_NRENAME(&fromnd->nl_nch, &tond->nl_nch,
3325                                             fdvp, tdvp, tond->nl_cred);
3326                 }
3327         }
3328         return (error);
3329 }
3330
3331 /*
3332  * rename_args(char *from, char *to)
3333  *
3334  * Rename files.  Source and destination must either both be directories,
3335  * or both not be directories.  If target is a directory, it must be empty.
3336  */
3337 int
3338 sys_rename(struct rename_args *uap)
3339 {
3340         struct nlookupdata fromnd, tond;
3341         int error;
3342
3343         error = nlookup_init(&fromnd, uap->from, UIO_USERSPACE, 0);
3344         if (error == 0) {
3345                 error = nlookup_init(&tond, uap->to, UIO_USERSPACE, 0);
3346                 if (error == 0)
3347                         error = kern_rename(&fromnd, &tond);
3348                 nlookup_done(&tond);
3349         }
3350         nlookup_done(&fromnd);
3351         return (error);
3352 }
3353
3354 int
3355 kern_mkdir(struct nlookupdata *nd, int mode)
3356 {
3357         struct thread *td = curthread;
3358         struct proc *p = td->td_proc;
3359         struct vnode *vp;
3360         struct vattr vattr;
3361         int error;
3362
3363         bwillinode(1);
3364         nd->nl_flags |= NLC_WILLBEDIR | NLC_CREATE | NLC_REFDVP;
3365         if ((error = nlookup(nd)) != 0)
3366                 return (error);
3367
3368         if (nd->nl_nch.ncp->nc_vp)
3369                 return (EEXIST);
3370         if ((error = ncp_writechk(&nd->nl_nch)) != 0)
3371                 return (error);
3372         VATTR_NULL(&vattr);
3373         vattr.va_type = VDIR;
3374         vattr.va_mode = (mode & ACCESSPERMS) &~ p->p_fd->fd_cmask;
3375
3376         vp = NULL;
3377         error = VOP_NMKDIR(&nd->nl_nch, nd->nl_dvp, &vp, p->p_ucred, &vattr);
3378         if (error == 0)
3379                 vput(vp);
3380         return (error);
3381 }
3382
3383 /*
3384  * mkdir_args(char *path, int mode)
3385  *
3386  * Make a directory file.
3387  */
3388 /* ARGSUSED */
3389 int
3390 sys_mkdir(struct mkdir_args *uap)
3391 {
3392         struct nlookupdata nd;
3393         int error;
3394
3395         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
3396         if (error == 0)
3397                 error = kern_mkdir(&nd, uap->mode);
3398         nlookup_done(&nd);
3399         return (error);
3400 }
3401
3402 int
3403 kern_rmdir(struct nlookupdata *nd)
3404 {
3405         int error;
3406
3407         bwillinode(1);
3408         nd->nl_flags |= NLC_DELETE | NLC_REFDVP;
3409         if ((error = nlookup(nd)) != 0)
3410                 return (error);
3411
3412         /*
3413          * Do not allow directories representing mount points to be
3414          * deleted, even if empty.  Check write perms on mount point
3415          * in case the vnode is aliased (aka nullfs).
3416          */
3417         if (nd->nl_nch.ncp->nc_flag & (NCF_ISMOUNTPT))
3418                 return (EINVAL);
3419         if ((error = ncp_writechk(&nd->nl_nch)) != 0)
3420                 return (error);
3421         error = VOP_NRMDIR(&nd->nl_nch, nd->nl_dvp, nd->nl_cred);
3422         return (error);
3423 }
3424
3425 /*
3426  * rmdir_args(char *path)
3427  *
3428  * Remove a directory file.
3429  */
3430 /* ARGSUSED */
3431 int
3432 sys_rmdir(struct rmdir_args *uap)
3433 {
3434         struct nlookupdata nd;
3435         int error;
3436
3437         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
3438         if (error == 0)
3439                 error = kern_rmdir(&nd);
3440         nlookup_done(&nd);
3441         return (error);
3442 }
3443
3444 int
3445 kern_getdirentries(int fd, char *buf, u_int count, long *basep, int *res,
3446     enum uio_seg direction)
3447 {
3448         struct thread *td = curthread;
3449         struct proc *p = td->td_proc;
3450         struct vnode *vp;
3451         struct file *fp;
3452         struct uio auio;
3453         struct iovec aiov;
3454         off_t loff;
3455         int error, eofflag;
3456
3457         if ((error = holdvnode(p->p_fd, fd, &fp)) != 0)
3458                 return (error);
3459         if ((fp->f_flag & FREAD) == 0) {
3460                 error = EBADF;
3461                 goto done;
3462         }
3463         vp = (struct vnode *)fp->f_data;
3464 unionread:
3465         if (vp->v_type != VDIR) {
3466                 error = EINVAL;
3467                 goto done;
3468         }
3469         aiov.iov_base = buf;
3470         aiov.iov_len = count;
3471         auio.uio_iov = &aiov;
3472         auio.uio_iovcnt = 1;
3473         auio.uio_rw = UIO_READ;
3474         auio.uio_segflg = direction;
3475         auio.uio_td = td;
3476         auio.uio_resid = count;
3477         loff = auio.uio_offset = fp->f_offset;
3478         error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, NULL, NULL);
3479         fp->f_offset = auio.uio_offset;
3480         if (error)
3481                 goto done;
3482         if (count == auio.uio_resid) {
3483                 if (union_dircheckp) {
3484                         error = union_dircheckp(td, &vp, fp);
3485                         if (error == -1)
3486                                 goto unionread;
3487                         if (error)
3488                                 goto done;
3489                 }
3490 #if 0
3491                 if ((vp->v_flag & VROOT) &&
3492                     (vp->v_mount->mnt_flag & MNT_UNION)) {
3493                         struct vnode *tvp = vp;
3494                         vp = vp->v_mount->mnt_vnodecovered;
3495                         vref(vp);
3496                         fp->f_data = vp;
3497                         fp->f_offset = 0;
3498                         vrele(tvp);
3499                         goto unionread;
3500                 }
3501 #endif
3502         }
3503
3504         /*
3505          * WARNING!  *basep may not be wide enough to accomodate the
3506          * seek offset.   XXX should we hack this to return the upper 32 bits
3507          * for offsets greater then 4G?
3508          */
3509         if (basep) {
3510                 *basep = (long)loff;
3511         }
3512         *res = count - auio.uio_resid;
3513 done:
3514         fdrop(fp);
3515         return (error);
3516 }
3517
3518 /*
3519  * getdirentries_args(int fd, char *buf, u_int conut, long *basep)
3520  *
3521  * Read a block of directory entries in a file system independent format.
3522  */
3523 int
3524 sys_getdirentries(struct getdirentries_args *uap)
3525 {
3526         long base;
3527         int error;
3528
3529         error = kern_getdirentries(uap->fd, uap->buf, uap->count, &base,
3530                                    &uap->sysmsg_result, UIO_USERSPACE);
3531
3532         if (error == 0 && uap->basep)
3533                 error = copyout(&base, uap->basep, sizeof(*uap->basep));
3534         return (error);
3535 }
3536
3537 /*
3538  * getdents_args(int fd, char *buf, size_t count)
3539  */
3540 int
3541 sys_getdents(struct getdents_args *uap)
3542 {
3543         int error;
3544
3545         error = kern_getdirentries(uap->fd, uap->buf, uap->count, NULL,
3546             &uap->sysmsg_result, UIO_USERSPACE);
3547
3548         return (error);
3549 }
3550
3551 /*
3552  * umask(int newmask)
3553  *
3554  * Set the mode mask for creation of filesystem nodes.
3555  *
3556  * MP SAFE
3557  */
3558 int
3559 sys_umask(struct umask_args *uap)
3560 {
3561         struct thread *td = curthread;
3562         struct proc *p = td->td_proc;
3563         struct filedesc *fdp;
3564
3565         fdp = p->p_fd;
3566         uap->sysmsg_result = fdp->fd_cmask;
3567         fdp->fd_cmask = uap->newmask & ALLPERMS;
3568         return (0);
3569 }
3570
3571 /*
3572  * revoke(char *path)
3573  *
3574  * Void all references to file by ripping underlying filesystem
3575  * away from vnode.
3576  */
3577 /* ARGSUSED */
3578 int
3579 sys_revoke(struct revoke_args *uap)
3580 {
3581         struct nlookupdata nd;
3582         struct vattr vattr;
3583         struct vnode *vp;
3584         struct ucred *cred;
3585         int error;
3586
3587         vp = NULL;
3588         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
3589         if (error == 0)
3590                 error = nlookup(&nd);
3591         if (error == 0)
3592                 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
3593         cred = crhold(nd.nl_cred);
3594         nlookup_done(&nd);
3595         if (error == 0) {
3596                 if (error == 0)
3597                         error = VOP_GETATTR(vp, &vattr);
3598                 if (error == 0 && cred->cr_uid != vattr.va_uid)
3599                         error = priv_check_cred(cred, PRIV_VFS_REVOKE, 0);
3600                 if (error == 0 && (vp->v_type == VCHR || vp->v_type == VBLK)) {
3601                         if (count_udev(vp->v_umajor, vp->v_uminor) > 0)
3602                                 error = vrevoke(vp, cred);
3603                 } else if (error == 0) {
3604                         error = vrevoke(vp, cred);
3605                 }
3606                 vrele(vp);
3607         }
3608         if (cred)
3609                 crfree(cred);
3610         return (error);
3611 }
3612
3613 /*
3614  * getfh_args(char *fname, fhandle_t *fhp)
3615  *
3616  * Get (NFS) file handle
3617  *
3618  * NOTE: We use the fsid of the covering mount, even if it is a nullfs
3619  * mount.  This allows nullfs mounts to be explicitly exported.
3620  *
3621  * WARNING: nullfs mounts of HAMMER PFS ROOTs are safe.
3622  *
3623  *          nullfs mounts of subdirectories are not safe.  That is, it will
3624  *          work, but you do not really have protection against access to
3625  *          the related parent directories.
3626  */
3627 int
3628 sys_getfh(struct getfh_args *uap)
3629 {
3630         struct thread *td = curthread;
3631         struct nlookupdata nd;
3632         fhandle_t fh;
3633         struct vnode *vp;
3634         struct mount *mp;
3635         int error;
3636
3637         /*
3638          * Must be super user
3639          */
3640         if ((error = priv_check(td, PRIV_ROOT)) != 0)
3641                 return (error);
3642
3643         vp = NULL;
3644         error = nlookup_init(&nd, uap->fname, UIO_USERSPACE, NLC_FOLLOW);
3645         if (error == 0)
3646                 error = nlookup(&nd);
3647         if (error == 0)
3648                 error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
3649         mp = nd.nl_nch.mount;
3650         nlookup_done(&nd);
3651         if (error == 0) {
3652                 bzero(&fh, sizeof(fh));
3653                 fh.fh_fsid = mp->mnt_stat.f_fsid;
3654                 error = VFS_VPTOFH(vp, &fh.fh_fid);
3655                 vput(vp);
3656                 if (error == 0)
3657                         error = copyout(&fh, uap->fhp, sizeof(fh));
3658         }
3659         return (error);
3660 }
3661
3662 /*
3663  * fhopen_args(const struct fhandle *u_fhp, int flags)
3664  *
3665  * syscall for the rpc.lockd to use to translate a NFS file handle into
3666  * an open descriptor.
3667  *
3668  * warning: do not remove the priv_check() call or this becomes one giant
3669  * security hole.
3670  */
3671 int
3672 sys_fhopen(struct fhopen_args *uap)
3673 {
3674         struct thread *td = curthread;
3675         struct proc *p = td->td_proc;
3676         struct mount *mp;
3677         struct vnode *vp;
3678         struct fhandle fhp;
3679         struct vattr vat;
3680         struct vattr *vap = &vat;
3681         struct flock lf;
3682         int fmode, mode, error, type;
3683         struct file *nfp;
3684         struct file *fp;
3685         int indx;
3686
3687         /*
3688          * Must be super user
3689          */
3690         error = priv_check(td, PRIV_ROOT);
3691         if (error)
3692                 return (error);
3693
3694         fmode = FFLAGS(uap->flags);
3695         /* why not allow a non-read/write open for our lockd? */
3696         if (((fmode & (FREAD | FWRITE)) == 0) || (fmode & O_CREAT))
3697                 return (EINVAL);
3698         error = copyin(uap->u_fhp, &fhp, sizeof(fhp));
3699         if (error)
3700                 return(error);
3701         /* find the mount point */
3702         mp = vfs_getvfs(&fhp.fh_fsid);
3703         if (mp == NULL)
3704                 return (ESTALE);
3705         /* now give me my vnode, it gets returned to me locked */
3706         error = VFS_FHTOVP(mp, NULL, &fhp.fh_fid, &vp);
3707         if (error)
3708                 return (error);
3709         /*
3710          * from now on we have to make sure not
3711          * to forget about the vnode
3712          * any error that causes an abort must vput(vp)
3713          * just set error = err and 'goto bad;'.
3714          */
3715
3716         /*
3717          * from vn_open
3718          */
3719         if (vp->v_type == VLNK) {
3720                 error = EMLINK;
3721                 goto bad;
3722         }
3723         if (vp->v_type == VSOCK) {
3724                 error = EOPNOTSUPP;
3725                 goto bad;
3726         }
3727         mode = 0;
3728         if (fmode & (FWRITE | O_TRUNC)) {
3729                 if (vp->v_type == VDIR) {
3730                         error = EISDIR;
3731                         goto bad;
3732                 }
3733                 error = vn_writechk(vp, NULL);
3734                 if (error)
3735                         goto bad;
3736                 mode |= VWRITE;
3737         }
3738         if (fmode & FREAD)
3739                 mode |= VREAD;
3740         if (mode) {
3741                 error = VOP_ACCESS(vp, mode, p->p_ucred);
3742                 if (error)
3743                         goto bad;
3744         }
3745         if (fmode & O_TRUNC) {
3746                 vn_unlock(vp);                          /* XXX */
3747                 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);   /* XXX */
3748                 VATTR_NULL(vap);
3749                 vap->va_size = 0;
3750                 error = VOP_SETATTR(vp, vap, p->p_ucred);
3751                 if (error)
3752                         goto bad;
3753         }
3754
3755         /*
3756          * VOP_OPEN needs the file pointer so it can potentially override
3757          * it.
3758          *
3759          * WARNING! no f_nchandle will be associated when fhopen()ing a
3760          * directory.  XXX
3761          */
3762         if ((error = falloc(p, &nfp, &indx)) != 0)
3763                 goto bad;
3764         fp = nfp;
3765
3766         error = VOP_OPEN(vp, fmode, p->p_ucred, fp);
3767         if (error) {
3768                 /*
3769                  * setting f_ops this way prevents VOP_CLOSE from being
3770                  * called or fdrop() releasing the vp from v_data.   Since
3771                  * the VOP_OPEN failed we don't want to VOP_CLOSE.
3772                  */
3773                 fp->f_ops = &badfileops;
3774                 fp->f_data = NULL;
3775                 goto bad_drop;
3776         }
3777
3778         /*
3779          * The fp is given its own reference, we still have our ref and lock.
3780          *
3781          * Assert that all regular files must be created with a VM object.
3782          */
3783         if (vp->v_type == VREG && vp->v_object == NULL) {
3784                 kprintf("fhopen: regular file did not have VM object: %p\n", vp);
3785                 goto bad_drop;
3786         }
3787
3788         /*
3789          * The open was successful.  Handle any locking requirements.
3790          */
3791         if (fmode & (O_EXLOCK | O_SHLOCK)) {
3792                 lf.l_whence = SEEK_SET;
3793                 lf.l_start = 0;
3794                 lf.l_len = 0;
3795                 if (fmode & O_EXLOCK)
3796                         lf.l_type = F_WRLCK;
3797                 else
3798                         lf.l_type = F_RDLCK;
3799                 if (fmode & FNONBLOCK)
3800                         type = 0;
3801                 else
3802                         type = F_WAIT;
3803                 vn_unlock(vp);
3804                 if ((error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type)) != 0) {
3805                         /*
3806                          * release our private reference.
3807                          */
3808                         fsetfd(p, NULL, indx);
3809                         fdrop(fp);
3810                         vrele(vp);
3811                         return (error);
3812                 }
3813                 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3814                 fp->f_flag |= FHASLOCK;
3815         }
3816
3817         /*
3818          * Clean up.  Associate the file pointer with the previously
3819          * reserved descriptor and return it.
3820          */
3821         vput(vp);
3822         fsetfd(p, fp, indx);
3823         fdrop(fp);
3824         uap->sysmsg_result = indx;
3825         return (0);
3826
3827 bad_drop:
3828         fsetfd(p, NULL, indx);
3829         fdrop(fp);
3830 bad:
3831         vput(vp);
3832         return (error);
3833 }
3834
3835 /*
3836  * fhstat_args(struct fhandle *u_fhp, struct stat *sb)
3837  */
3838 int
3839 sys_fhstat(struct fhstat_args *uap)
3840 {
3841         struct thread *td = curthread;
3842         struct stat sb;
3843         fhandle_t fh;
3844         struct mount *mp;
3845         struct vnode *vp;
3846         int error;
3847
3848         /*
3849          * Must be super user
3850          */
3851         error = priv_check(td, PRIV_ROOT);
3852         if (error)
3853                 return (error);
3854
3855         error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
3856         if (error)
3857                 return (error);
3858
3859         if ((mp = vfs_getvfs(&fh.fh_fsid)) == NULL)
3860                 return (ESTALE);
3861         if ((error = VFS_FHTOVP(mp, NULL, &fh.fh_fid, &vp)))
3862                 return (error);
3863         error = vn_stat(vp, &sb, td->td_proc->p_ucred);
3864         vput(vp);
3865         if (error)
3866                 return (error);
3867         error = copyout(&sb, uap->sb, sizeof(sb));
3868         return (error);
3869 }
3870
3871 /*
3872  * fhstatfs_args(struct fhandle *u_fhp, struct statfs *buf)
3873  */
3874 int
3875 sys_fhstatfs(struct fhstatfs_args *uap)
3876 {
3877         struct thread *td = curthread;
3878         struct proc *p = td->td_proc;
3879         struct statfs *sp;
3880         struct mount *mp;
3881         struct vnode *vp;
3882         struct statfs sb;
3883         char *fullpath, *freepath;
3884         fhandle_t fh;
3885         int error;
3886
3887         /*
3888          * Must be super user
3889          */
3890         if ((error = priv_check(td, PRIV_ROOT)))
3891                 return (error);
3892
3893         if ((error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t))) != 0)
3894                 return (error);
3895
3896         if ((mp = vfs_getvfs(&fh.fh_fsid)) == NULL)
3897                 return (ESTALE);
3898
3899         if (p != NULL && !chroot_visible_mnt(mp, p))
3900                 return (ESTALE);
3901
3902         if ((error = VFS_FHTOVP(mp, NULL, &fh.fh_fid, &vp)))
3903                 return (error);
3904         mp = vp->v_mount;
3905         sp = &mp->mnt_stat;
3906         vput(vp);
3907         if ((error = VFS_STATFS(mp, sp, p->p_ucred)) != 0)
3908                 return (error);
3909
3910         error = mount_path(p, mp, &fullpath, &freepath);
3911         if (error)
3912                 return(error);
3913         bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
3914         strlcpy(sp->f_mntonname, fullpath, sizeof(sp->f_mntonname));
3915         kfree(freepath, M_TEMP);
3916
3917         sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
3918         if (priv_check(td, PRIV_ROOT)) {
3919                 bcopy(sp, &sb, sizeof(sb));
3920                 sb.f_fsid.val[0] = sb.f_fsid.val[1] = 0;
3921                 sp = &sb;
3922         }
3923         return (copyout(sp, uap->buf, sizeof(*sp)));
3924 }
3925
3926 /*
3927  * fhstatvfs_args(struct fhandle *u_fhp, struct statvfs *buf)
3928  */
3929 int
3930 sys_fhstatvfs(struct fhstatvfs_args *uap)
3931 {
3932         struct thread *td = curthread;
3933         struct proc *p = td->td_proc;
3934         struct statvfs *sp;
3935         struct mount *mp;
3936         struct vnode *vp;
3937         fhandle_t fh;
3938         int error;
3939
3940         /*
3941          * Must be super user
3942          */
3943         if ((error = priv_check(td, PRIV_ROOT)))
3944                 return (error);
3945
3946         if ((error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t))) != 0)
3947                 return (error);
3948
3949         if ((mp = vfs_getvfs(&fh.fh_fsid)) == NULL)
3950                 return (ESTALE);
3951
3952         if (p != NULL && !chroot_visible_mnt(mp, p))
3953                 return (ESTALE);
3954
3955         if ((error = VFS_FHTOVP(mp, NULL, &fh.fh_fid, &vp)))
3956                 return (error);
3957         mp = vp->v_mount;
3958         sp = &mp->mnt_vstat;
3959         vput(vp);
3960         if ((error = VFS_STATVFS(mp, sp, p->p_ucred)) != 0)
3961                 return (error);
3962
3963         sp->f_flag = 0;
3964         if (mp->mnt_flag & MNT_RDONLY)
3965                 sp->f_flag |= ST_RDONLY;
3966         if (mp->mnt_flag & MNT_NOSUID)
3967                 sp->f_flag |= ST_NOSUID;
3968
3969         return (copyout(sp, uap->buf, sizeof(*sp)));
3970 }
3971
3972
3973 /*
3974  * Syscall to push extended attribute configuration information into the
3975  * VFS.  Accepts a path, which it converts to a mountpoint, as well as
3976  * a command (int cmd), and attribute name and misc data.  For now, the
3977  * attribute name is left in userspace for consumption by the VFS_op.
3978  * It will probably be changed to be copied into sysspace by the
3979  * syscall in the future, once issues with various consumers of the
3980  * attribute code have raised their hands.
3981  *
3982  * Currently this is used only by UFS Extended Attributes.
3983  */
3984 int
3985 sys_extattrctl(struct extattrctl_args *uap)
3986 {
3987         struct nlookupdata nd;
3988         struct mount *mp;
3989         struct vnode *vp;
3990         int error;
3991
3992         vp = NULL;
3993         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
3994         if (error == 0)
3995                 error = nlookup(&nd);
3996         if (error == 0) {
3997                 mp = nd.nl_nch.mount;
3998                 error = VFS_EXTATTRCTL(mp, uap->cmd,
3999                                 uap->attrname, uap->arg,
4000                                 nd.nl_cred);
4001         }
4002         nlookup_done(&nd);
4003         return (error);
4004 }
4005
4006 /*
4007  * Syscall to set a named extended attribute on a file or directory.
4008  * Accepts attribute name, and a uio structure pointing to the data to set.
4009  * The uio is consumed in the style of writev().  The real work happens
4010  * in VOP_SETEXTATTR().
4011  */
4012 int
4013 sys_extattr_set_file(struct extattr_set_file_args *uap)
4014 {
4015         char attrname[EXTATTR_MAXNAMELEN];
4016         struct iovec aiov[UIO_SMALLIOV];
4017         struct iovec *needfree;
4018         struct nlookupdata nd;
4019         struct iovec *iov;
4020         struct vnode *vp;
4021         struct uio auio;
4022         u_int iovlen;
4023         u_int cnt;
4024         int error;
4025         int i;
4026
4027         error = copyin(uap->attrname, attrname, EXTATTR_MAXNAMELEN);
4028         if (error)
4029                 return (error);
4030
4031         vp = NULL;
4032         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
4033         if (error == 0)
4034                 error = nlookup(&nd);
4035         if (error == 0)
4036                 error = ncp_writechk(&nd.nl_nch);
4037         if (error == 0)
4038                 error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
4039         if (error) {
4040                 nlookup_done(&nd);
4041                 return (error);
4042         }
4043
4044         needfree = NULL;
4045         iovlen = uap->iovcnt * sizeof(struct iovec);
4046         if (uap->iovcnt > UIO_SMALLIOV) {
4047                 if (uap->iovcnt > UIO_MAXIOV) {
4048                         error = EINVAL;
4049                         goto done;
4050                 }
4051                 MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK);
4052                 needfree = iov;
4053         } else {
4054                 iov = aiov;
4055         }
4056         auio.uio_iov = iov;
4057         auio.uio_iovcnt = uap->iovcnt;
4058         auio.uio_rw = UIO_WRITE;
4059         auio.uio_segflg = UIO_USERSPACE;
4060         auio.uio_td = nd.nl_td;
4061         auio.uio_offset = 0;
4062         if ((error = copyin(uap->iovp, iov, iovlen)))
4063                 goto done;
4064         auio.uio_resid = 0;
4065         for (i = 0; i < uap->iovcnt; i++) {
4066                 if (iov->iov_len > INT_MAX - auio.uio_resid) {
4067                         error = EINVAL;
4068                         goto done;
4069                 }
4070                 auio.uio_resid += iov->iov_len;
4071                 iov++;
4072         }
4073         cnt = auio.uio_resid;
4074         error = VOP_SETEXTATTR(vp, attrname, &auio, nd.nl_cred);
4075         cnt -= auio.uio_resid;
4076         uap->sysmsg_result = cnt;
4077 done:
4078         vput(vp);
4079         nlookup_done(&nd);
4080         if (needfree)
4081                 FREE(needfree, M_IOV);
4082         return (error);
4083 }
4084
4085 /*
4086  * Syscall to get a named extended attribute on a file or directory.
4087  * Accepts attribute name, and a uio structure pointing to a buffer for the
4088  * data.  The uio is consumed in the style of readv().  The real work
4089  * happens in VOP_GETEXTATTR();
4090  */
4091 int
4092 sys_extattr_get_file(struct extattr_get_file_args *uap)
4093 {
4094         char attrname[EXTATTR_MAXNAMELEN];
4095         struct iovec aiov[UIO_SMALLIOV];
4096         struct iovec *needfree;
4097         struct nlookupdata nd;
4098         struct iovec *iov;
4099         struct vnode *vp;
4100         struct uio auio;
4101         u_int iovlen;
4102         u_int cnt;
4103         int error;
4104         int i;
4105
4106         error = copyin(uap->attrname, attrname, EXTATTR_MAXNAMELEN);
4107         if (error)
4108                 return (error);
4109
4110         vp = NULL;
4111         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
4112         if (error == 0)
4113                 error = nlookup(&nd);
4114         if (error == 0)
4115                 error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
4116         if (error) {
4117                 nlookup_done(&nd);
4118                 return (error);
4119         }
4120
4121         iovlen = uap->iovcnt * sizeof (struct iovec);
4122         needfree = NULL;
4123         if (uap->iovcnt > UIO_SMALLIOV) {
4124                 if (uap->iovcnt > UIO_MAXIOV) {
4125                         error = EINVAL;
4126                         goto done;
4127                 }
4128                 MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK);
4129                 needfree = iov;
4130         } else {
4131                 iov = aiov;
4132         }
4133         auio.uio_iov = iov;
4134         auio.uio_iovcnt = uap->iovcnt;
4135         auio.uio_rw = UIO_READ;
4136         auio.uio_segflg = UIO_USERSPACE;
4137         auio.uio_td = nd.nl_td;
4138         auio.uio_offset = 0;
4139         if ((error = copyin(uap->iovp, iov, iovlen)))
4140                 goto done;
4141         auio.uio_resid = 0;
4142         for (i = 0; i < uap->iovcnt; i++) {
4143                 if (iov->iov_len > INT_MAX - auio.uio_resid) {
4144                         error = EINVAL;
4145                         goto done;
4146                 }
4147                 auio.uio_resid += iov->iov_len;
4148                 iov++;
4149         }
4150         cnt = auio.uio_resid;
4151         error = VOP_GETEXTATTR(vp, attrname, &auio, nd.nl_cred);
4152         cnt -= auio.uio_resid;
4153         uap->sysmsg_result = cnt;
4154 done:
4155         vput(vp);
4156         nlookup_done(&nd);
4157         if (needfree)
4158                 FREE(needfree, M_IOV);
4159         return(error);
4160 }
4161
4162 /*
4163  * Syscall to delete a named extended attribute from a file or directory.
4164  * Accepts attribute name.  The real work happens in VOP_SETEXTATTR().
4165  */
4166 int
4167 sys_extattr_delete_file(struct extattr_delete_file_args *uap)
4168 {
4169         char attrname[EXTATTR_MAXNAMELEN];
4170         struct nlookupdata nd;
4171         struct vnode *vp;
4172         int error;
4173
4174         error = copyin(uap->attrname, attrname, EXTATTR_MAXNAMELEN);
4175         if (error)
4176                 return(error);
4177
4178         vp = NULL;
4179         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
4180         if (error == 0)
4181                 error = nlookup(&nd);
4182         if (error == 0)
4183                 error = ncp_writechk(&nd.nl_nch);
4184         if (error == 0)
4185                 error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
4186         if (error) {
4187                 nlookup_done(&nd);
4188                 return (error);
4189         }
4190
4191         error = VOP_SETEXTATTR(vp, attrname, NULL, nd.nl_cred);
4192         vput(vp);
4193         nlookup_done(&nd);
4194         return(error);
4195 }
4196
4197 /*
4198  * Determine if the mount is visible to the process.
4199  */
4200 static int
4201 chroot_visible_mnt(struct mount *mp, struct proc *p)
4202 {
4203         struct nchandle nch;
4204
4205         /*
4206          * Traverse from the mount point upwards.  If we hit the process
4207          * root then the mount point is visible to the process.
4208          */
4209         nch = mp->mnt_ncmountpt;
4210         while (nch.ncp) {
4211                 if (nch.mount == p->p_fd->fd_nrdir.mount &&
4212                     nch.ncp == p->p_fd->fd_nrdir.ncp) {
4213                         return(1);
4214                 }
4215                 if (nch.ncp == nch.mount->mnt_ncmountpt.ncp) {
4216                         nch = nch.mount->mnt_ncmounton;
4217                 } else {
4218                         nch.ncp = nch.ncp->nc_parent;
4219                 }
4220         }
4221
4222         /*
4223          * If the mount point is not visible to the process, but the
4224          * process root is in a subdirectory of the mount, return
4225          * TRUE anyway.
4226          */
4227         if (p->p_fd->fd_nrdir.mount == mp)
4228                 return(1);
4229
4230         return(0);
4231 }
4232