bsd/miscfs/nullfs/null_vfsops.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  24 /*
  25  * Copyright (c) 1992, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * This code is derived from software donated to Berkeley by
  29  * Jan-Simon Pendry.
  30  *
  31  * Redistribution and use in source and binary forms, with or without
  32  * modification, are permitted provided that the following conditions
  33  * are met:
  34  * 1. Redistributions of source code must retain the above copyright
  35  *    notice, this list of conditions and the following disclaimer.
  36  * 2. Redistributions in binary form must reproduce the above copyright
  37  *    notice, this list of conditions and the following disclaimer in the
  38  *    documentation and/or other materials provided with the distribution.
  39  * 3. All advertising materials mentioning features or use of this software
  40  *    must display the following acknowledgement:
  41  *      This product includes software developed by the University of
  42  *      California, Berkeley and its contributors.
  43  * 4. Neither the name of the University nor the names of its contributors
  44  *    may be used to endorse or promote products derived from this software
  45  *    without specific prior written permission.
  46  *
  47  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  48  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  49  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  50  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  51  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  52  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  53  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  54  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  55  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  56  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  57  * SUCH DAMAGE.
  58  *
  59  *      @(#)null_vfsops.c       8.7 (Berkeley) 5/14/95
  60  *
  61  * @(#)lofs_vfsops.c    1.2 (Berkeley) 6/18/92
  62  */
  63
  64 /*
  65  * Null Layer
  66  * (See null_vnops.c for a description of what this does.)
  67  */
  68
  69 #include <sys/param.h>
  70 #include <sys/systm.h>
  71 #include <sys/proc.h>
  72 #include <sys/kauth.h>
  73 #include <sys/time.h>
  74 #include <sys/types.h>
  75 #include <sys/vnode.h>
  76 #include <sys/mount_internal.h>
  77 #include <sys/namei.h>
  78 #include <sys/malloc.h>
  79 #include <miscfs/nullfs/null.h>
  80
  81 /*
  82  * Mount null layer
  83  */
  84 static int
  85 nullfs_mount(mp, devvp, data, context)
  86         struct mount *mp;
  87         vnode_t devvp;
  88         user_addr_t data;
  89         vfs_context_t context;
  90 {
  91         int error = 0;
  92         struct user_null_args args;
  93         struct vnode *lowerrootvp, *vp;
  94         struct vnode *nullm_rootvp;
  95         struct null_mount *xmp;
  96         u_int size;
  97
  98 #ifdef NULLFS_DIAGNOSTIC
  99         printf("nullfs_mount(mp = %x)\n", mp);
 100 #endif
 101
 102         /*
 103          * Update is a no-op
 104          */
 105         if (mp->mnt_flag & MNT_UPDATE) {
 106                 return (ENOTSUP);
 107                 /* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, devvp, data,  p);*/
 108         }
 109
 110         /*
 111          * Get argument
 112          */
 113         if (vfs_context_is64bit(context)) {
 114                 error = copyin(data, (caddr_t)&args, sizeof (args));
 115         }
 116         else {
 117                 struct null_args temp;
 118                 error = copyin(data, (caddr_t)&temp, sizeof (temp));
 119                 args.target = CAST_USER_ADDR_T(temp.target);
 120         }
 121         if (error)
 122                 return (error);
 123
 124         /*
 125          * Find lower node
 126          */
 127         NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
 128                 UIO_USERSPACE, args.target, context);
 129         if (error = namei(ndp))
 130                 return (error);
 131         nameidone(ndp);
 132         /*
 133          * Sanity check on lower vnode
 134          */
 135         lowerrootvp = ndp->ni_vp;
 136
 137         vnode_put(ndp->ni_dvp);
 138         ndp->ni_dvp = NULL;
 139
 140         xmp = (struct null_mount *) _MALLOC(sizeof(struct null_mount),
 141                                 M_UFSMNT, M_WAITOK);    /* XXX */
 142
 143         /*
 144          * Save reference to underlying FS
 145          */
 146         xmp->nullm_vfs = lowerrootvp->v_mount;
 147
 148         /*
 149          * Save reference.  Each mount also holds
 150          * a reference on the root vnode.
 151          */
 152         error = null_node_create(mp, lowerrootvp, &vp);
 153         /*
 154          * Make sure the node alias worked
 155          */
 156         if (error) {
 157                 vnode_put(lowerrootvp);
 158                 FREE(xmp, M_UFSMNT);    /* XXX */
 159                 return (error);
 160         }
 161
 162         /*
 163          * Keep a held reference to the root vnode.
 164          * It is vnode_put'd in nullfs_unmount.
 165          */
 166         nullm_rootvp = vp;
 167         nullm_rootvp->v_flag |= VROOT;
 168         xmp->nullm_rootvp = nullm_rootvp;
 169         if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL)
 170                 mp->mnt_flag |= MNT_LOCAL;
 171         mp->mnt_data = (qaddr_t) xmp;
 172         vfs_getnewfsid(mp);
 173
 174         (void) copyinstr(args.target, mp->mnt_vfsstat.f_mntfromname, MAXPATHLEN - 1,
 175             &size);
 176         bzero(mp->mnt_vfsstat.f_mntfromname + size, MNAMELEN - size);
 177 #ifdef NULLFS_DIAGNOSTIC
 178         printf("nullfs_mount: lower %s, alias at %s\n",
 179                 mp->mnt_vfsstat.f_mntfromname, mp->mnt_vfsstat.f_mntonname);
 180 #endif
 181         return (0);
 182 }
 183
 184 /*
 185  * VFS start.  Nothing needed here - the start routine
 186  * on the underlying filesystem will have been called
 187  * when that filesystem was mounted.
 188  */
 189 static int
 190 nullfs_start(mp, flags, context)
 191         struct mount *mp;
 192         int flags;
 193         vfs_context_t context;
 194 {
 195         return (0);
 196         /* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, context); */
 197 }
 198
 199 /*
 200  * Free reference to null layer
 201  */
 202 static int
 203 nullfs_unmount(mp, mntflags, context)
 204         struct mount *mp;
 205         int mntflags;
 206         vfs_context_t context;
 207 {
 208         struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
 209         int error;
 210         int flags = 0;
 211         int force = 0;
 212
 213 #ifdef NULLFS_DIAGNOSTIC
 214         printf("nullfs_unmount(mp = %x)\n", mp);
 215 #endif
 216
 217         if (mntflags & MNT_FORCE) {
 218                 flags |= FORCECLOSE;
 219                 force = 1;
 220         }
 221
 222         if ( (nullm_rootvp->v_usecount > 1) && !force )
 223                 return (EBUSY);
 224         if ( (error = vflush(mp, nullm_rootvp, flags)) && !force )
 225                 return (error);
 226
 227 #ifdef NULLFS_DIAGNOSTIC
 228         vprint("alias root of lower", nullm_rootvp);
 229 #endif
 230         /*
 231          * Release reference on underlying root vnode
 232          */
 233         vnode_put(nullm_rootvp);
 234         /*
 235          * And blow it away for future re-use
 236          */
 237         vnode_reclaim(nullm_rootvp);
 238         /*
 239          * Finally, throw away the null_mount structure
 240          */
 241         FREE(mp->mnt_data, M_UFSMNT);   /* XXX */
 242         mp->mnt_data = 0;
 243         return 0;
 244 }
 245
 246 static int
 247 nullfs_root(mp, vpp, context)
 248         struct mount *mp;
 249         struct vnode **vpp;
 250         vfs_context_t context;
 251 {
 252         struct proc *p = curproc;       /* XXX */
 253         struct vnode *vp;
 254
 255 #ifdef NULLFS_DIAGNOSTIC
 256         printf("nullfs_root(mp = %x, vp = %x->%x)\n", mp,
 257                         MOUNTTONULLMOUNT(mp)->nullm_rootvp,
 258                         NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
 259                         );
 260 #endif
 261
 262         /*
 263          * Return locked reference to root.
 264          */
 265         vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
 266         vnode_get(vp);
 267         *vpp = vp;
 268         return 0;
 269 }
 270
 271 static int
 272 nullfs_quotactl(mp, cmd, uid, datap, context)
 273         struct mount *mp;
 274         int cmd;
 275         uid_t uid;
 276         caddr_t datap;
 277         vfs_context_t context;
 278 {
 279         return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, datap, context);
 280 }
 281
 282 static int
 283 nullfs_statfs(mp, sbp, context)
 284         struct mount *mp;
 285         struct vfsstatfs *sbp;
 286         vfs_context_t context;
 287 {
 288         int error;
 289         struct vfsstatfs mstat;
 290
 291 #ifdef NULLFS_DIAGNOSTIC
 292         printf("nullfs_statfs(mp = %x, vp = %x->%x)\n", mp,
 293                         MOUNTTONULLMOUNT(mp)->nullm_rootvp,
 294                         NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
 295                         );
 296 #endif
 297
 298         bzero(&mstat, sizeof(mstat));
 299
 300         error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, context);
 301         if (error)
 302                 return (error);
 303
 304         /* now copy across the "interesting" information and fake the rest */
 305         //sbp->f_type = mstat.f_type;
 306         sbp->f_flags = mstat.f_flags;
 307         sbp->f_bsize = mstat.f_bsize;
 308         sbp->f_iosize = mstat.f_iosize;
 309         sbp->f_blocks = mstat.f_blocks;
 310         sbp->f_bfree = mstat.f_bfree;
 311         sbp->f_bavail = mstat.f_bavail;
 312         sbp->f_files = mstat.f_files;
 313         sbp->f_ffree = mstat.f_ffree;
 314         return (0);
 315 }
 316
 317 static int
 318 nullfs_sync(__unused struct mount *mp, __unused int waitfor,
 319         __unused kauth_cred_t cred, __unused vfs_context_t context)
 320 {
 321         /*
 322          * XXX - Assumes no data cached at null layer.
 323          */
 324         return (0);
 325 }
 326
 327 static int
 328 nullfs_vget(mp, ino, vpp, context)
 329         struct mount *mp;
 330         ino64_t ino;
 331         struct vnode **vpp;
 332         vfs_context_t context;
 333 {
 334
 335         return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp, context);
 336 }
 337
 338 static int
 339 nullfs_fhtovp(mp, fhlen, fhp, vpp, context)
 340         struct mount *mp;
 341         int fhlen;
 342         unsigned char *fhp;
 343         struct vnode **vpp;
 344         vfs_context_t context;
 345 {
 346
 347         return VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fhlen, fhp, vpp, context);
 348 }
 349
 350 static int
 351 nullfs_vptofh(vp, fhlenp, fhp, context)
 352         struct vnode *vp;
 353         int *fhlenp;
 354         unsigned char *fhp;
 355         vfs_context_t context;
 356 {
 357         return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhlenp, fhp, context);
 358 }
 359
 360 int nullfs_init (struct vfsconf *);
 361
 362 #define nullfs_sysctl (int (*) (int *, u_int, user_addr_t, size_t *, user_addr_t, size_t, proc_t))eopnotsupp
 363
 364 struct vfsops null_vfsops = {
 365         nullfs_mount,
 366         nullfs_start,
 367         nullfs_unmount,
 368         nullfs_root,
 369         nullfs_quotactl,
 370         nullfs_statfs,
 371         nullfs_sync,
 372         nullfs_vget,
 373         nullfs_fhtovp,
 374         nullfs_vptofh,
 375         nullfs_init,
 376         nullfs_sysctl
 377 };