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  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  23 /*
  24  * Copyright (c) 1992, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * This code is derived from software donated to Berkeley by
  28  * Jan-Simon Pendry.
  29  *
  30  * Redistribution and use in source and binary forms, with or without
  31  * modification, are permitted provided that the following conditions
  32  * are met:
  33  * 1. Redistributions of source code must retain the above copyright
  34  *    notice, this list of conditions and the following disclaimer.
  35  * 2. Redistributions in binary form must reproduce the above copyright
  36  *    notice, this list of conditions and the following disclaimer in the
  37  *    documentation and/or other materials provided with the distribution.
  38  * 3. All advertising materials mentioning features or use of this software
  39  *    must display the following acknowledgement:
  40  *      This product includes software developed by the University of
  41  *      California, Berkeley and its contributors.
  42  * 4. Neither the name of the University nor the names of its contributors
  43  *    may be used to endorse or promote products derived from this software
  44  *    without specific prior written permission.
  45  *
  46  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  47  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  48  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  49  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  50  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  51  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  52  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  53  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  54  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  55  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  56  * SUCH DAMAGE.
  57  *
  58  *      @(#)null_vfsops.c       8.7 (Berkeley) 5/14/95
  59  *
  60  * @(#)lofs_vfsops.c    1.2 (Berkeley) 6/18/92
  61  */
  62
  63 /*
  64  * Null Layer
  65  * (See null_vnops.c for a description of what this does.)
  66  */
  67
  68 #include <sys/param.h>
  69 #include <sys/systm.h>
  70 #include <sys/proc.h>
  71 #include <sys/kauth.h>
  72 #include <sys/time.h>
  73 #include <sys/types.h>
  74 #include <sys/vnode.h>
  75 #include <sys/mount_internal.h>
  76 #include <sys/namei.h>
  77 #include <sys/malloc.h>
  78 #include <miscfs/nullfs/null.h>
  79
  80 /*
  81  * Mount null layer
  82  */
  83 static int
  84 nullfs_mount(mp, devvp, data, context)
  85         struct mount *mp;
  86         vnode_t devvp;
  87         user_addr_t data;
  88         vfs_context_t context;
  89 {
  90         int error = 0;
  91         struct user_null_args args;
  92         struct vnode *lowerrootvp, *vp;
  93         struct vnode *nullm_rootvp;
  94         struct null_mount *xmp;
  95         u_int size;
  96
  97 #ifdef NULLFS_DIAGNOSTIC
  98         printf("nullfs_mount(mp = %x)\n", mp);
  99 #endif
 100
 101         /*
 102          * Update is a no-op
 103          */
 104         if (mp->mnt_flag & MNT_UPDATE) {
 105                 return (ENOTSUP);
 106                 /* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, devvp, data,  p);*/
 107         }
 108
 109         /*
 110          * Get argument
 111          */
 112         if (vfs_context_is64bit(context)) {
 113                 error = copyin(data, (caddr_t)&args, sizeof (args));
 114         }
 115         else {
 116                 struct null_args temp;
 117                 error = copyin(data, (caddr_t)&temp, sizeof (temp));
 118                 args.target = CAST_USER_ADDR_T(temp.target);
 119         }
 120         if (error)
 121                 return (error);
 122
 123         /*
 124          * Find lower node
 125          */
 126         NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
 127                 UIO_USERSPACE, args.target, context);
 128         if (error = namei(ndp))
 129                 return (error);
 130         nameidone(ndp);
 131         /*
 132          * Sanity check on lower vnode
 133          */
 134         lowerrootvp = ndp->ni_vp;
 135
 136         vnode_put(ndp->ni_dvp);
 137         ndp->ni_dvp = NULL;
 138
 139         xmp = (struct null_mount *) _MALLOC(sizeof(struct null_mount),
 140                                 M_UFSMNT, M_WAITOK);    /* XXX */
 141
 142         /*
 143          * Save reference to underlying FS
 144          */
 145         xmp->nullm_vfs = lowerrootvp->v_mount;
 146
 147         /*
 148          * Save reference.  Each mount also holds
 149          * a reference on the root vnode.
 150          */
 151         error = null_node_create(mp, lowerrootvp, &vp);
 152         /*
 153          * Make sure the node alias worked
 154          */
 155         if (error) {
 156                 vnode_put(lowerrootvp);
 157                 FREE(xmp, M_UFSMNT);    /* XXX */
 158                 return (error);
 159         }
 160
 161         /*
 162          * Keep a held reference to the root vnode.
 163          * It is vnode_put'd in nullfs_unmount.
 164          */
 165         nullm_rootvp = vp;
 166         nullm_rootvp->v_flag |= VROOT;
 167         xmp->nullm_rootvp = nullm_rootvp;
 168         if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL)
 169                 mp->mnt_flag |= MNT_LOCAL;
 170         mp->mnt_data = (qaddr_t) xmp;
 171         vfs_getnewfsid(mp);
 172
 173         (void) copyinstr(args.target, mp->mnt_vfsstat.f_mntfromname, MAXPATHLEN - 1,
 174             &size);
 175         bzero(mp->mnt_vfsstat.f_mntfromname + size, MNAMELEN - size);
 176 #ifdef NULLFS_DIAGNOSTIC
 177         printf("nullfs_mount: lower %s, alias at %s\n",
 178                 mp->mnt_vfsstat.f_mntfromname, mp->mnt_vfsstat.f_mntonname);
 179 #endif
 180         return (0);
 181 }
 182
 183 /*
 184  * VFS start.  Nothing needed here - the start routine
 185  * on the underlying filesystem will have been called
 186  * when that filesystem was mounted.
 187  */
 188 static int
 189 nullfs_start(mp, flags, context)
 190         struct mount *mp;
 191         int flags;
 192         vfs_context_t context;
 193 {
 194         return (0);
 195         /* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, context); */
 196 }
 197
 198 /*
 199  * Free reference to null layer
 200  */
 201 static int
 202 nullfs_unmount(mp, mntflags, context)
 203         struct mount *mp;
 204         int mntflags;
 205         vfs_context_t context;
 206 {
 207         struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
 208         int error;
 209         int flags = 0;
 210         int force = 0;
 211
 212 #ifdef NULLFS_DIAGNOSTIC
 213         printf("nullfs_unmount(mp = %x)\n", mp);
 214 #endif
 215
 216         if (mntflags & MNT_FORCE) {
 217                 flags |= FORCECLOSE;
 218                 force = 1;
 219         }
 220
 221         if ( (nullm_rootvp->v_usecount > 1) && !force )
 222                 return (EBUSY);
 223         if ( (error = vflush(mp, nullm_rootvp, flags)) && !force )
 224                 return (error);
 225
 226 #ifdef NULLFS_DIAGNOSTIC
 227         vprint("alias root of lower", nullm_rootvp);
 228 #endif
 229         /*
 230          * Release reference on underlying root vnode
 231          */
 232         vnode_put(nullm_rootvp);
 233         /*
 234          * And blow it away for future re-use
 235          */
 236         vnode_reclaim(nullm_rootvp);
 237         /*
 238          * Finally, throw away the null_mount structure
 239          */
 240         FREE(mp->mnt_data, M_UFSMNT);   /* XXX */
 241         mp->mnt_data = 0;
 242         return 0;
 243 }
 244
 245 static int
 246 nullfs_root(mp, vpp, context)
 247         struct mount *mp;
 248         struct vnode **vpp;
 249         vfs_context_t context;
 250 {
 251         struct proc *p = curproc;       /* XXX */
 252         struct vnode *vp;
 253
 254 #ifdef NULLFS_DIAGNOSTIC
 255         printf("nullfs_root(mp = %x, vp = %x->%x)\n", mp,
 256                         MOUNTTONULLMOUNT(mp)->nullm_rootvp,
 257                         NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
 258                         );
 259 #endif
 260
 261         /*
 262          * Return locked reference to root.
 263          */
 264         vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
 265         vnode_get(vp);
 266         *vpp = vp;
 267         return 0;
 268 }
 269
 270 static int
 271 nullfs_quotactl(mp, cmd, uid, datap, context)
 272         struct mount *mp;
 273         int cmd;
 274         uid_t uid;
 275         caddr_t datap;
 276         vfs_context_t context;
 277 {
 278         return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, datap, context);
 279 }
 280
 281 static int
 282 nullfs_statfs(mp, sbp, context)
 283         struct mount *mp;
 284         struct vfsstatfs *sbp;
 285         vfs_context_t context;
 286 {
 287         int error;
 288         struct vfsstatfs mstat;
 289
 290 #ifdef NULLFS_DIAGNOSTIC
 291         printf("nullfs_statfs(mp = %x, vp = %x->%x)\n", mp,
 292                         MOUNTTONULLMOUNT(mp)->nullm_rootvp,
 293                         NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
 294                         );
 295 #endif
 296
 297         bzero(&mstat, sizeof(mstat));
 298
 299         error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, context);
 300         if (error)
 301                 return (error);
 302
 303         /* now copy across the "interesting" information and fake the rest */
 304         //sbp->f_type = mstat.f_type;
 305         sbp->f_flags = mstat.f_flags;
 306         sbp->f_bsize = mstat.f_bsize;
 307         sbp->f_iosize = mstat.f_iosize;
 308         sbp->f_blocks = mstat.f_blocks;
 309         sbp->f_bfree = mstat.f_bfree;
 310         sbp->f_bavail = mstat.f_bavail;
 311         sbp->f_files = mstat.f_files;
 312         sbp->f_ffree = mstat.f_ffree;
 313         return (0);
 314 }
 315
 316 static int
 317 nullfs_sync(__unused struct mount *mp, __unused int waitfor,
 318         __unused kauth_cred_t cred, __unused vfs_context_t context)
 319 {
 320         /*
 321          * XXX - Assumes no data cached at null layer.
 322          */
 323         return (0);
 324 }
 325
 326 static int
 327 nullfs_vget(mp, ino, vpp, context)
 328         struct mount *mp;
 329         ino64_t ino;
 330         struct vnode **vpp;
 331         vfs_context_t context;
 332 {
 333
 334         return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp, context);
 335 }
 336
 337 static int
 338 nullfs_fhtovp(mp, fhlen, fhp, vpp, context)
 339         struct mount *mp;
 340         int fhlen;
 341         unsigned char *fhp;
 342         struct vnode **vpp;
 343         vfs_context_t context;
 344 {
 345
 346         return VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fhlen, fhp, vpp, context);
 347 }
 348
 349 static int
 350 nullfs_vptofh(vp, fhlenp, fhp, context)
 351         struct vnode *vp;
 352         int *fhlenp;
 353         unsigned char *fhp;
 354         vfs_context_t context;
 355 {
 356         return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhlenp, fhp, context);
 357 }
 358
 359 int nullfs_init (struct vfsconf *);
 360
 361 #define nullfs_sysctl (int (*) (int *, u_int, user_addr_t, size_t *, user_addr_t, size_t, proc_t))eopnotsupp
 362
 363 struct vfsops null_vfsops = {
 364         nullfs_mount,
 365         nullfs_start,
 366         nullfs_unmount,
 367         nullfs_root,
 368         nullfs_quotactl,
 369         nullfs_statfs,
 370         nullfs_sync,
 371         nullfs_vget,
 372         nullfs_fhtovp,
 373         nullfs_vptofh,
 374         nullfs_init,
 375         nullfs_sysctl
 376 };