bsd/miscfs/devfs/devfs_vfsops.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*-
  26  * Copyright 1997,1998 Julian Elischer.  All rights reserved.
  27  * julian@freebsd.org
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions are
  31  * met:
  32  *  1. Redistributions of source code must retain the above copyright
  33  *     notice, this list of conditions and the following disclaimer.
  34  *  2. Redistributions in binary form must reproduce the above copyright notice,
  35  *     this list of conditions and the following disclaimer in the documentation
  36  *     and/or other materials provided with the distribution.
  37  *
  38  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS
  39  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  40  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  41  * DISCLAIMED.  IN NO EVENT SHALL THE HOLDER OR CONTRIBUTORS BE LIABLE FOR
  42  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  43  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  44  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  45  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  46  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  47  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  48  * SUCH DAMAGE.
  49  *
  50  * devfs_vfsops.c
  51  *
  52  */
  53 /*
  54  * HISTORY
  55  *  Dieter Siegmund (dieter@apple.com) Wed Jul 14 13:37:59 PDT 1999
  56  *  - modified devfs_statfs() to use devfs_stats to calculate the
  57  *    amount of memory used by devfs
  58  */
  59
  60
  61 #include <sys/param.h>
  62 #include <sys/systm.h>
  63 #include <sys/kernel.h>
  64 #include <sys/vnode.h>
  65 #include <sys/proc.h>
  66 #include <sys/mount.h>
  67 #include <sys/malloc.h>
  68
  69 #include "devfs.h"
  70 #include "devfsdefs.h"
  71
  72 static int devfs_statfs( struct mount *mp, struct statfs *sbp, struct proc *p);
  73
  74 static struct vfsconf * devfs_vfsp = 0;
  75 static int              kernel_mount = 0;
  76
  77
  78 /*-
  79  * Called from the generic VFS startups.
  80  * This is the second stage of DEVFS initialisation.
  81  * The probed devices have already been loaded and the
  82  * basic structure of the DEVFS created.
  83  * We take the oportunity to mount the hidden DEVFS layer, so that
  84  * devices from devfs get sync'd.
  85  */
  86 static int
  87 devfs_init(struct vfsconf *vfsp)
  88 {
  89     devfs_vfsp = vfsp; /* remember this for devfs_kernel_mount below */
  90
  91     if (devfs_sinit())
  92         return (EOPNOTSUPP);
  93     printf("devfs enabled\n");
  94     devfs_make_node(makedev(0, 0), DEVFS_CHAR,
  95                     UID_ROOT, GID_WHEEL, 0622, "console");
  96     devfs_make_node(makedev(2, 0), DEVFS_CHAR,
  97                     UID_ROOT, GID_WHEEL, 0666, "tty");
  98     devfs_make_node(makedev(3, 0), DEVFS_CHAR,
  99                     UID_ROOT, GID_KMEM, 0640, "mem");
 100     devfs_make_node(makedev(3, 1), DEVFS_CHAR,
 101                     UID_ROOT, GID_KMEM, 0640, "kmem");
 102     devfs_make_node(makedev(3, 2), DEVFS_CHAR,
 103                     UID_ROOT, GID_WHEEL, 0666, "null");
 104     devfs_make_node(makedev(3, 3), DEVFS_CHAR,
 105                     UID_ROOT, GID_WHEEL, 0666, "zero");
 106     devfs_make_node(makedev(6, 0), DEVFS_CHAR,
 107                     UID_ROOT, GID_WHEEL, 0600, "klog");
 108     return 0;
 109 }
 110
 111 /*-
 112  *  mp   - pointer to 'mount' structure
 113  *  path - addr in user space of mount point (ie /usr or whatever)
 114  *  data - addr in user space of mount params including the
 115  *         name of the block special file to treat as a filesystem.
 116  *         (NOT USED)
 117  *  ndp  - namei data pointer (NOT USED)
 118  *  p    - proc pointer
 119  * devfs is special in that it doesn't require any device to be mounted..
 120  * It makes up its data as it goes along.
 121  * it must be mounted during single user.. until it is, only std{in/out/err}
 122  * and the root filesystem are available.
 123  */
 124 /*proto*/
 125 int
 126 devfs_mount(struct mount *mp, char *path, caddr_t data,
 127             struct nameidata *ndp, struct proc *p)
 128 {
 129         struct devfsmount *devfs_mp_p;  /* devfs specific mount info */
 130         int error;
 131         size_t size;
 132
 133         /*-
 134          *  If they just want to update, we don't need to do anything.
 135          */
 136         if (mp->mnt_flag & MNT_UPDATE)
 137         {
 138                 return 0;
 139         }
 140
 141         /*-
 142          *  Well, it's not an update, it's a real mount request.
 143          *  Time to get dirty.
 144          * HERE we should check to see if we are already mounted here.
 145          */
 146
 147         MALLOC(devfs_mp_p, struct devfsmount *, sizeof(struct devfsmount),
 148                M_DEVFSMNT, M_WAITOK);
 149         if (devfs_mp_p == NULL)
 150                 return (ENOMEM);
 151         bzero(devfs_mp_p,sizeof(*devfs_mp_p));
 152         devfs_mp_p->mount = mp;
 153
 154         /*-
 155          *  Fill out some fields
 156          */
 157         mp->mnt_data = (qaddr_t)devfs_mp_p;
 158         mp->mnt_stat.f_type = mp->mnt_vfc->vfc_typenum;
 159         mp->mnt_stat.f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 160         mp->mnt_stat.f_fsid.val[1] = mp->mnt_stat.f_type;
 161         mp->mnt_flag |= MNT_LOCAL;
 162
 163         DEVFS_LOCK(p);
 164         error = dev_dup_plane(devfs_mp_p);
 165         DEVFS_UNLOCK(p);
 166         if (error) {
 167                 mp->mnt_data = (qaddr_t)0;
 168                 FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 169                 return (error);
 170         }
 171
 172         /*-
 173          *  Copy in the name of the directory the filesystem
 174          *  is to be mounted on.
 175          *  And we clear the remainder of the character strings
 176          *  to be tidy.
 177          */
 178
 179         if (!kernel_mount) {
 180                 copyinstr(path, (caddr_t)mp->mnt_stat.f_mntonname,
 181                         sizeof(mp->mnt_stat.f_mntonname)-1, &size);
 182                 bzero(mp->mnt_stat.f_mntonname + size,
 183                         sizeof(mp->mnt_stat.f_mntonname) - size);
 184         }
 185         bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
 186         bcopy("devfs",mp->mnt_stat.f_mntfromname, 5);
 187         DEVFS_INCR_MOUNTS();
 188         (void)devfs_statfs(mp, &mp->mnt_stat, p);
 189         return 0;
 190 }
 191
 192
 193 static int
 194 devfs_start(struct mount *mp, int flags, struct proc *p)
 195 {
 196         return 0;
 197 }
 198
 199 /*-
 200  *  Unmount the filesystem described by mp.
 201  */
 202 static int
 203 devfs_unmount( struct mount *mp, int mntflags, struct proc *p)
 204 {
 205         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 206         int flags = 0;
 207         int force = 0;
 208         int error;
 209
 210         if (mntflags & MNT_FORCE) {
 211                 flags |= FORCECLOSE;
 212                 force = 1;
 213         }
 214         error = vflush(mp, NULLVP, flags);
 215         if (error && !force)
 216                 return error;
 217
 218         DEVFS_LOCK(p);
 219         devfs_free_plane(devfs_mp_p);
 220         DEVFS_UNLOCK(p);
 221         FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 222         DEVFS_DECR_MOUNTS();
 223         mp->mnt_data = (qaddr_t)0;
 224         mp->mnt_flag &= ~MNT_LOCAL;
 225
 226         return 0;
 227 }
 228
 229 /* return the address of the root vnode  in *vpp */
 230 static int
 231 devfs_root(struct mount *mp, struct vnode **vpp)
 232 {
 233         struct devfsmount *devfs_mp_p = (struct devfsmount *)(mp->mnt_data);
 234         int error;
 235
 236         error = devfs_dntovn(devfs_mp_p->plane_root->de_dnp,vpp,
 237                              current_proc());
 238         return error;
 239 }
 240
 241 static int
 242 devfs_quotactl(struct mount *mp, int cmds, uid_t uid, caddr_t arg,
 243                struct proc *p)
 244 {
 245         return EOPNOTSUPP;
 246 }
 247
 248 static int
 249 devfs_statfs( struct mount *mp, struct statfs *sbp, struct proc *p)
 250 {
 251         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 252
 253         /*-
 254          *  Fill in the stat block.
 255          */
 256         sbp->f_type   = mp->mnt_stat.f_type;
 257         sbp->f_flags  = 0;              /* XXX */
 258         sbp->f_bsize  = 512;
 259         sbp->f_iosize = 512;
 260         sbp->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 261                          + devfs_stats.nodes * sizeof(devnode_t)
 262                          + devfs_stats.entries * sizeof(devdirent_t)
 263                          + devfs_stats.stringspace
 264                          ) / sbp->f_bsize;
 265         sbp->f_bfree  = 0;
 266         sbp->f_bavail = 0;
 267         sbp->f_files  = devfs_stats.nodes;
 268         sbp->f_ffree  = 0;
 269         sbp->f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 270         sbp->f_fsid.val[1] = mp->mnt_stat.f_type;
 271
 272         /*-
 273          *  Copy the mounted on and mounted from names into
 274          *  the passed in stat block, if it is not the one
 275          *  in the mount structure.
 276          */
 277         if (sbp != &mp->mnt_stat) {
 278                 bcopy((caddr_t)mp->mnt_stat.f_mntonname,
 279                         (caddr_t)&sbp->f_mntonname[0], MNAMELEN);
 280                 bcopy((caddr_t)mp->mnt_stat.f_mntfromname,
 281                         (caddr_t)&sbp->f_mntfromname[0], MNAMELEN);
 282         }
 283         return 0;
 284 }
 285
 286 static int
 287 devfs_sync(struct mount *mp, int waitfor,struct ucred *cred,struct proc *p)
 288 {
 289     return (0);
 290 }
 291
 292
 293 static int
 294 devfs_vget(struct mount *mp, void * ino,struct vnode **vpp)
 295 {
 296         return EOPNOTSUPP;
 297 }
 298
 299 /*************************************************************
 300  * The concept of exporting a kernel generated devfs is stupid
 301  * So don't handle filehandles
 302  */
 303
 304 static int
 305 devfs_fhtovp (struct mount *mp, struct fid *fhp, struct mbuf *nam,
 306               struct vnode **vpp, int *exflagsp, struct ucred **credanonp)
 307 {
 308         return (EINVAL);
 309 }
 310
 311
 312 static int
 313 devfs_vptofh (struct vnode *vp, struct fid *fhp)
 314 {
 315         return (EINVAL);
 316 }
 317
 318 static int
 319 devfs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
 320         int *name;
 321         u_int namelen;
 322         void *oldp;
 323         size_t *oldlenp;
 324         void *newp;
 325         size_t newlen;
 326         struct proc *p;
 327 {
 328     return (EOPNOTSUPP);
 329 }
 330
 331 #include <sys/namei.h>
 332
 333 /*
 334  * Function: devfs_kernel_mount
 335  * Purpose:
 336  *   Mount devfs at the given mount point from within the kernel.
 337  */
 338 int
 339 devfs_kernel_mount(char * mntname)
 340 {
 341         struct mount *mp;
 342         int error;
 343         struct proc *procp;
 344         struct nameidata nd;
 345         struct vnode  * vp;
 346
 347         if (devfs_vfsp == NULL) {
 348             printf("devfs_kernel_mount: devfs_vfsp is NULL\n");
 349             return (EINVAL);
 350         }
 351         procp = current_proc();
 352
 353         /*
 354          * Get vnode to be covered
 355          */
 356         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
 357             mntname, procp);
 358         if ((error = namei(&nd))) {
 359             printf("devfs_kernel_mount: failed to find directory '%s', %d",
 360                    mntname, error);
 361             return (error);
 362         }
 363         vp = nd.ni_vp;
 364         if ((error = vinvalbuf(vp, V_SAVE, procp->p_ucred, procp, 0, 0))) {
 365             printf("devfs_kernel_mount: vinval failed: %d\n", error);
 366             vput(vp);
 367             return (error);
 368         }
 369         if (vp->v_type != VDIR) {
 370             printf("devfs_kernel_mount: '%s' is not a directory\n", mntname);
 371             vput(vp);
 372             return (ENOTDIR);
 373         }
 374         if (vp->v_mountedhere != NULL) {
 375             vput(vp);
 376             return (EBUSY);
 377         }
 378
 379         /*
 380          * Allocate and initialize the filesystem.
 381          */
 382         mp = _MALLOC_ZONE((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK);
 383         bzero((char *)mp, (u_long)sizeof(struct mount));
 384
 385     /* Initialize the default IO constraints */
 386     mp->mnt_maxreadcnt = mp->mnt_maxwritecnt = MAXPHYS;
 387     mp->mnt_segreadcnt = mp->mnt_segwritecnt = 32;
 388
 389         lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, 0);
 390         (void)vfs_busy(mp, LK_NOWAIT, 0, procp);
 391         LIST_INIT(&mp->mnt_vnodelist);
 392         mp->mnt_op = devfs_vfsp->vfc_vfsops;
 393         mp->mnt_vfc = devfs_vfsp;
 394         devfs_vfsp->vfc_refcount++;
 395         mp->mnt_flag = 0;
 396         mp->mnt_flag |= devfs_vfsp->vfc_flags & MNT_VISFLAGMASK;
 397         strncpy(mp->mnt_stat.f_fstypename, devfs_vfsp->vfc_name, MFSNAMELEN);
 398         vp->v_mountedhere = mp;
 399         mp->mnt_vnodecovered = vp;
 400         mp->mnt_stat.f_owner = procp->p_ucred->cr_uid;
 401         (void) copystr(mntname, mp->mnt_stat.f_mntonname, MNAMELEN - 1, 0);
 402
 403         kernel_mount = 1;
 404         error = devfs_mount(mp, mntname, NULL, NULL, procp);
 405         kernel_mount = 0;
 406         if (error) {
 407             printf("devfs_kernel_mount: mount %s failed: %d", mntname, error);
 408             mp->mnt_vfc->vfc_refcount--;
 409             vfs_unbusy(mp, procp);
 410             _FREE_ZONE(mp, sizeof (struct mount), M_MOUNT);
 411             vput(vp);
 412             return (error);
 413         }
 414         printf("devfs on %s\n", mntname);
 415         simple_lock(&mountlist_slock);
 416         CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list);
 417         simple_unlock(&mountlist_slock);
 418         VOP_UNLOCK(vp, 0, procp);
 419         vfs_unbusy(mp, procp);
 420         return (0);
 421 }
 422
 423 struct vfsops devfs_vfsops = {
 424         devfs_mount,
 425         devfs_start,
 426         devfs_unmount,
 427         devfs_root,
 428         devfs_quotactl,
 429         devfs_statfs,
 430         devfs_sync,
 431         devfs_vget,
 432         devfs_fhtovp,
 433         devfs_vptofh,
 434         devfs_init,
 435         devfs_sysctl,
 436 };