bsd/miscfs/devfs/devfs_vfsops.c

   1 /*
   2  * Copyright (c) 2000-2002 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     devfs_make_node(makedev(0, 0), DEVFS_CHAR,
  94                     UID_ROOT, GID_WHEEL, 0622, "console");
  95     devfs_make_node(makedev(2, 0), DEVFS_CHAR,
  96                     UID_ROOT, GID_WHEEL, 0666, "tty");
  97     devfs_make_node(makedev(3, 0), DEVFS_CHAR,
  98                     UID_ROOT, GID_KMEM, 0640, "mem");
  99     devfs_make_node(makedev(3, 1), DEVFS_CHAR,
 100                     UID_ROOT, GID_KMEM, 0640, "kmem");
 101     devfs_make_node(makedev(3, 2), DEVFS_CHAR,
 102                     UID_ROOT, GID_WHEEL, 0666, "null");
 103     devfs_make_node(makedev(3, 3), DEVFS_CHAR,
 104                     UID_ROOT, GID_WHEEL, 0666, "zero");
 105     devfs_make_node(makedev(6, 0), DEVFS_CHAR,
 106                     UID_ROOT, GID_WHEEL, 0600, "klog");
 107     return 0;
 108 }
 109
 110 /*-
 111  *  mp   - pointer to 'mount' structure
 112  *  path - addr in user space of mount point (ie /usr or whatever)
 113  *  data - addr in user space of mount params including the
 114  *         name of the block special file to treat as a filesystem.
 115  *         (NOT USED)
 116  *  ndp  - namei data pointer (NOT USED)
 117  *  p    - proc pointer
 118  * devfs is special in that it doesn't require any device to be mounted..
 119  * It makes up its data as it goes along.
 120  * it must be mounted during single user.. until it is, only std{in/out/err}
 121  * and the root filesystem are available.
 122  */
 123 /*proto*/
 124 int
 125 devfs_mount(struct mount *mp, char *path, caddr_t data,
 126             struct nameidata *ndp, struct proc *p)
 127 {
 128         struct devfsmount *devfs_mp_p;  /* devfs specific mount info */
 129         int error;
 130         size_t size;
 131
 132         /*-
 133          *  If they just want to update, we don't need to do anything.
 134          */
 135         if (mp->mnt_flag & MNT_UPDATE)
 136         {
 137                 return 0;
 138         }
 139
 140         /*-
 141          *  Well, it's not an update, it's a real mount request.
 142          *  Time to get dirty.
 143          * HERE we should check to see if we are already mounted here.
 144          */
 145
 146         MALLOC(devfs_mp_p, struct devfsmount *, sizeof(struct devfsmount),
 147                M_DEVFSMNT, M_WAITOK);
 148         if (devfs_mp_p == NULL)
 149                 return (ENOMEM);
 150         bzero(devfs_mp_p,sizeof(*devfs_mp_p));
 151         devfs_mp_p->mount = mp;
 152
 153         /*-
 154          *  Fill out some fields
 155          */
 156         mp->mnt_data = (qaddr_t)devfs_mp_p;
 157         mp->mnt_stat.f_type = mp->mnt_vfc->vfc_typenum;
 158         mp->mnt_stat.f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 159         mp->mnt_stat.f_fsid.val[1] = mp->mnt_stat.f_type;
 160         mp->mnt_flag |= MNT_LOCAL;
 161
 162         DEVFS_LOCK(p);
 163         error = dev_dup_plane(devfs_mp_p);
 164         DEVFS_UNLOCK(p);
 165         if (error) {
 166                 mp->mnt_data = (qaddr_t)0;
 167                 FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 168                 return (error);
 169         }
 170
 171         /*-
 172          *  Copy in the name of the directory the filesystem
 173          *  is to be mounted on.
 174          *  And we clear the remainder of the character strings
 175          *  to be tidy.
 176          */
 177
 178         if (!kernel_mount) {
 179                 copyinstr(path, (caddr_t)mp->mnt_stat.f_mntonname,
 180                         sizeof(mp->mnt_stat.f_mntonname)-1, &size);
 181                 bzero(mp->mnt_stat.f_mntonname + size,
 182                         sizeof(mp->mnt_stat.f_mntonname) - size);
 183         }
 184         bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
 185         bcopy("devfs",mp->mnt_stat.f_mntfromname, 5);
 186         DEVFS_INCR_MOUNTS();
 187         (void)devfs_statfs(mp, &mp->mnt_stat, p);
 188         return 0;
 189 }
 190
 191
 192 static int
 193 devfs_start(struct mount *mp, int flags, struct proc *p)
 194 {
 195         return 0;
 196 }
 197
 198 /*-
 199  *  Unmount the filesystem described by mp.
 200  */
 201 static int
 202 devfs_unmount( struct mount *mp, int mntflags, struct proc *p)
 203 {
 204         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 205         int flags = 0;
 206         int force = 0;
 207         int error;
 208
 209         if (mntflags & MNT_FORCE) {
 210                 flags |= FORCECLOSE;
 211                 force = 1;
 212         }
 213         error = vflush(mp, NULLVP, flags);
 214         if (error && !force)
 215                 return error;
 216
 217         DEVFS_LOCK(p);
 218         devfs_free_plane(devfs_mp_p);
 219         DEVFS_UNLOCK(p);
 220         FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 221         DEVFS_DECR_MOUNTS();
 222         mp->mnt_data = (qaddr_t)0;
 223         mp->mnt_flag &= ~MNT_LOCAL;
 224
 225         return 0;
 226 }
 227
 228 /* return the address of the root vnode  in *vpp */
 229 static int
 230 devfs_root(struct mount *mp, struct vnode **vpp)
 231 {
 232         struct devfsmount *devfs_mp_p = (struct devfsmount *)(mp->mnt_data);
 233         int error;
 234
 235         error = devfs_dntovn(devfs_mp_p->plane_root->de_dnp,vpp,
 236                              current_proc());
 237         return error;
 238 }
 239
 240 static int
 241 devfs_quotactl(struct mount *mp, int cmds, uid_t uid, caddr_t arg,
 242                struct proc *p)
 243 {
 244         return EOPNOTSUPP;
 245 }
 246
 247 static int
 248 devfs_statfs( struct mount *mp, struct statfs *sbp, struct proc *p)
 249 {
 250         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 251
 252         /*-
 253          *  Fill in the stat block.
 254          */
 255         sbp->f_type   = mp->mnt_stat.f_type;
 256         sbp->f_flags  = 0;              /* XXX */
 257         sbp->f_bsize  = 512;
 258         sbp->f_iosize = 512;
 259         sbp->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 260                          + devfs_stats.nodes * sizeof(devnode_t)
 261                          + devfs_stats.entries * sizeof(devdirent_t)
 262                          + devfs_stats.stringspace
 263                          ) / sbp->f_bsize;
 264         sbp->f_bfree  = 0;
 265         sbp->f_bavail = 0;
 266         sbp->f_files  = devfs_stats.nodes;
 267         sbp->f_ffree  = 0;
 268         sbp->f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 269         sbp->f_fsid.val[1] = mp->mnt_stat.f_type;
 270
 271         /*-
 272          *  Copy the mounted on and mounted from names into
 273          *  the passed in stat block, if it is not the one
 274          *  in the mount structure.
 275          */
 276         if (sbp != &mp->mnt_stat) {
 277                 bcopy((caddr_t)mp->mnt_stat.f_mntonname,
 278                         (caddr_t)&sbp->f_mntonname[0], MNAMELEN);
 279                 bcopy((caddr_t)mp->mnt_stat.f_mntfromname,
 280                         (caddr_t)&sbp->f_mntfromname[0], MNAMELEN);
 281         }
 282         return 0;
 283 }
 284
 285 static int
 286 devfs_sync(struct mount *mp, int waitfor,struct ucred *cred,struct proc *p)
 287 {
 288     return (0);
 289 }
 290
 291
 292 static int
 293 devfs_vget(struct mount *mp, void * ino,struct vnode **vpp)
 294 {
 295         return EOPNOTSUPP;
 296 }
 297
 298 /*************************************************************
 299  * The concept of exporting a kernel generated devfs is stupid
 300  * So don't handle filehandles
 301  */
 302
 303 static int
 304 devfs_fhtovp (struct mount *mp, struct fid *fhp, struct mbuf *nam,
 305               struct vnode **vpp, int *exflagsp, struct ucred **credanonp)
 306 {
 307         return (EINVAL);
 308 }
 309
 310
 311 static int
 312 devfs_vptofh (struct vnode *vp, struct fid *fhp)
 313 {
 314         return (EINVAL);
 315 }
 316
 317 static int
 318 devfs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
 319         int *name;
 320         u_int namelen;
 321         void *oldp;
 322         size_t *oldlenp;
 323         void *newp;
 324         size_t newlen;
 325         struct proc *p;
 326 {
 327     return (EOPNOTSUPP);
 328 }
 329
 330 #include <sys/namei.h>
 331
 332 /*
 333  * Function: devfs_kernel_mount
 334  * Purpose:
 335  *   Mount devfs at the given mount point from within the kernel.
 336  */
 337 int
 338 devfs_kernel_mount(char * mntname)
 339 {
 340         struct mount *mp;
 341         int error;
 342         struct proc *procp;
 343         struct nameidata nd;
 344         struct vnode  * vp;
 345
 346         if (devfs_vfsp == NULL) {
 347             printf("devfs_kernel_mount: devfs_vfsp is NULL\n");
 348             return (EINVAL);
 349         }
 350         procp = current_proc();
 351
 352         /*
 353          * Get vnode to be covered
 354          */
 355         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
 356             mntname, procp);
 357         if ((error = namei(&nd))) {
 358             printf("devfs_kernel_mount: failed to find directory '%s', %d",
 359                    mntname, error);
 360             return (error);
 361         }
 362         vp = nd.ni_vp;
 363         if ((error = vinvalbuf(vp, V_SAVE, procp->p_ucred, procp, 0, 0))) {
 364             printf("devfs_kernel_mount: vinval failed: %d\n", error);
 365             vput(vp);
 366             return (error);
 367         }
 368         if (vp->v_type != VDIR) {
 369             printf("devfs_kernel_mount: '%s' is not a directory\n", mntname);
 370             vput(vp);
 371             return (ENOTDIR);
 372         }
 373         if (vp->v_mountedhere != NULL) {
 374             vput(vp);
 375             return (EBUSY);
 376         }
 377
 378         /*
 379          * Allocate and initialize the filesystem.
 380          */
 381         MALLOC_ZONE(mp, struct mount *, (u_long)sizeof(struct mount),
 382                 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
 410             if (mp->mnt_kern_flag & MNTK_IO_XINFO)
 411                     FREE(mp->mnt_xinfo_ptr, M_TEMP);
 412             vfs_unbusy(mp, procp);
 413
 414             FREE_ZONE(mp, sizeof (struct mount), M_MOUNT);
 415             vput(vp);
 416             return (error);
 417         }
 418         simple_lock(&mountlist_slock);
 419         CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list);
 420         simple_unlock(&mountlist_slock);
 421         VOP_UNLOCK(vp, 0, procp);
 422         vfs_unbusy(mp, procp);
 423         return (0);
 424 }
 425
 426 struct vfsops devfs_vfsops = {
 427         devfs_mount,
 428         devfs_start,
 429         devfs_unmount,
 430         devfs_root,
 431         devfs_quotactl,
 432         devfs_statfs,
 433         devfs_sync,
 434         devfs_vget,
 435         devfs_fhtovp,
 436         devfs_vptofh,
 437         devfs_init,
 438         devfs_sysctl,
 439 };