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