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