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 error;
 205
 206         if (mntflags & MNT_FORCE) {
 207                 flags |= FORCECLOSE;
 208         }
 209         error = vflush(mp, NULLVP, flags);
 210         if (error)
 211                 return error;
 212
 213         DEVFS_LOCK(p);
 214         devfs_free_plane(devfs_mp_p);
 215         DEVFS_UNLOCK(p);
 216         FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 217         DEVFS_DECR_MOUNTS();
 218         mp->mnt_data = (qaddr_t)0;
 219         mp->mnt_flag &= ~MNT_LOCAL;
 220
 221         return 0;
 222 }
 223
 224 /* return the address of the root vnode  in *vpp */
 225 static int
 226 devfs_root(struct mount *mp, struct vnode **vpp)
 227 {
 228         struct devfsmount *devfs_mp_p = (struct devfsmount *)(mp->mnt_data);
 229         int error;
 230
 231         error = devfs_dntovn(devfs_mp_p->plane_root->de_dnp,vpp,
 232                              current_proc());
 233         return error;
 234 }
 235
 236 static int
 237 devfs_quotactl(struct mount *mp, int cmds, uid_t uid, caddr_t arg,
 238                struct proc *p)
 239 {
 240         return EOPNOTSUPP;
 241 }
 242
 243 static int
 244 devfs_statfs( struct mount *mp, struct statfs *sbp, struct proc *p)
 245 {
 246         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 247
 248         /*-
 249          *  Fill in the stat block.
 250          */
 251         sbp->f_type   = mp->mnt_stat.f_type;
 252         sbp->f_flags  = 0;              /* XXX */
 253         sbp->f_bsize  = 512;
 254         sbp->f_iosize = 512;
 255         sbp->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 256                          + devfs_stats.nodes * sizeof(devnode_t)
 257                          + devfs_stats.entries * sizeof(devdirent_t)
 258                          + devfs_stats.stringspace
 259                          ) / sbp->f_bsize;
 260         sbp->f_bfree  = 0;
 261         sbp->f_bavail = 0;
 262         sbp->f_files  = devfs_stats.nodes;
 263         sbp->f_ffree  = 0;
 264         sbp->f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 265         sbp->f_fsid.val[1] = mp->mnt_stat.f_type;
 266
 267         /*-
 268          *  Copy the mounted on and mounted from names into
 269          *  the passed in stat block, if it is not the one
 270          *  in the mount structure.
 271          */
 272         if (sbp != &mp->mnt_stat) {
 273                 bcopy((caddr_t)mp->mnt_stat.f_mntonname,
 274                         (caddr_t)&sbp->f_mntonname[0], MNAMELEN);
 275                 bcopy((caddr_t)mp->mnt_stat.f_mntfromname,
 276                         (caddr_t)&sbp->f_mntfromname[0], MNAMELEN);
 277         }
 278         return 0;
 279 }
 280
 281 static int
 282 devfs_sync(struct mount *mp, int waitfor,struct ucred *cred,struct proc *p)
 283 {
 284     return (0);
 285 }
 286
 287
 288 static int
 289 devfs_vget(struct mount *mp, void * ino,struct vnode **vpp)
 290 {
 291         return EOPNOTSUPP;
 292 }
 293
 294 /*************************************************************
 295  * The concept of exporting a kernel generated devfs is stupid
 296  * So don't handle filehandles
 297  */
 298
 299 static int
 300 devfs_fhtovp (struct mount *mp, struct fid *fhp, struct mbuf *nam,
 301               struct vnode **vpp, int *exflagsp, struct ucred **credanonp)
 302 {
 303         return (EINVAL);
 304 }
 305
 306
 307 static int
 308 devfs_vptofh (struct vnode *vp, struct fid *fhp)
 309 {
 310         return (EINVAL);
 311 }
 312
 313 static int
 314 devfs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
 315         int *name;
 316         u_int namelen;
 317         void *oldp;
 318         size_t *oldlenp;
 319         void *newp;
 320         size_t newlen;
 321         struct proc *p;
 322 {
 323     return (EOPNOTSUPP);
 324 }
 325
 326 #include <sys/namei.h>
 327
 328 /*
 329  * Function: devfs_kernel_mount
 330  * Purpose:
 331  *   Mount devfs at the given mount point from within the kernel.
 332  */
 333 int
 334 devfs_kernel_mount(char * mntname)
 335 {
 336         struct mount *mp;
 337         int error;
 338         struct proc *procp;
 339         struct nameidata nd;
 340         struct vnode  * vp;
 341
 342         if (devfs_vfsp == NULL) {
 343             printf("devfs_kernel_mount: devfs_vfsp is NULL\n");
 344             return (EINVAL);
 345         }
 346         procp = current_proc();
 347
 348         /*
 349          * Get vnode to be covered
 350          */
 351         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
 352             mntname, procp);
 353         if ((error = namei(&nd))) {
 354             printf("devfs_kernel_mount: failed to find directory '%s', %d",
 355                    mntname, error);
 356             return (error);
 357         }
 358         vp = nd.ni_vp;
 359         if ((error = vinvalbuf(vp, V_SAVE, procp->p_ucred, procp, 0, 0))) {
 360             printf("devfs_kernel_mount: vinval failed: %d\n", error);
 361             vput(vp);
 362             return (error);
 363         }
 364         if (vp->v_type != VDIR) {
 365             printf("devfs_kernel_mount: '%s' is not a directory\n", mntname);
 366             vput(vp);
 367             return (ENOTDIR);
 368         }
 369         if (vp->v_mountedhere != NULL) {
 370             vput(vp);
 371             return (EBUSY);
 372         }
 373
 374         /*
 375          * Allocate and initialize the filesystem.
 376          */
 377         mp = _MALLOC_ZONE((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK);
 378         bzero((char *)mp, (u_long)sizeof(struct mount));
 379
 380     /* Initialize the default IO constraints */
 381     mp->mnt_maxreadcnt = mp->mnt_maxwritecnt = MAXPHYS;
 382     mp->mnt_segreadcnt = mp->mnt_segwritecnt = 32;
 383
 384         lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, 0);
 385         (void)vfs_busy(mp, LK_NOWAIT, 0, procp);
 386         LIST_INIT(&mp->mnt_vnodelist);
 387         mp->mnt_op = devfs_vfsp->vfc_vfsops;
 388         mp->mnt_vfc = devfs_vfsp;
 389         devfs_vfsp->vfc_refcount++;
 390         mp->mnt_flag = 0;
 391         mp->mnt_flag |= devfs_vfsp->vfc_flags & MNT_VISFLAGMASK;
 392         strncpy(mp->mnt_stat.f_fstypename, devfs_vfsp->vfc_name, MFSNAMELEN);
 393         vp->v_mountedhere = mp;
 394         mp->mnt_vnodecovered = vp;
 395         mp->mnt_stat.f_owner = procp->p_ucred->cr_uid;
 396         (void) copystr(mntname, mp->mnt_stat.f_mntonname, MNAMELEN - 1, 0);
 397
 398         kernel_mount = 1;
 399         error = devfs_mount(mp, mntname, NULL, NULL, procp);
 400         kernel_mount = 0;
 401         if (error) {
 402             printf("devfs_kernel_mount: mount %s failed: %d", mntname, error);
 403             mp->mnt_vfc->vfc_refcount--;
 404             vfs_unbusy(mp, procp);
 405             _FREE_ZONE(mp, sizeof (struct mount), M_MOUNT);
 406             vput(vp);
 407             return (error);
 408         }
 409         printf("devfs on %s\n", mntname);
 410         simple_lock(&mountlist_slock);
 411         CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list);
 412         simple_unlock(&mountlist_slock);
 413         VOP_UNLOCK(vp, 0, procp);
 414         vfs_unbusy(mp, procp);
 415         return (0);
 416 }
 417
 418 struct vfsops devfs_vfsops = {
 419         devfs_mount,
 420         devfs_start,
 421         devfs_unmount,
 422         devfs_root,
 423         devfs_quotactl,
 424         devfs_statfs,
 425         devfs_sync,
 426         devfs_vget,
 427         devfs_fhtovp,
 428         devfs_vptofh,
 429         devfs_init,
 430         devfs_sysctl,
 431 };