bsd/miscfs/devfs/devfs_vfsops.c

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*-
  31  * Copyright 1997,1998 Julian Elischer.  All rights reserved.
  32  * julian@freebsd.org
  33  *
  34  * Redistribution and use in source and binary forms, with or without
  35  * modification, are permitted provided that the following conditions are
  36  * met:
  37  *  1. Redistributions of source code must retain the above copyright
  38  *     notice, this list of conditions and the following disclaimer.
  39  *  2. Redistributions in binary form must reproduce the above copyright notice,
  40  *     this list of conditions and the following disclaimer in the documentation
  41  *     and/or other materials provided with the distribution.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS
  44  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  45  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  46  * DISCLAIMED.  IN NO EVENT SHALL THE HOLDER OR CONTRIBUTORS BE LIABLE FOR
  47  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  49  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  50  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  53  * SUCH DAMAGE.
  54  *
  55  * devfs_vfsops.c
  56  *
  57  */
  58 /*
  59  * HISTORY
  60  *  Dieter Siegmund (dieter@apple.com) Wed Jul 14 13:37:59 PDT 1999
  61  *  - modified devfs_statfs() to use devfs_stats to calculate the
  62  *    amount of memory used by devfs
  63  */
  64
  65
  66 #include <sys/param.h>
  67 #include <sys/systm.h>
  68 #include <sys/kernel.h>
  69 #include <sys/vnode_internal.h>
  70 #include <sys/proc.h>
  71 #include <sys/kauth.h>
  72 #include <sys/mount_internal.h>
  73 #include <sys/malloc.h>
  74
  75 #include "devfs.h"
  76 #include "devfsdefs.h"
  77
  78 static int devfs_statfs( struct mount *mp, struct vfsstatfs *sbp, vfs_context_t context);
  79 static int devfs_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t context);
  80
  81 static struct vfstable * devfs_vfsp = 0;
  82
  83
  84 /*-
  85  * Called from the generic VFS startups.
  86  * This is the second stage of DEVFS initialisation.
  87  * The probed devices have already been loaded and the
  88  * basic structure of the DEVFS created.
  89  * We take the oportunity to mount the hidden DEVFS layer, so that
  90  * devices from devfs get sync'd.
  91  */
  92 static int
  93 devfs_init(struct vfsconf *vfsp)
  94 {
  95     devfs_vfsp = (struct vfstable *)vfsp; /* remember this for devfs_kernel_mount below */
  96
  97     if (devfs_sinit())
  98         return (ENOTSUP);
  99     devfs_make_node(makedev(0, 0), DEVFS_CHAR,
 100                     UID_ROOT, GID_WHEEL, 0622, "console");
 101     devfs_make_node(makedev(2, 0), DEVFS_CHAR,
 102                     UID_ROOT, GID_WHEEL, 0666, "tty");
 103     devfs_make_node(makedev(3, 0), DEVFS_CHAR,
 104                     UID_ROOT, GID_KMEM, 0640, "mem");
 105     devfs_make_node(makedev(3, 1), DEVFS_CHAR,
 106                     UID_ROOT, GID_KMEM, 0640, "kmem");
 107     devfs_make_node(makedev(3, 2), DEVFS_CHAR,
 108                     UID_ROOT, GID_WHEEL, 0666, "null");
 109     devfs_make_node(makedev(3, 3), DEVFS_CHAR,
 110                     UID_ROOT, GID_WHEEL, 0666, "zero");
 111     devfs_make_node(makedev(6, 0), DEVFS_CHAR,
 112                     UID_ROOT, GID_WHEEL, 0600, "klog");
 113     return 0;
 114 }
 115
 116 /*-
 117  *  mp   - pointer to 'mount' structure
 118  *  path - addr in user space of mount point (ie /usr or whatever)
 119  *  data - addr in user space of mount params including the
 120  *         name of the block special file to treat as a filesystem.
 121  *         (NOT USED)
 122  *  ndp  - namei data pointer (NOT USED)
 123  *  p    - proc pointer
 124  * devfs is special in that it doesn't require any device to be mounted..
 125  * It makes up its data as it goes along.
 126  * it must be mounted during single user.. until it is, only std{in/out/err}
 127  * and the root filesystem are available.
 128  */
 129 /*proto*/
 130 int
 131 devfs_mount(struct mount *mp, __unused vnode_t devvp, __unused user_addr_t data, vfs_context_t context)
 132 {
 133         struct devfsmount *devfs_mp_p;  /* devfs specific mount info */
 134         int error;
 135
 136         /*-
 137          *  If they just want to update, we don't need to do anything.
 138          */
 139         if (mp->mnt_flag & MNT_UPDATE)
 140         {
 141                 return 0;
 142         }
 143
 144         /* Advisory locking should be handled at the VFS layer */
 145         vfs_setlocklocal(mp);
 146
 147         /*-
 148          *  Well, it's not an update, it's a real mount request.
 149          *  Time to get dirty.
 150          * HERE we should check to see if we are already mounted here.
 151          */
 152
 153         MALLOC(devfs_mp_p, struct devfsmount *, sizeof(struct devfsmount),
 154                M_DEVFSMNT, M_WAITOK);
 155         if (devfs_mp_p == NULL)
 156                 return (ENOMEM);
 157         bzero(devfs_mp_p,sizeof(*devfs_mp_p));
 158         devfs_mp_p->mount = mp;
 159
 160         /*-
 161          *  Fill out some fields
 162          */
 163         mp->mnt_data = (qaddr_t)devfs_mp_p;
 164         mp->mnt_vfsstat.f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 165         mp->mnt_vfsstat.f_fsid.val[1] = vfs_typenum(mp);
 166         mp->mnt_flag |= MNT_LOCAL;
 167
 168         DEVFS_LOCK();
 169         error = dev_dup_plane(devfs_mp_p);
 170         DEVFS_UNLOCK();
 171
 172         if (error) {
 173                 mp->mnt_data = (qaddr_t)0;
 174                 FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 175                 return (error);
 176         } else
 177                 DEVFS_INCR_MOUNTS();
 178
 179         /*-
 180          *  Copy in the name of the directory the filesystem
 181          *  is to be mounted on.
 182          *  And we clear the remainder of the character strings
 183          *  to be tidy.
 184          */
 185
 186         bzero(mp->mnt_vfsstat.f_mntfromname, MAXPATHLEN);
 187         bcopy("devfs",mp->mnt_vfsstat.f_mntfromname, 5);
 188         (void)devfs_statfs(mp, &mp->mnt_vfsstat, context);
 189
 190         return 0;
 191 }
 192
 193
 194 static int
 195 devfs_start(__unused struct mount *mp, __unused int flags, __unused vfs_context_t context)
 196 {
 197         return 0;
 198 }
 199
 200 /*-
 201  *  Unmount the filesystem described by mp.
 202  */
 203 static int
 204 devfs_unmount( struct mount *mp, int mntflags, __unused vfs_context_t context)
 205 {
 206         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 207         int flags = 0;
 208         int force = 0;
 209         int error;
 210
 211         if (mntflags & MNT_FORCE) {
 212                 flags |= FORCECLOSE;
 213                 force = 1;
 214         }
 215         error = vflush(mp, NULLVP, flags);
 216         if (error && !force)
 217                 return error;
 218
 219         DEVFS_LOCK();
 220         devfs_free_plane(devfs_mp_p);
 221         DEVFS_UNLOCK();
 222
 223         DEVFS_DECR_MOUNTS();
 224
 225         FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 226         mp->mnt_data = (qaddr_t)0;
 227         mp->mnt_flag &= ~MNT_LOCAL;
 228
 229         return 0;
 230 }
 231
 232 /* return the address of the root vnode  in *vpp */
 233 static int
 234 devfs_root(struct mount *mp, struct vnode **vpp, vfs_context_t context)
 235 {
 236         struct devfsmount *devfs_mp_p = (struct devfsmount *)(mp->mnt_data);
 237         int error;
 238
 239         DEVFS_LOCK();
 240         error = devfs_dntovn(devfs_mp_p->plane_root->de_dnp, vpp, context->vc_proc);
 241         DEVFS_UNLOCK();
 242
 243         return error;
 244 }
 245
 246 static int
 247 devfs_statfs( struct mount *mp, struct vfsstatfs *sbp, __unused vfs_context_t context)
 248 {
 249         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 250
 251         /*-
 252          *  Fill in the stat block.
 253          */
 254         //sbp->f_type   = mp->mnt_vfsstat.f_type;
 255         sbp->f_flags  = 0;              /* XXX */
 256         sbp->f_bsize  = 512;
 257         sbp->f_iosize = 512;
 258         sbp->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 259                          + devfs_stats.nodes * sizeof(devnode_t)
 260                          + devfs_stats.entries * sizeof(devdirent_t)
 261                          + devfs_stats.stringspace
 262                          ) / sbp->f_bsize;
 263         sbp->f_bfree  = 0;
 264         sbp->f_bavail = 0;
 265         sbp->f_files  = devfs_stats.nodes;
 266         sbp->f_ffree  = 0;
 267         sbp->f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 268         sbp->f_fsid.val[1] = vfs_typenum(mp);
 269
 270         return 0;
 271 }
 272
 273 static int
 274 devfs_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t context)
 275 {
 276         VFSATTR_RETURN(fsap, f_objcount, devfs_stats.nodes);
 277         VFSATTR_RETURN(fsap, f_maxobjcount, devfs_stats.nodes);
 278         VFSATTR_RETURN(fsap, f_bsize, 512);
 279         VFSATTR_RETURN(fsap, f_iosize, 512);
 280         if (VFSATTR_IS_ACTIVE(fsap, f_blocks) || VFSATTR_IS_ACTIVE(fsap, f_bused)) {
 281                 fsap->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 282                          + devfs_stats.nodes * sizeof(devnode_t)
 283                          + devfs_stats.entries * sizeof(devdirent_t)
 284                          + devfs_stats.stringspace
 285                          ) / fsap->f_bsize;
 286                 fsap->f_bused = fsap->f_blocks;
 287                 VFSATTR_SET_SUPPORTED(fsap, f_blocks);
 288                 VFSATTR_SET_SUPPORTED(fsap, f_bused);
 289         }
 290         VFSATTR_RETURN(fsap, f_bfree, 0);
 291         VFSATTR_RETURN(fsap, f_bavail, 0);
 292         VFSATTR_RETURN(fsap, f_files, devfs_stats.nodes);
 293         VFSATTR_RETURN(fsap, f_ffree, 0);
 294         VFSATTR_RETURN(fsap, f_fssubtype, 0);
 295
 296         return 0;
 297 }
 298
 299 static int
 300 devfs_sync(__unused struct mount *mp, __unused int waitfor, __unused vfs_context_t context)
 301 {
 302     return (0);
 303 }
 304
 305
 306 static int
 307 devfs_vget(__unused struct mount *mp, __unused ino64_t ino, __unused struct vnode **vpp, __unused vfs_context_t context)
 308 {
 309         return ENOTSUP;
 310 }
 311
 312 /*************************************************************
 313  * The concept of exporting a kernel generated devfs is stupid
 314  * So don't handle filehandles
 315  */
 316
 317 static int
 318 devfs_fhtovp (__unused struct mount *mp, __unused int fhlen, __unused unsigned char *fhp, __unused struct vnode **vpp, __unused vfs_context_t context)
 319 {
 320         return (EINVAL);
 321 }
 322
 323
 324 static int
 325 devfs_vptofh (__unused struct vnode *vp, __unused int *fhlenp, __unused unsigned char *fhp, __unused vfs_context_t context)
 326 {
 327         return (EINVAL);
 328 }
 329
 330 static int
 331 devfs_sysctl(__unused int *name, __unused u_int namelen, __unused user_addr_t oldp,
 332              __unused size_t *oldlenp, __unused user_addr_t newp,
 333              __unused size_t newlen, __unused vfs_context_t context)
 334 {
 335     return (ENOTSUP);
 336 }
 337
 338 #include <sys/namei.h>
 339
 340 /*
 341  * Function: devfs_kernel_mount
 342  * Purpose:
 343  *   Mount devfs at the given mount point from within the kernel.
 344  */
 345 int
 346 devfs_kernel_mount(char * mntname)
 347 {
 348         struct mount *mp;
 349         int error;
 350         struct nameidata nd;
 351         struct vnode  * vp;
 352         struct vfs_context context;
 353
 354         if (devfs_vfsp == NULL) {
 355             printf("devfs_kernel_mount: devfs_vfsp is NULL\n");
 356             return (EINVAL);
 357         }
 358         context.vc_proc = current_proc();
 359         context.vc_ucred = kauth_cred_get();
 360
 361         /*
 362          * Get vnode to be covered
 363          */
 364         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE32,
 365             CAST_USER_ADDR_T(mntname), &context);
 366         if ((error = namei(&nd))) {
 367             printf("devfs_kernel_mount: failed to find directory '%s', %d",
 368                    mntname, error);
 369             return (error);
 370         }
 371         nameidone(&nd);
 372         vp = nd.ni_vp;
 373
 374         if ((error = VNOP_FSYNC(vp, MNT_WAIT, &context))) {
 375             printf("devfs_kernel_mount: vnop_fsync failed: %d\n", error);
 376             vnode_put(vp);
 377             return (error);
 378         }
 379         if ((error = buf_invalidateblks(vp, BUF_WRITE_DATA, 0, 0))) {
 380             printf("devfs_kernel_mount: buf_invalidateblks failed: %d\n", error);
 381             vnode_put(vp);
 382             return (error);
 383         }
 384         if (vnode_isdir(vp) == 0) {
 385             printf("devfs_kernel_mount: '%s' is not a directory\n", mntname);
 386             vnode_put(vp);
 387             return (ENOTDIR);
 388         }
 389         if ((vnode_mountedhere(vp))) {
 390             vnode_put(vp);
 391             return (EBUSY);
 392         }
 393
 394         /*
 395          * Allocate and initialize the filesystem.
 396          */
 397         MALLOC_ZONE(mp, struct mount *, (u_long)sizeof(struct mount),
 398                 M_MOUNT, M_WAITOK);
 399         bzero((char *)mp, (u_long)sizeof(struct mount));
 400
 401         /* Initialize the default IO constraints */
 402         mp->mnt_maxreadcnt = mp->mnt_maxwritecnt = MAXPHYS;
 403         mp->mnt_segreadcnt = mp->mnt_segwritecnt = 32;
 404
 405         mount_lock_init(mp);
 406         TAILQ_INIT(&mp->mnt_vnodelist);
 407         TAILQ_INIT(&mp->mnt_workerqueue);
 408         TAILQ_INIT(&mp->mnt_newvnodes);
 409
 410         (void)vfs_busy(mp, LK_NOWAIT);
 411         mp->mnt_op = devfs_vfsp->vfc_vfsops;
 412         mp->mnt_vtable = devfs_vfsp;
 413         devfs_vfsp->vfc_refcount++;
 414         devfs_vfsp->vfc_threadsafe = TRUE;
 415         devfs_vfsp->vfc_64bitready = TRUE;
 416         mp->mnt_flag = 0;
 417         mp->mnt_flag |= devfs_vfsp->vfc_flags & MNT_VISFLAGMASK;
 418         strncpy(mp->mnt_vfsstat.f_fstypename, devfs_vfsp->vfc_name, MFSTYPENAMELEN);
 419         vp->v_mountedhere = mp;
 420         mp->mnt_vnodecovered = vp;
 421         mp->mnt_vfsstat.f_owner = kauth_cred_getuid(kauth_cred_get());
 422         (void) copystr(mntname, mp->mnt_vfsstat.f_mntonname, MAXPATHLEN - 1, 0);
 423
 424         error = devfs_mount(mp, NULL, NULL, &context);
 425
 426         if (error) {
 427             printf("devfs_kernel_mount: mount %s failed: %d", mntname, error);
 428             mp->mnt_vtable->vfc_refcount--;
 429
 430             vfs_unbusy(mp);
 431
 432             mount_lock_destroy(mp);
 433             FREE_ZONE(mp, sizeof (struct mount), M_MOUNT);
 434             vnode_put(vp);
 435             return (error);
 436         }
 437         vnode_ref(vp);
 438         vnode_put(vp);
 439         vfs_unbusy(mp);
 440         mount_list_add(mp);
 441         return (0);
 442 }
 443
 444 struct vfsops devfs_vfsops = {
 445         devfs_mount,
 446         devfs_start,
 447         devfs_unmount,
 448         devfs_root,
 449         NULL,                           /* quotactl */
 450         devfs_vfs_getattr,
 451         devfs_sync,
 452         devfs_vget,
 453         devfs_fhtovp,
 454         devfs_vptofh,
 455         devfs_init,
 456         devfs_sysctl
 457 };