bsd/miscfs/devfs/devfs_vfsops.c

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_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 License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*-
  29  * Copyright 1997,1998 Julian Elischer.  All rights reserved.
  30  * julian@freebsd.org
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions are
  34  * met:
  35  *  1. Redistributions of source code must retain the above copyright
  36  *     notice, this list of conditions and the following disclaimer.
  37  *  2. Redistributions in binary form must reproduce the above copyright notice,
  38  *     this list of conditions and the following disclaimer in the documentation
  39  *     and/or other materials provided with the distribution.
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS
  42  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  43  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  44  * DISCLAIMED.  IN NO EVENT SHALL THE HOLDER OR CONTRIBUTORS BE LIABLE FOR
  45  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  47  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  48  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * devfs_vfsops.c
  54  *
  55  */
  56 /*
  57  * HISTORY
  58  *  Dieter Siegmund (dieter@apple.com) Wed Jul 14 13:37:59 PDT 1999
  59  *  - modified devfs_statfs() to use devfs_stats to calculate the
  60  *    amount of memory used by devfs
  61  */
  62
  63
  64 #include <sys/param.h>
  65 #include <sys/systm.h>
  66 #include <sys/kernel.h>
  67 #include <sys/vnode_internal.h>
  68 #include <sys/proc.h>
  69 #include <sys/kauth.h>
  70 #include <sys/mount_internal.h>
  71 #include <sys/malloc.h>
  72
  73 #include "devfs.h"
  74 #include "devfsdefs.h"
  75
  76 static int devfs_statfs( struct mount *mp, struct vfsstatfs *sbp, vfs_context_t context);
  77 static int devfs_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t context);
  78
  79 static struct vfstable * devfs_vfsp = 0;
  80
  81
  82 /*-
  83  * Called from the generic VFS startups.
  84  * This is the second stage of DEVFS initialisation.
  85  * The probed devices have already been loaded and the
  86  * basic structure of the DEVFS created.
  87  * We take the oportunity to mount the hidden DEVFS layer, so that
  88  * devices from devfs get sync'd.
  89  */
  90 static int
  91 devfs_init(struct vfsconf *vfsp)
  92 {
  93     devfs_vfsp = (struct vfstable *)vfsp; /* remember this for devfs_kernel_mount below */
  94
  95     if (devfs_sinit())
  96         return (ENOTSUP);
  97     devfs_make_node(makedev(0, 0), DEVFS_CHAR,
  98                     UID_ROOT, GID_WHEEL, 0622, "console");
  99     devfs_make_node(makedev(2, 0), DEVFS_CHAR,
 100                     UID_ROOT, GID_WHEEL, 0666, "tty");
 101     devfs_make_node(makedev(3, 0), DEVFS_CHAR,
 102                     UID_ROOT, GID_KMEM, 0640, "mem");
 103     devfs_make_node(makedev(3, 1), DEVFS_CHAR,
 104                     UID_ROOT, GID_KMEM, 0640, "kmem");
 105     devfs_make_node(makedev(3, 2), DEVFS_CHAR,
 106                     UID_ROOT, GID_WHEEL, 0666, "null");
 107     devfs_make_node(makedev(3, 3), DEVFS_CHAR,
 108                     UID_ROOT, GID_WHEEL, 0666, "zero");
 109     devfs_make_node(makedev(6, 0), DEVFS_CHAR,
 110                     UID_ROOT, GID_WHEEL, 0600, "klog");
 111     return 0;
 112 }
 113
 114 /*-
 115  *  mp   - pointer to 'mount' structure
 116  *  path - addr in user space of mount point (ie /usr or whatever)
 117  *  data - addr in user space of mount params including the
 118  *         name of the block special file to treat as a filesystem.
 119  *         (NOT USED)
 120  *  ndp  - namei data pointer (NOT USED)
 121  *  p    - proc pointer
 122  * devfs is special in that it doesn't require any device to be mounted..
 123  * It makes up its data as it goes along.
 124  * it must be mounted during single user.. until it is, only std{in/out/err}
 125  * and the root filesystem are available.
 126  */
 127 /*proto*/
 128 int
 129 devfs_mount(struct mount *mp, __unused vnode_t devvp, __unused user_addr_t data, vfs_context_t context)
 130 {
 131         struct devfsmount *devfs_mp_p;  /* devfs specific mount info */
 132         int error;
 133
 134         /*-
 135          *  If they just want to update, we don't need to do anything.
 136          */
 137         if (mp->mnt_flag & MNT_UPDATE)
 138         {
 139                 return 0;
 140         }
 141
 142         /* Advisory locking should be handled at the VFS layer */
 143         vfs_setlocklocal(mp);
 144
 145         /*-
 146          *  Well, it's not an update, it's a real mount request.
 147          *  Time to get dirty.
 148          * HERE we should check to see if we are already mounted here.
 149          */
 150
 151         MALLOC(devfs_mp_p, struct devfsmount *, sizeof(struct devfsmount),
 152                M_DEVFSMNT, M_WAITOK);
 153         if (devfs_mp_p == NULL)
 154                 return (ENOMEM);
 155         bzero(devfs_mp_p,sizeof(*devfs_mp_p));
 156         devfs_mp_p->mount = mp;
 157
 158         /*-
 159          *  Fill out some fields
 160          */
 161         mp->mnt_data = (qaddr_t)devfs_mp_p;
 162         mp->mnt_vfsstat.f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 163         mp->mnt_vfsstat.f_fsid.val[1] = vfs_typenum(mp);
 164         mp->mnt_flag |= MNT_LOCAL;
 165
 166         DEVFS_LOCK();
 167         error = dev_dup_plane(devfs_mp_p);
 168         DEVFS_UNLOCK();
 169
 170         if (error) {
 171                 mp->mnt_data = (qaddr_t)0;
 172                 FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 173                 return (error);
 174         } else
 175                 DEVFS_INCR_MOUNTS();
 176
 177         /*-
 178          *  Copy in the name of the directory the filesystem
 179          *  is to be mounted on.
 180          *  And we clear the remainder of the character strings
 181          *  to be tidy.
 182          */
 183
 184         bzero(mp->mnt_vfsstat.f_mntfromname, MAXPATHLEN);
 185         bcopy("devfs",mp->mnt_vfsstat.f_mntfromname, 5);
 186         (void)devfs_statfs(mp, &mp->mnt_vfsstat, context);
 187
 188         return 0;
 189 }
 190
 191
 192 static int
 193 devfs_start(__unused struct mount *mp, __unused int flags, __unused vfs_context_t context)
 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, __unused vfs_context_t context)
 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();
 218         devfs_free_plane(devfs_mp_p);
 219         DEVFS_UNLOCK();
 220
 221         DEVFS_DECR_MOUNTS();
 222
 223         FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 224         mp->mnt_data = (qaddr_t)0;
 225         mp->mnt_flag &= ~MNT_LOCAL;
 226
 227         return 0;
 228 }
 229
 230 /* return the address of the root vnode  in *vpp */
 231 static int
 232 devfs_root(struct mount *mp, struct vnode **vpp, vfs_context_t context)
 233 {
 234         struct devfsmount *devfs_mp_p = (struct devfsmount *)(mp->mnt_data);
 235         int error;
 236
 237         DEVFS_LOCK();
 238         error = devfs_dntovn(devfs_mp_p->plane_root->de_dnp, vpp, context->vc_proc);
 239         DEVFS_UNLOCK();
 240
 241         return error;
 242 }
 243
 244 static int
 245 devfs_statfs( struct mount *mp, struct vfsstatfs *sbp, __unused vfs_context_t context)
 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_vfsstat.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] = vfs_typenum(mp);
 267
 268         return 0;
 269 }
 270
 271 static int
 272 devfs_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t context)
 273 {
 274         VFSATTR_RETURN(fsap, f_objcount, devfs_stats.nodes);
 275         VFSATTR_RETURN(fsap, f_maxobjcount, devfs_stats.nodes);
 276         VFSATTR_RETURN(fsap, f_bsize, 512);
 277         VFSATTR_RETURN(fsap, f_iosize, 512);
 278         if (VFSATTR_IS_ACTIVE(fsap, f_blocks) || VFSATTR_IS_ACTIVE(fsap, f_bused)) {
 279                 fsap->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 280                          + devfs_stats.nodes * sizeof(devnode_t)
 281                          + devfs_stats.entries * sizeof(devdirent_t)
 282                          + devfs_stats.stringspace
 283                          ) / fsap->f_bsize;
 284                 fsap->f_bused = fsap->f_blocks;
 285                 VFSATTR_SET_SUPPORTED(fsap, f_blocks);
 286                 VFSATTR_SET_SUPPORTED(fsap, f_bused);
 287         }
 288         VFSATTR_RETURN(fsap, f_bfree, 0);
 289         VFSATTR_RETURN(fsap, f_bavail, 0);
 290         VFSATTR_RETURN(fsap, f_files, devfs_stats.nodes);
 291         VFSATTR_RETURN(fsap, f_ffree, 0);
 292         VFSATTR_RETURN(fsap, f_fssubtype, 0);
 293
 294         return 0;
 295 }
 296
 297 static int
 298 devfs_sync(__unused struct mount *mp, __unused int waitfor, __unused vfs_context_t context)
 299 {
 300     return (0);
 301 }
 302
 303
 304 static int
 305 devfs_vget(__unused struct mount *mp, __unused ino64_t ino, __unused struct vnode **vpp, __unused vfs_context_t context)
 306 {
 307         return ENOTSUP;
 308 }
 309
 310 /*************************************************************
 311  * The concept of exporting a kernel generated devfs is stupid
 312  * So don't handle filehandles
 313  */
 314
 315 static int
 316 devfs_fhtovp (__unused struct mount *mp, __unused int fhlen, __unused unsigned char *fhp, __unused struct vnode **vpp, __unused vfs_context_t context)
 317 {
 318         return (EINVAL);
 319 }
 320
 321
 322 static int
 323 devfs_vptofh (__unused struct vnode *vp, __unused int *fhlenp, __unused unsigned char *fhp, __unused vfs_context_t context)
 324 {
 325         return (EINVAL);
 326 }
 327
 328 static int
 329 devfs_sysctl(__unused int *name, __unused u_int namelen, __unused user_addr_t oldp,
 330              __unused size_t *oldlenp, __unused user_addr_t newp,
 331              __unused size_t newlen, __unused vfs_context_t context)
 332 {
 333     return (ENOTSUP);
 334 }
 335
 336 #include <sys/namei.h>
 337
 338 /*
 339  * Function: devfs_kernel_mount
 340  * Purpose:
 341  *   Mount devfs at the given mount point from within the kernel.
 342  */
 343 int
 344 devfs_kernel_mount(char * mntname)
 345 {
 346         struct mount *mp;
 347         int error;
 348         struct nameidata nd;
 349         struct vnode  * vp;
 350         struct vfs_context context;
 351
 352         if (devfs_vfsp == NULL) {
 353             printf("devfs_kernel_mount: devfs_vfsp is NULL\n");
 354             return (EINVAL);
 355         }
 356         context.vc_proc = current_proc();
 357         context.vc_ucred = kauth_cred_get();
 358
 359         /*
 360          * Get vnode to be covered
 361          */
 362         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE32,
 363             CAST_USER_ADDR_T(mntname), &context);
 364         if ((error = namei(&nd))) {
 365             printf("devfs_kernel_mount: failed to find directory '%s', %d",
 366                    mntname, error);
 367             return (error);
 368         }
 369         nameidone(&nd);
 370         vp = nd.ni_vp;
 371
 372         if ((error = VNOP_FSYNC(vp, MNT_WAIT, &context))) {
 373             printf("devfs_kernel_mount: vnop_fsync failed: %d\n", error);
 374             vnode_put(vp);
 375             return (error);
 376         }
 377         if ((error = buf_invalidateblks(vp, BUF_WRITE_DATA, 0, 0))) {
 378             printf("devfs_kernel_mount: buf_invalidateblks failed: %d\n", error);
 379             vnode_put(vp);
 380             return (error);
 381         }
 382         if (vnode_isdir(vp) == 0) {
 383             printf("devfs_kernel_mount: '%s' is not a directory\n", mntname);
 384             vnode_put(vp);
 385             return (ENOTDIR);
 386         }
 387         if ((vnode_mountedhere(vp))) {
 388             vnode_put(vp);
 389             return (EBUSY);
 390         }
 391
 392         /*
 393          * Allocate and initialize the filesystem.
 394          */
 395         MALLOC_ZONE(mp, struct mount *, (u_long)sizeof(struct mount),
 396                 M_MOUNT, M_WAITOK);
 397         bzero((char *)mp, (u_long)sizeof(struct mount));
 398
 399         /* Initialize the default IO constraints */
 400         mp->mnt_maxreadcnt = mp->mnt_maxwritecnt = MAXPHYS;
 401         mp->mnt_segreadcnt = mp->mnt_segwritecnt = 32;
 402
 403         mount_lock_init(mp);
 404         TAILQ_INIT(&mp->mnt_vnodelist);
 405         TAILQ_INIT(&mp->mnt_workerqueue);
 406         TAILQ_INIT(&mp->mnt_newvnodes);
 407
 408         (void)vfs_busy(mp, LK_NOWAIT);
 409         mp->mnt_op = devfs_vfsp->vfc_vfsops;
 410         mp->mnt_vtable = devfs_vfsp;
 411         devfs_vfsp->vfc_refcount++;
 412         devfs_vfsp->vfc_threadsafe = TRUE;
 413         devfs_vfsp->vfc_64bitready = TRUE;
 414         mp->mnt_flag = 0;
 415         mp->mnt_flag |= devfs_vfsp->vfc_flags & MNT_VISFLAGMASK;
 416         strncpy(mp->mnt_vfsstat.f_fstypename, devfs_vfsp->vfc_name, MFSTYPENAMELEN);
 417         vp->v_mountedhere = mp;
 418         mp->mnt_vnodecovered = vp;
 419         mp->mnt_vfsstat.f_owner = kauth_cred_getuid(kauth_cred_get());
 420         (void) copystr(mntname, mp->mnt_vfsstat.f_mntonname, MAXPATHLEN - 1, 0);
 421
 422         error = devfs_mount(mp, NULL, NULL, &context);
 423
 424         if (error) {
 425             printf("devfs_kernel_mount: mount %s failed: %d", mntname, error);
 426             mp->mnt_vtable->vfc_refcount--;
 427
 428             vfs_unbusy(mp);
 429
 430             mount_lock_destroy(mp);
 431             FREE_ZONE(mp, sizeof (struct mount), M_MOUNT);
 432             vnode_put(vp);
 433             return (error);
 434         }
 435         vnode_ref(vp);
 436         vnode_put(vp);
 437         vfs_unbusy(mp);
 438         mount_list_add(mp);
 439         return (0);
 440 }
 441
 442 struct vfsops devfs_vfsops = {
 443         devfs_mount,
 444         devfs_start,
 445         devfs_unmount,
 446         devfs_root,
 447         NULL,                           /* quotactl */
 448         devfs_vfs_getattr,
 449         devfs_sync,
 450         devfs_vget,
 451         devfs_fhtovp,
 452         devfs_vptofh,
 453         devfs_init,
 454         devfs_sysctl
 455 };