bsd/miscfs/devfs/devfs_vfsops.c

   1 /*
   2  * Copyright (c) 2000-2004 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 extern int setup_kmem;
  83
  84
  85 /*-
  86  * Called from the generic VFS startups.
  87  * This is the second stage of DEVFS initialisation.
  88  * The probed devices have already been loaded and the
  89  * basic structure of the DEVFS created.
  90  * We take the oportunity to mount the hidden DEVFS layer, so that
  91  * devices from devfs get sync'd.
  92  */
  93 static int
  94 devfs_init(struct vfsconf *vfsp)
  95 {
  96     devfs_vfsp = (struct vfstable *)vfsp; /* remember this for devfs_kernel_mount below */
  97
  98     if (devfs_sinit())
  99         return (ENOTSUP);
 100     devfs_make_node(makedev(0, 0), DEVFS_CHAR,
 101                     UID_ROOT, GID_WHEEL, 0622, "console");
 102     devfs_make_node(makedev(2, 0), DEVFS_CHAR,
 103                     UID_ROOT, GID_WHEEL, 0666, "tty");
 104     if (setup_kmem) {
 105         devfs_setup_kmem();
 106     }
 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 __private_extern__ void
 117 devfs_setup_kmem(void)
 118 {
 119         devfs_make_node(makedev(3, 0), DEVFS_CHAR,
 120                     UID_ROOT, GID_KMEM, 0640, "mem");
 121         devfs_make_node(makedev(3, 1), DEVFS_CHAR,
 122                     UID_ROOT, GID_KMEM, 0640, "kmem");
 123 }
 124
 125
 126 /*-
 127  *  mp   - pointer to 'mount' structure
 128  *  path - addr in user space of mount point (ie /usr or whatever)
 129  *  data - addr in user space of mount params including the
 130  *         name of the block special file to treat as a filesystem.
 131  *         (NOT USED)
 132  *  ndp  - namei data pointer (NOT USED)
 133  *  p    - proc pointer
 134  * devfs is special in that it doesn't require any device to be mounted..
 135  * It makes up its data as it goes along.
 136  * it must be mounted during single user.. until it is, only std{in/out/err}
 137  * and the root filesystem are available.
 138  */
 139 /*proto*/
 140 int
 141 devfs_mount(struct mount *mp, __unused vnode_t devvp, __unused user_addr_t data, vfs_context_t context)
 142 {
 143         struct devfsmount *devfs_mp_p;  /* devfs specific mount info */
 144         int error;
 145
 146         /*-
 147          *  If they just want to update, we don't need to do anything.
 148          */
 149         if (mp->mnt_flag & MNT_UPDATE)
 150         {
 151                 return 0;
 152         }
 153
 154         /* Advisory locking should be handled at the VFS layer */
 155         vfs_setlocklocal(mp);
 156
 157         /*-
 158          *  Well, it's not an update, it's a real mount request.
 159          *  Time to get dirty.
 160          * HERE we should check to see if we are already mounted here.
 161          */
 162
 163         MALLOC(devfs_mp_p, struct devfsmount *, sizeof(struct devfsmount),
 164                M_DEVFSMNT, M_WAITOK);
 165         if (devfs_mp_p == NULL)
 166                 return (ENOMEM);
 167         bzero(devfs_mp_p,sizeof(*devfs_mp_p));
 168         devfs_mp_p->mount = mp;
 169
 170         /*-
 171          *  Fill out some fields
 172          */
 173         mp->mnt_data = (qaddr_t)devfs_mp_p;
 174         mp->mnt_vfsstat.f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 175         mp->mnt_vfsstat.f_fsid.val[1] = vfs_typenum(mp);
 176         mp->mnt_flag |= MNT_LOCAL;
 177
 178         DEVFS_LOCK();
 179         error = dev_dup_plane(devfs_mp_p);
 180         DEVFS_UNLOCK();
 181
 182         if (error) {
 183                 mp->mnt_data = (qaddr_t)0;
 184                 FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 185                 return (error);
 186         } else
 187                 DEVFS_INCR_MOUNTS();
 188
 189         /*-
 190          *  Copy in the name of the directory the filesystem
 191          *  is to be mounted on.
 192          *  And we clear the remainder of the character strings
 193          *  to be tidy.
 194          */
 195
 196         bzero(mp->mnt_vfsstat.f_mntfromname, MAXPATHLEN);
 197         bcopy("devfs",mp->mnt_vfsstat.f_mntfromname, 5);
 198         (void)devfs_statfs(mp, &mp->mnt_vfsstat, context);
 199
 200         return 0;
 201 }
 202
 203
 204 static int
 205 devfs_start(__unused struct mount *mp, __unused int flags, __unused vfs_context_t context)
 206 {
 207         return 0;
 208 }
 209
 210 /*-
 211  *  Unmount the filesystem described by mp.
 212  */
 213 static int
 214 devfs_unmount( struct mount *mp, int mntflags, __unused vfs_context_t context)
 215 {
 216         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 217         int flags = 0;
 218         int force = 0;
 219         int error;
 220
 221         if (mntflags & MNT_FORCE) {
 222                 flags |= FORCECLOSE;
 223                 force = 1;
 224         }
 225         error = vflush(mp, NULLVP, flags);
 226         if (error && !force)
 227                 return error;
 228
 229         DEVFS_LOCK();
 230         devfs_free_plane(devfs_mp_p);
 231         DEVFS_UNLOCK();
 232
 233         DEVFS_DECR_MOUNTS();
 234
 235         FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 236         mp->mnt_data = (qaddr_t)0;
 237         mp->mnt_flag &= ~MNT_LOCAL;
 238
 239         return 0;
 240 }
 241
 242 /* return the address of the root vnode  in *vpp */
 243 static int
 244 devfs_root(struct mount *mp, struct vnode **vpp, vfs_context_t context)
 245 {
 246         struct devfsmount *devfs_mp_p = (struct devfsmount *)(mp->mnt_data);
 247         int error;
 248
 249         DEVFS_LOCK();
 250         error = devfs_dntovn(devfs_mp_p->plane_root->de_dnp, vpp, context->vc_proc);
 251         DEVFS_UNLOCK();
 252
 253         return error;
 254 }
 255
 256 static int
 257 devfs_statfs( struct mount *mp, struct vfsstatfs *sbp, __unused vfs_context_t context)
 258 {
 259         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 260
 261         /*-
 262          *  Fill in the stat block.
 263          */
 264         //sbp->f_type   = mp->mnt_vfsstat.f_type;
 265         sbp->f_flags  = 0;              /* XXX */
 266         sbp->f_bsize  = 512;
 267         sbp->f_iosize = 512;
 268         sbp->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 269                          + devfs_stats.nodes * sizeof(devnode_t)
 270                          + devfs_stats.entries * sizeof(devdirent_t)
 271                          + devfs_stats.stringspace
 272                          ) / sbp->f_bsize;
 273         sbp->f_bfree  = 0;
 274         sbp->f_bavail = 0;
 275         sbp->f_files  = devfs_stats.nodes;
 276         sbp->f_ffree  = 0;
 277         sbp->f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 278         sbp->f_fsid.val[1] = vfs_typenum(mp);
 279
 280         return 0;
 281 }
 282
 283 static int
 284 devfs_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t context)
 285 {
 286         VFSATTR_RETURN(fsap, f_objcount, devfs_stats.nodes);
 287         VFSATTR_RETURN(fsap, f_maxobjcount, devfs_stats.nodes);
 288         VFSATTR_RETURN(fsap, f_bsize, 512);
 289         VFSATTR_RETURN(fsap, f_iosize, 512);
 290         if (VFSATTR_IS_ACTIVE(fsap, f_blocks) || VFSATTR_IS_ACTIVE(fsap, f_bused)) {
 291                 fsap->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 292                          + devfs_stats.nodes * sizeof(devnode_t)
 293                          + devfs_stats.entries * sizeof(devdirent_t)
 294                          + devfs_stats.stringspace
 295                          ) / fsap->f_bsize;
 296                 fsap->f_bused = fsap->f_blocks;
 297                 VFSATTR_SET_SUPPORTED(fsap, f_blocks);
 298                 VFSATTR_SET_SUPPORTED(fsap, f_bused);
 299         }
 300         VFSATTR_RETURN(fsap, f_bfree, 0);
 301         VFSATTR_RETURN(fsap, f_bavail, 0);
 302         VFSATTR_RETURN(fsap, f_files, devfs_stats.nodes);
 303         VFSATTR_RETURN(fsap, f_ffree, 0);
 304         VFSATTR_RETURN(fsap, f_fssubtype, 0);
 305
 306         return 0;
 307 }
 308
 309 static int
 310 devfs_sync(__unused struct mount *mp, __unused int waitfor, __unused vfs_context_t context)
 311 {
 312     return (0);
 313 }
 314
 315
 316 static int
 317 devfs_vget(__unused struct mount *mp, __unused ino64_t ino, __unused struct vnode **vpp, __unused vfs_context_t context)
 318 {
 319         return ENOTSUP;
 320 }
 321
 322 /*************************************************************
 323  * The concept of exporting a kernel generated devfs is stupid
 324  * So don't handle filehandles
 325  */
 326
 327 static int
 328 devfs_fhtovp (__unused struct mount *mp, __unused int fhlen, __unused unsigned char *fhp, __unused struct vnode **vpp, __unused vfs_context_t context)
 329 {
 330         return (EINVAL);
 331 }
 332
 333
 334 static int
 335 devfs_vptofh (__unused struct vnode *vp, __unused int *fhlenp, __unused unsigned char *fhp, __unused vfs_context_t context)
 336 {
 337         return (EINVAL);
 338 }
 339
 340 static int
 341 devfs_sysctl(__unused int *name, __unused u_int namelen, __unused user_addr_t oldp,
 342              __unused size_t *oldlenp, __unused user_addr_t newp,
 343              __unused size_t newlen, __unused vfs_context_t context)
 344 {
 345     return (ENOTSUP);
 346 }
 347
 348 #include <sys/namei.h>
 349
 350 /*
 351  * Function: devfs_kernel_mount
 352  * Purpose:
 353  *   Mount devfs at the given mount point from within the kernel.
 354  */
 355 int
 356 devfs_kernel_mount(char * mntname)
 357 {
 358         struct mount *mp;
 359         int error;
 360         struct nameidata nd;
 361         struct vnode  * vp;
 362         struct vfs_context context;
 363
 364         if (devfs_vfsp == NULL) {
 365             printf("devfs_kernel_mount: devfs_vfsp is NULL\n");
 366             return (EINVAL);
 367         }
 368         context.vc_proc = current_proc();
 369         context.vc_ucred = kauth_cred_get();
 370
 371         /*
 372          * Get vnode to be covered
 373          */
 374         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE32,
 375             CAST_USER_ADDR_T(mntname), &context);
 376         if ((error = namei(&nd))) {
 377             printf("devfs_kernel_mount: failed to find directory '%s', %d",
 378                    mntname, error);
 379             return (error);
 380         }
 381         nameidone(&nd);
 382         vp = nd.ni_vp;
 383
 384         if ((error = VNOP_FSYNC(vp, MNT_WAIT, &context))) {
 385             printf("devfs_kernel_mount: vnop_fsync failed: %d\n", error);
 386             vnode_put(vp);
 387             return (error);
 388         }
 389         if ((error = buf_invalidateblks(vp, BUF_WRITE_DATA, 0, 0))) {
 390             printf("devfs_kernel_mount: buf_invalidateblks failed: %d\n", error);
 391             vnode_put(vp);
 392             return (error);
 393         }
 394         if (vnode_isdir(vp) == 0) {
 395             printf("devfs_kernel_mount: '%s' is not a directory\n", mntname);
 396             vnode_put(vp);
 397             return (ENOTDIR);
 398         }
 399         if ((vnode_mountedhere(vp))) {
 400             vnode_put(vp);
 401             return (EBUSY);
 402         }
 403
 404         /*
 405          * Allocate and initialize the filesystem.
 406          */
 407         MALLOC_ZONE(mp, struct mount *, (u_long)sizeof(struct mount),
 408                 M_MOUNT, M_WAITOK);
 409         bzero((char *)mp, (u_long)sizeof(struct mount));
 410
 411         /* Initialize the default IO constraints */
 412         mp->mnt_maxreadcnt = mp->mnt_maxwritecnt = MAXPHYS;
 413         mp->mnt_segreadcnt = mp->mnt_segwritecnt = 32;
 414
 415         mount_lock_init(mp);
 416         TAILQ_INIT(&mp->mnt_vnodelist);
 417         TAILQ_INIT(&mp->mnt_workerqueue);
 418         TAILQ_INIT(&mp->mnt_newvnodes);
 419
 420         (void)vfs_busy(mp, LK_NOWAIT);
 421         mp->mnt_op = devfs_vfsp->vfc_vfsops;
 422         mp->mnt_vtable = devfs_vfsp;
 423         devfs_vfsp->vfc_refcount++;
 424         devfs_vfsp->vfc_threadsafe = TRUE;
 425         devfs_vfsp->vfc_64bitready = TRUE;
 426         mp->mnt_flag = 0;
 427         mp->mnt_flag |= devfs_vfsp->vfc_flags & MNT_VISFLAGMASK;
 428         strncpy(mp->mnt_vfsstat.f_fstypename, devfs_vfsp->vfc_name, MFSTYPENAMELEN);
 429         vp->v_mountedhere = mp;
 430         mp->mnt_vnodecovered = vp;
 431         mp->mnt_vfsstat.f_owner = kauth_cred_getuid(kauth_cred_get());
 432         (void) copystr(mntname, mp->mnt_vfsstat.f_mntonname, MAXPATHLEN - 1, 0);
 433
 434         error = devfs_mount(mp, NULL, NULL, &context);
 435
 436         if (error) {
 437             printf("devfs_kernel_mount: mount %s failed: %d", mntname, error);
 438             mp->mnt_vtable->vfc_refcount--;
 439
 440             vfs_unbusy(mp);
 441
 442             mount_lock_destroy(mp);
 443             FREE_ZONE(mp, sizeof (struct mount), M_MOUNT);
 444             vnode_put(vp);
 445             return (error);
 446         }
 447         vnode_ref(vp);
 448         vnode_put(vp);
 449         vfs_unbusy(mp);
 450         mount_list_add(mp);
 451         return (0);
 452 }
 453
 454 struct vfsops devfs_vfsops = {
 455         devfs_mount,
 456         devfs_start,
 457         devfs_unmount,
 458         devfs_root,
 459         NULL,                           /* quotactl */
 460         devfs_vfs_getattr,
 461         devfs_sync,
 462         devfs_vget,
 463         devfs_fhtovp,
 464         devfs_vptofh,
 465         devfs_init,
 466         devfs_sysctl
 467 };