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 extern int setup_kmem;
  81
  82
  83 /*-
  84  * Called from the generic VFS startups.
  85  * This is the second stage of DEVFS initialisation.
  86  * The probed devices have already been loaded and the
  87  * basic structure of the DEVFS created.
  88  * We take the oportunity to mount the hidden DEVFS layer, so that
  89  * devices from devfs get sync'd.
  90  */
  91 static int
  92 devfs_init(struct vfsconf *vfsp)
  93 {
  94     devfs_vfsp = (struct vfstable *)vfsp; /* remember this for devfs_kernel_mount below */
  95
  96     if (devfs_sinit())
  97         return (ENOTSUP);
  98     devfs_make_node(makedev(0, 0), DEVFS_CHAR,
  99                     UID_ROOT, GID_WHEEL, 0622, "console");
 100     devfs_make_node(makedev(2, 0), DEVFS_CHAR,
 101                     UID_ROOT, GID_WHEEL, 0666, "tty");
 102     if (setup_kmem) {
 103         devfs_setup_kmem();
 104     }
 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 __private_extern__ void
 115 devfs_setup_kmem(void)
 116 {
 117         devfs_make_node(makedev(3, 0), DEVFS_CHAR,
 118                     UID_ROOT, GID_KMEM, 0640, "mem");
 119         devfs_make_node(makedev(3, 1), DEVFS_CHAR,
 120                     UID_ROOT, GID_KMEM, 0640, "kmem");
 121 }
 122
 123
 124 /*-
 125  *  mp   - pointer to 'mount' structure
 126  *  path - addr in user space of mount point (ie /usr or whatever)
 127  *  data - addr in user space of mount params including the
 128  *         name of the block special file to treat as a filesystem.
 129  *         (NOT USED)
 130  *  ndp  - namei data pointer (NOT USED)
 131  *  p    - proc pointer
 132  * devfs is special in that it doesn't require any device to be mounted..
 133  * It makes up its data as it goes along.
 134  * it must be mounted during single user.. until it is, only std{in/out/err}
 135  * and the root filesystem are available.
 136  */
 137 /*proto*/
 138 int
 139 devfs_mount(struct mount *mp, __unused vnode_t devvp, __unused user_addr_t data, vfs_context_t context)
 140 {
 141         struct devfsmount *devfs_mp_p;  /* devfs specific mount info */
 142         int error;
 143
 144         /*-
 145          *  If they just want to update, we don't need to do anything.
 146          */
 147         if (mp->mnt_flag & MNT_UPDATE)
 148         {
 149                 return 0;
 150         }
 151
 152         /* Advisory locking should be handled at the VFS layer */
 153         vfs_setlocklocal(mp);
 154
 155         /*-
 156          *  Well, it's not an update, it's a real mount request.
 157          *  Time to get dirty.
 158          * HERE we should check to see if we are already mounted here.
 159          */
 160
 161         MALLOC(devfs_mp_p, struct devfsmount *, sizeof(struct devfsmount),
 162                M_DEVFSMNT, M_WAITOK);
 163         if (devfs_mp_p == NULL)
 164                 return (ENOMEM);
 165         bzero(devfs_mp_p,sizeof(*devfs_mp_p));
 166         devfs_mp_p->mount = mp;
 167
 168         /*-
 169          *  Fill out some fields
 170          */
 171         mp->mnt_data = (qaddr_t)devfs_mp_p;
 172         mp->mnt_vfsstat.f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 173         mp->mnt_vfsstat.f_fsid.val[1] = vfs_typenum(mp);
 174         mp->mnt_flag |= MNT_LOCAL;
 175
 176         DEVFS_LOCK();
 177         error = dev_dup_plane(devfs_mp_p);
 178         DEVFS_UNLOCK();
 179
 180         if (error) {
 181                 mp->mnt_data = (qaddr_t)0;
 182                 FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 183                 return (error);
 184         } else
 185                 DEVFS_INCR_MOUNTS();
 186
 187         /*-
 188          *  Copy in the name of the directory the filesystem
 189          *  is to be mounted on.
 190          *  And we clear the remainder of the character strings
 191          *  to be tidy.
 192          */
 193
 194         bzero(mp->mnt_vfsstat.f_mntfromname, MAXPATHLEN);
 195         bcopy("devfs",mp->mnt_vfsstat.f_mntfromname, 5);
 196         (void)devfs_statfs(mp, &mp->mnt_vfsstat, context);
 197
 198         return 0;
 199 }
 200
 201
 202 static int
 203 devfs_start(__unused struct mount *mp, __unused int flags, __unused vfs_context_t context)
 204 {
 205         return 0;
 206 }
 207
 208 /*-
 209  *  Unmount the filesystem described by mp.
 210  */
 211 static int
 212 devfs_unmount( struct mount *mp, int mntflags, __unused vfs_context_t context)
 213 {
 214         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 215         int flags = 0;
 216         int force = 0;
 217         int error;
 218
 219         if (mntflags & MNT_FORCE) {
 220                 flags |= FORCECLOSE;
 221                 force = 1;
 222         }
 223         error = vflush(mp, NULLVP, flags);
 224         if (error && !force)
 225                 return error;
 226
 227         DEVFS_LOCK();
 228         devfs_free_plane(devfs_mp_p);
 229         DEVFS_UNLOCK();
 230
 231         DEVFS_DECR_MOUNTS();
 232
 233         FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 234         mp->mnt_data = (qaddr_t)0;
 235         mp->mnt_flag &= ~MNT_LOCAL;
 236
 237         return 0;
 238 }
 239
 240 /* return the address of the root vnode  in *vpp */
 241 static int
 242 devfs_root(struct mount *mp, struct vnode **vpp, vfs_context_t context)
 243 {
 244         struct devfsmount *devfs_mp_p = (struct devfsmount *)(mp->mnt_data);
 245         int error;
 246
 247         DEVFS_LOCK();
 248         error = devfs_dntovn(devfs_mp_p->plane_root->de_dnp, vpp, context->vc_proc);
 249         DEVFS_UNLOCK();
 250
 251         return error;
 252 }
 253
 254 static int
 255 devfs_statfs( struct mount *mp, struct vfsstatfs *sbp, __unused vfs_context_t context)
 256 {
 257         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 258
 259         /*-
 260          *  Fill in the stat block.
 261          */
 262         //sbp->f_type   = mp->mnt_vfsstat.f_type;
 263         sbp->f_flags  = 0;              /* XXX */
 264         sbp->f_bsize  = 512;
 265         sbp->f_iosize = 512;
 266         sbp->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 267                          + devfs_stats.nodes * sizeof(devnode_t)
 268                          + devfs_stats.entries * sizeof(devdirent_t)
 269                          + devfs_stats.stringspace
 270                          ) / sbp->f_bsize;
 271         sbp->f_bfree  = 0;
 272         sbp->f_bavail = 0;
 273         sbp->f_files  = devfs_stats.nodes;
 274         sbp->f_ffree  = 0;
 275         sbp->f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 276         sbp->f_fsid.val[1] = vfs_typenum(mp);
 277
 278         return 0;
 279 }
 280
 281 static int
 282 devfs_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t context)
 283 {
 284         VFSATTR_RETURN(fsap, f_objcount, devfs_stats.nodes);
 285         VFSATTR_RETURN(fsap, f_maxobjcount, devfs_stats.nodes);
 286         VFSATTR_RETURN(fsap, f_bsize, 512);
 287         VFSATTR_RETURN(fsap, f_iosize, 512);
 288         if (VFSATTR_IS_ACTIVE(fsap, f_blocks) || VFSATTR_IS_ACTIVE(fsap, f_bused)) {
 289                 fsap->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 290                          + devfs_stats.nodes * sizeof(devnode_t)
 291                          + devfs_stats.entries * sizeof(devdirent_t)
 292                          + devfs_stats.stringspace
 293                          ) / fsap->f_bsize;
 294                 fsap->f_bused = fsap->f_blocks;
 295                 VFSATTR_SET_SUPPORTED(fsap, f_blocks);
 296                 VFSATTR_SET_SUPPORTED(fsap, f_bused);
 297         }
 298         VFSATTR_RETURN(fsap, f_bfree, 0);
 299         VFSATTR_RETURN(fsap, f_bavail, 0);
 300         VFSATTR_RETURN(fsap, f_files, devfs_stats.nodes);
 301         VFSATTR_RETURN(fsap, f_ffree, 0);
 302         VFSATTR_RETURN(fsap, f_fssubtype, 0);
 303
 304         return 0;
 305 }
 306
 307 static int
 308 devfs_sync(__unused struct mount *mp, __unused int waitfor, __unused vfs_context_t context)
 309 {
 310     return (0);
 311 }
 312
 313
 314 static int
 315 devfs_vget(__unused struct mount *mp, __unused ino64_t ino, __unused struct vnode **vpp, __unused vfs_context_t context)
 316 {
 317         return ENOTSUP;
 318 }
 319
 320 /*************************************************************
 321  * The concept of exporting a kernel generated devfs is stupid
 322  * So don't handle filehandles
 323  */
 324
 325 static int
 326 devfs_fhtovp (__unused struct mount *mp, __unused int fhlen, __unused unsigned char *fhp, __unused struct vnode **vpp, __unused vfs_context_t context)
 327 {
 328         return (EINVAL);
 329 }
 330
 331
 332 static int
 333 devfs_vptofh (__unused struct vnode *vp, __unused int *fhlenp, __unused unsigned char *fhp, __unused vfs_context_t context)
 334 {
 335         return (EINVAL);
 336 }
 337
 338 static int
 339 devfs_sysctl(__unused int *name, __unused u_int namelen, __unused user_addr_t oldp,
 340              __unused size_t *oldlenp, __unused user_addr_t newp,
 341              __unused size_t newlen, __unused vfs_context_t context)
 342 {
 343     return (ENOTSUP);
 344 }
 345
 346 #include <sys/namei.h>
 347
 348 /*
 349  * Function: devfs_kernel_mount
 350  * Purpose:
 351  *   Mount devfs at the given mount point from within the kernel.
 352  */
 353 int
 354 devfs_kernel_mount(char * mntname)
 355 {
 356         struct mount *mp;
 357         int error;
 358         struct nameidata nd;
 359         struct vnode  * vp;
 360         struct vfs_context context;
 361
 362         if (devfs_vfsp == NULL) {
 363             printf("devfs_kernel_mount: devfs_vfsp is NULL\n");
 364             return (EINVAL);
 365         }
 366         context.vc_proc = current_proc();
 367         context.vc_ucred = kauth_cred_get();
 368
 369         /*
 370          * Get vnode to be covered
 371          */
 372         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE32,
 373             CAST_USER_ADDR_T(mntname), &context);
 374         if ((error = namei(&nd))) {
 375             printf("devfs_kernel_mount: failed to find directory '%s', %d",
 376                    mntname, error);
 377             return (error);
 378         }
 379         nameidone(&nd);
 380         vp = nd.ni_vp;
 381
 382         if ((error = VNOP_FSYNC(vp, MNT_WAIT, &context))) {
 383             printf("devfs_kernel_mount: vnop_fsync failed: %d\n", error);
 384             vnode_put(vp);
 385             return (error);
 386         }
 387         if ((error = buf_invalidateblks(vp, BUF_WRITE_DATA, 0, 0))) {
 388             printf("devfs_kernel_mount: buf_invalidateblks failed: %d\n", error);
 389             vnode_put(vp);
 390             return (error);
 391         }
 392         if (vnode_isdir(vp) == 0) {
 393             printf("devfs_kernel_mount: '%s' is not a directory\n", mntname);
 394             vnode_put(vp);
 395             return (ENOTDIR);
 396         }
 397         if ((vnode_mountedhere(vp))) {
 398             vnode_put(vp);
 399             return (EBUSY);
 400         }
 401
 402         /*
 403          * Allocate and initialize the filesystem.
 404          */
 405         MALLOC_ZONE(mp, struct mount *, (u_long)sizeof(struct mount),
 406                 M_MOUNT, M_WAITOK);
 407         bzero((char *)mp, (u_long)sizeof(struct mount));
 408
 409         /* Initialize the default IO constraints */
 410         mp->mnt_maxreadcnt = mp->mnt_maxwritecnt = MAXPHYS;
 411         mp->mnt_segreadcnt = mp->mnt_segwritecnt = 32;
 412
 413         mount_lock_init(mp);
 414         TAILQ_INIT(&mp->mnt_vnodelist);
 415         TAILQ_INIT(&mp->mnt_workerqueue);
 416         TAILQ_INIT(&mp->mnt_newvnodes);
 417
 418         (void)vfs_busy(mp, LK_NOWAIT);
 419         mp->mnt_op = devfs_vfsp->vfc_vfsops;
 420         mp->mnt_vtable = devfs_vfsp;
 421         devfs_vfsp->vfc_refcount++;
 422         devfs_vfsp->vfc_threadsafe = TRUE;
 423         devfs_vfsp->vfc_64bitready = TRUE;
 424         mp->mnt_flag = 0;
 425         mp->mnt_flag |= devfs_vfsp->vfc_flags & MNT_VISFLAGMASK;
 426         strncpy(mp->mnt_vfsstat.f_fstypename, devfs_vfsp->vfc_name, MFSTYPENAMELEN);
 427         vp->v_mountedhere = mp;
 428         mp->mnt_vnodecovered = vp;
 429         mp->mnt_vfsstat.f_owner = kauth_cred_getuid(kauth_cred_get());
 430         (void) copystr(mntname, mp->mnt_vfsstat.f_mntonname, MAXPATHLEN - 1, 0);
 431
 432         error = devfs_mount(mp, NULL, NULL, &context);
 433
 434         if (error) {
 435             printf("devfs_kernel_mount: mount %s failed: %d", mntname, error);
 436             mp->mnt_vtable->vfc_refcount--;
 437
 438             vfs_unbusy(mp);
 439
 440             mount_lock_destroy(mp);
 441             FREE_ZONE(mp, sizeof (struct mount), M_MOUNT);
 442             vnode_put(vp);
 443             return (error);
 444         }
 445         vnode_ref(vp);
 446         vnode_put(vp);
 447         vfs_unbusy(mp);
 448         mount_list_add(mp);
 449         return (0);
 450 }
 451
 452 struct vfsops devfs_vfsops = {
 453         devfs_mount,
 454         devfs_start,
 455         devfs_unmount,
 456         devfs_root,
 457         NULL,                           /* quotactl */
 458         devfs_vfs_getattr,
 459         devfs_sync,
 460         devfs_vget,
 461         devfs_fhtovp,
 462         devfs_vptofh,
 463         devfs_init,
 464         devfs_sysctl
 465 };