bsd/miscfs/devfs/devfs_vfsops.c

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_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. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*-
  24  * Copyright 1997,1998 Julian Elischer.  All rights reserved.
  25  * julian@freebsd.org
  26  *
  27  * Redistribution and use in source and binary forms, with or without
  28  * modification, are permitted provided that the following conditions are
  29  * met:
  30  *  1. Redistributions of source code must retain the above copyright
  31  *     notice, this list of conditions and the following disclaimer.
  32  *  2. Redistributions in binary form must reproduce the above copyright notice,
  33  *     this list of conditions and the following disclaimer in the documentation
  34  *     and/or other materials provided with the distribution.
  35  *
  36  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS
  37  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  38  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  39  * DISCLAIMED.  IN NO EVENT SHALL THE HOLDER OR CONTRIBUTORS BE LIABLE FOR
  40  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  41  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  42  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  43  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  44  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  45  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  46  * SUCH DAMAGE.
  47  *
  48  * devfs_vfsops.c
  49  *
  50  */
  51 /*
  52  * HISTORY
  53  *  Dieter Siegmund (dieter@apple.com) Wed Jul 14 13:37:59 PDT 1999
  54  *  - modified devfs_statfs() to use devfs_stats to calculate the
  55  *    amount of memory used by devfs
  56  */
  57
  58
  59 #include <sys/param.h>
  60 #include <sys/systm.h>
  61 #include <sys/kernel.h>
  62 #include <sys/vnode_internal.h>
  63 #include <sys/proc.h>
  64 #include <sys/kauth.h>
  65 #include <sys/mount_internal.h>
  66 #include <sys/malloc.h>
  67
  68 #include "devfs.h"
  69 #include "devfsdefs.h"
  70
  71 static int devfs_statfs( struct mount *mp, struct vfsstatfs *sbp, vfs_context_t context);
  72 static int devfs_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t context);
  73
  74 static struct vfstable * devfs_vfsp = 0;
  75
  76
  77 /*-
  78  * Called from the generic VFS startups.
  79  * This is the second stage of DEVFS initialisation.
  80  * The probed devices have already been loaded and the
  81  * basic structure of the DEVFS created.
  82  * We take the oportunity to mount the hidden DEVFS layer, so that
  83  * devices from devfs get sync'd.
  84  */
  85 static int
  86 devfs_init(struct vfsconf *vfsp)
  87 {
  88     devfs_vfsp = (struct vfstable *)vfsp; /* remember this for devfs_kernel_mount below */
  89
  90     if (devfs_sinit())
  91         return (ENOTSUP);
  92     devfs_make_node(makedev(0, 0), DEVFS_CHAR,
  93                     UID_ROOT, GID_WHEEL, 0622, "console");
  94     devfs_make_node(makedev(2, 0), DEVFS_CHAR,
  95                     UID_ROOT, GID_WHEEL, 0666, "tty");
  96     devfs_make_node(makedev(3, 0), DEVFS_CHAR,
  97                     UID_ROOT, GID_KMEM, 0640, "mem");
  98     devfs_make_node(makedev(3, 1), DEVFS_CHAR,
  99                     UID_ROOT, GID_KMEM, 0640, "kmem");
 100     devfs_make_node(makedev(3, 2), DEVFS_CHAR,
 101                     UID_ROOT, GID_WHEEL, 0666, "null");
 102     devfs_make_node(makedev(3, 3), DEVFS_CHAR,
 103                     UID_ROOT, GID_WHEEL, 0666, "zero");
 104     devfs_make_node(makedev(6, 0), DEVFS_CHAR,
 105                     UID_ROOT, GID_WHEEL, 0600, "klog");
 106     return 0;
 107 }
 108
 109 /*-
 110  *  mp   - pointer to 'mount' structure
 111  *  path - addr in user space of mount point (ie /usr or whatever)
 112  *  data - addr in user space of mount params including the
 113  *         name of the block special file to treat as a filesystem.
 114  *         (NOT USED)
 115  *  ndp  - namei data pointer (NOT USED)
 116  *  p    - proc pointer
 117  * devfs is special in that it doesn't require any device to be mounted..
 118  * It makes up its data as it goes along.
 119  * it must be mounted during single user.. until it is, only std{in/out/err}
 120  * and the root filesystem are available.
 121  */
 122 /*proto*/
 123 int
 124 devfs_mount(struct mount *mp, __unused vnode_t devvp, __unused user_addr_t data, vfs_context_t context)
 125 {
 126         struct devfsmount *devfs_mp_p;  /* devfs specific mount info */
 127         int error;
 128
 129         /*-
 130          *  If they just want to update, we don't need to do anything.
 131          */
 132         if (mp->mnt_flag & MNT_UPDATE)
 133         {
 134                 return 0;
 135         }
 136
 137         /* Advisory locking should be handled at the VFS layer */
 138         vfs_setlocklocal(mp);
 139
 140         /*-
 141          *  Well, it's not an update, it's a real mount request.
 142          *  Time to get dirty.
 143          * HERE we should check to see if we are already mounted here.
 144          */
 145
 146         MALLOC(devfs_mp_p, struct devfsmount *, sizeof(struct devfsmount),
 147                M_DEVFSMNT, M_WAITOK);
 148         if (devfs_mp_p == NULL)
 149                 return (ENOMEM);
 150         bzero(devfs_mp_p,sizeof(*devfs_mp_p));
 151         devfs_mp_p->mount = mp;
 152
 153         /*-
 154          *  Fill out some fields
 155          */
 156         mp->mnt_data = (qaddr_t)devfs_mp_p;
 157         mp->mnt_vfsstat.f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 158         mp->mnt_vfsstat.f_fsid.val[1] = vfs_typenum(mp);
 159         mp->mnt_flag |= MNT_LOCAL;
 160
 161         DEVFS_LOCK();
 162         error = dev_dup_plane(devfs_mp_p);
 163         DEVFS_UNLOCK();
 164
 165         if (error) {
 166                 mp->mnt_data = (qaddr_t)0;
 167                 FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 168                 return (error);
 169         } else
 170                 DEVFS_INCR_MOUNTS();
 171
 172         /*-
 173          *  Copy in the name of the directory the filesystem
 174          *  is to be mounted on.
 175          *  And we clear the remainder of the character strings
 176          *  to be tidy.
 177          */
 178
 179         bzero(mp->mnt_vfsstat.f_mntfromname, MAXPATHLEN);
 180         bcopy("devfs",mp->mnt_vfsstat.f_mntfromname, 5);
 181         (void)devfs_statfs(mp, &mp->mnt_vfsstat, context);
 182
 183         return 0;
 184 }
 185
 186
 187 static int
 188 devfs_start(__unused struct mount *mp, __unused int flags, __unused vfs_context_t context)
 189 {
 190         return 0;
 191 }
 192
 193 /*-
 194  *  Unmount the filesystem described by mp.
 195  */
 196 static int
 197 devfs_unmount( struct mount *mp, int mntflags, __unused vfs_context_t context)
 198 {
 199         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 200         int flags = 0;
 201         int force = 0;
 202         int error;
 203
 204         if (mntflags & MNT_FORCE) {
 205                 flags |= FORCECLOSE;
 206                 force = 1;
 207         }
 208         error = vflush(mp, NULLVP, flags);
 209         if (error && !force)
 210                 return error;
 211
 212         DEVFS_LOCK();
 213         devfs_free_plane(devfs_mp_p);
 214         DEVFS_UNLOCK();
 215
 216         DEVFS_DECR_MOUNTS();
 217
 218         FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 219         mp->mnt_data = (qaddr_t)0;
 220         mp->mnt_flag &= ~MNT_LOCAL;
 221
 222         return 0;
 223 }
 224
 225 /* return the address of the root vnode  in *vpp */
 226 static int
 227 devfs_root(struct mount *mp, struct vnode **vpp, vfs_context_t context)
 228 {
 229         struct devfsmount *devfs_mp_p = (struct devfsmount *)(mp->mnt_data);
 230         int error;
 231
 232         DEVFS_LOCK();
 233         error = devfs_dntovn(devfs_mp_p->plane_root->de_dnp, vpp, context->vc_proc);
 234         DEVFS_UNLOCK();
 235
 236         return error;
 237 }
 238
 239 static int
 240 devfs_statfs( struct mount *mp, struct vfsstatfs *sbp, __unused vfs_context_t context)
 241 {
 242         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 243
 244         /*-
 245          *  Fill in the stat block.
 246          */
 247         //sbp->f_type   = mp->mnt_vfsstat.f_type;
 248         sbp->f_flags  = 0;              /* XXX */
 249         sbp->f_bsize  = 512;
 250         sbp->f_iosize = 512;
 251         sbp->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 252                          + devfs_stats.nodes * sizeof(devnode_t)
 253                          + devfs_stats.entries * sizeof(devdirent_t)
 254                          + devfs_stats.stringspace
 255                          ) / sbp->f_bsize;
 256         sbp->f_bfree  = 0;
 257         sbp->f_bavail = 0;
 258         sbp->f_files  = devfs_stats.nodes;
 259         sbp->f_ffree  = 0;
 260         sbp->f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 261         sbp->f_fsid.val[1] = vfs_typenum(mp);
 262
 263         return 0;
 264 }
 265
 266 static int
 267 devfs_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t context)
 268 {
 269         VFSATTR_RETURN(fsap, f_objcount, devfs_stats.nodes);
 270         VFSATTR_RETURN(fsap, f_maxobjcount, devfs_stats.nodes);
 271         VFSATTR_RETURN(fsap, f_bsize, 512);
 272         VFSATTR_RETURN(fsap, f_iosize, 512);
 273         if (VFSATTR_IS_ACTIVE(fsap, f_blocks) || VFSATTR_IS_ACTIVE(fsap, f_bused)) {
 274                 fsap->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 275                          + devfs_stats.nodes * sizeof(devnode_t)
 276                          + devfs_stats.entries * sizeof(devdirent_t)
 277                          + devfs_stats.stringspace
 278                          ) / fsap->f_bsize;
 279                 fsap->f_bused = fsap->f_blocks;
 280                 VFSATTR_SET_SUPPORTED(fsap, f_blocks);
 281                 VFSATTR_SET_SUPPORTED(fsap, f_bused);
 282         }
 283         VFSATTR_RETURN(fsap, f_bfree, 0);
 284         VFSATTR_RETURN(fsap, f_bavail, 0);
 285         VFSATTR_RETURN(fsap, f_files, devfs_stats.nodes);
 286         VFSATTR_RETURN(fsap, f_ffree, 0);
 287         VFSATTR_RETURN(fsap, f_fssubtype, 0);
 288
 289         return 0;
 290 }
 291
 292 static int
 293 devfs_sync(__unused struct mount *mp, __unused int waitfor, __unused vfs_context_t context)
 294 {
 295     return (0);
 296 }
 297
 298
 299 static int
 300 devfs_vget(__unused struct mount *mp, __unused ino64_t ino, __unused struct vnode **vpp, __unused vfs_context_t context)
 301 {
 302         return ENOTSUP;
 303 }
 304
 305 /*************************************************************
 306  * The concept of exporting a kernel generated devfs is stupid
 307  * So don't handle filehandles
 308  */
 309
 310 static int
 311 devfs_fhtovp (__unused struct mount *mp, __unused int fhlen, __unused unsigned char *fhp, __unused struct vnode **vpp, __unused vfs_context_t context)
 312 {
 313         return (EINVAL);
 314 }
 315
 316
 317 static int
 318 devfs_vptofh (__unused struct vnode *vp, __unused int *fhlenp, __unused unsigned char *fhp, __unused vfs_context_t context)
 319 {
 320         return (EINVAL);
 321 }
 322
 323 static int
 324 devfs_sysctl(__unused int *name, __unused u_int namelen, __unused user_addr_t oldp,
 325              __unused size_t *oldlenp, __unused user_addr_t newp,
 326              __unused size_t newlen, __unused vfs_context_t context)
 327 {
 328     return (ENOTSUP);
 329 }
 330
 331 #include <sys/namei.h>
 332
 333 /*
 334  * Function: devfs_kernel_mount
 335  * Purpose:
 336  *   Mount devfs at the given mount point from within the kernel.
 337  */
 338 int
 339 devfs_kernel_mount(char * mntname)
 340 {
 341         struct mount *mp;
 342         int error;
 343         struct nameidata nd;
 344         struct vnode  * vp;
 345         struct vfs_context context;
 346
 347         if (devfs_vfsp == NULL) {
 348             printf("devfs_kernel_mount: devfs_vfsp is NULL\n");
 349             return (EINVAL);
 350         }
 351         context.vc_proc = current_proc();
 352         context.vc_ucred = kauth_cred_get();
 353
 354         /*
 355          * Get vnode to be covered
 356          */
 357         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE32,
 358             CAST_USER_ADDR_T(mntname), &context);
 359         if ((error = namei(&nd))) {
 360             printf("devfs_kernel_mount: failed to find directory '%s', %d",
 361                    mntname, error);
 362             return (error);
 363         }
 364         nameidone(&nd);
 365         vp = nd.ni_vp;
 366
 367         if ((error = VNOP_FSYNC(vp, MNT_WAIT, &context))) {
 368             printf("devfs_kernel_mount: vnop_fsync failed: %d\n", error);
 369             vnode_put(vp);
 370             return (error);
 371         }
 372         if ((error = buf_invalidateblks(vp, BUF_WRITE_DATA, 0, 0))) {
 373             printf("devfs_kernel_mount: buf_invalidateblks failed: %d\n", error);
 374             vnode_put(vp);
 375             return (error);
 376         }
 377         if (vnode_isdir(vp) == 0) {
 378             printf("devfs_kernel_mount: '%s' is not a directory\n", mntname);
 379             vnode_put(vp);
 380             return (ENOTDIR);
 381         }
 382         if ((vnode_mountedhere(vp))) {
 383             vnode_put(vp);
 384             return (EBUSY);
 385         }
 386
 387         /*
 388          * Allocate and initialize the filesystem.
 389          */
 390         MALLOC_ZONE(mp, struct mount *, (u_long)sizeof(struct mount),
 391                 M_MOUNT, M_WAITOK);
 392         bzero((char *)mp, (u_long)sizeof(struct mount));
 393
 394         /* Initialize the default IO constraints */
 395         mp->mnt_maxreadcnt = mp->mnt_maxwritecnt = MAXPHYS;
 396         mp->mnt_segreadcnt = mp->mnt_segwritecnt = 32;
 397
 398         mount_lock_init(mp);
 399         TAILQ_INIT(&mp->mnt_vnodelist);
 400         TAILQ_INIT(&mp->mnt_workerqueue);
 401         TAILQ_INIT(&mp->mnt_newvnodes);
 402
 403         (void)vfs_busy(mp, LK_NOWAIT);
 404         mp->mnt_op = devfs_vfsp->vfc_vfsops;
 405         mp->mnt_vtable = devfs_vfsp;
 406         devfs_vfsp->vfc_refcount++;
 407         devfs_vfsp->vfc_threadsafe = TRUE;
 408         devfs_vfsp->vfc_64bitready = TRUE;
 409         mp->mnt_flag = 0;
 410         mp->mnt_flag |= devfs_vfsp->vfc_flags & MNT_VISFLAGMASK;
 411         strncpy(mp->mnt_vfsstat.f_fstypename, devfs_vfsp->vfc_name, MFSTYPENAMELEN);
 412         vp->v_mountedhere = mp;
 413         mp->mnt_vnodecovered = vp;
 414         mp->mnt_vfsstat.f_owner = kauth_cred_getuid(kauth_cred_get());
 415         (void) copystr(mntname, mp->mnt_vfsstat.f_mntonname, MAXPATHLEN - 1, 0);
 416
 417         error = devfs_mount(mp, NULL, NULL, &context);
 418
 419         if (error) {
 420             printf("devfs_kernel_mount: mount %s failed: %d", mntname, error);
 421             mp->mnt_vtable->vfc_refcount--;
 422
 423             vfs_unbusy(mp);
 424
 425             mount_lock_destroy(mp);
 426             FREE_ZONE(mp, sizeof (struct mount), M_MOUNT);
 427             vnode_put(vp);
 428             return (error);
 429         }
 430         vnode_ref(vp);
 431         vnode_put(vp);
 432         vfs_unbusy(mp);
 433         mount_list_add(mp);
 434         return (0);
 435 }
 436
 437 struct vfsops devfs_vfsops = {
 438         devfs_mount,
 439         devfs_start,
 440         devfs_unmount,
 441         devfs_root,
 442         NULL,                           /* quotactl */
 443         devfs_vfs_getattr,
 444         devfs_sync,
 445         devfs_vget,
 446         devfs_fhtovp,
 447         devfs_vptofh,
 448         devfs_init,
 449         devfs_sysctl
 450 };