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  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*-
  23  * Copyright 1997,1998 Julian Elischer.  All rights reserved.
  24  * julian@freebsd.org
  25  *
  26  * Redistribution and use in source and binary forms, with or without
  27  * modification, are permitted provided that the following conditions are
  28  * met:
  29  *  1. Redistributions of source code must retain the above copyright
  30  *     notice, this list of conditions and the following disclaimer.
  31  *  2. Redistributions in binary form must reproduce the above copyright notice,
  32  *     this list of conditions and the following disclaimer in the documentation
  33  *     and/or other materials provided with the distribution.
  34  *
  35  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS
  36  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  37  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  38  * DISCLAIMED.  IN NO EVENT SHALL THE HOLDER OR CONTRIBUTORS BE LIABLE FOR
  39  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  40  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  41  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  42  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  43  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  44  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  45  * SUCH DAMAGE.
  46  *
  47  * devfs_vfsops.c
  48  *
  49  */
  50 /*
  51  * HISTORY
  52  *  Dieter Siegmund (dieter@apple.com) Wed Jul 14 13:37:59 PDT 1999
  53  *  - modified devfs_statfs() to use devfs_stats to calculate the
  54  *    amount of memory used by devfs
  55  */
  56
  57
  58 #include <sys/param.h>
  59 #include <sys/systm.h>
  60 #include <sys/kernel.h>
  61 #include <sys/vnode_internal.h>
  62 #include <sys/proc.h>
  63 #include <sys/kauth.h>
  64 #include <sys/mount_internal.h>
  65 #include <sys/malloc.h>
  66
  67 #include "devfs.h"
  68 #include "devfsdefs.h"
  69
  70 static int devfs_statfs( struct mount *mp, struct vfsstatfs *sbp, vfs_context_t context);
  71 static int devfs_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t context);
  72
  73 static struct vfstable * devfs_vfsp = 0;
  74
  75
  76 /*-
  77  * Called from the generic VFS startups.
  78  * This is the second stage of DEVFS initialisation.
  79  * The probed devices have already been loaded and the
  80  * basic structure of the DEVFS created.
  81  * We take the oportunity to mount the hidden DEVFS layer, so that
  82  * devices from devfs get sync'd.
  83  */
  84 static int
  85 devfs_init(struct vfsconf *vfsp)
  86 {
  87     devfs_vfsp = (struct vfstable *)vfsp; /* remember this for devfs_kernel_mount below */
  88
  89     if (devfs_sinit())
  90         return (ENOTSUP);
  91     devfs_make_node(makedev(0, 0), DEVFS_CHAR,
  92                     UID_ROOT, GID_WHEEL, 0622, "console");
  93     devfs_make_node(makedev(2, 0), DEVFS_CHAR,
  94                     UID_ROOT, GID_WHEEL, 0666, "tty");
  95     devfs_make_node(makedev(3, 0), DEVFS_CHAR,
  96                     UID_ROOT, GID_KMEM, 0640, "mem");
  97     devfs_make_node(makedev(3, 1), DEVFS_CHAR,
  98                     UID_ROOT, GID_KMEM, 0640, "kmem");
  99     devfs_make_node(makedev(3, 2), DEVFS_CHAR,
 100                     UID_ROOT, GID_WHEEL, 0666, "null");
 101     devfs_make_node(makedev(3, 3), DEVFS_CHAR,
 102                     UID_ROOT, GID_WHEEL, 0666, "zero");
 103     devfs_make_node(makedev(6, 0), DEVFS_CHAR,
 104                     UID_ROOT, GID_WHEEL, 0600, "klog");
 105     return 0;
 106 }
 107
 108 /*-
 109  *  mp   - pointer to 'mount' structure
 110  *  path - addr in user space of mount point (ie /usr or whatever)
 111  *  data - addr in user space of mount params including the
 112  *         name of the block special file to treat as a filesystem.
 113  *         (NOT USED)
 114  *  ndp  - namei data pointer (NOT USED)
 115  *  p    - proc pointer
 116  * devfs is special in that it doesn't require any device to be mounted..
 117  * It makes up its data as it goes along.
 118  * it must be mounted during single user.. until it is, only std{in/out/err}
 119  * and the root filesystem are available.
 120  */
 121 /*proto*/
 122 int
 123 devfs_mount(struct mount *mp, __unused vnode_t devvp, __unused user_addr_t data, vfs_context_t context)
 124 {
 125         struct devfsmount *devfs_mp_p;  /* devfs specific mount info */
 126         int error;
 127
 128         /*-
 129          *  If they just want to update, we don't need to do anything.
 130          */
 131         if (mp->mnt_flag & MNT_UPDATE)
 132         {
 133                 return 0;
 134         }
 135
 136         /* Advisory locking should be handled at the VFS layer */
 137         vfs_setlocklocal(mp);
 138
 139         /*-
 140          *  Well, it's not an update, it's a real mount request.
 141          *  Time to get dirty.
 142          * HERE we should check to see if we are already mounted here.
 143          */
 144
 145         MALLOC(devfs_mp_p, struct devfsmount *, sizeof(struct devfsmount),
 146                M_DEVFSMNT, M_WAITOK);
 147         if (devfs_mp_p == NULL)
 148                 return (ENOMEM);
 149         bzero(devfs_mp_p,sizeof(*devfs_mp_p));
 150         devfs_mp_p->mount = mp;
 151
 152         /*-
 153          *  Fill out some fields
 154          */
 155         mp->mnt_data = (qaddr_t)devfs_mp_p;
 156         mp->mnt_vfsstat.f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 157         mp->mnt_vfsstat.f_fsid.val[1] = vfs_typenum(mp);
 158         mp->mnt_flag |= MNT_LOCAL;
 159
 160         DEVFS_LOCK();
 161         error = dev_dup_plane(devfs_mp_p);
 162         DEVFS_UNLOCK();
 163
 164         if (error) {
 165                 mp->mnt_data = (qaddr_t)0;
 166                 FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 167                 return (error);
 168         } else
 169                 DEVFS_INCR_MOUNTS();
 170
 171         /*-
 172          *  Copy in the name of the directory the filesystem
 173          *  is to be mounted on.
 174          *  And we clear the remainder of the character strings
 175          *  to be tidy.
 176          */
 177
 178         bzero(mp->mnt_vfsstat.f_mntfromname, MAXPATHLEN);
 179         bcopy("devfs",mp->mnt_vfsstat.f_mntfromname, 5);
 180         (void)devfs_statfs(mp, &mp->mnt_vfsstat, context);
 181
 182         return 0;
 183 }
 184
 185
 186 static int
 187 devfs_start(__unused struct mount *mp, __unused int flags, __unused vfs_context_t context)
 188 {
 189         return 0;
 190 }
 191
 192 /*-
 193  *  Unmount the filesystem described by mp.
 194  */
 195 static int
 196 devfs_unmount( struct mount *mp, int mntflags, __unused vfs_context_t context)
 197 {
 198         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 199         int flags = 0;
 200         int force = 0;
 201         int error;
 202
 203         if (mntflags & MNT_FORCE) {
 204                 flags |= FORCECLOSE;
 205                 force = 1;
 206         }
 207         error = vflush(mp, NULLVP, flags);
 208         if (error && !force)
 209                 return error;
 210
 211         DEVFS_LOCK();
 212         devfs_free_plane(devfs_mp_p);
 213         DEVFS_UNLOCK();
 214
 215         DEVFS_DECR_MOUNTS();
 216
 217         FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 218         mp->mnt_data = (qaddr_t)0;
 219         mp->mnt_flag &= ~MNT_LOCAL;
 220
 221         return 0;
 222 }
 223
 224 /* return the address of the root vnode  in *vpp */
 225 static int
 226 devfs_root(struct mount *mp, struct vnode **vpp, vfs_context_t context)
 227 {
 228         struct devfsmount *devfs_mp_p = (struct devfsmount *)(mp->mnt_data);
 229         int error;
 230
 231         DEVFS_LOCK();
 232         error = devfs_dntovn(devfs_mp_p->plane_root->de_dnp, vpp, context->vc_proc);
 233         DEVFS_UNLOCK();
 234
 235         return error;
 236 }
 237
 238 static int
 239 devfs_statfs( struct mount *mp, struct vfsstatfs *sbp, __unused vfs_context_t context)
 240 {
 241         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 242
 243         /*-
 244          *  Fill in the stat block.
 245          */
 246         //sbp->f_type   = mp->mnt_vfsstat.f_type;
 247         sbp->f_flags  = 0;              /* XXX */
 248         sbp->f_bsize  = 512;
 249         sbp->f_iosize = 512;
 250         sbp->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 251                          + devfs_stats.nodes * sizeof(devnode_t)
 252                          + devfs_stats.entries * sizeof(devdirent_t)
 253                          + devfs_stats.stringspace
 254                          ) / sbp->f_bsize;
 255         sbp->f_bfree  = 0;
 256         sbp->f_bavail = 0;
 257         sbp->f_files  = devfs_stats.nodes;
 258         sbp->f_ffree  = 0;
 259         sbp->f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 260         sbp->f_fsid.val[1] = vfs_typenum(mp);
 261
 262         return 0;
 263 }
 264
 265 static int
 266 devfs_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t context)
 267 {
 268         VFSATTR_RETURN(fsap, f_objcount, devfs_stats.nodes);
 269         VFSATTR_RETURN(fsap, f_maxobjcount, devfs_stats.nodes);
 270         VFSATTR_RETURN(fsap, f_bsize, 512);
 271         VFSATTR_RETURN(fsap, f_iosize, 512);
 272         if (VFSATTR_IS_ACTIVE(fsap, f_blocks) || VFSATTR_IS_ACTIVE(fsap, f_bused)) {
 273                 fsap->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 274                          + devfs_stats.nodes * sizeof(devnode_t)
 275                          + devfs_stats.entries * sizeof(devdirent_t)
 276                          + devfs_stats.stringspace
 277                          ) / fsap->f_bsize;
 278                 fsap->f_bused = fsap->f_blocks;
 279                 VFSATTR_SET_SUPPORTED(fsap, f_blocks);
 280                 VFSATTR_SET_SUPPORTED(fsap, f_bused);
 281         }
 282         VFSATTR_RETURN(fsap, f_bfree, 0);
 283         VFSATTR_RETURN(fsap, f_bavail, 0);
 284         VFSATTR_RETURN(fsap, f_files, devfs_stats.nodes);
 285         VFSATTR_RETURN(fsap, f_ffree, 0);
 286         VFSATTR_RETURN(fsap, f_fssubtype, 0);
 287
 288         return 0;
 289 }
 290
 291 static int
 292 devfs_sync(__unused struct mount *mp, __unused int waitfor, __unused vfs_context_t context)
 293 {
 294     return (0);
 295 }
 296
 297
 298 static int
 299 devfs_vget(__unused struct mount *mp, __unused ino64_t ino, __unused struct vnode **vpp, __unused vfs_context_t context)
 300 {
 301         return ENOTSUP;
 302 }
 303
 304 /*************************************************************
 305  * The concept of exporting a kernel generated devfs is stupid
 306  * So don't handle filehandles
 307  */
 308
 309 static int
 310 devfs_fhtovp (__unused struct mount *mp, __unused int fhlen, __unused unsigned char *fhp, __unused struct vnode **vpp, __unused vfs_context_t context)
 311 {
 312         return (EINVAL);
 313 }
 314
 315
 316 static int
 317 devfs_vptofh (__unused struct vnode *vp, __unused int *fhlenp, __unused unsigned char *fhp, __unused vfs_context_t context)
 318 {
 319         return (EINVAL);
 320 }
 321
 322 static int
 323 devfs_sysctl(__unused int *name, __unused u_int namelen, __unused user_addr_t oldp,
 324              __unused size_t *oldlenp, __unused user_addr_t newp,
 325              __unused size_t newlen, __unused vfs_context_t context)
 326 {
 327     return (ENOTSUP);
 328 }
 329
 330 #include <sys/namei.h>
 331
 332 /*
 333  * Function: devfs_kernel_mount
 334  * Purpose:
 335  *   Mount devfs at the given mount point from within the kernel.
 336  */
 337 int
 338 devfs_kernel_mount(char * mntname)
 339 {
 340         struct mount *mp;
 341         int error;
 342         struct nameidata nd;
 343         struct vnode  * vp;
 344         struct vfs_context context;
 345
 346         if (devfs_vfsp == NULL) {
 347             printf("devfs_kernel_mount: devfs_vfsp is NULL\n");
 348             return (EINVAL);
 349         }
 350         context.vc_proc = current_proc();
 351         context.vc_ucred = kauth_cred_get();
 352
 353         /*
 354          * Get vnode to be covered
 355          */
 356         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE32,
 357             CAST_USER_ADDR_T(mntname), &context);
 358         if ((error = namei(&nd))) {
 359             printf("devfs_kernel_mount: failed to find directory '%s', %d",
 360                    mntname, error);
 361             return (error);
 362         }
 363         nameidone(&nd);
 364         vp = nd.ni_vp;
 365
 366         if ((error = VNOP_FSYNC(vp, MNT_WAIT, &context))) {
 367             printf("devfs_kernel_mount: vnop_fsync failed: %d\n", error);
 368             vnode_put(vp);
 369             return (error);
 370         }
 371         if ((error = buf_invalidateblks(vp, BUF_WRITE_DATA, 0, 0))) {
 372             printf("devfs_kernel_mount: buf_invalidateblks failed: %d\n", error);
 373             vnode_put(vp);
 374             return (error);
 375         }
 376         if (vnode_isdir(vp) == 0) {
 377             printf("devfs_kernel_mount: '%s' is not a directory\n", mntname);
 378             vnode_put(vp);
 379             return (ENOTDIR);
 380         }
 381         if ((vnode_mountedhere(vp))) {
 382             vnode_put(vp);
 383             return (EBUSY);
 384         }
 385
 386         /*
 387          * Allocate and initialize the filesystem.
 388          */
 389         MALLOC_ZONE(mp, struct mount *, (u_long)sizeof(struct mount),
 390                 M_MOUNT, M_WAITOK);
 391         bzero((char *)mp, (u_long)sizeof(struct mount));
 392
 393         /* Initialize the default IO constraints */
 394         mp->mnt_maxreadcnt = mp->mnt_maxwritecnt = MAXPHYS;
 395         mp->mnt_segreadcnt = mp->mnt_segwritecnt = 32;
 396
 397         mount_lock_init(mp);
 398         TAILQ_INIT(&mp->mnt_vnodelist);
 399         TAILQ_INIT(&mp->mnt_workerqueue);
 400         TAILQ_INIT(&mp->mnt_newvnodes);
 401
 402         (void)vfs_busy(mp, LK_NOWAIT);
 403         mp->mnt_op = devfs_vfsp->vfc_vfsops;
 404         mp->mnt_vtable = devfs_vfsp;
 405         devfs_vfsp->vfc_refcount++;
 406         devfs_vfsp->vfc_threadsafe = TRUE;
 407         devfs_vfsp->vfc_64bitready = TRUE;
 408         mp->mnt_flag = 0;
 409         mp->mnt_flag |= devfs_vfsp->vfc_flags & MNT_VISFLAGMASK;
 410         strncpy(mp->mnt_vfsstat.f_fstypename, devfs_vfsp->vfc_name, MFSTYPENAMELEN);
 411         vp->v_mountedhere = mp;
 412         mp->mnt_vnodecovered = vp;
 413         mp->mnt_vfsstat.f_owner = kauth_cred_getuid(kauth_cred_get());
 414         (void) copystr(mntname, mp->mnt_vfsstat.f_mntonname, MAXPATHLEN - 1, 0);
 415
 416         error = devfs_mount(mp, NULL, NULL, &context);
 417
 418         if (error) {
 419             printf("devfs_kernel_mount: mount %s failed: %d", mntname, error);
 420             mp->mnt_vtable->vfc_refcount--;
 421
 422             vfs_unbusy(mp);
 423
 424             mount_lock_destroy(mp);
 425             FREE_ZONE(mp, sizeof (struct mount), M_MOUNT);
 426             vnode_put(vp);
 427             return (error);
 428         }
 429         vnode_ref(vp);
 430         vnode_put(vp);
 431         vfs_unbusy(mp);
 432         mount_list_add(mp);
 433         return (0);
 434 }
 435
 436 struct vfsops devfs_vfsops = {
 437         devfs_mount,
 438         devfs_start,
 439         devfs_unmount,
 440         devfs_root,
 441         NULL,                           /* quotactl */
 442         devfs_vfs_getattr,
 443         devfs_sync,
 444         devfs_vget,
 445         devfs_fhtovp,
 446         devfs_vptofh,
 447         devfs_init,
 448         devfs_sysctl
 449 };