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 extern int setup_kmem;
  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     if (setup_kmem) {
  97         devfs_setup_kmem();
  98     }
  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 __private_extern__ void
 109 devfs_setup_kmem(void)
 110 {
 111         devfs_make_node(makedev(3, 0), DEVFS_CHAR,
 112                     UID_ROOT, GID_KMEM, 0640, "mem");
 113         devfs_make_node(makedev(3, 1), DEVFS_CHAR,
 114                     UID_ROOT, GID_KMEM, 0640, "kmem");
 115 }
 116
 117
 118 /*-
 119  *  mp   - pointer to 'mount' structure
 120  *  path - addr in user space of mount point (ie /usr or whatever)
 121  *  data - addr in user space of mount params including the
 122  *         name of the block special file to treat as a filesystem.
 123  *         (NOT USED)
 124  *  ndp  - namei data pointer (NOT USED)
 125  *  p    - proc pointer
 126  * devfs is special in that it doesn't require any device to be mounted..
 127  * It makes up its data as it goes along.
 128  * it must be mounted during single user.. until it is, only std{in/out/err}
 129  * and the root filesystem are available.
 130  */
 131 /*proto*/
 132 int
 133 devfs_mount(struct mount *mp, __unused vnode_t devvp, __unused user_addr_t data, vfs_context_t context)
 134 {
 135         struct devfsmount *devfs_mp_p;  /* devfs specific mount info */
 136         int error;
 137
 138         /*-
 139          *  If they just want to update, we don't need to do anything.
 140          */
 141         if (mp->mnt_flag & MNT_UPDATE)
 142         {
 143                 return 0;
 144         }
 145
 146         /* Advisory locking should be handled at the VFS layer */
 147         vfs_setlocklocal(mp);
 148
 149         /*-
 150          *  Well, it's not an update, it's a real mount request.
 151          *  Time to get dirty.
 152          * HERE we should check to see if we are already mounted here.
 153          */
 154
 155         MALLOC(devfs_mp_p, struct devfsmount *, sizeof(struct devfsmount),
 156                M_DEVFSMNT, M_WAITOK);
 157         if (devfs_mp_p == NULL)
 158                 return (ENOMEM);
 159         bzero(devfs_mp_p,sizeof(*devfs_mp_p));
 160         devfs_mp_p->mount = mp;
 161
 162         /*-
 163          *  Fill out some fields
 164          */
 165         mp->mnt_data = (qaddr_t)devfs_mp_p;
 166         mp->mnt_vfsstat.f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 167         mp->mnt_vfsstat.f_fsid.val[1] = vfs_typenum(mp);
 168         mp->mnt_flag |= MNT_LOCAL;
 169
 170         DEVFS_LOCK();
 171         error = dev_dup_plane(devfs_mp_p);
 172         DEVFS_UNLOCK();
 173
 174         if (error) {
 175                 mp->mnt_data = (qaddr_t)0;
 176                 FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 177                 return (error);
 178         } else
 179                 DEVFS_INCR_MOUNTS();
 180
 181         /*-
 182          *  Copy in the name of the directory the filesystem
 183          *  is to be mounted on.
 184          *  And we clear the remainder of the character strings
 185          *  to be tidy.
 186          */
 187
 188         bzero(mp->mnt_vfsstat.f_mntfromname, MAXPATHLEN);
 189         bcopy("devfs",mp->mnt_vfsstat.f_mntfromname, 5);
 190         (void)devfs_statfs(mp, &mp->mnt_vfsstat, context);
 191
 192         return 0;
 193 }
 194
 195
 196 static int
 197 devfs_start(__unused struct mount *mp, __unused int flags, __unused vfs_context_t context)
 198 {
 199         return 0;
 200 }
 201
 202 /*-
 203  *  Unmount the filesystem described by mp.
 204  */
 205 static int
 206 devfs_unmount( struct mount *mp, int mntflags, __unused vfs_context_t context)
 207 {
 208         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 209         int flags = 0;
 210         int force = 0;
 211         int error;
 212
 213         if (mntflags & MNT_FORCE) {
 214                 flags |= FORCECLOSE;
 215                 force = 1;
 216         }
 217         error = vflush(mp, NULLVP, flags);
 218         if (error && !force)
 219                 return error;
 220
 221         DEVFS_LOCK();
 222         devfs_free_plane(devfs_mp_p);
 223         DEVFS_UNLOCK();
 224
 225         DEVFS_DECR_MOUNTS();
 226
 227         FREE((caddr_t)devfs_mp_p, M_DEVFSMNT);
 228         mp->mnt_data = (qaddr_t)0;
 229         mp->mnt_flag &= ~MNT_LOCAL;
 230
 231         return 0;
 232 }
 233
 234 /* return the address of the root vnode  in *vpp */
 235 static int
 236 devfs_root(struct mount *mp, struct vnode **vpp, vfs_context_t context)
 237 {
 238         struct devfsmount *devfs_mp_p = (struct devfsmount *)(mp->mnt_data);
 239         int error;
 240
 241         DEVFS_LOCK();
 242         error = devfs_dntovn(devfs_mp_p->plane_root->de_dnp, vpp, context->vc_proc);
 243         DEVFS_UNLOCK();
 244
 245         return error;
 246 }
 247
 248 static int
 249 devfs_statfs( struct mount *mp, struct vfsstatfs *sbp, __unused vfs_context_t context)
 250 {
 251         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 252
 253         /*-
 254          *  Fill in the stat block.
 255          */
 256         //sbp->f_type   = mp->mnt_vfsstat.f_type;
 257         sbp->f_flags  = 0;              /* XXX */
 258         sbp->f_bsize  = 512;
 259         sbp->f_iosize = 512;
 260         sbp->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 261                          + devfs_stats.nodes * sizeof(devnode_t)
 262                          + devfs_stats.entries * sizeof(devdirent_t)
 263                          + devfs_stats.stringspace
 264                          ) / sbp->f_bsize;
 265         sbp->f_bfree  = 0;
 266         sbp->f_bavail = 0;
 267         sbp->f_files  = devfs_stats.nodes;
 268         sbp->f_ffree  = 0;
 269         sbp->f_fsid.val[0] = (int32_t)(void *)devfs_mp_p;
 270         sbp->f_fsid.val[1] = vfs_typenum(mp);
 271
 272         return 0;
 273 }
 274
 275 static int
 276 devfs_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t context)
 277 {
 278         VFSATTR_RETURN(fsap, f_objcount, devfs_stats.nodes);
 279         VFSATTR_RETURN(fsap, f_maxobjcount, devfs_stats.nodes);
 280         VFSATTR_RETURN(fsap, f_bsize, 512);
 281         VFSATTR_RETURN(fsap, f_iosize, 512);
 282         if (VFSATTR_IS_ACTIVE(fsap, f_blocks) || VFSATTR_IS_ACTIVE(fsap, f_bused)) {
 283                 fsap->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 284                          + devfs_stats.nodes * sizeof(devnode_t)
 285                          + devfs_stats.entries * sizeof(devdirent_t)
 286                          + devfs_stats.stringspace
 287                          ) / fsap->f_bsize;
 288                 fsap->f_bused = fsap->f_blocks;
 289                 VFSATTR_SET_SUPPORTED(fsap, f_blocks);
 290                 VFSATTR_SET_SUPPORTED(fsap, f_bused);
 291         }
 292         VFSATTR_RETURN(fsap, f_bfree, 0);
 293         VFSATTR_RETURN(fsap, f_bavail, 0);
 294         VFSATTR_RETURN(fsap, f_files, devfs_stats.nodes);
 295         VFSATTR_RETURN(fsap, f_ffree, 0);
 296         VFSATTR_RETURN(fsap, f_fssubtype, 0);
 297
 298         return 0;
 299 }
 300
 301 static int
 302 devfs_sync(__unused struct mount *mp, __unused int waitfor, __unused vfs_context_t context)
 303 {
 304     return (0);
 305 }
 306
 307
 308 static int
 309 devfs_vget(__unused struct mount *mp, __unused ino64_t ino, __unused struct vnode **vpp, __unused vfs_context_t context)
 310 {
 311         return ENOTSUP;
 312 }
 313
 314 /*************************************************************
 315  * The concept of exporting a kernel generated devfs is stupid
 316  * So don't handle filehandles
 317  */
 318
 319 static int
 320 devfs_fhtovp (__unused struct mount *mp, __unused int fhlen, __unused unsigned char *fhp, __unused struct vnode **vpp, __unused vfs_context_t context)
 321 {
 322         return (EINVAL);
 323 }
 324
 325
 326 static int
 327 devfs_vptofh (__unused struct vnode *vp, __unused int *fhlenp, __unused unsigned char *fhp, __unused vfs_context_t context)
 328 {
 329         return (EINVAL);
 330 }
 331
 332 static int
 333 devfs_sysctl(__unused int *name, __unused u_int namelen, __unused user_addr_t oldp,
 334              __unused size_t *oldlenp, __unused user_addr_t newp,
 335              __unused size_t newlen, __unused vfs_context_t context)
 336 {
 337     return (ENOTSUP);
 338 }
 339
 340 #include <sys/namei.h>
 341
 342 /*
 343  * Function: devfs_kernel_mount
 344  * Purpose:
 345  *   Mount devfs at the given mount point from within the kernel.
 346  */
 347 int
 348 devfs_kernel_mount(char * mntname)
 349 {
 350         struct mount *mp;
 351         int error;
 352         struct nameidata nd;
 353         struct vnode  * vp;
 354         struct vfs_context context;
 355
 356         if (devfs_vfsp == NULL) {
 357             printf("devfs_kernel_mount: devfs_vfsp is NULL\n");
 358             return (EINVAL);
 359         }
 360         context.vc_proc = current_proc();
 361         context.vc_ucred = kauth_cred_get();
 362
 363         /*
 364          * Get vnode to be covered
 365          */
 366         NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE32,
 367             CAST_USER_ADDR_T(mntname), &context);
 368         if ((error = namei(&nd))) {
 369             printf("devfs_kernel_mount: failed to find directory '%s', %d",
 370                    mntname, error);
 371             return (error);
 372         }
 373         nameidone(&nd);
 374         vp = nd.ni_vp;
 375
 376         if ((error = VNOP_FSYNC(vp, MNT_WAIT, &context))) {
 377             printf("devfs_kernel_mount: vnop_fsync failed: %d\n", error);
 378             vnode_put(vp);
 379             return (error);
 380         }
 381         if ((error = buf_invalidateblks(vp, BUF_WRITE_DATA, 0, 0))) {
 382             printf("devfs_kernel_mount: buf_invalidateblks failed: %d\n", error);
 383             vnode_put(vp);
 384             return (error);
 385         }
 386         if (vnode_isdir(vp) == 0) {
 387             printf("devfs_kernel_mount: '%s' is not a directory\n", mntname);
 388             vnode_put(vp);
 389             return (ENOTDIR);
 390         }
 391         if ((vnode_mountedhere(vp))) {
 392             vnode_put(vp);
 393             return (EBUSY);
 394         }
 395
 396         /*
 397          * Allocate and initialize the filesystem.
 398          */
 399         MALLOC_ZONE(mp, struct mount *, (u_long)sizeof(struct mount),
 400                 M_MOUNT, M_WAITOK);
 401         bzero((char *)mp, (u_long)sizeof(struct mount));
 402
 403         /* Initialize the default IO constraints */
 404         mp->mnt_maxreadcnt = mp->mnt_maxwritecnt = MAXPHYS;
 405         mp->mnt_segreadcnt = mp->mnt_segwritecnt = 32;
 406
 407         mount_lock_init(mp);
 408         TAILQ_INIT(&mp->mnt_vnodelist);
 409         TAILQ_INIT(&mp->mnt_workerqueue);
 410         TAILQ_INIT(&mp->mnt_newvnodes);
 411
 412         (void)vfs_busy(mp, LK_NOWAIT);
 413         mp->mnt_op = devfs_vfsp->vfc_vfsops;
 414         mp->mnt_vtable = devfs_vfsp;
 415         devfs_vfsp->vfc_refcount++;
 416         devfs_vfsp->vfc_threadsafe = TRUE;
 417         devfs_vfsp->vfc_64bitready = TRUE;
 418         mp->mnt_flag = 0;
 419         mp->mnt_flag |= devfs_vfsp->vfc_flags & MNT_VISFLAGMASK;
 420         strncpy(mp->mnt_vfsstat.f_fstypename, devfs_vfsp->vfc_name, MFSTYPENAMELEN);
 421         vp->v_mountedhere = mp;
 422         mp->mnt_vnodecovered = vp;
 423         mp->mnt_vfsstat.f_owner = kauth_cred_getuid(kauth_cred_get());
 424         (void) copystr(mntname, mp->mnt_vfsstat.f_mntonname, MAXPATHLEN - 1, 0);
 425
 426         error = devfs_mount(mp, NULL, NULL, &context);
 427
 428         if (error) {
 429             printf("devfs_kernel_mount: mount %s failed: %d", mntname, error);
 430             mp->mnt_vtable->vfc_refcount--;
 431
 432             vfs_unbusy(mp);
 433
 434             mount_lock_destroy(mp);
 435             FREE_ZONE(mp, sizeof (struct mount), M_MOUNT);
 436             vnode_put(vp);
 437             return (error);
 438         }
 439         vnode_ref(vp);
 440         vnode_put(vp);
 441         vfs_unbusy(mp);
 442         mount_list_add(mp);
 443         return (0);
 444 }
 445
 446 struct vfsops devfs_vfsops = {
 447         devfs_mount,
 448         devfs_start,
 449         devfs_unmount,
 450         devfs_root,
 451         NULL,                           /* quotactl */
 452         devfs_vfs_getattr,
 453         devfs_sync,
 454         devfs_vget,
 455         devfs_fhtovp,
 456         devfs_vptofh,
 457         devfs_init,
 458         devfs_sysctl
 459 };