bsd/miscfs/fdesc/fdesc_vfsops.c

   1 /*
   2  * Copyright (c) 2000 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 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  29 /*
  30  * Copyright (c) 1992, 1993, 1995
  31  *      The Regents of the University of California.  All rights reserved.
  32  *
  33  * This code is derived from software donated to Berkeley by
  34  * Jan-Simon Pendry.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 3. All advertising materials mentioning features or use of this software
  45  *    must display the following acknowledgement:
  46  *      This product includes software developed by the University of
  47  *      California, Berkeley and its contributors.
  48  * 4. Neither the name of the University nor the names of its contributors
  49  *    may be used to endorse or promote products derived from this software
  50  *    without specific prior written permission.
  51  *
  52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  62  * SUCH DAMAGE.
  63  *
  64  *      @(#)fdesc_vfsops.c      8.10 (Berkeley) 5/14/95
  65  *
  66  */
  67
  68 /*
  69  * /dev/fd Filesystem
  70  */
  71
  72 #include <sys/param.h>
  73 #include <sys/systm.h>
  74 #include <sys/time.h>
  75 #include <sys/types.h>
  76 #include <sys/proc_internal.h>
  77 #include <sys/resourcevar.h>
  78 #include <sys/filedesc.h>
  79 #include <sys/vnode.h>
  80 #include <sys/mount_internal.h>
  81 #include <sys/namei.h>
  82 #include <sys/malloc.h>
  83 #include <miscfs/fdesc/fdesc.h>
  84
  85 /*
  86  * Mount the per-process file descriptors (/dev/fd)
  87  */
  88 int
  89 fdesc_mount(struct mount *mp, vnode_t devvp, __unused user_addr_t data, vfs_context_t context)
  90 {
  91         int error = 0;
  92         struct fdescmount *fmp;
  93         struct vnode *rvp;
  94
  95         /*
  96          * Update is a no-op
  97          */
  98         if (mp->mnt_flag & MNT_UPDATE)
  99                 return (ENOTSUP);
 100
 101         error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp, VDIR);
 102         if (error)
 103                 return (error);
 104
 105         MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount),
 106                                 M_UFSMNT, M_WAITOK);    /* XXX */
 107
 108         vnode_setnoflush(rvp);
 109         vnode_ref(rvp);
 110         vnode_put(rvp);
 111
 112         fmp->f_root = rvp;
 113         /* XXX -- don't mark as local to work around fts() problems */
 114         /*mp->mnt_flag |= MNT_LOCAL;*/
 115         mp->mnt_data = (qaddr_t) fmp;
 116         vfs_getnewfsid(mp);
 117
 118         bzero(mp->mnt_vfsstat.f_mntfromname, MAXPATHLEN);
 119         bcopy("fdesc", mp->mnt_vfsstat.f_mntfromname, sizeof("fdesc"));
 120         return (0);
 121 }
 122
 123 int
 124 fdesc_start(mp, flags, context)
 125         struct mount *mp;
 126         int flags;
 127         vfs_context_t context;
 128 {
 129         return (0);
 130 }
 131
 132 int
 133 fdesc_unmount(mp, mntflags, context)
 134         struct mount *mp;
 135         int mntflags;
 136         vfs_context_t context;
 137 {
 138         int error;
 139         int flags = 0;
 140         int force = 0;
 141         struct vnode *rvp = VFSTOFDESC(mp)->f_root;
 142
 143         if (mntflags & MNT_FORCE) {
 144                 flags |= FORCECLOSE;
 145                 force = 1;
 146         }
 147
 148         if ( vnode_isinuse(rvp, 1) && !force )
 149                 return (EBUSY);
 150         if ( (error = vflush(mp, rvp, flags|SKIPSYSTEM)) && !force )
 151                 return (error);
 152
 153         /*
 154          * And mark for recycle after we drop its reference; it away for future re-use
 155          */
 156         vnode_recycle(rvp);
 157         /*
 158          * Release reference on underlying root vnode
 159          */
 160         vnode_rele(rvp);
 161         /*
 162          * Finally, throw away the fdescmount structure
 163          */
 164         _FREE(mp->mnt_data, M_UFSMNT);  /* XXX */
 165         mp->mnt_data = 0;
 166
 167         return (0);
 168 }
 169
 170 int
 171 fdesc_root(mp, vpp, context)
 172         struct mount *mp;
 173         struct vnode **vpp;
 174         vfs_context_t context;
 175 {
 176         struct vnode *vp;
 177
 178         /*
 179          * Return locked reference to root.
 180          */
 181         vp = VFSTOFDESC(mp)->f_root;
 182         vnode_get(vp);
 183         *vpp = vp;
 184         return (0);
 185 }
 186
 187 int
 188 fdesc_statfs(mp, sbp, context)
 189         struct mount *mp;
 190         struct vfsstatfs *sbp;
 191         vfs_context_t context;
 192 {
 193         struct proc *p = vfs_context_proc(context);
 194         struct filedesc *fdp;
 195         int lim;
 196         int i;
 197         int last;
 198         int freefd;
 199
 200         /*
 201          * Compute number of free file descriptors.
 202          * [ Strange results will ensue if the open file
 203          * limit is ever reduced below the current number
 204          * of open files... ]
 205          */
 206         lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur;
 207         fdp = p->p_fd;
 208         last = min(fdp->fd_nfiles, lim);
 209         freefd = 0;
 210         for (i = fdp->fd_freefile; i < last; i++)
 211                 if (fdp->fd_ofiles[i] == NULL &&
 212                                 !(fdp->fd_ofileflags[i] & UF_RESERVED))
 213                         freefd++;
 214
 215         /*
 216          * Adjust for the fact that the fdesc array may not
 217          * have been fully allocated yet.
 218          */
 219         if (fdp->fd_nfiles < lim)
 220                 freefd += (lim - fdp->fd_nfiles);
 221
 222         sbp->f_flags = 0;
 223         sbp->f_bsize = DEV_BSIZE;
 224         sbp->f_iosize = DEV_BSIZE;
 225         sbp->f_blocks = (uint64_t)2;            /* 1K to keep df happy */
 226         sbp->f_bfree = 0;
 227         sbp->f_bavail = 0;
 228         sbp->f_files = (uint64_t)((unsigned long)(lim + 1));            /* Allow for "." */
 229         sbp->f_ffree = (uint64_t)((unsigned long)freefd);               /* See comments above */
 230
 231         return (0);
 232 }
 233
 234 static int
 235 fdesc_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t context)
 236 {
 237         VFSATTR_RETURN(fsap, f_bsize, DEV_BSIZE);
 238         VFSATTR_RETURN(fsap, f_iosize, DEV_BSIZE);
 239         VFSATTR_RETURN(fsap, f_blocks, 2);
 240         VFSATTR_RETURN(fsap, f_bfree, 0);
 241         VFSATTR_RETURN(fsap, f_bavail, 0);
 242         VFSATTR_RETURN(fsap, f_fssubtype, 0);
 243
 244         if (VFSATTR_IS_ACTIVE(fsap, f_objcount) ||
 245             VFSATTR_IS_ACTIVE(fsap, f_maxobjcount) ||
 246             VFSATTR_IS_ACTIVE(fsap, f_files) ||
 247             VFSATTR_IS_ACTIVE(fsap, f_ffree))
 248         {
 249                 struct proc *p = vfs_context_proc(context);
 250                 struct filedesc *fdp;
 251                 int lim;
 252                 int i;
 253                 int last;
 254                 int freefd;
 255
 256                 /*
 257                  * Compute number of free file descriptors.
 258                  * [ Strange results will ensue if the open file
 259                  * limit is ever reduced below the current number
 260                  * of open files... ]
 261                  */
 262                 lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur;
 263                 fdp = p->p_fd;
 264                 last = min(fdp->fd_nfiles, lim);
 265                 freefd = 0;
 266                 for (i = fdp->fd_freefile; i < last; i++)
 267                         if (fdp->fd_ofiles[i] == NULL &&
 268                                         !(fdp->fd_ofileflags[i] & UF_RESERVED))
 269                                 freefd++;
 270
 271                 /*
 272                  * Adjust for the fact that the fdesc array may not
 273                  * have been fully allocated yet.
 274                  */
 275                 if (fdp->fd_nfiles < lim)
 276                         freefd += (lim - fdp->fd_nfiles);
 277
 278                 VFSATTR_RETURN(fsap, f_objcount, lim+1);
 279                 VFSATTR_RETURN(fsap, f_maxobjcount, lim+1);
 280                 VFSATTR_RETURN(fsap, f_files, lim+1);
 281                 VFSATTR_RETURN(fsap, f_ffree, freefd);
 282         }
 283
 284         return 0;
 285 }
 286
 287 int
 288 fdesc_sync(mp, waitfor, context)
 289         struct mount *mp;
 290         int waitfor;
 291         vfs_context_t context;
 292 {
 293
 294         return (0);
 295 }
 296
 297 #define fdesc_fhtovp (int (*) (mount_t, int, unsigned char *, vnode_t *, vfs_context_t))eopnotsupp
 298 #define fdesc_sysctl (int (*) (int *, u_int, user_addr_t, size_t *, user_addr_t, size_t, vfs_context_t))eopnotsupp
 299 #define fdesc_vget (int (*) (mount_t, ino64_t, vnode_t *, vfs_context_t))eopnotsupp
 300 #define fdesc_vptofh (int (*) (vnode_t, int *, unsigned char *, vfs_context_t))eopnotsupp
 301
 302 struct vfsops fdesc_vfsops = {
 303         fdesc_mount,
 304         fdesc_start,
 305         fdesc_unmount,
 306         fdesc_root,
 307         NULL,                   /* quotactl */
 308         fdesc_vfs_getattr,
 309         fdesc_sync,
 310         fdesc_vget,
 311         fdesc_fhtovp,
 312         fdesc_vptofh,
 313         fdesc_init,
 314         fdesc_sysctl
 315 };