sys/vfs/procfs/procfs_vfsops.c

   1 /*
   2  * Copyright (c) 1993 Jan-Simon Pendry
   3  * Copyright (c) 1993
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * This code is derived from software contributed to Berkeley by
   7  * Jan-Simon Pendry.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  *      @(#)procfs_vfsops.c     8.7 (Berkeley) 5/10/95
  34  *
  35  * $FreeBSD: src/sys/miscfs/procfs/procfs_vfsops.c,v 1.32.2.1 2001/10/15 20:42:01 des Exp $
  36  */
  37
  38 /*
  39  * procfs VFS interface
  40  */
  41
  42 #include <sys/param.h>
  43 #include <sys/systm.h>
  44 #include <sys/kernel.h>
  45 #include <sys/proc.h>
  46 #include <sys/mount.h>
  47 #include <sys/vnode.h>
  48 #include <vfs/procfs/procfs.h>
  49
  50 extern struct vop_ops procfs_vnode_vops;
  51
  52 static int      procfs_mount (struct mount *mp, char *path, caddr_t data,
  53                                   struct ucred *cred);
  54 static int      procfs_statfs (struct mount *mp, struct statfs *sbp,
  55                                 struct ucred *cred);
  56 static int      procfs_unmount (struct mount *mp, int mntflags);
  57
  58 /*
  59  * VFS Operations.
  60  *
  61  * mount system call
  62  */
  63 /* ARGSUSED */
  64 static int
  65 procfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
  66 {
  67         size_t size;
  68         int error;
  69
  70         if (mp->mnt_flag & MNT_UPDATE)
  71                 return (EOPNOTSUPP);
  72
  73         if (mp->mnt_vfc->vfc_refcount == 1 && (error = at_exit(procfs_exit))) {
  74                 kprintf("procfs:  cannot register procfs_exit with at_exit\n");
  75                 return(error);
  76         }
  77
  78         mp->mnt_flag |= MNT_LOCAL;
  79         mp->mnt_kern_flag |= MNTK_NOSTKMNT;
  80         mp->mnt_data = NULL;
  81         vfs_getnewfsid(mp);
  82
  83         size = sizeof("procfs") - 1;
  84         bcopy("procfs", mp->mnt_stat.f_mntfromname, size);
  85         bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
  86         procfs_statfs(mp, &mp->mnt_stat, cred);
  87         vfs_add_vnodeops(mp, &procfs_vnode_vops, &mp->mnt_vn_norm_ops);
  88
  89         return (0);
  90 }
  91
  92 /*
  93  * unmount system call
  94  */
  95 static int
  96 procfs_unmount(struct mount *mp, int mntflags)
  97 {
  98         int error;
  99         int flags = 0;
 100
 101         if (mntflags & MNT_FORCE)
 102                 flags |= FORCECLOSE;
 103
 104         error = vflush(mp, 0, flags);
 105         if (error)
 106                 return (error);
 107
 108         if (mp->mnt_vfc->vfc_refcount == 1)
 109                 rm_at_exit(procfs_exit);
 110
 111         return (0);
 112 }
 113
 114 /*
 115  * Sets *vpp to the root procfs vnode, referenced and exclusively locked.
 116  */
 117 int
 118 procfs_root(struct mount *mp, struct vnode **vpp)
 119 {
 120         return (procfs_allocvp(mp, vpp, 0, Proot));
 121 }
 122
 123 /*
 124  * Get file system statistics.
 125  */
 126 static int
 127 procfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
 128 {
 129         sbp->f_bsize = PAGE_SIZE;
 130         sbp->f_iosize = PAGE_SIZE;
 131         sbp->f_blocks = 1;      /* avoid divide by zero in some df's */
 132         sbp->f_bfree = 0;
 133         sbp->f_bavail = 0;
 134         sbp->f_files = maxproc;                 /* approx */
 135         sbp->f_ffree = maxproc - nprocs;        /* approx */
 136
 137         if (sbp != &mp->mnt_stat) {
 138                 sbp->f_type = mp->mnt_vfc->vfc_typenum;
 139                 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
 140                 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
 141         }
 142
 143         return (0);
 144 }
 145
 146 static struct vfsops procfs_vfsops = {
 147         .vfs_mount =            procfs_mount,
 148         .vfs_unmount =          procfs_unmount,
 149         .vfs_root =             procfs_root,
 150         .vfs_statfs =           procfs_statfs,
 151 };
 152
 153 VFS_SET(procfs_vfsops, procfs, VFCF_SYNTHETIC | VFCF_MPSAFE);
 154 MODULE_VERSION(procfs, 1);