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. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed by the University of
  20  *      California, Berkeley and its contributors.
  21  * 4. Neither the name of the University nor the names of its contributors
  22  *    may be used to endorse or promote products derived from this software
  23  *    without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  35  * SUCH DAMAGE.
  36  *
  37  *      @(#)procfs_vfsops.c     8.7 (Berkeley) 5/10/95
  38  *
  39  * $FreeBSD: src/sys/miscfs/procfs/procfs_vfsops.c,v 1.32.2.1 2001/10/15 20:42:01 des Exp $
  40  * $DragonFly: src/sys/vfs/procfs/procfs_vfsops.c,v 1.17 2007/09/03 17:06:24 dillon Exp $
  41  */
  42
  43 /*
  44  * procfs VFS interface
  45  */
  46
  47 #include <sys/param.h>
  48 #include <sys/systm.h>
  49 #include <sys/kernel.h>
  50 #include <sys/proc.h>
  51 #include <sys/mount.h>
  52 #include <sys/vnode.h>
  53 #include <vfs/procfs/procfs.h>
  54
  55 extern struct vop_ops procfs_vnode_vops;
  56
  57 static int      procfs_mount (struct mount *mp, char *path, caddr_t data,
  58                                   struct ucred *cred);
  59 static int      procfs_statfs (struct mount *mp, struct statfs *sbp,
  60                                 struct ucred *cred);
  61 static int      procfs_unmount (struct mount *mp, int mntflags);
  62
  63 /*
  64  * VFS Operations.
  65  *
  66  * mount system call
  67  */
  68 /* ARGSUSED */
  69 static int
  70 procfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
  71 {
  72         size_t size;
  73         int error;
  74
  75         if (mp->mnt_flag & MNT_UPDATE)
  76                 return (EOPNOTSUPP);
  77
  78         if (mp->mnt_vfc->vfc_refcount == 1 && (error = at_exit(procfs_exit))) {
  79                 kprintf("procfs:  cannot register procfs_exit with at_exit\n");
  80                 return(error);
  81         }
  82
  83         mp->mnt_flag |= MNT_LOCAL;
  84         mp->mnt_kern_flag |= MNTK_NOSTKMNT;
  85         mp->mnt_data = 0;
  86         vfs_getnewfsid(mp);
  87
  88         size = sizeof("procfs") - 1;
  89         bcopy("procfs", mp->mnt_stat.f_mntfromname, size);
  90         bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
  91         procfs_statfs(mp, &mp->mnt_stat, cred);
  92         vfs_add_vnodeops(mp, &procfs_vnode_vops, &mp->mnt_vn_norm_ops);
  93
  94         return (0);
  95 }
  96
  97 /*
  98  * unmount system call
  99  */
 100 static int
 101 procfs_unmount(struct mount *mp, int mntflags)
 102 {
 103         int error;
 104         int flags = 0;
 105
 106         if (mntflags & MNT_FORCE)
 107                 flags |= FORCECLOSE;
 108
 109         error = vflush(mp, 0, flags);
 110         if (error)
 111                 return (error);
 112
 113         if (mp->mnt_vfc->vfc_refcount == 1)
 114                 rm_at_exit(procfs_exit);
 115
 116         return (0);
 117 }
 118
 119 /*
 120  * Sets *vpp to the root procfs vnode, referenced and exclusively locked.
 121  */
 122 int
 123 procfs_root(struct mount *mp, struct vnode **vpp)
 124 {
 125         return (procfs_allocvp(mp, vpp, 0, Proot));
 126 }
 127
 128 /*
 129  * Get file system statistics.
 130  */
 131 static int
 132 procfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
 133 {
 134         sbp->f_bsize = PAGE_SIZE;
 135         sbp->f_iosize = PAGE_SIZE;
 136         sbp->f_blocks = 1;      /* avoid divide by zero in some df's */
 137         sbp->f_bfree = 0;
 138         sbp->f_bavail = 0;
 139         sbp->f_files = maxproc;                 /* approx */
 140         sbp->f_ffree = maxproc - nprocs;        /* approx */
 141
 142         if (sbp != &mp->mnt_stat) {
 143                 sbp->f_type = mp->mnt_vfc->vfc_typenum;
 144                 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
 145                 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
 146         }
 147
 148         return (0);
 149 }
 150
 151 static struct vfsops procfs_vfsops = {
 152         .vfs_mount =            procfs_mount,
 153         .vfs_unmount =          procfs_unmount,
 154         .vfs_root =             procfs_root,
 155         .vfs_statfs =           procfs_statfs,
 156         .vfs_sync =             vfs_stdsync
 157 };
 158
 159 VFS_SET(procfs_vfsops, procfs, VFCF_SYNTHETIC);
 160 MODULE_VERSION(procfs, 1);