FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_conf.c

     /*
      * Copyright (c) 1989, 1993
      *      The Regents of the University of California.  All rights reserved.
      * Copyright (c) 1995 Artisoft, Inc.  All Rights Reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by the University of
     *      California, Berkeley and its contributors.
     * 4. Neither the name of the University nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     *      @(#)vfs_conf.c  8.8 (Berkeley) 3/31/94
     * $FreeBSD: src/sys/kern/vfs_conf.c,v 1.11.4.2 1999/09/05 08:15:41 peter Exp $
     */
    
    /*
     * PURPOSE:     This file abstracts the root mounting interface from
     *              the per file system semantics for handling mounts,
     *              the overall intent of which is to move the BSD
     *              internals dependence out of the FS code, both to
     *              make the FS code more portable and to free up some
     *              of the BSD internals so that they may more easily
     *              be changed.
     *
     * NOTE1:       Code is single entry/single exit to aid debugging
     *              and conversion for kernel multithreading.
     *
     * NOTE2:       Code notes lock state in headers on entry and exit
     *              as an aid to conversion for kernel multithreading
     *              on SMP reentrancy
     */
    #include <sys/param.h>          /* dev_t (types.h)*/
    #include <sys/systm.h>          /* rootvp*/
    #include <sys/proc.h>           /* curproc*/
    #include <sys/vnode.h>          /* NULLVP*/
    #include <sys/mount.h>          /* struct mount*/
    #include <sys/malloc.h>         /* M_MOUNT*/
    
    /*
     * GLOBALS
     */
    int (*mountroot) __P((void *));
    struct vnode *rootvnode;
    struct vfsops   *mountrootvfsops;
    
    
    /*
     * Common root mount code shared by all filesystems
     */
    #define ROOTDIR         "/"
    #define ROOTNAME        "root_device"
    
    
    
    /*
     * vfs_mountroot
     *
     * Common entry point for root mounts
     *
     * PARAMETERS:
     *              data    pointer to the vfs_ops for the FS type mounting
     *
     * RETURNS:     0       Success
     *              !0      error number (errno.h)
     *
     * LOCK STATE:
     *              ENTRY
     *                      <no locks held>
     *              EXIT
     *                      <no locks held>
     *
     * NOTES:
     *              This code is currently supported only for use for
     *              the FFS file system type.  This is a matter of
     *              fixing the other file systems, not this code!
     */
    int
   vfs_mountroot(data)
           void                    *data;
   {
           struct mount            *mp;
           u_int                   size;
           int                     err = 0;
           struct proc             *p = curproc;   /* XXX */
           struct vfsops           *mnt_op = (struct vfsops *)data;
   
           /*
            *  New root mount structure
            */
           mp = malloc((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK);
           bzero((char *)mp, (u_long)sizeof(struct mount));
           mp->mnt_op              = mnt_op;
           mp->mnt_flag            = MNT_ROOTFS;
           mp->mnt_vnodecovered    = NULLVP;
   
           /*
            * Lock mount point
            */
           if( ( err = vfs_lock(mp)) != 0)
                   goto error_1;
   
           /* Save "last mounted on" info for mount point (NULL pad)*/
           copystr(        ROOTDIR,                        /* mount point*/
                           mp->mnt_stat.f_mntonname,       /* save area*/
                           MNAMELEN - 1,                   /* max size*/
                           &size);                         /* real size*/
           bzero( mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
   
           /* Save "mounted from" info for mount point (NULL pad)*/
           copystr(        ROOTNAME,                       /* device name*/
                           mp->mnt_stat.f_mntfromname,     /* save area*/
                           MNAMELEN - 1,                   /* max size*/
                           &size);                         /* real size*/
           bzero( mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
   
           /*
            * Attempt the mount.
            *
            * If the mount fails, and it was an attempt to mount something
            * which looks like it might have been within a disk slice, try
            * again mounting the compatability slice instead.
            */
           err = VFS_MOUNT( mp, NULL, NULL, NULL, p);
           if( (err == ENXIO) && (rootdev & 0xff0000)) {
                   rootdev &= ~0xff0000;
                   err = VFS_MOUNT( mp, NULL, NULL, NULL, p);
           }
           if( err)
                   goto error_2;
   
           /* Add fs to list of mounted file systems*/
           CIRCLEQ_INSERT_TAIL( &mountlist, mp, mnt_list);
   
           /* Unlock mount point*/
           vfs_unlock(mp);
   
           /* root mount, update system time from FS specific data*/
           inittodr( mp->mnt_time);
   
           goto success;
   
   
   error_2:        /* mount error*/
   
           /* unlock before failing*/
           vfs_unlock( mp);
   
   error_1:        /* lock error*/
   
           /* free mount struct before failing*/
           free( mp, M_MOUNT);
   
   success:
           return( err);
   }

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