int close_vfs(void)
{
if (!root_vnode) return -1;
unregister_filesystem(&ext2_fs_type);
unregister_filesystem(&devfs_fs_type);
unregister_filesystem(&initrd_fs_type);
super_block *sb = root_vnode->sb;
free_sb_inodes(sb);
d_umount(sb);
free(sb);
unregister_filesystem(&rootfs_type);
root_vnode = 0;
return 0;
}
static int do_umount(kdev_t dev, int unmount_root, int flags)
{
struct super_block * sb;
int retval;
retval = -ENOENT;
sb = get_super(dev);
if (!sb || !sb->s_root)
goto out;
/*
* Before checking whether the filesystem is still busy,
* make sure the kernel doesn't hold any quota files open
* on the device. If the umount fails, too bad -- there
* are no quotas running any more. Just turn them on again.
*/
DQUOT_OFF(dev);
acct_auto_close(dev);
/*
* If we may have to abort operations to get out of this
* mount, and they will themselves hold resources we must
* allow the fs to do things. In the Unix tradition of
* 'Gee thats tricky lets do it in userspace' the umount_begin
* might fail to complete on the first run through as other tasks
* must return, and the like. Thats for the mount program to worry
* about for the moment.
*/
if( (flags&MNT_FORCE) && sb->s_op->umount_begin)
sb->s_op->umount_begin(sb);
/*
* Shrink dcache, then fsync. This guarantees that if the
* filesystem is quiescent at this point, then (a) only the
* root entry should be in use and (b) that root entry is
* clean.
*/
shrink_dcache_sb(sb);
fsync_dev(dev);
if (dev==ROOT_DEV && !unmount_root) {
/*
* Special case for "unmounting" root ...
* we just try to remount it readonly.
*/
retval = 0;
if (!(sb->s_flags & MS_RDONLY))
retval = do_remount_sb(sb, MS_RDONLY, 0);
return retval;
}
retval = d_umount(sb);
if (retval)
goto out;
if (sb->s_op) {
if (sb->s_op->write_super && sb->s_dirt)
sb->s_op->write_super(sb);
}
lock_super(sb);
if (sb->s_op) {
if (sb->s_op->put_super)
sb->s_op->put_super(sb);
}
/* Forget any remaining inodes */
if (invalidate_inodes(sb)) {
printk("VFS: Busy inodes after unmount. "
"Self-destruct in 5 seconds. Have a nice day...\n");
}
sb->s_dev = 0; /* Free the superblock */
unlock_super(sb);
remove_vfsmnt(dev);
out:
return retval;
}
