static int umount_dev(kdev_t dev, int flags)
{
int retval;
struct inode * inode = get_empty_inode();
retval = -ENOMEM;
if (!inode)
goto out;
inode->i_rdev = dev;
retval = -ENXIO;
if (MAJOR(dev) >= MAX_BLKDEV)
goto out_iput;
fsync_dev(dev);
down(&mount_sem);
retval = do_umount(dev, 0, flags);
if (!retval) {
fsync_dev(dev);
if (dev != ROOT_DEV) {
blkdev_release(inode);
put_unnamed_dev(dev);
}
}
up(&mount_sem);
out_iput:
iput(inode);
out:
return retval;
}
asmlinkage int sys_umount(char * name)
{
struct inode * inode;
kdev_t dev;
int retval;
struct inode dummy_inode;
if (!suser())
return -EPERM;
retval = namei(name, &inode);
if (retval) {
retval = lnamei(name, &inode);
if (retval)
return retval;
}
if (S_ISBLK(inode->i_mode)) {
dev = inode->i_rdev;
if (IS_NODEV(inode)) {
iput(inode);
return -EACCES;
}
} else {
if (!inode->i_sb || inode != inode->i_sb->s_mounted) {
iput(inode);
return -EINVAL;
}
dev = inode->i_sb->s_dev;
iput(inode);
memset(&dummy_inode, 0, sizeof(dummy_inode));
dummy_inode.i_rdev = dev;
inode = &dummy_inode;
}
if (MAJOR(dev) >= MAX_BLKDEV) {
iput(inode);
return -ENXIO;
}
retval = do_umount(dev,0);
if (!retval) {
fsync_dev(dev);
if (dev != ROOT_DEV) {
blkdev_release (inode);
if (MAJOR(dev) == UNNAMED_MAJOR)
put_unnamed_dev(dev);
}
}
if (inode != &dummy_inode)
iput(inode);
if (retval)
return retval;
fsync_dev(dev);
return 0;
}