[PATCH]initrd unmount problem

[Go Taniguchi]

Hi,

It seems that ioctl_by_bdev() in fs/block_dev.c has a problem.
When initrd is unmounted it can cause OOPS. 
This problem occurs in recent ac patches.
May be vanilla too.

change_root() in fs/super.c calls ioctl_by_bdev() in
fs/block_dev.c which does not set inode_fake.i_bdev.

But ioctl of ramdisk (rd_ioctl() in rd.c) accesses to
i_bdev->bd_openers of the inode and which causes OOPS.

I attach the patch.

- GO!

--- linux/fs/block_dev.c.orig   Mon May 28 12:40:12 2001
+++ linux/fs/block_dev.c        Mon May 28 12:40:12 2001
@@ -602,6 +602,7 @@
        if (!bdev->bd_op->ioctl)
                return -EINVAL;
        inode_fake.i_rdev=rdev;
+       inode_fake.i_bdev=bdev;
        init_waitqueue_head(&inode_fake.i_wait);
        set_fs(KERNEL_DS);
        res = bdev->bd_op->ioctl(&inode_fake, NULL, cmd, arg);