Re: 2.1.47 oops (crash)

Martin von Loewis (
Thu, 31 Jul 1997 00:44:03 +0200

> If autofs wasn't implicated, then we should indeed start looking for
> something where the hashes do not match the parents..

You've probably noticed it: some of the oopses were related to amd
umounting some file system, which then would case a negative d_count
on some totally unrelated dentry.

Also, there was the report of ext2 inodes surviving an umount and
suddenly re-appearing on another file system.

Something is wrong with unmounting. Here's a theory:

- iput removes the inode from the hash list only if nlink is zero
- iget, if the inode is not found, invokes get_new_inode
- get_new_inode, under certain circumstances, searches the hash list
- find_inode on the hash list searches for identical superblock and
inode number

So if the superblock is recycled, and the inode was not put with
i_nlink==0, it may get recycled by the wrong file system. All kinds
of strange things can happen.

I hope I'm missing something.