[LU-8543] ll_revalidate_dentry unsafe usage of parent inode

• Type: Bug
• Resolution: Unresolved
• Priority: Major
• Labels: patch
• Severity: 3
• Assignee: Oleg Drokin
• Reporter: Oleg Drokin

Description

Al Viro advises us that we cannot just use parent inode like that unguarded.

There are two problems.
First, by the time we get to ll_Revalidate, the parent might change since nothing locks it, but there's nothing we could do about it.
But the other problem - the parent inode could be freed while we are there and we do not hold a reference - so this should be fixed.
We should convert to something like dget_parent.