Re: [PATCH] VFS autmounter support

[H. Peter Anvin]

David Howells wrote:
>>
>>That's actually not true.  It's lstat() that mustn't cause the automount
>>point to mount -- stat() only comes into play if lstat() resolves to a
>>symlink.  However, lstat() never invokes follow_link, so creating a
>>dentry with a follow_link method resolving to itself, and an associated
>>dummy directory inode, does what's required.
> 
> That _is_ actually true. Doing "ls -l" in that directory would otherwise cause
> a mount storm.
> 

It's not.  ls -l and all the GUI tools do lstat(), not stat().

> follow_link resolving to itself? Surely that'll cause ELOOP very quickly? And
> where does this "dummy directory inode" live?

Nope.  You can follow_link() nonrecursively.  You need a dummy directory 
inode to mount upon anyway.

	-hpa