Re: Deep look into VFS

[Martin Dalecki <dalecki@evision-ventures.com>]

Alexander Viro wrote:
> 
> On Wed, 5 Dec 2001, Martin Dalecki wrote:
> 
> > Unless I'm compleatly misguided the lock on the superblock
> > should entierly prevent the race described inside the header comment
> > and we should be able to delete clear_inode from this function.
> 
> Huh?  We drop that lock before the return from this function.  So if you
> move clear_inode() after the return, you lose that protections.
> 
> What's more, you can't more that lock_super()/unlock_super() into iput()
> itself - you need it _not_ taken in the beginning of ext2_delete_inode()
> and you don't want it for quite a few filesystems.
> 
> Nothing VFS-specific here, just a bog-standard "you lose protection of
> semaphore once you call up()"...

Ummmmm... that is well trivially true... of course (I'm 
slapping a hand on my forehead). 

Thank you for answering!