Re: review: s/i_flags_lock/i_inner_lock/g

David Chinner
2008-04-29T21:29:25Z

On Tue, Apr 29, 2008 at 01:37:57AM -0400, Christoph Hellwig wrote:
> On Tue, Apr 29, 2008 at 03:15:23PM +1000, Timothy Shimmin wrote:
> > Hi there,
> >
> > As part of future plans to cache incore versions of acls
> > off the inode, we want to protect its modification by a spin lock.
> > Dave suggested that we use the i_flags_lock but rename it to
> > reflect its more general purpose on other fields, such as "i_inner_lock".
> > This patch is then basically s/i_flags_lock/i_inner_lock/g.
>
> Not too happpy about that, as I'd rather kill this lock in it's current
> form and use atomic bitops on the flags. I'd rather use i_lock in the
> Linux inode for the ACLs.

The problem with that is that some of the flags work together and can't
be used as separate bitops. eg. xfs_finish_reclaim() and xfs_iget_core().
Hence they currently need to be protected by a spinlock.

Also, protecting something in the XFs inode with the linux inode lock
could have issues with the lifecycle differences between the inodes.
Just something to be careful of....

Cheers,

Dave.
--
Dave Chinner
Principal Engineer
SGI Australian Software Group