Re: [PATCH 08/21] fs: rework icount to be a locked variable

Al Viro
2010-10-21T19:40:48Z

On Thu, Oct 21, 2010 at 11:49:33AM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> The inode reference count is currently an atomic variable so that it
> can be sampled/modified outside the inode_lock. However, the
> inode_lock is still needed to synchronise the final reference count
> and checks against the inode state.
>
> To avoid needing the protection of the inode lock, protect the inode
> reference count with the per-inode i_lock and convert it to a normal
> variable. To avoid existing out-of-tree code accidentally compiling
> against the new method, rename the i_count field to i_ref. This is
> relatively straight forward as there are limited external references
> to the i_count field remaining.

BTW, the same thing as with Nick's set - separate patch for "clone the
reference to inode we are already holding" helper, in front of queue.