[PATCH 05/19] drm: move dev_mapping to the minor node

[Dave Airlie]

On Mon, Apr 30, 2012 at 6:53 PM, Dave Airlie <airlied at gmail.com> wrote:
>>
>> Do you have pointers to that discussion (assuming it was on sime mailing
>> list)? The least I can do, while I am at it, is try to understand it and
>> see if I can incorporate some ideas from there in the rework of the patch.
>
> Nope it was an offhand discussion on irc while we were talking about
> some other ugly code.

Okay I think it was the code in coda,

       if (coda_inode->i_mapping == &coda_inode->i_data)
                coda_inode->i_mapping = host_inode->i_mapping;

        /* only allow additional mmaps as long as userspace isn't changing
         * the container file on us! */
        else if (coda_inode->i_mapping != host_inode->i_mapping) {
                spin_unlock(&cii->c_lock);
                return -EBUSY;
        }

We could use code like that to change the i_mapping, instead of failing.

Dave.