Am 09.02.2017 um 13:17 schrieb Jan Kara:

quoted

So ->capabilities is now zero by default since you use __GFP_ZERO in
bdi_alloc().
At least for UBIFS I'll add a comment on this, otherwise it is not so
clear that UBIFS wants a BDI with no capabilities and how it achieves that.

OK, I've modified the comment to:

         * Read-ahead will be disabled because @sb->s_bdi->ra_pages is 0. Also
         * @sb->s_bdi->capabilities are initialized to 0 so there won't be any
         * writeback happening.
         */

Nice!

Thanks,
//richard