On Thu, Sep 30, 2010 at 01:38:07AM +0200, Jan Kara wrote: > > No. For one thing we don't need any exception for correctnes alone - > > even the block device variant would work fine with the default case. > Here I don't agree. If you don't have some kind of exception, sb->s_bdi > for both "block" and "mtd_inodefs" filesystems points to > noop_backing_dev_info and you get no writeback for that one. So it isn't > just a performance issue but also a correctness one.
Indeed - for internal filesystems that require writeback the change causes trouble if they haven't registered a s_bdi. But for all user visible filesystems that doesn't happen as we require s_bdi for sync or even unmounts to work. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
