On 10/31/2012 12:36 PM, Darrick J. Wong wrote: > On Wed, Oct 31, 2012 at 12:56:14PM +0100, Jan Kara wrote: <snip> >> You are right that we need a mechanism to push the flags from the devices >> through various storage layers up into the bdi filesystem sees to make >> things reliable. > > md/dm will call blk_integrity_register, so pushing the "stable page writes > required" flag through the various layers is already taken care of. If devices > and filesystems can both indicate that they want stable page writes, I'll have > to keep track of however many users there are. > Please note again the iscsi case. Say the admin defined half of an md iscsi devices with data_integrity and half without. For me I would like an OR. If any underline device needs "stable pages" they all get them. Please also provide - or how easy is to make an API - for the like of iscsi that given a request_queue, set the BDI's "stable pages" on. Something like: /* stable_pages can only be turned on never off */ blk_set_stable_pages(struct request_queue); > It does seem like less work to fix all the filesystems than to dork around with > another flag. Sure if that is possible, that will be perfect, then I do not need to keep the old "unstable pages" code around at all. Thanks for working on this Boaz -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
