On Tue, Jul 06, 2021 at 10:29:41PM -0700, Satya Tangirala wrote: > From: Satya Tangirala <satyat@xxxxxxxxxx> > > Handle any error from blk_ksm_register() in the callers. Previously, > the callers ignored the return value because blk_ksm_register() wouldn't > fail as long as the request_queue didn't have integrity support too, but > as this is no longer the case, it's safer for the callers to just handle > the return value appropriately. > > Signed-off-by: Satya Tangirala <satyat@xxxxxxxxxx> > --- > drivers/md/dm-table.c | 17 ++++++++++++++++- > 1 file changed, 16 insertions(+), 1 deletion(-) > > diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c > index 29cbfc3e3c4b..c79c0fbe80dd 100644 > --- a/drivers/md/dm-table.c > +++ b/drivers/md/dm-table.c > @@ -1343,6 +1343,20 @@ static int dm_table_construct_keyslot_manager(struct dm_table *t) > */ > t->ksm = ksm; > > + /* > + * At this point, t->ksm is either NULL or *not* empty (i.e. will support > + * at least 1 crypto capability), the request queue doesn't support > + * integrity, and it also satisfies all the block layer constraints > + * "sufficiently" (as in the constraints of the DM device's request queue > + * won't preclude any of the intersection of the supported capabilities > + * of the underlying devices, since if some capability were precluded by > + * the DM device's request queue's constraints, that capability would > + * also have been precluded by one of the child device's request queues). > + * > + * Hence any future attempt to call blk_ksm_register() on t->ksm (if it's > + * not NULL) will succeed. > + */ > + > return 0; I don't think this properly answers the question I had on the previous version of this patch, which was not just how we know that blk_ksm_register() will succeed later, but also how we know that the blk_ksm_is_superset() check done above is valid when some of the crypto capabilities may be cleared by blk_ksm_register() later. Is the assumption actually that in the device-mapper case, blk_ksm_register() will never clear any crypto capabilities at all? If so, can that be explained properly? - Eric
