On Fri, Jun 24 2016 at 2:23pm -0400, Toshi Kani <[email protected]> wrote:
> Change dm-stripe to implement direct_access function, > stripe_direct_access(), which maps bdev and sector and > calls direct_access function of its physical target device. > > Signed-off-by: Toshi Kani <[email protected]> > Cc: Alasdair Kergon <[email protected]> > Cc: Dan Williams <[email protected]> > Cc: Ross Zwisler <[email protected]> > --- > drivers/md/dm-stripe.c | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c > index 48f1c01..8925f6a 100644 > --- a/drivers/md/dm-stripe.c > +++ b/drivers/md/dm-stripe.c > @@ -308,6 +308,30 @@ static int stripe_map(struct dm_target *ti, struct bio > *bio) > return DM_MAPIO_REMAPPED; > } > > +static long stripe_direct_access(struct dm_target *ti, sector_t sector, > + void __pmem **kaddr, pfn_t *pfn, long size) > +{ > + struct stripe_c *sc; > + struct block_device *bdev; > + uint32_t stripe; > + struct blk_dax_ctl dax = { > + .size = size, > + }; > + long ret; > + > + sc = ti->private; > + stripe_map_sector(sc, sector, &stripe, &dax.sector); > + > + dax.sector += sc->stripe[stripe].physical_start; > + bdev = sc->stripe[stripe].dev->bdev; > + > + ret = bdev_direct_access(bdev, &dax); > + *kaddr = dax.addr; > + *pfn = dax.pfn; > + > + return ret; > +} > + > /* > * Stripe status: > * > @@ -425,6 +449,7 @@ static struct target_type stripe_target = { > .status = stripe_status, > .iterate_devices = stripe_iterate_devices, > .io_hints = stripe_io_hints, > + .direct_access = stripe_direct_access, > }; > > int __init dm_stripe_init(void) Thanks, once jens queues the block changes I'll be able to pull this in to linux-dm.git BTW, if in your testing you could evaluate/quantify any extra overhead from DM that'd be useful to share. It could be there are bottlenecks that need to be fixed, etc. Mike -- dm-devel mailing list [email protected] https://www.redhat.com/mailman/listinfo/dm-devel
