From f6e629bd2379dceb547be93915314307871a7f6c Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Tue, 28 Jun 2016 13:37:16 -0600 Subject: dm snap: add fake origin_direct_access dax-capable mapped-device is marked as DM_TYPE_DAX_BIO_BASED, which supports both dax and bio-based operations. dm-snap needs to work with dax-capable device when bio-based operation is used. Add fake origin_direct_access() to origin device so that its origin device is also marked as DM_TYPE_DAX_BIO_BASED for dax-capable device. This allows to extend target's DM table. dm-snap works normally when bio-based operation is used. dm-snap does not support dax operation, and mount with dax option to a target device or snapshot device fails. Signed-off-by: Toshi Kani Cc: Mike Snitzer Cc: Alasdair Kergon Cc: Dan Williams Signed-off-by: Mike Snitzer --- drivers/md/dm-snap.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'drivers/md/dm-snap.c') diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index 69ab1ff5f5c9..c472f0465f0e 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -2301,6 +2301,13 @@ static int origin_map(struct dm_target *ti, struct bio *bio) return do_origin(o->dev, bio); } +static long origin_direct_access(struct dm_target *ti, sector_t sector, + void __pmem **kaddr, pfn_t *pfn, long size) +{ + DMWARN("device does not support dax."); + return -EIO; +} + /* * Set the target "max_io_len" field to the minimum of all the snapshots' * chunk sizes. @@ -2360,6 +2367,7 @@ static struct target_type origin_target = { .postsuspend = origin_postsuspend, .status = origin_status, .iterate_devices = origin_iterate_devices, + .direct_access = origin_direct_access, }; static struct target_type snapshot_target = { -- cgit v1.2.1