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authorToshi Kani <toshi.kani@hpe.com>2016-06-28 13:37:16 -0600
committerMike Snitzer <snitzer@redhat.com>2016-07-20 23:49:51 -0400
commitf6e629bd2379dceb547be93915314307871a7f6c (patch)
tree3a2ef8ed074e273c081eca2ca0adfd4bce6f561d /drivers/md/dm-snap.c
parentbeec25b4573bc310f5a12cf33207b20ecc30945c (diff)
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 <toshi.kani@hpe.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-snap.c')
-rw-r--r--drivers/md/dm-snap.c8
1 files changed, 8 insertions, 0 deletions
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 = {