[PATCH] device-mapper snapshot: metadata reading separation
More snapshot metadata reading into separate function, to prepare for changing
the place it gets called from.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index ab54f99..4b9dd8f 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -371,6 +371,20 @@
return (n + size) & ~size;
}
+static void read_snapshot_metadata(struct dm_snapshot *s)
+{
+ if (s->have_metadata)
+ return;
+
+ if (s->store.read_metadata(&s->store)) {
+ down_write(&s->lock);
+ s->valid = 0;
+ up_write(&s->lock);
+ }
+
+ s->have_metadata = 1;
+}
+
/*
* Construct a snapshot mapping: <origin_dev> <COW-dev> <p/n> <chunk-size>
*/
@@ -848,16 +862,7 @@
{
struct dm_snapshot *s = (struct dm_snapshot *) ti->private;
- if (s->have_metadata)
- return;
-
- if (s->store.read_metadata(&s->store)) {
- down_write(&s->lock);
- s->valid = 0;
- up_write(&s->lock);
- }
-
- s->have_metadata = 1;
+ read_snapshot_metadata(s);
}
static int snapshot_status(struct dm_target *ti, status_type_t type,