[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>

1 files changed, 15 insertions, 10 deletions

diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index ab54f99b7c3b..4b9dd8fb1e5c 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -371,6 +371,20 @@ static inline ulong round_up(ulong n, ulong size)
         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 @@ static void snapshot_resume(struct dm_target *ti)
 {
         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,