dm exception store: introduce area_location function

Move this logic to a function, because it will be reused later.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c
index 41f408068a7c..824cf31967c5 100644
--- a/drivers/md/dm-exception-store.c
+++ b/drivers/md/dm-exception-store.c
@@ -209,6 +209,14 @@ static int chunk_io(struct pstore *ps, uint32_t chunk, int rw, int metadata)
 }
 
 /*
+ * Convert a metadata area index to a chunk index.
+ */
+static chunk_t area_location(struct pstore *ps, chunk_t area)
+{
+        return 1 + ((ps->exceptions_per_area + 1) * area);
+}
+
+/*
  * Read or write a metadata area.  Remembering to skip the first
  * chunk which holds the header.
  */
@@ -217,8 +225,7 @@ static int area_io(struct pstore *ps, uint32_t area, int rw)
         int r;
         uint32_t chunk;
 
-        /* convert a metadata area index to a chunk index */
-        chunk = 1 + ((ps->exceptions_per_area + 1) * area);
+        chunk = area_location(ps, area);
 
         r = chunk_io(ps, chunk, rw, 0);
         if (r)