super1: make internal bitmap size calculations more consistent

Determining internal bitmap size is performed using two different
functions (bitmap_sectors() and calc_bitmap_size()) and in
getinfo_super1() it is calculated in yet another way. Each of these
methods give slightly different results. The most accurate is
calc_bitmap_size() but it also has a rounding issue. So:

- fix the rounding issue in calc_bitmap_size() using bitmap_bits()
- replace usages of bitmap_sectors() and open-coded calculations with
  calc_bitmap_size()
- remove bitmap_sectors()
- move bitmap_bits() to mdadm.h as inline - otherwise mdassemble won't
  compile (it does not use bitmap.c)

Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/mdadm.h b/mdadm.h
index 0516c826..41a44945 100755
--- a/mdadm.h
+++ b/mdadm.h
@@ -1331,7 +1331,14 @@ extern int CreateBitmap(char *filename, int force, char uuid[16],
 extern int ExamineBitmap(char *filename, int brief, struct supertype *st);
 extern int Write_rules(char *rule_name);
 extern int bitmap_update_uuid(int fd, int *uuid, int swap);
-extern unsigned long bitmap_sectors(struct bitmap_super_s *bsb);
+
+/* calculate the size of the bitmap given the array size and bitmap chunksize */
+static inline unsigned long long
+bitmap_bits(unsigned long long array_size, unsigned long chunksize)
+{
+	return (array_size * 512 + chunksize - 1) / chunksize;
+}
+
 extern int Dump_metadata(char *dev, char *dir, struct context *c,
 			 struct supertype *st);
 extern int Restore_metadata(char *dev, char *dir, struct context *c,