Manage: allow adding device that is just large enough to v1.x array.

When adding a device to an array, we check that it is large enough.

Currently the check makes sure there is also room for a reasonably
sized bitmap.  But if the array doesn't have a bitmap, then this test
might be too restrictive.
So when adding, only insist there is enough space for the current
bitmap.
When Creating, still require room for the standard sized bitmap.

This resolved Debian Bug 500309

1 files changed, 12 insertions, 1 deletions

diff --git a/super1.c b/super1.c
index fe915f8..e1d0219 100644
--- a/super1.c
+++ b/super1.c
@@ -1214,10 +1214,21 @@ static struct supertype *match_metadata_desc1(char *arg)
  */
 static __u64 avail_size1(struct supertype *st, __u64 devsize)
 {
+	struct mdp_superblock_1 *super = st->sb;
 	if (devsize < 24)
 		return 0;
 
-	devsize -= choose_bm_space(devsize);
+	if (super == NULL)
+		/* creating:  allow suitable space for bitmap */
+		devsize -= choose_bm_space(devsize);
+#ifndef MDASSEMBLE
+	else if (__le32_to_cpu(super->feature_map)&MD_FEATURE_BITMAP_OFFSET) {
+		/* hot-add. allow for actual size of bitmap */
+		struct bitmap_super_s *bsb;
+		bsb = (struct bitmap_super_s *)(((char*)super)+1024);
+		devsize -= bitmap_sectors(bsb);
+	}
+#endif
 
 	switch(st->minor_version) {
 	case -1: /* no specified.  Now time to set default */