super1: improve calculation of space_before/space_after

1/ these must allow for bad-block-list
2/ they must match the kernel, which has a 32k buffer after the
   superblock.

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/super1.c b/super1.c
index 08d94a324c13d25c2e1529f05847688beeade380..1ce26683ac856edeff85ba442b3153b031865fe2 100644 (file)
--- a/super1.c
+++ b/super1.c
@@ -910,15 +910,24 @@ static void getinfo_super1(struct supertype *st, struct mdinfo *info, char *map)
                unsigned long long end;
                info->space_before = info->data_offset;
                end = super_offset;
-               if (info->bitmap_offset < 0)
-                       end += info->bitmap_offset;
+
+               if (sb->bblog_offset && sb->bblog_size) {
+                       unsigned long long bboffset = super_offset;
+                       bboffset += (int32_t)__le32_to_cpu(sb->bblog_offset);
+                       if (bboffset < end)
+                               end = bboffset;
+               }
+
+               if (super_offset + info->bitmap_offset < end)
+                       end = super_offset + info->bitmap_offset;
+
                if (info->data_offset + data_size < end)
                        info->space_after = end - data_size - info->data_offset;
                else
                        info->space_after = 0;
        } else {
-               info->space_before = (info->data_offset -
-                                     super_offset);
+               unsigned long long earliest;
+               earliest = super_offset + (32+4)*2; /* match kernel */
                if (info->bitmap_offset > 0) {
                        unsigned long long bmend = info->bitmap_offset;
                        unsigned long long size = __le64_to_cpu(bsb->sync_size);
@@ -927,13 +936,21 @@ static void getinfo_super1(struct supertype *st, struct mdinfo *info, char *map)
                        size += sizeof(bitmap_super_t);
                        size = ROUND_UP(size, 4096);
                        size /= 512;
-                       size += bmend;
-                       if (size < info->space_before)
-                               info->space_before -= size;
-                       else
-                               info->space_before = 0;
-               } else
-                       info->space_before -= 8; /* superblock */
+                       bmend += size;
+                       if (bmend > earliest)
+                               bmend = earliest;
+               }
+               if (sb->bblog_offset && sb->bblog_size) {
+                       unsigned long long bbend = super_offset;
+                       bbend += (int32_t)__le32_to_cpu(sb->bblog_offset);
+                       bbend += __le32_to_cpu(sb->bblog_size);
+                       if (bbend > earliest)
+                               earliest = bbend;
+               }
+               if (earliest < info->data_offset)
+                       info->space_before = info->data_offset - earliest;
+               else
+                       info->space_before = 0;
                info->space_after = misc->device_size - data_size - info->data_offset;
        }