With 64K sectorsize, 1G sized block group cannot span across bitmaps.
To execute test_bitmaps() function, this commit allocates
"BITS_PER_BITMAP * sectorsize + PAGE_SIZE" sized block group.
Reviewed-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Feifei Xu <xufeifei@linux.vnet.ibm.com>
Signed-off-by: David Sterba <dsterba@suse.com>
 
        test_msg("Running btrfs free space cache tests\n");
 
-       cache = btrfs_alloc_dummy_block_group(1024 * 1024 * 1024, sectorsize);
+       /*
+        * For ppc64 (with 64k page size), bytes per bitmap might be
+        * larger than 1G.  To make bitmap test available in ppc64,
+        * alloc dummy block group whose size cross bitmaps.
+        */
+       cache = btrfs_alloc_dummy_block_group(BITS_PER_BITMAP * sectorsize
+                                       + PAGE_SIZE, sectorsize);
        if (!cache) {
                test_msg("Couldn't run the tests\n");
                return 0;