2 files changed, 10 insertions, 3 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index dd4ff9c87358..54450fa1af39 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1358,13 +1358,17 @@ static int ext4_check_descriptors (struct super_block * sb)
         ext4_fsblk_t inode_table;
         struct ext4_group_desc * gdp = NULL;
         int desc_block = 0;
+        int flexbg_flag = 0;
         int i;
 
+        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
+                flexbg_flag = 1;
+
         ext4_debug ("Checking group descriptors");
 
         for (i = 0; i < sbi->s_groups_count; i++)
         {
-                if (i == sbi->s_groups_count - 1)
+                if (i == sbi->s_groups_count - 1 || flexbg_flag)
                         last_block = ext4_blocks_count(sbi->s_es) - 1;
                 else
                         last_block = first_block +
@@ -1409,7 +1413,8 @@ static int ext4_check_descriptors (struct super_block * sb)
                                    le16_to_cpu(gdp->bg_checksum));
                         return 0;
                 }
-                first_block += EXT4_BLOCKS_PER_GROUP(sb);
+                if (!flexbg_flag)
+                        first_block += EXT4_BLOCKS_PER_GROUP(sb);
                 gdp = (struct ext4_group_desc *)
                         ((__u8 *)gdp + EXT4_DESC_SIZE(sb));
         }
diff --git a/include/linux/ext4_fs.h b/include/linux/ext4_fs.h
index 722d4ef12bf3..46b304d18345 100644
--- a/include/linux/ext4_fs.h
+++ b/include/linux/ext4_fs.h
@@ -682,13 +682,15 @@ static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
 #define EXT4_FEATURE_INCOMPAT_META_BG           0x0010
 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
+#define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
 
 #define EXT4_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
 #define EXT4_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
                                          EXT4_FEATURE_INCOMPAT_META_BG| \
                                          EXT4_FEATURE_INCOMPAT_EXTENTS| \
-                                         EXT4_FEATURE_INCOMPAT_64BIT)
+                                         EXT4_FEATURE_INCOMPAT_64BIT| \
+                                         EXT4_FEATURE_INCOMPAT_FLEX_BG)
 #define EXT4_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \