1 files changed, 62 insertions, 9 deletions

diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 30494c5da843..9cc80b9cc8d8 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -43,6 +43,46 @@ void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
 
 }
 
+static int ext4_block_in_group(struct super_block *sb, ext4_fsblk_t block,
+                        ext4_group_t block_group)
+{
+        ext4_group_t actual_group;
+        ext4_get_group_no_and_offset(sb, block, &actual_group, 0);
+        if (actual_group == block_group)
+                return 1;
+        return 0;
+}
+
+static int ext4_group_used_meta_blocks(struct super_block *sb,
+                                ext4_group_t block_group)
+{
+        ext4_fsblk_t tmp;
+        struct ext4_sb_info *sbi = EXT4_SB(sb);
+        /* block bitmap, inode bitmap, and inode table blocks */
+        int used_blocks = sbi->s_itb_per_group + 2;
+
+        if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) {
+                struct ext4_group_desc *gdp;
+                struct buffer_head *bh;
+
+                gdp = ext4_get_group_desc(sb, block_group, &bh);
+                if (!ext4_block_in_group(sb, ext4_block_bitmap(sb, gdp),
+                                        block_group))
+                        used_blocks--;
+
+                if (!ext4_block_in_group(sb, ext4_inode_bitmap(sb, gdp),
+                                        block_group))
+                        used_blocks--;
+
+                tmp = ext4_inode_table(sb, gdp);
+                for (; tmp < ext4_inode_table(sb, gdp) +
+                                sbi->s_itb_per_group; tmp++) {
+                        if (!ext4_block_in_group(sb, tmp, block_group))
+                                used_blocks -= 1;
+                }
+        }
+        return used_blocks;
+}
 /* Initializes an uninitialized block bitmap if given, and returns the
  * number of blocks free in the group. */
 unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
@@ -105,20 +145,34 @@ unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
         free_blocks = group_blocks - bit_max;
 
         if (bh) {
-                ext4_fsblk_t start;
+                ext4_fsblk_t start, tmp;
+                int flex_bg = 0;
 
                 for (bit = 0; bit < bit_max; bit++)
                         ext4_set_bit(bit, bh->b_data);
 
                 start = ext4_group_first_block_no(sb, block_group);
 
-                /* Set bits for block and inode bitmaps, and inode table */
-                ext4_set_bit(ext4_block_bitmap(sb, gdp) - start, bh->b_data);
-                ext4_set_bit(ext4_inode_bitmap(sb, gdp) - start, bh->b_data);
-                for (bit = (ext4_inode_table(sb, gdp) - start),
-                     bit_max = bit + sbi->s_itb_per_group; bit < bit_max; bit++)
-                        ext4_set_bit(bit, bh->b_data);
+                if (EXT4_HAS_INCOMPAT_FEATURE(sb,
+                                              EXT4_FEATURE_INCOMPAT_FLEX_BG))
+                        flex_bg = 1;
 
+                /* Set bits for block and inode bitmaps, and inode table */
+                tmp = ext4_block_bitmap(sb, gdp);
+                if (!flex_bg || ext4_block_in_group(sb, tmp, block_group))
+                        ext4_set_bit(tmp - start, bh->b_data);
+
+                tmp = ext4_inode_bitmap(sb, gdp);
+                if (!flex_bg || ext4_block_in_group(sb, tmp, block_group))
+                        ext4_set_bit(tmp - start, bh->b_data);
+
+                tmp = ext4_inode_table(sb, gdp);
+                for (; tmp < ext4_inode_table(sb, gdp) +
+                                sbi->s_itb_per_group; tmp++) {
+                        if (!flex_bg ||
+                                ext4_block_in_group(sb, tmp, block_group))
+                                ext4_set_bit(tmp - start, bh->b_data);
+                }
                 /*
                  * Also if the number of blocks within the group is
                  * less than the blocksize * 8 ( which is the size
@@ -126,8 +180,7 @@ unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
                  */
                 mark_bitmap_end(group_blocks, sb->s_blocksize * 8, bh->b_data);
         }
-
-        return free_blocks - sbi->s_itb_per_group - 2;
+        return free_blocks - ext4_group_used_meta_blocks(sb, block_group);
 }