ext4: convert number of blocks to clusters properly

commit 810da240 upstream.

We're using macro EXT4_B2C() to convert number of blocks to number of
clusters for bigalloc file systems.  However, we should be using
EXT4_NUM_B2C().
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
[bwh: Backported to 3.2:
 - Adjust context
 - Drop changes in ext4_setup_new_descs() and ext4_calculate_overhead()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

fs/ext4/balloc.c

@@ -571,7 +571,7 @@ ext4_fsblk_t ext4_count_free_clusters(struct super_block *sb)
 	brelse(bitmap_bh);
 	printk(KERN_DEBUG "ext4_count_free_clusters: stored = %llu"
 	       ", computed = %llu, %llu\n",
-	       EXT4_B2C(EXT4_SB(sb), ext4_free_blocks_count(es)),
+	       EXT4_NUM_B2C(EXT4_SB(sb), ext4_free_blocks_count(es)),
 	       desc_count, bitmap_count);
 	return bitmap_count;
 #else

fs/ext4/mballoc.c

@@ -3485,7 +3485,7 @@ ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
 			win = offs;
 
 		ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical -
-			EXT4_B2C(sbi, win);
+			EXT4_NUM_B2C(sbi, win);
 		BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
 		BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len);
 	}
@@ -4634,7 +4634,7 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
 			EXT4_BLOCKS_PER_GROUP(sb);
 		count -= overflow;
 	}
-	count_clusters = EXT4_B2C(sbi, count);
+	count_clusters = EXT4_NUM_B2C(sbi, count);
 	bitmap_bh = ext4_read_block_bitmap(sb, block_group);
 	if (!bitmap_bh) {
 		err = -EIO;
@@ -4865,11 +4865,11 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
 	desc->bg_checksum = ext4_group_desc_csum(sbi, block_group, desc);
 	ext4_unlock_group(sb, block_group);
 	percpu_counter_add(&sbi->s_freeclusters_counter,
-			   EXT4_B2C(sbi, blocks_freed));
+			   EXT4_NUM_B2C(sbi, blocks_freed));
 
 	if (sbi->s_log_groups_per_flex) {
 		ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
-		atomic_add(EXT4_B2C(sbi, blocks_freed),
+		atomic_add(EXT4_NUM_B2C(sbi, blocks_freed),
 			   &sbi->s_flex_groups[flex_group].free_clusters);
 	}
 

fs/ext4/resize.c

@@ -938,7 +938,7 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
 
 	/* Update the free space counts */
 	percpu_counter_add(&sbi->s_freeclusters_counter,
-			   EXT4_B2C(sbi, input->free_blocks_count));
+			   EXT4_NUM_B2C(sbi, input->free_blocks_count));
 	percpu_counter_add(&sbi->s_freeinodes_counter,
 			   EXT4_INODES_PER_GROUP(sb));
 
@@ -946,7 +946,7 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
 	    sbi->s_log_groups_per_flex) {
 		ext4_group_t flex_group;
 		flex_group = ext4_flex_group(sbi, input->group);
-		atomic_add(EXT4_B2C(sbi, input->free_blocks_count),
+		atomic_add(EXT4_NUM_B2C(sbi, input->free_blocks_count),
 			   &sbi->s_flex_groups[flex_group].free_clusters);
 		atomic_add(EXT4_INODES_PER_GROUP(sb),
 			   &sbi->s_flex_groups[flex_group].free_inodes);