ext4: Fix accounting of reserved metadata blocks

Commit 0637c6f4 had a typo which caused the reserved metadata blocks to
not be released correctly.   Fix this.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

fs/ext4/inode.c

@@ -1076,9 +1076,9 @@ static void ext4_da_update_reserve_space(struct inode *inode, int used)
 		 * only when we have written all of the delayed
 		 * allocation blocks.
 		 */
-		mdb_free = ei->i_allocated_meta_blocks;
+		mdb_free = ei->i_reserved_meta_blocks;
+		ei->i_reserved_meta_blocks = 0;
 		percpu_counter_sub(&sbi->s_dirtyblocks_counter, mdb_free);
-		ei->i_allocated_meta_blocks = 0;
 	}
 	spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
 
@@ -1889,8 +1889,8 @@ static void ext4_da_release_space(struct inode *inode, int to_free)
 		 * only when we have written all of the delayed
 		 * allocation blocks.
 		 */
-		to_free += ei->i_allocated_meta_blocks;
-		ei->i_allocated_meta_blocks = 0;
+		to_free += ei->i_reserved_meta_blocks;
+		ei->i_reserved_meta_blocks = 0;
 	}
 
 	/* update fs dirty blocks counter */