Btrfs: fix check-integrity to look at the referenced data properly

We were looking at file_extent_num_bytes unconditionally when looking at
referenced data bytes, but this isn't correct for compression.  Fix this by
checking the compression of the file extent we are and setting num_bytes to
disk_num_bytes in the case of compression so that we are marking the proper
bytes as referenced.  This fixes check_int_data freaking out when running
btrfs/004.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <clm@fb.com>

fs/btrfs/check-integrity.c

@@ -1456,10 +1456,14 @@ static int btrfsic_handle_extent_data(
 	btrfsic_read_from_block_data(block_ctx, &file_extent_item,
 				     file_extent_item_offset,
 				     sizeof(struct btrfs_file_extent_item));
-	next_bytenr = btrfs_stack_file_extent_disk_bytenr(&file_extent_item) +
-		      btrfs_stack_file_extent_offset(&file_extent_item);
-	generation = btrfs_stack_file_extent_generation(&file_extent_item);
-	num_bytes = btrfs_stack_file_extent_num_bytes(&file_extent_item);
+	next_bytenr = btrfs_stack_file_extent_disk_bytenr(&file_extent_item);
+	if (btrfs_stack_file_extent_compression(&file_extent_item) ==
+	    BTRFS_COMPRESS_NONE) {
+		next_bytenr += btrfs_stack_file_extent_offset(&file_extent_item);
+		num_bytes = btrfs_stack_file_extent_num_bytes(&file_extent_item);
+	} else {
+		num_bytes = btrfs_stack_file_extent_disk_num_bytes(&file_extent_item);
+	}
 	generation = btrfs_stack_file_extent_generation(&file_extent_item);
 
 	if (state->print_mask & BTRFSIC_PRINT_MASK_VERY_VERBOSE)

fs/btrfs/ctree.h

@@ -2927,6 +2927,10 @@ BTRFS_SETGET_STACK_FUNCS(stack_file_extent_generation,
 			 struct btrfs_file_extent_item, generation, 64);
 BTRFS_SETGET_STACK_FUNCS(stack_file_extent_num_bytes,
 			 struct btrfs_file_extent_item, num_bytes, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_file_extent_disk_num_bytes,
+			 struct btrfs_file_extent_item, disk_num_bytes, 64);
+BTRFS_SETGET_STACK_FUNCS(stack_file_extent_compression,
+			 struct btrfs_file_extent_item, compression, 8);
 
 static inline unsigned long
 btrfs_file_extent_inline_start(struct btrfs_file_extent_item *e)