btrfs: print-tree: print more information about dir items

Currently we only print the object id component of the location key from a
dir item and the flags. We are missing the whole key, transid and the name
and data lengths. We are also ignoring the fact that we can have multiple
dir item objects encoded in a single item for a BTRFS_DIR_ITEM_KEY key, so
what we print is only for the first item.

Improve on this by iterating on all dir items and print the missing
information. This is done with the same format as in btrfs-progs, what
we miss is printing the names and data since not only that would require
some processing and escaping like in btrfs-progs, but it would also reveal
information that may be sensitive and users may not want to share that in
case that get a leaf dumped in dmesg.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Author: fdmanana

fs/btrfs/print-tree.c

@@ -257,20 +257,41 @@ static void print_inode_item(const struct extent_buffer *eb, int i)
 	print_timespec(eb, &ii->otime, "\t\totime ", "\n");
 }
 
+static void print_dir_item(const struct extent_buffer *eb, int i)
+{
+	const u32 size = btrfs_item_size(eb, i);
+	struct btrfs_dir_item *di = btrfs_item_ptr(eb, i, struct btrfs_dir_item);
+	u32 cur = 0;
+
+	while (cur < size) {
+		const u32 name_len = btrfs_dir_name_len(eb, di);
+		const u32 data_len = btrfs_dir_data_len(eb, di);
+		const u32 len = sizeof(*di) + name_len + data_len;
+		struct btrfs_key location;
+
+		btrfs_dir_item_key_to_cpu(eb, di, &location);
+		pr_info("\t\tlocation key (%llu %u %llu) type %d\n",
+			location.objectid, location.type, location.offset,
+			btrfs_dir_ftype(eb, di));
+		pr_info("\t\ttransid %llu data_len %u name_len %u\n",
+			btrfs_dir_transid(eb, di), data_len, name_len);
+		di = (struct btrfs_dir_item *)((char *)di + len);
+		cur += len;
+	}
+}
+
 void btrfs_print_leaf(const struct extent_buffer *l)
 {
 	struct btrfs_fs_info *fs_info;
 	int i;
 	u32 type, nr;
 	struct btrfs_root_item *ri;
-	struct btrfs_dir_item *di;
 	struct btrfs_block_group_item *bi;
 	struct btrfs_file_extent_item *fi;
 	struct btrfs_extent_data_ref *dref;
 	struct btrfs_shared_data_ref *sref;
 	struct btrfs_dev_extent *dev_extent;
 	struct btrfs_key key;
-	struct btrfs_key found_key;
 
 	if (!l)
 		return;
@@ -294,11 +315,7 @@ void btrfs_print_leaf(const struct extent_buffer *l)
 			print_inode_item(l, i);
 			break;
 		case BTRFS_DIR_ITEM_KEY:
-			di = btrfs_item_ptr(l, i, struct btrfs_dir_item);
-			btrfs_dir_item_key_to_cpu(l, di, &found_key);
-			pr_info("\t\tdir oid %llu flags %u\n",
-				found_key.objectid,
-				btrfs_dir_flags(l, di));
+			print_dir_item(l, i);
 			break;
 		case BTRFS_ROOT_ITEM_KEY:
 			ri = btrfs_item_ptr(l, i, struct btrfs_root_item);