Add debug-tree -e to print all allocated extents, and show-blocks to graph them

1 files changed, 117 insertions, 16 deletions

diff --git a/debug-tree.c b/debug-tree.c
index 368b8fb3..7a2d0d06 100644
--- a/debug-tree.c
+++ b/debug-tree.c
@@ -18,6 +18,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <uuid/uuid.h>
 #include "kerncompat.h"
 #include "radix-tree.h"
@@ -26,7 +27,79 @@
 #include "print-tree.h"
 #include "transaction.h"
 
-int main(int ac, char **av) {
+static int print_usage(void)
+{
+	fprintf(stderr, "usage: debug-tree [ -e ] device\n");
+	exit(1);
+}
+
+static void print_extent_leaf(struct btrfs_root *root, struct extent_buffer *l)
+{
+	int i;
+	struct btrfs_item *item;
+	struct btrfs_extent_ref *ref;
+	struct btrfs_key key;
+	static u64 last = 0;
+	static u64 last_len = 0;
+	u32 nr = btrfs_header_nritems(l);
+	u32 type;
+
+	for (i = 0 ; i < nr ; i++) {
+		item = btrfs_item_nr(l, i);
+		btrfs_item_key_to_cpu(l, &key, i);
+		type = btrfs_key_type(&key);
+		switch (type) {
+		case BTRFS_EXTENT_ITEM_KEY:
+			last_len = key.offset;
+			last = key.objectid;
+			break;
+		case BTRFS_EXTENT_REF_KEY:
+			ref = btrfs_item_ptr(l, i, struct btrfs_extent_ref);
+			printf("%llu %llu extent back ref root %llu gen %llu "
+			       "owner %llu offset %llu\n",
+			       (unsigned long long)last,
+			       (unsigned long long)last_len,
+			       (unsigned long long)btrfs_ref_root(l, ref),
+			       (unsigned long long)btrfs_ref_generation(l, ref),
+			       (unsigned long long)btrfs_ref_objectid(l, ref),
+			       (unsigned long long)btrfs_ref_offset(l, ref));
+			break;
+		};
+		fflush(stdout);
+	}
+}
+
+static void print_extents(struct btrfs_root *root, struct extent_buffer *eb)
+{
+	int i;
+	u32 nr;
+	u32 size;
+
+	if (!eb)
+		return;
+	if (btrfs_is_leaf(eb)) {
+		print_extent_leaf(root, eb);
+		return;
+	}
+	size = btrfs_level_size(root, btrfs_header_level(eb) - 1);
+	nr = btrfs_header_nritems(eb);
+	for (i = 0; i < nr; i++) {
+		struct extent_buffer *next = read_tree_block(root,
+					     btrfs_node_blockptr(eb, i),
+					     size);
+		if (btrfs_is_leaf(next) &&
+		    btrfs_header_level(eb) != 1)
+			BUG();
+		if (btrfs_header_level(next) !=
+			btrfs_header_level(eb) - 1)
+			BUG();
+		print_extents(root, next);
+		free_extent_buffer(next);
+	}
+}
+
+int main(int ac, char **av)
+{
 	struct btrfs_root *root;
 	struct btrfs_path path;
 	struct btrfs_key key;
@@ -36,20 +109,37 @@ int main(int ac, char **av) {
 	char uuidbuf[37];
 	int ret;
 	int slot;
+	int extent_only = 0;
 
-	if (ac != 2) {
-		fprintf(stderr, "usage: %s device\n", av[0]);
-		exit(1);
-	}
 	radix_tree_init();
-	root = open_ctree(av[1], 0);
+
+	while(1) {
+		int c;
+		c = getopt(ac, av, "e");
+		if (c < 0)
+			break;
+		switch(c) {
+			case 'e':
+				extent_only = 1;
+				break;
+			default:
+				print_usage();
+		}
+	}
+	ac = ac - optind;
+	if (ac != 1)
+		print_usage();
+
+	root = open_ctree(av[optind], 0);
 	if (!root) {
-		fprintf(stderr, "unable to open %s\n", av[1]);
+		fprintf(stderr, "unable to open %s\n", av[optind]);
 		exit(1);
 	}
-	printf("root tree\n");
-	btrfs_print_tree(root->fs_info->tree_root,
-			 root->fs_info->tree_root->node);
+	if (!extent_only) {
+		printf("root tree\n");
+		btrfs_print_tree(root->fs_info->tree_root,
+				 root->fs_info->tree_root->node);
+	}
 	btrfs_init_path(&path);
 	key.offset = 0;
 	key.objectid = 0;
@@ -71,6 +161,8 @@ int main(int ac, char **av) {
 		if (btrfs_key_type(&found_key) == BTRFS_ROOT_ITEM_KEY) {
 			unsigned long offset;
 			struct extent_buffer *buf;
+			int skip = extent_only;
+
 			offset = btrfs_item_ptr_offset(leaf, slot);
 			read_extent_buffer(leaf, &ri, offset, sizeof(ri));
 			buf = read_tree_block(root->fs_info->tree_root,
@@ -81,18 +173,27 @@ int main(int ac, char **av) {
 				printf("root ");
 				break;
 			case BTRFS_EXTENT_TREE_OBJECTID:
-				printf("extent tree ");
+				skip = 0;
+				if (!extent_only)
+					printf("extent tree ");
 				break;
 			}
-			printf("tree %llu %u %llu\n",
-			       (unsigned long long)found_key.objectid,
-			       found_key.type,
-			       (unsigned long long)found_key.offset);
-			btrfs_print_tree(root, buf);
+			if (!skip && !extent_only) {
+				printf("tree %llu %u %llu\n",
+				       (unsigned long long)found_key.objectid,
+				       found_key.type,
+				       (unsigned long long)found_key.offset);
+				btrfs_print_tree(root, buf);
+			} else if (extent_only && !skip) {
+				print_extents(root, buf);
+			}
 		}
 		path.slots[0]++;
 	}
 	btrfs_release_path(root, &path);
+	if (extent_only)
+		return 0;
+
 	printf("total bytes %llu\n",
 	       (unsigned long long)btrfs_super_total_bytes(&root->fs_info->super_copy));
 	printf("bytes used %llu\n",