X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=btrfs-find-root.c;h=e2d2e70c408c94ce4b4e5f6eaf3e94584b803e2d;hb=992aa558397e519d2251cdc6c4d3a9e019b240a0;hp=b48c800497189df8f46a5cd8e2ae28e8d4b5c617;hpb=51c5811583536b5c7c7e140aef9312fec28d75f0;p=platform%2Fupstream%2Fbtrfs-progs.git

diff --git a/btrfs-find-root.c b/btrfs-find-root.c
index b48c800..e2d2e70 100644
--- a/btrfs-find-root.c
+++ b/btrfs-find-root.c
@@ -16,335 +16,207 @@
  * Boston, MA 021110-1307, USA.
  */
 
-#define _XOPEN_SOURCE 500
-#define _GNU_SOURCE 1
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <fcntl.h>
 #include <sys/stat.h>
 #include <zlib.h>
+#include <getopt.h>
+
 #include "kerncompat.h"
 #include "ctree.h"
 #include "disk-io.h"
 #include "print-tree.h"
 #include "transaction.h"
 #include "list.h"
-#include "version.h"
 #include "volumes.h"
 #include "utils.h"
 #include "crc32c.h"
+#include "extent-cache.h"
+#include "find-root.h"
+#include "help.h"
 
-static u16 csum_size = 0;
-static u64 search_objectid = BTRFS_ROOT_TREE_OBJECTID;
-static u64 search_generation = 0;
-static unsigned long search_level = 0;
-
-static void usage(void)
+static void find_root_usage(void)
 {
-	fprintf(stderr, "Usage: find-roots [-o search_objectid] "
+	fprintf(stderr, "Usage: find-roots [-a] [-o search_objectid] "
 		"[ -g search_generation ] [ -l search_level ] <device>\n");
 }
 
-static int csum_block(void *buf, u32 len)
+/*
+ * Get reliable generation and level for given root.
+ *
+ * We have two sources of gen/level: superblock and tree root.
+ * superblock include the following level:
+ *   Root, chunk, log
+ * and the following generations:
+ *   Root, chunk, uuid
+ * Other gen/leven can only be read from its btrfs_tree_root if possible.
+ *
+ * Currently we only believe things from superblock.
+ */
+static void get_root_gen_and_level(u64 objectid, struct btrfs_fs_info *fs_info,
+				   u64 *ret_gen, u8 *ret_level)
 {
-	char *result;
-	u32 crc = ~(u32)0;
-	int ret = 0;
-
-	result = malloc(csum_size * sizeof(char));
-	if (!result) {
-		fprintf(stderr, "No memory\n");
-		return 1;
+	struct btrfs_super_block *super = fs_info->super_copy;
+	u64 gen = (u64)-1;
+	u8 level = (u8)-1;
+
+	switch (objectid) {
+	case BTRFS_ROOT_TREE_OBJECTID:
+		level = btrfs_super_root_level(super);
+		gen = btrfs_super_generation(super);
+		break;
+	case BTRFS_CHUNK_TREE_OBJECTID:
+		level = btrfs_super_chunk_root_level(super);
+		gen = btrfs_super_chunk_root_generation(super);
+		break;
+	case BTRFS_TREE_LOG_OBJECTID:
+		level = btrfs_super_log_root_level(super);
+		gen = btrfs_super_log_root_transid(super);
+		break;
+	case BTRFS_UUID_TREE_OBJECTID:
+		gen = btrfs_super_uuid_tree_generation(super);
+		break;
 	}
-
-	len -= BTRFS_CSUM_SIZE;
-	crc = crc32c(crc, buf + BTRFS_CSUM_SIZE, len);
-	btrfs_csum_final(crc, result);
-
-	if (memcmp(buf, result, csum_size))
-		ret = 1;
-	free(result);
-	return ret;
-}
-
-static struct btrfs_root *open_ctree_broken(int fd, const char *device)
-{
-	struct btrfs_fs_info *fs_info;
-	struct btrfs_super_block *disk_super;
-	struct btrfs_fs_devices *fs_devices = NULL;
-	struct extent_buffer *eb;
-	int ret;
-
-	fs_info = btrfs_new_fs_info(0, BTRFS_SUPER_INFO_OFFSET);
-	if (!fs_info) {
-		fprintf(stderr, "Failed to allocate memory for fs_info\n");
-		return NULL;
+	if (gen != (u64)-1) {
+		printf("Superblock thinks the generation is %llu\n", gen);
+		if (ret_gen)
+			*ret_gen = gen;
+	} else {
+		printf("Superblock doesn't contain generation info for root %llu\n",
+		       objectid);
 	}
-
-	ret = btrfs_scan_fs_devices(fd, device, &fs_devices, 0);
-	if (ret)
-		goto out;
-
-	fs_info->fs_devices = fs_devices;
-
-	ret = btrfs_open_devices(fs_devices, O_RDONLY);
-	if (ret)
-		goto out_devices;
-
-	disk_super = fs_info->super_copy;
-	ret = btrfs_read_dev_super(fs_devices->latest_bdev,
-				   disk_super, fs_info->super_bytenr);
-	if (ret) {
-		printk("No valid btrfs found\n");
-		goto out_devices;
+	if (level != (u8)-1) {
+		printf("Superblock thinks the level is %u\n", level);
+		if (ret_level)
+			*ret_level = level;
+	} else {
+		printf("Superblock doesn't contain the level info for root %llu\n",
+		       objectid);
 	}
-
-	memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE);
-
-	ret = btrfs_check_fs_compatibility(disk_super, 0);
-	if (ret)
-		goto out_devices;
-
-	ret = btrfs_setup_chunk_tree_and_device_map(fs_info);
-	if (ret)
-		goto out_chunk;
-
-	eb = fs_info->chunk_root->node;
-	read_extent_buffer(eb, fs_info->chunk_tree_uuid,
-			   (unsigned long)btrfs_header_chunk_tree_uuid(eb),
-			   BTRFS_UUID_SIZE);
-
-	return fs_info->chunk_root;
-out_chunk:
-	free_extent_buffer(fs_info->chunk_root->node);
-	btrfs_cleanup_all_caches(fs_info);
-out_devices:
-	btrfs_close_devices(fs_info->fs_devices);
-out:
-	btrfs_free_fs_info(fs_info);
-	return NULL;
 }
 
-static int search_iobuf(struct btrfs_root *root, void *iobuf,
-			size_t iobuf_size, off_t offset)
+static void print_one_result(struct cache_extent *tree_block,
+			     u8 level, u64 generation,
+			     struct btrfs_find_root_filter *filter)
 {
-	u64 gen = search_generation;
-	u64 objectid = search_objectid;
-	u32 size = btrfs_super_nodesize(root->fs_info->super_copy);
-	u8 level = search_level;
-	size_t block_off = 0;
-
-	while (block_off < iobuf_size) {
-		void *block = iobuf + block_off;
-		struct btrfs_header *header = block;
-		u64 h_byte, h_level, h_gen, h_owner;
-
-//		printf("searching %Lu\n", offset + block_off);
-		h_byte = btrfs_stack_header_bytenr(header);
-		h_owner = btrfs_stack_header_owner(header);
-		h_level = header->level;
-		h_gen = btrfs_stack_header_generation(header);
-
-		if (h_owner != objectid)
-			goto next;
-		if (h_byte != (offset + block_off))
-			goto next;
-		if (h_level < level)
-			goto next;
-		level = h_level;
-		if (csum_block(block, size)) {
-			fprintf(stderr, "Well block %Lu seems good, "
-				"but the csum doesn't match\n",
-				h_byte);
-			goto next;
-		}
-		if (h_gen != gen) {
-			fprintf(stderr, "Well block %Lu seems great, "
-				"but generation doesn't match, "
-				"have=%Lu, want=%Lu level %Lu\n", h_byte,
-				h_gen, gen, h_level);
-			goto next;
-		}
-		printf("Found tree root at %Lu gen %Lu level %Lu\n", h_byte,
-		       h_gen, h_level);
-		return 0;
-next:
-		block_off += size;
-	}
-
-	return 1;
+	int unsure = 0;
+
+	if (filter->match_gen == (u64)-1 || filter->match_level == (u8)-1)
+		unsure = 1;
+	printf("Well block %llu(gen: %llu level: %u) seems good, ",
+	       tree_block->start, generation, level);
+	if (unsure)
+		printf("but we are unsure about the correct generation/level\n");
+	else if (level == filter->match_level &&
+		 generation == filter->match_gen)
+		printf("and it matches superblock\n");
+	else
+		printf("but generation/level doesn't match, want gen: %llu level: %u\n",
+		       filter->match_gen, filter->match_level);
 }
 
-static int read_physical(struct btrfs_root *root, int fd, u64 offset,
-			 u64 bytenr, u64 len)
+static void print_find_root_result(struct cache_tree *result,
+				   struct btrfs_find_root_filter *filter)
 {
-	char *iobuf = malloc(len);
-	ssize_t done;
-	size_t total_read = 0;
-	int ret = 1;
-
-	if (!iobuf) {
-		fprintf(stderr, "No memory\n");
-		return -1;
-	}
-
-	while (total_read < len) {
-		done = pread64(fd, iobuf + total_read, len - total_read,
-			       bytenr + total_read);
-		if (done < 0) {
-			fprintf(stderr, "Failed to read: %s\n",
-				strerror(errno));
-			ret = -1;
-			goto out;
-		}
-		total_read += done;
+	struct btrfs_find_root_gen_cache *gen_cache;
+	struct cache_extent *cache;
+	struct cache_extent *tree_block;
+	u64 generation = 0;
+	u8 level = 0;
+
+	for (cache = last_cache_extent(result);
+	     cache; cache = prev_cache_extent(cache)) {
+		gen_cache = container_of(cache,
+				struct btrfs_find_root_gen_cache, cache);
+		level = gen_cache->highest_level;
+		generation = cache->start;
+		/* For exact found one, skip it as it's output before */
+		if (level == filter->match_level &&
+		    generation == filter->match_gen &&
+		    !filter->search_all)
+			continue;
+		for (tree_block = last_cache_extent(&gen_cache->eb_tree);
+		     tree_block; tree_block = prev_cache_extent(tree_block))
+			print_one_result(tree_block, level, generation, filter);
 	}
-
-	ret = search_iobuf(root, iobuf, total_read, offset);
-out:
-	free(iobuf);
-	return ret;
 }
 
-static int find_root(struct btrfs_root *root)
+int main(int argc, char **argv)
 {
-	struct btrfs_multi_bio *multi = NULL;
-	struct btrfs_device *device;
-	u64 metadata_offset = 0, metadata_size = 0;
-	off_t offset = 0;
-	off_t bytenr;
-	int fd;
-	int err;
-	int ret = 1;
-
-	printf("Super think's the tree root is at %Lu, chunk root %Lu\n",
-	       btrfs_super_root(root->fs_info->super_copy),
-	       btrfs_super_chunk_root(root->fs_info->super_copy));
-
-	err = btrfs_next_metadata(&root->fs_info->mapping_tree,
-				  &metadata_offset, &metadata_size);
-	if (err)
-		return ret;
+	struct btrfs_fs_info *fs_info;
+	struct btrfs_find_root_filter filter = {0};
+	struct cache_tree result;
+	struct cache_extent *found;
+	int ret;
 
-	offset = metadata_offset;
+	/* Default to search root tree */
+	filter.objectid = BTRFS_ROOT_TREE_OBJECTID;
+	filter.match_gen = (u64)-1;
+	filter.match_level = (u8)-1;
 	while (1) {
-		u64 map_length = 4096;
-		u64 type;
+		static const struct option long_options[] = {
+			{ "help", no_argument, NULL, GETOPT_VAL_HELP},
+			{ NULL, 0, NULL, 0 }
+		};
+		int c = getopt_long(argc, argv, "al:o:g:", long_options, NULL);
 
-		if (offset >
-		    btrfs_super_total_bytes(root->fs_info->super_copy)) {
-			printf("Went past the fs size, exiting");
+		if (c < 0)
 			break;
-		}
-		if (offset >= (metadata_offset + metadata_size)) {
-			err = btrfs_next_metadata(&root->fs_info->mapping_tree,
-						  &metadata_offset,
-						  &metadata_size);
-			if (err) {
-				printf("No more metdata to scan, exiting\n");
-				break;
-			}
-			offset = metadata_offset;
-		}
-		err = __btrfs_map_block(&root->fs_info->mapping_tree, READ,
-				      offset, &map_length, &type,
-				      &multi, 0, NULL);
-		if (err) {
-			offset += map_length;
-			continue;
-		}
 
-		if (!(type & BTRFS_BLOCK_GROUP_METADATA)) {
-			offset += map_length;
-			kfree(multi);
-			continue;
-		}
-
-		device = multi->stripes[0].dev;
-		fd = device->fd;
-		bytenr = multi->stripes[0].physical;
-		kfree(multi);
-
-		err = read_physical(root, fd, offset, bytenr, map_length);
-		if (!err) {
-			ret = 0;
+		switch (c) {
+		case 'a':
+			filter.search_all = 1;
 			break;
-		} else if (err < 0) {
-			ret = err;
+		case 'o':
+			filter.objectid = arg_strtou64(optarg);
 			break;
-		}
-		offset += map_length;
-	}
-	return ret;
-}
-
-int main(int argc, char **argv)
-{
-	struct btrfs_root *root;
-	int dev_fd;
-	int opt;
-	int ret;
-
-	while ((opt = getopt(argc, argv, "l:o:g:")) != -1) {
-		switch(opt) {
-			errno = 0;
-			case 'o':
-				search_objectid = (u64)strtoll(optarg, NULL,
-							       10);
-				if (errno) {
-					fprintf(stderr, "Error parsing "
-						"objectid\n");
-					exit(1);
-				}
-				break;
-			case 'g':
-				search_generation = (u64)strtoll(optarg, NULL,
-							       10);
-				if (errno) {
-					fprintf(stderr, "Error parsing "
-						"generation\n");
-					exit(1);
-				}
-				break;
-			case 'l':
-				search_level = strtol(optarg, NULL, 10);
-				if (errno) {
-					fprintf(stderr, "Error parsing "
-						"level\n");
-					exit(1);
-				}
-				break;
-			default:
-				usage();
-				exit(1);
+		case 'g':
+			filter.generation = arg_strtou64(optarg);
+			break;
+		case 'l':
+			filter.level = arg_strtou64(optarg);
+			break;
+		case GETOPT_VAL_HELP:
+		default:
+			find_root_usage();
+			exit(c != GETOPT_VAL_HELP);
 		}
 	}
 
-	if (optind >= argc) {
-		usage();
+	set_argv0(argv);
+	if (check_argc_min(argc - optind, 1)) {
+		find_root_usage();
 		exit(1);
 	}
 
-	dev_fd = open(argv[optind], O_RDONLY);
-	if (dev_fd < 0) {
-		fprintf(stderr, "Failed to open device %s\n", argv[optind]);
+	fs_info = open_ctree_fs_info(argv[optind], 0, 0, 0,
+			OPEN_CTREE_CHUNK_ROOT_ONLY |
+			OPEN_CTREE_IGNORE_CHUNK_TREE_ERROR);
+	if (!fs_info) {
+		error("open ctree failed");
 		exit(1);
 	}
-
-	root = open_ctree_broken(dev_fd, argv[optind]);
-	close(dev_fd);
-
-	if (!root) {
-		fprintf(stderr, "Open ctree failed\n");
-		exit(1);
+	cache_tree_init(&result);
+
+	get_root_gen_and_level(filter.objectid, fs_info,
+			       &filter.match_gen, &filter.match_level);
+	ret = btrfs_find_root_search(fs_info, &filter, &result, &found);
+	if (ret < 0) {
+		fprintf(stderr, "Fail to search the tree root: %s\n",
+			strerror(-ret));
+		goto out;
 	}
-
-	if (search_generation == 0)
-		search_generation = btrfs_super_generation(root->fs_info->super_copy);
-
-	csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
-	ret = find_root(root);
-	close_ctree(root);
+	if (ret > 0) {
+		printf("Found tree root at %llu gen %llu level %u\n",
+		       found->start, filter.match_gen, filter.match_level);
+		ret = 0;
+	}
+	print_find_root_result(&result, &filter);
+out:
+	btrfs_find_root_free(&result);
+	close_ctree_fs_info(fs_info);
+	btrfs_close_all_devices();
 	return ret;
 }