Merge branch 'baserock/tiagogomes/btrfs2' into baserock/morphbaserock/morph

1 files changed, 434 insertions, 0 deletions

diff --git a/btrfs-find-root.c b/btrfs-find-root.c
new file mode 100644
index 0000000..810d835
--- /dev/null
+++ b/btrfs-find-root.c
@@ -0,0 +1,434 @@
+/*
+ * Copyright (C) 2011 Red Hat.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * 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 "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"
+
+static u16 csum_size = 0;
+static u64 search_objectid = BTRFS_ROOT_TREE_OBJECTID;
+
+static void usage()
+{
+	fprintf(stderr, "Usage: find-roots [-o search_objectid] <device>\n");
+}
+
+int csum_block(void *buf, u32 len)
+{
+	char *result;
+	u32 crc = ~(u32)0;
+	int ret = 0;
+
+	result = malloc(csum_size * sizeof(char));
+	if (!result) {
+		fprintf(stderr, "No memory\n");
+		return 1;
+	}
+
+	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 int close_all_devices(struct btrfs_fs_info *fs_info)
+{
+	struct list_head *list;
+	struct list_head *next;
+	struct btrfs_device *device;
+
+	return 0;
+
+	list = &fs_info->fs_devices->devices;
+	list_for_each(next, list) {
+		device = list_entry(next, struct btrfs_device, dev_list);
+		close(device->fd);
+	}
+	return 0;
+}
+
+static struct btrfs_root *open_ctree_broken(int fd, const char *device)
+{
+	u32 sectorsize;
+	u32 nodesize;
+	u32 leafsize;
+	u32 blocksize;
+	u32 stripesize;
+	u64 generation;
+	struct btrfs_root *tree_root = malloc(sizeof(struct btrfs_root));
+	struct btrfs_root *extent_root = malloc(sizeof(struct btrfs_root));
+	struct btrfs_root *chunk_root = malloc(sizeof(struct btrfs_root));
+	struct btrfs_root *dev_root = malloc(sizeof(struct btrfs_root));
+	struct btrfs_root *csum_root = malloc(sizeof(struct btrfs_root));
+	struct btrfs_fs_info *fs_info = malloc(sizeof(*fs_info));
+	int ret;
+	struct btrfs_super_block *disk_super;
+	struct btrfs_fs_devices *fs_devices = NULL;
+	u64 total_devs;
+	u64 features;
+
+	ret = btrfs_scan_one_device(fd, device, &fs_devices,
+				    &total_devs, BTRFS_SUPER_INFO_OFFSET);
+
+	if (ret) {
+		fprintf(stderr, "No valid Btrfs found on %s\n", device);
+		goto out;
+	}
+
+	if (total_devs != 1) {
+		ret = btrfs_scan_for_fsid(fs_devices, total_devs, 1);
+		if (ret)
+			goto out;
+	}
+
+	memset(fs_info, 0, sizeof(*fs_info));
+	fs_info->super_copy = calloc(1, BTRFS_SUPER_INFO_SIZE);
+	fs_info->tree_root = tree_root;
+	fs_info->extent_root = extent_root;
+	fs_info->chunk_root = chunk_root;
+	fs_info->dev_root = dev_root;
+	fs_info->csum_root = csum_root;
+
+	fs_info->readonly = 1;
+
+	extent_io_tree_init(&fs_info->extent_cache);
+	extent_io_tree_init(&fs_info->free_space_cache);
+	extent_io_tree_init(&fs_info->block_group_cache);
+	extent_io_tree_init(&fs_info->pinned_extents);
+	extent_io_tree_init(&fs_info->pending_del);
+	extent_io_tree_init(&fs_info->extent_ins);
+	cache_tree_init(&fs_info->fs_root_cache);
+
+	cache_tree_init(&fs_info->mapping_tree.cache_tree);
+
+	mutex_init(&fs_info->fs_mutex);
+	fs_info->fs_devices = fs_devices;
+	INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
+	INIT_LIST_HEAD(&fs_info->space_info);
+
+	__setup_root(4096, 4096, 4096, 4096, tree_root,
+		     fs_info, BTRFS_ROOT_TREE_OBJECTID);
+
+	ret = btrfs_open_devices(fs_devices, O_RDONLY);
+	if (ret)
+		goto out_cleanup;
+
+	fs_info->super_bytenr = BTRFS_SUPER_INFO_OFFSET;
+	disk_super = fs_info->super_copy;
+	ret = btrfs_read_dev_super(fs_devices->latest_bdev,
+				   disk_super, BTRFS_SUPER_INFO_OFFSET);
+	if (ret) {
+		printk("No valid btrfs found\n");
+		goto out_devices;
+	}
+
+	memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE);
+
+
+	features = btrfs_super_incompat_flags(disk_super) &
+		   ~BTRFS_FEATURE_INCOMPAT_SUPP;
+	if (features) {
+		printk("couldn't open because of unsupported "
+		       "option features (%Lx).\n", features);
+		goto out_devices;
+	}
+
+	features = btrfs_super_incompat_flags(disk_super);
+	if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
+		features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
+		btrfs_set_super_incompat_flags(disk_super, features);
+	}
+
+	nodesize = btrfs_super_nodesize(disk_super);
+	leafsize = btrfs_super_leafsize(disk_super);
+	sectorsize = btrfs_super_sectorsize(disk_super);
+	stripesize = btrfs_super_stripesize(disk_super);
+	tree_root->nodesize = nodesize;
+	tree_root->leafsize = leafsize;
+	tree_root->sectorsize = sectorsize;
+	tree_root->stripesize = stripesize;
+
+	ret = btrfs_read_sys_array(tree_root);
+	if (ret)
+		goto out_devices;
+	blocksize = btrfs_level_size(tree_root,
+				     btrfs_super_chunk_root_level(disk_super));
+	generation = btrfs_super_chunk_root_generation(disk_super);
+
+	__setup_root(nodesize, leafsize, sectorsize, stripesize,
+		     chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
+
+	chunk_root->node = read_tree_block(chunk_root,
+					   btrfs_super_chunk_root(disk_super),
+					   blocksize, generation);
+	if (!chunk_root->node) {
+		printk("Couldn't read chunk root\n");
+		goto out_devices;
+	}
+
+	read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
+	         (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
+		 BTRFS_UUID_SIZE);
+
+	if (!(btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_METADUMP)) {
+		ret = btrfs_read_chunk_tree(chunk_root);
+		if (ret)
+			goto out_chunk;
+	}
+
+	return fs_info->chunk_root;
+out_chunk:
+	free_extent_buffer(fs_info->chunk_root->node);
+out_devices:
+	close_all_devices(fs_info);
+out_cleanup:
+	extent_io_tree_cleanup(&fs_info->extent_cache);
+	extent_io_tree_cleanup(&fs_info->free_space_cache);
+	extent_io_tree_cleanup(&fs_info->block_group_cache);
+	extent_io_tree_cleanup(&fs_info->pinned_extents);
+	extent_io_tree_cleanup(&fs_info->pending_del);
+	extent_io_tree_cleanup(&fs_info->extent_ins);
+out:
+	free(tree_root);
+	free(extent_root);
+	free(chunk_root);
+	free(dev_root);
+	free(csum_root);
+	free(fs_info);
+	return NULL;
+}
+
+static int search_iobuf(struct btrfs_root *root, void *iobuf,
+			size_t iobuf_size, off_t offset)
+{
+	u64 gen = btrfs_super_generation(root->fs_info->super_copy);
+	u64 objectid = search_objectid;
+	u32 size = btrfs_super_nodesize(root->fs_info->super_copy);
+	u8 level = root->fs_info->super_copy->root_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 = le64_to_cpu(header->bytenr);
+		h_owner = le64_to_cpu(header->owner);
+		h_level = header->level;
+		h_gen = le64_to_cpu(header->generation);
+
+		if (h_owner != objectid)
+			goto next;
+		if (h_byte != (offset + block_off))
+			goto next;
+		if (h_level != level)
+			goto next;
+		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\n", h_byte, h_gen,
+				gen);
+			goto next;
+		}
+		printf("Found tree root at %Lu\n", h_byte);
+		return 0;
+next:
+		block_off += size;
+	}
+
+	return 1;
+}
+
+static int read_physical(struct btrfs_root *root, int fd, u64 offset,
+			 u64 bytenr, u64 len)
+{
+	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;
+	}
+
+	ret = search_iobuf(root, iobuf, total_read, offset);
+out:
+	free(iobuf);
+	return ret;
+}
+
+static int find_root(struct btrfs_root *root)
+{
+	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;
+
+	offset = metadata_offset;
+	while (1) {
+		u64 map_length = 4096;
+		u64 type;
+
+		if (offset >
+		    btrfs_super_total_bytes(root->fs_info->super_copy)) {
+			printf("Went past the fs size, exiting");
+			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;
+			break;
+		} else if (err < 0) {
+			ret = err;
+			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, "o:")) != -1) {
+		switch(opt) {
+			case 'o':
+				errno = 0;
+				search_objectid = (u64)strtoll(optarg, NULL,
+							       10);
+				if (errno) {
+					fprintf(stderr, "Error parsing "
+						"objectid\n");
+					exit(1);
+				}
+				break;
+			default:
+				usage();
+				exit(1);
+		}
+	}
+
+	if (optind >= argc) {
+		usage();
+		exit(1);
+	}
+
+	dev_fd = open(argv[optind], O_RDONLY);
+	if (dev_fd < 0) {
+		fprintf(stderr, "Failed to open device %s\n", argv[optind]);
+		exit(1);
+	}
+
+	root = open_ctree_broken(dev_fd, argv[optind]);
+	close(dev_fd);
+
+	if (!root) {
+		fprintf(stderr, "Open ctree failed\n");
+		exit(1);
+	}
+
+	csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
+	ret = find_root(root);
+	close_ctree(root);
+	return ret;
+}