Ejemplo n.º 1
0
struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
				     u32 blocksize, u64 parent_transid)
{
	int ret;
	struct extent_buffer *eb;
	u64 best_transid = 0;
	int mirror_num = 0;
	int good_mirror = 0;
	int num_copies;
	int ignore = 0;

	eb = btrfs_find_create_tree_block(root, bytenr, blocksize);
	if (!eb)
		return NULL;

	if (btrfs_buffer_uptodate(eb, parent_transid))
		return eb;

	while (1) {
		ret = read_whole_eb(root->fs_info, eb, mirror_num);
		if (ret == 0 && check_tree_block(root, eb) == 0 &&
		    csum_tree_block(root, eb, 1) == 0 &&
		    verify_parent_transid(eb->tree, eb, parent_transid, ignore)
		    == 0) {
			btrfs_set_buffer_uptodate(eb);
			return eb;
		}
		if (ignore) {
			if (check_tree_block(root, eb))
				printk("read block failed check_tree_block\n");
			else
				printk("Csum didn't match\n");
			break;
		}
		num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
					      eb->start, eb->len);
		if (num_copies == 1) {
			ignore = 1;
			continue;
		}
		if (btrfs_header_generation(eb) > best_transid) {
			best_transid = btrfs_header_generation(eb);
			good_mirror = mirror_num;
		}
		mirror_num++;
		if (mirror_num > num_copies) {
			mirror_num = good_mirror;
			ignore = 1;
			continue;
		}
	}
	free_extent_buffer(eb);
	return NULL;
}
Ejemplo n.º 2
0
struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
				     u32 blocksize, u64 parent_transid)
{
	int ret;
	int dev_nr;
	struct extent_buffer *eb;
	u64 length;
	struct btrfs_multi_bio *multi = NULL;
	struct btrfs_device *device;
	int mirror_num = 0;
	int num_copies;

	eb = btrfs_find_create_tree_block(root, bytenr, blocksize);
	if (!eb)
		return NULL;

	if (btrfs_buffer_uptodate(eb, parent_transid))
		return eb;

	dev_nr = 0;
	length = blocksize;
	while (1) {
		ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
				      eb->start, &length, &multi, mirror_num);
		BUG_ON(ret);
		device = multi->stripes[0].dev;
		eb->fd = device->fd;
		device->total_ios++;
		eb->dev_bytenr = multi->stripes[0].physical;
		kfree(multi);
		ret = read_extent_from_disk(eb);
		if (ret == 0 && check_tree_block(root, eb) == 0 &&
		    csum_tree_block(root, eb, 1) == 0 &&
		    verify_parent_transid(eb->tree, eb, parent_transid) == 0) {
			btrfs_set_buffer_uptodate(eb);
			return eb;
		}
		num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
					      eb->start, eb->len);
		if (num_copies == 1) {
			break;
		}
		mirror_num++;
		if (mirror_num > num_copies) {
			break;
		}
	}
	free_extent_buffer(eb);
	return NULL;
}
Ejemplo n.º 3
0
/*
 * Logical and len is the exact value of a extent.
 * And offset is the offset inside the extent. It's only used for case
 * where user only want to print part of the extent.
 *
 * Caller *MUST* ensure the range [logical,logical+len) are in one extent.
 * Or we can encounter the following case, causing a -ENOENT error:
 * |<-----given parameter------>|
 *		|<------ Extent A ----->|
 */
static int print_mapping_info(struct btrfs_fs_info *fs_info, u64 logical,
			      u64 len)
{
	int num_copies;
	int mirror_num;
	int ret = 0;

	num_copies = btrfs_num_copies(&fs_info->mapping_tree, logical, len);
	for (mirror_num = 1; mirror_num <= num_copies; mirror_num++) {
		ret = __print_mapping_info(fs_info, logical, len, mirror_num);
		if (ret < 0)
			return ret;
	}
	return ret;
}
struct extent_buffer *debug_read_block(struct btrfs_root *root, u64 bytenr,
				     u32 blocksize, int copy)
{
	int ret;
	struct extent_buffer *eb;
	u64 length;
	struct btrfs_multi_bio *multi = NULL;
	struct btrfs_device *device;
	int num_copies;
	int mirror_num = 1;

	eb = btrfs_find_create_tree_block(root, bytenr, blocksize);
	if (!eb)
		return NULL;

	length = blocksize;
	while (1) {
		ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
				      eb->start, &length, &multi, mirror_num);
		BUG_ON(ret);
		device = multi->stripes[0].dev;
		eb->fd = device->fd;
		device->total_ios++;
		eb->dev_bytenr = multi->stripes[0].physical;

		fprintf(info_file, "mirror %d logical %Lu physical %Lu "
			"device %s\n", mirror_num, (unsigned long long)bytenr,
			(unsigned long long)eb->dev_bytenr, device->name);
		kfree(multi);

		if (!copy || mirror_num == copy)
			ret = read_extent_from_disk(eb);

		num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
					      eb->start, eb->len);
		if (num_copies == 1)
			break;

		mirror_num++;
		if (mirror_num > num_copies)
			break;
	}
	return eb;
}
Ejemplo n.º 5
0
struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
				     u32 blocksize, u64 parent_transid)
{
	int ret;
	struct extent_buffer *eb;
	u64 length;
	u64 best_transid = 0;
	struct btrfs_multi_bio *multi = NULL;
	struct btrfs_device *device;
	int mirror_num = 0;
	int good_mirror = 0;
	int num_copies;
	int ignore = 0;

	eb = btrfs_find_create_tree_block(root, bytenr, blocksize);
	if (!eb)
		return NULL;

	if (btrfs_buffer_uptodate(eb, parent_transid))
		return eb;

	length = blocksize;
	while (1) {
		ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
				      eb->start, &length, &multi, mirror_num);
		if (ret) {
			printk("Couldn't map the block %Lu\n", bytenr);
			break;
		}
		device = multi->stripes[0].dev;
		eb->fd = device->fd;
		device->total_ios++;
		eb->dev_bytenr = multi->stripes[0].physical;
		kfree(multi);
		ret = read_extent_from_disk(eb);

		if (ret == 0 && check_tree_block(root, eb) == 0 &&
		    csum_tree_block(root, eb, 1) == 0 &&
		    verify_parent_transid(eb->tree, eb, parent_transid, ignore)
		    == 0) {
			btrfs_set_buffer_uptodate(eb);
			return eb;
		}
		if (ignore) {
			if (check_tree_block(root, eb))
				printk("read block failed check_tree_block\n");
			else
				printk("Csum didn't match\n");
			break;
		}
		num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
					      eb->start, eb->len);
		if (num_copies == 1) {
			ignore = 1;
			continue;
		}
		if (btrfs_header_generation(eb) > best_transid) {
			best_transid = btrfs_header_generation(eb);
			good_mirror = mirror_num;
		}
		mirror_num++;
		if (mirror_num > num_copies) {
			mirror_num = good_mirror;
			ignore = 1;
			continue;
		}
	}
	free_extent_buffer(eb);
	return NULL;
}
Ejemplo n.º 6
0
static int copy_one_extent(struct btrfs_root *root, int fd,
			   struct extent_buffer *leaf,
			   struct btrfs_file_extent_item *fi, u64 pos)
{
	struct btrfs_multi_bio *multi = NULL;
	struct btrfs_device *device;
	char *inbuf, *outbuf = NULL;
	ssize_t done, total = 0;
	u64 bytenr;
	u64 ram_size;
	u64 disk_size;
	u64 num_bytes;
	u64 length;
	u64 size_left;
	u64 dev_bytenr;
	u64 offset;
	u64 count = 0;
	int compress;
	int ret;
	int dev_fd;
	int mirror_num = 1;
	int num_copies;

	compress = btrfs_file_extent_compression(leaf, fi);
	bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
	disk_size = btrfs_file_extent_disk_num_bytes(leaf, fi);
	ram_size = btrfs_file_extent_ram_bytes(leaf, fi);
	offset = btrfs_file_extent_offset(leaf, fi);
	num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
	size_left = disk_size;
	if (compress == BTRFS_COMPRESS_NONE)
		bytenr += offset;

	if (verbose && offset)
		printf("offset is %Lu\n", offset);
	/* we found a hole */
	if (disk_size == 0)
		return 0;

	inbuf = malloc(size_left);
	if (!inbuf) {
		fprintf(stderr, "No memory\n");
		return -ENOMEM;
	}

	if (compress != BTRFS_COMPRESS_NONE) {
		outbuf = calloc(1, ram_size);
		if (!outbuf) {
			fprintf(stderr, "No memory\n");
			free(inbuf);
			return -ENOMEM;
		}
	}
again:
	length = size_left;
	ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
			      bytenr, &length, &multi, mirror_num, NULL);
	if (ret) {
		fprintf(stderr, "Error mapping block %d\n", ret);
		goto out;
	}
	device = multi->stripes[0].dev;
	dev_fd = device->fd;
	device->total_ios++;
	dev_bytenr = multi->stripes[0].physical;
	kfree(multi);

	if (size_left < length)
		length = size_left;

	done = pread(dev_fd, inbuf+count, length, dev_bytenr);
	/* Need both checks, or we miss negative values due to u64 conversion */
	if (done < 0 || done < length) {
		num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
					      bytenr, length);
		mirror_num++;
		/* mirror_num is 1-indexed, so num_copies is a valid mirror. */
		if (mirror_num > num_copies) {
			ret = -1;
			fprintf(stderr, "Exhausted mirrors trying to read\n");
			goto out;
		}
		fprintf(stderr, "Trying another mirror\n");
		goto again;
	}

	mirror_num = 1;
	size_left -= length;
	count += length;
	bytenr += length;
	if (size_left)
		goto again;

	if (compress == BTRFS_COMPRESS_NONE) {
		while (total < num_bytes) {
			done = pwrite(fd, inbuf+total, num_bytes-total,
				      pos+total);
			if (done < 0) {
				ret = -1;
				fprintf(stderr, "Error writing: %d %s\n", errno, strerror(errno));
				goto out;
			}
			total += done;
		}
		ret = 0;
		goto out;
	}

	ret = decompress(inbuf, outbuf, disk_size, &ram_size, compress);
	if (ret) {
		num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
					      bytenr, length);
		mirror_num++;
		if (mirror_num >= num_copies) {
			ret = -1;
			goto out;
		}
		fprintf(stderr, "Trying another mirror\n");
		goto again;
	}

	while (total < num_bytes) {
		done = pwrite(fd, outbuf + offset + total,
			      num_bytes - total,
			      pos + total);
		if (done < 0) {
			ret = -1;
			goto out;
		}
		total += done;
	}
out:
	free(inbuf);
	free(outbuf);
	return ret;
}