btrfs-progs/btrfs-show-super.c

/*
 * Copyright (C) 2012 STRATO AG.  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 <ctype.h>
#include <uuid/uuid.h>
#include <errno.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 "utils.h"
#include "crc32c.h"

static void print_usage(void);
static void dump_superblock(struct btrfs_super_block *sb, int full);
int main(int argc, char **argv);
static int load_and_dump_sb(char *, int fd, u64 sb_bytenr, int full, int force);


static void print_usage(void)
{
	fprintf(stderr,
		"usage: btrfs-show-super [-i super_mirror|-a|-f|-F] dev [dev..]\n");
	fprintf(stderr, "\t-f : print full superblock information\n");
	fprintf(stderr, "\t-a : print information of all superblocks\n");
	fprintf(stderr, "\t-i <super_mirror> : specify which mirror to print out\n");
	fprintf(stderr, "\t-F : attempt to dump superblocks with bad magic\n");
	fprintf(stderr, "%s\n", BTRFS_BUILD_VERSION);
}

int main(int argc, char **argv)
{
	int opt;
	int all = 0;
	int full = 0;
	int force = 0;
	char *filename;
	int fd = -1;
	int i;
	u64 arg;
	u64 sb_bytenr = btrfs_sb_offset(0);

	while ((opt = getopt(argc, argv, "fFai:")) != -1) {
		switch (opt) {
		case 'i':
			arg = arg_strtou64(optarg);
			if (arg >= BTRFS_SUPER_MIRROR_MAX) {
				fprintf(stderr,
					"Illegal super_mirror %llu\n",
					arg);
				print_usage();
				exit(1);
			}
			sb_bytenr = btrfs_sb_offset(arg);
			break;

		case 'a':
			all = 1;
			break;
		case 'f':
			full = 1;
			break;
		case 'F':
			force = 1;
			break;
		default:
			print_usage();
			exit(1);
		}
	}

	set_argv0(argv);
	if (check_argc_min(argc - optind, 1)) {
		print_usage();
		exit(1);
	}

	for (i = optind; i < argc; i++) {
		filename = argv[i];
		fd = open(filename, O_RDONLY, 0666);
		if (fd < 0) {
			fprintf(stderr, "Could not open %s\n", filename);
			exit(1);
		}

		if (all) {
			int idx;
			for (idx = 0; idx < BTRFS_SUPER_MIRROR_MAX; idx++) {
				sb_bytenr = btrfs_sb_offset(idx);
				if (load_and_dump_sb(filename, fd,
						sb_bytenr, full, force)) {
					close(fd);
					exit(1);
				}

				putchar('\n');
			}
		} else {
			load_and_dump_sb(filename, fd, sb_bytenr, full, force);
			putchar('\n');
		}
		close(fd);
	}

	exit(0);
}

static int load_and_dump_sb(char *filename, int fd, u64 sb_bytenr, int full,
		int force)
{
	u8 super_block_data[BTRFS_SUPER_INFO_SIZE];
	struct btrfs_super_block *sb;
	u64 ret;

	sb = (struct btrfs_super_block *)super_block_data;

	ret = pread64(fd, super_block_data, BTRFS_SUPER_INFO_SIZE, sb_bytenr);
	if (ret != BTRFS_SUPER_INFO_SIZE) {
		int e = errno;

		/* check if the disk if too short for further superblock */
		if (ret == 0 && e == 0)
			return 0;

		fprintf(stderr,
		   "ERROR: Failed to read the superblock on %s at %llu\n",
		   filename, (unsigned long long)sb_bytenr);
		fprintf(stderr,
		   "ERROR: error = '%s', errno = %d\n", strerror(e), e);
		return 1;
	}
	printf("superblock: bytenr=%llu, device=%s\n", sb_bytenr, filename);
	printf("---------------------------------------------------------\n");
	if (btrfs_super_magic(sb) != BTRFS_MAGIC && !force) {
		fprintf(stderr,
		    "ERROR: bad magic on superblock on %s at %llu\n",
		    filename, (unsigned long long)sb_bytenr);
	} else {
		dump_superblock(sb, full);
	}
	return 0;
}

static int check_csum_sblock(void *sb, int csum_size)
{
	char result[BTRFS_CSUM_SIZE];
	u32 crc = ~(u32)0;

	crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE,
				crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
	btrfs_csum_final(crc, result);

	return !memcmp(sb, &result, csum_size);
}

static void print_sys_chunk_array(struct btrfs_super_block *sb)
{
	struct extent_buffer *buf;
	struct btrfs_disk_key *disk_key;
	struct btrfs_chunk *chunk;
	struct btrfs_key key;
	u8 *ptr, *array_end;
	u32 num_stripes;
	u32 len = 0;
	int i = 0;

	buf = malloc(sizeof(*buf) + sizeof(*sb));
	if (!buf) {
		fprintf(stderr, "%s\n", strerror(ENOMEM));
		exit(1);
	}
	write_extent_buffer(buf, sb, 0, sizeof(*sb));
	ptr = sb->sys_chunk_array;
	array_end = ptr + btrfs_super_sys_array_size(sb);

	while (ptr < array_end) {
		disk_key = (struct btrfs_disk_key *)ptr;
		btrfs_disk_key_to_cpu(&key, disk_key);

		printf("\titem %d ", i);
		btrfs_print_key(disk_key);

		len = sizeof(*disk_key);
		putchar('\n');
		ptr += len;

		if (key.type == BTRFS_CHUNK_ITEM_KEY) {
			chunk = (struct btrfs_chunk *)(ptr - (u8 *)sb);
			print_chunk(buf, chunk);
			num_stripes = btrfs_chunk_num_stripes(buf, chunk);
			len = btrfs_chunk_item_size(num_stripes);
		} else {
			BUG();
		}

		ptr += len;
		i++;
	}

	free(buf);
}

static int empty_backup(struct btrfs_root_backup *backup)
{
	if (backup == NULL ||
		(backup->tree_root == 0 &&
		 backup->tree_root_gen == 0))
		return 1;
	return 0;
}

static void print_root_backup(struct btrfs_root_backup *backup)
{
	printf("\t\tbackup_tree_root:\t%llu\tgen: %llu\tlevel: %d\n",
			btrfs_backup_tree_root(backup),
			btrfs_backup_tree_root_gen(backup),
			btrfs_backup_tree_root_level(backup));
	printf("\t\tbackup_chunk_root:\t%llu\tgen: %llu\tlevel: %d\n",
			btrfs_backup_chunk_root(backup),
			btrfs_backup_chunk_root_gen(backup),
			btrfs_backup_chunk_root_level(backup));
	printf("\t\tbackup_extent_root:\t%llu\tgen: %llu\tlevel: %d\n",
			btrfs_backup_extent_root(backup),
			btrfs_backup_extent_root_gen(backup),
			btrfs_backup_extent_root_level(backup));
	printf("\t\tbackup_fs_root:\t\t%llu\tgen: %llu\tlevel: %d\n",
			btrfs_backup_fs_root(backup),
			btrfs_backup_fs_root_gen(backup),
			btrfs_backup_fs_root_level(backup));
	printf("\t\tbackup_dev_root:\t%llu\tgen: %llu\tlevel: %d\n",
			btrfs_backup_dev_root(backup),
			btrfs_backup_dev_root_gen(backup),
			btrfs_backup_dev_root_level(backup));
	printf("\t\tbackup_csum_root:\t%llu\tgen: %llu\tlevel: %d\n",
			btrfs_backup_csum_root(backup),
			btrfs_backup_csum_root_gen(backup),
			btrfs_backup_csum_root_level(backup));

	printf("\t\tbackup_total_bytes:\t%llu\n",
					btrfs_backup_total_bytes(backup));
	printf("\t\tbackup_bytes_used:\t%llu\n",
					btrfs_backup_bytes_used(backup));
	printf("\t\tbackup_num_devices:\t%llu\n",
					btrfs_backup_num_devices(backup));
	putchar('\n');
}

static void print_backup_roots(struct btrfs_super_block *sb)
{
	struct btrfs_root_backup *backup;
	int i;

	for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
		backup = sb->super_roots + i;
		if (!empty_backup(backup)) {
			printf("\tbackup %d:\n", i);
			print_root_backup(backup);
		}
	}
}

struct readable_flag_entry {
	u64 bit;
	char *output;
};

#define DEF_INCOMPAT_FLAG_ENTRY(bit_name)		\
	{BTRFS_FEATURE_INCOMPAT_##bit_name, #bit_name}

struct readable_flag_entry incompat_flags_array[] = {
	DEF_INCOMPAT_FLAG_ENTRY(MIXED_BACKREF),
	DEF_INCOMPAT_FLAG_ENTRY(DEFAULT_SUBVOL),
	DEF_INCOMPAT_FLAG_ENTRY(MIXED_GROUPS),
	DEF_INCOMPAT_FLAG_ENTRY(COMPRESS_LZO),
	DEF_INCOMPAT_FLAG_ENTRY(COMPRESS_LZOv2),
	DEF_INCOMPAT_FLAG_ENTRY(BIG_METADATA),
	DEF_INCOMPAT_FLAG_ENTRY(EXTENDED_IREF),
	DEF_INCOMPAT_FLAG_ENTRY(RAID56),
	DEF_INCOMPAT_FLAG_ENTRY(SKINNY_METADATA),
	DEF_INCOMPAT_FLAG_ENTRY(NO_HOLES)
};
static const int incompat_flags_num = sizeof(incompat_flags_array) /
				      sizeof(struct readable_flag_entry);

static void print_readable_incompat_flag(u64 flag)
{
	int i;
	int first = 1;
	struct readable_flag_entry *entry;

	if (!flag)
		return;
	printf("\t\t\t( ");
	for (i = 0; i < incompat_flags_num; i++) {
		entry = incompat_flags_array + i;
		if (flag & entry->bit) {
			if (first)
				printf("%s ", entry->output);
			else
				printf("|\n\t\t\t  %s ", entry->output);
		}
		first = 0;
	}
	flag &= ~BTRFS_FEATURE_INCOMPAT_SUPP;
	if (flag) {
		if (first)
			printf("unknown flag: 0x%llx ", flag);
		else
			printf("|\n\t\t\t  unknown flag: 0x%llx ", flag);
	}
	printf(")\n");
}

static void dump_superblock(struct btrfs_super_block *sb, int full)
{
	int i;
	char *s, buf[BTRFS_UUID_UNPARSED_SIZE];
	u8 *p;

	printf("csum\t\t\t0x");
	for (i = 0, p = sb->csum; i < btrfs_super_csum_size(sb); i++)
		printf("%02x", p[i]);
	if (check_csum_sblock(sb, btrfs_super_csum_size(sb)))
		printf(" [match]");
	else
		printf(" [DON'T MATCH]");
	putchar('\n');

	printf("bytenr\t\t\t%llu\n",
		(unsigned long long)btrfs_super_bytenr(sb));
	printf("flags\t\t\t0x%llx\n",
		(unsigned long long)btrfs_super_flags(sb));

	printf("magic\t\t\t");
	s = (char *) &sb->magic;
	for (i = 0; i < 8; i++)
		putchar(isprint(s[i]) ? s[i] : '.');
	if (btrfs_super_magic(sb) == BTRFS_MAGIC)
		printf(" [match]\n");
	else
		printf(" [DON'T MATCH]\n");

	uuid_unparse(sb->fsid, buf);
	printf("fsid\t\t\t%s\n", buf);

	printf("label\t\t\t");
	s = sb->label;
	for (i = 0; i < BTRFS_LABEL_SIZE && s[i]; i++)
		putchar(isprint(s[i]) ? s[i] : '.');
	putchar('\n');

	printf("generation\t\t%llu\n",
	       (unsigned long long)btrfs_super_generation(sb));
	printf("root\t\t\t%llu\n", (unsigned long long)btrfs_super_root(sb));
	printf("sys_array_size\t\t%llu\n",
	       (unsigned long long)btrfs_super_sys_array_size(sb));
	printf("chunk_root_generation\t%llu\n",
	       (unsigned long long)btrfs_super_chunk_root_generation(sb));
	printf("root_level\t\t%llu\n",
	       (unsigned long long)btrfs_super_root_level(sb));
	printf("chunk_root\t\t%llu\n",
	       (unsigned long long)btrfs_super_chunk_root(sb));
	printf("chunk_root_level\t%llu\n",
	       (unsigned long long)btrfs_super_chunk_root_level(sb));
	printf("log_root\t\t%llu\n",
	       (unsigned long long)btrfs_super_log_root(sb));
	printf("log_root_transid\t%llu\n",
	       (unsigned long long)btrfs_super_log_root_transid(sb));
	printf("log_root_level\t\t%llu\n",
	       (unsigned long long)btrfs_super_log_root_level(sb));
	printf("total_bytes\t\t%llu\n",
	       (unsigned long long)btrfs_super_total_bytes(sb));
	printf("bytes_used\t\t%llu\n",
	       (unsigned long long)btrfs_super_bytes_used(sb));
	printf("sectorsize\t\t%llu\n",
	       (unsigned long long)btrfs_super_sectorsize(sb));
	printf("nodesize\t\t%llu\n",
	       (unsigned long long)btrfs_super_nodesize(sb));
	printf("leafsize\t\t%llu\n",
	       (unsigned long long)btrfs_super_leafsize(sb));
	printf("stripesize\t\t%llu\n",
	       (unsigned long long)btrfs_super_stripesize(sb));
	printf("root_dir\t\t%llu\n",
	       (unsigned long long)btrfs_super_root_dir(sb));
	printf("num_devices\t\t%llu\n",
	       (unsigned long long)btrfs_super_num_devices(sb));
	printf("compat_flags\t\t0x%llx\n",
	       (unsigned long long)btrfs_super_compat_flags(sb));
	printf("compat_ro_flags\t\t0x%llx\n",
	       (unsigned long long)btrfs_super_compat_ro_flags(sb));
	printf("incompat_flags\t\t0x%llx\n",
	       (unsigned long long)btrfs_super_incompat_flags(sb));
	print_readable_incompat_flag(btrfs_super_incompat_flags(sb));
	printf("csum_type\t\t%llu\n",
	       (unsigned long long)btrfs_super_csum_type(sb));
	printf("csum_size\t\t%llu\n",
	       (unsigned long long)btrfs_super_csum_size(sb));
	printf("cache_generation\t%llu\n",
	       (unsigned long long)btrfs_super_cache_generation(sb));
	printf("uuid_tree_generation\t%llu\n",
	       (unsigned long long)btrfs_super_uuid_tree_generation(sb));

	uuid_unparse(sb->dev_item.uuid, buf);
	printf("dev_item.uuid\t\t%s\n", buf);

	uuid_unparse(sb->dev_item.fsid, buf);
	printf("dev_item.fsid\t\t%s %s\n", buf,
		!memcmp(sb->dev_item.fsid, sb->fsid, BTRFS_FSID_SIZE) ?
			"[match]" : "[DON'T MATCH]");

	printf("dev_item.type\t\t%llu\n", (unsigned long long)
	       btrfs_stack_device_type(&sb->dev_item));
	printf("dev_item.total_bytes\t%llu\n", (unsigned long long)
	       btrfs_stack_device_total_bytes(&sb->dev_item));
	printf("dev_item.bytes_used\t%llu\n", (unsigned long long)
	       btrfs_stack_device_bytes_used(&sb->dev_item));
	printf("dev_item.io_align\t%u\n", (unsigned int)
	       btrfs_stack_device_io_align(&sb->dev_item));
	printf("dev_item.io_width\t%u\n", (unsigned int)
	       btrfs_stack_device_io_width(&sb->dev_item));
	printf("dev_item.sector_size\t%u\n", (unsigned int)
	       btrfs_stack_device_sector_size(&sb->dev_item));
	printf("dev_item.devid\t\t%llu\n",
	       btrfs_stack_device_id(&sb->dev_item));
	printf("dev_item.dev_group\t%u\n", (unsigned int)
	       btrfs_stack_device_group(&sb->dev_item));
	printf("dev_item.seek_speed\t%u\n", (unsigned int)
	       btrfs_stack_device_seek_speed(&sb->dev_item));
	printf("dev_item.bandwidth\t%u\n", (unsigned int)
	       btrfs_stack_device_bandwidth(&sb->dev_item));
	printf("dev_item.generation\t%llu\n", (unsigned long long)
	       btrfs_stack_device_generation(&sb->dev_item));
	if (full) {
		printf("sys_chunk_array[%d]:\n", BTRFS_SYSTEM_CHUNK_ARRAY_SIZE);
		print_sys_chunk_array(sb);
		printf("backup_roots[%d]:\n", BTRFS_NUM_BACKUP_ROOTS);
		print_backup_roots(sb);
	}
}