btrfs-show-super.c

   1 /*
   2  * Copyright (C) 2012 STRATO AG.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #define _XOPEN_SOURCE 500
  20 #define _GNU_SOURCE 1
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24 #include <fcntl.h>
  25 #include <sys/stat.h>
  26 #include <ctype.h>
  27 #include <uuid/uuid.h>
  28 #include <errno.h>
  29
  30 #include "kerncompat.h"
  31 #include "ctree.h"
  32 #include "disk-io.h"
  33 #include "print-tree.h"
  34 #include "transaction.h"
  35 #include "list.h"
  36 #include "version.h"
  37 #include "utils.h"
  38 #include "crc32c.h"
  39
  40 static void print_usage(void);
  41 static void dump_superblock(struct btrfs_super_block *sb);
  42 int main(int argc, char **argv);
  43 static int load_and_dump_sb(char *, int fd, u64 sb_bytenr);
  44
  45
  46 static void print_usage(void)
  47 {
  48         fprintf(stderr,
  49                 "usage: btrfs-show-super [-i super_mirror|-a] dev [dev..]\n");
  50         fprintf(stderr, "\tThe super_mirror number is between 0 and %d.\n",
  51                 BTRFS_SUPER_MIRROR_MAX - 1);
  52         fprintf(stderr, "\tIf -a is passed all the superblocks are showed.\n");
  53         fprintf(stderr, "%s\n", BTRFS_BUILD_VERSION);
  54 }
  55
  56 int main(int argc, char **argv)
  57 {
  58         int opt;
  59         int all = 0;
  60         char *filename;
  61         int fd = -1;
  62         int arg, i;
  63         u64 sb_bytenr = btrfs_sb_offset(0);
  64
  65         while ((opt = getopt(argc, argv, "ai:")) != -1) {
  66                 switch (opt) {
  67                 case 'i':
  68                         arg = atoi(optarg);
  69
  70                         if (arg < 0 || arg >= BTRFS_SUPER_MIRROR_MAX) {
  71                                 fprintf(stderr,
  72                                         "Illegal super_mirror %d\n",
  73                                         arg);
  74                                 print_usage();
  75                                 exit(1);
  76                         }
  77                         sb_bytenr = btrfs_sb_offset(arg);
  78                         break;
  79
  80                 case 'a':
  81                         all = 1;
  82                         break;
  83
  84                 default:
  85                         print_usage();
  86                         exit(1);
  87                 }
  88         }
  89
  90         if (argc < optind + 1) {
  91                 print_usage();
  92                 exit(1);
  93         }
  94
  95         for (i = optind; i < argc; i++) {
  96                 filename = argv[i];
  97                 fd = open(filename, O_RDONLY, 0666);
  98                 if (fd < 0) {
  99                         fprintf(stderr, "Could not open %s\n", filename);
 100                         exit(1);
 101                 }
 102
 103                 if (all) {
 104                         int idx;
 105                         for (idx = 0; idx < BTRFS_SUPER_MIRROR_MAX; idx++) {
 106                                 sb_bytenr = btrfs_sb_offset(idx);
 107                                 if (load_and_dump_sb(filename, fd, sb_bytenr)) {
 108                                         close(fd);
 109                                         exit(1);
 110                                 }
 111
 112                                 putchar('\n');
 113                         }
 114                 } else {
 115                         load_and_dump_sb(filename, fd, sb_bytenr);
 116                         putchar('\n');
 117                 }
 118                 close(fd);
 119         }
 120
 121         exit(0);
 122 }
 123
 124 static int load_and_dump_sb(char *filename, int fd, u64 sb_bytenr)
 125 {
 126         u8 super_block_data[BTRFS_SUPER_INFO_SIZE];
 127         struct btrfs_super_block *sb;
 128         u64 ret;
 129
 130         sb = (struct btrfs_super_block *)super_block_data;
 131
 132         ret = pread64(fd, super_block_data, BTRFS_SUPER_INFO_SIZE, sb_bytenr);
 133         if (ret != BTRFS_SUPER_INFO_SIZE) {
 134                 int e = errno;
 135
 136                 /* check if the disk if too short for further superblock */
 137                 if (ret == 0 && e == 0)
 138                         return 0;
 139
 140                 fprintf(stderr,
 141                    "ERROR: Failed to read the superblock on %s at %llu\n",
 142                    filename, (unsigned long long)sb_bytenr);
 143                 fprintf(stderr,
 144                    "ERROR: error = '%s', errno = %d\n", strerror(e), e);
 145                 return 1;
 146         }
 147         printf("superblock: bytenr=%llu, device=%s\n", sb_bytenr, filename);
 148         printf("---------------------------------------------------------\n");
 149         dump_superblock(sb);
 150         return 0;
 151 }
 152
 153 static int check_csum_sblock(void *sb, int csum_size)
 154 {
 155         char result[BTRFS_CSUM_SIZE];
 156         u32 crc = ~(u32)0;
 157
 158         crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE,
 159                                 crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
 160         btrfs_csum_final(crc, result);
 161
 162         return !memcmp(sb, &result, csum_size);
 163 }
 164
 165 static void dump_superblock(struct btrfs_super_block *sb)
 166 {
 167         int i;
 168         char *s, buf[36+1];
 169         u8 *p;
 170
 171         printf("csum\t\t\t0x");
 172         for (i = 0, p = sb->csum; i < btrfs_super_csum_size(sb); i++)
 173                 printf("%02x", p[i]);
 174         if (check_csum_sblock(sb, btrfs_super_csum_size(sb)))
 175                 printf(" [match]");
 176         else
 177                 printf(" [DON'T MATCH]");
 178         putchar('\n');
 179
 180         printf("bytenr\t\t\t%llu\n",
 181                 (unsigned long long)btrfs_super_bytenr(sb));
 182         printf("flags\t\t\t0x%llx\n",
 183                 (unsigned long long)btrfs_super_flags(sb));
 184
 185         printf("magic\t\t\t");
 186         s = (char *) &sb->magic;
 187         for (i = 0; i < 8; i++)
 188                 putchar(isprint(s[i]) ? s[i] : '.');
 189         if (btrfs_super_magic(sb) == BTRFS_MAGIC)
 190                 printf(" [match]\n");
 191         else
 192                 printf(" [DON'T MATCH]\n");
 193
 194         uuid_unparse(sb->fsid, buf);
 195         printf("fsid\t\t\t%s\n", buf);
 196
 197         printf("label\t\t\t");
 198         s = sb->label;
 199         for (i = 0; i < BTRFS_LABEL_SIZE && s[i]; i++)
 200                 putchar(isprint(s[i]) ? s[i] : '.');
 201         putchar('\n');
 202
 203         printf("generation\t\t%llu\n",
 204                (unsigned long long)btrfs_super_generation(sb));
 205         printf("root\t\t\t%llu\n", (unsigned long long)btrfs_super_root(sb));
 206         printf("sys_array_size\t\t%llu\n",
 207                (unsigned long long)btrfs_super_sys_array_size(sb));
 208         printf("chunk_root_generation\t%llu\n",
 209                (unsigned long long)btrfs_super_chunk_root_generation(sb));
 210         printf("root_level\t\t%llu\n",
 211                (unsigned long long)btrfs_super_root_level(sb));
 212         printf("chunk_root\t\t%llu\n",
 213                (unsigned long long)btrfs_super_chunk_root(sb));
 214         printf("chunk_root_level\t%llu\n",
 215                (unsigned long long)btrfs_super_chunk_root_level(sb));
 216         printf("log_root\t\t%llu\n",
 217                (unsigned long long)btrfs_super_log_root(sb));
 218         printf("log_root_transid\t%llu\n",
 219                (unsigned long long)btrfs_super_log_root_transid(sb));
 220         printf("log_root_level\t\t%llu\n",
 221                (unsigned long long)btrfs_super_log_root_level(sb));
 222         printf("total_bytes\t\t%llu\n",
 223                (unsigned long long)btrfs_super_total_bytes(sb));
 224         printf("bytes_used\t\t%llu\n",
 225                (unsigned long long)btrfs_super_bytes_used(sb));
 226         printf("sectorsize\t\t%llu\n",
 227                (unsigned long long)btrfs_super_sectorsize(sb));
 228         printf("nodesize\t\t%llu\n",
 229                (unsigned long long)btrfs_super_nodesize(sb));
 230         printf("leafsize\t\t%llu\n",
 231                (unsigned long long)btrfs_super_leafsize(sb));
 232         printf("stripesize\t\t%llu\n",
 233                (unsigned long long)btrfs_super_stripesize(sb));
 234         printf("root_dir\t\t%llu\n",
 235                (unsigned long long)btrfs_super_root_dir(sb));
 236         printf("num_devices\t\t%llu\n",
 237                (unsigned long long)btrfs_super_num_devices(sb));
 238         printf("compat_flags\t\t0x%llx\n",
 239                (unsigned long long)btrfs_super_compat_flags(sb));
 240         printf("compat_ro_flags\t\t0x%llx\n",
 241                (unsigned long long)btrfs_super_compat_ro_flags(sb));
 242         printf("incompat_flags\t\t0x%llx\n",
 243                (unsigned long long)btrfs_super_incompat_flags(sb));
 244         printf("csum_type\t\t%llu\n",
 245                (unsigned long long)btrfs_super_csum_type(sb));
 246         printf("csum_size\t\t%llu\n",
 247                (unsigned long long)btrfs_super_csum_size(sb));
 248         printf("cache_generation\t%llu\n",
 249                (unsigned long long)btrfs_super_cache_generation(sb));
 250         printf("uuid_tree_generation\t%llu\n",
 251                (unsigned long long)btrfs_super_uuid_tree_generation(sb));
 252
 253         uuid_unparse(sb->dev_item.uuid, buf);
 254         printf("dev_item.uuid\t\t%s\n", buf);
 255
 256         uuid_unparse(sb->dev_item.fsid, buf);
 257         printf("dev_item.fsid\t\t%s %s\n", buf,
 258                 !memcmp(sb->dev_item.fsid, sb->fsid, BTRFS_FSID_SIZE) ?
 259                         "[match]" : "[DON'T MATCH]");
 260
 261         printf("dev_item.type\t\t%llu\n", (unsigned long long)
 262                btrfs_stack_device_type(&sb->dev_item));
 263         printf("dev_item.total_bytes\t%llu\n", (unsigned long long)
 264                btrfs_stack_device_total_bytes(&sb->dev_item));
 265         printf("dev_item.bytes_used\t%llu\n", (unsigned long long)
 266                btrfs_stack_device_bytes_used(&sb->dev_item));
 267         printf("dev_item.io_align\t%u\n", (unsigned int)
 268                btrfs_stack_device_io_align(&sb->dev_item));
 269         printf("dev_item.io_width\t%u\n", (unsigned int)
 270                btrfs_stack_device_io_width(&sb->dev_item));
 271         printf("dev_item.sector_size\t%u\n", (unsigned int)
 272                btrfs_stack_device_sector_size(&sb->dev_item));
 273         printf("dev_item.devid\t\t%llu\n",
 274                btrfs_stack_device_id(&sb->dev_item));
 275         printf("dev_item.dev_group\t%u\n", (unsigned int)
 276                btrfs_stack_device_group(&sb->dev_item));
 277         printf("dev_item.seek_speed\t%u\n", (unsigned int)
 278                btrfs_stack_device_seek_speed(&sb->dev_item));
 279         printf("dev_item.bandwidth\t%u\n", (unsigned int)
 280                btrfs_stack_device_bandwidth(&sb->dev_item));
 281         printf("dev_item.generation\t%llu\n", (unsigned long long)
 282                btrfs_stack_device_generation(&sb->dev_item));
 283 }