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                         close(fd);
 101                         exit(1);
 102                 }
 103
 104                 if (all) {
 105                         int idx;
 106                         for (idx = 0; idx < BTRFS_SUPER_MIRROR_MAX; idx++) {
 107                                 sb_bytenr = btrfs_sb_offset(idx);
 108                                 if (load_and_dump_sb(filename, fd, sb_bytenr)) {
 109                                         close(fd);
 110                                         exit(1);
 111                                 }
 112
 113                                 putchar('\n');
 114                         }
 115                 } else {
 116                         load_and_dump_sb(filename, fd, sb_bytenr);
 117                         putchar('\n');
 118                 }
 119                 close(fd);
 120         }
 121
 122         exit(0);
 123 }
 124
 125 static int load_and_dump_sb(char *filename, int fd, u64 sb_bytenr)
 126 {
 127         u8 super_block_data[BTRFS_SUPER_INFO_SIZE];
 128         struct btrfs_super_block *sb;
 129         u64 ret;
 130
 131         sb = (struct btrfs_super_block *)super_block_data;
 132
 133         ret = pread64(fd, super_block_data, BTRFS_SUPER_INFO_SIZE, sb_bytenr);
 134         if (ret != BTRFS_SUPER_INFO_SIZE) {
 135                 int e = errno;
 136
 137                 /* check if the disk if too short for further superblock */
 138                 if (ret == 0 && e == 0)
 139                         return 0;
 140
 141                 fprintf(stderr,
 142                    "ERROR: Failed to read the superblock on %s at %llu\n",
 143                    filename, (unsigned long long)sb_bytenr);
 144                 fprintf(stderr,
 145                    "ERROR: error = '%s', errno = %d\n", strerror(e), e);
 146                 return 1;
 147         }
 148         printf("superblock: bytenr=%llu, device=%s\n", sb_bytenr, filename);
 149         printf("---------------------------------------------------------\n");
 150         dump_superblock(sb);
 151         return 0;
 152 }
 153
 154 static int check_csum_sblock(void *sb, int csum_size)
 155 {
 156         char result[csum_size];
 157         u32 crc = ~(u32)0;
 158
 159         crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE,
 160                                 crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
 161         btrfs_csum_final(crc, result);
 162
 163         return !memcmp(sb, &result, csum_size);
 164 }
 165
 166 static void dump_superblock(struct btrfs_super_block *sb)
 167 {
 168         int i;
 169         char *s, buf[36+1];
 170         u8 *p;
 171
 172         printf("csum\t\t\t0x");
 173         for (i = 0, p = sb->csum; i < btrfs_super_csum_size(sb); i++)
 174                 printf("%02x", p[i]);
 175         if (check_csum_sblock(sb, btrfs_super_csum_size(sb)))
 176                 printf(" [match]");
 177         else
 178                 printf(" [DON'T MATCH]");
 179         putchar('\n');
 180
 181         printf("bytenr\t\t\t%llu\n",
 182                 (unsigned long long)btrfs_super_bytenr(sb));
 183         printf("flags\t\t\t0x%llx\n",
 184                 (unsigned long long)btrfs_super_flags(sb));
 185
 186         printf("magic\t\t\t");
 187         s = (char *) &sb->magic;
 188         for (i = 0; i < 8; i++)
 189                 putchar(isprint(s[i]) ? s[i] : '.');
 190         if (sb->magic == cpu_to_le64(BTRFS_MAGIC))
 191                 printf(" [match]\n");
 192         else
 193                 printf(" [DON'T MATCH]\n");
 194
 195         uuid_unparse(sb->fsid, buf);
 196         printf("fsid\t\t\t%s\n", buf);
 197
 198         printf("label\t\t\t");
 199         s = sb->label;
 200         for (i = 0; i < BTRFS_LABEL_SIZE && s[i]; i++)
 201                 putchar(isprint(s[i]) ? s[i] : '.');
 202         putchar('\n');
 203
 204         printf("generation\t\t%llu\n",
 205                (unsigned long long)btrfs_super_generation(sb));
 206         printf("root\t\t\t%llu\n", (unsigned long long)btrfs_super_root(sb));
 207         printf("sys_array_size\t\t%llu\n",
 208                (unsigned long long)btrfs_super_sys_array_size(sb));
 209         printf("chunk_root_generation\t%llu\n",
 210                (unsigned long long)btrfs_super_chunk_root_generation(sb));
 211         printf("root_level\t\t%llu\n",
 212                (unsigned long long)btrfs_super_root_level(sb));
 213         printf("chunk_root\t\t%llu\n",
 214                (unsigned long long)btrfs_super_chunk_root(sb));
 215         printf("chunk_root_level\t%llu\n",
 216                (unsigned long long)btrfs_super_chunk_root_level(sb));
 217         printf("log_root\t\t%llu\n",
 218                (unsigned long long)btrfs_super_log_root(sb));
 219         printf("log_root_transid\t%llu\n",
 220                (unsigned long long)btrfs_super_log_root_transid(sb));
 221         printf("log_root_level\t\t%llu\n",
 222                (unsigned long long)btrfs_super_log_root_level(sb));
 223         printf("total_bytes\t\t%llu\n",
 224                (unsigned long long)btrfs_super_total_bytes(sb));
 225         printf("bytes_used\t\t%llu\n",
 226                (unsigned long long)btrfs_super_bytes_used(sb));
 227         printf("sectorsize\t\t%llu\n",
 228                (unsigned long long)btrfs_super_sectorsize(sb));
 229         printf("nodesize\t\t%llu\n",
 230                (unsigned long long)btrfs_super_nodesize(sb));
 231         printf("leafsize\t\t%llu\n",
 232                (unsigned long long)btrfs_super_leafsize(sb));
 233         printf("stripesize\t\t%llu\n",
 234                (unsigned long long)btrfs_super_stripesize(sb));
 235         printf("root_dir\t\t%llu\n",
 236                (unsigned long long)btrfs_super_root_dir(sb));
 237         printf("num_devices\t\t%llu\n",
 238                (unsigned long long)btrfs_super_num_devices(sb));
 239         printf("compat_flags\t\t0x%llx\n",
 240                (unsigned long long)btrfs_super_compat_flags(sb));
 241         printf("compat_ro_flags\t\t0x%llx\n",
 242                (unsigned long long)btrfs_super_compat_ro_flags(sb));
 243         printf("incompat_flags\t\t0x%llx\n",
 244                (unsigned long long)btrfs_super_incompat_flags(sb));
 245         printf("csum_type\t\t%llu\n",
 246                (unsigned long long)btrfs_super_csum_type(sb));
 247         printf("csum_size\t\t%llu\n",
 248                (unsigned long long)btrfs_super_csum_size(sb));
 249         printf("cache_generation\t%llu\n",
 250                (unsigned long long)btrfs_super_cache_generation(sb));
 251
 252         uuid_unparse(sb->dev_item.uuid, buf);
 253         printf("dev_item.uuid\t\t%s\n", buf);
 254
 255         uuid_unparse(sb->dev_item.fsid, buf);
 256         printf("dev_item.fsid\t\t%s %s\n", buf,
 257                 !memcmp(sb->dev_item.fsid, sb->fsid, BTRFS_FSID_SIZE) ?
 258                         "[match]" : "[DON'T MATCH]");
 259
 260         printf("dev_item.type\t\t%llu\n", (unsigned long long)
 261                btrfs_stack_device_type(&sb->dev_item));
 262         printf("dev_item.total_bytes\t%llu\n", (unsigned long long)
 263                btrfs_stack_device_total_bytes(&sb->dev_item));
 264         printf("dev_item.bytes_used\t%llu\n", (unsigned long long)
 265                btrfs_stack_device_bytes_used(&sb->dev_item));
 266         printf("dev_item.io_align\t%u\n", (unsigned int)
 267                btrfs_stack_device_io_align(&sb->dev_item));
 268         printf("dev_item.io_width\t%u\n", (unsigned int)
 269                btrfs_stack_device_io_width(&sb->dev_item));
 270         printf("dev_item.sector_size\t%u\n", (unsigned int)
 271                btrfs_stack_device_sector_size(&sb->dev_item));
 272         printf("dev_item.devid\t\t%llu\n",
 273                btrfs_stack_device_id(&sb->dev_item));
 274         printf("dev_item.dev_group\t%u\n", (unsigned int)
 275                btrfs_stack_device_group(&sb->dev_item));
 276         printf("dev_item.seek_speed\t%u\n", (unsigned int)
 277                btrfs_stack_device_seek_speed(&sb->dev_item));
 278         printf("dev_item.bandwidth\t%u\n", (unsigned int)
 279                btrfs_stack_device_bandwidth(&sb->dev_item));
 280         printf("dev_item.generation\t%llu\n", (unsigned long long)
 281                btrfs_stack_device_generation(&sb->dev_item));
 282 }