btrfs-progs: show-super: Add option to print superblock at given bytenr
[platform/upstream/btrfs-progs.git] / btrfs-show-super.c
index c2ad332..d8ad69e 100644 (file)
@@ -16,8 +16,6 @@
  * Boston, MA 021110-1307, USA.
  */
 
-#define _XOPEN_SOURCE 500
-#define _GNU_SOURCE 1
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.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);
+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] dev [dev..]\n");
+               "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, "%s\n", BTRFS_BUILD_VERSION);
+       fprintf(stderr, "\t-F : attempt to dump superblocks with bad magic\n");
+       fprintf(stderr, "\t-s <bytenr> : specify alternate superblock offset\n");
+       fprintf(stderr, "%s\n", PACKAGE_STRING);
 }
 
 int main(int argc, char **argv)
@@ -58,13 +57,14 @@ 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, "fai:")) != -1) {
+       while ((opt = getopt(argc, argv, "fFai:s:")) != -1) {
                switch (opt) {
                case 'i':
                        arg = arg_strtou64(optarg);
@@ -84,13 +84,21 @@ int main(int argc, char **argv)
                case 'f':
                        full = 1;
                        break;
+               case 'F':
+                       force = 1;
+                       break;
+               case 's':
+                       sb_bytenr = arg_strtou64(optarg);
+                       all = 0;
+                       break;
                default:
                        print_usage();
                        exit(1);
                }
        }
 
-       if (argc < optind + 1) {
+       set_argv0(argv);
+       if (check_argc_min(argc - optind, 1)) {
                print_usage();
                exit(1);
        }
@@ -108,7 +116,7 @@ int main(int argc, char **argv)
                        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)) {
+                                               sb_bytenr, full, force)) {
                                        close(fd);
                                        exit(1);
                                }
@@ -116,7 +124,7 @@ int main(int argc, char **argv)
                                putchar('\n');
                        }
                } else {
-                       load_and_dump_sb(filename, fd, sb_bytenr, full);
+                       load_and_dump_sb(filename, fd, sb_bytenr, full, force);
                        putchar('\n');
                }
                close(fd);
@@ -125,7 +133,8 @@ int main(int argc, char **argv)
        exit(0);
 }
 
-static int load_and_dump_sb(char *filename, int fd, u64 sb_bytenr, int full)
+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;
@@ -150,7 +159,13 @@ static int load_and_dump_sb(char *filename, int fd, u64 sb_bytenr, int full)
        }
        printf("superblock: bytenr=%llu, device=%s\n", sb_bytenr, filename);
        printf("---------------------------------------------------------\n");
-       dump_superblock(sb, full);
+       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;
 }
 
@@ -272,6 +287,95 @@ static void print_backup_roots(struct btrfs_super_block *sb)
        }
 }
 
+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);
+
+#define DEF_HEADER_FLAG_ENTRY(bit_name)                        \
+       {BTRFS_HEADER_FLAG_##bit_name, #bit_name}
+#define DEF_SUPER_FLAG_ENTRY(bit_name)                 \
+       {BTRFS_SUPER_FLAG_##bit_name, #bit_name}
+
+struct readable_flag_entry super_flags_array[] = {
+       DEF_HEADER_FLAG_ENTRY(WRITTEN),
+       DEF_HEADER_FLAG_ENTRY(RELOC),
+       DEF_SUPER_FLAG_ENTRY(CHANGING_FSID),
+       DEF_SUPER_FLAG_ENTRY(SEEDING),
+       DEF_SUPER_FLAG_ENTRY(METADUMP),
+       DEF_SUPER_FLAG_ENTRY(METADUMP_V2)
+};
+static const int super_flags_num = ARRAY_SIZE(super_flags_array);
+
+#define BTRFS_SUPER_FLAG_SUPP  (BTRFS_HEADER_FLAG_WRITTEN |\
+                                BTRFS_HEADER_FLAG_RELOC |\
+                                BTRFS_SUPER_FLAG_CHANGING_FSID |\
+                                BTRFS_SUPER_FLAG_SEEDING |\
+                                BTRFS_SUPER_FLAG_METADUMP |\
+                                BTRFS_SUPER_FLAG_METADUMP_V2)
+
+static void __print_readable_flag(u64 flag, struct readable_flag_entry *array,
+                                 int array_size, u64 supported_flags)
+{
+       int i;
+       int first = 1;
+       struct readable_flag_entry *entry;
+
+       if (!flag)
+               return;
+
+       printf("\t\t\t( ");
+       for (i = 0; i < array_size; i++) {
+               entry = array + i;
+               if (flag & entry->bit) {
+                       if (first)
+                               printf("%s ", entry->output);
+                       else
+                               printf("|\n\t\t\t  %s ", entry->output);
+                       first = 0;
+               }
+       }
+       flag &= ~supported_flags;
+       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 print_readable_incompat_flag(u64 flag)
+{
+       return __print_readable_flag(flag, incompat_flags_array,
+                                    incompat_flags_num,
+                                    BTRFS_FEATURE_INCOMPAT_SUPP);
+}
+
+static void print_readable_super_flag(u64 flag)
+{
+       return __print_readable_flag(flag, super_flags_array,
+                                    super_flags_num, BTRFS_SUPER_FLAG_SUPP);
+}
+
 static void dump_superblock(struct btrfs_super_block *sb, int full)
 {
        int i;
@@ -291,6 +395,7 @@ static void dump_superblock(struct btrfs_super_block *sb, int full)
                (unsigned long long)btrfs_super_bytenr(sb));
        printf("flags\t\t\t0x%llx\n",
                (unsigned long long)btrfs_super_flags(sb));
+       print_readable_super_flag(btrfs_super_flags(sb));
 
        printf("magic\t\t\t");
        s = (char *) &sb->magic;
@@ -351,6 +456,7 @@ static void dump_superblock(struct btrfs_super_block *sb, int full)
               (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",