btrfs-progs: show-super: Add option to print superblock at given bytenr

[platform/upstream/btrfs-progs.git] / btrfs-show-super.c

diff --git a/btrfs-show-super.c b/btrfs-show-super.c
index 430ddfe..d8ad69e 100644 (file)
--- a/btrfs-show-super.c
+++ b/btrfs-show-super.c
@@ -48,6 +48,7 @@ static void print_usage(void)
        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, "\t-s <bytenr> : specify alternate superblock offset\n");
        fprintf(stderr, "%s\n", PACKAGE_STRING);
 }
 
@@ -63,7 +64,7 @@ int main(int argc, char **argv)
        u64 arg;
        u64 sb_bytenr = btrfs_sb_offset(0);
 
-       while ((opt = getopt(argc, argv, "fFai:")) != -1) {
+       while ((opt = getopt(argc, argv, "fFai:s:")) != -1) {
                switch (opt) {
                case 'i':
                        arg = arg_strtou64(optarg);
@@ -86,6 +87,10 @@ int main(int argc, char **argv)
                case 'F':
                        force = 1;
                        break;
+               case 's':
+                       sb_bytenr = arg_strtou64(optarg);
+                       all = 0;
+                       break;
                default:
                        print_usage();
                        exit(1);
@@ -305,6 +310,28 @@ struct readable_flag_entry incompat_flags_array[] = {
 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)
 {
@@ -343,6 +370,12 @@ static void print_readable_incompat_flag(u64 flag)
                                     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;
@@ -362,6 +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;