diff options
| -rw-r--r-- | Documentation/btrfs-show-super.txt | 4 | ||||
| -rw-r--r-- | btrfs-show-super.c | 26 |
2 files changed, 23 insertions, 7 deletions
diff --git a/Documentation/btrfs-show-super.txt b/Documentation/btrfs-show-super.txt index e06157f5..62da6259 100644 --- a/Documentation/btrfs-show-super.txt +++ b/Documentation/btrfs-show-super.txt @@ -31,6 +31,10 @@ Specify which mirror to print out. <super_mirror> is between 0 and 2. If several '-i <super_mirror>' are given, only the last one is valid. +-F:: +Attempt to print the superblock even if no superblock magic is found. May end +badly. + EXIT STATUS ----------- *btrfs-show-super* will return 0 if no error happened. diff --git a/btrfs-show-super.c b/btrfs-show-super.c index c2ad332b..ed0311fc 100644 --- a/btrfs-show-super.c +++ b/btrfs-show-super.c @@ -40,16 +40,17 @@ 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, "\t-F : attempt to dump superblocks with bad magic\n"); fprintf(stderr, "%s\n", BTRFS_BUILD_VERSION); } @@ -58,13 +59,14 @@ 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:")) != -1) { switch (opt) { case 'i': arg = arg_strtou64(optarg); @@ -84,6 +86,9 @@ int main(int argc, char **argv) case 'f': full = 1; break; + case 'F': + force = 1; + break; default: print_usage(); exit(1); @@ -108,7 +113,7 @@ 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 +121,7 @@ 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 +130,8 @@ 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 +156,13 @@ 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; } |