inspect-internal dump-superblock's load_and_dump_sb() already reads a super block from a file descriptor and places it into a 'struct btrfs_super_block'.
For inspect-internal dump-csum we need this super block as well but don't care about printing it. Separate the read from the dump phase so we can re-use it elsewhere. Signed-off-by: Johannes Thumshirn <jthumsh...@suse.de> --- cmds-inspect-dump-super.c | 6 +++--- utils.c | 17 +++++++++++++++++ utils.h | 2 ++ 3 files changed, 22 insertions(+), 3 deletions(-) diff --git a/cmds-inspect-dump-super.c b/cmds-inspect-dump-super.c index 7815c863f2ed..516760fad3da 100644 --- a/cmds-inspect-dump-super.c +++ b/cmds-inspect-dump-super.c @@ -483,10 +483,10 @@ static int load_and_dump_sb(char *filename, int fd, u64 sb_bytenr, int full, sb = (struct btrfs_super_block *)super_block_data; - ret = pread64(fd, super_block_data, BTRFS_SUPER_INFO_SIZE, sb_bytenr); - if (ret != BTRFS_SUPER_INFO_SIZE) { + ret = load_sb(fd, sb_bytenr, sb, BTRFS_SUPER_INFO_SIZE); + if (ret) { /* check if the disk if too short for further superblock */ - if (ret == 0 && errno == 0) + if (ret == -ENOSPC) return 0; error("failed to read the superblock on %s at %llu", diff --git a/utils.c b/utils.c index 9e26c884cc6c..b15cfcf5a434 100644 --- a/utils.c +++ b/utils.c @@ -2593,3 +2593,20 @@ void print_all_devices(struct list_head *devices) print_device_info(dev, "\t"); printf("\n"); } + +int load_sb(int fd, u64 bytenr, struct btrfs_super_block *sb, size_t size) +{ + int ret; + + if (size != BTRFS_SUPER_INFO_SIZE) + return -EINVAL; + + ret = pread64(fd, sb, size, bytenr); + if (ret != size) { + if (ret == 0 && errno == 0) + return -ENOSPC; + + return -errno; + } + return 0; +} diff --git a/utils.h b/utils.h index 7c5eb798557d..65549374b19c 100644 --- a/utils.h +++ b/utils.h @@ -171,6 +171,8 @@ unsigned long total_memory(void); void print_device_info(struct btrfs_device *device, char *prefix); void print_all_devices(struct list_head *devices); +int load_sb(int fd, u64 bytenr, struct btrfs_super_block *sb, size_t size); + /* * Global program state, configurable by command line and available to * functions without extra context passing. -- 2.16.4