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 | 15 ++++++--------- utils.c | 15 +++++++++++++++ utils.h | 2 ++ 3 files changed, 23 insertions(+), 9 deletions(-) diff --git a/cmds-inspect-dump-super.c b/cmds-inspect-dump-super.c index 7815c863f2ed..879f979f526a 100644 --- a/cmds-inspect-dump-super.c +++ b/cmds-inspect-dump-super.c @@ -477,16 +477,13 @@ static void dump_superblock(struct btrfs_super_block *sb, 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; + struct btrfs_super_block sb; u64 ret; - 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); + 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", @@ -496,11 +493,11 @@ 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"); - if (btrfs_super_magic(sb) != BTRFS_MAGIC && !force) { + if (btrfs_super_magic(&sb) != BTRFS_MAGIC && !force) { error("bad magic on superblock on %s at %llu", filename, (unsigned long long)sb_bytenr); } else { - dump_superblock(sb, full); + dump_superblock(&sb, full); } return 0; } diff --git a/utils.c b/utils.c index 9e26c884cc6c..04908b174708 100644 --- a/utils.c +++ b/utils.c @@ -2593,3 +2593,18 @@ 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 = sizeof(sizeof(struct btrfs_super_block)); + int ret; + + ret = pread64(fd, sb, size, bytenr); + if (ret != size) { + if (ret == 0 && errno == 0) + return -EINVAL; + + return -errno; + } + return 0; +} diff --git a/utils.h b/utils.h index 7c5eb798557d..f0b9ec372893 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); + /* * Global program state, configurable by command line and available to * functions without extra context passing. -- 2.16.4