From 3296d058b7cebb3a7a6c86988db72bed8cde49e1 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Tue, 20 Sep 2016 10:19:02 +0800 Subject: [PATCH] btrfs-progs: super-recover: Reuse btrfs_read_dev_super function We have enhanced super block validation check in disk_io.c, while super-recover doesn't use that function and use a custom one. That is duplicated, so reuse btrfs_read_dev_super to handle it, which not only enhanced super check, but also reduce the code length. Reported-by: hawken Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- super-recover.c | 39 +++++++++++---------------------------- 1 file changed, 11 insertions(+), 28 deletions(-) diff --git a/super-recover.c b/super-recover.c index ecd12152..5298d46c 100644 --- a/super-recover.c +++ b/super-recover.c @@ -88,24 +88,6 @@ void free_recover_superblock(struct btrfs_recover_superblock *recover) } } -static int check_super(u64 bytenr, struct btrfs_super_block *sb) -{ - int csum_size = btrfs_super_csum_size(sb); - u8 result[csum_size]; - u32 crc = ~(u32)0; - - if (btrfs_super_bytenr(sb) != bytenr) - return 0; - if (sb->magic != cpu_to_le64(BTRFS_MAGIC)) - return 0; - - crc = btrfs_csum_data(NULL, (char *)sb + BTRFS_CSUM_SIZE, - crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE); - btrfs_csum_final(crc, result); - - return !memcmp(sb, &result, csum_size); -} - static int add_superblock_record(struct btrfs_super_block *sb, char *fname, u64 bytenr, struct list_head *head) { @@ -133,24 +115,20 @@ read_dev_supers(char *filename, struct btrfs_recover_superblock *recover) int i, ret, fd; u8 buf[BTRFS_SUPER_INFO_SIZE]; u64 max_gen, bytenr; + struct btrfs_super_block *sb = (struct btrfs_super_block *)buf; + /* just ignore errno that were set in btrfs_scan_fs_devices() */ errno = 0; - struct btrfs_super_block *sb = (struct btrfs_super_block *)buf; - fd = open(filename, O_RDONLY); if (fd < 0) return -errno; for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { bytenr = btrfs_sb_offset(i); - ret = pread64(fd, buf, sizeof(buf), bytenr); - if (ret < sizeof(buf)) { - ret = -errno; - goto out; - } - ret = check_super(bytenr, sb); - if (ret) { + + ret = btrfs_read_dev_super(fd, sb, bytenr, SBREAD_DEFAULT); + if (!ret) { ret = add_superblock_record(sb, filename, bytenr, &recover->good_supers); if (ret) @@ -158,13 +136,18 @@ read_dev_supers(char *filename, struct btrfs_recover_superblock *recover) max_gen = btrfs_super_generation(sb); if (max_gen > recover->max_generation) recover->max_generation = max_gen; - } else { + } else if (ret == -EIO){ + /* + * Skip superblock which doesn't exist, only adds + * really corrupted superblock + */ ret = add_superblock_record(sb, filename, bytenr, &recover->bad_supers); if (ret) goto out; } } + ret = 0; out: close(fd); return ret;