(updated for thinko: when proper flag *is* set on both primary & backup) Recent e2fsprogs (1.40.3 and higher) fsck compares primary superblock to backups, and if things differ, it forces a full check. However, the kernel has a penchant for updating flags the first time a feature is used - attributes, large files, etc. However, it only updates these on the primary sb. This then causes the new e2fsck behavior to trigger a full check. I think these flags can be safely ignored on this check; having them set on the primary but not the backups doesn't indicate corruption; if they're wrongly set on the primary, really no damage is done, and if the backup is used, but it doesn't have the flags set when it should, I'm pretty sure e2fsck can cope with that. I'll admit the patch below is not glamorous. Any comments, either on the style(sic) or the intent of the patch? Thanks, -Eric Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx> Index: e2fsprogs-1.40.4/e2fsck/super.c =================================================================== --- e2fsprogs-1.40.4.orig/e2fsck/super.c +++ e2fsprogs-1.40.4/e2fsck/super.c @@ -814,10 +814,32 @@ int check_backup_super_block(e2fsck_t ct continue; } -#define SUPER_DIFFERENT(x) (fs->super->x != tfs->super->x) - if (SUPER_DIFFERENT(s_feature_compat) || - SUPER_DIFFERENT(s_feature_incompat) || - SUPER_DIFFERENT(s_feature_ro_compat) || + /* + * A few flags are set on the fly by the kernel, but + * only in the primary superblock. They are safe + * to copy even if they differ. + */ + +#define FEATURE_COMPAT_IGNORE (EXT2_FEATURE_COMPAT_EXT_ATTR) +#define FEATURE_RO_COMPAT_IGNORE (EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \ + EXT4_FEATURE_RO_COMPAT_DIR_NLINK) +#define FEATURE_INCOMPAT_IGNORE (EXT3_FEATURE_INCOMPAT_EXTENTS) + +#define SUPER_COMPAT_DIFFERENT(x) \ + (( fs->super->x & ~FEATURE_COMPAT_IGNORE) != \ + (tfs->super->x & ~FEATURE_COMPAT_IGNORE)) +#define SUPER_INCOMPAT_DIFFERENT(x) \ + (( fs->super->x & ~FEATURE_INCOMPAT_IGNORE) != \ + (tfs->super->x & ~FEATURE_INCOMPAT_IGNORE)) +#define SUPER_RO_COMPAT_DIFFERENT(x) \ + (( fs->super->x & ~FEATURE_RO_COMPAT_IGNORE) != \ + (tfs->super->x & ~FEATURE_RO_COMPAT_IGNORE)) +#define SUPER_DIFFERENT(x) \ + (fs->super->x != tfs->super->x) + + if (SUPER_COMPAT_DIFFERENT(s_feature_compat) || + SUPER_INCOMPAT_DIFFERENT(s_feature_incompat) || + SUPER_RO_COMPAT_DIFFERENT(s_feature_ro_compat) || SUPER_DIFFERENT(s_blocks_count) || SUPER_DIFFERENT(s_inodes_count) || memcmp(fs->super->s_uuid, tfs->super->s_uuid, - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
