This patch adds the check for features which is incompatible for current supported feature sets.

Now if the bcache device created by bcache-tools has features that current kernel doesn't support, read_super() will fail with error messoage. E.g. if an unsupported incompatible feature detected, bcache register will fail with dmesg "bcache: register_bcache() error : Unsupported incompatible feature found".

Fixes: d721a43ff69c ("bcache: increase super block version for cache device and backing device") Fixes: ffa470327572 ("bcache: add bucket_size_hi into struct cache_sb_disk for large bucket") Signed-off-by: Coly Li colyli@suse.de Cc: stable@vger.kernel.org # 5.9+ --- drivers/md/bcache/features.h | 15 +++++++++++++++ drivers/md/bcache/super.c | 14 ++++++++++++++ 2 files changed, 29 insertions(+)

diff --git a/drivers/md/bcache/features.h b/drivers/md/bcache/features.h index 32c5bbda2f0d..e73724c2b49b 100644 --- a/drivers/md/bcache/features.h +++ b/drivers/md/bcache/features.h @@ -79,6 +79,21 @@ static inline void bch_clear_feature_##name(struct cache_sb *sb) \

BCH_FEATURE_INCOMPAT_FUNCS(large_bucket, LARGE_BUCKET);

+static inline bool bch_has_unknown_compat_features(struct cache_sb *sb) +{ + return ((sb->feature_compat & ~BCH_FEATURE_COMPAT_SUPP) != 0); +} + +static inline bool bch_has_unknown_ro_compat_features(struct cache_sb *sb) +{ + return ((sb->feature_ro_compat & ~BCH_FEATURE_RO_COMPAT_SUPP) != 0); +} + +static inline bool bch_has_unknown_incompat_features(struct cache_sb *sb) +{ + return ((sb->feature_incompat & ~BCH_FEATURE_INCOMPAT_SUPP) != 0); +} + int bch_print_cache_set_feature_compat(struct cache_set *c, char *buf, int size); int bch_print_cache_set_feature_ro_compat(struct cache_set *c, char *buf, int size); int bch_print_cache_set_feature_incompat(struct cache_set *c, char *buf, int size); diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index a4752ac410dc..1804df5c866b 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -228,6 +228,20 @@ static const char *read_super(struct cache_sb *sb, struct block_device *bdev, sb->feature_compat = le64_to_cpu(s->feature_compat); sb->feature_incompat = le64_to_cpu(s->feature_incompat); sb->feature_ro_compat = le64_to_cpu(s->feature_ro_compat); + + /* Check incompatible features */ + err = "Unsupported compatible feature found"; + if (bch_has_unknown_compat_features(sb)) + goto err; + + err = "Unsupported read-only compatible feature found"; + if (bch_has_unknown_ro_compat_features(sb)) + goto err; + + err = "Unsupported incompatible feature found"; + if (bch_has_unknown_incompat_features(sb)) + goto err; + err = read_super_common(sb, bdev, s); if (err) goto err;