Commit 1dfc0686 authored by Coly Li's avatar Coly Li Committed by Jens Axboe
Browse files

bcache: check unsupported feature sets for bcache register 



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: d721a43f ("bcache: increase super block version for cache device and backing device")
Fixes: ffa47032 ("bcache: add bucket_size_hi into struct cache_sb_disk for large bucket")
Signed-off-by: default avatarColy Li <colyli@suse.de>
Cc: stable@vger.kernel.org # 5.9+
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f7b4943d

drivers/md/bcache/features.h

+15 −0
Original line number Diff line number Diff line
@@ -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);

drivers/md/bcache/super.c

+14 −0
Original line number Diff line number Diff line
@@ -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;