block: export blk-crypto symbols required by dm-inlinecrypt

bio_crypt_set_ctx(), blk_crypto_init_key(), and
blk_crypto_start_using_key() are needed to use inline encryption; see
Documentation/block/inline-encryption.rst.  Export them so that
dm-inlinecrypt can use them.  The only reason these weren't exported
before was that inline encryption was previously used only by fs/crypto/
which is built-in code.

Signed-off-by: Eric Biggers <ebiggers@google.com>

Author: ebiggers

block/blk-crypto.c

@@ -116,6 +116,7 @@ void bio_crypt_set_ctx(struct bio *bio, const struct blk_crypto_key *key,
 
 	bio->bi_crypt_context = bc;
 }
+EXPORT_SYMBOL_GPL(bio_crypt_set_ctx);
 
 void __bio_crypt_free_ctx(struct bio *bio)
 {
@@ -349,6 +350,7 @@ int blk_crypto_init_key(struct blk_crypto_key *blk_key,
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(blk_crypto_init_key);
 
 bool blk_crypto_config_supported_natively(struct block_device *bdev,
 					  const struct blk_crypto_config *cfg)
@@ -399,6 +401,7 @@ int blk_crypto_start_using_key(struct block_device *bdev,
 	}
 	return blk_crypto_fallback_start_using_mode(key->crypto_cfg.crypto_mode);
 }
+EXPORT_SYMBOL_GPL(blk_crypto_start_using_key);
 
 /**
  * blk_crypto_evict_key() - Evict a blk_crypto_key from a block_device