[PATCH 3/9] blk-crypto: add a bio_crypt_ctx() helper

[Christoph Hellwig <hch@lst.de>]

This returns the bio_crypt_ctx if CONFIG_BLK_INLINE_ENCRYPTION is enabled
and a crypto context is attached to the bio, else NULL.

The use case is to allow safely dereferencing the context in common code
without needed #ifdef CONFIG_BLK_INLINE_ENCRYPTION.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
---
 include/linux/blk-crypto.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/include/linux/blk-crypto.h b/include/linux/blk-crypto.h
index 58b0c5254a67..eb80df19be68 100644
--- a/include/linux/blk-crypto.h
+++ b/include/linux/blk-crypto.h
@@ -132,6 +132,11 @@ static inline bool bio_has_crypt_ctx(struct bio *bio)
 	return bio->bi_crypt_context;
 }
 
+static inline struct bio_crypt_ctx *bio_crypt_ctx(struct bio *bio)
+{
+	return bio->bi_crypt_context;
+}
+
 void bio_crypt_set_ctx(struct bio *bio, const struct blk_crypto_key *key,
 		       const u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
 		       gfp_t gfp_mask);
@@ -169,6 +174,11 @@ static inline bool bio_has_crypt_ctx(struct bio *bio)
 	return false;
 }
 
+static inline struct bio_crypt_ctx *bio_crypt_ctx(struct bio *bio)
+{
+	return NULL;
+}
+
 #endif /* CONFIG_BLK_INLINE_ENCRYPTION */
 
 int __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask);
-- 
2.47.3