On Thu, Mar 12, 2020 at 01:02:51AM -0700, Satya Tangirala wrote:

+int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key,
+				     const u8 *raw_key,
+				     const struct fscrypt_info *ci)
+{
+	const struct inode *inode = ci->ci_inode;
+	struct super_block *sb = inode->i_sb;
+	enum blk_crypto_mode_num crypto_mode = ci->ci_mode->blk_crypto_mode;
+	unsigned int blk_crypto_dun_bytes;

'blk_crypto_dun_bytes' is overly verbose.  'dun_bytes' would still be just as
clear.

This comment also applies to the parameter to blk_crypto_init_key().

+/**
+ * fscrypt_set_bio_crypt_ctx_bh - prepare a file contents bio for inline
+ *				  encryption
+ * @bio: a bio which will eventually be submitted to the file
+ * @first_bh: the first buffer_head for which I/O will be submitted
+ * @gfp_mask: memory allocation flags
+ *
+ * Same as fscrypt_set_bio_crypt_ctx(), except this takes a buffer_head instead
+ * of an inode and block number directly.
+ */
+void fscrypt_set_bio_crypt_ctx_bh(struct bio *bio,
+				 const struct buffer_head *first_bh,
+				 gfp_t gfp_mask)
+{
+	const struct inode *inode;
+	u64 first_lblk;
+
+	if (bh_get_inode_and_lblk_num(first_bh, &inode, &first_lblk))
+		fscrypt_set_bio_crypt_ctx(bio, inode, first_lblk, gfp_mask);
+}
+EXPORT_SYMBOL_GPL(fscrypt_set_bio_crypt_ctx_bh);

Nit: the continuation lines for the function arguments aren't aligned.

- Eric