One more thing:

On Thu, May 14, 2020 at 12:37:25AM +0000, Satya Tangirala wrote:

+/* Enable inline encryption for this file if supported. */
+void fscrypt_select_encryption_impl(struct fscrypt_info *ci)
+{
+	const struct inode *inode = ci->ci_inode;
+	struct super_block *sb = inode->i_sb;
+	struct blk_crypto_config crypto_cfg;
+	int num_devs;
+	struct request_queue **devs;
+	int i;
+
+	/* The file must need contents encryption, not filenames encryption */
+	if (!fscrypt_needs_contents_encryption(inode))
+		return;
+
+	/* The crypto mode must be valid */
+	if (ci->ci_mode->blk_crypto_mode == BLK_ENCRYPTION_MODE_INVALID)
+		return;
+
+	/* The filesystem must be mounted with -o inlinecrypt */
+	if (!(sb->s_flags & SB_INLINECRYPT))
+		return;
+
+	/*
+	 * blk-crypto must support the crypto configuration we'll use for the
+	 * inode on all devices in the sb
+	 */
+	crypto_cfg.crypto_mode = ci->ci_mode->blk_crypto_mode;
+	crypto_cfg.data_unit_size = sb->s_blocksize;
+	crypto_cfg.dun_bytes = fscrypt_get_dun_bytes(ci);
+	num_devs = fscrypt_get_num_devices(sb);
+	devs = kmalloc_array(num_devs, sizeof(*devs), GFP_NOFS);
+	if (!devs)
+		return;

This function needs to return an error code, so that if this memory allocation
fails, the error is not ignored.

- Eric