@@ -1,6 +1,8 @@
 config JBD2
 	tristate
 	select CRC32
+	select CRYPTO
+	select CRYPTO_CRC32C
 	help
 	  This is a generic journaling layer for block devices that support
 	  both 32-bit and 64-bit block numbers.  It is currently used by

@@ -1284,6 +1284,16 @@ static int journal_get_superblock(journal_t *journal)
 		goto out;
 	}
 
+	/* Load the checksum driver */
+	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2)) {
+		journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
+		if (IS_ERR(journal->j_chksum_driver)) {
+			err = PTR_ERR(journal->j_chksum_driver);
+			journal->j_chksum_driver = NULL;
+			goto out;
+		}
+	}
+
 	set_buffer_verified(bh);
 
 	return 0;

@@ -1440,6 +1450,8 @@ int jbd2_journal_destroy(journal_t *journal)
 		iput(journal->j_inode);
 	if (journal->j_revoke)
 		jbd2_journal_destroy_revoke(journal);
+	if (journal->j_chksum_driver)
+		crypto_free_shash(journal->j_chksum_driver);
 	kfree(journal->j_wbuf);
 	kfree(journal);
 

@@ -1556,6 +1568,16 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
 		sb->s_checksum_type = JBD2_CRC32C_CHKSUM;
 		sb->s_feature_compat &=
 			~cpu_to_be32(JBD2_FEATURE_COMPAT_CHECKSUM);
+
+		/* Load the checksum driver */
+		if (journal->j_chksum_driver == NULL) {
+			journal->j_chksum_driver = crypto_alloc_shash("crc32c",
+								      0, 0);
+			if (IS_ERR(journal->j_chksum_driver)) {
+				journal->j_chksum_driver = NULL;
+				return 0;
+			}
+		}
 	}
 
 	/* If enabling v1 checksums, downgrade superblock */

@@ -31,6 +31,7 @@
 #include <linux/mutex.h>
 #include <linux/timer.h>
 #include <linux/slab.h>
+#include <crypto/hash.h>
 #endif
 
 #define journal_oom_retry 1

@@ -945,6 +946,9 @@ struct journal_s
 
 	/* Precomputed UUID checksum */
 	__u32 j_uuid_csum;
+
+	/* Reference to checksum algorithm driver via cryptoapi */
+	struct crypto_shash *j_chksum_driver;
 };
 
 /*

@@ -1263,6 +1267,25 @@ static inline int jbd_space_needed(journal_t *journal)
 
 extern int jbd_blocks_per_page(struct inode *inode);
 
+static inline u32 jbd2_chksum(journal_t *journal, u32 crc,
+			      const void *address, unsigned int length)
+{
+	struct {
+		struct shash_desc shash;
+		char ctx[crypto_shash_descsize(journal->j_chksum_driver)];
+	} desc;
+	int err;
+
+	desc.shash.tfm = journal->j_chksum_driver;
+	desc.shash.flags = 0;
+	*(u32 *)desc.ctx = crc;
+
+	err = crypto_shash_update(&desc.shash, address, length);
+	BUG_ON(err);
+
+	return *(u32 *)desc.ctx;
+}
+
 #ifdef __KERNEL__
 
 #define buffer_trace_init(bh)	do {} while (0)