This introduces crc_t10dif_update() which enables to calculate CRC
for a block which straddles multiple SG elements by calling multiple
times. This also converts crc_t10dif() to use crc_t10dif_update() as
they are almost same.
Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Acked-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Cc: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: linux-crypto@xxxxxxxxxxxxxxx
Cc: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Cc: Sagi Grimberg <sagig@xxxxxxxxxxxx>
Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: "James E.J. Bottomley" <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Cc: target-devel@xxxxxxxxxxxxxxx
---
* Changes from v3:
- Reduce duplicated code between crc_t10dif_update and crc_t10dif,
suggested by Tim and Herbert
include/linux/crc-t10dif.h | 1 +
lib/crc-t10dif.c | 13 ++++++++++---
2 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/include/linux/crc-t10dif.h b/include/linux/crc-t10dif.h
index cf53d07..d81961e 100644
--- a/include/linux/crc-t10dif.h
+++ b/include/linux/crc-t10dif.h
@@ -9,5 +9,6 @@
extern __u16 crc_t10dif_generic(__u16 crc, const unsigned char *buffer,
size_t len);
extern __u16 crc_t10dif(unsigned char const *, size_t);
+extern __u16 crc_t10dif_update(__u16 crc, unsigned char const *, size_t);
#endif
diff --git a/lib/crc-t10dif.c b/lib/crc-t10dif.c
index dfe6ec1..d775737 100644
--- a/lib/crc-t10dif.c
+++ b/lib/crc-t10dif.c
@@ -19,7 +19,7 @@
static struct crypto_shash *crct10dif_tfm;
static struct static_key crct10dif_fallback __read_mostly;
-__u16 crc_t10dif(const unsigned char *buffer, size_t len)
+__u16 crc_t10dif_update(__u16 crc, const unsigned char *buffer, size_t len)
{
struct {
struct shash_desc shash;
@@ -28,17 +28,24 @@ __u16 crc_t10dif(const unsigned char *buffer, size_t len)
int err;
if (static_key_false(&crct10dif_fallback))
- return crc_t10dif_generic(0, buffer, len);
+ return crc_t10dif_generic(crc, buffer, len);
desc.shash.tfm = crct10dif_tfm;
desc.shash.flags = 0;
- *(__u16 *)desc.ctx = 0;
+ err = crypto_shash_import(&desc.shash, &crc);
+ BUG_ON(err);
err = crypto_shash_update(&desc.shash, buffer, len);
BUG_ON(err);
return *(__u16 *)desc.ctx;
}
+EXPORT_SYMBOL(crc_t10dif_update);
+
+__u16 crc_t10dif(const unsigned char *buffer, size_t len)
+{
+ return crc_t10dif_update(0, buffer, len);
+}
EXPORT_SYMBOL(crc_t10dif);
static int __init crc_t10dif_mod_init(void)
--
1.9.1
--
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