On Sat, 2015-04-25 at 23:33 +0900, Akinobu Mita wrote:
> This introduces crc_t10dif_update() which enables to calculate CRC
> for a block which straddles multiple SG elements by calling multiple
> times.
>
> Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
> 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
> ---
> * New patch from v3
>
> include/linux/crc-t10dif.h | 1 +
> lib/crc-t10dif.c | 23 +++++++++++++++++++++++
> 2 files changed, 24 insertions(+)
>
> 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..7cdbe2e 100644
> --- a/lib/crc-t10dif.c
> +++ b/lib/crc-t10dif.c
> @@ -19,6 +19,29 @@
> static struct crypto_shash *crct10dif_tfm;
> static struct static_key crct10dif_fallback __read_mostly;
>
> +__u16 crc_t10dif_update(__u16 crc, const unsigned char *buffer, size_t len)
> +{
> + struct {
> + struct shash_desc shash;
> + char ctx[2];
> + } desc;
> + int err;
> +
> + if (static_key_false(&crct10dif_fallback))
> + return crc_t10dif_generic(crc, buffer, len);
> +
> + desc.shash.tfm = crct10dif_tfm;
> + desc.shash.flags = 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)
> {
> struct {
There are a lot of duplicated code between crc_t10dif_update and
crc_t10dif. The only difference is for the update function
we import the crc value. I will prefer that we consolidate the code
into a local inline function that crc_t10dif_update and
crc_t10dif invoke to get rid of all the duplication.
Probably something like:
diff --git a/lib/crc-t10dif.c b/lib/crc-t10dif.c
index dfe6ec1..0248f78 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)
+static inline __u16 __crc_t10dif_update(__u16 crc, const unsigned char *buffer, size_t len, bool update)
{
struct {
struct shash_desc shash;
@@ -28,17 +28,33 @@ __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;
+
+ if (update) {
+ err = crypto_shash_import(&desc.shash, &crc);
+ BUG_ON(err);
+ } else
+ *(__u16 *)desc.ctx = 0;
err = crypto_shash_update(&desc.shash, buffer, len);
BUG_ON(err);
return *(__u16 *)desc.ctx;
}
+
+__u16 crc_t10dif_update(__u16 crc, const unsigned char *buffer, size_t len)
+{
+ return __crc_t10dif_update(crc, buffer, len, true);
+}
+EXPORT_SYMBOL(crc_t10dif_update);
+
+__u16 crc_t10dif(const unsigned char *buffer, size_t len)
+{
+ return __crc_t10dif_update(0, buffer, len, false);
+}
EXPORT_SYMBOL(crc_t10dif);
Thanks.
Tim
--
To unsubscribe from this list: send the line "unsubscribe linux-crypto" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
