lib: introduce crc_t10dif_update()

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.

(remove extra function call in crc_t10dif() and crc_t10dif_update -
 Tim + Herbert)

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: target-devel@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Akinobu Mita 2015-05-01 15:23:50 +09:00 committed by Nicholas Bellinger
parent 5835812f13
commit 10081fb532
2 changed files with 10 additions and 3 deletions

View File

@ -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

View File

@ -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 +28,23 @@ __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;
*(__u16 *)desc.ctx = crc;
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)