[PATCH v2 08/21] dm-crypt: Make use of the new sg_map helper in 4 call sites

[Logan Gunthorpe <logang-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>]

Very straightforward conversion to the new function in all four spots.

Signed-off-by: Logan Gunthorpe <logang-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
Cc: Alasdair Kergon <agk-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Mike Snitzer <snitzer-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 drivers/md/dm-crypt.c | 39 ++++++++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 13 deletions(-)

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 8dbecf1..841f1fc 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -635,9 +635,12 @@ static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
 
 	if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
 		sg = crypt_get_sg_data(cc, dmreq->sg_in);
-		src = kmap_atomic(sg_page(sg));
-		r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset);
-		kunmap_atomic(src);
+		src = sg_map(sg, 0, SG_KMAP_ATOMIC);
+		if (IS_ERR(src))
+			return PTR_ERR(src);
+
+		r = crypt_iv_lmk_one(cc, iv, dmreq, src);
+		sg_unmap(sg, src, 0, SG_KMAP_ATOMIC);
 	} else
 		memset(iv, 0, cc->iv_size);
 
@@ -655,14 +658,18 @@ static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
 		return 0;
 
 	sg = crypt_get_sg_data(cc, dmreq->sg_out);
-	dst = kmap_atomic(sg_page(sg));
-	r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset);
+	dst = sg_map(sg, 0, SG_KMAP_ATOMIC);
+	if (IS_ERR(dst))
+		return PTR_ERR(dst);
+
+	r = crypt_iv_lmk_one(cc, iv, dmreq, dst);
 
 	/* Tweak the first block of plaintext sector */
 	if (!r)
-		crypto_xor(dst + sg->offset, iv, cc->iv_size);
+		crypto_xor(dst, iv, cc->iv_size);
+
+	sg_unmap(sg, dst, 0, SG_KMAP_ATOMIC);
 
-	kunmap_atomic(dst);
 	return r;
 }
 
@@ -786,9 +793,12 @@ static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
 	/* Remove whitening from ciphertext */
 	if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
 		sg = crypt_get_sg_data(cc, dmreq->sg_in);
-		src = kmap_atomic(sg_page(sg));
-		r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset);
-		kunmap_atomic(src);
+		src = sg_map(sg, 0, SG_KMAP_ATOMIC);
+		if (IS_ERR(src))
+			return PTR_ERR(src);
+
+		r = crypt_iv_tcw_whitening(cc, dmreq, src);
+		sg_unmap(sg, src, 0, SG_KMAP_ATOMIC);
 	}
 
 	/* Calculate IV */
@@ -812,9 +822,12 @@ static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
 
 	/* Apply whitening on ciphertext */
 	sg = crypt_get_sg_data(cc, dmreq->sg_out);
-	dst = kmap_atomic(sg_page(sg));
-	r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset);
-	kunmap_atomic(dst);
+	dst = sg_map(sg, 0, SG_KMAP_ATOMIC);
+	if (IS_ERR(dst))
+		return PTR_ERR(dst);
+
+	r = crypt_iv_tcw_whitening(cc, dmreq, dst);
+	sg_unmap(sg, dst, 0, SG_KMAP_ATOMIC);
 
 	return r;
 }
-- 
2.1.4