From: Christoph Hellwig <hch@lst.de>
Date: Tue, 27 Jul 2021 07:56:45 +0200
Subject: [PATCH] block: use bvec_kmap_local in t10_pi_type1_{prepare,complete}
Git-commit: 8aec120a9ca80c14ce002505cea1e1639f8e9ea5
Patch-mainline: v5.15-rc1
References: jsc#PED1183

Using local kmaps slightly reduces the chances to stray writes, and
the bvec interface cleans up the code a little bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210727055646.118787-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 block/t10-pi.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/block/t10-pi.c b/block/t10-pi.c
index d910534b3a41..00c203b2a921 100644
--- a/block/t10-pi.c
+++ b/block/t10-pi.c
@@ -147,11 +147,10 @@ static void t10_pi_type1_prepare(struct request *rq)
 			break;
 
 		bip_for_each_vec(iv, bip, iter) {
-			void *p, *pmap;
 			unsigned int j;
+			void *p;
 
-			pmap = kmap_atomic(iv.bv_page);
-			p = pmap + iv.bv_offset;
+			p = bvec_kmap_local(&iv);
 			for (j = 0; j < iv.bv_len; j += tuple_sz) {
 				struct t10_pi_tuple *pi = p;
 
@@ -161,8 +160,7 @@ static void t10_pi_type1_prepare(struct request *rq)
 				ref_tag++;
 				p += tuple_sz;
 			}
-
-			kunmap_atomic(pmap);
+			kunmap_local(p);
 		}
 
 		bip->bip_flags |= BIP_MAPPED_INTEGRITY;
@@ -195,11 +193,10 @@ static void t10_pi_type1_complete(struct request *rq, unsigned int nr_bytes)
 		struct bvec_iter iter;
 
 		bip_for_each_vec(iv, bip, iter) {
-			void *p, *pmap;
 			unsigned int j;
+			void *p;
 
-			pmap = kmap_atomic(iv.bv_page);
-			p = pmap + iv.bv_offset;
+			p = bvec_kmap_local(&iv);
 			for (j = 0; j < iv.bv_len && intervals; j += tuple_sz) {
 				struct t10_pi_tuple *pi = p;
 
@@ -210,8 +207,7 @@ static void t10_pi_type1_complete(struct request *rq, unsigned int nr_bytes)
 				intervals--;
 				p += tuple_sz;
 			}
-
-			kunmap_atomic(pmap);
+			kunmap_local(p);
 		}
 	}
 }
-- 
2.35.3