[PATCH 14/15] block: use bvec_kmap_local in t10_pi_type1_{prepare,complete}

From: Christoph Hellwig
Date: Tue Jul 27 2021 - 02:23:41 EST


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@xxxxxx>
Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
---
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);
}
}
}
--
2.30.2