[PATCH 10/18] dm-writecache: use bvec_kmap_local instead of bvec_kmap_irq

From: Christoph Hellwig
Date: Tue Jun 15 2021 - 09:30:49 EST


There is no need to disable interrupts in bio_copy_block, and the local
only mappings helps to avoid any sort of problems with stray writes
into the bio data.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
---
drivers/md/dm-writecache.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index aecc246ade26..93ca454eaca9 100644
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -1205,14 +1205,13 @@ static void memcpy_flushcache_optimized(void *dest, void *source, size_t size)
static void bio_copy_block(struct dm_writecache *wc, struct bio *bio, void *data)
{
void *buf;
- unsigned long flags;
unsigned size;
int rw = bio_data_dir(bio);
unsigned remaining_size = wc->block_size;

do {
struct bio_vec bv = bio_iter_iovec(bio, bio->bi_iter);
- buf = bvec_kmap_irq(&bv, &flags);
+ buf = bvec_kmap_local(&bv);
size = bv.bv_len;
if (unlikely(size > remaining_size))
size = remaining_size;
@@ -1230,7 +1229,7 @@ static void bio_copy_block(struct dm_writecache *wc, struct bio *bio, void *data
memcpy_flushcache_optimized(data, buf, size);
}

- bvec_kunmap_irq(buf, &flags);
+ kunmap_local(buf);

data = (char *)data + size;
remaining_size -= size;
--
2.30.2