bcache: Fix flash_dev_cache_miss() for real this time
The code was using sectors to count the number of sectors it was zeroing... but
then it passed it to bio_advance()... after it had been set to 0. Amusing...
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 5d5d031..fc14ba3 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -1203,22 +1203,13 @@
static int flash_dev_cache_miss(struct btree *b, struct search *s,
struct bio *bio, unsigned sectors)
{
- struct bio_vec bv;
- struct bvec_iter iter;
+ unsigned bytes = min(sectors, bio_sectors(bio)) << 9;
- /* Zero fill bio */
+ swap(bio->bi_iter.bi_size, bytes);
+ zero_fill_bio(bio);
+ swap(bio->bi_iter.bi_size, bytes);
- bio_for_each_segment(bv, bio, iter) {
- unsigned j = min(bv.bv_len >> 9, sectors);
-
- void *p = kmap(bv.bv_page);
- memset(p + bv.bv_offset, 0, j << 9);
- kunmap(bv.bv_page);
-
- sectors -= j;
- }
-
- bio_advance(bio, min(sectors << 9, bio->bi_iter.bi_size));
+ bio_advance(bio, bytes);
if (!bio->bi_iter.bi_size)
return MAP_DONE;