block: really clone the block cgroup in bio_clone_blkg_association

bio_clone_blkg_association is supposed to clone the associatation, but actually ends up doing a search with a tryget. As we know we have a reference on the source cgroup just get an unconditional additional reference to it and call it a day. That also removes the need for a RCU critical section. Acked-by: Tejun Heo <[email protected]> Reviewed-by: Johannes Thumshirn <[email protected]> Signed-off-by: Christoph Hellwig <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
pop-os · Jun 29, 2020 · d92c370 · d92c370
1 parent db9819c
commit d92c370
Showing 1 changed file with 6 additions and 6 deletions.
diff --git a/block/bio.c b/block/bio.c
@@ -1737,12 +1737,12 @@ EXPORT_SYMBOL_GPL(bio_associate_blkg);
  */
 void bio_clone_blkg_association(struct bio *dst, struct bio *src)
 {
-	rcu_read_lock();
-
-	if (src->bi_blkg)
-		__bio_associate_blkg(dst, src->bi_blkg);
-
-	rcu_read_unlock();
+	if (src->bi_blkg) {
+		if (dst->bi_blkg)
+			blkg_put(dst->bi_blkg);
+		blkg_get(src->bi_blkg);
+		dst->bi_blkg = src->bi_blkg;
+	}
 }
 EXPORT_SYMBOL_GPL(bio_clone_blkg_association);
 #endif /* CONFIG_BLK_CGROUP */