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Subject[PATCH 03/14] block: really clone the block cgroup in bio_clone_blkg_association
Date
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.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/bio.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 8aef4460b32e0e..e1d01acce8070c 100644
--- 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 */
--
2.26.2
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