From 6ab2187992f4b0112852e5a097a2b6c7d167e2e5 Mon Sep 17 00:00:00 2001 From: Dennis Zhou Date: Wed, 19 Dec 2018 16:43:21 -0600 Subject: blkcg: clean up blkg_tryget_closest() The implementation of blkg_tryget_closest() wasn't super obvious and became a point of suspicion when debugging [1]. So let's clean it up so it's obviously not the problem. Also add missing RCU read locking to bio_clone_blkg_association(), which got exposed by adding the RCU read lock held check in blkg_tryget_closest(). [1] https://lore.kernel.org/linux-block/a7e97e4b-0dd8-3a54-23b7-a0f27b17fde8@kernel.dk/ Signed-off-by: Dennis Zhou Signed-off-by: Jens Axboe --- block/bio.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'block/bio.c') diff --git a/block/bio.c b/block/bio.c index c288b9057042..9194d8ad3d5e 100644 --- a/block/bio.c +++ b/block/bio.c @@ -2096,8 +2096,12 @@ 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(); } EXPORT_SYMBOL_GPL(bio_clone_blkg_association); #endif /* CONFIG_BLK_CGROUP */ -- cgit