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authorJan Kara <jack@suse.cz>2022-04-01 12:27:49 +0200
committerJens Axboe <axboe@kernel.dk>2022-04-17 19:34:29 -0600
commit4e54a2493e582361adc3bfbf06c7d50d19d18837 (patch)
treeeb83d33e016c6e55c9871aae1ba01e8b82b0f0fc /block/bfq-iosched.c
parent09f871868080c33992cd6a9b72a5ca49582578fa (diff)
bfq: Get rid of __bio_blkcg() usage
BFQ usage of __bio_blkcg() is a relict from the past. Furthermore if bio would not be associated with any blkcg, the usage of __bio_blkcg() in BFQ is prone to races with the task being migrated between cgroups as __bio_blkcg() calls at different places could return different blkcgs. Convert BFQ to the new situation where bio->bi_blkg is initialized in bio_set_dev() and thus practically always valid. This allows us to save blkcg_gq lookup and noticeably simplify the code. CC: stable@vger.kernel.org Fixes: 0fe061b9f03c ("blkcg: fix ref count issue with bio_blkcg() using task_css") Tested-by: "yukuai (C)" <yukuai3@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220401102752.8599-8-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bfq-iosched.c')
-rw-r--r--block/bfq-iosched.c11
1 files changed, 1 insertions, 10 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index d7cf930b47bb..e47c75f1fa0f 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5726,14 +5726,7 @@ static struct bfq_queue *bfq_get_queue(struct bfq_data *bfqd,
struct bfq_queue *bfqq;
struct bfq_group *bfqg;
- rcu_read_lock();
-
- bfqg = bfq_find_set_group(bfqd, __bio_blkcg(bio));
- if (!bfqg) {
- bfqq = &bfqd->oom_bfqq;
- goto out;
- }
-
+ bfqg = bfq_bio_bfqg(bfqd, bio);
if (!is_sync) {
async_bfqq = bfq_async_queue_prio(bfqd, bfqg, ioprio_class,
ioprio);
@@ -5779,8 +5772,6 @@ out:
if (bfqq != &bfqd->oom_bfqq && is_sync && !respawn)
bfqq = bfq_do_or_sched_stable_merge(bfqd, bfqq, bic);
-
- rcu_read_unlock();
return bfqq;
}