diff options
| author | Jan Kara <jack@suse.cz> | 2022-06-06 19:56:39 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-09 10:21:31 +0200 |
| commit | 0285718e28259e41f405a038ee0e6bb984fd1b34 (patch) | |
| tree | 92d623efbce9d074372d9af1b83f6466ebfcc5e1 /block/bfq-iosched.c | |
| parent | 80b0a2b3dfea5de3224ba756830b9243709c6e9e (diff) | |
bfq: Get rid of __bio_blkcg() usage
commit 4e54a2493e582361adc3bfbf06c7d50d19d18837 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'block/bfq-iosched.c')
| -rw-r--r-- | block/bfq-iosched.c | 10 |
1 files changed, 1 insertions, 9 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 3b605d8d99bf..592d32a46c4c 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -5162,14 +5162,7 @@ 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); @@ -5213,7 +5206,6 @@ static struct bfq_queue *bfq_get_queue(struct bfq_data *bfqd, out: bfqq->ref++; /* get a process reference to this queue */ bfq_log_bfqq(bfqd, bfqq, "get_queue, at end: %p, %d", bfqq, bfqq->ref); - rcu_read_unlock(); return bfqq; } |