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| author | Dennis Zhou (Facebook) <dennisszhou@gmail.com> | 2018-09-11 20:41:27 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-09-22 04:29:03 +0200 |
| commit | 49f4c2dc2b5066e9211101c59cc0828e81d41614 (patch) | |
| tree | 217391585a20535d3c2606d98659786bf73682e2 /block/blk-iolatency.c | |
| parent | blkcg: fix ref count issue with bio_blkcg using task_css (diff) | |
| download | linux-49f4c2dc2b5066e9211101c59cc0828e81d41614.tar.xz linux-49f4c2dc2b5066e9211101c59cc0828e81d41614.zip | |
blkcg: update blkg_lookup_create to do locking
To know when to create a blkg, the general pattern is to do a
blkg_lookup and if that fails, lock and then do a lookup again and if
that fails finally create. It doesn't make much sense for everyone who
wants to do creation to write this themselves.
This changes blkg_lookup_create to do locking and implement this
pattern. The old blkg_lookup_create is renamed to __blkg_lookup_create.
If a call site wants to do its own error handling or already owns the
queue lock, they can use __blkg_lookup_create. This will be used in
upcoming patches.
Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-iolatency.c')
| -rw-r--r-- | block/blk-iolatency.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index 82450c37f2aa..ffde3ab9f84c 100644 --- a/block/blk-iolatency.c +++ b/block/blk-iolatency.c @@ -407,7 +407,7 @@ static void blkcg_iolatency_throttle(struct rq_qos *rqos, struct bio *bio, if (unlikely(!blkg)) { if (!lock) spin_lock_irq(q->queue_lock); - blkg = blkg_lookup_create(blkcg, q); + blkg = __blkg_lookup_create(blkcg, q); if (IS_ERR(blkg)) blkg = NULL; if (!lock) |