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authorChristoph Hellwig <hch@lst.de>2022-09-21 20:04:49 +0200
committerJens Axboe <axboe@kernel.dk>2022-09-26 19:09:31 -0600
commitf753526e327bc849c445c084d0f374e992038ae9 (patch)
treec27a5b9517059afbd651744999bf73add92fb07e
parentblk-cgroup: cleanup the blkg_lookup family of functions (diff)
downloadlinux-dev-f753526e327bc849c445c084d0f374e992038ae9.tar.xz
linux-dev-f753526e327bc849c445c084d0f374e992038ae9.zip
blk-cgroup: remove blkg_lookup_check
The combinations of an error check with an ERR_PTR return and a lookup with a NULL return leads to ugly handling of the return values in the callers. Just open coding the check and the lookup is much simpler. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Andreas Herrmann <aherrmann@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20220921180501.1539876-6-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--block/blk-cgroup.c36
1 files changed, 10 insertions, 26 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index d1216760d025..1306112d7648 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -602,25 +602,6 @@ u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v)
}
EXPORT_SYMBOL_GPL(__blkg_prfill_u64);
-/* Performs queue bypass and policy enabled checks then looks up blkg. */
-static struct blkcg_gq *blkg_lookup_check(struct blkcg *blkcg,
- const struct blkcg_policy *pol,
- struct request_queue *q)
-{
- struct blkcg_gq *blkg;
-
- WARN_ON_ONCE(!rcu_read_lock_held());
- lockdep_assert_held(&q->queue_lock);
-
- if (!blkcg_policy_enabled(q, pol))
- return ERR_PTR(-EOPNOTSUPP);
-
- blkg = blkg_lookup(blkcg, q);
- if (blkg)
- blkg_update_hint(blkcg, blkg);
- return blkg;
-}
-
/**
* blkcg_conf_open_bdev - parse and open bdev for per-blkg config update
* @inputp: input string pointer
@@ -697,14 +678,16 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
rcu_read_lock();
spin_lock_irq(&q->queue_lock);
- blkg = blkg_lookup_check(blkcg, pol, q);
- if (IS_ERR(blkg)) {
- ret = PTR_ERR(blkg);
+ if (!blkcg_policy_enabled(q, pol)) {
+ ret = -EOPNOTSUPP;
goto fail_unlock;
}
- if (blkg)
+ blkg = blkg_lookup(blkcg, q);
+ if (blkg) {
+ blkg_update_hint(blkcg, blkg);
goto success;
+ }
/*
* Create blkgs walking down from blkcg_root to @blkcg, so that all
@@ -740,14 +723,15 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
rcu_read_lock();
spin_lock_irq(&q->queue_lock);
- blkg = blkg_lookup_check(pos, pol, q);
- if (IS_ERR(blkg)) {
- ret = PTR_ERR(blkg);
+ if (!blkcg_policy_enabled(q, pol)) {
blkg_free(new_blkg);
+ ret = -EOPNOTSUPP;
goto fail_preloaded;
}
+ blkg = blkg_lookup(pos, q);
if (blkg) {
+ blkg_update_hint(pos, blkg);
blkg_free(new_blkg);
} else {
blkg = blkg_create(pos, q, new_blkg);