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authorChristoph Hellwig <hch@lst.de>2022-04-20 06:27:17 +0200
committerJens Axboe <axboe@kernel.dk>2022-05-02 14:06:20 -0600
commitbbb1ebe7a909db4de49777fb7676d5bf293f34c9 (patch)
tree0cff6de0224344909db8e482e9167d93b94f8c2a /block
parentf4a6a61cb6d40d9ae63e47743d33200f3efe3fe7 (diff)
blk-cgroup: replace bio_blkcg with bio_blkcg_css
All callers of bio_blkcg actually want the CSS, so replace it with an interface that does return the CSS. This now allows to move struct blkcg_gq to block/blk-cgroup.h instead of exposing it in a public header. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20220420042723.1010598-10-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-cgroup.c18
-rw-r--r--block/blk-cgroup.h67
2 files changed, 81 insertions, 4 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index bb52797c02bd..8e32cc494808 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -156,6 +156,22 @@ static void blkg_async_bio_workfn(struct work_struct *work)
}
/**
+ * bio_blkcg_css - return the blkcg CSS associated with a bio
+ * @bio: target bio
+ *
+ * This returns the CSS for the blkcg associated with a bio, or %NULL if not
+ * associated. Callers are expected to either handle %NULL or know association
+ * has been done prior to calling this.
+ */
+struct cgroup_subsys_state *bio_blkcg_css(struct bio *bio)
+{
+ if (!bio || !bio->bi_blkg)
+ return NULL;
+ return &bio->bi_blkg->blkcg->css;
+}
+EXPORT_SYMBOL_GPL(bio_blkcg_css);
+
+/**
* blkcg_parent - get the parent of a blkcg
* @blkcg: blkcg of interest
*
@@ -1938,7 +1954,7 @@ void bio_associate_blkg(struct bio *bio)
rcu_read_lock();
if (bio->bi_blkg)
- css = &bio_blkcg(bio)->css;
+ css = bio_blkcg_css(bio);
else
css = blkcg_css();
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index b00fb1169e7c..03405ddf2a7b 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -25,6 +25,64 @@ struct blkg_policy_data;
#define BLKG_STAT_CPU_BATCH (INT_MAX / 2)
#ifdef CONFIG_BLK_CGROUP
+
+enum blkg_iostat_type {
+ BLKG_IOSTAT_READ,
+ BLKG_IOSTAT_WRITE,
+ BLKG_IOSTAT_DISCARD,
+
+ BLKG_IOSTAT_NR,
+};
+
+struct blkg_iostat {
+ u64 bytes[BLKG_IOSTAT_NR];
+ u64 ios[BLKG_IOSTAT_NR];
+};
+
+struct blkg_iostat_set {
+ struct u64_stats_sync sync;
+ struct blkg_iostat cur;
+ struct blkg_iostat last;
+};
+
+/* association between a blk cgroup and a request queue */
+struct blkcg_gq {
+ /* Pointer to the associated request_queue */
+ struct request_queue *q;
+ struct list_head q_node;
+ struct hlist_node blkcg_node;
+ struct blkcg *blkcg;
+
+ /* all non-root blkcg_gq's are guaranteed to have access to parent */
+ struct blkcg_gq *parent;
+
+ /* reference count */
+ struct percpu_ref refcnt;
+
+ /* is this blkg online? protected by both blkcg and q locks */
+ bool online;
+
+ struct blkg_iostat_set __percpu *iostat_cpu;
+ struct blkg_iostat_set iostat;
+
+ struct blkg_policy_data *pd[BLKCG_MAX_POLS];
+
+ spinlock_t async_bio_lock;
+ struct bio_list async_bios;
+ union {
+ struct work_struct async_bio_work;
+ struct work_struct free_work;
+ };
+
+ atomic_t use_delay;
+ atomic64_t delay_nsec;
+ atomic64_t delay_start;
+ u64 last_delay;
+ int last_use;
+
+ struct rcu_head rcu_head;
+};
+
struct blkcg {
struct cgroup_subsys_state css;
spinlock_t lock;
@@ -173,9 +231,9 @@ static inline struct cgroup_subsys_state *blkcg_css(void)
*
* In order to avoid priority inversions we sometimes need to issue a bio as if
* it were attached to the root blkg, and then backcharge to the actual owning
- * blkg. The idea is we do bio_blkcg() to look up the actual context for the
- * bio and attach the appropriate blkg to the bio. Then we call this helper and
- * if it is true run with the root blkg for that queue and then do any
+ * blkg. The idea is we do bio_blkcg_css() to look up the actual context for
+ * the bio and attach the appropriate blkg to the bio. Then we call this helper
+ * and if it is true run with the root blkg for that queue and then do any
* backcharging to the originating cgroup once the io is complete.
*/
static inline bool bio_issue_as_root_blkg(struct bio *bio)
@@ -464,6 +522,9 @@ struct blkcg_policy_data {
struct blkcg_policy {
};
+struct blkcg {
+};
+
#ifdef CONFIG_BLOCK
static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; }