blk-mq-debugfs: support rq_qos
blk-mq-debugfs has been proved as very helpful for debug some
tough issues, such as IO hang.
We have seen blk-wbt related IO hang several times, even inside
Red Hat BZ, there is such report not sovled yet, so this patch
adds support debugfs on rq_qos.
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index a32bb79..2793e91 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -23,6 +23,7 @@
#include "blk-mq.h"
#include "blk-mq-debugfs.h"
#include "blk-mq-tag.h"
+#include "blk-rq-qos.h"
static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
{
@@ -856,6 +857,15 @@ int blk_mq_debugfs_register(struct request_queue *q)
goto err;
}
+ if (q->rq_qos) {
+ struct rq_qos *rqos = q->rq_qos;
+
+ while (rqos) {
+ blk_mq_debugfs_register_rqos(rqos);
+ rqos = rqos->next;
+ }
+ }
+
return 0;
err:
@@ -978,6 +988,50 @@ void blk_mq_debugfs_unregister_sched(struct request_queue *q)
q->sched_debugfs_dir = NULL;
}
+void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
+{
+ debugfs_remove_recursive(rqos->debugfs_dir);
+ rqos->debugfs_dir = NULL;
+}
+
+int blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
+{
+ struct request_queue *q = rqos->q;
+ const char *dir_name = rq_qos_id_to_name(rqos->id);
+
+ if (!q->debugfs_dir)
+ return -ENOENT;
+
+ if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)
+ return 0;
+
+ if (!q->rqos_debugfs_dir) {
+ q->rqos_debugfs_dir = debugfs_create_dir("rqos",
+ q->debugfs_dir);
+ if (!q->rqos_debugfs_dir)
+ return -ENOMEM;
+ }
+
+ rqos->debugfs_dir = debugfs_create_dir(dir_name,
+ rqos->q->rqos_debugfs_dir);
+ if (!rqos->debugfs_dir)
+ return -ENOMEM;
+
+ if (!debugfs_create_files(rqos->debugfs_dir, rqos,
+ rqos->ops->debugfs_attrs))
+ goto err;
+ return 0;
+ err:
+ blk_mq_debugfs_unregister_rqos(rqos);
+ return -ENOMEM;
+}
+
+void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q)
+{
+ debugfs_remove_recursive(q->rqos_debugfs_dir);
+ q->rqos_debugfs_dir = NULL;
+}
+
int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
struct blk_mq_hw_ctx *hctx)
{