When verifying whether or not a blk-mq driver forgot to kick the
requeue list after having requeued a request it is important to
be able to verify the contents of the requeue list. Hence export
that list through debugfs.
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Cc: Omar Sandoval <osandov@xxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxxx>
---
block/blk-mq-debugfs.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 9cb673bc7230..5092d90e37f6 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -341,6 +341,50 @@ static int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
return 0;
}
+static void *queue_requeue_list_start(struct seq_file *m, loff_t *pos)
+ __acquires(&q->requeue_lock)
+{
+ struct request_queue *q = m->private;
+
+ spin_lock(&q->requeue_lock);
+ return seq_list_start(&q->requeue_list, *pos);
+}
+
+static void *queue_requeue_list_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct request_queue *q = m->private;
+
+ return seq_list_next(v, &q->requeue_list, pos);
+}
+
+static void queue_requeue_list_stop(struct seq_file *m, void *v)
+ __releases(&q->requeue_lock)
+{
+ struct request_queue *q = m->private;
+
+ spin_unlock(&q->requeue_lock);
+}
+
+static const struct seq_operations queue_requeue_list_seq_ops = {
+ .start = queue_requeue_list_start,
+ .next = queue_requeue_list_next,
+ .stop = queue_requeue_list_stop,
+ .show = blk_mq_debugfs_rq_show,
+};
+
+static int queue_requeue_list_open(struct inode *inode, struct file *file)
+{
+ return blk_mq_debugfs_seq_open(inode, file,
+ &queue_requeue_list_seq_ops);
+}
+
+static const struct file_operations queue_requeue_list_fops = {
+ .open = queue_requeue_list_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos)
__acquires(&hctx->lock)
{
@@ -831,6 +875,7 @@ static const struct file_operations ctx_completed_fops = {
};
static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
+ {"requeue_list", 0400, &queue_requeue_list_fops},
{"poll_stat", 0400, &queue_poll_stat_fops},
{"state", 0600, &blk_queue_flags_fops},
{},
--
2.12.2
