[PATCH v2 2/4] blk-mq-debugfs: Show requeue list
From: Bart Van Assche <hidden>
Date: 2017-05-31 21:30:48
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
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 <redacted> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Omar Sandoval <redacted> Cc: Ming Lei <redacted> --- block/blk-mq-debugfs.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index d56ddd7a1285..8b06a12c1461 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c@@ -308,6 +308,37 @@ int blk_mq_debugfs_rq_show(struct seq_file *m, void *v) } EXPORT_SYMBOL_GPL(blk_mq_debugfs_rq_show); +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_irq(&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_irq(&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 void *hctx_dispatch_start(struct seq_file *m, loff_t *pos) __acquires(&hctx->lock) {
@@ -665,6 +696,7 @@ const struct file_operations blk_mq_debugfs_fops = { static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = { {"poll_stat", 0400, queue_poll_stat_show}, + {"requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops}, {"state", 0600, queue_state_show, queue_state_write}, {}, };
--
2.12.2