[PATCH v2] blk-mq-debugfs: Show more request state information

[PATCH v2] blk-mq-debugfs: Show more request state information

[Bart Van Assche]

Since commit 634f9e4631a8 ("blk-mq: remove REQ_ATOM_COMPLETE usages
from blk-mq") blk_rq_is_complete() only reports whether or not a
request has completed for legacy queues. Hence modify the
blk-mq-debugfs code such that it shows the blk-mq request state
again.

Fixes: 634f9e4631a8 ("blk-mq: remove REQ_ATOM_COMPLETE usages from blk-mq")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Tejun Heo <tj@kernel.org>
---

Changes compared to v1:
- Added an out-of-bounds check to the access of the request state name array
  as requested by Jens.

 block/blk-mq-debugfs.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index bd21d5b9f65f..58b3b79cbe83 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -350,6 +350,20 @@ static const char *const rqf_name[] = {
 };
 #undef RQF_NAME
 
+static const char *const blk_mq_rq_state_name_array[] = {
+	[MQ_RQ_IDLE]		= "idle",
+	[MQ_RQ_IN_FLIGHT]	= "in_flight",
+	[MQ_RQ_COMPLETE]	= "complete",
+};
+
+static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
+{
+	if (WARN_ON_ONCE((unsigned int)rq_state >
+			 ARRAY_SIZE(blk_mq_rq_state_name_array)))
+		return "(?)";
+	return blk_mq_rq_state_name_array[rq_state];
+}
+
 int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 {
 	const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
@@ -366,7 +380,7 @@ int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
 	seq_puts(m, ", .rq_flags=");
 	blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
 		       ARRAY_SIZE(rqf_name));
-	seq_printf(m, ", complete=%d", blk_rq_is_complete(rq));
+	seq_printf(m, ", .state=%s", blk_mq_rq_state_name(blk_mq_rq_state(rq)));
 	seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
 		   rq->internal_tag);
 	if (mq_ops->show_rq)
-- 
2.16.2

Re: [PATCH v2] blk-mq-debugfs: Show more request state information

[Jens Axboe]

On 3/16/18 10:31 AM, Bart Van Assche wrote:
> Since commit 634f9e4631a8 ("blk-mq: remove REQ_ATOM_COMPLETE usages
> from blk-mq") blk_rq_is_complete() only reports whether or not a
> request has completed for legacy queues. Hence modify the
> blk-mq-debugfs code such that it shows the blk-mq request state
> again.

Thanks, applied.

-- 
Jens Axboe