blk-mq: Add blk_mq_ops.show_rq()

This new callback function will be used in the next patch to show
more information about SCSI requests.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index ac39093c4ef78919425d01c3c9a3945f86fc0bd1..bcd2a7d4a3a52fc23f26ee2e119a110579dadde6 100644 (file)
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -311,6 +311,7 @@ static const char *const rqf_name[] = {
 static int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
 {
        struct request *rq = list_entry_rq(v);
+       const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
        const unsigned int op = rq->cmd_flags & REQ_OP_MASK;
 
        seq_printf(m, "%p {.op=", rq);
@@ -324,8 +325,11 @@ static int blk_mq_debugfs_rq_show(struct seq_file *m, void *v)
        seq_puts(m, ", .rq_flags=");
        blk_flags_show(m, (__force unsigned int)rq->rq_flags, rqf_name,
                       ARRAY_SIZE(rqf_name));
-       seq_printf(m, ", .tag=%d, .internal_tag=%d}\n", rq->tag,
+       seq_printf(m, ", .tag=%d, .internal_tag=%d", rq->tag,
                   rq->internal_tag);
+       if (mq_ops->show_rq)
+               mq_ops->show_rq(m, rq);
+       seq_puts(m, "}\n");
        return 0;
 }
 

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 0c4dadb85f62a5e3605be6b37845779d8bcfd73c..32bd8eb5ba67b11c673bbb4ade84ab400892d4ca 100644 (file)
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -142,6 +142,14 @@ struct blk_mq_ops {
        reinit_request_fn       *reinit_request;
 
        map_queues_fn           *map_queues;
+
+#ifdef CONFIG_BLK_DEBUG_FS
+       /*
+        * Used by the debugfs implementation to show driver-specific
+        * information about a request.
+        */
+       void (*show_rq)(struct seq_file *m, struct request *rq);
+#endif
 };
 
 enum {