nvme: add disk name to trace events

This will print the disk name to the nvme event trace for io requests so
a user can better distinguish traffic to different disks. This can be used
to  create disk based filters. For example, to see only nvme0n2 traffic:

  echo "disk == \"nvme0n2\"" > /sys/kernel/debug/tracing/events/nvme/filter

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
[hch: turned __assign_disk_name into an inline function]
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/host/trace.c b/drivers/nvme/host/trace.c
index 41944bbef8353e6b7fbf9a58127b62be0ac66a53..25b0e310f4a813e87e3a9d4a9eadc0c17e40eb6b 100644 (file)
--- a/drivers/nvme/host/trace.c
+++ b/drivers/nvme/host/trace.c
@@ -128,3 +128,14 @@ const char *nvme_trace_parse_nvm_cmd(struct trace_seq *p,
                return nvme_trace_common(p, cdw10);
        }
 }
+
+const char *nvme_trace_disk_name(struct trace_seq *p, char *name)
+{
+       const char *ret = trace_seq_buffer_ptr(p);
+
+       if (*name)
+               trace_seq_printf(p, "disk=%s, ", name);
+       trace_seq_putc(p, 0);
+
+       return ret;
+}

diff --git a/drivers/nvme/host/trace.h b/drivers/nvme/host/trace.h
index 35b8c72478d533763d4a8a505c566c879700a55c..a490790d669136d91a7350b15a7273eff7e2cbd7 100644 (file)
--- a/drivers/nvme/host/trace.h
+++ b/drivers/nvme/host/trace.h
@@ -78,10 +78,25 @@ const char *nvme_trace_parse_nvm_cmd(struct trace_seq *p, u8 opcode,
         nvme_trace_parse_nvm_cmd(p, opcode, cdw10) :           \
         nvme_trace_parse_admin_cmd(p, opcode, cdw10))
 
+const char *nvme_trace_disk_name(struct trace_seq *p, char *name);
+#define __print_disk_name(name)                                \
+       nvme_trace_disk_name(p, name)
+
+#ifndef TRACE_HEADER_MULTI_READ
+static inline void __assign_disk_name(char *name, struct gendisk *disk)
+{
+       if (disk)
+               memcpy(name, disk->disk_name, DISK_NAME_LEN);
+       else
+               memset(name, 0, DISK_NAME_LEN);
+}
+#endif
+
 TRACE_EVENT(nvme_setup_cmd,
            TP_PROTO(struct request *req, struct nvme_command *cmd),
            TP_ARGS(req, cmd),
            TP_STRUCT__entry(
+               __array(char, disk, DISK_NAME_LEN)
                __field(int, ctrl_id)
                __field(int, qid)
                __field(u8, opcode)
@@ -99,12 +114,14 @@ TRACE_EVENT(nvme_setup_cmd,
                __entry->cid = cmd->common.command_id;
                __entry->nsid = le32_to_cpu(cmd->common.nsid);
                __entry->metadata = le64_to_cpu(cmd->common.metadata);
+               __assign_disk_name(__entry->disk, req->rq_disk);
                memcpy(__entry->cdw10, cmd->common.cdw10,
                       sizeof(__entry->cdw10));
            ),
-           TP_printk("nvme%d: qid=%d, cmdid=%u, nsid=%u, flags=0x%x, meta=0x%llx, cmd=(%s %s)",
-                     __entry->ctrl_id, __entry->qid, __entry->cid,
-                     __entry->nsid, __entry->flags, __entry->metadata,
+           TP_printk("nvme%d: %sqid=%d, cmdid=%u, nsid=%u, flags=0x%x, meta=0x%llx, cmd=(%s %s)",
+                     __entry->ctrl_id, __print_disk_name(__entry->disk),
+                     __entry->qid, __entry->cid, __entry->nsid,
+                     __entry->flags, __entry->metadata,
                      show_opcode_name(__entry->qid, __entry->opcode),
                      parse_nvme_cmd(__entry->qid, __entry->opcode, __entry->cdw10))
 );
@@ -113,6 +130,7 @@ TRACE_EVENT(nvme_complete_rq,
            TP_PROTO(struct request *req),
            TP_ARGS(req),
            TP_STRUCT__entry(
+               __array(char, disk, DISK_NAME_LEN)
                __field(int, ctrl_id)
                __field(int, qid)
                __field(int, cid)
@@ -129,11 +147,12 @@ TRACE_EVENT(nvme_complete_rq,
                __entry->retries = nvme_req(req)->retries;
                __entry->flags = nvme_req(req)->flags;
                __entry->status = nvme_req(req)->status;
+               __assign_disk_name(__entry->disk, req->rq_disk);
            ),
-           TP_printk("nvme%d: qid=%d, cmdid=%u, res=%llu, retries=%u, flags=0x%x, status=%u",
-                     __entry->ctrl_id,  __entry->qid, __entry->cid,
-                     __entry->result, __entry->retries, __entry->flags,
-                     __entry->status)
+           TP_printk("nvme%d: %sqid=%d, cmdid=%u, res=%llu, retries=%u, flags=0x%x, status=%u",
+                     __entry->ctrl_id, __print_disk_name(__entry->disk),
+                     __entry->qid, __entry->cid, __entry->result,
+                     __entry->retries, __entry->flags, __entry->status)
 
 );