scsi: iscsi: Capture iscsi debug messages using tracepoints

This commit enhances iscsi initiator modules to capture iscsi debug
messages using linux kernel tracepoint facility:

https://www.kernel.org/doc/Documentation/trace/tracepoints.txt

The following tracepoint events have been created under the iscsi
tracepoint event group:

iscsi_dbg_conn - to capture connection debug messages (libiscsi module)

iscsi_dbg_session - to capture session debug messages (libiscsi module)

iscsi_dbg_eh - to capture error handling debug messages (libiscsi module)

iscsi_dbg_tcp - to capture iscsi tcp debug messages (libiscsi_tcp module)

iscsi_dbg_sw_tcp - to capture iscsi sw tcp debug messages (iscsi_tcp module)

iscsi_dbg_trans_session - to cpature iscsi transsport sess debug messages
	(scsi_transport_iscsi module)

iscsi_dbg_trans_conn - to capture iscsi transport conn debug messages
	(scsi_transport_iscsi module)

[mkp: typos]

Signed-off-by: Fred Herard <fred.herard@oracle.com>
Reviewed-by: Rajan Shanmugavelu <rajan.shanmugavelu@oracle.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 0175684..cae6368 100644 (file)
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -44,6 +44,7 @@
 #include <scsi/scsi_host.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_transport_iscsi.h>
+#include <trace/events/iscsi.h>
 
 #include "iscsi_tcp.h"
 
@@ -72,6 +73,9 @@ MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module "
                        iscsi_conn_printk(KERN_INFO, _conn,     \
                                             "%s " dbg_fmt,     \
                                             __func__, ##arg);  \
+               iscsi_dbg_trace(trace_iscsi_dbg_sw_tcp,         \
+                               &(_conn)->cls_conn->dev,        \
+                               "%s " dbg_fmt, __func__, ##arg);\
        } while (0);
 
 

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 93c66eb..d8e0135 100644 (file)
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -40,6 +40,7 @@
 #include <scsi/scsi_transport.h>
 #include <scsi/scsi_transport_iscsi.h>
 #include <scsi/libiscsi.h>
+#include <trace/events/iscsi.h>
 
 static int iscsi_dbg_lib_conn;
 module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
@@ -68,6 +69,9 @@ MODULE_PARM_DESC(debug_libiscsi_eh,
                        iscsi_conn_printk(KERN_INFO, _conn,     \
                                             "%s " dbg_fmt,     \
                                             __func__, ##arg);  \
+               iscsi_dbg_trace(trace_iscsi_dbg_conn,           \
+                               &(_conn)->cls_conn->dev,        \
+                               "%s " dbg_fmt, __func__, ##arg);\
        } while (0);
 
 #define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)                   \
@@ -76,6 +80,9 @@ MODULE_PARM_DESC(debug_libiscsi_eh,
                        iscsi_session_printk(KERN_INFO, _session,       \
                                             "%s " dbg_fmt,             \
                                             __func__, ##arg);          \
+               iscsi_dbg_trace(trace_iscsi_dbg_session,                \
+                               &(_session)->cls_session->dev,          \
+                               "%s " dbg_fmt, __func__, ##arg);        \
        } while (0);
 
 #define ISCSI_DBG_EH(_session, dbg_fmt, arg...)                                \
@@ -84,6 +91,9 @@ MODULE_PARM_DESC(debug_libiscsi_eh,
                        iscsi_session_printk(KERN_INFO, _session,       \
                                             "%s " dbg_fmt,             \
                                             __func__, ##arg);          \
+               iscsi_dbg_trace(trace_iscsi_dbg_eh,                     \
+                               &(_session)->cls_session->dev,          \
+                               "%s " dbg_fmt, __func__, ##arg);        \
        } while (0);
 
 inline void iscsi_conn_queue_work(struct iscsi_conn *conn)

diff --git a/drivers/scsi/libiscsi_tcp.c b/drivers/scsi/libiscsi_tcp.c
index 4fcb9e6..8a6b1b3 100644 (file)
--- a/drivers/scsi/libiscsi_tcp.c
+++ b/drivers/scsi/libiscsi_tcp.c
@@ -43,6 +43,7 @@
 #include <scsi/scsi_host.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_transport_iscsi.h>
+#include <trace/events/iscsi.h>
 
 #include "iscsi_tcp.h"
 
@@ -65,6 +66,9 @@ MODULE_PARM_DESC(debug_libiscsi_tcp, "Turn on debugging for libiscsi_tcp "
                        iscsi_conn_printk(KERN_INFO, _conn,     \
                                             "%s " dbg_fmt,     \
                                             __func__, ##arg);  \
+               iscsi_dbg_trace(trace_iscsi_dbg_tcp,            \
+                               &(_conn)->cls_conn->dev,        \
+                               "%s " dbg_fmt, __func__, ##arg);\
        } while (0);
 
 static int iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn,

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 6fd2fe2..ffae269 100644 (file)
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -37,6 +37,18 @@
 
 #define ISCSI_TRANSPORT_VERSION "2.0-870"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/iscsi.h>
+
+/*
+ * Export tracepoint symbols to be used by other modules.
+ */
+EXPORT_TRACEPOINT_SYMBOL_GPL(iscsi_dbg_conn);
+EXPORT_TRACEPOINT_SYMBOL_GPL(iscsi_dbg_eh);
+EXPORT_TRACEPOINT_SYMBOL_GPL(iscsi_dbg_session);
+EXPORT_TRACEPOINT_SYMBOL_GPL(iscsi_dbg_tcp);
+EXPORT_TRACEPOINT_SYMBOL_GPL(iscsi_dbg_sw_tcp);
+
 static int dbg_session;
 module_param_named(debug_session, dbg_session, int,
                   S_IRUGO | S_IWUSR);
@@ -59,6 +71,9 @@ MODULE_PARM_DESC(debug_conn,
                        iscsi_cls_session_printk(KERN_INFO, _session,   \
                                                 "%s: " dbg_fmt,        \
                                                 __func__, ##arg);      \
+               iscsi_dbg_trace(trace_iscsi_dbg_trans_session,          \
+                               &(_session)->dev,                       \
+                               "%s " dbg_fmt, __func__, ##arg);        \
        } while (0);
 
 #define ISCSI_DBG_TRANS_CONN(_conn, dbg_fmt, arg...)                   \
@@ -66,7 +81,10 @@ MODULE_PARM_DESC(debug_conn,
                if (dbg_conn)                                           \
                        iscsi_cls_conn_printk(KERN_INFO, _conn,         \
                                              "%s: " dbg_fmt,           \
-                                             __func__, ##arg); \
+                                             __func__, ##arg);         \
+               iscsi_dbg_trace(trace_iscsi_dbg_trans_conn,             \
+                               &(_conn)->dev,                          \
+                               "%s " dbg_fmt, __func__, ##arg);        \
        } while (0);
 
 struct iscsi_internal {
@@ -4497,6 +4515,20 @@ int iscsi_unregister_transport(struct iscsi_transport *tt)
 }
 EXPORT_SYMBOL_GPL(iscsi_unregister_transport);
 
+void iscsi_dbg_trace(void (*trace)(struct device *dev, struct va_format *),
+                    struct device *dev, const char *fmt, ...)
+{
+       struct va_format vaf;
+       va_list args;
+
+       va_start(args, fmt);
+       vaf.fmt = fmt;
+       vaf.va = &args;
+       trace(dev, &vaf);
+       va_end(args);
+}
+EXPORT_SYMBOL_GPL(iscsi_dbg_trace);
+
 static __init int iscsi_transport_init(void)
 {
        int err;

diff --git a/include/trace/events/iscsi.h b/include/trace/events/iscsi.h
new file mode 100644 (file)
index 0000000..87408fa
--- /dev/null
+++ b/include/trace/events/iscsi.h
@@ -0,0 +1,107 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM iscsi
+
+#if !defined(_TRACE_ISCSI_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_ISCSI_H
+
+#include <linux/tracepoint.h>
+
+/* max debug message length */
+#define ISCSI_MSG_MAX  256
+
+/*
+ * Declare tracepoint helper function.
+ */
+void iscsi_dbg_trace(void (*trace)(struct device *dev, struct va_format *),
+                    struct device *dev, const char *fmt, ...);
+
+/*
+ * Declare event class for iscsi debug messages.
+ */
+DECLARE_EVENT_CLASS(iscsi_log_msg,
+
+       TP_PROTO(struct device *dev, struct va_format *vaf),
+
+       TP_ARGS(dev, vaf),
+
+       TP_STRUCT__entry(
+               __string(dname,         dev_name(dev)           )
+               __dynamic_array(char,   msg, ISCSI_MSG_MAX      )
+       ),
+
+       TP_fast_assign(
+               __assign_str(dname, dev_name(dev));
+               vsnprintf(__get_str(msg), ISCSI_MSG_MAX, vaf->fmt, *vaf->va);
+       ),
+
+       TP_printk("%s: %s",__get_str(dname),  __get_str(msg)
+       )
+);
+
+/*
+ * Define event to capture iscsi connection debug messages.
+ */
+DEFINE_EVENT(iscsi_log_msg, iscsi_dbg_conn,
+       TP_PROTO(struct device *dev, struct va_format *vaf),
+
+       TP_ARGS(dev, vaf)
+);
+
+/*
+ * Define event to capture iscsi session debug messages.
+ */
+DEFINE_EVENT(iscsi_log_msg, iscsi_dbg_session,
+       TP_PROTO(struct device *dev, struct va_format *vaf),
+
+       TP_ARGS(dev, vaf)
+);
+
+/*
+ * Define event to capture iscsi error handling debug messages.
+ */
+DEFINE_EVENT(iscsi_log_msg, iscsi_dbg_eh,
+        TP_PROTO(struct device *dev, struct va_format *vaf),
+
+        TP_ARGS(dev, vaf)
+);
+
+/*
+ * Define event to capture iscsi tcp debug messages.
+ */
+DEFINE_EVENT(iscsi_log_msg, iscsi_dbg_tcp,
+        TP_PROTO(struct device *dev, struct va_format *vaf),
+
+        TP_ARGS(dev, vaf)
+);
+
+/*
+ * Define event to capture iscsi sw tcp debug messages.
+ */
+DEFINE_EVENT(iscsi_log_msg, iscsi_dbg_sw_tcp,
+       TP_PROTO(struct device *dev, struct va_format *vaf),
+
+       TP_ARGS(dev, vaf)
+);
+
+/*
+ * Define event to capture iscsi transport session debug messages.
+ */
+DEFINE_EVENT(iscsi_log_msg, iscsi_dbg_trans_session,
+       TP_PROTO(struct device *dev, struct va_format *vaf),
+
+       TP_ARGS(dev, vaf)
+);
+
+/*
+ * Define event to capture iscsi transport connection debug messages.
+ */
+DEFINE_EVENT(iscsi_log_msg, iscsi_dbg_trans_conn,
+       TP_PROTO(struct device *dev, struct va_format *vaf),
+
+       TP_ARGS(dev, vaf)
+);
+
+#endif /* _TRACE_ISCSI_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>