net/9p: Convert net/9p protocol dumps to tracepoints

This helps in more control over debugging.
root@qemu-img-64:~# ls /pass/123
ls: cannot access /pass/123: No such file or directory
root@qemu-img-64:~# cat /sys/kernel/debug/tracing/trace
# tracer: nop
#
#           TASK-PID    CPU#    TIMESTAMP  FUNCTION
#              | |       |          |         |
              ls-1536  [001]    70.928584: 9p_protocol_dump: clnt 18446612132784021504 P9_TWALK(tag = 1)
000: 16 00 00 00 6e 01 00 01 00 00 00 02 00 00 00 01
010: 00 03 00 31 32 33 00 00 00 ff ff ff ff 00 00 00

              ls-1536  [001]    70.928587: <stack trace>
 => trace_9p_protocol_dump
 => p9pdu_finalize
 => p9_client_rpc
 => p9_client_walk
 => v9fs_vfs_lookup
 => d_alloc_and_lookup
 => walk_component
 => path_lookupat
              ls-1536  [000]    70.929696: 9p_protocol_dump: clnt 18446612132784021504 P9_RLERROR(tag = 1)
000: 0b 00 00 00 07 01 00 02 00 00 00 4e 03 00 02 00
010: 00 00 00 00 03 00 02 00 00 00 00 00 ff 43 00 00

              ls-1536  [000]    70.929697: <stack trace>
 => trace_9p_protocol_dump
 => p9_client_rpc
 => p9_client_walk
 => v9fs_vfs_lookup
 => d_alloc_and_lookup
 => walk_component
 => path_lookupat
 => do_path_lookup

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

3 files changed, 179 insertions, 6 deletions

diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h
index d83a01300871..2d70b95b3b55 100644
--- a/include/net/9p/9p.h
+++ b/include/net/9p/9p.h
@@ -76,11 +76,8 @@ do {  \
 	} \
 } while (0)
 
-#define P9_DUMP_PKT(way, pdu) p9pdu_dump(way, pdu)
-
 #else
 #define P9_DPRINTK(level, format, arg...)  do { } while (0)
-#define P9_DUMP_PKT(way, pdu) do { } while (0)
 #endif
 
 
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index d479d7dcc4d5..fc9b90b0c052 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -240,8 +240,8 @@ int p9_client_read(struct p9_fid *fid, char *data, char __user *udata,
 int p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
 							u64 offset, u32 count);
 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset);
-int p9dirent_read(char *buf, int len, struct p9_dirent *dirent,
-							int proto_version);
+int p9dirent_read(struct p9_client *clnt, char *buf, int len,
+		  struct p9_dirent *dirent);
 struct p9_wstat *p9_client_stat(struct p9_fid *fid);
 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *attr);
@@ -259,7 +259,7 @@ struct p9_req_t *p9_tag_lookup(struct p9_client *, u16);
 void p9_client_cb(struct p9_client *c, struct p9_req_t *req);
 
 int p9_parse_header(struct p9_fcall *, int32_t *, int8_t *, int16_t *, int);
-int p9stat_read(char *, int, struct p9_wstat *, int);
+int p9stat_read(struct p9_client *, char *, int, struct p9_wstat *);
 void p9stat_free(struct p9_wstat *);
 
 int p9_is_proto_dotu(struct p9_client *clnt);
diff --git a/include/trace/events/9p.h b/include/trace/events/9p.h
new file mode 100644
index 000000000000..beeaed8398ec
--- /dev/null
+++ b/include/trace/events/9p.h
@@ -0,0 +1,176 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM 9p
+
+#if !defined(_TRACE_9P_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_9P_H
+
+#include <linux/tracepoint.h>
+
+#define show_9p_op(type)						\
+	__print_symbolic(type,						\
+			 { P9_TLERROR,		"P9_TLERROR" },		\
+			 { P9_RLERROR,		"P9_RLERROR" },		\
+			 { P9_TSTATFS,		"P9_TSTATFS" },		\
+			 { P9_RSTATFS,		"P9_RSTATFS" },		\
+			 { P9_TLOPEN,		"P9_TLOPEN" },		\
+			 { P9_RLOPEN,		"P9_RLOPEN" },		\
+			 { P9_TLCREATE,		"P9_TLCREATE" },	\
+			 { P9_RLCREATE,		"P9_RLCREATE" },	\
+			 { P9_TSYMLINK,		"P9_TSYMLINK" },	\
+			 { P9_RSYMLINK,		"P9_RSYMLINK" },	\
+			 { P9_TMKNOD,		"P9_TMKNOD" },		\
+			 { P9_RMKNOD,		"P9_RMKNOD" },		\
+			 { P9_TRENAME,		"P9_TRENAME" },		\
+			 { P9_RRENAME,		"P9_RRENAME" },		\
+			 { P9_TREADLINK,	"P9_TREADLINK" },	\
+			 { P9_RREADLINK,	"P9_RREADLINK" },	\
+			 { P9_TGETATTR,		"P9_TGETATTR" },	\
+			 { P9_RGETATTR,		"P9_RGETATTR" },	\
+			 { P9_TSETATTR,		"P9_TSETATTR" },	\
+			 { P9_RSETATTR,		"P9_RSETATTR" },	\
+			 { P9_TXATTRWALK,	"P9_TXATTRWALK" },	\
+			 { P9_RXATTRWALK,	"P9_RXATTRWALK" },	\
+			 { P9_TXATTRCREATE,	"P9_TXATTRCREATE" },	\
+			 { P9_RXATTRCREATE,	"P9_RXATTRCREATE" },	\
+			 { P9_TREADDIR,		"P9_TREADDIR" },	\
+			 { P9_RREADDIR,		"P9_RREADDIR" },	\
+			 { P9_TFSYNC,		"P9_TFSYNC" },		\
+			 { P9_RFSYNC,		"P9_RFSYNC" },		\
+			 { P9_TLOCK,		"P9_TLOCK" },		\
+			 { P9_RLOCK,		"P9_RLOCK" },		\
+			 { P9_TGETLOCK,		"P9_TGETLOCK" },	\
+			 { P9_RGETLOCK,		"P9_RGETLOCK" },	\
+			 { P9_TLINK,		"P9_TLINK" },		\
+			 { P9_RLINK,		"P9_RLINK" },		\
+			 { P9_TMKDIR,		"P9_TMKDIR" },		\
+			 { P9_RMKDIR,		"P9_RMKDIR" },		\
+			 { P9_TRENAMEAT,	"P9_TRENAMEAT" },	\
+			 { P9_RRENAMEAT,	"P9_RRENAMEAT" },	\
+			 { P9_TUNLINKAT,	"P9_TUNLINKAT" },	\
+			 { P9_RUNLINKAT,	"P9_RUNLINKAT" },	\
+			 { P9_TVERSION,		"P9_TVERSION" },	\
+			 { P9_RVERSION,		"P9_RVERSION" },	\
+			 { P9_TAUTH,		"P9_TAUTH" },		\
+			 { P9_RAUTH,		"P9_RAUTH" },		\
+			 { P9_TATTACH,		"P9_TATTACH" },		\
+			 { P9_RATTACH,		"P9_RATTACH" },		\
+			 { P9_TERROR,		"P9_TERROR" },		\
+			 { P9_RERROR,		"P9_RERROR" },		\
+			 { P9_TFLUSH,		"P9_TFLUSH" },		\
+			 { P9_RFLUSH,		"P9_RFLUSH" },		\
+			 { P9_TWALK,		"P9_TWALK" },		\
+			 { P9_RWALK,		"P9_RWALK" },		\
+			 { P9_TOPEN,		"P9_TOPEN" },		\
+			 { P9_ROPEN,		"P9_ROPEN" },		\
+			 { P9_TCREATE,		"P9_TCREATE" },		\
+			 { P9_RCREATE,		"P9_RCREATE" },		\
+			 { P9_TREAD,		"P9_TREAD" },		\
+			 { P9_RREAD,		"P9_RREAD" },		\
+			 { P9_TWRITE,		"P9_TWRITE" },		\
+			 { P9_RWRITE,		"P9_RWRITE" },		\
+			 { P9_TCLUNK,		"P9_TCLUNK" },		\
+			 { P9_RCLUNK,		"P9_RCLUNK" },		\
+			 { P9_TREMOVE,		"P9_TREMOVE" },		\
+			 { P9_RREMOVE,		"P9_RREMOVE" },		\
+			 { P9_TSTAT,		"P9_TSTAT" },		\
+			 { P9_RSTAT,		"P9_RSTAT" },		\
+			 { P9_TWSTAT,		"P9_TWSTAT" },		\
+			 { P9_RWSTAT,		"P9_RWSTAT" })
+
+TRACE_EVENT(9p_client_req,
+	    TP_PROTO(struct p9_client *clnt, int8_t type, int tag),
+
+	    TP_ARGS(clnt, type, tag),
+
+	    TP_STRUCT__entry(
+		    __field(    void *,		clnt			     )
+		    __field(	__u8,		type			     )
+		    __field(	__u32,		tag			     )
+		    ),
+
+	    TP_fast_assign(
+		    __entry->clnt    =  clnt;
+		    __entry->type    =  type;
+		    __entry->tag     =  tag;
+		    ),
+
+	    TP_printk("client %lu request %s tag  %d",
+		    (long)__entry->clnt, show_9p_op(__entry->type),
+		    __entry->tag)
+ );
+
+TRACE_EVENT(9p_client_res,
+	    TP_PROTO(struct p9_client *clnt, int8_t type, int tag, int err),
+
+	    TP_ARGS(clnt, type, tag, err),
+
+	    TP_STRUCT__entry(
+		    __field(    void *,		clnt			     )
+		    __field(	__u8,		type			     )
+		    __field(	__u32,		tag			     )
+		    __field(	__u32,		err			     )
+		    ),
+
+	    TP_fast_assign(
+		    __entry->clnt    =  clnt;
+		    __entry->type    =  type;
+		    __entry->tag     =  tag;
+		    __entry->err     =  err;
+		    ),
+
+	    TP_printk("client %lu response %s tag  %d err %d",
+		      (long)__entry->clnt, show_9p_op(__entry->type),
+		      __entry->tag, __entry->err)
+);
+
+/* dump 32 bytes of protocol data */
+#define P9_PROTO_DUMP_SZ 32
+TRACE_EVENT(9p_protocol_dump,
+	    TP_PROTO(struct p9_client *clnt, struct p9_fcall *pdu),
+
+	    TP_ARGS(clnt, pdu),
+
+	    TP_STRUCT__entry(
+		    __field(	void *,		clnt				)
+		    __field(	__u8,		type				)
+		    __field(	__u16,		tag				)
+		    __array(	unsigned char,	line,	P9_PROTO_DUMP_SZ	)
+		    ),
+
+	    TP_fast_assign(
+		    __entry->clnt   =  clnt;
+		    __entry->type   =  pdu->id;
+		    __entry->tag    =  pdu->tag;
+		    memcpy(__entry->line, pdu->sdata, P9_PROTO_DUMP_SZ);
+		    ),
+	    TP_printk("clnt %lu %s(tag = %d)\n%.3x: "
+		      "%02x %02x %02x %02x %02x %02x %02x %02x "
+		      "%02x %02x %02x %02x %02x %02x %02x %02x\n"
+		      "%.3x: "
+		      "%02x %02x %02x %02x %02x %02x %02x %02x "
+		      "%02x %02x %02x %02x %02x %02x %02x %02x\n",
+		      (long)__entry->clnt, show_9p_op(__entry->type),
+		      __entry->tag, 0,
+		      __entry->line[0],  __entry->line[1],
+		      __entry->line[2],  __entry->line[3],
+		      __entry->line[4],  __entry->line[5],
+		      __entry->line[6],  __entry->line[7],
+		      __entry->line[8],  __entry->line[9],
+		      __entry->line[10], __entry->line[11],
+		      __entry->line[12], __entry->line[13],
+		      __entry->line[14], __entry->line[15],
+		      16,
+		      __entry->line[16], __entry->line[17],
+		      __entry->line[18], __entry->line[19],
+		      __entry->line[20], __entry->line[21],
+		      __entry->line[22], __entry->line[23],
+		      __entry->line[24], __entry->line[25],
+		      __entry->line[26], __entry->line[27],
+		      __entry->line[28], __entry->line[29],
+		      __entry->line[30], __entry->line[31])
+ );
+
+#endif /* _TRACE_9P_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>