[PATCH 00/10] Refactor APIs for creating output handler

[PATCH 00/10] Refactor APIs for creating output handler

[Tzvetomir Stoyanov (VMware)]

In the trace-cmd library there are various APIs for allocating and
initializing output handler to a trace file. The existing APIs are use
case oriented, with a lot of parameters. Extending them for new use
cases, adding more input parameters, will make the library more complex
and not easy to use.
Almost all use case oriented APIs for output handler creation are
removed and replaced with new flow, which is easier to be extended with
new parameters.

Removed APIs:
 tracecmd_create_init_fd_msg()
 tracecmd_create_init_file_glob()
 tracecmd_create_init_fd_glob()
 tracecmd_create_init_file_override()

New APIs:
 tracecmd_output_allocate()
 tracecmd_output_set_msg()
 tracecmd_output_set_trace_dir()
 tracecmd_output_set_kallsyms()
 tracecmd_output_set_from_input()
 tracecmd_output_write_init()
 tracecmd_output_write_headers()

The new tracecmd_output_allocate() API allocates memory and performs
minimal initialization of an output handler to a trace file. No data
is written in the file.
The tracecmd_output_set_...() APIs can be used to set various
parameters to the newly allocated output handler, that affect the way
the data is written into the file.
When the output handler is configured for the desired use case, the
tracecmd_output_write_init() is used to start writing to the file, it
writes initial magic bytes.
The tracecmd_output_write_headers() API is used to write the initial
headers into the file.


This patch-set depends on "[PATCH v4 0/6] trace-cmd fixes and clean-ups",
should be applied on top of it:
  https://lore.kernel.org/linux-trace-devel/20211008041124.972956-1-tz.stoyanov@gmail.com/

Tzvetomir Stoyanov (VMware) (10):
  trace-cmd library: New API for allocating an output handler
  trace-cmd library: New API for setting a message context to an output
    handler
  trace-cmd library: New API for setting a custom trace directory to an
    output handler
  trace-cmd library: New API for setting a custom kallsyms to an output
    handler
  trace-cmd library: New API to inherit parameters from an existing
    trace file
  trace-cmd library: New API tracecmd_output_write_init
  trace-cmd library: New API to write headers of a trace file
  trace-cmd library: Use the new flow when creating output handler
  trace-cmd: Use the new flow when creating output handler
  trace-cmd library: Remove deprecated APIs for creating an output
    handler

 .../include/private/trace-cmd-private.h       |  25 +-
 lib/trace-cmd/trace-output.c                  | 397 +++++++++++-------
 tracecmd/trace-record.c                       |  55 ++-
 tracecmd/trace-restore.c                      |  32 +-
 4 files changed, 347 insertions(+), 162 deletions(-)

-- 
2.31.1

[PATCH 01/10] trace-cmd library: New API for allocating an output handler

[Tzvetomir Stoyanov (VMware)]

The API only allocates a handler and performs minimal initialization.
No data is written in the file.
  tracecmd_output_allocate()

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 .../include/private/trace-cmd-private.h       |  4 ++-
 lib/trace-cmd/trace-output.c                  | 36 +++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index c58b09e9..b4cee0f6 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -102,7 +102,8 @@ static inline int tracecmd_host_bigendian(void)
 /* --- Opening and Reading the trace.dat file --- */
 
 enum tracecmd_file_states {
-	TRACECMD_FILE_INIT = 1,
+	TRACECMD_FILE_ALLOCATED = 0,
+	TRACECMD_FILE_INIT,
 	TRACECMD_FILE_HEADERS,
 	TRACECMD_FILE_FTRACE_EVENTS,
 	TRACECMD_FILE_ALL_EVENTS,
@@ -268,6 +269,7 @@ struct tracecmd_event_list {
 struct tracecmd_option;
 struct tracecmd_msg_handle;
 
+struct tracecmd_output *tracecmd_output_allocate(int fd);
 struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, int cpus);
 struct tracecmd_output *
 tracecmd_create_init_file_glob(const char *output_file,
diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index fe1d1aaa..3878b963 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -59,6 +59,7 @@ struct tracecmd_output {
 	unsigned long		file_state;
 	unsigned long		file_version;
 	size_t			options_start;
+	bool			big_endian;
 
 	struct list_head	options;
 	struct tracecmd_msg_handle *msg_handle;
@@ -883,6 +884,41 @@ out_free:
 	return ret;
 }
 
+/**
+ * tracecmd_output_allocate - allocate new output handler to a trace file
+ * @handle: file descriptor to an empty file, it can be -1 if the handler
+ *	    will not write to a file
+ *
+ * This API only allocates a handler and performs minimal initialization.
+ * No data is written in the file.
+ *
+ * Returns pointer to a newly allocated file descriptor, that can be used
+ * with other library APIs. In case of an error, NULL is returned. The returned
+ * handler must be freed with tracecmd_output_close() or tracecmd_output_free()
+ */
+struct tracecmd_output *tracecmd_output_allocate(int fd)
+{
+	struct tracecmd_output *handle;
+
+	handle = calloc(1, sizeof(*handle));
+	if (!handle)
+		return NULL;
+
+	handle->fd = fd;
+
+	handle->file_version = FILE_VERSION;
+
+	handle->page_size = getpagesize();
+	handle->big_endian = tracecmd_host_bigendian();
+
+	list_head_init(&handle->options);
+
+	handle->file_state = TRACECMD_FILE_ALLOCATED;
+
+	return handle;
+}
+
+
 static int select_file_version(struct tracecmd_output *handle,
 				struct tracecmd_input *ihandle)
 {
-- 
2.31.1

[PATCH 02/10] trace-cmd library: New API for setting a message context to an output handler

[Tzvetomir Stoyanov (VMware)]

The new API associates previously created handler to message context
with given output handler. The message context is used by the output
handler to send data over a network, instead writing to a local file.
 tracecmd_output_allocate()

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 .../include/private/trace-cmd-private.h       |  2 ++
 lib/trace-cmd/trace-output.c                  | 22 +++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index b4cee0f6..2f34af13 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -270,6 +270,8 @@ struct tracecmd_option;
 struct tracecmd_msg_handle;
 
 struct tracecmd_output *tracecmd_output_allocate(int fd);
+int tracecmd_output_set_msg(struct tracecmd_output *handler,
+			    struct tracecmd_msg_handle *msg_handle);
 struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, int cpus);
 struct tracecmd_output *
 tracecmd_create_init_file_glob(const char *output_file,
diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index 3878b963..d73c4f99 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -918,6 +918,28 @@ struct tracecmd_output *tracecmd_output_allocate(int fd)
 	return handle;
 }
 
+/**
+ * tracecmd_output_set_msg - associated an output file handler with network message handler
+ * @handle: output handler to a trace file.
+ * @msg_handle: network handler, allocated by tracecmd_msg_handle_alloc()
+ *
+ * This API associates an output file handler with a network stream. All subsequent API calls
+ * with this output file handler will send data over the network using the @msg_handle, instead
+ * of writing to a file.
+ * This API must be called after the handler file version is set and before
+ * tracecmd_output_write_init().
+ *
+ * Returns 0 on success, or -1 if the output file handler is not allocated or not in expected state.
+ */
+int tracecmd_output_set_msg(struct tracecmd_output *handler, struct tracecmd_msg_handle *msg_handle)
+{
+	if (!handler || handler->file_state != TRACECMD_FILE_ALLOCATED)
+		return -1;
+
+	handler->msg_handle = msg_handle;
+
+	return 0;
+}
 
 static int select_file_version(struct tracecmd_output *handle,
 				struct tracecmd_input *ihandle)
-- 
2.31.1

[PATCH 03/10] trace-cmd library: New API for setting a custom trace directory to an output handler

[Tzvetomir Stoyanov (VMware)]

The new API associates a custom tracing directory with an output file
handler. It is used when creating the trace file instead of the system
default tracing directory.
 tracecmd_output_set_trace_dir()

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 .../include/private/trace-cmd-private.h       |  1 +
 lib/trace-cmd/trace-output.c                  | 27 +++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index 2f34af13..ad9d5265 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -272,6 +272,7 @@ struct tracecmd_msg_handle;
 struct tracecmd_output *tracecmd_output_allocate(int fd);
 int tracecmd_output_set_msg(struct tracecmd_output *handler,
 			    struct tracecmd_msg_handle *msg_handle);
+int tracecmd_output_set_trace_dir(struct tracecmd_output *handler, const char *tracing_dir);
 struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, int cpus);
 struct tracecmd_output *
 tracecmd_create_init_file_glob(const char *output_file,
diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index d73c4f99..a5d7ed5f 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -941,6 +941,33 @@ int tracecmd_output_set_msg(struct tracecmd_output *handler, struct tracecmd_msg
 	return 0;
 }
 
+/**
+ * tracecmd_output_set_trace_dir - Set a custom tracing dir, instead of system default
+ * @handle: output handler to a trace file.
+ * @tracing_dir: full path to a directory with tracing files
+ *
+ * This API associates an output file handler with a custom tracing directory, to be used when
+ * creating the trace file instead of the system default tracing directory.
+ * This API must be called before tracecmd_output_write_init().
+ *
+ * Returns 0 on success, or -1 if the output file handler is not allocated or not in expected state.
+ */
+int tracecmd_output_set_trace_dir(struct tracecmd_output *handler, const char *tracing_dir)
+{
+	if (!handler || handler->file_state != TRACECMD_FILE_ALLOCATED)
+		return -1;
+
+	free(handler->tracing_dir);
+	if (tracing_dir) {
+		handler->tracing_dir = strdup(tracing_dir);
+		if (!handler->tracing_dir)
+			return -1;
+	} else
+		handler->tracing_dir = NULL;
+
+	return 0;
+}
+
 static int select_file_version(struct tracecmd_output *handle,
 				struct tracecmd_input *ihandle)
 {
-- 
2.31.1

[PATCH 04/10] trace-cmd library: New API for setting a custom kallsyms to an output handler

[Tzvetomir Stoyanov (VMware)]

The new API associates an output file handler with a custom kernel symbols
file. It is used when creating the trace file instead of the system default
kernel symbols file.
 tracecmd_output_set_kallsyms()

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 .../include/private/trace-cmd-private.h       |  1 +
 lib/trace-cmd/trace-output.c                  | 32 +++++++++++++++++--
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index ad9d5265..8ef448eb 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -273,6 +273,7 @@ struct tracecmd_output *tracecmd_output_allocate(int fd);
 int tracecmd_output_set_msg(struct tracecmd_output *handler,
 			    struct tracecmd_msg_handle *msg_handle);
 int tracecmd_output_set_trace_dir(struct tracecmd_output *handler, const char *tracing_dir);
+int tracecmd_output_set_kallsyms(struct tracecmd_output *handler, const char *kallsyms);
 struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, int cpus);
 struct tracecmd_output *
 tracecmd_create_init_file_glob(const char *output_file,
diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index a5d7ed5f..c654561a 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -54,6 +54,7 @@ struct tracecmd_output {
 	int			cpus;
 	struct tep_handle	*pevent;
 	char			*tracing_dir;
+	char			*kallsyms;
 	int			nr_options;
 	bool			quiet;
 	unsigned long		file_state;
@@ -767,8 +768,8 @@ static int read_proc_kallsyms(struct tracecmd_output *handle,
 		return -1;
 	}
 
-	if (kallsyms)
-		path = kallsyms;
+	if (handle->kallsyms)
+		path = handle->kallsyms;
 
 	ret = stat(path, &st);
 	if (ret < 0) {
@@ -968,6 +969,33 @@ int tracecmd_output_set_trace_dir(struct tracecmd_output *handler, const char *t
 	return 0;
 }
 
+/**
+ * tracecmd_output_set_kallsyms - Set a custom kernel symbols file, instead of system default
+ * @handle: output handler to a trace file.
+ * @tracing_dir: full path to a file with kernel symbols
+ *
+ * This API associates an output file handler with a custom kernel symbols file, to be used when
+ * creating the trace file instead of the system default kernel symbols file.
+ * This API must be called before tracecmd_output_write_init().
+ *
+ * Returns 0 on success, or -1 if the output file handler is not allocated or not in expected state.
+ */
+int tracecmd_output_set_kallsyms(struct tracecmd_output *handler, const char *kallsyms)
+{
+	if (!handler || handler->file_state != TRACECMD_FILE_ALLOCATED)
+		return -1;
+
+	free(handler->kallsyms);
+	if (kallsyms) {
+		handler->kallsyms = strdup(kallsyms);
+		if (!handler->kallsyms)
+			return -1;
+	} else
+		handler->kallsyms = NULL;
+
+	return 0;
+}
+
 static int select_file_version(struct tracecmd_output *handle,
 				struct tracecmd_input *ihandle)
 {
-- 
2.31.1

[PATCH 05/10] trace-cmd library: New API to inherit parameters from an existing trace file

[Tzvetomir Stoyanov (VMware)]

The new API initializes previously allocated output handler with
parameters from an input handler to a trace file.
 tracecmd_output_set_from_input()

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 .../include/private/trace-cmd-private.h       |  1 +
 lib/trace-cmd/trace-output.c                  | 33 +++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index 8ef448eb..da1dbb09 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -274,6 +274,7 @@ int tracecmd_output_set_msg(struct tracecmd_output *handler,
 			    struct tracecmd_msg_handle *msg_handle);
 int tracecmd_output_set_trace_dir(struct tracecmd_output *handler, const char *tracing_dir);
 int tracecmd_output_set_kallsyms(struct tracecmd_output *handler, const char *kallsyms);
+int tracecmd_output_set_from_input(struct tracecmd_output *handler, struct tracecmd_input *ihandle);
 struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, int cpus);
 struct tracecmd_output *
 tracecmd_create_init_file_glob(const char *output_file,
diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index c654561a..7db3729b 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -996,6 +996,39 @@ int tracecmd_output_set_kallsyms(struct tracecmd_output *handler, const char *ka
 	return 0;
 }
 
+/**
+ * tracecmd_output_set_from_input - Inherit parameters from an existing trace file
+ * @handle: output handler to a trace file.
+ * @ihandle: input handler to an existing trace file.
+ *
+ * This API copies parameters from input handler @ihandle, associated with an existing trace file,
+ * to the output handler @handle, associated with file that is going to be created.
+ * These parameters are copied:
+ *  - tep handler
+ *  - page size
+ *  - file endian
+ *  - file version
+ *  - file compression protocol
+ * This API must be called before tracecmd_output_write_init().
+ *
+ * Returns 0 on success, or -1 if the output file handler is not allocated or not in expected state.
+ */
+int tracecmd_output_set_from_input(struct tracecmd_output *handler, struct tracecmd_input *ihandle)
+{
+	if (!handler || !ihandle || handler->file_state != TRACECMD_FILE_ALLOCATED)
+		return -1;
+
+	/* get endian, page size, file version and compression */
+	/* Use the pevent of the ihandle for later writes */
+	handler->pevent = tracecmd_get_tep(ihandle);
+	tep_ref(handler->pevent);
+	handler->page_size = tracecmd_page_size(ihandle);
+	handler->file_version = tracecmd_get_in_file_version(ihandle);
+	handler->big_endian = tep_is_file_bigendian(handler->pevent);
+
+	return 0;
+}
+
 static int select_file_version(struct tracecmd_output *handle,
 				struct tracecmd_input *ihandle)
 {
-- 
2.31.1

[PATCH 06/10] trace-cmd library: New API tracecmd_output_write_init

[Tzvetomir Stoyanov (VMware)]

The API writes initial magic bits in a trace file.
 tracecmd_output_write_init()

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 .../include/private/trace-cmd-private.h       |  1 +
 lib/trace-cmd/trace-output.c                  | 54 +++++++++++++++++++
 2 files changed, 55 insertions(+)

diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index da1dbb09..08ec765f 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -275,6 +275,7 @@ int tracecmd_output_set_msg(struct tracecmd_output *handler,
 int tracecmd_output_set_trace_dir(struct tracecmd_output *handler, const char *tracing_dir);
 int tracecmd_output_set_kallsyms(struct tracecmd_output *handler, const char *kallsyms);
 int tracecmd_output_set_from_input(struct tracecmd_output *handler, struct tracecmd_input *ihandle);
+int tracecmd_output_write_init(struct tracecmd_output *handler);
 struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, int cpus);
 struct tracecmd_output *
 tracecmd_create_init_file_glob(const char *output_file,
diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index 7db3729b..6e4549f9 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -1029,6 +1029,60 @@ int tracecmd_output_set_from_input(struct tracecmd_output *handler, struct trace
 	return 0;
 }
 
+/**
+ * tracecmd_output_write_init - Write the initial magics in the trace file
+ * @handle: output handler to a trace file.
+ *
+ * This API must be called after all tracecmd_output_set_...() APIs and before writing anything
+ * to the trace file. This initial information is written in the file:
+ *  - initial file magic bytes
+ *  - file version
+ *  - data endian
+ *  - long size
+ *  - page size
+ *  - compression header
+ *
+ * Returns 0 on success, or -1 if the output file handler is not allocated or not in expected state.
+ */
+int tracecmd_output_write_init(struct tracecmd_output *handler)
+{
+	char buf[BUFSIZ];
+	int endian4;
+
+	if (!handler || handler->file_state != TRACECMD_FILE_ALLOCATED)
+		return -1;
+
+	buf[0] = 23;
+	buf[1] = 8;
+	buf[2] = 68;
+	memcpy(buf + 3, "tracing", 7);
+
+	if (do_write_check(handler, buf, 10))
+		return -1;
+
+	sprintf(buf, "%lu", handler->file_version);
+	if (do_write_check(handler, buf, strlen(buf) + 1))
+		return -1;
+
+	if (handler->big_endian)
+		buf[0] = 1;
+	else
+		buf[0] = 0;
+	if (do_write_check(handler, buf, 1))
+		return -1;
+
+	/* save size of long (this may not be what the kernel is) */
+	buf[0] = sizeof(long);
+	if (do_write_check(handler, buf, 1))
+		return -1;
+
+	endian4 = convert_endian_4(handler, handler->page_size);
+	if (do_write_check(handler, &endian4, 4))
+		return -1;
+	handler->file_state = TRACECMD_FILE_INIT;
+	return 0;
+}
+
 static int select_file_version(struct tracecmd_output *handle,
 				struct tracecmd_input *ihandle)
 {
-- 
2.31.1

[PATCH 07/10] trace-cmd library: New API to write headers of a trace file

[Tzvetomir Stoyanov (VMware)]

The API writes metadata headers in a trace file.
 tracecmd_output_write_headers()

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 .../include/private/trace-cmd-private.h       |  3 ++
 lib/trace-cmd/trace-output.c                  | 44 +++++++++++++++++--
 2 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index 08ec765f..086e6906 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -276,6 +276,9 @@ int tracecmd_output_set_trace_dir(struct tracecmd_output *handler, const char *t
 int tracecmd_output_set_kallsyms(struct tracecmd_output *handler, const char *kallsyms);
 int tracecmd_output_set_from_input(struct tracecmd_output *handler, struct tracecmd_input *ihandle);
 int tracecmd_output_write_init(struct tracecmd_output *handler);
+int tracecmd_output_write_headers(struct tracecmd_output *handler,
+				  struct tracecmd_event_list *list);
+
 struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, int cpus);
 struct tracecmd_output *
 tracecmd_create_init_file_glob(const char *output_file,
diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index 6e4549f9..f8a16d82 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -684,7 +684,7 @@ static int read_event_files(struct tracecmd_output *handle,
 			break;
 	}
 	/* all events are listed, use a global glob */
-	if (list)
+	if (!event_list || list)
 		event_list = &all_events;
 
 	systems = create_event_list(handle, event_list);
@@ -754,8 +754,7 @@ err:
 		tracecmd_warning("can't set kptr_restrict");
 }
 
-static int read_proc_kallsyms(struct tracecmd_output *handle,
-			      const char *kallsyms)
+static int read_proc_kallsyms(struct tracecmd_output *handle)
 {
 	unsigned int size, check_size, endian4;
 	const char *path = "/proc/kallsyms";
@@ -1083,6 +1082,43 @@ int tracecmd_output_write_init(struct tracecmd_output *handler)
 	return 0;
 }
 
+/**
+ * tracecmd_output_write_headers - Write the trace file headers
+ * @handle: output handler to a trace file.
+ * @list: desired events that will be included in the trace file.
+ *	  It can be NULL for all available events
+ *
+ * These headers are written in the file:
+ *  - header files from the tracing directory
+ *  - ftrace events from the tracing directory
+ *  - event file from the tracing directory - all or only the one from @list
+ *  - kernel symbols from the tracing directory
+ *  - kernel printk strings from the tracing directory
+ *
+ * Returns 0 on success, or -1 in case of an error.
+ */
+int tracecmd_output_write_headers(struct tracecmd_output *handler,
+				  struct tracecmd_event_list *list)
+{
+	if (!handler || handler->file_state < TRACECMD_FILE_ALLOCATED)
+		return -1;
+
+	/* Write init data, if not written yet */
+	if (handler->file_state < TRACECMD_FILE_INIT && tracecmd_output_write_init(handler))
+		return -1;
+	if (read_header_files(handler))
+		return -1;
+	if (read_ftrace_files(handler))
+		return -1;
+	if (read_event_files(handler, list))
+		return -1;
+	if (read_proc_kallsyms(handler))
+		return -1;
+	if (read_ftrace_printk(handler))
+		return -1;
+	return 0;
+}
+
 static int select_file_version(struct tracecmd_output *handle,
 				struct tracecmd_input *ihandle)
 {
@@ -1181,7 +1217,7 @@ create_file_fd(int fd, struct tracecmd_input *ihandle,
 	if (read_event_files(handle, list))
 		goto out_free;
 
-	if (read_proc_kallsyms(handle, kallsyms))
+	if (read_proc_kallsyms(handle))
 		goto out_free;
 
 	if (read_ftrace_printk(handle))
-- 
2.31.1

[PATCH 08/10] trace-cmd library: Use the new flow when creating output handler

[Tzvetomir Stoyanov (VMware)]

The trace-cmd library APIs, that create a new output handler to a trace
file, are converted to use the newly introduced APIs. Affected are:
 tracecmd_create_file_latency()
 tracecmd_create_init_fd()
 tracecmd_create_init_file()
 tracecmd_copy()

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 lib/trace-cmd/trace-output.c | 54 ++++++++++++++++++++++++++++++++----
 1 file changed, 48 insertions(+), 6 deletions(-)

diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index f8a16d82..9ea85b1c 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -1503,11 +1503,19 @@ struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, in
 {
 	struct tracecmd_output *handle;
 	char *path;
+	int fd;
 
-	handle = create_file(output_file, NULL, NULL, NULL, &all_event_list);
-	if (!handle)
+	fd = open(output_file, O_RDWR | O_CREAT | O_TRUNC | O_LARGEFILE, 0644);
+	if (fd < 0)
 		return NULL;
 
+	handle = tracecmd_output_allocate(fd);
+	if (!handle)
+		goto out_free;
+	if (tracecmd_output_write_init(handle))
+		goto out_free;
+	if (tracecmd_output_write_headers(handle, NULL))
+		goto out_free;
 	/*
 	 * Save the command lines;
 	 */
@@ -1801,7 +1809,20 @@ struct tracecmd_output *tracecmd_get_output_handle_fd(int fd)
 
 struct tracecmd_output *tracecmd_create_init_fd(int fd)
 {
-	return create_file_fd(fd, NULL, NULL, NULL, &all_event_list, NULL);
+	struct tracecmd_output *out;
+
+	out = tracecmd_output_allocate(fd);
+	if (!out)
+		return NULL;
+	if (tracecmd_output_write_init(out))
+		goto error;
+	if (tracecmd_output_write_headers(out, NULL))
+		goto error;
+
+	return out;
+error:
+	tracecmd_output_close(out);
+	return NULL;
 }
 
 struct tracecmd_output *
@@ -1826,7 +1847,20 @@ tracecmd_create_init_file_glob(const char *output_file,
 
 struct tracecmd_output *tracecmd_create_init_file(const char *output_file)
 {
-	return create_file(output_file, NULL, NULL, NULL, &all_event_list);
+	struct tracecmd_output *handle;
+	int fd;
+
+	fd = open(output_file, O_RDWR | O_CREAT | O_TRUNC | O_LARGEFILE, 0644);
+	if (fd < 0)
+		return NULL;
+	handle = tracecmd_create_init_fd(fd);
+	if (!handle) {
+		close(fd);
+		unlink(output_file);
+		return NULL;
+	}
+
+	return handle;
 }
 
 struct tracecmd_output *tracecmd_create_init_file_override(const char *output_file,
@@ -1849,11 +1883,19 @@ struct tracecmd_output *tracecmd_copy(struct tracecmd_input *ihandle,
 				      const char *file)
 {
 	struct tracecmd_output *handle;
+	int fd;
 
-	handle = create_file(file, ihandle, NULL, NULL, &all_event_list);
-	if (!handle)
+	fd = open(file, O_RDWR | O_CREAT | O_TRUNC | O_LARGEFILE, 0644);
+	if (fd < 0)
 		return NULL;
 
+	handle = tracecmd_output_allocate(fd);
+	if (!handle)
+		goto out_free;
+	if (tracecmd_output_set_from_input(handle, ihandle))
+		goto out_free;
+	tracecmd_output_write_init(handle);
+
 	if (tracecmd_copy_headers(ihandle, handle->fd, 0, 0) < 0)
 		goto out_free;
 
-- 
2.31.1

[PATCH 09/10] trace-cmd: Use the new flow when creating output handler

[Tzvetomir Stoyanov (VMware)]

The trace-cmd commands, that create a new output handler to a trace
file, are converted to use the newly introduced trace-cmd APIs.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 tracecmd/trace-record.c  | 55 +++++++++++++++++++++++++++++++++++-----
 tracecmd/trace-restore.c | 32 +++++++++++++++++++++--
 2 files changed, 79 insertions(+), 8 deletions(-)

diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 1767a6c6..15e07cf0 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -3689,6 +3689,25 @@ again:
 
 static void add_options(struct tracecmd_output *handle, struct common_record_context *ctx);
 
+static struct tracecmd_output *create_net_output(struct common_record_context *ctx,
+						 struct tracecmd_msg_handle *msg_handle)
+{
+	struct tracecmd_output *out;
+
+	out = tracecmd_output_allocate(-1);
+	if (!out)
+		return NULL;
+	if (tracecmd_output_set_msg(out, msg_handle))
+		goto error;
+	if (tracecmd_output_write_headers(out, listed_events))
+		goto error;
+
+	return out;
+error:
+	tracecmd_output_close(out);
+	return NULL;
+}
+
 static struct tracecmd_msg_handle *
 setup_connection(struct buffer_instance *instance, struct common_record_context *ctx)
 {
@@ -3700,7 +3719,7 @@ setup_connection(struct buffer_instance *instance, struct common_record_context
 
 	/* Now create the handle through this socket */
 	if (msg_handle->version == V3_PROTOCOL) {
-		network_handle = tracecmd_create_init_fd_msg(msg_handle, listed_events);
+		network_handle = create_net_output(ctx, msg_handle);
 		if (!network_handle)
 			goto error;
 		tracecmd_set_quiet(network_handle, quiet);
@@ -3718,10 +3737,11 @@ setup_connection(struct buffer_instance *instance, struct common_record_context
 		if (ret)
 			goto error;
 	} else {
-		network_handle = tracecmd_create_init_fd_glob(msg_handle->fd,
-							      listed_events);
+		network_handle = tracecmd_output_allocate(msg_handle->fd);
 		if (!network_handle)
 			goto error;
+		if (tracecmd_output_write_headers(network_handle, listed_events))
+			goto error;
 		tracecmd_set_quiet(network_handle, quiet);
 	}
 
@@ -4067,8 +4087,7 @@ static void setup_agent(struct buffer_instance *instance,
 {
 	struct tracecmd_output *network_handle;
 
-	network_handle = tracecmd_create_init_fd_msg(instance->msg_handle,
-						     listed_events);
+	network_handle = create_net_output(ctx, instance->msg_handle);
 	add_options(network_handle, ctx);
 	tracecmd_write_cmdlines(network_handle);
 	tracecmd_write_cpus(network_handle, instance->cpu_count);
@@ -4437,6 +4456,30 @@ static void write_guest_file(struct buffer_instance *instance)
 	free(temp_files);
 }
 
+static struct tracecmd_output *create_output(struct common_record_context *ctx)
+{
+	struct tracecmd_output *out;
+	int fd;
+
+	fd = open(ctx->output, O_RDWR | O_CREAT | O_TRUNC | O_LARGEFILE, 0644);
+	if (fd < 0)
+		return NULL;
+
+	out = tracecmd_output_allocate(fd);
+	if (!out)
+		goto error;
+	if (tracecmd_output_write_headers(out, listed_events))
+		goto error;
+	return out;
+error:
+	if (out)
+		tracecmd_output_close(out);
+	else
+		close(fd);
+	unlink(ctx->output);
+	return NULL;
+}
+
 static void record_data(struct common_record_context *ctx)
 {
 	struct tracecmd_option **buffer_options;
@@ -4491,7 +4534,7 @@ static void record_data(struct common_record_context *ctx)
 				touch_file(temp_files[i]);
 		}
 
-		handle = tracecmd_create_init_file_glob(ctx->output, listed_events);
+		handle = create_output(ctx);
 		if (!handle)
 			die("Error creating output file");
 		tracecmd_set_quiet(handle, quiet);
diff --git a/tracecmd/trace-restore.c b/tracecmd/trace-restore.c
index 280a37f0..8d2fcae8 100644
--- a/tracecmd/trace-restore.c
+++ b/tracecmd/trace-restore.c
@@ -22,6 +22,35 @@
 
 #include "trace-local.h"
 
+static struct tracecmd_output *create_output(const char *file,
+					     const char *tracing_dir, const char *kallsyms)
+{
+	struct tracecmd_output *out;
+	int fd;
+
+	fd = open(file, O_RDWR | O_CREAT | O_TRUNC | O_LARGEFILE, 0644);
+	if (fd < 0)
+		return NULL;
+
+	out = tracecmd_output_allocate(fd);
+	if (!out)
+		goto error;
+	if (tracing_dir && tracecmd_output_set_trace_dir(out, tracing_dir))
+		goto error;
+	if (kallsyms && tracecmd_output_set_kallsyms(out, kallsyms))
+		goto error;
+	if (tracecmd_output_write_headers(out, NULL))
+		goto error;
+	return out;
+error:
+	if (out)
+		tracecmd_output_close(out);
+	else
+		close(fd);
+	unlink(file);
+	return NULL;
+}
+
 void trace_restore (int argc, char **argv)
 {
 	struct tracecmd_output *handle;
@@ -90,8 +119,7 @@ void trace_restore (int argc, char **argv)
 			usage(argv);
 		}
 
-		handle = tracecmd_create_init_file_override(output, tracing_dir,
-							    kallsyms);
+		handle = create_output(output, tracing_dir, kallsyms);
 		if (!handle)
 			die("Unabled to create output file %s", output);
 		if (tracecmd_write_cmdlines(handle) < 0)
-- 
2.31.1

[PATCH 10/10] trace-cmd library: Remove deprecated APIs for creating an output handler

[Tzvetomir Stoyanov (VMware)]

With the introduction of the new output handler creation flow, some of
the old APIs are not used any more. Removed unused APIs:
 tracecmd_create_init_file_glob()
 tracecmd_create_init_fd_glob()
 tracecmd_create_init_fd_msg()
 tracecmd_create_init_file_override()

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 .../include/private/trace-cmd-private.h       |  12 +-
 lib/trace-cmd/trace-output.c                  | 165 ------------------
 2 files changed, 1 insertion(+), 176 deletions(-)

diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index 086e6906..167f3804 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -280,19 +280,9 @@ int tracecmd_output_write_headers(struct tracecmd_output *handler,
 				  struct tracecmd_event_list *list);
 
 struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, int cpus);
-struct tracecmd_output *
-tracecmd_create_init_file_glob(const char *output_file,
-			       struct tracecmd_event_list *list);
 struct tracecmd_output *tracecmd_create_init_fd(int fd);
-struct tracecmd_output *
-tracecmd_create_init_fd_glob(int fd, struct tracecmd_event_list *list);
-struct tracecmd_output *
-tracecmd_create_init_fd_msg(struct tracecmd_msg_handle *msg_handle,
-			    struct tracecmd_event_list *list);
+
 struct tracecmd_output *tracecmd_create_init_file(const char *output_file);
-struct tracecmd_output *tracecmd_create_init_file_override(const char *output_file,
-							   const char *tracing_dir,
-							   const char *kallsyms);
 struct tracecmd_option *tracecmd_add_option(struct tracecmd_output *handle,
 					    unsigned short id, int size,
 					    const void *data);
diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index 9ea85b1c..27f296dd 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -31,11 +31,6 @@
 typedef unsigned long long	tsize_t;
 typedef long long		stsize_t;
 
-static struct tracecmd_event_list all_event_list = {
-	.next = NULL,
-	.glob = "all"
-};
-
 struct tracecmd_option {
 	unsigned short	id;
 	int		size;
@@ -1119,139 +1114,6 @@ int tracecmd_output_write_headers(struct tracecmd_output *handler,
 	return 0;
 }
 
-static int select_file_version(struct tracecmd_output *handle,
-				struct tracecmd_input *ihandle)
-{
-	if (ihandle)
-		handle->file_version = tracecmd_get_in_file_version(ihandle);
-	else
-		handle->file_version = FILE_VERSION;
-
-	return 0;
-}
-
-static struct tracecmd_output *
-create_file_fd(int fd, struct tracecmd_input *ihandle,
-	       const char *tracing_dir,
-	       const char *kallsyms,
-	       struct tracecmd_event_list *list,
-	       struct tracecmd_msg_handle *msg_handle)
-{
-	struct tracecmd_output *handle;
-	struct tep_handle *pevent;
-	char buf[BUFSIZ];
-	int endian4;
-
-	handle = malloc(sizeof(*handle));
-	if (!handle)
-		return NULL;
-	memset(handle, 0, sizeof(*handle));
-
-	list_head_init(&handle->options);
-
-	handle->fd = fd;
-	if (tracing_dir) {
-		handle->tracing_dir = strdup(tracing_dir);
-		if (!handle->tracing_dir)
-			goto out_free;
-	}
-
-	handle->msg_handle = msg_handle;
-
-	if (select_file_version(handle, ihandle))
-		goto out_free;
-
-	buf[0] = 23;
-	buf[1] = 8;
-	buf[2] = 68;
-	memcpy(buf + 3, "tracing", 7);
-
-	if (do_write_check(handle, buf, 10))
-		goto out_free;
-
-	sprintf(buf, "%lu", handle->file_version);
-	if (do_write_check(handle, buf, strlen(buf) + 1))
-		goto out_free;
-
-	/* get endian and page size */
-	if (ihandle) {
-		pevent = tracecmd_get_tep(ihandle);
-		/* Use the pevent of the ihandle for later writes */
-		handle->pevent = tracecmd_get_tep(ihandle);
-		tep_ref(pevent);
-		if (tep_is_file_bigendian(pevent))
-			buf[0] = 1;
-		else
-			buf[0] = 0;
-		handle->page_size = tracecmd_page_size(ihandle);
-	} else {
-		if (tracecmd_host_bigendian())
-			buf[0] = 1;
-		else
-			buf[0] = 0;
-		handle->page_size = getpagesize();
-	}
-
-	if (do_write_check(handle, buf, 1))
-		goto out_free;
-
-	/* save size of long (this may not be what the kernel is) */
-	buf[0] = sizeof(long);
-	if (do_write_check(handle, buf, 1))
-		goto out_free;
-
-	endian4 = convert_endian_4(handle, handle->page_size);
-	if (do_write_check(handle, &endian4, 4))
-		goto out_free;
-	handle->file_state = TRACECMD_FILE_INIT;
-
-	if (ihandle)
-		return handle;
-
-	if (read_header_files(handle))
-		goto out_free;
-
-	if (read_ftrace_files(handle))
-		goto out_free;
-
-	if (read_event_files(handle, list))
-		goto out_free;
-
-	if (read_proc_kallsyms(handle))
-		goto out_free;
-
-	if (read_ftrace_printk(handle))
-		goto out_free;
-
-	return handle;
-
- out_free:
-	tracecmd_output_close(handle);
-	return NULL;
-}
-
-static struct tracecmd_output *create_file(const char *output_file,
-					   struct tracecmd_input *ihandle,
-					   const char *tracing_dir,
-					   const char *kallsyms,
-					   struct tracecmd_event_list *list)
-{
-	struct tracecmd_output *handle;
-	int fd;
-
-	fd = open(output_file, O_RDWR | O_CREAT | O_TRUNC | O_LARGEFILE, 0644);
-	if (fd < 0)
-		return NULL;
-
-	handle = create_file_fd(fd, ihandle, tracing_dir, kallsyms, list, NULL);
-	if (!handle) {
-		close(fd);
-		unlink(output_file);
-	}
-
-	return handle;
-}
-
 /**
  * tracecmd_add_option_v - add options to the file
  * @handle: the output file handle name
@@ -1825,26 +1687,6 @@ error:
 	return NULL;
 }
 
-struct tracecmd_output *
-tracecmd_create_init_fd_msg(struct tracecmd_msg_handle *msg_handle,
-			    struct tracecmd_event_list *list)
-{
-	return create_file_fd(msg_handle->fd, NULL, NULL, NULL, list, msg_handle);
-}
-
-struct tracecmd_output *
-tracecmd_create_init_fd_glob(int fd, struct tracecmd_event_list *list)
-{
-	return create_file_fd(fd, NULL, NULL, NULL, list, NULL);
-}
-
-struct tracecmd_output *
-tracecmd_create_init_file_glob(const char *output_file,
-			       struct tracecmd_event_list *list)
-{
-	return create_file(output_file, NULL, NULL, NULL, list);
-}
-
 struct tracecmd_output *tracecmd_create_init_file(const char *output_file)
 {
 	struct tracecmd_output *handle;
@@ -1863,13 +1705,6 @@ struct tracecmd_output *tracecmd_create_init_file(const char *output_file)
 	return handle;
 }
 
-struct tracecmd_output *tracecmd_create_init_file_override(const char *output_file,
-							   const char *tracing_dir,
-							   const char *kallsyms)
-{
-	return create_file(output_file, NULL, tracing_dir, kallsyms, &all_event_list);
-}
-
 /**
  * tracecmd_copy - copy the headers of one trace.dat file for another
  * @ihandle: input handle of the trace.dat file to copy
-- 
2.31.1