There is lack of API to create an output trace handle to file with
given name, which is common use case. Existing flow is - the library
user should create the file, open it and pass a file descriptor to the
library for creating the output handle. The proposed new API
tracecmd_output_create()
has file name as input parameter. It creates a file with given name (or
truncates existing one) and create an output trace handle to that file.
The file name parameter is optional, if NULL is passed - the created
output trace handle will not be associated with a file.
Suggested-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
---
.../include/private/trace-cmd-private.h | 1 +
lib/trace-cmd/trace-output.c | 46 +++++++++++++------
tracecmd/trace-record.c | 12 ++---
tracecmd/trace-restore.c | 16 +++----
4 files changed, 44 insertions(+), 31 deletions(-)
diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index c7ade7ae..80027c9e 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -279,6 +279,7 @@ int tracecmd_output_write_init(struct tracecmd_output *handle);
int tracecmd_output_write_headers(struct tracecmd_output *handle,
struct tracecmd_event_list *list);
+struct tracecmd_output *tracecmd_output_create(const char *output_file);
struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, int cpus);
struct tracecmd_output *tracecmd_create_init_fd(int fd);
diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index 31f08751..2f8ebf25 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -1442,17 +1442,11 @@ struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, in
{
struct tracecmd_output *handle;
char *path;
- int fd;
- fd = open(output_file, O_RDWR | O_CREAT | O_TRUNC | O_LARGEFILE, 0644);
- if (fd < 0)
+ handle = tracecmd_output_create(output_file);
+ if (!handle)
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;
/*
@@ -1806,6 +1800,34 @@ struct tracecmd_output *tracecmd_get_output_handle_fd(int fd)
return NULL;
}
+/**
+ * tracecmd_output_create - Create new output handle to a trace file with given name
+ * @output_file: Name of the trace file that will be created.
+ *
+ * The @output_file parameter can be NULL. In this case the output handle is created
+ * and initialized, but is not associated with a file.
+ *
+ * Returns pointer to created outpuy handle, or NULL in case of an error.
+ */
+struct tracecmd_output *tracecmd_output_create(const char *output_file)
+{
+ struct tracecmd_output *out;
+ int fd = -1;
+
+ if (output_file) {
+ fd = open(output_file, O_RDWR | O_CREAT | O_TRUNC | O_LARGEFILE, 0644);
+ if (fd < 0)
+ return NULL;
+ }
+ out = tracecmd_output_allocate(fd);
+ if (!out && fd >= 0) {
+ close(fd);
+ unlink(output_file);
+ }
+
+ return out;
+}
+
struct tracecmd_output *tracecmd_create_init_fd(int fd)
{
struct tracecmd_output *out;
@@ -1855,15 +1877,11 @@ struct tracecmd_output *tracecmd_copy(struct tracecmd_input *ihandle,
const char *file)
{
struct tracecmd_output *handle;
- int fd;
- fd = open(file, O_RDWR | O_CREAT | O_TRUNC | O_LARGEFILE, 0644);
- if (fd < 0)
+ handle = tracecmd_output_create(file);
+ if (!handle)
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);
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index 3a84e116..677a4bd9 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -3694,7 +3694,7 @@ static struct tracecmd_output *create_net_output(struct common_record_context *c
{
struct tracecmd_output *out;
- out = tracecmd_output_allocate(-1);
+ out = tracecmd_output_create(NULL);
if (!out)
return NULL;
if (tracecmd_output_set_msg(out, msg_handle))
@@ -4458,23 +4458,21 @@ static void write_guest_file(struct buffer_instance *instance)
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)
+ if (!ctx->output)
return NULL;
- out = tracecmd_output_allocate(fd);
+ out = tracecmd_output_create(ctx->output);
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;
}
diff --git a/tracecmd/trace-restore.c b/tracecmd/trace-restore.c
index 8d2fcae8..23a7f4af 100644
--- a/tracecmd/trace-restore.c
+++ b/tracecmd/trace-restore.c
@@ -26,15 +26,11 @@ 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);
+ out = tracecmd_output_create(file);
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))
@@ -45,8 +41,6 @@ static struct tracecmd_output *create_output(const char *file,
error:
if (out)
tracecmd_output_close(out);
- else
- close(fd);
unlink(file);
return NULL;
}
@@ -155,8 +149,10 @@ void trace_restore (int argc, char **argv)
handle = tracecmd_copy(ihandle, output);
tracecmd_close(ihandle);
- } else
- handle = tracecmd_create_init_file(output);
+ } else {
+ handle = tracecmd_output_create(output);
+ tracecmd_output_write_headers(handle, NULL);
+ }
if (!handle)
die("error writing to %s", output);
--
2.33.1
|