From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>
As trace-cmd restore needs to read only a portion of the headers, it needs a
way to not read all of them. Export the tracecmd_file_state enums and pass
that as another parameter to tracecmd_read_headers(), in which it will stop
at the state requested.
If zero is passed in as the state, tracecmd_read_headers() will act in its
old behavior and read everything it can.
Now trace-cmd restore can call tracecmd_read_headers() and have it stop
after it reads the cmdlines.
Link: https://lore.kernel.org/linux-trace-devel/CAPpZLN5fdY+rb6s=X6bNykiqrjuTprvZxay9iDSEQxJXHURh3A@xxxxxxxxxxxxxx/
Suggested-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
.../include/private/trace-cmd-private.h | 7 +-
lib/trace-cmd/trace-input.c | 71 +++++++++++++++++--
lib/trace-cmd/trace-output.c | 2 +-
tracecmd/trace-hist.c | 2 +-
tracecmd/trace-mem.c | 2 +-
tracecmd/trace-read.c | 2 +-
tracecmd/trace-restore.c | 2 +-
tracecmd/trace-stream.c | 2 +-
8 files changed, 76 insertions(+), 14 deletions(-)
diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index fc968cc9efe1..ad863df8954f 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -95,8 +95,8 @@ static inline int tracecmd_host_bigendian(void)
/* --- Opening and Reading the trace.dat file --- */
-enum {
- TRACECMD_FILE_INIT,
+enum tracecmd_file_states {
+ TRACECMD_FILE_INIT = 1,
TRACECMD_FILE_HEADERS,
TRACECMD_FILE_FTRACE_EVENTS,
TRACECMD_FILE_ALL_EVENTS,
@@ -153,7 +153,8 @@ typedef void (*tracecmd_handle_init_func)(struct tracecmd_input *handle,
struct tracecmd_input *tracecmd_alloc(const char *file, int flags);
struct tracecmd_input *tracecmd_alloc_fd(int fd, int flags);
void tracecmd_ref(struct tracecmd_input *handle);
-int tracecmd_read_headers(struct tracecmd_input *handle);
+int tracecmd_read_headers(struct tracecmd_input *handle,
+ enum tracecmd_file_states state);
int tracecmd_get_parsing_failures(struct tracecmd_input *handle);
int tracecmd_long_size(struct tracecmd_input *handle);
int tracecmd_page_size(struct tracecmd_input *handle);
diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index b7166a9b1f40..1dcefc61bcbb 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -349,6 +349,9 @@ static int read_header_files(struct tracecmd_input *handle)
char *header;
char buf[BUFSIZ];
+ if (handle->file_state >= TRACECMD_FILE_HEADERS)
+ return 0;
+
if (do_read_check(handle, buf, 12))
return -1;
@@ -552,6 +555,9 @@ static int read_ftrace_files(struct tracecmd_input *handle, const char *regex)
int unique;
int ret;
+ if (handle->file_state >= TRACECMD_FILE_FTRACE_EVENTS)
+ return 0;
+
if (regex) {
sreg = &spreg;
ereg = &epreg;
@@ -620,6 +626,9 @@ static int read_event_files(struct tracecmd_input *handle, const char *regex)
int unique;
int ret;
+ if (handle->file_state >= TRACECMD_FILE_ALL_EVENTS)
+ return 0;
+
if (regex) {
sreg = &spreg;
ereg = &epreg;
@@ -702,6 +711,9 @@ static int read_proc_kallsyms(struct tracecmd_input *handle)
unsigned int size;
char *buf;
+ if (handle->file_state >= TRACECMD_FILE_KALLSYMS)
+ return 0;
+
if (read4(handle, &size) < 0)
return -1;
if (!size)
@@ -730,6 +742,9 @@ static int read_ftrace_printk(struct tracecmd_input *handle)
unsigned int size;
char *buf;
+ if (handle->file_state >= TRACECMD_FILE_PRINTK)
+ return 0;
+
if (read4(handle, &size) < 0)
return -1;
if (!size)
@@ -773,11 +788,15 @@ static int read_cpus(struct tracecmd_input *handle)
{
unsigned int cpus;
+ if (handle->file_state >= TRACECMD_FILE_CPU_COUNT)
+ return 0;
+
if (read4(handle, &cpus) < 0)
return -1;
handle->cpus = cpus;
tep_set_cpus(handle->pevent, handle->cpus);
+ handle->file_state = TRACECMD_FILE_CPU_COUNT;
return 0;
}
@@ -785,15 +804,26 @@ static int read_cpus(struct tracecmd_input *handle)
/**
* tracecmd_read_headers - read the header information from trace.dat
* @handle: input handle for the trace.dat file
+ * @state: The state to read up to or zero to read up to options.
*
* This reads the trace.dat file for various information. Like the
* format of the ring buffer, event formats, ftrace formats, kallsyms
- * and printk.
+ * and printk. This may be called multiple times with different @state
+ * values, to read partial data at a time. It will always continue
+ * where it left off.
*/
-int tracecmd_read_headers(struct tracecmd_input *handle)
+int tracecmd_read_headers(struct tracecmd_input *handle,
+ enum tracecmd_file_states state)
{
int ret;
+ /* Set to read all if state is zero */
+ if (!state)
+ state = TRACECMD_FILE_OPTIONS;
+
+ if (state <= handle->file_state)
+ return 0;
+
handle->parsing_failures = 0;
ret = read_header_files(handle);
@@ -802,28 +832,48 @@ int tracecmd_read_headers(struct tracecmd_input *handle)
tep_set_long_size(handle->pevent, handle->long_size);
+ if (state <= handle->file_state)
+ return 0;
+
ret = read_ftrace_files(handle, NULL);
if (ret < 0)
return -1;
+ if (state <= handle->file_state)
+ return 0;
+
ret = read_event_files(handle, NULL);
if (ret < 0)
return -1;
+ if (state <= handle->file_state)
+ return 0;
+
ret = read_proc_kallsyms(handle);
if (ret < 0)
return -1;
+ if (state <= handle->file_state)
+ return 0;
+
ret = read_ftrace_printk(handle);
if (ret < 0)
return -1;
+ if (state <= handle->file_state)
+ return 0;
+
if (read_and_parse_cmdlines(handle) < 0)
return -1;
+ if (state <= handle->file_state)
+ return 0;
+
if (read_cpus(handle) < 0)
return -1;
- handle->file_state = TRACECMD_FILE_CPU_COUNT;
+
+ if (state <= handle->file_state)
+ return 0;
if (read_options_type(handle) < 0)
return -1;
@@ -2668,6 +2718,9 @@ static int read_options_type(struct tracecmd_input *handle)
{
char buf[10];
+ if (handle->file_state >= TRACECMD_FILE_CPU_LATENCY)
+ return 0;
+
if (do_read_check(handle, buf, 10))
return -1;
@@ -2830,6 +2883,9 @@ static int read_and_parse_cmdlines(struct tracecmd_input *handle)
unsigned long long size;
char *cmdlines;
+ if (handle->file_state >= TRACECMD_FILE_CMD_LINES)
+ return 0;
+
if (read_data_and_size(handle, &cmdlines, &size) < 0)
return -1;
cmdlines[size] = 0;
@@ -3225,7 +3281,7 @@ struct tracecmd_input *tracecmd_open_fd(int fd, int flags)
if (!handle)
return NULL;
- if (tracecmd_read_headers(handle) < 0)
+ if (tracecmd_read_headers(handle, 0) < 0)
goto fail;
if ((ret = tracecmd_init_data(handle)) < 0)
@@ -3273,7 +3329,7 @@ struct tracecmd_input *tracecmd_open_head(const char *file, int flags)
if (!handle)
return NULL;
- if (tracecmd_read_headers(handle) < 0)
+ if (tracecmd_read_headers(handle, 0) < 0)
goto fail;
return handle;
@@ -3799,6 +3855,11 @@ tracecmd_buffer_instance_handle(struct tracecmd_input *handle, int indx)
goto error;
}
+ /*
+ * read_options_type() is called right after the CPU count so update
+ * file state accordingly.
+ */
+ new_handle->file_state = TRACECMD_FILE_CPU_COUNT;
ret = read_options_type(new_handle);
if (!ret)
ret = read_cpu_data(new_handle);
diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index 3e59bf7fdf5d..a26fd8537a1d 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -1540,7 +1540,7 @@ struct tracecmd_output *tracecmd_get_output_handle_fd(int fd)
ihandle = tracecmd_alloc_fd(fd2, TRACECMD_FL_LOAD_NO_PLUGINS);
if (!ihandle)
return NULL;
- tracecmd_read_headers(ihandle);
+ tracecmd_read_headers(ihandle, 0);
/* move the file descriptor to the end */
if (lseek(fd, 0, SEEK_END) == (off_t)-1)
diff --git a/tracecmd/trace-hist.c b/tracecmd/trace-hist.c
index 3b59ac6f27ab..efb790acb807 100644
--- a/tracecmd/trace-hist.c
+++ b/tracecmd/trace-hist.c
@@ -1043,7 +1043,7 @@ void trace_hist(int argc, char **argv)
if (!handle)
die("can't open %s\n", input_file);
- ret = tracecmd_read_headers(handle);
+ ret = tracecmd_read_headers(handle, 0);
if (ret)
return;
diff --git a/tracecmd/trace-mem.c b/tracecmd/trace-mem.c
index 3453c3a75fcc..25eb08612b06 100644
--- a/tracecmd/trace-mem.c
+++ b/tracecmd/trace-mem.c
@@ -554,7 +554,7 @@ void trace_mem(int argc, char **argv)
if (!handle)
die("can't open %s\n", input_file);
- ret = tracecmd_read_headers(handle);
+ ret = tracecmd_read_headers(handle, 0);
if (ret)
return;
diff --git a/tracecmd/trace-read.c b/tracecmd/trace-read.c
index 56fc0626d486..22e8635ce60a 100644
--- a/tracecmd/trace-read.c
+++ b/tracecmd/trace-read.c
@@ -1826,7 +1826,7 @@ void trace_report (int argc, char **argv)
return;
}
- ret = tracecmd_read_headers(handle);
+ ret = tracecmd_read_headers(handle, 0);
if (check_event_parsing) {
if (ret || tracecmd_get_parsing_failures(handle))
exit(EINVAL);
diff --git a/tracecmd/trace-restore.c b/tracecmd/trace-restore.c
index 13f803053582..280a37f0a8ca 100644
--- a/tracecmd/trace-restore.c
+++ b/tracecmd/trace-restore.c
@@ -122,7 +122,7 @@ void trace_restore (int argc, char **argv)
if (!ihandle)
die("error reading file %s", input);
/* make sure headers are ok */
- if (tracecmd_read_headers(ihandle) < 0)
+ if (tracecmd_read_headers(ihandle, TRACECMD_FILE_CMD_LINES) < 0)
die("error reading file %s headers", input);
handle = tracecmd_copy(ihandle, output);
diff --git a/tracecmd/trace-stream.c b/tracecmd/trace-stream.c
index e230cf89cfd1..f503bf770366 100644
--- a/tracecmd/trace-stream.c
+++ b/tracecmd/trace-stream.c
@@ -59,7 +59,7 @@ trace_stream_init(struct buffer_instance *instance, int cpu, int fd, int cpus,
goto fail;
}
- if (tracecmd_read_headers(trace_input) < 0)
+ if (tracecmd_read_headers(trace_input, 0) < 0)
goto fail_free_input;
if (handle_init)
--
2.30.0
|