On Mon, 17 Jun 2019 14:52:17 +0300
tz.stoyanov@xxxxxxxxx wrote:
> From: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx>
>
> From: Tzvetomir Stoyanov <tstoyanov@xxxxxxxxxx>
>
> This patch implements a new tracecmd API, tracecmd_add_option_v()
> It adds new option in trace.dat, similar to tracecmd_add_option(),
> but the option's data is passed as list of buffers. The standard
> struct iovec is used as input parameter, containing the option's
> data buffers.
>
> Signed-off-by: Tzvetomir Stoyanov <tstoyanov@xxxxxxxxxx>
> ---
> include/trace-cmd/trace-cmd.h | 5 ++
> include/traceevent/event-parse.h | 1 +
> tracecmd/trace-output.c | 117 ++++++++++++++++++++++++++-----
> 3 files changed, 106 insertions(+), 17 deletions(-)
>
> diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h
> index ceb03f4..3919673 100644
> --- a/include/trace-cmd/trace-cmd.h
> +++ b/include/trace-cmd/trace-cmd.h
> @@ -245,11 +245,16 @@ struct tracecmd_output *tracecmd_create_init_file_override(const char *output_fi
> struct tracecmd_option *tracecmd_add_option(struct tracecmd_output *handle,
> unsigned short id, int size,
> const void *data);
> +struct tracecmd_option *
> +tracecmd_add_option_v(struct tracecmd_output *handle,
> + unsigned short id, const struct iovec *vector, int count);
> +
> struct tracecmd_option *tracecmd_add_buffer_option(struct tracecmd_output *handle,
> const char *name, int cpus);
>
> int tracecmd_write_cpus(struct tracecmd_output *handle, int cpus);
> int tracecmd_write_options(struct tracecmd_output *handle);
> +int tracecmd_append_options(struct tracecmd_output *handle);
The change log doesn't mention anything about tracecmd_append_options()?
> int tracecmd_update_option(struct tracecmd_output *handle,
> struct tracecmd_option *option, int size,
> const void *data);
> diff --git a/include/traceevent/event-parse.h b/include/traceevent/event-parse.h
> index 5e0fd19..62057b3 100644
> --- a/include/traceevent/event-parse.h
> +++ b/include/traceevent/event-parse.h
> @@ -11,6 +11,7 @@
> #include <stdio.h>
> #include <regex.h>
> #include <string.h>
> +#include <sys/uio.h>
>
> #include "trace-seq.h"
>
> diff --git a/tracecmd/trace-output.c b/tracecmd/trace-output.c
> index 33d6ce3..f7a2791 100644
> --- a/tracecmd/trace-output.c
> +++ b/tracecmd/trace-output.c
> @@ -883,21 +883,23 @@ static struct tracecmd_output *create_file(const char *output_file,
> }
>
> /**
> - * tracecmd_add_option - add options to the file
> + * tracecmd_add_option_v - add options to the file
> * @handle: the output file handle name
> * @id: the id of the option
> - * @size: the size of the option data
> - * @data: the data to write to the file.
> + * @vector: array of vectors, pointing to the data to write in the file
> + * @count: number of items in the vector array
> *
> * Returns handle to update option if needed.
> * Just the content can be updated, with smaller or equal to
> * content than the specified size.
> */
> struct tracecmd_option *
> -tracecmd_add_option(struct tracecmd_output *handle,
> - unsigned short id, int size, const void *data)
> +tracecmd_add_option_v(struct tracecmd_output *handle,
> + unsigned short id, const struct iovec *vector, int count)
Hmm, I think this is a bit overkill. I don't really see anything using
more than one or two data vectors. All I see would be at most a "count"
followed by a list of data, which is what I think you are using this
for.
I rather wait to implement something like this when there's more of a
need for it. I don't believe this change really requires it.
-- Steve
> {
> struct tracecmd_option *option;
> + char *data = NULL;
> + int i, size = 0;
>
> /*
> * We can only add options before they were written.
> @@ -906,32 +908,63 @@ tracecmd_add_option(struct tracecmd_output *handle,
> if (handle->options_written)
> return NULL;
>
> - handle->nr_options++;
> + for (i = 0; i < count; i++)
> + size += vector[i].iov_len;
> +
> + /* Some IDs (like TRACECMD_OPTION_TRACECLOCK) pass vector with 0 / NULL data */
> + if (size) {
> + data = malloc(size);
> + if (!data) {
> + warning("Insufficient memory");
> + return NULL;
> + }
> + }
>
> option = malloc(sizeof(*option));
> if (!option) {
> warning("Could not allocate space for option");
> + free(data);
> return NULL;
> }
>
> - option->id = id;
> - option->size = size;
> - option->data = malloc(size);
> - if (!option->data) {
> - warning("Insufficient memory");
> - free(option);
> - return NULL;
> + handle->nr_options++;
> + option->data = data;
> + for (i = 0; i < count; i++) {
> + if (vector[i].iov_base && vector[i].iov_len) {
> + memcpy(data, vector[i].iov_base, vector[i].iov_len);
> + data += vector[i].iov_len;
> + }
> }
> -
> - /* Some IDs (like TRACECMD_OPTION_TRACECLOCK) pass 0 / NULL data */
> - if (size)
> - memcpy(option->data, data, size);
> + option->size = size;
> + option->id = id;
>
> list_add_tail(&option->list, &handle->options);
>
> return option;
> }
>
> +/**
> + * tracecmd_add_option - add options to the file
> + * @handle: the output file handle name
> + * @id: the id of the option
> + * @size: the size of the option data
> + * @data: the data to write to the file.
> + *
> + * Returns handle to update option if needed.
> + * Just the content can be updated, with smaller or equal to
> + * content than the specified size.
> + */
> +struct tracecmd_option *
> +tracecmd_add_option(struct tracecmd_output *handle,
> + unsigned short id, int size, const void *data)
> +{
> + struct iovec vect;
> +
> + vect.iov_base = (void *) data;
> + vect.iov_len = size;
> + return tracecmd_add_option_v(handle, id, &vect, 1);
> +}
> +
> int tracecmd_write_cpus(struct tracecmd_output *handle, int cpus)
> {
> cpus = convert_endian_4(handle, cpus);
> @@ -979,6 +1012,56 @@ int tracecmd_write_options(struct tracecmd_output *handle)
> return 0;
> }
>
> +int tracecmd_append_options(struct tracecmd_output *handle)
> +{
> + struct tracecmd_option *options;
> + unsigned short option;
> + unsigned short endian2;
> + unsigned int endian4;
> + off_t offset;
> + int r;
> +
> + /* If already written, ignore */
> + if (handle->options_written)
> + return 0;
> +
> + if (lseek64(handle->fd, 0, SEEK_END) == (off_t)-1)
> + return -1;
> + offset = lseek64(handle->fd, -2, SEEK_CUR);
> + if (offset == (off_t)-1)
> + return -1;
> +
> + r = pread(handle->fd, &option, 2, offset);
> + if (r != 2 || option != TRACECMD_OPTION_DONE)
> + return -1;
> +
> + list_for_each_entry(options, &handle->options, list) {
> + endian2 = convert_endian_2(handle, options->id);
> + if (do_write_check(handle, &endian2, 2))
> + return -1;
> +
> + endian4 = convert_endian_4(handle, options->size);
> + if (do_write_check(handle, &endian4, 4))
> + return -1;
> +
> + /* Save the data location in case it needs to be updated */
> + options->offset = lseek64(handle->fd, 0, SEEK_CUR);
> +
> + if (do_write_check(handle, options->data,
> + options->size))
> + return -1;
> + }
> +
> + option = TRACECMD_OPTION_DONE;
> +
> + if (do_write_check(handle, &option, 2))
> + return -1;
> +
> + handle->options_written = 1;
> +
> + return 0;
> +}
> +
> int tracecmd_update_option(struct tracecmd_output *handle,
> struct tracecmd_option *option, int size,
> const void *data)
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