[8/8] trace: remove limitation on directory

  Remove arbitrary limit on 12 characters of the file prefix used for the
directory where to store the traces.
Simplify the code by relying on dynamic allocations.

Signed-off-by: David Marchand <david.marchand@redhat.com>
---
 lib/eal/common/eal_common_trace_utils.c | 68 +++++++++----------------
 lib/eal/common/eal_trace.h              |  5 +-
 2 files changed, 25 insertions(+), 48 deletions(-)
  

On Wed, Sep 21, 2022 at 5:35 PM David Marchand
<david.marchand@redhat.com> wrote:
>
> Remove arbitrary limit on 12 characters of the file prefix used for the
> directory where to store the traces.
> Simplify the code by relying on dynamic allocations.

Nice one.

>
> Signed-off-by: David Marchand <david.marchand@redhat.com>


Acked-by: Jerin Jacob <jerinj@marvell.com>

> ---
>  lib/eal/common/eal_common_trace_utils.c | 68 +++++++++----------------
>  lib/eal/common/eal_trace.h              |  5 +-
>  2 files changed, 25 insertions(+), 48 deletions(-)
>
> diff --git a/lib/eal/common/eal_common_trace_utils.c b/lib/eal/common/eal_common_trace_utils.c
> index 9b5a41ca12..9e0fe962de 100644
> --- a/lib/eal/common/eal_common_trace_utils.c
> +++ b/lib/eal/common/eal_common_trace_utils.c
> @@ -87,11 +87,11 @@ trace_uuid_generate(void)
>  }
>
>  static int
> -trace_session_name_generate(char *trace_dir)
> +trace_session_name_generate(char **trace_dir)
>  {
> +       char date[sizeof("YYYY-mm-dd-AM-HH-MM-SS")];
>         struct tm *tm_result;
>         time_t tm;
> -       int rc;
>
>         tm = time(NULL);
>         if ((int)tm == -1)
> @@ -101,38 +101,32 @@ trace_session_name_generate(char *trace_dir)
>         if (tm_result == NULL)
>                 goto fail;
>
> -       rc = rte_strscpy(trace_dir, eal_get_hugefile_prefix(),
> -                       TRACE_PREFIX_LEN);
> -       if (rc == -E2BIG)
> -               rc = TRACE_PREFIX_LEN - 1;
> -       trace_dir[rc++] = '-';
> -
> -       rc = strftime(trace_dir + rc, TRACE_DIR_STR_LEN - rc,
> -                       "%Y-%m-%d-%p-%I-%M-%S", tm_result);
> -       if (rc == 0) {
> +       if (strftime(date, sizeof(date), "%Y-%m-%d-%p-%I-%M-%S", tm_result) == 0) {
>                 errno = ENOSPC;
>                 goto fail;
>         }
>
> -       return rc;
> +       if (asprintf(trace_dir, "%s-%s", eal_get_hugefile_prefix(), date) == -1)
> +               goto fail;
> +
> +       return 0;
>  fail:
>         rte_errno = errno;
> -       return -rte_errno;
> +       return -1;
>  }
>
>  static int
>  trace_dir_update(const char *str)
>  {
>         struct trace *trace = trace_obj_get();
> -       int rc, remaining;
> -
> -       remaining = sizeof(trace->dir) - trace->dir_offset;
> -       rc = rte_strscpy(&trace->dir[0] + trace->dir_offset, str, remaining);
> -       if (rc < 0)
> -               goto fail;
> +       char *dir;
> +       int rc;
>
> -       trace->dir_offset += rc;
> -fail:
> +       rc = asprintf(&dir, "%s%s", trace->dir != NULL ? trace->dir : "", str);
> +       if (rc != -1) {
> +               free(trace->dir);
> +               trace->dir = dir;
> +       }
>         return rc;
>  }
>
> @@ -246,22 +240,15 @@ eal_trace_mode_args_save(const char *val)
>  int
>  eal_trace_dir_args_save(char const *val)
>  {
> -       struct trace *trace = trace_obj_get();
>         char *dir_path;
>         int rc;
>
> -       if (strlen(val) >= sizeof(trace->dir) - 1) {
> -               trace_err("input string is too big");
> -               return -ENAMETOOLONG;
> -       }
> -
>         if (asprintf(&dir_path, "%s/", val) == -1) {
>                 trace_err("failed to copy directory: %s", strerror(errno));
>                 return -ENOMEM;
>         }
>
>         rc = trace_dir_update(dir_path);
> -
>         free(dir_path);
>         return rc;
>  }
> @@ -289,10 +276,8 @@ trace_epoch_time_save(void)
>  }
>
>  static int
> -trace_dir_default_path_get(char *dir_path)
> +trace_dir_default_path_get(char **dir_path)
>  {
> -       struct trace *trace = trace_obj_get();
> -       uint32_t size = sizeof(trace->dir);
>         struct passwd *pwd;
>         char *home_dir;
>
> @@ -308,8 +293,8 @@ trace_dir_default_path_get(char *dir_path)
>         }
>
>         /* Append dpdk-traces to directory */
> -       if (snprintf(dir_path, size, "%s/dpdk-traces/", home_dir) < 0)
> -               return -ENAMETOOLONG;
> +       if (asprintf(dir_path, "%s/dpdk-traces/", home_dir) == -1)
> +               return -ENOMEM;
>
>         return 0;
>  }
> @@ -318,25 +303,19 @@ static int
>  trace_mkdir(void)
>  {
>         struct trace *trace = trace_obj_get();
> -       char session[TRACE_DIR_STR_LEN];
>         static bool already_done;
> -       char *dir_path;
> +       char *session;
>         int rc;
>
>         if (already_done)
>                 return 0;
>
> -       if (!trace->dir_offset) {
> -               dir_path = calloc(1, sizeof(trace->dir));
> -               if (dir_path == NULL) {
> -                       trace_err("fail to allocate memory");
> -                       return -ENOMEM;
> -               }
> +       if (trace->dir == NULL) {
> +               char *dir_path;
>
> -               rc = trace_dir_default_path_get(dir_path);
> +               rc = trace_dir_default_path_get(&dir_path);
>                 if (rc < 0) {
>                         trace_err("fail to get default path");
> -                       free(dir_path);
>                         return rc;
>                 }
>
> @@ -354,10 +333,11 @@ trace_mkdir(void)
>                 return -rte_errno;
>         }
>
> -       rc = trace_session_name_generate(session);
> +       rc = trace_session_name_generate(&session);
>         if (rc < 0)
>                 return rc;
>         rc = trace_dir_update(session);
> +       free(session);
>         if (rc < 0)
>                 return rc;
>
> diff --git a/lib/eal/common/eal_trace.h b/lib/eal/common/eal_trace.h
> index 26a18a2c48..d66bcfe198 100644
> --- a/lib/eal/common/eal_trace.h
> +++ b/lib/eal/common/eal_trace.h
> @@ -22,8 +22,6 @@
>  #define trace_crit(fmt, args...) \
>         RTE_LOG(CRIT, EAL, "%s():%u " fmt "\n", __func__, __LINE__, ## args)
>
> -#define TRACE_PREFIX_LEN 12
> -#define TRACE_DIR_STR_LEN (sizeof("YYYY-mm-dd-AM-HH-MM-SS") + TRACE_PREFIX_LEN)
>  #define TRACE_CTF_MAGIC 0xC1FC1FC1
>  #define TRACE_MAX_ARGS 32
>
> @@ -50,8 +48,7 @@ struct trace_arg {
>  };
>
>  struct trace {
> -       char dir[PATH_MAX];
> -       int dir_offset;
> +       char *dir;
>         int register_errno;
>         uint32_t status;
>         enum rte_trace_mode mode;
> --
> 2.37.3
>