Re: [PATCH] virtiofsd: use g_date_time_get_microsecond to get subsecond

[Dr. David Alan Gilbert]

* Yusuke Okada (yokada.996@gmail.com) wrote:
> From: Yusuke Okada <okada.yusuke@jp.fujitsu.com>
> 
> The "%f" specifier in g_date_time_format() is only available in glib
> 2.65.2 or later. If combined with older glib, the function returns null
> and the timestamp displayed as "(null)".

Well spotted; thanks for the patch.
I notice there's also a use in rocker and qga (Copying Dan and
Marc-Andre in who added them)

> For backward compatibility, g_date_time_get_microsecond should be used
> to retrieve subsecond.
> 
> In this patch the g_date_time_format() leaves subsecond field as "%06d"
> and let next snprintf to format with g_date_time_get_microsecond.
> 
> Signed-off-by: Yusuke Okada <okada.yusuke@jp.fujitsu.com>


Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  tools/virtiofsd/passthrough_ll.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/virtiofsd/passthrough_ll.c 
> b/tools/virtiofsd/passthrough_ll.c
> index 371a7bead6..20f0f41f99 100644
> --- a/tools/virtiofsd/passthrough_ll.c
> +++ b/tools/virtiofsd/passthrough_ll.c
> @@ -4185,6 +4185,7 @@ static void setup_nofile_rlimit(unsigned long 
> rlimit_nofile)
>  static void log_func(enum fuse_log_level level, const char *fmt, va_list ap)
>  {
>      g_autofree char *localfmt = NULL;
> +    char buf[64];
>  
>      if (current_log_level < level) {
>          return;
> @@ -4197,9 +4198,11 @@ static void log_func(enum fuse_log_level level, const 
> char *fmt, va_list ap)
>                                         fmt);
>          } else {
>              g_autoptr(GDateTime) now = g_date_time_new_now_utc();
> -            g_autofree char *nowstr = g_date_time_format(now, "%Y-%m-%d 
> %H:%M:%S.%f%z");
> +            g_autofree char *nowstr = g_date_time_format(now,
> +                                       "%Y-%m-%d %H:%M:%S.%%06d%z");
> +            snprintf(buf, 64, nowstr, g_date_time_get_microsecond(now));
>              localfmt = g_strdup_printf("[%s] [ID: %08ld] %s",
> -                                       nowstr, syscall(__NR_gettid), fmt);
> +                                       buf, syscall(__NR_gettid), fmt);
>          }
>          fmt = localfmt;
>      }
> -- 
> 2.31.1
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK