Re: [ndctl PATCH v3 1/6] cxl/monitor: Enable default_log and refactor sanity check

["Verma, Vishal L" <vishal.l.verma@intel.com>]

On Wed, 2023-05-31 at 10:19 +0800, Li Zhijian wrote:
> The default_log(/var/log/cxl-monitor.log) should be used when no '-l'
> argument is specified in daemon mode, but it was not working at all.
> 
> Here we assigned it a default log per its arguments, and simplify the
> sanity check so that it can be consistent with the document.

Avoid using 'we' as it can be ambiguous what / who it it referring to.
Also generally, use an imperative tone for changelogs - e.g. the above
line could just be "Simplify the sanity checks so that the default log
file is assigned correctly, and the behavior is consistent with the
documentation."

> 
> Please note that i also removed following addition stuff, since we have
> added this prefix if needed during parsing the FILENAME in
> parse_options_prefix().

Shouldn't be using "I did xyz.." in a commit message either - change to
imperative, e.g.: "Remove the filename prefix tweaking in
function_foo() since it is unnecessary."

> if (strncmp(monitor.log, "./", 2) != 0)
>     fix_filename(prefix, (const char **)&monitor.log);

Usually no need to include code snippets in changelogs - the details
are easily available in the actual commit itself. Instead describe what
you did and why if it isn't an obvious change.

> 
> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
> ---
> V2: exchange order of previous patch1 and patch2 # Alison
>     a few commit log updated
> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
> ---
>  cxl/monitor.c | 38 ++++++++++++++++++++------------------
>  1 file changed, 20 insertions(+), 18 deletions(-)
> 
> diff --git a/cxl/monitor.c b/cxl/monitor.c
> index e3469b9a4792..c6df2bad3c53 100644
> --- a/cxl/monitor.c
> +++ b/cxl/monitor.c
> @@ -164,6 +164,7 @@ int cmd_monitor(int argc, const char **argv, struct cxl_ctx *ctx)
>         };
>         const char *prefix ="./";
>         int rc = 0, i;
> +       const char *log;
>  
>         argc = parse_options_prefix(argc, argv, prefix, options, u, 0);
>         for (i = 0; i < argc; i++)
> @@ -171,32 +172,33 @@ int cmd_monitor(int argc, const char **argv, struct cxl_ctx *ctx)
>         if (argc)
>                 usage_with_options(u, options);
>  
> +       // sanity check

Use the /* comment */ style - ndctl follows the kernel's coding style
whenever applicable.

> +       if (monitor.daemon && monitor.log && !strncmp(monitor.log, "./", 2)) {
> +               error("standard or relative path for <file> will not work for daemon mode\n");

Just to reduce confusion about what 'standard' is and to emphesize that
it's a keyword, maybe reword this:

"relative path or 'standard' are not compatible with daemon mode"

> +               return -EINVAL;
> +       }
> +
>         log_init(&monitor.ctx, "cxl/monitor", "CXL_MONITOR_LOG");
> -       monitor.ctx.log_fn = log_standard;
> +       if (monitor.log)
> +               log = monitor.log;
> +       else
> +               log = monitor.daemon ? default_log : "./standard";

I think the original './standard' was used that way because
fix_filename() added the './' prefix. Note that the keyword used in the
nam page is just 'standard' - so shouldn't this just be using
'standard' rather than './standard'. Similarly, later when you strcmp,
that should also become just 'standard' of course. 

>  
>         if (monitor.verbose)
>                 monitor.ctx.log_priority = LOG_DEBUG;
>         else
>                 monitor.ctx.log_priority = LOG_INFO;
>  
> -       if (monitor.log) {
> -               if (strncmp(monitor.log, "./", 2) != 0)
> -                       fix_filename(prefix, (const char **)&monitor.log);
> -               if (strncmp(monitor.log, "./standard", 10) == 0 && !monitor.daemon) {
> -                       monitor.ctx.log_fn = log_standard;
> -               } else {
> -                       const char *log = monitor.log;
> -
> -                       if (!monitor.log)
> -                               log = default_log;
> -                       monitor.log_file = fopen(log, "a+");
> -                       if (!monitor.log_file) {
> -                               rc = -errno;
> -                               error("open %s failed: %d\n", monitor.log, rc);
> -                               goto out;
> -                       }
> -                       monitor.ctx.log_fn = log_file;
> +       if (strncmp(log, "./standard", 10) == 0)
> +               monitor.ctx.log_fn = log_standard;
> +       else {
> +               monitor.log_file = fopen(log, "a+");
> +               if (!monitor.log_file) {
> +                       rc = -errno;
> +                       error("open %s failed: %d\n", log, rc);
> +                       goto out;
>                 }
> +               monitor.ctx.log_fn = log_file;
>         }
>  
>         if (monitor.daemon) {