On Tue, 10 Nov 2020 14:22:48 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx> wrote:
\> +
> +/**
> + * tracefs_instances_walk - Iterate through all ftrace instances in the system
> + * @callback: user callback, called for each instance. Instance name is passed
> + * as input parameter. If the @callback returns non-zero,
> + * the iteration stops.
> + * @context: user context, passed to the @callback.
> + *
> + * Returns -1 in case of an error, 0 otherwise.
> + */
> +int tracefs_instances_walk(int (*callback)(const char *, void *), void *context)
> +{
> + struct dirent *dent;
> + char *path = NULL;
> + DIR *dir = NULL;
> + struct stat st;
> + int fret = -1;
> + int ret;
> +
> + path = tracefs_get_tracing_file("instances");
> + if (!path)
> + return -1;
> + ret = stat(path, &st);
> + if (ret < 0 || !S_ISDIR(st.st_mode))
> + goto out;
> +
> + dir = opendir(path);
> + if (!dir)
> + goto out;
> + fret = 0;
> + while ((dent = readdir(dir))) {
> + char *instance;
> +
> + if (strcmp(dent->d_name, ".") == 0 ||
> + strcmp(dent->d_name, "..") == 0)
> + continue;
> + instance = trace_append_file(path, dent->d_name);
> + ret = stat(instance, &st);
> + free(instance);
> + if (ret < 0 || !S_ISDIR(st.st_mode))
> + continue;
> + if (callback(dent->d_name, context))
Should we notify the caller of this function if the callback returned
non zero?
> + break;
> + }
> +
> +out:
Hmm, would dir ever be anything but non NULL here?
-- Steve
> + if (dir)
> + closedir(dir);
> + tracefs_put_tracing_file(path);
> + return fret;
> +}
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