log: Allow nvme_msg usage with invalid root pointer

24ac082 ("Add 'nvme_root_t' argument to nvme_msg()") and
19b1283 ("Move global logging variables into nvme_root_t") moved
the logging controller knobs into the root object. In case the pointer
is invalid we should not try to use it. Instead just bailing out just
log the line.

Signed-off-by: Daniel Wagner <[email protected]>

Author: dwsuse

src/nvme/log.c

@@ -53,38 +53,42 @@ __nvme_msg(nvme_root_t r, int lvl,
 	};
 	char *header __cleanup__(cleanup_charp) = NULL;
 	char *message __cleanup__(cleanup_charp) = NULL;
-	int idx;
+	int idx = 0;
 
-	if (r->log_timestamp) {
+	if (r && lvl > r->log_level)
+		return;
+
+	if (r && r->log_timestamp) {
 		struct timespec now;
 
 		clock_gettime(LOG_CLOCK, &now);
 		snprintf(timebuf, sizeof(timebuf), "%6ld.%06ld",
 			 (long)now.tv_sec, now.tv_nsec / 1000);
+		idx |= 1 << 2;
 	} else
 		*timebuf = '\0';
 
-	if (r->log_pid)
+	if (r && r->log_pid) {
 		snprintf(pidbuf, sizeof(pidbuf), "%ld", (long)getpid());
-	else
+		idx |= 1 << 1;
+	} else
 		*pidbuf = '\0';
 
-	idx = ((r->log_timestamp ? 1 : 0) << 2) |
-		((r->log_pid ? 1 : 0) << 1) | (func ? 1 : 0);
+	if (func)
+		idx |= 1 << 0;
 
-	if (asprintf(&header, formats[idx], timebuf, pidbuf, func ? func : "")
-	    == -1)
+	if (asprintf(&header, formats[idx],
+		     timebuf, pidbuf, func ? func : "") == -1)
 		header = NULL;
 
 	va_start(ap, format);
 	if (vasprintf(&message, format, ap) == -1)
 		message = NULL;
 	va_end(ap);
 
-	if (lvl <= r->log_level)
-		fprintf(fp, "%s%s", header ? header : "<error>",
-			message ? message : "<error>");
-
+	fprintf(fp, "%s%s",
+		header ? header : "<error>",
+		message ? message : "<error>");
 }
 
 void nvme_init_logging(nvme_root_t r, int lvl, bool log_pid, bool log_tstamp)