log: Add nvme root global variable to set for default output

Signed-off-by: Tokunori Ikegami <[email protected]>
[dwagner: export new function, update docs, reorder free sequence]
Signed-off-by: Daniel Wagner <[email protected]>

Author: ikegami-t

src/libnvme.map

@@ -5,6 +5,7 @@ LIBNVME_1_6 {
 		nvme_ctrl_find;
 		nvme_ctrl_get_src_addr;
 		nvme_ctrl_release_fd;
+		nvme_get_debug;
 		nvme_get_features_err_recovery2;
 		nvme_get_features_host_mem_buf2;
 		nvme_get_features_iocs_profile;
@@ -14,14 +15,14 @@ LIBNVME_1_6 {
 		nvme_host_release_fds;
 		nvme_ns_release_fd;
 		nvme_root_release_fds;
+		nvme_set_debug;
 		nvme_set_features_iocs_profile;
 		nvme_set_features_resv_mask2;
 		nvme_set_features_resv_persist2;
 		nvme_set_features_write_protect2;
+		nvme_set_root;
 		nvme_subsystem_get_iopolicy;
 		nvme_subsystem_release_fds;
-		nvme_set_debug;
-		nvme_get_debug;
 };
 
 LIBNVME_1_5 {

src/nvme/log.c

@@ -26,11 +26,13 @@
 #define LOG_CLOCK CLOCK_MONOTONIC
 #endif
 
+static nvme_root_t root;
+
 void __attribute__((format(printf, 4, 5)))
 __nvme_msg(nvme_root_t r, int lvl,
 	   const char *func, const char *format, ...)
 {
-	FILE *fp = r ? r->fp : stderr;
+	FILE *fp = stderr;
 	va_list ap;
 	char pidbuf[16];
 	char timebuf[32];
@@ -48,6 +50,12 @@ __nvme_msg(nvme_root_t r, int lvl,
 	char *message __cleanup__(cleanup_charp) = NULL;
 	int idx = 0;
 
+	if (!r)
+		r = root;
+
+	if (r)
+		fp = r->fp;
+
 	if (r && lvl > r->log_level)
 		return;
 
@@ -90,3 +98,8 @@ void nvme_init_logging(nvme_root_t r, int lvl, bool log_pid, bool log_tstamp)
 	r->log_pid = log_pid;
 	r->log_timestamp = log_tstamp;
 }
+
+void nvme_set_root(nvme_root_t r)
+{
+	root = r;
+}

src/nvme/log.h

@@ -35,4 +35,17 @@
  */
 void nvme_init_logging(nvme_root_t r, int lvl, bool log_pid, bool log_tstamp);
 
+/**
+ * nvme_set_root() - Set nvme_root_t context
+ * @r:		nvme_root_t context
+ *
+ * In order to be able to log from code paths where no root object is passed in
+ * via the arguments use the the default one which can be set via this call.
+ * When creating a new root object with @nvme_create_root the global root object
+ * will be set as well. This means the global root object is always pointing to
+ * the latest created root object. Note the first @nvme_free_tree call will reset
+ * the global root object.
+ */
+void nvme_set_root(nvme_root_t r);
+
 #endif /* _LOG_H */

src/nvme/tree.c

@@ -198,6 +198,7 @@ nvme_root_t nvme_create_root(FILE *fp, int log_level)
 		r->fp = fp;
 	list_head_init(&r->hosts);
 	list_head_init(&r->endpoints);
+	nvme_set_root(r);
 	return r;
 }
 
@@ -364,6 +365,7 @@ void nvme_free_tree(nvme_root_t r)
 		free(r->config_file);
 	if (r->application)
 		free(r->application);
+	nvme_set_root(NULL);
 	free(r);
 }