Drop svc pidfile matching, only match against PID in pidfile

With the redesign from <svc/path/to/pidfile> to <pid/name:id> in d1fac6f
we moved to matching svc_t only against their PID, which could pop up in
any *.pid or */pid in /var/run.  This patch drops the (hopefully) last
remnants of the old <svc/> legacy.

To ensure we don't try reading the PID value from socket files, like
/var/run/initctl, we add simple fnmatch() of the inotified file.  Two
calls to fnmatch(), for portability reasons, not every system has GNU
libc extensions like FNM_EXTMATCH.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

plugins/pidfile.c

@@ -22,6 +22,7 @@
  * THE SOFTWARE.
  */
 
+#include <fnmatch.h>
 #include <glob.h>
 #include <limits.h>
 #include <paths.h>
@@ -69,6 +70,9 @@ static void pidfile_update_conds(char *dir, char *name, uint32_t mask)
 	_d("Got dir: %s, name: %s, mask: %08x", dir, name, mask);
 	snprintf(fn, sizeof(fn), "%s/%s", dir, name);
 
+	if (fnmatch("*\\.pid", fn, 0) && fnmatch("*/pid", fn, 0))
+		return;
+
 	svc = svc_find_by_pidfile(fn);
 	if (!svc) {
 		_d("No matching svc for %s", fn);

src/svc.c

@@ -395,7 +395,7 @@ svc_t *svc_find_by_nameid(char *name, char *id)
 }
 
 /**
- * svc_find_by_plidfile - Find an service object by its PID file
+ * svc_find_by_plidfile - Find a service by its PID file
  * @fn: PID file, can be absolute path or relative to /run
  *
  * This function is primarily used by the pidfile plugin to track the
@@ -412,32 +412,13 @@ svc_t *svc_find_by_nameid(char *name, char *id)
 svc_t *svc_find_by_pidfile(char *fn)
 {
 	svc_t *svc, *iter = NULL;
-	char adjpath[strlen(fn) + 10]; /* + sizeof("/var/run/") */
+	pid_t pid;
-	char fnpath[PATH_MAX];
 
-	pid_runpath(fn, adjpath, sizeof(adjpath));
+	pid = pid_file_read(fn);
-	if (!realpath(adjpath, fnpath)) {
+	if (pid == -1)
-		if (errno != ENOENT)
-			_pe("adjpath: %s, errno %d", adjpath, errno);
 		return NULL;
-	}
 
 	for (svc = svc_iterator(&iter, 1); svc; svc = svc_iterator(&iter, 0)) {
-		char path[PATH_MAX];
-		char *pidfn;
-		pid_t pid;
-
-		pidfn = pid_file(svc);
-		if (!pidfn || !realpath(pidfn, path)) {
-			if (errno != ENOENT)
-				_pe("pidfn: %s, errno %d", pidfn ?: "<NULL>", errno);
-			continue;
-		}
-
-		if (!string_compare(fnpath, path))
-			continue;
-
-		pid = pid_file_read(path);
 		if (svc->pid != pid)
 			continue;