util: promote rmrf() from tmpfiles.c, fix silent mksubsys() skip

rmrf() is needed outside tmpfiles.c.  The move also deduplicates the
nftw callback: the contents-only removal used by tmpfiles 'D' entries
is now rmcontents(), sharing the callback with rmrf().

mksubsys() did nothing at all when the user could not be resolved, no
directory and no message, and callers had no way to tell.  Now the
directory is always created, ownership is best effort, and an unknown
user is warned about.

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

src/tmpfiles.c

@@ -130,33 +130,6 @@ static int parse_mm(char *arg, int *major, int *minor)
 	return 0;
 }
 
-static int do_delete(const char *fpath, const struct stat *sb, int tflag, struct FTW *ftw)
-{
-	(void)sb;
-	(void)tflag;
-
-	if (ftw->level == 0)
-		return 1;
-
-	if (remove(fpath) && errno != EBUSY)
-		warn("Failed removing %s", fpath);
-
-	return 0;
-
-}
-
-static int rmrf(const char *path)
-{
-	if (!fisdir(path))
-		return 0;
-
-	nftw(path, do_delete, 20, FTW_DEPTH | FTW_PHYS);
-	if (remove(path) && errno != ENOENT)
-		warn("Failed removing path %s", path);
-
-	return 0;
-}
-
 static void mkparent(char *path, mode_t mode)
 {
 	mkpath(dirname(strdupa(path)), mode);
@@ -465,9 +438,7 @@ static void tmpfiles(char *line)
 		case 'd':
 			break;
 		case 'D':
-			if (fisdir(path)) {
-				nftw(path, do_delete, 20, FTW_DEPTH | FTW_PHYS);
-			}
+			rmcontents(path);
 			break;
 		case 'e':
 		case 'f':

src/util.c

@@ -45,6 +45,7 @@
 # include <sys/ioctl.h>
 #endif
 #include <sys/resource.h>
+#include <ftw.h>		/* rmrf() */
 #include <sys/sysinfo.h>	/* sysinfo() */
 #include <sys/vfs.h>		/* statfs */
 #include <linux/magic.h>
@@ -310,6 +311,42 @@ int getcgroup(char *buf, size_t len)
 	return 0;
 }
 
+static int rmrf_cb(const char *fpath, const struct stat *sb, int tflag, struct FTW *ftw)
+{
+	(void)sb;
+	(void)tflag;
+
+	if (ftw->level == 0)
+		return 0;
+
+	if (remove(fpath) && errno != EBUSY)
+		warn("Failed removing %s", fpath);
+
+	return 0;
+}
+
+/* empty a directory but keep it, silently ignores a missing path */
+int rmcontents(const char *path)
+{
+	if (!fisdir(path))
+		return 0;
+
+	return nftw(path, rmrf_cb, 20, FTW_DEPTH | FTW_PHYS);
+}
+
+/* rm -rf, silently ignores a missing path */
+int rmrf(const char *path)
+{
+	if (!fisdir(path))
+		return 0;
+
+	nftw(path, rmrf_cb, 20, FTW_DEPTH | FTW_PHYS);
+	if (remove(path) && errno != ENOENT)
+		warn("Failed removing path %s", path);
+
+	return 0;
+}
+
 int mksubsys(const char *dir, mode_t mode, char *user, char *group)
 {
 	mode_t omask;
@@ -318,18 +355,20 @@ int mksubsys(const char *dir, mode_t mode, char *user, char *group)
 
 	omask = umask(0);
 
+	rc = makedir(dir, mode);
+	if (rc && errno == EEXIST)
+		rc = chmod(dir, mode);
+
 	uid = getuser(user, NULL);
 	if (uid >= 0) {
 		gid = getgroup(group);
 		if (gid < 0)
 			gid = 0;
 
-		rc = makedir(dir, mode);
-		if (rc && errno == EEXIST)
-			rc = chmod(dir, mode);
 		if (chown(dir, uid, gid))
 			err(1, "Failed chown(%s, %d, %d)", dir, uid, gid);
-	}
+	} else
+		warnx("Cannot find user %s, %s is owned by root", user, dir);
 
 	umask(omask);
 

src/util.h

@@ -72,6 +72,8 @@ int   getcuser     (char *buf, size_t len);
 int   getcgroup    (char *buf, size_t len);
 
 int   mksubsys     (const char *dir, mode_t mode, char *user, char *group);
+int   rmcontents   (const char *path);
+int   rmrf         (const char *path);
 
 char *fslurp       (size_t *lenp, const char *fmt, ...)    __attribute__ ((format (printf, 2, 3)));
 char *vfslurp      (size_t *lenp, const char *fmt, va_list ap);