Add mkdir_errno_wrapper() and use instead of mkdir() in various places

We'd pass pointers to mkdir and mkdir_label to call in various places. mkdir
returns the error in errno while mkdir_label returns the error directly.

src/basic/cgroup-util.c

@@ -779,13 +779,11 @@ int cg_create(const char *controller, const char *path) {
         if (r < 0)
                 return r;
 
-        if (mkdir(fs, 0755) < 0) {
-
-                if (errno == EEXIST)
-                        return 0;
-
-                return -errno;
-        }
+        r = mkdir_errno_wrapper(fs, 0755);
+        if (r == -EEXIST)
+                return 0;
+        if (r < 0)
+                return r;
 
         r = cg_hybrid_unified();
         if (r < 0)

src/basic/label.c

@@ -50,11 +50,8 @@ int mkdir_label(const char *path, mode_t mode) {
         if (r < 0)
                 return r;
 
-        if (mkdir(path, mode) < 0)
-                r = -errno;
-
+        r = mkdir_errno_wrapper(path, mode);
         mac_selinux_create_file_clear();
-
         if (r < 0)
                 return r;
 

src/basic/mkdir.c

@@ -35,6 +35,8 @@ int mkdir_safe_internal(const char *path, mode_t mode, uid_t uid, gid_t gid, boo
         struct stat st;
         int r;
 
+        assert(_mkdir != mkdir);
+
         if (_mkdir(path, mode) >= 0) {
                 r = chmod_and_chown(path, mode, uid, gid);
                 if (r < 0)
@@ -68,8 +70,14 @@ int mkdir_safe_internal(const char *path, mode_t mode, uid_t uid, gid_t gid, boo
         return 0;
 }
 
+int mkdir_errno_wrapper(const char *pathname, mode_t mode) {
+        if (mkdir(pathname, mode) < 0)
+                return -errno;
+        return 0;
+}
+
 int mkdir_safe(const char *path, mode_t mode, uid_t uid, gid_t gid, bool follow_symlink) {
-        return mkdir_safe_internal(path, mode, uid, gid, follow_symlink, mkdir);
+        return mkdir_safe_internal(path, mode, uid, gid, follow_symlink, mkdir_errno_wrapper);
 }
 
 int mkdir_parents_internal(const char *prefix, const char *path, mode_t mode, mkdir_func_t _mkdir) {
@@ -77,6 +85,7 @@ int mkdir_parents_internal(const char *prefix, const char *path, mode_t mode, mk
         int r;
 
         assert(path);
+        assert(_mkdir != mkdir);
 
         if (prefix && !path_startswith(path, prefix))
                 return -ENOTDIR;
@@ -104,8 +113,7 @@ int mkdir_parents_internal(const char *prefix, const char *path, mode_t mode, mk
                 e = p + strcspn(p, "/");
                 p = e + strspn(e, "/");
 
-                /* Is this the last component? If so, then we're
-                 * done */
+                /* Is this the last component? If so, then we're done */
                 if (*p == 0)
                         return 0;
 
@@ -116,13 +124,13 @@ int mkdir_parents_internal(const char *prefix, const char *path, mode_t mode, mk
                         continue;
 
                 r = _mkdir(t, mode);
-                if (r < 0 && errno != EEXIST)
-                        return -errno;
+                if (r < 0 && r != -EEXIST)
+                        return r;
         }
 }
 
 int mkdir_parents(const char *path, mode_t mode) {
-        return mkdir_parents_internal(NULL, path, mode, mkdir);
+        return mkdir_parents_internal(NULL, path, mode, mkdir_errno_wrapper);
 }
 
 int mkdir_p_internal(const char *prefix, const char *path, mode_t mode, mkdir_func_t _mkdir) {
@@ -130,17 +138,19 @@ int mkdir_p_internal(const char *prefix, const char *path, mode_t mode, mkdir_fu
 
         /* Like mkdir -p */
 
+        assert(_mkdir != mkdir);
+
         r = mkdir_parents_internal(prefix, path, mode, _mkdir);
         if (r < 0)
                 return r;
 
         r = _mkdir(path, mode);
-        if (r < 0 && (errno != EEXIST || is_dir(path, true) <= 0))
-                return -errno;
+        if (r < 0 && (r != -EEXIST || is_dir(path, true) <= 0))
+                return r;
 
         return 0;
 }
 
 int mkdir_p(const char *path, mode_t mode) {
-        return mkdir_p_internal(NULL, path, mode, mkdir);
+        return mkdir_p_internal(NULL, path, mode, mkdir_errno_wrapper);
 }

src/basic/mkdir.h

@@ -23,6 +23,7 @@
 
 #include <sys/types.h>
 
+int mkdir_errno_wrapper(const char *pathname, mode_t mode);
 int mkdir_safe(const char *path, mode_t mode, uid_t uid, gid_t gid, bool follow_symlink);
 int mkdir_parents(const char *path, mode_t mode);
 int mkdir_p(const char *path, mode_t mode);