cgroup_fuse: rework cgfs_get_key()

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/cgroup_fuse.c b/src/cgroup_fuse.c
index a93614b6fd11362f8a28881ce601d4f1012cab19..baa50dc19f8954fe5dbb9fc570e976bfb9f2ca42 100644 (file)
--- a/src/cgroup_fuse.c
+++ b/src/cgroup_fuse.c
@@ -304,11 +304,10 @@ out:
 static struct cgfs_files *cgfs_get_key(const char *controller,
                                       const char *cgroup, const char *file)
 {
-       int ret, cfd;
-       size_t len;
-       char *fnam;
-       struct stat sb;
+       __do_free char *path = NULL;
        struct cgfs_files *newkey;
+       int cfd, ret;
+       struct stat sb;
 
        cfd = get_cgroup_fd_handle_named(controller);
        if (cfd < 0)
@@ -320,23 +319,16 @@ static struct cgfs_files *cgfs_get_key(const char *controller,
        if (file && strchr(file, '/'))
                return NULL;
 
-       /* Make sure we pass a relative path to *at() family of functions.
-        * . + /cgroup + / + file + \0
-        */
-       len = strlen(cgroup) + 3;
        if (file)
-               len += strlen(file) + 1;
-       fnam = alloca(len);
-       snprintf(fnam, len, "%s%s%s%s", dot_or_empty(cgroup), cgroup,
-                file ? "/" : "", file ? file : "");
-
-       ret = fstatat(cfd, fnam, &sb, 0);
+               path = must_make_path_relative(cgroup, file, NULL);
+       else
+               path = must_make_path_relative(cgroup, NULL);
+       ret = fstatat(cfd, path, &sb, 0);
        if (ret < 0)
                return NULL;
 
-       do {
-               newkey = malloc(sizeof(struct cgfs_files));
-       } while (!newkey);
+       newkey = must_realloc(NULL, sizeof(struct cgfs_files));
+
        if (file)
                newkey->name = must_copy_string(file);
        else if (strrchr(cgroup, '/'))
@@ -471,10 +463,10 @@ static bool perms_include(int fmode, mode_t req_mode)
 
 static void free_key(struct cgfs_files *k)
 {
-       if (!k)
-               return;
-       free_disarm(k->name);
-       free_disarm(k);
+       if (k) {
+               free_disarm(k->name);
+               free_disarm(k);
+       }
 }
 
 /*