Revert "cgfsng: avoid tiny race window"

This reverts commit 17e55991744576bca20e370a6d829da99c3fc801.

Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>

diff --git a/src/lxc/cgroups/cgfsng.c b/src/lxc/cgroups/cgfsng.c
index ec4501c33e4e50a25f5bea3c22dd6d16c641a43a..0fc9b11d2c01acaec95358f8866f649147599fb8 100644 (file)
--- a/src/lxc/cgroups/cgfsng.c
+++ b/src/lxc/cgroups/cgfsng.c
@@ -1257,50 +1257,13 @@ on_error:
        return bret;
 }
 
-static int mkdir_eexist_on_last(const char *dir, mode_t mode)
-{
-       const char *tmp = dir;
-       const char *orig = dir;
-       size_t orig_len;
-
-       orig_len = strlen(dir);
-       do {
-               int ret;
-               size_t cur_len;
-               char *makeme;
-
-               dir = tmp + strspn(tmp, "/");
-               tmp = dir + strcspn(dir, "/");
-
-               errno = ENOMEM;
-               cur_len = dir - orig;
-               makeme = strndup(orig, cur_len);
-               if (!makeme)
-                       return -1;
-
-               ret = mkdir(makeme, mode);
-               if (ret < 0) {
-                       if ((errno != EEXIST) || (orig_len == cur_len)) {
-                               SYSERROR("Failed to create directory \"%s\"", makeme);
-                               free(makeme);
-                               return -1;
-                       }
-               }
-               free(makeme);
-
-       } while (tmp != dir);
-
-       return 0;
-}
-
 static bool monitor_create_path_for_hierarchy(struct hierarchy *h, char *cgname)
 {
        int ret;
 
        h->monitor_full_path = must_make_path(h->mountpoint, h->container_base_path, cgname, NULL);
-       ret = mkdir_eexist_on_last(h->monitor_full_path, 0755);
-       if (ret < 0) {
-               ERROR("Failed to create cgroup \"%s\"", h->monitor_full_path);
+       if (dir_exists(h->monitor_full_path)) {
+               ERROR("The cgroup \"%s\" already existed", h->monitor_full_path);
                return false;
        }
 
@@ -1309,6 +1272,12 @@ static bool monitor_create_path_for_hierarchy(struct hierarchy *h, char *cgname)
                return false;
        }
 
+       ret = mkdir_p(h->monitor_full_path, 0755);
+       if (ret < 0) {
+               ERROR("Failed to create cgroup \"%s\"", h->monitor_full_path);
+               return false;
+       }
+
        return cg_unified_create_cgroup(h, cgname);
 }
 
@@ -1317,9 +1286,8 @@ static bool container_create_path_for_hierarchy(struct hierarchy *h, char *cgnam
        int ret;
 
        h->container_full_path = must_make_path(h->mountpoint, h->container_base_path, cgname, NULL);
-       ret = mkdir_eexist_on_last(h->container_full_path, 0755);
-       if (ret < 0) {
-               ERROR("Failed to create cgroup \"%s\"", h->container_full_path);
+       if (dir_exists(h->container_full_path)) {
+               ERROR("The cgroup \"%s\" already existed", h->container_full_path);
                return false;
        }
 
@@ -1328,6 +1296,12 @@ static bool container_create_path_for_hierarchy(struct hierarchy *h, char *cgnam
                return false;
        }
 
+       ret = mkdir_p(h->container_full_path, 0755);
+       if (ret < 0) {
+               ERROR("Failed to create cgroup \"%s\"", h->container_full_path);
+               return false;
+       }
+
        return cg_unified_create_cgroup(h, cgname);
 }
 

diff --git a/src/lxc/utils.c b/src/lxc/utils.c
index 1af6f512c7cc841b67b201cdc27b289d35ffbb83..ff6ea3fd73ecc9f749dcbe99988364ba60db48bf 100644 (file)
--- a/src/lxc/utils.c
+++ b/src/lxc/utils.c
@@ -221,31 +221,26 @@ extern int get_u16(unsigned short *val, const char *arg, int base)
        return 0;
 }
 
-int mkdir_p(const char *dir, mode_t mode)
+extern int mkdir_p(const char *dir, mode_t mode)
 {
        const char *tmp = dir;
        const char *orig = dir;
-       do {
-               int ret;
-               char *makeme;
+       char *makeme;
 
+       do {
                dir = tmp + strspn(tmp, "/");
                tmp = dir + strcspn(dir, "/");
 
-               errno = ENOMEM;
                makeme = strndup(orig, dir - orig);
-               if (!makeme)
-                       return -1;
-
-               ret = mkdir(makeme, mode);
-               if (ret < 0 && errno != EEXIST) {
-                       SYSERROR("Failed to create directory \"%s\"", makeme);
-                       free(makeme);
-                       return -1;
+               if (*makeme) {
+                       if (mkdir(makeme, mode) && errno != EEXIST) {
+                               SYSERROR("failed to create directory '%s'", makeme);
+                               free(makeme);
+                               return -1;
+                       }
                }
                free(makeme);
-
-       } while (tmp != dir);
+       } while(tmp != dir);
 
        return 0;
 }