From: LiFeng <lifeng68@huawei.com>
Date: Wed, 7 Feb 2018 16:39:59 +0000 (-0500)
Subject: cgfsng: do MS_REMOUNT
X-Git-Tag: lxc-2.0.10~351
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a566f76fc2cdfee3771822d406323fa42be896e4;p=thirdparty%2Flxc.git

cgfsng: do MS_REMOUNT

Perform MS_REMOUNT on mounts with MS_RDONLY.

Signed-off-by: LiFeng <lifeng68@huawei.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---

diff --git a/src/lxc/cgroups/cgfsng.c b/src/lxc/cgroups/cgfsng.c
index 9314f727d..03a36d4d5 100644
--- a/src/lxc/cgroups/cgfsng.c
+++ b/src/lxc/cgroups/cgfsng.c
@@ -1926,6 +1926,15 @@ static int do_secondstage_mounts_if_needed(int type, struct hierarchy *h,
 				cgpath);
 		return -1;
 	}
+
+	if (flags & MS_RDONLY) {
+		if (mount(sourcepath, cgpath, "cgroup", MS_REMOUNT | flags | MS_RDONLY, NULL) < 0) {
+			free(sourcepath);
+			SYSERROR("Error remounting %s read-only", cgpath);
+			return -1;
+		}
+	}
+
 	free(sourcepath);
 	INFO("Completed second stage cgroup automounts for %s", cgpath);
 	return 0;