conf: mount devpts without "max" on EINVAL

The "max" option to devpts got introduced in kernel 3.4.

Closes #2490.

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

diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index ff9bd091b21e16397a32fa7b977f76ae52cefeb8..bc35c9ff65ee730f2a938e0e3c4ef6043848a27c 100644 (file)
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -1612,7 +1612,7 @@ static const struct id_map *find_mapped_nsid_entry(struct lxc_conf *conf, unsign
 static int lxc_setup_devpts(struct lxc_conf *conf)
 {
        int ret;
-       const char *default_devpts_mntopts = "gid=5,newinstance,ptmxmode=0666,mode=0620";
+       char default_devpts_mntopts[] = "gid=5,newinstance,ptmxmode=0666,mode=0620";
        char devpts_mntopts[256];
 
        if (conf->pty_max <= 0) {
@@ -1642,9 +1642,20 @@ static int lxc_setup_devpts(struct lxc_conf *conf)
        /* mount new devpts instance */
        ret = mount("devpts", "/dev/pts", "devpts", MS_NOSUID | MS_NOEXEC, devpts_mntopts);
        if (ret < 0) {
+               /* try mounting without "max" */
+               if (errno == EINVAL) {
+                       devpts_mntopts[sizeof(default_devpts_mntopts) - 1] = '\0';
+                       ret = mount("devpts", "/dev/pts", "devpts",
+                                   MS_NOSUID | MS_NOEXEC, devpts_mntopts);
+                       if (ret < 0) {
+                               SYSERROR("Failed to mount new devpts instance");
+                               return -1;
+                       }
+               }
+
                /* try mounting without gid=5 */
-               ret = mount("devpts", "/dev/pts", "devpts",
-                           MS_NOSUID | MS_NOEXEC, devpts_mntopts + sizeof("gid=5"));
+               ret = mount("devpts", "/dev/pts", "devpts", MS_NOSUID | MS_NOEXEC,
+                           devpts_mntopts + sizeof("gid=5"));
                if (ret < 0) {
                        SYSERROR("Failed to mount new devpts instance");
                        return -1;