userns: Rename id_map_mutex to userns_state_mutex

Generalize id_map_mutex so it can be used for more state of a user namespace.

Cc: stable@vger.kernel.org
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 1e34de2fbd60fdefbed0abf4d5fd0f057323dffc..44a555ac6104860f0603be2d3927a781cd68bc3b 100644 (file)
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -24,6 +24,7 @@
 #include <linux/fs_struct.h>
 
 static struct kmem_cache *user_ns_cachep __read_mostly;
+static DEFINE_MUTEX(userns_state_mutex);
 
 static bool new_idmap_permitted(const struct file *file,
                                struct user_namespace *ns, int cap_setid,
@@ -583,9 +584,6 @@ static bool mappings_overlap(struct uid_gid_map *new_map,
        return false;
 }
 
-
-static DEFINE_MUTEX(id_map_mutex);
-
 static ssize_t map_write(struct file *file, const char __user *buf,
                         size_t count, loff_t *ppos,
                         int cap_setid,
@@ -602,7 +600,7 @@ static ssize_t map_write(struct file *file, const char __user *buf,
        ssize_t ret = -EINVAL;
 
        /*
-        * The id_map_mutex serializes all writes to any given map.
+        * The userns_state_mutex serializes all writes to any given map.
         *
         * Any map is only ever written once.
         *
@@ -620,7 +618,7 @@ static ssize_t map_write(struct file *file, const char __user *buf,
         * order and smp_rmb() is guaranteed that we don't have crazy
         * architectures returning stale data.
         */
-       mutex_lock(&id_map_mutex);
+       mutex_lock(&userns_state_mutex);
 
        ret = -EPERM;
        /* Only allow one successful write to the map */
@@ -750,7 +748,7 @@ static ssize_t map_write(struct file *file, const char __user *buf,
        *ppos = count;
        ret = count;
 out:
-       mutex_unlock(&id_map_mutex);
+       mutex_unlock(&userns_state_mutex);
        if (page)
                free_page(page);
        return ret;
@@ -845,12 +843,12 @@ bool userns_may_setgroups(const struct user_namespace *ns)
 {
        bool allowed;
 
-       mutex_lock(&id_map_mutex);
+       mutex_lock(&userns_state_mutex);
        /* It is not safe to use setgroups until a gid mapping in
         * the user namespace has been established.
         */
        allowed = ns->gid_map.nr_extents != 0;
-       mutex_unlock(&id_map_mutex);
+       mutex_unlock(&userns_state_mutex);
 
        return allowed;
 }