Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm...

[mirror_ubuntu-artful-kernel.git] / fs / namespace.c

diff --git a/fs/namespace.c b/fs/namespace.c
index 02c6875dd9457624bfced03bf1721bb5d494944f..c7cb8a526c05fbaa5ba18934cd04eda1eb2a6e60 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -590,24 +590,35 @@ static void delayed_free_vfsmnt(struct rcu_head *head)
 }
 
 /* call under rcu_read_lock */
-bool legitimize_mnt(struct vfsmount *bastard, unsigned seq)
+int __legitimize_mnt(struct vfsmount *bastard, unsigned seq)
 {
        struct mount *mnt;
        if (read_seqretry(&mount_lock, seq))
-               return false;
+               return 1;
        if (bastard == NULL)
-               return true;
+               return 0;
        mnt = real_mount(bastard);
        mnt_add_count(mnt, 1);
        if (likely(!read_seqretry(&mount_lock, seq)))
-               return true;
+               return 0;
        if (bastard->mnt_flags & MNT_SYNC_UMOUNT) {
                mnt_add_count(mnt, -1);
-               return false;
+               return 1;
+       }
+       return -1;
+}
+
+/* call under rcu_read_lock */
+bool legitimize_mnt(struct vfsmount *bastard, unsigned seq)
+{
+       int res = __legitimize_mnt(bastard, seq);
+       if (likely(!res))
+               return true;
+       if (unlikely(res < 0)) {
+               rcu_read_unlock();
+               mntput(bastard);
+               rcu_read_lock();
        }
-       rcu_read_unlock();
-       mntput(bastard);
-       rcu_read_lock();
        return false;
 }
 
@@ -1215,7 +1226,7 @@ EXPORT_SYMBOL(replace_mount_options);
 /* iterator; we want it to have access to namespace_sem, thus here... */
 static void *m_start(struct seq_file *m, loff_t *pos)
 {
-       struct proc_mounts *p = proc_mounts(m);
+       struct proc_mounts *p = m->private;
 
        down_read(&namespace_sem);
        if (p->cached_event == p->ns->event) {
@@ -1236,7 +1247,7 @@ static void *m_start(struct seq_file *m, loff_t *pos)
 
 static void *m_next(struct seq_file *m, void *v, loff_t *pos)
 {
-       struct proc_mounts *p = proc_mounts(m);
+       struct proc_mounts *p = m->private;
 
        p->cached_mount = seq_list_next(v, &p->ns->list, pos);
        p->cached_index = *pos;
@@ -1250,7 +1261,7 @@ static void m_stop(struct seq_file *m, void *v)
 
 static int m_show(struct seq_file *m, void *v)
 {
-       struct proc_mounts *p = proc_mounts(m);
+       struct proc_mounts *p = m->private;
        struct mount *r = list_entry(v, struct mount, mnt_list);
        return p->show(m, &r->mnt);
 }