allow attaching fs_pin to a group not associated with some superblock

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 13 insertions, 7 deletions

diff --git a/fs/fs_pin.c b/fs/fs_pin.c
index 5eb39a93a560..50ef7d2ef03c 100644
--- a/fs/fs_pin.c
+++ b/fs/fs_pin.c
@@ -14,14 +14,20 @@ void pin_remove(struct fs_pin *pin)
         spin_unlock(&pin_lock);
 }
 
-void pin_insert(struct fs_pin *pin, struct vfsmount *m)
+void pin_insert_group(struct fs_pin *pin, struct vfsmount *m, struct hlist_head *p)
 {
         spin_lock(&pin_lock);
-        hlist_add_head(&pin->s_list, &m->mnt_sb->s_pins);
+        if (p)
+                hlist_add_head(&pin->s_list, p);
         hlist_add_head(&pin->m_list, &real_mount(m)->mnt_pins);
         spin_unlock(&pin_lock);
 }
 
+void pin_insert(struct fs_pin *pin, struct vfsmount *m)
+{
+        pin_insert_group(pin, m, &m->mnt_sb->s_pins);
+}
+
 void mnt_pin_kill(struct mount *m)
 {
         while (1) {
@@ -38,18 +44,18 @@ void mnt_pin_kill(struct mount *m)
         }
 }
 
-void sb_pin_kill(struct super_block *sb)
+void group_pin_kill(struct hlist_head *p)
 {
         while (1) {
-                struct hlist_node *p;
+                struct hlist_node *q;
                 struct fs_pin *pin;
                 rcu_read_lock();
-                p = ACCESS_ONCE(sb->s_pins.first);
-                if (!p) {
+                q = ACCESS_ONCE(p->first);
+                if (!q) {
                         rcu_read_unlock();
                         break;
                 }
-                pin = hlist_entry(p, struct fs_pin, s_list);
+                pin = hlist_entry(q, struct fs_pin, s_list);
                 pin->kill(pin);
         }
 }