Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

[cascardo/linux.git] / fs / namespace.c

diff --git a/fs/namespace.c b/fs/namespace.c
index 0acabea..a01c773 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -16,7 +16,6 @@
 #include <linux/namei.h>
 #include <linux/security.h>
 #include <linux/idr.h>
-#include <linux/acct.h>                /* acct_auto_close_mnt */
 #include <linux/init.h>                /* init_rootfs */
 #include <linux/fs_struct.h>   /* get_fs_root et.al. */
 #include <linux/fsnotify.h>    /* fsnotify_vfsmount_delete */
@@ -779,6 +778,20 @@ static void attach_mnt(struct mount *mnt,
        list_add_tail(&mnt->mnt_child, &parent->mnt_mounts);
 }
 
+static void attach_shadowed(struct mount *mnt,
+                       struct mount *parent,
+                       struct mount *shadows)
+{
+       if (shadows) {
+               hlist_add_behind_rcu(&mnt->mnt_hash, &shadows->mnt_hash);
+               list_add(&mnt->mnt_child, &shadows->mnt_child);
+       } else {
+               hlist_add_head_rcu(&mnt->mnt_hash,
+                               m_hash(&parent->mnt, mnt->mnt_mountpoint));
+               list_add_tail(&mnt->mnt_child, &parent->mnt_mounts);
+       }
+}
+
 /*
  * vfsmount lock must be held for write
  */
@@ -797,12 +810,7 @@ static void commit_tree(struct mount *mnt, struct mount *shadows)
 
        list_splice(&head, n->list.prev);
 
-       if (shadows)
-               hlist_add_behind_rcu(&mnt->mnt_hash, &shadows->mnt_hash);
-       else
-               hlist_add_head_rcu(&mnt->mnt_hash,
-                               m_hash(&parent->mnt, mnt->mnt_mountpoint));
-       list_add_tail(&mnt->mnt_child, &parent->mnt_mounts);
+       attach_shadowed(mnt, parent, shadows);
        touch_mnt_namespace(n);
 }
 
@@ -951,7 +959,6 @@ static struct mount *clone_mnt(struct mount *old, struct dentry *root,
 
 static void mntput_no_expire(struct mount *mnt)
 {
-put_again:
        rcu_read_lock();
        mnt_add_count(mnt, -1);
        if (likely(mnt->mnt_ns)) { /* shouldn't be the last one */
@@ -964,14 +971,6 @@ put_again:
                unlock_mount_hash();
                return;
        }
-       if (unlikely(mnt->mnt_pinned)) {
-               mnt_add_count(mnt, mnt->mnt_pinned + 1);
-               mnt->mnt_pinned = 0;
-               rcu_read_unlock();
-               unlock_mount_hash();
-               acct_auto_close_mnt(&mnt->mnt);
-               goto put_again;
-       }
        if (unlikely(mnt->mnt.mnt_flags & MNT_DOOMED)) {
                rcu_read_unlock();
                unlock_mount_hash();
@@ -994,6 +993,8 @@ put_again:
         * so mnt_get_writers() below is safe.
         */
        WARN_ON(mnt_get_writers(mnt));
+       if (unlikely(mnt->mnt_pins.first))
+               mnt_pin_kill(mnt);
        fsnotify_vfsmount_delete(&mnt->mnt);
        dput(mnt->mnt.mnt_root);
        deactivate_super(mnt->mnt.mnt_sb);
@@ -1021,25 +1022,15 @@ struct vfsmount *mntget(struct vfsmount *mnt)
 }
 EXPORT_SYMBOL(mntget);
 
-void mnt_pin(struct vfsmount *mnt)
-{
-       lock_mount_hash();
-       real_mount(mnt)->mnt_pinned++;
-       unlock_mount_hash();
-}
-EXPORT_SYMBOL(mnt_pin);
-
-void mnt_unpin(struct vfsmount *m)
+struct vfsmount *mnt_clone_internal(struct path *path)
 {
-       struct mount *mnt = real_mount(m);
-       lock_mount_hash();
-       if (mnt->mnt_pinned) {
-               mnt_add_count(mnt, 1);
-               mnt->mnt_pinned--;
-       }
-       unlock_mount_hash();
+       struct mount *p;
+       p = clone_mnt(real_mount(path->mnt), path->dentry, CL_PRIVATE);
+       if (IS_ERR(p))
+               return ERR_CAST(p);
+       p->mnt.mnt_flags |= MNT_INTERNAL;
+       return &p->mnt;
 }
-EXPORT_SYMBOL(mnt_unpin);
 
 static inline void mangle(struct seq_file *m, const char *s)
 {
@@ -1505,6 +1496,7 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
                        continue;
 
                for (s = r; s; s = next_mnt(s, r)) {
+                       struct mount *t = NULL;
                        if (!(flag & CL_COPY_UNBINDABLE) &&
                            IS_MNT_UNBINDABLE(s)) {
                                s = skip_mnt_tree(s);
@@ -1526,7 +1518,14 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
                                goto out;
                        lock_mount_hash();
                        list_add_tail(&q->mnt_list, &res->mnt_list);
-                       attach_mnt(q, parent, p->mnt_mp);
+                       mnt_set_mountpoint(parent, p->mnt_mp, q);
+                       if (!list_empty(&parent->mnt_mounts)) {
+                               t = list_last_entry(&parent->mnt_mounts,
+                                       struct mount, mnt_child);
+                               if (t->mnt_mp != p->mnt_mp)
+                                       t = NULL;
+                       }
+                       attach_shadowed(q, parent, t);
                        unlock_mount_hash();
                }
        }