vfs: spread struct mount - clone_mnt/copy_tree result

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

1 files changed, 21 insertions, 18 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index c7fa75f0fd92..6051a034db96 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -687,7 +687,7 @@ vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void
 }
 EXPORT_SYMBOL_GPL(vfs_kern_mount);
 
-static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root,
+static struct mount *clone_mnt(struct vfsmount *old, struct dentry *root,
                                         int flag)
 {
         struct super_block *sb = old->mnt_sb;
@@ -733,7 +733,7 @@ static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root,
                                 list_add(&mnt->mnt.mnt_expire, &old->mnt_expire);
                 }
         }
-        return &mnt->mnt;
+        return mnt;
 
  out_free:
         free_vfsmnt(mnt);
@@ -1408,10 +1408,11 @@ static int mount_is_safe(struct path *path)
 #endif
 }
 
-struct vfsmount *copy_tree(struct vfsmount *mnt, struct dentry *dentry,
+struct mount *copy_tree(struct vfsmount *mnt, struct dentry *dentry,
                                         int flag)
 {
-        struct vfsmount *res, *p, *q, *r;
+        struct mount *res, *q;
+        struct vfsmount *p, *r;
         struct path path;
 
         if (!(flag & CL_COPY_ALL) && IS_MNT_UNBINDABLE(mnt))
@@ -1420,7 +1421,7 @@ struct vfsmount *copy_tree(struct vfsmount *mnt, struct dentry *dentry,
         res = q = clone_mnt(mnt, dentry, flag);
         if (!q)
                 goto Enomem;
-        q->mnt_mountpoint = mnt->mnt_mountpoint;
+        q->mnt.mnt_mountpoint = mnt->mnt_mountpoint;
 
         p = mnt;
         list_for_each_entry(r, &mnt->mnt_mounts, mnt_child) {
@@ -1435,17 +1436,17 @@ struct vfsmount *copy_tree(struct vfsmount *mnt, struct dentry *dentry,
                         }
                         while (p != s->mnt.mnt_parent) {
                                 p = p->mnt_parent;
-                                q = q->mnt_parent;
+                                q = real_mount(q->mnt.mnt_parent);
                         }
                         p = &s->mnt;
-                        path.mnt = q;
+                        path.mnt = &q->mnt;
                         path.dentry = p->mnt_mountpoint;
                         q = clone_mnt(p, p->mnt_root, flag);
                         if (!q)
                                 goto Enomem;
                         br_write_lock(vfsmount_lock);
-                        list_add_tail(&q->mnt_list, &res->mnt_list);
-                        attach_mnt(real_mount(q), &path);
+                        list_add_tail(&q->mnt.mnt_list, &res->mnt.mnt_list);
+                        attach_mnt(q, &path);
                         br_write_unlock(vfsmount_lock);
                 }
         }
@@ -1454,7 +1455,7 @@ Enomem:
         if (res) {
                 LIST_HEAD(umount_list);
                 br_write_lock(vfsmount_lock);
-                umount_tree(res, 0, &umount_list);
+                umount_tree(&res->mnt, 0, &umount_list);
                 br_write_unlock(vfsmount_lock);
                 release_mounts(&umount_list);
         }
@@ -1463,11 +1464,11 @@ Enomem:
 
 struct vfsmount *collect_mounts(struct path *path)
 {
-        struct vfsmount *tree;
+        struct mount *tree;
         down_write(&namespace_sem);
         tree = copy_tree(path->mnt, path->dentry, CL_COPY_ALL | CL_PRIVATE);
         up_write(&namespace_sem);
-        return tree;
+        return tree ? &tree->mnt : NULL;
 }
 
 void drop_collected_mounts(struct vfsmount *mnt)
@@ -1739,7 +1740,7 @@ static int do_loopback(struct path *path, char *old_name,
 {
         LIST_HEAD(umount_list);
         struct path old_path;
-        struct vfsmount *mnt = NULL;
+        struct mount *mnt = NULL;
         int err = mount_is_safe(path);
         if (err)
                 return err;
@@ -1769,10 +1770,10 @@ static int do_loopback(struct path *path, char *old_name,
         if (!mnt)
                 goto out2;
 
-        err = graft_tree(mnt, path);
+        err = graft_tree(&mnt->mnt, path);
         if (err) {
                 br_write_lock(vfsmount_lock);
-                umount_tree(mnt, 0, &umount_list);
+                umount_tree(&mnt->mnt, 0, &umount_list);
                 br_write_unlock(vfsmount_lock);
         }
 out2:
@@ -2385,6 +2386,7 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
         struct mnt_namespace *new_ns;
         struct vfsmount *rootmnt = NULL, *pwdmnt = NULL;
         struct mount *p, *q;
+        struct mount *new;
 
         new_ns = alloc_mnt_ns();
         if (IS_ERR(new_ns))
@@ -2392,13 +2394,14 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
 
         down_write(&namespace_sem);
         /* First pass: copy the tree topology */
-        new_ns->root = copy_tree(mnt_ns->root, mnt_ns->root->mnt_root,
+        new = copy_tree(mnt_ns->root, mnt_ns->root->mnt_root,
                                         CL_COPY_ALL | CL_EXPIRE);
-        if (!new_ns->root) {
+        if (!new) {
                 up_write(&namespace_sem);
                 kfree(new_ns);
                 return ERR_PTR(-ENOMEM);
         }
+        new_ns->root = &new->mnt;
         br_write_lock(vfsmount_lock);
         list_add_tail(&new_ns->list, &new_ns->root->mnt_list);
         br_write_unlock(vfsmount_lock);
@@ -2409,7 +2412,7 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
          * fs_struct, so tsk->fs->lock is not needed.
          */
         p = real_mount(mnt_ns->root);
-        q = real_mount(new_ns->root);
+        q = new;
         while (p) {
                 q->mnt.mnt_ns = new_ns;
                 __mnt_make_longterm(&q->mnt);