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

[sfrench/cifs-2.6.git] / fs / overlayfs / util.c

diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 117794582f9fa597d34d8843aa8bdfb7a99cbe76..b9b239fa5cfd28d18b120696d05e817330e44241 100644 (file)
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -430,7 +430,7 @@ void ovl_inuse_unlock(struct dentry *dentry)
        }
 }
 
-/* Called must hold OVL_I(inode)->oi_lock */
+/* Caller must hold OVL_I(inode)->lock */
 static void ovl_cleanup_index(struct dentry *dentry)
 {
        struct inode *dir = ovl_indexdir(dentry->d_sb)->d_inode;
@@ -469,6 +469,9 @@ static void ovl_cleanup_index(struct dentry *dentry)
        err = PTR_ERR(index);
        if (!IS_ERR(index))
                err = ovl_cleanup(dir, index);
+       else
+               index = NULL;
+
        inode_unlock(dir);
        if (err)
                goto fail;
@@ -557,3 +560,22 @@ void ovl_nlink_end(struct dentry *dentry, bool locked)
                mutex_unlock(&OVL_I(d_inode(dentry))->lock);
        }
 }
+
+int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir)
+{
+       /* Workdir should not be the same as upperdir */
+       if (workdir == upperdir)
+               goto err;
+
+       /* Workdir should not be subdir of upperdir and vice versa */
+       if (lock_rename(workdir, upperdir) != NULL)
+               goto err_unlock;
+
+       return 0;
+
+err_unlock:
+       unlock_rename(workdir, upperdir);
+err:
+       pr_err("overlayfs: failed to lock workdir+upperdir\n");
+       return -EIO;
+}