1 files changed, 42 insertions, 3 deletions

diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 117794582f9f..d6bb1c9f5e7a 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -17,7 +17,6 @@
 #include <linux/namei.h>
 #include <linux/ratelimit.h>
 #include "overlayfs.h"
-#include "ovl_entry.h"
 
 int ovl_want_write(struct dentry *dentry)
 {
@@ -125,7 +124,12 @@ void ovl_path_lower(struct dentry *dentry, struct path *path)
 {
 	struct ovl_entry *oe = dentry->d_fsdata;
 
-	*path = oe->numlower ? oe->lowerstack[0] : (struct path) { };
+	if (oe->numlower) {
+		path->mnt = oe->lowerstack[0].layer->mnt;
+		path->dentry = oe->lowerstack[0].dentry;
+	} else {
+		*path = (struct path) { };
+	}
 }
 
 enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path)
@@ -329,6 +333,19 @@ void ovl_copy_up_end(struct dentry *dentry)
 	mutex_unlock(&OVL_I(d_inode(dentry))->lock);
 }
 
+bool ovl_check_origin_xattr(struct dentry *dentry)
+{
+	int res;
+
+	res = vfs_getxattr(dentry, OVL_XATTR_ORIGIN, NULL, 0);
+
+	/* Zero size value means "copied up but origin unknown" */
+	if (res >= 0)
+		return true;
+
+	return false;
+}
+
 bool ovl_check_dir_xattr(struct dentry *dentry, const char *name)
 {
 	int res;
@@ -430,7 +447,7 @@ 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 +486,9 @@ 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 +577,22 @@ 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;
+}