ovl: use vfs_tmpfile_open() helper

If tmpfile is used for copy up, then use this helper to create the tmpfile
and open it at the same time.  This will later allow filesystems such as
fuse to do this operation atomically.

Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 87759165d32b..0f9dbd0e2ff5 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -310,14 +310,16 @@ static inline int ovl_do_whiteout(struct ovl_fs *ofs,
 	return err;
 }
 
-static inline struct dentry *ovl_do_tmpfile(struct ovl_fs *ofs,
-					    struct dentry *dentry, umode_t mode)
+static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs,
+					  struct dentry *dentry, umode_t mode)
 {
-	struct dentry *ret = vfs_tmpfile(ovl_upper_mnt_userns(ofs), dentry, mode, 0);
-	int err = PTR_ERR_OR_ZERO(ret);
+	struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry };
+	struct file *file = vfs_tmpfile_open(ovl_upper_mnt_userns(ofs), &path, mode,
+					O_LARGEFILE | O_WRONLY, current_cred());
+	int err = PTR_ERR_OR_ZERO(file);
 
 	pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
-	return ret;
+	return file;
 }
 
 static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs,
@@ -401,7 +403,7 @@ void ovl_inode_update(struct inode *inode, struct dentry *upperdentry);
 void ovl_dir_modified(struct dentry *dentry, bool impurity);
 u64 ovl_dentry_version_get(struct dentry *dentry);
 bool ovl_is_whiteout(struct dentry *dentry);
-struct file *ovl_path_open(struct path *path, int flags);
+struct file *ovl_path_open(const struct path *path, int flags);
 int ovl_copy_up_start(struct dentry *dentry, int flags);
 void ovl_copy_up_end(struct dentry *dentry);
 bool ovl_already_copied_up(struct dentry *dentry, int flags);