ovl: add ovl_mmap() (2f502839) · Commits · e / devices / android_kernel_fairphone_FP4

fs/overlayfs/file.c

+32 −0

Original line number	Diff line number	Diff line
		@@ -255,6 +255,37 @@ static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)
		return ret;
		}

		static int ovl_mmap(struct file file, struct vm_area_struct vma)
		{
		struct file *realfile = file->private_data;
		const struct cred *old_cred;
		int ret;

		if (!realfile->f_op->mmap)
		return -ENODEV;

		if (WARN_ON(file != vma->vm_file))
		return -EIO;

		vma->vm_file = get_file(realfile);

		old_cred = ovl_override_creds(file_inode(file)->i_sb);
		ret = call_mmap(vma->vm_file, vma);
		revert_creds(old_cred);

		if (ret) {
		/* Drop reference count from new vm_file value */
		fput(realfile);
		} else {
		/* Drop reference count from previous vm_file value */
		fput(file);
		}

		ovl_file_accessed(file);

		return ret;
		}

		const struct file_operations ovl_file_operations = {
		.open = ovl_open,
		.release = ovl_release,
		@@ -262,4 +293,5 @@ const struct file_operations ovl_file_operations = {
		.read_iter = ovl_read_iter,
		.write_iter = ovl_write_iter,
		.fsync = ovl_fsync,
		.mmap = ovl_mmap,
		};