From nobody Sat Feb 7 20:44:02 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E100C77B7E for ; Mon, 29 May 2023 10:27:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231781AbjE2K1U (ORCPT ); Mon, 29 May 2023 06:27:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33704 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231466AbjE2K1P (ORCPT ); Mon, 29 May 2023 06:27:15 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76F47C2 for ; Mon, 29 May 2023 03:27:14 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 156DC62340 for ; Mon, 29 May 2023 10:27:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3FBF9C433D2; Mon, 29 May 2023 10:27:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1685356033; bh=2J0FBu1GLBGRIwQwggebk9BRVoGLrhgLuRFIuckJHHI=; h=From:To:Cc:Subject:Date:From; b=ZzFpUyN1Y0Elgj3/GK6QytCMNyzm0lSghJfxOy4B+QZ/2pqiGQ83xBbFFnHlXHiYA SMT8UDDbDer7ud8vybF0cqIpRgm2pXLgreUXkf0pH5Y9RlgQmUUmskM2cS82BuD/2w HOaUpc9Q7V0vhnlXtXpgNrxcs6moh/qGjifY6oWcerz6hcdnRwliMhH9r7DR0Hn9UW uOJ3rSuWyfktLvl1l9solrbXJBjU0brN3YP3nWKWZAvmWMTBC8d821h/aanUNUDpX8 J+woCbqvJ7iYeXfpg+B9JrlpktwQGGJIKPTq2r8jDzPxo1AhdszwXdFsno+IAj4AWz d/aXcc1S5PzGA== From: Chao Yu To: jaegeuk@kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Chao Yu Subject: [PATCH] f2fs: fix to avoid mmap vs set_compress_option case Date: Mon, 29 May 2023 18:27:05 +0800 Message-Id: <20230529102705.2546993-1-chao@kernel.org> X-Mailer: git-send-email 2.40.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Compression option in inode should not be changed after they have been used, however, it may happen in below race case: Thread A Thread B - f2fs_ioc_set_compress_option - check f2fs_is_mmap_file() - check get_dirty_pages() - check F2FS_HAS_BLOCKS() - f2fs_file_mmap - set_inode_flag(FI_MMAP_FILE) - fault - do_page_mkwrite - f2fs_vm_page_mkwrite - f2fs_get_block_locked - fault_dirty_shared_page - set_page_dirty - update i_compress_algorithm - update i_log_cluster_size - update i_cluster_size Avoid such race condition by covering f2fs_file_mmap() w/ inode lock. Fixes: e1e8debec656 ("f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl") Signed-off-by: Chao Yu --- fs/f2fs/file.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 7b097ab2f5e4..685ded62fc28 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -519,17 +519,25 @@ static loff_t f2fs_llseek(struct file *file, loff_t o= ffset, int whence) static int f2fs_file_mmap(struct file *file, struct vm_area_struct *vma) { struct inode *inode =3D file_inode(file); + int ret =3D 0; =20 if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) return -EIO; =20 - if (!f2fs_is_compress_backend_ready(inode)) - return -EOPNOTSUPP; + inode_lock(inode); + + if (!f2fs_is_compress_backend_ready(inode)) { + ret =3D -EOPNOTSUPP; + goto out_unlock; + } =20 file_accessed(file); vma->vm_ops =3D &f2fs_file_vm_ops; set_inode_flag(inode, FI_MMAP_FILE); - return 0; + +out_unlock: + inode_unlock(inode); + return ret; } =20 static int f2fs_file_open(struct inode *inode, struct file *filp) --=20 2.40.1