From nobody Sat Feb 7 20:47:50 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 53F8AC7EE29 for ; Mon, 29 May 2023 10:47:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231435AbjE2KrR (ORCPT ); Mon, 29 May 2023 06:47:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230321AbjE2KrP (ORCPT ); Mon, 29 May 2023 06:47:15 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CDAAFB2 for ; Mon, 29 May 2023 03:47:14 -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 662AA6235A for ; Mon, 29 May 2023 10:47:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A1AFDC433D2; Mon, 29 May 2023 10:47:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1685357233; bh=p/JAPWlDlZsRf7RefrcupA6Ov+l7wpHejJQECxSubZ8=; h=From:To:Cc:Subject:Date:From; b=EpV1NHYx3TY0K+KckvIZU6XCIIYbfhNZimuoZzikenGGRC5msuC0C5KBNecdgMf9k v0SpoQJQKDSdR9LHvJGkJxYFegctz0o81HLAdje69jmnwemb1kWxXgoIsuOD7i3+xy wqNULq1TWQL+/bo7jKwHypqYtg3jpPb8ztyQzmTBMPIubVw5EQ08b1Z7UChdK5wYH3 wx7D0jOBS1XbldBcqBpkrB93BEm5Vp8vAkXjkCqQZLl7JIp7AoV4v8dHI5OX29hSt7 hyaTo2JNiu0jfCRIP7nN2LqMnIaBhFWm+bJYTiL7SYHaY0RzJWgCc4r/9BJOptZ1rB hmB05MlPfKlww== From: Chao Yu To: jaegeuk@kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Chao Yu Subject: [PATCH v2] f2fs: fix to avoid mmap vs set_compress_option case Date: Mon, 29 May 2023 18:47:09 +0800 Message-Id: <20230529104709.2560779-1-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, meanwhile add mmap file check condition in f2fs_may_compress() as well. Fixes: e1e8debec656 ("f2fs: add F2FS_IOC_SET_COMPRESS_OPTION ioctl") Signed-off-by: Chao Yu --- v2: - add mmap file check condition in f2fs_may_compress() fs/f2fs/f2fs.h | 3 ++- fs/f2fs/file.c | 14 +++++++++++--- 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 9bd83fb28439..0db8b37c7a4d 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -4487,7 +4487,8 @@ static inline bool f2fs_low_mem_mode(struct f2fs_sb_i= nfo *sbi) static inline bool f2fs_may_compress(struct inode *inode) { if (IS_SWAPFILE(inode) || f2fs_is_pinned_file(inode) || - f2fs_is_atomic_file(inode) || f2fs_has_inline_data(inode)) + f2fs_is_atomic_file(inode) || f2fs_has_inline_data(inode) || + f2fs_is_mmap_file(inode)) return false; return S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode); } 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