From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6D648F9C5 for ; Thu, 28 Dec 2023 15:33:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ipbAH/Wr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9075C433C8; Thu, 28 Dec 2023 15:33:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1703777622; bh=5yDsdWwaOqkj18xvk96SZBr48BQYi9xMppuyMIAULmU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=ipbAH/Wrp+ob6Xz/zB6i7pWjWD21xpgwi8d2rw2pVIqCBvEHGuX4I8jd+DJs0lhKG h2BBoxE8exC0WvB1G47rLd1XRlQ0YFDzg7Do22yyNTMQ7S9bsXy8UCTTPKZe+f2zmC 0qmK9RaswodQXcH8JIraTOjvkOkhnDSM8UishL/tahB1aKFDWu8P2U2vxqqRP9XYJs OXE46j+jQDiLFoZ3KxrEF/TP9wU73NL2vZW/RsrfDfs4V23kbES0utEbpLxQ7m0eig qO/xhxNmiPib6F1CFcxs2wAwaPt7SLC4H6Hi19Hl+mW+s2ZvKbFvaHJLFC/WivTuS8 BYL6quMrgPTfw== Message-ID: <19a1340f-0a0d-40a0-9d00-0faf171480f2@kernel.org> Date: Thu, 28 Dec 2023 23:33:37 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 5/6] f2fs: fix to restrict condition of compress inode conversion Content-Language: en-US To: Jaegeuk Kim Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org References: <20231210113547.3412782-1-chao@kernel.org> <20231210113547.3412782-5-chao@kernel.org> <5884e300-5384-4a49-9f8d-8cced50f4e6d@kernel.org> From: Chao Yu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2023/12/13 6:21, Jaegeuk Kim wrote: > On 12/12, Chao Yu wrote: >> On 2023/12/12 6:11, Jaegeuk Kim wrote: >>> On 12/10, Chao Yu wrote: >>>> This patch adds i_size check during compress inode conversion in order >>>> to avoid .page_mkwrite races w/ conversion. >>> >>> Which race condition do you see? >> >> Something like: >> >> - f2fs_setflags_common >> - check S_ISREG && F2FS_HAS_BLOCKS >> - mkwrite >> - f2fs_get_block_locked >> : update metadata in old inode's disk layout > > Don't we need to prevent setting this for mmapped file? Oh, we have used i_sem lock to prevent such race case, however we missed f2fs_disable_compressed_file(): - f2fs_disable_compressed_file - check inode_has_data - f2fs_file_mmap - mkwrite - f2fs_get_block_locked : update metadata in compressed inode's disk layout - fi->i_flags &= ~F2FS_COMPR_FL - clear_inode_flag(inode, FI_COMPRESSED_FILE); Thanks, > >> - set_compress_context >> >> Thanks, >> >>> >>>> >>>> Fixes: 4c8ff7095bef ("f2fs: support data compression") >>>> Signed-off-by: Chao Yu >>>> --- >>>> fs/f2fs/f2fs.h | 8 +++++++- >>>> fs/f2fs/file.c | 5 ++--- >>>> 2 files changed, 9 insertions(+), 4 deletions(-) >>>> >>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h >>>> index 65294e3b0bef..c9b8a1953913 100644 >>>> --- a/fs/f2fs/f2fs.h >>>> +++ b/fs/f2fs/f2fs.h >>>> @@ -4397,13 +4397,19 @@ static inline int set_compress_context(struct inode *inode) >>>> #endif >>>> } >>>> +static inline bool inode_has_data(struct inode *inode) >>>> +{ >>>> + return (S_ISREG(inode->i_mode) && >>>> + (F2FS_HAS_BLOCKS(inode) || i_size_read(inode))); >>>> +} >>>> + >>>> static inline bool f2fs_disable_compressed_file(struct inode *inode) >>>> { >>>> struct f2fs_inode_info *fi = F2FS_I(inode); >>>> if (!f2fs_compressed_file(inode)) >>>> return true; >>>> - if (S_ISREG(inode->i_mode) && F2FS_HAS_BLOCKS(inode)) >>>> + if (inode_has_data(inode)) >>>> return false; >>>> fi->i_flags &= ~F2FS_COMPR_FL; >>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c >>>> index 1a3c29a9a6a0..8af4b29c3e1a 100644 >>>> --- a/fs/f2fs/file.c >>>> +++ b/fs/f2fs/file.c >>>> @@ -1922,8 +1922,7 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask) >>>> f2fs_down_write(&F2FS_I(inode)->i_sem); >>>> if (!f2fs_may_compress(inode) || >>>> - (S_ISREG(inode->i_mode) && >>>> - F2FS_HAS_BLOCKS(inode))) { >>>> + inode_has_data(inode)) { >>>> f2fs_up_write(&F2FS_I(inode)->i_sem); >>>> return -EINVAL; >>>> } >>>> @@ -3996,7 +3995,7 @@ static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long arg) >>>> goto out; >>>> } >>>> - if (F2FS_HAS_BLOCKS(inode)) { >>>> + if (inode_has_data(inode)) { >>>> ret = -EFBIG; >>>> goto out; >>>> } >>>> -- >>>> 2.40.1