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 D872319E98A for ; Tue, 25 Mar 2025 08:09:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742890165; cv=none; b=fqLEHxF6NGaLbLz62Wpnrv5bi8mDktSWsj4MC6jgY5RDxWMGCPaus6EzXLSswMq3YHRt/mG5HxbsyCDdEfSznRdY1fJP5ibT1HQpM4fZI3DrD86rwug360+CHB0rLK3Jk9VbnIprlhb2U/a9wigDwJ7PsY2jQ6bu8gVY2czGMPk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742890165; c=relaxed/simple; bh=t7ku1Yjv6c5+qa7d3xQ27A85ZDF0wVyffRWddMb6pmo=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=oIGiN6wW1Ik9p13iTspK76uENFtTyJY+ZRDiGKqyqSSTDFQVLEhL6rvWoFD8BGbEwbhTMNM3qL0lq5DDnSUeYfRZ/UoiKOUmRRPoxnxmFCFMjwFsO9Gxhq3l5ZkUXGVeKZWWrOI3AJ34O6gJmonz+CxUO4f/g7b1bqdzAFiASAM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=F27BsnLZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="F27BsnLZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6AF85C4CEE4; Tue, 25 Mar 2025 08:09:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742890165; bh=t7ku1Yjv6c5+qa7d3xQ27A85ZDF0wVyffRWddMb6pmo=; h=Date:Cc:Subject:To:References:From:In-Reply-To:From; b=F27BsnLZ88Cj6eKSR/GsIDu9JFjnbDybcenIapq4WyFl4xsd18gDrlRAYTIgD02AH YEibtBuB2WH9nIeFD0ZTa7LPIISwlap82XdK8VOHlnDmRl/vdsd62SctAVTe0T+2b4 4ULNZytLTrHBK4hbPKALe3B1STUE0yR1/Zjz1ct08DfJbaCI56RLg9SjXQX+0PsFJm 7Lwu1g65OB3VcD5xWKdKGLaiUpwzXuzo7IwChNkViaLPw7++SeJbW72JL6gCl7Sf5K 3AR5/b7lF+w1K0Mon/974n0UC9xANZAsjGCk+2MeefkkieCqu0uU9zMCsdagaSUTfT PKc5zMDBmFAcg== Message-ID: <1afd3158-19bb-472b-905e-6ae0c6e7a416@kernel.org> Date: Tue, 25 Mar 2025 16:09:21 +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 Cc: chao@kernel.org, jaegeuk@kernel.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [f2fs-dev] [PATCH] f2fs: add a fast path in finish_preallocate_blocks() To: Zhiguo Niu References: <20250324113249.3084413-1-chao@kernel.org> Content-Language: en-US From: Chao Yu In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 3/25/25 14:31, Zhiguo Niu wrote: > Chao Yu via Linux-f2fs-devel > 于2025年3月24日周一 19:36写道： >> >> This patch uses i_sem to protect access/update on f2fs_inode_info.flag >> in finish_preallocate_blocks(), it avoids grabbing inode_lock() in >> each open(). >> >> Signed-off-by: Chao Yu >> --- >> fs/f2fs/file.c | 40 +++++++++++++++++++++++----------------- >> 1 file changed, 23 insertions(+), 17 deletions(-) >> >> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c >> index abbcbb5865a3..bb6ba3269de0 100644 >> --- a/fs/f2fs/file.c >> +++ b/fs/f2fs/file.c >> @@ -554,19 +554,24 @@ static int f2fs_file_mmap(struct file *file, struct vm_area_struct *vma) >> >> static int finish_preallocate_blocks(struct inode *inode) >> { >> - int ret; >> + int ret = 0; >> + bool opened; >> >> - inode_lock(inode); >> - if (is_inode_flag_set(inode, FI_OPENED_FILE)) { >> - inode_unlock(inode); >> + f2fs_down_read(&F2FS_I(inode)->i_sem); >> + opened = is_inode_flag_set(inode, FI_OPENED_FILE); >> + f2fs_up_read(&F2FS_I(inode)->i_sem); >> + if (opened) >> return 0; >> - } >> >> - if (!file_should_truncate(inode)) { >> - set_inode_flag(inode, FI_OPENED_FILE); >> - inode_unlock(inode); >> - return 0; >> - } >> + inode_lock(inode); >> + f2fs_down_read(&F2FS_I(inode)->i_sem); >> + opened = is_inode_flag_set(inode, FI_OPENED_FILE); >> + f2fs_up_read(&F2FS_I(inode)->i_sem); > Hi Chao, > F2FS_I(inode)->i_sem is not needed for this judgment FI_OPENED_FILE area? > because inode_lock has been hold and this is a write lock, if process > A get inode_lock, > other proccesses will be blocked inode_lock until inode_unlock with > FI_OPENED_FILE been set? > how do you think? Zhiguo, Agreed, let me update it. Thank you. Thanks, > thanks！ >> + if (opened) >> + goto out_unlock; >> + >> + if (!file_should_truncate(inode)) >> + goto out_update; >> >> f2fs_down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); >> filemap_invalidate_lock(inode->i_mapping); >> @@ -576,16 +581,17 @@ static int finish_preallocate_blocks(struct inode *inode) >> >> filemap_invalidate_unlock(inode->i_mapping); >> f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); >> - >> - if (!ret) >> - set_inode_flag(inode, FI_OPENED_FILE); >> - >> - inode_unlock(inode); >> if (ret) >> - return ret; >> + goto out_unlock; >> >> file_dont_truncate(inode); >> - return 0; >> +out_update: >> + f2fs_down_write(&F2FS_I(inode)->i_sem); >> + set_inode_flag(inode, FI_OPENED_FILE); >> + f2fs_up_write(&F2FS_I(inode)->i_sem); >> +out_unlock: >> + inode_unlock(inode); >> + return ret; >> } >> >> static int f2fs_file_open(struct inode *inode, struct file *filp) >> -- >> 2.48.1 >> >> >> >> _______________________________________________ >> Linux-f2fs-devel mailing list >> Linux-f2fs-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel