From mboxrd@z Thu Jan 1 00:00:00 1970 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02C56C433EF for ; Wed, 17 Nov 2021 19:32:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E056761B30 for ; Wed, 17 Nov 2021 19:32:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240491AbhKQTfv (ORCPT ); Wed, 17 Nov 2021 14:35:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:44848 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229554AbhKQTfk (ORCPT ); Wed, 17 Nov 2021 14:35:40 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2712160EC0; Wed, 17 Nov 2021 19:32:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1637177561; bh=g00KGiwKq0c5GKG/NMxsXMBFgM4TzSJPcq+6DQgNKQg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=n2j6y12alc2/GCrEV9hC34AFz/ikE5v2/atx/7IQYbP2mWLTs5//I1nPwrQRGVKuc zhSUYteBhLF5rAzUp9f+x86MDF+7BXmg74EzoaPWLRANvSiXf/hIj1VViZRMDYW9fw 7zeWfVmibAeBC9O4FXWjnM6R5GFTAgBwlcetofWmgg0OzUdiHT6jnC/VV1BtCTpLfw UL8c9GLGqbJC/mzz2Gp7MB4RAxjLSnQz7TMRF08cXup1IV7Qe/nwnl5Zw6V+QnXLag MQV8/3fgwr2RPXjfwKhkzJlrU4GEgW9UlSA57nRpN2OVoHhvDwZ/+KJkizVNnKaGF9 S6BN/F0QmozNw== Date: Wed, 17 Nov 2021 11:32:39 -0800 From: Jaegeuk Kim To: Chao Yu Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [f2fs-dev] [PATCH 2/6] f2fs: do not expose unwritten blocks to user by DIO Message-ID: References: <20211116214510.2934905-1-jaegeuk@kernel.org> <20211116214510.2934905-2-jaegeuk@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/17, Chao Yu wrote: > On 2021/11/17 5:45, Jaegeuk Kim wrote: > > DIO preallocates physical blocks before writing data, but if an error occurrs > > or power-cut happens, we can see block contents from the disk. This patch tries > > to fix it by 1) turning to buffered writes for DIO into holes, 2) truncating > > unwritten blocks from error or power-cut. > > > > Signed-off-by: Jaegeuk Kim > > --- > > fs/f2fs/data.c | 5 ++++- > > fs/f2fs/f2fs.h | 5 +++++ > > fs/f2fs/file.c | 24 +++++++++++++++++++++++- > > 3 files changed, 32 insertions(+), 2 deletions(-) > > > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > > index 3b27fb7daa8b..7ac1a39fcad2 100644 > > --- a/fs/f2fs/data.c > > +++ b/fs/f2fs/data.c > > @@ -1543,8 +1543,11 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, > > flag != F2FS_GET_BLOCK_DIO); > > err = __allocate_data_block(&dn, > > map->m_seg_type); > > - if (!err) > > + if (!err) { > > + if (flag == F2FS_GET_BLOCK_PRE_DIO) > > + file_need_truncate(inode); > > We will leave FADVISE_TRUNC_BIT flag in below call path, is this as expected? > > - fallocate > - expand_inode_data > - f2fs_map_blocks(F2FS_GET_BLOCK_PRE_DIO) I missed it. :) --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1698,6 +1698,7 @@ static int expand_inode_data(struct inode *inode, loff_t offset, map.m_seg_type = CURSEG_COLD_DATA_PINNED; err = f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_DIO); + file_dont_truncate(inode); up_write(&sbi->pin_sem); > > Thanks, > > > set_inode_flag(inode, FI_APPEND_WRITE); > > + } > > } > > if (err) > > goto sync_out; > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > > index be871a79c634..14bea669f87e 100644 > > --- a/fs/f2fs/f2fs.h > > +++ b/fs/f2fs/f2fs.h > > @@ -654,6 +654,7 @@ enum { > > #define FADVISE_KEEP_SIZE_BIT 0x10 > > #define FADVISE_HOT_BIT 0x20 > > #define FADVISE_VERITY_BIT 0x40 > > +#define FADVISE_TRUNC_BIT 0x80 > > #define FADVISE_MODIFIABLE_BITS (FADVISE_COLD_BIT | FADVISE_HOT_BIT) > > @@ -681,6 +682,10 @@ enum { > > #define file_is_verity(inode) is_file(inode, FADVISE_VERITY_BIT) > > #define file_set_verity(inode) set_file(inode, FADVISE_VERITY_BIT) > > +#define file_should_truncate(inode) is_file(inode, FADVISE_TRUNC_BIT) > > +#define file_need_truncate(inode) set_file(inode, FADVISE_TRUNC_BIT) > > +#define file_dont_truncate(inode) clear_file(inode, FADVISE_TRUNC_BIT) > > + > > #define DEF_DIR_LEVEL 0 > > enum { > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > > index 4bf77a5bf998..ec8de0662437 100644 > > --- a/fs/f2fs/file.c > > +++ b/fs/f2fs/file.c > > @@ -960,10 +960,21 @@ int f2fs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, > > down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); > > filemap_invalidate_lock(inode->i_mapping); > > + /* > > + * Truncate stale preallocated blocks used by the previous DIO. > > + */ > > + if (file_should_truncate(inode)) { > > + err = f2fs_truncate(inode); > > + if (err) > > + goto out_unlock; > > + file_dont_truncate(inode); > > + } > > + > > truncate_setsize(inode, attr->ia_size); > > if (attr->ia_size <= old_size) > > err = f2fs_truncate(inode); > > +out_unlock: > > /* > > * do not trim all blocks after i_size if target size is > > * larger than i_size. > > @@ -4257,6 +4268,13 @@ static int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *iter) > > /* If it will be an out-of-place direct write, don't bother. */ > > if (dio && f2fs_lfs_mode(sbi)) > > return 0; > > + /* > > + * Don't preallocate holes aligned to DIO_SKIP_HOLES which turns into > > + * buffered IO, if DIO meets any holes. > > + */ > > + if (dio && i_size_read(inode) && > > + (F2FS_BYTES_TO_BLK(pos) < F2FS_BLK_ALIGN(i_size_read(inode)))) > > + return 0; > > /* No-wait I/O can't allocate blocks. */ > > if (iocb->ki_flags & IOCB_NOWAIT) > > @@ -4366,10 +4384,14 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) > > if (preallocated > 0 && i_size_read(inode) < target_size) { > > down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); > > filemap_invalidate_lock(inode->i_mapping); > > - f2fs_truncate(inode); > > + if (!f2fs_truncate(inode)) > > + file_dont_truncate(inode); > > filemap_invalidate_unlock(inode->i_mapping); > > up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); > > + } else { > > + file_dont_truncate(inode); > > } > > + > > clear_inode_flag(inode, FI_PREALLOCATED_ALL); > > if (ret > 0) > >