From: Miao Xie Subject: Re: [PATCH 1/4] ext4: fix forgetten xattr lock protection in ext4_expand_extra_isize Date: Thu, 13 Jul 2017 20:55:55 +0800 Message-ID: References: <1499360993-17130-1-git-send-email-miaoxie@huawei.com> Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset="gbk" Content-Transfer-Encoding: 7bit Cc: , , , , , To: Return-path: Received: from szxga03-in.huawei.com ([45.249.212.189]:8923 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751165AbdGMM4r (ORCPT ); Thu, 13 Jul 2017 08:56:47 -0400 In-Reply-To: <1499360993-17130-1-git-send-email-miaoxie@huawei.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Ping...... on 2017/7/7 at 1:09, Miao Xie wrote: > We should avoid the contention between the i_extra_isize update and > the inline data insertion, so move the xattr trylock in front of > i_extra_isize update. > > Signed-off-by: Miao Xie > Reviewed-by: Wang Shilong > --- > fs/ext4/inode.c | 18 ++++++++++++++++-- > fs/ext4/xattr.c | 10 ---------- > 2 files changed, 16 insertions(+), 12 deletions(-) > > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index 5cf82d0..4af3edc 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -5639,10 +5639,15 @@ static int ext4_expand_extra_isize(struct inode *inode, > { > struct ext4_inode *raw_inode; > struct ext4_xattr_ibody_header *header; > + int no_expand; > + int error; > > if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) > return 0; > > + if (ext4_write_trylock_xattr(inode, &no_expand) == 0) > + return 0; > + > raw_inode = ext4_raw_inode(&iloc); > > header = IHDR(inode, raw_inode); > @@ -5654,12 +5659,21 @@ static int ext4_expand_extra_isize(struct inode *inode, > EXT4_I(inode)->i_extra_isize, 0, > new_extra_isize - EXT4_I(inode)->i_extra_isize); > EXT4_I(inode)->i_extra_isize = new_extra_isize; > + ext4_write_unlock_xattr(inode, &no_expand); > return 0; > } > > /* try to expand with EAs present */ > - return ext4_expand_extra_isize_ea(inode, new_extra_isize, > - raw_inode, handle); > + error = ext4_expand_extra_isize_ea(inode, new_extra_isize, > + raw_inode, handle); > + if (error) { > + /* > + * Inode size expansion failed; don't try again > + */ > + no_expand = 1; > + } > + ext4_write_unlock_xattr(inode, &no_expand); > + return error; > } > > /* > diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c > index 5d3c253..12ee5fb 100644 > --- a/fs/ext4/xattr.c > +++ b/fs/ext4/xattr.c > @@ -1472,10 +1472,6 @@ int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, > int error = 0, tried_min_extra_isize = 0; > int s_min_extra_isize = le16_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_min_extra_isize); > int isize_diff; /* How much do we need to grow i_extra_isize */ > - int no_expand; > - > - if (ext4_write_trylock_xattr(inode, &no_expand) == 0) > - return 0; > > retry: > isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize; > @@ -1558,16 +1554,10 @@ int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, > EXT4_I(inode)->i_extra_isize = new_extra_isize; > brelse(bh); > out: > - ext4_write_unlock_xattr(inode, &no_expand); > return 0; > > cleanup: > brelse(bh); > - /* > - * Inode size expansion failed; don't try again > - */ > - no_expand = 1; > - ext4_write_unlock_xattr(inode, &no_expand); > return error; > } > >