From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hou Pengyang Subject: Re: [PATCH] f2fs: fix conflict between atomic_write and truncate Date: Tue, 13 Dec 2016 09:34:29 +0800 Message-ID: <584F5025.9000004@huawei.com> References: <20161212131618.92800-1-houpengyang@huawei.com> <20161212191851.GC61413@jaegeuk.local> <584F4AD8.4000008@huawei.com> <20161213012109.GA8811@jaegeuk.local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1cGbzo-00052d-KJ for linux-f2fs-devel@lists.sourceforge.net; Tue, 13 Dec 2016 01:35:08 +0000 Received: from [119.145.14.66] (helo=szxga03-in.huawei.com) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1cGbzk-0006vn-KB for linux-f2fs-devel@lists.sourceforge.net; Tue, 13 Dec 2016 01:35:08 +0000 In-Reply-To: <20161213012109.GA8811@jaegeuk.local> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: Jaegeuk Kim Cc: chao@kernel.org, linux-f2fs-devel@lists.sourceforge.net On 2016/12/13 9:21, Jaegeuk Kim wrote: > Hi, > > On 12/13, Hou Pengyang wrote: >> On 2016/12/13 3:18, Jaegeuk Kim wrote: >>> Hi Pengyang, >>> >> Hi, kim, >>> On 12/12, Hou Pengyang wrote: >>>> In fsync_node_pages path, after locking the last_page for setting dirty, >>>> we should check if the page has been truncated. Or there may be a mem leak, >>>> as this dirty last_page will NOT be found in next page-cache travese. >>>> >>>> This patch adds page->mapping checking, and will NOT rewrite the page if >>>> it has been truncated. >>>> >>>> Signed-off-by: Hou Pengyang >>>> --- >>>> fs/f2fs/node.c | 5 +++++ >>>> 1 file changed, 5 insertions(+) >>>> >>>> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c >>>> index c1bbfdc..78c5b50 100644 >>>> --- a/fs/f2fs/node.c >>>> +++ b/fs/f2fs/node.c >>>> @@ -1410,6 +1410,11 @@ int fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode, >>>> "Retry to write fsync mark: ino=%u, idx=%lx", >>>> ino, last_page->index); >>>> lock_page(last_page); >>> >>> We grabbed a reference count for this last_page, and thus, it won't be released. >>> Something that I missed? >>> >> Some path (e.g. shrink) would NOT release the page if we've grabbed it, >> But truncate operation will invalidate the page from page-cache >> regardless of the page reference. > > This is a node page, and we guarantee that nobody will truncate them. > Did you hit an issue regarding to this? > As my view, the truncate operations may lead to the related node pages being truncated, or I miss something. > Thanks, > >> Patch: 0fac558b965 f2fs: make atomic/volatile operation exclusive >> seems fix this issue by adding inode_lock(inode) to avoid conflict >> between atomic/volatile and truncate operation. >> >> But this patch makes codes more robust. >> >> Thanks. >> >>> Thanks, >>> >>>> + if (unlikely(last_page->mapping != NODE_MAPPING(sbi))) { >>>> + unlock_page(last_page); >>>> + f2fs_put_page(last_page, 0); >>>> + goto out; >>>> + } >>>> f2fs_wait_on_page_writeback(last_page, NODE, true); >>>> set_page_dirty(last_page); >>>> unlock_page(last_page); >>>> -- >>>> 2.10.1 >>>> >>>> >>>> ------------------------------------------------------------------------------ >>>> Developer Access Program for Intel Xeon Phi Processors >>>> Access to Intel Xeon Phi processor-based developer platforms. >>>> With one year of Intel Parallel Studio XE. >>>> Training and support from Colfax. >>>> Order your platform today.http://sdm.link/xeonphi >>>> _______________________________________________ >>>> Linux-f2fs-devel mailing list >>>> Linux-f2fs-devel@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel >>> >>> . >>> >> >> >> >> ------------------------------------------------------------------------------ >> Check out the vibrant tech community on one of the world's most >> engaging tech sites, SlashDot.org! http://sdm.link/slashdot >> _______________________________________________ >> Linux-f2fs-devel mailing list >> Linux-f2fs-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel > > . > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot