From patchwork Wed Jul 26 17:11:01 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 9865433 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 30B72602B1 for ; Wed, 26 Jul 2017 17:11:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1C5C92879F for ; Wed, 26 Jul 2017 17:11:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 111B0287A6; Wed, 26 Jul 2017 17:11:08 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A31842879F for ; Wed, 26 Jul 2017 17:11:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751616AbdGZRLG (ORCPT ); Wed, 26 Jul 2017 13:11:06 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:59130 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750930AbdGZRLF (ORCPT ); Wed, 26 Jul 2017 13:11:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=Gzpcn/Nmo8ULLmnwnAtH1vRRSzZ0mga5MYD5jqqFjfc=; b=mQY2wlQNsexMfpFt8hSr+i6cH 4AcU3k3tUzYsiw6fmLUVZOPkD8f87aEIn992snfhphZH/KuYdz8USwy/NbPa95vIhwgq6sLd71wkp Sveb+fMqN2tTAscDaDIuzxI6f4YZOcr/inRWpJOeu55CtVXk5mWOGWougyfiB3Wdq3B/CPIg/OT+T U5PaX6R9pt5HygOFo3zygOXjEwSM3Z/dWfRgJM/tlcIf9g7sb5MKxRKP+NvKZp4+pHmLlGLfmwzwh vsJLR/Ap4clYu/HV+OYu4ypa2cPjj78Ehsn/T4pe9OnG/fNrmsYST0h7RzRUuAVKZFLJWfkHlGxn6 Pb+f7oWRA==; Received: from willy by bombadil.infradead.org with local (Exim 4.87 #1 (Red Hat Linux)) id 1daPpu-0007Sr-0W; Wed, 26 Jul 2017 17:11:02 +0000 Date: Wed, 26 Jul 2017 10:11:01 -0700 From: Matthew Wilcox To: OGAWA Hirofumi Cc: Johannes Thumshirn , Ross Zwisler , "Kani, Toshimitsu" , "linux-nvdimm@lists.01.org" , "linux-fsdevel@vger.kernel.org" Subject: Re: FIle copy to FAT FS on NVDIMM hits BUG_ON at fs/buffer.c:3305! Message-ID: <20170726171101.GA15980@bombadil.infradead.org> References: <1501018096.2042.70.camel@hpe.com> <20170725222247.GA26391@linux.intel.com> <20170726082159.GE4039@linux-x5ow.site> <87d18neemb.fsf@devron> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <87d18neemb.fsf@devron> User-Agent: Mutt/1.8.0 (2017-02-23) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Wed, Jul 26, 2017 at 06:23:08PM +0900, OGAWA Hirofumi wrote: > The locking of this path seems to be broken. The guy familiar to > bdev_write_page() path will made real fix though, The following patch > should be explaining enough what is wrong. > > In short, clean_buffers() must be called before unlocking lock_page(). Thanks for that. This should fix the problem while not leaking the unlock_page call outside bdev_write_page. --- 8< --- Signed-off-by: Matthew Wilcox Tested-by: Toshi Kani diff --git a/fs/block_dev.c b/fs/block_dev.c index 9941dc8342df..3fbe75bdd257 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -716,10 +716,12 @@ int bdev_write_page(struct block_device *bdev, sector_t sector, set_page_writeback(page); result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, true); - if (result) + if (result) { end_page_writeback(page); - else + } else { + clean_page_buffers(page); unlock_page(page); + } blk_queue_exit(bdev->bd_queue); return result; } diff --git a/fs/mpage.c b/fs/mpage.c index 2e4c41ccb5c9..d97b003f1607 100644 --- a/fs/mpage.c +++ b/fs/mpage.c @@ -468,6 +468,16 @@ static void clean_buffers(struct page *page, unsigned first_unmapped) try_to_free_buffers(page); } +/* + * For situations where we want to clean all buffers attached to a page. + * We don't need to calculate how many buffers are attached to the page, + * we just need to specify a number larger than the maximum number of buffers. + */ +void clean_page_buffers(struct page *page) +{ + clean_buffers(page, PAGE_SIZE); +} + static int __mpage_writepage(struct page *page, struct writeback_control *wbc, void *data) { @@ -605,10 +615,8 @@ static int __mpage_writepage(struct page *page, struct writeback_control *wbc, if (bio == NULL) { if (first_unmapped == blocks_per_page) { if (!bdev_write_page(bdev, blocks[0] << (blkbits - 9), - page, wbc)) { - clean_buffers(page, first_unmapped); + page, wbc)) goto out; - } } bio = mpage_alloc(bdev, blocks[0] << (blkbits - 9), BIO_MAX_PAGES, GFP_NOFS|__GFP_HIGH); diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index c8dae555eccf..446b24cac67d 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -232,6 +232,7 @@ int generic_write_end(struct file *, struct address_space *, loff_t, unsigned, unsigned, struct page *, void *); void page_zero_new_buffers(struct page *page, unsigned from, unsigned to); +void clean_page_buffers(struct page *page); int cont_write_begin(struct file *, struct address_space *, loff_t, unsigned, unsigned, struct page **, void **, get_block_t *, loff_t *);