From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755153AbdL1Rwl (ORCPT ); Thu, 28 Dec 2017 12:52:41 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:58893 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754321AbdL1RN6 (ORCPT ); Thu, 28 Dec 2017 12:13:58 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Matthew Wilcox" , "Linus Torvalds" , "Ross Zwisler" , "Matthew Wilcox" , "Johannes Thumshirn" , "Toshi Kani" , "OGAWA Hirofumi" Date: Thu, 28 Dec 2017 17:05:44 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 115/204] fs/mpage.c: fix mpage_writepage() for pages with buffers In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.52-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Matthew Wilcox commit f892760aa66a2d657deaf59538fb69433036767c upstream. When using FAT on a block device which supports rw_page, we can hit BUG_ON(!PageLocked(page)) in try_to_free_buffers(). This is because we call clean_buffers() after unlocking the page we've written. Introduce a new clean_page_buffers() which cleans all buffers associated with a page and call it from within bdev_write_page(). [akpm@linux-foundation.org: s/PAGE_SIZE/~0U/ per Linus and Matthew] Link: http://lkml.kernel.org/r/20171006211541.GA7409@bombadil.infradead.org Signed-off-by: Matthew Wilcox Reported-by: Toshi Kani Reported-by: OGAWA Hirofumi Tested-by: Toshi Kani Acked-by: Johannes Thumshirn Cc: Ross Zwisler Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- fs/block_dev.c | 6 ++++-- fs/mpage.c | 14 +++++++++++--- include/linux/buffer_head.h | 1 + 3 files changed, 16 insertions(+), 5 deletions(-) --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -419,10 +419,12 @@ int bdev_write_page(struct block_device return -EOPNOTSUPP; set_page_writeback(page); result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, rw); - if (result) + if (result) { end_page_writeback(page); - else + } else { + clean_page_buffers(page); unlock_page(page); + } return result; } EXPORT_SYMBOL_GPL(bdev_write_page); --- a/fs/mpage.c +++ b/fs/mpage.c @@ -457,6 +457,16 @@ static void clean_buffers(struct page *p 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, ~0U); +} + static int __mpage_writepage(struct page *page, struct writeback_control *wbc, void *data) { @@ -594,10 +604,8 @@ alloc_new: 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_get_nr_vecs(bdev), GFP_NOFS|__GFP_HIGH); --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -222,6 +222,7 @@ int generic_write_end(struct file *, str 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 *);