From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx49NaHRUsOfpGw9yJktfc/vh0wVRidb1nXG0Mt8eR3eK0Xgfqi6bMyGz7uQ5vLoOuHmWke8q ARC-Seal: i=1; a=rsa-sha256; t=1524406765; cv=none; d=google.com; s=arc-20160816; b=1JyALIXCtTz00s5xfmXIuPzD1ytFIBZIF3+te+Rs+zQl0wXeDn1Ir2R+obhn+BZJEP nfNGL1fcPgevsiRs/4toJUyK4eDXYWnejFLDEWtQt0CMYR+soNFr0I0/z425GASBkU56 2hTbCSdJJe21O7iYMm/OY3JFMh+VtQIje0iWF6dZPL3IwJFg2gSxoEkW86a9EHHznEE6 hriYcdwcruhOs2JCNTaF9efHlHKDpU0rstor+3oY60fUiodeBTB5WvHPObvfL4e28M52 bO/U3AXv/GESXatrBQw4tNiPssCfshk3stPlVU3SXnaThTJdZtmHrGIdLmlwJ4P36Dp7 ULug== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=0bHJMxHrOdfJJHUQq5ppWSbgyqtfDOqCS/mtQz0wB3Y=; b=gwPHyUeYQM0uG1cP08a2wGEhQUkCUW2qzQ5Z4yVO+l9S0uB9lhvcQ153PIA/i8TssO vZeBqiHxO7FHH7ptXGQC+wrc/udX2h2kW5WVIer0sa4MAHBIgeLzRVk6bJWE81uaag/6 BB3JeOVC2LOUr0675BxUs8jwUlBVJJUyA2/Qbnheh8FZaf7fG9l1fFKxj/+Jf6gYUVjb mhaa66E7Q7lcPnehF1cz5SRoaheUOBMx+50F3n9XKnmRRrd5haAHINz7SHNIIS3fqRcY RBL+3nB7IjbCeSvei0AQ+SrV5JAWgOTuMKWla4qseQgIzuwtCRBXNarr8W6Lv5niA68U Jf0g== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, wangguang , Theodore Tso , Nathan Chancellor Subject: [PATCH 4.4 95/97] ext4: bugfix for mmaped pages in mpage_release_unused_pages() Date: Sun, 22 Apr 2018 15:54:13 +0200 Message-Id: <20180422135310.354979867@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180422135304.577223025@linuxfoundation.org> References: <20180422135304.577223025@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1598456348546351551?= X-GMAIL-MSGID: =?utf-8?q?1598456348546351551?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: wangguang commit 4e800c0359d9a53e6bf0ab216954971b2515247f upstream. Pages clear buffers after ext4 delayed block allocation failed, However, it does not clean its pte_dirty flag. if the pages unmap ,in cording to the pte_dirty , unmap_page_range may try to call __set_page_dirty, which may lead to the bugon at mpage_prepare_extent_to_map:head = page_buffers(page);. This patch just call clear_page_dirty_for_io to clean pte_dirty at mpage_release_unused_pages for pages mmaped. Steps to reproduce the bug: （1） mmap a file in ext4 addr = (char *)mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); memset(addr, 'i', 4096); （2） return EIO at ext4_writepages->mpage_map_and_submit_extent->mpage_map_one_extent which causes this log message to be print: ext4_msg(sb, KERN_CRIT, "Delayed block allocation failed for " "inode %lu at logical offset %llu with" " max blocks %u with error %d", inode->i_ino, (unsigned long long)map->m_lblk, (unsigned)map->m_len, -err); (3）Unmap the addr cause warning at __set_page_dirty:WARN_ON_ONCE(warn && !PageUptodate(page)); (4) wait for a minute,then bugon happen. Cc: stable@vger.kernel.org Signed-off-by: wangguang Signed-off-by: Theodore Ts'o [@nathanchance: Resolved conflict from lack of 09cbfeaf1a5a6] Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman --- fs/ext4/inode.c | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1515,6 +1515,8 @@ static void mpage_release_unused_pages(s BUG_ON(!PageLocked(page)); BUG_ON(PageWriteback(page)); if (invalidate) { + if (page_mapped(page)) + clear_page_dirty_for_io(page); block_invalidatepage(page, 0, PAGE_CACHE_SIZE); ClearPageUptodate(page); }