From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Elder Subject: [PATCH] rbd: flush dcache after zeroing page data Date: Thu, 23 May 2013 07:11:45 -0500 Message-ID: <519E0781.4000603@inktank.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ie0-f177.google.com ([209.85.223.177]:38821 "EHLO mail-ie0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753645Ab3EWMLq (ORCPT ); Thu, 23 May 2013 08:11:46 -0400 Received: by mail-ie0-f177.google.com with SMTP id 9so8329678iec.22 for ; Thu, 23 May 2013 05:11:46 -0700 (PDT) Received: from [172.22.22.4] (c-71-195-31-37.hsd1.mn.comcast.net. [71.195.31.37]) by mx.google.com with ESMTPSA id uv10sm11577183igb.3.2013.05.23.05.11.44 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 23 May 2013 05:11:45 -0700 (PDT) Sender: ceph-devel-owner@vger.kernel.org List-ID: To: ceph-devel@vger.kernel.org Neither zero_bio_chain() nor zero_pages() contains a call to flush caches after zeroing a portion of a page. This can cause problems on architectures that have caches that allow virtual address aliasing. This resolves: http://tracker.ceph.com/issues/4777 Signed-off-by: Alex Elder --- drivers/block/rbd.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 6e377a0..f860dd6 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -1124,6 +1124,7 @@ static void zero_bio_chain(struct bio *chain, int start_ofs) buf = bvec_kmap_irq(bv, &flags); memset(buf + remainder, 0, bv->bv_len - remainder); + flush_dcache_page(bv->bv_page); bvec_kunmap_irq(buf, &flags); } pos += bv->bv_len; @@ -1156,6 +1157,7 @@ static void zero_pages(struct page **pages, u64 offset, u64 end) local_irq_save(flags); kaddr = kmap_atomic(*page); memset(kaddr + page_offset, 0, length); + flush_dcache_page(*page); kunmap_atomic(kaddr); local_irq_restore(flags); -- 1.7.9.5