From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Elder Subject: Re: [PATCH 1/4] rbd: verify rbd image order value Date: Fri, 26 Oct 2012 17:06:01 -0500 Message-ID: <508B0949.7000906@inktank.com> References: <5085791C.9010205@inktank.com> <5085798C.8010605@inktank.com> <50882D25.8010706@inktank.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ia0-f174.google.com ([209.85.210.174]:38641 "EHLO mail-ia0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966617Ab2JZWGF (ORCPT ); Fri, 26 Oct 2012 18:06:05 -0400 Received: by mail-ia0-f174.google.com with SMTP id y32so2550800iag.19 for ; Fri, 26 Oct 2012 15:06:04 -0700 (PDT) In-Reply-To: <50882D25.8010706@inktank.com> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Josh Durgin Cc: ceph-devel@vger.kernel.org On 10/24/2012 01:02 PM, Josh Durgin wrote: > Might want to add some output so we can tell which error > is being hit. This is true for all of the cases that fail, not just those I'm adding here. I'll implement this suggestion separately too, probably next week. -Alex > Reviewed-by: Josh Durgin > > On 10/22/2012 09:51 AM, Alex Elder wrote: >> This adds a verification that an rbd image's object order is >> within the upper and lower bounds supported by this implementation. >> >> It must be at least 9 (SECTOR_SHIFT), because the Linux bio system >> assumes that minimum granularity. >> >> It also must be less than 32 (at the moment anyway) because there >> exist spots in the code that store the size of a "segment" (object >> backing an rbd image) in a signed int variable, which can be 32 bits >> including the sign. We should be able to relax this limit once >> we've verified the code uses 64-bit types where needed. >> >> Note that the CLI tool already limits the order to the range 12-25. >> >> Signed-off-by: Alex Elder >> --- >> drivers/block/rbd.c | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c >> index d032883..4734446 100644 >> --- a/drivers/block/rbd.c >> +++ b/drivers/block/rbd.c >> @@ -533,6 +533,16 @@ static bool rbd_dev_ondisk_valid(struct >> rbd_image_header_ondisk *ondisk) >> if (memcmp(&ondisk->text, RBD_HEADER_TEXT, sizeof >> (RBD_HEADER_TEXT))) >> return false; >> >> + /* The bio layer requires at least sector-sized I/O */ >> + >> + if (ondisk->options.order < SECTOR_SHIFT) >> + return false; >> + >> + /* If we use u64 in a few spots we may be able to loosen this */ >> + >> + if (ondisk->options.order > 8 * sizeof (int) - 1) >> + return false; >> + >> /* >> * The size of a snapshot header has to fit in a size_t, and >> * that limits the number of snapshots. >> >