From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Elder Subject: Re: [PATCH 1/4] rbd: define rbd_update_size() Date: Tue, 09 Oct 2012 16:46:11 -0700 Message-ID: <5074B743.6040601@inktank.com> References: <50748FA5.4030508@inktank.com> <50749074.5030603@inktank.com> <5074B2F0.50008@inktank.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pa0-f46.google.com ([209.85.220.46]:59463 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751266Ab2JIXqO (ORCPT ); Tue, 9 Oct 2012 19:46:14 -0400 Received: by mail-pa0-f46.google.com with SMTP id hz1so5756433pad.19 for ; Tue, 09 Oct 2012 16:46:14 -0700 (PDT) In-Reply-To: <5074B2F0.50008@inktank.com> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Josh Durgin Cc: ceph-devel@vger.kernel.org On 10/09/2012 04:27 PM, Josh Durgin wrote: > On 10/09/2012 02:00 PM, Alex Elder wrote: >> Encapsulate the code that handles the case where an image's size has >> been found to have changed. This is done in anticipation of the >> next patch, which will make this common code for format 1 and 2 >> images. >> >> Signed-off-by: Alex Elder >> --- >> drivers/block/rbd.c | 22 +++++++++++++--------- >> 1 file changed, 13 insertions(+), 9 deletions(-) >> >> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c >> index bb3d9be..d36e6d7 100644 >> --- a/drivers/block/rbd.c >> +++ b/drivers/block/rbd.c >> @@ -1716,6 +1716,16 @@ static void __rbd_remove_all_snaps(struct >> rbd_device *rbd_dev) >> __rbd_remove_snap_dev(snap); >> } >> >> +static void rbd_update_size(struct rbd_device *rbd_dev) >> +{ >> + sector_t size = (sector_t) rbd_dev->header.image_size / SECTOR_SIZE; >> + >> + rbd_assert(rbd_dev->mapping.snap_id == CEPH_NOSNAP); > > I might be confused since it's been a while since I looked at these > refactorings, but I think this should still be a conditional block > instead of an assert. > > Even if we've only mapped a snapshot, the non-snapshot version could > still be resized. This function now only gets called if we find that the size has changed as a result of a refresh. The assertion is to verify that won't happen for a snapshot. Since I'm returning a value here I may be able to be a little less hardcore and return -EIO instead. -Alex >> + dout("setting size to %llu sectors", (unsigned long long) size); >> + rbd_dev->mapping.size = (u64) size; >> + set_capacity(rbd_dev->disk, size); >> +} >> + >> /* >> * only read the first part of the ondisk header, without the snaps >> info >> */ >> @@ -1731,15 +1741,9 @@ static int __rbd_refresh_header(struct rbd_device >> *rbd_dev, u64 *hver) >> down_write(&rbd_dev->header_rwsem); >> >> /* resized? */ >> - if (rbd_dev->mapping.snap_id == CEPH_NOSNAP) { >> - sector_t size = (sector_t) h.image_size / SECTOR_SIZE; >> - >> - if (size != (sector_t) rbd_dev->mapping.size) { >> - dout("setting size to %llu sectors", >> - (unsigned long long) size); >> - rbd_dev->mapping.size = (u64) size; >> - set_capacity(rbd_dev->disk, size); >> - } >> + if (rbd_dev->header.image_size != h.image_size) { >> + rbd_dev->header.image_size = h.image_size; >> + rbd_update_size(rbd_dev); >> } >> >> /* rbd_dev->header.object_prefix shouldn't change */ >