From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josh Durgin Subject: Re: [PATCH 2/9] rbd: add code to get the size of a v2 rbd image Date: Wed, 19 Sep 2012 11:52:42 -0700 Message-ID: <505A147A.3050007@inktank.com> References: <504A6273.7030807@inktank.com> <504A6379.7010308@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-pb0-f46.google.com ([209.85.160.46]:53460 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756865Ab2ISSwp (ORCPT ); Wed, 19 Sep 2012 14:52:45 -0400 Received: by pbbrr13 with SMTP id rr13so3150892pbb.19 for ; Wed, 19 Sep 2012 11:52:45 -0700 (PDT) In-Reply-To: <504A6379.7010308@inktank.com> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Alex Elder Cc: ceph-devel@vger.kernel.org Reviewed-by: Josh Durgin On 09/07/2012 02:13 PM, Alex Elder wrote: > The size of an rbd format 2 image is fetched from the server using a > "get_size" method. The same method is used for getting the size of > a snapshot, so structure this addition with a generic helper routine > that we can get this information for either. > > Signed-off-by: Alex Elder > --- > drivers/block/rbd.c | 53 > +++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 53 insertions(+) > > diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c > index 019e695..24d12e3 100644 > --- a/drivers/block/rbd.c > +++ b/drivers/block/rbd.c > @@ -2123,6 +2123,47 @@ static char *rbd_dev_v1_snap_info(struct > rbd_device *rbd_dev, u32 which, > } > > /* > + * Get the size and object order for an image snapshot, or if > + * snap_id is CEPH_NOSNAP, gets this information for the base > + * image. > + */ > +static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id, > + u8 *order, u64 *snap_size) > +{ > + __le64 snapid = cpu_to_le64(snap_id); > + int ret; > + struct { > + u8 order; > + __le64 size; > + } __attribute__ ((packed)) size_buf = { 0 }; > + > + ret = rbd_req_sync_exec(rbd_dev, rbd_dev->header_name, > + "rbd", "get_size", > + (char *) &snapid, sizeof (snapid), > + (char *) &size_buf, sizeof (size_buf), > + CEPH_OSD_FLAG_READ, NULL); > + dout("%s: rbd_req_sync_exec returned %d\n", __func__, ret); > + if (ret < 0) > + return ret; > + > + *order = size_buf.order; > + *snap_size = le64_to_cpu(size_buf.size); > + > + dout(" snap_id 0x%016llx order = %u, snap_size = %llu\n", > + (unsigned long long) snap_id, (unsigned int) *order, > + (unsigned long long) *snap_size); > + > + return 0; > +} > + > +static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev) > +{ > + return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP, > + &rbd_dev->header.obj_order, > + &rbd_dev->header.image_size); > +} > + > +/* > * Scan the rbd device's current snapshot list and compare it to the > * newly-received snapshot context. Remove any existing snapshots > * not present in the new snapshot context. Add a new snapshot for > @@ -2631,6 +2672,7 @@ out_err: > static int rbd_dev_v2_probe(struct rbd_device *rbd_dev) > { > size_t size; > + int ret; > > /* > * Image id was filled in by the caller. Record the header > @@ -2642,12 +2684,23 @@ static int rbd_dev_v2_probe(struct rbd_device > *rbd_dev) > return -ENOMEM; > sprintf(rbd_dev->header_name, "%s%s", > RBD_HEADER_PREFIX, rbd_dev->image_id); > + > + /* Get the size and object order for the image */ > + > + ret = rbd_dev_v2_image_size(rbd_dev); > + if (ret < 0) > + goto out_err; > rbd_dev->image_format = 2; > > dout("discovered version 2 image, header name is %s\n", > rbd_dev->header_name); > > return -ENOTSUPP; > +out_err: > + kfree(rbd_dev->header_name); > + rbd_dev->header_name = NULL; > + > + return ret; > } > > /* >