From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josh Durgin Subject: Re: [PATCH 2/2] rbd: rename snap_exists field Date: Mon, 29 Oct 2012 13:46:45 -0700 Message-ID: <508EEB35.90106@inktank.com> References: <508B11E3.3040108@inktank.com> <508B1327.3090008@inktank.com> <508B13FA.7060407@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]:45557 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756592Ab2J2Uqz (ORCPT ); Mon, 29 Oct 2012 16:46:55 -0400 Received: by mail-pb0-f46.google.com with SMTP id rr4so4528835pbb.19 for ; Mon, 29 Oct 2012 13:46:55 -0700 (PDT) In-Reply-To: <508B13FA.7060407@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 10/26/2012 03:51 PM, Alex Elder wrote: > A Boolean field "snap_exists" in an rbd mapping is used to indicate > whether a mapped snapshot has been removed from an image's snapshot > context, to stop sending requests for that snapshot as soon as we > know it's gone. > > Generalize the interpretation of this field so it applies to > non-snapshot (i.e. "head") mappings. That is, define its value > to be false until the mapping has been set, and then define it to be > true for both snapshot mappings or head mappings. > > Rename the field "exists" to reflect the broader interpretation. > The rbd_mapping structure is on its way out, so move the field > back into the rbd_device structure. > > Signed-off-by: Alex Elder > --- > drivers/block/rbd.c | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-) > > diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c > index 05525b2..fb44d4d 100644 > --- a/drivers/block/rbd.c > +++ b/drivers/block/rbd.c > @@ -168,7 +168,6 @@ struct rbd_snap { > struct rbd_mapping { > u64 size; > u64 features; > - bool snap_exists; > bool read_only; > }; > > @@ -189,6 +188,7 @@ struct rbd_device { > spinlock_t lock; /* queue lock */ > > struct rbd_image_header header; > + bool exists; > char *image_id; > size_t image_id_len; > char *image_name; > @@ -690,16 +690,15 @@ static int rbd_dev_set_mapping(struct rbd_device > *rbd_dev, char *snap_name) > rbd_dev->snap_id = CEPH_NOSNAP; > rbd_dev->mapping.size = rbd_dev->header.image_size; > rbd_dev->mapping.features = rbd_dev->header.features; > - rbd_dev->mapping.snap_exists = false; > ret = 0; > } else { > ret = snap_by_name(rbd_dev, snap_name); > if (ret < 0) > goto done; > - rbd_dev->mapping.snap_exists = true; > rbd_dev->mapping.read_only = true; > } > rbd_dev->snap_name = snap_name; > + rbd_dev->exists = true; > done: > return ret; > } > @@ -1562,8 +1561,8 @@ static void rbd_rq_fn(struct request_queue *q) > > down_read(&rbd_dev->header_rwsem); > > - if (rbd_dev->snap_id != CEPH_NOSNAP && > - !rbd_dev->mapping.snap_exists) { > + if (!rbd_dev->exists) { > + rbd_assert(rbd_dev->snap_id != CEPH_NOSNAP); > up_read(&rbd_dev->header_rwsem); > dout("request for non-existent snapshot"); > spin_lock_irq(q->queue_lock); > @@ -2569,7 +2568,7 @@ static int rbd_dev_snaps_update(struct rbd_device > *rbd_dev) > /* Existing snapshot not in the new snap context */ > > if (rbd_dev->snap_id == snap->id) > - rbd_dev->mapping.snap_exists = false; > + rbd_dev->exists = false; > __rbd_remove_snap_dev(snap); > dout("%ssnap id %llu has been removed\n", > rbd_dev->snap_id == snap->id ? "mapped " : "", >