From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Elder Subject: [PATCH] rbd: get and check striping parameters Date: Sun, 21 Apr 2013 16:18:00 -0500 Message-ID: <51745788.5060109@inktank.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ie0-f169.google.com ([209.85.223.169]:61091 "EHLO mail-ie0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751720Ab3DUVSB (ORCPT ); Sun, 21 Apr 2013 17:18:01 -0400 Received: by mail-ie0-f169.google.com with SMTP id ar20so6537669iec.0 for ; Sun, 21 Apr 2013 14:18:01 -0700 (PDT) Sender: ceph-devel-owner@vger.kernel.org List-ID: To: ceph-devel@vger.kernel.org If an rbd format 2 image indicates it supports the STRIPINGV2 feature we need to find out its stripe unit and stripe count in order to know whether we can use it. We don't yet support fancy striping fully, but if the default parameters are used the behavior is indistinguishible from non-fancy striping. This is necessary because some images require the STRIPINGV2 feature even if they use the default parameters. (Which is to say the feature bit was erroneously set even if the feature was not used.) This resolves: http://tracker.ceph.com/issues/4709 Signed-off-by: Alex Elder --- drivers/block/rbd.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 3013cdb0..d23cc8f 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -317,6 +317,9 @@ struct rbd_device { u64 parent_overlap; struct rbd_device *parent; + u64 stripe_unit; + u64 stripe_count; + /* protects updating the header */ struct rw_semaphore header_rwsem; @@ -3748,6 +3751,56 @@ out_err: return ret; } +static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev) +{ + struct { + __le64 stripe_unit; + __le64 stripe_count; + } __attribute__ ((packed)) striping_info_buf = { 0 }; + size_t size = sizeof (striping_info_buf); + void *p; + u64 obj_size; + u64 stripe_unit; + u64 stripe_count; + int ret; + + ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_name, + "rbd", "get_stripe_unit_count", NULL, 0, + (char *)&striping_info_buf, size, NULL); + dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret); + if (ret < 0) + return ret; + if (ret < size) + return -ERANGE; + + /* + * We don't actually support the "fancy striping" feature + * (STRIPINGV2) yet, but if the striping sizes are the + * defaults the behavior is the same as before. So find + * out, and only fail if the image has non-default values. + */ + ret = -EINVAL; + obj_size = (u64)1 << rbd_dev->header.obj_order; + p = &striping_info_buf; + stripe_unit = ceph_decode_64(&p); + if (stripe_unit != obj_size) { + rbd_warn(rbd_dev, "unsupported stripe unit " + "(got %llu want %llu)", + stripe_unit, obj_size); + return -EINVAL; + } + stripe_count = ceph_decode_64(&p); + if (stripe_count != 1) { + rbd_warn(rbd_dev, "unsupported stripe count " + "(got %llu want 1)", stripe_count); + return -EINVAL; + } + rbd_dev->stripe_unit = stripe_unit; + rbd_dev->stripe_count = stripe_count; + + return 0; +} + static char *rbd_dev_image_name(struct rbd_device *rbd_dev) { size_t image_id_size; @@ -4672,6 +4725,14 @@ static int rbd_dev_v2_probe(struct rbd_device *rbd_dev) goto out_err; } + /* If the image supports fancy striping, get its parameters */ + + if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) { + ret = rbd_dev_v2_striping_info(rbd_dev); + if (ret < 0) + goto out_err; + } + /* crypto and compression type aren't (yet) supported for v2 images */ rbd_dev->header.crypt_type = 0; -- 1.7.9.5