From 6f293e47850a873d0ccc39882be7b3ef6e1043b6 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Thu, 5 Nov 2015 15:20:57 +0100 Subject: [PATCH 1/2] rbd: make qemu's cache setting override any ceph setting Message-id: <1446736858-29005-2-git-send-email-stefanha@redhat.com> Patchwork-id: 68293 O-Subject: [RHEL-7.2.z qemu-kvm PATCH 1/2] rbd: make qemu's cache setting override any ceph setting Bugzilla: 1279389 RH-Acked-by: Max Reitz RH-Acked-by: Jeffrey Cody RH-Acked-by: Kevin Wolf From: Josh Durgin To be safe, when cache=none is used ceph settings should not be able to override it to turn on caching. This was previously possible with rbd_cache=true in the rbd device configuration or a ceph configuration file. Similarly, rbd settings could have turned off caching when qemu requested it, although this would just be a performance problem. Fix this by changing rbd's cache setting to match qemu after all other ceph settings have been applied. Signed-off-by: Josh Durgin Reviewed-by: Jeff Cody Signed-off-by: Kevin Wolf (cherry picked from commit 99a3c89d5d538dc6c360e35dffb797cfe06e9cda) Signed-off-by: Miroslav Rezanina Conflicts: block/rbd.c - downstream doesn't use Error **errp Signed-off-by: Stefan Hajnoczi --- block/rbd.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/block/rbd.c b/block/rbd.c index 4eea455..11a39ac 100644 --- a/block/rbd.c +++ b/block/rbd.c @@ -501,19 +501,6 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict *options, int flags, s->snap = g_strdup(snap_buf); } - /* - * Fallback to more conservative semantics if setting cache - * options fails. Ignore errors from setting rbd_cache because the - * only possible error is that the option does not exist, and - * librbd defaults to no caching. If write through caching cannot - * be set up, fall back to no caching. - */ - if (flags & BDRV_O_NOCACHE) { - rados_conf_set(s->cluster, "rbd_cache", "false"); - } else { - rados_conf_set(s->cluster, "rbd_cache", "true"); - } - if (strstr(conf, "conf=") == NULL) { /* try default location, but ignore failure */ rados_conf_read_file(s->cluster, NULL); @@ -527,6 +514,19 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict *options, int flags, } } + /* + * Fallback to more conservative semantics if setting cache + * options fails. Ignore errors from setting rbd_cache because the + * only possible error is that the option does not exist, and + * librbd defaults to no caching. If write through caching cannot + * be set up, fall back to no caching. + */ + if (flags & BDRV_O_NOCACHE) { + rados_conf_set(s->cluster, "rbd_cache", "false"); + } else { + rados_conf_set(s->cluster, "rbd_cache", "true"); + } + r = rados_connect(s->cluster); if (r < 0) { error_report("error connecting"); -- 1.8.3.1