Blame SOURCES/kvm-rbd-make-qemu-s-cache-setting-override-any-ceph-sett.patch

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