From b55e2f4749d2e4ebfc7dfc8782de85391c1026e8 Mon Sep 17 00:00:00 2001

From: Fam Zheng <famz@redhat.com>

Date: Fri, 17 Jan 2014 03:08:00 +0100

Subject: [PATCH 17/34] commit: Support commit active layer

RH-Author: Fam Zheng <famz@redhat.com>

Message-id: <1389928083-8921-16-git-send-email-famz@redhat.com>

Patchwork-id: 56777

O-Subject: [RHEL-7 qemu-kvm PATCH 15/18] commit: Support commit active layer

Bugzilla: 1041301

RH-Acked-by: Jeffrey Cody <jcody@redhat.com>

RH-Acked-by: Kevin Wolf <kwolf@redhat.com>

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

If active is top, it will be mirrored to base, (with block/mirror.c

code), then the image is switched when user completes the block job.

QMP documentation is updated.

Signed-off-by: Fam Zheng <famz@redhat.com>

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

(cherry picked from commit 20a63d2cec838c2dde4d246c4d7abe747d9b7a11)

Signed-off-by: Fam Zheng <famz@redhat.com>

---

 block/mirror.c   | 11 +++++++++++

 blockdev.c       |  9 +++++++--

 qapi-schema.json |  5 +++--

 3 files changed, 21 insertions(+), 4 deletions(-)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 block/mirror.c   |   11 +++++++++++

 blockdev.c       |    9 +++++++--

 qapi-schema.json |    5 +++--

 3 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/block/mirror.c b/block/mirror.c

index 01fe379..6e1f9b1 100644

--- a/block/mirror.c

+++ b/block/mirror.c

@@ -478,6 +478,13 @@ immediate_exit:

             bdrv_reopen(s->target, bdrv_get_flags(s->common.bs), NULL);

         }

         bdrv_swap(s->target, s->common.bs);

+        if (s->common.driver->job_type == BLOCK_JOB_TYPE_COMMIT) {

+            /* drop the bs loop chain formed by the swap: break the loop then

+             * trigger the unref from the top one */

+            BlockDriverState *p = s->base->backing_hd;

+            s->base->backing_hd = NULL;

+            bdrv_unref(p);

+        }

     }

     bdrv_unref(s->target);

     block_job_completed(&s->common, ret);

@@ -620,6 +627,10 @@ void commit_active_start(BlockDriverState *bs, BlockDriverState *base,

                          BlockDriverCompletionFunc *cb,

                          void *opaque, Error **errp)

 {

+    if (bdrv_reopen(base, bs->open_flags, errp)) {

+        return;

+    }

+    bdrv_ref(base);

     mirror_start_job(bs, base, speed, 0, 0,

                      on_error, on_error, cb, opaque, errp,

                      &commit_active_job_driver, false, base);

diff --git a/blockdev.c b/blockdev.c

index d795af2..33a5f5f 100644

--- a/blockdev.c

+++ b/blockdev.c

@@ -1510,8 +1510,13 @@ void qmp_block_commit(const char *device,

         return;

     }

-    commit_start(bs, base_bs, top_bs, speed, on_error, block_job_cb, bs,

-                &local_err);

+    if (top_bs == bs) {

+        commit_active_start(bs, base_bs, speed, on_error, block_job_cb,

+                            bs, &local_err);

+    } else {

+        commit_start(bs, base_bs, top_bs, speed, on_error, block_job_cb, bs,

+                    &local_err);

+    }

     if (local_err != NULL) {

         error_propagate(errp, local_err);

         return;

diff --git a/qapi-schema.json b/qapi-schema.json

index b0bd53c..a783e8e 100644

--- a/qapi-schema.json

+++ b/qapi-schema.json

@@ -1837,9 +1837,11 @@

 #

 # @top:              The file name of the backing image within the image chain,

 #                    which contains the topmost data to be committed down.

-#                    Note, the active layer as 'top' is currently unsupported.

 #

 #                    If top == base, that is an error.

+#                    If top == active, the job will not be completed by itself,

+#                    user needs to complete the job with the block-job-complete

+#                    command after getting the ready event. (Since 2.0)

 #

 #

 # @speed:  #optional the maximum speed, in bytes per second

@@ -1849,7 +1851,6 @@

 #          If @device does not exist, DeviceNotFound

 #          If image commit is not supported by this device, NotSupported

 #          If @base or @top is invalid, a generic error is returned

-#          If @top is the active layer, or omitted, a generic error is returned

 #          If @speed is invalid, InvalidParameter

 #

 # Since: 1.3

-- 

1.7.1