From a89c41261dee7c365995d9f5f98bcdb543e42775 Mon Sep 17 00:00:00 2001

From: John Snow <jsnow@redhat.com>

Date: Mon, 10 Sep 2018 18:17:43 +0200

Subject: [PATCH 05/25] block/mirror: utilize job_exit shim

RH-Author: John Snow <jsnow@redhat.com>

Message-id: <20180910181803.11781-6-jsnow@redhat.com>

Patchwork-id: 82098

O-Subject: [RHEL-7.6 qemu-kvm-rhev PATCH 05/25] block/mirror: utilize job_exit shim

Bugzilla: 1626061

RH-Acked-by: Max Reitz <mreitz@redhat.com>

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

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

Change the manual deferment to mirror_exit into the implicit

callback to job_exit and the mirror_exit callback.

This does change the order of some bdrv_unref calls and job_completed,

but thanks to the new context in which we call .exit, this is safe to

defer the possible flushing of any nodes to the job_finalize_single

cleanup stage.

Signed-off-by: John Snow <jsnow@redhat.com>

Message-id: 20180830015734.19765-6-jsnow@redhat.com

Reviewed-by: Max Reitz <mreitz@redhat.com>

Reviewed-by: Jeff Cody <jcody@redhat.com>

Signed-off-by: Max Reitz <mreitz@redhat.com>

(cherry picked from commit 7b508f6b7a38a8d9729772fa6e525da883fb120b)

Signed-off-by: John Snow <jsnow@redhat.com>

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

---

 block/mirror.c | 30 +++++++++++-------------------

 1 file changed, 11 insertions(+), 19 deletions(-)

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

index 459f944..0ab0822 100644

--- a/block/mirror.c

+++ b/block/mirror.c

@@ -480,25 +480,21 @@ static void mirror_wait_for_all_io(MirrorBlockJob *s)

     }

 }

-typedef struct {

-    int ret;

-} MirrorExitData;

-

-static void mirror_exit(Job *job, void *opaque)

+static void mirror_exit(Job *job)

 {

     MirrorBlockJob *s = container_of(job, MirrorBlockJob, common.job);

     BlockJob *bjob = &s->common;

-    MirrorExitData *data = opaque;

     AioContext *replace_aio_context = NULL;

     BlockDriverState *src = s->source;

     BlockDriverState *target_bs = blk_bs(s->target);

     BlockDriverState *mirror_top_bs = s->mirror_top_bs;

     Error *local_err = NULL;

+    int ret = job->ret;

     bdrv_release_dirty_bitmap(src, s->dirty_bitmap);

-    /* Make sure that the source BDS doesn't go away before we called

-     * job_completed(). */

+    /* Make sure that the source BDS doesn't go away during bdrv_replace_node,

+     * before we can call bdrv_drained_end */

     bdrv_ref(src);

     bdrv_ref(mirror_top_bs);

     bdrv_ref(target_bs);

@@ -524,7 +520,7 @@ static void mirror_exit(Job *job, void *opaque)

             bdrv_set_backing_hd(target_bs, backing, &local_err);

             if (local_err) {

                 error_report_err(local_err);

-                data->ret = -EPERM;

+                ret = -EPERM;

             }

         }

     }

@@ -534,7 +530,7 @@ static void mirror_exit(Job *job, void *opaque)

         aio_context_acquire(replace_aio_context);

     }

-    if (s->should_complete && data->ret == 0) {

+    if (s->should_complete && ret == 0) {

         BlockDriverState *to_replace = src;

         if (s->to_replace) {

             to_replace = s->to_replace;

@@ -551,7 +547,7 @@ static void mirror_exit(Job *job, void *opaque)

         bdrv_drained_end(target_bs);

         if (local_err) {

             error_report_err(local_err);

-            data->ret = -EPERM;

+            ret = -EPERM;

         }

     }

     if (s->to_replace) {

@@ -581,12 +577,11 @@ static void mirror_exit(Job *job, void *opaque)

     blk_set_perm(bjob->blk, 0, BLK_PERM_ALL, &error_abort);

     blk_insert_bs(bjob->blk, mirror_top_bs, &error_abort);

-    job_completed(job, data->ret);

-

-    g_free(data);

     bdrv_drained_end(src);

     bdrv_unref(mirror_top_bs);

     bdrv_unref(src);

+

+    job->ret = ret;

 }

 static void mirror_throttle(MirrorBlockJob *s)

@@ -686,7 +681,6 @@ static int mirror_flush(MirrorBlockJob *s)

 static int coroutine_fn mirror_run(Job *job, Error **errp)

 {

     MirrorBlockJob *s = container_of(job, MirrorBlockJob, common.job);

-    MirrorExitData *data;

     BlockDriverState *bs = s->source;

     BlockDriverState *target_bs = blk_bs(s->target);

     bool need_drain = true;

@@ -896,14 +890,10 @@ immediate_exit:

     g_free(s->in_flight_bitmap);

     bdrv_dirty_iter_free(s->dbi);

-    data = g_malloc(sizeof(*data));

-    data->ret = ret;

-

     if (need_drain) {

         bdrv_drained_begin(bs);

     }

-    job_defer_to_main_loop(&s->common.job, mirror_exit, data);

     return ret;

 }

@@ -996,6 +986,7 @@ static const BlockJobDriver mirror_job_driver = {

         .user_resume            = block_job_user_resume,

         .drain                  = block_job_drain,

         .run                    = mirror_run,

+        .exit                   = mirror_exit,

         .pause                  = mirror_pause,

         .complete               = mirror_complete,

     },

@@ -1011,6 +1002,7 @@ static const BlockJobDriver commit_active_job_driver = {

         .user_resume            = block_job_user_resume,

         .drain                  = block_job_drain,

         .run                    = mirror_run,

+        .exit                   = mirror_exit,

         .pause                  = mirror_pause,

         .complete               = mirror_complete,

     },

-- 

1.8.3.1