From ba0f4624b12b27820e7e59b5e2a6a84f9736533d Mon Sep 17 00:00:00 2001

From: Kevin Wolf <kwolf@redhat.com>

Date: Tue, 26 Jun 2018 09:48:18 +0200

Subject: [PATCH 110/268] job: Add job_drain()

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

Message-id: <20180626094856.6924-36-kwolf@redhat.com>

Patchwork-id: 81119

O-Subject: [RHV-7.6 qemu-kvm-rhev PATCH v2 35/73] job: Add job_drain()

Bugzilla: 1513543

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

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

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

block_job_drain() contains a blk_drain() call which cannot be moved to

Job, so add a new JobDriver callback JobDriver.drain which has a common

implementation for all BlockJobs. In addition to this we keep the

existing BlockJobDriver.drain callback that is called by the common

drain implementation for all block jobs.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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

(cherry picked from commit b69f777dd9ba992fdd35828a90eefcd88c0ec332)

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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

---

 block/backup.c               |  1 +

 block/commit.c               |  1 +

 block/mirror.c               |  2 ++

 block/stream.c               |  1 +

 blockjob.c                   | 20 ++++++++++----------

 include/block/blockjob_int.h | 12 ++++++++++++

 include/qemu/job.h           | 13 +++++++++++++

 job.c                        | 11 +++++++++++

 tests/test-bdrv-drain.c      |  1 +

 tests/test-blockjob-txn.c    |  1 +

 tests/test-blockjob.c        |  2 ++

 11 files changed, 55 insertions(+), 10 deletions(-)

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

index bd31282..ca7d990 100644

--- a/block/backup.c

+++ b/block/backup.c

@@ -529,6 +529,7 @@ static const BlockJobDriver backup_job_driver = {

         .job_type               = JOB_TYPE_BACKUP,

         .free                   = block_job_free,

         .user_resume            = block_job_user_resume,

+        .drain                  = block_job_drain,

         .start                  = backup_run,

         .commit                 = backup_commit,

         .abort                  = backup_abort,

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

index e53b2d7..02a8af9 100644

--- a/block/commit.c

+++ b/block/commit.c

@@ -221,6 +221,7 @@ static const BlockJobDriver commit_job_driver = {

         .job_type      = JOB_TYPE_COMMIT,

         .free          = block_job_free,

         .user_resume   = block_job_user_resume,

+        .drain         = block_job_drain,

         .start         = commit_run,

     },

 };

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

index c3951d1..a579bd8 100644

--- a/block/mirror.c

+++ b/block/mirror.c

@@ -992,6 +992,7 @@ static const BlockJobDriver mirror_job_driver = {

         .job_type               = JOB_TYPE_MIRROR,

         .free                   = block_job_free,

         .user_resume            = block_job_user_resume,

+        .drain                  = block_job_drain,

         .start                  = mirror_run,

         .pause                  = mirror_pause,

     },

@@ -1006,6 +1007,7 @@ static const BlockJobDriver commit_active_job_driver = {

         .job_type               = JOB_TYPE_COMMIT,

         .free                   = block_job_free,

         .user_resume            = block_job_user_resume,

+        .drain                  = block_job_drain,

         .start                  = mirror_run,

         .pause                  = mirror_pause,

     },

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

index eee0253..b996278 100644

--- a/block/stream.c

+++ b/block/stream.c

@@ -215,6 +215,7 @@ static const BlockJobDriver stream_job_driver = {

         .free          = block_job_free,

         .start         = stream_run,

         .user_resume   = block_job_user_resume,

+        .drain         = block_job_drain,

     },

 };

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

index 4cac367..63e1669 100644

--- a/blockjob.c

+++ b/blockjob.c

@@ -169,14 +169,13 @@ static void block_job_attached_aio_context(AioContext *new_context,

     job_resume(&job->job);

 }

-static void block_job_drain(BlockJob *job)

+void block_job_drain(Job *job)

 {

-    /* If job is !job->job.busy this kicks it into the next pause point. */

-    block_job_enter(job);

+    BlockJob *bjob = container_of(job, BlockJob, job);

-    blk_drain(job->blk);

-    if (job->driver->drain) {

-        job->driver->drain(job);

+    blk_drain(bjob->blk);

+    if (bjob->driver->drain) {

+        bjob->driver->drain(bjob);

     }

 }

@@ -190,7 +189,7 @@ static void block_job_detach_aio_context(void *opaque)

     job_pause(&job->job);

     while (!job->job.paused && !job_is_completed(&job->job)) {

-        block_job_drain(job);

+        job_drain(&job->job);

     }

     job->job.aio_context = NULL;

@@ -327,11 +326,11 @@ static int block_job_finish_sync(BlockJob *job,

         job_unref(&job->job);

         return -EBUSY;

     }

-    /* block_job_drain calls block_job_enter, and it should be enough to

-     * induce progress until the job completes or moves to the main thread.

+    /* job_drain calls job_enter, and it should be enough to induce progress

+     * until the job completes or moves to the main thread.

     */

     while (!job->job.deferred_to_main_loop && !job_is_completed(&job->job)) {

-        block_job_drain(job);

+        job_drain(&job->job);

     }

     while (!job_is_completed(&job->job)) {

         aio_poll(qemu_get_aio_context(), true);

@@ -713,6 +712,7 @@ void *block_job_create(const char *job_id, const BlockJobDriver *driver,

     assert(is_block_job(&job->job));

     assert(job->job.driver->free == &block_job_free);

     assert(job->job.driver->user_resume == &block_job_user_resume);

+    assert(job->job.driver->drain == &block_job_drain);

     job->driver        = driver;

     job->blk           = blk;

diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h

index bf2b762..38fe22d 100644

--- a/include/block/blockjob_int.h

+++ b/include/block/blockjob_int.h

@@ -65,6 +65,10 @@ struct BlockJobDriver {

      * If the callback is not NULL, it will be invoked when the job has to be

      * synchronously cancelled or completed; it should drain BlockDriverStates

      * as required to ensure progress.

+     *

+     * Block jobs must use the default implementation for job_driver.drain,

+     * which will in turn call this callback after doing generic block job

+     * stuff.

      */

     void (*drain)(BlockJob *job);

 };

@@ -112,6 +116,14 @@ void block_job_free(Job *job);

 void block_job_user_resume(Job *job);

 /**

+ * block_job_drain:

+ * Callback to be used for JobDriver.drain in all block jobs. Drains the main

+ * block node associated with the block jobs and calls BlockJobDriver.drain for

+ * job-specific actions.

+ */

+void block_job_drain(Job *job);

+

+/**

  * block_job_yield:

  * @job: The job that calls the function.

  *

diff --git a/include/qemu/job.h b/include/qemu/job.h

index 2648c74..aebc195 100644

--- a/include/qemu/job.h

+++ b/include/qemu/job.h

@@ -167,6 +167,13 @@ struct JobDriver {

      */

     void (*user_resume)(Job *job);

+    /*

+     * If the callback is not NULL, it will be invoked when the job has to be

+     * synchronously cancelled or completed; it should drain any activities

+     * as required to ensure progress.

+     */

+    void (*drain)(Job *job);

+

     /**

      * If the callback is not NULL, it will be invoked when all the jobs

      * belonging to the same transaction complete; or upon this job's

@@ -325,6 +332,12 @@ bool job_user_paused(Job *job);

  */

 void job_user_resume(Job *job, Error **errp);

+/*

+ * Drain any activities as required to ensure progress. This can be called in a

+ * loop to synchronously complete a job.

+ */

+void job_drain(Job *job);

+

 /**

  * Get the next element from the list of block jobs after @job, or the

  * first one if @job is %NULL.

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

index 64b64da..3772a35 100644

--- a/job.c

+++ b/job.c

@@ -367,6 +367,17 @@ void coroutine_fn job_sleep_ns(Job *job, int64_t ns)

     job_pause_point(job);

 }

+void job_drain(Job *job)

+{

+    /* If job is !busy this kicks it into the next pause point. */

+    job_enter(job);

+

+    if (job->driver->drain) {

+        job->driver->drain(job);

+    }

+}

+

+

 /**

  * All jobs must allow a pause point before entering their job proper. This

  * ensures that jobs can be paused prior to being started, then resumed later.

diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c

index c993512..58ea566 100644

--- a/tests/test-bdrv-drain.c

+++ b/tests/test-bdrv-drain.c

@@ -525,6 +525,7 @@ BlockJobDriver test_job_driver = {

         .instance_size  = sizeof(TestBlockJob),

         .free           = block_job_free,

         .user_resume    = block_job_user_resume,

+        .drain          = block_job_drain,

         .start          = test_job_start,

     },

     .complete       = test_job_complete,

diff --git a/tests/test-blockjob-txn.c b/tests/test-blockjob-txn.c

index 60e9fa2..1572f8d 100644

--- a/tests/test-blockjob-txn.c

+++ b/tests/test-blockjob-txn.c

@@ -79,6 +79,7 @@ static const BlockJobDriver test_block_job_driver = {

         .instance_size = sizeof(TestBlockJob),

         .free          = block_job_free,

         .user_resume   = block_job_user_resume,

+        .drain         = block_job_drain,

         .start         = test_block_job_run,

     },

 };

diff --git a/tests/test-blockjob.c b/tests/test-blockjob.c

index 1fe6803..592a136 100644

--- a/tests/test-blockjob.c

+++ b/tests/test-blockjob.c

@@ -21,6 +21,7 @@ static const BlockJobDriver test_block_job_driver = {

         .instance_size = sizeof(BlockJob),

         .free          = block_job_free,

         .user_resume   = block_job_user_resume,

+        .drain         = block_job_drain,

     },

 };

@@ -201,6 +202,7 @@ static const BlockJobDriver test_cancel_driver = {

         .instance_size = sizeof(CancelJob),

         .free          = block_job_free,

         .user_resume   = block_job_user_resume,

+        .drain         = block_job_drain,

         .start         = cancel_job_start,

     },

     .complete      = cancel_job_complete,

-- 

1.8.3.1