From 15606cc179623a45cc36fd3a769897678083e804 Mon Sep 17 00:00:00 2001

From: Kevin Wolf <kwolf@redhat.com>

Date: Tue, 26 Jun 2018 09:48:40 +0200

Subject: [PATCH 71/89] block/create: Make x-blockdev-create a job

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

Message-id: <20180626094856.6924-58-kwolf@redhat.com>

Patchwork-id: 81066

O-Subject: [RHV-7.6 qemu-kvm-rhev PATCH v2 57/73] block/create: Make x-blockdev-create a job

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>

This changes the x-blockdev-create QMP command so that it doesn't block

the monitor and the main loop any more, but starts a background job that

performs the image creation.

The basic job as implemented here is all that is necessary to make image

creation asynchronous and to provide a QMP interface that can be marked

stable, but it still lacks a few features that jobs usually provide: The

job will ignore pause commands and it doesn't publish more than very

basic progress yet (total-progress is 1 and current-progress advances

from 0 to 1 when the driver callbacks returns). These features can be

added later without breaking compatibility.

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

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

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

(cherry picked from commit e5ab4347f9f53495e31fcef5e232c7c6be4a0567)

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

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

---

 block/create.c           | 67 +++++++++++++++++++++++++++++++++---------------

 qapi/block-core.json     | 14 ++++++----

 qapi/job.json            |  4 ++-

 tests/qemu-iotests/group | 14 +++++-----

 4 files changed, 66 insertions(+), 33 deletions(-)

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

index 8bd8a03..1a263e4 100644

--- a/block/create.c

+++ b/block/create.c

@@ -24,28 +24,51 @@

 #include "qemu/osdep.h"

 #include "block/block_int.h"

+#include "qemu/job.h"

 #include "qapi/qapi-commands-block-core.h"

+#include "qapi/qapi-visit-block-core.h"

+#include "qapi/clone-visitor.h"

 #include "qapi/error.h"

-typedef struct BlockdevCreateCo {

+typedef struct BlockdevCreateJob {

+    Job common;

     BlockDriver *drv;

     BlockdevCreateOptions *opts;

     int ret;

-    Error **errp;

-} BlockdevCreateCo;

+    Error *err;

+} BlockdevCreateJob;

-static void coroutine_fn bdrv_co_create_co_entry(void *opaque)

+static void blockdev_create_complete(Job *job, void *opaque)

 {

-    BlockdevCreateCo *cco = opaque;

-    cco->ret = cco->drv->bdrv_co_create(cco->opts, cco->errp);

+    BlockdevCreateJob *s = container_of(job, BlockdevCreateJob, common);

+

+    job_completed(job, s->ret, s->err);

 }

-void qmp_x_blockdev_create(BlockdevCreateOptions *options, Error **errp)

+static void coroutine_fn blockdev_create_run(void *opaque)

 {

+    BlockdevCreateJob *s = opaque;

+

+    job_progress_set_remaining(&s->common, 1);

+    s->ret = s->drv->bdrv_co_create(s->opts, &s->err);

+    job_progress_update(&s->common, 1);

+

+    qapi_free_BlockdevCreateOptions(s->opts);

+    job_defer_to_main_loop(&s->common, blockdev_create_complete, NULL);

+}

+

+static const JobDriver blockdev_create_job_driver = {

+    .instance_size = sizeof(BlockdevCreateJob),

+    .job_type      = JOB_TYPE_CREATE,

+    .start         = blockdev_create_run,

+};

+

+void qmp_x_blockdev_create(const char *job_id, BlockdevCreateOptions *options,

+                           Error **errp)

+{

+    BlockdevCreateJob *s;

     const char *fmt = BlockdevDriver_str(options->driver);

     BlockDriver *drv = bdrv_find_format(fmt);

-    Coroutine *co;

-    BlockdevCreateCo cco;

     /* If the driver is in the schema, we know that it exists. But it may not

      * be whitelisted. */

@@ -55,22 +78,24 @@ void qmp_x_blockdev_create(BlockdevCreateOptions *options, Error **errp)

         return;

     }

-    /* Call callback if it exists */

+    /* Error out if the driver doesn't support .bdrv_co_create */

     if (!drv->bdrv_co_create) {

         error_setg(errp, "Driver does not support blockdev-create");

         return;

     }

-    cco = (BlockdevCreateCo) {

-        .drv = drv,

-        .opts = options,

-        .ret = -EINPROGRESS,

-        .errp = errp,

-    };

-

-    co = qemu_coroutine_create(bdrv_co_create_co_entry, &cco;;

-    qemu_coroutine_enter(co);

-    while (cco.ret == -EINPROGRESS) {

-        aio_poll(qemu_get_aio_context(), true);

+    /* Create the block job */

+    /* TODO Running in the main context. Block drivers need to error out or add

+     * locking when they use a BDS in a different AioContext. */

+    s = job_create(job_id, &blockdev_create_job_driver, NULL,

+                   qemu_get_aio_context(), JOB_DEFAULT | JOB_MANUAL_DISMISS,

+                   NULL, NULL, errp);

+    if (!s) {

+        return;

     }

+

+    s->drv = drv,

+    s->opts = QAPI_CLONE(BlockdevCreateOptions, options),

+

+    job_start(&s->common);

 }

diff --git a/qapi/block-core.json b/qapi/block-core.json

index 67e613a..d22d1db 100644

--- a/qapi/block-core.json

+++ b/qapi/block-core.json

@@ -4027,14 +4027,18 @@

 ##

 # @x-blockdev-create:

 #

-# Create an image format on a given node.

-# TODO Replace with something asynchronous (block job?)

+# Starts a job to create an image format on a given node. The job is

+# automatically finalized, but a manual job-dismiss is required.

 #

-# Since: 2.12

+# @job-id:          Identifier for the newly created job.

+#

+# @options:         Options for the image creation.

+#

+# Since: 3.0

 ##

 { 'command': 'x-blockdev-create',

-  'data': 'BlockdevCreateOptions',

-  'boxed': true }

+  'data': { 'job-id': 'str',

+            'options': 'BlockdevCreateOptions' } }

 ##

 # @blockdev-open-tray:

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

index 970124d..69c1970 100644

--- a/qapi/job.json

+++ b/qapi/job.json

@@ -17,10 +17,12 @@

 #

 # @backup: drive backup job type, see "drive-backup"

 #

+# @create: image creation job type, see "x-blockdev-create" (since 3.0)

+#

 # Since: 1.7

 ##

 { 'enum': 'JobType',

-  'data': ['commit', 'stream', 'mirror', 'backup'] }

+  'data': ['commit', 'stream', 'mirror', 'backup', 'create'] }

 ##

 # @JobStatus:

diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group

index 5c55adc..37ec5f1 100644

--- a/tests/qemu-iotests/group

+++ b/tests/qemu-iotests/group

@@ -204,14 +204,16 @@

 203 rw auto

 204 rw auto quick

 205 rw auto quick

-206 rw auto

-207 rw auto

+# TODO The following commented out tests need to be reworked to work

+# with the x-blockdev-create job

+#206 rw auto

+#207 rw auto

 208 rw auto quick

 209 rw auto quick

-210 rw auto

-211 rw auto quick

-212 rw auto quick

-213 rw auto quick

+#210 rw auto

+#211 rw auto quick

+#212 rw auto quick

+#213 rw auto quick

 214 rw auto

 215 rw auto quick

 216 rw auto quick

-- 

1.8.3.1