From 952f7f53cdd4320d1a0328481fa578dd199eb1ce Mon Sep 17 00:00:00 2001
From: Sergio Lopez <slp@redhat.com>
Date: Wed, 8 Jan 2020 15:31:32 +0100
Subject: [PATCH] blockdev: unify qmp_drive_backup and drive-backup transaction
 paths

Issuing a drive-backup from qmp_drive_backup takes a slightly
different path than when it's issued from a transaction. In the code,
this is manifested as some redundancy between do_drive_backup() and
drive_backup_prepare().

This change unifies both paths, merging do_drive_backup() and
drive_backup_prepare(), and changing qmp_drive_backup() to create a
transaction instead of calling do_backup_common() direcly.

As a side-effect, now qmp_drive_backup() is executed inside a drained
section, as it happens when creating a drive-backup transaction. This
change is visible from the user's perspective, as the job gets paused
and immediately resumed before starting the actual work.

Also fix tests 141, 185 and 219 to cope with the extra
JOB_STATUS_CHANGE lines.

Signed-off-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 blockdev.c                 | 224 +++++++++++++++++--------------------
 tests/qemu-iotests/141.out |   2 +
 tests/qemu-iotests/185.out |   2 +
 tests/qemu-iotests/219     |   7 +-
 tests/qemu-iotests/219.out |   8 ++
 5 files changed, 117 insertions(+), 126 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 99b1cafb8f..7016054688 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1804,39 +1804,128 @@ typedef struct DriveBackupState {
     BlockJob *job;
 } DriveBackupState;
 
-static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn,
-                            Error **errp);
+static BlockJob *do_backup_common(BackupCommon *backup,
+                                  BlockDriverState *bs,
+                                  BlockDriverState *target_bs,
+                                  AioContext *aio_context,
+                                  JobTxn *txn, Error **errp);
 
 static void drive_backup_prepare(BlkActionState *common, Error **errp)
 {
     DriveBackupState *state = DO_UPCAST(DriveBackupState, common, common);
-    BlockDriverState *bs;
     DriveBackup *backup;
+    BlockDriverState *bs;
+    BlockDriverState *target_bs;
+    BlockDriverState *source = NULL;
     AioContext *aio_context;
+    QDict *options;
     Error *local_err = NULL;
+    int flags;
+    int64_t size;
+    bool set_backing_hd = false;
 
     assert(common->action->type == TRANSACTION_ACTION_KIND_DRIVE_BACKUP);
     backup = common->action->u.drive_backup.data;
 
+    if (!backup->has_mode) {
+        backup->mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
+    }
+
     bs = bdrv_lookup_bs(backup->device, backup->device, errp);
     if (!bs) {
         return;
     }
 
+    if (!bs->drv) {
+        error_setg(errp, "Device has no medium");
+        return;
+    }
+
     aio_context = bdrv_get_aio_context(bs);
     aio_context_acquire(aio_context);
 
     /* Paired with .clean() */
     bdrv_drained_begin(bs);
 
-    state->bs = bs;
+    if (!backup->has_format) {
+        backup->format = backup->mode == NEW_IMAGE_MODE_EXISTING ?
+                         NULL : (char *) bs->drv->format_name;
+    }
+
+    /* Early check to avoid creating target */
+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
+        goto out;
+    }
+
+    flags = bs->open_flags | BDRV_O_RDWR;
+
+    /*
+     * See if we have a backing HD we can use to create our new image
+     * on top of.
+     */
+    if (backup->sync == MIRROR_SYNC_MODE_TOP) {
+        source = backing_bs(bs);
+        if (!source) {
+            backup->sync = MIRROR_SYNC_MODE_FULL;
+        }
+    }
+    if (backup->sync == MIRROR_SYNC_MODE_NONE) {
+        source = bs;
+        flags |= BDRV_O_NO_BACKING;
+        set_backing_hd = true;
+    }
+
+    size = bdrv_getlength(bs);
+    if (size < 0) {
+        error_setg_errno(errp, -size, "bdrv_getlength failed");
+        goto out;
+    }
+
+    if (backup->mode != NEW_IMAGE_MODE_EXISTING) {
+        assert(backup->format);
+        if (source) {
+            bdrv_refresh_filename(source);
+            bdrv_img_create(backup->target, backup->format, source->filename,
+                            source->drv->format_name, NULL,
+                            size, flags, false, &local_err);
+        } else {
+            bdrv_img_create(backup->target, backup->format, NULL, NULL, NULL,
+                            size, flags, false, &local_err);
+        }
+    }
 
-    state->job = do_drive_backup(backup, common->block_job_txn, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         goto out;
     }
 
+    options = qdict_new();
+    qdict_put_str(options, "discard", "unmap");
+    qdict_put_str(options, "detect-zeroes", "unmap");
+    if (backup->format) {
+        qdict_put_str(options, "driver", backup->format);
+    }
+
+    target_bs = bdrv_open(backup->target, NULL, options, flags, errp);
+    if (!target_bs) {
+        goto out;
+    }
+
+    if (set_backing_hd) {
+        bdrv_set_backing_hd(target_bs, source, &local_err);
+        if (local_err) {
+            goto unref;
+        }
+    }
+
+    state->bs = bs;
+
+    state->job = do_backup_common(qapi_DriveBackup_base(backup),
+                                  bs, target_bs, aio_context,
+                                  common->block_job_txn, errp);
+
+unref:
+    bdrv_unref(target_bs);
 out:
     aio_context_release(aio_context);
 }
@@ -3564,126 +3653,13 @@ static BlockJob *do_backup_common(BackupCommon *backup,
     return job;
 }
 
-static BlockJob *do_drive_backup(DriveBackup *backup, JobTxn *txn,
-                                 Error **errp)
-{
-    BlockDriverState *bs;
-    BlockDriverState *target_bs;
-    BlockDriverState *source = NULL;
-    BlockJob *job = NULL;
-    AioContext *aio_context;
-    QDict *options;
-    Error *local_err = NULL;
-    int flags;
-    int64_t size;
-    bool set_backing_hd = false;
-
-    if (!backup->has_mode) {
-        backup->mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
-    }
-
-    bs = bdrv_lookup_bs(backup->device, backup->device, errp);
-    if (!bs) {
-        return NULL;
-    }
-
-    if (!bs->drv) {
-        error_setg(errp, "Device has no medium");
-        return NULL;
-    }
-
-    aio_context = bdrv_get_aio_context(bs);
-    aio_context_acquire(aio_context);
-
-    if (!backup->has_format) {
-        backup->format = backup->mode == NEW_IMAGE_MODE_EXISTING ?
-                         NULL : (char *) bs->drv->format_name;
-    }
-
-    /* Early check to avoid creating target */
-    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
-        goto out;
-    }
-
-    flags = bs->open_flags | BDRV_O_RDWR;
-
-    /*
-     * See if we have a backing HD we can use to create our new image
-     * on top of.
-     */
-    if (backup->sync == MIRROR_SYNC_MODE_TOP) {
-        source = backing_bs(bs);
-        if (!source) {
-            backup->sync = MIRROR_SYNC_MODE_FULL;
-        }
-    }
-    if (backup->sync == MIRROR_SYNC_MODE_NONE) {
-        source = bs;
-        flags |= BDRV_O_NO_BACKING;
-        set_backing_hd = true;
-    }
-
-    size = bdrv_getlength(bs);
-    if (size < 0) {
-        error_setg_errno(errp, -size, "bdrv_getlength failed");
-        goto out;
-    }
-
-    if (backup->mode != NEW_IMAGE_MODE_EXISTING) {
-        assert(backup->format);
-        if (source) {
-            bdrv_refresh_filename(source);
-            bdrv_img_create(backup->target, backup->format, source->filename,
-                            source->drv->format_name, NULL,
-                            size, flags, false, &local_err);
-        } else {
-            bdrv_img_create(backup->target, backup->format, NULL, NULL, NULL,
-                            size, flags, false, &local_err);
-        }
-    }
-
-    if (local_err) {
-        error_propagate(errp, local_err);
-        goto out;
-    }
-
-    options = qdict_new();
-    qdict_put_str(options, "discard", "unmap");
-    qdict_put_str(options, "detect-zeroes", "unmap");
-    if (backup->format) {
-        qdict_put_str(options, "driver", backup->format);
-    }
-
-    target_bs = bdrv_open(backup->target, NULL, options, flags, errp);
-    if (!target_bs) {
-        goto out;
-    }
-
-    if (set_backing_hd) {
-        bdrv_set_backing_hd(target_bs, source, &local_err);
-        if (local_err) {
-            goto unref;
-        }
-    }
-
-    job = do_backup_common(qapi_DriveBackup_base(backup),
-                           bs, target_bs, aio_context, txn, errp);
-
-unref:
-    bdrv_unref(target_bs);
-out:
-    aio_context_release(aio_context);
-    return job;
-}
-
-void qmp_drive_backup(DriveBackup *arg, Error **errp)
+void qmp_drive_backup(DriveBackup *backup, Error **errp)
 {
-
-    BlockJob *job;
-    job = do_drive_backup(arg, NULL, errp);
-    if (job) {
-        job_start(&job->job);
-    }
+    TransactionAction action = {
+        .type = TRANSACTION_ACTION_KIND_DRIVE_BACKUP,
+        .u.drive_backup.data = backup,
+    };
+    blockdev_do_action(&action, errp);
 }
 
 BlockDeviceInfoList *qmp_query_named_block_nodes(Error **errp)
diff --git a/tests/qemu-iotests/141.out b/tests/qemu-iotests/141.out
index 4d71d9dcae..07e0ec66d7 100644
--- a/tests/qemu-iotests/141.out
+++ b/tests/qemu-iotests/141.out
@@ -10,6 +10,8 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/m.
 Formatting 'TEST_DIR/o.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.IMGFMT backing_fmt=IMGFMT
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "created", "id": "job0"}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "running", "id": "job0"}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "paused", "id": "job0"}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "running", "id": "job0"}}
 {"return": {}}
 {"error": {"class": "GenericError", "desc": "Node drv0 is in use"}}
 {"return": {}}
diff --git a/tests/qemu-iotests/185.out b/tests/qemu-iotests/185.out
index ddfbf3c765..a233be7f58 100644
--- a/tests/qemu-iotests/185.out
+++ b/tests/qemu-iotests/185.out
@@ -51,6 +51,8 @@ Formatting 'TEST_DIR/t.qcow2.copy', fmt=qcow2 size=67108864 cluster_size=65536 l
 Formatting 'TEST_DIR/t.qcow2.copy', fmt=qcow2 size=67108864 cluster_size=65536 lazy_refcounts=off refcount_bits=16
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "created", "id": "disk"}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "running", "id": "disk"}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "paused", "id": "disk"}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "running", "id": "disk"}}
 {"return": {}}
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false, "reason": "host-qmp-quit"}}
diff --git a/tests/qemu-iotests/219 b/tests/qemu-iotests/219
index e0c51662c0..655f54d881 100755
--- a/tests/qemu-iotests/219
+++ b/tests/qemu-iotests/219
@@ -63,7 +63,7 @@ def test_pause_resume(vm):
                 # logged immediately
                 iotests.log(vm.qmp('query-jobs'))
 
-def test_job_lifecycle(vm, job, job_args, has_ready=False):
+def test_job_lifecycle(vm, job, job_args, has_ready=False, is_mirror=False):
     global img_size
 
     iotests.log('')
@@ -135,6 +135,9 @@ def test_job_lifecycle(vm, job, job_args, has_ready=False):
     iotests.log('Waiting for PENDING state...')
     iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))
     iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))
+    if is_mirror:
+        iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))
+        iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))
 
     if not job_args.get('auto-finalize', True):
         # PENDING state:
@@ -218,7 +221,7 @@ with iotests.FilePath('disk.img') as disk_path, \
 
     for auto_finalize in [True, False]:
         for auto_dismiss in [True, False]:
-            test_job_lifecycle(vm, 'drive-backup', job_args={
+            test_job_lifecycle(vm, 'drive-backup', is_mirror=True, job_args={
                 'device': 'drive0-node',
                 'target': copy_path,
                 'sync': 'full',
diff --git a/tests/qemu-iotests/219.out b/tests/qemu-iotests/219.out
index 8ebd3fee60..0ea5d0b9d5 100644
--- a/tests/qemu-iotests/219.out
+++ b/tests/qemu-iotests/219.out
@@ -135,6 +135,8 @@ Pause/resume in RUNNING
 {"return": {}}
 
 Waiting for PENDING state...
+{"data": {"id": "job0", "status": "paused"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
+{"data": {"id": "job0", "status": "running"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"id": "job0", "status": "waiting"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"id": "job0", "status": "pending"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"id": "job0", "status": "concluded"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
@@ -186,6 +188,8 @@ Pause/resume in RUNNING
 {"return": {}}
 
 Waiting for PENDING state...
+{"data": {"id": "job0", "status": "paused"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
+{"data": {"id": "job0", "status": "running"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"id": "job0", "status": "waiting"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"id": "job0", "status": "pending"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"id": "job0", "status": "concluded"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
@@ -245,6 +249,8 @@ Pause/resume in RUNNING
 {"return": {}}
 
 Waiting for PENDING state...
+{"data": {"id": "job0", "status": "paused"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
+{"data": {"id": "job0", "status": "running"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"id": "job0", "status": "waiting"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"id": "job0", "status": "pending"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"return": [{"current-progress": 4194304, "id": "job0", "status": "pending", "total-progress": 4194304, "type": "backup"}]}
@@ -304,6 +310,8 @@ Pause/resume in RUNNING
 {"return": {}}
 
 Waiting for PENDING state...
+{"data": {"id": "job0", "status": "paused"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
+{"data": {"id": "job0", "status": "running"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"id": "job0", "status": "waiting"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"id": "job0", "status": "pending"}, "event": "JOB_STATUS_CHANGE", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"return": [{"current-progress": 4194304, "id": "job0", "status": "pending", "total-progress": 4194304, "type": "backup"}]}
-- 
2.27.0