[Qemu-devel] [PATCH v5 0/4] qmp: Add "blockdev-backup"

[Qemu-devel] [PATCH v5 0/4] qmp: Add "blockdev-backup"

[Fam Zheng]

v5: Address Max's and Markus' comments:
    Split patch 1. (Markus)
    Fix typos and pastos. (Markus, Max)
    Actually acquire aio context. (Max)
    Drop unnecessary initialization of fields in blockdev_backup_prepare. (Max)
    Add "sync" in the document example.
    Add Max's rev-by in patch 4.

The existing drive-backup command accepts a target file path, but that
interface provides little flexibility on the properties of target block device,
compared to what is possible with "blockdev-add", "drive_add" or "-drive".

This is also a building block to allow image fleecing (creating a point in time
snapshot and export with nbd-server-add).

(For symmetry, blockdev-mirror will be added in a separate series.)

Fam


Fam Zheng (4):
  qapi: Comment version info in TransactionAction
  qmp: Add command 'blockdev-backup'
  block: Add blockdev-backup to transaction
  qemu-iotests: Test blockdev-backup in 055

 block/backup.c             |  28 ++++++
 blockdev.c                 | 133 ++++++++++++++++++++++++++++
 qapi-schema.json           |   8 ++
 qapi/block-core.json       |  54 ++++++++++++
 qmp-commands.hx            |  42 +++++++++
 tests/qemu-iotests/055     | 211 +++++++++++++++++++++++++++++++++++++--------
 tests/qemu-iotests/055.out |   4 +-
 7 files changed, 441 insertions(+), 39 deletions(-)

-- 
1.9.3

[Qemu-devel] [PATCH v5 1/4] qapi: Comment version info in TransactionAction

[Fam Zheng]

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 qapi-schema.json | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/qapi-schema.json b/qapi-schema.json
index 563b4ad..47d99cf 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1254,6 +1254,12 @@
 #
 # A discriminated record of operations that can be performed with
 # @transaction.
+#
+# Since 1.1
+#
+# drive-backup since 1.6
+# abort since 1.6
+# blockdev-snapshot-internal-sync since 1.7
 ##
 { 'union': 'TransactionAction',
   'data': {
-- 
1.9.3

[Qemu-devel] [PATCH v5 2/4] qmp: Add command 'blockdev-backup'

[Fam Zheng]

Similar to drive-backup, but this command uses a device id as target
instead of creating/opening an image file.

Also add blocker on target bs, since the target is also a named device
now.

Add check and report error for bs == target which became possible but is
an illegal case with introduction of blockdev-backup.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block/backup.c       | 28 +++++++++++++++++++++++++++
 blockdev.c           | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 qapi/block-core.json | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 qmp-commands.hx      | 42 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 178 insertions(+)

diff --git a/block/backup.c b/block/backup.c
index 792e655..1c535b1 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -360,6 +360,7 @@ static void coroutine_fn backup_run(void *opaque)
     hbitmap_free(job->bitmap);
 
     bdrv_iostatus_disable(target);
+    bdrv_op_unblock_all(target, job->common.blocker);
 
     data = g_malloc(sizeof(*data));
     data->ret = ret;
@@ -379,6 +380,11 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
     assert(target);
     assert(cb);
 
+    if (bs == target) {
+        error_setg(errp, "Source and target cannot be the same");
+        return;
+    }
+
     if ((on_source_error == BLOCKDEV_ON_ERROR_STOP ||
          on_source_error == BLOCKDEV_ON_ERROR_ENOSPC) &&
         !bdrv_iostatus_is_enabled(bs)) {
@@ -386,6 +392,26 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
         return;
     }
 
+    if (!bdrv_is_inserted(bs)) {
+        error_setg(errp, "Device is not inserted: %s",
+                   bdrv_get_device_name(bs));
+        return;
+    }
+
+    if (!bdrv_is_inserted(target)) {
+        error_setg(errp, "Device is not inserted: %s",
+                   bdrv_get_device_name(target));
+        return;
+    }
+
+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
+        return;
+    }
+
+    if (bdrv_op_is_blocked(target, BLOCK_OP_TYPE_BACKUP_TARGET, errp)) {
+        return;
+    }
+
     len = bdrv_getlength(bs);
     if (len < 0) {
         error_setg_errno(errp, -len, "unable to get length for '%s'",
@@ -399,6 +425,8 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
         return;
     }
 
+    bdrv_op_block_all(target, job->common.blocker);
+
     job->on_source_error = on_source_error;
     job->on_target_error = on_target_error;
     job->target = target;
diff --git a/blockdev.c b/blockdev.c
index 5651a8e..dbbab1d 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -2240,6 +2240,8 @@ void qmp_drive_backup(const char *device, const char *target,
     aio_context = bdrv_get_aio_context(bs);
     aio_context_acquire(aio_context);
 
+    /* Although backup_run has this check too, we need to use bs->drv below, so
+     * do an early check redundantly. */
     if (!bdrv_is_inserted(bs)) {
         error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
         goto out;
@@ -2256,6 +2258,7 @@ void qmp_drive_backup(const char *device, const char *target,
         }
     }
 
+    /* Early check to avoid creating target */
     if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
         goto out;
     }
@@ -2323,6 +2326,57 @@ BlockDeviceInfoList *qmp_query_named_block_nodes(Error **errp)
     return bdrv_named_nodes_list();
 }
 
+void qmp_blockdev_backup(const char *device, const char *target,
+                         enum MirrorSyncMode sync,
+                         bool has_speed, int64_t speed,
+                         bool has_on_source_error,
+                         BlockdevOnError on_source_error,
+                         bool has_on_target_error,
+                         BlockdevOnError on_target_error,
+                         Error **errp)
+{
+    BlockDriverState *bs;
+    BlockDriverState *target_bs;
+    Error *local_err = NULL;
+    AioContext *aio_context;
+
+    if (!has_speed) {
+        speed = 0;
+    }
+    if (!has_on_source_error) {
+        on_source_error = BLOCKDEV_ON_ERROR_REPORT;
+    }
+    if (!has_on_target_error) {
+        on_target_error = BLOCKDEV_ON_ERROR_REPORT;
+    }
+
+    bs = bdrv_find(device);
+    if (!bs) {
+        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
+        return;
+    }
+
+    aio_context = bdrv_get_aio_context(bs);
+    aio_context_acquire(aio_context);
+
+    target_bs = bdrv_find(target);
+    if (!target_bs) {
+        error_set(errp, QERR_DEVICE_NOT_FOUND, target);
+        goto out;
+    }
+
+    bdrv_ref(target_bs);
+    bdrv_set_aio_context(target_bs, bdrv_get_aio_context(bs));
+    backup_start(bs, target_bs, speed, sync, on_source_error, on_target_error,
+                 block_job_cb, bs, &local_err);
+    if (local_err != NULL) {
+        bdrv_unref(target_bs);
+        error_propagate(errp, local_err);
+    }
+out:
+    aio_context_release(aio_context);
+}
+
 #define DEFAULT_MIRROR_BUF_SIZE   (10 << 20)
 
 void qmp_drive_mirror(const char *device, const char *target,
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 6e8db15..d9f0598 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -703,6 +703,41 @@
             '*on-target-error': 'BlockdevOnError' } }
 
 ##
+# @BlockdevBackup
+#
+# @device: the name of the device which should be copied.
+#
+# @target: the name of the backup target device.
+#
+# @sync: what parts of the disk image should be copied to the destination
+#        (all the disk, only the sectors allocated in the topmost image, or
+#        only new I/O).
+#
+# @speed: #optional the maximum speed, in bytes per second. The default is 0,
+#         for unlimited.
+#
+# @on-source-error: #optional the action to take on an error on the source,
+#                   default 'report'.  'stop' and 'enospc' can only be used
+#                   if the block device supports io-status (see BlockInfo).
+#
+# @on-target-error: #optional the action to take on an error on the target,
+#                   default 'report' (no limitations, since this applies to
+#                   a different block device than @device).
+#
+# Note that @on-source-error and @on-target-error only affect background I/O.
+# If an error occurs during a guest write request, the device's rerror/werror
+# actions will be used.
+#
+# Since: 2.3
+##
+{ 'type': 'BlockdevBackup',
+  'data': { 'device': 'str', 'target': 'str',
+            'sync': 'MirrorSyncMode',
+            '*speed': 'int',
+            '*on-source-error': 'BlockdevOnError',
+            '*on-target-error': 'BlockdevOnError' } }
+
+##
 # @blockdev-snapshot-sync
 #
 # Generates a synchronous snapshot of a block device.
@@ -822,6 +857,25 @@
 { 'command': 'drive-backup', 'data': 'DriveBackup' }
 
 ##
+# @blockdev-backup
+#
+# Start a point-in-time copy of a block device to a new destination.  The
+# status of ongoing blockdev-backup operations can be checked with
+# query-block-jobs where the BlockJobInfo.type field has the value 'backup'.
+# The operation can be stopped before it has completed using the
+# block-job-cancel command.
+#
+# For the arguments, see the documentation of BlockdevBackup.
+#
+# Returns: Nothing on success.
+#          If @device or @target is not a valid block device, DeviceNotFound.
+#
+# Since 2.3
+##
+{ 'command': 'blockdev-backup', 'data': 'BlockdevBackup' }
+
+
+##
 # @query-named-block-nodes
 #
 # Get the named block driver list
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 3348782..a7bb90b 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -1094,6 +1094,48 @@ Example:
                                                "sync": "full",
                                                "target": "backup.img" } }
 <- { "return": {} }
+
+EQMP
+
+    {
+        .name       = "blockdev-backup",
+        .args_type  = "sync:s,device:B,target:B,speed:i?,"
+                      "on-source-error:s?,on-target-error:s?",
+        .mhandler.cmd_new = qmp_marshal_input_blockdev_backup,
+    },
+
+SQMP
+blockdev-backup
+------------
+
+The device version of drive-backup: this command takes an existing named device
+as backup target.
+
+Arguments:
+
+- "device": the name of the device which should be copied.
+            (json-string)
+- "target": the name of the backup target device. (json-string)
+- "sync": what parts of the disk image should be copied to the destination;
+          possibilities include "full" for all the disk, "top" for only the
+          sectors allocated in the topmost image, or "none" to only replicate
+          new I/O (MirrorSyncMode).
+- "speed": the maximum speed, in bytes per second (json-int, optional)
+- "on-source-error": the action to take on an error on the source, default
+                     'report'.  'stop' and 'enospc' can only be used
+                     if the block device supports io-status.
+                     (BlockdevOnError, optional)
+- "on-target-error": the action to take on an error on the target, default
+                     'report' (no limitations, since this applies to
+                     a different block device than device).
+                     (BlockdevOnError, optional)
+
+Example:
+-> { "execute": "blockdev-backup", "arguments": { "device": "src-id",
+                                                  "sync": "full",
+                                                  "target": "tgt-id" } }
+<- { "return": {} }
+
 EQMP
 
     {
-- 
1.9.3

[Qemu-devel] [PATCH v5 3/4] block: Add blockdev-backup to transaction

[Fam Zheng]

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 blockdev.c       | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 qapi-schema.json |  2 ++
 2 files changed, 81 insertions(+)

diff --git a/blockdev.c b/blockdev.c
index dbbab1d..9f9ae88 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1559,6 +1559,79 @@ static void drive_backup_clean(BlkTransactionState *common)
     }
 }
 
+typedef struct BlockdevBackupState {
+    BlkTransactionState common;
+    BlockDriverState *bs;
+    BlockJob *job;
+    AioContext *aio_context;
+} BlockdevBackupState;
+
+static void blockdev_backup_prepare(BlkTransactionState *common, Error **errp)
+{
+    BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
+    BlockdevBackup *backup;
+    BlockDriverState *bs, *target;
+    Error *local_err = NULL;
+
+    assert(common->action->kind == TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP);
+    backup = common->action->blockdev_backup;
+
+    bs = bdrv_find(backup->device);
+    if (!bs) {
+        error_set(errp, QERR_DEVICE_NOT_FOUND, backup->device);
+        return;
+    }
+
+    target = bdrv_find(backup->target);
+    if (!target) {
+        error_set(errp, QERR_DEVICE_NOT_FOUND, backup->target);
+        return;
+    }
+
+    /* AioContext is released in .clean() */
+    state->aio_context = bdrv_get_aio_context(bs);
+    if (state->aio_context != bdrv_get_aio_context(target)) {
+        state->aio_context = NULL;
+        error_setg(errp, "Backup between two IO threads is not implemented");
+        return;
+    }
+    aio_context_acquire(state->aio_context);
+
+    qmp_blockdev_backup(backup->device, backup->target,
+                        backup->sync,
+                        backup->has_speed, backup->speed,
+                        backup->has_on_source_error, backup->on_source_error,
+                        backup->has_on_target_error, backup->on_target_error,
+                        &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    state->bs = bdrv_find(backup->device);
+    state->job = state->bs->job;
+}
+
+static void blockdev_backup_abort(BlkTransactionState *common)
+{
+    BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
+    BlockDriverState *bs = state->bs;
+
+    /* Only cancel if it's the job we started */
+    if (bs && bs->job && bs->job == state->job) {
+        block_job_cancel_sync(bs->job);
+    }
+}
+
+static void blockdev_backup_clean(BlkTransactionState *common)
+{
+    BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
+
+    if (state->aio_context) {
+        aio_context_release(state->aio_context);
+    }
+}
+
 static void abort_prepare(BlkTransactionState *common, Error **errp)
 {
     error_setg(errp, "Transaction aborted using Abort action");
@@ -1582,6 +1655,12 @@ static const BdrvActionOps actions[] = {
         .abort = drive_backup_abort,
         .clean = drive_backup_clean,
     },
+    [TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP] = {
+        .instance_size = sizeof(BlockdevBackupState),
+        .prepare = blockdev_backup_prepare,
+        .abort = blockdev_backup_abort,
+        .clean = blockdev_backup_clean,
+    },
     [TRANSACTION_ACTION_KIND_ABORT] = {
         .instance_size = sizeof(BlkTransactionState),
         .prepare = abort_prepare,
diff --git a/qapi-schema.json b/qapi-schema.json
index 47d99cf..fbfc52f 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1260,11 +1260,13 @@
 # drive-backup since 1.6
 # abort since 1.6
 # blockdev-snapshot-internal-sync since 1.7
+# blockdev-backup since 2.3
 ##
 { 'union': 'TransactionAction',
   'data': {
        'blockdev-snapshot-sync': 'BlockdevSnapshot',
        'drive-backup': 'DriveBackup',
+       'blockdev-backup': 'BlockdevBackup',
        'abort': 'Abort',
        'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal'
    } }
-- 
1.9.3

[Qemu-devel] [PATCH v5 4/4] qemu-iotests: Test blockdev-backup in 055

[Fam Zheng]

This applies cases on drive-backup on blockdev-backup, except cases with
target format and mode.

Also add a case to check source == target.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 tests/qemu-iotests/055     | 211 +++++++++++++++++++++++++++++++++++++--------
 tests/qemu-iotests/055.out |   4 +-
 2 files changed, 176 insertions(+), 39 deletions(-)

diff --git a/tests/qemu-iotests/055 b/tests/qemu-iotests/055
index 0872444..e81d4d0 100755
--- a/tests/qemu-iotests/055
+++ b/tests/qemu-iotests/055
@@ -1,8 +1,8 @@
 #!/usr/bin/env python
 #
-# Tests for drive-backup
+# Tests for drive-backup and blockdev-backup
 #
-# Copyright (C) 2013 Red Hat, Inc.
+# Copyright (C) 2013, 2014 Red Hat, Inc.
 #
 # Based on 041.
 #
@@ -27,6 +27,7 @@ from iotests import qemu_img, qemu_io
 
 test_img = os.path.join(iotests.test_dir, 'test.img')
 target_img = os.path.join(iotests.test_dir, 'target.img')
+blockdev_target_img = os.path.join(iotests.test_dir, 'blockdev-target.img')
 
 class TestSingleDrive(iotests.QMPTestCase):
     image_len = 64 * 1024 * 1024 # MB
@@ -38,34 +39,41 @@ class TestSingleDrive(iotests.QMPTestCase):
         qemu_io('-f', iotests.imgfmt, '-c', 'write -P0xd5 1M 32k', test_img)
         qemu_io('-f', iotests.imgfmt, '-c', 'write -P0xdc 32M 124k', test_img)
         qemu_io('-f', iotests.imgfmt, '-c', 'write -P0xdc 67043328 64k', test_img)
+        qemu_img('create', '-f', iotests.imgfmt, blockdev_target_img, str(TestSingleDrive.image_len))
 
-        self.vm = iotests.VM().add_drive(test_img)
+        self.vm = iotests.VM().add_drive(test_img).add_drive(blockdev_target_img)
         self.vm.launch()
 
     def tearDown(self):
         self.vm.shutdown()
         os.remove(test_img)
+        os.remove(blockdev_target_img)
         try:
             os.remove(target_img)
         except OSError:
             pass
 
-    def test_cancel(self):
+    def do_test_cancel(self, cmd, target):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('drive-backup', device='drive0',
-                             target=target_img, sync='full')
+        result = self.vm.qmp(cmd, device='drive0', target=target, sync='full')
         self.assert_qmp(result, 'return', {})
 
         event = self.cancel_and_wait()
         self.assert_qmp(event, 'data/type', 'backup')
 
-    def test_pause(self):
+    def test_cancel_drive_backup(self):
+        self.do_test_cancel('drive-backup', target_img)
+
+    def test_cancel_blockdev_backup(self):
+        self.do_test_cancel('blockdev-backup', 'drive1')
+
+    def do_test_pause(self, cmd, target, image):
         self.assert_no_active_block_jobs()
 
         self.vm.pause_drive('drive0')
-        result = self.vm.qmp('drive-backup', device='drive0',
-                             target=target_img, sync='full')
+        result = self.vm.qmp(cmd, device='drive0',
+                             target=target, sync='full')
         self.assert_qmp(result, 'return', {})
 
         result = self.vm.qmp('block-job-pause', device='drive0')
@@ -86,14 +94,25 @@ class TestSingleDrive(iotests.QMPTestCase):
         self.wait_until_completed()
 
         self.vm.shutdown()
-        self.assertTrue(iotests.compare_images(test_img, target_img),
+        self.assertTrue(iotests.compare_images(test_img, image),
                         'target image does not match source after backup')
 
+    def test_pause_drive_backup(self):
+        self.do_test_pause('drive-backup', target_img, target_img)
+
+    def test_pause_blockdev_backup(self):
+        self.do_test_pause('blockdev-backup', 'drive1', blockdev_target_img)
+
     def test_medium_not_found(self):
         result = self.vm.qmp('drive-backup', device='ide1-cd0',
                              target=target_img, sync='full')
         self.assert_qmp(result, 'error/class', 'GenericError')
 
+    def test_medium_not_found_blockdev_backup(self):
+        result = self.vm.qmp('blockdev-backup', device='ide1-cd0',
+                             target='drive1', sync='full')
+        self.assert_qmp(result, 'error/class', 'GenericError')
+
     def test_image_not_found(self):
         result = self.vm.qmp('drive-backup', device='drive0',
                              target=target_img, sync='full', mode='existing')
@@ -105,31 +124,53 @@ class TestSingleDrive(iotests.QMPTestCase):
                              format='spaghetti-noodles')
         self.assert_qmp(result, 'error/class', 'GenericError')
 
-    def test_device_not_found(self):
-        result = self.vm.qmp('drive-backup', device='nonexistent',
-                             target=target_img, sync='full')
+    def do_test_device_not_found(self, cmd, **args):
+        result = self.vm.qmp(cmd, **args)
         self.assert_qmp(result, 'error/class', 'DeviceNotFound')
 
+    def test_device_not_found(self):
+        self.do_test_device_not_found('drive-backup', device='nonexistent',
+                                      target=target_img, sync='full')
+
+        self.do_test_device_not_found('blockdev-backup', device='nonexistent',
+                                      target='drive0', sync='full')
+
+        self.do_test_device_not_found('blockdev-backup', device='drive0',
+                                      target='nonexistent', sync='full')
+
+        self.do_test_device_not_found('blockdev-backup', device='nonexistent',
+                                      target='nonexistent', sync='full')
+
+    def test_target_is_source(self):
+        result = self.vm.qmp('blockdev-backup', device='drive0',
+                             target='drive0', sync='full')
+        self.assert_qmp(result, 'error/class', 'GenericError')
+
 class TestSetSpeed(iotests.QMPTestCase):
     image_len = 80 * 1024 * 1024 # MB
 
     def setUp(self):
         qemu_img('create', '-f', iotests.imgfmt, test_img, str(TestSetSpeed.image_len))
         qemu_io('-f', iotests.imgfmt, '-c', 'write -P1 0 512', test_img)
-        self.vm = iotests.VM().add_drive(test_img)
+        qemu_img('create', '-f', iotests.imgfmt, blockdev_target_img, str(TestSingleDrive.image_len))
+
+        self.vm = iotests.VM().add_drive(test_img).add_drive(blockdev_target_img)
         self.vm.launch()
 
     def tearDown(self):
         self.vm.shutdown()
         os.remove(test_img)
-        os.remove(target_img)
+        os.remove(blockdev_target_img)
+        try:
+            os.remove(target_img)
+        except OSError:
+            pass
 
-    def test_set_speed(self):
+    def do_test_set_speed(self, cmd, target):
         self.assert_no_active_block_jobs()
 
         self.vm.pause_drive('drive0')
-        result = self.vm.qmp('drive-backup', device='drive0',
-                             target=target_img, sync='full')
+        result = self.vm.qmp(cmd, device='drive0', target=target, sync='full')
         self.assert_qmp(result, 'return', {})
 
         # Default speed is 0
@@ -148,10 +189,10 @@ class TestSetSpeed(iotests.QMPTestCase):
         event = self.cancel_and_wait(resume=True)
         self.assert_qmp(event, 'data/type', 'backup')
 
-        # Check setting speed in drive-backup works
+        # Check setting speed option works
         self.vm.pause_drive('drive0')
-        result = self.vm.qmp('drive-backup', device='drive0',
-                             target=target_img, sync='full', speed=4*1024*1024)
+        result = self.vm.qmp(cmd, device='drive0',
+                             target=target, sync='full', speed=4*1024*1024)
         self.assert_qmp(result, 'return', {})
 
         result = self.vm.qmp('query-block-jobs')
@@ -161,18 +202,24 @@ class TestSetSpeed(iotests.QMPTestCase):
         event = self.cancel_and_wait(resume=True)
         self.assert_qmp(event, 'data/type', 'backup')
 
-    def test_set_speed_invalid(self):
+    def test_set_speed_drive_backup(self):
+        self.do_test_set_speed('drive-backup', target_img)
+
+    def test_set_speed_blockdev_backup(self):
+        self.do_test_set_speed('blockdev-backup', 'drive1')
+
+    def do_test_set_speed_invalid(self, cmd, target):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('drive-backup', device='drive0',
-                             target=target_img, sync='full', speed=-1)
+        result = self.vm.qmp(cmd, device='drive0',
+                             target=target, sync='full', speed=-1)
         self.assert_qmp(result, 'error/class', 'GenericError')
 
         self.assert_no_active_block_jobs()
 
         self.vm.pause_drive('drive0')
-        result = self.vm.qmp('drive-backup', device='drive0',
-                             target=target_img, sync='full')
+        result = self.vm.qmp(cmd, device='drive0',
+                             target=target, sync='full')
         self.assert_qmp(result, 'return', {})
 
         result = self.vm.qmp('block-job-set-speed', device='drive0', speed=-1)
@@ -181,6 +228,12 @@ class TestSetSpeed(iotests.QMPTestCase):
         event = self.cancel_and_wait(resume=True)
         self.assert_qmp(event, 'data/type', 'backup')
 
+    def test_set_speed_invalid_drive_backup(self):
+        self.do_test_set_speed_invalid('drive-backup', target_img)
+
+    def test_set_speed_invalid_blockdev_backup(self):
+        self.do_test_set_speed_invalid('blockdev-backup',  'drive1')
+
 class TestSingleTransaction(iotests.QMPTestCase):
     image_len = 64 * 1024 * 1024 # MB
 
@@ -190,41 +243,50 @@ class TestSingleTransaction(iotests.QMPTestCase):
         qemu_io('-f', iotests.imgfmt, '-c', 'write -P0xd5 1M 32k', test_img)
         qemu_io('-f', iotests.imgfmt, '-c', 'write -P0xdc 32M 124k', test_img)
         qemu_io('-f', iotests.imgfmt, '-c', 'write -P0xdc 67043328 64k', test_img)
+        qemu_img('create', '-f', iotests.imgfmt, blockdev_target_img, str(TestSingleDrive.image_len))
 
-        self.vm = iotests.VM().add_drive(test_img)
+        self.vm = iotests.VM().add_drive(test_img).add_drive(blockdev_target_img)
         self.vm.launch()
 
     def tearDown(self):
         self.vm.shutdown()
         os.remove(test_img)
+        os.remove(blockdev_target_img)
         try:
             os.remove(target_img)
         except OSError:
             pass
 
-    def test_cancel(self):
+    def do_test_cancel(self, cmd, target):
         self.assert_no_active_block_jobs()
 
         result = self.vm.qmp('transaction', actions=[{
-                'type': 'drive-backup',
+                'type': cmd,
                 'data': { 'device': 'drive0',
-                          'target': target_img,
+                          'target': target,
                           'sync': 'full' },
             }
         ])
+
         self.assert_qmp(result, 'return', {})
 
         event = self.cancel_and_wait()
         self.assert_qmp(event, 'data/type', 'backup')
 
-    def test_pause(self):
+    def test_cancel_drive_backup(self):
+        self.do_test_cancel('drive-backup', target_img)
+
+    def test_cancel_blockdev_backup(self):
+        self.do_test_cancel('blockdev-backup', 'drive1')
+
+    def do_test_pause(self, cmd, target, image):
         self.assert_no_active_block_jobs()
 
         self.vm.pause_drive('drive0')
         result = self.vm.qmp('transaction', actions=[{
-                'type': 'drive-backup',
+                'type': cmd,
                 'data': { 'device': 'drive0',
-                          'target': target_img,
+                          'target': target,
                           'sync': 'full' },
             }
         ])
@@ -248,19 +310,31 @@ class TestSingleTransaction(iotests.QMPTestCase):
         self.wait_until_completed()
 
         self.vm.shutdown()
-        self.assertTrue(iotests.compare_images(test_img, target_img),
+        self.assertTrue(iotests.compare_images(test_img, image),
                         'target image does not match source after backup')
 
-    def test_medium_not_found(self):
+    def test_pause_drive_backup(self):
+        self.do_test_pause('drive-backup', target_img, target_img)
+
+    def test_pause_blockdev_backup(self):
+        self.do_test_pause('blockdev-backup', 'drive1', blockdev_target_img)
+
+    def do_test_medium_not_found(self, cmd, target):
         result = self.vm.qmp('transaction', actions=[{
-                'type': 'drive-backup',
+                'type': cmd,
                 'data': { 'device': 'ide1-cd0',
-                          'target': target_img,
+                          'target': target,
                           'sync': 'full' },
             }
         ])
         self.assert_qmp(result, 'error/class', 'GenericError')
 
+    def test_medium_not_found_drive_backup(self):
+        self.do_test_medium_not_found('drive-backup', target_img)
+
+    def test_medium_not_found_blockdev_backup(self):
+        self.do_test_medium_not_found('blockdev-backup', 'drive1')
+
     def test_image_not_found(self):
         result = self.vm.qmp('transaction', actions=[{
                 'type': 'drive-backup',
@@ -283,6 +357,43 @@ class TestSingleTransaction(iotests.QMPTestCase):
         ])
         self.assert_qmp(result, 'error/class', 'DeviceNotFound')
 
+        result = self.vm.qmp('transaction', actions=[{
+                'type': 'blockdev-backup',
+                'data': { 'device': 'nonexistent',
+                          'target': 'drive1',
+                          'sync': 'full' },
+            }
+        ])
+        self.assert_qmp(result, 'error/class', 'DeviceNotFound')
+
+        result = self.vm.qmp('transaction', actions=[{
+                'type': 'blockdev-backup',
+                'data': { 'device': 'drive0',
+                          'target': 'nonexistent',
+                          'sync': 'full' },
+            }
+        ])
+        self.assert_qmp(result, 'error/class', 'DeviceNotFound')
+
+        result = self.vm.qmp('transaction', actions=[{
+                'type': 'blockdev-backup',
+                'data': { 'device': 'nonexistent',
+                          'target': 'nonexistent',
+                          'sync': 'full' },
+            }
+        ])
+        self.assert_qmp(result, 'error/class', 'DeviceNotFound')
+
+    def test_target_is_source(self):
+        result = self.vm.qmp('transaction', actions=[{
+                'type': 'blockdev-backup',
+                'data': { 'device': 'drive0',
+                          'target': 'drive0',
+                          'sync': 'full' },
+            }
+        ])
+        self.assert_qmp(result, 'error/class', 'GenericError')
+
     def test_abort(self):
         result = self.vm.qmp('transaction', actions=[{
                 'type': 'drive-backup',
@@ -298,5 +409,31 @@ class TestSingleTransaction(iotests.QMPTestCase):
         self.assert_qmp(result, 'error/class', 'GenericError')
         self.assert_no_active_block_jobs()
 
+        result = self.vm.qmp('transaction', actions=[{
+                'type': 'blockdev-backup',
+                'data': { 'device': 'nonexistent',
+                          'target': 'drive1',
+                          'sync': 'full' },
+            }, {
+                'type': 'Abort',
+                'data': {},
+            }
+        ])
+        self.assert_qmp(result, 'error/class', 'GenericError')
+        self.assert_no_active_block_jobs()
+
+        result = self.vm.qmp('transaction', actions=[{
+                'type': 'blockdev-backup',
+                'data': { 'device': 'drive0',
+                          'target': 'nonexistent',
+                          'sync': 'full' },
+            }, {
+                'type': 'Abort',
+                'data': {},
+            }
+        ])
+        self.assert_qmp(result, 'error/class', 'GenericError')
+        self.assert_no_active_block_jobs()
+
 if __name__ == '__main__':
     iotests.main(supported_fmts=['raw', 'qcow2'])
diff --git a/tests/qemu-iotests/055.out b/tests/qemu-iotests/055.out
index 6323079..42314e9 100644
--- a/tests/qemu-iotests/055.out
+++ b/tests/qemu-iotests/055.out
@@ -1,5 +1,5 @@
-..............
+........................
 ----------------------------------------------------------------------
-Ran 14 tests
+Ran 24 tests
 
 OK
-- 
1.9.3

Re: [Qemu-devel] [PATCH v5 2/4] qmp: Add command 'blockdev-backup'

[John Snow]

On 12/17/2014 07:51 AM, Fam Zheng wrote:
> Similar to drive-backup, but this command uses a device id as target
> instead of creating/opening an image file.
>
> Also add blocker on target bs, since the target is also a named device
> now.
>
> Add check and report error for bs == target which became possible but is
> an illegal case with introduction of blockdev-backup.
>
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>   block/backup.c       | 28 +++++++++++++++++++++++++++
>   blockdev.c           | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>   qapi/block-core.json | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>   qmp-commands.hx      | 42 ++++++++++++++++++++++++++++++++++++++++
>   4 files changed, 178 insertions(+)
>
> diff --git a/block/backup.c b/block/backup.c
> index 792e655..1c535b1 100644
> --- a/block/backup.c
> +++ b/block/backup.c
> @@ -360,6 +360,7 @@ static void coroutine_fn backup_run(void *opaque)
>       hbitmap_free(job->bitmap);
>
>       bdrv_iostatus_disable(target);
> +    bdrv_op_unblock_all(target, job->common.blocker);
>
>       data = g_malloc(sizeof(*data));
>       data->ret = ret;
> @@ -379,6 +380,11 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
>       assert(target);
>       assert(cb);
>
> +    if (bs == target) {
> +        error_setg(errp, "Source and target cannot be the same");
> +        return;
> +    }
> +
>       if ((on_source_error == BLOCKDEV_ON_ERROR_STOP ||
>            on_source_error == BLOCKDEV_ON_ERROR_ENOSPC) &&
>           !bdrv_iostatus_is_enabled(bs)) {
> @@ -386,6 +392,26 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
>           return;
>       }
>
> +    if (!bdrv_is_inserted(bs)) {
> +        error_setg(errp, "Device is not inserted: %s",
> +                   bdrv_get_device_name(bs));
> +        return;
> +    }
> +
> +    if (!bdrv_is_inserted(target)) {
> +        error_setg(errp, "Device is not inserted: %s",
> +                   bdrv_get_device_name(target));
> +        return;
> +    }
> +
> +    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
> +        return;
> +    }
> +
> +    if (bdrv_op_is_blocked(target, BLOCK_OP_TYPE_BACKUP_TARGET, errp)) {
> +        return;
> +    }
> +
>       len = bdrv_getlength(bs);
>       if (len < 0) {
>           error_setg_errno(errp, -len, "unable to get length for '%s'",
> @@ -399,6 +425,8 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
>           return;
>       }
>
> +    bdrv_op_block_all(target, job->common.blocker);
> +
>       job->on_source_error = on_source_error;
>       job->on_target_error = on_target_error;
>       job->target = target;
> diff --git a/blockdev.c b/blockdev.c
> index 5651a8e..dbbab1d 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -2240,6 +2240,8 @@ void qmp_drive_backup(const char *device, const char *target,
>       aio_context = bdrv_get_aio_context(bs);
>       aio_context_acquire(aio_context);
>
> +    /* Although backup_run has this check too, we need to use bs->drv below, so
> +     * do an early check redundantly. */
>       if (!bdrv_is_inserted(bs)) {
>           error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
>           goto out;
> @@ -2256,6 +2258,7 @@ void qmp_drive_backup(const char *device, const char *target,
>           }
>       }
>
> +    /* Early check to avoid creating target */
>       if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
>           goto out;
>       }
> @@ -2323,6 +2326,57 @@ BlockDeviceInfoList *qmp_query_named_block_nodes(Error **errp)
>       return bdrv_named_nodes_list();
>   }
>
> +void qmp_blockdev_backup(const char *device, const char *target,
> +                         enum MirrorSyncMode sync,
> +                         bool has_speed, int64_t speed,
> +                         bool has_on_source_error,
> +                         BlockdevOnError on_source_error,
> +                         bool has_on_target_error,
> +                         BlockdevOnError on_target_error,
> +                         Error **errp)
> +{
> +    BlockDriverState *bs;
> +    BlockDriverState *target_bs;
> +    Error *local_err = NULL;
> +    AioContext *aio_context;
> +
> +    if (!has_speed) {
> +        speed = 0;
> +    }
> +    if (!has_on_source_error) {
> +        on_source_error = BLOCKDEV_ON_ERROR_REPORT;
> +    }
> +    if (!has_on_target_error) {
> +        on_target_error = BLOCKDEV_ON_ERROR_REPORT;
> +    }
> +
> +    bs = bdrv_find(device);
> +    if (!bs) {
> +        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
> +        return;
> +    }
> +
> +    aio_context = bdrv_get_aio_context(bs);
> +    aio_context_acquire(aio_context);
> +
> +    target_bs = bdrv_find(target);
> +    if (!target_bs) {
> +        error_set(errp, QERR_DEVICE_NOT_FOUND, target);
> +        goto out;
> +    }
> +
> +    bdrv_ref(target_bs);
> +    bdrv_set_aio_context(target_bs, bdrv_get_aio_context(bs));

why call bdrv_get_aio_context(bs) again instead of just using 
aio_context? Will this cause issues?

> +    backup_start(bs, target_bs, speed, sync, on_source_error, on_target_error,
> +                 block_job_cb, bs, &local_err);
> +    if (local_err != NULL) {
> +        bdrv_unref(target_bs);
> +        error_propagate(errp, local_err);
> +    }
> +out:
> +    aio_context_release(aio_context);
> +}
> +
>   #define DEFAULT_MIRROR_BUF_SIZE   (10 << 20)
>
>   void qmp_drive_mirror(const char *device, const char *target,
> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index 6e8db15..d9f0598 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -703,6 +703,41 @@
>               '*on-target-error': 'BlockdevOnError' } }
>
>   ##
> +# @BlockdevBackup
> +#
> +# @device: the name of the device which should be copied.
> +#
> +# @target: the name of the backup target device.
> +#
> +# @sync: what parts of the disk image should be copied to the destination
> +#        (all the disk, only the sectors allocated in the topmost image, or
> +#        only new I/O).
> +#
> +# @speed: #optional the maximum speed, in bytes per second. The default is 0,
> +#         for unlimited.
> +#
> +# @on-source-error: #optional the action to take on an error on the source,
> +#                   default 'report'.  'stop' and 'enospc' can only be used
> +#                   if the block device supports io-status (see BlockInfo).
> +#
> +# @on-target-error: #optional the action to take on an error on the target,
> +#                   default 'report' (no limitations, since this applies to
> +#                   a different block device than @device).
> +#
> +# Note that @on-source-error and @on-target-error only affect background I/O.
> +# If an error occurs during a guest write request, the device's rerror/werror
> +# actions will be used.
> +#
> +# Since: 2.3
> +##
> +{ 'type': 'BlockdevBackup',
> +  'data': { 'device': 'str', 'target': 'str',
> +            'sync': 'MirrorSyncMode',
> +            '*speed': 'int',
> +            '*on-source-error': 'BlockdevOnError',
> +            '*on-target-error': 'BlockdevOnError' } }
> +
> +##
>   # @blockdev-snapshot-sync
>   #
>   # Generates a synchronous snapshot of a block device.
> @@ -822,6 +857,25 @@
>   { 'command': 'drive-backup', 'data': 'DriveBackup' }
>
>   ##
> +# @blockdev-backup
> +#
> +# Start a point-in-time copy of a block device to a new destination.  The
> +# status of ongoing blockdev-backup operations can be checked with
> +# query-block-jobs where the BlockJobInfo.type field has the value 'backup'.
> +# The operation can be stopped before it has completed using the
> +# block-job-cancel command.
> +#
> +# For the arguments, see the documentation of BlockdevBackup.
> +#
> +# Returns: Nothing on success.
> +#          If @device or @target is not a valid block device, DeviceNotFound.
> +#
> +# Since 2.3
> +##
> +{ 'command': 'blockdev-backup', 'data': 'BlockdevBackup' }
> +
> +
> +##
>   # @query-named-block-nodes
>   #
>   # Get the named block driver list
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index 3348782..a7bb90b 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -1094,6 +1094,48 @@ Example:
>                                                  "sync": "full",
>                                                  "target": "backup.img" } }
>   <- { "return": {} }
> +
> +EQMP
> +
> +    {
> +        .name       = "blockdev-backup",
> +        .args_type  = "sync:s,device:B,target:B,speed:i?,"
> +                      "on-source-error:s?,on-target-error:s?",
> +        .mhandler.cmd_new = qmp_marshal_input_blockdev_backup,
> +    },
> +
> +SQMP
> +blockdev-backup
> +------------

^ Pad out the dashes to match the line length of the command. Mentioning 
only because Eric got me on that one last time :)

> +
> +The device version of drive-backup: this command takes an existing named device
> +as backup target.
> +
> +Arguments:
> +
> +- "device": the name of the device which should be copied.
> +            (json-string)
> +- "target": the name of the backup target device. (json-string)
> +- "sync": what parts of the disk image should be copied to the destination;
> +          possibilities include "full" for all the disk, "top" for only the
> +          sectors allocated in the topmost image, or "none" to only replicate
> +          new I/O (MirrorSyncMode).
> +- "speed": the maximum speed, in bytes per second (json-int, optional)
> +- "on-source-error": the action to take on an error on the source, default
> +                     'report'.  'stop' and 'enospc' can only be used
> +                     if the block device supports io-status.
> +                     (BlockdevOnError, optional)
> +- "on-target-error": the action to take on an error on the target, default
> +                     'report' (no limitations, since this applies to
> +                     a different block device than device).
> +                     (BlockdevOnError, optional)
> +
> +Example:
> +-> { "execute": "blockdev-backup", "arguments": { "device": "src-id",
> +                                                  "sync": "full",
> +                                                  "target": "tgt-id" } }
> +<- { "return": {} }
> +
>   EQMP
>
>       {
>

Re: [Qemu-devel] [PATCH v5 1/4] qapi: Comment version info in TransactionAction

[Eric Blake]

[-- Attachment #1: Type: text/plain, Size: 776 bytes --]

On 12/17/2014 05:51 AM, Fam Zheng wrote:
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  qapi-schema.json | 6 ++++++
>  1 file changed, 6 insertions(+)

Reviewed-by: Eric Blake <eblake@redhat.com>

> 
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 563b4ad..47d99cf 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -1254,6 +1254,12 @@
>  #
>  # A discriminated record of operations that can be performed with
>  # @transaction.
> +#
> +# Since 1.1
> +#
> +# drive-backup since 1.6
> +# abort since 1.6
> +# blockdev-snapshot-internal-sync since 1.7
>  ##
>  { 'union': 'TransactionAction',
>    'data': {
> 

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 539 bytes --]

Re: [Qemu-devel] [PATCH v5 3/4] block: Add blockdev-backup to transaction

[John Snow]

On 12/17/2014 07:51 AM, Fam Zheng wrote:
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>   blockdev.c       | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>   qapi-schema.json |  2 ++
>   2 files changed, 81 insertions(+)
>
> diff --git a/blockdev.c b/blockdev.c
> index dbbab1d..9f9ae88 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -1559,6 +1559,79 @@ static void drive_backup_clean(BlkTransactionState *common)
>       }
>   }
>
> +typedef struct BlockdevBackupState {
> +    BlkTransactionState common;
> +    BlockDriverState *bs;
> +    BlockJob *job;
> +    AioContext *aio_context;
> +} BlockdevBackupState;
> +
> +static void blockdev_backup_prepare(BlkTransactionState *common, Error **errp)
> +{
> +    BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
> +    BlockdevBackup *backup;
> +    BlockDriverState *bs, *target;
> +    Error *local_err = NULL;
> +
> +    assert(common->action->kind == TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP);
> +    backup = common->action->blockdev_backup;
> +
> +    bs = bdrv_find(backup->device);
> +    if (!bs) {
> +        error_set(errp, QERR_DEVICE_NOT_FOUND, backup->device);
> +        return;
> +    }
> +
> +    target = bdrv_find(backup->target);
> +    if (!target) {
> +        error_set(errp, QERR_DEVICE_NOT_FOUND, backup->target);
> +        return;
> +    }
> +
> +    /* AioContext is released in .clean() */
> +    state->aio_context = bdrv_get_aio_context(bs);
> +    if (state->aio_context != bdrv_get_aio_context(target)) {
> +        state->aio_context = NULL;
> +        error_setg(errp, "Backup between two IO threads is not implemented");
> +        return;
> +    }
> +    aio_context_acquire(state->aio_context);
> +
> +    qmp_blockdev_backup(backup->device, backup->target,
> +                        backup->sync,
> +                        backup->has_speed, backup->speed,
> +                        backup->has_on_source_error, backup->on_source_error,
> +                        backup->has_on_target_error, backup->on_target_error,
> +                        &local_err);
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return;
> +    }
> +
> +    state->bs = bdrv_find(backup->device);

Just some questions:

why not use 'bs' instead of calling the function again? Granted, it 
should work a second time if it worked once.

> +    state->job = state->bs->job;

Why stash both bs and bs->job? Can the BDS change what its job member 
points to between .prepare() and .abort() ?

> +}
> +
> +static void blockdev_backup_abort(BlkTransactionState *common)
> +{
> +    BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
> +    BlockDriverState *bs = state->bs;
> +
> +    /* Only cancel if it's the job we started */
> +    if (bs && bs->job && bs->job == state->job) {
> +        block_job_cancel_sync(bs->job);
> +    }
> +}
> +
> +static void blockdev_backup_clean(BlkTransactionState *common)
> +{
> +    BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
> +
> +    if (state->aio_context) {
> +        aio_context_release(state->aio_context);
> +    }
> +}
> +
>   static void abort_prepare(BlkTransactionState *common, Error **errp)
>   {
>       error_setg(errp, "Transaction aborted using Abort action");
> @@ -1582,6 +1655,12 @@ static const BdrvActionOps actions[] = {
>           .abort = drive_backup_abort,
>           .clean = drive_backup_clean,
>       },
> +    [TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP] = {
> +        .instance_size = sizeof(BlockdevBackupState),
> +        .prepare = blockdev_backup_prepare,
> +        .abort = blockdev_backup_abort,
> +        .clean = blockdev_backup_clean,
> +    },
>       [TRANSACTION_ACTION_KIND_ABORT] = {
>           .instance_size = sizeof(BlkTransactionState),
>           .prepare = abort_prepare,
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 47d99cf..fbfc52f 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -1260,11 +1260,13 @@
>   # drive-backup since 1.6
>   # abort since 1.6
>   # blockdev-snapshot-internal-sync since 1.7
> +# blockdev-backup since 2.3
>   ##
>   { 'union': 'TransactionAction',
>     'data': {
>          'blockdev-snapshot-sync': 'BlockdevSnapshot',
>          'drive-backup': 'DriveBackup',
> +       'blockdev-backup': 'BlockdevBackup',
>          'abort': 'Abort',
>          'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal'
>      } }
>

At any rate, regardless of the answers to my questions:
Reviewed-by: John Snow <jsnow@redhat.com>

Re: [Qemu-devel] [PATCH v5 2/4] qmp: Add command 'blockdev-backup'

[Fam Zheng]

On Wed, 12/17 15:53, John Snow wrote:
> >+    aio_context = bdrv_get_aio_context(bs);
> >+    aio_context_acquire(aio_context);
> >+
> >+    target_bs = bdrv_find(target);
> >+    if (!target_bs) {
> >+        error_set(errp, QERR_DEVICE_NOT_FOUND, target);
> >+        goto out;
> >+    }
> >+
> >+    bdrv_ref(target_bs);
> >+    bdrv_set_aio_context(target_bs, bdrv_get_aio_context(bs));
> 
> why call bdrv_get_aio_context(bs) again instead of just using aio_context?
> Will this cause issues?

Could be simply aio_context.

[...]

> >diff --git a/qmp-commands.hx b/qmp-commands.hx
> >index 3348782..a7bb90b 100644
> >--- a/qmp-commands.hx
> >+++ b/qmp-commands.hx
> >@@ -1094,6 +1094,48 @@ Example:
> >                                                 "sync": "full",
> >                                                 "target": "backup.img" } }
> >  <- { "return": {} }
> >+
> >+EQMP
> >+
> >+    {
> >+        .name       = "blockdev-backup",
> >+        .args_type  = "sync:s,device:B,target:B,speed:i?,"
> >+                      "on-source-error:s?,on-target-error:s?",
> >+        .mhandler.cmd_new = qmp_marshal_input_blockdev_backup,
> >+    },
> >+
> >+SQMP
> >+blockdev-backup
> >+------------
> 
> ^ Pad out the dashes to match the line length of the command. Mentioning
> only because Eric got me on that one last time :)

OK, thanks.

Fam

Re: [Qemu-devel] [PATCH v5 3/4] block: Add blockdev-backup to transaction

[Fam Zheng]

On Wed, 12/17 16:20, John Snow wrote:
> On 12/17/2014 07:51 AM, Fam Zheng wrote:
> >Signed-off-by: Fam Zheng <famz@redhat.com>
> >---
> >  blockdev.c       | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  qapi-schema.json |  2 ++
> >  2 files changed, 81 insertions(+)
> >
> >diff --git a/blockdev.c b/blockdev.c
> >index dbbab1d..9f9ae88 100644
> >--- a/blockdev.c
> >+++ b/blockdev.c
> >@@ -1559,6 +1559,79 @@ static void drive_backup_clean(BlkTransactionState *common)
> >      }
> >  }
> >
> >+typedef struct BlockdevBackupState {
> >+    BlkTransactionState common;
> >+    BlockDriverState *bs;
> >+    BlockJob *job;
> >+    AioContext *aio_context;
> >+} BlockdevBackupState;
> >+
> >+static void blockdev_backup_prepare(BlkTransactionState *common, Error **errp)
> >+{
> >+    BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
> >+    BlockdevBackup *backup;
> >+    BlockDriverState *bs, *target;
> >+    Error *local_err = NULL;
> >+
> >+    assert(common->action->kind == TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP);
> >+    backup = common->action->blockdev_backup;
> >+
> >+    bs = bdrv_find(backup->device);
> >+    if (!bs) {
> >+        error_set(errp, QERR_DEVICE_NOT_FOUND, backup->device);
> >+        return;
> >+    }
> >+
> >+    target = bdrv_find(backup->target);
> >+    if (!target) {
> >+        error_set(errp, QERR_DEVICE_NOT_FOUND, backup->target);
> >+        return;
> >+    }
> >+
> >+    /* AioContext is released in .clean() */
> >+    state->aio_context = bdrv_get_aio_context(bs);
> >+    if (state->aio_context != bdrv_get_aio_context(target)) {
> >+        state->aio_context = NULL;
> >+        error_setg(errp, "Backup between two IO threads is not implemented");
> >+        return;
> >+    }
> >+    aio_context_acquire(state->aio_context);
> >+
> >+    qmp_blockdev_backup(backup->device, backup->target,
> >+                        backup->sync,
> >+                        backup->has_speed, backup->speed,
> >+                        backup->has_on_source_error, backup->on_source_error,
> >+                        backup->has_on_target_error, backup->on_target_error,
> >+                        &local_err);
> >+    if (local_err) {
> >+        error_propagate(errp, local_err);
> >+        return;
> >+    }
> >+
> >+    state->bs = bdrv_find(backup->device);
> 
> Just some questions:
> 
> why not use 'bs' instead of calling the function again? Granted, it should
> work a second time if it worked once.

Yeah, it should be "bs", a mistake but not wrong.

> 
> >+    state->job = state->bs->job;
> 
> Why stash both bs and bs->job? Can the BDS change what its job member points
> to between .prepare() and .abort() ?

Copied from drive_backup_prepare. Actually there is a comment about this in
blockdev_backup_abort below:

> 
> >+}
> >+
> >+static void blockdev_backup_abort(BlkTransactionState *common)
> >+{
> >+    BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
> >+    BlockDriverState *bs = state->bs;
> >+
> >+    /* Only cancel if it's the job we started */
> >+    if (bs && bs->job && bs->job == state->job) {

I think there is one case this is useful: a transaction containing two block
jobs, which *will* fail and abort(). With this check, only the right (started)
block_job_cancel_sync is called.

> >+        block_job_cancel_sync(bs->job);
> >+    }
> >+}
> >+
> >+static void blockdev_backup_clean(BlkTransactionState *common)
> >+{
> >+    BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
> >+
> >+    if (state->aio_context) {
> >+        aio_context_release(state->aio_context);
> >+    }
> >+}
> >+
> >  static void abort_prepare(BlkTransactionState *common, Error **errp)
> >  {
> >      error_setg(errp, "Transaction aborted using Abort action");
> >@@ -1582,6 +1655,12 @@ static const BdrvActionOps actions[] = {
> >          .abort = drive_backup_abort,
> >          .clean = drive_backup_clean,
> >      },
> >+    [TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP] = {
> >+        .instance_size = sizeof(BlockdevBackupState),
> >+        .prepare = blockdev_backup_prepare,
> >+        .abort = blockdev_backup_abort,
> >+        .clean = blockdev_backup_clean,
> >+    },
> >      [TRANSACTION_ACTION_KIND_ABORT] = {
> >          .instance_size = sizeof(BlkTransactionState),
> >          .prepare = abort_prepare,
> >diff --git a/qapi-schema.json b/qapi-schema.json
> >index 47d99cf..fbfc52f 100644
> >--- a/qapi-schema.json
> >+++ b/qapi-schema.json
> >@@ -1260,11 +1260,13 @@
> >  # drive-backup since 1.6
> >  # abort since 1.6
> >  # blockdev-snapshot-internal-sync since 1.7
> >+# blockdev-backup since 2.3
> >  ##
> >  { 'union': 'TransactionAction',
> >    'data': {
> >         'blockdev-snapshot-sync': 'BlockdevSnapshot',
> >         'drive-backup': 'DriveBackup',
> >+       'blockdev-backup': 'BlockdevBackup',
> >         'abort': 'Abort',
> >         'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal'
> >     } }
> >
> 
> At any rate, regardless of the answers to my questions:
> Reviewed-by: John Snow <jsnow@redhat.com>
> 

Thanks! I'm going to fix the above bdrv_find() while keeping your rev-by. I
hope that is OK for you. :)

Fam