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* [Qemu-devel] [PATCH v6 00/14] block: incremental backup transactions using BlockJobTxn
@ 2015-09-15  6:11 Fam Zheng
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 01/14] qapi: Add transaction support to block-dirty-bitmap operations Fam Zheng
                   ` (13 more replies)
  0 siblings, 14 replies; 29+ messages in thread
From: Fam Zheng @ 2015-09-15  6:11 UTC (permalink / raw)
  To: qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

v6: Address comments from Max and Eric (many thanks for reviewing!):
    Add Max's reviews.
    Don't leak txn. [Max]
    Unusual comment ending "**/" -> "*/". [Eric]
    Fix the stale block_job_txn_prepare_to_complete comment. [Max]
    Move "block_job_txn_unref" to below FOREACH block. [Max]
    Split "base" and "txn" in qapi schema, so that transactional-cancel is only
    visible in transaction. [Eric]

v5: Address comments from Max Reitz:
    2.4 -> 2.5 in qapi docs.
    Don't leak txn object.
    English syntax fixes.
    Really leave the "cancelled" status of failed job.
    Remove a superfluous added line.

v4: Address comments from John and Stefan, including:
    Rename function: backup_cleanup_sync_bitmap.
    Rename and add comments for .commit and .abort.
    Call .commit and .abort for both txn and non-txn.
    Drop patch 9 in v3.
    Improve the txn implementation. Acquire context locks as accessing them.
    Add refcnt patch for BlockJob.
    Adjust txn unit test code.

This is based on top of the work by Stefan Hajnoczi and John Snow.

Recap: motivation for block job transactions
--------------------------------------------
If an incremental backup block job fails then we reclaim the bitmap so
the job can be retried.  The problem comes when multiple jobs are started as
part of a qmp 'transaction' command.  We need to group these jobs in a
transaction so that either all jobs complete successfully or all bitmaps are
reclaimed.

Without transactions, there is a case where some jobs complete successfully and
throw away their bitmaps, making it impossible to retry the backup by rerunning
the command if one of the jobs fails.

How does this implementation work?
----------------------------------
These patches add a BlockJobTxn object with the following API:

  txn = block_job_txn_new();
  block_job_txn_add_job(txn, job1);
  block_job_txn_add_job(txn, job2);

The jobs either both complete successfully or they both fail/cancel.  If the
user cancels job1 then job2 will also be cancelled and vice versa.

Jobs objects stay alive waiting for other jobs to complete, even if the
coroutines have returned.  They can be cancelled by the user during this time.
Job blockers are still in effect and no other block job can run on this device
in the meantime (since QEMU currently only allows 1 job per device).  This is
the main drawback to this approach but reasonable since you probably don't want
to run other jobs/operations until you're sure the backup was successful (you
won't be able to retry a failed backup if there's a new job running).


Fam Zheng (6):
  backup: Extract dirty bitmap handling as a separate function
  blockjob: Introduce reference count
  blockjob: Add .commit and .abort block job actions
  blockjob: Add "completed" and "ret" in BlockJob
  blockjob: Simplify block_job_finish_sync
  block: Add block job transactions

John Snow (4):
  qapi: Add transaction support to block-dirty-bitmap operations
  iotests: add transactional incremental backup test
  block: rename BlkTransactionState and BdrvActionOps
  iotests: 124 - transactional failure test

Kashyap Chamarthy (1):
  qmp-commands.hx: Update the supported 'transaction' operations

Stefan Hajnoczi (3):
  blockdev: make BlockJobTxn available to qmp 'transaction'
  block/backup: support block job transactions
  tests: add BlockJobTxn unit test

 block.c                    |  19 ++-
 block/backup.c             |  50 +++++--
 block/mirror.c             |   2 +-
 blockdev.c                 | 354 +++++++++++++++++++++++++++++++++++----------
 blockjob.c                 | 185 +++++++++++++++++++----
 docs/bitmaps.md            |   6 +-
 include/block/block.h      |   2 +-
 include/block/block_int.h  |   6 +-
 include/block/blockjob.h   |  83 ++++++++++-
 qapi-schema.json           |  10 +-
 qapi/block-core.json       |  29 ++++
 qmp-commands.hx            |  21 ++-
 tests/Makefile             |   3 +
 tests/qemu-iotests/124     | 182 ++++++++++++++++++++++-
 tests/qemu-iotests/124.out |   4 +-
 tests/test-blockjob-txn.c  | 244 +++++++++++++++++++++++++++++++
 16 files changed, 1057 insertions(+), 143 deletions(-)
 create mode 100644 tests/test-blockjob-txn.c

-- 
2.4.3

^ permalink raw reply	[flat|nested] 29+ messages in thread

* [Qemu-devel] [PATCH v6 01/14] qapi: Add transaction support to block-dirty-bitmap operations
  2015-09-15  6:11 [Qemu-devel] [PATCH v6 00/14] block: incremental backup transactions using BlockJobTxn Fam Zheng
@ 2015-09-15  6:11 ` Fam Zheng
  2015-09-15 14:36   ` Eric Blake
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 02/14] iotests: add transactional incremental backup test Fam Zheng
                   ` (12 subsequent siblings)
  13 siblings, 1 reply; 29+ messages in thread
From: Fam Zheng @ 2015-09-15  6:11 UTC (permalink / raw)
  To: qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

From: John Snow <jsnow@redhat.com>

This adds two qmp commands to transactions.

block-dirty-bitmap-add allows you to create a bitmap simultaneously
alongside a new full backup to accomplish a clean synchronization
point.

block-dirty-bitmap-clear allows you to reset a bitmap back to as-if
it were new, which can also be used alongside a full backup to
accomplish a clean synchronization point.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block.c                   |  19 +++++++-
 blockdev.c                | 114 +++++++++++++++++++++++++++++++++++++++++++++-
 docs/bitmaps.md           |   6 +--
 include/block/block.h     |   1 -
 include/block/block_int.h |   3 ++
 qapi-schema.json          |   6 ++-
 6 files changed, 139 insertions(+), 10 deletions(-)

diff --git a/block.c b/block.c
index cb5d7ae..35881e3 100644
--- a/block.c
+++ b/block.c
@@ -3566,10 +3566,25 @@ void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
     hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors);
 }
 
-void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap)
+void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out)
 {
     assert(bdrv_dirty_bitmap_enabled(bitmap));
-    hbitmap_reset_all(bitmap->bitmap);
+    if (!out) {
+        hbitmap_reset_all(bitmap->bitmap);
+    } else {
+        HBitmap *backup = bitmap->bitmap;
+        bitmap->bitmap = hbitmap_alloc(bitmap->size,
+                                       hbitmap_granularity(backup));
+        *out = backup;
+    }
+}
+
+void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in)
+{
+    HBitmap *tmp = bitmap->bitmap;
+    assert(bdrv_dirty_bitmap_enabled(bitmap));
+    bitmap->bitmap = in;
+    hbitmap_free(tmp);
 }
 
 void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
diff --git a/blockdev.c b/blockdev.c
index 6b48be6..b1e7f2a 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1714,6 +1714,106 @@ static void blockdev_backup_clean(BlkTransactionState *common)
     }
 }
 
+typedef struct BlockDirtyBitmapState {
+    BlkTransactionState common;
+    BdrvDirtyBitmap *bitmap;
+    BlockDriverState *bs;
+    AioContext *aio_context;
+    HBitmap *backup;
+    bool prepared;
+} BlockDirtyBitmapState;
+
+static void block_dirty_bitmap_add_prepare(BlkTransactionState *common,
+                                           Error **errp)
+{
+    Error *local_err = NULL;
+    BlockDirtyBitmapAdd *action;
+    BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
+                                             common, common);
+
+    action = common->action->block_dirty_bitmap_add;
+    /* AIO context taken and released within qmp_block_dirty_bitmap_add */
+    qmp_block_dirty_bitmap_add(action->node, action->name,
+                               action->has_granularity, action->granularity,
+                               &local_err);
+
+    if (!local_err) {
+        state->prepared = true;
+    } else {
+        error_propagate(errp, local_err);
+    }
+}
+
+static void block_dirty_bitmap_add_abort(BlkTransactionState *common)
+{
+    BlockDirtyBitmapAdd *action;
+    BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
+                                             common, common);
+
+    action = common->action->block_dirty_bitmap_add;
+    /* Should not be able to fail: IF the bitmap was added via .prepare(),
+     * then the node reference and bitmap name must have been valid.
+     */
+    if (state->prepared) {
+        qmp_block_dirty_bitmap_remove(action->node, action->name, &error_abort);
+    }
+}
+
+static void block_dirty_bitmap_clear_prepare(BlkTransactionState *common,
+                                             Error **errp)
+{
+    BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
+                                             common, common);
+    BlockDirtyBitmap *action;
+
+    action = common->action->block_dirty_bitmap_clear;
+    state->bitmap = block_dirty_bitmap_lookup(action->node,
+                                              action->name,
+                                              &state->bs,
+                                              &state->aio_context,
+                                              errp);
+    if (!state->bitmap) {
+        return;
+    }
+
+    if (bdrv_dirty_bitmap_frozen(state->bitmap)) {
+        error_setg(errp, "Cannot modify a frozen bitmap");
+        return;
+    } else if (!bdrv_dirty_bitmap_enabled(state->bitmap)) {
+        error_setg(errp, "Cannot clear a disabled bitmap");
+        return;
+    }
+
+    bdrv_clear_dirty_bitmap(state->bitmap, &state->backup);
+    /* AioContext is released in .clean() */
+}
+
+static void block_dirty_bitmap_clear_abort(BlkTransactionState *common)
+{
+    BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
+                                             common, common);
+
+    bdrv_undo_clear_dirty_bitmap(state->bitmap, state->backup);
+}
+
+static void block_dirty_bitmap_clear_commit(BlkTransactionState *common)
+{
+    BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
+                                             common, common);
+
+    hbitmap_free(state->backup);
+}
+
+static void block_dirty_bitmap_clear_clean(BlkTransactionState *common)
+{
+    BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
+                                             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");
@@ -1754,6 +1854,18 @@ static const BdrvActionOps actions[] = {
         .abort = internal_snapshot_abort,
         .clean = internal_snapshot_clean,
     },
+    [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ADD] = {
+        .instance_size = sizeof(BlockDirtyBitmapState),
+        .prepare = block_dirty_bitmap_add_prepare,
+        .abort = block_dirty_bitmap_add_abort,
+    },
+    [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_CLEAR] = {
+        .instance_size = sizeof(BlockDirtyBitmapState),
+        .prepare = block_dirty_bitmap_clear_prepare,
+        .commit = block_dirty_bitmap_clear_commit,
+        .abort = block_dirty_bitmap_clear_abort,
+        .clean = block_dirty_bitmap_clear_clean,
+    }
 };
 
 /*
@@ -2137,7 +2249,7 @@ void qmp_block_dirty_bitmap_clear(const char *node, const char *name,
         goto out;
     }
 
-    bdrv_clear_dirty_bitmap(bitmap);
+    bdrv_clear_dirty_bitmap(bitmap, NULL);
 
  out:
     aio_context_release(aio_context);
diff --git a/docs/bitmaps.md b/docs/bitmaps.md
index fa87f07..9fd8ea6 100644
--- a/docs/bitmaps.md
+++ b/docs/bitmaps.md
@@ -97,11 +97,7 @@ which is included at the end of this document.
 }
 ```
 
-## Transactions (Not yet implemented)
-
-* Transactional commands are forthcoming in a future version,
-  and are not yet available for use. This section serves as
-  documentation of intent for their design and usage.
+## Transactions
 
 ### Justification
 
diff --git a/include/block/block.h b/include/block/block.h
index 0acd104..f70bec4 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -504,7 +504,6 @@ void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
                            int64_t cur_sector, int nr_sectors);
 void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
                              int64_t cur_sector, int nr_sectors);
-void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap);
 void bdrv_dirty_iter_init(BdrvDirtyBitmap *bitmap, struct HBitmapIter *hbi);
 void bdrv_set_dirty_iter(struct HBitmapIter *hbi, int64_t offset);
 int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 14ad4c3..281d790 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -664,4 +664,7 @@ void blk_dev_resize_cb(BlockBackend *blk);
 
 void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors);
 
+void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
+void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in);
+
 #endif /* BLOCK_INT_H */
diff --git a/qapi-schema.json b/qapi-schema.json
index 4060b78..46d464f 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1493,6 +1493,8 @@
 # abort since 1.6
 # blockdev-snapshot-internal-sync since 1.7
 # blockdev-backup since 2.3
+# block-dirty-bitmap-add since 2.5
+# block-dirty-bitmap-clear since 2.5
 ##
 { 'union': 'TransactionAction',
   'data': {
@@ -1500,7 +1502,9 @@
        'drive-backup': 'DriveBackup',
        'blockdev-backup': 'BlockdevBackup',
        'abort': 'Abort',
-       'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal'
+       'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal',
+       'block-dirty-bitmap-add': 'BlockDirtyBitmapAdd',
+       'block-dirty-bitmap-clear': 'BlockDirtyBitmap'
    } }
 
 ##
-- 
2.4.3

^ permalink raw reply related	[flat|nested] 29+ messages in thread

* [Qemu-devel] [PATCH v6 02/14] iotests: add transactional incremental backup test
  2015-09-15  6:11 [Qemu-devel] [PATCH v6 00/14] block: incremental backup transactions using BlockJobTxn Fam Zheng
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 01/14] qapi: Add transaction support to block-dirty-bitmap operations Fam Zheng
@ 2015-09-15  6:11 ` Fam Zheng
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 03/14] block: rename BlkTransactionState and BdrvActionOps Fam Zheng
                   ` (11 subsequent siblings)
  13 siblings, 0 replies; 29+ messages in thread
From: Fam Zheng @ 2015-09-15  6:11 UTC (permalink / raw)
  To: qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

From: John Snow <jsnow@redhat.com>

Test simple usage cases for using transactions to create
and synchronize incremental backups.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
---
 tests/qemu-iotests/124     | 54 ++++++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/124.out |  4 ++--
 2 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/tests/qemu-iotests/124 b/tests/qemu-iotests/124
index 9ccd118..9c1977e 100644
--- a/tests/qemu-iotests/124
+++ b/tests/qemu-iotests/124
@@ -36,6 +36,23 @@ def try_remove(img):
         pass
 
 
+def transaction_action(action, **kwargs):
+    return {
+        'type': action,
+        'data': kwargs
+    }
+
+
+def transaction_bitmap_clear(node, name, **kwargs):
+    return transaction_action('block-dirty-bitmap-clear',
+                              node=node, name=name, **kwargs)
+
+
+def transaction_drive_backup(device, target, **kwargs):
+    return transaction_action('drive-backup', device=device, target=target,
+                              **kwargs)
+
+
 class Bitmap:
     def __init__(self, name, drive):
         self.name = name
@@ -264,6 +281,43 @@ class TestIncrementalBackup(iotests.QMPTestCase):
         return self.do_incremental_simple(granularity=131072)
 
 
+    def test_incremental_transaction(self):
+        '''Test: Verify backups made from transactionally created bitmaps.
+
+        Create a bitmap "before" VM execution begins, then create a second
+        bitmap AFTER writes have already occurred. Use transactions to create
+        a full backup and synchronize both bitmaps to this backup.
+        Create an incremental backup through both bitmaps and verify that
+        both backups match the current drive0 image.
+        '''
+
+        drive0 = self.drives[0]
+        bitmap0 = self.add_bitmap('bitmap0', drive0)
+        self.hmp_io_writes(drive0['id'], (('0xab', 0, 512),
+                                          ('0xfe', '16M', '256k'),
+                                          ('0x64', '32736k', '64k')))
+        bitmap1 = self.add_bitmap('bitmap1', drive0)
+
+        result = self.vm.qmp('transaction', actions=[
+            transaction_bitmap_clear(bitmap0.drive['id'], bitmap0.name),
+            transaction_bitmap_clear(bitmap1.drive['id'], bitmap1.name),
+            transaction_drive_backup(drive0['id'], drive0['backup'],
+                                     sync='full', format=drive0['fmt'])
+        ])
+        self.assert_qmp(result, 'return', {})
+        self.wait_until_completed(drive0['id'])
+        self.files.append(drive0['backup'])
+
+        self.hmp_io_writes(drive0['id'], (('0x9a', 0, 512),
+                                          ('0x55', '8M', '352k'),
+                                          ('0x78', '15872k', '1M')))
+        # Both bitmaps should be correctly in sync.
+        self.create_incremental(bitmap0)
+        self.create_incremental(bitmap1)
+        self.vm.shutdown()
+        self.check_backups()
+
+
     def test_incremental_failure(self):
         '''Test: Verify backups made after a failure are correct.
 
diff --git a/tests/qemu-iotests/124.out b/tests/qemu-iotests/124.out
index 2f7d390..594c16f 100644
--- a/tests/qemu-iotests/124.out
+++ b/tests/qemu-iotests/124.out
@@ -1,5 +1,5 @@
-.......
+........
 ----------------------------------------------------------------------
-Ran 7 tests
+Ran 8 tests
 
 OK
-- 
2.4.3

^ permalink raw reply related	[flat|nested] 29+ messages in thread

* [Qemu-devel] [PATCH v6 03/14] block: rename BlkTransactionState and BdrvActionOps
  2015-09-15  6:11 [Qemu-devel] [PATCH v6 00/14] block: incremental backup transactions using BlockJobTxn Fam Zheng
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 01/14] qapi: Add transaction support to block-dirty-bitmap operations Fam Zheng
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 02/14] iotests: add transactional incremental backup test Fam Zheng
@ 2015-09-15  6:11 ` Fam Zheng
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 04/14] backup: Extract dirty bitmap handling as a separate function Fam Zheng
                   ` (10 subsequent siblings)
  13 siblings, 0 replies; 29+ messages in thread
From: Fam Zheng @ 2015-09-15  6:11 UTC (permalink / raw)
  To: qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

From: John Snow <jsnow@redhat.com>

These structures are misnomers, somewhat.

(1) BlockTransactionState is not state for a transaction,
    but is rather state for a single transaction action.
    Rename it "BlkActionState" to be more accurate.

(2) The BdrvActionOps describes operations for the BlkActionState,
    above. This name might imply a 'BdrvAction' or a 'BdrvActionState',
    which there isn't.
    Rename this to 'BlkActionOps' to match 'BlkActionState'.

Lastly, update the surrounding in-line documentation and comments
to reflect the current nature of how Transactions operate.

This patch changes only comments and names, and should not affect
behavior in any way.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
---
 blockdev.c | 116 ++++++++++++++++++++++++++++++++++---------------------------
 1 file changed, 65 insertions(+), 51 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index b1e7f2a..4ebded8 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1246,43 +1246,57 @@ static BdrvDirtyBitmap *block_dirty_bitmap_lookup(const char *node,
 
 /* New and old BlockDriverState structs for atomic group operations */
 
-typedef struct BlkTransactionState BlkTransactionState;
+typedef struct BlkActionState BlkActionState;
 
-/* Only prepare() may fail. In a single transaction, only one of commit() or
-   abort() will be called, clean() will always be called if it present. */
-typedef struct BdrvActionOps {
-    /* Size of state struct, in bytes. */
+/**
+ * BlkActionOps:
+ * Table of operations that define an Action.
+ *
+ * @instance_size: Size of state struct, in bytes.
+ * @prepare: Prepare the work, must NOT be NULL.
+ * @commit: Commit the changes, can be NULL.
+ * @abort: Abort the changes on fail, can be NULL.
+ * @clean: Clean up resources after all transaction actions have called
+ *         commit() or abort(). Can be NULL.
+ *
+ * Only prepare() may fail. In a single transaction, only one of commit() or
+ * abort() will be called. clean() will always be called if it is present.
+ */
+typedef struct BlkActionOps {
     size_t instance_size;
-    /* Prepare the work, must NOT be NULL. */
-    void (*prepare)(BlkTransactionState *common, Error **errp);
-    /* Commit the changes, can be NULL. */
-    void (*commit)(BlkTransactionState *common);
-    /* Abort the changes on fail, can be NULL. */
-    void (*abort)(BlkTransactionState *common);
-    /* Clean up resource in the end, can be NULL. */
-    void (*clean)(BlkTransactionState *common);
-} BdrvActionOps;
+    void (*prepare)(BlkActionState *common, Error **errp);
+    void (*commit)(BlkActionState *common);
+    void (*abort)(BlkActionState *common);
+    void (*clean)(BlkActionState *common);
+} BlkActionOps;
 
-/*
- * This structure must be arranged as first member in child type, assuming
- * that compiler will also arrange it to the same address with parent instance.
- * Later it will be used in free().
+/**
+ * BlkActionState:
+ * Describes one Action's state within a Transaction.
+ *
+ * @action: QAPI-defined enum identifying which Action to perform.
+ * @ops: Table of ActionOps this Action can perform.
+ * @entry: List membership for all Actions in this Transaction.
+ *
+ * This structure must be arranged as first member in a subclassed type,
+ * assuming that the compiler will also arrange it to the same offsets as the
+ * base class.
  */
-struct BlkTransactionState {
+struct BlkActionState {
     TransactionAction *action;
-    const BdrvActionOps *ops;
-    QSIMPLEQ_ENTRY(BlkTransactionState) entry;
+    const BlkActionOps *ops;
+    QSIMPLEQ_ENTRY(BlkActionState) entry;
 };
 
 /* internal snapshot private data */
 typedef struct InternalSnapshotState {
-    BlkTransactionState common;
+    BlkActionState common;
     BlockDriverState *bs;
     AioContext *aio_context;
     QEMUSnapshotInfo sn;
 } InternalSnapshotState;
 
-static void internal_snapshot_prepare(BlkTransactionState *common,
+static void internal_snapshot_prepare(BlkActionState *common,
                                       Error **errp)
 {
     Error *local_err = NULL;
@@ -1378,7 +1392,7 @@ static void internal_snapshot_prepare(BlkTransactionState *common,
     state->bs = bs;
 }
 
-static void internal_snapshot_abort(BlkTransactionState *common)
+static void internal_snapshot_abort(BlkActionState *common)
 {
     InternalSnapshotState *state =
                              DO_UPCAST(InternalSnapshotState, common, common);
@@ -1401,7 +1415,7 @@ static void internal_snapshot_abort(BlkTransactionState *common)
     }
 }
 
-static void internal_snapshot_clean(BlkTransactionState *common)
+static void internal_snapshot_clean(BlkActionState *common)
 {
     InternalSnapshotState *state = DO_UPCAST(InternalSnapshotState,
                                              common, common);
@@ -1413,13 +1427,13 @@ static void internal_snapshot_clean(BlkTransactionState *common)
 
 /* external snapshot private data */
 typedef struct ExternalSnapshotState {
-    BlkTransactionState common;
+    BlkActionState common;
     BlockDriverState *old_bs;
     BlockDriverState *new_bs;
     AioContext *aio_context;
 } ExternalSnapshotState;
 
-static void external_snapshot_prepare(BlkTransactionState *common,
+static void external_snapshot_prepare(BlkActionState *common,
                                       Error **errp)
 {
     BlockDriver *drv;
@@ -1540,7 +1554,7 @@ static void external_snapshot_prepare(BlkTransactionState *common,
     }
 }
 
-static void external_snapshot_commit(BlkTransactionState *common)
+static void external_snapshot_commit(BlkActionState *common)
 {
     ExternalSnapshotState *state =
                              DO_UPCAST(ExternalSnapshotState, common, common);
@@ -1558,7 +1572,7 @@ static void external_snapshot_commit(BlkTransactionState *common)
     aio_context_release(state->aio_context);
 }
 
-static void external_snapshot_abort(BlkTransactionState *common)
+static void external_snapshot_abort(BlkActionState *common)
 {
     ExternalSnapshotState *state =
                              DO_UPCAST(ExternalSnapshotState, common, common);
@@ -1571,13 +1585,13 @@ static void external_snapshot_abort(BlkTransactionState *common)
 }
 
 typedef struct DriveBackupState {
-    BlkTransactionState common;
+    BlkActionState common;
     BlockDriverState *bs;
     AioContext *aio_context;
     BlockJob *job;
 } DriveBackupState;
 
-static void drive_backup_prepare(BlkTransactionState *common, Error **errp)
+static void drive_backup_prepare(BlkActionState *common, Error **errp)
 {
     DriveBackupState *state = DO_UPCAST(DriveBackupState, common, common);
     BlockDriverState *bs;
@@ -1618,7 +1632,7 @@ static void drive_backup_prepare(BlkTransactionState *common, Error **errp)
     state->job = state->bs->job;
 }
 
-static void drive_backup_abort(BlkTransactionState *common)
+static void drive_backup_abort(BlkActionState *common)
 {
     DriveBackupState *state = DO_UPCAST(DriveBackupState, common, common);
     BlockDriverState *bs = state->bs;
@@ -1629,7 +1643,7 @@ static void drive_backup_abort(BlkTransactionState *common)
     }
 }
 
-static void drive_backup_clean(BlkTransactionState *common)
+static void drive_backup_clean(BlkActionState *common)
 {
     DriveBackupState *state = DO_UPCAST(DriveBackupState, common, common);
 
@@ -1639,13 +1653,13 @@ static void drive_backup_clean(BlkTransactionState *common)
 }
 
 typedef struct BlockdevBackupState {
-    BlkTransactionState common;
+    BlkActionState common;
     BlockDriverState *bs;
     BlockJob *job;
     AioContext *aio_context;
 } BlockdevBackupState;
 
-static void blockdev_backup_prepare(BlkTransactionState *common, Error **errp)
+static void blockdev_backup_prepare(BlkActionState *common, Error **errp)
 {
     BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
     BlockdevBackup *backup;
@@ -1694,7 +1708,7 @@ static void blockdev_backup_prepare(BlkTransactionState *common, Error **errp)
     state->job = state->bs->job;
 }
 
-static void blockdev_backup_abort(BlkTransactionState *common)
+static void blockdev_backup_abort(BlkActionState *common)
 {
     BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
     BlockDriverState *bs = state->bs;
@@ -1705,7 +1719,7 @@ static void blockdev_backup_abort(BlkTransactionState *common)
     }
 }
 
-static void blockdev_backup_clean(BlkTransactionState *common)
+static void blockdev_backup_clean(BlkActionState *common)
 {
     BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
 
@@ -1715,7 +1729,7 @@ static void blockdev_backup_clean(BlkTransactionState *common)
 }
 
 typedef struct BlockDirtyBitmapState {
-    BlkTransactionState common;
+    BlkActionState common;
     BdrvDirtyBitmap *bitmap;
     BlockDriverState *bs;
     AioContext *aio_context;
@@ -1723,7 +1737,7 @@ typedef struct BlockDirtyBitmapState {
     bool prepared;
 } BlockDirtyBitmapState;
 
-static void block_dirty_bitmap_add_prepare(BlkTransactionState *common,
+static void block_dirty_bitmap_add_prepare(BlkActionState *common,
                                            Error **errp)
 {
     Error *local_err = NULL;
@@ -1744,7 +1758,7 @@ static void block_dirty_bitmap_add_prepare(BlkTransactionState *common,
     }
 }
 
-static void block_dirty_bitmap_add_abort(BlkTransactionState *common)
+static void block_dirty_bitmap_add_abort(BlkActionState *common)
 {
     BlockDirtyBitmapAdd *action;
     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
@@ -1759,7 +1773,7 @@ static void block_dirty_bitmap_add_abort(BlkTransactionState *common)
     }
 }
 
-static void block_dirty_bitmap_clear_prepare(BlkTransactionState *common,
+static void block_dirty_bitmap_clear_prepare(BlkActionState *common,
                                              Error **errp)
 {
     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
@@ -1788,7 +1802,7 @@ static void block_dirty_bitmap_clear_prepare(BlkTransactionState *common,
     /* AioContext is released in .clean() */
 }
 
-static void block_dirty_bitmap_clear_abort(BlkTransactionState *common)
+static void block_dirty_bitmap_clear_abort(BlkActionState *common)
 {
     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
                                              common, common);
@@ -1796,7 +1810,7 @@ static void block_dirty_bitmap_clear_abort(BlkTransactionState *common)
     bdrv_undo_clear_dirty_bitmap(state->bitmap, state->backup);
 }
 
-static void block_dirty_bitmap_clear_commit(BlkTransactionState *common)
+static void block_dirty_bitmap_clear_commit(BlkActionState *common)
 {
     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
                                              common, common);
@@ -1804,7 +1818,7 @@ static void block_dirty_bitmap_clear_commit(BlkTransactionState *common)
     hbitmap_free(state->backup);
 }
 
-static void block_dirty_bitmap_clear_clean(BlkTransactionState *common)
+static void block_dirty_bitmap_clear_clean(BlkActionState *common)
 {
     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
                                              common, common);
@@ -1814,17 +1828,17 @@ static void block_dirty_bitmap_clear_clean(BlkTransactionState *common)
     }
 }
 
-static void abort_prepare(BlkTransactionState *common, Error **errp)
+static void abort_prepare(BlkActionState *common, Error **errp)
 {
     error_setg(errp, "Transaction aborted using Abort action");
 }
 
-static void abort_commit(BlkTransactionState *common)
+static void abort_commit(BlkActionState *common)
 {
     g_assert_not_reached(); /* this action never succeeds */
 }
 
-static const BdrvActionOps actions[] = {
+static const BlkActionOps actions[] = {
     [TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC] = {
         .instance_size = sizeof(ExternalSnapshotState),
         .prepare  = external_snapshot_prepare,
@@ -1844,7 +1858,7 @@ static const BdrvActionOps actions[] = {
         .clean = blockdev_backup_clean,
     },
     [TRANSACTION_ACTION_KIND_ABORT] = {
-        .instance_size = sizeof(BlkTransactionState),
+        .instance_size = sizeof(BlkActionState),
         .prepare = abort_prepare,
         .commit = abort_commit,
     },
@@ -1875,10 +1889,10 @@ static const BdrvActionOps actions[] = {
 void qmp_transaction(TransactionActionList *dev_list, Error **errp)
 {
     TransactionActionList *dev_entry = dev_list;
-    BlkTransactionState *state, *next;
+    BlkActionState *state, *next;
     Error *local_err = NULL;
 
-    QSIMPLEQ_HEAD(snap_bdrv_states, BlkTransactionState) snap_bdrv_states;
+    QSIMPLEQ_HEAD(snap_bdrv_states, BlkActionState) snap_bdrv_states;
     QSIMPLEQ_INIT(&snap_bdrv_states);
 
     /* drain all i/o before any operations */
@@ -1887,7 +1901,7 @@ void qmp_transaction(TransactionActionList *dev_list, Error **errp)
     /* We don't do anything in this loop that commits us to the operations */
     while (NULL != dev_entry) {
         TransactionAction *dev_info = NULL;
-        const BdrvActionOps *ops;
+        const BlkActionOps *ops;
 
         dev_info = dev_entry->value;
         dev_entry = dev_entry->next;
-- 
2.4.3

^ permalink raw reply related	[flat|nested] 29+ messages in thread

* [Qemu-devel] [PATCH v6 04/14] backup: Extract dirty bitmap handling as a separate function
  2015-09-15  6:11 [Qemu-devel] [PATCH v6 00/14] block: incremental backup transactions using BlockJobTxn Fam Zheng
                   ` (2 preceding siblings ...)
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 03/14] block: rename BlkTransactionState and BdrvActionOps Fam Zheng
@ 2015-09-15  6:11 ` Fam Zheng
  2015-09-18 11:02   ` Max Reitz
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 05/14] blockjob: Introduce reference count Fam Zheng
                   ` (9 subsequent siblings)
  13 siblings, 1 reply; 29+ messages in thread
From: Fam Zheng @ 2015-09-15  6:11 UTC (permalink / raw)
  To: qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

This will be reused by the coming new transactional completion code.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
---
 block/backup.c | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/block/backup.c b/block/backup.c
index 965654d..609b199 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -211,6 +211,22 @@ static void backup_iostatus_reset(BlockJob *job)
     bdrv_iostatus_reset(s->target);
 }
 
+static void backup_cleanup_sync_bitmap(BackupBlockJob *job, int ret)
+{
+    BdrvDirtyBitmap *bm;
+    BlockDriverState *bs = job->common.bs;
+
+    if (ret < 0 || block_job_is_cancelled(&job->common)) {
+        /* Merge the successor back into the parent, delete nothing. */
+        bm = bdrv_reclaim_dirty_bitmap(bs, job->sync_bitmap, NULL);
+        assert(bm);
+    } else {
+        /* Everything is fine, delete this bitmap and install the backup. */
+        bm = bdrv_dirty_bitmap_abdicate(bs, job->sync_bitmap, NULL);
+        assert(bm);
+    }
+}
+
 static const BlockJobDriver backup_job_driver = {
     .instance_size  = sizeof(BackupBlockJob),
     .job_type       = BLOCK_JOB_TYPE_BACKUP,
@@ -430,16 +446,7 @@ static void coroutine_fn backup_run(void *opaque)
     qemu_co_rwlock_unlock(&job->flush_rwlock);
 
     if (job->sync_bitmap) {
-        BdrvDirtyBitmap *bm;
-        if (ret < 0 || block_job_is_cancelled(&job->common)) {
-            /* Merge the successor back into the parent, delete nothing. */
-            bm = bdrv_reclaim_dirty_bitmap(bs, job->sync_bitmap, NULL);
-            assert(bm);
-        } else {
-            /* Everything is fine, delete this bitmap and install the backup. */
-            bm = bdrv_dirty_bitmap_abdicate(bs, job->sync_bitmap, NULL);
-            assert(bm);
-        }
+        backup_cleanup_sync_bitmap(job, ret);
     }
     hbitmap_free(job->bitmap);
 
-- 
2.4.3

^ permalink raw reply related	[flat|nested] 29+ messages in thread

* [Qemu-devel] [PATCH v6 05/14] blockjob: Introduce reference count
  2015-09-15  6:11 [Qemu-devel] [PATCH v6 00/14] block: incremental backup transactions using BlockJobTxn Fam Zheng
                   ` (3 preceding siblings ...)
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 04/14] backup: Extract dirty bitmap handling as a separate function Fam Zheng
@ 2015-09-15  6:11 ` Fam Zheng
  2015-09-21 22:19   ` John Snow
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 06/14] blockjob: Add .commit and .abort block job actions Fam Zheng
                   ` (8 subsequent siblings)
  13 siblings, 1 reply; 29+ messages in thread
From: Fam Zheng @ 2015-09-15  6:11 UTC (permalink / raw)
  To: qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

So that block_job_complete_sync can be simplified.

Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block/mirror.c           |  2 +-
 blockjob.c               | 22 ++++++++++++++--------
 include/block/blockjob.h | 18 +++++++++++++++---
 3 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/block/mirror.c b/block/mirror.c
index a258926..3472ad4 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -736,7 +736,7 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target,
     s->dirty_bitmap = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp);
     if (!s->dirty_bitmap) {
         g_free(s->replaces);
-        block_job_release(bs);
+        block_job_unref(&s->common);
         return;
     }
     bdrv_set_enable_write_cache(s->target, true);
diff --git a/blockjob.c b/blockjob.c
index 62bb906..ec12887 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -58,6 +58,7 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
     job->cb            = cb;
     job->opaque        = opaque;
     job->busy          = true;
+    job->refcnt        = 1;
     bs->job = job;
 
     /* Only set speed when necessary to avoid NotSupported error */
@@ -66,7 +67,7 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
 
         block_job_set_speed(job, speed, &local_err);
         if (local_err) {
-            block_job_release(bs);
+            block_job_unref(job);
             error_propagate(errp, local_err);
             return NULL;
         }
@@ -74,14 +75,19 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
     return job;
 }
 
-void block_job_release(BlockDriverState *bs)
+void block_job_ref(BlockJob *job)
 {
-    BlockJob *job = bs->job;
+    ++job->refcnt;
+}
 
-    bs->job = NULL;
-    bdrv_op_unblock_all(bs, job->blocker);
-    error_free(job->blocker);
-    g_free(job);
+void block_job_unref(BlockJob *job)
+{
+    if (--job->refcnt == 0) {
+        job->bs->job = NULL;
+        bdrv_op_unblock_all(job->bs, job->blocker);
+        error_free(job->blocker);
+        g_free(job);
+    }
 }
 
 void block_job_completed(BlockJob *job, int ret)
@@ -90,7 +96,7 @@ void block_job_completed(BlockJob *job, int ret)
 
     assert(bs->job == job);
     job->cb(job->opaque, ret);
-    block_job_release(bs);
+    block_job_unref(job);
 }
 
 void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
diff --git a/include/block/blockjob.h b/include/block/blockjob.h
index dd9d5e6..3e7ad21 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -122,6 +122,9 @@ struct BlockJob {
 
     /** The opaque value that is passed to the completion function.  */
     void *opaque;
+
+    /** Reference count of the block job */
+    int refcnt;
 };
 
 /**
@@ -166,12 +169,21 @@ void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns);
 void block_job_yield(BlockJob *job);
 
 /**
- * block_job_release:
+ * block_job_ref:
  * @bs: The block device.
  *
- * Release job resources when an error occurred or job completed.
+ * Grab a reference to the block job. Should be paired with block_job_unref.
  */
-void block_job_release(BlockDriverState *bs);
+void block_job_ref(BlockJob *job);
+
+/**
+ * block_job_unref:
+ * @bs: The block device.
+ *
+ * Release reference to the block job and release resources if it is the last
+ * reference.
+ */
+void block_job_unref(BlockJob *job);
 
 /**
  * block_job_completed:
-- 
2.4.3

^ permalink raw reply related	[flat|nested] 29+ messages in thread

* [Qemu-devel] [PATCH v6 06/14] blockjob: Add .commit and .abort block job actions
  2015-09-15  6:11 [Qemu-devel] [PATCH v6 00/14] block: incremental backup transactions using BlockJobTxn Fam Zheng
                   ` (4 preceding siblings ...)
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 05/14] blockjob: Introduce reference count Fam Zheng
@ 2015-09-15  6:11 ` Fam Zheng
  2015-09-21 22:29   ` John Snow
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 07/14] blockjob: Add "completed" and "ret" in BlockJob Fam Zheng
                   ` (7 subsequent siblings)
  13 siblings, 1 reply; 29+ messages in thread
From: Fam Zheng @ 2015-09-15  6:11 UTC (permalink / raw)
  To: qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
---
 include/block/blockjob.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/include/block/blockjob.h b/include/block/blockjob.h
index 3e7ad21..a7b497c 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -50,6 +50,24 @@ typedef struct BlockJobDriver {
      * manually.
      */
     void (*complete)(BlockJob *job, Error **errp);
+
+    /**
+     * 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
+     * completion if it is not in a transaction. Skipped if NULL.
+     *
+     * Exactly one of .commit() and .abort() will be called for each job.
+     */
+    void (*commit)(BlockJob *job);
+
+    /**
+     * If the callback is not NULL, it will be invoked when any job in the
+     * same transaction fails; or upon this job's failure (due to error or
+     * cancellation) if it is not in a transaction. Skipped if NULL.
+     *
+     * Exactly one of .commit() and .abort() will be called for each job.
+     */
+    void (*abort)(BlockJob *job);
 } BlockJobDriver;
 
 /**
-- 
2.4.3

^ permalink raw reply related	[flat|nested] 29+ messages in thread

* [Qemu-devel] [PATCH v6 07/14] blockjob: Add "completed" and "ret" in BlockJob
  2015-09-15  6:11 [Qemu-devel] [PATCH v6 00/14] block: incremental backup transactions using BlockJobTxn Fam Zheng
                   ` (5 preceding siblings ...)
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 06/14] blockjob: Add .commit and .abort block job actions Fam Zheng
@ 2015-09-15  6:11 ` Fam Zheng
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 08/14] blockjob: Simplify block_job_finish_sync Fam Zheng
                   ` (6 subsequent siblings)
  13 siblings, 0 replies; 29+ messages in thread
From: Fam Zheng @ 2015-09-15  6:11 UTC (permalink / raw)
  To: qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

They are set when block_job_completed is called.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 blockjob.c               | 3 +++
 include/block/blockjob.h | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/blockjob.c b/blockjob.c
index ec12887..293b62a 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -95,6 +95,9 @@ void block_job_completed(BlockJob *job, int ret)
     BlockDriverState *bs = job->bs;
 
     assert(bs->job == job);
+    assert(!job->completed);
+    job->completed = true;
+    job->ret = ret;
     job->cb(job->opaque, ret);
     block_job_unref(job);
 }
diff --git a/include/block/blockjob.h b/include/block/blockjob.h
index a7b497c..f6e4c86 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -143,6 +143,15 @@ struct BlockJob {
 
     /** Reference count of the block job */
     int refcnt;
+
+    /* True if this job has reported completion by calling block_job_completed.
+     */
+    bool completed;
+
+    /* ret code passed to block_job_completed.
+     */
+    int ret;
+
 };
 
 /**
-- 
2.4.3

^ permalink raw reply related	[flat|nested] 29+ messages in thread

* [Qemu-devel] [PATCH v6 08/14] blockjob: Simplify block_job_finish_sync
  2015-09-15  6:11 [Qemu-devel] [PATCH v6 00/14] block: incremental backup transactions using BlockJobTxn Fam Zheng
                   ` (6 preceding siblings ...)
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 07/14] blockjob: Add "completed" and "ret" in BlockJob Fam Zheng
@ 2015-09-15  6:11 ` Fam Zheng
  2015-09-21 22:50   ` John Snow
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 09/14] block: Add block job transactions Fam Zheng
                   ` (5 subsequent siblings)
  13 siblings, 1 reply; 29+ messages in thread
From: Fam Zheng @ 2015-09-15  6:11 UTC (permalink / raw)
  To: qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

With job->completed and job->ret to replace BlockFinishData.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 blockjob.c | 27 ++++++---------------------
 1 file changed, 6 insertions(+), 21 deletions(-)

diff --git a/blockjob.c b/blockjob.c
index 293b62a..36c18e0 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -185,43 +185,28 @@ struct BlockFinishData {
     int ret;
 };
 
-static void block_job_finish_cb(void *opaque, int ret)
-{
-    struct BlockFinishData *data = opaque;
-
-    data->cancelled = block_job_is_cancelled(data->job);
-    data->ret = ret;
-    data->cb(data->opaque, ret);
-}
-
 static int block_job_finish_sync(BlockJob *job,
                                  void (*finish)(BlockJob *, Error **errp),
                                  Error **errp)
 {
-    struct BlockFinishData data;
     BlockDriverState *bs = job->bs;
     Error *local_err = NULL;
+    int ret;
 
     assert(bs->job == job);
 
-    /* Set up our own callback to store the result and chain to
-     * the original callback.
-     */
-    data.job = job;
-    data.cb = job->cb;
-    data.opaque = job->opaque;
-    data.ret = -EINPROGRESS;
-    job->cb = block_job_finish_cb;
-    job->opaque = &data;
+    block_job_ref(job);
     finish(job, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         return -EBUSY;
     }
-    while (data.ret == -EINPROGRESS) {
+    while (!job->completed) {
         aio_poll(bdrv_get_aio_context(bs), true);
     }
-    return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
+    ret = (job->cancelled && job->ret == 0) ? -ECANCELED : job->ret;
+    block_job_unref(job);
+    return ret;
 }
 
 /* A wrapper around block_job_cancel() taking an Error ** parameter so it may be
-- 
2.4.3

^ permalink raw reply related	[flat|nested] 29+ messages in thread

* [Qemu-devel] [PATCH v6 09/14] block: Add block job transactions
  2015-09-15  6:11 [Qemu-devel] [PATCH v6 00/14] block: incremental backup transactions using BlockJobTxn Fam Zheng
                   ` (7 preceding siblings ...)
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 08/14] blockjob: Simplify block_job_finish_sync Fam Zheng
@ 2015-09-15  6:11 ` Fam Zheng
  2015-09-18 11:16   ` Max Reitz
  2015-09-21 23:23   ` John Snow
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 10/14] blockdev: make BlockJobTxn available to qmp 'transaction' Fam Zheng
                   ` (4 subsequent siblings)
  13 siblings, 2 replies; 29+ messages in thread
From: Fam Zheng @ 2015-09-15  6:11 UTC (permalink / raw)
  To: qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

Sometimes block jobs must execute as a transaction group.  Finishing
jobs wait until all other jobs are ready to complete successfully.
Failure or cancellation of one job cancels the other jobs in the group.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
[Rewrite the implementation which is now contained in block_job_completed.
--Fam]
Signed-off-by: Fam Zheng <famz@redhat.com>
---
 blockjob.c               | 135 ++++++++++++++++++++++++++++++++++++++++++++++-
 include/block/block.h    |   1 +
 include/block/blockjob.h |  38 +++++++++++++
 3 files changed, 172 insertions(+), 2 deletions(-)

diff --git a/blockjob.c b/blockjob.c
index 36c18e0..91e8d3c 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -36,6 +36,19 @@
 #include "qemu/timer.h"
 #include "qapi-event.h"
 
+/* Transactional group of block jobs */
+struct BlockJobTxn {
+
+    /* Is this txn being cancelled? */
+    bool aborting;
+
+    /* List of jobs */
+    QLIST_HEAD(, BlockJob) jobs;
+
+    /* Reference count */
+    int refcnt;
+};
+
 void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
                        int64_t speed, BlockCompletionFunc *cb,
                        void *opaque, Error **errp)
@@ -90,6 +103,86 @@ void block_job_unref(BlockJob *job)
     }
 }
 
+static void block_job_completed_single(BlockJob *job)
+{
+    if (!job->ret) {
+        if (job->driver->commit) {
+            job->driver->commit(job);
+        }
+    } else {
+        if (job->driver->abort) {
+            job->driver->abort(job);
+        }
+    }
+    job->cb(job->opaque, job->ret);
+    if (job->txn) {
+        block_job_txn_unref(job->txn);
+    }
+    block_job_unref(job);
+}
+
+static void block_job_completed_txn_abort(BlockJob *job)
+{
+    AioContext *ctx;
+    BlockJobTxn *txn = job->txn;
+    BlockJob *other_job, *next;
+
+    if (txn->aborting) {
+        /*
+         * We are cancelled by another job, which will handle everything.
+         */
+        return;
+    }
+    txn->aborting = true;
+    /* We are the first failed job. Cancel other jobs. */
+    QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
+        ctx = bdrv_get_aio_context(other_job->bs);
+        aio_context_acquire(ctx);
+    }
+    QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
+        if (other_job == job || other_job->completed) {
+            /* Other jobs are "effectively" cancelled by us, set the status for
+             * them; this job, however, may or may not be cancelled, depending
+             * on the caller, so leave it. */
+            if (other_job != job) {
+                other_job->cancelled = true;
+            }
+            continue;
+        }
+        block_job_cancel_sync(other_job);
+        assert(other_job->completed);
+    }
+    QLIST_FOREACH_SAFE(other_job, &txn->jobs, txn_list, next) {
+        ctx = bdrv_get_aio_context(other_job->bs);
+        block_job_completed_single(other_job);
+        aio_context_release(ctx);
+    }
+}
+
+static void block_job_completed_txn_success(BlockJob *job)
+{
+    AioContext *ctx;
+    BlockJobTxn *txn = job->txn;
+    BlockJob *other_job, *next;
+    /*
+     * Successful completion, see if there are other running jobs in this
+     * txn.
+     */
+    QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
+        if (!other_job->completed) {
+            return;
+        }
+    }
+    /* We are the last completed job, commit the transaction. */
+    QLIST_FOREACH_SAFE(other_job, &txn->jobs, txn_list, next) {
+        ctx = bdrv_get_aio_context(other_job->bs);
+        aio_context_acquire(ctx);
+        assert(other_job->ret == 0);
+        block_job_completed_single(other_job);
+        aio_context_release(ctx);
+    }
+}
+
 void block_job_completed(BlockJob *job, int ret)
 {
     BlockDriverState *bs = job->bs;
@@ -98,8 +191,13 @@ void block_job_completed(BlockJob *job, int ret)
     assert(!job->completed);
     job->completed = true;
     job->ret = ret;
-    job->cb(job->opaque, ret);
-    block_job_unref(job);
+    if (!job->txn) {
+        block_job_completed_single(job);
+    } else if (ret < 0 || block_job_is_cancelled(job)) {
+        block_job_completed_txn_abort(job);
+    } else {
+        block_job_completed_txn_success(job);
+    }
 }
 
 void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
@@ -398,3 +496,36 @@ void block_job_defer_to_main_loop(BlockJob *job,
 
     qemu_bh_schedule(data->bh);
 }
+
+BlockJobTxn *block_job_txn_new(void)
+{
+    BlockJobTxn *txn = g_new0(BlockJobTxn, 1);
+    QLIST_INIT(&txn->jobs);
+    txn->refcnt = 1;
+    return txn;
+}
+
+static void block_job_txn_ref(BlockJobTxn *txn)
+{
+    txn->refcnt++;
+}
+
+void block_job_txn_unref(BlockJobTxn *txn)
+{
+    if (--txn->refcnt == 0) {
+        g_free(txn);
+    }
+}
+
+void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job)
+{
+    if (!txn) {
+        return;
+    }
+
+    assert(!job->txn);
+    job->txn = txn;
+
+    QLIST_INSERT_HEAD(&txn->jobs, job, txn_list);
+    block_job_txn_ref(txn);
+}
diff --git a/include/block/block.h b/include/block/block.h
index f70bec4..514b233 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -14,6 +14,7 @@ typedef struct BlockDriver BlockDriver;
 typedef struct BlockJob BlockJob;
 typedef struct BdrvChild BdrvChild;
 typedef struct BdrvChildRole BdrvChildRole;
+typedef struct BlockJobTxn BlockJobTxn;
 
 typedef struct BlockDriverInfo {
     /* in bytes, 0 if irrelevant */
diff --git a/include/block/blockjob.h b/include/block/blockjob.h
index f6e4c86..4999682 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -152,6 +152,9 @@ struct BlockJob {
      */
     int ret;
 
+    /** Non-NULL if this job is part of a transaction */
+    BlockJobTxn *txn;
+    QLIST_ENTRY(BlockJob) txn_list;
 };
 
 /**
@@ -395,4 +398,39 @@ void block_job_defer_to_main_loop(BlockJob *job,
                                   BlockJobDeferToMainLoopFn *fn,
                                   void *opaque);
 
+/**
+ * block_job_txn_new:
+ *
+ * Allocate and return a new block job transaction.  Jobs can be added to the
+ * transaction using block_job_txn_add_job().
+ *
+ * The transaction is automatically freed when the last job completes or is
+ * cancelled.
+ *
+ * All jobs in the transaction either complete successfully or fail/cancel as a
+ * group.  Jobs wait for each other before completing.  Cancelling one job
+ * cancels all jobs in the transaction.
+ */
+BlockJobTxn *block_job_txn_new(void);
+
+/**
+ * block_job_txn_unref:
+ *
+ * Release a reference that was previously acquired with block_job_txn_add_job
+ * or block_job_txn_new. If it's the last reference to the object, it will be
+ * freed.
+ */
+void block_job_txn_unref(BlockJobTxn *txn);
+
+/**
+ * block_job_txn_add_job:
+ * @txn: The transaction (may be NULL)
+ * @job: Job to add to the transaction
+ *
+ * Add @job to the transaction.  The @job must not already be in a transaction.
+ * The block job driver must call block_job_txn_unref() in the end to release
+ * the reference that is automatically grabbed here.
+ */
+void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job);
+
 #endif
-- 
2.4.3

^ permalink raw reply related	[flat|nested] 29+ messages in thread

* [Qemu-devel] [PATCH v6 10/14] blockdev: make BlockJobTxn available to qmp 'transaction'
  2015-09-15  6:11 [Qemu-devel] [PATCH v6 00/14] block: incremental backup transactions using BlockJobTxn Fam Zheng
                   ` (8 preceding siblings ...)
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 09/14] block: Add block job transactions Fam Zheng
@ 2015-09-15  6:11 ` Fam Zheng
  2015-09-18 11:20   ` Max Reitz
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 11/14] block/backup: support block job transactions Fam Zheng
                   ` (3 subsequent siblings)
  13 siblings, 1 reply; 29+ messages in thread
From: Fam Zheng @ 2015-09-15  6:11 UTC (permalink / raw)
  To: qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

From: Stefan Hajnoczi <stefanha@redhat.com>

Provide a BlockJobTxn to actions executed in a qmp 'transaction'
command.  This allows actions to make their block jobs either complete
as a group or fail/cancel together.

The next patch adds the first user.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
---
 blockdev.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/blockdev.c b/blockdev.c
index 4ebded8..93a9eef 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1285,6 +1285,7 @@ typedef struct BlkActionOps {
 struct BlkActionState {
     TransactionAction *action;
     const BlkActionOps *ops;
+    BlockJobTxn *block_job_txn;
     QSIMPLEQ_ENTRY(BlkActionState) entry;
 };
 
@@ -1889,12 +1890,15 @@ static const BlkActionOps actions[] = {
 void qmp_transaction(TransactionActionList *dev_list, Error **errp)
 {
     TransactionActionList *dev_entry = dev_list;
+    BlockJobTxn *block_job_txn;
     BlkActionState *state, *next;
     Error *local_err = NULL;
 
     QSIMPLEQ_HEAD(snap_bdrv_states, BlkActionState) snap_bdrv_states;
     QSIMPLEQ_INIT(&snap_bdrv_states);
 
+    block_job_txn = block_job_txn_new();
+
     /* drain all i/o before any operations */
     bdrv_drain_all();
 
@@ -1914,6 +1918,7 @@ void qmp_transaction(TransactionActionList *dev_list, Error **errp)
         state = g_malloc0(ops->instance_size);
         state->ops = ops;
         state->action = dev_info;
+        state->block_job_txn = block_job_txn;
         QSIMPLEQ_INSERT_TAIL(&snap_bdrv_states, state, entry);
 
         state->ops->prepare(state, &local_err);
@@ -1946,6 +1951,7 @@ exit:
         }
         g_free(state);
     }
+    block_job_txn_unref(block_job_txn);
 }
 
 
-- 
2.4.3

^ permalink raw reply related	[flat|nested] 29+ messages in thread

* [Qemu-devel] [PATCH v6 11/14] block/backup: support block job transactions
  2015-09-15  6:11 [Qemu-devel] [PATCH v6 00/14] block: incremental backup transactions using BlockJobTxn Fam Zheng
                   ` (9 preceding siblings ...)
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 10/14] blockdev: make BlockJobTxn available to qmp 'transaction' Fam Zheng
@ 2015-09-15  6:11 ` Fam Zheng
  2015-09-15 14:43   ` Eric Blake
  2015-09-18 11:40   ` Max Reitz
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 12/14] iotests: 124 - transactional failure test Fam Zheng
                   ` (2 subsequent siblings)
  13 siblings, 2 replies; 29+ messages in thread
From: Fam Zheng @ 2015-09-15  6:11 UTC (permalink / raw)
  To: qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

From: Stefan Hajnoczi <stefanha@redhat.com>

Join the transaction when the 'transactional-cancel' QMP argument is
true.

This ensures that the sync bitmap is not thrown away if another block
job in the transaction is cancelled or fails.  This is critical so
incremental backup with multiple disks can be retried in case of
cancellation/failure.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block/backup.c            |  25 +++++++--
 blockdev.c                | 132 +++++++++++++++++++++++++++++++++++-----------
 include/block/block_int.h |   3 +-
 qapi-schema.json          |   4 +-
 qapi/block-core.json      |  29 ++++++++++
 5 files changed, 155 insertions(+), 38 deletions(-)

diff --git a/block/backup.c b/block/backup.c
index 609b199..5880116 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -227,11 +227,29 @@ static void backup_cleanup_sync_bitmap(BackupBlockJob *job, int ret)
     }
 }
 
+static void backup_commit(BlockJob *job)
+{
+    BackupBlockJob *s = container_of(job, BackupBlockJob, common);
+    if (s->sync_bitmap) {
+        backup_cleanup_sync_bitmap(s, 0);
+    }
+}
+
+static void backup_abort(BlockJob *job)
+{
+    BackupBlockJob *s = container_of(job, BackupBlockJob, common);
+    if (s->sync_bitmap) {
+        backup_cleanup_sync_bitmap(s, -1);
+    }
+}
+
 static const BlockJobDriver backup_job_driver = {
     .instance_size  = sizeof(BackupBlockJob),
     .job_type       = BLOCK_JOB_TYPE_BACKUP,
     .set_speed      = backup_set_speed,
     .iostatus_reset = backup_iostatus_reset,
+    .commit         = backup_commit,
+    .abort          = backup_abort,
 };
 
 static BlockErrorAction backup_error_action(BackupBlockJob *job,
@@ -444,10 +462,6 @@ static void coroutine_fn backup_run(void *opaque)
     /* wait until pending backup_do_cow() calls have completed */
     qemu_co_rwlock_wrlock(&job->flush_rwlock);
     qemu_co_rwlock_unlock(&job->flush_rwlock);
-
-    if (job->sync_bitmap) {
-        backup_cleanup_sync_bitmap(job, ret);
-    }
     hbitmap_free(job->bitmap);
 
     bdrv_iostatus_disable(target);
@@ -464,7 +478,7 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
                   BlockdevOnError on_source_error,
                   BlockdevOnError on_target_error,
                   BlockCompletionFunc *cb, void *opaque,
-                  Error **errp)
+                  BlockJobTxn *txn, Error **errp)
 {
     int64_t len;
 
@@ -546,6 +560,7 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
                        sync_bitmap : NULL;
     job->common.len = len;
     job->common.co = qemu_coroutine_create(backup_run);
+    block_job_txn_add_job(txn, &job->common);
     qemu_coroutine_enter(job->common.co, job);
     return;
 
diff --git a/blockdev.c b/blockdev.c
index 93a9eef..79207c8 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1592,16 +1592,31 @@ typedef struct DriveBackupState {
     BlockJob *job;
 } DriveBackupState;
 
+static void do_drive_backup(const char *device, const char *target,
+                            bool has_format, const char *format,
+                            enum MirrorSyncMode sync,
+                            bool has_mode, enum NewImageMode mode,
+                            bool has_speed, int64_t speed,
+                            bool has_bitmap, const char *bitmap,
+                            bool has_on_source_error,
+                            BlockdevOnError on_source_error,
+                            bool has_on_target_error,
+                            BlockdevOnError on_target_error,
+                            BlockJobTxn *txn, Error **errp);
+
 static void drive_backup_prepare(BlkActionState *common, Error **errp)
 {
     DriveBackupState *state = DO_UPCAST(DriveBackupState, common, common);
     BlockDriverState *bs;
     BlockBackend *blk;
+    DriveBackupTxn *backup_txn;
     DriveBackup *backup;
+    BlockJobTxn *txn = NULL;
     Error *local_err = NULL;
 
     assert(common->action->kind == TRANSACTION_ACTION_KIND_DRIVE_BACKUP);
-    backup = common->action->drive_backup;
+    backup_txn = common->action->drive_backup;
+    backup = backup_txn->base;
 
     blk = blk_by_name(backup->device);
     if (!blk) {
@@ -1615,15 +1630,20 @@ static void drive_backup_prepare(BlkActionState *common, Error **errp)
     state->aio_context = bdrv_get_aio_context(bs);
     aio_context_acquire(state->aio_context);
 
-    qmp_drive_backup(backup->device, backup->target,
-                     backup->has_format, backup->format,
-                     backup->sync,
-                     backup->has_mode, backup->mode,
-                     backup->has_speed, backup->speed,
-                     backup->has_bitmap, backup->bitmap,
-                     backup->has_on_source_error, backup->on_source_error,
-                     backup->has_on_target_error, backup->on_target_error,
-                     &local_err);
+    if (backup_txn->has_transactional_cancel &&
+        backup_txn->transactional_cancel) {
+        txn = common->block_job_txn;
+    }
+
+    do_drive_backup(backup->device, backup->target,
+                    backup->has_format, backup->format,
+                    backup->sync,
+                    backup->has_mode, backup->mode,
+                    backup->has_speed, backup->speed,
+                    backup->has_bitmap, backup->bitmap,
+                    backup->has_on_source_error, backup->on_source_error,
+                    backup->has_on_target_error, backup->on_target_error,
+                    txn, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         return;
@@ -1660,16 +1680,28 @@ typedef struct BlockdevBackupState {
     AioContext *aio_context;
 } BlockdevBackupState;
 
+static void do_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,
+                               BlockJobTxn *txn, Error **errp);
+
 static void blockdev_backup_prepare(BlkActionState *common, Error **errp)
 {
     BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);
+    BlockdevBackupTxn *backup_txn;
     BlockdevBackup *backup;
     BlockDriverState *bs, *target;
     BlockBackend *blk;
+    BlockJobTxn *txn = NULL;
     Error *local_err = NULL;
 
     assert(common->action->kind == TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP);
-    backup = common->action->blockdev_backup;
+    backup_txn = common->action->blockdev_backup;
+    backup = backup_txn->base;
 
     blk = blk_by_name(backup->device);
     if (!blk) {
@@ -1694,12 +1726,17 @@ static void blockdev_backup_prepare(BlkActionState *common, Error **errp)
     }
     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 (backup_txn->has_transactional_cancel &&
+        backup_txn->transactional_cancel) {
+        txn = common->block_job_txn;
+    }
+
+    do_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,
+                       txn, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         return;
@@ -2582,15 +2619,17 @@ out:
     aio_context_release(aio_context);
 }
 
-void qmp_drive_backup(const char *device, const char *target,
-                      bool has_format, const char *format,
-                      enum MirrorSyncMode sync,
-                      bool has_mode, enum NewImageMode mode,
-                      bool has_speed, int64_t speed,
-                      bool has_bitmap, const char *bitmap,
-                      bool has_on_source_error, BlockdevOnError on_source_error,
-                      bool has_on_target_error, BlockdevOnError on_target_error,
-                      Error **errp)
+static void do_drive_backup(const char *device, const char *target,
+                            bool has_format, const char *format,
+                            enum MirrorSyncMode sync,
+                            bool has_mode, enum NewImageMode mode,
+                            bool has_speed, int64_t speed,
+                            bool has_bitmap, const char *bitmap,
+                            bool has_on_source_error,
+                            BlockdevOnError on_source_error,
+                            bool has_on_target_error,
+                            BlockdevOnError on_target_error,
+                            BlockJobTxn *txn, Error **errp)
 {
     BlockBackend *blk;
     BlockDriverState *bs;
@@ -2707,7 +2746,7 @@ void qmp_drive_backup(const char *device, const char *target,
 
     backup_start(bs, target_bs, speed, sync, bmap,
                  on_source_error, on_target_error,
-                 block_job_cb, bs, &local_err);
+                 block_job_cb, bs, txn, &local_err);
     if (local_err != NULL) {
         bdrv_unref(target_bs);
         error_propagate(errp, local_err);
@@ -2718,19 +2757,37 @@ out:
     aio_context_release(aio_context);
 }
 
+void qmp_drive_backup(const char *device, const char *target,
+                      bool has_format, const char *format,
+                      enum MirrorSyncMode sync,
+                      bool has_mode, enum NewImageMode mode,
+                      bool has_speed, int64_t speed,
+                      bool has_bitmap, const char *bitmap,
+                      bool has_on_source_error, BlockdevOnError on_source_error,
+                      bool has_on_target_error, BlockdevOnError on_target_error,
+                      Error **errp)
+{
+    return do_drive_backup(device, target, has_format, format, sync,
+                           has_mode, mode, has_speed, speed,
+                           has_bitmap, bitmap,
+                           has_on_source_error, on_source_error,
+                           has_on_target_error, on_target_error,
+                           NULL, errp);
+}
+
 BlockDeviceInfoList *qmp_query_named_block_nodes(Error **errp)
 {
     return bdrv_named_nodes_list(errp);
 }
 
-void qmp_blockdev_backup(const char *device, const char *target,
+void do_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)
+                         BlockJobTxn *txn, Error **errp)
 {
     BlockBackend *blk;
     BlockDriverState *bs;
@@ -2768,7 +2825,7 @@ void qmp_blockdev_backup(const char *device, const char *target,
     bdrv_ref(target_bs);
     bdrv_set_aio_context(target_bs, aio_context);
     backup_start(bs, target_bs, speed, sync, NULL, on_source_error,
-                 on_target_error, block_job_cb, bs, &local_err);
+                 on_target_error, block_job_cb, bs, txn, &local_err);
     if (local_err != NULL) {
         bdrv_unref(target_bs);
         error_propagate(errp, local_err);
@@ -2777,6 +2834,21 @@ out:
     aio_context_release(aio_context);
 }
 
+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)
+{
+    do_blockdev_backup(device, target, sync, has_speed, speed,
+                       has_on_source_error, on_source_error,
+                       has_on_target_error, on_target_error,
+                       NULL, errp);
+}
+
 void qmp_drive_mirror(const char *device, const char *target,
                       bool has_format, const char *format,
                       bool has_node_name, const char *node_name,
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 281d790..6fd07a2 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -643,6 +643,7 @@ void mirror_start(BlockDriverState *bs, BlockDriverState *target,
  * @on_target_error: The action to take upon error writing to the target.
  * @cb: Completion function for the job.
  * @opaque: Opaque pointer value passed to @cb.
+ * @txn: Transaction that this job is part of (may be NULL).
  *
  * Start a backup operation on @bs.  Clusters in @bs are written to @target
  * until the job is cancelled or manually completed.
@@ -653,7 +654,7 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target,
                   BlockdevOnError on_source_error,
                   BlockdevOnError on_target_error,
                   BlockCompletionFunc *cb, void *opaque,
-                  Error **errp);
+                  BlockJobTxn *txn, Error **errp);
 
 void blk_dev_change_media_cb(BlockBackend *blk, bool load);
 bool blk_dev_has_removable_media(BlockBackend *blk);
diff --git a/qapi-schema.json b/qapi-schema.json
index 46d464f..b872458 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1499,8 +1499,8 @@
 { 'union': 'TransactionAction',
   'data': {
        'blockdev-snapshot-sync': 'BlockdevSnapshot',
-       'drive-backup': 'DriveBackup',
-       'blockdev-backup': 'BlockdevBackup',
+       'drive-backup': 'DriveBackupTxn',
+       'blockdev-backup': 'BlockdevBackupTxn',
        'abort': 'Abort',
        'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal',
        'block-dirty-bitmap-add': 'BlockDirtyBitmapAdd',
diff --git a/qapi/block-core.json b/qapi/block-core.json
index bb2189e..c57f9a0 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -736,6 +736,11 @@
 #                   default 'report' (no limitations, since this applies to
 #                   a different block device than @device).
 #
+# @transactional-cancel: #optional whether failure or cancellation of other
+#                        block jobs with @transactional-cancel true in the same
+#                        transaction causes the whole group to cancel.
+#                        (Since 2.5)
+#
 # 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.
@@ -750,6 +755,18 @@
             '*on-target-error': 'BlockdevOnError' } }
 
 ##
+# @DriveBackupTxn
+#
+# @transactional-cancel: #optional whether failure or cancellation of other
+#                        block jobs with @transactional-cancel true in the same
+#                        transaction causes the whole group to cancel.
+#
+# Since: 2.5
+##
+{ 'struct': 'DriveBackupTxn', 'base': 'DriveBackup',
+  'data': {'*transactional-cancel': 'bool' } }
+
+##
 # @BlockdevBackup
 #
 # @device: the name of the device which should be copied.
@@ -785,6 +802,18 @@
             '*on-target-error': 'BlockdevOnError' } }
 
 ##
+# @BlockdevBackupTxn
+#
+# @transactional-cancel: #optional whether failure or cancellation of other
+#                        block jobs with @transactional-cancel true in the same
+#                        transaction causes the whole group to cancel.
+#
+# Since: 2.5
+##
+{ 'struct': 'BlockdevBackupTxn', 'base': 'BlockdevBackup',
+  'data': {'*transactional-cancel': 'bool' } }
+
+##
 # @blockdev-snapshot-sync
 #
 # Generates a synchronous snapshot of a block device.
-- 
2.4.3

^ permalink raw reply related	[flat|nested] 29+ messages in thread

* [Qemu-devel] [PATCH v6 12/14] iotests: 124 - transactional failure test
  2015-09-15  6:11 [Qemu-devel] [PATCH v6 00/14] block: incremental backup transactions using BlockJobTxn Fam Zheng
                   ` (10 preceding siblings ...)
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 11/14] block/backup: support block job transactions Fam Zheng
@ 2015-09-15  6:11 ` Fam Zheng
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 13/14] qmp-commands.hx: Update the supported 'transaction' operations Fam Zheng
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 14/14] tests: add BlockJobTxn unit test Fam Zheng
  13 siblings, 0 replies; 29+ messages in thread
From: Fam Zheng @ 2015-09-15  6:11 UTC (permalink / raw)
  To: qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

From: John Snow <jsnow@redhat.com>

Use a transaction to request an incremental backup across two drives.
Coerce one of the jobs to fail, and then re-run the transaction.

Verify that no bitmap data was lost due to the partial transaction
failure.

To support the 'transactional-cancel' QMP argument name it's necessary
for transaction_action() to convert underscores in Python argument names
to hyphens for QMP argument names.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
---
 tests/qemu-iotests/124     | 130 ++++++++++++++++++++++++++++++++++++++++++++-
 tests/qemu-iotests/124.out |   4 +-
 2 files changed, 130 insertions(+), 4 deletions(-)

diff --git a/tests/qemu-iotests/124 b/tests/qemu-iotests/124
index 9c1977e..33d00ef 100644
--- a/tests/qemu-iotests/124
+++ b/tests/qemu-iotests/124
@@ -39,7 +39,7 @@ def try_remove(img):
 def transaction_action(action, **kwargs):
     return {
         'type': action,
-        'data': kwargs
+        'data': dict((k.replace('_', '-'), v) for k, v in kwargs.iteritems())
     }
 
 
@@ -139,9 +139,12 @@ class TestIncrementalBackup(iotests.QMPTestCase):
     def do_qmp_backup(self, error='Input/output error', **kwargs):
         res = self.vm.qmp('drive-backup', **kwargs)
         self.assert_qmp(res, 'return', {})
+        return self.wait_qmp_backup(kwargs['device'], error)
 
+
+    def wait_qmp_backup(self, device, error='Input/output error'):
         event = self.vm.event_wait(name="BLOCK_JOB_COMPLETED",
-                                   match={'data': {'device': kwargs['device']}})
+                                   match={'data': {'device': device}})
         self.assertNotEqual(event, None)
 
         try:
@@ -156,6 +159,12 @@ class TestIncrementalBackup(iotests.QMPTestCase):
             return False
 
 
+    def wait_qmp_backup_cancelled(self, device):
+        event = self.vm.event_wait(name='BLOCK_JOB_CANCELLED',
+                                   match={'data': {'device': device}})
+        self.assertNotEqual(event, None)
+
+
     def create_anchor_backup(self, drive=None):
         if drive is None:
             drive = self.drives[-1]
@@ -375,6 +384,123 @@ class TestIncrementalBackup(iotests.QMPTestCase):
         self.check_backups()
 
 
+    def test_transaction_failure(self):
+        '''Test: Verify backups made from a transaction that partially fails.
+
+        Add a second drive with its own unique pattern, and add a bitmap to each
+        drive. Use blkdebug to interfere with the backup on just one drive and
+        attempt to create a coherent incremental backup across both drives.
+
+        verify a failure in one but not both, then delete the failed stubs and
+        re-run the same transaction.
+
+        verify that both incrementals are created successfully.
+        '''
+
+        # Create a second drive, with pattern:
+        drive1 = self.add_node('drive1')
+        self.img_create(drive1['file'], drive1['fmt'])
+        io_write_patterns(drive1['file'], (('0x14', 0, 512),
+                                           ('0x5d', '1M', '32k'),
+                                           ('0xcd', '32M', '124k')))
+
+        # Create a blkdebug interface to this img as 'drive1'
+        result = self.vm.qmp('blockdev-add', options={
+            'id': drive1['id'],
+            'driver': drive1['fmt'],
+            'file': {
+                'driver': 'blkdebug',
+                'image': {
+                    'driver': 'file',
+                    'filename': drive1['file']
+                },
+                'set-state': [{
+                    'event': 'flush_to_disk',
+                    'state': 1,
+                    'new_state': 2
+                }],
+                'inject-error': [{
+                    'event': 'read_aio',
+                    'errno': 5,
+                    'state': 2,
+                    'immediately': False,
+                    'once': True
+                }],
+            }
+        })
+        self.assert_qmp(result, 'return', {})
+
+        # Create bitmaps and full backups for both drives
+        drive0 = self.drives[0]
+        dr0bm0 = self.add_bitmap('bitmap0', drive0)
+        dr1bm0 = self.add_bitmap('bitmap0', drive1)
+        self.create_anchor_backup(drive0)
+        self.create_anchor_backup(drive1)
+        self.assert_no_active_block_jobs()
+        self.assertFalse(self.vm.get_qmp_events(wait=False))
+
+        # Emulate some writes
+        self.hmp_io_writes(drive0['id'], (('0xab', 0, 512),
+                                          ('0xfe', '16M', '256k'),
+                                          ('0x64', '32736k', '64k')))
+        self.hmp_io_writes(drive1['id'], (('0xba', 0, 512),
+                                          ('0xef', '16M', '256k'),
+                                          ('0x46', '32736k', '64k')))
+
+        # Create incremental backup targets
+        target0 = self.prepare_backup(dr0bm0)
+        target1 = self.prepare_backup(dr1bm0)
+
+        # Ask for a new incremental backup per-each drive,
+        # expecting drive1's backup to fail:
+        transaction = [
+            transaction_drive_backup(drive0['id'], target0, sync='incremental',
+                                     format=drive0['fmt'], mode='existing',
+                                     bitmap=dr0bm0.name,
+                                     transactional_cancel=True),
+            transaction_drive_backup(drive1['id'], target1, sync='incremental',
+                                     format=drive1['fmt'], mode='existing',
+                                     bitmap=dr1bm0.name,
+                                     transactional_cancel=True),
+        ]
+        result = self.vm.qmp('transaction', actions=transaction)
+        self.assert_qmp(result, 'return', {})
+
+        # Observe that drive0's backup is cancelled and drive1 completes with
+        # an error.
+        self.wait_qmp_backup_cancelled(drive0['id'])
+        self.assertFalse(self.wait_qmp_backup(drive1['id']))
+        error = self.vm.event_wait('BLOCK_JOB_ERROR')
+        self.assert_qmp(error, 'data', {'device': drive1['id'],
+                                        'action': 'report',
+                                        'operation': 'read'})
+        self.assertFalse(self.vm.get_qmp_events(wait=False))
+        self.assert_no_active_block_jobs()
+
+        # Delete drive0's successful target and eliminate our record of the
+        # unsuccessful drive1 target. Then re-run the same transaction.
+        dr0bm0.del_target()
+        dr1bm0.del_target()
+        target0 = self.prepare_backup(dr0bm0)
+        target1 = self.prepare_backup(dr1bm0)
+
+        # Re-run the exact same transaction.
+        result = self.vm.qmp('transaction', actions=transaction)
+        self.assert_qmp(result, 'return', {})
+
+        # Both should complete successfully this time.
+        self.assertTrue(self.wait_qmp_backup(drive0['id']))
+        self.assertTrue(self.wait_qmp_backup(drive1['id']))
+        self.make_reference_backup(dr0bm0)
+        self.make_reference_backup(dr1bm0)
+        self.assertFalse(self.vm.get_qmp_events(wait=False))
+        self.assert_no_active_block_jobs()
+
+        # And the images should of course validate.
+        self.vm.shutdown()
+        self.check_backups()
+
+
     def test_sync_dirty_bitmap_missing(self):
         self.assert_no_active_block_jobs()
         self.files.append(self.err_img)
diff --git a/tests/qemu-iotests/124.out b/tests/qemu-iotests/124.out
index 594c16f..dae404e 100644
--- a/tests/qemu-iotests/124.out
+++ b/tests/qemu-iotests/124.out
@@ -1,5 +1,5 @@
-........
+.........
 ----------------------------------------------------------------------
-Ran 8 tests
+Ran 9 tests
 
 OK
-- 
2.4.3

^ permalink raw reply related	[flat|nested] 29+ messages in thread

* [Qemu-devel] [PATCH v6 13/14] qmp-commands.hx: Update the supported 'transaction' operations
  2015-09-15  6:11 [Qemu-devel] [PATCH v6 00/14] block: incremental backup transactions using BlockJobTxn Fam Zheng
                   ` (11 preceding siblings ...)
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 12/14] iotests: 124 - transactional failure test Fam Zheng
@ 2015-09-15  6:11 ` Fam Zheng
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 14/14] tests: add BlockJobTxn unit test Fam Zheng
  13 siblings, 0 replies; 29+ messages in thread
From: Fam Zheng @ 2015-09-15  6:11 UTC (permalink / raw)
  To: qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

From: Kashyap Chamarthy <kchamart@redhat.com>

Although the canonical source of reference for QMP commands is
qapi-schema.json, for consistency's sake, update qmp-commands.hx to
state the list of supported transactionable operations, namely:

    drive-backup
    blockdev-backup
    blockdev-snapshot-internal-sync
    abort
    block-dirty-bitmap-add
    block-dirty-bitmap-clear

Signed-off-by: Kashyap Chamarthy <kchamart@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
---
 qmp-commands.hx | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/qmp-commands.hx b/qmp-commands.hx
index 9848fd8..4df59df 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -1263,11 +1263,22 @@ SQMP
 transaction
 -----------
 
-Atomically operate on one or more block devices.  The only supported operations
-for now are drive-backup, internal and external snapshotting.  A list of
-dictionaries is accepted, that contains the actions to be performed.
-If there is any failure performing any of the operations, all operations
-for the group are abandoned.
+Atomically operate on one or more block devices.  Operations that are
+currently supported:
+
+    - drive-backup
+    - blockdev-backup
+    - blockdev-snapshot-sync
+    - blockdev-snapshot-internal-sync
+    - abort
+    - block-dirty-bitmap-add
+    - block-dirty-bitmap-clear
+
+Refer to the qemu/qapi-schema.json file for minimum required QEMU
+versions for these operations.  A list of dictionaries is accepted,
+that contains the actions to be performed.  If there is any failure
+performing any of the operations, all operations for the group are
+abandoned.
 
 For external snapshots, the dictionary contains the device, the file to use for
 the new snapshot, and the format.  The default format, if not specified, is
-- 
2.4.3

^ permalink raw reply related	[flat|nested] 29+ messages in thread

* [Qemu-devel] [PATCH v6 14/14] tests: add BlockJobTxn unit test
  2015-09-15  6:11 [Qemu-devel] [PATCH v6 00/14] block: incremental backup transactions using BlockJobTxn Fam Zheng
                   ` (12 preceding siblings ...)
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 13/14] qmp-commands.hx: Update the supported 'transaction' operations Fam Zheng
@ 2015-09-15  6:11 ` Fam Zheng
  2015-09-18 11:45   ` Max Reitz
  13 siblings, 1 reply; 29+ messages in thread
From: Fam Zheng @ 2015-09-15  6:11 UTC (permalink / raw)
  To: qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

From: Stefan Hajnoczi <stefanha@redhat.com>

The BlockJobTxn unit test verifies that both single jobs and pairs of
jobs behave as a transaction group.  Either all jobs complete
successfully or the group is cancelled.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 tests/Makefile            |   3 +
 tests/test-blockjob-txn.c | 244 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 247 insertions(+)
 create mode 100644 tests/test-blockjob-txn.c

diff --git a/tests/Makefile b/tests/Makefile
index 34c6136..89ce2f3 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -45,6 +45,8 @@ check-unit-y += tests/test-thread-pool$(EXESUF)
 gcov-files-test-thread-pool-y = thread-pool.c
 gcov-files-test-hbitmap-y = util/hbitmap.c
 check-unit-y += tests/test-hbitmap$(EXESUF)
+gcov-files-test-hbitmap-y = blockjob.c
+check-unit-y += tests/test-blockjob-txn$(EXESUF)
 check-unit-y += tests/test-x86-cpuid$(EXESUF)
 # all code tested by test-x86-cpuid is inside topology.h
 gcov-files-test-x86-cpuid-y =
@@ -294,6 +296,7 @@ tests/test-coroutine$(EXESUF): tests/test-coroutine.o $(block-obj-y) libqemuutil
 tests/test-aio$(EXESUF): tests/test-aio.o $(block-obj-y) libqemuutil.a libqemustub.a
 tests/test-rfifolock$(EXESUF): tests/test-rfifolock.o libqemuutil.a libqemustub.a
 tests/test-throttle$(EXESUF): tests/test-throttle.o $(block-obj-y) libqemuutil.a libqemustub.a
+tests/test-blockjob-txn$(EXESUF): tests/test-blockjob-txn.o $(block-obj-y) libqemuutil.a libqemustub.a
 tests/test-thread-pool$(EXESUF): tests/test-thread-pool.o $(block-obj-y) libqemuutil.a libqemustub.a
 tests/test-iov$(EXESUF): tests/test-iov.o libqemuutil.a
 tests/test-hbitmap$(EXESUF): tests/test-hbitmap.o libqemuutil.a libqemustub.a
diff --git a/tests/test-blockjob-txn.c b/tests/test-blockjob-txn.c
new file mode 100644
index 0000000..000f70e
--- /dev/null
+++ b/tests/test-blockjob-txn.c
@@ -0,0 +1,244 @@
+/*
+ * Blockjob transactions tests
+ *
+ * Copyright Red Hat, Inc. 2015
+ *
+ * Authors:
+ *  Stefan Hajnoczi    <stefanha@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ */
+
+#include <glib.h>
+#include "qapi/error.h"
+#include "qemu/main-loop.h"
+#include "block/blockjob.h"
+
+typedef struct {
+    BlockJob common;
+    unsigned int iterations;
+    bool use_timer;
+    int rc;
+    int *result;
+} TestBlockJob;
+
+static const BlockJobDriver test_block_job_driver = {
+    .instance_size = sizeof(TestBlockJob),
+};
+
+static void test_block_job_complete(BlockJob *job, void *opaque)
+{
+    BlockDriverState *bs = job->bs;
+    int rc = (intptr_t)opaque;
+
+    if (block_job_is_cancelled(job)) {
+        rc = -ECANCELED;
+    }
+
+    block_job_completed(job, rc);
+    bdrv_unref(bs);
+}
+
+static void coroutine_fn test_block_job_run(void *opaque)
+{
+    TestBlockJob *s = opaque;
+    BlockJob *job = &s->common;
+
+    while (s->iterations--) {
+        if (s->use_timer) {
+            block_job_sleep_ns(job, QEMU_CLOCK_REALTIME, 0);
+        } else {
+            block_job_yield(job);
+        }
+
+        if (block_job_is_cancelled(job)) {
+            break;
+        }
+    }
+
+    block_job_defer_to_main_loop(job, test_block_job_complete,
+                                 (void *)(intptr_t)s->rc);
+}
+
+typedef struct {
+    TestBlockJob *job;
+    int *result;
+} TestBlockJobCBData;
+
+static void test_block_job_cb(void *opaque, int ret)
+{
+    TestBlockJobCBData *data = opaque;
+    if (!ret && block_job_is_cancelled(&data->job->common)) {
+        ret = -ECANCELED;
+    }
+    *data->result = ret;
+    g_free(data);
+}
+
+/* Create a block job that completes with a given return code after a given
+ * number of event loop iterations.  The return code is stored in the given
+ * result pointer.
+ *
+ * The event loop iterations can either be handled automatically with a 0 delay
+ * timer, or they can be stepped manually by entering the coroutine.
+ */
+static BlockJob *test_block_job_start(unsigned int iterations,
+                                      bool use_timer,
+                                      int rc, int *result)
+{
+    BlockDriverState *bs;
+    TestBlockJob *s;
+    TestBlockJobCBData *data;
+
+    data = g_new0(TestBlockJobCBData, 1);
+    bs = bdrv_new();
+    s = block_job_create(&test_block_job_driver, bs, 0, test_block_job_cb,
+                         data, &error_abort);
+    s->iterations = iterations;
+    s->use_timer = use_timer;
+    s->rc = rc;
+    s->result = result;
+    s->common.co = qemu_coroutine_create(test_block_job_run);
+    data->job = s;
+    data->result = result;
+    qemu_coroutine_enter(s->common.co, s);
+    return &s->common;
+}
+
+static void test_single_job(int expected)
+{
+    BlockJob *job;
+    BlockJobTxn *txn;
+    int result = -EINPROGRESS;
+
+    txn = block_job_txn_new();
+    job = test_block_job_start(1, true, expected, &result);
+    block_job_txn_add_job(txn, job);
+
+    if (expected == -ECANCELED) {
+        block_job_cancel(job);
+    }
+
+    while (result == -EINPROGRESS) {
+        aio_poll(qemu_get_aio_context(), true);
+    }
+    g_assert_cmpint(result, ==, expected);
+}
+
+static void test_single_job_success(void)
+{
+    test_single_job(0);
+}
+
+static void test_single_job_failure(void)
+{
+    test_single_job(-EIO);
+}
+
+static void test_single_job_cancel(void)
+{
+    test_single_job(-ECANCELED);
+}
+
+static void test_pair_jobs(int expected1, int expected2)
+{
+    BlockJob *job1;
+    BlockJob *job2;
+    BlockJobTxn *txn;
+    int result1 = -EINPROGRESS;
+    int result2 = -EINPROGRESS;
+
+    txn = block_job_txn_new();
+    job1 = test_block_job_start(1, true, expected1, &result1);
+    block_job_txn_add_job(txn, job1);
+    job2 = test_block_job_start(2, true, expected2, &result2);
+    block_job_txn_add_job(txn, job2);
+
+    if (expected1 == -ECANCELED) {
+        block_job_cancel(job1);
+    }
+    if (expected2 == -ECANCELED) {
+        block_job_cancel(job2);
+    }
+
+    while (result1 == -EINPROGRESS || result2 == -EINPROGRESS) {
+        aio_poll(qemu_get_aio_context(), true);
+    }
+
+    /* Failure or cancellation of one job cancels the other job */
+    if (expected1 != 0) {
+        expected2 = -ECANCELED;
+    } else if (expected2 != 0) {
+        expected1 = -ECANCELED;
+    }
+
+    g_assert_cmpint(result1, ==, expected1);
+    g_assert_cmpint(result2, ==, expected2);
+}
+
+static void test_pair_jobs_success(void)
+{
+    test_pair_jobs(0, 0);
+}
+
+static void test_pair_jobs_failure(void)
+{
+    /* Test both orderings.  The two jobs run for a different number of
+     * iterations so the code path is different depending on which job fails
+     * first.
+     */
+    test_pair_jobs(-EIO, 0);
+    test_pair_jobs(0, -EIO);
+}
+
+static void test_pair_jobs_cancel(void)
+{
+    test_pair_jobs(-ECANCELED, 0);
+    test_pair_jobs(0, -ECANCELED);
+}
+
+static void test_pair_jobs_fail_cancel_race(void)
+{
+    BlockJob *job1;
+    BlockJob *job2;
+    BlockJobTxn *txn;
+    int result1 = -EINPROGRESS;
+    int result2 = -EINPROGRESS;
+
+    txn = block_job_txn_new();
+    job1 = test_block_job_start(1, true, -ECANCELED, &result1);
+    block_job_txn_add_job(txn, job1);
+    job2 = test_block_job_start(2, false, 0, &result2);
+    block_job_txn_add_job(txn, job2);
+
+    block_job_cancel(job1);
+
+    /* Now make job2 finish before the main loop kicks jobs.  This simulates
+     * the race between a pending kick and another job completing.
+     */
+    block_job_enter(job2);
+    block_job_enter(job2);
+
+    while (result1 == -EINPROGRESS || result2 == -EINPROGRESS) {
+        aio_poll(qemu_get_aio_context(), true);
+    }
+
+    g_assert_cmpint(result1, ==, -ECANCELED);
+    g_assert_cmpint(result2, ==, -ECANCELED);
+}
+
+int main(int argc, char **argv)
+{
+    qemu_init_main_loop(&error_abort);
+
+    g_test_init(&argc, &argv, NULL);
+    g_test_add_func("/single/success", test_single_job_success);
+    g_test_add_func("/single/failure", test_single_job_failure);
+    g_test_add_func("/single/cancel", test_single_job_cancel);
+    g_test_add_func("/pair/success", test_pair_jobs_success);
+    g_test_add_func("/pair/failure", test_pair_jobs_failure);
+    g_test_add_func("/pair/cancel", test_pair_jobs_cancel);
+    g_test_add_func("/pair/fail-cancel-race", test_pair_jobs_fail_cancel_race);
+    return g_test_run();
+}
-- 
2.4.3

^ permalink raw reply related	[flat|nested] 29+ messages in thread

* Re: [Qemu-devel] [PATCH v6 01/14] qapi: Add transaction support to block-dirty-bitmap operations
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 01/14] qapi: Add transaction support to block-dirty-bitmap operations Fam Zheng
@ 2015-09-15 14:36   ` Eric Blake
  0 siblings, 0 replies; 29+ messages in thread
From: Eric Blake @ 2015-09-15 14:36 UTC (permalink / raw)
  To: Fam Zheng, qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

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On 09/15/2015 12:11 AM, Fam Zheng wrote:
> From: John Snow <jsnow@redhat.com>
> 
> This adds two qmp commands to transactions.
> 
> block-dirty-bitmap-add allows you to create a bitmap simultaneously
> alongside a new full backup to accomplish a clean synchronization
> point.
> 
> block-dirty-bitmap-clear allows you to reset a bitmap back to as-if
> it were new, which can also be used alongside a full backup to
> accomplish a clean synchronization point.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> Signed-off-by: John Snow <jsnow@redhat.com>
> Reviewed-by: Max Reitz <mreitz@redhat.com>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Fam Zheng <famz@redhat.com>

The double S-o-b that I pointed out on v5 is still here.
And my R-b on v5 still holds :)

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


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* Re: [Qemu-devel] [PATCH v6 11/14] block/backup: support block job transactions
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 11/14] block/backup: support block job transactions Fam Zheng
@ 2015-09-15 14:43   ` Eric Blake
  2015-09-18 11:40   ` Max Reitz
  1 sibling, 0 replies; 29+ messages in thread
From: Eric Blake @ 2015-09-15 14:43 UTC (permalink / raw)
  To: Fam Zheng, qemu-devel
  Cc: Kevin Wolf, Jeff Cody, Max Reitz, vsementsov, stefanha, John Snow

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On 09/15/2015 12:11 AM, Fam Zheng wrote:
> From: Stefan Hajnoczi <stefanha@redhat.com>
> 
> Join the transaction when the 'transactional-cancel' QMP argument is
> true.
> 
> This ensures that the sync bitmap is not thrown away if another block
> job in the transaction is cancelled or fails.  This is critical so
> incremental backup with multiple disks can be retried in case of
> cancellation/failure.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  block/backup.c            |  25 +++++++--
>  blockdev.c                | 132 +++++++++++++++++++++++++++++++++++-----------
>  include/block/block_int.h |   3 +-
>  qapi-schema.json          |   4 +-
>  qapi/block-core.json      |  29 ++++++++++
>  5 files changed, 155 insertions(+), 38 deletions(-)
> 

> +++ b/qapi/block-core.json
> @@ -736,6 +736,11 @@
>  #                   default 'report' (no limitations, since this applies to
>  #                   a different block device than @device).
>  #
> +# @transactional-cancel: #optional whether failure or cancellation of other
> +#                        block jobs with @transactional-cancel true in the same
> +#                        transaction causes the whole group to cancel.
> +#                        (Since 2.5)
> +#

Spurious hunk here.

> @@ -750,6 +755,18 @@
>              '*on-target-error': 'BlockdevOnError' } }
>  
>  ##
> +# @DriveBackupTxn
> +#
> +# @transactional-cancel: #optional whether failure or cancellation of other
> +#                        block jobs with @transactional-cancel true in the same
> +#                        transaction causes the whole group to cancel.
> +#

Maybe mention default false here...

> +# Since: 2.5
> +##
> +{ 'struct': 'DriveBackupTxn', 'base': 'DriveBackup',
> +  'data': {'*transactional-cancel': 'bool' } }
> +
> +##
>  # @BlockdevBackup
>  #
>  # @device: the name of the device which should be copied.
> @@ -785,6 +802,18 @@
>              '*on-target-error': 'BlockdevOnError' } }
>  
>  ##
> +# @BlockdevBackupTxn
> +#
> +# @transactional-cancel: #optional whether failure or cancellation of other
> +#                        block jobs with @transactional-cancel true in the same
> +#                        transaction causes the whole group to cancel.

and again here.

With those three fixes,
Reviewed-by: Eric Blake <eblake@redhat.com>

(and we can simplify it later when more qapi patches land)

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


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* Re: [Qemu-devel] [PATCH v6 04/14] backup: Extract dirty bitmap handling as a separate function
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 04/14] backup: Extract dirty bitmap handling as a separate function Fam Zheng
@ 2015-09-18 11:02   ` Max Reitz
  0 siblings, 0 replies; 29+ messages in thread
From: Max Reitz @ 2015-09-18 11:02 UTC (permalink / raw)
  To: Fam Zheng, qemu-devel
  Cc: Kevin Wolf, Jeff Cody, vsementsov, stefanha, John Snow

[-- Attachment #1: Type: text/plain, Size: 367 bytes --]

On 15.09.2015 08:11, Fam Zheng wrote:
> This will be reused by the coming new transactional completion code.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> Reviewed-by: John Snow <jsnow@redhat.com>
> ---
>  block/backup.c | 27 +++++++++++++++++----------
>  1 file changed, 17 insertions(+), 10 deletions(-)

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


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* Re: [Qemu-devel] [PATCH v6 09/14] block: Add block job transactions
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 09/14] block: Add block job transactions Fam Zheng
@ 2015-09-18 11:16   ` Max Reitz
  2015-09-21 23:23   ` John Snow
  1 sibling, 0 replies; 29+ messages in thread
From: Max Reitz @ 2015-09-18 11:16 UTC (permalink / raw)
  To: Fam Zheng, qemu-devel
  Cc: Kevin Wolf, Jeff Cody, vsementsov, stefanha, John Snow

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On 15.09.2015 08:11, Fam Zheng wrote:
> Sometimes block jobs must execute as a transaction group.  Finishing
> jobs wait until all other jobs are ready to complete successfully.
> Failure or cancellation of one job cancels the other jobs in the group.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> [Rewrite the implementation which is now contained in block_job_completed.
> --Fam]
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  blockjob.c               | 135 ++++++++++++++++++++++++++++++++++++++++++++++-
>  include/block/block.h    |   1 +
>  include/block/blockjob.h |  38 +++++++++++++
>  3 files changed, 172 insertions(+), 2 deletions(-)
> 

[...]

> diff --git a/include/block/blockjob.h b/include/block/blockjob.h
> index f6e4c86..4999682 100644
> --- a/include/block/blockjob.h
> +++ b/include/block/blockjob.h

[...]

> @@ -395,4 +398,39 @@ void block_job_defer_to_main_loop(BlockJob *job,

[...]

> +
> +/**
> + * block_job_txn_add_job:
> + * @txn: The transaction (may be NULL)
> + * @job: Job to add to the transaction
> + *
> + * Add @job to the transaction.  The @job must not already be in a transaction.
> + * The block job driver must call block_job_txn_unref() in the end to release
> + * the reference that is automatically grabbed here.

Ah, this looks like I got the right version this time. *cough cough*

So, to repeat myself:

To me that sounds a bit as if this should be called e.g. in
block/backup.c:backup_complete(). Maybe add that this is called
automatically by block_job_completed()?

Either way:

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

> + */
> +void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job);
> +
>  #endif



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^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [Qemu-devel] [PATCH v6 10/14] blockdev: make BlockJobTxn available to qmp 'transaction'
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 10/14] blockdev: make BlockJobTxn available to qmp 'transaction' Fam Zheng
@ 2015-09-18 11:20   ` Max Reitz
  0 siblings, 0 replies; 29+ messages in thread
From: Max Reitz @ 2015-09-18 11:20 UTC (permalink / raw)
  To: Fam Zheng, qemu-devel
  Cc: Kevin Wolf, Jeff Cody, vsementsov, stefanha, John Snow

[-- Attachment #1: Type: text/plain, Size: 2246 bytes --]

On 15.09.2015 08:11, Fam Zheng wrote:
> From: Stefan Hajnoczi <stefanha@redhat.com>
> 
> Provide a BlockJobTxn to actions executed in a qmp 'transaction'
> command.  This allows actions to make their block jobs either complete
> as a group or fail/cancel together.
> 
> The next patch adds the first user.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> Reviewed-by: Fam Zheng <famz@redhat.com>
> Reviewed-by: John Snow <jsnow@redhat.com>

I'm still wondering which covert channel you are using to get these R-bs
from John.

Until I know I myself will have to resort to this open channel here:

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

> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  blockdev.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/blockdev.c b/blockdev.c
> index 4ebded8..93a9eef 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -1285,6 +1285,7 @@ typedef struct BlkActionOps {
>  struct BlkActionState {
>      TransactionAction *action;
>      const BlkActionOps *ops;
> +    BlockJobTxn *block_job_txn;
>      QSIMPLEQ_ENTRY(BlkActionState) entry;
>  };
>  
> @@ -1889,12 +1890,15 @@ static const BlkActionOps actions[] = {
>  void qmp_transaction(TransactionActionList *dev_list, Error **errp)
>  {
>      TransactionActionList *dev_entry = dev_list;
> +    BlockJobTxn *block_job_txn;
>      BlkActionState *state, *next;
>      Error *local_err = NULL;
>  
>      QSIMPLEQ_HEAD(snap_bdrv_states, BlkActionState) snap_bdrv_states;
>      QSIMPLEQ_INIT(&snap_bdrv_states);
>  
> +    block_job_txn = block_job_txn_new();
> +
>      /* drain all i/o before any operations */
>      bdrv_drain_all();
>  
> @@ -1914,6 +1918,7 @@ void qmp_transaction(TransactionActionList *dev_list, Error **errp)
>          state = g_malloc0(ops->instance_size);
>          state->ops = ops;
>          state->action = dev_info;
> +        state->block_job_txn = block_job_txn;
>          QSIMPLEQ_INSERT_TAIL(&snap_bdrv_states, state, entry);
>  
>          state->ops->prepare(state, &local_err);
> @@ -1946,6 +1951,7 @@ exit:
>          }
>          g_free(state);
>      }
> +    block_job_txn_unref(block_job_txn);
>  }
>  
>  
> 



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* Re: [Qemu-devel] [PATCH v6 11/14] block/backup: support block job transactions
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 11/14] block/backup: support block job transactions Fam Zheng
  2015-09-15 14:43   ` Eric Blake
@ 2015-09-18 11:40   ` Max Reitz
  1 sibling, 0 replies; 29+ messages in thread
From: Max Reitz @ 2015-09-18 11:40 UTC (permalink / raw)
  To: Fam Zheng, qemu-devel
  Cc: Kevin Wolf, Jeff Cody, vsementsov, stefanha, John Snow

[-- Attachment #1: Type: text/plain, Size: 920 bytes --]

On 15.09.2015 08:11, Fam Zheng wrote:
> From: Stefan Hajnoczi <stefanha@redhat.com>
> 
> Join the transaction when the 'transactional-cancel' QMP argument is
> true.
> 
> This ensures that the sync bitmap is not thrown away if another block
> job in the transaction is cancelled or fails.  This is critical so
> incremental backup with multiple disks can be retried in case of
> cancellation/failure.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  block/backup.c            |  25 +++++++--
>  blockdev.c                | 132 +++++++++++++++++++++++++++++++++++-----------
>  include/block/block_int.h |   3 +-
>  qapi-schema.json          |   4 +-
>  qapi/block-core.json      |  29 ++++++++++
>  5 files changed, 155 insertions(+), 38 deletions(-)

With the changes proposed by Eric:

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


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* Re: [Qemu-devel] [PATCH v6 14/14] tests: add BlockJobTxn unit test
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 14/14] tests: add BlockJobTxn unit test Fam Zheng
@ 2015-09-18 11:45   ` Max Reitz
  2015-09-22  2:11     ` Fam Zheng
  0 siblings, 1 reply; 29+ messages in thread
From: Max Reitz @ 2015-09-18 11:45 UTC (permalink / raw)
  To: Fam Zheng, qemu-devel
  Cc: Kevin Wolf, Jeff Cody, vsementsov, stefanha, John Snow

[-- Attachment #1: Type: text/plain, Size: 2170 bytes --]

On 15.09.2015 08:11, Fam Zheng wrote:
> From: Stefan Hajnoczi <stefanha@redhat.com>
> 
> The BlockJobTxn unit test verifies that both single jobs and pairs of
> jobs behave as a transaction group.  Either all jobs complete
> successfully or the group is cancelled.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Fam Zheng <famz@redhat.com>
> Reviewed-by: Max Reitz <mreitz@redhat.com>
> ---
>  tests/Makefile            |   3 +
>  tests/test-blockjob-txn.c | 244 ++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 247 insertions(+)
>  create mode 100644 tests/test-blockjob-txn.c
> 
> diff --git a/tests/Makefile b/tests/Makefile
> index 34c6136..89ce2f3 100644
> --- a/tests/Makefile
> +++ b/tests/Makefile
> @@ -45,6 +45,8 @@ check-unit-y += tests/test-thread-pool$(EXESUF)
>  gcov-files-test-thread-pool-y = thread-pool.c
>  gcov-files-test-hbitmap-y = util/hbitmap.c
>  check-unit-y += tests/test-hbitmap$(EXESUF)
> +gcov-files-test-hbitmap-y = blockjob.c
> +check-unit-y += tests/test-blockjob-txn$(EXESUF)
>  check-unit-y += tests/test-x86-cpuid$(EXESUF)
>  # all code tested by test-x86-cpuid is inside topology.h
>  gcov-files-test-x86-cpuid-y =
> @@ -294,6 +296,7 @@ tests/test-coroutine$(EXESUF): tests/test-coroutine.o $(block-obj-y) libqemuutil
>  tests/test-aio$(EXESUF): tests/test-aio.o $(block-obj-y) libqemuutil.a libqemustub.a
>  tests/test-rfifolock$(EXESUF): tests/test-rfifolock.o libqemuutil.a libqemustub.a
>  tests/test-throttle$(EXESUF): tests/test-throttle.o $(block-obj-y) libqemuutil.a libqemustub.a
> +tests/test-blockjob-txn$(EXESUF): tests/test-blockjob-txn.o $(block-obj-y) libqemuutil.a libqemustub.a
>  tests/test-thread-pool$(EXESUF): tests/test-thread-pool.o $(block-obj-y) libqemuutil.a libqemustub.a
>  tests/test-iov$(EXESUF): tests/test-iov.o libqemuutil.a
>  tests/test-hbitmap$(EXESUF): tests/test-hbitmap.o libqemuutil.a libqemustub.a

This needs an update due to b124533e. The context is obvious, and I
guess for the new line itself it's
s/\$(block-obj-y).*$/$(test-block-obj-y)/.

If that is indeed so, feel free to keep my R-b.

Max


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* Re: [Qemu-devel] [PATCH v6 05/14] blockjob: Introduce reference count
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 05/14] blockjob: Introduce reference count Fam Zheng
@ 2015-09-21 22:19   ` John Snow
  0 siblings, 0 replies; 29+ messages in thread
From: John Snow @ 2015-09-21 22:19 UTC (permalink / raw)
  To: Fam Zheng, qemu-devel
  Cc: Kevin Wolf, Jeff Cody, vsementsov, stefanha, Max Reitz



On 09/15/2015 02:11 AM, Fam Zheng wrote:
> So that block_job_complete_sync can be simplified.
> 
> Reviewed-by: Max Reitz <mreitz@redhat.com>
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  block/mirror.c           |  2 +-
>  blockjob.c               | 22 ++++++++++++++--------
>  include/block/blockjob.h | 18 +++++++++++++++---
>  3 files changed, 30 insertions(+), 12 deletions(-)
> 
> diff --git a/block/mirror.c b/block/mirror.c
> index a258926..3472ad4 100644
> --- a/block/mirror.c
> +++ b/block/mirror.c
> @@ -736,7 +736,7 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target,
>      s->dirty_bitmap = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp);
>      if (!s->dirty_bitmap) {
>          g_free(s->replaces);
> -        block_job_release(bs);
> +        block_job_unref(&s->common);
>          return;
>      }
>      bdrv_set_enable_write_cache(s->target, true);
> diff --git a/blockjob.c b/blockjob.c
> index 62bb906..ec12887 100644
> --- a/blockjob.c
> +++ b/blockjob.c
> @@ -58,6 +58,7 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
>      job->cb            = cb;
>      job->opaque        = opaque;
>      job->busy          = true;
> +    job->refcnt        = 1;
>      bs->job = job;
>  
>      /* Only set speed when necessary to avoid NotSupported error */
> @@ -66,7 +67,7 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
>  
>          block_job_set_speed(job, speed, &local_err);
>          if (local_err) {
> -            block_job_release(bs);
> +            block_job_unref(job);
>              error_propagate(errp, local_err);
>              return NULL;
>          }
> @@ -74,14 +75,19 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
>      return job;
>  }
>  
> -void block_job_release(BlockDriverState *bs)
> +void block_job_ref(BlockJob *job)
>  {
> -    BlockJob *job = bs->job;
> +    ++job->refcnt;
> +}
>  
> -    bs->job = NULL;
> -    bdrv_op_unblock_all(bs, job->blocker);
> -    error_free(job->blocker);
> -    g_free(job);
> +void block_job_unref(BlockJob *job)
> +{
> +    if (--job->refcnt == 0) {
> +        job->bs->job = NULL;
> +        bdrv_op_unblock_all(job->bs, job->blocker);
> +        error_free(job->blocker);
> +        g_free(job);
> +    }
>  }
>  
>  void block_job_completed(BlockJob *job, int ret)
> @@ -90,7 +96,7 @@ void block_job_completed(BlockJob *job, int ret)
>  
>      assert(bs->job == job);
>      job->cb(job->opaque, ret);
> -    block_job_release(bs);
> +    block_job_unref(job);
>  }
>  
>  void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
> diff --git a/include/block/blockjob.h b/include/block/blockjob.h
> index dd9d5e6..3e7ad21 100644
> --- a/include/block/blockjob.h
> +++ b/include/block/blockjob.h
> @@ -122,6 +122,9 @@ struct BlockJob {
>  
>      /** The opaque value that is passed to the completion function.  */
>      void *opaque;
> +
> +    /** Reference count of the block job */
> +    int refcnt;
>  };
>  
>  /**
> @@ -166,12 +169,21 @@ void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns);
>  void block_job_yield(BlockJob *job);
>  
>  /**
> - * block_job_release:
> + * block_job_ref:
>   * @bs: The block device.
>   *
> - * Release job resources when an error occurred or job completed.
> + * Grab a reference to the block job. Should be paired with block_job_unref.
>   */
> -void block_job_release(BlockDriverState *bs);
> +void block_job_ref(BlockJob *job);
> +
> +/**
> + * block_job_unref:
> + * @bs: The block device.
> + *
> + * Release reference to the block job and release resources if it is the last
> + * reference.
> + */
> +void block_job_unref(BlockJob *job);
>  
>  /**
>   * block_job_completed:
> 

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

^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [Qemu-devel] [PATCH v6 06/14] blockjob: Add .commit and .abort block job actions
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 06/14] blockjob: Add .commit and .abort block job actions Fam Zheng
@ 2015-09-21 22:29   ` John Snow
  2015-09-22  2:15     ` Fam Zheng
  0 siblings, 1 reply; 29+ messages in thread
From: John Snow @ 2015-09-21 22:29 UTC (permalink / raw)
  To: Fam Zheng, qemu-devel
  Cc: Kevin Wolf, Jeff Cody, vsementsov, stefanha, Max Reitz



On 09/15/2015 02:11 AM, Fam Zheng wrote:
> Reviewed-by: Max Reitz <mreitz@redhat.com>
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  include/block/blockjob.h | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/include/block/blockjob.h b/include/block/blockjob.h
> index 3e7ad21..a7b497c 100644
> --- a/include/block/blockjob.h
> +++ b/include/block/blockjob.h
> @@ -50,6 +50,24 @@ typedef struct BlockJobDriver {
>       * manually.
>       */
>      void (*complete)(BlockJob *job, Error **errp);
> +
> +    /**
> +     * 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
> +     * completion if it is not in a transaction. Skipped if NULL.
> +     *
> +     * Exactly one of .commit() and .abort() will be called for each job.
> +     */
> +    void (*commit)(BlockJob *job);
> +

I find this phrasing strange, but maybe it's just me. "Exactly one of
commit and abort will be called for each job" implies [to me] that it'd
be possible to call commit for one, but abort for different jobs [in a
transaction] -- but clearly we don't mean that. It is the "for each job"
that implies an iteration over a collection to me.

Just above we say "[commit] will be invoked when all the jobs belonging
to the same transaction are complete" which itself implies either all
jobs will be committed or all jobs will be aborted.

Maybe:

"All jobs will complete with a call to either .commit() or .abort() but
never both."

But I might be being too bikesheddy.

> +    /**
> +     * If the callback is not NULL, it will be invoked when any job in the
> +     * same transaction fails; or upon this job's failure (due to error or
> +     * cancellation) if it is not in a transaction. Skipped if NULL.
> +     *
> +     * Exactly one of .commit() and .abort() will be called for each job.
> +     */
> +    void (*abort)(BlockJob *job);
>  } BlockJobDriver;
>  
>  /**
> 

I'm probably just too picky.

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

^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [Qemu-devel] [PATCH v6 08/14] blockjob: Simplify block_job_finish_sync
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 08/14] blockjob: Simplify block_job_finish_sync Fam Zheng
@ 2015-09-21 22:50   ` John Snow
  0 siblings, 0 replies; 29+ messages in thread
From: John Snow @ 2015-09-21 22:50 UTC (permalink / raw)
  To: Fam Zheng, qemu-devel
  Cc: Kevin Wolf, Jeff Cody, vsementsov, stefanha, Max Reitz



On 09/15/2015 02:11 AM, Fam Zheng wrote:
> With job->completed and job->ret to replace BlockFinishData.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> Reviewed-by: Max Reitz <mreitz@redhat.com>
> ---
>  blockjob.c | 27 ++++++---------------------
>  1 file changed, 6 insertions(+), 21 deletions(-)
> 
> diff --git a/blockjob.c b/blockjob.c
> index 293b62a..36c18e0 100644
> --- a/blockjob.c
> +++ b/blockjob.c
> @@ -185,43 +185,28 @@ struct BlockFinishData {
>      int ret;
>  };
>  
> -static void block_job_finish_cb(void *opaque, int ret)
> -{
> -    struct BlockFinishData *data = opaque;
> -
> -    data->cancelled = block_job_is_cancelled(data->job);
> -    data->ret = ret;
> -    data->cb(data->opaque, ret);
> -}
> -
>  static int block_job_finish_sync(BlockJob *job,
>                                   void (*finish)(BlockJob *, Error **errp),
>                                   Error **errp)
>  {
> -    struct BlockFinishData data;
>      BlockDriverState *bs = job->bs;
>      Error *local_err = NULL;
> +    int ret;
>  
>      assert(bs->job == job);
>  
> -    /* Set up our own callback to store the result and chain to
> -     * the original callback.
> -     */
> -    data.job = job;
> -    data.cb = job->cb;
> -    data.opaque = job->opaque;
> -    data.ret = -EINPROGRESS;
> -    job->cb = block_job_finish_cb;
> -    job->opaque = &data;
> +    block_job_ref(job);
>      finish(job, &local_err);
>      if (local_err) {
>          error_propagate(errp, local_err);
>          return -EBUSY;
>      }
> -    while (data.ret == -EINPROGRESS) {
> +    while (!job->completed) {
>          aio_poll(bdrv_get_aio_context(bs), true);
>      }
> -    return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret;
> +    ret = (job->cancelled && job->ret == 0) ? -ECANCELED : job->ret;
> +    block_job_unref(job);
> +    return ret;
>  }
>  
>  /* A wrapper around block_job_cancel() taking an Error ** parameter so it may be
> 

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

^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [Qemu-devel] [PATCH v6 09/14] block: Add block job transactions
  2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 09/14] block: Add block job transactions Fam Zheng
  2015-09-18 11:16   ` Max Reitz
@ 2015-09-21 23:23   ` John Snow
  2015-09-22  2:32     ` Fam Zheng
  1 sibling, 1 reply; 29+ messages in thread
From: John Snow @ 2015-09-21 23:23 UTC (permalink / raw)
  To: Fam Zheng, qemu-devel
  Cc: Kevin Wolf, Jeff Cody, vsementsov, stefanha, Max Reitz



On 09/15/2015 02:11 AM, Fam Zheng wrote:
> Sometimes block jobs must execute as a transaction group.  Finishing
> jobs wait until all other jobs are ready to complete successfully.
> Failure or cancellation of one job cancels the other jobs in the group.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> [Rewrite the implementation which is now contained in block_job_completed.
> --Fam]
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  blockjob.c               | 135 ++++++++++++++++++++++++++++++++++++++++++++++-
>  include/block/block.h    |   1 +
>  include/block/blockjob.h |  38 +++++++++++++
>  3 files changed, 172 insertions(+), 2 deletions(-)
> 
> diff --git a/blockjob.c b/blockjob.c
> index 36c18e0..91e8d3c 100644
> --- a/blockjob.c
> +++ b/blockjob.c
> @@ -36,6 +36,19 @@
>  #include "qemu/timer.h"
>  #include "qapi-event.h"
>  
> +/* Transactional group of block jobs */
> +struct BlockJobTxn {
> +
> +    /* Is this txn being cancelled? */
> +    bool aborting;
> +
> +    /* List of jobs */
> +    QLIST_HEAD(, BlockJob) jobs;
> +
> +    /* Reference count */
> +    int refcnt;
> +};
> +
>  void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs,
>                         int64_t speed, BlockCompletionFunc *cb,
>                         void *opaque, Error **errp)
> @@ -90,6 +103,86 @@ void block_job_unref(BlockJob *job)
>      }
>  }
>  
> +static void block_job_completed_single(BlockJob *job)
> +{
> +    if (!job->ret) {
> +        if (job->driver->commit) {
> +            job->driver->commit(job);
> +        }
> +    } else {
> +        if (job->driver->abort) {
> +            job->driver->abort(job);
> +        }
> +    }
> +    job->cb(job->opaque, job->ret);
> +    if (job->txn) {
> +        block_job_txn_unref(job->txn);
> +    }
> +    block_job_unref(job);
> +}
> +
> +static void block_job_completed_txn_abort(BlockJob *job)
> +{
> +    AioContext *ctx;
> +    BlockJobTxn *txn = job->txn;
> +    BlockJob *other_job, *next;
> +
> +    if (txn->aborting) {
> +        /*
> +         * We are cancelled by another job, which will handle everything.
> +         */
> +        return;
> +    }
> +    txn->aborting = true;
> +    /* We are the first failed job. Cancel other jobs. */
> +    QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
> +        ctx = bdrv_get_aio_context(other_job->bs);
> +        aio_context_acquire(ctx);
> +    }
> +    QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
> +        if (other_job == job || other_job->completed) {
> +            /* Other jobs are "effectively" cancelled by us, set the status for
> +             * them; this job, however, may or may not be cancelled, depending
> +             * on the caller, so leave it. */
> +            if (other_job != job) {
> +                other_job->cancelled = true;
> +            }
> +            continue;
> +        }

This loop reads strangely to me due to this structure:

if (other_job == job || ...) {
  if (other_job != job) {
    ...
  }
}

why not:

foreach(...) {
  if (other_job == job) {
    continue;
  }

  if (other_job->completed) {
    other_job->cancelled = true;
    continue;
  }

  /* job is neither ours, nor completed */
  block_job_cancel_sync(other_job);
  assert(other_job->completed);
}

> +        block_job_cancel_sync(other_job);
> +        assert(other_job->completed);
> +    }
> +    QLIST_FOREACH_SAFE(other_job, &txn->jobs, txn_list, next) {
> +        ctx = bdrv_get_aio_context(other_job->bs);
> +        block_job_completed_single(other_job);
> +        aio_context_release(ctx);
> +    }
> +}
> +
> +static void block_job_completed_txn_success(BlockJob *job)
> +{
> +    AioContext *ctx;
> +    BlockJobTxn *txn = job->txn;
> +    BlockJob *other_job, *next;
> +    /*
> +     * Successful completion, see if there are other running jobs in this
> +     * txn.
> +     */
> +    QLIST_FOREACH(other_job, &txn->jobs, txn_list) {
> +        if (!other_job->completed) {
> +            return;
> +        }
> +    }
> +    /* We are the last completed job, commit the transaction. */
> +    QLIST_FOREACH_SAFE(other_job, &txn->jobs, txn_list, next) {
> +        ctx = bdrv_get_aio_context(other_job->bs);
> +        aio_context_acquire(ctx);
> +        assert(other_job->ret == 0);

Here we assert that all jobs have a retcode of zero to be in the success
callback, but ...

> +        block_job_completed_single(other_job);
> +        aio_context_release(ctx);
> +    }
> +}
> +
>  void block_job_completed(BlockJob *job, int ret)
>  {
>      BlockDriverState *bs = job->bs;
> @@ -98,8 +191,13 @@ void block_job_completed(BlockJob *job, int ret)
>      assert(!job->completed);
>      job->completed = true;
>      job->ret = ret;
> -    job->cb(job->opaque, ret);
> -    block_job_unref(job);
> +    if (!job->txn) {
> +        block_job_completed_single(job);
> +    } else if (ret < 0 || block_job_is_cancelled(job)) {
> +        block_job_completed_txn_abort(job);
> +    } else {

over here it just appears we assert that ret is simply greater than or
equal to zero.

> +        block_job_completed_txn_success(job);
> +    }
>  }
>  
>  void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp)
> @@ -398,3 +496,36 @@ void block_job_defer_to_main_loop(BlockJob *job,
>  
>      qemu_bh_schedule(data->bh);
>  }
> +
> +BlockJobTxn *block_job_txn_new(void)
> +{
> +    BlockJobTxn *txn = g_new0(BlockJobTxn, 1);
> +    QLIST_INIT(&txn->jobs);
> +    txn->refcnt = 1;
> +    return txn;
> +}
> +
> +static void block_job_txn_ref(BlockJobTxn *txn)
> +{
> +    txn->refcnt++;
> +}
> +
> +void block_job_txn_unref(BlockJobTxn *txn)
> +{
> +    if (--txn->refcnt == 0) {
> +        g_free(txn);
> +    }
> +}
> +
> +void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job)
> +{
> +    if (!txn) {
> +        return;
> +    }
> +
> +    assert(!job->txn);
> +    job->txn = txn;
> +
> +    QLIST_INSERT_HEAD(&txn->jobs, job, txn_list);
> +    block_job_txn_ref(txn);
> +}

I guess we don't consider the list insertion to be a reference to the
job that we need to pick up, which also keeps txn_unref minimalist.

> diff --git a/include/block/block.h b/include/block/block.h
> index f70bec4..514b233 100644
> --- a/include/block/block.h
> +++ b/include/block/block.h
> @@ -14,6 +14,7 @@ typedef struct BlockDriver BlockDriver;
>  typedef struct BlockJob BlockJob;
>  typedef struct BdrvChild BdrvChild;
>  typedef struct BdrvChildRole BdrvChildRole;
> +typedef struct BlockJobTxn BlockJobTxn;
>  
>  typedef struct BlockDriverInfo {
>      /* in bytes, 0 if irrelevant */
> diff --git a/include/block/blockjob.h b/include/block/blockjob.h
> index f6e4c86..4999682 100644
> --- a/include/block/blockjob.h
> +++ b/include/block/blockjob.h
> @@ -152,6 +152,9 @@ struct BlockJob {
>       */
>      int ret;
>  
> +    /** Non-NULL if this job is part of a transaction */
> +    BlockJobTxn *txn;
> +    QLIST_ENTRY(BlockJob) txn_list;
>  };
>  
>  /**
> @@ -395,4 +398,39 @@ void block_job_defer_to_main_loop(BlockJob *job,
>                                    BlockJobDeferToMainLoopFn *fn,
>                                    void *opaque);
>  
> +/**
> + * block_job_txn_new:
> + *
> + * Allocate and return a new block job transaction.  Jobs can be added to the
> + * transaction using block_job_txn_add_job().
> + *
> + * The transaction is automatically freed when the last job completes or is
> + * cancelled.
> + *
> + * All jobs in the transaction either complete successfully or fail/cancel as a
> + * group.  Jobs wait for each other before completing.  Cancelling one job
> + * cancels all jobs in the transaction.
> + */
> +BlockJobTxn *block_job_txn_new(void);
> +
> +/**
> + * block_job_txn_unref:
> + *
> + * Release a reference that was previously acquired with block_job_txn_add_job
> + * or block_job_txn_new. If it's the last reference to the object, it will be
> + * freed.
> + */
> +void block_job_txn_unref(BlockJobTxn *txn);
> +
> +/**
> + * block_job_txn_add_job:
> + * @txn: The transaction (may be NULL)
> + * @job: Job to add to the transaction
> + *
> + * Add @job to the transaction.  The @job must not already be in a transaction.
> + * The block job driver must call block_job_txn_unref() in the end to release
> + * the reference that is automatically grabbed here.
> + */
> +void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job);
> +
>  #endif
> 

^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [Qemu-devel] [PATCH v6 14/14] tests: add BlockJobTxn unit test
  2015-09-18 11:45   ` Max Reitz
@ 2015-09-22  2:11     ` Fam Zheng
  0 siblings, 0 replies; 29+ messages in thread
From: Fam Zheng @ 2015-09-22  2:11 UTC (permalink / raw)
  To: Max Reitz
  Cc: Kevin Wolf, Jeff Cody, qemu-devel, vsementsov, stefanha,
	John Snow

On Fri, 09/18 13:45, Max Reitz wrote:
> On 15.09.2015 08:11, Fam Zheng wrote:
> > From: Stefan Hajnoczi <stefanha@redhat.com>
> > 
> > The BlockJobTxn unit test verifies that both single jobs and pairs of
> > jobs behave as a transaction group.  Either all jobs complete
> > successfully or the group is cancelled.
> > 
> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> > Signed-off-by: Fam Zheng <famz@redhat.com>
> > Reviewed-by: Max Reitz <mreitz@redhat.com>
> > ---
> >  tests/Makefile            |   3 +
> >  tests/test-blockjob-txn.c | 244 ++++++++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 247 insertions(+)
> >  create mode 100644 tests/test-blockjob-txn.c
> > 
> > diff --git a/tests/Makefile b/tests/Makefile
> > index 34c6136..89ce2f3 100644
> > --- a/tests/Makefile
> > +++ b/tests/Makefile
> > @@ -45,6 +45,8 @@ check-unit-y += tests/test-thread-pool$(EXESUF)
> >  gcov-files-test-thread-pool-y = thread-pool.c
> >  gcov-files-test-hbitmap-y = util/hbitmap.c
> >  check-unit-y += tests/test-hbitmap$(EXESUF)
> > +gcov-files-test-hbitmap-y = blockjob.c
> > +check-unit-y += tests/test-blockjob-txn$(EXESUF)
> >  check-unit-y += tests/test-x86-cpuid$(EXESUF)
> >  # all code tested by test-x86-cpuid is inside topology.h
> >  gcov-files-test-x86-cpuid-y =
> > @@ -294,6 +296,7 @@ tests/test-coroutine$(EXESUF): tests/test-coroutine.o $(block-obj-y) libqemuutil
> >  tests/test-aio$(EXESUF): tests/test-aio.o $(block-obj-y) libqemuutil.a libqemustub.a
> >  tests/test-rfifolock$(EXESUF): tests/test-rfifolock.o libqemuutil.a libqemustub.a
> >  tests/test-throttle$(EXESUF): tests/test-throttle.o $(block-obj-y) libqemuutil.a libqemustub.a
> > +tests/test-blockjob-txn$(EXESUF): tests/test-blockjob-txn.o $(block-obj-y) libqemuutil.a libqemustub.a
> >  tests/test-thread-pool$(EXESUF): tests/test-thread-pool.o $(block-obj-y) libqemuutil.a libqemustub.a
> >  tests/test-iov$(EXESUF): tests/test-iov.o libqemuutil.a
> >  tests/test-hbitmap$(EXESUF): tests/test-hbitmap.o libqemuutil.a libqemustub.a
> 
> This needs an update due to b124533e. The context is obvious, and I
> guess for the new line itself it's
> s/\$(block-obj-y).*$/$(test-block-obj-y)/.
> 
> If that is indeed so, feel free to keep my R-b.

Yes, thanks for pointint out. Also changed

s/libqemuutil.a libqemustub.a/$(test-util-obj-y)/

with your R-b.

Fam

^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [Qemu-devel] [PATCH v6 06/14] blockjob: Add .commit and .abort block job actions
  2015-09-21 22:29   ` John Snow
@ 2015-09-22  2:15     ` Fam Zheng
  0 siblings, 0 replies; 29+ messages in thread
From: Fam Zheng @ 2015-09-22  2:15 UTC (permalink / raw)
  To: John Snow
  Cc: Kevin Wolf, Jeff Cody, qemu-devel, Max Reitz, vsementsov,
	stefanha

On Mon, 09/21 18:29, John Snow wrote:
> 
> 
> On 09/15/2015 02:11 AM, Fam Zheng wrote:
> > Reviewed-by: Max Reitz <mreitz@redhat.com>
> > Signed-off-by: Fam Zheng <famz@redhat.com>
> > ---
> >  include/block/blockjob.h | 18 ++++++++++++++++++
> >  1 file changed, 18 insertions(+)
> > 
> > diff --git a/include/block/blockjob.h b/include/block/blockjob.h
> > index 3e7ad21..a7b497c 100644
> > --- a/include/block/blockjob.h
> > +++ b/include/block/blockjob.h
> > @@ -50,6 +50,24 @@ typedef struct BlockJobDriver {
> >       * manually.
> >       */
> >      void (*complete)(BlockJob *job, Error **errp);
> > +
> > +    /**
> > +     * 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
> > +     * completion if it is not in a transaction. Skipped if NULL.
> > +     *
> > +     * Exactly one of .commit() and .abort() will be called for each job.
> > +     */
> > +    void (*commit)(BlockJob *job);
> > +
> 
> I find this phrasing strange, but maybe it's just me. "Exactly one of
> commit and abort will be called for each job" implies [to me] that it'd
> be possible to call commit for one, but abort for different jobs [in a
> transaction] -- but clearly we don't mean that. It is the "for each job"
> that implies an iteration over a collection to me.
> 
> Just above we say "[commit] will be invoked when all the jobs belonging
> to the same transaction are complete" which itself implies either all
> jobs will be committed or all jobs will be aborted.
> 
> Maybe:
> 
> "All jobs will complete with a call to either .commit() or .abort() but
> never both."
> 
> But I might be being too bikesheddy.
> 
> > +    /**
> > +     * If the callback is not NULL, it will be invoked when any job in the
> > +     * same transaction fails; or upon this job's failure (due to error or
> > +     * cancellation) if it is not in a transaction. Skipped if NULL.
> > +     *
> > +     * Exactly one of .commit() and .abort() will be called for each job.
> > +     */
> > +    void (*abort)(BlockJob *job);
> >  } BlockJobDriver;
> >  
> >  /**
> > 
> 
> I'm probably just too picky.
> 
> Reviewed-by: John Snow <jsnow@redhat.com>
> 

No problem, It makese sense, I'll use your words :)

Thanks.

Fam

^ permalink raw reply	[flat|nested] 29+ messages in thread

* Re: [Qemu-devel] [PATCH v6 09/14] block: Add block job transactions
  2015-09-21 23:23   ` John Snow
@ 2015-09-22  2:32     ` Fam Zheng
  0 siblings, 0 replies; 29+ messages in thread
From: Fam Zheng @ 2015-09-22  2:32 UTC (permalink / raw)
  To: John Snow
  Cc: Kevin Wolf, Jeff Cody, qemu-devel, Max Reitz, vsementsov,
	stefanha

On Mon, 09/21 19:23, John Snow wrote:
> >  void block_job_completed(BlockJob *job, int ret)
> >  {
> >      BlockDriverState *bs = job->bs;
> > @@ -98,8 +191,13 @@ void block_job_completed(BlockJob *job, int ret)
> >      assert(!job->completed);
> >      job->completed = true;
> >      job->ret = ret;
> > -    job->cb(job->opaque, ret);
> > -    block_job_unref(job);
> > +    if (!job->txn) {
> > +        block_job_completed_single(job);
> > +    } else if (ret < 0 || block_job_is_cancelled(job)) {
> > +        block_job_completed_txn_abort(job);
> > +    } else {
> 
> over here it just appears we assert that ret is simply greater than or
> equal to zero.

Yeah, I don't think we have any possible positive ret value.

Fam

^ permalink raw reply	[flat|nested] 29+ messages in thread

end of thread, other threads:[~2015-09-22  2:32 UTC | newest]

Thread overview: 29+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2015-09-15  6:11 [Qemu-devel] [PATCH v6 00/14] block: incremental backup transactions using BlockJobTxn Fam Zheng
2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 01/14] qapi: Add transaction support to block-dirty-bitmap operations Fam Zheng
2015-09-15 14:36   ` Eric Blake
2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 02/14] iotests: add transactional incremental backup test Fam Zheng
2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 03/14] block: rename BlkTransactionState and BdrvActionOps Fam Zheng
2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 04/14] backup: Extract dirty bitmap handling as a separate function Fam Zheng
2015-09-18 11:02   ` Max Reitz
2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 05/14] blockjob: Introduce reference count Fam Zheng
2015-09-21 22:19   ` John Snow
2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 06/14] blockjob: Add .commit and .abort block job actions Fam Zheng
2015-09-21 22:29   ` John Snow
2015-09-22  2:15     ` Fam Zheng
2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 07/14] blockjob: Add "completed" and "ret" in BlockJob Fam Zheng
2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 08/14] blockjob: Simplify block_job_finish_sync Fam Zheng
2015-09-21 22:50   ` John Snow
2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 09/14] block: Add block job transactions Fam Zheng
2015-09-18 11:16   ` Max Reitz
2015-09-21 23:23   ` John Snow
2015-09-22  2:32     ` Fam Zheng
2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 10/14] blockdev: make BlockJobTxn available to qmp 'transaction' Fam Zheng
2015-09-18 11:20   ` Max Reitz
2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 11/14] block/backup: support block job transactions Fam Zheng
2015-09-15 14:43   ` Eric Blake
2015-09-18 11:40   ` Max Reitz
2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 12/14] iotests: 124 - transactional failure test Fam Zheng
2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 13/14] qmp-commands.hx: Update the supported 'transaction' operations Fam Zheng
2015-09-15  6:11 ` [Qemu-devel] [PATCH v6 14/14] tests: add BlockJobTxn unit test Fam Zheng
2015-09-18 11:45   ` Max Reitz
2015-09-22  2:11     ` Fam Zheng

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