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[Qemu-devel] [PATCH v11 10/13] qapi: Add transaction support to block-di
From: |
John Snow |
Subject: |
[Qemu-devel] [PATCH v11 10/13] qapi: Add transaction support to block-dirty-bitmap-{add, enable, disable} |
Date: |
Mon, 12 Jan 2015 11:31:02 -0500 |
From: Fam Zheng <address@hidden>
This adds three qmp commands to transactions.
Users can stop a dirty bitmap, start backup of it, and start another
dirty bitmap atomically, so that the dirty bitmap is tracked
incrementally and we don't miss any write.
Signed-off-by: Fam Zheng <address@hidden>
Signed-off-by: John Snow <address@hidden>
---
blockdev.c | 105 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
qapi-schema.json | 5 ++-
2 files changed, 109 insertions(+), 1 deletion(-)
diff --git a/blockdev.c b/blockdev.c
index 114a94c..e283581 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1602,6 +1602,94 @@ static void drive_backup_clean(BlkTransactionState
*common)
}
}
+static void block_dirty_bitmap_add_prepare(BlkTransactionState *common,
+ Error **errp)
+{
+ BlockDirtyBitmapAdd *action;
+
+ action = common->action->block_dirty_bitmap_add;
+ qmp_block_dirty_bitmap_add(action->node_ref, action->name,
+ action->has_granularity, action->granularity,
+ errp);
+}
+
+static void block_dirty_bitmap_add_abort(BlkTransactionState *common)
+{
+ BlockDirtyBitmapAdd *action;
+
+ action = common->action->block_dirty_bitmap_add;
+ /* Should not fail meaningfully: IF the bitmap was added via .prepare(),
+ * then the node reference and bitmap name must have been valid.
+ * THUS: any failure here could only indicate the lack of a bitmap at all.
+ */
+ qmp_block_dirty_bitmap_remove(action->node_ref, action->name, NULL);
+}
+
+typedef struct BlockDirtyBitmapState {
+ BlkTransactionState common;
+ BdrvDirtyBitmap *bitmap;
+ AioContext *aio_context;
+} BlockDirtyBitmapState;
+
+/**
+ * Enable and Disable re-use the same preparation.
+ */
+static void block_dirty_bitmap_toggle_prepare(BlkTransactionState *common,
+ Error **errp)
+{
+ BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
+ common, common);
+ BlockDirtyBitmap *action;
+ BlockDriverState *bs;
+
+ /* We may be used by either enable or disable;
+ * We use the "enable" member of the union here,
+ * but "disable" should be functionally equivalent: */
+ action = common->action->block_dirty_bitmap_enable;
+ assert(action == common->action->block_dirty_bitmap_disable);
+
+ state->bitmap = block_dirty_bitmap_lookup(action->node_ref,
+ action->name,
+ &bs,
+ errp);
+ if (!state->bitmap) {
+ return;
+ }
+
+ if (bdrv_dirty_bitmap_frozen(state->bitmap)) {
+ error_setg(errp, "Cannot enable/disable a bitmap that is frozen.\n");
+ return;
+ }
+
+ /* AioContext is released in .clean() */
+ state->aio_context = bdrv_get_aio_context(bs);
+ aio_context_acquire(state->aio_context);
+}
+
+static void block_dirty_bitmap_enable_commit(BlkTransactionState *common)
+{
+ BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
+ common, common);
+ bdrv_enable_dirty_bitmap(state->bitmap);
+}
+
+static void block_dirty_bitmap_disable_commit(BlkTransactionState *common)
+{
+ BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
+ common, common);
+ bdrv_disable_dirty_bitmap(state->bitmap);
+}
+
+static void block_dirty_bitmap_toggle_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");
@@ -1636,6 +1724,23 @@ static const BdrvActionOps actions[] = {
.abort = internal_snapshot_abort,
.clean = internal_snapshot_clean,
},
+ [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ADD] = {
+ .instance_size = sizeof(BlkTransactionState),
+ .prepare = block_dirty_bitmap_add_prepare,
+ .abort = block_dirty_bitmap_add_abort,
+ },
+ [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ENABLE] = {
+ .instance_size = sizeof(BlockDirtyBitmapState),
+ .prepare = block_dirty_bitmap_toggle_prepare,
+ .commit = block_dirty_bitmap_enable_commit,
+ .clean = block_dirty_bitmap_toggle_clean,
+ },
+ [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_DISABLE] = {
+ .instance_size = sizeof(BlockDirtyBitmapState),
+ .prepare = block_dirty_bitmap_toggle_prepare,
+ .commit = block_dirty_bitmap_disable_commit,
+ .clean = block_dirty_bitmap_toggle_clean,
+ },
};
/*
diff --git a/qapi-schema.json b/qapi-schema.json
index 563b4ad..85f55d9 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1260,7 +1260,10 @@
'blockdev-snapshot-sync': 'BlockdevSnapshot',
'drive-backup': 'DriveBackup',
'abort': 'Abort',
- 'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal'
+ 'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal',
+ 'block-dirty-bitmap-add': 'BlockDirtyBitmapAdd',
+ 'block-dirty-bitmap-enable': 'BlockDirtyBitmap',
+ 'block-dirty-bitmap-disable': 'BlockDirtyBitmap'
} }
##
--
1.9.3
- [Qemu-devel] [PATCH v11 11/13] qmp: Add dirty bitmap status fields in query-block, (continued)
- [Qemu-devel] [PATCH v11 12/13] qemu-iotests: Add tests for drive-backup sync=dirty-bitmap, John Snow, 2015/01/12
- [Qemu-devel] [PATCH v11 10/13] qapi: Add transaction support to block-dirty-bitmap-{add, enable, disable},
John Snow <=
- [Qemu-devel] [PATCH v11 13/13] block: BdrvDirtyBitmap miscellaneous fixup, John Snow, 2015/01/12
- Re: [Qemu-devel] [PATCH v11 00/13] block: Incremental backup series, Fam Zheng, 2015/01/12
- Re: [Qemu-devel] [PATCH v11 00/13] block: Incremental backup series, John Snow, 2015/01/13
- Re: [Qemu-devel] [PATCH v11 00/13] block: Incremental backup series, John Snow, 2015/01/29
- Re: [Qemu-devel] [PATCH v11 00/13] block: Incremental backup series, Vladimir Sementsov-Ogievskiy, 2015/01/30