Make it possible to set bitmap 'frozen' without a successor. This is needed to protect the bitmap during outgoing bitmap postcopy migration.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> --- include/block/dirty-bitmap.h | 1 + block/dirty-bitmap.c | 22 ++++++++++++++++++++-- 2 files changed, 21 insertions(+), 2 deletions(-) diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h index a9e2a92e4f..ae6d697850 100644 --- a/include/block/dirty-bitmap.h +++ b/include/block/dirty-bitmap.h @@ -39,6 +39,7 @@ uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs); uint32_t bdrv_dirty_bitmap_granularity(const BdrvDirtyBitmap *bitmap); bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap *bitmap); bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap); +void bdrv_dirty_bitmap_set_frozen(BdrvDirtyBitmap *bitmap, bool frozen); const char *bdrv_dirty_bitmap_name(const BdrvDirtyBitmap *bitmap); int64_t bdrv_dirty_bitmap_size(const BdrvDirtyBitmap *bitmap); DirtyBitmapStatus bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap); diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c index 7578863aa1..67fc6bd6e0 100644 --- a/block/dirty-bitmap.c +++ b/block/dirty-bitmap.c @@ -40,6 +40,8 @@ struct BdrvDirtyBitmap { QemuMutex *mutex; HBitmap *bitmap; /* Dirty bitmap implementation */ HBitmap *meta; /* Meta dirty bitmap */ + bool frozen; /* Bitmap is frozen, it can't be modified + through QMP */ BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status */ char *name; /* Optional non-empty unique ID */ int64_t size; /* Size of the bitmap, in bytes */ @@ -183,13 +185,22 @@ const char *bdrv_dirty_bitmap_name(const BdrvDirtyBitmap *bitmap) /* Called with BQL taken. */ bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap) { - return bitmap->successor; + return bitmap->frozen; +} + +/* Called with BQL taken. */ +void bdrv_dirty_bitmap_set_frozen(BdrvDirtyBitmap *bitmap, bool frozen) +{ + qemu_mutex_lock(bitmap->mutex); + assert(bitmap->successor == NULL); + bitmap->frozen = frozen; + qemu_mutex_unlock(bitmap->mutex); } /* Called with BQL taken. */ bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap *bitmap) { - return !(bitmap->disabled || bitmap->successor); + return !(bitmap->disabled || (bitmap->successor != NULL)); } /* Called with BQL taken. */ @@ -234,6 +245,7 @@ int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs, /* Install the successor and freeze the parent */ bitmap->successor = child; + bitmap->frozen = true; return 0; } @@ -266,6 +278,8 @@ BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState *bs, name = bitmap->name; bitmap->name = NULL; successor->name = name; + assert(bitmap->frozen); + bitmap->frozen = false; bitmap->successor = NULL; successor->persistent = bitmap->persistent; bitmap->persistent = false; @@ -298,6 +312,8 @@ BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs, return NULL; } bdrv_release_dirty_bitmap(bs, successor); + assert(parent->frozen); + parent->frozen = false; parent->successor = NULL; return parent; @@ -439,6 +455,8 @@ void bdrv_dirty_bitmap_release_successor(BlockDriverState *bs, if (parent->successor) { bdrv_release_dirty_bitmap_locked(bs, parent->successor); + assert(parent->frozen); + parent->frozen = false; parent->successor = NULL; } -- 2.11.1