block/migration: Disable cache invalidate for incoming migration

When migrated using libvirt with "--copy-storage-all", at the end of
migration there is race between NBD mirroring task trying to do flush
and migration completion, both end up invalidating cache. Since qcow2
driver does not handle this situation very well, random crashes happen.

This disables the BDRV_O_INCOMING flag for the block device being migrated
once the cache has been invalidated.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

--

fixed parens by hand
Signed-off-by: Juan Quintela <quintela@redhat.com>

1 files changed, 5 insertions, 13 deletions

diff --git a/block.c b/block.c
index d3aebeb050..27533f3a81 100644
--- a/block.c
+++ b/block.c
@@ -5043,6 +5043,11 @@ void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp)
         return;
     }
 
+    if (!(bs->open_flags & BDRV_O_INCOMING)) {
+        return;
+    }
+    bs->open_flags &= ~BDRV_O_INCOMING;
+
     if (bs->drv->bdrv_invalidate_cache) {
         bs->drv->bdrv_invalidate_cache(bs, &local_err);
     } else if (bs->file) {
@@ -5078,19 +5083,6 @@ void bdrv_invalidate_cache_all(Error **errp)
     }
 }
 
-void bdrv_clear_incoming_migration_all(void)
-{
-    BlockDriverState *bs;
-
-    QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
-        AioContext *aio_context = bdrv_get_aio_context(bs);
-
-        aio_context_acquire(aio_context);
-        bs->open_flags = bs->open_flags & ~(BDRV_O_INCOMING);
-        aio_context_release(aio_context);
-    }
-}
-
 int bdrv_flush(BlockDriverState *bs)
 {
     Coroutine *co;