block: bdrv_invalidate_cache: invalidate children first

Current implementation invalidates firstly parent bds and then its
children. This leads to the following bug:

after incoming migration, in bdrv_invalidate_cache_all:
1. invalidate parent bds - reopen it with BDRV_O_INACTIVE cleared
2. child is not yet invalidated
3. parent check that its BDRV_O_INACTIVE is cleared
4. parent writes to child
5. assert in bdrv_co_pwritev, as BDRV_O_INACTIVE is set for child

This patch fixes it by just changing invalidate sequence: invalidate
children first.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20170131112308.54189-1-vsementsov@virtuozzo.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2017-01-31 14:23:08 +03:00 committed by Max Reitz
parent a6baa60807
commit 16e977d506

11
block.c
View File

@ -3248,19 +3248,18 @@ void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp)
if (!(bs->open_flags & BDRV_O_INACTIVE)) {
return;
}
bs->open_flags &= ~BDRV_O_INACTIVE;
if (bs->drv->bdrv_invalidate_cache) {
bs->drv->bdrv_invalidate_cache(bs, &local_err);
QLIST_FOREACH(child, &bs->children, next) {
bdrv_invalidate_cache(child->bs, &local_err);
if (local_err) {
bs->open_flags |= BDRV_O_INACTIVE;
error_propagate(errp, local_err);
return;
}
}
QLIST_FOREACH(child, &bs->children, next) {
bdrv_invalidate_cache(child->bs, &local_err);
bs->open_flags &= ~BDRV_O_INACTIVE;
if (bs->drv->bdrv_invalidate_cache) {
bs->drv->bdrv_invalidate_cache(bs, &local_err);
if (local_err) {
bs->open_flags |= BDRV_O_INACTIVE;
error_propagate(errp, local_err);