The Wednesday 05 Mar 2014 à 23:22:30 (+0100), Max Reitz wrote :
> On 04.03.2014 17:42, Benoît Canet wrote:
> >Moving only the node_name one field could lead to some inconsitencies where a
> >node_name was defined on a bs which was not registered in the graph node
> >list.
> >
> >bdrv_swap between a named node bs and a non named node bs would lead to this.
> >
> >bdrv_make_anon would then crash because it would try to remove the bs from
> >the
> >graph node list while it is not in it.
> >
> >This patch remove named node bses from the graph node list before doing the
> >swap
> >then insert them back.
> >
> >Signed-off-by: Benoit Canet <ben...@irqsave.net>
> >---
> > block.c | 24 +++++++++++++++++++-----
> > 1 file changed, 19 insertions(+), 5 deletions(-)
> >
> >diff --git a/block.c b/block.c
> >index 749835c..71349e5 100644
> >--- a/block.c
> >+++ b/block.c
> >@@ -1846,11 +1846,6 @@ static void bdrv_move_feature_fields(BlockDriverState
> >*bs_dest,
> > pstrcpy(bs_dest->device_name, sizeof(bs_dest->device_name),
> > bs_src->device_name);
> > bs_dest->device_list = bs_src->device_list;
> >-
> >- /* keep the same entry in graph_bdrv_states
> >- * We do want to swap name but don't want to swap linked list entries
> >- */
> >- bs_dest->node_list = bs_src->node_list;
> > }
> > /*
> >@@ -1869,6 +1864,17 @@ void bdrv_swap(BlockDriverState *bs_new,
> >BlockDriverState *bs_old)
> > {
> > BlockDriverState tmp;
> >+ /* The code need to swap the node_name but simply swapping node_list
> >won't
>
> *needs
>
> >+ * work so first remove the nodes from the graph list, do the swap then
> >+ * insert them back if needed.
> >+ */
> >+ if (bs_new->node_name[0] != '\0') {
> >+ QTAILQ_REMOVE(&graph_bdrv_states, bs_new, node_list);
> >+ }
> >+ if (bs_old->node_name[0] != '\0') {
> >+ QTAILQ_REMOVE(&graph_bdrv_states, bs_old, node_list);
> >+ }
> >+
> > /* bs_new must be anonymous and shouldn't have anything fancy enabled
> > */
> > assert(bs_new->device_name[0] == '\0');
> > assert(QLIST_EMPTY(&bs_new->dirty_bitmaps));
> >@@ -1897,6 +1903,14 @@ void bdrv_swap(BlockDriverState *bs_new,
> >BlockDriverState *bs_old)
> > assert(bs_new->io_limits_enabled == false);
> > assert(!throttle_have_timer(&bs_new->throttle_state));
> >+ /* insert back the nodes in the graph node list if needed */
>
> The word order seems strange, I guess I'd put the "back" behind
> "nodes" (and maybe "into" instead of "in").
>
> >+ if (bs_new->node_name[0] != '\0') {
> >+ QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs_new, node_list);
> >+ }
> >+ if (bs_old->node_name[0] != '\0') {
> >+ QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs_old, node_list);
> >+ }
> >+
> > bdrv_rebind(bs_new);
> > bdrv_rebind(bs_old);
> > }
>
> Reviewed-by: Max Reitz <mre...@redhat.com>
>
Thanks a lot I'll respin while adding your reviewed-by.
Best regards
Benoît
