Re: [Qemu-devel] [PATCH v2] more check for replaced node

[Stefan Hajnoczi <stefanha@gmail.com>]

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On Wed, Jul 15, 2015 at 11:22:52AM +0800, Wen Congyang wrote:
> On 07/15/2015 11:05 AM, Fam Zheng wrote:
> > On Wed, 07/15 09:41, Wen Congyang wrote:
> >> We use mirror+replace to fix quorum's broken child. bs/s->common.bs
> >> is quorum, and to_replace is the broken child. The new child is target_bs.
> >> Without this patch, the replace node can be any node, and it can be
> >> top BDS with BB, or another quorum's child. We just check if the broken
> >> child is part of the quorum BDS in this patch.
> >>
> >> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
> >> ---
> >>  block.c               | 5 +++--
> >>  block/mirror.c        | 3 ++-
> >>  blockdev.c            | 2 +-
> >>  include/block/block.h | 3 ++-
> >>  4 files changed, 8 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/block.c b/block.c
> >> index d088ee0..090923c 100644
> >> --- a/block.c
> >> +++ b/block.c
> >> @@ -4077,7 +4077,8 @@ bool bdrv_is_first_non_filter(BlockDriverState *candidate)
> >>      return false;
> >>  }
> >>  
> >> -BlockDriverState *check_to_replace_node(const char *node_name, Error **errp)
> >> +BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
> >> +                                        const char *node_name, Error **errp)
> >>  {
> >>      BlockDriverState *to_replace_bs = bdrv_find_node(node_name);
> >>      AioContext *aio_context;
> >> @@ -4100,7 +4101,7 @@ BlockDriverState *check_to_replace_node(const char *node_name, Error **errp)
> >>       * Another benefit is that this tests exclude backing files which are
> >>       * blocked by the backing blockers.
> >>       */
> >> -    if (!bdrv_is_first_non_filter(to_replace_bs)) {
> >> +    if (!bdrv_recurse_is_first_non_filter(parent_bs, to_replace_bs)) {
> >>          error_setg(errp, "Only top most non filter can be replaced");
> >>          to_replace_bs = NULL;
> >>          goto out;
> >> diff --git a/block/mirror.c b/block/mirror.c
> >> index 238a070..b81077e 100644
> >> --- a/block/mirror.c
> >> +++ b/block/mirror.c
> >> @@ -626,7 +626,8 @@ static void mirror_complete(BlockJob *job, Error **errp)
> >>      if (s->replaces) {
> >>          AioContext *replace_aio_context;
> >>  
> >> -        s->to_replace = check_to_replace_node(s->replaces, &local_err);
> >> +        s->to_replace = check_to_replace_node(s->common.bs, s->replaces,
> >> +                                              &local_err);
> > 
> > Why is the check in qmp_drive_mirror not enough? Isn't this redundant?
> 
> I don't know why we check it twice. And I think it is redundant too.

Okay, does that mean you are dropping this patch now?

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