Re: [PATCH] blkdebug: ignore invalid rules in non-coroutine context

[Kevin Wolf <kwolf@redhat.com>]

Am 17.01.2023 um 16:44 hat Kevin Wolf geschrieben:
> Am 15.12.2022 um 14:02 hat Paolo Bonzini geschrieben:
> > blkdebug events can be called from either non-coroutine or coroutine
> > contexts.  However, suspend actions only make sense from within
> > a coroutine.  Currently, using those action would lead to an abort() in
> > qemu_coroutine_yield() ("Co-routine is yielding to no one").  Catch them
> > and print an error instead.
> > 
> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> > ---
> >  block.c                          |  2 +-
> >  block/blkdebug.c                 | 10 ++++++++--
> >  include/block/block-io.h         |  2 +-
> >  include/block/block_int-common.h |  3 ++-
> >  4 files changed, 12 insertions(+), 5 deletions(-)
> > 
> > diff --git a/block.c b/block.c
> > index 3f2bd128570e..49c66475c73e 100644
> > --- a/block.c
> > +++ b/block.c
> > @@ -6334,7 +6334,7 @@ BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs)
> >      return drv->bdrv_get_specific_stats(bs);
> >  }
> >  
> > -void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event)
> > +void coroutine_mixed_fn bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event)
> >  {
> >      IO_CODE();
> >      if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) {
> > diff --git a/block/blkdebug.c b/block/blkdebug.c
> > index 4265ca125e25..ce297961b7db 100644
> > --- a/block/blkdebug.c
> > +++ b/block/blkdebug.c
> > @@ -31,6 +31,7 @@
> >  #include "block/qdict.h"
> >  #include "qemu/module.h"
> >  #include "qemu/option.h"
> > +#include "qemu/error-report.h"
> >  #include "qapi/qapi-visit-block-core.h"
> >  #include "qapi/qmp/qdict.h"
> >  #include "qapi/qmp/qlist.h"
> > @@ -837,7 +838,7 @@ static void process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
> >      }
> >  }
> >  
> > -static void blkdebug_debug_event(BlockDriverState *bs, BlkdebugEvent event)
> > +static void coroutine_mixed_fn blkdebug_debug_event(BlockDriverState *bs, BlkdebugEvent event)
> >  {
> >      BDRVBlkdebugState *s = bs->opaque;
> >      struct BlkdebugRule *rule, *next;
> > @@ -855,7 +856,12 @@ static void blkdebug_debug_event(BlockDriverState *bs, BlkdebugEvent event)
> >      }
> >  
> >      while (actions_count[ACTION_SUSPEND] > 0) {
> > -        qemu_coroutine_yield();
> > +        if (qemu_in_coroutine()) {
> > +            qemu_coroutine_yield();
> > +        } else {
> > +            error_report("Non-coroutine event %s cannot suspend\n",
> > +                         BlkdebugEvent_lookup.array[event]);
> 
> error_report() already adds a newline, so we shouldn't have an "\n"
> here.
> 
> > +        }
> >          actions_count[ACTION_SUSPEND]--;
> >      }
> >  }
> 
> Thanks, fixed this up and applied to the block branch.

In fact, this conflicts with a patch in my series:

[PATCH v2 13/14] block: Convert bdrv_debug_event() to co_wrapper_mixed

Resolving the conflict essentially reverts this one because after that
patch it actually is a coroutine_fn. So I may just drop this one agian.

Kevin