Re: [PULL 21/50] block/block-backend.c: assertions for block-backend

[Philippe Mathieu-Daudé]

On 16/3/22 15:46, Emanuele Giuseppe Esposito wrote:
> Am 16/03/2022 um 13:53 schrieb Philippe Mathieu-Daudé:
> > On 16/3/22 13:44, Philippe Mathieu-Daudé wrote:
> > > Hi,
> > >
> > > On 4/3/22 17:46, Kevin Wolf wrote:
> > > > From: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> > > >
> > > > All the global state (GS) API functions will check that
> > > > qemu_in_main_thread() returns true. If not, it means
> > > > that the safety of BQL cannot be guaranteed, and
> > > > they need to be moved to I/O.
> > >
> > > I'm getting this crash:
> > >
> > > $ qemu-system-i386
> > > Assertion failed: (qemu_in_main_thread()), function blk_all_next, file
> > > block-backend.c, line 552.
> > > Abort trap: 6
> > >
> > > Assertion failed: (qemu_in_main_thread()), function blk_all_next, file
> > > block-backend.c, line 552.
> > > qemu-system-i386 was compiled with optimization - stepping may behave
> > > oddly; variables may not be available.
> > > Process 76914 stopped
> > > * thread #1, queue = 'com.apple.main-thread', stop reason = hit
> > > program assert
> > >       frame #4: 0x000000010057c2d4 qemu-system-i386`blk_all_next.cold.1
> > > at block-backend.c:552:5 [opt]
> > >      549    */
> > >      550   BlockBackend *blk_all_next(BlockBackend *blk)
> > >      551   {
> > > -> 552       GLOBAL_STATE_CODE();
> > >      553       return blk ? QTAILQ_NEXT(blk, link)
> > >      554                  : QTAILQ_FIRST(&block_backends);
> > >      555   }
> > > Target 1: (qemu-system-i386) stopped.
> >
> > Forgot to paste the backtrace:
> >
> > (lldb) bt
> > * thread #1, queue = 'com.apple.main-thread', stop reason = hit program
> > assert
> >      frame #0: 0x00000001908c99b8 libsystem_kernel.dylib`__pthread_kill + 8
> >      frame #1: 0x00000001908fceb0 libsystem_pthread.dylib`pthread_kill + 288
> >      frame #2: 0x000000019083a314 libsystem_c.dylib`abort + 164
> >      frame #3: 0x000000019083972c libsystem_c.dylib`__assert_rtn + 300
> >    * frame #4: 0x000000010057c2d4 qemu-system-i386`blk_all_next.cold.1 at
> > block-backend.c:552:5 [opt]
> >      frame #5: 0x00000001003c00b4
> > qemu-system-i386`blk_all_next(blk=<unavailable>) at
> > block-backend.c:552:5 [opt]
> >      frame #6: 0x00000001003d8f04
> > qemu-system-i386`qmp_query_block(errp=0x0000000000000000) at
> > qapi.c:591:16 [opt]
> >      frame #7: 0x000000010003ab0c qemu-system-i386`main [inlined]
> > addRemovableDevicesMenuItems at cocoa.m:1756:21 [opt]
> >      frame #8: 0x000000010003ab04
> > qemu-system-i386`main(argc=<unavailable>, argv=<unavailable>) at
> > cocoa.m:1980:5 [opt]
> >      frame #9: 0x00000001012690f4 dyld`start + 520
>
> I think Paolo and Peter talked about this a couple of days ago on #qemu,
> and have already found a solution if I remember correctly.
>
> Maybe it's worth to check with them first.

Maybe this discussion?

20220307151004.578069-1-pbonzini@redhat.com/">https://lore.kernel.org/qemu-devel/20220307151004.578069-1-pbonzini@redhat.com/

> Emanuele
> > > Bisected to this patch:
> > >
> > > 0439c5a4623d674efa0c72abd62ca6e98bb7cf87 is the first bad commit
> > >
> > > > Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> > > > Message-Id: <20220303151616.325444-9-eesposit@redhat.com>
> > > > Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> > > > ---
> > > >    block/block-backend.c  | 78 ++++++++++++++++++++++++++++++++++++++++++
> > > >    softmmu/qdev-monitor.c |  2 ++
> > > >    2 files changed, 80 insertions(+)