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

[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

> 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(+)