> -----Original Message-----
> From: Philippe Mathieu-Daudé <phi...@linaro.org>
> Sent: Wednesday, April 17, 2024 2:14 PM
> To: Li Zhijian <lizhij...@fujitsu.com>; Zhang, Hailiang
> <zhanghaili...@xfusion.com>; pet...@redhat.com; faro...@suse.de
> Cc: qemu-devel@nongnu.org; Zhang, Chen <chen.zh...@intel.com>; Wen
> Congyang <wencongya...@huawei.com>; Xie Changlong
> <xiechanglon...@gmail.com>
> Subject: Re: [PATCH v2] migration/colo: Fix bdrv_graph_rdlock_main_loop:
> Assertion `!qemu_in_coroutine()' failed.
>
> On 17/4/24 04:56, Li Zhijian via wrote:
> > bdrv_activate_all() should not be called from the coroutine context,
> > move it to the QEMU thread colo_process_incoming_thread() with the
> > bql_lock protected.
> >
> > The backtrace is as follows:
> > #4 0x0000561af7948362 in bdrv_graph_rdlock_main_loop ()
> at ../block/graph-lock.c:260
> > #5 0x0000561af7907a68 in graph_lockable_auto_lock_mainloop
> (x=0x7fd29810be7b) at /patch/to/qemu/include/block/graph-lock.h:259
> > #6 0x0000561af79167d1 in bdrv_activate_all (errp=0x7fd29810bed0)
> at ../block.c:6906
> > #7 0x0000561af762b4af in colo_incoming_co () at ../migration/colo.c:935
> > #8 0x0000561af7607e57 in process_incoming_migration_co (opaque=0x0)
> at ../migration/migration.c:793
> > #9 0x0000561af7adbeeb in coroutine_trampoline (i0=-106876144,
> i1=22042) at ../util/coroutine-ucontext.c:175
> > #10 0x00007fd2a5cf21c0 in () at /lib64/libc.so.6
> >
> > CC: Fabiano Rosas <faro...@suse.de>
>
> Cc: qemu-sta...@nongnu.org
>
> > Closes: https://gitlab.com/qemu-project/qemu/-/issues/2277
> > Fixes: 2b3912f135 ("block: Mark bdrv_first_blk() and
> > bdrv_is_root_node() GRAPH_RDLOCK")
> > Signed-off-by: Li Zhijian <lizhij...@fujitsu.com>
It looks good to me. And already verified this patch in my environment.
After address Phillippe's comments please add:
Reviewed-by: Zhang Chen <chen.zh...@intel.com>
Tested-by: Zhang Chen <chen.zh...@intel.com>
Thanks
Chen
> > ---
> > V2: fix missing bql_unlock() in error path.
> > ---
> > migration/colo.c | 18 ++++++++++--------
> > 1 file changed, 10 insertions(+), 8 deletions(-)
> >
> > diff --git a/migration/colo.c b/migration/colo.c index
> > 84632a603e..5600a43d78 100644
> > --- a/migration/colo.c
> > +++ b/migration/colo.c
> > @@ -835,6 +835,16 @@ static void *colo_process_incoming_thread(void
> *opaque)
> > return NULL;
> > }
> >
> > + /* Make sure all file formats throw away their mutable metadata */
> > + bql_lock();
>
> Note there is also the convenient BQL_LOCK_GUARD() macro.
>
> > + bdrv_activate_all(&local_err);
> > + if (local_err) {
> > + bql_unlock();
> > + error_report_err(local_err);
> > + return NULL;
> > + }
> > + bql_unlock();
> > +
> > failover_init_state();
