Is bdrv_poll_co() IO_CODE()?

Is bdrv_poll_co() IO_CODE()?

[Stefan Hajnoczi]

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Hi,
bdrv_coroutine_enter() is IO_CODE but is called from any coroutine
wrapper function. When there is an IOThread and main loop code calls a
coroutine wrapper function then I think bdrv_coroutine_enter() is called
from outside IO_CODE?

Thanks,
Stefan

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Re: Is bdrv_poll_co() IO_CODE()?

[Paolo Bonzini]

On 11/10/22 22:25, Stefan Hajnoczi wrote:
> Hi,
> bdrv_coroutine_enter() is IO_CODE but is called from any coroutine
> wrapper function. When there is an IOThread and main loop code calls a
> coroutine wrapper function then I think bdrv_coroutine_enter() is called
> from outside IO_CODE?

No, I think bdrv_poll_co() should be IO_OR_GS_CODE().

"These functions use BDRV_POLL_WHILE(bs), which requires the caller to 
be either in the main thread and hold the BlockdriverState (bs) 
AioContext lock, or directly in the home thread that runs the bs 
AioContext. Calling them from another thread in another AioContext would 
cause deadlocks." describes it very well.

bdrv_coroutine_enter() is IO_CODE because it's able to start the 
coroutine on the right iothread (using aio_co_schedule() if needed).

Paolo