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Date:   Sun, 20 Aug 2023 19:18:59 +0100
From:   Matthew Wilcox <willy@infradead.org>
To:     Jens Axboe <axboe@kernel.dk>
Cc:     Qu Wenruo <quwenruo.btrfs@gmx.com>,
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Subject: Re: Possible io_uring related race leads to btrfs data csum mismatch
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On Sun, Aug 20, 2023 at 08:11:04AM -0600, Jens Axboe wrote:
> +static int io_get_single_event(struct io_event *event)
> +{
> +	int ret;
> +
> +	do {
> +		/*
> +		 * We can get -EINTR if competing with io_uring using signal
> +		 * based notifications. For that case, just retry the wait.
> +		 */
> +		ret = io_getevents(io_ctx, 1, 1, event, NULL);
> +		if (ret != -EINTR)
> +			break;
> +	} while (1);
> +
> +	return ret;
> +}

Is there a reason to prefer this style over:

	do {
		ret = io_getevents(io_ctx, 1, 1, event, NULL);
	} while (ret == -1 && errno == EINTR);

(we need to check errno, here, right?  Or is io_getevents() special
somehow?)