6.1-stable review patch. If anyone has any objections, please let me know.
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From: Pavel Begunkov asml.silence@gmail.com
[ Upstream commit a7d755ed9ce9738af3db602eb29d32774a180bc7 ]
Leaving the CQ critical section in the middle of a overflow flushing can cause cqe reordering since the cache cq pointers are reset and any new cqe emitters that might get called in between are not going to be forced into io_cqe_cache_refill().
Fixes: eac2ca2d682f9 ("io_uring: check if we need to reschedule during overflow flush") Signed-off-by: Pavel Begunkov asml.silence@gmail.com Link: https://lore.kernel.org/r/90ba817f1a458f091f355f407de1c911d2b93bbf.174748378... Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- io_uring/io_uring.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index f39d66589180e..ad462724246a7 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -627,6 +627,7 @@ static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force) * to care for a non-real case. */ if (need_resched()) { + ctx->cqe_sentinel = ctx->cqe_cached; io_cq_unlock_post(ctx); mutex_unlock(&ctx->uring_lock); cond_resched();