From: Pavel Begunkov asml.silence@gmail.com
[ Upstream commit 634578f800652035debba3098d8ab0d21af7c7a5 ]
It's not safe to call io_cqring_overflow_flush() for IOPOLL mode without hodling uring_lock, because it does synchronisation differently. Make sure we have it.
As for io_ring_exit_work(), we don't even need it there because io_ring_ctx_wait_and_kill() already set force flag making all overflowed requests to be dropped.
Cc: stable@vger.kernel.org # 5.5+ Signed-off-by: Pavel Begunkov asml.silence@gmail.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- fs/io_uring.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c index 0621f581943cd..b9d3209a5f9de 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -8369,8 +8369,6 @@ static void io_ring_exit_work(struct work_struct *work) * as nobody else will be looking for them. */ do { - if (ctx->rings) - io_cqring_overflow_flush(ctx, true, NULL, NULL); io_iopoll_try_reap_events(ctx); } while (!wait_for_completion_timeout(&ctx->ref_comp, HZ/20)); io_ring_ctx_free(ctx); @@ -8380,6 +8378,8 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) { mutex_lock(&ctx->uring_lock); percpu_ref_kill(&ctx->refs); + if (ctx->rings) + io_cqring_overflow_flush(ctx, true, NULL, NULL); mutex_unlock(&ctx->uring_lock);
io_kill_timeouts(ctx, NULL); @@ -8389,8 +8389,6 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) io_wq_cancel_all(ctx->io_wq);
/* if we failed setting up the ctx, we might not have any rings */ - if (ctx->rings) - io_cqring_overflow_flush(ctx, true, NULL, NULL); io_iopoll_try_reap_events(ctx); idr_for_each(&ctx->personality_idr, io_remove_personalities, ctx);
@@ -8654,7 +8652,9 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx, }
io_cancel_defer_files(ctx, task, files); + io_ring_submit_lock(ctx, (ctx->flags & IORING_SETUP_IOPOLL)); io_cqring_overflow_flush(ctx, true, task, files); + io_ring_submit_unlock(ctx, (ctx->flags & IORING_SETUP_IOPOLL));
while (__io_uring_cancel_task_requests(ctx, task, files)) { io_run_task_work(); @@ -8956,8 +8956,10 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, */ ret = 0; if (ctx->flags & IORING_SETUP_SQPOLL) { + io_ring_submit_lock(ctx, (ctx->flags & IORING_SETUP_IOPOLL)); if (!list_empty_careful(&ctx->cq_overflow_list)) io_cqring_overflow_flush(ctx, false, NULL, NULL); + io_ring_submit_unlock(ctx, (ctx->flags & IORING_SETUP_IOPOLL)); if (flags & IORING_ENTER_SQ_WAKEUP) wake_up(&ctx->sq_data->wait); if (flags & IORING_ENTER_SQ_WAIT)