Commit a6a4b66b authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for-linus-20190516' of git://git.kernel.dk/linux-block 

Pull io_uring fixes from Jens Axboe:
 "A small set of fixes for io_uring.

  This contains:

   - smp_rmb() cleanup for io_cqring_events() (Jackie)

   - io_cqring_wait() simplification (Jackie)

   - removal of dead 'ev_flags' passing (me)

   - SQ poll CPU affinity verification fix (me)

   - SQ poll wait fix (Roman)

   - SQE command prep cleanup and fix (Stefan)"

* tag 'for-linus-20190516' of git://git.kernel.dk/linux-block:
  io_uring: use wait_event_interruptible for cq_wait conditional wait
  io_uring: adjust smp_rmb inside io_cqring_events
  io_uring: fix infinite wait in khread_park() on io_finish_async()
  io_uring: remove 'ev_flags' argument
  io_uring: fix failure to verify SQ_AFF cpu
  io_uring: fix race condition reading SQE data
parents 1718de78 fdb288a6

fs/io_uring.c

+31 −57
Original line number Diff line number Diff line
@@ -231,7 +231,6 @@ struct io_ring_ctx { 
	struct task_struct	*sqo_thread;	/* if using sq thread polling */

	struct mm_struct	*sqo_mm;

	wait_queue_head_t	sqo_wait;

	unsigned		sqo_stop;



	struct {

		/* CQ ring */
@@ -329,9 +328,8 @@ struct io_kiocb { 
#define REQ_F_IOPOLL_COMPLETED	2	/* polled IO has completed */

#define REQ_F_FIXED_FILE	4	/* ctx owns file */

#define REQ_F_SEQ_PREV		8	/* sequential with previous */

#define REQ_F_PREPPED		16	/* prep already done */

#define REQ_F_IO_DRAIN		32	/* drain existing IO first */

#define REQ_F_IO_DRAINED	64	/* drain done */

#define REQ_F_IO_DRAIN		16	/* drain existing IO first */

#define REQ_F_IO_DRAINED	32	/* drain done */

	u64			user_data;

	u32			error;	/* iopoll result from callback */

	u32			sequence;
@@ -490,7 +488,7 @@ static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx) 
}



static void io_cqring_fill_event(struct io_ring_ctx *ctx, u64 ki_user_data,

				 long res, unsigned ev_flags)

				 long res)

{

	struct io_uring_cqe *cqe;
@@ -503,7 +501,7 @@ static void io_cqring_fill_event(struct io_ring_ctx *ctx, u64 ki_user_data, 
	if (cqe) {

		WRITE_ONCE(cqe->user_data, ki_user_data);

		WRITE_ONCE(cqe->res, res);

		WRITE_ONCE(cqe->flags, ev_flags);

		WRITE_ONCE(cqe->flags, 0);

	} else {

		unsigned overflow = READ_ONCE(ctx->cq_ring->overflow);
@@ -522,12 +520,12 @@ static void io_cqring_ev_posted(struct io_ring_ctx *ctx) 
}



static void io_cqring_add_event(struct io_ring_ctx *ctx, u64 user_data,

				long res, unsigned ev_flags)

				long res)

{

	unsigned long flags;



	spin_lock_irqsave(&ctx->completion_lock, flags);

	io_cqring_fill_event(ctx, user_data, res, ev_flags);

	io_cqring_fill_event(ctx, user_data, res);

	io_commit_cqring(ctx);

	spin_unlock_irqrestore(&ctx->completion_lock, flags);
@@ -629,7 +627,7 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events, 
		req = list_first_entry(done, struct io_kiocb, list);

		list_del(&req->list);



		io_cqring_fill_event(ctx, req->user_data, req->error, 0);

		io_cqring_fill_event(ctx, req->user_data, req->error);

		(*nr_events)++;



		if (refcount_dec_and_test(&req->refs)) {
@@ -777,7 +775,7 @@ static void io_complete_rw(struct kiocb *kiocb, long res, long res2) 


	kiocb_end_write(kiocb);



	io_cqring_add_event(req->ctx, req->user_data, res, 0);

	io_cqring_add_event(req->ctx, req->user_data, res);

	io_put_req(req);

}
@@ -896,9 +894,6 @@ static int io_prep_rw(struct io_kiocb *req, const struct sqe_submit *s, 


	if (!req->file)

		return -EBADF;

	/* For -EAGAIN retry, everything is already prepped */

	if (req->flags & REQ_F_PREPPED)

		return 0;



	if (force_nonblock && !io_file_supports_async(req->file))

		force_nonblock = false;
@@ -941,7 +936,6 @@ static int io_prep_rw(struct io_kiocb *req, const struct sqe_submit *s, 
			return -EINVAL;

		kiocb->ki_complete = io_complete_rw;

	}

	req->flags |= REQ_F_PREPPED;

	return 0;

}
@@ -1216,7 +1210,7 @@ static int io_nop(struct io_kiocb *req, u64 user_data) 
	if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))

		return -EINVAL;



	io_cqring_add_event(ctx, user_data, err, 0);

	io_cqring_add_event(ctx, user_data, err);

	io_put_req(req);

	return 0;

}
@@ -1227,16 +1221,12 @@ static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe) 


	if (!req->file)

		return -EBADF;

	/* Prep already done (EAGAIN retry) */

	if (req->flags & REQ_F_PREPPED)

		return 0;



	if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))

		return -EINVAL;

	if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index))

		return -EINVAL;



	req->flags |= REQ_F_PREPPED;

	return 0;

}
@@ -1265,7 +1255,7 @@ static int io_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe, 
				end > 0 ? end : LLONG_MAX,

				fsync_flags & IORING_FSYNC_DATASYNC);



	io_cqring_add_event(req->ctx, sqe->user_data, ret, 0);

	io_cqring_add_event(req->ctx, sqe->user_data, ret);

	io_put_req(req);

	return 0;

}
@@ -1277,16 +1267,12 @@ static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe) 


	if (!req->file)

		return -EBADF;

	/* Prep already done (EAGAIN retry) */

	if (req->flags & REQ_F_PREPPED)

		return 0;



	if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))

		return -EINVAL;

	if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index))

		return -EINVAL;



	req->flags |= REQ_F_PREPPED;

	return ret;

}
@@ -1313,7 +1299,7 @@ static int io_sync_file_range(struct io_kiocb *req, 


	ret = sync_file_range(req->rw.ki_filp, sqe_off, sqe_len, flags);



	io_cqring_add_event(req->ctx, sqe->user_data, ret, 0);

	io_cqring_add_event(req->ctx, sqe->user_data, ret);

	io_put_req(req);

	return 0;

}
@@ -1371,7 +1357,7 @@ static int io_poll_remove(struct io_kiocb *req, const struct io_uring_sqe *sqe) 
	}

	spin_unlock_irq(&ctx->completion_lock);



	io_cqring_add_event(req->ctx, sqe->user_data, ret, 0);

	io_cqring_add_event(req->ctx, sqe->user_data, ret);

	io_put_req(req);

	return 0;

}
@@ -1380,7 +1366,7 @@ static void io_poll_complete(struct io_ring_ctx *ctx, struct io_kiocb *req, 
			     __poll_t mask)

{

	req->poll.done = true;

	io_cqring_fill_event(ctx, req->user_data, mangle_poll(mask), 0);

	io_cqring_fill_event(ctx, req->user_data, mangle_poll(mask));

	io_commit_cqring(ctx);

}
@@ -1700,7 +1686,7 @@ restart: 
		io_put_req(req);



		if (ret) {

			io_cqring_add_event(ctx, sqe->user_data, ret, 0);

			io_cqring_add_event(ctx, sqe->user_data, ret);

			io_put_req(req);

		}
@@ -2005,7 +1991,7 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, struct sqe_submit *sqes, 
			continue;

		}



		io_cqring_add_event(ctx, sqes[i].sqe->user_data, ret, 0);

		io_cqring_add_event(ctx, sqes[i].sqe->user_data, ret);

	}



	if (statep)
@@ -2028,7 +2014,7 @@ static int io_sq_thread(void *data) 
	set_fs(USER_DS);



	timeout = inflight = 0;

	while (!kthread_should_stop() && !ctx->sqo_stop) {

	while (!kthread_should_park()) {

		bool all_fixed, mm_fault = false;

		int i;
@@ -2090,7 +2076,7 @@ static int io_sq_thread(void *data) 
			smp_mb();



			if (!io_get_sqring(ctx, &sqes[0])) {

				if (kthread_should_stop()) {

				if (kthread_should_park()) {

					finish_wait(&ctx->sqo_wait, &wait);

					break;

				}
@@ -2140,7 +2126,6 @@ static int io_sq_thread(void *data) 
		mmput(cur_mm);

	}



	if (kthread_should_park())

	kthread_parkme();



	return 0;
@@ -2170,7 +2155,7 @@ static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit) 


		ret = io_submit_sqe(ctx, &s, statep);

		if (ret)

			io_cqring_add_event(ctx, s.sqe->user_data, ret, 0);

			io_cqring_add_event(ctx, s.sqe->user_data, ret);

	}

	io_commit_sqring(ctx);
@@ -2182,6 +2167,8 @@ static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit) 


static unsigned io_cqring_events(struct io_cq_ring *ring)

{

	/* See comment at the top of this file */

	smp_rmb();

	return READ_ONCE(ring->r.tail) - READ_ONCE(ring->r.head);

}
@@ -2194,11 +2181,8 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, 
{

	struct io_cq_ring *ring = ctx->cq_ring;

	sigset_t ksigmask, sigsaved;

	DEFINE_WAIT(wait);

	int ret;



	/* See comment at the top of this file */

	smp_rmb();

	if (io_cqring_events(ring) >= min_events)

		return 0;
@@ -2216,23 +2200,9 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, 
			return ret;

	}



	do {

		prepare_to_wait(&ctx->wait, &wait, TASK_INTERRUPTIBLE);



		ret = 0;

		/* See comment at the top of this file */

		smp_rmb();

		if (io_cqring_events(ring) >= min_events)

			break;



		schedule();



	ret = wait_event_interruptible(ctx->wait, io_cqring_events(ring) >= min_events);

	if (ret == -ERESTARTSYS)

		ret = -EINTR;

		if (signal_pending(current))

			break;

	} while (1);



	finish_wait(&ctx->wait, &wait);



	if (sig)

		restore_user_sigmask(sig, &sigsaved);
@@ -2273,8 +2243,11 @@ static int io_sqe_files_unregister(struct io_ring_ctx *ctx) 
static void io_sq_thread_stop(struct io_ring_ctx *ctx)

{

	if (ctx->sqo_thread) {

		ctx->sqo_stop = 1;

		mb();

		/*

		 * The park is a bit of a work-around, without it we get

		 * warning spews on shutdown with SQPOLL set and affinity

		 * set to a single CPU.

		 */

		kthread_park(ctx->sqo_thread);

		kthread_stop(ctx->sqo_thread);

		ctx->sqo_thread = NULL;
@@ -2467,10 +2440,11 @@ static int io_sq_offload_start(struct io_ring_ctx *ctx, 
			ctx->sq_thread_idle = HZ;



		if (p->flags & IORING_SETUP_SQ_AFF) {

			int cpu = array_index_nospec(p->sq_thread_cpu,

							nr_cpu_ids);

			int cpu = p->sq_thread_cpu;



			ret = -EINVAL;

			if (cpu >= nr_cpu_ids)

				goto err;

			if (!cpu_online(cpu))

				goto err;

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