Commit 85394299 authored by Jens Axboe's avatar Jens Axboe
Browse files

Merge branch 'io_uring-5.5' into for-linus 

* io_uring-5.5:
  io_uring: fix a typo in a comment
  io_uring: hook all linked requests via link_list
  io_uring: fix error handling in io_queue_link_head
  io_uring: use hash table for poll command lookups
parents ece841ab 0b4295b5

fs/io_uring.c

+69 −71
Original line number Diff line number Diff line
@@ -145,7 +145,7 @@ struct io_rings { 
	/*

	 * Number of completion events lost because the queue was full;

	 * this should be avoided by the application by making sure

	 * there are not more requests pending thatn there is space in

	 * there are not more requests pending than there is space in

	 * the completion queue.

	 *

	 * Written by the kernel, shouldn't be modified by the
@@ -275,7 +275,8 @@ struct io_ring_ctx { 
		 * manipulate the list, hence no extra locking is needed there.

		 */

		struct list_head	poll_list;

		struct rb_root		cancel_tree;

		struct hlist_head	*cancel_hash;

		unsigned		cancel_hash_bits;



		spinlock_t		inflight_lock;

		struct list_head	inflight_list;
@@ -355,7 +356,7 @@ struct io_kiocb { 
	struct io_ring_ctx	*ctx;

	union {

		struct list_head	list;

		struct rb_node		rb_node;

		struct hlist_node	hash_node;

	};

	struct list_head	link_list;

	unsigned int		flags;
@@ -444,6 +445,7 @@ static void io_ring_ctx_ref_free(struct percpu_ref *ref) 
static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)

{

	struct io_ring_ctx *ctx;

	int hash_bits;



	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);

	if (!ctx)
@@ -457,6 +459,21 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) 
	if (!ctx->completions)

		goto err;



	/*

	 * Use 5 bits less than the max cq entries, that should give us around

	 * 32 entries per hash list if totally full and uniformly spread.

	 */

	hash_bits = ilog2(p->cq_entries);

	hash_bits -= 5;

	if (hash_bits <= 0)

		hash_bits = 1;

	ctx->cancel_hash_bits = hash_bits;

	ctx->cancel_hash = kmalloc((1U << hash_bits) * sizeof(struct hlist_head),

					GFP_KERNEL);

	if (!ctx->cancel_hash)

		goto err;

	__hash_init(ctx->cancel_hash, 1U << hash_bits);



	if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free,

			    PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))

		goto err;
@@ -470,7 +487,6 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) 
	init_waitqueue_head(&ctx->wait);

	spin_lock_init(&ctx->completion_lock);

	INIT_LIST_HEAD(&ctx->poll_list);

	ctx->cancel_tree = RB_ROOT;

	INIT_LIST_HEAD(&ctx->defer_list);

	INIT_LIST_HEAD(&ctx->timeout_list);

	init_waitqueue_head(&ctx->inflight_wait);
@@ -481,6 +497,7 @@ err: 
	if (ctx->fallback_req)

		kmem_cache_free(req_cachep, ctx->fallback_req);

	kfree(ctx->completions);

	kfree(ctx->cancel_hash);

	kfree(ctx);

	return NULL;

}
@@ -899,7 +916,6 @@ static bool io_link_cancel_timeout(struct io_kiocb *req) 
static void io_req_link_next(struct io_kiocb *req, struct io_kiocb **nxtptr)

{

	struct io_ring_ctx *ctx = req->ctx;

	struct io_kiocb *nxt;

	bool wake_ev = false;



	/* Already got next link */
@@ -911,24 +927,21 @@ static void io_req_link_next(struct io_kiocb *req, struct io_kiocb **nxtptr) 
	 * potentially happen if the chain is messed up, check to be on the

	 * safe side.

	 */

	nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb, list);

	while (nxt) {

		list_del_init(&nxt->list);

	while (!list_empty(&req->link_list)) {

		struct io_kiocb *nxt = list_first_entry(&req->link_list,

						struct io_kiocb, link_list);



		if ((req->flags & REQ_F_LINK_TIMEOUT) &&

		    (nxt->flags & REQ_F_TIMEOUT)) {

		if (unlikely((req->flags & REQ_F_LINK_TIMEOUT) &&

			     (nxt->flags & REQ_F_TIMEOUT))) {

			list_del_init(&nxt->link_list);

			wake_ev |= io_link_cancel_timeout(nxt);

			nxt = list_first_entry_or_null(&req->link_list,

							struct io_kiocb, list);

			req->flags &= ~REQ_F_LINK_TIMEOUT;

			continue;

		}

		if (!list_empty(&req->link_list)) {

			INIT_LIST_HEAD(&nxt->link_list);

			list_splice(&req->link_list, &nxt->link_list);

			nxt->flags |= REQ_F_LINK;

		}



		list_del_init(&req->link_list);

		if (!list_empty(&nxt->link_list))

			nxt->flags |= REQ_F_LINK;

		*nxtptr = nxt;

		break;

	}
@@ -944,15 +957,15 @@ static void io_req_link_next(struct io_kiocb *req, struct io_kiocb **nxtptr) 
static void io_fail_links(struct io_kiocb *req)

{

	struct io_ring_ctx *ctx = req->ctx;

	struct io_kiocb *link;

	unsigned long flags;



	spin_lock_irqsave(&ctx->completion_lock, flags);



	while (!list_empty(&req->link_list)) {

		link = list_first_entry(&req->link_list, struct io_kiocb, list);

		list_del_init(&link->list);

		struct io_kiocb *link = list_first_entry(&req->link_list,

						struct io_kiocb, link_list);



		list_del_init(&link->link_list);

		trace_io_uring_fail_link(req, link);



		if ((req->flags & REQ_F_LINK_TIMEOUT) &&
@@ -2260,14 +2273,6 @@ out: 
#endif

}



static inline void io_poll_remove_req(struct io_kiocb *req)

{

	if (!RB_EMPTY_NODE(&req->rb_node)) {

		rb_erase(&req->rb_node, &req->ctx->cancel_tree);

		RB_CLEAR_NODE(&req->rb_node);

	}

}



static void io_poll_remove_one(struct io_kiocb *req)

{

	struct io_poll_iocb *poll = &req->poll;
@@ -2279,17 +2284,21 @@ static void io_poll_remove_one(struct io_kiocb *req) 
		io_queue_async_work(req);

	}

	spin_unlock(&poll->head->lock);

	io_poll_remove_req(req);

	hash_del(&req->hash_node);

}



static void io_poll_remove_all(struct io_ring_ctx *ctx)

{

	struct rb_node *node;

	struct hlist_node *tmp;

	struct io_kiocb *req;

	int i;



	spin_lock_irq(&ctx->completion_lock);

	while ((node = rb_first(&ctx->cancel_tree)) != NULL) {

		req = rb_entry(node, struct io_kiocb, rb_node);

	for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {

		struct hlist_head *list;



		list = &ctx->cancel_hash[i];

		hlist_for_each_entry_safe(req, tmp, list, hash_node)

			io_poll_remove_one(req);

	}

	spin_unlock_irq(&ctx->completion_lock);
@@ -2297,18 +2306,12 @@ static void io_poll_remove_all(struct io_ring_ctx *ctx) 


static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr)

{

	struct rb_node *p, *parent = NULL;

	struct hlist_head *list;

	struct io_kiocb *req;



	p = ctx->cancel_tree.rb_node;

	while (p) {

		parent = p;

		req = rb_entry(parent, struct io_kiocb, rb_node);

		if (sqe_addr < req->user_data) {

			p = p->rb_left;

		} else if (sqe_addr > req->user_data) {

			p = p->rb_right;

		} else {

	list = &ctx->cancel_hash[hash_long(sqe_addr, ctx->cancel_hash_bits)];

	hlist_for_each_entry(req, list, hash_node) {

		if (sqe_addr == req->user_data) {

			io_poll_remove_one(req);

			return 0;

		}
@@ -2390,7 +2393,7 @@ static void io_poll_complete_work(struct io_wq_work **workptr) 
		spin_unlock_irq(&ctx->completion_lock);

		return;

	}

	io_poll_remove_req(req);

	hash_del(&req->hash_node);

	io_poll_complete(req, mask, ret);

	spin_unlock_irq(&ctx->completion_lock);
@@ -2425,7 +2428,7 @@ static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, 
	 * for finalizing the request, mark us as having grabbed that already.

	 */

	if (mask && spin_trylock_irqsave(&ctx->completion_lock, flags)) {

		io_poll_remove_req(req);

		hash_del(&req->hash_node);

		io_poll_complete(req, mask, 0);

		req->flags |= REQ_F_COMP_LOCKED;

		io_put_req(req);
@@ -2463,20 +2466,10 @@ static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head, 
static void io_poll_req_insert(struct io_kiocb *req)

{

	struct io_ring_ctx *ctx = req->ctx;

	struct rb_node **p = &ctx->cancel_tree.rb_node;

	struct rb_node *parent = NULL;

	struct io_kiocb *tmp;



	while (*p) {

		parent = *p;

		tmp = rb_entry(parent, struct io_kiocb, rb_node);

		if (req->user_data < tmp->user_data)

			p = &(*p)->rb_left;

		else

			p = &(*p)->rb_right;

	}

	rb_link_node(&req->rb_node, parent, p);

	rb_insert_color(&req->rb_node, &ctx->cancel_tree);

	struct hlist_head *list;



	list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)];

	hlist_add_head(&req->hash_node, list);

}



static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe,
@@ -2504,7 +2497,7 @@ static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe, 
	INIT_IO_WORK(&req->work, io_poll_complete_work);

	events = READ_ONCE(sqe->poll_events);

	poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP;

	RB_CLEAR_NODE(&req->rb_node);

	INIT_HLIST_NODE(&req->hash_node);



	poll->head = NULL;

	poll->done = false;
@@ -3173,10 +3166,11 @@ static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer) 
	 * We don't expect the list to be empty, that will only happen if we

	 * race with the completion of the linked work.

	 */

	if (!list_empty(&req->list)) {

		prev = list_entry(req->list.prev, struct io_kiocb, link_list);

	if (!list_empty(&req->link_list)) {

		prev = list_entry(req->link_list.prev, struct io_kiocb,

				  link_list);

		if (refcount_inc_not_zero(&prev->refs)) {

			list_del_init(&req->list);

			list_del_init(&req->link_list);

			prev->flags &= ~REQ_F_LINK_TIMEOUT;

		} else

			prev = NULL;
@@ -3206,7 +3200,7 @@ static void io_queue_linked_timeout(struct io_kiocb *req) 
	 * we got a chance to setup the timer

	 */

	spin_lock_irq(&ctx->completion_lock);

	if (!list_empty(&req->list)) {

	if (!list_empty(&req->link_list)) {

		struct io_timeout_data *data = &req->io->timeout;



		data->timer.function = io_link_timeout_fn;
@@ -3226,7 +3220,8 @@ static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req) 
	if (!(req->flags & REQ_F_LINK))

		return NULL;



	nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb, list);

	nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb,

					link_list);

	if (!nxt || nxt->sqe->opcode != IORING_OP_LINK_TIMEOUT)

		return NULL;
@@ -3318,7 +3313,7 @@ static inline void io_queue_link_head(struct io_kiocb *req) 


#define SQE_VALID_FLAGS	(IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK)



static void io_submit_sqe(struct io_kiocb *req, struct io_submit_state *state,

static bool io_submit_sqe(struct io_kiocb *req, struct io_submit_state *state,

			  struct io_kiocb **link)

{

	struct io_ring_ctx *ctx = req->ctx;
@@ -3337,7 +3332,7 @@ static void io_submit_sqe(struct io_kiocb *req, struct io_submit_state *state, 
err_req:

		io_cqring_add_event(req, ret);

		io_double_put_req(req);

		return;

		return false;

	}



	/*
@@ -3367,7 +3362,7 @@ err_req: 
			goto err_req;

		}

		trace_io_uring_link(ctx, req, prev);

		list_add_tail(&req->list, &prev->link_list);

		list_add_tail(&req->link_list, &prev->link_list);

	} else if (req->sqe->flags & IOSQE_IO_LINK) {

		req->flags |= REQ_F_LINK;
@@ -3376,6 +3371,8 @@ err_req: 
	} else {

		io_queue_sqe(req);

	}



	return true;

}



/*
@@ -3505,6 +3502,7 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr, 
			}

		}



		submitted++;

		sqe_flags = req->sqe->flags;



		req->ring_file = ring_file;
@@ -3514,9 +3512,8 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr, 
		req->needs_fixed_file = async;

		trace_io_uring_submit_sqe(ctx, req->sqe->user_data,

					  true, async);

		io_submit_sqe(req, statep, &link);

		submitted++;



		if (!io_submit_sqe(req, statep, &link))

			break;

		/*

		 * If previous wasn't linked and we have a linked command,

		 * that's the end of the chain. Submit the previous link.
@@ -4644,6 +4641,7 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx) 
	free_uid(ctx->user);

	put_cred(ctx->creds);

	kfree(ctx->completions);

	kfree(ctx->cancel_hash);

	kmem_cache_free(req_cachep, ctx->fallback_req);

	kfree(ctx);

}

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