4 files changed, 36 insertions, 127 deletions

diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index 4b9ba523978d..d8ca27da1341 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -291,7 +291,7 @@ struct io_ring_ctx {
 
 		struct xarray		io_bl_xa;
 
-		struct io_hash_table	cancel_table_locked;
+		struct io_hash_table	cancel_table;
 		struct io_alloc_cache	apoll_cache;
 		struct io_alloc_cache	netmsg_cache;
 		struct io_alloc_cache	rw_cache;
@@ -342,7 +342,6 @@ struct io_ring_ctx {
 
 	struct list_head	io_buffers_comp;
 	struct list_head	cq_overflow_list;
-	struct io_hash_table	cancel_table;
 
 	struct hlist_head	waitid_list;
 
@@ -459,7 +458,6 @@ enum {
 	REQ_F_DOUBLE_POLL_BIT,
 	REQ_F_APOLL_MULTISHOT_BIT,
 	REQ_F_CLEAR_POLLIN_BIT,
-	REQ_F_HASH_LOCKED_BIT,
 	/* keep async read/write and isreg together and in order */
 	REQ_F_SUPPORT_NOWAIT_BIT,
 	REQ_F_ISREG_BIT,
@@ -534,8 +532,6 @@ enum {
 	REQ_F_APOLL_MULTISHOT	= IO_REQ_FLAG(REQ_F_APOLL_MULTISHOT_BIT),
 	/* recvmsg special flag, clear EPOLLIN */
 	REQ_F_CLEAR_POLLIN	= IO_REQ_FLAG(REQ_F_CLEAR_POLLIN_BIT),
-	/* hashed into ->cancel_hash_locked, protected by ->uring_lock */
-	REQ_F_HASH_LOCKED	= IO_REQ_FLAG(REQ_F_HASH_LOCKED_BIT),
 	/* don't use lazy poll wake for this request */
 	REQ_F_POLL_NO_LAZY	= IO_REQ_FLAG(REQ_F_POLL_NO_LAZY_BIT),
 	/* file is pollable */
diff --git a/io_uring/fdinfo.c b/io_uring/fdinfo.c
index 6b1247664b35..a6bac533edbe 100644
--- a/io_uring/fdinfo.c
+++ b/io_uring/fdinfo.c
@@ -190,22 +190,13 @@ __cold void io_uring_show_fdinfo(struct seq_file *m, struct file *file)
 	}
 
 	seq_puts(m, "PollList:\n");
-	for (i = 0; i < (1U << ctx->cancel_table.hash_bits); i++) {
+	for (i = 0; has_lock && i < (1U << ctx->cancel_table.hash_bits); i++) {
 		struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i];
-		struct io_hash_bucket *hbl = &ctx->cancel_table_locked.hbs[i];
 		struct io_kiocb *req;
 
-		spin_lock(&hb->lock);
 		hlist_for_each_entry(req, &hb->list, hash_node)
 			seq_printf(m, "  op=%d, task_works=%d\n", req->opcode,
 					task_work_pending(req->task));
-		spin_unlock(&hb->lock);
-
-		if (!has_lock)
-			continue;
-		hlist_for_each_entry(req, &hbl->list, hash_node)
-			seq_printf(m, "  op=%d, task_works=%d\n", req->opcode,
-					task_work_pending(req->task));
 	}
 
 	if (has_lock)
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index b2736e3491b8..f4e069cd03a5 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -294,8 +294,6 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
 	hash_bits = clamp(hash_bits, 1, 8);
 	if (io_alloc_hash_table(&ctx->cancel_table, hash_bits))
 		goto err;
-	if (io_alloc_hash_table(&ctx->cancel_table_locked, hash_bits))
-		goto err;
 	if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free,
 			    0, GFP_KERNEL))
 		goto err;
@@ -361,7 +359,6 @@ err:
 	io_alloc_cache_free(&ctx->msg_cache, io_msg_cache_free);
 	io_futex_cache_free(ctx);
 	kfree(ctx->cancel_table.hbs);
-	kfree(ctx->cancel_table_locked.hbs);
 	xa_destroy(&ctx->io_bl_xa);
 	kfree(ctx);
 	return NULL;
@@ -2774,7 +2771,6 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
 		io_wq_put_hash(ctx->hash_map);
 	io_napi_free(ctx);
 	kfree(ctx->cancel_table.hbs);
-	kfree(ctx->cancel_table_locked.hbs);
 	xa_destroy(&ctx->io_bl_xa);
 	kfree(ctx);
 }
diff --git a/io_uring/poll.c b/io_uring/poll.c
index 175c279e59ea..217d667e0622 100644
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -122,28 +122,6 @@ static void io_poll_req_insert(struct io_kiocb *req)
 {
 	struct io_hash_table *table = &req->ctx->cancel_table;
 	u32 index = hash_long(req->cqe.user_data, table->hash_bits);
-	struct io_hash_bucket *hb = &table->hbs[index];
-
-	spin_lock(&hb->lock);
-	hlist_add_head(&req->hash_node, &hb->list);
-	spin_unlock(&hb->lock);
-}
-
-static void io_poll_req_delete(struct io_kiocb *req)
-{
-	struct io_hash_table *table = &req->ctx->cancel_table;
-	u32 index = hash_long(req->cqe.user_data, table->hash_bits);
-	spinlock_t *lock = &table->hbs[index].lock;
-
-	spin_lock(lock);
-	hash_del(&req->hash_node);
-	spin_unlock(lock);
-}
-
-static void io_poll_req_insert_locked(struct io_kiocb *req)
-{
-	struct io_hash_table *table = &req->ctx->cancel_table_locked;
-	u32 index = hash_long(req->cqe.user_data, table->hash_bits);
 
 	lockdep_assert_held(&req->ctx->uring_lock);
 
@@ -154,19 +132,14 @@ static void io_poll_tw_hash_eject(struct io_kiocb *req, struct io_tw_state *ts)
 {
 	struct io_ring_ctx *ctx = req->ctx;
 
-	if (req->flags & REQ_F_HASH_LOCKED) {
-		/*
-		 * ->cancel_table_locked is protected by ->uring_lock in
-		 * contrast to per bucket spinlocks. Likely, tctx_task_work()
-		 * already grabbed the mutex for us, but there is a chance it
-		 * failed.
-		 */
-		io_tw_lock(ctx, ts);
-		hash_del(&req->hash_node);
-		req->flags &= ~REQ_F_HASH_LOCKED;
-	} else {
-		io_poll_req_delete(req);
-	}
+	/*
+	 * ->cancel_table_locked is protected by ->uring_lock in
+	 * contrast to per bucket spinlocks. Likely, tctx_task_work()
+	 * already grabbed the mutex for us, but there is a chance it
+	 * failed.
+	 */
+	io_tw_lock(ctx, ts);
+	hash_del(&req->hash_node);
 }
 
 static void io_init_poll_iocb(struct io_poll *poll, __poll_t events)
@@ -563,12 +536,13 @@ static bool io_poll_can_finish_inline(struct io_kiocb *req,
 	return pt->owning || io_poll_get_ownership(req);
 }
 
-static void io_poll_add_hash(struct io_kiocb *req)
+static void io_poll_add_hash(struct io_kiocb *req, unsigned int issue_flags)
 {
-	if (req->flags & REQ_F_HASH_LOCKED)
-		io_poll_req_insert_locked(req);
-	else
-		io_poll_req_insert(req);
+	struct io_ring_ctx *ctx = req->ctx;
+
+	io_ring_submit_lock(ctx, issue_flags);
+	io_poll_req_insert(req);
+	io_ring_submit_unlock(ctx, issue_flags);
 }
 
 /*
@@ -605,11 +579,6 @@ static int __io_arm_poll_handler(struct io_kiocb *req,
 	ipt->owning = issue_flags & IO_URING_F_UNLOCKED;
 	atomic_set(&req->poll_refs, (int)ipt->owning);
 
-	/* io-wq doesn't hold uring_lock */
-	if (issue_flags & IO_URING_F_UNLOCKED)
-		req->flags &= ~REQ_F_HASH_LOCKED;
-
-
 	/*
 	 * Exclusive waits may only wake a limited amount of entries
 	 * rather than all of them, this may interfere with lazy
@@ -638,7 +607,7 @@ static int __io_arm_poll_handler(struct io_kiocb *req,
 	if (mask &&
 	   ((poll->events & (EPOLLET|EPOLLONESHOT)) == (EPOLLET|EPOLLONESHOT))) {
 		if (!io_poll_can_finish_inline(req, ipt)) {
-			io_poll_add_hash(req);
+			io_poll_add_hash(req, issue_flags);
 			return 0;
 		}
 		io_poll_remove_entries(req);
@@ -647,7 +616,7 @@ static int __io_arm_poll_handler(struct io_kiocb *req,
 		return 1;
 	}
 
-	io_poll_add_hash(req);
+	io_poll_add_hash(req, issue_flags);
 
 	if (mask && (poll->events & EPOLLET) &&
 	    io_poll_can_finish_inline(req, ipt)) {
@@ -720,12 +689,6 @@ int io_arm_poll_handler(struct io_kiocb *req, unsigned issue_flags)
 	__poll_t mask = POLLPRI | POLLERR | EPOLLET;
 	int ret;
 
-	/*
-	 * apoll requests already grab the mutex to complete in the tw handler,
-	 * so removal from the mutex-backed hash is free, use it by default.
-	 */
-	req->flags |= REQ_F_HASH_LOCKED;
-
 	if (!def->pollin && !def->pollout)
 		return IO_APOLL_ABORTED;
 	if (!io_file_can_poll(req))
@@ -761,18 +724,22 @@ int io_arm_poll_handler(struct io_kiocb *req, unsigned issue_flags)
 	return IO_APOLL_OK;
 }
 
-static __cold bool io_poll_remove_all_table(struct task_struct *tsk,
-					    struct io_hash_table *table,
-					    bool cancel_all)
+/*
+ * Returns true if we found and killed one or more poll requests
+ */
+__cold bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk,
+			       bool cancel_all)
 {
-	unsigned nr_buckets = 1U << table->hash_bits;
+	unsigned nr_buckets = 1U << ctx->cancel_table.hash_bits;
 	struct hlist_node *tmp;
 	struct io_kiocb *req;
 	bool found = false;
 	int i;
 
+	lockdep_assert_held(&ctx->uring_lock);
+
 	for (i = 0; i < nr_buckets; i++) {
-		struct io_hash_bucket *hb = &table->hbs[i];
+		struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i];
 
 		spin_lock(&hb->lock);
 		hlist_for_each_entry_safe(req, tmp, &hb->list, hash_node) {
@@ -787,28 +754,13 @@ static __cold bool io_poll_remove_all_table(struct task_struct *tsk,
 	return found;
 }
 
-/*
- * Returns true if we found and killed one or more poll requests
- */
-__cold bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk,
-			       bool cancel_all)
-	__must_hold(&ctx->uring_lock)
-{
-	bool ret;
-
-	ret = io_poll_remove_all_table(tsk, &ctx->cancel_table, cancel_all);
-	ret |= io_poll_remove_all_table(tsk, &ctx->cancel_table_locked, cancel_all);
-	return ret;
-}
-
 static struct io_kiocb *io_poll_find(struct io_ring_ctx *ctx, bool poll_only,
 				     struct io_cancel_data *cd,
-				     struct io_hash_table *table,
 				     struct io_hash_bucket **out_bucket)
 {
 	struct io_kiocb *req;
-	u32 index = hash_long(cd->data, table->hash_bits);
-	struct io_hash_bucket *hb = &table->hbs[index];
+	u32 index = hash_long(cd->data, ctx->cancel_table.hash_bits);
+	struct io_hash_bucket *hb = &ctx->cancel_table.hbs[index];
 
 	*out_bucket = NULL;
 
@@ -831,17 +783,16 @@ static struct io_kiocb *io_poll_find(struct io_ring_ctx *ctx, bool poll_only,
 
 static struct io_kiocb *io_poll_file_find(struct io_ring_ctx *ctx,
 					  struct io_cancel_data *cd,
-					  struct io_hash_table *table,
 					  struct io_hash_bucket **out_bucket)
 {
-	unsigned nr_buckets = 1U << table->hash_bits;
+	unsigned nr_buckets = 1U << ctx->cancel_table.hash_bits;
 	struct io_kiocb *req;
 	int i;
 
 	*out_bucket = NULL;
 
 	for (i = 0; i < nr_buckets; i++) {
-		struct io_hash_bucket *hb = &table->hbs[i];
+		struct io_hash_bucket *hb = &ctx->cancel_table.hbs[i];
 
 		spin_lock(&hb->lock);
 		hlist_for_each_entry(req, &hb->list, hash_node) {
@@ -866,17 +817,16 @@ static int io_poll_disarm(struct io_kiocb *req)
 	return 0;
 }
 
-static int __io_poll_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd,
-			    struct io_hash_table *table)
+static int __io_poll_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd)
 {
 	struct io_hash_bucket *bucket;
 	struct io_kiocb *req;
 
 	if (cd->flags & (IORING_ASYNC_CANCEL_FD | IORING_ASYNC_CANCEL_OP |
 			 IORING_ASYNC_CANCEL_ANY))
-		req = io_poll_file_find(ctx, cd, table, &bucket);
+		req = io_poll_file_find(ctx, cd, &bucket);
 	else
-		req = io_poll_find(ctx, false, cd, table, &bucket);
+		req = io_poll_find(ctx, false, cd, &bucket);
 
 	if (req)
 		io_poll_cancel_req(req);
@@ -890,12 +840,8 @@ int io_poll_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd,
 {
 	int ret;
 
-	ret = __io_poll_cancel(ctx, cd, &ctx->cancel_table);
-	if (ret != -ENOENT)
-		return ret;
-
 	io_ring_submit_lock(ctx, issue_flags);
-	ret = __io_poll_cancel(ctx, cd, &ctx->cancel_table_locked);
+	ret = __io_poll_cancel(ctx, cd);
 	io_ring_submit_unlock(ctx, issue_flags);
 	return ret;
 }
@@ -972,13 +918,6 @@ int io_poll_add(struct io_kiocb *req, unsigned int issue_flags)
 
 	ipt.pt._qproc = io_poll_queue_proc;
 
-	/*
-	 * If sqpoll or single issuer, there is no contention for ->uring_lock
-	 * and we'll end up holding it in tw handlers anyway.
-	 */
-	if (req->ctx->flags & (IORING_SETUP_SQPOLL|IORING_SETUP_SINGLE_ISSUER))
-		req->flags |= REQ_F_HASH_LOCKED;
-
 	ret = __io_arm_poll_handler(req, poll, &ipt, poll->events, issue_flags);
 	if (ret > 0) {
 		io_req_set_res(req, ipt.result_mask, 0);
@@ -997,18 +936,7 @@ int io_poll_remove(struct io_kiocb *req, unsigned int issue_flags)
 	int ret2, ret = 0;
 
 	io_ring_submit_lock(ctx, issue_flags);
-	preq = io_poll_find(ctx, true, &cd, &ctx->cancel_table, &bucket);
-	ret2 = io_poll_disarm(preq);
-	if (bucket)
-		spin_unlock(&bucket->lock);
-	if (!ret2)
-		goto found;
-	if (ret2 != -ENOENT) {
-		ret = ret2;
-		goto out;
-	}
-
-	preq = io_poll_find(ctx, true, &cd, &ctx->cancel_table_locked, &bucket);
+	preq = io_poll_find(ctx, true, &cd, &bucket);
 	ret2 = io_poll_disarm(preq);
 	if (bucket)
 		spin_unlock(&bucket->lock);
@@ -1016,8 +944,6 @@ int io_poll_remove(struct io_kiocb *req, unsigned int issue_flags)
 		ret = ret2;
 		goto out;
 	}
-
-found:
 	if (WARN_ON_ONCE(preq->opcode != IORING_OP_POLL_ADD)) {
 		ret = -EFAULT;
 		goto out;