Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEADgrafted

Changes:

Make expedited grace periods expedite normal RCU callbacks

Miscellaneous fixes:
 * Improve diagnostic output with character task states.
 * Mark accesses to inform KCSAN of concurrency design.
 * Move from kmalloc() to kmalloc_obj().
 * Documentation updates.
 * Improve handling of RCU deferred quiescent states.
 * Clean up unused function arguments and structure fields.
 * Reduce show_rcu_gp_kthreads() stack space.

Tasks RCU updates:
 * Clean up after SRCU re-implementation of Tasks Trace RCU.
 * Mark accesses to inform KCSAN of concurrency design.
 * Add ->lazy_timer status to diagnostic output.
 * Remove an unnecessary memory barrier.
 * Fix a data race, courtesy of KCSAN.
 * Documentation updates.
 * Convert cond_resched_tasks_rcu_qs() from macro to static inline
   function.

SRCU updates:
 * Add Rust helpers for SRCU.
 * Avoid losing queued work at cleanup_srcu_struct() time.

Torture-test updates:
 * Preparation work for immediate RCU priority deboosting.
 * Test RCU readers from real interrupt handlers (as opposed to softirq).
 * Simplify code through use of cpumask_next_wrap().
 * Improve diagnostic output with character task states.
 * Add rcutorture.nwriters parameter to allow lightweight stall testing,
   and rcutorture.stall_only to make doing so easier.
 * Test an RCU Tasks Trace grace period implying an RCU grace period.
 * Make RCU Tasks Trace torturing track reader batches.
 * Fix a data race, courtesy of KCSAN.
 * Plug a shuffle_tmp_mask memory leak on kthread spawn failure.

1 files changed, 49 insertions, 0 deletions

diff --git a/io_uring/cancel.h b/io_uring/cancel.h
new file mode 100644
index 000000000..1b201a094
--- /dev/null
+++ b/io_uring/cancel.h
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef IORING_CANCEL_H
+#define IORING_CANCEL_H
+
+#include <linux/io_uring_types.h>
+
+struct io_cancel_data {
+	struct io_ring_ctx *ctx;
+	u64 data;
+	struct file *file;
+	u8 opcode;
+	u32 flags;
+	int seq;
+};
+
+int io_async_cancel_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
+int io_async_cancel(struct io_kiocb *req, unsigned int issue_flags);
+
+int io_try_cancel(struct io_uring_task *tctx, struct io_cancel_data *cd,
+		  unsigned int issue_flags);
+
+int io_sync_cancel(struct io_ring_ctx *ctx, void __user *arg);
+bool io_cancel_req_match(struct io_kiocb *req, struct io_cancel_data *cd);
+bool io_match_task_safe(struct io_kiocb *head, struct io_uring_task *tctx,
+			bool cancel_all);
+
+bool io_cancel_remove_all(struct io_ring_ctx *ctx, struct io_uring_task *tctx,
+			  struct hlist_head *list, bool cancel_all,
+			  bool (*cancel)(struct io_kiocb *));
+int io_cancel_remove(struct io_ring_ctx *ctx, struct io_cancel_data *cd,
+		     unsigned int issue_flags, struct hlist_head *list,
+		     bool (*cancel)(struct io_kiocb *));
+__cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
+					 struct io_uring_task *tctx,
+					 bool cancel_all, bool is_sqpoll_thread);
+__cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd);
+__cold bool io_cancel_ctx_cb(struct io_wq_work *work, void *data);
+
+static inline bool io_cancel_match_sequence(struct io_kiocb *req, int sequence)
+{
+	if (req->cancel_seq_set && sequence == req->work.cancel_seq)
+		return true;
+
+	req->cancel_seq_set = true;
+	req->work.cancel_seq = sequence;
+	return false;
+}
+
+#endif