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, 107 insertions, 0 deletions

diff --git a/fs/lockd/trace.h b/fs/lockd/trace.h
new file mode 100644
index 000000000..a11d04e8c
--- /dev/null
+++ b/fs/lockd/trace.h
@@ -0,0 +1,107 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM lockd
+
+#if !defined(_TRACE_LOCKD_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_LOCKD_H
+
+#include <linux/tracepoint.h>
+#include <linux/crc32.h>
+#include <linux/nfs.h>
+
+#include "lockd.h"
+
+#ifdef CONFIG_LOCKD_V4
+#define NLM_STATUS_LIST					\
+	nlm_status_code(LCK_GRANTED)			\
+	nlm_status_code(LCK_DENIED)			\
+	nlm_status_code(LCK_DENIED_NOLOCKS)		\
+	nlm_status_code(LCK_BLOCKED)			\
+	nlm_status_code(LCK_DENIED_GRACE_PERIOD)	\
+	nlm_status_code(DEADLCK)			\
+	nlm_status_code(ROFS)				\
+	nlm_status_code(STALE_FH)			\
+	nlm_status_code(FBIG)				\
+	nlm_status_code_end(FAILED)
+#else
+#define NLM_STATUS_LIST					\
+	nlm_status_code(LCK_GRANTED)			\
+	nlm_status_code(LCK_DENIED)			\
+	nlm_status_code(LCK_DENIED_NOLOCKS)		\
+	nlm_status_code(LCK_BLOCKED)			\
+	nlm_status_code_end(LCK_DENIED_GRACE_PERIOD)
+#endif
+
+#undef nlm_status_code
+#undef nlm_status_code_end
+#define nlm_status_code(x)	TRACE_DEFINE_ENUM(NLM_##x);
+#define nlm_status_code_end(x)	TRACE_DEFINE_ENUM(NLM_##x);
+
+NLM_STATUS_LIST
+
+#undef nlm_status_code
+#undef nlm_status_code_end
+#define nlm_status_code(x)	{ NLM_##x, #x },
+#define nlm_status_code_end(x)	{ NLM_##x, #x }
+
+#define show_nlm_status(x)	__print_symbolic(x, NLM_STATUS_LIST)
+
+DECLARE_EVENT_CLASS(nlmclnt_lock_event,
+		TP_PROTO(
+			const struct lockd_lock *lock,
+			const struct sockaddr *addr,
+			unsigned int addrlen,
+			__be32 status
+		),
+
+		TP_ARGS(lock, addr, addrlen, status),
+
+		TP_STRUCT__entry(
+			__field(u32, oh)
+			__field(u32, svid)
+			__field(u32, fh)
+			__field(unsigned long, status)
+			__field(loff_t, start)
+			__field(loff_t, end)
+			__sockaddr(addr, addrlen)
+		),
+
+		TP_fast_assign(
+			__entry->oh = ~crc32_le(0xffffffff, lock->oh.data, lock->oh.len);
+			__entry->svid = lock->svid;
+			__entry->fh = nfs_fhandle_hash(&lock->fh);
+			__entry->start = lock->fl.fl_start;
+			__entry->end = lock->fl.fl_end;
+			__entry->status = be32_to_cpu(status);
+			__assign_sockaddr(addr, addr, addrlen);
+		),
+
+		TP_printk(
+			"addr=%pISpc oh=0x%08x svid=0x%08x fh=0x%08x start=%lld end=%lld status=%s",
+			__get_sockaddr(addr), __entry->oh, __entry->svid,
+			__entry->fh, __entry->start, __entry->end,
+			show_nlm_status(__entry->status)
+		)
+);
+
+#define DEFINE_NLMCLNT_EVENT(name)				\
+	DEFINE_EVENT(nlmclnt_lock_event, name,			\
+			TP_PROTO(				\
+				const struct lockd_lock *lock,	\
+				const struct sockaddr *addr,	\
+				unsigned int addrlen,		\
+				__be32	status			\
+			),					\
+			TP_ARGS(lock, addr, addrlen, status))
+
+DEFINE_NLMCLNT_EVENT(nlmclnt_test);
+DEFINE_NLMCLNT_EVENT(nlmclnt_lock);
+DEFINE_NLMCLNT_EVENT(nlmclnt_unlock);
+DEFINE_NLMCLNT_EVENT(nlmclnt_grant);
+
+#endif /* _TRACE_LOCKD_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE trace
+#include <trace/define_trace.h>