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, 276 insertions, 0 deletions

diff --git a/fs/jffs2/debug.h b/fs/jffs2/debug.h
new file mode 100644
index 000000000..40e203b6e
--- /dev/null
+++ b/fs/jffs2/debug.h
@@ -0,0 +1,276 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright © 2001-2007 Red Hat, Inc.
+ * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
+ *
+ * Created by David Woodhouse <dwmw2@infradead.org>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ */
+
+#ifndef _JFFS2_DEBUG_H_
+#define _JFFS2_DEBUG_H_
+
+#include <linux/printk.h>
+#include <linux/sched.h>
+
+#ifndef CONFIG_JFFS2_FS_DEBUG
+#define CONFIG_JFFS2_FS_DEBUG 0
+#endif
+
+#if CONFIG_JFFS2_FS_DEBUG > 0
+/* Enable "paranoia" checks and dumps */
+#define JFFS2_DBG_PARANOIA_CHECKS
+#define JFFS2_DBG_DUMPS
+
+/*
+ * By defining/undefining the below macros one may select debugging messages
+ * fro specific JFFS2 subsystems.
+ */
+#define JFFS2_DBG_READINODE_MESSAGES
+#define JFFS2_DBG_FRAGTREE_MESSAGES
+#define JFFS2_DBG_DENTLIST_MESSAGES
+#define JFFS2_DBG_NODEREF_MESSAGES
+#define JFFS2_DBG_INOCACHE_MESSAGES
+#define JFFS2_DBG_SUMMARY_MESSAGES
+#define JFFS2_DBG_FSBUILD_MESSAGES
+#endif
+
+#if CONFIG_JFFS2_FS_DEBUG > 1
+#define JFFS2_DBG_FRAGTREE2_MESSAGES
+#define JFFS2_DBG_READINODE2_MESSAGES
+#define JFFS2_DBG_MEMALLOC_MESSAGES
+#endif
+
+/* Sanity checks are supposed to be light-weight and enabled by default */
+#define JFFS2_DBG_SANITY_CHECKS
+
+/*
+ * Dx() are mainly used for debugging messages, they must go away and be
+ * superseded by nicer dbg_xxx() macros...
+ */
+#if CONFIG_JFFS2_FS_DEBUG > 0
+#define DEBUG
+#define D1(x) x
+#else
+#define D1(x)
+#endif
+
+#if CONFIG_JFFS2_FS_DEBUG > 1
+#define D2(x) x
+#else
+#define D2(x)
+#endif
+
+#define jffs2_dbg(level, fmt, ...)		\
+do {						\
+	if (CONFIG_JFFS2_FS_DEBUG >= level)	\
+		pr_debug(fmt, ##__VA_ARGS__);	\
+} while (0)
+
+/* The prefixes of JFFS2 messages */
+#define JFFS2_DBG		KERN_DEBUG
+#define JFFS2_DBG_PREFIX	"[JFFS2 DBG]"
+#define JFFS2_DBG_MSG_PREFIX	JFFS2_DBG JFFS2_DBG_PREFIX
+
+/* JFFS2 message macros */
+#define JFFS2_ERROR(fmt, ...)					\
+	pr_err("error: (%d) %s: " fmt,				\
+	       task_pid_nr(current), __func__, ##__VA_ARGS__)
+
+#define JFFS2_WARNING(fmt, ...)						\
+	pr_warn("warning: (%d) %s: " fmt,				\
+		task_pid_nr(current), __func__, ##__VA_ARGS__)
+
+#define JFFS2_NOTICE(fmt, ...)						\
+	pr_notice("notice: (%d) %s: " fmt,				\
+		  task_pid_nr(current), __func__, ##__VA_ARGS__)
+
+#define JFFS2_DEBUG(fmt, ...)						\
+	printk(KERN_DEBUG "[JFFS2 DBG] (%d) %s: " fmt,			\
+	       task_pid_nr(current), __func__, ##__VA_ARGS__)
+
+/*
+ * We split our debugging messages on several parts, depending on the JFFS2
+ * subsystem the message belongs to.
+ */
+/* Read inode debugging messages */
+#ifdef JFFS2_DBG_READINODE_MESSAGES
+#define dbg_readinode(fmt, ...)	JFFS2_DEBUG(fmt, ##__VA_ARGS__)
+#else
+#define dbg_readinode(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
+#endif
+#ifdef JFFS2_DBG_READINODE2_MESSAGES
+#define dbg_readinode2(fmt, ...)	JFFS2_DEBUG(fmt, ##__VA_ARGS__)
+#else
+#define dbg_readinode2(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
+#endif
+
+/* Fragtree build debugging messages */
+#ifdef JFFS2_DBG_FRAGTREE_MESSAGES
+#define dbg_fragtree(fmt, ...)	JFFS2_DEBUG(fmt, ##__VA_ARGS__)
+#else
+#define dbg_fragtree(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
+#endif
+#ifdef JFFS2_DBG_FRAGTREE2_MESSAGES
+#define dbg_fragtree2(fmt, ...)	JFFS2_DEBUG(fmt, ##__VA_ARGS__)
+#else
+#define dbg_fragtree2(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
+#endif
+
+/* Directory entry list manilulation debugging messages */
+#ifdef JFFS2_DBG_DENTLIST_MESSAGES
+#define dbg_dentlist(fmt, ...)	JFFS2_DEBUG(fmt, ##__VA_ARGS__)
+#else
+#define dbg_dentlist(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
+#endif
+
+/* Print the messages about manipulating node_refs */
+#ifdef JFFS2_DBG_NODEREF_MESSAGES
+#define dbg_noderef(fmt, ...)	JFFS2_DEBUG(fmt, ##__VA_ARGS__)
+#else
+#define dbg_noderef(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
+#endif
+
+/* Manipulations with the list of inodes (JFFS2 inocache) */
+#ifdef JFFS2_DBG_INOCACHE_MESSAGES
+#define dbg_inocache(fmt, ...)	JFFS2_DEBUG(fmt, ##__VA_ARGS__)
+#else
+#define dbg_inocache(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
+#endif
+
+/* Summary debugging messages */
+#ifdef JFFS2_DBG_SUMMARY_MESSAGES
+#define dbg_summary(fmt, ...)	JFFS2_DEBUG(fmt, ##__VA_ARGS__)
+#else
+#define dbg_summary(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
+#endif
+
+/* File system build messages */
+#ifdef JFFS2_DBG_FSBUILD_MESSAGES
+#define dbg_fsbuild(fmt, ...)	JFFS2_DEBUG(fmt, ##__VA_ARGS__)
+#else
+#define dbg_fsbuild(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
+#endif
+
+/* Watch the object allocations */
+#ifdef JFFS2_DBG_MEMALLOC_MESSAGES
+#define dbg_memalloc(fmt, ...)	JFFS2_DEBUG(fmt, ##__VA_ARGS__)
+#else
+#define dbg_memalloc(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
+#endif
+
+/* Watch the XATTR subsystem */
+#ifdef JFFS2_DBG_XATTR_MESSAGES
+#define dbg_xattr(fmt, ...)  JFFS2_DEBUG(fmt, ##__VA_ARGS__)
+#else
+#define dbg_xattr(fmt, ...)  no_printk(fmt, ##__VA_ARGS__)
+#endif 
+
+/* "Sanity" checks */
+void
+__jffs2_dbg_acct_sanity_check_nolock(struct jffs2_sb_info *c,
+				     struct jffs2_eraseblock *jeb);
+void
+__jffs2_dbg_acct_sanity_check(struct jffs2_sb_info *c,
+			      struct jffs2_eraseblock *jeb);
+
+/* "Paranoia" checks */
+void
+__jffs2_dbg_fragtree_paranoia_check(struct jffs2_inode_info *f);
+void
+__jffs2_dbg_fragtree_paranoia_check_nolock(struct jffs2_inode_info *f);
+void
+__jffs2_dbg_acct_paranoia_check(struct jffs2_sb_info *c,
+			   	struct jffs2_eraseblock *jeb);
+void
+__jffs2_dbg_acct_paranoia_check_nolock(struct jffs2_sb_info *c,
+				       struct jffs2_eraseblock *jeb);
+void
+__jffs2_dbg_prewrite_paranoia_check(struct jffs2_sb_info *c,
+				    uint32_t ofs, int len);
+
+/* "Dump" functions */
+void
+__jffs2_dbg_dump_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb);
+void
+__jffs2_dbg_dump_jeb_nolock(struct jffs2_eraseblock *jeb);
+void
+__jffs2_dbg_dump_block_lists(struct jffs2_sb_info *c);
+void
+__jffs2_dbg_dump_block_lists_nolock(struct jffs2_sb_info *c);
+void
+__jffs2_dbg_dump_node_refs(struct jffs2_sb_info *c,
+		 	   struct jffs2_eraseblock *jeb);
+void
+__jffs2_dbg_dump_node_refs_nolock(struct jffs2_sb_info *c,
+				  struct jffs2_eraseblock *jeb);
+void
+__jffs2_dbg_dump_fragtree(struct jffs2_inode_info *f);
+void
+__jffs2_dbg_dump_fragtree_nolock(struct jffs2_inode_info *f);
+void
+__jffs2_dbg_dump_buffer(unsigned char *buf, int len, uint32_t offs);
+void
+__jffs2_dbg_dump_node(struct jffs2_sb_info *c, uint32_t ofs);
+
+#ifdef JFFS2_DBG_PARANOIA_CHECKS
+#define jffs2_dbg_fragtree_paranoia_check(f)			\
+	__jffs2_dbg_fragtree_paranoia_check(f)
+#define jffs2_dbg_fragtree_paranoia_check_nolock(f)		\
+	__jffs2_dbg_fragtree_paranoia_check_nolock(f)
+#define jffs2_dbg_acct_paranoia_check(c, jeb)			\
+	__jffs2_dbg_acct_paranoia_check(c,jeb)
+#define jffs2_dbg_acct_paranoia_check_nolock(c, jeb)		\
+	__jffs2_dbg_acct_paranoia_check_nolock(c,jeb)
+#define jffs2_dbg_prewrite_paranoia_check(c, ofs, len)		\
+	__jffs2_dbg_prewrite_paranoia_check(c, ofs, len)
+#else
+#define jffs2_dbg_fragtree_paranoia_check(f)
+#define jffs2_dbg_fragtree_paranoia_check_nolock(f)
+#define jffs2_dbg_acct_paranoia_check(c, jeb)
+#define jffs2_dbg_acct_paranoia_check_nolock(c, jeb)
+#define jffs2_dbg_prewrite_paranoia_check(c, ofs, len)
+#endif /* !JFFS2_PARANOIA_CHECKS */
+
+#ifdef JFFS2_DBG_DUMPS
+#define jffs2_dbg_dump_jeb(c, jeb)				\
+	__jffs2_dbg_dump_jeb(c, jeb);
+#define jffs2_dbg_dump_jeb_nolock(jeb)				\
+	__jffs2_dbg_dump_jeb_nolock(jeb);
+#define jffs2_dbg_dump_block_lists(c)				\
+	__jffs2_dbg_dump_block_lists(c)
+#define jffs2_dbg_dump_block_lists_nolock(c)			\
+	__jffs2_dbg_dump_block_lists_nolock(c)
+#define jffs2_dbg_dump_fragtree(f)				\
+	__jffs2_dbg_dump_fragtree(f);
+#define jffs2_dbg_dump_fragtree_nolock(f)			\
+	__jffs2_dbg_dump_fragtree_nolock(f);
+#define jffs2_dbg_dump_buffer(buf, len, offs)			\
+	__jffs2_dbg_dump_buffer(*buf, len, offs);
+#define jffs2_dbg_dump_node(c, ofs)				\
+	__jffs2_dbg_dump_node(c, ofs);
+#else
+#define jffs2_dbg_dump_jeb(c, jeb)
+#define jffs2_dbg_dump_jeb_nolock(jeb)
+#define jffs2_dbg_dump_block_lists(c)
+#define jffs2_dbg_dump_block_lists_nolock(c)
+#define jffs2_dbg_dump_fragtree(f)
+#define jffs2_dbg_dump_fragtree_nolock(f)
+#define jffs2_dbg_dump_buffer(buf, len, offs)
+#define jffs2_dbg_dump_node(c, ofs)
+#endif /* !JFFS2_DBG_DUMPS */
+
+#ifdef JFFS2_DBG_SANITY_CHECKS
+#define jffs2_dbg_acct_sanity_check(c, jeb)			\
+	__jffs2_dbg_acct_sanity_check(c, jeb)
+#define jffs2_dbg_acct_sanity_check_nolock(c, jeb)		\
+	__jffs2_dbg_acct_sanity_check_nolock(c, jeb)
+#else
+#define jffs2_dbg_acct_sanity_check(c, jeb)
+#define jffs2_dbg_acct_sanity_check_nolock(c, jeb)
+#endif /* !JFFS2_DBG_SANITY_CHECKS */
+
+#endif /* _JFFS2_DEBUG_H_ */