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, 150 insertions, 0 deletions

diff --git a/Documentation/filesystems/api-summary.rst b/Documentation/filesystems/api-summary.rst
new file mode 100644
index 000000000..bd7e3d5db
--- /dev/null
+++ b/Documentation/filesystems/api-summary.rst
@@ -0,0 +1,150 @@
+=============================
+Linux Filesystems API summary
+=============================
+
+This section contains API-level documentation, mostly taken from the source
+code itself.
+
+The Linux VFS
+=============
+
+The Filesystem types
+--------------------
+
+.. kernel-doc:: include/linux/fs.h
+   :internal:
+
+The Directory Cache
+-------------------
+
+.. kernel-doc:: fs/dcache.c
+   :export:
+
+.. kernel-doc:: include/linux/dcache.h
+   :internal:
+
+Inode Handling
+--------------
+
+.. kernel-doc:: fs/inode.c
+   :export:
+
+.. kernel-doc:: fs/bad_inode.c
+   :export:
+
+Registration and Superblocks
+----------------------------
+
+.. kernel-doc:: fs/super.c
+   :export:
+
+File Locks
+----------
+
+.. kernel-doc:: fs/locks.c
+   :export:
+
+.. kernel-doc:: fs/locks.c
+   :internal:
+
+Other Functions
+---------------
+
+.. kernel-doc:: fs/mpage.c
+   :export:
+
+.. kernel-doc:: fs/namei.c
+   :export:
+
+.. kernel-doc:: fs/open.c
+   :export:
+
+.. kernel-doc:: block/bio.c
+   :export:
+
+.. kernel-doc:: fs/seq_file.c
+   :export:
+
+.. kernel-doc:: fs/filesystems.c
+   :export:
+
+.. kernel-doc:: fs/fs-writeback.c
+   :export:
+
+.. kernel-doc:: fs/anon_inodes.c
+   :export:
+
+.. kernel-doc:: fs/attr.c
+   :export:
+
+.. kernel-doc:: fs/d_path.c
+   :export:
+
+.. kernel-doc:: fs/dax.c
+   :export:
+
+.. kernel-doc:: fs/libfs.c
+   :export:
+
+.. kernel-doc:: fs/posix_acl.c
+   :export:
+
+.. kernel-doc:: fs/stat.c
+   :export:
+
+.. kernel-doc:: fs/sync.c
+   :export:
+
+.. kernel-doc:: fs/xattr.c
+   :export:
+
+.. kernel-doc:: fs/namespace.c
+   :export:
+
+The proc filesystem
+===================
+
+sysctl interface
+----------------
+
+.. kernel-doc:: kernel/sysctl.c
+   :export:
+
+proc filesystem interface
+-------------------------
+
+.. kernel-doc:: fs/proc/base.c
+   :internal:
+
+Events based on file descriptors
+================================
+
+.. kernel-doc:: fs/eventfd.c
+   :export:
+
+eventpoll (epoll) interfaces
+============================
+
+.. kernel-doc:: fs/eventpoll.c
+   :internal:
+
+The Filesystem for Exporting Kernel Objects
+===========================================
+
+.. kernel-doc:: fs/sysfs/file.c
+   :export:
+
+.. kernel-doc:: fs/sysfs/symlink.c
+   :export:
+
+The debugfs filesystem
+======================
+
+debugfs interface
+-----------------
+
+.. kernel-doc:: fs/debugfs/inode.c
+   :export:
+
+.. kernel-doc:: fs/debugfs/file.c
+   :export: