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, 52 insertions, 0 deletions

diff --git a/fs/btrfs/relocation.h b/fs/btrfs/relocation.h
new file mode 100644
index 000000000..bb7a86e7d
--- /dev/null
+++ b/fs/btrfs/relocation.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef BTRFS_RELOCATION_H
+#define BTRFS_RELOCATION_H
+
+#include <linux/types.h>
+
+struct extent_buffer;
+struct btrfs_fs_info;
+struct btrfs_root;
+struct btrfs_trans_handle;
+struct btrfs_ordered_extent;
+struct btrfs_pending_snapshot;
+
+static inline bool should_relocate_using_remap_tree(const struct btrfs_block_group *bg)
+{
+	if (!btrfs_fs_incompat(bg->fs_info, REMAP_TREE))
+		return false;
+
+	if (bg->flags & (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA_REMAP))
+		return false;
+
+	return true;
+}
+
+int btrfs_relocate_block_group(struct btrfs_fs_info *fs_info, u64 group_start,
+			       bool verbose);
+int btrfs_init_reloc_root(struct btrfs_trans_handle *trans, struct btrfs_root *root);
+int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
+			    struct btrfs_root *root);
+int btrfs_recover_relocation(struct btrfs_fs_info *fs_info);
+int btrfs_reloc_clone_csums(struct btrfs_ordered_extent *ordered);
+int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
+			  struct btrfs_root *root,
+			  const struct extent_buffer *buf,
+			  struct extent_buffer *cow);
+void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot *pending,
+			      u64 *bytes_to_reserve);
+int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
+			      struct btrfs_pending_snapshot *pending);
+int btrfs_should_cancel_balance(const struct btrfs_fs_info *fs_info);
+struct btrfs_root *find_reloc_root(struct btrfs_fs_info *fs_info, u64 bytenr);
+bool btrfs_should_ignore_reloc_root(const struct btrfs_root *root);
+u64 btrfs_get_reloc_bg_bytenr(struct btrfs_fs_info *fs_info);
+int btrfs_translate_remap(struct btrfs_fs_info *fs_info, u64 *logical, u64 *length);
+int btrfs_remove_extent_from_remap_tree(struct btrfs_trans_handle *trans,
+					struct btrfs_path *path,
+					u64 bytenr, u64 num_bytes);
+int btrfs_last_identity_remap_gone(struct btrfs_chunk_map *chunk_map,
+				   struct btrfs_block_group *bg);
+
+#endif