Merge branch 'akpm' (patches from Andrew)

Merge yet more updates from Andrew Morton:
 "This is the post-linux-next queue. Material which was based on or
  dependent upon material which was in -next.

  69 patches.

  Subsystems affected by this patch series: mm (migration and zsmalloc),
  sysctl, proc, and lib"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (69 commits)
  mm: hide the FRONTSWAP Kconfig symbol
  frontswap: remove support for multiple ops
  mm: mark swap_lock and swap_active_head static
  frontswap: simplify frontswap_register_ops
  frontswap: remove frontswap_test
  mm: simplify try_to_unuse
  frontswap: remove the frontswap exports
  frontswap: simplify frontswap_init
  frontswap: remove frontswap_curr_pages
  frontswap: remove frontswap_shrink
  frontswap: remove frontswap_tmem_exclusive_gets
  frontswap: remove frontswap_writethrough
  mm: remove cleancache
  lib/stackdepot: always do filter_irq_stacks() in stack_depot_save()
  lib/stackdepot: allow optional init and stack_table allocation by kvmalloc()
  proc: remove PDE_DATA() completely
  fs: proc: store PDE()->data into inode->i_private
  zsmalloc: replace get_cpu_var with local_lock
  zsmalloc: replace per zpage lock with pool->migrate_lock
  locking/rwlocks: introduce write_lock_nested
  ...

29 files changed, 127 insertions, 264 deletions

diff --git a/include/linux/aio.h b/include/linux/aio.h
index b83e68dd006f..86892a4fe7c8 100644
--- a/include/linux/aio.h
+++ b/include/linux/aio.h
@@ -20,8 +20,4 @@ static inline void kiocb_set_cancel_fn(struct kiocb *req,
 				       kiocb_cancel_fn *cancel) { }
 #endif /* CONFIG_AIO */
 
-/* for sysctl: */
-extern unsigned long aio_nr;
-extern unsigned long aio_max_nr;
-
 #endif /* __LINUX__AIO_H */
diff --git a/include/linux/cleancache.h b/include/linux/cleancache.h
deleted file mode 100644
index 5f5730c1d324..000000000000
--- a/include/linux/cleancache.h
+++ /dev/null
@@ -1,124 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _LINUX_CLEANCACHE_H
-#define _LINUX_CLEANCACHE_H
-
-#include <linux/fs.h>
-#include <linux/exportfs.h>
-#include <linux/mm.h>
-
-#define CLEANCACHE_NO_POOL		-1
-#define CLEANCACHE_NO_BACKEND		-2
-#define CLEANCACHE_NO_BACKEND_SHARED	-3
-
-#define CLEANCACHE_KEY_MAX 6
-
-/*
- * cleancache requires every file with a page in cleancache to have a
- * unique key unless/until the file is removed/truncated.  For some
- * filesystems, the inode number is unique, but for "modern" filesystems
- * an exportable filehandle is required (see exportfs.h)
- */
-struct cleancache_filekey {
-	union {
-		ino_t ino;
-		__u32 fh[CLEANCACHE_KEY_MAX];
-		u32 key[CLEANCACHE_KEY_MAX];
-	} u;
-};
-
-struct cleancache_ops {
-	int (*init_fs)(size_t);
-	int (*init_shared_fs)(uuid_t *uuid, size_t);
-	int (*get_page)(int, struct cleancache_filekey,
-			pgoff_t, struct page *);
-	void (*put_page)(int, struct cleancache_filekey,
-			pgoff_t, struct page *);
-	void (*invalidate_page)(int, struct cleancache_filekey, pgoff_t);
-	void (*invalidate_inode)(int, struct cleancache_filekey);
-	void (*invalidate_fs)(int);
-};
-
-extern int cleancache_register_ops(const struct cleancache_ops *ops);
-extern void __cleancache_init_fs(struct super_block *);
-extern void __cleancache_init_shared_fs(struct super_block *);
-extern int  __cleancache_get_page(struct page *);
-extern void __cleancache_put_page(struct page *);
-extern void __cleancache_invalidate_page(struct address_space *, struct page *);
-extern void __cleancache_invalidate_inode(struct address_space *);
-extern void __cleancache_invalidate_fs(struct super_block *);
-
-#ifdef CONFIG_CLEANCACHE
-#define cleancache_enabled (1)
-static inline bool cleancache_fs_enabled_mapping(struct address_space *mapping)
-{
-	return mapping->host->i_sb->cleancache_poolid >= 0;
-}
-static inline bool cleancache_fs_enabled(struct page *page)
-{
-	return cleancache_fs_enabled_mapping(page->mapping);
-}
-#else
-#define cleancache_enabled (0)
-#define cleancache_fs_enabled(_page) (0)
-#define cleancache_fs_enabled_mapping(_page) (0)
-#endif
-
-/*
- * The shim layer provided by these inline functions allows the compiler
- * to reduce all cleancache hooks to nothingness if CONFIG_CLEANCACHE
- * is disabled, to a single global variable check if CONFIG_CLEANCACHE
- * is enabled but no cleancache "backend" has dynamically enabled it,
- * and, for the most frequent cleancache ops, to a single global variable
- * check plus a superblock element comparison if CONFIG_CLEANCACHE is enabled
- * and a cleancache backend has dynamically enabled cleancache, but the
- * filesystem referenced by that cleancache op has not enabled cleancache.
- * As a result, CONFIG_CLEANCACHE can be enabled by default with essentially
- * no measurable performance impact.
- */
-
-static inline void cleancache_init_fs(struct super_block *sb)
-{
-	if (cleancache_enabled)
-		__cleancache_init_fs(sb);
-}
-
-static inline void cleancache_init_shared_fs(struct super_block *sb)
-{
-	if (cleancache_enabled)
-		__cleancache_init_shared_fs(sb);
-}
-
-static inline int cleancache_get_page(struct page *page)
-{
-	if (cleancache_enabled && cleancache_fs_enabled(page))
-		return __cleancache_get_page(page);
-	return -1;
-}
-
-static inline void cleancache_put_page(struct page *page)
-{
-	if (cleancache_enabled && cleancache_fs_enabled(page))
-		__cleancache_put_page(page);
-}
-
-static inline void cleancache_invalidate_page(struct address_space *mapping,
-					struct page *page)
-{
-	/* careful... page->mapping is NULL sometimes when this is called */
-	if (cleancache_enabled && cleancache_fs_enabled_mapping(mapping))
-		__cleancache_invalidate_page(mapping, page);
-}
-
-static inline void cleancache_invalidate_inode(struct address_space *mapping)
-{
-	if (cleancache_enabled && cleancache_fs_enabled_mapping(mapping))
-		__cleancache_invalidate_inode(mapping);
-}
-
-static inline void cleancache_invalidate_fs(struct super_block *sb)
-{
-	if (cleancache_enabled)
-		__cleancache_invalidate_fs(sb);
-}
-
-#endif /* _LINUX_CLEANCACHE_H */
diff --git a/include/linux/coredump.h b/include/linux/coredump.h
index 78fcd776b185..248a68c668b4 100644
--- a/include/linux/coredump.h
+++ b/include/linux/coredump.h
@@ -14,10 +14,6 @@ struct core_vma_metadata {
 	unsigned long dump_size;
 };
 
-extern int core_uses_pid;
-extern char core_pattern[];
-extern unsigned int core_pipe_limit;
-
 /*
  * These are the only things you should do on a core-file: use only these
  * functions to write out all the necessary info.
@@ -37,4 +33,10 @@ extern void do_coredump(const kernel_siginfo_t *siginfo);
 static inline void do_coredump(const kernel_siginfo_t *siginfo) {}
 #endif
 
+#if defined(CONFIG_COREDUMP) && defined(CONFIG_SYSCTL)
+extern void validate_coredump_safety(void);
+#else
+static inline void validate_coredump_safety(void) {}
+#endif
+
 #endif /* _LINUX_COREDUMP_H */
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 9e23d33bb6f1..f5bba51480b2 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -61,16 +61,6 @@ extern const struct qstr empty_name;
 extern const struct qstr slash_name;
 extern const struct qstr dotdot_name;
 
-struct dentry_stat_t {
-	long nr_dentry;
-	long nr_unused;
-	long age_limit;		/* age in seconds */
-	long want_pages;	/* pages requested by system */
-	long nr_negative;	/* # of unused negative dentries */
-	long dummy;		/* Reserved for future use */
-};
-extern struct dentry_stat_t dentry_stat;
-
 /*
  * Try to keep struct dentry aligned on 64 byte cachelines (this will
  * give reasonable cacheline footprint with larger lines without the
diff --git a/include/linux/dnotify.h b/include/linux/dnotify.h
index b87c3b85a166..b1d26f9f1c9f 100644
--- a/include/linux/dnotify.h
+++ b/include/linux/dnotify.h
@@ -29,7 +29,6 @@ struct dnotify_struct {
 			    FS_CREATE | FS_RENAME |\
 			    FS_MOVED_FROM | FS_MOVED_TO)
 
-extern int dir_notify_enable;
 extern void dnotify_flush(struct file *, fl_owner_t);
 extern int fcntl_dirnotify(int, struct file *, unsigned long);
 
diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h
index 3afdf339d53c..419cadcd7ff5 100644
--- a/include/linux/fanotify.h
+++ b/include/linux/fanotify.h
@@ -5,8 +5,6 @@
 #include <linux/sysctl.h>
 #include <uapi/linux/fanotify.h>
 
-extern struct ctl_table fanotify_table[]; /* for sysctl */
-
 #define FAN_GROUP_FLAG(group, flag) \
 	((group)->fanotify_data.flags & (flag))
 
diff --git a/include/linux/frontswap.h b/include/linux/frontswap.h
index b07d88c92bb2..a631bac12220 100644
--- a/include/linux/frontswap.h
+++ b/include/linux/frontswap.h
@@ -7,31 +7,17 @@
 #include <linux/bitops.h>
 #include <linux/jump_label.h>
 
-/*
- * Return code to denote that requested number of
- * frontswap pages are unused(moved to page cache).
- * Used in shmem_unuse and try_to_unuse.
- */
-#define FRONTSWAP_PAGES_UNUSED	2
-
 struct frontswap_ops {
 	void (*init)(unsigned); /* this swap type was just swapon'ed */
 	int (*store)(unsigned, pgoff_t, struct page *); /* store a page */
 	int (*load)(unsigned, pgoff_t, struct page *); /* load a page */
 	void (*invalidate_page)(unsigned, pgoff_t); /* page no longer needed */
 	void (*invalidate_area)(unsigned); /* swap type just swapoff'ed */
-	struct frontswap_ops *next; /* private pointer to next ops */
 };
 
-extern void frontswap_register_ops(struct frontswap_ops *ops);
-extern void frontswap_shrink(unsigned long);
-extern unsigned long frontswap_curr_pages(void);
-extern void frontswap_writethrough(bool);
-#define FRONTSWAP_HAS_EXCLUSIVE_GETS
-extern void frontswap_tmem_exclusive_gets(bool);
+int frontswap_register_ops(const struct frontswap_ops *ops);
 
-extern bool __frontswap_test(struct swap_info_struct *, pgoff_t);
-extern void __frontswap_init(unsigned type, unsigned long *map);
+extern void frontswap_init(unsigned type, unsigned long *map);
 extern int __frontswap_store(struct page *page);
 extern int __frontswap_load(struct page *page);
 extern void __frontswap_invalidate_page(unsigned, pgoff_t);
@@ -45,11 +31,6 @@ static inline bool frontswap_enabled(void)
 	return static_branch_unlikely(&frontswap_enabled_key);
 }
 
-static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
-{
-	return __frontswap_test(sis, offset);
-}
-
 static inline void frontswap_map_set(struct swap_info_struct *p,
 				     unsigned long *map)
 {
@@ -68,11 +49,6 @@ static inline bool frontswap_enabled(void)
 	return false;
 }
 
-static inline bool frontswap_test(struct swap_info_struct *sis, pgoff_t offset)
-{
-	return false;
-}
-
 static inline void frontswap_map_set(struct swap_info_struct *p,
 				     unsigned long *map)
 {
@@ -112,11 +88,4 @@ static inline void frontswap_invalidate_area(unsigned type)
 		__frontswap_invalidate_area(type);
 }
 
-static inline void frontswap_init(unsigned type, unsigned long *map)
-{
-#ifdef CONFIG_FRONTSWAP
-	__frontswap_init(type, map);
-#endif
-}
-
 #endif /* _LINUX_FRONTSWAP_H */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c8510da6cc6d..f3daaea16554 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -79,15 +79,8 @@ extern void __init inode_init_early(void);
 extern void __init files_init(void);
 extern void __init files_maxfiles_init(void);
 
-extern struct files_stat_struct files_stat;
 extern unsigned long get_max_files(void);
 extern unsigned int sysctl_nr_open;
-extern struct inodes_stat_t inodes_stat;
-extern int leases_enable, lease_break_time;
-extern int sysctl_protected_symlinks;
-extern int sysctl_protected_hardlinks;
-extern int sysctl_protected_fifos;
-extern int sysctl_protected_regular;
 
 typedef __kernel_rwf_t rwf_t;
 
@@ -1542,11 +1535,6 @@ struct super_block {
 
 	const struct dentry_operations *s_d_op; /* default d_op for dentries */
 
-	/*
-	 * Saved pool identifier for cleancache (-1 means none)
-	 */
-	int cleancache_poolid;
-
 	struct shrinker s_shrink;	/* per-sb shrinker handle */
 
 	/* Number of inodes with nlink == 0 but still referenced */
@@ -3533,12 +3521,6 @@ ssize_t simple_attr_write(struct file *file, const char __user *buf,
 			  size_t len, loff_t *ppos);
 
 struct ctl_table;
-int proc_nr_files(struct ctl_table *table, int write,
-		  void *buffer, size_t *lenp, loff_t *ppos);
-int proc_nr_dentry(struct ctl_table *table, int write,
-		  void *buffer, size_t *lenp, loff_t *ppos);
-int proc_nr_inodes(struct ctl_table *table, int write,
-		   void *buffer, size_t *lenp, loff_t *ppos);
 int __init list_bdev_fs_names(char *buf, size_t size);
 
 #define __FMODE_EXEC		((__force int) FMODE_EXEC)
diff --git a/include/linux/inotify.h b/include/linux/inotify.h
index 6a24905f6e1e..8d20caa1b268 100644
--- a/include/linux/inotify.h
+++ b/include/linux/inotify.h
@@ -7,11 +7,8 @@
 #ifndef _LINUX_INOTIFY_H
 #define _LINUX_INOTIFY_H
 
-#include <linux/sysctl.h>
 #include <uapi/linux/inotify.h>
 
-extern struct ctl_table inotify_table[]; /* for sysctl */
-
 #define ALL_INOTIFY_BITS (IN_ACCESS | IN_MODIFY | IN_ATTRIB | IN_CLOSE_WRITE | \
 			  IN_CLOSE_NOWRITE | IN_OPEN | IN_MOVED_FROM | \
 			  IN_MOVED_TO | IN_CREATE | IN_DELETE | \
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index 8c8f7a4d93af..19b884353b15 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -348,12 +348,6 @@ extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs);
 
 DEFINE_INSN_CACHE_OPS(optinsn);
 
-#ifdef CONFIG_SYSCTL
-extern int sysctl_kprobes_optimization;
-extern int proc_kprobes_optimization_handler(struct ctl_table *table,
-					     int write, void *buffer,
-					     size_t *length, loff_t *ppos);
-#endif /* CONFIG_SYSCTL */
 extern void wait_for_kprobe_optimizer(void);
 #else /* !CONFIG_OPTPROBES */
 static inline void wait_for_kprobe_optimizer(void) { }
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 4850cc5bf813..db96e10eb8da 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -40,6 +40,8 @@ extern int migrate_huge_page_move_mapping(struct address_space *mapping,
 				  struct page *newpage, struct page *page);
 extern int migrate_page_move_mapping(struct address_space *mapping,
 		struct page *newpage, struct page *page, int extra_count);
+void migration_entry_wait_on_locked(swp_entry_t entry, pte_t *ptep,
+				spinlock_t *ptl);
 void folio_migrate_flags(struct folio *newfolio, struct folio *folio);
 void folio_migrate_copy(struct folio *newfolio, struct folio *folio);
 int folio_migrate_mapping(struct address_space *mapping,
diff --git a/include/linux/mount.h b/include/linux/mount.h
index 5d92a7e1a742..7f18a7555dff 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -113,9 +113,6 @@ extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list);
 extern void mark_mounts_for_expiry(struct list_head *mounts);
 
 extern dev_t name_to_dev_t(const char *name);
-
-extern unsigned int sysctl_mount_max;
-
 extern bool path_is_mountpoint(const struct path *path);
 
 extern void kern_unmount_array(struct vfsmount *mnt[], unsigned int num);
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index fc5642431b92..c00c618ef290 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -238,10 +238,6 @@ void pipe_lock(struct pipe_inode_info *);
 void pipe_unlock(struct pipe_inode_info *);
 void pipe_double_lock(struct pipe_inode_info *, struct pipe_inode_info *);
 
-extern unsigned int pipe_max_size;
-extern unsigned long pipe_user_pages_hard;
-extern unsigned long pipe_user_pages_soft;
-
 /* Wait for a pipe to be readable/writable while dropping the pipe lock */
 void pipe_wait_readable(struct pipe_inode_info *);
 void pipe_wait_writable(struct pipe_inode_info *);
diff --git a/include/linux/poll.h b/include/linux/poll.h
index 1cdc32b1f1b0..a9e0e1c2d1f2 100644
--- a/include/linux/poll.h
+++ b/include/linux/poll.h
@@ -8,12 +8,10 @@
 #include <linux/wait.h>
 #include <linux/string.h>
 #include <linux/fs.h>
-#include <linux/sysctl.h>
 #include <linux/uaccess.h>
 #include <uapi/linux/poll.h>
 #include <uapi/linux/eventpoll.h>
 
-extern struct ctl_table epoll_table[]; /* for sysctl */
 /* ~832 bytes of stack space used max in sys_select/sys_poll before allocating
    additional memory. */
 #ifdef __clang__
diff --git a/include/linux/printk.h b/include/linux/printk.h
index 9497f6b98339..1522df223c0f 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -183,10 +183,6 @@ extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 extern int printk_delay_msec;
 extern int dmesg_restrict;
 
-extern int
-devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write, void *buf,
-			  size_t *lenp, loff_t *ppos);
-
 extern void wake_up_klogd(void);
 
 char *log_buf_addr_get(void);
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index 01b9268451a8..81d6e4ec2294 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -110,7 +110,16 @@ extern struct proc_dir_entry *proc_create_data(const char *, umode_t,
 struct proc_dir_entry *proc_create(const char *name, umode_t mode, struct proc_dir_entry *parent, const struct proc_ops *proc_ops);
 extern void proc_set_size(struct proc_dir_entry *, loff_t);
 extern void proc_set_user(struct proc_dir_entry *, kuid_t, kgid_t);
-extern void *PDE_DATA(const struct inode *);
+
+/*
+ * Obtain the private data passed by user through proc_create_data() or
+ * related.
+ */
+static inline void *pde_data(const struct inode *inode)
+{
+	return inode->i_private;
+}
+
 extern void *proc_get_parent_data(const struct inode *);
 extern void proc_remove(struct proc_dir_entry *);
 extern void remove_proc_entry(const char *, struct proc_dir_entry *);
@@ -191,7 +200,7 @@ proc_create_data(const char *name, umode_t mode, struct proc_dir_entry *parent,
 
 static inline void proc_set_size(struct proc_dir_entry *de, loff_t size) {}
 static inline void proc_set_user(struct proc_dir_entry *de, kuid_t uid, kgid_t gid) {}
-static inline void *PDE_DATA(const struct inode *inode) {BUG(); return NULL;}
+static inline void *pde_data(const struct inode *inode) {BUG(); return NULL;}
 static inline void *proc_get_parent_data(const struct inode *inode) { BUG(); return NULL; }
 
 static inline void proc_remove(struct proc_dir_entry *de) {}
diff --git a/include/linux/ref_tracker.h b/include/linux/ref_tracker.h
index c11c9db5825c..60f3453be23e 100644
--- a/include/linux/ref_tracker.h
+++ b/include/linux/ref_tracker.h
@@ -4,6 +4,7 @@
 #include <linux/refcount.h>
 #include <linux/types.h>
 #include <linux/spinlock.h>
+#include <linux/stackdepot.h>
 
 struct ref_tracker;
 
@@ -26,6 +27,7 @@ static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir,
 	spin_lock_init(&dir->lock);
 	dir->quarantine_avail = quarantine_count;
 	refcount_set(&dir->untracked, 1);
+	stack_depot_init();
 }
 
 void ref_tracker_dir_exit(struct ref_tracker_dir *dir);
diff --git a/include/linux/rwlock.h b/include/linux/rwlock.h
index 2c0ad417ce3c..8f416c5e929e 100644
--- a/include/linux/rwlock.h
+++ b/include/linux/rwlock.h
@@ -55,6 +55,12 @@ do {								\
 #define write_lock(lock)	_raw_write_lock(lock)
 #define read_lock(lock)		_raw_read_lock(lock)
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+#define write_lock_nested(lock, subclass)	_raw_write_lock_nested(lock, subclass)
+#else
+#define write_lock_nested(lock, subclass)	_raw_write_lock(lock)
+#endif
+
 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
 
 #define read_lock_irqsave(lock, flags)			\
diff --git a/include/linux/rwlock_api_smp.h b/include/linux/rwlock_api_smp.h
index f1db6f17c4fb..dceb0a59b692 100644
--- a/include/linux/rwlock_api_smp.h
+++ b/include/linux/rwlock_api_smp.h
@@ -17,6 +17,7 @@
 
 void __lockfunc _raw_read_lock(rwlock_t *lock)		__acquires(lock);
 void __lockfunc _raw_write_lock(rwlock_t *lock)		__acquires(lock);
+void __lockfunc _raw_write_lock_nested(rwlock_t *lock, int subclass)	__acquires(lock);
 void __lockfunc _raw_read_lock_bh(rwlock_t *lock)	__acquires(lock);
 void __lockfunc _raw_write_lock_bh(rwlock_t *lock)	__acquires(lock);
 void __lockfunc _raw_read_lock_irq(rwlock_t *lock)	__acquires(lock);
@@ -209,6 +210,13 @@ static inline void __raw_write_lock(rwlock_t *lock)
 	LOCK_CONTENDED(lock, do_raw_write_trylock, do_raw_write_lock);
 }
 
+static inline void __raw_write_lock_nested(rwlock_t *lock, int subclass)
+{
+	preempt_disable();
+	rwlock_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+	LOCK_CONTENDED(lock, do_raw_write_trylock, do_raw_write_lock);
+}
+
 #endif /* !CONFIG_GENERIC_LOCKBREAK || CONFIG_DEBUG_LOCK_ALLOC */
 
 static inline void __raw_write_unlock(rwlock_t *lock)
diff --git a/include/linux/rwlock_rt.h b/include/linux/rwlock_rt.h
index 49c1f3842ed5..8544ff05e594 100644
--- a/include/linux/rwlock_rt.h
+++ b/include/linux/rwlock_rt.h
@@ -28,6 +28,7 @@ extern void rt_read_lock(rwlock_t *rwlock);
 extern int rt_read_trylock(rwlock_t *rwlock);
 extern void rt_read_unlock(rwlock_t *rwlock);
 extern void rt_write_lock(rwlock_t *rwlock);
+extern void rt_write_lock_nested(rwlock_t *rwlock, int subclass);
 extern int rt_write_trylock(rwlock_t *rwlock);
 extern void rt_write_unlock(rwlock_t *rwlock);
 
@@ -83,6 +84,15 @@ static __always_inline void write_lock(rwlock_t *rwlock)
 	rt_write_lock(rwlock);
 }
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static __always_inline void write_lock_nested(rwlock_t *rwlock, int subclass)
+{
+	rt_write_lock_nested(rwlock, subclass);
+}
+#else
+#define write_lock_nested(lock, subclass)	rt_write_lock(((void)(subclass), (lock)))
+#endif
+
 static __always_inline void write_lock_bh(rwlock_t *rwlock)
 {
 	local_bh_disable();
diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h
index 304f431178fd..c19dd5a2c05c 100644
--- a/include/linux/sched/sysctl.h
+++ b/include/linux/sched/sysctl.h
@@ -7,20 +7,8 @@
 struct ctl_table;
 
 #ifdef CONFIG_DETECT_HUNG_TASK
-
-#ifdef CONFIG_SMP
-extern unsigned int sysctl_hung_task_all_cpu_backtrace;
-#else
-#define sysctl_hung_task_all_cpu_backtrace 0
-#endif /* CONFIG_SMP */
-
-extern int	     sysctl_hung_task_check_count;
-extern unsigned int  sysctl_hung_task_panic;
+/* used for hung_task and block/ */
 extern unsigned long sysctl_hung_task_timeout_secs;
-extern unsigned long sysctl_hung_task_check_interval_secs;
-extern int sysctl_hung_task_warnings;
-int proc_dohung_task_timeout_secs(struct ctl_table *table, int write,
-		void *buffer, size_t *lenp, loff_t *ppos);
 #else
 /* Avoid need for ifdefs elsewhere in the code */
 enum { sysctl_hung_task_timeout_secs = 0 };
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index 72dbb44a4573..88cc16444b43 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -209,7 +209,7 @@ static const struct file_operations __name ## _fops = {			\
 #define DEFINE_PROC_SHOW_ATTRIBUTE(__name)				\
 static int __name ## _open(struct inode *inode, struct file *file)	\
 {									\
-	return single_open(file, __name ## _show, PDE_DATA(inode));	\
+	return single_open(file, __name ## _show, pde_data(inode));	\
 }									\
 									\
 static const struct proc_ops __name ## _proc_ops = {			\
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 166158b6e917..e65b80ed09e7 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -83,8 +83,7 @@ extern void shmem_unlock_mapping(struct address_space *mapping);
 extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
 					pgoff_t index, gfp_t gfp_mask);
 extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
-extern int shmem_unuse(unsigned int type, bool frontswap,
-		       unsigned long *fs_pages_to_unuse);
+int shmem_unuse(unsigned int type);
 
 extern bool shmem_is_huge(struct vm_area_struct *vma,
 			  struct inode *inode, pgoff_t index);
diff --git a/include/linux/spinlock_api_up.h b/include/linux/spinlock_api_up.h
index d0d188861ad6..b8ba00ccccde 100644
--- a/include/linux/spinlock_api_up.h
+++ b/include/linux/spinlock_api_up.h
@@ -59,6 +59,7 @@
 #define _raw_spin_lock_nested(lock, subclass)	__LOCK(lock)
 #define _raw_read_lock(lock)			__LOCK(lock)
 #define _raw_write_lock(lock)			__LOCK(lock)
+#define _raw_write_lock_nested(lock, subclass)	__LOCK(lock)
 #define _raw_spin_lock_bh(lock)			__LOCK_BH(lock)
 #define _raw_read_lock_bh(lock)			__LOCK_BH(lock)
 #define _raw_write_lock_bh(lock)		__LOCK_BH(lock)
diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h
index c34b55a6e554..17f992fe6355 100644
--- a/include/linux/stackdepot.h
+++ b/include/linux/stackdepot.h
@@ -19,6 +19,22 @@ depot_stack_handle_t __stack_depot_save(unsigned long *entries,
 					unsigned int nr_entries,
 					gfp_t gfp_flags, bool can_alloc);
 
+/*
+ * Every user of stack depot has to call this during its own init when it's
+ * decided that it will be calling stack_depot_save() later.
+ *
+ * The alternative is to select STACKDEPOT_ALWAYS_INIT to have stack depot
+ * enabled as part of mm_init(), for subsystems where it's known at compile time
+ * that stack depot will be used.
+ */
+int stack_depot_init(void);
+
+#ifdef CONFIG_STACKDEPOT_ALWAYS_INIT
+static inline int stack_depot_early_init(void)	{ return stack_depot_init(); }
+#else
+static inline int stack_depot_early_init(void)	{ return 0; }
+#endif
+
 depot_stack_handle_t stack_depot_save(unsigned long *entries,
 				      unsigned int nr_entries, gfp_t gfp_flags);
 
@@ -30,13 +46,4 @@ int stack_depot_snprint(depot_stack_handle_t handle, char *buf, size_t size,
 
 void stack_depot_print(depot_stack_handle_t stack);
 
-#ifdef CONFIG_STACKDEPOT
-int stack_depot_init(void);
-#else
-static inline int stack_depot_init(void)
-{
-	return 0;
-}
-#endif	/* CONFIG_STACKDEPOT */
-
 #endif
diff --git a/include/linux/stackleak.h b/include/linux/stackleak.h
index a59db2f08e76..ccaab2043fcd 100644
--- a/include/linux/stackleak.h
+++ b/include/linux/stackleak.h
@@ -23,11 +23,6 @@ static inline void stackleak_task_init(struct task_struct *t)
 # endif
 }
 
-#ifdef CONFIG_STACKLEAK_RUNTIME_DISABLE
-int stack_erasing_sysctl(struct ctl_table *table, int write,
-			void *buffer, size_t *lenp, loff_t *ppos);
-#endif
-
 #else /* !CONFIG_GCC_PLUGIN_STACKLEAK */
 static inline void stackleak_task_init(struct task_struct *t) { }
 #endif
diff --git a/include/linux/swapfile.h b/include/linux/swapfile.h
index e06febf62978..54078542134c 100644
--- a/include/linux/swapfile.h
+++ b/include/linux/swapfile.h
@@ -6,10 +6,7 @@
  * these were static in swapfile.c but frontswap.c needs them and we don't
  * want to expose them to the dozens of source files that include swap.h
  */
-extern spinlock_t swap_lock;
-extern struct plist_head swap_active_head;
 extern struct swap_info_struct *swap_info[];
-extern int try_to_unuse(unsigned int, bool, unsigned long);
 extern unsigned long generic_max_swapfile_size(void);
 extern unsigned long max_swapfile_size(void);
 
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 1fa2b69c6fc3..180adf7da785 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -38,12 +38,28 @@ struct ctl_table_header;
 struct ctl_dir;
 
 /* Keep the same order as in fs/proc/proc_sysctl.c */
-#define SYSCTL_ZERO	((void *)&sysctl_vals[0])
-#define SYSCTL_ONE	((void *)&sysctl_vals[1])
-#define SYSCTL_INT_MAX	((void *)&sysctl_vals[2])
+#define SYSCTL_NEG_ONE			((void *)&sysctl_vals[0])
+#define SYSCTL_ZERO			((void *)&sysctl_vals[1])
+#define SYSCTL_ONE			((void *)&sysctl_vals[2])
+#define SYSCTL_TWO			((void *)&sysctl_vals[3])
+#define SYSCTL_FOUR			((void *)&sysctl_vals[4])
+#define SYSCTL_ONE_HUNDRED		((void *)&sysctl_vals[5])
+#define SYSCTL_TWO_HUNDRED		((void *)&sysctl_vals[6])
+#define SYSCTL_ONE_THOUSAND		((void *)&sysctl_vals[7])
+#define SYSCTL_THREE_THOUSAND		((void *)&sysctl_vals[8])
+#define SYSCTL_INT_MAX			((void *)&sysctl_vals[9])
+
+/* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
+#define SYSCTL_MAXOLDUID		((void *)&sysctl_vals[10])
 
 extern const int sysctl_vals[];
 
+#define SYSCTL_LONG_ZERO	((void *)&sysctl_long_vals[0])
+#define SYSCTL_LONG_ONE		((void *)&sysctl_long_vals[1])
+#define SYSCTL_LONG_MAX		((void *)&sysctl_long_vals[2])
+
+extern const unsigned long sysctl_long_vals[];
+
 typedef int proc_handler(struct ctl_table *ctl, int write, void *buffer,
 		size_t *lenp, loff_t *ppos);
 
@@ -178,6 +194,20 @@ struct ctl_path {
 
 #ifdef CONFIG_SYSCTL
 
+#define DECLARE_SYSCTL_BASE(_name, _table)				\
+static struct ctl_table _name##_base_table[] = {			\
+	{								\
+		.procname	= #_name,				\
+		.mode		= 0555,					\
+		.child		= _table,				\
+	},								\
+	{ },								\
+}
+
+extern int __register_sysctl_base(struct ctl_table *base_table);
+
+#define register_sysctl_base(_name) __register_sysctl_base(_name##_base_table)
+
 void proc_sys_poll_notify(struct ctl_table_poll *poll);
 
 extern void setup_sysctl_set(struct ctl_table_set *p,
@@ -198,8 +228,19 @@ struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
 
 void unregister_sysctl_table(struct ctl_table_header * table);
 
-extern int sysctl_init(void);
+extern int sysctl_init_bases(void);
+extern void __register_sysctl_init(const char *path, struct ctl_table *table,
+				 const char *table_name);
+#define register_sysctl_init(path, table) __register_sysctl_init(path, table, #table)
+extern struct ctl_table_header *register_sysctl_mount_point(const char *path);
+
 void do_sysctl_args(void);
+int do_proc_douintvec(struct ctl_table *table, int write,
+		      void *buffer, size_t *lenp, loff_t *ppos,
+		      int (*conv)(unsigned long *lvalp,
+				  unsigned int *valp,
+				  int write, void *data),
+		      void *data);
 
 extern int pwrsw_enabled;
 extern int unaligned_enabled;
@@ -207,16 +248,28 @@ extern int unaligned_dump_stack;
 extern int no_unaligned_warning;
 
 extern struct ctl_table sysctl_mount_point[];
-extern struct ctl_table random_table[];
-extern struct ctl_table firmware_config_table[];
-extern struct ctl_table epoll_table[];
 
 #else /* CONFIG_SYSCTL */
+
+#define DECLARE_SYSCTL_BASE(_name, _table)
+
+static inline int __register_sysctl_base(struct ctl_table *base_table)
+{
+	return 0;
+}
+
+#define register_sysctl_base(table) __register_sysctl_base(table)
+
 static inline struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
 {
 	return NULL;
 }
 
+static inline struct sysctl_header *register_sysctl_mount_point(const char *path)
+{
+	return NULL;
+}
+
 static inline struct ctl_table_header *register_sysctl_paths(
 			const struct ctl_path *path, struct ctl_table *table)
 {
diff --git a/include/scsi/sg.h b/include/scsi/sg.h
index 843cefb8efce..068e35d36557 100644
--- a/include/scsi/sg.h
+++ b/include/scsi/sg.h
@@ -29,10 +29,6 @@
  * For utility and test programs see: http://sg.danny.cz/sg/sg3_utils.html
  */
 
-#ifdef __KERNEL__
-extern int sg_big_buff; /* for sysctl */
-#endif
-
 
 typedef struct sg_iovec /* same structure as used by readv() Linux system */
 {                       /* call. It defines one scatter-gather element. */