Merge branch 'akpm' (Andrew's patch-bomb)

Merge third batch of patches from Andrew Morton:
 - Some MM stragglers
 - core SMP library cleanups (on_each_cpu_mask)
 - Some IPI optimisations
 - kexec
 - kdump
 - IPMI
 - the radix-tree iterator work
 - various other misc bits.

 "That'll do for -rc1.  I still have ~10 patches for 3.4, will send
  those along when they've baked a little more."

* emailed from Andrew Morton <akpm@linux-foundation.org>: (35 commits)
  backlight: fix typo in tosa_lcd.c
  crc32: add help text for the algorithm select option
  mm: move hugepage test examples to tools/testing/selftests/vm
  mm: move slabinfo.c to tools/vm
  mm: move page-types.c from Documentation to tools/vm
  selftests/Makefile: make `run_tests' depend on `all'
  selftests: launch individual selftests from the main Makefile
  radix-tree: use iterators in find_get_pages* functions
  radix-tree: rewrite gang lookup using iterator
  radix-tree: introduce bit-optimized iterator
  fs/proc/namespaces.c: prevent crash when ns_entries[] is empty
  nbd: rename the nbd_device variable from lo to nbd
  pidns: add reboot_pid_ns() to handle the reboot syscall
  sysctl: use bitmap library functions
  ipmi: use locks on watchdog timeout set on reboot
  ipmi: simplify locking
  ipmi: fix message handling during panics
  ipmi: use a tasklet for handling received messages
  ipmi: increase KCS timeouts
  ipmi: decrease the IPMI message transaction time in interrupt mode
  ...

include/linux/cpumask.h

@@ -810,11 +810,10 @@ static inline const struct cpumask *get_cpu_mask(unsigned int cpu)
 #else /* NR_CPUS > 1 */
 int __first_cpu(const cpumask_t *srcp);
 int __next_cpu(int n, const cpumask_t *srcp);
-int __any_online_cpu(const cpumask_t *mask);
 
 #define first_cpu(src)		__first_cpu(&(src))
 #define next_cpu(n, src)	__next_cpu((n), &(src))
-#define any_online_cpu(mask) __any_online_cpu(&(mask))
+#define any_online_cpu(mask) cpumask_any_and(&mask, cpu_online_mask)
 #define for_each_cpu_mask(cpu, mask)			\
 	for ((cpu) = -1;				\
 		(cpu) = next_cpu((cpu), (mask)),	\

include/linux/mm.h

@@ -954,7 +954,7 @@ extern void truncate_pagecache(struct inode *inode, loff_t old, loff_t new);
 extern void truncate_setsize(struct inode *inode, loff_t newsize);
 extern int vmtruncate(struct inode *inode, loff_t offset);
 extern int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end);
-
+void truncate_pagecache_range(struct inode *inode, loff_t offset, loff_t end);
 int truncate_inode_page(struct address_space *mapping, struct page *page);
 int generic_error_remove_page(struct address_space *mapping, struct page *page);
 

include/linux/pid_namespace.h

@@ -33,6 +33,7 @@ struct pid_namespace {
 #endif
 	gid_t pid_gid;
 	int hide_pid;
+	int reboot;	/* group exit code if this pidns was rebooted */
 };
 
 extern struct pid_namespace init_pid_ns;
@@ -48,6 +49,7 @@ static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
 extern struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *ns);
 extern void free_pid_ns(struct kref *kref);
 extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
+extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
 
 static inline void put_pid_ns(struct pid_namespace *ns)
 {
@@ -75,11 +77,15 @@ static inline void put_pid_ns(struct pid_namespace *ns)
 {
 }
 
-
 static inline void zap_pid_ns_processes(struct pid_namespace *ns)
 {
 	BUG();
 }
+
+static inline int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
+{
+	return 0;
+}
 #endif /* CONFIG_PID_NS */
 
 extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);

include/linux/radix-tree.h

@@ -2,6 +2,7 @@
  * Copyright (C) 2001 Momchil Velikov
  * Portions Copyright (C) 2001 Christoph Hellwig
  * Copyright (C) 2006 Nick Piggin
+ * Copyright (C) 2012 Konstantin Khlebnikov
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -257,4 +258,199 @@ static inline void radix_tree_preload_end(void)
 	preempt_enable();
 }
 
+/**
+ * struct radix_tree_iter - radix tree iterator state
+ *
+ * @index:	index of current slot
+ * @next_index:	next-to-last index for this chunk
+ * @tags:	bit-mask for tag-iterating
+ *
+ * This radix tree iterator works in terms of "chunks" of slots.  A chunk is a
+ * subinterval of slots contained within one radix tree leaf node.  It is
+ * described by a pointer to its first slot and a struct radix_tree_iter
+ * which holds the chunk's position in the tree and its size.  For tagged
+ * iteration radix_tree_iter also holds the slots' bit-mask for one chosen
+ * radix tree tag.
+ */
+struct radix_tree_iter {
+	unsigned long	index;
+	unsigned long	next_index;
+	unsigned long	tags;
+};
+
+#define RADIX_TREE_ITER_TAG_MASK	0x00FF	/* tag index in lower byte */
+#define RADIX_TREE_ITER_TAGGED		0x0100	/* lookup tagged slots */
+#define RADIX_TREE_ITER_CONTIG		0x0200	/* stop at first hole */
+
+/**
+ * radix_tree_iter_init - initialize radix tree iterator
+ *
+ * @iter:	pointer to iterator state
+ * @start:	iteration starting index
+ * Returns:	NULL
+ */
+static __always_inline void **
+radix_tree_iter_init(struct radix_tree_iter *iter, unsigned long start)
+{
+	/*
+	 * Leave iter->tags uninitialized. radix_tree_next_chunk() will fill it
+	 * in the case of a successful tagged chunk lookup.  If the lookup was
+	 * unsuccessful or non-tagged then nobody cares about ->tags.
+	 *
+	 * Set index to zero to bypass next_index overflow protection.
+	 * See the comment in radix_tree_next_chunk() for details.
+	 */
+	iter->index = 0;
+	iter->next_index = start;
+	return NULL;
+}
+
+/**
+ * radix_tree_next_chunk - find next chunk of slots for iteration
+ *
+ * @root:	radix tree root
+ * @iter:	iterator state
+ * @flags:	RADIX_TREE_ITER_* flags and tag index
+ * Returns:	pointer to chunk first slot, or NULL if there no more left
+ *
+ * This function looks up the next chunk in the radix tree starting from
+ * @iter->next_index.  It returns a pointer to the chunk's first slot.
+ * Also it fills @iter with data about chunk: position in the tree (index),
+ * its end (next_index), and constructs a bit mask for tagged iterating (tags).
+ */
+void **radix_tree_next_chunk(struct radix_tree_root *root,
+			     struct radix_tree_iter *iter, unsigned flags);
+
+/**
+ * radix_tree_chunk_size - get current chunk size
+ *
+ * @iter:	pointer to radix tree iterator
+ * Returns:	current chunk size
+ */
+static __always_inline unsigned
+radix_tree_chunk_size(struct radix_tree_iter *iter)
+{
+	return iter->next_index - iter->index;
+}
+
+/**
+ * radix_tree_next_slot - find next slot in chunk
+ *
+ * @slot:	pointer to current slot
+ * @iter:	pointer to interator state
+ * @flags:	RADIX_TREE_ITER_*, should be constant
+ * Returns:	pointer to next slot, or NULL if there no more left
+ *
+ * This function updates @iter->index in the case of a successful lookup.
+ * For tagged lookup it also eats @iter->tags.
+ */
+static __always_inline void **
+radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
+{
+	if (flags & RADIX_TREE_ITER_TAGGED) {
+		iter->tags >>= 1;
+		if (likely(iter->tags & 1ul)) {
+			iter->index++;
+			return slot + 1;
+		}
+		if (!(flags & RADIX_TREE_ITER_CONTIG) && likely(iter->tags)) {
+			unsigned offset = __ffs(iter->tags);
+
+			iter->tags >>= offset;
+			iter->index += offset + 1;
+			return slot + offset + 1;
+		}
+	} else {
+		unsigned size = radix_tree_chunk_size(iter) - 1;
+
+		while (size--) {
+			slot++;
+			iter->index++;
+			if (likely(*slot))
+				return slot;
+			if (flags & RADIX_TREE_ITER_CONTIG)
+				break;
+		}
+	}
+	return NULL;
+}
+
+/**
+ * radix_tree_for_each_chunk - iterate over chunks
+ *
+ * @slot:	the void** variable for pointer to chunk first slot
+ * @root:	the struct radix_tree_root pointer
+ * @iter:	the struct radix_tree_iter pointer
+ * @start:	iteration starting index
+ * @flags:	RADIX_TREE_ITER_* and tag index
+ *
+ * Locks can be released and reacquired between iterations.
+ */
+#define radix_tree_for_each_chunk(slot, root, iter, start, flags)	\
+	for (slot = radix_tree_iter_init(iter, start) ;			\
+	      (slot = radix_tree_next_chunk(root, iter, flags)) ;)
+
+/**
+ * radix_tree_for_each_chunk_slot - iterate over slots in one chunk
+ *
+ * @slot:	the void** variable, at the beginning points to chunk first slot
+ * @iter:	the struct radix_tree_iter pointer
+ * @flags:	RADIX_TREE_ITER_*, should be constant
+ *
+ * This macro is designed to be nested inside radix_tree_for_each_chunk().
+ * @slot points to the radix tree slot, @iter->index contains its index.
+ */
+#define radix_tree_for_each_chunk_slot(slot, iter, flags)		\
+	for (; slot ; slot = radix_tree_next_slot(slot, iter, flags))
+
+/**
+ * radix_tree_for_each_slot - iterate over non-empty slots
+ *
+ * @slot:	the void** variable for pointer to slot
+ * @root:	the struct radix_tree_root pointer
+ * @iter:	the struct radix_tree_iter pointer
+ * @start:	iteration starting index
+ *
+ * @slot points to radix tree slot, @iter->index contains its index.
+ */
+#define radix_tree_for_each_slot(slot, root, iter, start)		\
+	for (slot = radix_tree_iter_init(iter, start) ;			\
+	     slot || (slot = radix_tree_next_chunk(root, iter, 0)) ;	\
+	     slot = radix_tree_next_slot(slot, iter, 0))
+
+/**
+ * radix_tree_for_each_contig - iterate over contiguous slots
+ *
+ * @slot:	the void** variable for pointer to slot
+ * @root:	the struct radix_tree_root pointer
+ * @iter:	the struct radix_tree_iter pointer
+ * @start:	iteration starting index
+ *
+ * @slot points to radix tree slot, @iter->index contains its index.
+ */
+#define radix_tree_for_each_contig(slot, root, iter, start)		\
+	for (slot = radix_tree_iter_init(iter, start) ;			\
+	     slot || (slot = radix_tree_next_chunk(root, iter,		\
+				RADIX_TREE_ITER_CONTIG)) ;		\
+	     slot = radix_tree_next_slot(slot, iter,			\
+				RADIX_TREE_ITER_CONTIG))
+
+/**
+ * radix_tree_for_each_tagged - iterate over tagged slots
+ *
+ * @slot:	the void** variable for pointer to slot
+ * @root:	the struct radix_tree_root pointer
+ * @iter:	the struct radix_tree_iter pointer
+ * @start:	iteration starting index
+ * @tag:	tag index
+ *
+ * @slot points to radix tree slot, @iter->index contains its index.
+ */
+#define radix_tree_for_each_tagged(slot, root, iter, start, tag)	\
+	for (slot = radix_tree_iter_init(iter, start) ;			\
+	     slot || (slot = radix_tree_next_chunk(root, iter,		\
+			      RADIX_TREE_ITER_TAGGED | tag)) ;		\
+	     slot = radix_tree_next_slot(slot, iter,			\
+				RADIX_TREE_ITER_TAGGED))
+
 #endif /* _LINUX_RADIX_TREE_H */

include/linux/smp.h

@@ -101,6 +101,22 @@ static inline void call_function_init(void) { }
  */
 int on_each_cpu(smp_call_func_t func, void *info, int wait);
 
+/*
+ * Call a function on processors specified by mask, which might include
+ * the local one.
+ */
+void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
+		void *info, bool wait);
+
+/*
+ * Call a function on each processor for which the supplied function
+ * cond_func returns a positive value. This may include the local
+ * processor.
+ */
+void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
+		smp_call_func_t func, void *info, bool wait,
+		gfp_t gfp_flags);
+
 /*
  * Mark the boot cpu "online" so that it can call console drivers in
  * printk() and can access its per-cpu storage.
@@ -132,6 +148,36 @@ static inline int up_smp_call_function(smp_call_func_t func, void *info)
 		local_irq_enable();		\
 		0;				\
 	})
+/*
+ * Note we still need to test the mask even for UP
+ * because we actually can get an empty mask from
+ * code that on SMP might call us without the local
+ * CPU in the mask.
+ */
+#define on_each_cpu_mask(mask, func, info, wait) \
+	do {						\
+		if (cpumask_test_cpu(0, (mask))) {	\
+			local_irq_disable();		\
+			(func)(info);			\
+			local_irq_enable();		\
+		}					\
+	} while (0)
+/*
+ * Preemption is disabled here to make sure the cond_func is called under the
+ * same condtions in UP and SMP.
+ */
+#define on_each_cpu_cond(cond_func, func, info, wait, gfp_flags)\
+	do {							\
+		void *__info = (info);				\
+		preempt_disable();				\
+		if ((cond_func)(0, __info)) {			\
+			local_irq_disable();			\
+			(func)(__info);				\
+			local_irq_enable();			\
+		}						\
+		preempt_enable();				\
+	} while (0)
+
 static inline void smp_send_reschedule(int cpu) { }
 #define num_booting_cpus()			1
 #define smp_prepare_boot_cpu()			do {} while (0)

include/linux/swap.h

@@ -21,6 +21,9 @@ struct bio;
 #define SWAP_FLAG_PRIO_SHIFT	0
 #define SWAP_FLAG_DISCARD	0x10000 /* discard swap cluster after use */
 
+#define SWAP_FLAGS_VALID	(SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \
+				 SWAP_FLAG_DISCARD)
+
 static inline int current_is_kswapd(void)
 {
 	return current->flags & PF_KSWAPD;