Merge branch 'akpm'

Quoth Andrew:
  "Random fixes.  And a simple new LED driver which I'm trying to sneak
   in while you're not looking."

Sneaking successful.

* akpm:
  score: fix off-by-one index into syscall table
  mm: fix rss count leakage during migration
  SHM_UNLOCK: fix Unevictable pages stranded after swap
  SHM_UNLOCK: fix long unpreemptible section
  kdump: define KEXEC_NOTE_BYTES arch specific for s390x
  mm/hugetlb.c: undo change to page mapcount in fault handler
  mm: memcg: update the correct soft limit tree during migration
  proc: clear_refs: do not clear reserved pages
  drivers/video/backlight/l4f00242t03.c: return proper error in l4f00242t03_probe if regulator_get() fails
  drivers/video/backlight/adp88x0_bl.c: fix bit testing logic
  kprobes: initialize before using a hlist
  ipc/mqueue: simplify reading msgqueue limit
  leds: add led driver for Bachmann's ot200
  mm: __count_immobile_pages(): make sure the node is online
  mm: fix NULL ptr dereference in __count_immobile_pages
  mm: fix warnings regarding enum migrate_mode

arch/s390/include/asm/kexec.h

@@ -42,6 +42,24 @@
 /* The native architecture */
 #define KEXEC_ARCH KEXEC_ARCH_S390
 
+/*
+ * Size for s390x ELF notes per CPU
+ *
+ * Seven notes plus zero note at the end: prstatus, fpregset, timer,
+ * tod_cmp, tod_reg, control regs, and prefix
+ */
+#define KEXEC_NOTE_BYTES \
+	(ALIGN(sizeof(struct elf_note), 4) * 8 + \
+	 ALIGN(sizeof("CORE"), 4) * 7 + \
+	 ALIGN(sizeof(struct elf_prstatus), 4) + \
+	 ALIGN(sizeof(elf_fpregset_t), 4) + \
+	 ALIGN(sizeof(u64), 4) + \
+	 ALIGN(sizeof(u64), 4) + \
+	 ALIGN(sizeof(u32), 4) + \
+	 ALIGN(sizeof(u64) * 16, 4) + \
+	 ALIGN(sizeof(u32), 4) \
+	)
+
 /* Provide a dummy definition to avoid build failures. */
 static inline void crash_setup_regs(struct pt_regs *newregs,
 					struct pt_regs *oldregs) { }

arch/score/kernel/entry.S

@@ -408,7 +408,7 @@ ENTRY(handle_sys)
 	sw	r9, [r0, PT_EPC]
 
 	cmpi.c	r27, __NR_syscalls 	# check syscall number
-	bgtu	illegal_syscall
+	bgeu	illegal_syscall
 
 	slli	r8, r27, 2		# get syscall routine
 	la	r11, sys_call_table

drivers/leds/Kconfig

@@ -403,6 +403,13 @@ config LEDS_MAX8997
 	  This option enables support for on-chip LED drivers on
 	  MAXIM MAX8997 PMIC.
 
+config LEDS_OT200
+	tristate "LED support for the Bachmann OT200"
+	depends on LEDS_CLASS && HAS_IOMEM
+	help
+	  This option enables support for the LEDs on the Bachmann OT200.
+	  Say Y to enable LEDs on the Bachmann OT200.
+
 config LEDS_TRIGGERS
 	bool "LED Trigger support"
 	depends on LEDS_CLASS

drivers/leds/Makefile

@@ -28,6 +28,7 @@ obj-$(CONFIG_LEDS_LP5523)		+= leds-lp5523.o
 obj-$(CONFIG_LEDS_TCA6507)		+= leds-tca6507.o
 obj-$(CONFIG_LEDS_CLEVO_MAIL)		+= leds-clevo-mail.o
 obj-$(CONFIG_LEDS_HP6XX)		+= leds-hp6xx.o
+obj-$(CONFIG_LEDS_OT200)		+= leds-ot200.o
 obj-$(CONFIG_LEDS_FSG)			+= leds-fsg.o
 obj-$(CONFIG_LEDS_PCA955X)		+= leds-pca955x.o
 obj-$(CONFIG_LEDS_DA903X)		+= leds-da903x.o

drivers/leds/leds-ot200.c

+/*
+ * Bachmann ot200 leds driver.
+ *
+ * Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+ *         Christian Gmeiner <christian.gmeiner@gmail.com>
+ *
+ * License: GPL as published by the FSF.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/leds.h>
+#include <linux/io.h>
+#include <linux/module.h>
+
+
+struct ot200_led {
+	struct led_classdev cdev;
+	const char *name;
+	unsigned long port;
+	u8 mask;
+};
+
+/*
+ * The device has three leds on the back panel (led_err, led_init and led_run)
+ * and can handle up to seven leds on the front panel.
+ */
+
+static struct ot200_led leds[] = {
+	{
+		.name = "led_run",
+		.port = 0x5a,
+		.mask = BIT(0),
+	},
+	{
+		.name = "led_init",
+		.port = 0x5a,
+		.mask = BIT(1),
+	},
+	{
+		.name = "led_err",
+		.port = 0x5a,
+		.mask = BIT(2),
+	},
+	{
+		.name = "led_1",
+		.port = 0x49,
+		.mask = BIT(7),
+	},
+	{
+		.name = "led_2",
+		.port = 0x49,
+		.mask = BIT(6),
+	},
+	{
+		.name = "led_3",
+		.port = 0x49,
+		.mask = BIT(5),
+	},
+	{
+		.name = "led_4",
+		.port = 0x49,
+		.mask = BIT(4),
+	},
+	{
+		.name = "led_5",
+		.port = 0x49,
+		.mask = BIT(3),
+	},
+	{
+		.name = "led_6",
+		.port = 0x49,
+		.mask = BIT(2),
+	},
+	{
+		.name = "led_7",
+		.port = 0x49,
+		.mask = BIT(1),
+	}
+};
+
+static DEFINE_SPINLOCK(value_lock);
+
+/*
+ * we need to store the current led states, as it is not
+ * possible to read the current led state via inb().
+ */
+static u8 leds_back;
+static u8 leds_front;
+
+static void ot200_led_brightness_set(struct led_classdev *led_cdev,
+		enum led_brightness value)
+{
+	struct ot200_led *led = container_of(led_cdev, struct ot200_led, cdev);
+	u8 *val;
+	unsigned long flags;
+
+	spin_lock_irqsave(&value_lock, flags);
+
+	if (led->port == 0x49)
+		val = &leds_front;
+	else if (led->port == 0x5a)
+		val = &leds_back;
+	else
+		BUG();
+
+	if (value == LED_OFF)
+		*val &= ~led->mask;
+	else
+		*val |= led->mask;
+
+	outb(*val, led->port);
+	spin_unlock_irqrestore(&value_lock, flags);
+}
+
+static int __devinit ot200_led_probe(struct platform_device *pdev)
+{
+	int i;
+	int ret;
+
+	for (i = 0; i < ARRAY_SIZE(leds); i++) {
+
+		leds[i].cdev.name = leds[i].name;
+		leds[i].cdev.brightness_set = ot200_led_brightness_set;
+
+		ret = led_classdev_register(&pdev->dev, &leds[i].cdev);
+		if (ret < 0)
+			goto err;
+	}
+
+	leds_front = 0;		/* turn off all front leds */
+	leds_back = BIT(1);	/* turn on init led */
+	outb(leds_front, 0x49);
+	outb(leds_back, 0x5a);
+
+	return 0;
+
+err:
+	for (i = i - 1; i >= 0; i--)
+		led_classdev_unregister(&leds[i].cdev);
+
+	return ret;
+}
+
+static int __devexit ot200_led_remove(struct platform_device *pdev)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(leds); i++)
+		led_classdev_unregister(&leds[i].cdev);
+
+	return 0;
+}
+
+static struct platform_driver ot200_led_driver = {
+	.probe		= ot200_led_probe,
+	.remove		= __devexit_p(ot200_led_remove),
+	.driver		= {
+		.name	= "leds-ot200",
+		.owner	= THIS_MODULE,
+	},
+};
+
+module_platform_driver(ot200_led_driver);
+
+MODULE_AUTHOR("Sebastian A. Siewior <bigeasy@linutronix.de>");
+MODULE_DESCRIPTION("ot200 LED driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:leds-ot200");

drivers/video/backlight/adp8860_bl.c

@@ -146,7 +146,7 @@ static int adp8860_set_bits(struct i2c_client *client, int reg, uint8_t bit_mask
 
 	ret = adp8860_read(client, reg, &reg_val);
 
-	if (!ret && ((reg_val & bit_mask) == 0)) {
+	if (!ret && ((reg_val & bit_mask) != bit_mask)) {
 		reg_val |= bit_mask;
 		ret = adp8860_write(client, reg, reg_val);
 	}

drivers/video/backlight/adp8870_bl.c

@@ -160,7 +160,7 @@ static int adp8870_set_bits(struct i2c_client *client, int reg, uint8_t bit_mask
 
 	ret = adp8870_read(client, reg, &reg_val);
 
-	if (!ret && ((reg_val & bit_mask) == 0)) {
+	if (!ret && ((reg_val & bit_mask) != bit_mask)) {
 		reg_val |= bit_mask;
 		ret = adp8870_write(client, reg, reg_val);
 	}

drivers/video/backlight/l4f00242t03.c

@@ -190,6 +190,7 @@ static int __devinit l4f00242t03_probe(struct spi_device *spi)
 
 	priv->io_reg = regulator_get(&spi->dev, "vdd");
 	if (IS_ERR(priv->io_reg)) {
+		ret = PTR_ERR(priv->io_reg);
 		dev_err(&spi->dev, "%s: Unable to get the IO regulator\n",
 		       __func__);
 		goto err3;
@@ -197,6 +198,7 @@ static int __devinit l4f00242t03_probe(struct spi_device *spi)
 
 	priv->core_reg = regulator_get(&spi->dev, "vcore");
 	if (IS_ERR(priv->core_reg)) {
+		ret = PTR_ERR(priv->core_reg);
 		dev_err(&spi->dev, "%s: Unable to get the core regulator\n",
 		       __func__);
 		goto err4;

fs/proc/task_mmu.c

@@ -518,6 +518,9 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
 		if (!page)
 			continue;
 
+		if (PageReserved(page))
+			continue;
+
 		/* Clear accessed and referenced bits. */
 		ptep_test_and_clear_young(vma, addr, pte);
 		ClearPageReferenced(page);

include/linux/fs.h

@@ -10,6 +10,7 @@
 #include <linux/ioctl.h>
 #include <linux/blk_types.h>
 #include <linux/types.h>
+#include <linux/migrate_mode.h>
 
 /*
  * It's silly to have NR_OPEN bigger than NR_FILE, but you can change
@@ -526,7 +527,6 @@ enum positive_aop_returns {
 struct page;
 struct address_space;
 struct writeback_control;
-enum migrate_mode;
 
 struct iov_iter {
 	const struct iovec *iov;

include/linux/kexec.h

@@ -50,9 +50,11 @@
  * note header.  For kdump, the code in vmcore.c runs in the context
  * of the second kernel to combine them into one note.
  */
+#ifndef KEXEC_NOTE_BYTES
 #define KEXEC_NOTE_BYTES ( (KEXEC_NOTE_HEAD_BYTES * 2) +		\
 			    KEXEC_CORE_NOTE_NAME_BYTES +		\
 			    KEXEC_CORE_NOTE_DESC_BYTES )
+#endif
 
 /*
  * This structure is used to hold the arguments that are used when loading

include/linux/migrate.h

@@ -3,22 +3,10 @@
 
 #include <linux/mm.h>
 #include <linux/mempolicy.h>
+#include <linux/migrate_mode.h>
 
 typedef struct page *new_page_t(struct page *, unsigned long private, int **);
 
-/*
- * MIGRATE_ASYNC means never block
- * MIGRATE_SYNC_LIGHT in the current implementation means to allow blocking
- *	on most operations but not ->writepage as the potential stall time
- *	is too significant
- * MIGRATE_SYNC will block when migrating pages
- */
-enum migrate_mode {
-	MIGRATE_ASYNC,
-	MIGRATE_SYNC_LIGHT,
-	MIGRATE_SYNC,
-};
-
 #ifdef CONFIG_MIGRATION
 #define PAGE_MIGRATION 1
 

include/linux/migrate_mode.h

+#ifndef MIGRATE_MODE_H_INCLUDED
+#define MIGRATE_MODE_H_INCLUDED
+/*
+ * MIGRATE_ASYNC means never block
+ * MIGRATE_SYNC_LIGHT in the current implementation means to allow blocking
+ *	on most operations but not ->writepage as the potential stall time
+ *	is too significant
+ * MIGRATE_SYNC will block when migrating pages
+ */
+enum migrate_mode {
+	MIGRATE_ASYNC,
+	MIGRATE_SYNC_LIGHT,
+	MIGRATE_SYNC,
+};
+
+#endif		/* MIGRATE_MODE_H_INCLUDED */

include/linux/shmem_fs.h

@@ -48,6 +48,7 @@ extern struct file *shmem_file_setup(const char *name,
 					loff_t size, unsigned long flags);
 extern int shmem_zero_setup(struct vm_area_struct *);
 extern int shmem_lock(struct file *file, int lock, struct user_struct *user);
+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);

include/linux/swap.h

@@ -273,7 +273,7 @@ static inline int zone_reclaim(struct zone *z, gfp_t mask, unsigned int order)
 #endif
 
 extern int page_evictable(struct page *page, struct vm_area_struct *vma);
-extern void scan_mapping_unevictable_pages(struct address_space *);
+extern void check_move_unevictable_pages(struct page **, int nr_pages);
 
 extern unsigned long scan_unevictable_pages;
 extern int scan_unevictable_handler(struct ctl_table *, int,

ipc/mqueue.c

@@ -128,7 +128,6 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
 
 	if (S_ISREG(mode)) {
 		struct mqueue_inode_info *info;
-		struct task_struct *p = current;
 		unsigned long mq_bytes, mq_msg_tblsz;
 
 		inode->i_fop = &mqueue_file_operations;
@@ -159,7 +158,7 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
 
 		spin_lock(&mq_lock);
 		if (u->mq_bytes + mq_bytes < u->mq_bytes ||
-		    u->mq_bytes + mq_bytes > task_rlimit(p, RLIMIT_MSGQUEUE)) {
+		    u->mq_bytes + mq_bytes > rlimit(RLIMIT_MSGQUEUE)) {
 			spin_unlock(&mq_lock);
 			/* mqueue_evict_inode() releases info->messages */
 			ret = -EMFILE;

ipc/shm.c

@@ -870,9 +870,7 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
 	case SHM_LOCK:
 	case SHM_UNLOCK:
 	{
-		struct file *uninitialized_var(shm_file);
-
-		lru_add_drain_all();  /* drain pagevecs to lru lists */
+		struct file *shm_file;
 
 		shp = shm_lock_check(ns, shmid);
 		if (IS_ERR(shp)) {
@@ -895,22 +893,31 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
 		err = security_shm_shmctl(shp, cmd);
 		if (err)
 			goto out_unlock;
-		
-		if(cmd==SHM_LOCK) {
+
+		shm_file = shp->shm_file;
+		if (is_file_hugepages(shm_file))
+			goto out_unlock;
+
+		if (cmd == SHM_LOCK) {
 			struct user_struct *user = current_user();
-			if (!is_file_hugepages(shp->shm_file)) {
-				err = shmem_lock(shp->shm_file, 1, user);
-				if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){
-					shp->shm_perm.mode |= SHM_LOCKED;
-					shp->mlock_user = user;
-				}
+			err = shmem_lock(shm_file, 1, user);
+			if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) {
+				shp->shm_perm.mode |= SHM_LOCKED;
+				shp->mlock_user = user;
 			}
-		} else if (!is_file_hugepages(shp->shm_file)) {
-			shmem_lock(shp->shm_file, 0, shp->mlock_user);
-			shp->shm_perm.mode &= ~SHM_LOCKED;
-			shp->mlock_user = NULL;
+			goto out_unlock;
 		}
+
+		/* SHM_UNLOCK */
+		if (!(shp->shm_perm.mode & SHM_LOCKED))
+			goto out_unlock;
+		shmem_lock(shm_file, 0, shp->mlock_user);
+		shp->shm_perm.mode &= ~SHM_LOCKED;
+		shp->mlock_user = NULL;
+		get_file(shm_file);
 		shm_unlock(shp);
+		shmem_unlock_mapping(shm_file->f_mapping);
+		fput(shm_file);
 		goto out;
 	}
 	case IPC_RMID:

kernel/kprobes.c

@@ -1077,6 +1077,7 @@ void __kprobes kprobe_flush_task(struct task_struct *tk)
 		/* Early boot.  kretprobe_table_locks not yet initialized. */
 		return;
 
+	INIT_HLIST_HEAD(&empty_rp);
 	hash = hash_ptr(tk, KPROBE_HASH_BITS);
 	head = &kretprobe_inst_table[hash];
 	kretprobe_table_lock(hash, &flags);
@@ -1085,7 +1086,6 @@ void __kprobes kprobe_flush_task(struct task_struct *tk)
 			recycle_rp_inst(ri, &empty_rp);
 	}
 	kretprobe_table_unlock(hash, &flags);
-	INIT_HLIST_HEAD(&empty_rp);
 	hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
 		hlist_del(&ri->hlist);
 		kfree(ri);

mm/hugetlb.c

@@ -2508,6 +2508,7 @@ static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
 {
 	struct hstate *h = hstate_vma(vma);
 	int ret = VM_FAULT_SIGBUS;
+	int anon_rmap = 0;
 	pgoff_t idx;
 	unsigned long size;
 	struct page *page;
@@ -2562,14 +2563,13 @@ static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
 			spin_lock(&inode->i_lock);
 			inode->i_blocks += blocks_per_huge_page(h);
 			spin_unlock(&inode->i_lock);
-			page_dup_rmap(page);
 		} else {
 			lock_page(page);
 			if (unlikely(anon_vma_prepare(vma))) {
 				ret = VM_FAULT_OOM;
 				goto backout_unlocked;
 			}
-			hugepage_add_new_anon_rmap(page, vma, address);
+			anon_rmap = 1;
 		}
 	} else {
 		/*
@@ -2582,7 +2582,6 @@ static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
 			      VM_FAULT_SET_HINDEX(h - hstates);
 			goto backout_unlocked;
 		}
-		page_dup_rmap(page);
 	}
 
 	/*
@@ -2606,6 +2605,10 @@ static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	if (!huge_pte_none(huge_ptep_get(ptep)))
 		goto backout;
 
+	if (anon_rmap)
+		hugepage_add_new_anon_rmap(page, vma, address);
+	else
+		page_dup_rmap(page);
 	new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE)
 				&& (vma->vm_flags & VM_SHARED)));
 	set_huge_pte_at(mm, address, ptep, new_pte);

mm/memcontrol.c

@@ -3247,7 +3247,7 @@ int mem_cgroup_prepare_migration(struct page *page,
 		ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
 	else
 		ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
-	__mem_cgroup_commit_charge(memcg, page, 1, pc, ctype);
+	__mem_cgroup_commit_charge(memcg, newpage, 1, pc, ctype);
 	return ret;
 }
 

mm/memory.c

@@ -878,15 +878,24 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 			}
 			if (likely(!non_swap_entry(entry)))
 				rss[MM_SWAPENTS]++;
-			else if (is_write_migration_entry(entry) &&
-					is_cow_mapping(vm_flags)) {
-				/*
-				 * COW mappings require pages in both parent
-				 * and child to be set to read.
-				 */
-				make_migration_entry_read(&entry);
-				pte = swp_entry_to_pte(entry);
-				set_pte_at(src_mm, addr, src_pte, pte);
+			else if (is_migration_entry(entry)) {
+				page = migration_entry_to_page(entry);
+
+				if (PageAnon(page))
+					rss[MM_ANONPAGES]++;
+				else
+					rss[MM_FILEPAGES]++;
+
+				if (is_write_migration_entry(entry) &&
+				    is_cow_mapping(vm_flags)) {
+					/*
+					 * COW mappings require pages in both
+					 * parent and child to be set to read.
+					 */
+					make_migration_entry_read(&entry);
+					pte = swp_entry_to_pte(entry);
+					set_pte_at(src_mm, addr, src_pte, pte);
+				}
 			}
 		}
 		goto out_set_pte;
@@ -1191,6 +1200,16 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
 
 			if (!non_swap_entry(entry))
 				rss[MM_SWAPENTS]--;
+			else if (is_migration_entry(entry)) {
+				struct page *page;
+
+				page = migration_entry_to_page(entry);
+
+				if (PageAnon(page))
+					rss[MM_ANONPAGES]--;
+				else
+					rss[MM_FILEPAGES]--;
+			}
 			if (unlikely(!free_swap_and_cache(entry)))
 				print_bad_pte(vma, addr, ptent, NULL);
 		}

mm/page_alloc.c

@@ -5413,7 +5413,25 @@ __count_immobile_pages(struct zone *zone, struct page *page, int count)
 
 bool is_pageblock_removable_nolock(struct page *page)
 {
-	struct zone *zone = page_zone(page);
+	struct zone *zone;
+	unsigned long pfn;
+
+	/*
+	 * We have to be careful here because we are iterating over memory
+	 * sections which are not zone aware so we might end up outside of
+	 * the zone but still within the section.
+	 * We have to take care about the node as well. If the node is offline
+	 * its NODE_DATA will be NULL - see page_zone.
+	 */
+	if (!node_online(page_to_nid(page)))
+		return false;
+
+	zone = page_zone(page);
+	pfn = page_to_pfn(page);
+	if (zone->zone_start_pfn > pfn ||
+			zone->zone_start_pfn + zone->spanned_pages <= pfn)
+		return false;
+
 	return __count_immobile_pages(zone, page, 0);
 }
 

mm/shmem.c

@@ -379,7 +379,7 @@ static int shmem_free_swap(struct address_space *mapping,
 /*
  * Pagevec may contain swap entries, so shuffle up pages before releasing.
  */
-static void shmem_pagevec_release(struct pagevec *pvec)
+static void shmem_deswap_pagevec(struct pagevec *pvec)
 {
 	int i, j;
 
@@ -389,7 +389,36 @@ static void shmem_pagevec_release(struct pagevec *pvec)
 			pvec->pages[j++] = page;
 	}
 	pvec->nr = j;
-	pagevec_release(pvec);
+}
+
+/*
+ * SysV IPC SHM_UNLOCK restore Unevictable pages to their evictable lists.
+ */
+void shmem_unlock_mapping(struct address_space *mapping)
+{
+	struct pagevec pvec;
+	pgoff_t indices[PAGEVEC_SIZE];
+	pgoff_t index = 0;
+
+	pagevec_init(&pvec, 0);
+	/*
+	 * Minor point, but we might as well stop if someone else SHM_LOCKs it.
+	 */
+	while (!mapping_unevictable(mapping)) {
+		/*
+		 * Avoid pagevec_lookup(): find_get_pages() returns 0 as if it
+		 * has finished, if it hits a row of PAGEVEC_SIZE swap entries.
+		 */
+		pvec.nr = shmem_find_get_pages_and_swap(mapping, index,
+					PAGEVEC_SIZE, pvec.pages, indices);
+		if (!pvec.nr)
+			break;
+		index = indices[pvec.nr - 1] + 1;
+		shmem_deswap_pagevec(&pvec);
+		check_move_unevictable_pages(pvec.pages, pvec.nr);
+		pagevec_release(&pvec);
+		cond_resched();
+	}
 }
 
 /*
@@ -440,7 +469,8 @@ void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend)
 			}
 			unlock_page(page);
 		}
-		shmem_pagevec_release(&pvec);
+		shmem_deswap_pagevec(&pvec);
+		pagevec_release(&pvec);
 		mem_cgroup_uncharge_end();
 		cond_resched();
 		index++;
@@ -470,7 +500,8 @@ void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend)
 			continue;
 		}
 		if (index == start && indices[0] > end) {
-			shmem_pagevec_release(&pvec);
+			shmem_deswap_pagevec(&pvec);
+			pagevec_release(&pvec);
 			break;
 		}
 		mem_cgroup_uncharge_start();
@@ -494,7 +525,8 @@ void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend)
 			}
 			unlock_page(page);
 		}
-		shmem_pagevec_release(&pvec);
+		shmem_deswap_pagevec(&pvec);
+		pagevec_release(&pvec);
 		mem_cgroup_uncharge_end();
 		index++;
 	}
@@ -1068,13 +1100,6 @@ int shmem_lock(struct file *file, int lock, struct user_struct *user)
 		user_shm_unlock(inode->i_size, user);
 		info->flags &= ~VM_LOCKED;
 		mapping_clear_unevictable(file->f_mapping);
-		/*
-		 * Ensure that a racing putback_lru_page() can see
-		 * the pages of this mapping are evictable when we
-		 * skip them due to !PageLRU during the scan.
-		 */
-		smp_mb__after_clear_bit();
-		scan_mapping_unevictable_pages(file->f_mapping);
 	}
 	retval = 0;
 
@@ -2445,6 +2470,10 @@ int shmem_lock(struct file *file, int lock, struct user_struct *user)
 	return 0;
 }
 
+void shmem_unlock_mapping(struct address_space *mapping)
+{
+}
+
 void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend)
 {
 	truncate_inode_pages_range(inode->i_mapping, lstart, lend);

mm/vmscan.c

@@ -26,7 +26,6 @@
 #include <linux/buffer_head.h>	/* for try_to_release_page(),
 					buffer_heads_over_limit */
 #include <linux/mm_inline.h>
-#include <linux/pagevec.h>
 #include <linux/backing-dev.h>
 #include <linux/rmap.h>
 #include <linux/topology.h>
@@ -661,7 +660,7 @@ void putback_lru_page(struct page *page)
 		 * When racing with an mlock or AS_UNEVICTABLE clearing
 		 * (page is unlocked) make sure that if the other thread
 		 * does not observe our setting of PG_lru and fails
-		 * isolation/check_move_unevictable_page,
+		 * isolation/check_move_unevictable_pages,
 		 * we see PG_mlocked/AS_UNEVICTABLE cleared below and move
 		 * the page back to the evictable list.
 		 *
@@ -3499,100 +3498,61 @@ int page_evictable(struct page *page, struct vm_area_struct *vma)
 	return 1;
 }
 
+#ifdef CONFIG_SHMEM
 /**
- * check_move_unevictable_page - check page for evictability and move to appropriate zone lru list
- * @page: page to check evictability and move to appropriate lru list
- * @zone: zone page is in
+ * check_move_unevictable_pages - check pages for evictability and move to appropriate zone lru list
+ * @pages:	array of pages to check
+ * @nr_pages:	number of pages to check
  *
- * Checks a page for evictability and moves the page to the appropriate
- * zone lru list.
+ * Checks pages for evictability and moves them to the appropriate lru list.
  *
- * Restrictions: zone->lru_lock must be held, page must be on LRU and must
- * have PageUnevictable set.
+ * This function is only used for SysV IPC SHM_UNLOCK.
  */
-static void check_move_unevictable_page(struct page *page, struct zone *zone)
+void check_move_unevictable_pages(struct page **pages, int nr_pages)
 {
 	struct lruvec *lruvec;
+	struct zone *zone = NULL;
+	int pgscanned = 0;
+	int pgrescued = 0;
+	int i;
 
-	VM_BUG_ON(PageActive(page));
-retry:
-	ClearPageUnevictable(page);
-	if (page_evictable(page, NULL)) {
-		enum lru_list l = page_lru_base_type(page);
-
-		__dec_zone_state(zone, NR_UNEVICTABLE);
-		lruvec = mem_cgroup_lru_move_lists(zone, page,
-						   LRU_UNEVICTABLE, l);
-		list_move(&page->lru, &lruvec->lists[l]);
-		__inc_zone_state(zone, NR_INACTIVE_ANON + l);
-		__count_vm_event(UNEVICTABLE_PGRESCUED);
-	} else {
-		/*
-		 * rotate unevictable list
-		 */
-		SetPageUnevictable(page);
-		lruvec = mem_cgroup_lru_move_lists(zone, page, LRU_UNEVICTABLE,
-						   LRU_UNEVICTABLE);
-		list_move(&page->lru, &lruvec->lists[LRU_UNEVICTABLE]);
-		if (page_evictable(page, NULL))
-			goto retry;
-	}
-}
-
-/**
- * scan_mapping_unevictable_pages - scan an address space for evictable pages
- * @mapping: struct address_space to scan for evictable pages
- *
- * Scan all pages in mapping.  Check unevictable pages for
- * evictability and move them to the appropriate zone lru list.
- */
-void scan_mapping_unevictable_pages(struct address_space *mapping)
-{
-	pgoff_t next = 0;
-	pgoff_t end   = (i_size_read(mapping->host) + PAGE_CACHE_SIZE - 1) >>
-			 PAGE_CACHE_SHIFT;
-	struct zone *zone;
-	struct pagevec pvec;
-
-	if (mapping->nrpages == 0)
-		return;
-
-	pagevec_init(&pvec, 0);
-	while (next < end &&
-		pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) {
-		int i;
-		int pg_scanned = 0;
-
-		zone = NULL;
-
-		for (i = 0; i < pagevec_count(&pvec); i++) {
-			struct page *page = pvec.pages[i];
-			pgoff_t page_index = page->index;
-			struct zone *pagezone = page_zone(page);
+	for (i = 0; i < nr_pages; i++) {
+		struct page *page = pages[i];
+		struct zone *pagezone;
 
-			pg_scanned++;
-			if (page_index > next)
-				next = page_index;
-			next++;
+		pgscanned++;
+		pagezone = page_zone(page);
+		if (pagezone != zone) {
+			if (zone)
+				spin_unlock_irq(&zone->lru_lock);
+			zone = pagezone;
+			spin_lock_irq(&zone->lru_lock);
+		}
 
-			if (pagezone != zone) {
-				if (zone)
-					spin_unlock_irq(&zone->lru_lock);
-				zone = pagezone;
-				spin_lock_irq(&zone->lru_lock);
-			}
+		if (!PageLRU(page) || !PageUnevictable(page))
+			continue;
 
-			if (PageLRU(page) && PageUnevictable(page))
-				check_move_unevictable_page(page, zone);
+		if (page_evictable(page, NULL)) {
+			enum lru_list lru = page_lru_base_type(page);
+
+			VM_BUG_ON(PageActive(page));
+			ClearPageUnevictable(page);
+			__dec_zone_state(zone, NR_UNEVICTABLE);
+			lruvec = mem_cgroup_lru_move_lists(zone, page,
+						LRU_UNEVICTABLE, lru);
+			list_move(&page->lru, &lruvec->lists[lru]);
+			__inc_zone_state(zone, NR_INACTIVE_ANON + lru);
+			pgrescued++;
 		}
-		if (zone)
-			spin_unlock_irq(&zone->lru_lock);
-		pagevec_release(&pvec);
-
-		count_vm_events(UNEVICTABLE_PGSCANNED, pg_scanned);
 	}
 
+	if (zone) {
+		__count_vm_events(UNEVICTABLE_PGRESCUED, pgrescued);
+		__count_vm_events(UNEVICTABLE_PGSCANNED, pgscanned);
+		spin_unlock_irq(&zone->lru_lock);
+	}
 }
+#endif /* CONFIG_SHMEM */
 
 static void warn_scan_unevictable_pages(void)
 {