1 files changed, 337 insertions, 116 deletions

diff --git a/kernel/power/main.c b/kernel/power/main.c
index 31ec4a9b9d70..03b2c5495c77 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -6,7 +6,9 @@
  * Copyright (c) 2003 Open Source Development Lab
  */
 
+#include <linux/acpi.h>
 #include <linux/export.h>
+#include <linux/init.h>
 #include <linux/kobject.h>
 #include <linux/string.h>
 #include <linux/pm-trace.h>
@@ -16,10 +18,51 @@
 #include <linux/suspend.h>
 #include <linux/syscalls.h>
 #include <linux/pm_runtime.h>
+#include <linux/atomic.h>
+#include <linux/wait.h>
 
 #include "power.h"
 
 #ifdef CONFIG_PM_SLEEP
+/*
+ * The following functions are used by the suspend/hibernate code to temporarily
+ * change gfp_allowed_mask in order to avoid using I/O during memory allocations
+ * while devices are suspended.  To avoid races with the suspend/hibernate code,
+ * they should always be called with system_transition_mutex held
+ * (gfp_allowed_mask also should only be modified with system_transition_mutex
+ * held, unless the suspend/hibernate code is guaranteed not to run in parallel
+ * with that modification).
+ */
+static unsigned int saved_gfp_count;
+static gfp_t saved_gfp_mask;
+
+void pm_restore_gfp_mask(void)
+{
+	WARN_ON(!mutex_is_locked(&system_transition_mutex));
+
+	if (WARN_ON(!saved_gfp_count) || --saved_gfp_count)
+		return;
+
+	gfp_allowed_mask = saved_gfp_mask;
+	saved_gfp_mask = 0;
+
+	pm_pr_dbg("GFP mask restored\n");
+}
+
+void pm_restrict_gfp_mask(void)
+{
+	WARN_ON(!mutex_is_locked(&system_transition_mutex));
+
+	if (saved_gfp_count++) {
+		WARN_ON((saved_gfp_mask & ~(__GFP_IO | __GFP_FS)) != gfp_allowed_mask);
+		return;
+	}
+
+	saved_gfp_mask = gfp_allowed_mask;
+	gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS);
+
+	pm_pr_dbg("GFP mask restricted\n");
+}
 
 unsigned int lock_system_sleep(void)
 {
@@ -32,22 +75,6 @@ EXPORT_SYMBOL_GPL(lock_system_sleep);
 
 void unlock_system_sleep(unsigned int flags)
 {
-	/*
-	 * Don't use freezer_count() because we don't want the call to
-	 * try_to_freeze() here.
-	 *
-	 * Reason:
-	 * Fundamentally, we just don't need it, because freezing condition
-	 * doesn't come into effect until we release the
-	 * system_transition_mutex lock, since the freezer always works with
-	 * system_transition_mutex held.
-	 *
-	 * More importantly, in the case of hibernation,
-	 * unlock_system_sleep() gets called in snapshot_read() and
-	 * snapshot_write() when the freezing condition is still in effect.
-	 * Which means, if we use try_to_freeze() here, it would make them
-	 * enter the refrigerator, thus causing hibernation to lockup.
-	 */
 	if (!(flags & PF_NOFREEZE))
 		current->flags &= ~PF_NOFREEZE;
 	mutex_unlock(&system_transition_mutex);
@@ -67,6 +94,61 @@ void ksys_sync_helper(void)
 }
 EXPORT_SYMBOL_GPL(ksys_sync_helper);
 
+#if defined(CONFIG_SUSPEND) || defined(CONFIG_HIBERNATION)
+/* Wakeup events handling resolution while syncing file systems in jiffies */
+#define PM_FS_SYNC_WAKEUP_RESOLUTION	5
+
+static atomic_t pm_fs_sync_count = ATOMIC_INIT(0);
+static struct workqueue_struct *pm_fs_sync_wq;
+static DECLARE_WAIT_QUEUE_HEAD(pm_fs_sync_wait);
+
+static bool pm_fs_sync_completed(void)
+{
+	return atomic_read(&pm_fs_sync_count) == 0;
+}
+
+static void pm_fs_sync_work_fn(struct work_struct *work)
+{
+	ksys_sync_helper();
+
+	if (atomic_dec_and_test(&pm_fs_sync_count))
+		wake_up(&pm_fs_sync_wait);
+}
+static DECLARE_WORK(pm_fs_sync_work, pm_fs_sync_work_fn);
+
+/**
+ * pm_sleep_fs_sync() - Sync file systems in an interruptible way
+ *
+ * Return: 0 on successful file system sync, or -EBUSY if the file system sync
+ * was aborted.
+ */
+int pm_sleep_fs_sync(void)
+{
+	pm_wakeup_clear(0);
+
+	/*
+	 * Take back-to-back sleeps into account by queuing a subsequent fs sync
+	 * only if the previous fs sync is running or is not queued. Multiple fs
+	 * syncs increase the likelihood of saving the latest files immediately
+	 * before sleep.
+	 */
+	if (!work_pending(&pm_fs_sync_work)) {
+		atomic_inc(&pm_fs_sync_count);
+		queue_work(pm_fs_sync_wq, &pm_fs_sync_work);
+	}
+
+	while (!pm_fs_sync_completed()) {
+		if (pm_wakeup_pending())
+			return -EBUSY;
+
+		wait_event_timeout(pm_fs_sync_wait, pm_fs_sync_completed(),
+				   PM_FS_SYNC_WAKEUP_RESOLUTION);
+	}
+
+	return 0;
+}
+#endif /* CONFIG_SUSPEND || CONFIG_HIBERNATION */
+
 /* Routines for PM-transition notifications */
 
 static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
@@ -100,10 +182,18 @@ int pm_notifier_call_chain(unsigned long val)
 /* If set, devices may be suspended and resumed asynchronously. */
 int pm_async_enabled = 1;
 
+static int __init pm_async_setup(char *str)
+{
+	if (!strcmp(str, "off"))
+		pm_async_enabled = 0;
+	return 1;
+}
+__setup("pm_async=", pm_async_setup);
+
 static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
 			     char *buf)
 {
-	return sprintf(buf, "%d\n", pm_async_enabled);
+	return sysfs_emit(buf, "%d\n", pm_async_enabled);
 }
 
 static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
@@ -127,7 +217,7 @@ power_attr(pm_async);
 static ssize_t mem_sleep_show(struct kobject *kobj, struct kobj_attribute *attr,
 			      char *buf)
 {
-	char *s = buf;
+	ssize_t count = 0;
 	suspend_state_t i;
 
 	for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++) {
@@ -137,17 +227,17 @@ static ssize_t mem_sleep_show(struct kobject *kobj, struct kobj_attribute *attr,
 			const char *label = mem_sleep_states[i];
 
 			if (mem_sleep_current == i)
-				s += sprintf(s, "[%s] ", label);
+				count += sysfs_emit_at(buf, count, "[%s] ", label);
 			else
-				s += sprintf(s, "%s ", label);
+				count += sysfs_emit_at(buf, count, "%s ", label);
 		}
 	}
 
 	/* Convert the last space to a newline if needed. */
-	if (s != buf)
-		*(s-1) = '\n';
+	if (count > 0)
+		buf[count - 1] = '\n';
 
-	return (s - buf);
+	return count;
 }
 
 static suspend_state_t decode_suspend_state(const char *buf, size_t n)
@@ -198,17 +288,17 @@ static ssize_t mem_sleep_store(struct kobject *kobj, struct kobj_attribute *attr
 power_attr(mem_sleep);
 
 /*
- * sync_on_suspend: invoke ksys_sync_helper() before suspend.
+ * sync_on_suspend: Sync file systems before suspend.
  *
- * show() returns whether ksys_sync_helper() is invoked before suspend.
- * store() accepts 0 or 1.  0 disables ksys_sync_helper() and 1 enables it.
+ * show() returns whether file systems sync before suspend is enabled.
+ * store() accepts 0 or 1.  0 disables file systems sync and 1 enables it.
  */
 bool sync_on_suspend_enabled = !IS_ENABLED(CONFIG_SUSPEND_SKIP_SYNC);
 
 static ssize_t sync_on_suspend_show(struct kobject *kobj,
 				   struct kobj_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%d\n", sync_on_suspend_enabled);
+	return sysfs_emit(buf, "%d\n", sync_on_suspend_enabled);
 }
 
 static ssize_t sync_on_suspend_store(struct kobject *kobj,
@@ -245,22 +335,22 @@ static const char * const pm_tests[__TEST_AFTER_LAST] = {
 static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
 				char *buf)
 {
-	char *s = buf;
+	ssize_t count = 0;
 	int level;
 
 	for (level = TEST_FIRST; level <= TEST_MAX; level++)
 		if (pm_tests[level]) {
 			if (level == pm_test_level)
-				s += sprintf(s, "[%s] ", pm_tests[level]);
+				count += sysfs_emit_at(buf, count, "[%s] ", pm_tests[level]);
 			else
-				s += sprintf(s, "%s ", pm_tests[level]);
+				count += sysfs_emit_at(buf, count, "%s ", pm_tests[level]);
 		}
 
-	if (s != buf)
-		/* convert the last space to a newline */
-		*(s-1) = '\n';
+	/* Convert the last space to a newline if needed. */
+	if (count > 0)
+		buf[count - 1] = '\n';
 
-	return (s - buf);
+	return count;
 }
 
 static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
@@ -294,44 +384,117 @@ static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
 power_attr(pm_test);
 #endif /* CONFIG_PM_SLEEP_DEBUG */
 
-static char *suspend_step_name(enum suspend_stat_step step)
-{
-	switch (step) {
-	case SUSPEND_FREEZE:
-		return "freeze";
-	case SUSPEND_PREPARE:
-		return "prepare";
-	case SUSPEND_SUSPEND:
-		return "suspend";
-	case SUSPEND_SUSPEND_NOIRQ:
-		return "suspend_noirq";
-	case SUSPEND_RESUME_NOIRQ:
-		return "resume_noirq";
-	case SUSPEND_RESUME:
-		return "resume";
-	default:
-		return "";
+#define SUSPEND_NR_STEPS	SUSPEND_RESUME
+#define REC_FAILED_NUM		2
+
+struct suspend_stats {
+	unsigned int step_failures[SUSPEND_NR_STEPS];
+	unsigned int success;
+	unsigned int fail;
+	int last_failed_dev;
+	char failed_devs[REC_FAILED_NUM][40];
+	int last_failed_errno;
+	int errno[REC_FAILED_NUM];
+	int last_failed_step;
+	u64 last_hw_sleep;
+	u64 total_hw_sleep;
+	u64 max_hw_sleep;
+	enum suspend_stat_step failed_steps[REC_FAILED_NUM];
+};
+
+static struct suspend_stats suspend_stats;
+static DEFINE_MUTEX(suspend_stats_lock);
+
+void dpm_save_failed_dev(const char *name)
+{
+	mutex_lock(&suspend_stats_lock);
+
+	strscpy(suspend_stats.failed_devs[suspend_stats.last_failed_dev],
+		name, sizeof(suspend_stats.failed_devs[0]));
+	suspend_stats.last_failed_dev++;
+	suspend_stats.last_failed_dev %= REC_FAILED_NUM;
+
+	mutex_unlock(&suspend_stats_lock);
+}
+
+void dpm_save_failed_step(enum suspend_stat_step step)
+{
+	suspend_stats.step_failures[step-1]++;
+	suspend_stats.failed_steps[suspend_stats.last_failed_step] = step;
+	suspend_stats.last_failed_step++;
+	suspend_stats.last_failed_step %= REC_FAILED_NUM;
+}
+
+void dpm_save_errno(int err)
+{
+	if (!err) {
+		suspend_stats.success++;
+		return;
 	}
+
+	suspend_stats.fail++;
+
+	suspend_stats.errno[suspend_stats.last_failed_errno] = err;
+	suspend_stats.last_failed_errno++;
+	suspend_stats.last_failed_errno %= REC_FAILED_NUM;
+}
+
+void pm_report_hw_sleep_time(u64 t)
+{
+	suspend_stats.last_hw_sleep = t;
+	suspend_stats.total_hw_sleep += t;
 }
+EXPORT_SYMBOL_GPL(pm_report_hw_sleep_time);
+
+void pm_report_max_hw_sleep(u64 t)
+{
+	suspend_stats.max_hw_sleep = t;
+}
+EXPORT_SYMBOL_GPL(pm_report_max_hw_sleep);
+
+static const char * const suspend_step_names[] = {
+	[SUSPEND_WORKING] = "",
+	[SUSPEND_FREEZE] = "freeze",
+	[SUSPEND_PREPARE] = "prepare",
+	[SUSPEND_SUSPEND] = "suspend",
+	[SUSPEND_SUSPEND_LATE] = "suspend_late",
+	[SUSPEND_SUSPEND_NOIRQ] = "suspend_noirq",
+	[SUSPEND_RESUME_NOIRQ] = "resume_noirq",
+	[SUSPEND_RESUME_EARLY] = "resume_early",
+	[SUSPEND_RESUME] = "resume",
+};
+
+#define suspend_attr(_name, format_str)				\
+static ssize_t _name##_show(struct kobject *kobj,		\
+		struct kobj_attribute *attr, char *buf)		\
+{								\
+	return sysfs_emit(buf, format_str, suspend_stats._name);\
+}								\
+static struct kobj_attribute _name = __ATTR_RO(_name)
+
+suspend_attr(success, "%u\n");
+suspend_attr(fail, "%u\n");
+suspend_attr(last_hw_sleep, "%llu\n");
+suspend_attr(total_hw_sleep, "%llu\n");
+suspend_attr(max_hw_sleep, "%llu\n");
 
-#define suspend_attr(_name)					\
+#define suspend_step_attr(_name, step)		\
 static ssize_t _name##_show(struct kobject *kobj,		\
 		struct kobj_attribute *attr, char *buf)		\
 {								\
-	return sprintf(buf, "%d\n", suspend_stats._name);	\
+	return sysfs_emit(buf, "%u\n",				\
+		       suspend_stats.step_failures[step-1]);	\
 }								\
 static struct kobj_attribute _name = __ATTR_RO(_name)
 
-suspend_attr(success);
-suspend_attr(fail);
-suspend_attr(failed_freeze);
-suspend_attr(failed_prepare);
-suspend_attr(failed_suspend);
-suspend_attr(failed_suspend_late);
-suspend_attr(failed_suspend_noirq);
-suspend_attr(failed_resume);
-suspend_attr(failed_resume_early);
-suspend_attr(failed_resume_noirq);
+suspend_step_attr(failed_freeze, SUSPEND_FREEZE);
+suspend_step_attr(failed_prepare, SUSPEND_PREPARE);
+suspend_step_attr(failed_suspend, SUSPEND_SUSPEND);
+suspend_step_attr(failed_suspend_late, SUSPEND_SUSPEND_LATE);
+suspend_step_attr(failed_suspend_noirq, SUSPEND_SUSPEND_NOIRQ);
+suspend_step_attr(failed_resume, SUSPEND_RESUME);
+suspend_step_attr(failed_resume_early, SUSPEND_RESUME_EARLY);
+suspend_step_attr(failed_resume_noirq, SUSPEND_RESUME_NOIRQ);
 
 static ssize_t last_failed_dev_show(struct kobject *kobj,
 		struct kobj_attribute *attr, char *buf)
@@ -343,7 +506,7 @@ static ssize_t last_failed_dev_show(struct kobject *kobj,
 	index %= REC_FAILED_NUM;
 	last_failed_dev = suspend_stats.failed_devs[index];
 
-	return sprintf(buf, "%s\n", last_failed_dev);
+	return sysfs_emit(buf, "%s\n", last_failed_dev);
 }
 static struct kobj_attribute last_failed_dev = __ATTR_RO(last_failed_dev);
 
@@ -357,23 +520,21 @@ static ssize_t last_failed_errno_show(struct kobject *kobj,
 	index %= REC_FAILED_NUM;
 	last_failed_errno = suspend_stats.errno[index];
 
-	return sprintf(buf, "%d\n", last_failed_errno);
+	return sysfs_emit(buf, "%d\n", last_failed_errno);
 }
 static struct kobj_attribute last_failed_errno = __ATTR_RO(last_failed_errno);
 
 static ssize_t last_failed_step_show(struct kobject *kobj,
 		struct kobj_attribute *attr, char *buf)
 {
-	int index;
 	enum suspend_stat_step step;
-	char *last_failed_step = NULL;
+	int index;
 
 	index = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
 	index %= REC_FAILED_NUM;
 	step = suspend_stats.failed_steps[index];
-	last_failed_step = suspend_step_name(step);
 
-	return sprintf(buf, "%s\n", last_failed_step);
+	return sysfs_emit(buf, "%s\n", suspend_step_names[step]);
 }
 static struct kobj_attribute last_failed_step = __ATTR_RO(last_failed_step);
 
@@ -391,18 +552,37 @@ static struct attribute *suspend_attrs[] = {
 	&last_failed_dev.attr,
 	&last_failed_errno.attr,
 	&last_failed_step.attr,
+	&last_hw_sleep.attr,
+	&total_hw_sleep.attr,
+	&max_hw_sleep.attr,
 	NULL,
 };
 
+static umode_t suspend_attr_is_visible(struct kobject *kobj, struct attribute *attr, int idx)
+{
+	if (attr != &last_hw_sleep.attr &&
+	    attr != &total_hw_sleep.attr &&
+	    attr != &max_hw_sleep.attr)
+		return 0444;
+
+#ifdef CONFIG_ACPI
+	if (acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0)
+		return 0444;
+#endif
+	return 0;
+}
+
 static const struct attribute_group suspend_attr_group = {
 	.name = "suspend_stats",
 	.attrs = suspend_attrs,
+	.is_visible = suspend_attr_is_visible,
 };
 
 #ifdef CONFIG_DEBUG_FS
 static int suspend_stats_show(struct seq_file *s, void *unused)
 {
 	int i, index, last_dev, last_errno, last_step;
+	enum suspend_stat_step step;
 
 	last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
 	last_dev %= REC_FAILED_NUM;
@@ -410,47 +590,35 @@ static int suspend_stats_show(struct seq_file *s, void *unused)
 	last_errno %= REC_FAILED_NUM;
 	last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
 	last_step %= REC_FAILED_NUM;
-	seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
-			"%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
-			"success", suspend_stats.success,
-			"fail", suspend_stats.fail,
-			"failed_freeze", suspend_stats.failed_freeze,
-			"failed_prepare", suspend_stats.failed_prepare,
-			"failed_suspend", suspend_stats.failed_suspend,
-			"failed_suspend_late",
-				suspend_stats.failed_suspend_late,
-			"failed_suspend_noirq",
-				suspend_stats.failed_suspend_noirq,
-			"failed_resume", suspend_stats.failed_resume,
-			"failed_resume_early",
-				suspend_stats.failed_resume_early,
-			"failed_resume_noirq",
-				suspend_stats.failed_resume_noirq);
+
+	seq_printf(s, "success: %u\nfail: %u\n",
+		   suspend_stats.success, suspend_stats.fail);
+
+	for (step = SUSPEND_FREEZE; step <= SUSPEND_NR_STEPS; step++)
+		seq_printf(s, "failed_%s: %u\n", suspend_step_names[step],
+			   suspend_stats.step_failures[step-1]);
+
 	seq_printf(s,	"failures:\n  last_failed_dev:\t%-s\n",
-			suspend_stats.failed_devs[last_dev]);
+		   suspend_stats.failed_devs[last_dev]);
 	for (i = 1; i < REC_FAILED_NUM; i++) {
 		index = last_dev + REC_FAILED_NUM - i;
 		index %= REC_FAILED_NUM;
-		seq_printf(s, "\t\t\t%-s\n",
-			suspend_stats.failed_devs[index]);
+		seq_printf(s, "\t\t\t%-s\n", suspend_stats.failed_devs[index]);
 	}
 	seq_printf(s,	"  last_failed_errno:\t%-d\n",
 			suspend_stats.errno[last_errno]);
 	for (i = 1; i < REC_FAILED_NUM; i++) {
 		index = last_errno + REC_FAILED_NUM - i;
 		index %= REC_FAILED_NUM;
-		seq_printf(s, "\t\t\t%-d\n",
-			suspend_stats.errno[index]);
+		seq_printf(s, "\t\t\t%-d\n", suspend_stats.errno[index]);
 	}
 	seq_printf(s,	"  last_failed_step:\t%-s\n",
-			suspend_step_name(
-				suspend_stats.failed_steps[last_step]));
+		   suspend_step_names[suspend_stats.failed_steps[last_step]]);
 	for (i = 1; i < REC_FAILED_NUM; i++) {
 		index = last_step + REC_FAILED_NUM - i;
 		index %= REC_FAILED_NUM;
 		seq_printf(s, "\t\t\t%-s\n",
-			suspend_step_name(
-				suspend_stats.failed_steps[index]));
+			   suspend_step_names[suspend_stats.failed_steps[index]]);
 	}
 
 	return 0;
@@ -467,6 +635,10 @@ static int __init pm_debugfs_init(void)
 late_initcall(pm_debugfs_init);
 #endif /* CONFIG_DEBUG_FS */
 
+bool pm_sleep_transition_in_progress(void)
+{
+	return pm_suspend_in_progress() || hibernation_in_progress();
+}
 #endif /* CONFIG_PM_SLEEP */
 
 #ifdef CONFIG_PM_SLEEP_DEBUG
@@ -481,7 +653,7 @@ bool pm_print_times_enabled;
 static ssize_t pm_print_times_show(struct kobject *kobj,
 				   struct kobj_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%d\n", pm_print_times_enabled);
+	return sysfs_emit(buf, "%d\n", pm_print_times_enabled);
 }
 
 static ssize_t pm_print_times_store(struct kobject *kobj,
@@ -504,7 +676,7 @@ power_attr(pm_print_times);
 
 static inline void pm_print_times_init(void)
 {
-	pm_print_times_enabled = !!initcall_debug;
+	pm_print_times_enabled = initcall_debug;
 }
 
 static ssize_t pm_wakeup_irq_show(struct kobject *kobj,
@@ -514,17 +686,23 @@ static ssize_t pm_wakeup_irq_show(struct kobject *kobj,
 	if (!pm_wakeup_irq())
 		return -ENODATA;
 
-	return sprintf(buf, "%u\n", pm_wakeup_irq());
+	return sysfs_emit(buf, "%u\n", pm_wakeup_irq());
 }
 
 power_attr_ro(pm_wakeup_irq);
 
 bool pm_debug_messages_on __read_mostly;
 
+bool pm_debug_messages_should_print(void)
+{
+	return pm_debug_messages_on && pm_sleep_transition_in_progress();
+}
+EXPORT_SYMBOL_GPL(pm_debug_messages_should_print);
+
 static ssize_t pm_debug_messages_show(struct kobject *kobj,
 				      struct kobj_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%d\n", pm_debug_messages_on);
+	return sysfs_emit(buf, "%d\n", pm_debug_messages_on);
 }
 
 static ssize_t pm_debug_messages_store(struct kobject *kobj,
@@ -572,21 +750,23 @@ struct kobject *power_kobj;
 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
 			  char *buf)
 {
-	char *s = buf;
+	ssize_t count = 0;
 #ifdef CONFIG_SUSPEND
 	suspend_state_t i;
 
 	for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
 		if (pm_states[i])
-			s += sprintf(s,"%s ", pm_states[i]);
+			count += sysfs_emit_at(buf, count, "%s ", pm_states[i]);
 
 #endif
 	if (hibernation_available())
-		s += sprintf(s, "disk ");
-	if (s != buf)
-		/* convert the last space to a newline */
-		*(s-1) = '\n';
-	return (s - buf);
+		count += sysfs_emit_at(buf, count, "disk ");
+
+	/* Convert the last space to a newline if needed. */
+	if (count > 0)
+		buf[count - 1] = '\n';
+
+	return count;
 }
 
 static suspend_state_t decode_state(const char *buf, size_t n)
@@ -686,7 +866,7 @@ static ssize_t wakeup_count_show(struct kobject *kobj,
 	unsigned int val;
 
 	return pm_get_wakeup_count(&val, true) ?
-		sprintf(buf, "%u\n", val) : -EINTR;
+		sysfs_emit(buf, "%u\n", val) : -EINTR;
 }
 
 static ssize_t wakeup_count_store(struct kobject *kobj,
@@ -728,17 +908,17 @@ static ssize_t autosleep_show(struct kobject *kobj,
 	suspend_state_t state = pm_autosleep_state();
 
 	if (state == PM_SUSPEND_ON)
-		return sprintf(buf, "off\n");
+		return sysfs_emit(buf, "off\n");
 
 #ifdef CONFIG_SUSPEND
 	if (state < PM_SUSPEND_MAX)
-		return sprintf(buf, "%s\n", pm_states[state] ?
+		return sysfs_emit(buf, "%s\n", pm_states[state] ?
 					pm_states[state] : "error");
 #endif
 #ifdef CONFIG_HIBERNATION
-	return sprintf(buf, "disk\n");
+	return sysfs_emit(buf, "disk\n");
 #else
-	return sprintf(buf, "error");
+	return sysfs_emit(buf, "error\n");
 #endif
 }
 
@@ -807,7 +987,7 @@ int pm_trace_enabled;
 static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
 			     char *buf)
 {
-	return sprintf(buf, "%d\n", pm_trace_enabled);
+	return sysfs_emit(buf, "%d\n", pm_trace_enabled);
 }
 
 static ssize_t
@@ -844,7 +1024,7 @@ power_attr_ro(pm_trace_dev_match);
 static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
 				      struct kobj_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%u\n", freeze_timeout_msecs);
+	return sysfs_emit(buf, "%u\n", freeze_timeout_msecs);
 }
 
 static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
@@ -864,6 +1044,34 @@ power_attr(pm_freeze_timeout);
 
 #endif	/* CONFIG_FREEZER*/
 
+#if defined(CONFIG_SUSPEND) || defined(CONFIG_HIBERNATION)
+bool filesystem_freeze_enabled = false;
+
+static ssize_t freeze_filesystems_show(struct kobject *kobj,
+				       struct kobj_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%d\n", filesystem_freeze_enabled);
+}
+
+static ssize_t freeze_filesystems_store(struct kobject *kobj,
+					struct kobj_attribute *attr,
+					const char *buf, size_t n)
+{
+	unsigned long val;
+
+	if (kstrtoul(buf, 10, &val))
+		return -EINVAL;
+
+	if (val > 1)
+		return -EINVAL;
+
+	filesystem_freeze_enabled = !!val;
+	return n;
+}
+
+power_attr(freeze_filesystems);
+#endif /* CONFIG_SUSPEND || CONFIG_HIBERNATION */
+
 static struct attribute * g[] = {
 	&state_attr.attr,
 #ifdef CONFIG_PM_TRACE
@@ -894,6 +1102,9 @@ static struct attribute * g[] = {
 #ifdef CONFIG_FREEZER
 	&pm_freeze_timeout_attr.attr,
 #endif
+#if defined(CONFIG_SUSPEND) || defined(CONFIG_HIBERNATION)
+	&freeze_filesystems_attr.attr,
+#endif
 	NULL,
 };
 
@@ -912,16 +1123,26 @@ static const struct attribute_group *attr_groups[] = {
 struct workqueue_struct *pm_wq;
 EXPORT_SYMBOL_GPL(pm_wq);
 
-static int __init pm_start_workqueue(void)
+static int __init pm_start_workqueues(void)
 {
-	pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
+	pm_wq = alloc_workqueue("pm", WQ_FREEZABLE | WQ_UNBOUND, 0);
+	if (!pm_wq)
+		return -ENOMEM;
 
-	return pm_wq ? 0 : -ENOMEM;
+#if defined(CONFIG_SUSPEND) || defined(CONFIG_HIBERNATION)
+	pm_fs_sync_wq = alloc_ordered_workqueue("pm_fs_sync", 0);
+	if (!pm_fs_sync_wq) {
+		destroy_workqueue(pm_wq);
+		return -ENOMEM;
+	}
+#endif
+
+	return 0;
 }
 
 static int __init pm_init(void)
 {
-	int error = pm_start_workqueue();
+	int error = pm_start_workqueues();
 	if (error)
 		return error;
 	hibernate_image_size_init();