1 files changed, 30 insertions, 14 deletions

diff --git a/kernel/power/user.c b/kernel/power/user.c
index 740723bb3885..3f9e3efb9f6e 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -26,6 +26,7 @@
 
 #include "power.h"
 
+static bool need_wait;
 
 static struct snapshot_data {
 	struct snapshot_handle handle;
@@ -46,12 +47,13 @@ int is_hibernate_resume_dev(dev_t dev)
 static int snapshot_open(struct inode *inode, struct file *filp)
 {
 	struct snapshot_data *data;
+	unsigned int sleep_flags;
 	int error;
 
 	if (!hibernation_available())
 		return -EPERM;
 
-	lock_system_sleep();
+	sleep_flags = lock_system_sleep();
 
 	if (!hibernate_acquire()) {
 		error = -EBUSY;
@@ -78,7 +80,7 @@ static int snapshot_open(struct inode *inode, struct file *filp)
 		 * Resuming.  We may need to wait for the image device to
 		 * appear.
 		 */
-		wait_for_device_probe();
+		need_wait = true;
 
 		data->swap = -1;
 		data->mode = O_WRONLY;
@@ -97,7 +99,7 @@ static int snapshot_open(struct inode *inode, struct file *filp)
 	data->dev = 0;
 
  Unlock:
-	unlock_system_sleep();
+	unlock_system_sleep(sleep_flags);
 
 	return error;
 }
@@ -105,8 +107,9 @@ static int snapshot_open(struct inode *inode, struct file *filp)
 static int snapshot_release(struct inode *inode, struct file *filp)
 {
 	struct snapshot_data *data;
+	unsigned int sleep_flags;
 
-	lock_system_sleep();
+	sleep_flags = lock_system_sleep();
 
 	swsusp_free();
 	data = filp->private_data;
@@ -123,7 +126,7 @@ static int snapshot_release(struct inode *inode, struct file *filp)
 			PM_POST_HIBERNATION : PM_POST_RESTORE);
 	hibernate_release();
 
-	unlock_system_sleep();
+	unlock_system_sleep(sleep_flags);
 
 	return 0;
 }
@@ -131,11 +134,12 @@ static int snapshot_release(struct inode *inode, struct file *filp)
 static ssize_t snapshot_read(struct file *filp, char __user *buf,
                              size_t count, loff_t *offp)
 {
+	loff_t pg_offp = *offp & ~PAGE_MASK;
 	struct snapshot_data *data;
+	unsigned int sleep_flags;
 	ssize_t res;
-	loff_t pg_offp = *offp & ~PAGE_MASK;
 
-	lock_system_sleep();
+	sleep_flags = lock_system_sleep();
 
 	data = filp->private_data;
 	if (!data->ready) {
@@ -156,7 +160,7 @@ static ssize_t snapshot_read(struct file *filp, char __user *buf,
 		*offp += res;
 
  Unlock:
-	unlock_system_sleep();
+	unlock_system_sleep(sleep_flags);
 
 	return res;
 }
@@ -164,11 +168,17 @@ static ssize_t snapshot_read(struct file *filp, char __user *buf,
 static ssize_t snapshot_write(struct file *filp, const char __user *buf,
                               size_t count, loff_t *offp)
 {
+	loff_t pg_offp = *offp & ~PAGE_MASK;
 	struct snapshot_data *data;
+	unsigned long sleep_flags;
 	ssize_t res;
-	loff_t pg_offp = *offp & ~PAGE_MASK;
 
-	lock_system_sleep();
+	if (need_wait) {
+		wait_for_device_probe();
+		need_wait = false;
+	}
+
+	sleep_flags = lock_system_sleep();
 
 	data = filp->private_data;
 
@@ -177,7 +187,7 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf,
 		if (res <= 0)
 			goto unlock;
 	} else {
-		res = PAGE_SIZE - pg_offp;
+		res = PAGE_SIZE;
 	}
 
 	if (!data_of(data->handle)) {
@@ -190,7 +200,7 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf,
 	if (res > 0)
 		*offp += res;
 unlock:
-	unlock_system_sleep();
+	unlock_system_sleep(sleep_flags);
 
 	return res;
 }
@@ -244,6 +254,11 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
 	loff_t size;
 	sector_t offset;
 
+	if (need_wait) {
+		wait_for_device_probe();
+		need_wait = false;
+	}
+
 	if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
 		return -ENOTTY;
 	if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
@@ -302,7 +317,9 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
 		break;
 
 	case SNAPSHOT_ATOMIC_RESTORE:
-		snapshot_write_finalize(&data->handle);
+		error = snapshot_write_finalize(&data->handle);
+		if (error)
+			break;
 		if (data->mode != O_WRONLY || !data->frozen ||
 		    !snapshot_image_loaded(&data->handle)) {
 			error = -EPERM;
@@ -430,7 +447,6 @@ static const struct file_operations snapshot_fops = {
 	.release = snapshot_release,
 	.read = snapshot_read,
 	.write = snapshot_write,
-	.llseek = no_llseek,
 	.unlocked_ioctl = snapshot_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = snapshot_compat_ioctl,