Merge branch 'linus' into core/iommu

2 files changed, 29 insertions, 0 deletions

diff --git a/fs/sysfs/Kconfig b/fs/sysfs/Kconfig
new file mode 100644
index 00000000000..f4b67588b9d
--- /dev/null
+++ b/fs/sysfs/Kconfig
@@ -0,0 +1,23 @@
+config SYSFS
+	bool "sysfs file system support" if EMBEDDED
+	default y
+	help
+	The sysfs filesystem is a virtual filesystem that the kernel uses to
+	export internal kernel objects, their attributes, and their
+	relationships to one another.
+
+	Users can use sysfs to ascertain useful information about the running
+	kernel, such as the devices the kernel has discovered on each bus and
+	which driver each is bound to. sysfs can also be used to tune devices
+	and other kernel subsystems.
+
+	Some system agents rely on the information in sysfs to operate.
+	/sbin/hotplug uses device and object attributes in sysfs to assist in
+	delegating policy decisions, like persistently naming devices.
+
+	sysfs is currently used by the block subsystem to mount the root
+	partition.  If sysfs is disabled you must specify the boot device on
+	the kernel boot command line via its major and minor numbers.  For
+	example, "root=03:01" for /dev/hda1.
+
+	Designers of embedded systems may wish to say N here to conserve space.
diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
index 66f6e58a7e4..f2c478c3424 100644
--- a/fs/sysfs/bin.c
+++ b/fs/sysfs/bin.c
@@ -63,6 +63,9 @@ read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off)
 	int count = min_t(size_t, bytes, PAGE_SIZE);
 	char *temp;
 
+	if (!bytes)
+		return 0;
+
 	if (size) {
 		if (offs > size)
 			return 0;
@@ -131,6 +134,9 @@ static ssize_t write(struct file *file, const char __user *userbuf,
 	int count = min_t(size_t, bytes, PAGE_SIZE);
 	char *temp;
 
+	if (!bytes)
+		return 0;
+
 	if (size) {
 		if (offs > size)
 			return 0;