Merge 3.15-rc6 into driver-core-next

We want the kernfs fixes in this branch as well for testing.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 8fa8dea..4b7b452 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -1,10 +1,10 @@
 menu "Generic Driver Options"
 
-config UEVENT_HELPER_PATH
-	string "path to uevent helper"
-	default ""
+config UEVENT_HELPER
+	bool "Support for uevent helper"
+	default y
 	help
-	  Path to uevent helper program forked by the kernel for
+	  The uevent helper program is forked by the kernel for
 	  every uevent.
 	  Before the switch to the netlink-based uevent source, this was
 	  used to hook hotplug scripts into kernel device events. It
@@ -15,8 +15,13 @@
 	  that it creates a high system load, or on smaller systems
 	  it is known to create out-of-memory situations during bootup.
 
-	  To disable user space helper program execution at early boot
-	  time specify an empty string here. This setting can be altered
+config UEVENT_HELPER_PATH
+	string "path to uevent helper"
+	depends on UEVENT_HELPER
+	default ""
+	help
+	  To disable user space helper program execution at by default
+	  specify an empty string here. This setting can still be altered
 	  via /proc/sys/kernel/hotplug or via /sys/kernel/uevent_helper
 	  later at runtime.
 
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index ac127cd..a693f5b 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -714,6 +714,7 @@
 		return ERR_PTR(-ENOMEM);
 
 	ida_init(&root->ino_ida);
+	INIT_LIST_HEAD(&root->supers);
 
 	kn = __kernfs_new_node(root, "", S_IFDIR | S_IRUGO | S_IXUGO,
 			       KERNFS_DIR);
diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index 5e9a80c..e3d37f6 100644
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -14,6 +14,7 @@
 #include <linux/poll.h>
 #include <linux/pagemap.h>
 #include <linux/sched.h>
+#include <linux/fsnotify.h>
 
 #include "kernfs-internal.h"
 
@@ -790,20 +791,48 @@
  */
 void kernfs_notify(struct kernfs_node *kn)
 {
+	struct kernfs_root *root = kernfs_root(kn);
 	struct kernfs_open_node *on;
+	struct kernfs_super_info *info;
 	unsigned long flags;
 
+	if (WARN_ON(kernfs_type(kn) != KERNFS_FILE))
+		return;
+
+	/* kick poll */
 	spin_lock_irqsave(&kernfs_open_node_lock, flags);
 
-	if (!WARN_ON(kernfs_type(kn) != KERNFS_FILE)) {
-		on = kn->attr.open;
-		if (on) {
-			atomic_inc(&on->event);
-			wake_up_interruptible(&on->poll);
-		}
+	on = kn->attr.open;
+	if (on) {
+		atomic_inc(&on->event);
+		wake_up_interruptible(&on->poll);
 	}
 
 	spin_unlock_irqrestore(&kernfs_open_node_lock, flags);
+
+	/* kick fsnotify */
+	mutex_lock(&kernfs_mutex);
+
+	list_for_each_entry(info, &root->supers, node) {
+		struct inode *inode;
+		struct dentry *dentry;
+
+		inode = ilookup(info->sb, kn->ino);
+		if (!inode)
+			continue;
+
+		dentry = d_find_any_alias(inode);
+		if (dentry) {
+			fsnotify_parent(NULL, dentry, FS_MODIFY);
+			fsnotify(inode, FS_MODIFY, inode, FSNOTIFY_EVENT_INODE,
+				 NULL, 0);
+			dput(dentry);
+		}
+
+		iput(inode);
+	}
+
+	mutex_unlock(&kernfs_mutex);
 }
 EXPORT_SYMBOL_GPL(kernfs_notify);
 
diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index 8be13b2..dc84a3e 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -49,6 +49,8 @@
  * mount.c
  */
 struct kernfs_super_info {
+	struct super_block	*sb;
+
 	/*
 	 * The root associated with this super_block.  Each super_block is
 	 * identified by the root and ns it's associated with.
@@ -62,6 +64,9 @@
 	 * an array and compare kernfs_node tag against every entry.
 	 */
 	const void		*ns;
+
+	/* anchored at kernfs_root->supers, protected by kernfs_mutex */
+	struct list_head	node;
 };
 #define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info))
 
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index 6a5f04a..f25a7c0 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -68,6 +68,7 @@
 	struct inode *inode;
 	struct dentry *root;
 
+	info->sb = sb;
 	sb->s_blocksize = PAGE_CACHE_SIZE;
 	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 	sb->s_magic = SYSFS_MAGIC;
@@ -166,12 +167,18 @@
 		*new_sb_created = !sb->s_root;
 
 	if (!sb->s_root) {
+		struct kernfs_super_info *info = kernfs_info(sb);
+
 		error = kernfs_fill_super(sb);
 		if (error) {
 			deactivate_locked_super(sb);
 			return ERR_PTR(error);
 		}
 		sb->s_flags |= MS_ACTIVE;
+
+		mutex_lock(&kernfs_mutex);
+		list_add(&info->node, &root->supers);
+		mutex_unlock(&kernfs_mutex);
 	}
 
 	return dget(sb->s_root);
@@ -190,6 +197,10 @@
 	struct kernfs_super_info *info = kernfs_info(sb);
 	struct kernfs_node *root_kn = sb->s_root->d_fsdata;
 
+	mutex_lock(&kernfs_mutex);
+	list_del(&info->node);
+	mutex_unlock(&kernfs_mutex);
+
 	/*
 	 * Remove the superblock from fs_supers/s_instances
 	 * so we can't find it, before freeing kernfs_super_info.
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index ca1be5c..c841688 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -161,6 +161,10 @@
 	/* private fields, do not use outside kernfs proper */
 	struct ida		ino_ida;
 	struct kernfs_syscall_ops *syscall_ops;
+
+	/* list of kernfs_super_info of this root, protected by kernfs_mutex */
+	struct list_head	supers;
+
 	wait_queue_head_t	deactivate_waitq;
 };
 
diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index f896a33..2d61b90 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -32,8 +32,10 @@
 #define UEVENT_NUM_ENVP			32	/* number of env pointers */
 #define UEVENT_BUFFER_SIZE		2048	/* buffer for the variables */
 
+#ifdef CONFIG_UEVENT_HELPER
 /* path to the userspace helper executed on an event */
 extern char uevent_helper[];
+#endif
 
 /* counter to tag the uevent, read only except for the kobject core */
 extern u64 uevent_seqnum;
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index 2495a9b..6683cce 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -37,6 +37,7 @@
 }
 KERNEL_ATTR_RO(uevent_seqnum);
 
+#ifdef CONFIG_UEVENT_HELPER
 /* uevent helper program, used during early boot */
 static ssize_t uevent_helper_show(struct kobject *kobj,
 				  struct kobj_attribute *attr, char *buf)
@@ -56,7 +57,7 @@
 	return count;
 }
 KERNEL_ATTR_RW(uevent_helper);
-
+#endif
 
 #ifdef CONFIG_PROFILING
 static ssize_t profiling_show(struct kobject *kobj,
@@ -189,7 +190,9 @@
 static struct attribute * kernel_attrs[] = {
 	&fscaps_attr.attr,
 	&uevent_seqnum_attr.attr,
+#ifdef CONFIG_UEVENT_HELPER
 	&uevent_helper_attr.attr,
+#endif
 #ifdef CONFIG_PROFILING
 	&profiling_attr.attr,
 #endif
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 74f5b58..bc966a8 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -643,7 +643,7 @@
 		.extra2		= &one,
 	},
 #endif
-
+#ifdef CONFIG_UEVENT_HELPER
 	{
 		.procname	= "hotplug",
 		.data		= &uevent_helper,
@@ -651,7 +651,7 @@
 		.mode		= 0644,
 		.proc_handler	= proc_dostring,
 	},
-
+#endif
 #ifdef CONFIG_CHR_DEV_SG
 	{
 		.procname	= "sg-big-buff",
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 4e3bd71..9ebf9e2 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -29,7 +29,9 @@
 
 
 u64 uevent_seqnum;
+#ifdef CONFIG_UEVENT_HELPER
 char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
+#endif
 #ifdef CONFIG_NET
 struct uevent_sock {
 	struct list_head list;
@@ -109,6 +111,7 @@
 }
 #endif
 
+#ifdef CONFIG_UEVENT_HELPER
 static int kobj_usermode_filter(struct kobject *kobj)
 {
 	const struct kobj_ns_type_operations *ops;
@@ -147,6 +150,7 @@
 {
 	kfree(info->data);
 }
+#endif
 
 /**
  * kobject_uevent_env - send an uevent with environmental data
@@ -323,6 +327,7 @@
 #endif
 	mutex_unlock(&uevent_sock_mutex);
 
+#ifdef CONFIG_UEVENT_HELPER
 	/* call uevent_helper, usually only enabled during early boot */
 	if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {
 		struct subprocess_info *info;
@@ -347,6 +352,7 @@
 			env = NULL;	/* freed by cleanup_uevent_env */
 		}
 	}
+#endif
 
 exit:
 	kfree(devpath);