Merge branch 'quilt/driver-core'

13 files changed, 450 insertions, 23 deletions

diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 8f006f96ff53..ee377270beb9 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -8,6 +8,31 @@ config UEVENT_HELPER_PATH
 	  Path to uevent helper program forked by the kernel for
 	  every uevent.
 
+config DEVTMPFS
+	bool "Create a kernel maintained /dev tmpfs (EXPERIMENTAL)"
+	depends on HOTPLUG && SHMEM && TMPFS
+	help
+	  This creates a tmpfs filesystem, and mounts it at bootup
+	  and mounts it at /dev. The kernel driver core creates device
+	  nodes for all registered devices in that filesystem. All device
+	  nodes are owned by root and have the default mode of 0600.
+	  Userspace can add and delete the nodes as needed. This is
+	  intended to simplify bootup, and make it possible to delay
+	  the initial coldplug at bootup done by udev in userspace.
+	  It should also provide a simpler way for rescue systems
+	  to bring up a kernel with dynamic major/minor numbers.
+	  Meaningful symlinks, permissions and device ownership must
+	  still be handled by userspace.
+	  If unsure, say N here.
+
+config DEVTMPFS_MOUNT
+	bool "Automount devtmpfs at /dev"
+	depends on DEVTMPFS
+	help
+	  This will mount devtmpfs at /dev if the kernel mounts the root
+	  filesystem. It will not affect initramfs based mounting.
+	  If unsure, say N here.
+
 config STANDALONE
 	bool "Select only drivers that don't need compile-time external firmware" if EXPERIMENTAL
 	default y
diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index b5b8ba512b28..68b225aa2266 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -4,6 +4,7 @@ obj-y			:= core.o sys.o bus.o dd.o \
 			   driver.o class.o platform.o \
 			   cpu.o firmware.o init.o map.o devres.o \
 			   attribute_container.o transport_class.o
+obj-$(CONFIG_DEVTMPFS)	+= devtmpfs.o
 obj-y			+= power/
 obj-$(CONFIG_HAS_DMA)	+= dma-mapping.o
 obj-$(CONFIG_ISA)	+= isa.o
diff --git a/drivers/base/base.h b/drivers/base/base.h
index b528145a078f..45be568a7d96 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -134,3 +134,9 @@ static inline void module_add_driver(struct module *mod,
 				     struct device_driver *drv) { }
 static inline void module_remove_driver(struct device_driver *drv) { }
 #endif
+
+#ifdef CONFIG_DEVTMPFS
+extern int devtmpfs_init(void);
+#else
+static inline int devtmpfs_init(void) { return 0; }
+#endif
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 7ecb1938e590..f82dacedd08e 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -921,6 +921,8 @@ int device_add(struct device *dev)
 		error = device_create_sys_dev_entry(dev);
 		if (error)
 			goto devtattrError;
+
+		devtmpfs_create_node(dev);
 	}
 
 	error = device_add_class_symlinks(dev);
@@ -1067,6 +1069,7 @@ void device_del(struct device *dev)
 	if (parent)
 		klist_del(&dev->p->knode_parent);
 	if (MAJOR(dev->devt)) {
+		devtmpfs_delete_node(dev);
 		device_remove_sys_dev_entry(dev);
 		device_remove_file(dev, &devt_attr);
 	}
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index f0106875f01d..13bd3cbdf155 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -11,8 +11,8 @@
  *
  * Copyright (c) 2002-5 Patrick Mochel
  * Copyright (c) 2002-3 Open Source Development Labs
- * Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de>
- * Copyright (c) 2007 Novell Inc.
+ * Copyright (c) 2007-2009 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (c) 2007-2009 Novell Inc.
  *
  * This file is released under the GPLv2
  */
@@ -380,3 +380,19 @@ void driver_detach(struct device_driver *drv)
 		put_device(dev);
 	}
 }
+
+/*
+ * These exports can't be _GPL due to .h files using this within them, and it
+ * might break something that was previously working...
+ */
+void *dev_get_drvdata(const struct device *dev)
+{
+	return dev->dd_DO_NOT_USE;
+}
+EXPORT_SYMBOL(dev_get_drvdata);
+
+void dev_set_drvdata(struct device *dev, void *data)
+{
+	dev->dd_DO_NOT_USE = data;
+}
+EXPORT_SYMBOL(dev_set_drvdata);
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
new file mode 100644
index 000000000000..51c410ffa145
--- /dev/null
+++ b/drivers/base/devtmpfs.c
@@ -0,0 +1,367 @@
+/*
+ * devtmpfs - kernel-maintained tmpfs-based /dev
+ *
+ * Copyright (C) 2009, Kay Sievers <kay.sievers@vrfy.org>
+ *
+ * During bootup, before any driver core device is registered,
+ * devtmpfs, a tmpfs-based filesystem is created. Every driver-core
+ * device which requests a device node, will add a node in this
+ * filesystem. The node is named after the the name of the device,
+ * or the susbsytem can provide a custom name. All devices are
+ * owned by root and have a mode of 0600.
+ */
+
+#include <linux/kernel.h>
+#include <linux/syscalls.h>
+#include <linux/mount.h>
+#include <linux/device.h>
+#include <linux/genhd.h>
+#include <linux/namei.h>
+#include <linux/fs.h>
+#include <linux/shmem_fs.h>
+#include <linux/cred.h>
+#include <linux/init_task.h>
+
+static struct vfsmount *dev_mnt;
+
+#if defined CONFIG_DEVTMPFS_MOUNT
+static int dev_mount = 1;
+#else
+static int dev_mount;
+#endif
+
+static int __init mount_param(char *str)
+{
+	dev_mount = simple_strtoul(str, NULL, 0);
+	return 1;
+}
+__setup("devtmpfs.mount=", mount_param);
+
+static int dev_get_sb(struct file_system_type *fs_type, int flags,
+		      const char *dev_name, void *data, struct vfsmount *mnt)
+{
+	return get_sb_single(fs_type, flags, data, shmem_fill_super, mnt);
+}
+
+static struct file_system_type dev_fs_type = {
+	.name = "devtmpfs",
+	.get_sb = dev_get_sb,
+	.kill_sb = kill_litter_super,
+};
+
+#ifdef CONFIG_BLOCK
+static inline int is_blockdev(struct device *dev)
+{
+	return dev->class == &block_class;
+}
+#else
+static inline int is_blockdev(struct device *dev) { return 0; }
+#endif
+
+static int dev_mkdir(const char *name, mode_t mode)
+{
+	struct nameidata nd;
+	struct dentry *dentry;
+	int err;
+
+	err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
+			      name, LOOKUP_PARENT, &nd);
+	if (err)
+		return err;
+
+	dentry = lookup_create(&nd, 1);
+	if (!IS_ERR(dentry)) {
+		err = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode);
+		dput(dentry);
+	} else {
+		err = PTR_ERR(dentry);
+	}
+	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
+
+	path_put(&nd.path);
+	return err;
+}
+
+static int create_path(const char *nodepath)
+{
+	char *path;
+	struct nameidata nd;
+	int err = 0;
+
+	path = kstrdup(nodepath, GFP_KERNEL);
+	if (!path)
+		return -ENOMEM;
+
+	err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
+			      path, LOOKUP_PARENT, &nd);
+	if (err == 0) {
+		struct dentry *dentry;
+
+		/* create directory right away */
+		dentry = lookup_create(&nd, 1);
+		if (!IS_ERR(dentry)) {
+			err = vfs_mkdir(nd.path.dentry->d_inode,
+					dentry, 0775);
+			dput(dentry);
+		}
+		mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
+
+		path_put(&nd.path);
+	} else if (err == -ENOENT) {
+		char *s;
+
+		/* parent directories do not exist, create them */
+		s = path;
+		while (1) {
+			s = strchr(s, '/');
+			if (!s)
+				break;
+			s[0] = '\0';
+			err = dev_mkdir(path, 0755);
+			if (err && err != -EEXIST)
+				break;
+			s[0] = '/';
+			s++;
+		}
+	}
+
+	kfree(path);
+	return err;
+}
+
+int devtmpfs_create_node(struct device *dev)
+{
+	const char *tmp = NULL;
+	const char *nodename;
+	const struct cred *curr_cred;
+	mode_t mode;
+	struct nameidata nd;
+	struct dentry *dentry;
+	int err;
+
+	if (!dev_mnt)
+		return 0;
+
+	nodename = device_get_nodename(dev, &tmp);
+	if (!nodename)
+		return -ENOMEM;
+
+	if (is_blockdev(dev))
+		mode = S_IFBLK|0600;
+	else
+		mode = S_IFCHR|0600;
+
+	curr_cred = override_creds(&init_cred);
+	err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
+			      nodename, LOOKUP_PARENT, &nd);
+	if (err == -ENOENT) {
+		/* create missing parent directories */
+		create_path(nodename);
+		err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
+				      nodename, LOOKUP_PARENT, &nd);
+		if (err)
+			goto out;
+	}
+
+	dentry = lookup_create(&nd, 0);
+	if (!IS_ERR(dentry)) {
+		err = vfs_mknod(nd.path.dentry->d_inode,
+				dentry, mode, dev->devt);
+		/* mark as kernel created inode */
+		if (!err)
+			dentry->d_inode->i_private = &dev_mnt;
+		dput(dentry);
+	} else {
+		err = PTR_ERR(dentry);
+	}
+	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
+
+	path_put(&nd.path);
+out:
+	kfree(tmp);
+	revert_creds(curr_cred);
+	return err;
+}
+
+static int dev_rmdir(const char *name)
+{
+	struct nameidata nd;
+	struct dentry *dentry;
+	int err;
+
+	err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
+			      name, LOOKUP_PARENT, &nd);
+	if (err)
+		return err;
+
+	mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
+	dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
+	if (!IS_ERR(dentry)) {
+		if (dentry->d_inode)
+			err = vfs_rmdir(nd.path.dentry->d_inode, dentry);
+		else
+			err = -ENOENT;
+		dput(dentry);
+	} else {
+		err = PTR_ERR(dentry);
+	}
+	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
+
+	path_put(&nd.path);
+	return err;
+}
+
+static int delete_path(const char *nodepath)
+{
+	const char *path;
+	int err = 0;
+
+	path = kstrdup(nodepath, GFP_KERNEL);
+	if (!path)
+		return -ENOMEM;
+
+	while (1) {
+		char *base;
+
+		base = strrchr(path, '/');
+		if (!base)
+			break;
+		base[0] = '\0';
+		err = dev_rmdir(path);
+		if (err)
+			break;
+	}
+
+	kfree(path);
+	return err;
+}
+
+static int dev_mynode(struct device *dev, struct inode *inode, struct kstat *stat)
+{
+	/* did we create it */
+	if (inode->i_private != &dev_mnt)
+		return 0;
+
+	/* does the dev_t match */
+	if (is_blockdev(dev)) {
+		if (!S_ISBLK(stat->mode))
+			return 0;
+	} else {
+		if (!S_ISCHR(stat->mode))
+			return 0;
+	}
+	if (stat->rdev != dev->devt)
+		return 0;
+
+	/* ours */
+	return 1;
+}
+
+int devtmpfs_delete_node(struct device *dev)
+{
+	const char *tmp = NULL;
+	const char *nodename;
+	const struct cred *curr_cred;
+	struct nameidata nd;
+	struct dentry *dentry;
+	struct kstat stat;
+	int deleted = 1;
+	int err;
+
+	if (!dev_mnt)
+		return 0;
+
+	nodename = device_get_nodename(dev, &tmp);
+	if (!nodename)
+		return -ENOMEM;
+
+	curr_cred = override_creds(&init_cred);
+	err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,
+			      nodename, LOOKUP_PARENT, &nd);
+	if (err)
+		goto out;
+
+	mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
+	dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len);
+	if (!IS_ERR(dentry)) {
+		if (dentry->d_inode) {
+			err = vfs_getattr(nd.path.mnt, dentry, &stat);
+			if (!err && dev_mynode(dev, dentry->d_inode, &stat)) {
+				err = vfs_unlink(nd.path.dentry->d_inode,
+						 dentry);
+				if (!err || err == -ENOENT)
+					deleted = 1;
+			}
+		} else {
+			err = -ENOENT;
+		}
+		dput(dentry);
+	} else {
+		err = PTR_ERR(dentry);
+	}
+	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
+
+	path_put(&nd.path);
+	if (deleted && strchr(nodename, '/'))
+		delete_path(nodename);
+out:
+	kfree(tmp);
+	revert_creds(curr_cred);
+	return err;
+}
+
+/*
+ * If configured, or requested by the commandline, devtmpfs will be
+ * auto-mounted after the kernel mounted the root filesystem.
+ */
+int devtmpfs_mount(const char *mountpoint)
+{
+	struct path path;
+	int err;
+
+	if (!dev_mount)
+		return 0;
+
+	if (!dev_mnt)
+		return 0;
+
+	err = kern_path(mountpoint, LOOKUP_FOLLOW, &path);
+	if (err)
+		return err;
+	err = do_add_mount(dev_mnt, &path, 0, NULL);
+	if (err)
+		printk(KERN_INFO "devtmpfs: error mounting %i\n", err);
+	else
+		printk(KERN_INFO "devtmpfs: mounted\n");
+	path_put(&path);
+	return err;
+}
+
+/*
+ * Create devtmpfs instance, driver-core devices will add their device
+ * nodes here.
+ */
+int __init devtmpfs_init(void)
+{
+	int err;
+	struct vfsmount *mnt;
+
+	err = register_filesystem(&dev_fs_type);
+	if (err) {
+		printk(KERN_ERR "devtmpfs: unable to register devtmpfs "
+		       "type %i\n", err);
+		return err;
+	}
+
+	mnt = kern_mount(&dev_fs_type);
+	if (IS_ERR(mnt)) {
+		err = PTR_ERR(mnt);
+		printk(KERN_ERR "devtmpfs: unable to create devtmpfs %i\n", err);
+		unregister_filesystem(&dev_fs_type);
+		return err;
+	}
+	dev_mnt = mnt;
+
+	printk(KERN_INFO "devtmpfs: initialized\n");
+	return 0;
+}
diff --git a/drivers/base/init.c b/drivers/base/init.c
index 7bd9b6a5b01f..c8a934e79421 100644
--- a/drivers/base/init.c
+++ b/drivers/base/init.c
@@ -20,6 +20,7 @@
 void __init driver_init(void)
 {
 	/* These are the core pieces */
+	devtmpfs_init();
 	devices_init();
 	buses_init();
 	classes_init();
diff --git a/include/linux/device.h b/include/linux/device.h
index ed4e39f2c423..24bb007039a9 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -2,7 +2,8 @@
  * device.h - generic, centralized driver model
  *
  * Copyright (c) 2001-2003 Patrick Mochel <mochel@osdl.org>
- * Copyright (c) 2004-2007 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (c) 2004-2009 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (c) 2008-2009 Novell Inc.
  *
  * This file is released under the GPLv2
  *
@@ -382,7 +383,10 @@ struct device {
 	struct bus_type	*bus;		/* type of bus device is on */
 	struct device_driver *driver;	/* which driver has allocated this
 					   device */
-	void		*driver_data;	/* data private to the driver */
+	void		*dd_DO_NOT_USE;	/* data private to the driver, do
+					 * not directly touch this field,
+					 * use the dev_get/set_drvdata()
+					 * functions instead. */
 	void		*platform_data;	/* Platform specific data, device
 					   core doesn't touch it */
 	struct dev_pm_info	power;
@@ -448,16 +452,6 @@ static inline void set_dev_node(struct device *dev, int node)
 }
 #endif
 
-static inline void *dev_get_drvdata(const struct device *dev)
-{
-	return dev->driver_data;
-}
-
-static inline void dev_set_drvdata(struct device *dev, void *data)
-{
-	dev->driver_data = data;
-}
-
 static inline unsigned int dev_get_uevent_suppress(const struct device *dev)
 {
 	return dev->kobj.uevent_suppress;
@@ -491,6 +485,8 @@ extern int device_rename(struct device *dev, char *new_name);
 extern int device_move(struct device *dev, struct device *new_parent,
 		       enum dpm_order dpm_order);
 extern const char *device_get_nodename(struct device *dev, const char **tmp);
+extern void *dev_get_drvdata(const struct device *dev);
+extern void dev_set_drvdata(struct device *dev, void *data);
 
 /*
  * Root device objects for grouping under /sys/devices
@@ -548,6 +544,16 @@ extern void put_device(struct device *dev);
 
 extern void wait_for_device_probe(void);
 
+#ifdef CONFIG_DEVTMPFS
+extern int devtmpfs_create_node(struct device *dev);
+extern int devtmpfs_delete_node(struct device *dev);
+extern int devtmpfs_mount(const char *mountpoint);
+#else
+static inline int devtmpfs_create_node(struct device *dev) { return 0; }
+static inline int devtmpfs_delete_node(struct device *dev) { return 0; }
+static inline int devtmpfs_mount(const char *mountpoint) { return 0; }
+#endif
+
 /* drivers/base/power/shutdown.c */
 extern void device_shutdown(void);
 
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index fd83f2584b15..9d3c70723cea 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -42,6 +42,9 @@ static inline struct shmem_inode_info *SHMEM_I(struct inode *inode)
 	return container_of(inode, struct shmem_inode_info, vfs_inode);
 }
 
+extern int init_tmpfs(void);
+extern int shmem_fill_super(struct super_block *sb, void *data, int silent);
+
 #ifdef CONFIG_TMPFS_POSIX_ACL
 int shmem_permission(struct inode *, int);
 int shmem_acl_init(struct inode *, struct inode *);
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 093f65915501..bb008d064c1a 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -415,7 +415,7 @@ void __init prepare_namespace(void)
 
 	mount_root();
 out:
+	devtmpfs_mount("dev");
 	sys_mount(".", "/", NULL, MS_MOVE, NULL);
 	sys_chroot(".");
 }
-
diff --git a/init/main.c b/init/main.c
index e341b4b06cc6..259e88dbe362 100644
--- a/init/main.c
+++ b/init/main.c
@@ -68,6 +68,7 @@
 #include <linux/async.h>
 #include <linux/kmemcheck.h>
 #include <linux/kmemtrace.h>
+#include <linux/shmem_fs.h>
 #include <trace/boot.h>
 
 #include <asm/io.h>
@@ -803,6 +804,7 @@ static void __init do_basic_setup(void)
 	init_workqueues();
 	cpuset_init_smp();
 	usermodehelper_init();
+	init_tmpfs();
 	driver_init();
 	init_irq_proc();
 	do_ctors();
diff --git a/mm/shmem.c b/mm/shmem.c
index e89d7ec18eda..940c248c7dc1 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2297,8 +2297,7 @@ static void shmem_put_super(struct super_block *sb)
 	sb->s_fs_info = NULL;
 }
 
-static int shmem_fill_super(struct super_block *sb,
-			    void *data, int silent)
+int shmem_fill_super(struct super_block *sb, void *data, int silent)
 {
 	struct inode *inode;
 	struct dentry *root;
@@ -2523,7 +2522,7 @@ static struct file_system_type tmpfs_fs_type = {
 	.kill_sb	= kill_litter_super,
 };
 
-static int __init init_tmpfs(void)
+int __init init_tmpfs(void)
 {
 	int error;
 
@@ -2580,7 +2579,7 @@ static struct file_system_type tmpfs_fs_type = {
 	.kill_sb	= kill_litter_super,
 };
 
-static int __init init_tmpfs(void)
+int __init init_tmpfs(void)
 {
 	BUG_ON(register_filesystem(&tmpfs_fs_type) != 0);
 
@@ -2691,5 +2690,3 @@ int shmem_zero_setup(struct vm_area_struct *vma)
 	vma->vm_ops = &shmem_vm_ops;
 	return 0;
 }
-
-module_init(init_tmpfs)
diff --git a/sound/soc/codecs/wm8988.c b/sound/soc/codecs/wm8988.c
index c05f71803aa8..8c0fdf84aac3 100644
--- a/sound/soc/codecs/wm8988.c
+++ b/sound/soc/codecs/wm8988.c
@@ -1037,14 +1037,14 @@ static int __devinit wm8988_spi_probe(struct spi_device *spi)
 	codec->control_data = spi;
 	codec->dev = &spi->dev;
 
-	spi->dev.driver_data = wm8988;
+	dev_set_drvdata(&spi->dev, wm8988);
 
 	return wm8988_register(wm8988);
 }
 
 static int __devexit wm8988_spi_remove(struct spi_device *spi)
 {
-	struct wm8988_priv *wm8988 = spi->dev.driver_data;
+	struct wm8988_priv *wm8988 = dev_get_drvdata(&spi->dev);
 
 	wm8988_unregister(wm8988);