Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 684 insertions, 0 deletions

diff --git a/drivers/misc/enclosure.c b/drivers/misc/enclosure.c
new file mode 100644
index 000000000..de457378c
--- /dev/null
+++ b/drivers/misc/enclosure.c
@@ -0,0 +1,684 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Enclosure Services
+ *
+ * Copyright (C) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
+ *
+**-----------------------------------------------------------------------------
+**
+**
+**-----------------------------------------------------------------------------
+*/
+#include <linux/device.h>
+#include <linux/enclosure.h>
+#include <linux/err.h>
+#include <linux/list.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/string_choices.h>
+
+static LIST_HEAD(container_list);
+static DEFINE_MUTEX(container_list_lock);
+static struct class enclosure_class;
+
+/**
+ * enclosure_find - find an enclosure given a parent device
+ * @dev:	the parent to match against
+ * @start:	Optional enclosure device to start from (NULL if none)
+ *
+ * Looks through the list of registered enclosures to find all those
+ * with @dev as a parent.  Returns NULL if no enclosure is
+ * found. @start can be used as a starting point to obtain multiple
+ * enclosures per parent (should begin with NULL and then be set to
+ * each returned enclosure device). Obtains a reference to the
+ * enclosure class device which must be released with put_device().
+ * If @start is not NULL, a reference must be taken on it which is
+ * released before returning (this allows a loop through all
+ * enclosures to exit with only the reference on the enclosure of
+ * interest held).  Note that the @dev may correspond to the actual
+ * device housing the enclosure, in which case no iteration via @start
+ * is required.
+ */
+struct enclosure_device *enclosure_find(struct device *dev,
+					struct enclosure_device *start)
+{
+	struct enclosure_device *edev;
+
+	mutex_lock(&container_list_lock);
+	edev = list_prepare_entry(start, &container_list, node);
+	if (start)
+		put_device(&start->edev);
+
+	list_for_each_entry_continue(edev, &container_list, node) {
+		struct device *parent = edev->edev.parent;
+		/* parent might not be immediate, so iterate up to
+		 * the root of the tree if necessary */
+		while (parent) {
+			if (parent == dev) {
+				get_device(&edev->edev);
+				mutex_unlock(&container_list_lock);
+				return edev;
+			}
+			parent = parent->parent;
+		}
+	}
+	mutex_unlock(&container_list_lock);
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(enclosure_find);
+
+/**
+ * enclosure_for_each_device - calls a function for each enclosure
+ * @fn:		the function to call
+ * @data:	the data to pass to each call
+ *
+ * Loops over all the enclosures calling the function.
+ *
+ * Note, this function uses a mutex which will be held across calls to
+ * @fn, so it must have non atomic context, and @fn may (although it
+ * should not) sleep or otherwise cause the mutex to be held for
+ * indefinite periods
+ */
+int enclosure_for_each_device(int (*fn)(struct enclosure_device *, void *),
+			      void *data)
+{
+	int error = 0;
+	struct enclosure_device *edev;
+
+	mutex_lock(&container_list_lock);
+	list_for_each_entry(edev, &container_list, node) {
+		error = fn(edev, data);
+		if (error)
+			break;
+	}
+	mutex_unlock(&container_list_lock);
+
+	return error;
+}
+EXPORT_SYMBOL_GPL(enclosure_for_each_device);
+
+/**
+ * enclosure_register - register device as an enclosure
+ *
+ * @dev:	device containing the enclosure
+ * @name:	chosen device name
+ * @components:	number of components in the enclosure
+ * @cb:         platform call-backs
+ *
+ * This sets up the device for being an enclosure.  Note that @dev does
+ * not have to be a dedicated enclosure device.  It may be some other type
+ * of device that additionally responds to enclosure services
+ */
+struct enclosure_device *
+enclosure_register(struct device *dev, const char *name, int components,
+		   struct enclosure_component_callbacks *cb)
+{
+	struct enclosure_device *edev =
+		kzalloc_flex(*edev, component, components);
+	int err, i;
+
+	BUG_ON(!cb);
+
+	if (!edev)
+		return ERR_PTR(-ENOMEM);
+
+	edev->components = components;
+
+	edev->edev.class = &enclosure_class;
+	edev->edev.parent = get_device(dev);
+	edev->cb = cb;
+	dev_set_name(&edev->edev, "%s", name);
+	err = device_register(&edev->edev);
+	if (err)
+		goto err;
+
+	for (i = 0; i < components; i++) {
+		edev->component[i].number = -1;
+		edev->component[i].slot = -1;
+		edev->component[i].power_status = -1;
+	}
+
+	mutex_lock(&container_list_lock);
+	list_add_tail(&edev->node, &container_list);
+	mutex_unlock(&container_list_lock);
+
+	return edev;
+
+ err:
+	put_device(edev->edev.parent);
+	kfree(edev);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(enclosure_register);
+
+static struct enclosure_component_callbacks enclosure_null_callbacks;
+
+/**
+ * enclosure_unregister - remove an enclosure
+ *
+ * @edev:	the registered enclosure to remove;
+ */
+void enclosure_unregister(struct enclosure_device *edev)
+{
+	int i;
+
+	mutex_lock(&container_list_lock);
+	list_del(&edev->node);
+	mutex_unlock(&container_list_lock);
+
+	for (i = 0; i < edev->components; i++)
+		if (edev->component[i].number != -1)
+			device_unregister(&edev->component[i].cdev);
+
+	/* prevent any callbacks into service user */
+	edev->cb = &enclosure_null_callbacks;
+	device_unregister(&edev->edev);
+}
+EXPORT_SYMBOL_GPL(enclosure_unregister);
+
+#define ENCLOSURE_NAME_SIZE	64
+#define COMPONENT_NAME_SIZE	64
+
+static void enclosure_link_name(struct enclosure_component *cdev, char *name)
+{
+	snprintf(name, ENCLOSURE_NAME_SIZE, "enclosure_device:%s",
+		 dev_name(&cdev->cdev));
+}
+
+static void enclosure_remove_links(struct enclosure_component *cdev)
+{
+	char name[ENCLOSURE_NAME_SIZE];
+
+	enclosure_link_name(cdev, name);
+
+	/*
+	 * In odd circumstances, like multipath devices, something else may
+	 * already have removed the links, so check for this condition first.
+	 */
+	if (cdev->dev->kobj.sd)
+		sysfs_remove_link(&cdev->dev->kobj, name);
+
+	if (cdev->cdev.kobj.sd)
+		sysfs_remove_link(&cdev->cdev.kobj, "device");
+}
+
+static int enclosure_add_links(struct enclosure_component *cdev)
+{
+	int error;
+	char name[ENCLOSURE_NAME_SIZE];
+
+	error = sysfs_create_link(&cdev->cdev.kobj, &cdev->dev->kobj, "device");
+	if (error)
+		return error;
+
+	enclosure_link_name(cdev, name);
+	error = sysfs_create_link(&cdev->dev->kobj, &cdev->cdev.kobj, name);
+	if (error)
+		sysfs_remove_link(&cdev->cdev.kobj, "device");
+
+	return error;
+}
+
+static void enclosure_release(struct device *cdev)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev);
+
+	put_device(cdev->parent);
+	kfree(edev);
+}
+
+static void enclosure_component_release(struct device *dev)
+{
+	struct enclosure_component *cdev = to_enclosure_component(dev);
+
+	if (cdev->dev) {
+		enclosure_remove_links(cdev);
+		put_device(cdev->dev);
+	}
+	put_device(dev->parent);
+}
+
+static struct enclosure_component *
+enclosure_component_find_by_name(struct enclosure_device *edev,
+				const char *name)
+{
+	int i;
+	const char *cname;
+	struct enclosure_component *ecomp;
+
+	if (!edev || !name || !name[0])
+		return NULL;
+
+	for (i = 0; i < edev->components; i++) {
+		ecomp = &edev->component[i];
+		cname = dev_name(&ecomp->cdev);
+		if (ecomp->number != -1 &&
+		    cname && cname[0] &&
+		    !strcmp(cname, name))
+			return ecomp;
+	}
+
+	return NULL;
+}
+
+static const struct attribute_group *enclosure_component_groups[];
+
+/**
+ * enclosure_component_alloc - prepare a new enclosure component
+ * @edev:	the enclosure to add the component
+ * @number:	the device number
+ * @type:	the type of component being added
+ * @name:	an optional name to appear in sysfs (leave NULL if none)
+ *
+ * The name is optional for enclosures that give their components a unique
+ * name.  If not, leave the field NULL and a name will be assigned.
+ *
+ * Returns a pointer to the enclosure component or an error.
+ */
+struct enclosure_component *
+enclosure_component_alloc(struct enclosure_device *edev,
+			  unsigned int number,
+			  enum enclosure_component_type type,
+			  const char *name)
+{
+	struct enclosure_component *ecomp;
+	struct device *cdev;
+	int i;
+	char newname[COMPONENT_NAME_SIZE];
+
+	if (number >= edev->components)
+		return ERR_PTR(-EINVAL);
+
+	ecomp = &edev->component[number];
+
+	if (ecomp->number != -1)
+		return ERR_PTR(-EINVAL);
+
+	ecomp->type = type;
+	ecomp->number = number;
+	cdev = &ecomp->cdev;
+	cdev->parent = get_device(&edev->edev);
+
+	if (name && name[0]) {
+		/* Some hardware (e.g. enclosure in RX300 S6) has components
+		 * with non unique names. Registering duplicates in sysfs
+		 * will lead to warnings during bootup. So make the names
+		 * unique by appending consecutive numbers -1, -2, ... */
+		i = 1;
+		snprintf(newname, COMPONENT_NAME_SIZE,
+			 "%s", name);
+		while (enclosure_component_find_by_name(edev, newname))
+			snprintf(newname, COMPONENT_NAME_SIZE,
+				 "%s-%i", name, i++);
+		dev_set_name(cdev, "%s", newname);
+	} else
+		dev_set_name(cdev, "%u", number);
+
+	cdev->release = enclosure_component_release;
+	cdev->groups = enclosure_component_groups;
+
+	return ecomp;
+}
+EXPORT_SYMBOL_GPL(enclosure_component_alloc);
+
+/**
+ * enclosure_component_register - publishes an initialized enclosure component
+ * @ecomp:	component to add
+ *
+ * Returns 0 on successful registration, releases the component otherwise
+ */
+int enclosure_component_register(struct enclosure_component *ecomp)
+{
+	struct device *cdev;
+	int err;
+
+	cdev = &ecomp->cdev;
+	err = device_register(cdev);
+	if (err) {
+		ecomp->number = -1;
+		put_device(cdev);
+		return err;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(enclosure_component_register);
+
+/**
+ * enclosure_add_device - add a device as being part of an enclosure
+ * @edev:	the enclosure device being added to.
+ * @component:	the number of the component
+ * @dev:	the device being added
+ *
+ * Declares a real device to reside in slot (or identifier) @num of an
+ * enclosure.  This will cause the relevant sysfs links to appear.
+ * This function may also be used to change a device associated with
+ * an enclosure without having to call enclosure_remove_device() in
+ * between.
+ *
+ * Returns zero on success or an error.
+ */
+int enclosure_add_device(struct enclosure_device *edev, int component,
+			 struct device *dev)
+{
+	struct enclosure_component *cdev;
+	int err;
+
+	if (!edev || component >= edev->components)
+		return -EINVAL;
+
+	cdev = &edev->component[component];
+
+	if (cdev->dev == dev)
+		return -EEXIST;
+
+	if (cdev->dev) {
+		enclosure_remove_links(cdev);
+		put_device(cdev->dev);
+	}
+	cdev->dev = get_device(dev);
+	err = enclosure_add_links(cdev);
+	if (err) {
+		put_device(cdev->dev);
+		cdev->dev = NULL;
+	}
+	return err;
+}
+EXPORT_SYMBOL_GPL(enclosure_add_device);
+
+/**
+ * enclosure_remove_device - remove a device from an enclosure
+ * @edev:	the enclosure device
+ * @dev:	device to remove/put
+ *
+ * Returns zero on success or an error.
+ *
+ */
+int enclosure_remove_device(struct enclosure_device *edev, struct device *dev)
+{
+	struct enclosure_component *cdev;
+	int i;
+
+	if (!edev || !dev)
+		return -EINVAL;
+
+	for (i = 0; i < edev->components; i++) {
+		cdev = &edev->component[i];
+		if (cdev->dev == dev) {
+			enclosure_remove_links(cdev);
+			put_device(dev);
+			cdev->dev = NULL;
+			return 0;
+		}
+	}
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(enclosure_remove_device);
+
+/*
+ * sysfs pieces below
+ */
+
+static ssize_t components_show(struct device *cdev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev);
+
+	return sysfs_emit(buf, "%d\n", edev->components);
+}
+static DEVICE_ATTR_RO(components);
+
+static ssize_t id_show(struct device *cdev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev);
+
+	if (edev->cb->show_id)
+		return edev->cb->show_id(edev, buf);
+	return -EINVAL;
+}
+static DEVICE_ATTR_RO(id);
+
+static struct attribute *enclosure_class_attrs[] = {
+	&dev_attr_components.attr,
+	&dev_attr_id.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(enclosure_class);
+
+static struct class enclosure_class = {
+	.name			= "enclosure",
+	.dev_release		= enclosure_release,
+	.dev_groups		= enclosure_class_groups,
+};
+
+static const char *const enclosure_status[] = {
+	[ENCLOSURE_STATUS_UNSUPPORTED] = "unsupported",
+	[ENCLOSURE_STATUS_OK] = "OK",
+	[ENCLOSURE_STATUS_CRITICAL] = "critical",
+	[ENCLOSURE_STATUS_NON_CRITICAL] = "non-critical",
+	[ENCLOSURE_STATUS_UNRECOVERABLE] = "unrecoverable",
+	[ENCLOSURE_STATUS_NOT_INSTALLED] = "not installed",
+	[ENCLOSURE_STATUS_UNKNOWN] = "unknown",
+	[ENCLOSURE_STATUS_UNAVAILABLE] = "unavailable",
+	[ENCLOSURE_STATUS_MAX] = NULL,
+};
+
+static const char *const enclosure_type[] = {
+	[ENCLOSURE_COMPONENT_DEVICE] = "device",
+	[ENCLOSURE_COMPONENT_ARRAY_DEVICE] = "array device",
+};
+
+static ssize_t get_component_fault(struct device *cdev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+
+	if (edev->cb->get_fault)
+		edev->cb->get_fault(edev, ecomp);
+	return sysfs_emit(buf, "%d\n", ecomp->fault);
+}
+
+static ssize_t set_component_fault(struct device *cdev,
+				   struct device_attribute *attr,
+				   const char *buf, size_t count)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+	int val = simple_strtoul(buf, NULL, 0);
+
+	if (edev->cb->set_fault)
+		edev->cb->set_fault(edev, ecomp, val);
+	return count;
+}
+
+static ssize_t get_component_status(struct device *cdev,
+				    struct device_attribute *attr,char *buf)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+
+	if (edev->cb->get_status)
+		edev->cb->get_status(edev, ecomp);
+	return sysfs_emit(buf, "%s\n", enclosure_status[ecomp->status]);
+}
+
+static ssize_t set_component_status(struct device *cdev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t count)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+	int i;
+
+	for (i = 0; enclosure_status[i]; i++) {
+		if (strncmp(buf, enclosure_status[i],
+			    strlen(enclosure_status[i])) == 0 &&
+		    (buf[strlen(enclosure_status[i])] == '\n' ||
+		     buf[strlen(enclosure_status[i])] == '\0'))
+			break;
+	}
+
+	if (enclosure_status[i] && edev->cb->set_status) {
+		edev->cb->set_status(edev, ecomp, i);
+		return count;
+	} else
+		return -EINVAL;
+}
+
+static ssize_t get_component_active(struct device *cdev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+
+	if (edev->cb->get_active)
+		edev->cb->get_active(edev, ecomp);
+	return sysfs_emit(buf, "%d\n", ecomp->active);
+}
+
+static ssize_t set_component_active(struct device *cdev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t count)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+	int val = simple_strtoul(buf, NULL, 0);
+
+	if (edev->cb->set_active)
+		edev->cb->set_active(edev, ecomp, val);
+	return count;
+}
+
+static ssize_t get_component_locate(struct device *cdev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+
+	if (edev->cb->get_locate)
+		edev->cb->get_locate(edev, ecomp);
+	return sysfs_emit(buf, "%d\n", ecomp->locate);
+}
+
+static ssize_t set_component_locate(struct device *cdev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t count)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+	int val = simple_strtoul(buf, NULL, 0);
+
+	if (edev->cb->set_locate)
+		edev->cb->set_locate(edev, ecomp, val);
+	return count;
+}
+
+static ssize_t get_component_power_status(struct device *cdev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+
+	if (edev->cb->get_power_status)
+		edev->cb->get_power_status(edev, ecomp);
+
+	/* If still uninitialized, the callback failed or does not exist. */
+	if (ecomp->power_status == -1)
+		return (edev->cb->get_power_status) ? -EIO : -ENOTTY;
+
+	return sysfs_emit(buf, "%s\n", str_on_off(ecomp->power_status));
+}
+
+static ssize_t set_component_power_status(struct device *cdev,
+					  struct device_attribute *attr,
+					  const char *buf, size_t count)
+{
+	struct enclosure_device *edev = to_enclosure_device(cdev->parent);
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+	int val;
+
+	if (strncmp(buf, "on", 2) == 0 &&
+	    (buf[2] == '\n' || buf[2] == '\0'))
+		val = 1;
+	else if (strncmp(buf, "off", 3) == 0 &&
+	    (buf[3] == '\n' || buf[3] == '\0'))
+		val = 0;
+	else
+		return -EINVAL;
+
+	if (edev->cb->set_power_status)
+		edev->cb->set_power_status(edev, ecomp, val);
+	return count;
+}
+
+static ssize_t get_component_type(struct device *cdev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+
+	return sysfs_emit(buf, "%s\n", enclosure_type[ecomp->type]);
+}
+
+static ssize_t get_component_slot(struct device *cdev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct enclosure_component *ecomp = to_enclosure_component(cdev);
+	int slot;
+
+	/* if the enclosure does not override then use 'number' as a stand-in */
+	if (ecomp->slot >= 0)
+		slot = ecomp->slot;
+	else
+		slot = ecomp->number;
+
+	return sysfs_emit(buf, "%d\n", slot);
+}
+
+static DEVICE_ATTR(fault, S_IRUGO | S_IWUSR, get_component_fault,
+		    set_component_fault);
+static DEVICE_ATTR(status, S_IRUGO | S_IWUSR, get_component_status,
+		   set_component_status);
+static DEVICE_ATTR(active, S_IRUGO | S_IWUSR, get_component_active,
+		   set_component_active);
+static DEVICE_ATTR(locate, S_IRUGO | S_IWUSR, get_component_locate,
+		   set_component_locate);
+static DEVICE_ATTR(power_status, S_IRUGO | S_IWUSR, get_component_power_status,
+		   set_component_power_status);
+static DEVICE_ATTR(type, S_IRUGO, get_component_type, NULL);
+static DEVICE_ATTR(slot, S_IRUGO, get_component_slot, NULL);
+
+static struct attribute *enclosure_component_attrs[] = {
+	&dev_attr_fault.attr,
+	&dev_attr_status.attr,
+	&dev_attr_active.attr,
+	&dev_attr_locate.attr,
+	&dev_attr_power_status.attr,
+	&dev_attr_type.attr,
+	&dev_attr_slot.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(enclosure_component);
+
+static int __init enclosure_init(void)
+{
+	return class_register(&enclosure_class);
+}
+
+static void __exit enclosure_exit(void)
+{
+	class_unregister(&enclosure_class);
+}
+
+module_init(enclosure_init);
+module_exit(enclosure_exit);
+
+MODULE_AUTHOR("James Bottomley");
+MODULE_DESCRIPTION("Enclosure Services");
+MODULE_LICENSE("GPL v2");