diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 96df148ed96967f06e544893ae415ba2bb18699d..68adc3cc8ad207c2630ca4b2a6d6d8f8e1b1a94e 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -1,5 +1,11 @@
menu "SCSI device support"
+config RAID_ATTRS
+ tristate "RAID Transport Class"
+ default n
+ ---help---
+ Provides RAID
+
config SCSI
tristate "SCSI device support"
---help---
diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
index 3746fb9fa2f5b0518bd347447bd8d83d4ec20d1d..85f9e6bb34b9b71fefed5abf36e2701ba6b70443 100644
--- a/drivers/scsi/Makefile
+++ b/drivers/scsi/Makefile
@@ -22,6 +22,8 @@ subdir-$(CONFIG_PCMCIA) += pcmcia
obj-$(CONFIG_SCSI) += scsi_mod.o
+obj-$(CONFIG_RAID_ATTRS) += raid_class.o
+
# --- NOTE ORDERING HERE ---
# For kernel non-modular link, transport attributes need to
# be initialised before drivers
diff --git a/drivers/scsi/raid_class.c b/drivers/scsi/raid_class.c
new file mode 100644
index 0000000000000000000000000000000000000000..f1ea5027865f5851310769b08e0f5b53df163f71
--- /dev/null
+++ b/drivers/scsi/raid_class.c
@@ -0,0 +1,250 @@
+/*
+ * RAID Attributes
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/raid_class.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+
+#define RAID_NUM_ATTRS 3
+
+struct raid_internal {
+ struct raid_template r;
+ struct raid_function_template *f;
+ /* The actual attributes */
+ struct class_device_attribute private_attrs[RAID_NUM_ATTRS];
+ /* The array of null terminated pointers to attributes
+ * needed by scsi_sysfs.c */
+ struct class_device_attribute *attrs[RAID_NUM_ATTRS + 1];
+};
+
+struct raid_component {
+ struct list_head node;
+ struct device *dev;
+ int num;
+};
+
+#define to_raid_internal(tmpl) container_of(tmpl, struct raid_internal, r)
+
+#define tc_to_raid_internal(tcont) ({ \
+ struct raid_template *r = \
+ container_of(tcont, struct raid_template, raid_attrs); \
+ to_raid_internal(r); \
+})
+
+#define ac_to_raid_internal(acont) ({ \
+ struct transport_container *tc = \
+ container_of(acont, struct transport_container, ac); \
+ tc_to_raid_internal(tc); \
+})
+
+#define class_device_to_raid_internal(cdev) ({ \
+ struct attribute_container *ac = \
+ attribute_container_classdev_to_container(cdev); \
+ ac_to_raid_internal(ac); \
+})
+
+
+static int raid_match(struct attribute_container *cont, struct device *dev)
+{
+ /* We have to look for every subsystem that could house
+ * emulated RAID devices, so start with SCSI */
+ struct raid_internal *i = ac_to_raid_internal(cont);
+
+ if (scsi_is_sdev_device(dev)) {
+ struct scsi_device *sdev = to_scsi_device(dev);
+
+ if (i->f->cookie != sdev->host->hostt)
+ return 0;
+
+ return i->f->is_raid(dev);
+ }
+ /* FIXME: look at other subsystems too */
+ return 0;
+}
+
+static int raid_setup(struct transport_container *tc, struct device *dev,
+ struct class_device *cdev)
+{
+ struct raid_data *rd;
+
+ BUG_ON(class_get_devdata(cdev));
+
+ rd = kmalloc(sizeof(*rd), GFP_KERNEL);
+ if (!rd)
+ return -ENOMEM;
+
+ memset(rd, 0, sizeof(*rd));
+ INIT_LIST_HEAD(&rd->component_list);
+ class_set_devdata(cdev, rd);
+
+ return 0;
+}
+
+static int raid_remove(struct transport_container *tc, struct device *dev,
+ struct class_device *cdev)
+{
+ struct raid_data *rd = class_get_devdata(cdev);
+ struct raid_component *rc, *next;
+ class_set_devdata(cdev, NULL);
+ list_for_each_entry_safe(rc, next, &rd->component_list, node) {
+ char buf[40];
+ snprintf(buf, sizeof(buf), "component-%d", rc->num);
+ list_del(&rc->node);
+ sysfs_remove_link(&cdev->kobj, buf);
+ kfree(rc);
+ }
+ kfree(class_get_devdata(cdev));
+ return 0;
+}
+
+static DECLARE_TRANSPORT_CLASS(raid_class,
+ "raid_devices",
+ raid_setup,
+ raid_remove,
+ NULL);
+
+static struct {
+ enum raid_state value;
+ char *name;
+} raid_states[] = {
+ { RAID_ACTIVE, "active" },
+ { RAID_DEGRADED, "degraded" },
+ { RAID_RESYNCING, "resyncing" },
+ { RAID_OFFLINE, "offline" },
+};
+
+static const char *raid_state_name(enum raid_state state)
+{
+ int i;
+ char *name = NULL;
+
+ for (i = 0; i < sizeof(raid_states)/sizeof(raid_states[0]); i++) {
+ if (raid_states[i].value == state) {
+ name = raid_states[i].name;
+ break;
+ }
+ }
+ return name;
+}
+
+
+#define raid_attr_show_internal(attr, fmt, var, code) \
+static ssize_t raid_show_##attr(struct class_device *cdev, char *buf) \
+{ \
+ struct raid_data *rd = class_get_devdata(cdev); \
+ code \
+ return snprintf(buf, 20, #fmt "\n", var); \
+}
+
+#define raid_attr_ro_states(attr, states, code) \
+raid_attr_show_internal(attr, %s, name, \
+ const char *name; \
+ code \
+ name = raid_##states##_name(rd->attr); \
+) \
+static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
+
+
+#define raid_attr_ro_internal(attr, code) \
+raid_attr_show_internal(attr, %d, rd->attr, code) \
+static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
+
+#define ATTR_CODE(attr) \
+ struct raid_internal *i = class_device_to_raid_internal(cdev); \
+ if (i->f->get_##attr) \
+ i->f->get_##attr(cdev->dev);
+
+#define raid_attr_ro(attr) raid_attr_ro_internal(attr, )
+#define raid_attr_ro_fn(attr) raid_attr_ro_internal(attr, ATTR_CODE(attr))
+#define raid_attr_ro_state(attr) raid_attr_ro_states(attr, attr, ATTR_CODE(attr))
+
+raid_attr_ro(level);
+raid_attr_ro_fn(resync);
+raid_attr_ro_state(state);
+
+void raid_component_add(struct raid_template *r,struct device *raid_dev,
+ struct device *component_dev)
+{
+ struct class_device *cdev =
+ attribute_container_find_class_device(&r->raid_attrs.ac,
+ raid_dev);
+ struct raid_component *rc;
+ struct raid_data *rd = class_get_devdata(cdev);
+ char buf[40];
+
+ rc = kmalloc(sizeof(*rc), GFP_KERNEL);
+ if (!rc)
+ return;
+
+ INIT_LIST_HEAD(&rc->node);
+ rc->dev = component_dev;
+ rc->num = rd->component_count++;
+
+ snprintf(buf, sizeof(buf), "component-%d", rc->num);
+ list_add_tail(&rc->node, &rd->component_list);
+ sysfs_create_link(&cdev->kobj, &component_dev->kobj, buf);
+}
+EXPORT_SYMBOL(raid_component_add);
+
+struct raid_template *
+raid_class_attach(struct raid_function_template *ft)
+{
+ struct raid_internal *i = kmalloc(sizeof(struct raid_internal),
+ GFP_KERNEL);
+ int count = 0;
+
+ if (unlikely(!i))
+ return NULL;
+
+ memset(i, 0, sizeof(*i));
+
+ i->f = ft;
+
+ i->r.raid_attrs.ac.class = &raid_class.class;
+ i->r.raid_attrs.ac.match = raid_match;
+ i->r.raid_attrs.ac.attrs = &i->attrs[0];
+
+ attribute_container_register(&i->r.raid_attrs.ac);
+
+ i->attrs[count++] = &class_device_attr_level;
+ i->attrs[count++] = &class_device_attr_resync;
+ i->attrs[count++] = &class_device_attr_state;
+
+ i->attrs[count] = NULL;
+ BUG_ON(count > RAID_NUM_ATTRS);
+
+ return &i->r;
+}
+EXPORT_SYMBOL(raid_class_attach);
+
+void
+raid_class_release(struct raid_template *r)
+{
+ struct raid_internal *i = to_raid_internal(r);
+
+ attribute_container_unregister(&i->r.raid_attrs.ac);
+
+ kfree(i);
+}
+EXPORT_SYMBOL(raid_class_release);
+
+static __init int raid_init(void)
+{
+ return transport_class_register(&raid_class);
+}
+
+static __exit void raid_exit(void)
+{
+ transport_class_unregister(&raid_class);
+}
+
+MODULE_AUTHOR("James Bottomley");
+MODULE_DESCRIPTION("RAID device class");
+MODULE_LICENSE("GPL");
+
+module_init(raid_init);
+module_exit(raid_exit);
+
diff --git a/include/linux/raid_class.h b/include/linux/raid_class.h
new file mode 100644
index 0000000000000000000000000000000000000000..a71123c282728389fdc9b0e0d2e3d3d6ea44cce2
--- /dev/null
+++ b/include/linux/raid_class.h
@@ -0,0 +1,59 @@
+/*
+ */
+#include <linux/transport_class.h>
+
+struct raid_template {
+ struct transport_container raid_attrs;
+};
+
+struct raid_function_template {
+ void *cookie;
+ int (*is_raid)(struct device *);
+ void (*get_resync)(struct device *);
+ void (*get_state)(struct device *);
+};
+
+enum raid_state {
+ RAID_ACTIVE = 1,
+ RAID_DEGRADED,
+ RAID_RESYNCING,
+ RAID_OFFLINE,
+};
+
+struct raid_data {
+ struct list_head component_list;
+ int component_count;
+ int level;
+ enum raid_state state;
+ int resync;
+};
+
+#define DEFINE_RAID_ATTRIBUTE(type, attr) \
+static inline void \
+raid_set_##attr(struct raid_template *r, struct device *dev, type value) { \
+ struct class_device *cdev = \
+ attribute_container_find_class_device(&r->raid_attrs.ac, dev);\
+ struct raid_data *rd; \
+ BUG_ON(!cdev); \
+ rd = class_get_devdata(cdev); \
+ rd->attr = value; \
+} \
+static inline type \
+raid_get_##attr(struct raid_template *r, struct device *dev) { \
+ struct class_device *cdev = \
+ attribute_container_find_class_device(&r->raid_attrs.ac, dev);\
+ struct raid_data *rd; \
+ BUG_ON(!cdev); \
+ rd = class_get_devdata(cdev); \
+ return rd->attr; \
+}
+
+DEFINE_RAID_ATTRIBUTE(int, level)
+DEFINE_RAID_ATTRIBUTE(int, resync)
+DEFINE_RAID_ATTRIBUTE(enum raid_state, state)
+
+struct raid_template *raid_class_attach(struct raid_function_template *);
+void raid_class_release(struct raid_template *);
+
+void raid_component_add(struct raid_template *, struct device *,
+ struct device *);