--- /dev/null
+/*
+ * raid_class.c - implementation of a simple raid visualisation class
+ *
+ * Copyright (c) 2005 - James Bottomley <James.Bottomley@steeleye.com>
+ *
+ * This file is licensed under GPLv2
+ *
+ * This class is designed to allow raid attributes to be visualised and
+ * manipulated in a form independent of the underlying raid. Ultimately this
+ * should work for both hardware and software raids.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/string.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 device_attribute private_attrs[RAID_NUM_ATTRS];
+ /* The array of null terminated pointers to attributes
+ * needed by scsi_sysfs.c */
+ struct 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 device_to_raid_internal(dev) ({ \
+ struct attribute_container *ac = \
+ attribute_container_classdev_to_container(dev); \
+ 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 defined(CONFIG_SCSI) || defined(CONFIG_SCSI_MODULE)
+ 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);
+ }
+#endif
+ /* FIXME: look at other subsystems too */
+ return 0;
+}
+
+static int raid_setup(struct transport_container *tc, struct device *dev,
+ struct device *cdev)
+{
+ struct raid_data *rd;
+
+ BUG_ON(dev_get_drvdata(cdev));
+
+ rd = kzalloc(sizeof(*rd), GFP_KERNEL);
+ if (!rd)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&rd->component_list);
+ dev_set_drvdata(cdev, rd);
+
+ return 0;
+}
+
+static int raid_remove(struct transport_container *tc, struct device *dev,
+ struct device *cdev)
+{
+ struct raid_data *rd = dev_get_drvdata(cdev);
+ struct raid_component *rc, *next;
+ dev_printk(KERN_ERR, dev, "RAID REMOVE\n");
+ dev_set_drvdata(cdev, NULL);
+ list_for_each_entry_safe(rc, next, &rd->component_list, node) {
+ list_del(&rc->node);
+ dev_printk(KERN_ERR, rc->dev.parent, "RAID COMPONENT REMOVE\n");
+ device_unregister(&rc->dev);
+ }
+ dev_printk(KERN_ERR, dev, "RAID REMOVE DONE\n");
+ kfree(rd);
+ return 0;
+}
+
+static DECLARE_TRANSPORT_CLASS(raid_class,
+ "raid_devices",
+ raid_setup,
+ raid_remove,
+ NULL);
+
+static const struct {
+ enum raid_state value;
+ char *name;
+} raid_states[] = {
+ { RAID_STATE_UNKNOWN, "unknown" },
+ { RAID_STATE_ACTIVE, "active" },
+ { RAID_STATE_DEGRADED, "degraded" },
+ { RAID_STATE_RESYNCING, "resyncing" },
+ { RAID_STATE_OFFLINE, "offline" },
+};
+
+static const char *raid_state_name(enum raid_state state)
+{
+ int i;
+ char *name = NULL;
+
+ for (i = 0; i < ARRAY_SIZE(raid_states); i++) {
+ if (raid_states[i].value == state) {
+ name = raid_states[i].name;
+ break;
+ }
+ }
+ return name;
+}
+
+static struct {
+ enum raid_level value;
+ char *name;
+} raid_levels[] = {
+ { RAID_LEVEL_UNKNOWN, "unknown" },
+ { RAID_LEVEL_LINEAR, "linear" },
+ { RAID_LEVEL_0, "raid0" },
+ { RAID_LEVEL_1, "raid1" },
+ { RAID_LEVEL_10, "raid10" },
+ { RAID_LEVEL_1E, "raid1e" },
+ { RAID_LEVEL_3, "raid3" },
+ { RAID_LEVEL_4, "raid4" },
+ { RAID_LEVEL_5, "raid5" },
+ { RAID_LEVEL_50, "raid50" },
+ { RAID_LEVEL_6, "raid6" },
+};
+
+static const char *raid_level_name(enum raid_level level)
+{
+ int i;
+ char *name = NULL;
+
+ for (i = 0; i < ARRAY_SIZE(raid_levels); i++) {
+ if (raid_levels[i].value == level) {
+ name = raid_levels[i].name;
+ break;
+ }
+ }
+ return name;
+}
+
+#define raid_attr_show_internal(attr, fmt, var, code) \
+static ssize_t raid_show_##attr(struct device *dev, \
+ struct device_attribute *attr, \
+ char *buf) \
+{ \
+ struct raid_data *rd = dev_get_drvdata(dev); \
+ 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 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 DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
+
+#define ATTR_CODE(attr) \
+ struct raid_internal *i = device_to_raid_internal(dev); \
+ if (i->f->get_##attr) \
+ i->f->get_##attr(dev->parent);
+
+#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, )
+#define raid_attr_ro_state_fn(attr) raid_attr_ro_states(attr, attr, ATTR_CODE(attr))
+
+
+raid_attr_ro_state(level);
+raid_attr_ro_fn(resync);
+raid_attr_ro_state_fn(state);
+
+static void raid_component_release(struct device *dev)
+{
+ struct raid_component *rc =
+ container_of(dev, struct raid_component, dev);
+ dev_printk(KERN_ERR, rc->dev.parent, "COMPONENT RELEASE\n");
+ put_device(rc->dev.parent);
+ kfree(rc);
+}
+
+int raid_component_add(struct raid_template *r,struct device *raid_dev,
+ struct device *component_dev)
+{
+ struct device *cdev =
+ attribute_container_find_class_device(&r->raid_attrs.ac,
+ raid_dev);
+ struct raid_component *rc;
+ struct raid_data *rd = dev_get_drvdata(cdev);
+ int err;
+
+ rc = kzalloc(sizeof(*rc), GFP_KERNEL);
+ if (!rc)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&rc->node);
+ device_initialize(&rc->dev);
+ rc->dev.release = raid_component_release;
+ rc->dev.parent = get_device(component_dev);
+ rc->num = rd->component_count++;
+
+ dev_set_name(&rc->dev, "component-%d", rc->num);
+ list_add_tail(&rc->node, &rd->component_list);
+ rc->dev.class = &raid_class.class;
+ err = device_add(&rc->dev);
+ if (err)
+ goto err_out;
+
+ return 0;
+
+err_out:
+ list_del(&rc->node);
+ rd->component_count--;
+ put_device(component_dev);
+ kfree(rc);
+ return err;
+}
+EXPORT_SYMBOL(raid_component_add);
+
+struct raid_template *
+raid_class_attach(struct raid_function_template *ft)
+{
+ struct raid_internal *i = kzalloc(sizeof(struct raid_internal),
+ GFP_KERNEL);
+ int count = 0;
+
+ if (unlikely(!i))
+ return NULL;
+
+ 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++] = &dev_attr_level;
+ i->attrs[count++] = &dev_attr_resync;
+ i->attrs[count++] = &dev_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);
+
+ BUG_ON(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);
+
Code Review / kvmfornfv.git / blobdiff