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Diffstat (limited to '')
-rw-r--r-- | drivers/scsi/raid_class.c | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/drivers/scsi/raid_class.c b/drivers/scsi/raid_class.c new file mode 100644 index 0000000000..95a86e0dfd --- /dev/null +++ b/drivers/scsi/raid_class.c @@ -0,0 +1,268 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * raid_class.c - implementation of a simple raid visualisation class + * + * Copyright (c) 2005 - James Bottomley <James.Bottomley@steeleye.com> + * + * 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 (IS_ENABLED(CONFIG_SCSI) && 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 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" }, + { RAID_LEVEL_JBOD, "jbod" }, +}; + +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); + +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); + |