+++ /dev/null
-/*
- * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
- *
- * This file is released under the GPL.
- *
- * Multipath hardware handler registration.
- */
-
-#include "dm.h"
-#include "dm-hw-handler.h"
-
-#include <linux/slab.h>
-
-struct hwh_internal {
- struct hw_handler_type hwht;
-
- struct list_head list;
- long use;
-};
-
-#define hwht_to_hwhi(__hwht) container_of((__hwht), struct hwh_internal, hwht)
-
-static LIST_HEAD(_hw_handlers);
-static DECLARE_RWSEM(_hwh_lock);
-
-static struct hwh_internal *__find_hw_handler_type(const char *name)
-{
- struct hwh_internal *hwhi;
-
- list_for_each_entry(hwhi, &_hw_handlers, list) {
- if (!strcmp(name, hwhi->hwht.name))
- return hwhi;
- }
-
- return NULL;
-}
-
-static struct hwh_internal *get_hw_handler(const char *name)
-{
- struct hwh_internal *hwhi;
-
- down_read(&_hwh_lock);
- hwhi = __find_hw_handler_type(name);
- if (hwhi) {
- if ((hwhi->use == 0) && !try_module_get(hwhi->hwht.module))
- hwhi = NULL;
- else
- hwhi->use++;
- }
- up_read(&_hwh_lock);
-
- return hwhi;
-}
-
-struct hw_handler_type *dm_get_hw_handler(const char *name)
-{
- struct hwh_internal *hwhi;
-
- if (!name)
- return NULL;
-
- hwhi = get_hw_handler(name);
- if (!hwhi) {
- request_module("dm-%s", name);
- hwhi = get_hw_handler(name);
- }
-
- return hwhi ? &hwhi->hwht : NULL;
-}
-
-void dm_put_hw_handler(struct hw_handler_type *hwht)
-{
- struct hwh_internal *hwhi;
-
- if (!hwht)
- return;
-
- down_read(&_hwh_lock);
- hwhi = __find_hw_handler_type(hwht->name);
- if (!hwhi)
- goto out;
-
- if (--hwhi->use == 0)
- module_put(hwhi->hwht.module);
-
- BUG_ON(hwhi->use < 0);
-
- out:
- up_read(&_hwh_lock);
-}
-
-static struct hwh_internal *_alloc_hw_handler(struct hw_handler_type *hwht)
-{
- struct hwh_internal *hwhi = kzalloc(sizeof(*hwhi), GFP_KERNEL);
-
- if (hwhi)
- hwhi->hwht = *hwht;
-
- return hwhi;
-}
-
-int dm_register_hw_handler(struct hw_handler_type *hwht)
-{
- int r = 0;
- struct hwh_internal *hwhi = _alloc_hw_handler(hwht);
-
- if (!hwhi)
- return -ENOMEM;
-
- down_write(&_hwh_lock);
-
- if (__find_hw_handler_type(hwht->name)) {
- kfree(hwhi);
- r = -EEXIST;
- } else
- list_add(&hwhi->list, &_hw_handlers);
-
- up_write(&_hwh_lock);
-
- return r;
-}
-
-int dm_unregister_hw_handler(struct hw_handler_type *hwht)
-{
- struct hwh_internal *hwhi;
-
- down_write(&_hwh_lock);
-
- hwhi = __find_hw_handler_type(hwht->name);
- if (!hwhi) {
- up_write(&_hwh_lock);
- return -EINVAL;
- }
-
- if (hwhi->use) {
- up_write(&_hwh_lock);
- return -ETXTBSY;
- }
-
- list_del(&hwhi->list);
-
- up_write(&_hwh_lock);
-
- kfree(hwhi);
-
- return 0;
-}
-
-unsigned dm_scsi_err_handler(struct hw_handler *hwh, struct bio *bio)
-{
-#if 0
- int sense_key, asc, ascq;
-
- if (bio->bi_error & BIO_SENSE) {
- /* FIXME: This is just an initial guess. */
- /* key / asc / ascq */
- sense_key = (bio->bi_error >> 16) & 0xff;
- asc = (bio->bi_error >> 8) & 0xff;
- ascq = bio->bi_error & 0xff;
-
- switch (sense_key) {
- /* This block as a whole comes from the device.
- * So no point retrying on another path. */
- case 0x03: /* Medium error */
- case 0x05: /* Illegal request */
- case 0x07: /* Data protect */
- case 0x08: /* Blank check */
- case 0x0a: /* copy aborted */
- case 0x0c: /* obsolete - no clue ;-) */
- case 0x0d: /* volume overflow */
- case 0x0e: /* data miscompare */
- case 0x0f: /* reserved - no idea either. */
- return MP_ERROR_IO;
-
- /* For these errors it's unclear whether they
- * come from the device or the controller.
- * So just lets try a different path, and if
- * it eventually succeeds, user-space will clear
- * the paths again... */
- case 0x02: /* Not ready */
- case 0x04: /* Hardware error */
- case 0x09: /* vendor specific */
- case 0x0b: /* Aborted command */
- return MP_FAIL_PATH;
-
- case 0x06: /* Unit attention - might want to decode */
- if (asc == 0x04 && ascq == 0x01)
- /* "Unit in the process of
- * becoming ready" */
- return 0;
- return MP_FAIL_PATH;
-
- /* FIXME: For Unit Not Ready we may want
- * to have a generic pg activation
- * feature (START_UNIT). */
-
- /* Should these two ever end up in the
- * error path? I don't think so. */
- case 0x00: /* No sense */
- case 0x01: /* Recovered error */
- return 0;
- }
- }
-#endif
-
- /* We got no idea how to decode the other kinds of errors ->
- * assume generic error condition. */
- return MP_FAIL_PATH;
-}
-
-EXPORT_SYMBOL_GPL(dm_register_hw_handler);
-EXPORT_SYMBOL_GPL(dm_unregister_hw_handler);
-EXPORT_SYMBOL_GPL(dm_scsi_err_handler);
+++ /dev/null
-/*
- * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
- *
- * This file is released under the GPL.
- *
- * Multipath hardware handler registration.
- */
-
-#ifndef DM_HW_HANDLER_H
-#define DM_HW_HANDLER_H
-
-#include <linux/device-mapper.h>
-
-#include "dm-mpath.h"
-
-struct hw_handler_type;
-struct hw_handler {
- struct hw_handler_type *type;
- struct mapped_device *md;
- void *context;
-};
-
-/*
- * Constructs a hardware handler object, takes custom arguments
- */
-/* Information about a hardware handler type */
-struct hw_handler_type {
- char *name;
- struct module *module;
-
- int (*create) (struct hw_handler *handler, unsigned int argc,
- char **argv);
- void (*destroy) (struct hw_handler *hwh);
-
- void (*pg_init) (struct hw_handler *hwh, unsigned bypassed,
- struct dm_path *path);
- unsigned (*error) (struct hw_handler *hwh, struct bio *bio);
- int (*status) (struct hw_handler *hwh, status_type_t type,
- char *result, unsigned int maxlen);
-};
-
-/* Register a hardware handler */
-int dm_register_hw_handler(struct hw_handler_type *type);
-
-/* Unregister a hardware handler */
-int dm_unregister_hw_handler(struct hw_handler_type *type);
-
-/* Returns a registered hardware handler type */
-struct hw_handler_type *dm_get_hw_handler(const char *name);
-
-/* Releases a hardware handler */
-void dm_put_hw_handler(struct hw_handler_type *hwht);
-
-/* Default err function */
-unsigned dm_scsi_err_handler(struct hw_handler *hwh, struct bio *bio);
-
-/* Error flags for err and dm_pg_init_complete */
-#define MP_FAIL_PATH 1
-#define MP_BYPASS_PG 2
-#define MP_ERROR_IO 4 /* Don't retry this I/O */
-#define MP_RETRY 8
-
-#endif
projects / linux-2.6 / commitdiff