2 * PAV alias management for the DASD ECKD discipline
4 * Copyright IBM Corp. 2007
5 * Author(s): Stefan Weinhuber <wein@de.ibm.com>
8 #define KMSG_COMPONENT "dasd-eckd"
10 #include <linux/list.h>
11 #include <linux/slab.h>
12 #include <asm/ebcdic.h>
14 #include "dasd_eckd.h"
18 #endif /* PRINTK_HEADER */
19 #define PRINTK_HEADER "dasd(eckd):"
23 * General concept of alias management:
24 * - PAV and DASD alias management is specific to the eckd discipline.
25 * - A device is connected to an lcu as long as the device exists.
26 * dasd_alias_make_device_known_to_lcu will be called wenn the
27 * device is checked by the eckd discipline and
28 * dasd_alias_disconnect_device_from_lcu will be called
29 * before the device is deleted.
30 * - The dasd_alias_add_device / dasd_alias_remove_device
31 * functions mark the point when a device is 'ready for service'.
32 * - A summary unit check is a rare occasion, but it is mandatory to
33 * support it. It requires some complex recovery actions before the
34 * devices can be used again (see dasd_alias_handle_summary_unit_check).
35 * - dasd_alias_get_start_dev will find an alias device that can be used
36 * instead of the base device and does some (very simple) load balancing.
37 * This is the function that gets called for each I/O, so when improving
38 * something, this function should get faster or better, the rest has just
43 static void summary_unit_check_handling_work(struct work_struct *);
44 static void lcu_update_work(struct work_struct *);
45 static int _schedule_lcu_update(struct alias_lcu *, struct dasd_device *);
47 static struct alias_root aliastree = {
48 .serverlist = LIST_HEAD_INIT(aliastree.serverlist),
49 .lock = __SPIN_LOCK_UNLOCKED(aliastree.lock),
52 static struct alias_server *_find_server(struct dasd_uid *uid)
54 struct alias_server *pos;
55 list_for_each_entry(pos, &aliastree.serverlist, server) {
56 if (!strncmp(pos->uid.vendor, uid->vendor,
58 && !strncmp(pos->uid.serial, uid->serial,
65 static struct alias_lcu *_find_lcu(struct alias_server *server,
68 struct alias_lcu *pos;
69 list_for_each_entry(pos, &server->lculist, lcu) {
70 if (pos->uid.ssid == uid->ssid)
76 static struct alias_pav_group *_find_group(struct alias_lcu *lcu,
79 struct alias_pav_group *pos;
80 __u8 search_unit_addr;
82 /* for hyper pav there is only one group */
83 if (lcu->pav == HYPER_PAV) {
84 if (list_empty(&lcu->grouplist))
87 return list_first_entry(&lcu->grouplist,
88 struct alias_pav_group, group);
91 /* for base pav we have to find the group that matches the base */
92 if (uid->type == UA_BASE_DEVICE)
93 search_unit_addr = uid->real_unit_addr;
95 search_unit_addr = uid->base_unit_addr;
96 list_for_each_entry(pos, &lcu->grouplist, group) {
97 if (pos->uid.base_unit_addr == search_unit_addr &&
98 !strncmp(pos->uid.vduit, uid->vduit, sizeof(uid->vduit)))
104 static struct alias_server *_allocate_server(struct dasd_uid *uid)
106 struct alias_server *server;
108 server = kzalloc(sizeof(*server), GFP_KERNEL);
110 return ERR_PTR(-ENOMEM);
111 memcpy(server->uid.vendor, uid->vendor, sizeof(uid->vendor));
112 memcpy(server->uid.serial, uid->serial, sizeof(uid->serial));
113 INIT_LIST_HEAD(&server->server);
114 INIT_LIST_HEAD(&server->lculist);
118 static void _free_server(struct alias_server *server)
123 static struct alias_lcu *_allocate_lcu(struct dasd_uid *uid)
125 struct alias_lcu *lcu;
127 lcu = kzalloc(sizeof(*lcu), GFP_KERNEL);
129 return ERR_PTR(-ENOMEM);
130 lcu->uac = kzalloc(sizeof(*(lcu->uac)), GFP_KERNEL | GFP_DMA);
133 lcu->rsu_cqr = kzalloc(sizeof(*lcu->rsu_cqr), GFP_KERNEL | GFP_DMA);
136 lcu->rsu_cqr->cpaddr = kzalloc(sizeof(struct ccw1),
137 GFP_KERNEL | GFP_DMA);
138 if (!lcu->rsu_cqr->cpaddr)
140 lcu->rsu_cqr->data = kzalloc(16, GFP_KERNEL | GFP_DMA);
141 if (!lcu->rsu_cqr->data)
144 memcpy(lcu->uid.vendor, uid->vendor, sizeof(uid->vendor));
145 memcpy(lcu->uid.serial, uid->serial, sizeof(uid->serial));
146 lcu->uid.ssid = uid->ssid;
148 lcu->flags = NEED_UAC_UPDATE | UPDATE_PENDING;
149 INIT_LIST_HEAD(&lcu->lcu);
150 INIT_LIST_HEAD(&lcu->inactive_devices);
151 INIT_LIST_HEAD(&lcu->active_devices);
152 INIT_LIST_HEAD(&lcu->grouplist);
153 INIT_WORK(&lcu->suc_data.worker, summary_unit_check_handling_work);
154 INIT_DELAYED_WORK(&lcu->ruac_data.dwork, lcu_update_work);
155 spin_lock_init(&lcu->lock);
156 init_completion(&lcu->lcu_setup);
160 kfree(lcu->rsu_cqr->cpaddr);
167 return ERR_PTR(-ENOMEM);
170 static void _free_lcu(struct alias_lcu *lcu)
172 kfree(lcu->rsu_cqr->data);
173 kfree(lcu->rsu_cqr->cpaddr);
180 * This is the function that will allocate all the server and lcu data,
181 * so this function must be called first for a new device.
182 * If the return value is 1, the lcu was already known before, if it
183 * is 0, this is a new lcu.
184 * Negative return code indicates that something went wrong (e.g. -ENOMEM)
186 int dasd_alias_make_device_known_to_lcu(struct dasd_device *device)
188 struct dasd_eckd_private *private = device->private;
190 struct alias_server *server, *newserver;
191 struct alias_lcu *lcu, *newlcu;
194 device->discipline->get_uid(device, &uid);
195 spin_lock_irqsave(&aliastree.lock, flags);
196 server = _find_server(&uid);
198 spin_unlock_irqrestore(&aliastree.lock, flags);
199 newserver = _allocate_server(&uid);
200 if (IS_ERR(newserver))
201 return PTR_ERR(newserver);
202 spin_lock_irqsave(&aliastree.lock, flags);
203 server = _find_server(&uid);
205 list_add(&newserver->server, &aliastree.serverlist);
208 /* someone was faster */
209 _free_server(newserver);
213 lcu = _find_lcu(server, &uid);
215 spin_unlock_irqrestore(&aliastree.lock, flags);
216 newlcu = _allocate_lcu(&uid);
218 return PTR_ERR(newlcu);
219 spin_lock_irqsave(&aliastree.lock, flags);
220 lcu = _find_lcu(server, &uid);
222 list_add(&newlcu->lcu, &server->lculist);
225 /* someone was faster */
229 spin_lock(&lcu->lock);
230 list_add(&device->alias_list, &lcu->inactive_devices);
232 spin_unlock(&lcu->lock);
233 spin_unlock_irqrestore(&aliastree.lock, flags);
239 * This function removes a device from the scope of alias management.
240 * The complicated part is to make sure that it is not in use by
241 * any of the workers. If necessary cancel the work.
243 void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device)
245 struct dasd_eckd_private *private = device->private;
247 struct alias_lcu *lcu;
248 struct alias_server *server;
253 /* nothing to do if already disconnected */
256 device->discipline->get_uid(device, &uid);
257 spin_lock_irqsave(&lcu->lock, flags);
258 /* make sure that the workers don't use this device */
259 if (device == lcu->suc_data.device) {
260 spin_unlock_irqrestore(&lcu->lock, flags);
261 cancel_work_sync(&lcu->suc_data.worker);
262 spin_lock_irqsave(&lcu->lock, flags);
263 if (device == lcu->suc_data.device) {
264 dasd_put_device(device);
265 lcu->suc_data.device = NULL;
269 if (device == lcu->ruac_data.device) {
270 spin_unlock_irqrestore(&lcu->lock, flags);
272 cancel_delayed_work_sync(&lcu->ruac_data.dwork);
273 spin_lock_irqsave(&lcu->lock, flags);
274 if (device == lcu->ruac_data.device) {
275 dasd_put_device(device);
276 lcu->ruac_data.device = NULL;
280 spin_unlock_irqrestore(&lcu->lock, flags);
282 spin_lock_irqsave(&aliastree.lock, flags);
283 spin_lock(&lcu->lock);
284 list_del_init(&device->alias_list);
285 if (list_empty(&lcu->grouplist) &&
286 list_empty(&lcu->active_devices) &&
287 list_empty(&lcu->inactive_devices)) {
289 spin_unlock(&lcu->lock);
294 _schedule_lcu_update(lcu, NULL);
295 spin_unlock(&lcu->lock);
297 server = _find_server(&uid);
298 if (server && list_empty(&server->lculist)) {
299 list_del(&server->server);
300 _free_server(server);
302 spin_unlock_irqrestore(&aliastree.lock, flags);
306 * This function assumes that the unit address configuration stored
307 * in the lcu is up to date and will update the device uid before
308 * adding it to a pav group.
311 static int _add_device_to_lcu(struct alias_lcu *lcu,
312 struct dasd_device *device,
313 struct dasd_device *pos)
316 struct dasd_eckd_private *private = device->private;
317 struct alias_pav_group *group;
320 spin_lock(get_ccwdev_lock(device->cdev));
321 private->uid.type = lcu->uac->unit[private->uid.real_unit_addr].ua_type;
322 private->uid.base_unit_addr =
323 lcu->uac->unit[private->uid.real_unit_addr].base_ua;
325 spin_unlock(get_ccwdev_lock(device->cdev));
326 /* if we have no PAV anyway, we don't need to bother with PAV groups */
327 if (lcu->pav == NO_PAV) {
328 list_move(&device->alias_list, &lcu->active_devices);
331 group = _find_group(lcu, &uid);
333 group = kzalloc(sizeof(*group), GFP_ATOMIC);
336 memcpy(group->uid.vendor, uid.vendor, sizeof(uid.vendor));
337 memcpy(group->uid.serial, uid.serial, sizeof(uid.serial));
338 group->uid.ssid = uid.ssid;
339 if (uid.type == UA_BASE_DEVICE)
340 group->uid.base_unit_addr = uid.real_unit_addr;
342 group->uid.base_unit_addr = uid.base_unit_addr;
343 memcpy(group->uid.vduit, uid.vduit, sizeof(uid.vduit));
344 INIT_LIST_HEAD(&group->group);
345 INIT_LIST_HEAD(&group->baselist);
346 INIT_LIST_HEAD(&group->aliaslist);
347 list_add(&group->group, &lcu->grouplist);
349 if (uid.type == UA_BASE_DEVICE)
350 list_move(&device->alias_list, &group->baselist);
352 list_move(&device->alias_list, &group->aliaslist);
353 private->pavgroup = group;
357 static void _remove_device_from_lcu(struct alias_lcu *lcu,
358 struct dasd_device *device)
360 struct dasd_eckd_private *private = device->private;
361 struct alias_pav_group *group;
363 list_move(&device->alias_list, &lcu->inactive_devices);
364 group = private->pavgroup;
367 private->pavgroup = NULL;
368 if (list_empty(&group->baselist) && list_empty(&group->aliaslist)) {
369 list_del(&group->group);
373 if (group->next == device)
378 suborder_not_supported(struct dasd_ccw_req *cqr)
386 * intrc values ENODEV, ENOLINK and EPERM
387 * will be optained from sleep_on to indicate that no
388 * IO operation can be started
390 if (cqr->intrc == -ENODEV)
393 if (cqr->intrc == -ENOLINK)
396 if (cqr->intrc == -EPERM)
399 sense = dasd_get_sense(&cqr->irb);
404 msg_format = (sense[7] & 0xF0);
405 msg_no = (sense[7] & 0x0F);
407 /* command reject, Format 0 MSG 4 - invalid parameter */
408 if ((reason == 0x80) && (msg_format == 0x00) && (msg_no == 0x04))
414 static int read_unit_address_configuration(struct dasd_device *device,
415 struct alias_lcu *lcu)
417 struct dasd_psf_prssd_data *prssdp;
418 struct dasd_ccw_req *cqr;
423 cqr = dasd_kmalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ + 1 /* RSSD */,
424 (sizeof(struct dasd_psf_prssd_data)),
428 cqr->startdev = device;
429 cqr->memdev = device;
430 clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
432 cqr->expires = 20 * HZ;
434 /* Prepare for Read Subsystem Data */
435 prssdp = (struct dasd_psf_prssd_data *) cqr->data;
436 memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
437 prssdp->order = PSF_ORDER_PRSSD;
438 prssdp->suborder = 0x0e; /* Read unit address configuration */
439 /* all other bytes of prssdp must be zero */
442 ccw->cmd_code = DASD_ECKD_CCW_PSF;
443 ccw->count = sizeof(struct dasd_psf_prssd_data);
444 ccw->flags |= CCW_FLAG_CC;
445 ccw->cda = (__u32)(addr_t) prssdp;
447 /* Read Subsystem Data - feature codes */
448 memset(lcu->uac, 0, sizeof(*(lcu->uac)));
451 ccw->cmd_code = DASD_ECKD_CCW_RSSD;
452 ccw->count = sizeof(*(lcu->uac));
453 ccw->cda = (__u32)(addr_t) lcu->uac;
455 cqr->buildclk = get_tod_clock();
456 cqr->status = DASD_CQR_FILLED;
458 /* need to unset flag here to detect race with summary unit check */
459 spin_lock_irqsave(&lcu->lock, flags);
460 lcu->flags &= ~NEED_UAC_UPDATE;
461 spin_unlock_irqrestore(&lcu->lock, flags);
463 rc = dasd_sleep_on(cqr);
467 if (suborder_not_supported(cqr)) {
468 /* suborder not supported or device unusable for IO */
471 /* IO failed but should be retried */
472 spin_lock_irqsave(&lcu->lock, flags);
473 lcu->flags |= NEED_UAC_UPDATE;
474 spin_unlock_irqrestore(&lcu->lock, flags);
477 dasd_kfree_request(cqr, cqr->memdev);
481 static int _lcu_update(struct dasd_device *refdev, struct alias_lcu *lcu)
484 struct alias_pav_group *pavgroup, *tempgroup;
485 struct dasd_device *device, *tempdev;
487 struct dasd_eckd_private *private;
489 spin_lock_irqsave(&lcu->lock, flags);
490 list_for_each_entry_safe(pavgroup, tempgroup, &lcu->grouplist, group) {
491 list_for_each_entry_safe(device, tempdev, &pavgroup->baselist,
493 list_move(&device->alias_list, &lcu->active_devices);
494 private = device->private;
495 private->pavgroup = NULL;
497 list_for_each_entry_safe(device, tempdev, &pavgroup->aliaslist,
499 list_move(&device->alias_list, &lcu->active_devices);
500 private = device->private;
501 private->pavgroup = NULL;
503 list_del(&pavgroup->group);
506 spin_unlock_irqrestore(&lcu->lock, flags);
508 rc = read_unit_address_configuration(refdev, lcu);
512 spin_lock_irqsave(&lcu->lock, flags);
514 * there is another update needed skip the remaining handling
515 * the data might already be outdated
516 * but especially do not add the device to an LCU with pending
519 if (lcu->flags & NEED_UAC_UPDATE)
522 for (i = 0; i < MAX_DEVICES_PER_LCU; ++i) {
523 switch (lcu->uac->unit[i].ua_type) {
524 case UA_BASE_PAV_ALIAS:
527 case UA_HYPER_PAV_ALIAS:
528 lcu->pav = HYPER_PAV;
531 if (lcu->pav != NO_PAV)
535 list_for_each_entry_safe(device, tempdev, &lcu->active_devices,
537 _add_device_to_lcu(lcu, device, refdev);
540 spin_unlock_irqrestore(&lcu->lock, flags);
544 static void lcu_update_work(struct work_struct *work)
546 struct alias_lcu *lcu;
547 struct read_uac_work_data *ruac_data;
548 struct dasd_device *device;
552 ruac_data = container_of(work, struct read_uac_work_data, dwork.work);
553 lcu = container_of(ruac_data, struct alias_lcu, ruac_data);
554 device = ruac_data->device;
555 rc = _lcu_update(device, lcu);
557 * Need to check flags again, as there could have been another
558 * prepare_update or a new device a new device while we were still
559 * processing the data
561 spin_lock_irqsave(&lcu->lock, flags);
562 if ((rc && (rc != -EOPNOTSUPP)) || (lcu->flags & NEED_UAC_UPDATE)) {
563 DBF_DEV_EVENT(DBF_WARNING, device, "could not update"
564 " alias data in lcu (rc = %d), retry later", rc);
565 if (!schedule_delayed_work(&lcu->ruac_data.dwork, 30*HZ))
566 dasd_put_device(device);
568 dasd_put_device(device);
569 lcu->ruac_data.device = NULL;
570 lcu->flags &= ~UPDATE_PENDING;
572 spin_unlock_irqrestore(&lcu->lock, flags);
575 static int _schedule_lcu_update(struct alias_lcu *lcu,
576 struct dasd_device *device)
578 struct dasd_device *usedev = NULL;
579 struct alias_pav_group *group;
581 lcu->flags |= NEED_UAC_UPDATE;
582 if (lcu->ruac_data.device) {
583 /* already scheduled or running */
586 if (device && !list_empty(&device->alias_list))
589 if (!usedev && !list_empty(&lcu->grouplist)) {
590 group = list_first_entry(&lcu->grouplist,
591 struct alias_pav_group, group);
592 if (!list_empty(&group->baselist))
593 usedev = list_first_entry(&group->baselist,
596 else if (!list_empty(&group->aliaslist))
597 usedev = list_first_entry(&group->aliaslist,
601 if (!usedev && !list_empty(&lcu->active_devices)) {
602 usedev = list_first_entry(&lcu->active_devices,
603 struct dasd_device, alias_list);
606 * if we haven't found a proper device yet, give up for now, the next
607 * device that will be set active will trigger an lcu update
611 dasd_get_device(usedev);
612 lcu->ruac_data.device = usedev;
613 if (!schedule_delayed_work(&lcu->ruac_data.dwork, 0))
614 dasd_put_device(usedev);
618 int dasd_alias_add_device(struct dasd_device *device)
620 struct dasd_eckd_private *private = device->private;
621 __u8 uaddr = private->uid.real_unit_addr;
622 struct alias_lcu *lcu = private->lcu;
627 spin_lock_irqsave(&lcu->lock, flags);
629 * Check if device and lcu type differ. If so, the uac data may be
630 * outdated and needs to be updated.
632 if (private->uid.type != lcu->uac->unit[uaddr].ua_type) {
633 lcu->flags |= UPDATE_PENDING;
634 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
635 "uid type mismatch - trigger rescan");
637 if (!(lcu->flags & UPDATE_PENDING)) {
638 rc = _add_device_to_lcu(lcu, device, device);
640 lcu->flags |= UPDATE_PENDING;
642 if (lcu->flags & UPDATE_PENDING) {
643 list_move(&device->alias_list, &lcu->active_devices);
644 private->pavgroup = NULL;
645 _schedule_lcu_update(lcu, device);
647 spin_unlock_irqrestore(&lcu->lock, flags);
651 int dasd_alias_update_add_device(struct dasd_device *device)
653 struct dasd_eckd_private *private = device->private;
655 private->lcu->flags |= UPDATE_PENDING;
656 return dasd_alias_add_device(device);
659 int dasd_alias_remove_device(struct dasd_device *device)
661 struct dasd_eckd_private *private = device->private;
662 struct alias_lcu *lcu = private->lcu;
665 /* nothing to do if already removed */
668 spin_lock_irqsave(&lcu->lock, flags);
669 _remove_device_from_lcu(lcu, device);
670 spin_unlock_irqrestore(&lcu->lock, flags);
674 struct dasd_device *dasd_alias_get_start_dev(struct dasd_device *base_device)
676 struct dasd_eckd_private *alias_priv, *private = base_device->private;
677 struct alias_pav_group *group = private->pavgroup;
678 struct alias_lcu *lcu = private->lcu;
679 struct dasd_device *alias_device;
684 if (lcu->pav == NO_PAV ||
685 lcu->flags & (NEED_UAC_UPDATE | UPDATE_PENDING))
687 if (unlikely(!(private->features.feature[8] & 0x01))) {
689 * PAV enabled but prefix not, very unlikely
690 * seems to be a lost pathgroup
691 * use base device to do IO
693 DBF_DEV_EVENT(DBF_ERR, base_device, "%s",
694 "Prefix not enabled with PAV enabled\n");
698 spin_lock_irqsave(&lcu->lock, flags);
699 alias_device = group->next;
701 if (list_empty(&group->aliaslist)) {
702 spin_unlock_irqrestore(&lcu->lock, flags);
705 alias_device = list_first_entry(&group->aliaslist,
710 if (list_is_last(&alias_device->alias_list, &group->aliaslist))
711 group->next = list_first_entry(&group->aliaslist,
712 struct dasd_device, alias_list);
714 group->next = list_first_entry(&alias_device->alias_list,
715 struct dasd_device, alias_list);
716 spin_unlock_irqrestore(&lcu->lock, flags);
717 alias_priv = alias_device->private;
718 if ((alias_priv->count < private->count) && !alias_device->stopped &&
719 !test_bit(DASD_FLAG_OFFLINE, &alias_device->flags))
726 * Summary unit check handling depends on the way alias devices
727 * are handled so it is done here rather then in dasd_eckd.c
729 static int reset_summary_unit_check(struct alias_lcu *lcu,
730 struct dasd_device *device,
733 struct dasd_ccw_req *cqr;
738 strncpy((char *) &cqr->magic, "ECKD", 4);
739 ASCEBC((char *) &cqr->magic, 4);
741 ccw->cmd_code = DASD_ECKD_CCW_RSCK;
742 ccw->flags = CCW_FLAG_SLI;
744 ccw->cda = (__u32)(addr_t) cqr->data;
745 ((char *)cqr->data)[0] = reason;
747 clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
748 cqr->retries = 255; /* set retry counter to enable basic ERP */
749 cqr->startdev = device;
750 cqr->memdev = device;
752 cqr->expires = 5 * HZ;
753 cqr->buildclk = get_tod_clock();
754 cqr->status = DASD_CQR_FILLED;
756 rc = dasd_sleep_on_immediatly(cqr);
760 static void _restart_all_base_devices_on_lcu(struct alias_lcu *lcu)
762 struct alias_pav_group *pavgroup;
763 struct dasd_device *device;
764 struct dasd_eckd_private *private;
766 /* active and inactive list can contain alias as well as base devices */
767 list_for_each_entry(device, &lcu->active_devices, alias_list) {
768 private = device->private;
769 if (private->uid.type != UA_BASE_DEVICE)
771 dasd_schedule_block_bh(device->block);
772 dasd_schedule_device_bh(device);
774 list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
775 private = device->private;
776 if (private->uid.type != UA_BASE_DEVICE)
778 dasd_schedule_block_bh(device->block);
779 dasd_schedule_device_bh(device);
781 list_for_each_entry(pavgroup, &lcu->grouplist, group) {
782 list_for_each_entry(device, &pavgroup->baselist, alias_list) {
783 dasd_schedule_block_bh(device->block);
784 dasd_schedule_device_bh(device);
789 static void flush_all_alias_devices_on_lcu(struct alias_lcu *lcu)
791 struct alias_pav_group *pavgroup;
792 struct dasd_device *device, *temp;
793 struct dasd_eckd_private *private;
799 * Problem here ist that dasd_flush_device_queue may wait
800 * for termination of a request to complete. We can't keep
801 * the lcu lock during that time, so we must assume that
802 * the lists may have changed.
803 * Idea: first gather all active alias devices in a separate list,
804 * then flush the first element of this list unlocked, and afterwards
805 * check if it is still on the list before moving it to the
806 * active_devices list.
809 spin_lock_irqsave(&lcu->lock, flags);
810 list_for_each_entry_safe(device, temp, &lcu->active_devices,
812 private = device->private;
813 if (private->uid.type == UA_BASE_DEVICE)
815 list_move(&device->alias_list, &active);
818 list_for_each_entry(pavgroup, &lcu->grouplist, group) {
819 list_splice_init(&pavgroup->aliaslist, &active);
821 while (!list_empty(&active)) {
822 device = list_first_entry(&active, struct dasd_device,
824 spin_unlock_irqrestore(&lcu->lock, flags);
825 rc = dasd_flush_device_queue(device);
826 spin_lock_irqsave(&lcu->lock, flags);
828 * only move device around if it wasn't moved away while we
829 * were waiting for the flush
831 if (device == list_first_entry(&active,
832 struct dasd_device, alias_list)) {
833 list_move(&device->alias_list, &lcu->active_devices);
834 private = device->private;
835 private->pavgroup = NULL;
838 spin_unlock_irqrestore(&lcu->lock, flags);
841 static void _stop_all_devices_on_lcu(struct alias_lcu *lcu)
843 struct alias_pav_group *pavgroup;
844 struct dasd_device *device;
846 list_for_each_entry(device, &lcu->active_devices, alias_list) {
847 spin_lock(get_ccwdev_lock(device->cdev));
848 dasd_device_set_stop_bits(device, DASD_STOPPED_SU);
849 spin_unlock(get_ccwdev_lock(device->cdev));
851 list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
852 spin_lock(get_ccwdev_lock(device->cdev));
853 dasd_device_set_stop_bits(device, DASD_STOPPED_SU);
854 spin_unlock(get_ccwdev_lock(device->cdev));
856 list_for_each_entry(pavgroup, &lcu->grouplist, group) {
857 list_for_each_entry(device, &pavgroup->baselist, alias_list) {
858 spin_lock(get_ccwdev_lock(device->cdev));
859 dasd_device_set_stop_bits(device, DASD_STOPPED_SU);
860 spin_unlock(get_ccwdev_lock(device->cdev));
862 list_for_each_entry(device, &pavgroup->aliaslist, alias_list) {
863 spin_lock(get_ccwdev_lock(device->cdev));
864 dasd_device_set_stop_bits(device, DASD_STOPPED_SU);
865 spin_unlock(get_ccwdev_lock(device->cdev));
870 static void _unstop_all_devices_on_lcu(struct alias_lcu *lcu)
872 struct alias_pav_group *pavgroup;
873 struct dasd_device *device;
875 list_for_each_entry(device, &lcu->active_devices, alias_list) {
876 spin_lock(get_ccwdev_lock(device->cdev));
877 dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
878 spin_unlock(get_ccwdev_lock(device->cdev));
880 list_for_each_entry(device, &lcu->inactive_devices, alias_list) {
881 spin_lock(get_ccwdev_lock(device->cdev));
882 dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
883 spin_unlock(get_ccwdev_lock(device->cdev));
885 list_for_each_entry(pavgroup, &lcu->grouplist, group) {
886 list_for_each_entry(device, &pavgroup->baselist, alias_list) {
887 spin_lock(get_ccwdev_lock(device->cdev));
888 dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
889 spin_unlock(get_ccwdev_lock(device->cdev));
891 list_for_each_entry(device, &pavgroup->aliaslist, alias_list) {
892 spin_lock(get_ccwdev_lock(device->cdev));
893 dasd_device_remove_stop_bits(device, DASD_STOPPED_SU);
894 spin_unlock(get_ccwdev_lock(device->cdev));
899 static void summary_unit_check_handling_work(struct work_struct *work)
901 struct alias_lcu *lcu;
902 struct summary_unit_check_work_data *suc_data;
904 struct dasd_device *device;
906 suc_data = container_of(work, struct summary_unit_check_work_data,
908 lcu = container_of(suc_data, struct alias_lcu, suc_data);
909 device = suc_data->device;
911 /* 1. flush alias devices */
912 flush_all_alias_devices_on_lcu(lcu);
914 /* 2. reset summary unit check */
915 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
916 dasd_device_remove_stop_bits(device,
917 (DASD_STOPPED_SU | DASD_STOPPED_PENDING));
918 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
919 reset_summary_unit_check(lcu, device, suc_data->reason);
921 spin_lock_irqsave(&lcu->lock, flags);
922 _unstop_all_devices_on_lcu(lcu);
923 _restart_all_base_devices_on_lcu(lcu);
924 /* 3. read new alias configuration */
925 _schedule_lcu_update(lcu, device);
926 lcu->suc_data.device = NULL;
927 dasd_put_device(device);
928 spin_unlock_irqrestore(&lcu->lock, flags);
931 void dasd_alias_handle_summary_unit_check(struct work_struct *work)
933 struct dasd_device *device = container_of(work, struct dasd_device,
935 struct dasd_eckd_private *private = device->private;
936 struct alias_lcu *lcu;
941 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
942 "device not ready to handle summary"
943 " unit check (no lcu structure)");
946 spin_lock_irqsave(&lcu->lock, flags);
947 /* If this device is about to be removed just return and wait for
948 * the next interrupt on a different device
950 if (list_empty(&device->alias_list)) {
951 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
952 "device is in offline processing,"
953 " don't do summary unit check handling");
956 if (lcu->suc_data.device) {
957 /* already scheduled or running */
958 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
959 "previous instance of summary unit check worker"
963 _stop_all_devices_on_lcu(lcu);
964 /* prepare for lcu_update */
965 lcu->flags |= NEED_UAC_UPDATE | UPDATE_PENDING;
966 lcu->suc_data.reason = private->suc_reason;
967 lcu->suc_data.device = device;
968 dasd_get_device(device);
969 if (!schedule_work(&lcu->suc_data.worker))
970 dasd_put_device(device);
972 spin_unlock_irqrestore(&lcu->lock, flags);
974 clear_bit(DASD_FLAG_SUC, &device->flags);
975 dasd_put_device(device);