diff options
Diffstat (limited to 'drivers/s390/block/dasd_alias.c')
| -rw-r--r-- | drivers/s390/block/dasd_alias.c | 313 |
1 files changed, 189 insertions, 124 deletions
diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c index 184b1dbeb554..17ad5749e91d 100644 --- a/drivers/s390/block/dasd_alias.c +++ b/drivers/s390/block/dasd_alias.c @@ -185,14 +185,12 @@ static void _free_lcu(struct alias_lcu *lcu) */ int dasd_alias_make_device_known_to_lcu(struct dasd_device *device) { - struct dasd_eckd_private *private; + struct dasd_eckd_private *private = device->private; unsigned long flags; struct alias_server *server, *newserver; struct alias_lcu *lcu, *newlcu; struct dasd_uid uid; - private = (struct dasd_eckd_private *) device->private; - device->discipline->get_uid(device, &uid); spin_lock_irqsave(&aliastree.lock, flags); server = _find_server(&uid); @@ -244,14 +242,13 @@ int dasd_alias_make_device_known_to_lcu(struct dasd_device *device) */ void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device) { - struct dasd_eckd_private *private; + struct dasd_eckd_private *private = device->private; unsigned long flags; struct alias_lcu *lcu; struct alias_server *server; int was_pending; struct dasd_uid uid; - private = (struct dasd_eckd_private *) device->private; lcu = private->lcu; /* nothing to do if already disconnected */ if (!lcu) @@ -264,8 +261,10 @@ void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device) spin_unlock_irqrestore(&lcu->lock, flags); cancel_work_sync(&lcu->suc_data.worker); spin_lock_irqsave(&lcu->lock, flags); - if (device == lcu->suc_data.device) + if (device == lcu->suc_data.device) { + dasd_put_device(device); lcu->suc_data.device = NULL; + } } was_pending = 0; if (device == lcu->ruac_data.device) { @@ -273,8 +272,10 @@ void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device) was_pending = 1; cancel_delayed_work_sync(&lcu->ruac_data.dwork); spin_lock_irqsave(&lcu->lock, flags); - if (device == lcu->ruac_data.device) + if (device == lcu->ruac_data.device) { + dasd_put_device(device); lcu->ruac_data.device = NULL; + } } private->lcu = NULL; spin_unlock_irqrestore(&lcu->lock, flags); @@ -312,25 +313,15 @@ static int _add_device_to_lcu(struct alias_lcu *lcu, struct dasd_device *pos) { - struct dasd_eckd_private *private; + struct dasd_eckd_private *private = device->private; struct alias_pav_group *group; struct dasd_uid uid; - unsigned long flags; - - private = (struct dasd_eckd_private *) device->private; - /* only lock if not already locked */ - if (device != pos) - spin_lock_irqsave_nested(get_ccwdev_lock(device->cdev), flags, - CDEV_NESTED_SECOND); private->uid.type = lcu->uac->unit[private->uid.real_unit_addr].ua_type; private->uid.base_unit_addr = lcu->uac->unit[private->uid.real_unit_addr].base_ua; uid = private->uid; - if (device != pos) - spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); - /* if we have no PAV anyway, we don't need to bother with PAV groups */ if (lcu->pav == NO_PAV) { list_move(&device->alias_list, &lcu->active_devices); @@ -366,10 +357,9 @@ static int _add_device_to_lcu(struct alias_lcu *lcu, static void _remove_device_from_lcu(struct alias_lcu *lcu, struct dasd_device *device) { - struct dasd_eckd_private *private; + struct dasd_eckd_private *private = device->private; struct alias_pav_group *group; - private = (struct dasd_eckd_private *) device->private; list_move(&device->alias_list, &lcu->inactive_devices); group = private->pavgroup; if (!group) @@ -407,6 +397,130 @@ suborder_not_supported(struct dasd_ccw_req *cqr) return 0; } +/* + * This function tries to lock all devices on an lcu via trylock + * return NULL on success otherwise return first failed device + */ +static struct dasd_device *_trylock_all_devices_on_lcu(struct alias_lcu *lcu, + struct dasd_device *pos) + +{ + struct alias_pav_group *pavgroup; + struct dasd_device *device; + + list_for_each_entry(device, &lcu->active_devices, alias_list) { + if (device == pos) + continue; + if (!spin_trylock(get_ccwdev_lock(device->cdev))) + return device; + } + list_for_each_entry(device, &lcu->inactive_devices, alias_list) { + if (device == pos) + continue; + if (!spin_trylock(get_ccwdev_lock(device->cdev))) + return device; + } + list_for_each_entry(pavgroup, &lcu->grouplist, group) { + list_for_each_entry(device, &pavgroup->baselist, alias_list) { + if (device == pos) + continue; + if (!spin_trylock(get_ccwdev_lock(device->cdev))) + return device; + } + list_for_each_entry(device, &pavgroup->aliaslist, alias_list) { + if (device == pos) + continue; + if (!spin_trylock(get_ccwdev_lock(device->cdev))) + return device; + } + } + return NULL; +} + +/* + * unlock all devices except the one that is specified as pos + * stop if enddev is specified and reached + */ +static void _unlock_all_devices_on_lcu(struct alias_lcu *lcu, + struct dasd_device *pos, + struct dasd_device *enddev) + +{ + struct alias_pav_group *pavgroup; + struct dasd_device *device; + + list_for_each_entry(device, &lcu->active_devices, alias_list) { + if (device == pos) + continue; + if (device == enddev) + return; + spin_unlock(get_ccwdev_lock(device->cdev)); + } + list_for_each_entry(device, &lcu->inactive_devices, alias_list) { + if (device == pos) + continue; + if (device == enddev) + return; + spin_unlock(get_ccwdev_lock(device->cdev)); + } + list_for_each_entry(pavgroup, &lcu->grouplist, group) { + list_for_each_entry(device, &pavgroup->baselist, alias_list) { + if (device == pos) + continue; + if (device == enddev) + return; + spin_unlock(get_ccwdev_lock(device->cdev)); + } + list_for_each_entry(device, &pavgroup->aliaslist, alias_list) { + if (device == pos) + continue; + if (device == enddev) + return; + spin_unlock(get_ccwdev_lock(device->cdev)); + } + } +} + +/* + * this function is needed because the locking order + * device lock -> lcu lock + * needs to be assured when iterating over devices in an LCU + * + * if a device is specified in pos then the device lock is already hold + */ +static void _trylock_and_lock_lcu_irqsave(struct alias_lcu *lcu, + struct dasd_device *pos, + unsigned long *flags) +{ + struct dasd_device *failed; + + do { + spin_lock_irqsave(&lcu->lock, *flags); + failed = _trylock_all_devices_on_lcu(lcu, pos); + if (failed) { + _unlock_all_devices_on_lcu(lcu, pos, failed); + spin_unlock_irqrestore(&lcu->lock, *flags); + cpu_relax(); + } + } while (failed); +} + +static void _trylock_and_lock_lcu(struct alias_lcu *lcu, + struct dasd_device *pos) +{ + struct dasd_device *failed; + + do { + spin_lock(&lcu->lock); + failed = _trylock_all_devices_on_lcu(lcu, pos); + if (failed) { + _unlock_all_devices_on_lcu(lcu, pos, failed); + spin_unlock(&lcu->lock); + cpu_relax(); + } + } while (failed); +} + static int read_unit_address_configuration(struct dasd_device *device, struct alias_lcu *lcu) { @@ -483,13 +597,13 @@ static int _lcu_update(struct dasd_device *refdev, struct alias_lcu *lcu) list_for_each_entry_safe(device, tempdev, &pavgroup->baselist, alias_list) { list_move(&device->alias_list, &lcu->active_devices); - private = (struct dasd_eckd_private *) device->private; + private = device->private; private->pavgroup = NULL; } list_for_each_entry_safe(device, tempdev, &pavgroup->aliaslist, alias_list) { list_move(&device->alias_list, &lcu->active_devices); - private = (struct dasd_eckd_private *) device->private; + private = device->private; private->pavgroup = NULL; } list_del(&pavgroup->group); @@ -501,10 +615,7 @@ static int _lcu_update(struct dasd_device *refdev, struct alias_lcu *lcu) if (rc) return rc; - /* need to take cdev lock before lcu lock */ - spin_lock_irqsave_nested(get_ccwdev_lock(refdev->cdev), flags, - CDEV_NESTED_FIRST); - spin_lock(&lcu->lock); + _trylock_and_lock_lcu_irqsave(lcu, NULL, &flags); lcu->pav = NO_PAV; for (i = 0; i < MAX_DEVICES_PER_LCU; ++i) { switch (lcu->uac->unit[i].ua_type) { @@ -523,8 +634,8 @@ static int _lcu_update(struct dasd_device *refdev, struct alias_lcu *lcu) alias_list) { _add_device_to_lcu(lcu, device, refdev); } - spin_unlock(&lcu->lock); - spin_unlock_irqrestore(get_ccwdev_lock(refdev->cdev), flags); + _unlock_all_devices_on_lcu(lcu, NULL, NULL); + spin_unlock_irqrestore(&lcu->lock, flags); return 0; } @@ -549,8 +660,10 @@ static void lcu_update_work(struct work_struct *work) if ((rc && (rc != -EOPNOTSUPP)) || (lcu->flags & NEED_UAC_UPDATE)) { DBF_DEV_EVENT(DBF_WARNING, device, "could not update" " alias data in lcu (rc = %d), retry later", rc); - schedule_delayed_work(&lcu->ruac_data.dwork, 30*HZ); + if (!schedule_delayed_work(&lcu->ruac_data.dwork, 30*HZ)) + dasd_put_device(device); } else { + dasd_put_device(device); lcu->ruac_data.device = NULL; lcu->flags &= ~UPDATE_PENDING; } @@ -593,23 +706,22 @@ static int _schedule_lcu_update(struct alias_lcu *lcu, */ if (!usedev) return -EINVAL; + dasd_get_device(usedev); lcu->ruac_data.device = usedev; - schedule_delayed_work(&lcu->ruac_data.dwork, 0); + if (!schedule_delayed_work(&lcu->ruac_data.dwork, 0)) + dasd_put_device(usedev); return 0; } int dasd_alias_add_device(struct dasd_device *device) { - struct dasd_eckd_private *private; + struct dasd_eckd_private *private = device->private; struct alias_lcu *lcu; unsigned long flags; int rc; - private = (struct dasd_eckd_private *) device->private; lcu = private->lcu; rc = 0; - - /* need to take cdev lock before lcu lock */ spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); spin_lock(&lcu->lock); if (!(lcu->flags & UPDATE_PENDING)) { @@ -628,20 +740,18 @@ int dasd_alias_add_device(struct dasd_device *device) int dasd_alias_update_add_device(struct dasd_device *device) { - struct dasd_eckd_private *private; - private = (struct dasd_eckd_private *) device->private; + struct dasd_eckd_private *private = device->private; + private->lcu->flags |= UPDATE_PENDING; return dasd_alias_add_device(device); } int dasd_alias_remove_device(struct dasd_device *device) { - struct dasd_eckd_private *private; - struct alias_lcu *lcu; + struct dasd_eckd_private *private = device->private; + struct alias_lcu *lcu = private->lcu; unsigned long flags; - private = (struct dasd_eckd_private *) device->private; - lcu = private->lcu; /* nothing to do if already removed */ if (!lcu) return 0; @@ -653,16 +763,12 @@ int dasd_alias_remove_device(struct dasd_device *device) struct dasd_device *dasd_alias_get_start_dev(struct dasd_device *base_device) { - + struct dasd_eckd_private *alias_priv, *private = base_device->private; + struct alias_pav_group *group = private->pavgroup; + struct alias_lcu *lcu = private->lcu; struct dasd_device *alias_device; - struct alias_pav_group *group; - struct alias_lcu *lcu; - struct dasd_eckd_private *private, *alias_priv; unsigned long flags; - private = (struct dasd_eckd_private *) base_device->private; - group = private->pavgroup; - lcu = private->lcu; if (!group || !lcu) return NULL; if (lcu->pav == NO_PAV || @@ -698,7 +804,7 @@ struct dasd_device *dasd_alias_get_start_dev(struct dasd_device *base_device) group->next = list_first_entry(&alias_device->alias_list, struct dasd_device, alias_list); spin_unlock_irqrestore(&lcu->lock, flags); - alias_priv = (struct dasd_eckd_private *) alias_device->private; + alias_priv = alias_device->private; if ((alias_priv->count < private->count) && !alias_device->stopped && !test_bit(DASD_FLAG_OFFLINE, &alias_device->flags)) return alias_device; @@ -723,7 +829,7 @@ static int reset_summary_unit_check(struct alias_lcu *lcu, ASCEBC((char *) &cqr->magic, 4); ccw = cqr->cpaddr; ccw->cmd_code = DASD_ECKD_CCW_RSCK; - ccw->flags = 0 ; + ccw->flags = CCW_FLAG_SLI; ccw->count = 16; ccw->cda = (__u32)(addr_t) cqr->data; ((char *)cqr->data)[0] = reason; @@ -746,30 +852,19 @@ static void _restart_all_base_devices_on_lcu(struct alias_lcu *lcu) struct alias_pav_group *pavgroup; struct dasd_device *device; struct dasd_eckd_private *private; - unsigned long flags; /* active and inactive list can contain alias as well as base devices */ list_for_each_entry(device, &lcu->active_devices, alias_list) { - private = (struct dasd_eckd_private *) device->private; - spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); - if (private->uid.type != UA_BASE_DEVICE) { - spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), - flags); + private = device->private; + if (private->uid.type != UA_BASE_DEVICE) continue; - } - spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); dasd_schedule_block_bh(device->block); dasd_schedule_device_bh(device); } list_for_each_entry(device, &lcu->inactive_devices, alias_list) { - private = (struct dasd_eckd_private *) device->private; - spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); - if (private->uid.type != UA_BASE_DEVICE) { - spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), - flags); + private = device->private; + if (private->uid.type != UA_BASE_DEVICE) continue; - } - spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); dasd_schedule_block_bh(device->block); dasd_schedule_device_bh(device); } @@ -804,7 +899,7 @@ static void flush_all_alias_devices_on_lcu(struct alias_lcu *lcu) spin_lock_irqsave(&lcu->lock, flags); list_for_each_entry_safe(device, temp, &lcu->active_devices, alias_list) { - private = (struct dasd_eckd_private *) device->private; + private = device->private; if (private->uid.type == UA_BASE_DEVICE) continue; list_move(&device->alias_list, &active); @@ -826,45 +921,27 @@ static void flush_all_alias_devices_on_lcu(struct alias_lcu *lcu) if (device == list_first_entry(&active, struct dasd_device, alias_list)) { list_move(&device->alias_list, &lcu->active_devices); - private = (struct dasd_eckd_private *) device->private; + private = device->private; private->pavgroup = NULL; } } spin_unlock_irqrestore(&lcu->lock, flags); } -static void __stop_device_on_lcu(struct dasd_device *device, - struct dasd_device *pos) -{ - /* If pos == device then device is already locked! */ - if (pos == device) { - dasd_device_set_stop_bits(pos, DASD_STOPPED_SU); - return; - } - spin_lock(get_ccwdev_lock(pos->cdev)); - dasd_device_set_stop_bits(pos, DASD_STOPPED_SU); - spin_unlock(get_ccwdev_lock(pos->cdev)); -} - -/* - * This function is called in interrupt context, so the - * cdev lock for device is already locked! - */ -static void _stop_all_devices_on_lcu(struct alias_lcu *lcu, - struct dasd_device *device) +static void _stop_all_devices_on_lcu(struct alias_lcu *lcu) { struct alias_pav_group *pavgroup; - struct dasd_device *pos; + struct dasd_device *device; - list_for_each_entry(pos, &lcu->active_devices, alias_list) - __stop_device_on_lcu(device, pos); - list_for_each_entry(pos, &lcu->inactive_devices, alias_list) - __stop_device_on_lcu(device, pos); + list_for_each_entry(device, &lcu->active_devices, alias_list) + dasd_device_set_stop_bits(device, DASD_STOPPED_SU); + list_for_each_entry(device, &lcu->inactive_devices, alias_list) + dasd_device_set_stop_bits(device, DASD_STOPPED_SU); list_for_each_entry(pavgroup, &lcu->grouplist, group) { - list_for_each_entry(pos, &pavgroup->baselist, alias_list) - __stop_device_on_lcu(device, pos); - list_for_each_entry(pos, &pavgroup->aliaslist, alias_list) - __stop_device_on_lcu(device, pos); + list_for_each_entry(device, &pavgroup->baselist, alias_list) + dasd_device_set_stop_bits(device, DASD_STOPPED_SU); + list_for_each_entry(device, &pavgroup->aliaslist, alias_list) + dasd_device_set_stop_bits(device, DASD_STOPPED_SU); } } @@ -872,33 +949,16 @@ static void _unstop_all_devices_on_lcu(struct alias_lcu *lcu) { struct alias_pav_group *pavgroup; struct dasd_device *device; - unsigned long flags; - list_for_each_entry(device, &lcu->active_devices, alias_list) { - spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + list_for_each_entry(device, &lcu->active_devices, alias_list) dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); - spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); - } - - list_for_each_entry(device, &lcu->inactive_devices, alias_list) { - spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + list_for_each_entry(device, &lcu->inactive_devices, alias_list) dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); - spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); - } - list_for_each_entry(pavgroup, &lcu->grouplist, group) { - list_for_each_entry(device, &pavgroup->baselist, alias_list) { - spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + list_for_each_entry(device, &pavgroup->baselist, alias_list) dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); - spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), - flags); - } - list_for_each_entry(device, &pavgroup->aliaslist, alias_list) { - spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + list_for_each_entry(device, &pavgroup->aliaslist, alias_list) dasd_device_remove_stop_bits(device, DASD_STOPPED_SU); - spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), - flags); - } } } @@ -924,12 +984,14 @@ static void summary_unit_check_handling_work(struct work_struct *work) spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); reset_summary_unit_check(lcu, device, suc_data->reason); - spin_lock_irqsave(&lcu->lock, flags); + _trylock_and_lock_lcu_irqsave(lcu, NULL, &flags); _unstop_all_devices_on_lcu(lcu); _restart_all_base_devices_on_lcu(lcu); /* 3. read new alias configuration */ _schedule_lcu_update(lcu, device); lcu->suc_data.device = NULL; + dasd_put_device(device); + _unlock_all_devices_on_lcu(lcu, NULL, NULL); spin_unlock_irqrestore(&lcu->lock, flags); } @@ -939,13 +1001,11 @@ static void summary_unit_check_handling_work(struct work_struct *work) void dasd_alias_handle_summary_unit_check(struct dasd_device *device, struct irb *irb) { + struct dasd_eckd_private *private = device->private; struct alias_lcu *lcu; char reason; - struct dasd_eckd_private *private; char *sense; - private = (struct dasd_eckd_private *) device->private; - sense = dasd_get_sense(irb); if (sense) { reason = sense[8]; @@ -965,10 +1025,7 @@ void dasd_alias_handle_summary_unit_check(struct dasd_device *device, " unit check (no lcu structure)"); return; } - spin_lock(&lcu->lock); - _stop_all_devices_on_lcu(lcu, device); - /* prepare for lcu_update */ - private->lcu->flags |= NEED_UAC_UPDATE | UPDATE_PENDING; + _trylock_and_lock_lcu(lcu, device); /* If this device is about to be removed just return and wait for * the next interrupt on a different device */ @@ -976,6 +1033,7 @@ void dasd_alias_handle_summary_unit_check(struct dasd_device *device, DBF_DEV_EVENT(DBF_WARNING, device, "%s", "device is in offline processing," " don't do summary unit check handling"); + _unlock_all_devices_on_lcu(lcu, device, NULL); spin_unlock(&lcu->lock); return; } @@ -984,11 +1042,18 @@ void dasd_alias_handle_summary_unit_check(struct dasd_device *device, DBF_DEV_EVENT(DBF_WARNING, device, "%s", "previous instance of summary unit check worker" " still pending"); + _unlock_all_devices_on_lcu(lcu, device, NULL); spin_unlock(&lcu->lock); return ; } + _stop_all_devices_on_lcu(lcu); + /* prepare for lcu_update */ + private->lcu->flags |= NEED_UAC_UPDATE | UPDATE_PENDING; lcu->suc_data.reason = reason; lcu->suc_data.device = device; + dasd_get_device(device); + _unlock_all_devices_on_lcu(lcu, device, NULL); spin_unlock(&lcu->lock); - schedule_work(&lcu->suc_data.worker); + if (!schedule_work(&lcu->suc_data.worker)) + dasd_put_device(device); }; |