diff options
Diffstat (limited to 'drivers/s390/block/dasd_eckd.c')
| -rw-r--r-- | drivers/s390/block/dasd_eckd.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c index c8a226f070fa..d4d3bd33553b 100644 --- a/drivers/s390/block/dasd_eckd.c +++ b/drivers/s390/block/dasd_eckd.c @@ -6119,6 +6119,99 @@ static int dasd_hosts_print(struct dasd_device *device, struct seq_file *m) return 0; } +static struct dasd_device +*copy_relation_find_device(struct dasd_copy_relation *copy, + char *busid) +{ + int i; + + for (i = 0; i < DASD_CP_ENTRIES; i++) { + if (copy->entry[i].configured && + strncmp(copy->entry[i].busid, busid, DASD_BUS_ID_SIZE) == 0) + return copy->entry[i].device; + } + return NULL; +} + +/* + * set the new active/primary device + */ +static void copy_pair_set_active(struct dasd_copy_relation *copy, char *new_busid, + char *old_busid) +{ + int i; + + for (i = 0; i < DASD_CP_ENTRIES; i++) { + if (copy->entry[i].configured && + strncmp(copy->entry[i].busid, new_busid, + DASD_BUS_ID_SIZE) == 0) { + copy->active = ©->entry[i]; + copy->entry[i].primary = true; + } else if (copy->entry[i].configured && + strncmp(copy->entry[i].busid, old_busid, + DASD_BUS_ID_SIZE) == 0) { + copy->entry[i].primary = false; + } + } +} + +/* + * The function will swap the role of a given copy pair. + * During the swap operation the relation of the blockdevice is disconnected + * from the old primary and connected to the new. + * + * IO is paused on the block queue before swap and may be resumed afterwards. + */ +static int dasd_eckd_copy_pair_swap(struct dasd_device *device, char *prim_busid, + char *sec_busid) +{ + struct dasd_device *primary, *secondary; + struct dasd_copy_relation *copy; + struct dasd_block *block; + struct gendisk *gdp; + + copy = device->copy; + if (!copy) + return DASD_COPYPAIRSWAP_INVALID; + primary = copy->active->device; + if (!primary) + return DASD_COPYPAIRSWAP_INVALID; + /* double check if swap has correct primary */ + if (strncmp(dev_name(&primary->cdev->dev), prim_busid, DASD_BUS_ID_SIZE) != 0) + return DASD_COPYPAIRSWAP_PRIMARY; + + secondary = copy_relation_find_device(copy, sec_busid); + if (!secondary) + return DASD_COPYPAIRSWAP_SECONDARY; + + /* + * usually the device should be quiesced for swap + * for paranoia stop device and requeue requests again + */ + dasd_device_set_stop_bits(primary, DASD_STOPPED_PPRC); + dasd_device_set_stop_bits(secondary, DASD_STOPPED_PPRC); + dasd_generic_requeue_all_requests(primary); + + /* swap DASD internal device <> block assignment */ + block = primary->block; + primary->block = NULL; + secondary->block = block; + block->base = secondary; + /* set new primary device in COPY relation */ + copy_pair_set_active(copy, sec_busid, prim_busid); + + /* swap blocklayer device link */ + gdp = block->gdp; + dasd_add_link_to_gendisk(gdp, secondary); + + /* re-enable device */ + dasd_device_remove_stop_bits(primary, DASD_STOPPED_PPRC); + dasd_device_remove_stop_bits(secondary, DASD_STOPPED_PPRC); + dasd_schedule_device_bh(secondary); + + return DASD_COPYPAIRSWAP_SUCCESS; +} + /* * Perform Subsystem Function - Peer-to-Peer Remote Copy Extended Query */ @@ -6805,6 +6898,7 @@ static struct dasd_discipline dasd_eckd_discipline = { .ese_read = dasd_eckd_ese_read, .pprc_status = dasd_eckd_query_pprc_status, .pprc_enabled = dasd_eckd_pprc_enabled, + .copy_pair_swap = dasd_eckd_copy_pair_swap, }; static int __init |