On 12/17/2013 09:49 PM, Nicholas A. Bellinger wrote: > On Tue, 2013-12-17 at 09:18 +0100, Hannes Reinecke wrote: >> Referrals need an LBA map, which needs to be kept >> consistent across all target port groups. So >> instead of tying the map to the target port groups >> I've implemented a single attribute containing the >> entire map. >> >> Signed-off-by: Hannes Reinecke <[email protected]> >> --- >> drivers/target/target_core_alua.c | 101 +++++++++++++++++++ >> drivers/target/target_core_alua.h | 8 ++ >> drivers/target/target_core_configfs.c | 171 >> +++++++++++++++++++++++++++++++++ >> drivers/target/target_core_device.c | 1 + >> drivers/target/target_core_transport.c | 28 +++++- >> 5 files changed, 308 insertions(+), 1 deletion(-) >> > > Applied, with one comment below.. > > <SNIP> > >> diff --git a/drivers/target/target_core_configfs.c >> b/drivers/target/target_core_configfs.c >> index e74ef8c..1dbc1bc 100644 >> --- a/drivers/target/target_core_configfs.c >> +++ b/drivers/target/target_core_configfs.c >> @@ -1741,6 +1741,176 @@ static struct target_core_configfs_attribute >> target_core_attr_dev_alua_lu_gp = { >> .store = target_core_store_alua_lu_gp, >> }; >> >> +static ssize_t target_core_show_dev_lba_map(void *p, char *page) >> +{ >> + struct se_device *dev = p; >> + struct t10_alua_lba_map *map; >> + struct t10_alua_lba_map_member *mem; >> + char *b = page; >> + int bl = 0; >> + char state; >> + >> + spin_lock(&dev->t10_alua.lba_map_lock); >> + if (!list_empty(&dev->t10_alua.lba_map_list)) >> + bl += sprintf(b + bl, "%u %u\n", >> + dev->t10_alua.lba_map_segment_size, >> + dev->t10_alua.lba_map_segment_multiplier); >> + list_for_each_entry(map, &dev->t10_alua.lba_map_list, lba_map_list) { >> + bl += sprintf(b + bl, "%llu %llu", >> + map->lba_map_first_lba, map->lba_map_last_lba); >> + list_for_each_entry(mem, &map->lba_map_mem_list, >> + lba_map_mem_list) { >> + switch (mem->lba_map_mem_alua_state) { >> + case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED: >> + state = 'O'; >> + break; >> + case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED: >> + state = 'A'; >> + break; >> + case ALUA_ACCESS_STATE_STANDBY: >> + state = 'S'; >> + break; >> + case ALUA_ACCESS_STATE_UNAVAILABLE: >> + state = 'U'; >> + break; >> + default: >> + state = '.'; >> + break; >> + } >> + bl += sprintf(b + bl, " %d:%c", >> + mem->lba_map_mem_alua_pg_id, state); >> + } >> + bl += sprintf(b + bl, "\n"); >> + } >> + spin_unlock(&dev->t10_alua.lba_map_lock); > > The above loop can possibly overflow the passed *page.. > No. This is the reverse operation to the constructor in target_core_store_dev_lba_map().
Which (per definition) can only handle maps up to one page in size. And hence the resulting (formatted) map as constructed by target_core_show_dev_lba_map() will also fit on one page. > Care to send an incremental patch for this as well..? > > Btw, I assume this is not the only method for extracting the LBA map > from a running system, right..? > Of course you can run 'sg_referrals' here. But other than that it would be the only method. Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage [email protected] +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
