From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH 8/8] target_core_alua: Referrals configfs integration Date: Wed, 18 Dec 2013 09:15:21 +0100 Message-ID: <52B15999.9090207@suse.de> References: <1387268330-121064-1-git-send-email-hare@suse.de> <1387268330-121064-9-git-send-email-hare@suse.de> <1387313347.20247.316.camel@haakon3.risingtidesystems.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1387313347.20247.316.camel@haakon3.risingtidesystems.com> Sender: target-devel-owner@vger.kernel.org To: "Nicholas A. Bellinger" Cc: Nic Bellinger , target-devel@vger.kernel.org, linux-scsi@vger.kernel.org List-Id: linux-scsi@vger.kernel.org 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 >> --- >> 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(-) >> >=20 > Applied, with one comment below.. >=20 > >=20 >> 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 =3D { >> .store =3D target_core_store_alua_lu_gp, >> }; >> =20 >> +static ssize_t target_core_show_dev_lba_map(void *p, char *page) >> +{ >> + struct se_device *dev =3D p; >> + struct t10_alua_lba_map *map; >> + struct t10_alua_lba_map_member *mem; >> + char *b =3D page; >> + int bl =3D 0; >> + char state; >> + >> + spin_lock(&dev->t10_alua.lba_map_lock); >> + if (!list_empty(&dev->t10_alua.lba_map_list)) >> + bl +=3D 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 +=3D 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 =3D 'O'; >> + break; >> + case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED: >> + state =3D 'A'; >> + break; >> + case ALUA_ACCESS_STATE_STANDBY: >> + state =3D 'S'; >> + break; >> + case ALUA_ACCESS_STATE_UNAVAILABLE: >> + state =3D 'U'; >> + break; >> + default: >> + state =3D '.'; >> + break; >> + } >> + bl +=3D sprintf(b + bl, " %d:%c", >> + mem->lba_map_mem_alua_pg_id, state); >> + } >> + bl +=3D sprintf(b + bl, "\n"); >> + } >> + spin_unlock(&dev->t10_alua.lba_map_lock); >=20 > The above loop can possibly overflow the passed *page.. >=20 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..? >=20 > Btw, I assume this is not the only method for extracting the LBA map > from a running system, right..? >=20 Of course you can run 'sg_referrals' here. But other than that it would be the only method. Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=C3=BCrnberg GF: J. Hawn, J. Guild, F. Imend=C3=B6rffer, HRB 16746 (AG N=C3=BCrnberg= )