On Mon, 2015-03-30 at 11:11 +0300, Sagi Grimberg wrote:
> On 3/30/2015 6:28 AM, Nicholas A. Bellinger wrote:
> > From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
> >
> > This patch updates iscsi/iser-target to add a new fabric_prot_type
> > TPG attribute for iser-target, used for controlling LLD level
> > protection into LIO when the backend device does not support T10-PI.
> >
> > This is required for ib_isert to enable WRITE_STRIP + READ_INSERT
> > hardware offloads.
> >
> > It's disabled by default and controls which se_sesion->sess_prot_type
> > are set at iscsi_target_locate_portal() session registration time.
> >
> > Cc: Sagi Grimberg <sagig@xxxxxxxxxxxx>
> > Cc: Martin Petersen <martin.petersen@xxxxxxxxxx>
> > Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
> > ---
> > drivers/target/iscsi/iscsi_target_configfs.c | 22 ++++++++++++++++++++++
> > drivers/target/iscsi/iscsi_target_tpg.c | 19 +++++++++++++++++++
> > drivers/target/iscsi/iscsi_target_tpg.h | 1 +
> > include/target/iscsi/iscsi_target_core.h | 2 ++
> > 4 files changed, 44 insertions(+)
> >
> > diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configfs.c
> > index 95a67f6..9cb5ab4 100644
> > --- a/drivers/target/iscsi/iscsi_target_configfs.c
> > +++ b/drivers/target/iscsi/iscsi_target_configfs.c
> > @@ -1052,6 +1052,11 @@ TPG_ATTR(default_erl, S_IRUGO | S_IWUSR);
> > */
> > DEF_TPG_ATTRIB(t10_pi);
> > TPG_ATTR(t10_pi, S_IRUGO | S_IWUSR);
> > +/*
> > + * Define iscsi_tpg_attrib_s_fabric_prot_type
> > + */
> > +DEF_TPG_ATTRIB(fabric_prot_type);
> > +TPG_ATTR(fabric_prot_type, S_IRUGO | S_IWUSR);
> >
> > static struct configfs_attribute *lio_target_tpg_attrib_attrs[] = {
> > &iscsi_tpg_attrib_authentication.attr,
> > @@ -1065,6 +1070,7 @@ static struct configfs_attribute *lio_target_tpg_attrib_attrs[] = {
> > &iscsi_tpg_attrib_demo_mode_discovery.attr,
> > &iscsi_tpg_attrib_default_erl.attr,
> > &iscsi_tpg_attrib_t10_pi.attr,
> > + &iscsi_tpg_attrib_fabric_prot_type.attr,
> > NULL,
> > };
> >
> > @@ -1882,6 +1888,20 @@ static int lio_tpg_check_prod_mode_write_protect(
> > return tpg->tpg_attrib.prod_mode_write_protect;
> > }
> >
> > +static int lio_tpg_check_prot_fabric_only(
> > + struct se_portal_group *se_tpg)
> > +{
> > + struct iscsi_portal_group *tpg = se_tpg->se_tpg_fabric_ptr;
> > + /*
> > + * Only report fabric_prot_type if t10_pi has also been enabled
> > + * for incoming ib_isert sessions.
> > + */
> > + if (!tpg->tpg_attrib.t10_pi)
> > + return 0;
> > +
> > + return tpg->tpg_attrib.fabric_prot_type;
> > +}
> > +
> > static void lio_tpg_release_fabric_acl(
> > struct se_portal_group *se_tpg,
> > struct se_node_acl *se_acl)
> > @@ -1997,6 +2017,8 @@ int iscsi_target_register_configfs(void)
> > &lio_tpg_check_demo_mode_write_protect;
> > fabric->tf_ops.tpg_check_prod_mode_write_protect =
> > &lio_tpg_check_prod_mode_write_protect;
> > + fabric->tf_ops.tpg_check_prot_fabric_only =
> > + &lio_tpg_check_prot_fabric_only;
> > fabric->tf_ops.tpg_alloc_fabric_acl = &lio_tpg_alloc_fabric_acl;
> > fabric->tf_ops.tpg_release_fabric_acl = &lio_tpg_release_fabric_acl;
> > fabric->tf_ops.tpg_get_inst_index = &lio_tpg_get_inst_index;
> > diff --git a/drivers/target/iscsi/iscsi_target_tpg.c b/drivers/target/iscsi/iscsi_target_tpg.c
> > index bdd127c..3076e6f 100644
> > --- a/drivers/target/iscsi/iscsi_target_tpg.c
> > +++ b/drivers/target/iscsi/iscsi_target_tpg.c
> > @@ -228,6 +228,7 @@ static void iscsit_set_default_tpg_attribs(struct iscsi_portal_group *tpg)
> > a->demo_mode_discovery = TA_DEMO_MODE_DISCOVERY;
> > a->default_erl = TA_DEFAULT_ERL;
> > a->t10_pi = TA_DEFAULT_T10_PI;
> > + a->fabric_prot_type = TA_DEFAULT_FABRIC_PROT_TYPE;
> > }
> >
> > int iscsit_tpg_add_portal_group(struct iscsi_tiqn *tiqn, struct iscsi_portal_group *tpg)
> > @@ -878,3 +879,21 @@ int iscsit_ta_t10_pi(
> >
> > return 0;
> > }
> > +
> > +int iscsit_ta_fabric_prot_type(
> > + struct iscsi_portal_group *tpg,
> > + u32 prot_type)
> > +{
> > + struct iscsi_tpg_attrib *a = &tpg->tpg_attrib;
> > +
> > + if ((prot_type != 0) && (prot_type != 1) && (prot_type != 3)) {
> > + pr_err("Illegal value for fabric_prot_type: %u\n", prot_type);
> > + return -EINVAL;
> > + }
> > +
> > + a->fabric_prot_type = prot_type;
> > + pr_debug("iSCSI_TPG[%hu] - T10 Fabric Protection Type: %u\n",
> > + tpg->tpgt, prot_type);
>
> I wander what will happen if this is modified on the fly with active
> sessions, LUNs, IO...
>
> Should we restrict this to be modified only offline (no active
> sessions)?
Absolutely.
The tpg_check_prot_fabric_only() assignment of sess->sess_prot_type
is restricted to session creation time in __transport_register_session()
code, and changing of the value does not effect existing sessions.
--nab
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