From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch adds proper support for compatible reservation handling (CRH=1) as defined by
SPC-4 Section 15.7.3 'Exceptions to SPC-2 RESERVE and RELEASE behavior' in a new function
core_scsi2_emulate_crh(). This CRH=1 logic allows legacy RESERVE and RELEASE to be completed GOOD
status in the following cases when an >= SPC-3 reservation or registration(s) exist:
a) An I_T nexus that is a persistent reservation holder; or
b) An I_T nexus that is registered if a registrants only or
all registrants type persistent reservation is present.
This patch also adds a SPC-2 defined check in the new core_scsi2_emulate_crh() to return
RESERVATION_CONFLICT when any other >= SPC-3 registrations exist that are not allowed by
CRH=1 logic. It also adds the reserve check in core_scsi3_emulate_pr() to return RESERVATION_CONFLICT
for any received PERSISTENT_RESERVE_[IN,OUT] CDB when a legacy SPC-2 reservation is held.
Finally, this patch adds checks in core_scsi3_pr_seq_non_holder() and
core_scsi3_pr_reservation_check() to make the calls to core_scsi2_reservation_seq_non_holder()
and core_scsi2_reservation_check() respectively when a legacy SPC-2 reservation exists.
Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_pr.c | 176 +++++++++++++++++++++++++++++----------
include/target/target_core_pr.h | 1 +
2 files changed, 131 insertions(+), 46 deletions(-)
diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index 93c4f7c..a1fcb56 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -2,10 +2,10 @@
* Filename: target_core_pr.c
*
* This file contains SPC-3 compliant persistent reservations and
- * legacy SPC-2 reservations.
+ * legacy SPC-2 reservations with compatible reservation handling (CRH=1)
*
- * Copyright (c) 2009 Rising Tide, Inc.
- * Copyright (c) 2009 Linux-iSCSI.org
+ * Copyright (c) 2009, 2010 Rising Tide, Inc.
+ * Copyright (c) 2009, 2010 Linux-iSCSI.org
*
* Nicholas A. Bellinger <nab@xxxxxxxxxx>
*
@@ -120,6 +120,7 @@ int core_scsi2_reservation_release(se_cmd_t *cmd)
return 0;
}
dev->dev_reserved_node_acl = NULL;
+ dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
printk(KERN_INFO "SCSI-2 Released reservation for %s LUN: %u ->"
" MAPPED LUN: %u for %s\n", TPG_TFO(tpg)->get_fabric_name(),
SE_LUN(cmd)->unpacked_lun, cmd->se_deve->mapped_lun,
@@ -140,9 +141,8 @@ int core_scsi2_reservation_reserve(se_cmd_t *cmd)
(T_TASK(cmd)->t_task_cdb[1] & 0x02)) {
printk(KERN_ERR "LongIO and Obselete Bits set, returning"
" ILLEGAL_REQUEST\n");
- return -1;
+ return PYX_TRANSPORT_ILLEGAL_REQUEST;
}
-
/*
* This is currently the case for target_core_mod passthrough se_cmd_t
* ops
@@ -163,7 +163,7 @@ int core_scsi2_reservation_reserve(se_cmd_t *cmd)
cmd->se_deve->mapped_lun,
sess->se_node_acl->initiatorname);
spin_unlock(&dev->dev_reservation_lock);
- return 1;
+ return PYX_TRANSPORT_RESERVATION_CONFLICT;
}
dev->dev_reserved_node_acl = sess->se_node_acl;
@@ -178,6 +178,99 @@ int core_scsi2_reservation_reserve(se_cmd_t *cmd)
}
EXPORT_SYMBOL(core_scsi2_reservation_reserve);
+static t10_pr_registration_t *core_scsi3_locate_pr_reg(se_device_t *,
+ se_node_acl_t *);
+static void core_scsi3_put_pr_reg(t10_pr_registration_t *);
+
+/*
+ * Setup in target_core_transport.c:transport_generic_cmd_sequencer()
+ * and called via struct se_cmd_s->transport_emulate_cdb() in TCM processing
+ * thread context.
+ */
+int core_scsi2_emulate_crh(struct se_cmd_s *cmd)
+{
+ se_session_t *se_sess = cmd->se_sess;
+ se_subsystem_dev_t *su_dev = cmd->se_dev->se_sub_dev;
+ t10_pr_registration_t *pr_reg;
+ t10_reservation_template_t *pr_tmpl = &su_dev->t10_reservation;
+ unsigned char *cdb = &T_TASK(cmd)->t_task_cdb[0];
+ int crh = (T10_RES(su_dev)->res_type == SPC3_PERSISTENT_RESERVATIONS);
+ int conflict = 0;
+
+ if (!(se_sess))
+ return 0;
+
+ if (!(crh))
+ goto after_crh;
+
+ pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl);
+ if (pr_reg) {
+ /*
+ * From spc4r17 5.7.3 Exceptions to SPC-2 RESERVE and RELEASE
+ * behavior
+ *
+ * A RESERVE(6) or RESERVE(10) command shall complete with GOOD
+ * status, but no reservation shall be established and the
+ * persistent reservation shall not be changed, if the command
+ * is received from a) and b) below.
+ *
+ * A RELEASE(6) or RELEASE(10) command shall complete with GOOD
+ * status, but the persistent reservation shall not be released,
+ * if the command is received from a) and b)
+ *
+ * a) An I_T nexus that is a persistent reservation holder; or
+ * b) An I_T nexus that is registered if a registrants only or
+ * all registrants type persistent reservation is present.
+ *
+ * In all other cases, a RESERVE(6) command, RESERVE(10) command,
+ * RELEASE(6) command, or RELEASE(10) command shall be processed
+ * as defined in SPC-2.
+ */
+ if (pr_reg->pr_res_holder) {
+ core_scsi3_put_pr_reg(pr_reg);
+ return 0;
+ }
+ if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
+ (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
+ (pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
+ (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
+ core_scsi3_put_pr_reg(pr_reg);
+ return 0;
+ }
+ core_scsi3_put_pr_reg(pr_reg);
+ conflict = 1;
+ } else {
+ /*
+ * Following spc2r20 5.5.1 Reservations overview:
+ *
+ * If a logical unit has executed a PERSISTENT RESERVE OUT
+ * command with the REGISTER or the REGISTER AND IGNORE
+ * EXISTING KEY service action and is still registered by any
+ * initiator, all RESERVE commands and all RELEASE commands
+ * regardless of initiator shall conflict and shall terminate
+ * with a RESERVATION CONFLICT status.
+ */
+ spin_lock(&pr_tmpl->registration_lock);
+ conflict = (list_empty(&pr_tmpl->registration_list)) ? 0 : 1;
+ spin_unlock(&pr_tmpl->registration_lock);
+ }
+
+ if (conflict) {
+ printk(KERN_ERR "Received legacy SPC-2 RESERVE/RELEASE"
+ " while active SPC-3 registrations exist,"
+ " returning RESERVATION_CONFLICT\n");
+ return PYX_TRANSPORT_RESERVATION_CONFLICT;
+ }
+
+after_crh:
+ if ((cdb[0] == RESERVE) || (cdb[0] == RESERVE_10))
+ return core_scsi2_reservation_reserve(cmd);
+ else if ((cdb[0] == RELEASE) || (cdb[0] == RELEASE_10))
+ return core_scsi2_reservation_release(cmd);
+ else
+ return PYX_TRANSPORT_INVALID_CDB_FIELD;
+}
+
/*
* Begin SPC-3/SPC-4 Persistent Reservations emulation support
*
@@ -197,6 +290,12 @@ static int core_scsi3_pr_seq_non_holder(
int we = 0; /* Write Exclusive */
int legacy = 0; /* Act like a legacy device and return
* RESERVATION CONFLICT on some CDBs */
+ /*
+ * A legacy SPC-2 reservation is being held.
+ */
+ if (cmd->se_dev->dev_flags & DF_SPC2_RESERVATIONS)
+ return core_scsi2_reservation_seq_non_holder(cmd,
+ cdb, pr_reg_type);
se_deve = &se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
@@ -287,14 +386,15 @@ static int core_scsi3_pr_seq_non_holder(
return -1;
}
break;
- /* FIXME PR + legacy RELEASE + RESERVE */
case RELEASE:
case RELEASE_10:
- ret = 1; /* Conflict */
+ /* Handled by CRH=1 in core_scsi2_emulate_crh() */
+ ret = 0;
break;
case RESERVE:
case RESERVE_10:
- ret = 1; /* Conflict */
+ /* Handled by CRH=1 in core_scsi2_emulate_crh() */
+ ret = 0;
break;
case TEST_UNIT_READY:
ret = (legacy) ? 1 : 0; /* Conflict for legacy */
@@ -447,6 +547,11 @@ static int core_scsi3_pr_reservation_check(
if (!(sess))
return 0;
+ /*
+ * A legacy SPC-2 reservation is being held.
+ */
+ if (dev->dev_flags & DF_SPC2_RESERVATIONS)
+ return core_scsi2_reservation_check(cmd, pr_reg_type);
spin_lock(&dev->dev_reservation_lock);
if (!(dev->dev_pr_res_holder)) {
@@ -462,22 +567,6 @@ static int core_scsi3_pr_reservation_check(
return ret;
}
-static int core_scsi3_legacy_reserve(se_cmd_t *cmd)
-{
- /*
- * FIXME: See spc4r17 Section 5.7.3
- */
- return core_scsi2_reservation_reserve(cmd);
-}
-
-static int core_scsi3_legacy_release(se_cmd_t *cmd)
-{
- /*
- * FIXME: See spc4r17 Section 5.7.3
- */
- return core_scsi2_reservation_release(cmd);
-}
-
static t10_pr_registration_t *__core_scsi3_alloc_registration(
se_device_t *dev,
se_node_acl_t *nacl,
@@ -3342,12 +3431,7 @@ static int core_scsi3_pri_report_capabilities(se_cmd_t *cmd)
buf[0] = ((add_len << 8) & 0xff);
buf[1] = (add_len & 0xff);
- /*
- * FIXME: Leave these features disabled for now..
- */
-#if 0
buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
-#endif
buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
@@ -3535,6 +3619,22 @@ static int core_scsi3_emulate_pr_in(se_cmd_t *cmd, unsigned char *cdb)
int core_scsi3_emulate_pr(se_cmd_t *cmd)
{
unsigned char *cdb = &T_TASK(cmd)->t_task_cdb[0];
+ se_device_t *dev = cmd->se_dev;
+ /*
+ * Following spc2r20 5.5.1 Reservations overview:
+ *
+ * If a logical unit has been reserved by any RESERVE command and is
+ * still reserved by any initiator, all PERSISTENT RESERVE IN and all
+ * PERSISTENT RESERVE OUT commands shall conflict regardless of
+ * initiator or service action and shall terminate with a RESERVATION
+ * CONFLICT status.
+ */
+ if (dev->dev_flags & DF_SPC2_RESERVATIONS) {
+ printk(KERN_ERR "Received PERSISTENT_RESERVE CDB while legacy"
+ " SPC-2 reservation is held, returning"
+ " RESERVATION_CONFLICT\n");
+ return PYX_TRANSPORT_RESERVATION_CONFLICT;
+ }
return (cdb[0] == PERSISTENT_RESERVE_OUT) ?
core_scsi3_emulate_pr_out(cmd, cdb) :
@@ -3546,16 +3646,6 @@ static int core_pt_reservation_check(se_cmd_t *cmd, u32 *pr_res_type)
return 0;
}
-static int core_pt_reserve(se_cmd_t *cmd)
-{
- return 0;
-}
-
-static int core_pt_release(se_cmd_t *cmd)
-{
- return 0;
-}
-
static int core_pt_seq_non_holder(
se_cmd_t *cmd,
unsigned char *cdb,
@@ -3578,8 +3668,6 @@ int core_setup_reservations(se_device_t *dev)
!(DEV_ATTRIB(dev)->emulate_reservations)) {
rest->res_type = SPC_PASSTHROUGH;
rest->t10_reservation_check = &core_pt_reservation_check;
- rest->t10_reserve = &core_pt_reserve;
- rest->t10_release = &core_pt_release;
rest->t10_seq_non_holder = &core_pt_seq_non_holder;
printk(KERN_INFO "%s: Using SPC_PASSTHROUGH, no reservation"
" emulation\n", TRANSPORT(dev)->name);
@@ -3592,16 +3680,12 @@ int core_setup_reservations(se_device_t *dev)
if (TRANSPORT(dev)->get_device_rev(dev) >= SCSI_3) {
rest->res_type = SPC3_PERSISTENT_RESERVATIONS;
rest->t10_reservation_check = &core_scsi3_pr_reservation_check;
- rest->t10_reserve = &core_scsi3_legacy_reserve;
- rest->t10_release = &core_scsi3_legacy_release;
rest->t10_seq_non_holder = &core_scsi3_pr_seq_non_holder;
printk(KERN_INFO "%s: Using SPC3_PERSISTENT_RESERVATIONS"
" emulation\n", TRANSPORT(dev)->name);
} else {
rest->res_type = SPC2_RESERVATIONS;
rest->t10_reservation_check = &core_scsi2_reservation_check;
- rest->t10_reserve = &core_scsi2_reservation_reserve;
- rest->t10_release = &core_scsi2_reservation_release;
rest->t10_seq_non_holder =
&core_scsi2_reservation_seq_non_holder;
printk(KERN_INFO "%s: Using SPC2_RESERVATIONS emulation\n",
diff --git a/include/target/target_core_pr.h b/include/target/target_core_pr.h
index c791506..08e365b 100644
--- a/include/target/target_core_pr.h
+++ b/include/target/target_core_pr.h
@@ -45,6 +45,7 @@
extern struct kmem_cache *t10_pr_reg_cache;
+extern int core_scsi2_emulate_crh(struct se_cmd_s *);
extern int core_scsi3_alloc_aptpl_registration(
struct t10_reservation_template_s *, u64,
unsigned char *, u32, unsigned char *, u16, u32,
--
1.5.6.5
--
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