target: split core_scsi2_emulate_crh

Split core_scsi2_emulate_crh into one routine each for the reserve and
release side.  The common code now is in a helper called by both
routines.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

3 files changed, 102 insertions, 106 deletions

diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index 0c4f783f924c..830953a743d6 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -116,14 +116,99 @@ static int core_scsi2_reservation_check(struct se_cmd *cmd, u32 *pr_reg_type)
         return ret;
 }
 
-static int core_scsi2_reservation_release(struct se_cmd *cmd)
+static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
+                                        struct se_node_acl *, struct se_session *);
+static void core_scsi3_put_pr_reg(struct t10_pr_registration *);
+
+static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd, int *ret)
+{
+        struct se_session *se_sess = cmd->se_sess;
+        struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
+        struct t10_pr_registration *pr_reg;
+        struct t10_reservation *pr_tmpl = &su_dev->t10_pr;
+        int crh = (su_dev->t10_pr.res_type == SPC3_PERSISTENT_RESERVATIONS);
+        int conflict = 0;
+
+        if (!crh)
+                return false;
+
+        pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
+                        se_sess);
+        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);
+                        *ret = 0;
+                        return false;
+                }
+                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);
+                        *ret = 0;
+                        return true;
+                }
+                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) {
+                pr_err("Received legacy SPC-2 RESERVE/RELEASE"
+                        " while active SPC-3 registrations exist,"
+                        " returning RESERVATION_CONFLICT\n");
+                *ret = PYX_TRANSPORT_RESERVATION_CONFLICT;
+                return true;
+        }
+
+        return false;
+}
+
+int target_scsi2_reservation_release(struct se_cmd *cmd)
 {
         struct se_device *dev = cmd->se_dev;
         struct se_session *sess = cmd->se_sess;
         struct se_portal_group *tpg = sess->se_tpg;
+        int ret;
 
         if (!sess || !tpg)
                 return 0;
+        if (target_check_scsi2_reservation_conflict(cmd, &ret))
+                return ret;
 
         spin_lock(&dev->dev_reservation_lock);
         if (!dev->dev_reserved_node_acl || !sess) {
@@ -150,11 +235,12 @@ static int core_scsi2_reservation_release(struct se_cmd *cmd)
         return 0;
 }
 
-static int core_scsi2_reservation_reserve(struct se_cmd *cmd)
+int target_scsi2_reservation_reserve(struct se_cmd *cmd)
 {
         struct se_device *dev = cmd->se_dev;
         struct se_session *sess = cmd->se_sess;
         struct se_portal_group *tpg = sess->se_tpg;
+        int ret;
 
         if ((cmd->t_task_cdb[1] & 0x01) &&
             (cmd->t_task_cdb[1] & 0x02)) {
@@ -168,6 +254,8 @@ static int core_scsi2_reservation_reserve(struct se_cmd *cmd)
          */
         if (!sess || !tpg)
                 return 0;
+        if (target_check_scsi2_reservation_conflict(cmd, &ret))
+                return ret;
 
         spin_lock(&dev->dev_reservation_lock);
         if (dev->dev_reserved_node_acl &&
@@ -200,99 +288,6 @@ static int core_scsi2_reservation_reserve(struct se_cmd *cmd)
         return 0;
 }
 
-static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
-                                        struct se_node_acl *, struct se_session *);
-static void core_scsi3_put_pr_reg(struct t10_pr_registration *);
-
-/*
- * Setup in target_core_transport.c:transport_generic_cmd_sequencer()
- * and called via struct se_cmd->transport_emulate_cdb() in TCM processing
- * thread context.
- */
-int core_scsi2_emulate_crh(struct se_cmd *cmd)
-{
-        struct se_session *se_sess = cmd->se_sess;
-        struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
-        struct t10_pr_registration *pr_reg;
-        struct t10_reservation *pr_tmpl = &su_dev->t10_pr;
-        unsigned char *cdb = &cmd->t_task_cdb[0];
-        int crh = (su_dev->t10_pr.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,
-                        se_sess);
-        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) {
-                pr_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
@@ -418,12 +413,12 @@ static int core_scsi3_pr_seq_non_holder(
                 break;
         case RELEASE:
         case RELEASE_10:
-                /* Handled by CRH=1 in core_scsi2_emulate_crh() */
+                /* Handled by CRH=1 in target_scsi2_reservation_release() */
                 ret = 0;
                 break;
         case RESERVE:
         case RESERVE_10:
-                /* Handled by CRH=1 in core_scsi2_emulate_crh() */
+                /* Handled by CRH=1 in target_scsi2_reservation_reserve() */
                 ret = 0;
                 break;
         case TEST_UNIT_READY:
diff --git a/drivers/target/target_core_pr.h b/drivers/target/target_core_pr.h
index c8f47d064584..4e94a427e314 100644
--- a/drivers/target/target_core_pr.h
+++ b/drivers/target/target_core_pr.h
@@ -47,7 +47,8 @@ extern struct kmem_cache *t10_pr_reg_cache;
 
 extern int core_pr_dump_initiator_port(struct t10_pr_registration *,
                         char *, u32);
-extern int core_scsi2_emulate_crh(struct se_cmd *);
+extern int target_scsi2_reservation_release(struct se_cmd *cmd);
+extern int target_scsi2_reservation_reserve(struct se_cmd *cmd);
 extern int core_scsi3_alloc_aptpl_registration(
                         struct t10_reservation *, u64,
                         unsigned char *, unsigned char *, u32,
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index e84b26ffb17b..f4232934bac5 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2963,10 +2963,10 @@ static int transport_generic_cmd_sequencer(
                  * is running in SPC_PASSTHROUGH, and wants reservations
                  * emulation disabled.
                  */
-                cmd->transport_emulate_cdb =
-                                (su_dev->t10_pr.res_type !=
-                                 SPC_PASSTHROUGH) ?
-                                core_scsi2_emulate_crh : NULL;
+                if (su_dev->t10_pr.res_type != SPC_PASSTHROUGH) {
+                        cmd->transport_emulate_cdb =
+                                target_scsi2_reservation_reserve;
+                }
                 cmd->se_cmd_flags |= SCF_SCSI_NON_DATA_CDB;
                 break;
         case RELEASE:
@@ -2980,10 +2980,10 @@ static int transport_generic_cmd_sequencer(
                 else
                         size = cmd->data_length;
 
-                cmd->transport_emulate_cdb =
-                                (su_dev->t10_pr.res_type !=
-                                 SPC_PASSTHROUGH) ?
-                                core_scsi2_emulate_crh : NULL;
+                if (su_dev->t10_pr.res_type != SPC_PASSTHROUGH) {
+                        cmd->transport_emulate_cdb =
+                                target_scsi2_reservation_release;
+                }
                 cmd->se_cmd_flags |= SCF_SCSI_NON_DATA_CDB;
                 break;
         case SYNCHRONIZE_CACHE: