[PATCH 06/11] target_core_alua: Validate ALUA state transition

[Hannes Reinecke <hare@suse.de>]

As we now can modify the list of supported states we need to
validate the requested ALUA state when doing a state transition.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/target/target_core_alua.c | 85 ++++++++++++++++++++++++++-------------
 1 file changed, 56 insertions(+), 29 deletions(-)

diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
index a16115e..a420778 100644
--- a/drivers/target/target_core_alua.c
+++ b/drivers/target/target_core_alua.c
@@ -41,7 +41,8 @@
 #include "target_core_alua.h"
 #include "target_core_ua.h"
 
-static sense_reason_t core_alua_check_transition(int state, int *primary);
+static sense_reason_t core_alua_check_transition(int state, int valid,
+						 int *primary);
 static int core_alua_set_tg_pt_secondary_state(
 		struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
 		struct se_port *port, int explicit, int offline);
@@ -210,7 +211,7 @@ target_emulate_set_target_port_groups(struct se_cmd *cmd)
 	unsigned char *ptr;
 	sense_reason_t rc = TCM_NO_SENSE;
 	u32 len = 4; /* Skip over RESERVED area in header */
-	int alua_access_state, primary = 0;
+	int alua_access_state, primary = 0, valid_states;
 	u16 tg_pt_id, rtpi;
 
 	if (!l_port)
@@ -252,6 +253,7 @@ target_emulate_set_target_port_groups(struct se_cmd *cmd)
 		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
 		goto out;
 	}
+	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
 
 	ptr = &buf[4]; /* Skip over RESERVED area in header */
 
@@ -263,7 +265,8 @@ target_emulate_set_target_port_groups(struct se_cmd *cmd)
 		 * the state is a primary or secondary target port asymmetric
 		 * access state.
 		 */
-		rc = core_alua_check_transition(alua_access_state, &primary);
+		rc = core_alua_check_transition(alua_access_state,
+						valid_states, &primary);
 		if (rc) {
 			/*
 			 * If the SET TARGET PORT GROUPS attempts to establish
@@ -614,21 +617,57 @@ out:
 	return 0;
 }
 
+static char *core_alua_dump_state(int state)
+{
+	switch (state) {
+	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
+		return "Active/Optimized";
+	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
+		return "Active/NonOptimized";
+	case ALUA_ACCESS_STATE_STANDBY:
+		return "Standby";
+	case ALUA_ACCESS_STATE_UNAVAILABLE:
+		return "Unavailable";
+	case ALUA_ACCESS_STATE_OFFLINE:
+		return "Offline";
+	case ALUA_ACCESS_STATE_TRANSITION:
+		return "Transitioning";
+	default:
+		return "Unknown";
+	}
+
+	return NULL;
+}
+
 /*
  * Check implicit and explicit ALUA state change request.
  */
 static sense_reason_t
-core_alua_check_transition(int state, int *primary)
+core_alua_check_transition(int state, int valid, int *primary)
 {
+	/*
+	 * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
+	 * defined as primary target port asymmetric access states.
+	 */
 	switch (state) {
 	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
+		if (!(valid & ALUA_AO_SUP))
+			goto not_supported;
+		*primary = 1;
+		break;
 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
+		if (!(valid & ALUA_AN_SUP))
+			goto not_supported;
+		*primary = 1;
+		break;
 	case ALUA_ACCESS_STATE_STANDBY:
+		if (!(valid & ALUA_S_SUP))
+			goto not_supported;
+		*primary = 1;
+		break;
 	case ALUA_ACCESS_STATE_UNAVAILABLE:
-		/*
-		 * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
-		 * defined as primary target port asymmetric access states.
-		 */
+		if (!(valid & ALUA_U_SUP))
+			goto not_supported;
 		*primary = 1;
 		break;
 	case ALUA_ACCESS_STATE_OFFLINE:
@@ -636,6 +675,8 @@ core_alua_check_transition(int state, int *primary)
 		 * OFFLINE state is defined as a secondary target port
 		 * asymmetric access state.
 		 */
+		if (!(valid & ALUA_O_SUP))
+			goto not_supported;
 		*primary = 0;
 		break;
 	default:
@@ -644,26 +685,11 @@ core_alua_check_transition(int state, int *primary)
 	}
 
 	return 0;
-}
 
-static char *core_alua_dump_state(int state)
-{
-	switch (state) {
-	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
-		return "Active/Optimized";
-	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
-		return "Active/NonOptimized";
-	case ALUA_ACCESS_STATE_STANDBY:
-		return "Standby";
-	case ALUA_ACCESS_STATE_UNAVAILABLE:
-		return "Unavailable";
-	case ALUA_ACCESS_STATE_OFFLINE:
-		return "Offline";
-	default:
-		return "Unknown";
-	}
-
-	return NULL;
+not_supported:
+	pr_err("ALUA access state %s not supported",
+	       core_alua_dump_state(state));
+	return TCM_INVALID_PARAMETER_LIST;
 }
 
 char *core_alua_dump_status(int status)
@@ -884,9 +910,10 @@ int core_alua_do_port_transition(
 	struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
 	struct t10_alua_tg_pt_gp *tg_pt_gp;
 	unsigned char *md_buf;
-	int primary;
+	int primary, valid_states;
 
-	if (core_alua_check_transition(new_state, &primary) != 0)
+	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
+	if (core_alua_check_transition(new_state, valid_states, &primary) != 0)
 		return -EINVAL;
 
 	md_buf = kzalloc(l_tg_pt_gp->tg_pt_gp_md_buf_len, GFP_KERNEL);
-- 
1.7.12.4