target_core_alua: validate ALUA state transition

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>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 45 insertions, 10 deletions

diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
index fdcee326bfbc..292ecce98d1f 100644
--- a/drivers/target/target_core_alua.c
+++ b/drivers/target/target_core_alua.c
@@ -41,11 +41,14 @@
 #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);
 
+static char *core_alua_dump_state(int state);
+
 static u16 alua_lu_gps_counter;
 static u32 alua_lu_gps_count;
 
@@ -210,7 +213,7 @@ 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 +255,7 @@ 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 +267,8 @@ 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
@@ -618,17 +623,31 @@ out:
  * 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:
@@ -636,14 +655,27 @@ 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;
+        case ALUA_ACCESS_STATE_TRANSITION:
+                /*
+                 * Transitioning is set internally, and
+                 * cannot be selected manually.
+                 */
+                goto not_supported;
         default:
                 pr_err("Unknown ALUA access state: 0x%02x\n", state);
                 return TCM_INVALID_PARAMETER_LIST;
         }
 
         return 0;
+
+not_supported:
+        pr_err("ALUA access state %s not supported",
+               core_alua_dump_state(state));
+        return TCM_INVALID_PARAMETER_LIST;
 }
 
 static char *core_alua_dump_state(int state)
@@ -659,6 +691,8 @@ static char *core_alua_dump_state(int state)
                 return "Unavailable";
         case ALUA_ACCESS_STATE_OFFLINE:
                 return "Offline";
+        case ALUA_ACCESS_STATE_TRANSITION:
+                return "Transitioning";
         default:
                 return "Unknown";
         }
@@ -884,9 +918,10 @@ 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);