target: Better handling of AllRegistrants reservations

Fix AllRegistrants reservations in register_and_move() function where
the code didn't handle all of the registered devices as reservation
holders, resulting in the wrong warning message being displayed.

At the same time, introduce a helper function named
'is_reservation_holder()' that properly checks if a device is a
reservation holder, taking into account the reservation type. This
function cleans up the code and improves readability.

Signed-off-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Vangelis Koukis <vkoukis@arrikto.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index 2de6fb8cee8d83b8338472ee2a51dd02c078e833..7436fdaaad1231cb644266c41ed4e16a2af718a4 100644 (file)
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -78,6 +78,22 @@ enum preempt_type {
 static void __core_scsi3_complete_pro_release(struct se_device *, struct se_node_acl *,
                                              struct t10_pr_registration *, int, int);
 
+static int is_reservation_holder(
+       struct t10_pr_registration *pr_res_holder,
+       struct t10_pr_registration *pr_reg)
+{
+       int pr_res_type;
+
+       if (pr_res_holder) {
+               pr_res_type = pr_res_holder->pr_res_type;
+
+               return pr_res_holder == pr_reg ||
+                      pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
+                      pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG;
+       }
+       return 0;
+}
+
 static sense_reason_t
 target_scsi2_reservation_check(struct se_cmd *cmd)
 {
@@ -2287,7 +2303,6 @@ core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
        spin_lock(&dev->dev_reservation_lock);
        pr_res_holder = dev->dev_pr_res_holder;
        if (pr_res_holder) {
-               int pr_res_type = pr_res_holder->pr_res_type;
                /*
                 * From spc4r17 Section 5.7.9: Reserving:
                 *
@@ -2298,9 +2313,7 @@ core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
                 * the logical unit, then the command shall be completed with
                 * RESERVATION CONFLICT status.
                 */
-               if ((pr_res_holder != pr_reg) &&
-                   (pr_res_type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
-                   (pr_res_type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
+               if (!is_reservation_holder(pr_res_holder, pr_reg)) {
                        struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
                        pr_err("SPC-3 PR: Attempted RESERVE from"
                                " [%s]: %s while reservation already held by"
@@ -2477,7 +2490,6 @@ core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
        struct se_lun *se_lun = cmd->se_lun;
        struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
        struct t10_reservation *pr_tmpl = &dev->t10_pr;
-       int all_reg = 0;
        sense_reason_t ret = 0;
 
        if (!se_sess || !se_lun) {
@@ -2514,13 +2526,9 @@ core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
                spin_unlock(&dev->dev_reservation_lock);
                goto out_put_pr_reg;
        }
-       if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
-           (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
-               all_reg = 1;
 
-       if ((all_reg == 0) && (pr_res_holder != pr_reg)) {
+       if (!is_reservation_holder(pr_res_holder, pr_reg)) {
                /*
-                * Non 'All Registrants' PR Type cases..
                 * Release request from a registered I_T nexus that is not a
                 * persistent reservation holder. return GOOD status.
                 */
@@ -3375,7 +3383,7 @@ after_iport_check:
         * From spc4r17 section 5.7.8  Table 50 --
         *      Register behaviors for a REGISTER AND MOVE service action
         */
-       if (pr_res_holder != pr_reg) {
+       if (!is_reservation_holder(pr_res_holder, pr_reg)) {
                pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
                        " Nexus is not reservation holder\n");
                spin_unlock(&dev->dev_reservation_lock);