target: Fix compatible reservation handling (CRH=1) with legacy RESERVE/RELEASE

This patch addresses a bug with target_check_scsi2_reservation_conflict()
return checking in target_scsi2_reservation_[reserve,release]() that was
preventing CRH=1 operation from silently succeeding in the two special
cases defined by SPC-3, and not failing with reservation conflict status
when dealing with legacy RESERVE/RELEASE + active SPC-3 PR logic.

Also explictly set cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT during
the early non reservation holder failure from pr_ops->t10_seq_non_holder()
check in transport_generic_cmd_sequencer() for fabrics that already expect
it to be set.

This bug was originally introduced in mainline commit:

commit eacac00ce5bfde8086cd0615fb53c986f7f970fe
Author: Christoph Hellwig <hch@infradead.org>
Date:   Thu Nov 3 17:50:40 2011 -0400

    target: split core_scsi2_emulate_crh

Reported-by: Martin Svec <martin.svec@zoner.cz>
Cc: Martin Svec <martin.svec@zoner.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
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 b7c7793..63e703b 100644 (file)
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -117,7 +117,7 @@ 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)
+static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd)
 {
        struct se_session *se_sess = cmd->se_sess;
        struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
@@ -127,7 +127,7 @@ static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd, int *ret)
        int conflict = 0;
 
        if (!crh)
-               return false;
+               return -EINVAL;
 
        pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
                        se_sess);
@@ -155,16 +155,14 @@ static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd, int *ret)
                 */
                if (pr_reg->pr_res_holder) {
                        core_scsi3_put_pr_reg(pr_reg);
-                       *ret = 0;
-                       return false;
+                       return 1;
                }
                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;
+                       return 1;
                }
                core_scsi3_put_pr_reg(pr_reg);
                conflict = 1;
@@ -189,10 +187,10 @@ static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd, int *ret)
                        " while active SPC-3 registrations exist,"
                        " returning RESERVATION_CONFLICT\n");
                cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
-               return true;
+               return -EBUSY;
        }
 
-       return false;
+       return 0;
 }
 
 int target_scsi2_reservation_release(struct se_task *task)
@@ -201,12 +199,18 @@ int target_scsi2_reservation_release(struct se_task *task)
        struct se_device *dev = cmd->se_dev;
        struct se_session *sess = cmd->se_sess;
        struct se_portal_group *tpg = sess->se_tpg;
-       int ret = 0;
+       int ret = 0, rc;
 
        if (!sess || !tpg)
                goto out;
-       if (target_check_scsi2_reservation_conflict(cmd, &ret))
+       rc = target_check_scsi2_reservation_conflict(cmd);
+       if (rc == 1)
+               goto out;
+       else if (rc < 0) {
+               cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
+               ret = -EINVAL;
                goto out;
+       }
 
        ret = 0;
        spin_lock(&dev->dev_reservation_lock);
@@ -243,7 +247,7 @@ int target_scsi2_reservation_reserve(struct se_task *task)
        struct se_device *dev = cmd->se_dev;
        struct se_session *sess = cmd->se_sess;
        struct se_portal_group *tpg = sess->se_tpg;
-       int ret = 0;
+       int ret = 0, rc;
 
        if ((cmd->t_task_cdb[1] & 0x01) &&
            (cmd->t_task_cdb[1] & 0x02)) {
@@ -259,8 +263,14 @@ int target_scsi2_reservation_reserve(struct se_task *task)
         */
        if (!sess || !tpg)
                goto out;
-       if (target_check_scsi2_reservation_conflict(cmd, &ret))
+       rc = target_check_scsi2_reservation_conflict(cmd);
+       if (rc == 1)
                goto out;
+       else if (rc < 0) {
+               cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
+               ret = -EINVAL;
+               goto out;
+       }
 
        ret = 0;
        spin_lock(&dev->dev_reservation_lock);

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 58cea07..cd5cd95 100644 (file)
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2539,6 +2539,7 @@ static int transport_generic_cmd_sequencer(
                                        cmd, cdb, pr_reg_type) != 0) {
                        cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
                        cmd->se_cmd_flags |= SCF_SCSI_RESERVATION_CONFLICT;
+                       cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
                        cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
                        return -EBUSY;
                }