target: Convert ->transport_wait_for_tasks usage to transport_generic_free_cmd

This patch converts se_cmd->transport_wait_for_tasks(se_cmd, 1) usage to use
transport_generic_free_cmd() directly in target-core and iscsi-target fabric
usage.  The includes:

*) Removal of the optional transport_generic_free_cmd() call from within
   transport_generic_wait_for_tasks()
*) Usage of existing SCF_SUPPORTED_SAM_OPCODE to determine when
   transport_generic_wait_for_tasks() processing may occur instead of
   checking se_cmd->transport_wait_for_tasks()
*) Move transport_generic_wait_for_tasks() call ahead of core_dec_lacl_count()
   and transport_lun_remove_cmd() in transport_generic_free_cmd() to follow
   existing logic for iscsi-target w/ se_cmd->transport_wait_for_tasks(se_cmd, 1)
*) Removal of se_cmd->transport_wait_for_tasks() function pointer
*) Rename transport_generic_wait_for_tasks() -> transport_wait_for_tasks(), and
   add docbook comment.
*) Add EXPORT_SYMBOL for transport_wait_for_tasks()

For the case in iscsi_target_erl2.c:iscsit_prepare_cmds_for_realligance()
where se_cmd->transport_wait_for_tasks(se_cmd, 0) is called, this patch
adds a direct call to transport_wait_for_tasks().

(hch: Fix transport_generic_free_cmd() usage in iscsit_release_commands_from_conn)
(nab: Add patch: Ensure that TMRs hit wait_for_tasks logic during release)

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

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 354a833..e4b9ba2 100644 (file)
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -3940,7 +3940,6 @@ static void iscsit_release_commands_from_conn(struct iscsi_conn *conn)
 {
        struct iscsi_cmd *cmd = NULL, *cmd_tmp = NULL;
        struct iscsi_session *sess = conn->sess;
-       struct se_cmd *se_cmd;
        /*
         * We expect this function to only ever be called from either RX or TX
         * thread context via iscsit_close_connection() once the other context
@@ -3953,16 +3952,13 @@ static void iscsit_release_commands_from_conn(struct iscsi_conn *conn)
                        list_del(&cmd->i_list);
                        spin_unlock_bh(&conn->cmd_lock);
                        iscsit_increment_maxcmdsn(cmd, sess);
-                       se_cmd = &cmd->se_cmd;
                        /*
                         * Special cases for active iSCSI TMR, and
                         * transport_lookup_cmd_lun() failing from
                         * iscsit_get_lun_for_cmd() in iscsit_handle_scsi_cmd().
                         */
-                       if (cmd->tmr_req && se_cmd->transport_wait_for_tasks)
-                               se_cmd->transport_wait_for_tasks(se_cmd, 1);
-                       else if (cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD)
-                               transport_release_cmd(se_cmd);
+                       if (cmd->tmr_req)
+                               transport_generic_free_cmd(&cmd->se_cmd, 1);
                        else
                                iscsit_release_cmd(cmd);
 
@@ -3973,10 +3969,8 @@ static void iscsit_release_commands_from_conn(struct iscsi_conn *conn)
                spin_unlock_bh(&conn->cmd_lock);
 
                iscsit_increment_maxcmdsn(cmd, sess);
-               se_cmd = &cmd->se_cmd;
 
-               if (se_cmd->transport_wait_for_tasks)
-                       se_cmd->transport_wait_for_tasks(se_cmd, 1);
+               transport_generic_free_cmd(&cmd->se_cmd, 1);
 
                spin_lock_bh(&conn->cmd_lock);
        }

diff --git a/drivers/target/iscsi/iscsi_target_erl2.c b/drivers/target/iscsi/iscsi_target_erl2.c
index 000356b..c3803b2 100644 (file)
--- a/drivers/target/iscsi/iscsi_target_erl2.c
+++ b/drivers/target/iscsi/iscsi_target_erl2.c
@@ -143,12 +143,10 @@ void iscsit_free_connection_recovery_entires(struct iscsi_session *sess)
                        list_del(&cmd->i_list);
                        cmd->conn = NULL;
                        spin_unlock(&cr->conn_recovery_cmd_lock);
-                       if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD) ||
-                           !(cmd->se_cmd.transport_wait_for_tasks))
+                       if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD))
                                iscsit_release_cmd(cmd);
                        else
-                               cmd->se_cmd.transport_wait_for_tasks(
-                                               &cmd->se_cmd, 1);
+                               transport_generic_free_cmd(&cmd->se_cmd, 1);
                        spin_lock(&cr->conn_recovery_cmd_lock);
                }
                spin_unlock(&cr->conn_recovery_cmd_lock);
@@ -170,12 +168,10 @@ void iscsit_free_connection_recovery_entires(struct iscsi_session *sess)
                        list_del(&cmd->i_list);
                        cmd->conn = NULL;
                        spin_unlock(&cr->conn_recovery_cmd_lock);
-                       if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD) ||
-                           !(cmd->se_cmd.transport_wait_for_tasks))
+                       if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD))
                                iscsit_release_cmd(cmd);
                        else
-                               cmd->se_cmd.transport_wait_for_tasks(
-                                               &cmd->se_cmd, 1);
+                               transport_generic_free_cmd(&cmd->se_cmd, 1);
                        spin_lock(&cr->conn_recovery_cmd_lock);
                }
                spin_unlock(&cr->conn_recovery_cmd_lock);
@@ -260,12 +256,10 @@ void iscsit_discard_cr_cmds_by_expstatsn(
                iscsit_remove_cmd_from_connection_recovery(cmd, sess);
 
                spin_unlock(&cr->conn_recovery_cmd_lock);
-               if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD) ||
-                   !(cmd->se_cmd.transport_wait_for_tasks))
+               if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD))
                        iscsit_release_cmd(cmd);
                else
-                       cmd->se_cmd.transport_wait_for_tasks(
-                                       &cmd->se_cmd, 1);
+                       transport_generic_free_cmd(&cmd->se_cmd, 1);
                spin_lock(&cr->conn_recovery_cmd_lock);
        }
        spin_unlock(&cr->conn_recovery_cmd_lock);
@@ -319,12 +313,10 @@ int iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
                list_del(&cmd->i_list);
 
                spin_unlock_bh(&conn->cmd_lock);
-               if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD) ||
-                   !(cmd->se_cmd.transport_wait_for_tasks))
+               if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD))
                        iscsit_release_cmd(cmd);
                else
-                       cmd->se_cmd.transport_wait_for_tasks(
-                                       &cmd->se_cmd, 1);
+                       transport_generic_free_cmd(&cmd->se_cmd, 1);
                spin_lock_bh(&conn->cmd_lock);
        }
        spin_unlock_bh(&conn->cmd_lock);
@@ -378,12 +370,10 @@ int iscsit_prepare_cmds_for_realligance(struct iscsi_conn *conn)
                        list_del(&cmd->i_list);
                        spin_unlock_bh(&conn->cmd_lock);
 
-                       if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD) ||
-                           !(cmd->se_cmd.transport_wait_for_tasks))
+                       if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD))
                                iscsit_release_cmd(cmd);
                        else
-                               cmd->se_cmd.transport_wait_for_tasks(
-                                               &cmd->se_cmd, 1);
+                               transport_generic_free_cmd(&cmd->se_cmd, 1);
                        spin_lock_bh(&conn->cmd_lock);
                        continue;
                }
@@ -404,12 +394,10 @@ int iscsit_prepare_cmds_for_realligance(struct iscsi_conn *conn)
                        list_del(&cmd->i_list);
                        spin_unlock_bh(&conn->cmd_lock);
 
-                       if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD) ||
-                           !(cmd->se_cmd.transport_wait_for_tasks))
+                       if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD))
                                iscsit_release_cmd(cmd);
                        else
-                               cmd->se_cmd.transport_wait_for_tasks(
-                                               &cmd->se_cmd, 1);
+                               transport_generic_free_cmd(&cmd->se_cmd, 1);
                        spin_lock_bh(&conn->cmd_lock);
                        continue;
                }
@@ -434,9 +422,8 @@ int iscsit_prepare_cmds_for_realligance(struct iscsi_conn *conn)
 
                iscsit_free_all_datain_reqs(cmd);
 
-               if ((cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD) &&
-                    cmd->se_cmd.transport_wait_for_tasks)
-                       cmd->se_cmd.transport_wait_for_tasks(&cmd->se_cmd, 0);
+               if (cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD)
+                       transport_wait_for_tasks(&cmd->se_cmd);
                /*
                 * Add the struct iscsi_cmd to the connection recovery cmd list
                 */

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index ae1efc7..f8de042 100644 (file)
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1638,8 +1638,6 @@ static int transport_check_alloc_task_attr(struct se_cmd *cmd)
        return 0;
 }
 
-static void transport_generic_wait_for_tasks(struct se_cmd *, int);
-
 /*     transport_generic_allocate_tasks():
  *
  *     Called from fabric RX Thread.
@@ -1651,12 +1649,6 @@ int transport_generic_allocate_tasks(
        int ret;
 
        transport_generic_prepare_cdb(cdb);
-
-       /*
-        * This is needed for early exceptions.
-        */
-       cmd->transport_wait_for_tasks = &transport_generic_wait_for_tasks;
-
        /*
         * Ensure that the received CDB is less than the max (252 + 8) bytes
         * for VARIABLE_LENGTH_CMD
@@ -1739,7 +1731,7 @@ int transport_handle_cdb_direct(
         * Set TRANSPORT_NEW_CMD state and cmd->t_transport_active=1 following
         * transport_generic_handle_cdb*() -> transport_add_cmd_to_queue()
         * in existing usage to ensure that outstanding descriptors are handled
-        * correctly during shutdown via transport_generic_wait_for_tasks()
+        * correctly during shutdown via transport_wait_for_tasks()
         *
         * Also, we don't take cmd->t_state_lock here as we only expect
         * this to be called for initial descriptor submission.
@@ -1819,11 +1811,6 @@ EXPORT_SYMBOL(transport_generic_handle_data);
 int transport_generic_handle_tmr(
        struct se_cmd *cmd)
 {
-       /*
-        * This is needed for early exceptions.
-        */
-       cmd->transport_wait_for_tasks = &transport_generic_wait_for_tasks;
-
        transport_add_cmd_to_queue(cmd, TRANSPORT_PROCESS_TMR);
        return 0;
 }
@@ -2504,8 +2491,6 @@ void transport_new_cmd_failure(struct se_cmd *se_cmd)
        spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
 }
 
-static void transport_nop_wait_for_tasks(struct se_cmd *, int);
-
 static inline u32 transport_get_sectors_6(
        unsigned char *cdb,
        struct se_cmd *cmd,
@@ -2780,7 +2765,6 @@ static int transport_get_sense_data(struct se_cmd *cmd)
 static int
 transport_handle_reservation_conflict(struct se_cmd *cmd)
 {
-       cmd->transport_wait_for_tasks = &transport_nop_wait_for_tasks;
        cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
        cmd->se_cmd_flags |= SCF_SCSI_RESERVATION_CONFLICT;
        cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
@@ -2881,8 +2865,6 @@ static int transport_generic_cmd_sequencer(
         * Check for an existing UNIT ATTENTION condition
         */
        if (core_scsi3_ua_check(cmd, cdb) < 0) {
-               cmd->transport_wait_for_tasks =
-                               &transport_nop_wait_for_tasks;
                cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
                cmd->scsi_sense_reason = TCM_CHECK_CONDITION_UNIT_ATTENTION;
                return -EINVAL;
@@ -2892,7 +2874,6 @@ static int transport_generic_cmd_sequencer(
         */
        ret = su_dev->t10_alua.alua_state_check(cmd, cdb, &alua_ascq);
        if (ret != 0) {
-               cmd->transport_wait_for_tasks = &transport_nop_wait_for_tasks;
                /*
                 * Set SCSI additional sense code (ASC) to 'LUN Not Accessible';
                 * The ALUA additional sense code qualifier (ASCQ) is determined
@@ -3396,7 +3377,6 @@ static int transport_generic_cmd_sequencer(
                pr_warn("TARGET_CORE[%s]: Unsupported SCSI Opcode"
                        " 0x%02x, sending CHECK_CONDITION.\n",
                        cmd->se_tfo->get_fabric_name(), cdb[0]);
-               cmd->transport_wait_for_tasks = &transport_nop_wait_for_tasks;
                goto out_unsupported_cdb;
        }
 
@@ -4304,17 +4284,20 @@ EXPORT_SYMBOL(transport_release_cmd);
 
 void transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
 {
-       if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD))
+       if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
+               if (wait_for_tasks && cmd->se_tmr_req)
+                        transport_wait_for_tasks(cmd);
+
                transport_release_cmd(cmd);
-       else {
+       } else {
+               if (wait_for_tasks)
+                       transport_wait_for_tasks(cmd);
+
                core_dec_lacl_count(cmd->se_sess->se_node_acl, cmd);
 
                if (cmd->se_lun)
                        transport_lun_remove_cmd(cmd);
 
-               if (wait_for_tasks && cmd->transport_wait_for_tasks)
-                       cmd->transport_wait_for_tasks(cmd, 0);
-
                transport_free_dev_tasks(cmd);
 
                transport_put_cmd(cmd);
@@ -4322,13 +4305,6 @@ void transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
 }
 EXPORT_SYMBOL(transport_generic_free_cmd);
 
-static void transport_nop_wait_for_tasks(
-       struct se_cmd *cmd,
-       int remove_cmd)
-{
-       return;
-}
-
 /*     transport_lun_wait_for_tasks():
  *
  *     Called from ConfigFS context to stop the passed struct se_cmd to allow
@@ -4498,21 +4474,30 @@ int transport_clear_lun_from_sessions(struct se_lun *lun)
        return 0;
 }
 
-/*     transport_generic_wait_for_tasks():
+/**
+ * transport_wait_for_tasks - wait for completion to occur
+ * @cmd:       command to wait
  *
- *     Called from frontend or passthrough context to wait for storage engine
- *     to pause and/or release frontend generated struct se_cmd.
+ * Called from frontend fabric context to wait for storage engine
+ * to pause and/or release frontend generated struct se_cmd.
  */
-static void transport_generic_wait_for_tasks(
-       struct se_cmd *cmd,
-       int remove_cmd)
+void transport_wait_for_tasks(struct se_cmd *cmd)
 {
        unsigned long flags;
 
-       if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) && !(cmd->se_tmr_req))
-               return;
-
        spin_lock_irqsave(&cmd->t_state_lock, flags);
+       if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) && !(cmd->se_tmr_req)) {
+               spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+               return;
+       }
+       /*
+        * Only perform a possible wait_for_tasks if SCF_SUPPORTED_SAM_OPCODE
+        * has been set in transport_set_supported_SAM_opcode().
+        */
+       if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) && !cmd->se_tmr_req) {
+               spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+               return;
+       }
        /*
         * If we are already stopped due to an external event (ie: LUN shutdown)
         * sleep until the connection can have the passed struct se_cmd back.
@@ -4552,8 +4537,10 @@ static void transport_generic_wait_for_tasks(
                atomic_set(&cmd->transport_lun_stop, 0);
        }
        if (!atomic_read(&cmd->t_transport_active) ||
-            atomic_read(&cmd->t_transport_aborted))
-               goto remove;
+            atomic_read(&cmd->t_transport_aborted)) {
+               spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+               return;
+       }
 
        atomic_set(&cmd->t_transport_stop, 1);
 
@@ -4576,13 +4563,10 @@ static void transport_generic_wait_for_tasks(
        pr_debug("wait_for_tasks: Stopped wait_for_compltion("
                "&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
                cmd->se_tfo->get_task_tag(cmd));
-remove:
-       spin_unlock_irqrestore(&cmd->t_state_lock, flags);
-       if (!remove_cmd)
-               return;
 
-       transport_generic_free_cmd(cmd, 0);
+       spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 }
+EXPORT_SYMBOL(transport_wait_for_tasks);
 
 static int transport_get_sense_codes(
        struct se_cmd *cmd,

diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index c10e351..872cafc 100644 (file)
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -480,7 +480,6 @@ struct se_cmd {
        struct target_core_fabric_ops *se_tfo;
        int (*transport_emulate_cdb)(struct se_cmd *);
        void (*transport_split_cdb)(unsigned long long, u32, unsigned char *);
-       void (*transport_wait_for_tasks)(struct se_cmd *, int);
        void (*transport_complete_callback)(struct se_cmd *);
        int (*transport_qf_callback)(struct se_cmd *);
 

diff --git a/include/target/target_core_transport.h b/include/target/target_core_transport.h
index 549b6b3..371c24a 100644 (file)
--- a/include/target/target_core_transport.h
+++ b/include/target/target_core_transport.h
@@ -180,6 +180,7 @@ extern void __transport_stop_task_timer(struct se_task *, unsigned long *);
 extern int transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *, u32,
                                struct scatterlist *, u32);
 extern int transport_clear_lun_from_sessions(struct se_lun *);
+extern void transport_wait_for_tasks(struct se_cmd *);
 extern int transport_check_aborted_status(struct se_cmd *, int);
 extern int transport_send_check_condition_and_sense(struct se_cmd *, u8, int);
 extern void transport_send_task_abort(struct se_cmd *);