[SCSI] libiscsi: merge iscsi_mgmt_task and iscsi_cmd_task

There is no need to have the mgmt and cmd tasks separate
structs. It used to save a lot of memory when we overprealocated
memory for tasks, but the next patches will set up the
driver so in the future they can use a mempool or some other
common scsi command allocator and common tagging.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

2 files changed, 26 insertions, 44 deletions

diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 9be6a70faff5..d1c36759b350 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -85,18 +85,6 @@ enum {
         ISCSI_DIGEST_SIZE = sizeof(__u32),
 };
 
-struct iscsi_mgmt_task {
-        /*
-         * Becuae LLDs allocate their hdr differently, this is a pointer to
-         * that storage. It must be setup at session creation time.
-         */
-        struct iscsi_hdr        *hdr;
-        char                    *data;          /* mgmt payload */
-        unsigned                data_count;     /* counts data to be sent */
-        uint32_t                itt;            /* this ITT */
-        void                    *dd_data;       /* driver/transport data */
-        struct list_head        running;
-};
 
 enum {
         ISCSI_TASK_COMPLETED,
@@ -121,6 +109,7 @@ struct iscsi_cmd_task {
         /* offset in unsolicited stream (bytes); */
         unsigned                unsol_offset;
         unsigned                data_count;     /* remaining Data-Out */
+        char                    *data;          /* mgmt payload */
         struct scsi_cmnd        *sc;            /* associated SCSI cmd*/
         struct iscsi_conn       *conn;          /* used connection    */
 
@@ -162,7 +151,7 @@ struct iscsi_conn {
         unsigned long           last_ping;
         int                     ping_timeout;
         int                     recv_timeout;
-        struct iscsi_mgmt_task  *ping_mtask;
+        struct iscsi_cmd_task   *ping_ctask;
 
         /* iSCSI connection-wide sequencing */
         uint32_t                exp_statsn;
@@ -178,9 +167,8 @@ struct iscsi_conn {
          * should always fit in this buffer
          */
         char                    *data;
-        struct iscsi_mgmt_task  *login_mtask;   /* mtask used for login/text */
-        struct iscsi_mgmt_task  *mtask;         /* xmit mtask in progress */
-        struct iscsi_cmd_task   *ctask;         /* xmit ctask in progress */
+        struct iscsi_cmd_task   *login_ctask;   /* mtask used for login/text */
+        struct iscsi_cmd_task   *ctask;         /* xmit task in progress */
 
         /* xmit */
         struct list_head        mgmtqueue;      /* mgmt (control) xmit queue */
@@ -295,12 +283,10 @@ struct iscsi_session {
         int                     state;          /* session state           */
         int                     age;            /* counts session re-opens */
 
+        int                     scsi_cmds_max;  /* max scsi commands */
         int                     cmds_max;       /* size of cmds array */
         struct iscsi_cmd_task   **cmds;         /* Original Cmds arr */
         struct iscsi_pool       cmdpool;        /* PDU's pool */
-        int                     mgmtpool_max;   /* size of mgmt array */
-        struct iscsi_mgmt_task  **mgmt_cmds;    /* Original mgmt arr */
-        struct iscsi_pool       mgmtpool;       /* Mgmt PDU's pool */
 };
 
 struct iscsi_host {
@@ -345,7 +331,7 @@ extern void iscsi_host_free(struct Scsi_Host *shost);
  */
 extern struct iscsi_cls_session *
 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
-                    uint16_t, int, int, uint32_t);
+                    uint16_t, int, uint32_t);
 extern void iscsi_session_teardown(struct iscsi_cls_session *);
 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
@@ -388,8 +374,7 @@ extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
 extern struct iscsi_cmd_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
 extern void iscsi_requeue_ctask(struct iscsi_cmd_task *ctask);
-extern void iscsi_free_mgmt_task(struct iscsi_conn *conn,
-                                 struct iscsi_mgmt_task *mtask);
+extern void iscsi_put_ctask(struct iscsi_cmd_task *ctask);
 
 /*
  * generic helpers
diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
index 4028f121d548..3f24503dfdf9 100644
--- a/include/scsi/scsi_transport_iscsi.h
+++ b/include/scsi/scsi_transport_iscsi.h
@@ -34,7 +34,6 @@ struct Scsi_Host;
 struct iscsi_cls_conn;
 struct iscsi_conn;
 struct iscsi_cmd_task;
-struct iscsi_mgmt_task;
 struct sockaddr;
 
 /**
@@ -58,19 +57,22 @@ struct sockaddr;
  * @stop_conn:          suspend/recover/terminate connection
  * @send_pdu:           send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.
  * @session_recovery_timedout: notify LLD a block during recovery timed out
- * @init_cmd_task:      Initialize a iscsi_cmd_task and any internal structs.
- *                      Called from queuecommand with session lock held.
- * @init_mgmt_task:     Initialize a iscsi_mgmt_task and any internal structs.
- *                      Called from iscsi_conn_send_generic with xmitmutex.
- * @xmit_cmd_task:      Requests LLD to transfer cmd task. Returns 0 or the
+ * @init_task:          Initialize a iscsi_task and any internal structs.
+ *                      When offloading the data path, this is called from
+ *                      queuecommand with the session lock, or from the
+ *                      iscsi_conn_send_pdu context with the session lock.
+ *                      When not offloading the data path, this is called
+ *                      from the scsi work queue without the session lock.
+ * @xmit_task           Requests LLD to transfer cmd task. Returns 0 or the
  *                      the number of bytes transferred on success, and -Exyz
- *                      value on error.
- * @xmit_mgmt_task:     Requests LLD to transfer mgmt task. Returns 0 or the
- *                      the number of bytes transferred on success, and -Exyz
- *                      value on error.
- * @cleanup_cmd_task:   requests LLD to fail cmd task. Called with xmitmutex
- *                      and session->lock after the connection has been
- *                      suspended and terminated during recovery. If called
+ *                      value on error. When offloading the data path, this
+ *                      is called from queuecommand with the session lock, or
+ *                      from the iscsi_conn_send_pdu context with the session
+ *                      lock. When not offloading the data path, this is called
+ *                      from the scsi work queue without the session lock.
+ * @cleanup_task:       requests LLD to fail task. Called with session lock
+ *                      and after the connection has been suspended and
+ *                      terminated during recovery. If called
  *                      from abort task then connection is not suspended
  *                      or terminated but sk_callback_lock is held
  *
@@ -110,15 +112,10 @@ struct iscsi_transport {
                          char *data, uint32_t data_size);
         void (*get_stats) (struct iscsi_cls_conn *conn,
                            struct iscsi_stats *stats);
-        int (*init_cmd_task) (struct iscsi_cmd_task *ctask);
-        void (*init_mgmt_task) (struct iscsi_conn *conn,
-                                struct iscsi_mgmt_task *mtask);
-        int (*xmit_cmd_task) (struct iscsi_conn *conn,
-                              struct iscsi_cmd_task *ctask);
-        void (*cleanup_cmd_task) (struct iscsi_conn *conn,
-                                  struct iscsi_cmd_task *ctask);
-        int (*xmit_mgmt_task) (struct iscsi_conn *conn,
-                               struct iscsi_mgmt_task *mtask);
+        int (*init_task) (struct iscsi_cmd_task *task);
+        int (*xmit_task) (struct iscsi_cmd_task *task);
+        void (*cleanup_task) (struct iscsi_conn *conn,
+                                  struct iscsi_cmd_task *task);
         void (*session_recovery_timedout) (struct iscsi_cls_session *session);
         int (*ep_connect) (struct sockaddr *dst_addr, int non_blocking,
                            uint64_t *ep_handle);