[SCSI] tgt: add I_T nexus support

tgt uses scsi_host as I_T nexus. This works for ibmvstgt because it
creates one scsi_host for one initiator. However, other target drivers
don't work like that.

This adds I_T nexus support, which enable one scsi_host to handle
multiple initiators. New scsi_tgt_it_nexus_create/destroy functions
are expected be called transport classes. For example, ibmvstgt
creates an initiator remote port, then the srp transport calls
tgt_it_nexus_create. tgt doesn't manages I_T nexus, instead it tells
tgtd, user-space daemon, to create a new I_T nexus.

On the receiving the response from tgtd, tgt calls
shost->transportt->it_nexus_response. transports should notify a
lld. The srp transport uses it_nexus_response callback in
srp_function_template to do that.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

diff --git a/drivers/scsi/scsi_tgt_if.c b/drivers/scsi/scsi_tgt_if.c
index ca22ddf..9815a1a 100644 (file)
--- a/drivers/scsi/scsi_tgt_if.c
+++ b/drivers/scsi/scsi_tgt_if.c
@@ -102,7 +102,8 @@ static int tgt_uspace_send_event(u32 type, struct tgt_event *p)
        return 0;
 }
 
-int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, struct scsi_lun *lun, u64 tag)
+int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, u64 itn_id,
+                            struct scsi_lun *lun, u64 tag)
 {
        struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd);
        struct tgt_event ev;
@@ -110,6 +111,7 @@ int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, struct scsi_lun *lun, u64 ta
 
        memset(&ev, 0, sizeof(ev));
        ev.p.cmd_req.host_no = shost->host_no;
+       ev.p.cmd_req.itn_id = itn_id;
        ev.p.cmd_req.data_len = cmd->request_bufflen;
        memcpy(ev.p.cmd_req.scb, cmd->cmnd, sizeof(ev.p.cmd_req.scb));
        memcpy(ev.p.cmd_req.lun, lun, sizeof(ev.p.cmd_req.lun));
@@ -127,7 +129,7 @@ int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, struct scsi_lun *lun, u64 ta
        return err;
 }
 
-int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 tag)
+int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 itn_id, u64 tag)
 {
        struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd);
        struct tgt_event ev;
@@ -135,6 +137,7 @@ int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 tag)
 
        memset(&ev, 0, sizeof(ev));
        ev.p.cmd_done.host_no = shost->host_no;
+       ev.p.cmd_done.itn_id = itn_id;
        ev.p.cmd_done.tag = tag;
        ev.p.cmd_done.result = cmd->result;
 
@@ -149,14 +152,15 @@ int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 tag)
        return err;
 }
 
-int scsi_tgt_uspace_send_tsk_mgmt(int host_no, int function, u64 tag,
-                                 struct scsi_lun *scsilun, void *data)
+int scsi_tgt_uspace_send_tsk_mgmt(int host_no, u64 itn_id, int function,
+                                 u64 tag, struct scsi_lun *scsilun, void *data)
 {
        struct tgt_event ev;
        int err;
 
        memset(&ev, 0, sizeof(ev));
        ev.p.tsk_mgmt_req.host_no = host_no;
+       ev.p.tsk_mgmt_req.itn_id = itn_id;
        ev.p.tsk_mgmt_req.function = function;
        ev.p.tsk_mgmt_req.tag = tag;
        memcpy(ev.p.tsk_mgmt_req.lun, scsilun, sizeof(ev.p.tsk_mgmt_req.lun));
@@ -172,6 +176,29 @@ int scsi_tgt_uspace_send_tsk_mgmt(int host_no, int function, u64 tag,
        return err;
 }
 
+int scsi_tgt_uspace_send_it_nexus_request(int host_no, u64 itn_id,
+                                         int function, char *initiator_id)
+{
+       struct tgt_event ev;
+       int err;
+
+       memset(&ev, 0, sizeof(ev));
+       ev.p.it_nexus_req.host_no = host_no;
+       ev.p.it_nexus_req.function = function;
+       ev.p.it_nexus_req.itn_id = itn_id;
+       if (initiator_id)
+               strncpy(ev.p.it_nexus_req.initiator_id, initiator_id,
+                       sizeof(ev.p.it_nexus_req.initiator_id));
+
+       dprintk("%d %x %llx\n", host_no, function, (unsigned long long)itn_id);
+
+       err = tgt_uspace_send_event(TGT_KEVENT_IT_NEXUS_REQ, &ev);
+       if (err)
+               eprintk("tx buf is full, could not send\n");
+
+       return err;
+}
+
 static int event_recv_msg(struct tgt_event *ev)
 {
        int err = 0;
@@ -179,6 +206,7 @@ static int event_recv_msg(struct tgt_event *ev)
        switch (ev->hdr.type) {
        case TGT_UEVENT_CMD_RSP:
                err = scsi_tgt_kspace_exec(ev->p.cmd_rsp.host_no,
+                                          ev->p.cmd_rsp.itn_id,
                                           ev->p.cmd_rsp.result,
                                           ev->p.cmd_rsp.tag,
                                           ev->p.cmd_rsp.uaddr,
@@ -189,9 +217,15 @@ static int event_recv_msg(struct tgt_event *ev)
                break;
        case TGT_UEVENT_TSK_MGMT_RSP:
                err = scsi_tgt_kspace_tsk_mgmt(ev->p.tsk_mgmt_rsp.host_no,
+                                              ev->p.tsk_mgmt_rsp.itn_id,
                                               ev->p.tsk_mgmt_rsp.mid,
                                               ev->p.tsk_mgmt_rsp.result);
                break;
+       case TGT_UEVENT_IT_NEXUS_RSP:
+               err = scsi_tgt_kspace_it_nexus_rsp(ev->p.it_nexus_rsp.host_no,
+                                                  ev->p.it_nexus_rsp.itn_id,
+                                                  ev->p.it_nexus_rsp.result);
+               break;
        default:
                eprintk("unknown type %d\n", ev->hdr.type);
                err = -EINVAL;

diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
index 371b69c..fa79e54 100644 (file)
--- a/drivers/scsi/scsi_tgt_lib.c
+++ b/drivers/scsi/scsi_tgt_lib.c
@@ -27,6 +27,7 @@
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_host.h>
+#include <scsi/scsi_transport.h>
 #include <scsi/scsi_tgt.h>
 
 #include "scsi_tgt_priv.h"
@@ -46,6 +47,7 @@ struct scsi_tgt_cmd {
 
        struct list_head hash_list;
        struct request *rq;
+       u64 itn_id;
        u64 tag;
 };
 
@@ -185,12 +187,13 @@ static void scsi_tgt_cmd_destroy(struct work_struct *work)
 }
 
 static void init_scsi_tgt_cmd(struct request *rq, struct scsi_tgt_cmd *tcmd,
-                             u64 tag)
+                             u64 itn_id, u64 tag)
 {
        struct scsi_tgt_queuedata *qdata = rq->q->queuedata;
        unsigned long flags;
        struct list_head *head;
 
+       tcmd->itn_id = itn_id;
        tcmd->tag = tag;
        tcmd->bio = NULL;
        INIT_WORK(&tcmd->work, scsi_tgt_cmd_destroy);
@@ -301,14 +304,14 @@ EXPORT_SYMBOL_GPL(scsi_tgt_cmd_to_host);
  * @scsilun:   scsi lun
  * @tag:       unique value to identify this command for tmf
  */
-int scsi_tgt_queue_command(struct scsi_cmnd *cmd, struct scsi_lun *scsilun,
-                          u64 tag)
+int scsi_tgt_queue_command(struct scsi_cmnd *cmd, u64 itn_id,
+                          struct scsi_lun *scsilun, u64 tag)
 {
        struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data;
        int err;
 
-       init_scsi_tgt_cmd(cmd->request, tcmd, tag);
-       err = scsi_tgt_uspace_send_cmd(cmd, scsilun, tag);
+       init_scsi_tgt_cmd(cmd->request, tcmd, itn_id, tag);
+       err = scsi_tgt_uspace_send_cmd(cmd, itn_id, scsilun, tag);
        if (err)
                cmd_hashlist_del(cmd);
 
@@ -326,7 +329,7 @@ static void scsi_tgt_cmd_done(struct scsi_cmnd *cmd)
 
        dprintk("cmd %p %lu\n", cmd, rq_data_dir(cmd->request));
 
-       scsi_tgt_uspace_send_status(cmd, tcmd->tag);
+       scsi_tgt_uspace_send_status(cmd, tcmd->itn_id, tcmd->tag);
 
        if (cmd->request_buffer)
                scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len);
@@ -459,7 +462,7 @@ static struct request *tgt_cmd_hash_lookup(struct request_queue *q, u64 tag)
        return rq;
 }
 
-int scsi_tgt_kspace_exec(int host_no, int result, u64 tag,
+int scsi_tgt_kspace_exec(int host_no, u64 itn_id, int result, u64 tag,
                         unsigned long uaddr, u32 len, unsigned long sense_uaddr,
                         u32 sense_len, u8 rw)
 {
@@ -541,21 +544,22 @@ done:
        return err;
 }
 
-int scsi_tgt_tsk_mgmt_request(struct Scsi_Host *shost, int function, u64 tag,
-                             struct scsi_lun *scsilun, void *data)
+int scsi_tgt_tsk_mgmt_request(struct Scsi_Host *shost, u64 itn_id,
+                             int function, u64 tag, struct scsi_lun *scsilun,
+                             void *data)
 {
        int err;
 
        /* TODO: need to retry if this fails. */
-       err = scsi_tgt_uspace_send_tsk_mgmt(shost->host_no, function,
-                                           tag, scsilun, data);
+       err = scsi_tgt_uspace_send_tsk_mgmt(shost->host_no, itn_id,
+                                           function, tag, scsilun, data);
        if (err < 0)
                eprintk("The task management request lost!\n");
        return err;
 }
 EXPORT_SYMBOL_GPL(scsi_tgt_tsk_mgmt_request);
 
-int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 mid, int result)
+int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 itn_id, u64 mid, int result)
 {
        struct Scsi_Host *shost;
        int err = -EINVAL;
@@ -573,7 +577,60 @@ int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 mid, int result)
                goto done;
        }
 
-       err = shost->hostt->tsk_mgmt_response(mid, result);
+       err = shost->hostt->tsk_mgmt_response(shost, itn_id, mid, result);
+done:
+       scsi_host_put(shost);
+       return err;
+}
+
+int scsi_tgt_it_nexus_create(struct Scsi_Host *shost, u64 itn_id,
+                            char *initiator)
+{
+       int err;
+
+       /* TODO: need to retry if this fails. */
+       err = scsi_tgt_uspace_send_it_nexus_request(shost->host_no, itn_id, 0,
+                                                   initiator);
+       if (err < 0)
+               eprintk("The i_t_neuxs request lost, %d %llx!\n",
+                       shost->host_no, (unsigned long long)itn_id);
+       return err;
+}
+EXPORT_SYMBOL_GPL(scsi_tgt_it_nexus_create);
+
+int scsi_tgt_it_nexus_destroy(struct Scsi_Host *shost, u64 itn_id)
+{
+       int err;
+
+       /* TODO: need to retry if this fails. */
+       err = scsi_tgt_uspace_send_it_nexus_request(shost->host_no,
+                                                   itn_id, 1, NULL);
+       if (err < 0)
+               eprintk("The i_t_neuxs request lost, %d %llx!\n",
+                       shost->host_no, (unsigned long long)itn_id);
+       return err;
+}
+EXPORT_SYMBOL_GPL(scsi_tgt_it_nexus_destroy);
+
+int scsi_tgt_kspace_it_nexus_rsp(int host_no, u64 itn_id, int result)
+{
+       struct Scsi_Host *shost;
+       int err = -EINVAL;
+
+       dprintk("%d %d %llx\n", host_no, result, (unsigned long long) mid);
+
+       shost = scsi_host_lookup(host_no);
+       if (IS_ERR(shost)) {
+               printk(KERN_ERR "Could not find host no %d\n", host_no);
+               return err;
+       }
+
+       if (!shost->uspace_req_q) {
+               printk(KERN_ERR "Not target scsi host %d\n", host_no);
+               goto done;
+       }
+
+       err = shost->transportt->it_nexus_response(shost, itn_id, result);
 done:
        scsi_host_put(shost);
        return err;

diff --git a/drivers/scsi/scsi_tgt_priv.h b/drivers/scsi/scsi_tgt_priv.h
index e9e6db1..cb92888 100644 (file)
--- a/drivers/scsi/scsi_tgt_priv.h
+++ b/drivers/scsi/scsi_tgt_priv.h
@@ -15,12 +15,18 @@ do {                                                                \
 extern void scsi_tgt_if_exit(void);
 extern int scsi_tgt_if_init(void);
 
-extern int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, struct scsi_lun *lun,
-                                   u64 tag);
-extern int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 tag);
-extern int scsi_tgt_kspace_exec(int host_no, int result, u64 tag,
-                               unsigned long uaddr, u32 len, unsigned long sense_uaddr,
-                               u32 sense_len, u8 rw);
-extern int scsi_tgt_uspace_send_tsk_mgmt(int host_no, int function, u64 tag,
+extern int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, u64 it_nexus_id,
+                                   struct scsi_lun *lun, u64 tag);
+extern int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 it_nexus_id,
+                                      u64 tag);
+extern int scsi_tgt_kspace_exec(int host_no, u64 it_nexus_id, int result, u64 tag,
+                               unsigned long uaddr, u32 len,
+                               unsigned long sense_uaddr, u32 sense_len, u8 rw);
+extern int scsi_tgt_uspace_send_tsk_mgmt(int host_no, u64 it_nexus_id,
+                                        int function, u64 tag,
                                         struct scsi_lun *scsilun, void *data);
-extern int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 mid, int result);
+extern int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 it_nexus_id,
+                                   u64 mid, int result);
+extern int scsi_tgt_uspace_send_it_nexus_request(int host_no, u64 it_nexus_id,
+                                                int function, char *initiator);
+extern int scsi_tgt_kspace_it_nexus_rsp(int host_no, u64 it_nexus_id, int result);

diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 3b8a6a8..89c40c4 100644 (file)
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -146,7 +146,7 @@ struct scsi_host_template {
                                  void (*done)(struct scsi_cmnd *));
 
        /* Used as callback for the completion of task management request. */
-       int (* tsk_mgmt_response)(u64 mid, int result);
+       int (* tsk_mgmt_response)(struct Scsi_Host *, u64, u64 mid, int result);
 
        /*
         * This is an error handling strategy routine.  You don't need to

diff --git a/include/scsi/scsi_tgt.h b/include/scsi/scsi_tgt.h
index 4f44279..d0fefb9 100644 (file)
--- a/include/scsi/scsi_tgt.h
+++ b/include/scsi/scsi_tgt.h
@@ -11,9 +11,11 @@ struct scsi_lun;
 extern struct Scsi_Host *scsi_tgt_cmd_to_host(struct scsi_cmnd *);
 extern int scsi_tgt_alloc_queue(struct Scsi_Host *);
 extern void scsi_tgt_free_queue(struct Scsi_Host *);
-extern int scsi_tgt_queue_command(struct scsi_cmnd *, struct scsi_lun *, u64);
-extern int scsi_tgt_tsk_mgmt_request(struct Scsi_Host *, int, u64, struct scsi_lun *,
-                                    void *);
+extern int scsi_tgt_queue_command(struct scsi_cmnd *, u64, struct scsi_lun *, u64);
+extern int scsi_tgt_tsk_mgmt_request(struct Scsi_Host *, u64, int, u64,
+                                    struct scsi_lun *, void *);
 extern struct scsi_cmnd *scsi_host_get_command(struct Scsi_Host *,
                                               enum dma_data_direction, gfp_t);
 extern void scsi_host_put_command(struct Scsi_Host *, struct scsi_cmnd *);
+extern int scsi_tgt_it_nexus_create(struct Scsi_Host *, u64, char *);
+extern int scsi_tgt_it_nexus_destroy(struct Scsi_Host *, u64);

diff --git a/include/scsi/scsi_tgt_if.h b/include/scsi/scsi_tgt_if.h
index 4cf9dff..f2ee7c2 100644 (file)
--- a/include/scsi/scsi_tgt_if.h
+++ b/include/scsi/scsi_tgt_if.h
@@ -23,13 +23,15 @@
 #define __SCSI_TARGET_IF_H
 
 /* user -> kernel */
-#define        TGT_UEVENT_CMD_RSP      0x0001
-#define        TGT_UEVENT_TSK_MGMT_RSP 0x0002
+#define        TGT_UEVENT_CMD_RSP              0x0001
+#define        TGT_UEVENT_IT_NEXUS_RSP         0x0002
+#define        TGT_UEVENT_TSK_MGMT_RSP         0x0003
 
 /* kernel -> user */
-#define        TGT_KEVENT_CMD_REQ      0x1001
-#define        TGT_KEVENT_CMD_DONE     0x1002
-#define        TGT_KEVENT_TSK_MGMT_REQ 0x1003
+#define        TGT_KEVENT_CMD_REQ              0x1001
+#define        TGT_KEVENT_CMD_DONE             0x1002
+#define        TGT_KEVENT_IT_NEXUS_REQ         0x1003
+#define        TGT_KEVENT_TSK_MGMT_REQ         0x1004
 
 struct tgt_event_hdr {
        uint16_t version;
@@ -46,6 +48,7 @@ struct tgt_event {
                struct {
                        int host_no;
                        int result;
+                       aligned_u64 itn_id;
                        aligned_u64 tag;
                        aligned_u64 uaddr;
                        aligned_u64 sense_uaddr;
@@ -55,15 +58,22 @@ struct tgt_event {
                } cmd_rsp;
                struct {
                        int host_no;
-                       aligned_u64 mid;
                        int result;
+                       aligned_u64 itn_id;
+                       aligned_u64 mid;
                } tsk_mgmt_rsp;
-
+               struct {
+                       __s32 host_no;
+                       __s32 result;
+                       aligned_u64 itn_id;
+                       __u32 function;
+               } it_nexus_rsp;
 
                /* kernel -> user */
                struct {
                        int host_no;
                        uint32_t data_len;
+                       aligned_u64 itn_id;
                        uint8_t scb[16];
                        uint8_t lun[8];
                        int attribute;
@@ -71,16 +81,25 @@ struct tgt_event {
                } cmd_req;
                struct {
                        int host_no;
-                       aligned_u64 tag;
                        int result;
+                       aligned_u64 itn_id;
+                       aligned_u64 tag;
                } cmd_done;
                struct {
                        int host_no;
                        int function;
+                       aligned_u64 itn_id;
                        aligned_u64 tag;
                        uint8_t lun[8];
                        aligned_u64 mid;
                } tsk_mgmt_req;
+               struct {
+                       __s32 host_no;
+                       __u32 function;
+                       aligned_u64 itn_id;
+                       __u32 max_cmds;
+                       __u8 initiator_id[16];
+               } it_nexus_req;
        } p;
 } __attribute__ ((aligned (sizeof(uint64_t))));
 

diff --git a/include/scsi/scsi_transport.h b/include/scsi/scsi_transport.h
index 3c18baa..af5b3e1 100644 (file)
--- a/include/scsi/scsi_transport.h
+++ b/include/scsi/scsi_transport.h
@@ -65,6 +65,12 @@ struct scsi_transport_template {
         * EH_NOT_HANDLED       Begin normal error recovery
         */
        enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *);
+
+       /*
+        * Used as callback for the completion of i_t_nexus request
+        * for target drivers.
+        */
+       int (* it_nexus_response)(struct Scsi_Host *, u64, int);
 };
 
 #define transport_class_to_shost(tc) \