[SCSI] iscsi class: user device_for_each_child instead of duplicating session list

Currently we duplicate the list of sessions, because we were using the
test for if a session was on the host list to indicate if the session
was bound or unbound. We can instead use the target_id and fix up
the class so that drivers like bnx2i do not have to manage the target id
space.

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

diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
index 86d9c42..3a89039 100644 (file)
--- a/drivers/infiniband/ulp/iser/iscsi_iser.c
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.c
@@ -437,7 +437,7 @@ iscsi_iser_session_create(struct Scsi_Host *shost,
        cls_session = iscsi_session_setup(&iscsi_iser_transport, shost,
                                          ISCSI_DEF_XMIT_CMDS_MAX,
                                          sizeof(struct iscsi_iser_task),
-                                         initial_cmdsn);
+                                         initial_cmdsn, 0);
        if (!cls_session)
                goto remove_host;
        session = cls_session->dd_data;

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 33cd0ca..aa3c7f0 100644 (file)
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -1868,7 +1868,7 @@ iscsi_tcp_session_create(struct Scsi_Host *shost, uint16_t cmds_max,
 
        cls_session = iscsi_session_setup(&iscsi_tcp_transport, shost, cmds_max,
                                          sizeof(struct iscsi_tcp_task),
-                                         initial_cmdsn);
+                                         initial_cmdsn, 0);
        if (!cls_session)
                goto remove_host;
        session = cls_session->dd_data;

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 92ee6d9..e88b726 100644 (file)
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -1897,7 +1897,7 @@ EXPORT_SYMBOL_GPL(iscsi_host_free);
 struct iscsi_cls_session *
 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
                    uint16_t scsi_cmds_max, int cmd_task_size,
-                   uint32_t initial_cmdsn)
+                   uint32_t initial_cmdsn, unsigned int id)
 {
        struct iscsi_session *session;
        struct iscsi_cls_session *cls_session;
@@ -1957,7 +1957,7 @@ iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
        if (!try_module_get(iscsit->owner))
                goto module_get_fail;
 
-       if (iscsi_add_session(cls_session, 0))
+       if (iscsi_add_session(cls_session, id))
                goto cls_session_fail;
        return cls_session;
 

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 6b8516a..ac9d298 100644 (file)
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -119,9 +119,8 @@ static int iscsi_setup_host(struct transport_container *tc, struct device *dev,
        struct iscsi_cls_host *ihost = shost->shost_data;
 
        memset(ihost, 0, sizeof(*ihost));
-       INIT_LIST_HEAD(&ihost->sessions);
-       mutex_init(&ihost->mutex);
        atomic_set(&ihost->nr_scans, 0);
+       mutex_init(&ihost->mutex);
 
        snprintf(ihost->scan_workq_name, KOBJ_NAME_LEN, "iscsi_scan_%d",
                shost->host_no);
@@ -316,42 +315,76 @@ int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time)
 }
 EXPORT_SYMBOL_GPL(iscsi_scan_finished);
 
-static int iscsi_user_scan(struct Scsi_Host *shost, uint channel,
-                          uint id, uint lun)
+struct iscsi_scan_data {
+       unsigned int channel;
+       unsigned int id;
+       unsigned int lun;
+};
+
+static int iscsi_user_scan_session(struct device *dev, void *data)
 {
-       struct iscsi_cls_host *ihost = shost->shost_data;
+       struct iscsi_scan_data *scan_data = data;
        struct iscsi_cls_session *session;
+       struct Scsi_Host *shost;
+       struct iscsi_cls_host *ihost;
+       unsigned long flags;
+       unsigned int id;
+
+       if (!iscsi_is_session_dev(dev))
+               return 0;
+
+       session = iscsi_dev_to_session(dev);
+       shost = iscsi_session_to_shost(session);
+       ihost = shost->shost_data;
 
        mutex_lock(&ihost->mutex);
-       list_for_each_entry(session, &ihost->sessions, host_list) {
-               if ((channel == SCAN_WILD_CARD || channel == 0) &&
-                   (id == SCAN_WILD_CARD || id == session->target_id))
-                       scsi_scan_target(&session->dev, 0,
-                                        session->target_id, lun, 1);
+       spin_lock_irqsave(&session->lock, flags);
+       if (session->state != ISCSI_SESSION_LOGGED_IN) {
+               spin_unlock_irqrestore(&session->lock, flags);
+               mutex_unlock(&ihost->mutex);
+               return 0;
        }
-       mutex_unlock(&ihost->mutex);
+       id = session->target_id;
+       spin_unlock_irqrestore(&session->lock, flags);
 
+       if (id != ISCSI_MAX_TARGET) {
+               if ((scan_data->channel == SCAN_WILD_CARD ||
+                    scan_data->channel == 0) &&
+                   (scan_data->id == SCAN_WILD_CARD ||
+                    scan_data->id == id))
+                       scsi_scan_target(&session->dev, 0, id,
+                                        scan_data->lun, 1);
+       }
+       mutex_unlock(&ihost->mutex);
        return 0;
 }
 
+static int iscsi_user_scan(struct Scsi_Host *shost, uint channel,
+                          uint id, uint lun)
+{
+       struct iscsi_scan_data scan_data;
+
+       scan_data.channel = channel;
+       scan_data.id = id;
+       scan_data.lun = lun;
+
+       return device_for_each_child(&shost->shost_gendev, &scan_data,
+                                    iscsi_user_scan_session);
+}
+
 static void iscsi_scan_session(struct work_struct *work)
 {
        struct iscsi_cls_session *session =
                        container_of(work, struct iscsi_cls_session, scan_work);
        struct Scsi_Host *shost = iscsi_session_to_shost(session);
        struct iscsi_cls_host *ihost = shost->shost_data;
-       unsigned long flags;
+       struct iscsi_scan_data scan_data;
 
-       spin_lock_irqsave(&session->lock, flags);
-       if (session->state != ISCSI_SESSION_LOGGED_IN) {
-               spin_unlock_irqrestore(&session->lock, flags);
-               goto done;
-       }
-       spin_unlock_irqrestore(&session->lock, flags);
+       scan_data.channel = 0;
+       scan_data.id = SCAN_WILD_CARD;
+       scan_data.lun = SCAN_WILD_CARD;
 
-       scsi_scan_target(&session->dev, 0, session->target_id,
-                        SCAN_WILD_CARD, 1);
-done:
+       iscsi_user_scan_session(&session->dev, &scan_data);
        atomic_dec(&ihost->nr_scans);
 }
 
@@ -460,14 +493,18 @@ static void __iscsi_unbind_session(struct work_struct *work)
                                     unbind_work);
        struct Scsi_Host *shost = iscsi_session_to_shost(session);
        struct iscsi_cls_host *ihost = shost->shost_data;
+       unsigned long flags;
 
        /* Prevent new scans and make sure scanning is not in progress */
        mutex_lock(&ihost->mutex);
-       if (list_empty(&session->host_list)) {
+       spin_lock_irqsave(&session->lock, flags);
+       if (session->target_id == ISCSI_MAX_TARGET) {
+               spin_unlock_irqrestore(&session->lock, flags);
                mutex_unlock(&ihost->mutex);
                return;
        }
-       list_del_init(&session->host_list);
+       session->target_id = ISCSI_MAX_TARGET;
+       spin_unlock_irqrestore(&session->lock, flags);
        mutex_unlock(&ihost->mutex);
 
        scsi_remove_target(&session->dev);
@@ -497,7 +534,6 @@ iscsi_alloc_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
        session->recovery_tmo = 120;
        session->state = ISCSI_SESSION_FREE;
        INIT_DELAYED_WORK(&session->recovery_work, session_recovery_timedout);
-       INIT_LIST_HEAD(&session->host_list);
        INIT_LIST_HEAD(&session->sess_list);
        INIT_WORK(&session->unblock_work, __iscsi_unblock_session);
        INIT_WORK(&session->block_work, __iscsi_block_session);
@@ -516,16 +552,51 @@ iscsi_alloc_session(struct Scsi_Host *shost, struct iscsi_transport *transport,
 }
 EXPORT_SYMBOL_GPL(iscsi_alloc_session);
 
+static int iscsi_get_next_target_id(struct device *dev, void *data)
+{
+       struct iscsi_cls_session *session;
+       unsigned long flags;
+       int err = 0;
+
+       if (!iscsi_is_session_dev(dev))
+               return 0;
+
+       session = iscsi_dev_to_session(dev);
+       spin_lock_irqsave(&session->lock, flags);
+       if (*((unsigned int *) data) == session->target_id)
+               err = -EEXIST;
+       spin_unlock_irqrestore(&session->lock, flags);
+       return err;
+}
+
 int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
 {
        struct Scsi_Host *shost = iscsi_session_to_shost(session);
        struct iscsi_cls_host *ihost;
        unsigned long flags;
+       unsigned int id = target_id;
        int err;
 
        ihost = shost->shost_data;
        session->sid = atomic_add_return(1, &iscsi_session_nr);
-       session->target_id = target_id;
+
+       if (id == ISCSI_MAX_TARGET) {
+               for (id = 0; id < ISCSI_MAX_TARGET; id++) {
+                       err = device_for_each_child(&shost->shost_gendev, &id,
+                                                   iscsi_get_next_target_id);
+                       if (!err)
+                               break;
+               }
+
+               if (id == ISCSI_MAX_TARGET) {
+                       iscsi_cls_session_printk(KERN_ERR, session,
+                                                "Too many iscsi targets. Max "
+                                                "number of targets is %d.\n",
+                                                ISCSI_MAX_TARGET - 1);
+                       goto release_host;
+               }
+       }
+       session->target_id = id;
 
        snprintf(session->dev.bus_id, BUS_ID_SIZE, "session%u",
                 session->sid);
@@ -541,10 +612,6 @@ int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
        list_add(&session->sess_list, &sesslist);
        spin_unlock_irqrestore(&sesslock, flags);
 
-       mutex_lock(&ihost->mutex);
-       list_add(&session->host_list, &ihost->sessions);
-       mutex_unlock(&ihost->mutex);
-
        iscsi_session_event(session, ISCSI_KEVENT_CREATE_SESSION);
        return 0;
 

diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 176353c..13c92d7 100644 (file)
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -331,7 +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, uint32_t);
+                   uint16_t, int, uint32_t, unsigned int);
 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,

diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
index 0553240..d6b8231 100644 (file)
--- a/include/scsi/scsi_transport_iscsi.h
+++ b/include/scsi/scsi_transport_iscsi.h
@@ -161,9 +161,10 @@ enum {
        ISCSI_SESSION_FREE,
 };
 
+#define ISCSI_MAX_TARGET -1
+
 struct iscsi_cls_session {
        struct list_head sess_list;             /* item in session_list */
-       struct list_head host_list;
        struct iscsi_transport *transport;
        spinlock_t lock;
        struct work_struct block_work;
@@ -175,7 +176,7 @@ struct iscsi_cls_session {
        int recovery_tmo;
        struct delayed_work recovery_work;
 
-       int target_id;
+       unsigned int target_id;
 
        int state;
        int sid;                                /* session id */
@@ -193,7 +194,6 @@ struct iscsi_cls_session {
        iscsi_dev_to_session(_stgt->dev.parent)
 
 struct iscsi_cls_host {
-       struct list_head sessions;
        atomic_t nr_scans;
        struct mutex mutex;
        struct workqueue_struct *scan_workq;