[SCSI] Add target alloc/destroy callbacks to the host template

This gives the HBA driver notice when a target is created and
destroyed to allow it to manage its own target based allocations
accordingly.

This is a much reduced verson of the original patch sent in by
James.Smart@Emulex.com

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 5886115..4d273ce 100644 (file)
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -293,6 +293,10 @@ static void scsi_target_dev_release(struct device *dev)
 {
        struct device *parent = dev->parent;
        struct scsi_target *starget = to_scsi_target(dev);
+       struct Scsi_Host *shost = dev_to_shost(parent);
+
+       if (shost->hostt->target_destroy)
+               shost->hostt->target_destroy(starget);
        kfree(starget);
        put_device(parent);
 }
@@ -360,9 +364,23 @@ static struct scsi_target *scsi_alloc_target(struct device *parent,
        list_add_tail(&starget->siblings, &shost->__targets);
        spin_unlock_irqrestore(shost->host_lock, flags);
        /* allocate and add */
-       transport_setup_device(&starget->dev);
-       device_add(&starget->dev);
-       transport_add_device(&starget->dev);
+       transport_setup_device(dev);
+       device_add(dev);
+       transport_add_device(dev);
+       if (shost->hostt->target_alloc) {
+               int error = shost->hostt->target_alloc(starget);
+
+               if(error) {
+                       dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error);
+                       /* don't want scsi_target_reap to do the final
+                        * put because it will be under the host lock */
+                       get_device(dev);
+                       scsi_target_reap(starget);
+                       put_device(dev);
+                       return NULL;
+               }
+       }
+
        return starget;
 
  found:

diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index c018020..63c91dd 100644 (file)
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -154,7 +154,9 @@ struct scsi_target {
        unsigned int            id; /* target id ... replace
                                     * scsi_device.id eventually */
        unsigned long           create:1; /* signal that it needs to be added */
-       unsigned long           starget_data[0];
+       void                    *hostdata; /* available to low-level driver */
+       unsigned long           starget_data[0]; /* for the transport */
+       /* starget_data must be the last element!!!! */
 } __attribute__((aligned(sizeof(unsigned long))));
 
 #define to_scsi_target(d)      container_of(d, struct scsi_target, dev)

diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 1cee1e1..db9914a 100644 (file)
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -10,6 +10,7 @@ struct block_device;
 struct module;
 struct scsi_cmnd;
 struct scsi_device;
+struct scsi_target;
 struct Scsi_Host;
 struct scsi_host_cmd_pool;
 struct scsi_transport_template;
@@ -227,6 +228,30 @@ struct scsi_host_template {
         */
        void (* slave_destroy)(struct scsi_device *);
 
+       /*
+        * Before the mid layer attempts to scan for a new device attached
+        * to a target where no target currently exists, it will call this
+        * entry in your driver.  Should your driver need to allocate any
+        * structs or perform any other init items in order to send commands
+        * to a currently unused target, then this is where you can perform
+        * those allocations.
+        *
+        * Return values: 0 on success, non-0 on failure
+        *
+        * Status: OPTIONAL
+        */
+       int (* target_alloc)(struct scsi_target *);
+
+       /*
+        * Immediately prior to deallocating the target structure, and
+        * after all activity to attached scsi devices has ceased, the
+        * midlayer calls this point so that the driver may deallocate
+        * and terminate any references to the target.
+        *
+        * Status: OPTIONAL
+        */
+       void (* target_destroy)(struct scsi_target *);
+
        /*
         * fill in this function to allow the queue depth of this host
         * to be changeable (on a per device basis).  returns either