[SCSI] rework scsi_target allocation
The current target allocation code registeres each possible target
with sysfs; it will be deleted again if no useable LUN on this target
was found. This results in a string of 'target add/target remove' uevents.
Based on a patch by Hannes Reinecke <hare@suse.de> this patch reworks
the target allocation code so that only uevents for existing targets
are sent. The sysfs registration is split off from the existing
scsi_target_alloc() into a in a new scsi_add_target() function, which
should be called whenever an existing target is found. Only then a
uevent is sent, so we'll be generating events for existing targets
only.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index e1644b2..fcd7455 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -322,6 +322,21 @@
return NULL;
}
+static void scsi_target_destroy(struct scsi_target *starget)
+{
+ struct device *dev = &starget->dev;
+ struct Scsi_Host *shost = dev_to_shost(dev->parent);
+ unsigned long flags;
+
+ transport_destroy_device(dev);
+ spin_lock_irqsave(shost->host_lock, flags);
+ if (shost->hostt->target_destroy)
+ shost->hostt->target_destroy(starget);
+ list_del_init(&starget->siblings);
+ spin_unlock_irqrestore(shost->host_lock, flags);
+ put_device(dev);
+}
+
static void scsi_target_dev_release(struct device *dev)
{
struct device *parent = dev->parent;
@@ -406,7 +421,7 @@
starget->channel = channel;
INIT_LIST_HEAD(&starget->siblings);
INIT_LIST_HEAD(&starget->devices);
- starget->state = STARGET_RUNNING;
+ starget->state = STARGET_CREATED;
starget->scsi_level = SCSI_2;
retry:
spin_lock_irqsave(shost->host_lock, flags);
@@ -419,18 +434,6 @@
spin_unlock_irqrestore(shost->host_lock, flags);
/* allocate and add */
transport_setup_device(dev);
- error = device_add(dev);
- if (error) {
- dev_err(dev, "target device_add failed, error %d\n", error);
- spin_lock_irqsave(shost->host_lock, flags);
- list_del_init(&starget->siblings);
- spin_unlock_irqrestore(shost->host_lock, flags);
- transport_destroy_device(dev);
- put_device(parent);
- kfree(starget);
- return NULL;
- }
- transport_add_device(dev);
if (shost->hostt->target_alloc) {
error = shost->hostt->target_alloc(starget);
@@ -438,9 +441,7 @@
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);
+ scsi_target_destroy(starget);
return NULL;
}
}
@@ -467,18 +468,10 @@
{
struct scsi_target *starget =
container_of(work, struct scsi_target, ew.work);
- struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
- unsigned long flags;
transport_remove_device(&starget->dev);
device_del(&starget->dev);
- transport_destroy_device(&starget->dev);
- spin_lock_irqsave(shost->host_lock, flags);
- if (shost->hostt->target_destroy)
- shost->hostt->target_destroy(starget);
- list_del_init(&starget->siblings);
- spin_unlock_irqrestore(shost->host_lock, flags);
- put_device(&starget->dev);
+ scsi_target_destroy(starget);
}
/**
@@ -493,21 +486,25 @@
{
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
unsigned long flags;
+ enum scsi_target_state state;
+ int empty;
spin_lock_irqsave(shost->host_lock, flags);
-
- if (--starget->reap_ref == 0 && list_empty(&starget->devices)) {
- BUG_ON(starget->state == STARGET_DEL);
- starget->state = STARGET_DEL;
- spin_unlock_irqrestore(shost->host_lock, flags);
- execute_in_process_context(scsi_target_reap_usercontext,
- &starget->ew);
- return;
-
- }
+ state = starget->state;
+ empty = --starget->reap_ref == 0 &&
+ list_empty(&starget->devices) ? 1 : 0;
spin_unlock_irqrestore(shost->host_lock, flags);
- return;
+ if (!empty)
+ return;
+
+ BUG_ON(state == STARGET_DEL);
+ starget->state = STARGET_DEL;
+ if (state == STARGET_CREATED)
+ scsi_target_destroy(starget);
+ else
+ execute_in_process_context(scsi_target_reap_usercontext,
+ &starget->ew);
}
/**
@@ -1056,8 +1053,9 @@
scsi_inq_str(vend, result, 8, 16),
scsi_inq_str(mod, result, 16, 32));
});
+
}
-
+
res = SCSI_SCAN_TARGET_PRESENT;
goto out_free_result;
}
@@ -1497,7 +1495,6 @@
if (scsi_host_scan_allowed(shost))
scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
mutex_unlock(&shost->scan_mutex);
- transport_configure_device(&starget->dev);
scsi_target_reap(starget);
put_device(&starget->dev);
@@ -1578,7 +1575,6 @@
out_reap:
/* now determine if the target has any children at all
* and if not, nuke it */
- transport_configure_device(&starget->dev);
scsi_target_reap(starget);
put_device(&starget->dev);
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 84e2a8a..198aa45 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -809,6 +809,27 @@
return count;
}
+static int scsi_target_add(struct scsi_target *starget)
+{
+ int error;
+
+ if (starget->state != STARGET_CREATED)
+ return 0;
+
+ error = device_add(&starget->dev);
+ if (error) {
+ dev_err(&starget->dev, "target device_add failed, error %d\n", error);
+ get_device(&starget->dev);
+ scsi_target_reap(starget);
+ put_device(&starget->dev);
+ return error;
+ }
+ transport_add_device(&starget->dev);
+ starget->state = STARGET_RUNNING;
+
+ return 0;
+}
+
static struct device_attribute sdev_attr_queue_type_rw =
__ATTR(queue_type, S_IRUGO | S_IWUSR, show_queue_type_field,
sdev_store_queue_type_rw);
@@ -824,10 +845,16 @@
{
int error, i;
struct request_queue *rq = sdev->request_queue;
+ struct scsi_target *starget = sdev->sdev_target;
if ((error = scsi_device_set_state(sdev, SDEV_RUNNING)) != 0)
return error;
+ error = scsi_target_add(starget);
+ if (error)
+ return error;
+
+ transport_configure_device(&starget->dev);
error = device_add(&sdev->sdev_gendev);
if (error) {
put_device(sdev->sdev_gendev.parent);
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index b8b19e2..f6a9fe0 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -181,7 +181,8 @@
sdev_printk(prefix, (scmd)->device, fmt, ##a)
enum scsi_target_state {
- STARGET_RUNNING = 1,
+ STARGET_CREATED = 1,
+ STARGET_RUNNING,
STARGET_DEL,
};