Commit 643eb2d9 authored by James Bottomley's avatar James Bottomley

[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: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent f7120a4f
......@@ -322,6 +322,21 @@ out:
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 @@ static struct scsi_target *scsi_alloc_target(struct device *parent,
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 @@ static struct scsi_target *scsi_alloc_target(struct device *parent,
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 @@ static struct scsi_target *scsi_alloc_target(struct device *parent,
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 @@ static void scsi_target_reap_usercontext(struct work_struct *work)
{
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 @@ void scsi_target_reap(struct scsi_target *starget)
{
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);
state = starget->state;
empty = --starget->reap_ref == 0 &&
list_empty(&starget->devices) ? 1 : 0;
spin_unlock_irqrestore(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);
if (!empty)
return;
}
spin_unlock_irqrestore(shost->host_lock, flags);
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 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget,
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 @@ struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
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 @@ static void __scsi_scan_target(struct device *parent, unsigned int channel,
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);
......
......@@ -809,6 +809,27 @@ sdev_store_queue_type_rw(struct device *dev, struct device_attribute *attr,
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 scsi_sysfs_add_sdev(struct scsi_device *sdev)
{
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);
......
......@@ -181,7 +181,8 @@ struct scsi_device {
sdev_printk(prefix, (scmd)->device, fmt, ##a)
enum scsi_target_state {
STARGET_RUNNING = 1,
STARGET_CREATED = 1,
STARGET_RUNNING,
STARGET_DEL,
};
......
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