From 643eb2d932c97a0583381629d632d486934cf7ee Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Sat, 22 Mar 2008 22:42:27 -0500 Subject: [PATCH] [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 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 --- drivers/scsi/scsi_scan.c | 72 ++++++++++++++++++-------------------- drivers/scsi/scsi_sysfs.c | 27 ++++++++++++++ include/scsi/scsi_device.h | 3 +- 3 files changed, 63 insertions(+), 39 deletions(-) diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index e1644b270c..fcd7455ffc 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -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); diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 84e2a8ad83..198aa4571e 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -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); diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index b8b19e2f57..f6a9fe0ef0 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -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, }; -- 2.39.5