Below is a patch to add some hotplug infrastructure to the Linux SCSI subsystem.
New files: include/scsi/scsi_hotplug.h drivers/scsi/scsi_hotplug.c implements a new exported function:
extern int scsi_topology_hctl_action(struct Scsi_Host *shost, unsigned int channel, unsigned int id, unsigned int lun, enum scsi_topology_action action);
which invokes kobject_hotplug() on a temporary "scsi_topology" device. This device represents a target that exists on a topology (i.e. was just inserted into a hot plug enclosure, or was just created by a RAID controller management application) but is not yet hooked into the kernel.
In addition, two more infrastructure pieces are necessary: udev-050-scsi_topology.patch - adds the subsystem name "scsi_topology" to the list of devices *not* to wait for the creation of files in sysfs for - scsi_topology devices aren't to be registered in sysfs.
/etc/hotplug/scsi_topology.agent handles the hotplug call, and invokes /sys/class/scsi_host/hostX/scan and /sys/class/scsi_device/H:C:T:L:/device/delete as appropriate.
The flow is as follows:
# echo "2" > /sys/class/scsi_host/host2/logical_drive_created (to be done by a management application that knows it just created logical drive #2 on the controller)
megaraid_mbox.c sysfs method converts logical drive number to HCTL value, calls scsi_topology_hctl_action().
scsi_topology_hctl_action() invokes kobject_hotplug() with a scsi_topology subsystem device.
kobject_hotplug() calls /sbin/hotplug or /sbin/udevsend (more likely the latter), which invokes /etc/hotplug/scsi_topology.agent with the ACTION={add,remove}.
scsi_topology.agent invokes /sys/class/scsi_host/hostX/scan or /sys/class/scsi_device/H:C:T:L:/device/delete as appropriate.
From this point, we're back into known territory, with the device being made known, or deleted from, the kernel's view.
Thoughts?
Just curious why the following flow would not work/be preferred:
1. echo "2" > /sys/class/scsi_host/host2/logical_drive_created
2. megaraid_mbox.c sysfs method converts logical drive number to HCTL value, calls scsi_add_device.
3. scsi_add_device works as it does today and generates hotplug events
-Brian
-- Brian King eServer Storage I/O IBM Linux Technology Center - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
