drivers/scsi/scsi_transport_fc.c

Source file repositories/reference/linux-study-clean/drivers/scsi/scsi_transport_fc.c

File Facts

System
Linux kernel
Corpus path
drivers/scsi/scsi_transport_fc.c
Extension
.c
Size
133982 bytes
Lines
4415
Domain
Driver Families
Bucket
drivers/scsi
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

error = device_add(dev);
	if (error) {
		printk(KERN_ERR "FC Remote Port device_add failed\n");
		goto delete_rport;
	}
	transport_add_device(dev);
	transport_configure_device(dev);

	fc_bsg_rportadd(shost, rport);
	/* ignore any bsg add error - we just can't do sgio */

	if (rport->roles & FC_PORT_ROLE_FCP_TARGET) {
		/* initiate a scan of the target */
		rport->flags |= FC_RPORT_SCAN_PENDING;
		scsi_queue_work(shost, &rport->scan_work);
	}

	return rport;

delete_rport:
	transport_destroy_device(dev);
	spin_lock_irqsave(shost->host_lock, flags);
	list_del(&rport->peers);
	scsi_host_put(shost);			/* for fc_host->rport list */
	spin_unlock_irqrestore(shost->host_lock, flags);
	put_device(dev->parent);
	kfree(rport);
	return NULL;
}

/**
 * fc_remote_port_add - notify fc transport of the existence of a remote FC port.
 * @shost:	scsi host the remote port is connected to.
 * @channel:	Channel on shost port connected to.
 * @ids:	The world wide names, fc address, and FC4 port
 *		roles for the remote port.
 *
 * The LLDD calls this routine to notify the transport of the existence
 * of a remote port. The LLDD provides the unique identifiers (wwpn,wwn)
 * of the port, it's FC address (port_id), and the FC4 roles that are
 * active for the port.
 *
 * For ports that are FCP targets (aka scsi targets), the FC transport
 * maintains consistent target id bindings on behalf of the LLDD.
 * A consistent target id binding is an assignment of a target id to
 * a remote port identifier, which persists while the scsi host is
 * attached. The remote port can disappear, then later reappear, and
 * it's target id assignment remains the same. This allows for shifts
 * in FC addressing (if binding by wwpn or wwnn) with no apparent
 * changes to the scsi subsystem which is based on scsi host number and
 * target id values.  Bindings are only valid during the attachment of
 * the scsi host. If the host detaches, then later re-attaches, target
 * id bindings may change.
 *
 * This routine is responsible for returning a remote port structure.
 * The routine will search the list of remote ports it maintains
 * internally on behalf of consistent target id mappings. If found, the
 * remote port structure will be reused. Otherwise, a new remote port
 * structure will be allocated.
 *
 * Whenever a remote port is allocated, a new fc_remote_port class
 * device is created.
 *
 * Should not be called from interrupt context.
 *
 * Notes:
 *	This routine assumes no locks are held on entry.
 */
struct fc_rport *
fc_remote_port_add(struct Scsi_Host *shost, int channel,
	struct fc_rport_identifiers  *ids)
{
	struct fc_internal *fci = to_fc_internal(shost->transportt);
	struct fc_host_attrs *fc_host = shost_to_fc_host(shost);
	struct fc_rport *rport;
	unsigned long flags;
	int match = 0;

	/* ensure any stgt delete functions are done */
	fc_flush_work(shost);

	/*
	 * Search the list of "active" rports, for an rport that has been
	 * deleted, but we've held off the real delete while the target
	 * is in a "blocked" state.
	 */
	spin_lock_irqsave(shost->host_lock, flags);

	list_for_each_entry(rport, &fc_host->rports, peers) {

Annotation

Implementation Notes