This patch modifies the midlayer for the addition of transport objects to be layered between the scsi_host and the scsi_target. FC will be the first consumer - placing the remote port between the host and the target.
There are 4 areas of modification:
- Opening up the starget creation so that transports can
control the allocation and teardown of SCSI targets.
- Adding a linked list of targets to the shost, which is searched
at sdev creation when looking for a target already allocated by
a transport.
- Dealing with all the code that expects the device above the scsi
target to be a scsi host. The dev_to_shost() function is subverted
to start at the supplied device and check for a scsi host device.
If not a scsi host, go to the next parent and check again. Allows
any number of objects between the starget and shost, while providing
source compatibility.
- Addition of a scsi_forget_target() routine. The transport will
have a remove_host() function which will want to tear down the
scsi devices under whatever transport objects exist. On unload,
the driver will call the transport_remove_host() function
immediately prior to the scsi_remove_host() call.
In transport_remove_host(), in traversing the list of attached
sdevs, functions such as shost_for_each_device() are unusable,
as they utilize scsi_device_get(), which attempts to take
out references on the module, which is marked for deletion.
Therefore, we use a function that walks the __devices list w/o
enforcing the references.
-- James S
p00001_scsimid.patch
Description: p00001_scsimid.patch
