Initiator

[kundra]

As i am studying the source code of open iscsi , getting a problem in
some of the aspects that from where to actually start the code study .
As what i get there is transport template that sends or rcv the iscsi
data through the callbacks provided in it , But there is ioctl and
kcall this interface i am not understanding what is the use of kcall ,
log_debug exactly how it works so provide me direction to know betetr
about the kcall & log_debug stuff ...I am writing my queries
1) kcall
2)log_debug
3)ioctl
4) from where the iscsi request generates where the user pass the info
that it want to read this target device , write on this target device


Regards
Anshul Kundra

[Mike Christie]

On 01/29/2012 01:32 PM, kundra wrote:
> As i am studying the source code of open iscsi , getting a problem in
> some of the aspects that from where to actually start the code study .
> As what i get there is transport template that sends or rcv the iscsi
> data through the callbacks provided in it , But there is ioctl and

ioctl is not used in linux. It was used when the code worked on one of
the BSDs but it is not supported anymore.

> kcall this interface i am not understanding what is the use of kcall ,
> log_debug exactly how it works so provide me direction to know betetr
> about the kcall & log_debug stuff ...I am writing my queries
> 1) kcall
> 2)log_debug
> 3)ioctl
> 4) from where the iscsi request generates where the user pass the info
> that it want to read this target device , write on this target device
>

The initiator will call the iscsi_ipc callout which now ends up just
calling a netlink function in netlink.c. This will send down a netlink
request to the kernel driver. The kernel driver executes the request
then pass up to userspace the result. The netlink.c code will then parse
it and pass back the result to the initiator through the ipc_ev_clbk
callback or if it was a synchronous call it will just return to the
iscsi_ipc callout.

[kundra]

To Developer's
I have studied the netlink interface What i have understood from
code
study is that the request goes to the iscsi layer through the
netlink
interface after then the iscsi_tcp forwards the request through the
network
In response the iscsi_tcp Interface receives the response , then
response being read through the netlink interface , But issue is that
where the both netlink and iscsi_tcp interface are combining , they
are both seems to be different interfaces . Not able to find the
connection between them at any phase . Hope for instant reply

Regards
Anshul Kundra