Hi,
I've a block device driver which does the following,
Inside the request function I do something like this:
request(fn) {
while ((req = elv_next_request(q)) != NULL) {
....................set up the request;
spin_unlock_irq(q->queue_lock);
call the transfer(set_up_req) function;
spin_lock_irq(q->queue_lock);
}
spin_unlock_irq (q->queue_lock);
/* allow callback to execute as it needs the lock!!! */
spin_lock_irq (q->queue_lock);
}
and the transfer function calls the scsi_execute_asyn(....) with the callback function doing the end request. So, the ending of the request is done like below:
callback(fn) {
spin_lock_irqsave(q->queue_lock, flags);
if (!end_that_request_first(set_up_req->req, cmpstatus,
set_up_req->req->nr_sectors)) {
add_disk_randomness(...);
end_that_request_last(set_up_req->req,0);
}
spin_unlock_irqrestore(q->queue_lock, flags);
}
This code works fine with most of the kernel versions, but fails on some like , Linux 2.6.18-8.el5-xen
Please help me to find out where I'm going wrong?
when I say 'fails' it just hangs without any error ....I'm using dt(Data test) to write to the disk. The logs show that all the requests that have been sent for processing, have completed sucessfully. Its just that new requests never enter the request function. So, the dt writes almost half the data and then simply hangs.
The actual code does nothing but, call the scsi_execute_async , which
later on calls the callback function which is used to end the request.
So, both the callback function and the request function need to share
the queue lock. So the code samples I sent cover all the aspects of my
program. What I'm looking for here is how can I end the requests
asynchronously much later after the request processing is done. Please note
here that the asynchronous end requests is done by the callback function
of the scsi_execute_async, which needs to share the queue lock with
the request function.
when I say 'fails' it just hangs without any error ....I'm using
dt(Data
test) to write to the disk. The logs show that all the requests that
have
been sent for processing, have completed successfully. Its just that new
requests never enter the request function. So, the dt writes almost
half the
data and then simply hangs.
Thanks in advance for an early reply.
Anil P.
