On Oct 20, 2008, at 4:45 AM, FUJITA Tomonori wrote:
On Mon, 20 Oct 2008 03:59:18 -0700
Seokmann Ju <seokmann.ju@xxxxxxxxxx> wrote:
On Oct 14, 2008, at 7:13 AM, Seokmann Ju wrote:
On Oct 14, 2008, at 6:34 AM, FUJITA Tomonori wrote:
On Tue, 14 Oct 2008 04:44:17 -0700
Seokmann Ju <seokmann.ju@xxxxxxxxxx> wrote:
+static int
+fc_service_handler(struct Scsi_Host *shost, struct fc_rport
*rport,
+ struct request *req, struct request_queue *q)
+{
+ int ret;
+ struct request *rsp = req->next_rq;
+
+ if (!rsp) {
+ printk(KERN_ERR "ERROR: space for a FC service"
+ " response is missing\n");
+ return -EINVAL;
+ }
+
+ if ((req->bio->bi_vcnt > FC_SERVICE_MAX_SG) ||
+ (rsp->bio->bi_vcnt > FC_SERVICE_MAX_SG)) {
+ printk(KERN_ERR "ERROR: a FC service"
+ " supports no more than %d SGs\n", FC_SERVICE_MAX_SG);
+ return -EINVAL;
+ }
This doesn't look correct. bi_vcnt is not related with the number
of
sg. You use scatter-gather for large data transfer. You don't
need to
worry about bi_vcnt.
I see...
Is there is a way to check, then, how many SG entries the service
needs before the blk_rq_map_sg()?
As I wrote in the previous mail, via blk_queue_max_hw_segments()
and
blk_queue_max_phys_segments(), you can tell the block layer the
number
of sg segments you can handle.
One more question here...
With addition of a timer into the FC transport layer for fc_service
handing, the
system seems getting locked up, as below trace shows.
I've been trying to figure out the reasons but not able to do.
It seems like that there is something that I don't know,
fundamentally
about
the timer usage...
Could you please comments on what might be the things causing the
problem?
Hmm, why do you need to invent the own timeout mechanism?
I was trying to have similar timeout mechanism as in the SCSI I/O,
just like 'scsi_add_timer()' in scsi.c:scsi_dispatch_cmd()....
I assume this is not right approach...?
I think that you can use the block layer timeout feature. It doesn't
work for fc transport pass through? You can just remove struct
timer_list in struct fc_service. Check out how scsi-ml uses
blk_queue_rq_timed_out and blk_queue_rq_timeout.
OK. Thanks, I will try out this.
What are the exact name of those APIs, again?
It seems like that none of them are available in the source tree....
Seokmann
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