Michael Reed wrote:
> I'll give it a go and see if this fixes a possibly related issue I
> was experiencing on my test system.
>
> Thank you for working this up.
Well, this saves me some debugging. With your patch applied
I no longer experience a console hang if more than about 8
targets disappear at one.
THANK YOU.
Mike
>
> Mike
>
>
> James.Smart@xxxxxxxxxx wrote:
>> In the scenario that a link was broken, the devloss timer for each rport
>> was expire at roughly the same time, causing lots of "delete" workqueue items
>> being queued. Depth is dependent upon the number of rports that were on the link.
>>
>> The rport target remove calls were calling flush_scheduled_work(), which would
>> interrupt the stream, and start the next workqueue item, which did the same thing,
>> and so on until recursion depth was large.
>>
>> This fix stops the recursion in the initial delete path, and pushes it off to
>> a host-level work item that reaps the dead rports.
>>
>> James - this fix should be added to the final list of 2.6.15-rc5 patches you just posted.
>>
>> -- james s
>>
>>
>>
>> diff -upNr a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
>> --- a/drivers/scsi/scsi_transport_fc.c 2005-10-17 12:24:01.000000000 -0400
>> +++ b/drivers/scsi/scsi_transport_fc.c 2005-12-15 09:45:42.000000000 -0500
>> @@ -106,6 +106,7 @@ static struct {
>> { FC_PORTSTATE_LINKDOWN, "Linkdown" },
>> { FC_PORTSTATE_ERROR, "Error" },
>> { FC_PORTSTATE_LOOPBACK, "Loopback" },
>> + { FC_PORTSTATE_DELETED, "Deleted" },
>> };
>> fc_enum_name_search(port_state, fc_port_state, fc_port_state_names)
>> #define FC_PORTSTATE_MAX_NAMELEN 20
>> @@ -212,6 +213,7 @@ fc_bitfield_name_search(remote_port_role
>> #define FC_MGMTSRVR_PORTID 0x00000a
>>
>>
>> +static void fc_shost_remove_rports(void *data);
>> static void fc_timeout_deleted_rport(void *data);
>> static void fc_scsi_scan_rport(void *data);
>> static void fc_rport_terminate(struct fc_rport *rport);
>> @@ -319,6 +321,8 @@ static int fc_host_setup(struct transpor
>> fc_host_next_rport_number(shost) = 0;
>> fc_host_next_target_id(shost) = 0;
>>
>> + fc_host_flags(shost) = 0;
>> + INIT_WORK(&fc_host_rport_del_work(shost), fc_shost_remove_rports, shost);
>> return 0;
>> }
>>
>> @@ -388,6 +392,7 @@ show_fc_rport_##field (struct class_devi
>> struct fc_internal *i = to_fc_internal(shost->transportt); \
>> if ((i->f->get_rport_##field) && \
>> !((rport->port_state == FC_PORTSTATE_BLOCKED) || \
>> + (rport->port_state == FC_PORTSTATE_DELETED) || \
>> (rport->port_state == FC_PORTSTATE_NOTPRESENT))) \
>> i->f->get_rport_##field(rport); \
>> return snprintf(buf, sz, format_string, cast rport->field); \
>> @@ -403,6 +408,7 @@ store_fc_rport_##field(struct class_devi
>> struct Scsi_Host *shost = rport_to_shost(rport); \
>> struct fc_internal *i = to_fc_internal(shost->transportt); \
>> if ((rport->port_state == FC_PORTSTATE_BLOCKED) || \
>> + (rport->port_state == FC_PORTSTATE_DELETED) || \
>> (rport->port_state == FC_PORTSTATE_NOTPRESENT)) \
>> return -EBUSY; \
>> val = simple_strtoul(buf, NULL, 0); \
>> @@ -520,6 +526,7 @@ store_fc_rport_dev_loss_tmo(struct class
>> struct Scsi_Host *shost = rport_to_shost(rport);
>> struct fc_internal *i = to_fc_internal(shost->transportt);
>> if ((rport->port_state == FC_PORTSTATE_BLOCKED) ||
>> + (rport->port_state == FC_PORTSTATE_DELETED) ||
>> (rport->port_state == FC_PORTSTATE_NOTPRESENT))
>> return -EBUSY;
>> val = simple_strtoul(buf, NULL, 0);
>> @@ -1739,7 +1746,7 @@ fc_timeout_deleted_rport(void *data)
>> rport->maxframe_size = -1;
>> rport->supported_classes = FC_COS_UNSPECIFIED;
>> rport->roles = FC_RPORT_ROLE_UNKNOWN;
>> - rport->port_state = FC_PORTSTATE_NOTPRESENT;
>> + rport->port_state = FC_PORTSTATE_DELETED;
>>
>> /* remove the identifiers that aren't used in the consisting binding */
>> switch (fc_host_tgtid_bind_type(shost)) {
>> @@ -1759,14 +1766,23 @@ fc_timeout_deleted_rport(void *data)
>> break;
>> }
>>
>> - spin_unlock_irqrestore(shost->host_lock, flags);
>> -
>> /*
>> * As this only occurs if the remote port (scsi target)
>> * went away and didn't come back - we'll remove
>> * all attached scsi devices.
>> + *
>> + * We'll schedule the shost work item to perform the actual removal
>> + * to avoid recursion in the different flush calls if we perform
>> + * the removal in each target - and there are lots of targets
>> + * whose timeouts fire at the same time.
>> */
>> - fc_rport_tgt_remove(rport);
>> +
>> + if ( !(fc_host_flags(shost) & FC_SHOST_RPORT_DEL_SCHEDULED)) {
>> + fc_host_flags(shost) |= FC_SHOST_RPORT_DEL_SCHEDULED;
>> + scsi_queue_work(shost, &fc_host_rport_del_work(shost));
>> + }
>> +
>> + spin_unlock_irqrestore(shost->host_lock, flags);
>> }
>>
>> /**
>> @@ -1788,6 +1804,41 @@ fc_scsi_scan_rport(void *data)
>> }
>>
>>
>> +/**
>> + * fc_shost_remove_rports - called to remove all rports that are marked
>> + * as in a deleted (not connected) state.
>> + *
>> + * @data: shost whose rports are to be looked at
>> + **/
>> +static void
>> +fc_shost_remove_rports(void *data)
>> +{
>> + struct Scsi_Host *shost = (struct Scsi_Host *)data;
>> + struct fc_rport *rport, *next_rport;
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(shost->host_lock, flags);
>> + while (fc_host_flags(shost) & FC_SHOST_RPORT_DEL_SCHEDULED) {
>> +
>> + fc_host_flags(shost) &= ~FC_SHOST_RPORT_DEL_SCHEDULED;
>> +
>> +restart_search:
>> + list_for_each_entry_safe(rport, next_rport,
>> + &fc_host_rport_bindings(shost), peers) {
>> + if (rport->port_state == FC_PORTSTATE_DELETED) {
>> + rport->port_state = FC_PORTSTATE_NOTPRESENT;
>> + spin_unlock_irqrestore(shost->host_lock, flags);
>> + fc_rport_tgt_remove(rport);
>> + spin_lock_irqsave(shost->host_lock, flags);
>> + goto restart_search;
>> + }
>> + }
>> +
>> + }
>> + spin_unlock_irqrestore(shost->host_lock, flags);
>> +}
>> +
>> +
>> MODULE_AUTHOR("Martin Hicks");
>> MODULE_DESCRIPTION("FC Transport Attributes");
>> MODULE_LICENSE("GPL");
>> diff -upNr a/include/scsi/scsi_transport_fc.h b/include/scsi/scsi_transport_fc.h
>> --- a/include/scsi/scsi_transport_fc.h 2005-10-17 10:03:47.000000000 -0400
>> +++ b/include/scsi/scsi_transport_fc.h 2005-12-07 09:43:30.000000000 -0500
>> @@ -78,6 +78,7 @@ enum fc_port_state {
>> FC_PORTSTATE_LINKDOWN,
>> FC_PORTSTATE_ERROR,
>> FC_PORTSTATE_LOOPBACK,
>> + FC_PORTSTATE_DELETED,
>> };
>>
>>
>> @@ -324,8 +325,14 @@ struct fc_host_attrs {
>> struct list_head rport_bindings;
>> u32 next_rport_number;
>> u32 next_target_id;
>> + u8 flags;
>> + struct work_struct rport_del_work;
>> };
>>
>> +/* values for struct fc_host_attrs "flags" field: */
>> +#define FC_SHOST_RPORT_DEL_SCHEDULED 0x01
>> +
>> +
>> #define fc_host_node_name(x) \
>> (((struct fc_host_attrs *)(x)->shost_data)->node_name)
>> #define fc_host_port_name(x) \
>> @@ -364,6 +371,10 @@ struct fc_host_attrs {
>> (((struct fc_host_attrs *)(x)->shost_data)->next_rport_number)
>> #define fc_host_next_target_id(x) \
>> (((struct fc_host_attrs *)(x)->shost_data)->next_target_id)
>> +#define fc_host_flags(x) \
>> + (((struct fc_host_attrs *)(x)->shost_data)->flags)
>> +#define fc_host_rport_del_work(x) \
>> + (((struct fc_host_attrs *)(x)->shost_data)->rport_del_work)
>>
>>
>> /* The functions by which the transport class and the driver communicate */
>> -
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