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[SCSI] zfcp: Block FC transport rports early on errors

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Use the I/O blocking mechanism in the FC transport class to allow
faster failovers for multipathing:
- Call fc_remote_port_delete early to set the rport to BLOCKED.
- Check the rport status in queuecommand with fc_remote_portchkready
  to no longer accept new I/O for this port and fail the I/O with the
  appropriate scsi_cmnd result.
- Implement the terminate_rport_io handler to abort all pending I/O
  requests
- Return SCSI commands with DID_TRANSPORT_DISRUPTED while erp is
  running.
- When updating the remote port status, check for late changes and
  update the remote ports status accordingly.

Acked-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This commit is contained in:
Christof Schmitt
2009-03-02 13:09:08 +01:00
committed by James Bottomley
parent 2409549068
commit a2fa0aede0
7 changed files with 157 additions and 56 deletions
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119
drivers/s390/scsi/zfcp_scsi.c
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@@ -3,7 +3,7 @@
*
* Interface to Linux SCSI midlayer.
*
* Copyright IBM Corporation 2002, 2008
* Copyright IBM Corporation 2002, 2009
*/
#define KMSG_COMPONENT "zfcp"
@@ -57,8 +57,8 @@ static int zfcp_scsi_queuecommand(struct scsi_cmnd *scpnt,
{
struct zfcp_unit *unit;
struct zfcp_adapter *adapter;
int status;
int ret;
int status, scsi_result, ret;
struct fc_rport *rport = starget_to_rport(scsi_target(scpnt->device));
/* reset the status for this request */
scpnt->result = 0;
@@ -80,6 +80,14 @@ static int zfcp_scsi_queuecommand(struct scsi_cmnd *scpnt,
return 0;
}
scsi_result = fc_remote_port_chkready(rport);
if (unlikely(scsi_result)) {
scpnt->result = scsi_result;
zfcp_scsi_dbf_event_result("fail", 4, adapter, scpnt, NULL);
scpnt->scsi_done(scpnt);
return 0;
}
status = atomic_read(&unit->status);
if (unlikely((status & ZFCP_STATUS_COMMON_ERP_FAILED) ||
!(status & ZFCP_STATUS_COMMON_RUNNING))) {
@@ -473,6 +481,109 @@ static void zfcp_set_rport_dev_loss_tmo(struct fc_rport *rport, u32 timeout)
rport->dev_loss_tmo = timeout;
}
/**
* zfcp_scsi_dev_loss_tmo_callbk - Free any reference to rport
* @rport: The rport that is about to be deleted.
*/
static void zfcp_scsi_dev_loss_tmo_callbk(struct fc_rport *rport)
{
struct zfcp_port *port = rport->dd_data;
write_lock_irq(&zfcp_data.config_lock);
port->rport = NULL;
write_unlock_irq(&zfcp_data.config_lock);
}
/**
* zfcp_scsi_terminate_rport_io - Terminate all I/O on a rport
* @rport: The FC rport where to teminate I/O
*
* Abort all pending SCSI commands for a port by closing the
* port. Using a reopen for avoids a conflict with a shutdown
* overwriting a reopen.
*/
static void zfcp_scsi_terminate_rport_io(struct fc_rport *rport)
{
struct zfcp_port *port = rport->dd_data;
zfcp_erp_port_reopen(port, 0, "sctrpi1", NULL);
}
static void zfcp_scsi_rport_register(struct zfcp_port *port)
{
struct fc_rport_identifiers ids;
struct fc_rport *rport;
ids.node_name = port->wwnn;
ids.port_name = port->wwpn;
ids.port_id = port->d_id;
ids.roles = FC_RPORT_ROLE_FCP_TARGET;
rport = fc_remote_port_add(port->adapter->scsi_host, 0, &ids);
if (!rport) {
dev_err(&port->adapter->ccw_device->dev,
"Registering port 0x%016Lx failed\n",
(unsigned long long)port->wwpn);
return;
}
rport->dd_data = port;
rport->maxframe_size = port->maxframe_size;
rport->supported_classes = port->supported_classes;
port->rport = rport;
}
static void zfcp_scsi_rport_block(struct zfcp_port *port)
{
if (port->rport)
fc_remote_port_delete(port->rport);
}
void zfcp_scsi_schedule_rport_register(struct zfcp_port *port)
{
zfcp_port_get(port);
port->rport_task = RPORT_ADD;
if (!queue_work(zfcp_data.work_queue, &port->rport_work))
zfcp_port_put(port);
}
void zfcp_scsi_schedule_rport_block(struct zfcp_port *port)
{
zfcp_port_get(port);
port->rport_task = RPORT_DEL;
if (!queue_work(zfcp_data.work_queue, &port->rport_work))
zfcp_port_put(port);
}
void zfcp_scsi_schedule_rports_block(struct zfcp_adapter *adapter)
{
struct zfcp_port *port;
list_for_each_entry(port, &adapter->port_list_head, list)
zfcp_scsi_schedule_rport_block(port);
}
void zfcp_scsi_rport_work(struct work_struct *work)
{
struct zfcp_port *port = container_of(work, struct zfcp_port,
rport_work);
while (port->rport_task) {
if (port->rport_task == RPORT_ADD) {
port->rport_task = RPORT_NONE;
zfcp_scsi_rport_register(port);
} else {
port->rport_task = RPORT_NONE;
zfcp_scsi_rport_block(port);
}
}
zfcp_port_put(port);
}
struct fc_function_template zfcp_transport_functions = {
.show_starget_port_id = 1,
.show_starget_port_name = 1,
@@ -491,6 +602,8 @@ struct fc_function_template zfcp_transport_functions = {
.reset_fc_host_stats = zfcp_reset_fc_host_stats,
.set_rport_dev_loss_tmo = zfcp_set_rport_dev_loss_tmo,
.get_host_port_state = zfcp_get_host_port_state,
.dev_loss_tmo_callbk = zfcp_scsi_dev_loss_tmo_callbk,
.terminate_rport_io = zfcp_scsi_terminate_rport_io,
.show_host_port_state = 1,
/* no functions registered for following dynamic attributes but
directly set by LLDD */