Commit 9e4f5e29 authored by James Smart's avatar James Smart Committed by James Bottomley
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[SCSI] FC Pass Thru support

Attached is the ELS/CT pass-thru patch for the FC Transport. The patch
creates a generic framework that lays on top of bsg and the SGIO v4 ioctl
in order to pass transaction requests to LLDD's.

The interface supports the following operations:
  On an fc_host basis:
    Request login to the specified N_Port_ID, creating an fc_rport.
    Request logout of the specified N_Port_ID, deleting an fc_rport
    Send ELS request to specified N_Port_ID w/o requiring a login, and
      wait for ELS response.
    Send CT request to specified N_Port_ID and wait for CT response.
      Login is required, but LLDD is allowed to manage login and decide
      whether it stays in place after the request is satisfied.
    Vendor-Unique request. Allows a LLDD-specific request to be passed
      to the LLDD, and the passing of a response back to the application.
  On an fc_rport basis:
    Send ELS request to nport and wait for ELS response.
    Send CT request to nport and wait for CT response.

The patch also exports several headers from include/scsi such that
they can be available to user-space applications:
  include/scsi/scsi.h
  include/scsi/scsi_netlink.h
  include/scsi/scsi_netlink_fc.h
  include/scsi/scsi_bsg_fc.h

For further information, refer to the last RFC:
http://marc.info/?l=linux-scsi&m=123436574018579&w=2



Note: Documentation is still spotty and will be added later.

[bharrosh@panasas.com: update for new block API]
Signed-off-by: default avatarJames Smart <james.smart@emulex.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent e349792a
SCSI FC Tansport SCSI FC Tansport
============================================= =============================================
Date: 4/12/2007 Date: 11/18/2008
Kernel Revisions for features: Kernel Revisions for features:
rports : <<TBS>> rports : <<TBS>>
vports : 2.6.22 (? TBD) vports : 2.6.22
bsg support : 2.6.30 (?TBD?)
Introduction Introduction
...@@ -15,6 +16,7 @@ The FC transport can be found at: ...@@ -15,6 +16,7 @@ The FC transport can be found at:
drivers/scsi/scsi_transport_fc.c drivers/scsi/scsi_transport_fc.c
include/scsi/scsi_transport_fc.h include/scsi/scsi_transport_fc.h
include/scsi/scsi_netlink_fc.h include/scsi/scsi_netlink_fc.h
include/scsi/scsi_bsg_fc.h
This file is found at Documentation/scsi/scsi_fc_transport.txt This file is found at Documentation/scsi/scsi_fc_transport.txt
...@@ -472,6 +474,14 @@ int ...@@ -472,6 +474,14 @@ int
fc_vport_terminate(struct fc_vport *vport) fc_vport_terminate(struct fc_vport *vport)
FC BSG support (CT & ELS passthru, and more)
========================================================================
<< To Be Supplied >>
Credits Credits
======= =======
The following people have contributed to this document: The following people have contributed to this document:
......
...@@ -1271,6 +1271,11 @@ of interest: ...@@ -1271,6 +1271,11 @@ of interest:
hostdata[0] - area reserved for LLD at end of struct Scsi_Host. Size hostdata[0] - area reserved for LLD at end of struct Scsi_Host. Size
is set by the second argument (named 'xtr_bytes') to is set by the second argument (named 'xtr_bytes') to
scsi_host_alloc() or scsi_register(). scsi_host_alloc() or scsi_register().
vendor_id - a unique value that identifies the vendor supplying
the LLD for the Scsi_Host. Used most often in validating
vendor-specific message requests. Value consists of an
identifier type and a vendor-specific value.
See scsi_netlink.h for a description of valid formats.
The scsi_host structure is defined in include/scsi/scsi_host.h The scsi_host structure is defined in include/scsi/scsi_host.h
......
...@@ -35,6 +35,7 @@ ...@@ -35,6 +35,7 @@
#include <linux/netlink.h> #include <linux/netlink.h>
#include <net/netlink.h> #include <net/netlink.h>
#include <scsi/scsi_netlink_fc.h> #include <scsi/scsi_netlink_fc.h>
#include <scsi/scsi_bsg_fc.h>
#include "scsi_priv.h" #include "scsi_priv.h"
#include "scsi_transport_fc_internal.h" #include "scsi_transport_fc_internal.h"
...@@ -43,6 +44,10 @@ static void fc_vport_sched_delete(struct work_struct *work); ...@@ -43,6 +44,10 @@ static void fc_vport_sched_delete(struct work_struct *work);
static int fc_vport_setup(struct Scsi_Host *shost, int channel, static int fc_vport_setup(struct Scsi_Host *shost, int channel,
struct device *pdev, struct fc_vport_identifiers *ids, struct device *pdev, struct fc_vport_identifiers *ids,
struct fc_vport **vport); struct fc_vport **vport);
static int fc_bsg_hostadd(struct Scsi_Host *, struct fc_host_attrs *);
static int fc_bsg_rportadd(struct Scsi_Host *, struct fc_rport *);
static void fc_bsg_remove(struct request_queue *);
static void fc_bsg_goose_queue(struct fc_rport *);
/* /*
* Redefine so that we can have same named attributes in the * Redefine so that we can have same named attributes in the
...@@ -411,13 +416,26 @@ static int fc_host_setup(struct transport_container *tc, struct device *dev, ...@@ -411,13 +416,26 @@ static int fc_host_setup(struct transport_container *tc, struct device *dev,
return -ENOMEM; return -ENOMEM;
} }
fc_bsg_hostadd(shost, fc_host);
/* ignore any bsg add error - we just can't do sgio */
return 0;
}
static int fc_host_remove(struct transport_container *tc, struct device *dev,
struct device *cdev)
{
struct Scsi_Host *shost = dev_to_shost(dev);
struct fc_host_attrs *fc_host = shost_to_fc_host(shost);
fc_bsg_remove(fc_host->rqst_q);
return 0; return 0;
} }
static DECLARE_TRANSPORT_CLASS(fc_host_class, static DECLARE_TRANSPORT_CLASS(fc_host_class,
"fc_host", "fc_host",
fc_host_setup, fc_host_setup,
NULL, fc_host_remove,
NULL); NULL);
/* /*
...@@ -2375,6 +2393,7 @@ fc_rport_final_delete(struct work_struct *work) ...@@ -2375,6 +2393,7 @@ fc_rport_final_delete(struct work_struct *work)
scsi_flush_work(shost); scsi_flush_work(shost);
fc_terminate_rport_io(rport); fc_terminate_rport_io(rport);
/* /*
* Cancel any outstanding timers. These should really exist * Cancel any outstanding timers. These should really exist
* only when rmmod'ing the LLDD and we're asking for * only when rmmod'ing the LLDD and we're asking for
...@@ -2407,6 +2426,8 @@ fc_rport_final_delete(struct work_struct *work) ...@@ -2407,6 +2426,8 @@ fc_rport_final_delete(struct work_struct *work)
(i->f->dev_loss_tmo_callbk)) (i->f->dev_loss_tmo_callbk))
i->f->dev_loss_tmo_callbk(rport); i->f->dev_loss_tmo_callbk(rport);
fc_bsg_remove(rport->rqst_q);
transport_remove_device(dev); transport_remove_device(dev);
device_del(dev); device_del(dev);
transport_destroy_device(dev); transport_destroy_device(dev);
...@@ -2494,6 +2515,9 @@ fc_rport_create(struct Scsi_Host *shost, int channel, ...@@ -2494,6 +2515,9 @@ fc_rport_create(struct Scsi_Host *shost, int channel,
transport_add_device(dev); transport_add_device(dev);
transport_configure_device(dev); transport_configure_device(dev);
fc_bsg_rportadd(shost, rport);
/* ignore any bsg add error - we just can't do sgio */
if (rport->roles & FC_PORT_ROLE_FCP_TARGET) { if (rport->roles & FC_PORT_ROLE_FCP_TARGET) {
/* initiate a scan of the target */ /* initiate a scan of the target */
rport->flags |= FC_RPORT_SCAN_PENDING; rport->flags |= FC_RPORT_SCAN_PENDING;
...@@ -2658,6 +2682,8 @@ fc_remote_port_add(struct Scsi_Host *shost, int channel, ...@@ -2658,6 +2682,8 @@ fc_remote_port_add(struct Scsi_Host *shost, int channel,
spin_unlock_irqrestore(shost->host_lock, spin_unlock_irqrestore(shost->host_lock,
flags); flags);
fc_bsg_goose_queue(rport);
return rport; return rport;
} }
} }
...@@ -3343,6 +3369,592 @@ fc_vport_sched_delete(struct work_struct *work) ...@@ -3343,6 +3369,592 @@ fc_vport_sched_delete(struct work_struct *work)
} }
/*
* BSG support
*/
/**
* fc_destroy_bsgjob - routine to teardown/delete a fc bsg job
* @job: fc_bsg_job that is to be torn down
*/
static void
fc_destroy_bsgjob(struct fc_bsg_job *job)
{
unsigned long flags;
spin_lock_irqsave(&job->job_lock, flags);
if (job->ref_cnt) {
spin_unlock_irqrestore(&job->job_lock, flags);
return;
}
spin_unlock_irqrestore(&job->job_lock, flags);
put_device(job->dev); /* release reference for the request */
kfree(job->request_payload.sg_list);
kfree(job->reply_payload.sg_list);
kfree(job);
}
/**
* fc_bsg_jobdone - completion routine for bsg requests that the LLD has
* completed
* @job: fc_bsg_job that is complete
*/
static void
fc_bsg_jobdone(struct fc_bsg_job *job)
{
struct request *req = job->req;
struct request *rsp = req->next_rq;
unsigned long flags;
int err;
spin_lock_irqsave(&job->job_lock, flags);
job->state_flags |= FC_RQST_STATE_DONE;
job->ref_cnt--;
spin_unlock_irqrestore(&job->job_lock, flags);
err = job->req->errors = job->reply->result;
if (err < 0)
/* we're only returning the result field in the reply */
job->req->sense_len = sizeof(uint32_t);
else
job->req->sense_len = job->reply_len;
/* we assume all request payload was transferred, residual == 0 */
req->resid_len = 0;
if (rsp) {
WARN_ON(job->reply->reply_payload_rcv_len > rsp->resid_len);
/* set reply (bidi) residual */
rsp->resid_len -= min(job->reply->reply_payload_rcv_len,
rsp->resid_len);
}
blk_end_request_all(req, err);
fc_destroy_bsgjob(job);
}
/**
* fc_bsg_job_timeout - handler for when a bsg request timesout
* @req: request that timed out
*/
static enum blk_eh_timer_return
fc_bsg_job_timeout(struct request *req)
{
struct fc_bsg_job *job = (void *) req->special;
struct Scsi_Host *shost = job->shost;
struct fc_internal *i = to_fc_internal(shost->transportt);
unsigned long flags;
int err = 0, done = 0;
if (job->rport && job->rport->port_state == FC_PORTSTATE_BLOCKED)
return BLK_EH_RESET_TIMER;
spin_lock_irqsave(&job->job_lock, flags);
if (job->state_flags & FC_RQST_STATE_DONE)
done = 1;
else
job->ref_cnt++;
spin_unlock_irqrestore(&job->job_lock, flags);
if (!done && i->f->bsg_timeout) {
/* call LLDD to abort the i/o as it has timed out */
err = i->f->bsg_timeout(job);
if (err)
printk(KERN_ERR "ERROR: FC BSG request timeout - LLD "
"abort failed with status %d\n", err);
}
if (!done) {
spin_lock_irqsave(&job->job_lock, flags);
job->ref_cnt--;
spin_unlock_irqrestore(&job->job_lock, flags);
fc_destroy_bsgjob(job);
}
/* the blk_end_sync_io() doesn't check the error */
return BLK_EH_HANDLED;
}
static int
fc_bsg_map_buffer(struct fc_bsg_buffer *buf, struct request *req)
{
size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments);
BUG_ON(!req->nr_phys_segments);
buf->sg_list = kzalloc(sz, GFP_KERNEL);
if (!buf->sg_list)
return -ENOMEM;
sg_init_table(buf->sg_list, req->nr_phys_segments);
buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list);
buf->payload_len = blk_rq_bytes(req);
return 0;
}
/**
* fc_req_to_bsgjob - Allocate/create the fc_bsg_job structure for the
* bsg request
* @shost: SCSI Host corresponding to the bsg object
* @rport: (optional) FC Remote Port corresponding to the bsg object
* @req: BSG request that needs a job structure
*/
static int
fc_req_to_bsgjob(struct Scsi_Host *shost, struct fc_rport *rport,
struct request *req)
{
struct fc_internal *i = to_fc_internal(shost->transportt);
struct request *rsp = req->next_rq;
struct fc_bsg_job *job;
int ret;
BUG_ON(req->special);
job = kzalloc(sizeof(struct fc_bsg_job) + i->f->dd_bsg_size,
GFP_KERNEL);
if (!job)
return -ENOMEM;
/*
* Note: this is a bit silly.
* The request gets formatted as a SGIO v4 ioctl request, which
* then gets reformatted as a blk request, which then gets
* reformatted as a fc bsg request. And on completion, we have
* to wrap return results such that SGIO v4 thinks it was a scsi
* status. I hope this was all worth it.
*/
req->special = job;
job->shost = shost;
job->rport = rport;
job->req = req;
if (i->f->dd_bsg_size)
job->dd_data = (void *)&job[1];
spin_lock_init(&job->job_lock);
job->request = (struct fc_bsg_request *)req->cmd;
job->request_len = req->cmd_len;
job->reply = req->sense;
job->reply_len = SCSI_SENSE_BUFFERSIZE; /* Size of sense buffer
* allocated */
if (req->bio) {
ret = fc_bsg_map_buffer(&job->request_payload, req);
if (ret)
goto failjob_rls_job;
}
if (rsp && rsp->bio) {
ret = fc_bsg_map_buffer(&job->reply_payload, rsp);
if (ret)
goto failjob_rls_rqst_payload;
}
job->job_done = fc_bsg_jobdone;
if (rport)
job->dev = &rport->dev;
else
job->dev = &shost->shost_gendev;
get_device(job->dev); /* take a reference for the request */
job->ref_cnt = 1;
return 0;
failjob_rls_rqst_payload:
kfree(job->request_payload.sg_list);
failjob_rls_job:
kfree(job);
return -ENOMEM;
}
enum fc_dispatch_result {
FC_DISPATCH_BREAK, /* on return, q is locked, break from q loop */
FC_DISPATCH_LOCKED, /* on return, q is locked, continue on */
FC_DISPATCH_UNLOCKED, /* on return, q is unlocked, continue on */
};
/**
* fc_bsg_host_dispatch - process fc host bsg requests and dispatch to LLDD
* @shost: scsi host rport attached to
* @job: bsg job to be processed
*/
static enum fc_dispatch_result
fc_bsg_host_dispatch(struct request_queue *q, struct Scsi_Host *shost,
struct fc_bsg_job *job)
{
struct fc_internal *i = to_fc_internal(shost->transportt);
int cmdlen = sizeof(uint32_t); /* start with length of msgcode */
int ret;
/* Validate the host command */
switch (job->request->msgcode) {
case FC_BSG_HST_ADD_RPORT:
cmdlen += sizeof(struct fc_bsg_host_add_rport);
break;
case FC_BSG_HST_DEL_RPORT:
cmdlen += sizeof(struct fc_bsg_host_del_rport);
break;
case FC_BSG_HST_ELS_NOLOGIN:
cmdlen += sizeof(struct fc_bsg_host_els);
/* there better be a xmt and rcv payloads */
if ((!job->request_payload.payload_len) ||
(!job->reply_payload.payload_len)) {
ret = -EINVAL;
goto fail_host_msg;
}
break;
case FC_BSG_HST_CT:
cmdlen += sizeof(struct fc_bsg_host_ct);
/* there better be xmt and rcv payloads */
if ((!job->request_payload.payload_len) ||
(!job->reply_payload.payload_len)) {
ret = -EINVAL;
goto fail_host_msg;
}
break;
case FC_BSG_HST_VENDOR:
cmdlen += sizeof(struct fc_bsg_host_vendor);
if ((shost->hostt->vendor_id == 0L) ||
(job->request->rqst_data.h_vendor.vendor_id !=
shost->hostt->vendor_id)) {
ret = -ESRCH;
goto fail_host_msg;
}
break;
default:
ret = -EBADR;
goto fail_host_msg;
}
/* check if we really have all the request data needed */
if (job->request_len < cmdlen) {
ret = -ENOMSG;
goto fail_host_msg;
}
ret = i->f->bsg_request(job);
if (!ret)
return FC_DISPATCH_UNLOCKED;
fail_host_msg:
/* return the errno failure code as the only status */
BUG_ON(job->reply_len < sizeof(uint32_t));
job->reply->result = ret;
job->reply_len = sizeof(uint32_t);
fc_bsg_jobdone(job);
return FC_DISPATCH_UNLOCKED;
}
/*
* fc_bsg_goose_queue - restart rport queue in case it was stopped
* @rport: rport to be restarted
*/
static void
fc_bsg_goose_queue(struct fc_rport *rport)
{
int flagset;
if (!rport->rqst_q)
return;
get_device(&rport->dev);
spin_lock(rport->rqst_q->queue_lock);
flagset = test_bit(QUEUE_FLAG_REENTER, &rport->rqst_q->queue_flags) &&
!test_bit(QUEUE_FLAG_REENTER, &rport->rqst_q->queue_flags);
if (flagset)
queue_flag_set(QUEUE_FLAG_REENTER, rport->rqst_q);
__blk_run_queue(rport->rqst_q);
if (flagset)
queue_flag_clear(QUEUE_FLAG_REENTER, rport->rqst_q);
spin_unlock(rport->rqst_q->queue_lock);
put_device(&rport->dev);
}
/**
* fc_bsg_rport_dispatch - process rport bsg requests and dispatch to LLDD
* @shost: scsi host rport attached to
* @rport: rport request destined to
* @job: bsg job to be processed
*/
static enum fc_dispatch_result
fc_bsg_rport_dispatch(struct request_queue *q, struct Scsi_Host *shost,
struct fc_rport *rport, struct fc_bsg_job *job)
{
struct fc_internal *i = to_fc_internal(shost->transportt);
int cmdlen = sizeof(uint32_t); /* start with length of msgcode */
int ret;
/* Validate the rport command */
switch (job->request->msgcode) {
case FC_BSG_RPT_ELS:
cmdlen += sizeof(struct fc_bsg_rport_els);
goto check_bidi;
case FC_BSG_RPT_CT:
cmdlen += sizeof(struct fc_bsg_rport_ct);
check_bidi:
/* there better be xmt and rcv payloads */
if ((!job->request_payload.payload_len) ||
(!job->reply_payload.payload_len)) {
ret = -EINVAL;
goto fail_rport_msg;
}
break;
default:
ret = -EBADR;
goto fail_rport_msg;
}
/* check if we really have all the request data needed */
if (job->request_len < cmdlen) {
ret = -ENOMSG;
goto fail_rport_msg;
}
ret = i->f->bsg_request(job);
if (!ret)
return FC_DISPATCH_UNLOCKED;
fail_rport_msg:
/* return the errno failure code as the only status */
BUG_ON(job->reply_len < sizeof(uint32_t));
job->reply->result = ret;
job->reply_len = sizeof(uint32_t);
fc_bsg_jobdone(job);
return FC_DISPATCH_UNLOCKED;
}
/**
* fc_bsg_request_handler - generic handler for bsg requests
* @q: request queue to manage
* @shost: Scsi_Host related to the bsg object
* @rport: FC remote port related to the bsg object (optional)
* @dev: device structure for bsg object
*/
static void
fc_bsg_request_handler(struct request_queue *q, struct Scsi_Host *shost,
struct fc_rport *rport, struct device *dev)
{
struct request *req;
struct fc_bsg_job *job;
enum fc_dispatch_result ret;
if (!get_device(dev))
return;
while (!blk_queue_plugged(q)) {
if (rport && (rport->port_state == FC_PORTSTATE_BLOCKED))
break;
req = blk_fetch_request(q);
if (!req)
break;
if (rport && (rport->port_state != FC_PORTSTATE_ONLINE)) {
req->errors = -ENXIO;
spin_unlock_irq(q->queue_lock);
blk_end_request(req, -ENXIO, blk_rq_bytes(req));
spin_lock_irq(q->queue_lock);
continue;
}
spin_unlock_irq(q->queue_lock);
ret = fc_req_to_bsgjob(shost, rport, req);
if (ret) {
req->errors = ret;
blk_end_request(req, ret, blk_rq_bytes(req));
spin_lock_irq(q->queue_lock);
continue;
}
job = req->special;
/* check if we have the msgcode value at least */
if (job->request_len < sizeof(uint32_t)) {
BUG_ON(job->reply_len < sizeof(uint32_t));
job->reply->result = -ENOMSG;
job->reply_len = sizeof(uint32_t);