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linux/include/scsi/scsi_transport_iscsi.h
Mike Christie 289324b0c6 [SCSI] iscsi class: add callout to get iscsi_endpoint values 
For drivers using the ep callbacks the addr and port
are attached to the endpoint instead of the conn.
This adds a callout to the iscsi_transport to get
ep values. It also adds locking around the get
param call to make sure that ep_disconnect does
not free the LLD's ep interconnect structs from
under us (the ep has a refcount so it will not
go away but the LLD may have structs from other
subsystems that are not allocated in the ep so
we need to protect them from getting freed).

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-02-24 12:41:12 -05:00

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/*
* iSCSI transport class definitions
*
* Copyright (C) IBM Corporation, 2004
* Copyright (C) Mike Christie, 2004 - 2006
* Copyright (C) Dmitry Yusupov, 2004 - 2005
* Copyright (C) Alex Aizman, 2004 - 2005
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifndef SCSI_TRANSPORT_ISCSI_H
#define SCSI_TRANSPORT_ISCSI_H
#include <linux/device.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <scsi/iscsi_if.h>
struct scsi_transport_template;
struct iscsi_transport;
struct iscsi_endpoint;
struct Scsi_Host;
struct scsi_cmnd;
struct iscsi_cls_conn;
struct iscsi_conn;
struct iscsi_task;
struct sockaddr;
/**
* struct iscsi_transport - iSCSI Transport template
*
* @name: transport name
* @caps: iSCSI Data-Path capabilities
* @create_session: create new iSCSI session object
* @destroy_session: destroy existing iSCSI session object
* @create_conn: create new iSCSI connection
* @bind_conn: associate this connection with existing iSCSI session
* and specified transport descriptor
* @destroy_conn: destroy inactive iSCSI connection
* @set_param: set iSCSI parameter. Return 0 on success, -ENODATA
* when param is not supported, and a -Exx value on other
* error.
* @get_param get iSCSI parameter. Must return number of bytes
* copied to buffer on success, -ENODATA when param
* is not supported, and a -Exx value on other error
* @start_conn: set connection to be operational
* @stop_conn: suspend/recover/terminate connection
* @send_pdu: send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.
* @session_recovery_timedout: notify LLD a block during recovery timed out
* @init_task: Initialize a iscsi_task and any internal structs.
* When offloading the data path, this is called from
* queuecommand with the session lock, or from the
* iscsi_conn_send_pdu context with the session lock.
* When not offloading the data path, this is called
* from the scsi work queue without the session lock.
* @xmit_task Requests LLD to transfer cmd task. Returns 0 or the
* the number of bytes transferred on success, and -Exyz
* value on error. When offloading the data path, this
* is called from queuecommand with the session lock, or
* from the iscsi_conn_send_pdu context with the session
* lock. When not offloading the data path, this is called
* from the scsi work queue without the session lock.
* @cleanup_task: requests LLD to fail task. Called with session lock
* and after the connection has been suspended and
* terminated during recovery. If called
* from abort task then connection is not suspended
* or terminated but sk_callback_lock is held
*
* Template API provided by iSCSI Transport
*/
struct iscsi_transport {
struct module *owner;
char *name;
unsigned int caps;
/* LLD sets this to indicate what values it can export to sysfs */
uint64_t param_mask;
uint64_t host_param_mask;
struct iscsi_cls_session *(*create_session) (struct iscsi_endpoint *ep,
uint16_t cmds_max, uint16_t qdepth,
uint32_t sn);
void (*destroy_session) (struct iscsi_cls_session *session);
struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,
uint32_t cid);
int (*bind_conn) (struct iscsi_cls_session *session,
struct iscsi_cls_conn *cls_conn,
uint64_t transport_eph, int is_leading);
int (*start_conn) (struct iscsi_cls_conn *conn);
void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);
void (*destroy_conn) (struct iscsi_cls_conn *conn);
int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,
char *buf, int buflen);
int (*get_ep_param) (struct iscsi_endpoint *ep, enum iscsi_param param,
char *buf);
int (*get_conn_param) (struct iscsi_cls_conn *conn,
enum iscsi_param param, char *buf);
int (*get_session_param) (struct iscsi_cls_session *session,
enum iscsi_param param, char *buf);
int (*get_host_param) (struct Scsi_Host *shost,
enum iscsi_host_param param, char *buf);
int (*set_host_param) (struct Scsi_Host *shost,
enum iscsi_host_param param, char *buf,
int buflen);
int (*send_pdu) (struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
char *data, uint32_t data_size);
void (*get_stats) (struct iscsi_cls_conn *conn,
struct iscsi_stats *stats);
int (*init_task) (struct iscsi_task *task);
int (*xmit_task) (struct iscsi_task *task);
void (*cleanup_task) (struct iscsi_task *task);
int (*alloc_pdu) (struct iscsi_task *task, uint8_t opcode);
int (*xmit_pdu) (struct iscsi_task *task);
int (*init_pdu) (struct iscsi_task *task, unsigned int offset,
unsigned int count);
void (*parse_pdu_itt) (struct iscsi_conn *conn, itt_t itt,
int *index, int *age);
void (*session_recovery_timedout) (struct iscsi_cls_session *session);
struct iscsi_endpoint *(*ep_connect) (struct Scsi_Host *shost,
struct sockaddr *dst_addr,
int non_blocking);
int (*ep_poll) (struct iscsi_endpoint *ep, int timeout_ms);
void (*ep_disconnect) (struct iscsi_endpoint *ep);
int (*tgt_dscvr) (struct Scsi_Host *shost, enum iscsi_tgt_dscvr type,
uint32_t enable, struct sockaddr *dst_addr);
int (*set_path) (struct Scsi_Host *shost, struct iscsi_path *params);
};
/*
* transport registration upcalls
*/
extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);
extern int iscsi_unregister_transport(struct iscsi_transport *tt);
/*
* control plane upcalls
*/
extern void iscsi_conn_error_event(struct iscsi_cls_conn *conn,
enum iscsi_err error);
extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
char *data, uint32_t data_size);
extern int iscsi_offload_mesg(struct Scsi_Host *shost,
struct iscsi_transport *transport, uint32_t type,
char *data, uint16_t data_size);
struct iscsi_cls_conn {
struct list_head conn_list; /* item in connlist */
void *dd_data; /* LLD private data */
struct iscsi_transport *transport;
uint32_t cid; /* connection id */
struct mutex ep_mutex;
struct iscsi_endpoint *ep;
struct device dev; /* sysfs transport/container device */
};
#define iscsi_dev_to_conn(_dev) \
container_of(_dev, struct iscsi_cls_conn, dev)
#define iscsi_conn_to_session(_conn) \
iscsi_dev_to_session(_conn->dev.parent)
/* iscsi class session state */
enum {
ISCSI_SESSION_LOGGED_IN,
ISCSI_SESSION_FAILED,
ISCSI_SESSION_FREE,
};
#define ISCSI_MAX_TARGET -1
struct iscsi_cls_session {
struct list_head sess_list; /* item in session_list */
struct iscsi_transport *transport;
spinlock_t lock;
struct work_struct block_work;
struct work_struct unblock_work;
struct work_struct scan_work;
struct work_struct unbind_work;
/* recovery fields */
int recovery_tmo;
struct delayed_work recovery_work;
unsigned int target_id;
int state;
int sid; /* session id */
void *dd_data; /* LLD private data */
struct device dev; /* sysfs transport/container device */
};
#define iscsi_dev_to_session(_dev) \
container_of(_dev, struct iscsi_cls_session, dev)
#define iscsi_session_to_shost(_session) \
dev_to_shost(_session->dev.parent)
#define starget_to_session(_stgt) \
iscsi_dev_to_session(_stgt->dev.parent)
struct iscsi_cls_host {
atomic_t nr_scans;
struct mutex mutex;
};
extern void iscsi_host_for_each_session(struct Scsi_Host *shost,
void (*fn)(struct iscsi_cls_session *));
struct iscsi_endpoint {
void *dd_data; /* LLD private data */
struct device dev;
uint64_t id;
struct iscsi_cls_conn *conn;
};
/*
* session and connection functions that can be used by HW iSCSI LLDs
*/
#define iscsi_cls_session_printk(prefix, _cls_session, fmt, a...) \
dev_printk(prefix, &(_cls_session)->dev, fmt, ##a)
#define iscsi_cls_conn_printk(prefix, _cls_conn, fmt, a...) \
dev_printk(prefix, &(_cls_conn)->dev, fmt, ##a)
extern int iscsi_session_chkready(struct iscsi_cls_session *session);
extern struct iscsi_cls_session *iscsi_alloc_session(struct Scsi_Host *shost,
struct iscsi_transport *transport, int dd_size);
extern int iscsi_add_session(struct iscsi_cls_session *session,
unsigned int target_id);
extern int iscsi_session_event(struct iscsi_cls_session *session,
enum iscsi_uevent_e event);
extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,
struct iscsi_transport *t,
int dd_size,
unsigned int target_id);
extern void iscsi_remove_session(struct iscsi_cls_session *session);
extern void iscsi_free_session(struct iscsi_cls_session *session);
extern int iscsi_destroy_session(struct iscsi_cls_session *session);
extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
int dd_size, uint32_t cid);
extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
extern void iscsi_unblock_session(struct iscsi_cls_session *session);
extern void iscsi_block_session(struct iscsi_cls_session *session);
extern int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time);
extern struct iscsi_endpoint *iscsi_create_endpoint(int dd_size);
extern void iscsi_destroy_endpoint(struct iscsi_endpoint *ep);
extern struct iscsi_endpoint *iscsi_lookup_endpoint(u64 handle);
extern int iscsi_block_scsi_eh(struct scsi_cmnd *cmd);
#endif
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