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https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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3219e52941
We can race and misset the suspend bit if iscsi_write_space is called then iscsi_send returns with a failure indicating there is no space. To handle this this patch returns a error upwards allowing xmitworker to decide if we need to try and transmit again. For the no write space case xmitworker will not retry, and instead let iscsi_write_space queue it back up if needed (this relies on the work queue code to properly requeue us if needed). Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
229 lines
8.1 KiB
C
229 lines
8.1 KiB
C
/*
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* iSCSI transport class definitions
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*
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* Copyright (C) IBM Corporation, 2004
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* Copyright (C) Mike Christie, 2004 - 2006
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* Copyright (C) Dmitry Yusupov, 2004 - 2005
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* Copyright (C) Alex Aizman, 2004 - 2005
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#ifndef SCSI_TRANSPORT_ISCSI_H
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#define SCSI_TRANSPORT_ISCSI_H
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#include <linux/device.h>
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#include <scsi/iscsi_if.h>
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struct scsi_transport_template;
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struct iscsi_transport;
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struct Scsi_Host;
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struct mempool_zone;
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struct iscsi_cls_conn;
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struct iscsi_conn;
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struct iscsi_cmd_task;
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struct iscsi_mgmt_task;
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/**
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* struct iscsi_transport - iSCSI Transport template
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*
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* @name: transport name
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* @caps: iSCSI Data-Path capabilities
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* @create_session: create new iSCSI session object
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* @destroy_session: destroy existing iSCSI session object
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* @create_conn: create new iSCSI connection
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* @bind_conn: associate this connection with existing iSCSI session
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* and specified transport descriptor
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* @destroy_conn: destroy inactive iSCSI connection
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* @set_param: set iSCSI Data-Path operational parameter
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* @start_conn: set connection to be operational
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* @stop_conn: suspend/recover/terminate connection
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* @send_pdu: send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.
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* @session_recovery_timedout: notify LLD a block during recovery timed out
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* @suspend_conn_recv: susepend the recv side of the connection
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* @termincate_conn: destroy socket connection. Called with mutex lock.
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* @init_cmd_task: Initialize a iscsi_cmd_task and any internal structs.
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* Called from queuecommand with session lock held.
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* @init_mgmt_task: Initialize a iscsi_mgmt_task and any internal structs.
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* Called from iscsi_conn_send_generic with xmitmutex.
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* @xmit_cmd_task: Requests LLD to transfer cmd task. Returns 0 or the
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* the number of bytes transferred on success, and -Exyz
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* value on error.
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* @xmit_mgmt_task: Requests LLD to transfer mgmt task. Returns 0 or the
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* the number of bytes transferred on success, and -Exyz
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* value on error.
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* @cleanup_cmd_task: requests LLD to fail cmd task. Called with xmitmutex
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* and session->lock after the connection has been
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* suspended and terminated during recovery. If called
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* from abort task then connection is not suspended
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* or terminated but sk_callback_lock is held
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*
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* Template API provided by iSCSI Transport
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*/
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struct iscsi_transport {
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struct module *owner;
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char *name;
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unsigned int caps;
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/* LLD sets this to indicate what values it can export to sysfs */
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unsigned int param_mask;
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struct scsi_host_template *host_template;
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/* LLD connection data size */
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int conndata_size;
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/* LLD session data size */
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int sessiondata_size;
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int max_lun;
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unsigned int max_conn;
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unsigned int max_cmd_len;
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struct iscsi_cls_session *(*create_session) (struct iscsi_transport *it,
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struct scsi_transport_template *t, uint32_t sn, uint32_t *hn);
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void (*destroy_session) (struct iscsi_cls_session *session);
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struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,
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uint32_t cid);
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int (*bind_conn) (struct iscsi_cls_session *session,
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struct iscsi_cls_conn *cls_conn,
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uint64_t transport_eph, int is_leading);
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int (*start_conn) (struct iscsi_cls_conn *conn);
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void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);
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void (*destroy_conn) (struct iscsi_cls_conn *conn);
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int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,
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uint32_t value);
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int (*get_conn_param) (struct iscsi_cls_conn *conn,
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enum iscsi_param param, uint32_t *value);
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int (*get_session_param) (struct iscsi_cls_session *session,
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enum iscsi_param param, uint32_t *value);
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int (*get_conn_str_param) (struct iscsi_cls_conn *conn,
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enum iscsi_param param, char *buf);
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int (*get_session_str_param) (struct iscsi_cls_session *session,
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enum iscsi_param param, char *buf);
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int (*send_pdu) (struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
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char *data, uint32_t data_size);
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void (*get_stats) (struct iscsi_cls_conn *conn,
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struct iscsi_stats *stats);
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void (*suspend_conn_recv) (struct iscsi_conn *conn);
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void (*terminate_conn) (struct iscsi_conn *conn);
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void (*init_cmd_task) (struct iscsi_cmd_task *ctask);
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void (*init_mgmt_task) (struct iscsi_conn *conn,
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struct iscsi_mgmt_task *mtask,
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char *data, uint32_t data_size);
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int (*xmit_cmd_task) (struct iscsi_conn *conn,
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struct iscsi_cmd_task *ctask);
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void (*cleanup_cmd_task) (struct iscsi_conn *conn,
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struct iscsi_cmd_task *ctask);
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int (*xmit_mgmt_task) (struct iscsi_conn *conn,
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struct iscsi_mgmt_task *mtask);
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void (*session_recovery_timedout) (struct iscsi_cls_session *session);
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int (*ep_connect) (struct sockaddr *dst_addr, int non_blocking,
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uint64_t *ep_handle);
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int (*ep_poll) (uint64_t ep_handle, int timeout_ms);
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void (*ep_disconnect) (uint64_t ep_handle);
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};
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/*
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* transport registration upcalls
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*/
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extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);
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extern int iscsi_unregister_transport(struct iscsi_transport *tt);
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/*
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* control plane upcalls
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*/
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extern void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error);
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extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
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char *data, uint32_t data_size);
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/* Connection's states */
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#define ISCSI_CONN_INITIAL_STAGE 0
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#define ISCSI_CONN_STARTED 1
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#define ISCSI_CONN_STOPPED 2
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#define ISCSI_CONN_CLEANUP_WAIT 3
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struct iscsi_cls_conn {
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struct list_head conn_list; /* item in connlist */
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void *dd_data; /* LLD private data */
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struct iscsi_transport *transport;
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uint32_t cid; /* connection id */
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/* portal/group values we got during discovery */
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char *persistent_address;
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int persistent_port;
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/* portal/group values we are currently using */
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char *address;
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int port;
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int active; /* must be accessed with the connlock */
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struct device dev; /* sysfs transport/container device */
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struct mempool_zone *z_error;
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struct mempool_zone *z_pdu;
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struct list_head freequeue;
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};
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#define iscsi_dev_to_conn(_dev) \
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container_of(_dev, struct iscsi_cls_conn, dev)
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/* Session's states */
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#define ISCSI_STATE_FREE 1
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#define ISCSI_STATE_LOGGED_IN 2
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#define ISCSI_STATE_FAILED 3
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#define ISCSI_STATE_TERMINATE 4
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#define ISCSI_STATE_IN_RECOVERY 5
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#define ISCSI_STATE_RECOVERY_FAILED 6
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struct iscsi_cls_session {
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struct list_head sess_list; /* item in session_list */
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struct list_head host_list;
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struct iscsi_transport *transport;
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/* iSCSI values used as unique id by userspace. */
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char *targetname;
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int tpgt;
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/* recovery fields */
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int recovery_tmo;
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struct work_struct recovery_work;
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int target_id;
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int channel;
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int sid; /* session id */
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void *dd_data; /* LLD private data */
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struct device dev; /* sysfs transport/container device */
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};
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#define iscsi_dev_to_session(_dev) \
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container_of(_dev, struct iscsi_cls_session, dev)
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#define iscsi_session_to_shost(_session) \
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dev_to_shost(_session->dev.parent)
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struct iscsi_host {
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int next_target_id;
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struct list_head sessions;
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struct mutex mutex;
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};
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/*
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* session and connection functions that can be used by HW iSCSI LLDs
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*/
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extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,
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struct iscsi_transport *t, int channel);
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extern int iscsi_destroy_session(struct iscsi_cls_session *session);
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extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
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uint32_t cid);
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extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
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extern void iscsi_unblock_session(struct iscsi_cls_session *session);
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extern void iscsi_block_session(struct iscsi_cls_session *session);
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#endif
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