linux/drivers/target/tcm_fc/tcm_fc.h
Christoph Hellwig 58fc73d10f tcm_fc: Work queue based approach instead of managing own thread and event based mechanism
Problem: Changed from wake_up_interruptible -> wake_up_process and
wait_event_interruptible-> schedule_timeout_interruptible broke the FCoE
target.  Earlier approach of wake_up_interruptible was also looking at
'queue_cnt' which is not necessary, because it increment of 'queue_cnt'
with wake_up_inetrriptible / waker_up_process introduces race condition.

Fix: Instead of fixing the code which used wake_up_process and remove
'queue_cnt', using work_queue based approach is cleaner and acheives
same result. As well, work queue based approach has less programming
overhead and OS manages threads which processes work queues.

This patch is developed by Christoph Hellwig and reviwed+validated by
Kiran Patil.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kiran Patil <kiran.patil@intel.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2011-09-16 09:50:09 +00:00

188 lines
5.2 KiB
C

/*
* Copyright (c) 2010 Cisco Systems, Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef __TCM_FC_H__
#define __TCM_FC_H__
#define FT_VERSION "0.3"
#define FT_NAMELEN 32 /* length of ASCII WWPNs including pad */
#define FT_TPG_NAMELEN 32 /* max length of TPG name */
#define FT_LUN_NAMELEN 32 /* max length of LUN name */
struct ft_transport_id {
__u8 format;
__u8 __resvd1[7];
__u8 wwpn[8];
__u8 __resvd2[8];
} __attribute__((__packed__));
/*
* Session (remote port).
*/
struct ft_sess {
u32 port_id; /* for hash lookup use only */
u32 params;
u16 max_frame; /* maximum frame size */
u64 port_name; /* port name for transport ID */
struct ft_tport *tport;
struct se_session *se_sess;
struct hlist_node hash; /* linkage in ft_sess_hash table */
struct rcu_head rcu;
struct kref kref; /* ref for hash and outstanding I/Os */
};
/*
* Hash table of sessions per local port.
* Hash lookup by remote port FC_ID.
*/
#define FT_SESS_HASH_BITS 6
#define FT_SESS_HASH_SIZE (1 << FT_SESS_HASH_BITS)
/*
* Per local port data.
* This is created only after a TPG exists that allows target function
* for the local port. If the TPG exists, this is allocated when
* we're notified that the local port has been created, or when
* the first PRLI provider callback is received.
*/
struct ft_tport {
struct fc_lport *lport;
struct ft_tpg *tpg; /* NULL if TPG deleted before tport */
u32 sess_count; /* number of sessions in hash */
struct rcu_head rcu;
struct hlist_head hash[FT_SESS_HASH_SIZE]; /* list of sessions */
};
/*
* Node ID and authentication.
*/
struct ft_node_auth {
u64 port_name;
u64 node_name;
};
/*
* Node ACL for FC remote port session.
*/
struct ft_node_acl {
struct ft_node_auth node_auth;
struct se_node_acl se_node_acl;
};
struct ft_lun {
u32 index;
char name[FT_LUN_NAMELEN];
};
/*
* Target portal group (local port).
*/
struct ft_tpg {
u32 index;
struct ft_lport_acl *lport_acl;
struct ft_tport *tport; /* active tport or NULL */
struct list_head list; /* linkage in ft_lport_acl tpg_list */
struct list_head lun_list; /* head of LUNs */
struct se_portal_group se_tpg;
struct workqueue_struct *workqueue;
};
struct ft_lport_acl {
u64 wwpn;
char name[FT_NAMELEN];
struct list_head list;
struct list_head tpg_list;
struct se_wwn fc_lport_wwn;
};
/*
* Commands
*/
struct ft_cmd {
u32 lun; /* LUN from request */
struct ft_sess *sess; /* session held for cmd */
struct fc_seq *seq; /* sequence in exchange mgr */
struct se_cmd se_cmd; /* Local TCM I/O descriptor */
struct fc_frame *req_frame;
unsigned char *cdb; /* pointer to CDB inside frame */
u32 write_data_len; /* data received on writes */
struct work_struct work;
/* Local sense buffer */
unsigned char ft_sense_buffer[TRANSPORT_SENSE_BUFFER];
u32 was_ddp_setup:1; /* Set only if ddp is setup */
struct scatterlist *sg; /* Set only if DDP is setup */
u32 sg_cnt; /* No. of item in scatterlist */
};
extern struct list_head ft_lport_list;
extern struct mutex ft_lport_lock;
extern struct fc4_prov ft_prov;
extern struct target_fabric_configfs *ft_configfs;
/*
* Fabric methods.
*/
/*
* Session ops.
*/
void ft_sess_put(struct ft_sess *);
int ft_sess_shutdown(struct se_session *);
void ft_sess_close(struct se_session *);
void ft_sess_stop(struct se_session *, int, int);
int ft_sess_logged_in(struct se_session *);
u32 ft_sess_get_index(struct se_session *);
u32 ft_sess_get_port_name(struct se_session *, unsigned char *, u32);
void ft_sess_set_erl0(struct se_session *);
void ft_lport_add(struct fc_lport *, void *);
void ft_lport_del(struct fc_lport *, void *);
int ft_lport_notify(struct notifier_block *, unsigned long, void *);
/*
* IO methods.
*/
void ft_check_stop_free(struct se_cmd *);
void ft_release_cmd(struct se_cmd *);
int ft_queue_status(struct se_cmd *);
int ft_queue_data_in(struct se_cmd *);
int ft_write_pending(struct se_cmd *);
int ft_write_pending_status(struct se_cmd *);
u32 ft_get_task_tag(struct se_cmd *);
int ft_get_cmd_state(struct se_cmd *);
int ft_queue_tm_resp(struct se_cmd *);
int ft_is_state_remove(struct se_cmd *);
/*
* other internal functions.
*/
void ft_recv_req(struct ft_sess *, struct fc_frame *);
struct ft_tpg *ft_lport_find_tpg(struct fc_lport *);
struct ft_node_acl *ft_acl_get(struct ft_tpg *, struct fc_rport_priv *);
void ft_recv_write_data(struct ft_cmd *, struct fc_frame *);
void ft_dump_cmd(struct ft_cmd *, const char *caller);
ssize_t ft_format_wwn(char *, size_t, u64);
/*
* Underlying HW specific helper function
*/
void ft_invl_hw_context(struct ft_cmd *);
#endif /* __TCM_FC_H__ */