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kernel-fxtec-pro1x/include/scsi/scsi_transport_fc.h
James Smart aedf349773 [SCSI] FC transport: fixes for workq deadlocks 
As previously reported via Michael Reed, the FC transport took a hit
in 2.6.15 (perhaps a little earlier) when we solved a recursion error.
There are 2 deadlocks occurring:
- With scan and the delete items sharing the same workq, flushing the
  workq for the delete code was getting it stalled behind a very long
  running scan code path.
- There's a deadlock where scsi_remove_target() has to sit behind
  scsi_scan_target() due to contention over the scan_lock().

This patch resolves the 1st deadlock and significantly reduces the
odds of the second. So far, we have only replicated the 2nd deadlock
on a highly-parallel SMP system. More on the 2nd deadlock in a following
email.

This patch reworks the transport to:
- Only use the scsi host workq for scanning
- Use 2 other workq's internally. One for deletions, the other for
  scheduled deletions. Originally, we tried this with a single workq,
  but the occassional flushes of the scheduled queues was hitting the
  second deadlock with a slightly higher frequency. In the future, we'll
  look at the LLDD's and the transport to see if we can get rid of this
  extra overhead.
- When moving to the other workq's we tightened up some object states
  and some lock handling.
- Properly syncs adds/deletes
- minor code cleanups
  - directly reference fc_host_attrs, rather than through attribute
    macros
  - flush the right workq on delayed work cancel failures.

Large kudos to Michael Reed who has been working this issue for the last
month.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-04-13 13:25:16 -05:00

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/*
* FiberChannel transport specific attributes exported to sysfs.
*
* Copyright (c) 2003 Silicon Graphics, Inc. All rights reserved.
*
* 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
*
* ========
*
* Copyright (C) 2004-2005 James Smart, Emulex Corporation
* Rewrite for host, target, device, and remote port attributes,
* statistics, and service functions...
*
*/
#ifndef SCSI_TRANSPORT_FC_H
#define SCSI_TRANSPORT_FC_H
#include <linux/config.h>
#include <linux/sched.h>
#include <scsi/scsi.h>
struct scsi_transport_template;
/*
* FC Port definitions - Following FC HBAAPI guidelines
*
* Note: Not all binary values for the different fields match HBAAPI.
* Instead, we use densely packed ordinal values or enums.
* We get away with this as we never present the actual binary values
* externally. For sysfs, we always present the string that describes
* the value. Thus, an admin doesn't need a magic HBAAPI decoder ring
* to understand the values. The HBAAPI user-space library is free to
* convert the strings into the HBAAPI-specified binary values.
*
* Note: Not all HBAAPI-defined values are contained in the definitions
* below. Those not appropriate to an fc_host (e.g. FCP initiator) have
* been removed.
*/
/*
* fc_port_type: If you alter this, you also need to alter scsi_transport_fc.c
* (for the ascii descriptions).
*/
enum fc_port_type {
FC_PORTTYPE_UNKNOWN,
FC_PORTTYPE_OTHER,
FC_PORTTYPE_NOTPRESENT,
FC_PORTTYPE_NPORT, /* Attached to FPort */
FC_PORTTYPE_NLPORT, /* (Public) Loop w/ FLPort */
FC_PORTTYPE_LPORT, /* (Private) Loop w/o FLPort */
FC_PORTTYPE_PTP, /* Point to Point w/ another NPort */
};
/*
* fc_port_state: If you alter this, you also need to alter scsi_transport_fc.c
* (for the ascii descriptions).
*/
enum fc_port_state {
FC_PORTSTATE_UNKNOWN,
FC_PORTSTATE_NOTPRESENT,
FC_PORTSTATE_ONLINE,
FC_PORTSTATE_OFFLINE, /* User has taken Port Offline */
FC_PORTSTATE_BLOCKED,
FC_PORTSTATE_BYPASSED,
FC_PORTSTATE_DIAGNOSTICS,
FC_PORTSTATE_LINKDOWN,
FC_PORTSTATE_ERROR,
FC_PORTSTATE_LOOPBACK,
FC_PORTSTATE_DELETED,
};
/*
* FC Classes of Service
* Note: values are not enumerated, as they can be "or'd" together
* for reporting (e.g. report supported_classes). If you alter this list,
* you also need to alter scsi_transport_fc.c (for the ascii descriptions).
*/
#define FC_COS_UNSPECIFIED 0
#define FC_COS_CLASS1 2
#define FC_COS_CLASS2 4
#define FC_COS_CLASS3 8
#define FC_COS_CLASS4 0x10
#define FC_COS_CLASS6 0x40
/*
* FC Port Speeds
* Note: values are not enumerated, as they can be "or'd" together
* for reporting (e.g. report supported_speeds). If you alter this list,
* you also need to alter scsi_transport_fc.c (for the ascii descriptions).
*/
#define FC_PORTSPEED_UNKNOWN 0 /* Unknown - transceiver
incapable of reporting */
#define FC_PORTSPEED_1GBIT 1
#define FC_PORTSPEED_2GBIT 2
#define FC_PORTSPEED_4GBIT 4
#define FC_PORTSPEED_10GBIT 8
#define FC_PORTSPEED_NOT_NEGOTIATED (1 << 15) /* Speed not established */
/*
* fc_tgtid_binding_type: If you alter this, you also need to alter
* scsi_transport_fc.c (for the ascii descriptions).
*/
enum fc_tgtid_binding_type {
FC_TGTID_BIND_NONE,
FC_TGTID_BIND_BY_WWPN,
FC_TGTID_BIND_BY_WWNN,
FC_TGTID_BIND_BY_ID,
};
/*
* FC Remote Port Roles
* Note: values are not enumerated, as they can be "or'd" together
* for reporting (e.g. report roles). If you alter this list,
* you also need to alter scsi_transport_fc.c (for the ascii descriptions).
*/
#define FC_RPORT_ROLE_UNKNOWN 0x00
#define FC_RPORT_ROLE_FCP_TARGET 0x01
#define FC_RPORT_ROLE_FCP_INITIATOR 0x02
#define FC_RPORT_ROLE_IP_PORT 0x04
/*
* fc_rport_identifiers: This set of data contains all elements
* to uniquely identify a remote FC port. The driver uses this data
* to report the existence of a remote FC port in the topology. Internally,
* the transport uses this data for attributes and to manage consistent
* target id bindings.
*/
struct fc_rport_identifiers {
u64 node_name;
u64 port_name;
u32 port_id;
u32 roles;
};
/* Macro for use in defining Remote Port attributes */
#define FC_RPORT_ATTR(_name,_mode,_show,_store) \
struct class_device_attribute class_device_attr_rport_##_name = \
__ATTR(_name,_mode,_show,_store)
/*
* FC Remote Port Attributes
*
* This structure exists for each remote FC port that a LLDD notifies
* the subsystem of. A remote FC port may or may not be a SCSI Target,
* also be a SCSI initiator, IP endpoint, etc. As such, the remote
* port is considered a separate entity, independent of "role" (such
* as scsi target).
*
* --
*
* Attributes are based on HBAAPI V2.0 definitions. Only those
* attributes that are determinable by the local port (aka Host)
* are contained.
*
* Fixed attributes are not expected to change. The driver is
* expected to set these values after successfully calling
* fc_remote_port_add(). The transport fully manages all get functions
* w/o driver interaction.
*
* Dynamic attributes are expected to change. The driver participates
* in all get/set operations via functions provided by the driver.
*
* Private attributes are transport-managed values. They are fully
* managed by the transport w/o driver interaction.
*/
struct fc_rport { /* aka fc_starget_attrs */
/* Fixed Attributes */
u32 maxframe_size;
u32 supported_classes;
/* Dynamic Attributes */
u32 dev_loss_tmo; /* Remote Port loss timeout in seconds. */
/* Private (Transport-managed) Attributes */
u64 node_name;
u64 port_name;
u32 port_id;
u32 roles;
enum fc_port_state port_state; /* Will only be ONLINE or UNKNOWN */
u32 scsi_target_id;
/* exported data */
void *dd_data; /* Used for driver-specific storage */
/* internal data */
unsigned int channel;
u32 number;
u8 flags;
struct list_head peers;
struct device dev;
struct work_struct dev_loss_work;
struct work_struct scan_work;
struct work_struct stgt_delete_work;
struct work_struct rport_delete_work;
} __attribute__((aligned(sizeof(unsigned long))));
/* bit field values for struct fc_rport "flags" field: */
#define FC_RPORT_DEVLOSS_PENDING 0x01
#define FC_RPORT_SCAN_PENDING 0x02
#define dev_to_rport(d) \
container_of(d, struct fc_rport, dev)
#define transport_class_to_rport(classdev) \
dev_to_rport(classdev->dev)
#define rport_to_shost(r) \
dev_to_shost(r->dev.parent)
/*
* FC SCSI Target Attributes
*
* The SCSI Target is considered an extention of a remote port (as
* a remote port can be more than a SCSI Target). Within the scsi
* subsystem, we leave the Target as a separate entity. Doing so
* provides backward compatibility with prior FC transport api's,
* and lets remote ports be handled entirely within the FC transport
* and independently from the scsi subsystem. The drawback is that
* some data will be duplicated.
*/
struct fc_starget_attrs { /* aka fc_target_attrs */
/* Dynamic Attributes */
u64 node_name;
u64 port_name;
u32 port_id;
};
#define fc_starget_node_name(x) \
(((struct fc_starget_attrs *)&(x)->starget_data)->node_name)
#define fc_starget_port_name(x) \
(((struct fc_starget_attrs *)&(x)->starget_data)->port_name)
#define fc_starget_port_id(x) \
(((struct fc_starget_attrs *)&(x)->starget_data)->port_id)
#define starget_to_rport(s) \
scsi_is_fc_rport(s->dev.parent) ? dev_to_rport(s->dev.parent) : NULL
/*
* FC Local Port (Host) Statistics
*/
/* FC Statistics - Following FC HBAAPI v2.0 guidelines */
struct fc_host_statistics {
/* port statistics */
u64 seconds_since_last_reset;
u64 tx_frames;
u64 tx_words;
u64 rx_frames;
u64 rx_words;
u64 lip_count;
u64 nos_count;
u64 error_frames;
u64 dumped_frames;
u64 link_failure_count;
u64 loss_of_sync_count;
u64 loss_of_signal_count;
u64 prim_seq_protocol_err_count;
u64 invalid_tx_word_count;
u64 invalid_crc_count;
/* fc4 statistics (only FCP supported currently) */
u64 fcp_input_requests;
u64 fcp_output_requests;
u64 fcp_control_requests;
u64 fcp_input_megabytes;
u64 fcp_output_megabytes;
};
/*
* FC Local Port (Host) Attributes
*
* Attributes are based on HBAAPI V2.0 definitions.
* Note: OSDeviceName is determined by user-space library
*
* Fixed attributes are not expected to change. The driver is
* expected to set these values after successfully calling scsi_add_host().
* The transport fully manages all get functions w/o driver interaction.
*
* Dynamic attributes are expected to change. The driver participates
* in all get/set operations via functions provided by the driver.
*
* Private attributes are transport-managed values. They are fully
* managed by the transport w/o driver interaction.
*/
#define FC_FC4_LIST_SIZE 32
#define FC_SYMBOLIC_NAME_SIZE 256
#define FC_VERSION_STRING_SIZE 64
#define FC_SERIAL_NUMBER_SIZE 80
struct fc_host_attrs {
/* Fixed Attributes */
u64 node_name;
u64 port_name;
u64 permanent_port_name;
u32 supported_classes;
u8 supported_fc4s[FC_FC4_LIST_SIZE];
char symbolic_name[FC_SYMBOLIC_NAME_SIZE];
u32 supported_speeds;
u32 maxframe_size;
char serial_number[FC_SERIAL_NUMBER_SIZE];
/* Dynamic Attributes */
u32 port_id;
enum fc_port_type port_type;
enum fc_port_state port_state;
u8 active_fc4s[FC_FC4_LIST_SIZE];
u32 speed;
u64 fabric_name;
/* Private (Transport-managed) Attributes */
enum fc_tgtid_binding_type tgtid_bind_type;
/* internal data */
struct list_head rports;
struct list_head rport_bindings;
u32 next_rport_number;
u32 next_target_id;
/* work queues for rport state manipulation */
char work_q_name[KOBJ_NAME_LEN];
struct workqueue_struct *work_q;
char devloss_work_q_name[KOBJ_NAME_LEN];
struct workqueue_struct *devloss_work_q;
};
#define shost_to_fc_host(x) \
((struct fc_host_attrs *)(x)->shost_data)
#define fc_host_node_name(x) \
(((struct fc_host_attrs *)(x)->shost_data)->node_name)
#define fc_host_port_name(x) \
(((struct fc_host_attrs *)(x)->shost_data)->port_name)
#define fc_host_permanent_port_name(x) \
(((struct fc_host_attrs *)(x)->shost_data)->permanent_port_name)
#define fc_host_supported_classes(x) \
(((struct fc_host_attrs *)(x)->shost_data)->supported_classes)
#define fc_host_supported_fc4s(x) \
(((struct fc_host_attrs *)(x)->shost_data)->supported_fc4s)
#define fc_host_symbolic_name(x) \
(((struct fc_host_attrs *)(x)->shost_data)->symbolic_name)
#define fc_host_supported_speeds(x) \
(((struct fc_host_attrs *)(x)->shost_data)->supported_speeds)
#define fc_host_maxframe_size(x) \
(((struct fc_host_attrs *)(x)->shost_data)->maxframe_size)
#define fc_host_serial_number(x) \
(((struct fc_host_attrs *)(x)->shost_data)->serial_number)
#define fc_host_port_id(x) \
(((struct fc_host_attrs *)(x)->shost_data)->port_id)
#define fc_host_port_type(x) \
(((struct fc_host_attrs *)(x)->shost_data)->port_type)
#define fc_host_port_state(x) \
(((struct fc_host_attrs *)(x)->shost_data)->port_state)
#define fc_host_active_fc4s(x) \
(((struct fc_host_attrs *)(x)->shost_data)->active_fc4s)
#define fc_host_speed(x) \
(((struct fc_host_attrs *)(x)->shost_data)->speed)
#define fc_host_fabric_name(x) \
(((struct fc_host_attrs *)(x)->shost_data)->fabric_name)
#define fc_host_tgtid_bind_type(x) \
(((struct fc_host_attrs *)(x)->shost_data)->tgtid_bind_type)
#define fc_host_rports(x) \
(((struct fc_host_attrs *)(x)->shost_data)->rports)
#define fc_host_rport_bindings(x) \
(((struct fc_host_attrs *)(x)->shost_data)->rport_bindings)
#define fc_host_next_rport_number(x) \
(((struct fc_host_attrs *)(x)->shost_data)->next_rport_number)
#define fc_host_next_target_id(x) \
(((struct fc_host_attrs *)(x)->shost_data)->next_target_id)
#define fc_host_work_q_name(x) \
(((struct fc_host_attrs *)(x)->shost_data)->work_q_name)
#define fc_host_work_q(x) \
(((struct fc_host_attrs *)(x)->shost_data)->work_q)
#define fc_host_devloss_work_q_name(x) \
(((struct fc_host_attrs *)(x)->shost_data)->devloss_work_q_name)
#define fc_host_devloss_work_q(x) \
(((struct fc_host_attrs *)(x)->shost_data)->devloss_work_q)
/* The functions by which the transport class and the driver communicate */
struct fc_function_template {
void (*get_rport_dev_loss_tmo)(struct fc_rport *);
void (*set_rport_dev_loss_tmo)(struct fc_rport *, u32);
void (*get_starget_node_name)(struct scsi_target *);
void (*get_starget_port_name)(struct scsi_target *);
void (*get_starget_port_id)(struct scsi_target *);
void (*get_host_port_id)(struct Scsi_Host *);
void (*get_host_port_type)(struct Scsi_Host *);
void (*get_host_port_state)(struct Scsi_Host *);
void (*get_host_active_fc4s)(struct Scsi_Host *);
void (*get_host_speed)(struct Scsi_Host *);
void (*get_host_fabric_name)(struct Scsi_Host *);
struct fc_host_statistics * (*get_fc_host_stats)(struct Scsi_Host *);
void (*reset_fc_host_stats)(struct Scsi_Host *);
int (*issue_fc_host_lip)(struct Scsi_Host *);
/* allocation lengths for host-specific data */
u32 dd_fcrport_size;
/*
* The driver sets these to tell the transport class it
* wants the attributes displayed in sysfs. If the show_ flag
* is not set, the attribute will be private to the transport
* class
*/
/* remote port fixed attributes */
unsigned long show_rport_maxframe_size:1;
unsigned long show_rport_supported_classes:1;
unsigned long show_rport_dev_loss_tmo:1;
/*
* target dynamic attributes
* These should all be "1" if the driver uses the remote port
* add/delete functions (so attributes reflect rport values).
*/
unsigned long show_starget_node_name:1;
unsigned long show_starget_port_name:1;
unsigned long show_starget_port_id:1;
/* host fixed attributes */
unsigned long show_host_node_name:1;
unsigned long show_host_port_name:1;
unsigned long show_host_permanent_port_name:1;
unsigned long show_host_supported_classes:1;
unsigned long show_host_supported_fc4s:1;
unsigned long show_host_symbolic_name:1;
unsigned long show_host_supported_speeds:1;
unsigned long show_host_maxframe_size:1;
unsigned long show_host_serial_number:1;
/* host dynamic attributes */
unsigned long show_host_port_id:1;
unsigned long show_host_port_type:1;
unsigned long show_host_port_state:1;
unsigned long show_host_active_fc4s:1;
unsigned long show_host_speed:1;
unsigned long show_host_fabric_name:1;
};
/**
* fc_remote_port_chkready - called to validate the remote port state
* prior to initiating io to the port.
*
* Returns a scsi result code that can be returned by the LLDD.
*
* @rport: remote port to be checked
**/
static inline int
fc_remote_port_chkready(struct fc_rport *rport)
{
int result;
switch (rport->port_state) {
case FC_PORTSTATE_ONLINE:
if (rport->roles & FC_RPORT_ROLE_FCP_TARGET)
result = 0;
else if (rport->flags & FC_RPORT_DEVLOSS_PENDING)
result = DID_IMM_RETRY << 16;
else
result = DID_NO_CONNECT << 16;
break;
case FC_PORTSTATE_BLOCKED:
result = DID_IMM_RETRY << 16;
break;
default:
result = DID_NO_CONNECT << 16;
break;
}
return result;
}
struct scsi_transport_template *fc_attach_transport(
struct fc_function_template *);
void fc_release_transport(struct scsi_transport_template *);
void fc_remove_host(struct Scsi_Host *);
struct fc_rport *fc_remote_port_add(struct Scsi_Host *shost,
int channel, struct fc_rport_identifiers *ids);
void fc_remote_port_delete(struct fc_rport *rport);
void fc_remote_port_rolechg(struct fc_rport *rport, u32 roles);
int scsi_is_fc_rport(const struct device *);
static inline u64 wwn_to_u64(u8 *wwn)
{
return (u64)wwn[0] << 56 | (u64)wwn[1] << 48 |
(u64)wwn[2] << 40 | (u64)wwn[3] << 32 |
(u64)wwn[4] << 24 | (u64)wwn[5] << 16 |
(u64)wwn[6] << 8 | (u64)wwn[7];
}
#endif /* SCSI_TRANSPORT_FC_H */
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