linux/include/scsi/libfcoe.h
Vasu Dev c826a31457 [SCSI] fcoe: Out of order tx frames was causing several check condition SCSI status
frames followed by these errors in log.

	[sdp] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
	[sdp] Sense Key : Aborted Command [current]
	[sdp] Add. Sense: Data phase error

This was causing some test apps to exit due to write failure under heavy
load.

This was due to a race around adding and removing tx frame skb in
fcoe_pending_queue, Chris Leech helped me to find that brief unlocking
period when pulling skb from fcoe_pending_queue in various contexts
(fcoe_watchdog and fcoe_xmit) and then adding skb back into fcoe_pending_queue
up on a failed fcoe_start_io could change skb/tx frame order in
fcoe_pending_queue. Thanks Chris.

This patch allows only single context to pull skb from fcoe_pending_queue
at any time to prevent above described ordering issue/race by use of
fcoe_pending_queue_active flag.

This patch simplified fcoe_watchdog with modified fcoe_check_wait_queue by
use of FCOE_LOW_QUEUE_DEPTH instead previously used several conditionals
to clear and set lp->qfull.

I think FCOE_MAX_QUEUE_DEPTH with FCOE_LOW_QUEUE_DEPTH  will work better
in re/setting lp->qfull and these could be fine tuned for performance.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-10 09:09:21 -05:00

172 lines
4.7 KiB
C

/*
* Copyright(c) 2007 - 2008 Intel Corporation. All rights reserved.
*
* 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.
*
* Maintained at www.Open-FCoE.org
*/
#ifndef _LIBFCOE_H
#define _LIBFCOE_H
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <scsi/fc/fc_fcoe.h>
#include <scsi/libfc.h>
/*
* this percpu struct for fcoe
*/
struct fcoe_percpu_s {
int cpu;
struct task_struct *thread;
struct sk_buff_head fcoe_rx_list;
struct page *crc_eof_page;
int crc_eof_offset;
};
/*
* the fcoe sw transport private data
*/
struct fcoe_softc {
struct list_head list;
struct fc_lport *lp;
struct net_device *real_dev;
struct net_device *phys_dev; /* device with ethtool_ops */
struct packet_type fcoe_packet_type;
struct sk_buff_head fcoe_pending_queue;
u8 fcoe_pending_queue_active;
u8 dest_addr[ETH_ALEN];
u8 ctl_src_addr[ETH_ALEN];
u8 data_src_addr[ETH_ALEN];
/*
* fcoe protocol address learning related stuff
*/
u16 flogi_oxid;
u8 flogi_progress;
u8 address_mode;
};
static inline struct net_device *fcoe_netdev(
const struct fc_lport *lp)
{
return ((struct fcoe_softc *)lport_priv(lp))->real_dev;
}
static inline struct fcoe_hdr *skb_fcoe_header(const struct sk_buff *skb)
{
return (struct fcoe_hdr *)skb_network_header(skb);
}
static inline int skb_fcoe_offset(const struct sk_buff *skb)
{
return skb_network_offset(skb);
}
static inline struct fc_frame_header *skb_fc_header(const struct sk_buff *skb)
{
return (struct fc_frame_header *)skb_transport_header(skb);
}
static inline int skb_fc_offset(const struct sk_buff *skb)
{
return skb_transport_offset(skb);
}
static inline void skb_reset_fc_header(struct sk_buff *skb)
{
skb_reset_network_header(skb);
skb_set_transport_header(skb, skb_network_offset(skb) +
sizeof(struct fcoe_hdr));
}
static inline bool skb_fc_is_data(const struct sk_buff *skb)
{
return skb_fc_header(skb)->fh_r_ctl == FC_RCTL_DD_SOL_DATA;
}
static inline bool skb_fc_is_cmd(const struct sk_buff *skb)
{
return skb_fc_header(skb)->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD;
}
static inline bool skb_fc_has_exthdr(const struct sk_buff *skb)
{
return (skb_fc_header(skb)->fh_r_ctl == FC_RCTL_VFTH) ||
(skb_fc_header(skb)->fh_r_ctl == FC_RCTL_IFRH) ||
(skb_fc_header(skb)->fh_r_ctl == FC_RCTL_ENCH);
}
static inline bool skb_fc_is_roff(const struct sk_buff *skb)
{
return skb_fc_header(skb)->fh_f_ctl[2] & FC_FC_REL_OFF;
}
static inline u16 skb_fc_oxid(const struct sk_buff *skb)
{
return be16_to_cpu(skb_fc_header(skb)->fh_ox_id);
}
static inline u16 skb_fc_rxid(const struct sk_buff *skb)
{
return be16_to_cpu(skb_fc_header(skb)->fh_rx_id);
}
/* FIXME - DMA_BIDIRECTIONAL ? */
#define skb_cb(skb) ((struct fcoe_rcv_info *)&((skb)->cb[0]))
#define skb_cmd(skb) (skb_cb(skb)->fr_cmd)
#define skb_dir(skb) (skb_cmd(skb)->sc_data_direction)
static inline bool skb_fc_is_read(const struct sk_buff *skb)
{
if (skb_fc_is_cmd(skb) && skb_cmd(skb))
return skb_dir(skb) == DMA_FROM_DEVICE;
return false;
}
static inline bool skb_fc_is_write(const struct sk_buff *skb)
{
if (skb_fc_is_cmd(skb) && skb_cmd(skb))
return skb_dir(skb) == DMA_TO_DEVICE;
return false;
}
/* libfcoe funcs */
int fcoe_reset(struct Scsi_Host *shost);
u64 fcoe_wwn_from_mac(unsigned char mac[MAX_ADDR_LEN],
unsigned int scheme, unsigned int port);
u32 fcoe_fc_crc(struct fc_frame *fp);
int fcoe_xmit(struct fc_lport *, struct fc_frame *);
int fcoe_rcv(struct sk_buff *, struct net_device *,
struct packet_type *, struct net_device *);
int fcoe_percpu_receive_thread(void *arg);
void fcoe_clean_pending_queue(struct fc_lport *lp);
void fcoe_percpu_clean(struct fc_lport *lp);
void fcoe_watchdog(ulong vp);
int fcoe_link_ok(struct fc_lport *lp);
struct fc_lport *fcoe_hostlist_lookup(const struct net_device *);
int fcoe_hostlist_add(const struct fc_lport *);
int fcoe_hostlist_remove(const struct fc_lport *);
struct Scsi_Host *fcoe_host_alloc(struct scsi_host_template *, int);
int fcoe_libfc_config(struct fc_lport *, struct libfc_function_template *);
/* fcoe sw hba */
int __init fcoe_sw_init(void);
int __exit fcoe_sw_exit(void);
#endif /* _LIBFCOE_H */