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[SCSI] libfcoe: convert FIP to lock with mutex instead of spin lock
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It turns out most of the FIP work is now done from worker threads
or process context now, so there's no need to use a spin lock.

Change to use mutex instead of spin lock and delayed_work instead
of a timer.

This will make it nicer for the VN_port to VN_port feature that
will interact more with the libfc layers requiring that
spinlocks not be held.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
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Joe Eykholt authored and James Bottomley committed Jul 28, 2010
1 parent f90377a commit fdb068c
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Showing 2 changed files with 57 additions and 68 deletions.
116 changes: 55 additions & 61 deletions drivers/scsi/fcoe/libfcoe.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -113,7 +113,7 @@ void fcoe_ctlr_init(struct fcoe_ctlr *fip)
fip->state = FIP_ST_LINK_WAIT;
fip->mode = FIP_ST_AUTO;
INIT_LIST_HEAD(&fip->fcfs);
spin_lock_init(&fip->lock);
mutex_init(&fip->ctlr_mutex);
fip->flogi_oxid = FC_XID_UNKNOWN;
setup_timer(&fip->timer, fcoe_ctlr_timeout, (unsigned long)fip);
INIT_WORK(&fip->timer_work, fcoe_ctlr_timer_work);
Expand Down Expand Up @@ -159,10 +159,10 @@ void fcoe_ctlr_destroy(struct fcoe_ctlr *fip)
cancel_work_sync(&fip->recv_work);
skb_queue_purge(&fip->fip_recv_list);

spin_lock_bh(&fip->lock);
mutex_lock(&fip->ctlr_mutex);
fip->state = FIP_ST_DISABLED;
fcoe_ctlr_reset_fcfs(fip);
spin_unlock_bh(&fip->lock);
mutex_unlock(&fip->ctlr_mutex);
del_timer_sync(&fip->timer);
cancel_work_sync(&fip->timer_work);
}
Expand Down Expand Up @@ -255,19 +255,19 @@ static void fcoe_ctlr_solicit(struct fcoe_ctlr *fip, struct fcoe_fcf *fcf)
*/
void fcoe_ctlr_link_up(struct fcoe_ctlr *fip)
{
spin_lock_bh(&fip->lock);
mutex_lock(&fip->ctlr_mutex);
if (fip->state == FIP_ST_NON_FIP || fip->state == FIP_ST_AUTO) {
spin_unlock_bh(&fip->lock);
mutex_unlock(&fip->ctlr_mutex);
fc_linkup(fip->lp);
} else if (fip->state == FIP_ST_LINK_WAIT) {
fip->state = fip->mode;
spin_unlock_bh(&fip->lock);
mutex_unlock(&fip->ctlr_mutex);
if (fip->state == FIP_ST_AUTO)
LIBFCOE_FIP_DBG(fip, "%s", "setting AUTO mode.\n");
fc_linkup(fip->lp);
fcoe_ctlr_solicit(fip, NULL);
} else
spin_unlock_bh(&fip->lock);
mutex_unlock(&fip->ctlr_mutex);
}
EXPORT_SYMBOL(fcoe_ctlr_link_up);

Expand Down Expand Up @@ -300,11 +300,11 @@ int fcoe_ctlr_link_down(struct fcoe_ctlr *fip)
int link_dropped;

LIBFCOE_FIP_DBG(fip, "link down.\n");
spin_lock_bh(&fip->lock);
mutex_lock(&fip->ctlr_mutex);
fcoe_ctlr_reset(fip);
link_dropped = fip->state != FIP_ST_LINK_WAIT;
fip->state = FIP_ST_LINK_WAIT;
spin_unlock_bh(&fip->lock);
mutex_unlock(&fip->ctlr_mutex);

if (link_dropped)
fc_linkdown(fip->lp);
Expand Down Expand Up @@ -577,12 +577,12 @@ static unsigned long fcoe_ctlr_age_fcfs(struct fcoe_ctlr *fip)
unsigned long sel_time = 0;
struct fcoe_dev_stats *stats;

stats = per_cpu_ptr(fip->lp->dev_stats, get_cpu());

list_for_each_entry_safe(fcf, next, &fip->fcfs, list) {
deadline = fcf->time + fcf->fka_period + fcf->fka_period / 2;
if (fip->sel_fcf == fcf) {
if (time_after(jiffies, deadline)) {
stats = per_cpu_ptr(fip->lp->dev_stats,
smp_processor_id());
stats->MissDiscAdvCount++;
printk(KERN_INFO "libfcoe: host%d: "
"Missing Discovery Advertisement "
Expand All @@ -601,8 +601,6 @@ static unsigned long fcoe_ctlr_age_fcfs(struct fcoe_ctlr *fip)
WARN_ON(!fip->fcf_count);
fip->fcf_count--;
kfree(fcf);
stats = per_cpu_ptr(fip->lp->dev_stats,
smp_processor_id());
stats->VLinkFailureCount++;
} else {
if (time_after(next_timer, deadline))
Expand All @@ -612,6 +610,7 @@ static unsigned long fcoe_ctlr_age_fcfs(struct fcoe_ctlr *fip)
sel_time = fcf->time;
}
}
put_cpu();
if (sel_time && !fip->sel_fcf && !fip->sel_time) {
sel_time += msecs_to_jiffies(FCOE_CTLR_START_DELAY);
fip->sel_time = sel_time;
Expand Down Expand Up @@ -768,7 +767,7 @@ static void fcoe_ctlr_recv_adv(struct fcoe_ctlr *fip, struct sk_buff *skb)
if (fcoe_ctlr_parse_adv(fip, skb, &new))
return;

spin_lock_bh(&fip->lock);
mutex_lock(&fip->ctlr_mutex);
first = list_empty(&fip->fcfs);
found = NULL;
list_for_each_entry(fcf, &fip->fcfs, list) {
Expand Down Expand Up @@ -847,7 +846,7 @@ static void fcoe_ctlr_recv_adv(struct fcoe_ctlr *fip, struct sk_buff *skb)
mod_timer(&fip->timer, fip->sel_time);
}
out:
spin_unlock_bh(&fip->lock);
mutex_unlock(&fip->ctlr_mutex);
}

/**
Expand Down Expand Up @@ -1108,11 +1107,12 @@ static void fcoe_ctlr_recv_clr_vlink(struct fcoe_ctlr *fip,
if (is_vn_port)
fc_lport_reset(vn_port);
else {
spin_lock_bh(&fip->lock);
mutex_lock(&fip->ctlr_mutex);
per_cpu_ptr(lport->dev_stats,
smp_processor_id())->VLinkFailureCount++;
get_cpu())->VLinkFailureCount++;
put_cpu();
fcoe_ctlr_reset(fip);
spin_unlock_bh(&fip->lock);
mutex_unlock(&fip->ctlr_mutex);

fc_lport_reset(fip->lp);
fcoe_ctlr_solicit(fip, NULL);
Expand Down Expand Up @@ -1166,15 +1166,15 @@ static int fcoe_ctlr_recv_handler(struct fcoe_ctlr *fip, struct sk_buff *skb)
if (ntohs(fiph->fip_dl_len) * FIP_BPW + sizeof(*fiph) > skb->len)
goto drop;

spin_lock_bh(&fip->lock);
mutex_lock(&fip->ctlr_mutex);
state = fip->state;
if (state == FIP_ST_AUTO) {
fip->map_dest = 0;
fip->state = FIP_ST_ENABLED;
state = FIP_ST_ENABLED;
LIBFCOE_FIP_DBG(fip, "Using FIP mode\n");
}
spin_unlock_bh(&fip->lock);
mutex_unlock(&fip->ctlr_mutex);
if (state != FIP_ST_ENABLED)
goto drop;

Expand Down Expand Up @@ -1240,19 +1240,38 @@ static void fcoe_ctlr_select(struct fcoe_ctlr *fip)
/**
* fcoe_ctlr_timeout() - FIP timeout handler
* @arg: The FCoE controller that timed out
*
* Ages FCFs. Triggers FCF selection if possible. Sends keep-alives.
*/
static void fcoe_ctlr_timeout(unsigned long arg)
{
struct fcoe_ctlr *fip = (struct fcoe_ctlr *)arg;

schedule_work(&fip->timer_work);
}

/**
* fcoe_ctlr_timer_work() - Worker thread function for timer work
* @work: Handle to a FCoE controller
*
* Ages FCFs. Triggers FCF selection if possible.
* Sends keep-alives and resets.
*/
static void fcoe_ctlr_timer_work(struct work_struct *work)
{
struct fcoe_ctlr *fip;
struct fc_lport *vport;
u8 *mac;
u8 reset = 0;
u8 send_ctlr_ka = 0;
u8 send_port_ka = 0;
struct fcoe_fcf *sel;
struct fcoe_fcf *fcf;
unsigned long next_timer;

spin_lock_bh(&fip->lock);
fip = container_of(work, struct fcoe_ctlr, timer_work);

mutex_lock(&fip->ctlr_mutex);
if (fip->state == FIP_ST_DISABLED) {
spin_unlock_bh(&fip->lock);
mutex_unlock(&fip->ctlr_mutex);
return;
}

Expand Down Expand Up @@ -1286,66 +1305,41 @@ static void fcoe_ctlr_timeout(unsigned long arg)
"FIP Fibre-Channel Forwarder timed out. "
"Starting FCF discovery.\n",
fip->lp->host->host_no);
fip->reset_req = 1;
reset = 1;
schedule_work(&fip->timer_work);
}
}

if (sel && !sel->fd_flags) {
if (time_after_eq(jiffies, fip->ctlr_ka_time)) {
fip->ctlr_ka_time = jiffies + sel->fka_period;
fip->send_ctlr_ka = 1;
send_ctlr_ka = 1;
}
if (time_after(next_timer, fip->ctlr_ka_time))
next_timer = fip->ctlr_ka_time;

if (time_after_eq(jiffies, fip->port_ka_time)) {
fip->port_ka_time = jiffies +
msecs_to_jiffies(FIP_VN_KA_PERIOD);
fip->send_port_ka = 1;
send_port_ka = 1;
}
if (time_after(next_timer, fip->port_ka_time))
next_timer = fip->port_ka_time;
}
if (!list_empty(&fip->fcfs))
mod_timer(&fip->timer, next_timer);
if (fip->send_ctlr_ka || fip->send_port_ka)
schedule_work(&fip->timer_work);
spin_unlock_bh(&fip->lock);
}

/**
* fcoe_ctlr_timer_work() - Worker thread function for timer work
* @work: Handle to a FCoE controller
*
* Sends keep-alives and resets which must not
* be called from the timer directly, since they use a mutex.
*/
static void fcoe_ctlr_timer_work(struct work_struct *work)
{
struct fcoe_ctlr *fip;
struct fc_lport *vport;
u8 *mac;
int reset;

fip = container_of(work, struct fcoe_ctlr, timer_work);
spin_lock_bh(&fip->lock);
reset = fip->reset_req;
fip->reset_req = 0;
spin_unlock_bh(&fip->lock);
mutex_unlock(&fip->ctlr_mutex);

if (reset) {
fc_lport_reset(fip->lp);
/* restart things with a solicitation */
fcoe_ctlr_solicit(fip, NULL);
}

if (fip->send_ctlr_ka) {
fip->send_ctlr_ka = 0;
if (send_ctlr_ka)
fcoe_ctlr_send_keep_alive(fip, NULL, 0, fip->ctl_src_addr);
}
if (fip->send_port_ka) {
fip->send_port_ka = 0;

if (send_port_ka) {
mutex_lock(&fip->lp->lp_mutex);
mac = fip->get_src_addr(fip->lp);
fcoe_ctlr_send_keep_alive(fip, fip->lp, 1, mac);
Expand Down Expand Up @@ -1402,9 +1396,9 @@ int fcoe_ctlr_recv_flogi(struct fcoe_ctlr *fip, struct fc_lport *lport,
if (op == ELS_LS_ACC && fh->fh_r_ctl == FC_RCTL_ELS_REP &&
fip->flogi_oxid == ntohs(fh->fh_ox_id)) {

spin_lock_bh(&fip->lock);
mutex_lock(&fip->ctlr_mutex);
if (fip->state != FIP_ST_AUTO && fip->state != FIP_ST_NON_FIP) {
spin_unlock_bh(&fip->lock);
mutex_unlock(&fip->ctlr_mutex);
return -EINVAL;
}
fip->state = FIP_ST_NON_FIP;
Expand All @@ -1424,13 +1418,13 @@ int fcoe_ctlr_recv_flogi(struct fcoe_ctlr *fip, struct fc_lport *lport,
fip->map_dest = 0;
}
fip->flogi_oxid = FC_XID_UNKNOWN;
spin_unlock_bh(&fip->lock);
mutex_unlock(&fip->ctlr_mutex);
fc_fcoe_set_mac(fr_cb(fp)->granted_mac, fh->fh_d_id);
} else if (op == ELS_FLOGI && fh->fh_r_ctl == FC_RCTL_ELS_REQ && sa) {
/*
* Save source MAC for point-to-point responses.
*/
spin_lock_bh(&fip->lock);
mutex_lock(&fip->ctlr_mutex);
if (fip->state == FIP_ST_AUTO || fip->state == FIP_ST_NON_FIP) {
memcpy(fip->dest_addr, sa, ETH_ALEN);
fip->map_dest = 0;
Expand All @@ -1439,7 +1433,7 @@ int fcoe_ctlr_recv_flogi(struct fcoe_ctlr *fip, struct fc_lport *lport,
"Setting non-FIP mode\n");
fip->state = FIP_ST_NON_FIP;
}
spin_unlock_bh(&fip->lock);
mutex_unlock(&fip->ctlr_mutex);
}
return 0;
}
Expand Down
9 changes: 2 additions & 7 deletions include/scsi/libfcoe.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -75,14 +75,12 @@ enum fip_state {
* @flogi_count: number of FLOGI attempts in AUTO mode.
* @map_dest: use the FC_MAP mode for destination MAC addresses.
* @spma: supports SPMA server-provided MACs mode
* @send_ctlr_ka: need to send controller keep alive
* @send_port_ka: need to send port keep alives
* @dest_addr: MAC address of the selected FC forwarder.
* @ctl_src_addr: the native MAC address of our local port.
* @send: LLD-supplied function to handle sending FIP Ethernet frames
* @update_mac: LLD-supplied function to handle changes to MAC addresses.
* @get_src_addr: LLD-supplied function to supply a source MAC address.
* @lock: lock protecting this structure.
* @ctlr_mutex: lock protecting this structure.
*
* This structure is used by all FCoE drivers. It contains information
* needed by all FCoE low-level drivers (LLDs) as well as internal state
Expand All @@ -106,18 +104,15 @@ struct fcoe_ctlr {
u16 user_mfs;
u16 flogi_oxid;
u8 flogi_count;
u8 reset_req;
u8 map_dest;
u8 spma;
u8 send_ctlr_ka;
u8 send_port_ka;
u8 dest_addr[ETH_ALEN];
u8 ctl_src_addr[ETH_ALEN];

void (*send)(struct fcoe_ctlr *, struct sk_buff *);
void (*update_mac)(struct fc_lport *, u8 *addr);
u8 * (*get_src_addr)(struct fc_lport *);
spinlock_t lock;
struct mutex ctlr_mutex;
};

/**
Expand Down

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