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[SCSI] libfc: Move host_lock usage into ramp_up/down routines 

The host_lock is still used to protect the can_queue
value in the Scsi_Host, but it doesn't need to be held
and released by each caller. This patch moves the lock
usage into the fc_fcp_can_queue_ramp_up and
fc_fcp_can_queue_ramp_down routines.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
This commit is contained in:
Robert Love 2011-04-01 16:06:14 -07:00 committed by James Bottomley
parent 63ce249994
commit 9c8cce8e41
1 changed files with 15 additions and 10 deletions
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25
drivers/scsi/libfc/fc_fcp.c
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@ -335,22 +335,23 @@ static void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
/**
* fc_fcp_can_queue_ramp_up() - increases can_queue
* @lport: lport to ramp up can_queue
*
* Locking notes: Called with Scsi_Host lock held
*/
static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport)
{
struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
unsigned long flags;
int can_queue;
spin_lock_irqsave(lport->host->host_lock, flags);
if (si->last_can_queue_ramp_up_time &&
(time_before(jiffies, si->last_can_queue_ramp_up_time +
FC_CAN_QUEUE_PERIOD)))
return;
goto unlock;
if (time_before(jiffies, si->last_can_queue_ramp_down_time +
FC_CAN_QUEUE_PERIOD))
return;
goto unlock;
si->last_can_queue_ramp_up_time = jiffies;
@ -362,6 +363,9 @@ static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport)
lport->host->can_queue = can_queue;
shost_printk(KERN_ERR, lport->host, "libfc: increased "
"can_queue to %d.\n", can_queue);
unlock:
spin_unlock_irqrestore(lport->host->host_lock, flags);
}
/**
@ -373,18 +377,19 @@ static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport)
* commands complete or timeout, then try again with a reduced
* can_queue. Eventually we will hit the point where we run
* on all reserved structs.
*
* Locking notes: Called with Scsi_Host lock held
*/
static void fc_fcp_can_queue_ramp_down(struct fc_lport *lport)
{
struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
unsigned long flags;
int can_queue;
spin_lock_irqsave(lport->host->host_lock, flags);
if (si->last_can_queue_ramp_down_time &&
(time_before(jiffies, si->last_can_queue_ramp_down_time +
FC_CAN_QUEUE_PERIOD)))
return;
goto unlock;
si->last_can_queue_ramp_down_time = jiffies;
@ -395,6 +400,9 @@ static void fc_fcp_can_queue_ramp_down(struct fc_lport *lport)
lport->host->can_queue = can_queue;
shost_printk(KERN_ERR, lport->host, "libfc: Could not allocate frame.\n"
"Reducing can_queue to %d.\n", can_queue);
unlock:
spin_unlock_irqrestore(lport->host->host_lock, flags);
}
/*
@ -409,16 +417,13 @@ static inline struct fc_frame *fc_fcp_frame_alloc(struct fc_lport *lport,
size_t len)
{
struct fc_frame *fp;
unsigned long flags;
fp = fc_frame_alloc(lport, len);
if (likely(fp))
return fp;
/* error case */
spin_lock_irqsave(lport->host->host_lock, flags);
fc_fcp_can_queue_ramp_down(lport);
spin_unlock_irqrestore(lport->host->host_lock, flags);
return NULL;
}