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@xxxxxxxxx>
Tested-by: Ross Brattain <ross.b.brattain@xxxxxxxxx>
---
drivers/scsi/libfc/fc_fcp.c | 25 +++++++++++++++----------
1 files changed, 15 insertions(+), 10 deletions(-)
diff --git a/drivers/scsi/libfc/fc_fcp.c b/drivers/scsi/libfc/fc_fcp.c
index b1b03af..92ba9f0 100644
--- a/drivers/scsi/libfc/fc_fcp.c
+++ b/drivers/scsi/libfc/fc_fcp.c
@@ -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;
}
--
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