[PATCH 01/12] scsi_transport_srp: Introduce srp_wait_for_queuecommand()

Bart Van Assche
2015-04-30T08:56:42Z

Introduce the helper function srp_wait_for_queuecommand().
Move the definition of scsi_request_fn_active(). This patch
does not change any functionality. A second call to
scsi_wait_for_queuecommand() will be introduced in the next
patch.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: James Bottomley <JBottomley@Odin.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: <stable@vger.kernel.org> #v3.13
---
drivers/scsi/scsi_transport_srp.c | 52 ++++++++++++++++++++++-----------------
1 file changed, 29 insertions(+), 23 deletions(-)

diff --git a/drivers/scsi/scsi_transport_srp.c b/drivers/scsi/scsi_transport_srp.c
index ae45bd9..6ce1c48 100644
--- a/drivers/scsi/scsi_transport_srp.c
+++ b/drivers/scsi/scsi_transport_srp.c
@@ -396,6 +396,34 @@ static void srp_reconnect_work(struct work_struct *work)
}
}

+/**
+ * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn()
+ * @shost: SCSI host for which to count the number of scsi_request_fn() callers.
+ */
+static int scsi_request_fn_active(struct Scsi_Host *shost)
+{
+ struct scsi_device *sdev;
+ struct request_queue *q;
+ int request_fn_active = 0;
+
+ shost_for_each_device(sdev, shost) {
+ q = sdev->request_queue;
+
+ spin_lock_irq(q->queue_lock);
+ request_fn_active += q->request_fn_active;
+ spin_unlock_irq(q->queue_lock);
+ }
+
+ return request_fn_active;
+}
+
+/* Wait until ongoing shost->hostt->queuecommand() calls have finished. */
+static void srp_wait_for_queuecommand(struct Scsi_Host *shost)
+{
+ while (scsi_request_fn_active(shost))
+ msleep(20);
+}
+
static void __rport_fail_io_fast(struct srp_rport *rport)
{
struct Scsi_Host *shost = rport_to_shost(rport);
@@ -504,27 +532,6 @@ void srp_start_tl_fail_timers(struct srp_rport *rport)
EXPORT_SYMBOL(srp_start_tl_fail_timers);

/**
- * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn()
- * @shost: SCSI host for which to count the number of scsi_request_fn() callers.
- */
-static int scsi_request_fn_active(struct Scsi_Host *shost)
-{
- struct scsi_device *sdev;
- struct request_queue *q;
- int request_fn_active = 0;
-
- shost_for_each_device(sdev, shost) {
- q = sdev->request_queue;
-
- spin_lock_irq(q->queue_lock);
- request_fn_active += q->request_fn_active;
- spin_unlock_irq(q->queue_lock);
- }
-
- return request_fn_active;
-}
-
-/**
* srp_reconnect_rport() - reconnect to an SRP target port
* @rport: SRP target port.
*
@@ -559,8 +566,7 @@ int srp_reconnect_rport(struct srp_rport *rport)
if (res)
goto out;
scsi_target_block(&shost->shost_gendev);
- while (scsi_request_fn_active(shost))
- msleep(20);
+ srp_wait_for_queuecommand(shost);
res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV;
pr_debug("%s (state %d): transport.reconnect() returned %d\n",
dev_name(&shost->shost_gendev), rport->state, res);
--
2.1.4