3.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
commit be34c62ddf39d1931780b07a6f4241393e4ba2ee upstream.
Introduce the helper function srp_wait_for_queuecommand().
Move the definition of scsi_request_fn_active(). Add a comment
above srp_wait_for_queuecommand() that support for scsi-mq needs
to be added.
This patch does not change any functionality. A second call to
srp_wait_for_queuecommand() will be introduced in the next patch.
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Cc: James Bottomley <JBottomley@xxxxxxxx>
Cc: Sagi Grimberg <sagig@xxxxxxxxxxxx>
Cc: Sebastian Parschauer <sebastian.riemer@xxxxxxxxxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/scsi_transport_srp.c | 54 +++++++++++++++++++++-----------------
1 file changed, 31 insertions(+), 23 deletions(-)
--- a/drivers/scsi/scsi_transport_srp.c
+++ b/drivers/scsi/scsi_transport_srp.c
@@ -397,6 +397,36 @@ static void srp_reconnect_work(struct wo
}
}
+/**
+ * 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.
+ *
+ * To do: add support for scsi-mq in this function.
+ */
+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);
@@ -505,27 +535,6 @@ void srp_start_tl_fail_timers(struct srp
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.
*
@@ -560,8 +569,7 @@ int srp_reconnect_rport(struct srp_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);
--
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