[PATCH 3.19.y-ckt 082/156] IB/srp: Stop the scsi_eh_<n> and scsi_tmf_<n> threads if login fails

[Kamal Mostafa]

3.19.8-ckt8 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Bart Van Assche <bart.vanassche at sandisk.com>

commit bc44bd1d864664f3658352c6aaaa02557d49165d upstream.

scsi_host_alloc() not only allocates memory for a SCSI host but also
creates the scsi_eh_<n> kernel thread and the scsi_tmf_<n> workqueue.
Stop these threads if login fails by calling scsi_host_put().

Reported-by: Konstantin Krotov <kkv at clodo.ru>
Fixes: fb49c8bbaae7 ("Remove an extraneous scsi_host_put() from an error path")
Signed-off-by: Bart Van Assche <bart.vanassche at sandisk.com>
Cc: Sagi Grimberg <sagig at mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer at profitbricks.com>
Signed-off-by: Doug Ledford <dledford at redhat.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/infiniband/ulp/srp/ib_srp.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 201e6f9..7ce100b 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -2760,6 +2760,13 @@ static int srp_sdev_count(struct Scsi_Host *host)
 	return c;
 }
 
+/*
+ * Return values:
+ * < 0 upon failure. Caller is responsible for SRP target port cleanup.
+ * 0 and target->state == SRP_TARGET_REMOVED if asynchronous target port
+ *    removal has been scheduled.
+ * 0 and target->state != SRP_TARGET_REMOVED upon success.
+ */
 static int srp_add_target(struct srp_host *host, struct srp_target_port *target)
 {
 	struct srp_rport_identifiers ids;
@@ -3298,6 +3305,8 @@ out:
 	mutex_unlock(&host->add_target_mutex);
 
 	scsi_host_put(target->scsi_host);
+	if (ret < 0)
+		scsi_host_put(target->scsi_host);
 
 	return ret;
 
-- 
1.9.1