[3.19.y-ckt stable] Patch "IB/srp: Stop the scsi_eh_<n> and scsi_tmf_<n> threads if login fails" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    IB/srp: Stop the scsi_eh_<n> and scsi_tmf_<n> threads if login fails

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt8.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 68209189ded0606b75147ff6db7842afca160bba Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bart.vanassche at sandisk.com>
Date: Fri, 14 Aug 2015 11:01:09 -0700
Subject: IB/srp: Stop the scsi_eh_<n> and scsi_tmf_<n> threads if login fails

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