From c8f01919f9ca5cb9a9cc706b369c6bdc92c22b5b Mon Sep 17 00:00:00 2001
From: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>
Date: Thu, 10 May 2018 19:12:18 +0530
Subject: [PATCH] scsi: target: tcmu: fix error resetting qfull_time_out to
 default
Git-commit: 125966db1fea12575ee21b2b3fc95a59032406f0
Patch-mainline: v4.17-rc7
References: bsc#1118978

Problem:

$ cat /sys/kernel/config/target/core/user_0/block/attrib/qfull_time_out
-1

$ echo "-1" > /sys/kernel/config/target/core/user_0/block/attrib/qfull_time_out
-bash: echo: write error: Invalid argument

Fix:

This patch will help reset qfull_time_out to its default
i.e. qfull_time_out=-1.

Signed-off-by: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>
Acked-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: David Disseldorp <ddiss@suse.de>
---
 drivers/target/target_core_user.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 269f3d29d591..d0b3d390d17d 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -2174,6 +2174,8 @@ static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
 
 	if (val >= 0) {
 		udev->qfull_time_out = val * MSEC_PER_SEC;
+	} else if (val == -1) {
+		udev->qfull_time_out = val;
 	} else {
 		printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
 		return -EINVAL;
-- 
2.13.7