From 53a9829a45d4939829a0719eaa10a3fa46ea8e06 Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bart.vanassche@sandisk.com>
Date: Fri, 11 Dec 2015 01:40:41 +0000
Subject: [PATCH] ib_srpt: Fix a runtime warning

Avoid that the following warning is reported:

WARNING: CPU: 7 PID: 32692 at kernel/sched/core.c:7533 __might_sleep+0x82/0x90()
do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffffa08f5f0b>]
 srpt_compl_thread+0xab/0x1c0 [ib_srpt]
Call Trace:
 [<ffffffff81251afb>] dump_stack+0x4f/0x74
 [<ffffffff810574cb>] warn_slowpath_common+0x8b/0xd0
 [<ffffffff810575b1>] warn_slowpath_fmt+0x41/0x70
 [<ffffffff810804c2>] __might_sleep+0x82/0x90
 [<ffffffff81113f74>] mempool_alloc+0x94/0x180
 [<ffffffffa04ff80c>] scst_alloc_mgmt_cmd+0x4c/0x120 [scst]
 [<ffffffffa04dc1e4>] scst_pre_rx_mgmt_cmd+0x84/0x1e0 [scst]
 [<ffffffffa04dc6ea>] scst_rx_mgmt_fn+0x8a/0x3e0 [scst]
 [<ffffffffa08f53fe>] scst_rx_mgmt_fn_lun+0x6e/0x90 [ib_srpt]
 [<ffffffffa08f55e1>] srpt_handle_tsk_mgmt+0x1c1/0x2f0 [ib_srpt]
 [<ffffffffa08f58d0>] srpt_handle_new_iu+0x1c0/0x230 [ib_srpt]
 [<ffffffffa08f5cd9>] srpt_process_rcv_completion+0x89/0xd0 [ib_srpt]
 [<ffffffffa08f5d74>] srpt_process_one_compl+0x54/0x70 [ib_srpt]
 [<ffffffffa08f5df9>] srpt_poll+0x69/0x90 [ib_srpt]
 [<ffffffffa08f5e3e>] srpt_process_completion+0x1e/0x40 [ib_srpt]
 [<ffffffffa08f5f3c>] srpt_compl_thread+0xdc/0x1c0 [ib_srpt]


git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@6727 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 srpt/src/ib_srpt.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/srpt/src/ib_srpt.c b/srpt/src/ib_srpt.c
index 2d2895335..115175845 100644
--- a/srpt/src/ib_srpt.c
+++ b/srpt/src/ib_srpt.c
@@ -2068,13 +2068,18 @@ static int srpt_poll(struct srpt_rdma_ch *ch, int budget)
 	return processed;
 }
 
-static int srpt_process_completion(struct srpt_rdma_ch *ch, int budget)
+static int srpt_process_completion(struct srpt_rdma_ch *ch, int budget,
+				   bool thread_context)
 {
 	struct ib_cq *const cq = ch->cq;
 	int processed = 0, n = budget;
 
 	do {
+		if (thread_context)
+			set_current_state(TASK_RUNNING);
 		processed += srpt_poll(ch, n);
+		if (thread_context)
+			set_current_state(TASK_INTERRUPTIBLE);
 		n = ib_req_notify_cq(cq, IB_CQ_NEXT_COMP |
 				     IB_CQ_REPORT_MISSED_EVENTS);
 	} while (n > 0);
@@ -2143,6 +2148,7 @@ static int srpt_compl_thread(void *arg)
 {
 	enum { poll_budget = 65536 };
 	struct srpt_rdma_ch *ch;
+	int n;
 
 	/* Hibernation / freezing of the SRPT kernel thread is not supported. */
 	current->flags |= PF_NOFREEZE;
@@ -2151,8 +2157,10 @@ static int srpt_compl_thread(void *arg)
 	BUG_ON(!ch);
 
 	while (ch->state < CH_LIVE) {
-		set_current_state(TASK_INTERRUPTIBLE);
-		if (srpt_process_completion(ch, poll_budget) >= poll_budget)
+		n = srpt_process_completion(ch, poll_budget, true);
+		if (ch->state >= CH_LIVE)
+			break;
+		if (n >= poll_budget)
 			cond_resched();
 		else
 			schedule();
@@ -2161,8 +2169,10 @@ static int srpt_compl_thread(void *arg)
 	srpt_process_wait_list(ch);
 
 	while (ch->state < CH_DISCONNECTED) {
-		set_current_state(TASK_INTERRUPTIBLE);
-		if (srpt_process_completion(ch, poll_budget) >= poll_budget)
+		n = srpt_process_completion(ch, poll_budget, true);
+		if (ch->state >= CH_DISCONNECTED)
+			break;
+		if (n >= poll_budget)
 			cond_resched();
 		else
 			schedule();