[Scst-svn] [master] scst_targ: Check prepare_to_wait_exclusive_head() return value

[Gleb C. <lna...@ya...>]

Commit: 86d5b21
GitHub URL: https://github.com/SCST-project/scst/commit/86d5b218e4cbf98da04db81b8e320e490fbbe472
Author: Gleb Chesnokov
Date: 2023-06-30T10:56:09+03:00
Log Message:
-----------
scst_targ: Check prepare_to_wait_exclusive_head() return value

The prepare_to_wait_exclusive_head() function was modified in
commit d8894cbd1157 ("scst.h: Refactor wait_event_locked() to enhance
usability and clarity"). It now returns an error if the current
interruptible thread has pending signals.

This patch introduces the scst_wait_for_cmd() helper function for the
scst_cmd_thread(). This new function handles the return value of the
prepare_to_wait_exclusive_head() appropriately.

This patch fixes the following Coverity complaint:

    CID 321410 (#1 of 1): Unchecked return value (CHECKED_RETURN)
    check_return: Calling prepare_to_wait_exclusive_head without
    checking return value.

Modified Paths:
--------------
 scst/src/scst_targ.c | 51 ++++++++++-----
 1 file changed, 34 insertions(+), 17 deletions(-)

===================================================================
diff --git a/scst/src/scst_targ.c b/scst/src/scst_targ.c
index 70e212e..4b4eac7 100644
--- a/scst/src/scst_targ.c
+++ b/scst/src/scst_targ.c
@@ -4800,6 +4800,39 @@ static inline int test_cmd_threads(struct scst_cmd_thread_t *thr)
 	return res;
 }
 
+static inline int
+scst_wait_for_cmd(struct scst_cmd_threads *p_cmd_threads, struct scst_cmd_thread_t *thr)
+{
+	DEFINE_WAIT(wq_entry);
+	int ret = 0;
+
+	if (test_cmd_threads(thr))
+		return 0;
+
+	for (;;) {
+		long __int = prepare_to_wait_exclusive_head(&p_cmd_threads->cmd_list_waitQ,
+							    &wq_entry, TASK_INTERRUPTIBLE);
+
+		if (test_cmd_threads(thr))
+			break;
+
+		if (__int) {
+			ret = __int;
+			goto out;
+		}
+
+		spin_unlock(&thr->thr_cmd_list_lock);
+		spin_unlock_irq(&p_cmd_threads->cmd_list_lock);
+		schedule();
+		spin_lock_irq(&p_cmd_threads->cmd_list_lock);
+		spin_lock(&thr->thr_cmd_list_lock);
+	}
+	finish_wait(&p_cmd_threads->cmd_list_waitQ, &wq_entry);
+
+out:
+	return ret;
+}
+
 int scst_cmd_thread(void *arg)
 {
 	struct scst_cmd_thread_t *thr = arg;
@@ -4822,23 +4855,7 @@ int scst_cmd_thread(void *arg)
 	spin_lock_irq(&p_cmd_threads->cmd_list_lock);
 	spin_lock(&thr->thr_cmd_list_lock);
 	while (!kthread_should_stop()) {
-		if (!test_cmd_threads(thr)) {
-			DEFINE_WAIT(wait);
-
-			do {
-				prepare_to_wait_exclusive_head(
-					&p_cmd_threads->cmd_list_waitQ,
-					&wait, TASK_INTERRUPTIBLE);
-				if (test_cmd_threads(thr))
-					break;
-				spin_unlock(&thr->thr_cmd_list_lock);
-				spin_unlock_irq(&p_cmd_threads->cmd_list_lock);
-				schedule();
-				spin_lock_irq(&p_cmd_threads->cmd_list_lock);
-				spin_lock(&thr->thr_cmd_list_lock);
-			} while (!test_cmd_threads(thr));
-			finish_wait(&p_cmd_threads->cmd_list_waitQ, &wait);
-		}
+		scst_wait_for_cmd(p_cmd_threads, thr);
 
 		if (tm_dbg_is_release()) {
 			spin_unlock_irq(&p_cmd_threads->cmd_list_lock);