kfifo: fix warn_unused_result

Fix the "ignoring return value of '...', declared with attribute
warn_unused_result" compiler warning in several users of the new kfifo
API.

It removes the __must_check attribute from kfifo_in() and
kfifo_in_locked() which must not necessary performed.

Fix the allocation bug in the nozomi driver file, by moving out the
kfifo_alloc from the interrupt handler into the probe function.

Fix the kfifo_out() and kfifo_out_locked() users to handle a unexpected
end of fifo.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 12 insertions, 4 deletions

diff --git a/drivers/scsi/libiscsi_tcp.c b/drivers/scsi/libiscsi_tcp.c
index d51ffeca2ec..db6856c138f 100644
--- a/drivers/scsi/libiscsi_tcp.c
+++ b/drivers/scsi/libiscsi_tcp.c
@@ -990,8 +990,13 @@ static struct iscsi_r2t_info *iscsi_tcp_get_curr_r2t(struct iscsi_task *task)
                 }
 
                 if (r2t == NULL) {
-                        kfifo_out(&tcp_task->r2tqueue,
-                                    (void *)&tcp_task->r2t, sizeof(void *));
+                        if (kfifo_out(&tcp_task->r2tqueue,
+                            (void *)&tcp_task->r2t, sizeof(void *)) !=
+                            sizeof(void *)) {
+                                WARN_ONCE(1, "unexpected fifo state");
+                                r2t = NULL;
+                        }
+
                         r2t = tcp_task->r2t;
                 }
                 spin_unlock_bh(&session->lock);
diff --git a/drivers/scsi/libsrp.c b/drivers/scsi/libsrp.c
index 8424b8606ef..ab19b3b4be5 100644
--- a/drivers/scsi/libsrp.c
+++ b/drivers/scsi/libsrp.c
@@ -163,8 +163,11 @@ struct iu_entry *srp_iu_get(struct srp_target *target)
 {
         struct iu_entry *iue = NULL;
 
-        kfifo_out_locked(&target->iu_queue.queue, (void *) &iue,
-                        sizeof(void *), &target->iu_queue.lock);
+        if (kfifo_out_locked(&target->iu_queue.queue, (void *) &iue,
+                sizeof(void *), &target->iu_queue.lock) != sizeof(void *)) {
+                        WARN_ONCE(1, "unexpected fifo state");
+                        return NULL;
+        }
         if (!iue)
                 return iue;
         iue->target = target;