Re: [dm-devel] dm-writeboost testing

[Akira Hayakawa <ruby.wktk@gmail.com>]

Mikulas,

> The change seems ok. Please, also move this piece of code in flush_proc
> out of the spinlock:
>                         if (kthread_should_stop())
>                                 return 0;
> 
> It caused the workqueue warning I reported before and still causes warning 
> with kthreads:
> note: flush_daemon[5145] exited with preempt_count 1

You are right.
I fixed the bug.

diff --git a/Driver/dm-writeboost-daemon.c b/Driver/dm-writeboost-daemon.c
index 65974e2..cf790bf 100644
--- a/Driver/dm-writeboost-daemon.c
+++ b/Driver/dm-writeboost-daemon.c
@@ -29,7 +29,6 @@ int flush_proc(void *data)
                                cache->flush_wait_queue,
                                (!list_empty(&cache->flush_queue)),
                                msecs_to_jiffies(100));
-                       spin_lock_irqsave(&cache->flush_queue_lock, flags);

                        /*
                         * flush daemon can exit
@@ -37,6 +36,8 @@ int flush_proc(void *data)
                         */
                        if (kthread_should_stop())
                                return 0;
+                       else
+                               spin_lock_irqsave(&cache->flush_queue_lock, flags);
                }

> I will send you next email with more bugs that I found in your code
I will reply to you about this later.
So much bugs and some seems to be crucial.

Akira