From: Brian Behlendorf <behlendorf1@llnl.gov>
Date: Wed, 9 Dec 2015 01:04:31 +0000 (-0800)
Subject: Revert "Make taskq_member() use ->journal_info"
X-Git-Tag: spl-0.7.12~147
X-Git-Url: https://git.proxmox.com/?p=mirror_spl.git;a=commitdiff_plain;h=c5a8b1e163179cadcf2c5f81b000bf7f86f41369

Revert "Make taskq_member() use ->journal_info"

This reverts commit a430c11f0b1ef16ca5edf3059e4082709277376c.  Using
journal_info like this can cause a BUG at kernel fs/jbd2/transaction.c:425!

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #500
---

diff --git a/include/sys/taskq.h b/include/sys/taskq.h
index 65f9112..a43a86d 100644
--- a/include/sys/taskq.h
+++ b/include/sys/taskq.h
@@ -124,7 +124,7 @@ extern void taskq_wait_id(taskq_t *, taskqid_t);
 extern void taskq_wait_outstanding(taskq_t *, taskqid_t);
 extern void taskq_wait(taskq_t *);
 extern int taskq_cancel_id(taskq_t *, taskqid_t);
-#define	taskq_member(taskq, thread)	((taskq) == ((thread)->journal_info))
+extern int taskq_member(taskq_t *, void *);
 
 #define taskq_create_proc(name, nthreads, pri, min, max, proc, flags) \
     taskq_create(name, nthreads, pri, min, max, flags)
diff --git a/module/spl/spl-taskq.c b/module/spl/spl-taskq.c
index 0c5b230..2c2e3ad 100644
--- a/module/spl/spl-taskq.c
+++ b/module/spl/spl-taskq.c
@@ -448,6 +448,40 @@ taskq_wait(taskq_t *tq)
 }
 EXPORT_SYMBOL(taskq_wait);
 
+static int
+taskq_member_impl(taskq_t *tq, void *t)
+{
+	struct list_head *l;
+	taskq_thread_t *tqt;
+	int found = 0;
+
+	ASSERT(tq);
+	ASSERT(t);
+	ASSERT(spin_is_locked(&tq->tq_lock));
+
+	list_for_each(l, &tq->tq_thread_list) {
+		tqt = list_entry(l, taskq_thread_t, tqt_thread_list);
+		if (tqt->tqt_thread == (struct task_struct *)t) {
+			found = 1;
+			break;
+		}
+	}
+	return (found);
+}
+
+int
+taskq_member(taskq_t *tq, void *t)
+{
+	int found;
+
+	spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
+	found = taskq_member_impl(tq, t);
+	spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags);
+
+	return (found);
+}
+EXPORT_SYMBOL(taskq_member);
+
 /*
  * Cancel an already dispatched task given the task id.  Still pending tasks
  * will be immediately canceled, and if the task is active the function will
@@ -778,7 +812,6 @@ taskq_thread(void *args)
 	ASSERT(tqt);
 	tq = tqt->tqt_tq;
 	current->flags |= PF_NOFREEZE;
-	current->journal_info = tq;
 
 	#if defined(PF_MEMALLOC_NOIO)
 	(void) memalloc_noio_save();
@@ -844,8 +877,6 @@ taskq_thread(void *args)
 			/* Perform the requested task */
 			t->tqent_func(t->tqent_arg);
 
-			ASSERT3P(tq, ==, current->journal_info);
-
 			spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags);
 			tq->tq_nactive--;
 			list_del_init(&tqt->tqt_active_list);