Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking changes from Ingo Molnar:
 "The main changes in this cycle were:

   - pvqspinlock statistics fixes (Davidlohr Bueso)

   - flip atomic_fetch_or() arguments (Peter Zijlstra)

   - locktorture simplification (Paul E.  McKenney)

   - documentation updates (SeongJae Park, David Howells, Davidlohr
     Bueso, Paul E McKenney, Peter Zijlstra, Will Deacon)

   - various fixes"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/atomics: Flip atomic_fetch_or() arguments
  locking/pvqspinlock: Robustify init_qspinlock_stat()
  locking/pvqspinlock: Avoid double resetting of stats
  lcoking/locktorture: Simplify the torture_runnable computation
  locking/Documentation: Clarify that ACQUIRE applies to loads, RELEASE applies to stores
  locking/Documentation: State purpose of memory-barriers.txt
  locking/Documentation: Add disclaimer
  locking/Documentation/lockdep: Fix spelling mistakes
  locking/lockdep: Deinline register_lock_class(), save 2328 bytes
  locking/locktorture: Fix NULL pointer dereference for cleanup paths
  locking/locktorture: Fix deboosting NULL pointer dereference
  locking/Documentation: Mention smp_cond_acquire()
  locking/Documentation: Insert white spaces consistently
  locking/Documentation: Fix formatting inconsistencies
  locking/Documentation: Add missed subsection in TOC
  locking/Documentation: Fix missed s/lock/acquire renames
  locking/Documentation: Clarify relationship of barrier() to control dependencies

1 files changed, 14 insertions, 10 deletions

diff --git a/kernel/locking/qspinlock_stat.h b/kernel/locking/qspinlock_stat.h
index d734b7502001..22e025309845 100644
--- a/kernel/locking/qspinlock_stat.h
+++ b/kernel/locking/qspinlock_stat.h
@@ -191,8 +191,6 @@ static ssize_t qstat_write(struct file *file, const char __user *user_buf,
 
 		for (i = 0 ; i < qstat_num; i++)
 			WRITE_ONCE(ptr[i], 0);
-		for (i = 0 ; i < qstat_num; i++)
-			WRITE_ONCE(ptr[i], 0);
 	}
 	return count;
 }
@@ -214,10 +212,8 @@ static int __init init_qspinlock_stat(void)
 	struct dentry *d_qstat = debugfs_create_dir("qlockstat", NULL);
 	int i;
 
-	if (!d_qstat) {
-		pr_warn("Could not create 'qlockstat' debugfs directory\n");
-		return 0;
-	}
+	if (!d_qstat)
+		goto out;
 
 	/*
 	 * Create the debugfs files
@@ -227,12 +223,20 @@ static int __init init_qspinlock_stat(void)
 	 * performance.
 	 */
 	for (i = 0; i < qstat_num; i++)
-		debugfs_create_file(qstat_names[i], 0400, d_qstat,
-				   (void *)(long)i, &fops_qstat);
+		if (!debugfs_create_file(qstat_names[i], 0400, d_qstat,
+					 (void *)(long)i, &fops_qstat))
+			goto fail_undo;
+
+	if (!debugfs_create_file(qstat_names[qstat_reset_cnts], 0200, d_qstat,
+				 (void *)(long)qstat_reset_cnts, &fops_qstat))
+		goto fail_undo;
 
-	debugfs_create_file(qstat_names[qstat_reset_cnts], 0200, d_qstat,
-			   (void *)(long)qstat_reset_cnts, &fops_qstat);
 	return 0;
+fail_undo:
+	debugfs_remove_recursive(d_qstat);
+out:
+	pr_warn("Could not create 'qlockstat' debugfs entries\n");
+	return -ENOMEM;
 }
 fs_initcall(init_qspinlock_stat);