From 6c83cc3183d8efc6378788160d78a3a917a5ae96 Mon Sep 17 00:00:00 2001
From: Clark Williams <williams@redhat.com>
Date: Tue, 3 Jul 2018 13:34:30 -0500
Subject: [PATCH 015/283] fscache: initialize cookie hash table raw spinlocks

The fscache cookie mechanism uses a hash table of hlist_bl_head structures. The
PREEMPT_RT patcheset adds a raw spinlock to this structure and so on PREEMPT_RT
the structures get used uninitialized, causing warnings about bad magic numbers
when spinlock debugging is turned on.

Use the init function for fscache cookies.

Signed-off-by: Clark Williams <williams@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 fs/fscache/cookie.c     | 8 ++++++++
 fs/fscache/main.c       | 1 +
 include/linux/fscache.h | 1 +
 3 files changed, 10 insertions(+)

diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index c550512ce335..d5d57da32ffa 100644
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -962,3 +962,11 @@ int __fscache_check_consistency(struct fscache_cookie *cookie,
 	return -ESTALE;
 }
 EXPORT_SYMBOL(__fscache_check_consistency);
+
+void __init fscache_cookie_init(void)
+{
+	int i;
+
+	for (i = 0; i < (1 << fscache_cookie_hash_shift) - 1; i++)
+		INIT_HLIST_BL_HEAD(&fscache_cookie_hash[i]);
+}
diff --git a/fs/fscache/main.c b/fs/fscache/main.c
index 30ad89db1efc..1d5f1d679ffa 100644
--- a/fs/fscache/main.c
+++ b/fs/fscache/main.c
@@ -149,6 +149,7 @@ static int __init fscache_init(void)
 		ret = -ENOMEM;
 		goto error_cookie_jar;
 	}
+	fscache_cookie_init();
 
 	fscache_root = kobject_create_and_add("fscache", kernel_kobj);
 	if (!fscache_root)
diff --git a/include/linux/fscache.h b/include/linux/fscache.h
index 84b90a79d75a..87a9330eafa2 100644
--- a/include/linux/fscache.h
+++ b/include/linux/fscache.h
@@ -230,6 +230,7 @@ extern void __fscache_readpages_cancel(struct fscache_cookie *cookie,
 extern void __fscache_disable_cookie(struct fscache_cookie *, const void *, bool);
 extern void __fscache_enable_cookie(struct fscache_cookie *, const void *, loff_t,
 				    bool (*)(void *), void *);
+extern void fscache_cookie_init(void);
 
 /**
  * fscache_register_netfs - Register a filesystem as desiring caching services
-- 
2.20.1

