fs-jbd2-Replace-bit-spinlocks.patch

From 615878771b89d9af246a26647c44a17465623be0 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Sun, 23 Aug 2009 09:29:11 +0200
Subject: [PATCH] fs: jbd2: Replace bit spinlocks

commit 216e80982324cc1290350013ada9a7ea0aca501e in tip.

Bit spinlocks are not really RT friendly and in general I don't like
them as they escape the lockdep debugging. Make it use the bh locks as
we already did for jdb.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 fs/jbd2/transaction.c |    6 +++---
 include/linux/jbd2.h  |   21 +++++++++++++++------
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index bfc70f5..c3d924b 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -1452,7 +1452,7 @@ void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh)
 	transaction_t *transaction;
 	struct buffer_head *bh = jh2bh(jh);
 
-	J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh));
+	J_ASSERT_JH_SMP(jh, jbd_is_locked_bh_state(bh));
 	transaction = jh->b_transaction;
 	if (transaction)
 		assert_spin_locked(&transaction->t_journal->j_list_lock);
@@ -1898,7 +1898,7 @@ void __jbd2_journal_file_buffer(struct journal_head *jh,
 	int was_dirty = 0;
 	struct buffer_head *bh = jh2bh(jh);
 
-	J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh));
+	J_ASSERT_JH_SMP(jh, jbd_is_locked_bh_state(bh));
 	assert_spin_locked(&transaction->t_journal->j_list_lock);
 
 	J_ASSERT_JH(jh, jh->b_jlist < BJ_Types);
@@ -1986,7 +1986,7 @@ void __jbd2_journal_refile_buffer(struct journal_head *jh)
 	int was_dirty, jlist;
 	struct buffer_head *bh = jh2bh(jh);
 
-	J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh));
+	J_ASSERT_JH_SMP(jh, jbd_is_locked_bh_state(bh));
 	if (jh->b_transaction)
 		assert_spin_locked(&jh->b_transaction->t_journal->j_list_lock);
 
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index a4d2e9f..aba2690 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -302,6 +302,15 @@ typedef struct journal_superblock_s
 #define J_EXPECT_JH(jh, expr, why...)	__journal_expect(expr, ## why)
 #endif
 
+/*
+ * For assertions that are only valid on SMP (e.g. spin_is_locked()):
+ */
+#ifdef CONFIG_SMP
+# define J_ASSERT_JH_SMP(jh, expr)	J_ASSERT_JH(jh, expr)
+#else
+# define J_ASSERT_JH_SMP(jh, assert)	do { } while (0)
+#endif
+
 enum jbd_state_bits {
 	BH_JBD			/* Has an attached ext3 journal_head */
 	  = BH_PrivateStart,
@@ -338,32 +347,32 @@ static inline struct journal_head *bh2jh(struct buffer_head *bh)
 
 static inline void jbd_lock_bh_state(struct buffer_head *bh)
 {
-	bit_spin_lock(BH_State, &bh->b_state);
+	spin_lock(&bh->b_state_lock);
 }
 
 static inline int jbd_trylock_bh_state(struct buffer_head *bh)
 {
-	return bit_spin_trylock(BH_State, &bh->b_state);
+	return spin_trylock(&bh->b_state_lock);
 }
 
 static inline int jbd_is_locked_bh_state(struct buffer_head *bh)
 {
-	return bit_spin_is_locked(BH_State, &bh->b_state);
+	return spin_is_locked(&bh->b_state_lock);
 }
 
 static inline void jbd_unlock_bh_state(struct buffer_head *bh)
 {
-	bit_spin_unlock(BH_State, &bh->b_state);
+	spin_unlock(&bh->b_state_lock);
 }
 
 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
 {
-	bit_spin_lock(BH_JournalHead, &bh->b_state);
+	spin_lock(&bh->b_uptodate_lock);
 }
 
 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
 {
-	bit_spin_unlock(BH_JournalHead, &bh->b_state);
+	spin_unlock(&bh->b_uptodate_lock);
 }
 
 /* Flags in jbd_inode->i_flags */
-- 
1.7.0.4