From 0013b8ce24b7face67934b207303db71fa1c0e55 Mon Sep 17 00:00:00 2001
From: Dmitry Monakhov <dmonakhov@openvz.org>
Date: Wed, 12 Jun 2013 22:25:07 -0400
Subject: [PATCH] --- yaml --- r: 377615 b: refs/heads/master c:
 06a407f13daf9e48f0ef7189c7e54082b53940c7 h: refs/heads/master i:   377613:
 e51c9dd83f542036d909d5362fd18eda2f6aab83   377611:
 57e791a1c7b628f571c60f2589d393f26934d57b   377607:
 54b844a6c4ee5692fb1d7115a435f69fb3030599   377599:
 6bf9df42cc4d2ac52d78a067ba15a817e3c94d8b v: v3

---
 [refs]                     |  2 +-
 trunk/fs/ext4/super.c      | 36 +++++++++++++++++++++++++++++++++++-
 trunk/include/linux/jbd2.h | 13 +++++++++++++
 3 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 98b92e704feb..4a78bdecd7bd 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 9ff864462477206bc23b405a6ae506e92fb6dc9c
+refs/heads/master: 06a407f13daf9e48f0ef7189c7e54082b53940c7
diff --git a/trunk/fs/ext4/super.c b/trunk/fs/ext4/super.c
index 7c8e1713e203..0f77c2e4b888 100644
--- a/trunk/fs/ext4/super.c
+++ b/trunk/fs/ext4/super.c
@@ -69,6 +69,7 @@ static void ext4_mark_recovery_complete(struct super_block *sb,
 static void ext4_clear_journal_err(struct super_block *sb,
 				   struct ext4_super_block *es);
 static int ext4_sync_fs(struct super_block *sb, int wait);
+static int ext4_sync_fs_nojournal(struct super_block *sb, int wait);
 static int ext4_remount(struct super_block *sb, int *flags, char *data);
 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
 static int ext4_unfreeze(struct super_block *sb);
@@ -1097,6 +1098,7 @@ static const struct super_operations ext4_nojournal_sops = {
 	.dirty_inode	= ext4_dirty_inode,
 	.drop_inode	= ext4_drop_inode,
 	.evict_inode	= ext4_evict_inode,
+	.sync_fs	= ext4_sync_fs_nojournal,
 	.put_super	= ext4_put_super,
 	.statfs		= ext4_statfs,
 	.remount_fs	= ext4_remount,
@@ -4553,6 +4555,7 @@ static int ext4_sync_fs(struct super_block *sb, int wait)
 {
 	int ret = 0;
 	tid_t target;
+	bool needs_barrier = false;
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 
 	trace_ext4_sync_fs(sb, wait);
@@ -4563,10 +4566,41 @@ static int ext4_sync_fs(struct super_block *sb, int wait)
 	 * no dirty dquots
 	 */
 	dquot_writeback_dquots(sb, -1);
+	/*
+	 * Data writeback is possible w/o journal transaction, so barrier must
+	 * being sent at the end of the function. But we can skip it if
+	 * transaction_commit will do it for us.
+	 */
+	target = jbd2_get_latest_transaction(sbi->s_journal);
+	if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
+	    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
+		needs_barrier = true;
+
 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
 		if (wait)
-			jbd2_log_wait_commit(sbi->s_journal, target);
+			ret = jbd2_log_wait_commit(sbi->s_journal, target);
+	}
+	if (needs_barrier) {
+		int err;
+		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
+		if (!ret)
+			ret = err;
 	}
+
+	return ret;
+}
+
+static int ext4_sync_fs_nojournal(struct super_block *sb, int wait)
+{
+	int ret = 0;
+
+	trace_ext4_sync_fs(sb, wait);
+	flush_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
+	flush_workqueue(EXT4_SB(sb)->unrsv_conversion_wq);
+	dquot_writeback_dquots(sb, -1);
+	if (wait && test_opt(sb, BARRIER))
+		ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
+
 	return ret;
 }
 
diff --git a/trunk/include/linux/jbd2.h b/trunk/include/linux/jbd2.h
index c3645b9475f1..a79783faecad 100644
--- a/trunk/include/linux/jbd2.h
+++ b/trunk/include/linux/jbd2.h
@@ -1374,6 +1374,19 @@ static inline u32 jbd2_chksum(journal_t *journal, u32 crc,
 	return *(u32 *)desc.ctx;
 }
 
+/* Return most recent uncommitted transaction */
+static inline tid_t  jbd2_get_latest_transaction(journal_t *journal)
+{
+	tid_t tid;
+
+	read_lock(&journal->j_state_lock);
+	tid = journal->j_commit_request;
+	if (journal->j_running_transaction)
+		tid = journal->j_running_transaction->t_tid;
+	read_unlock(&journal->j_state_lock);
+	return tid;
+}
+
 #ifdef __KERNEL__
 
 #define buffer_trace_init(bh)	do {} while (0)