From 34a2d313c51f47cae50ccb89f4196462665f2c48 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@tuxera.com>
Date: Tue, 23 Nov 2010 14:38:21 +0100
Subject: hfsplus: flush disk caches in sync and fsync

Flush the disk cache in fsync and sync to make sure data actually is
on disk on completion of these system calls.  There is a nobarrier
mount option to disable this behaviour.  It's slightly misnamed now
that barrier actually are gone, but it matches the name used by all
major filesystems.

Signed-off-by: Christoph Hellwig <hch@tuxera.com>
---
 fs/hfsplus/hfsplus_fs.h |  1 +
 fs/hfsplus/inode.c      |  4 ++++
 fs/hfsplus/options.c    | 11 +++++++++++
 fs/hfsplus/super.c      |  5 +++++
 4 files changed, 21 insertions(+)

diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h
index 65c698f78ef..17ac254e72c 100644
--- a/fs/hfsplus/hfsplus_fs.h
+++ b/fs/hfsplus/hfsplus_fs.h
@@ -156,6 +156,7 @@ struct hfsplus_sb_info {
 #define HFSPLUS_SB_FORCE	2
 #define HFSPLUS_SB_HFSX		3
 #define HFSPLUS_SB_CASEFOLD	4
+#define HFSPLUS_SB_NOBARRIER	5
 
 static inline struct hfsplus_sb_info *HFSPLUS_SB(struct super_block *sb)
 {
diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
index bf6535b7326..bda7464c205 100644
--- a/fs/hfsplus/inode.c
+++ b/fs/hfsplus/inode.c
@@ -8,6 +8,7 @@
  * Inode handling routines
  */
 
+#include <linux/blkdev.h>
 #include <linux/mm.h>
 #include <linux/fs.h>
 #include <linux/pagemap.h>
@@ -334,6 +335,9 @@ int hfsplus_file_fsync(struct file *file, int datasync)
 			error = error2;
 	}
 
+	if (!test_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags))
+		blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
+
 	return error;
 }
 
diff --git a/fs/hfsplus/options.c b/fs/hfsplus/options.c
index 43b02b5525e..dbd9d0c426c 100644
--- a/fs/hfsplus/options.c
+++ b/fs/hfsplus/options.c
@@ -23,6 +23,7 @@ enum {
 	opt_umask, opt_uid, opt_gid,
 	opt_part, opt_session, opt_nls,
 	opt_nodecompose, opt_decompose,
+	opt_barrier, opt_nobarrier,
 	opt_force, opt_err
 };
 
@@ -37,6 +38,8 @@ static const match_table_t tokens = {
 	{ opt_nls, "nls=%s" },
 	{ opt_decompose, "decompose" },
 	{ opt_nodecompose, "nodecompose" },
+	{ opt_barrier, "barrier" },
+	{ opt_nobarrier, "nobarrier" },
 	{ opt_force, "force" },
 	{ opt_err, NULL }
 };
@@ -174,6 +177,12 @@ int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
 		case opt_nodecompose:
 			set_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
 			break;
+		case opt_barrier:
+			clear_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags);
+			break;
+		case opt_nobarrier:
+			set_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags);
+			break;
 		case opt_force:
 			set_bit(HFSPLUS_SB_FORCE, &sbi->flags);
 			break;
@@ -212,5 +221,7 @@ int hfsplus_show_options(struct seq_file *seq, struct vfsmount *mnt)
 		seq_printf(seq, ",nls=%s", sbi->nls->charset);
 	if (test_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags))
 		seq_printf(seq, ",nodecompose");
+	if (test_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags))
+		seq_printf(seq, ",nobarrier");
 	return 0;
 }
diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 036650123c4..154478c71f2 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -10,6 +10,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/pagemap.h>
+#include <linux/blkdev.h>
 #include <linux/fs.h>
 #include <linux/slab.h>
 #include <linux/vfs.h>
@@ -212,6 +213,10 @@ int hfsplus_sync_fs(struct super_block *sb, int wait)
 out:
 	mutex_unlock(&sbi->alloc_mutex);
 	mutex_unlock(&sbi->vh_mutex);
+
+	if (!test_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags))
+		blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
+
 	return error;
 }
 
-- 
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