[PATCH 11/11] hfsplus: flush disk caches in sync and fsync

[Christoph Hellwig <hch@lst.de>]

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>

Index: linux-2.6/fs/hfsplus/inode.c
===================================================================
--- linux-2.6.orig/fs/hfsplus/inode.c	2010-11-17 22:56:01.488273225 +0100
+++ linux-2.6/fs/hfsplus/inode.c	2010-11-17 23:03:35.845003983 +0100
@@ -8,6 +8,7 @@
  * Inode handling routines
  */
 
+#include <linux/blkdev.h>
 #include <linux/mm.h>
 #include <linux/fs.h>
 #include <linux/pagemap.h>
@@ -337,6 +338,9 @@ int hfsplus_file_fsync(struct file *file
 			error = error2;
 	}
 
+	if (!test_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags))
+		blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
+
 	return error;
 }
 
Index: linux-2.6/fs/hfsplus/super.c
===================================================================
--- linux-2.6.orig/fs/hfsplus/super.c	2010-11-17 22:56:01.505005590 +0100
+++ linux-2.6/fs/hfsplus/super.c	2010-11-17 23:03:43.735253739 +0100
@@ -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 *
 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;
 }
 
Index: linux-2.6/fs/hfsplus/hfsplus_fs.h
===================================================================
--- linux-2.6.orig/fs/hfsplus/hfsplus_fs.h	2010-11-17 22:56:01.488273225 +0100
+++ linux-2.6/fs/hfsplus/hfsplus_fs.h	2010-11-17 22:57:48.130255066 +0100
@@ -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)
 {
Index: linux-2.6/fs/hfsplus/options.c
===================================================================
--- linux-2.6.orig/fs/hfsplus/options.c	2010-11-17 22:43:05.314004052 +0100
+++ linux-2.6/fs/hfsplus/options.c	2010-11-17 22:57:48.135254228 +0100
@@ -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, s
 		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_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;
 }