diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index 188cbbd..4663f7d 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -1295,6 +1295,11 @@
 		rw = (pb->pb_flags & PBF_READ) ? READ : WRITE;
 	}
 
+	if (pb->pb_flags & PBF_ORDERED) {
+		ASSERT(!(pb->pb_flags & PBF_READ));
+		rw = WRITE_BARRIER;
+	}
+
 	/* Special code path for reading a sub page size pagebuf in --
 	 * we populate up the whole page, and hence the other metadata
 	 * in the same page.  This optimization is only valid when the
diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h
index 39c8ca1..fa21d1f 100644
--- a/fs/xfs/linux-2.6/xfs_buf.h
+++ b/fs/xfs/linux-2.6/xfs_buf.h
@@ -74,7 +74,7 @@
 	PBF_DELWRI = (1 << 6),  /* buffer has dirty pages                  */
 	PBF_STALE = (1 << 7),	/* buffer has been staled, do not find it  */
 	PBF_FS_MANAGED = (1 << 8),  /* filesystem controls freeing memory  */
-	PBF_FLUSH = (1 << 11),	    /* flush disk write cache		   */
+ 	PBF_ORDERED = (1 << 11),    /* use ordered writes		   */
 	PBF_READ_AHEAD = (1 << 12), /* asynchronous read-ahead		   */
 
 	/* flags used only as arguments to access routines */
@@ -383,9 +383,9 @@
 #define XFS_BUF_UNASYNC(x)	 ((x)->pb_flags &= ~PBF_ASYNC)
 #define XFS_BUF_ISASYNC(x)	 ((x)->pb_flags & PBF_ASYNC)
 
-#define XFS_BUF_FLUSH(x)	 ((x)->pb_flags |= PBF_FLUSH)
-#define XFS_BUF_UNFLUSH(x)	 ((x)->pb_flags &= ~PBF_FLUSH)
-#define XFS_BUF_ISFLUSH(x)	 ((x)->pb_flags & PBF_FLUSH)
+#define XFS_BUF_ORDERED(x)	 ((x)->pb_flags |= PBF_ORDERED)
+#define XFS_BUF_UNORDERED(x)	 ((x)->pb_flags &= ~PBF_ORDERED)
+#define XFS_BUF_ISORDERED(x)	 ((x)->pb_flags & PBF_ORDERED)
 
 #define XFS_BUF_SHUT(x)		 printk("XFS_BUF_SHUT not implemented yet\n")
 #define XFS_BUF_UNSHUT(x)	 printk("XFS_BUF_UNSHUT not implemented yet\n")
diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index 2302454..d2701cc 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -278,6 +278,72 @@
 		close_bdev_excl(bdev);
 }
 
+/*
+ * Try to write out the superblock using barriers.
+ */
+STATIC int
+xfs_barrier_test(
+	xfs_mount_t	*mp)
+{
+	xfs_buf_t	*sbp = xfs_getsb(mp, 0);
+	int		error;
+
+	XFS_BUF_UNDONE(sbp);
+	XFS_BUF_UNREAD(sbp);
+	XFS_BUF_UNDELAYWRITE(sbp);
+	XFS_BUF_WRITE(sbp);
+	XFS_BUF_UNASYNC(sbp);
+	XFS_BUF_ORDERED(sbp);
+
+	xfsbdstrat(mp, sbp);
+	error = xfs_iowait(sbp);
+
+	/*
+	 * Clear all the flags we set and possible error state in the
+	 * buffer.  We only did the write to try out whether barriers
+	 * worked and shouldn't leave any traces in the superblock
+	 * buffer.
+	 */
+	XFS_BUF_DONE(sbp);
+	XFS_BUF_ERROR(sbp, 0);
+	XFS_BUF_UNORDERED(sbp);
+
+	xfs_buf_relse(sbp);
+	return error;
+}
+
+void
+xfs_mountfs_check_barriers(xfs_mount_t *mp)
+{
+	int error;
+
+	if (mp->m_logdev_targp != mp->m_ddev_targp) {
+		xfs_fs_cmn_err(CE_NOTE, mp,
+		  "Disabling barriers, not supported with external log device");
+		mp->m_flags &= ~XFS_MOUNT_BARRIER;
+	}
+
+	if (mp->m_ddev_targp->pbr_bdev->bd_disk->queue->ordered ==
+					QUEUE_ORDERED_NONE) {
+		xfs_fs_cmn_err(CE_NOTE, mp,
+		  "Disabling barriers, not supported by the underlying device");
+		mp->m_flags &= ~XFS_MOUNT_BARRIER;
+	}
+
+	error = xfs_barrier_test(mp);
+	if (error) {
+		xfs_fs_cmn_err(CE_NOTE, mp,
+		  "Disabling barriers, trial barrier write failed");
+		mp->m_flags &= ~XFS_MOUNT_BARRIER;
+	}
+}
+
+void
+xfs_blkdev_issue_flush(
+	xfs_buftarg_t		*buftarg)
+{
+	blkdev_issue_flush(buftarg->pbr_bdev, NULL);
+}
 
 STATIC struct inode *
 linvfs_alloc_inode(
diff --git a/fs/xfs/linux-2.6/xfs_super.h b/fs/xfs/linux-2.6/xfs_super.h
index ec7e003..ad77e37 100644
--- a/fs/xfs/linux-2.6/xfs_super.h
+++ b/fs/xfs/linux-2.6/xfs_super.h
@@ -132,6 +132,7 @@
 extern int  xfs_blkdev_get(struct xfs_mount *, const char *,
 				struct block_device **);
 extern void xfs_blkdev_put(struct block_device *);
+extern void xfs_blkdev_issue_flush(struct xfs_buftarg *);
 
 extern struct export_operations linvfs_export_ops;
 
diff --git a/fs/xfs/xfs_clnt.h b/fs/xfs/xfs_clnt.h
index b3215ff..c93cb28 100644
--- a/fs/xfs/xfs_clnt.h
+++ b/fs/xfs/xfs_clnt.h
@@ -99,7 +99,7 @@
 						 * enforcement */
 #define XFSMNT_NOUUID		0x01000000	/* Ignore fs uuid */
 #define XFSMNT_DMAPI		0x02000000	/* enable dmapi/xdsm */
-#define XFSMNT_NOLOGFLUSH	0x04000000	/* Don't flush for log blocks */
+#define XFSMNT_BARRIER		0x04000000	/* use write barriers */
 #define XFSMNT_IDELETE		0x08000000	/* inode cluster delete */
 #define XFSMNT_SWALLOC		0x10000000	/* turn on stripe width
 						 * allocation */
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 51814c3..b9d3ad3 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -93,8 +93,11 @@
 STATIC void xlog_state_switch_iclogs(xlog_t		*log,
 				     xlog_in_core_t *iclog,
 				     int		eventual_size);
-STATIC int  xlog_state_sync(xlog_t *log, xfs_lsn_t lsn, uint flags);
-STATIC int  xlog_state_sync_all(xlog_t *log, uint flags);
+STATIC int  xlog_state_sync(xlog_t			*log,
+			    xfs_lsn_t 			lsn,
+			    uint			flags,
+			    int				*log_flushed);
+STATIC int  xlog_state_sync_all(xlog_t *log, uint flags, int *log_flushed);
 STATIC void xlog_state_want_sync(xlog_t	*log, xlog_in_core_t *iclog);
 
 /* local functions to manipulate grant head */
@@ -312,12 +315,17 @@
  * semaphore.
  */
 int
-xfs_log_force(xfs_mount_t *mp,
-	      xfs_lsn_t	  lsn,
-	      uint	  flags)
+_xfs_log_force(
+	xfs_mount_t	*mp,
+	xfs_lsn_t	lsn,
+	uint		flags,
+	int		*log_flushed)
 {
-	int	rval;
-	xlog_t *log = mp->m_log;
+	xlog_t		*log = mp->m_log;
+	int		dummy;
+
+	if (!log_flushed)
+		log_flushed = &dummy;
 
 #if defined(DEBUG) || defined(XLOG_NOLOG)
 	if (!xlog_debug && xlog_target == log->l_targ)
@@ -328,17 +336,12 @@
 
 	XFS_STATS_INC(xs_log_force);
 
-	if ((log->l_flags & XLOG_IO_ERROR) == 0) {
-		if (lsn == 0)
-			rval = xlog_state_sync_all(log, flags);
-		else
-			rval = xlog_state_sync(log, lsn, flags);
-	} else {
-		rval = XFS_ERROR(EIO);
-	}
-
-	return rval;
-
+	if (log->l_flags & XLOG_IO_ERROR)
+		return XFS_ERROR(EIO);
+	if (lsn == 0)
+		return xlog_state_sync_all(log, flags, log_flushed);
+	else
+		return xlog_state_sync(log, lsn, flags, log_flushed);
 }	/* xfs_log_force */
 
 /*
@@ -1467,14 +1470,13 @@
 	XFS_BUF_BUSY(bp);
 	XFS_BUF_ASYNC(bp);
 	/*
-	 * Do a disk write cache flush for the log block.
-	 * This is a bit of a sledgehammer, it would be better
-	 * to use a tag barrier here that just prevents reordering.
+	 * Do an ordered write for the log block.
+	 *
 	 * It may not be needed to flush the first split block in the log wrap
 	 * case, but do it anyways to be safe -AK
 	 */
-	if (!(log->l_mp->m_flags & XFS_MOUNT_NOLOGFLUSH))
-		XFS_BUF_FLUSH(bp);
+	if (log->l_mp->m_flags & XFS_MOUNT_BARRIER)
+		XFS_BUF_ORDERED(bp);
 
 	ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
 	ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize);
@@ -1505,8 +1507,8 @@
 		XFS_BUF_SET_FSPRIVATE(bp, iclog);
 		XFS_BUF_BUSY(bp);
 		XFS_BUF_ASYNC(bp);
-		if (!(log->l_mp->m_flags & XFS_MOUNT_NOLOGFLUSH))
-			XFS_BUF_FLUSH(bp);
+		if (log->l_mp->m_flags & XFS_MOUNT_BARRIER)
+			XFS_BUF_ORDERED(bp);
 		dptr = XFS_BUF_PTR(bp);
 		/*
 		 * Bump the cycle numbers at the start of each block
@@ -2951,7 +2953,7 @@
  *		not in the active nor dirty state.
  */
 STATIC int
-xlog_state_sync_all(xlog_t *log, uint flags)
+xlog_state_sync_all(xlog_t *log, uint flags, int *log_flushed)
 {
 	xlog_in_core_t	*iclog;
 	xfs_lsn_t	lsn;
@@ -3000,6 +3002,7 @@
 
 				if (xlog_state_release_iclog(log, iclog))
 					return XFS_ERROR(EIO);
+				*log_flushed = 1;
 				s = LOG_LOCK(log);
 				if (INT_GET(iclog->ic_header.h_lsn, ARCH_CONVERT) == lsn &&
 				    iclog->ic_state != XLOG_STATE_DIRTY)
@@ -3043,6 +3046,7 @@
 		 */
 		if (iclog->ic_state & XLOG_STATE_IOERROR)
 			return XFS_ERROR(EIO);
+		*log_flushed = 1;
 
 	} else {
 
@@ -3068,7 +3072,8 @@
 int
 xlog_state_sync(xlog_t	  *log,
 		xfs_lsn_t lsn,
-		uint	  flags)
+		uint	  flags,
+		int	  *log_flushed)
 {
     xlog_in_core_t	*iclog;
     int			already_slept = 0;
@@ -3120,6 +3125,7 @@
 			XFS_STATS_INC(xs_log_force_sleep);
 			sv_wait(&iclog->ic_prev->ic_writesema, PSWP,
 				&log->l_icloglock, s);
+			*log_flushed = 1;
 			already_slept = 1;
 			goto try_again;
 		} else {
@@ -3128,6 +3134,7 @@
 			LOG_UNLOCK(log, s);
 			if (xlog_state_release_iclog(log, iclog))
 				return XFS_ERROR(EIO);
+			*log_flushed = 1;
 			s = LOG_LOCK(log);
 		}
 	}
@@ -3152,6 +3159,7 @@
 		 */
 		if (iclog->ic_state & XLOG_STATE_IOERROR)
 			return XFS_ERROR(EIO);
+		*log_flushed = 1;
 	} else {		/* just return */
 		LOG_UNLOCK(log, s);
 	}
@@ -3606,6 +3614,7 @@
 	xlog_ticket_t	*tic;
 	xlog_t		*log;
 	int		retval;
+	int		dummy;
 	SPLDECL(s);
 	SPLDECL(s2);
 
@@ -3684,7 +3693,7 @@
 		 * Force the incore logs to disk before shutting the
 		 * log down completely.
 		 */
-		xlog_state_sync_all(log, XFS_LOG_FORCE|XFS_LOG_SYNC);
+		xlog_state_sync_all(log, XFS_LOG_FORCE|XFS_LOG_SYNC, &dummy);
 		s2 = LOG_LOCK(log);
 		retval = xlog_state_ioerror(log);
 		LOG_UNLOCK(log, s2);
diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h
index 1896111..dc920f8 100644
--- a/fs/xfs/xfs_log.h
+++ b/fs/xfs/xfs_log.h
@@ -174,9 +174,12 @@
 		       xfs_log_ticket_t ticket,
 		       void		**iclog,
 		       uint		flags);
-int	  xfs_log_force(struct xfs_mount *mp,
-			xfs_lsn_t	 lsn,
-			uint		 flags);
+int	  _xfs_log_force(struct xfs_mount *mp,
+			 xfs_lsn_t	lsn,
+			 uint		flags,
+			 int		*log_forced);
+#define xfs_log_force(mp, lsn, flags) \
+	_xfs_log_force(mp, lsn, flags, NULL);
 int	  xfs_log_mount(struct xfs_mount	*mp,
 			struct xfs_buftarg	*log_target,
 			xfs_daddr_t		start_block,
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 5affba3..bc55931 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -415,7 +415,7 @@
 						 * 32 bits in size */
 #define XFS_MOUNT_32BITINOOPT	0x00008000	/* saved mount option state */
 #define XFS_MOUNT_NOUUID	0x00010000	/* ignore uuid during mount */
-#define XFS_MOUNT_NOLOGFLUSH	0x00020000
+#define XFS_MOUNT_BARRIER	0x00020000
 #define XFS_MOUNT_IDELETE	0x00040000	/* delete empty inode clusters*/
 #define XFS_MOUNT_SWALLOC	0x00080000	/* turn on stripe width
 						 * allocation */
@@ -542,6 +542,7 @@
 extern void	xfs_mod_sb(xfs_trans_t *, __int64_t);
 extern void	xfs_mount_free(xfs_mount_t *mp, int remove_bhv);
 extern int	xfs_mountfs(struct vfs *, xfs_mount_t *mp, int);
+extern void	xfs_mountfs_check_barriers(xfs_mount_t *mp);
 
 extern int	xfs_unmountfs(xfs_mount_t *, struct cred *);
 extern void	xfs_unmountfs_close(xfs_mount_t *, struct cred *);
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 92efe27..5e33891 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -661,10 +661,11 @@
  */
  /*ARGSUSED*/
 int
-xfs_trans_commit(
+_xfs_trans_commit(
 	xfs_trans_t	*tp,
 	uint		flags,
-	xfs_lsn_t	*commit_lsn_p)
+	xfs_lsn_t	*commit_lsn_p,
+	int		*log_flushed)
 {
 	xfs_log_iovec_t		*log_vector;
 	int			nvec;
@@ -893,9 +894,11 @@
 	 * log out now and wait for it.
 	 */
 	if (sync) {
-		if (!error)
-			error = xfs_log_force(mp, commit_lsn,
-				      XFS_LOG_FORCE | XFS_LOG_SYNC);
+		if (!error) {
+			error = _xfs_log_force(mp, commit_lsn,
+				      XFS_LOG_FORCE | XFS_LOG_SYNC,
+				      log_flushed);
+		}
 		XFS_STATS_INC(xs_trans_sync);
 	} else {
 		XFS_STATS_INC(xs_trans_async);
diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
index a263aec..0cc7af5 100644
--- a/fs/xfs/xfs_trans.h
+++ b/fs/xfs/xfs_trans.h
@@ -1025,7 +1025,12 @@
 					 struct xfs_efd_log_item *,
 					 xfs_fsblock_t,
 					 xfs_extlen_t);
-int		xfs_trans_commit(xfs_trans_t *, uint flags, xfs_lsn_t *);
+int		_xfs_trans_commit(xfs_trans_t *,
+				  uint flags,
+				  xfs_lsn_t *,
+				  int *);
+#define xfs_trans_commit(tp, flags, lsn) \
+	_xfs_trans_commit(tp, flags, lsn, NULL)
 void		xfs_trans_cancel(xfs_trans_t *, int);
 void		xfs_trans_ail_init(struct xfs_mount *);
 xfs_lsn_t	xfs_trans_push_ail(struct xfs_mount *, xfs_lsn_t);
diff --git a/fs/xfs/xfs_vfsops.c b/fs/xfs/xfs_vfsops.c
index f1a904e..8238c75 100644
--- a/fs/xfs/xfs_vfsops.c
+++ b/fs/xfs/xfs_vfsops.c
@@ -321,8 +321,8 @@
 
 	if (ap->flags & XFSMNT_NOUUID)
 		mp->m_flags |= XFS_MOUNT_NOUUID;
-	if (ap->flags & XFSMNT_NOLOGFLUSH)
-		mp->m_flags |= XFS_MOUNT_NOLOGFLUSH;
+	if (ap->flags & XFSMNT_BARRIER)
+		mp->m_flags |= XFS_MOUNT_BARRIER;
 
 	return 0;
 }
@@ -512,8 +512,14 @@
 		goto error2;
 
 	error = XFS_IOINIT(vfsp, args, flags);
-	if (!error)
-		return 0;
+	if (error)
+		goto error2;
+
+	if ((args->flags & XFSMNT_BARRIER) &&
+	    !(XFS_MTOVFS(mp)->vfs_flag & VFS_RDONLY))
+		xfs_mountfs_check_barriers(mp);
+	return 0;
+
 error2:
 	if (mp->m_sb_bp)
 		xfs_freesb(mp);
@@ -656,19 +662,24 @@
 	else
 		mp->m_flags &= ~XFS_MOUNT_NOATIME;
 
-	if (!(vfsp->vfs_flag & VFS_RDONLY)) {
-		VFS_SYNC(vfsp, SYNC_FSDATA|SYNC_BDFLUSH|SYNC_ATTR, NULL, error);
+	if ((vfsp->vfs_flag & VFS_RDONLY) &&
+	    !(*flags & MS_RDONLY)) {
+		vfsp->vfs_flag &= ~VFS_RDONLY;
+
+		if (args->flags & XFSMNT_BARRIER)
+			xfs_mountfs_check_barriers(mp);
 	}
 
-	if (*flags & MS_RDONLY) {
+	if (!(vfsp->vfs_flag & VFS_RDONLY) &&
+	    (*flags & MS_RDONLY)) {
+		VFS_SYNC(vfsp, SYNC_FSDATA|SYNC_BDFLUSH|SYNC_ATTR, NULL, error);
+
 		xfs_quiesce_fs(mp);
 
 		/* Ok now write out an unmount record */
 		xfs_log_unmount_write(mp);
 		xfs_unmountfs_writesb(mp);
 		vfsp->vfs_flag |= VFS_RDONLY;
-	} else {
-		vfsp->vfs_flag &= ~VFS_RDONLY;
 	}
 
 	return 0;
@@ -1628,7 +1639,8 @@
 #define MNTOPT_ALLOCSIZE    "allocsize"    /* preferred allocation size */
 #define MNTOPT_IHASHSIZE    "ihashsize"    /* size of inode hash table */
 #define MNTOPT_NORECOVERY   "norecovery"   /* don't run XFS recovery */
-#define MNTOPT_NOLOGFLUSH   "nologflush"   /* don't hard flush on log writes */
+#define MNTOPT_BARRIER	"barrier"	/* use writer barriers for log write and
+					   unwritten extent conversion */
 #define MNTOPT_OSYNCISOSYNC "osyncisosync" /* o_sync is REALLY o_sync */
 #define MNTOPT_64BITINODE   "inode64"	/* inodes can be allocated anywhere */
 #define MNTOPT_IKEEP	"ikeep"		/* do not free empty inode clusters */
@@ -1791,8 +1803,8 @@
 #endif
 		} else if (!strcmp(this_char, MNTOPT_NOUUID)) {
 			args->flags |= XFSMNT_NOUUID;
-		} else if (!strcmp(this_char, MNTOPT_NOLOGFLUSH)) {
-			args->flags |= XFSMNT_NOLOGFLUSH;
+		} else if (!strcmp(this_char, MNTOPT_BARRIER)) {
+			args->flags |= XFSMNT_BARRIER;
 		} else if (!strcmp(this_char, MNTOPT_IKEEP)) {
 			args->flags &= ~XFSMNT_IDELETE;
 		} else if (!strcmp(this_char, MNTOPT_NOIKEEP)) {
@@ -1866,7 +1878,7 @@
 		{ XFS_MOUNT_NOUUID,		"," MNTOPT_NOUUID },
 		{ XFS_MOUNT_NORECOVERY,		"," MNTOPT_NORECOVERY },
 		{ XFS_MOUNT_OSYNCISOSYNC,	"," MNTOPT_OSYNCISOSYNC },
-		{ XFS_MOUNT_NOLOGFLUSH,		"," MNTOPT_NOLOGFLUSH },
+		{ XFS_MOUNT_BARRIER,		"," MNTOPT_BARRIER },
 		{ XFS_MOUNT_IDELETE,		"," MNTOPT_NOIKEEP },
 		{ 0, NULL }
 	};
diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 58bfe62..e2bf2ef 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -1118,6 +1118,7 @@
 	xfs_inode_t	*ip;
 	xfs_trans_t	*tp;
 	int		error;
+	int		log_flushed = 0, changed = 1;
 
 	vn_trace_entry(BHV_TO_VNODE(bdp),
 			__FUNCTION__, (inst_t *)__return_address);
@@ -1171,10 +1172,18 @@
 		xfs_iunlock(ip, XFS_ILOCK_SHARED);
 
 		if (xfs_ipincount(ip)) {
-			xfs_log_force(ip->i_mount, (xfs_lsn_t)0,
+			_xfs_log_force(ip->i_mount, (xfs_lsn_t)0,
 				      XFS_LOG_FORCE |
 				      ((flag & FSYNC_WAIT)
-				       ? XFS_LOG_SYNC : 0));
+				       ? XFS_LOG_SYNC : 0),
+				      &log_flushed);
+		} else {
+			/*
+			 * If the inode is not pinned and nothing
+			 * has changed we don't need to flush the
+			 * cache.
+			 */
+			changed = 0;
 		}
 		error = 0;
 	} else	{
@@ -1210,10 +1219,27 @@
 		xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 		if (flag & FSYNC_WAIT)
 			xfs_trans_set_sync(tp);
-		error = xfs_trans_commit(tp, 0, NULL);
+		error = _xfs_trans_commit(tp, 0, NULL, &log_flushed);
 
 		xfs_iunlock(ip, XFS_ILOCK_EXCL);
 	}
+
+	if ((ip->i_mount->m_flags & XFS_MOUNT_BARRIER) && changed) {
+		/*
+		 * If the log write didn't issue an ordered tag we need
+		 * to flush the disk cache for the data device now.
+		 */
+		if (!log_flushed)
+			xfs_blkdev_issue_flush(ip->i_mount->m_ddev_targp);
+
+		/*
+		 * If this inode is on the RT dev we need to flush that
+		 * cache aswell.
+		 */
+		if (ip->i_d.di_flags & XFS_DIFLAG_REALTIME)
+			xfs_blkdev_issue_flush(ip->i_mount->m_rtdev_targp);
+	}
+
 	return error;
 }