xfs: replace barriers with explicit flush / FUA usage

Switch to the WRITE_FLUSH_FUA flag for log writes and remove the EOPNOTSUPP
detection for barriers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h
index d072e5f..d533d64 100644
--- a/fs/xfs/linux-2.6/xfs_buf.h
+++ b/fs/xfs/linux-2.6/xfs_buf.h
@@ -86,14 +86,6 @@
  */
 #define _XBF_PAGE_LOCKED	(1 << 22)
 
-/*
- * If we try a barrier write, but it fails we have to communicate
- * this to the upper layers.  Unfortunately b_error gets overwritten
- * when the buffer is re-issued so we have to add another flag to
- * keep this information.
- */
-#define _XFS_BARRIER_FAILED	(1 << 23)
-
 typedef unsigned int xfs_buf_flags_t;
 
 #define XFS_BUF_FLAGS \
@@ -114,8 +106,7 @@
 	{ _XBF_PAGES,		"PAGES" }, \
 	{ _XBF_RUN_QUEUES,	"RUN_QUEUES" }, \
 	{ _XBF_DELWRI_Q,	"DELWRI_Q" }, \
-	{ _XBF_PAGE_LOCKED,	"PAGE_LOCKED" }, \
-	{ _XFS_BARRIER_FAILED,	"BARRIER_FAILED" }
+	{ _XBF_PAGE_LOCKED,	"PAGE_LOCKED" }
 
 
 typedef enum {