[XFS] Fix remount vs no/barrier options by ensuring we clear unwanted

flags from iclog buffers before submitting them for writing.

SGI-PV: 954772
SGI-Modid: xfs-linux-melb:xfs-kern:26605a
Signed-off-by: Nathan Scott <nathans@sgi.com>

fs/xfs/linux-2.6/xfs_buf.h

@@ -246,8 +246,8 @@ extern void xfs_buf_trace(xfs_buf_t *, char *, void *, void *);
 #define BUF_BUSY		XBF_DONT_BLOCK
 
 #define XFS_BUF_BFLAGS(bp)	((bp)->b_flags)
-#define XFS_BUF_ZEROFLAGS(bp)	\
-	((bp)->b_flags &= ~(XBF_READ|XBF_WRITE|XBF_ASYNC|XBF_DELWRI))
+#define XFS_BUF_ZEROFLAGS(bp)	((bp)->b_flags &= \
+		~(XBF_READ|XBF_WRITE|XBF_ASYNC|XBF_DELWRI|XBF_ORDERED))
 
 #define XFS_BUF_STALE(bp)	((bp)->b_flags |= XFS_B_STALE)
 #define XFS_BUF_UNSTALE(bp)	((bp)->b_flags &= ~XFS_B_STALE)

fs/xfs/xfs_log.c

@@ -1430,15 +1430,14 @@ xlog_sync(xlog_t		*log,
 	}
 	XFS_BUF_SET_PTR(bp, (xfs_caddr_t) &(iclog->ic_header), count);
 	XFS_BUF_SET_FSPRIVATE(bp, iclog);	/* save for later */
+	XFS_BUF_ZEROFLAGS(bp);
 	XFS_BUF_BUSY(bp);
 	XFS_BUF_ASYNC(bp);
 	/*
 	 * 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
+	 * Its unnecessary to flush the first split block in the log wrap case.
 	 */
-	if (log->l_mp->m_flags & XFS_MOUNT_BARRIER)
+	if (!split && (log->l_mp->m_flags & XFS_MOUNT_BARRIER))
 		XFS_BUF_ORDERED(bp);
 
 	ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
@@ -1468,6 +1467,7 @@ xlog_sync(xlog_t		*log,
 		XFS_BUF_SET_PTR(bp, (xfs_caddr_t)((__psint_t)&(iclog->ic_header)+
 					    (__psint_t)count), split);
 		XFS_BUF_SET_FSPRIVATE(bp, iclog);
+		XFS_BUF_ZEROFLAGS(bp);
 		XFS_BUF_BUSY(bp);
 		XFS_BUF_ASYNC(bp);
 		if (log->l_mp->m_flags & XFS_MOUNT_BARRIER)