xfs: merge xfs_buf_zero and xfs_buf_iomove

xfs_buf_zero is the only caller of xfs_buf_iomove.  Remove support
for copying from or to the buffer in xfs_buf_iomove and merge the
two functions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

fs/xfs/xfs_buf.c

@@ -1613,16 +1613,11 @@ xfs_buf_offset(
 	return page_address(page) + (offset & (PAGE_SIZE-1));
 }
 
-/*
- *	Move data into or out of a buffer.
- */
 void
-xfs_buf_iomove(
-	xfs_buf_t		*bp,	/* buffer to process		*/
-	size_t			boff,	/* starting buffer offset	*/
-	size_t			bsize,	/* length to copy		*/
-	void			*data,	/* data address			*/
-	xfs_buf_rw_t		mode)	/* read/write/zero flag		*/
+xfs_buf_zero(
+	struct xfs_buf		*bp,
+	size_t			boff,
+	size_t			bsize)
 {
 	size_t			bend;
 
@@ -1639,19 +1634,9 @@ xfs_buf_iomove(
 
 		ASSERT((csize + page_offset) <= PAGE_SIZE);
 
-		switch (mode) {
-		case XBRW_ZERO:
-			memset(page_address(page) + page_offset, 0, csize);
-			break;
-		case XBRW_READ:
-			memcpy(data, page_address(page) + page_offset, csize);
-			break;
-		case XBRW_WRITE:
-			memcpy(page_address(page) + page_offset, data, csize);
-		}
+		memset(page_address(page) + page_offset, 0, csize);
 
 		boff += csize;
-		data += csize;
 	}
 }
 

fs/xfs/xfs_buf.h

@@ -21,12 +21,6 @@
 
 #define XFS_BUF_DADDR_NULL	((xfs_daddr_t) (-1LL))
 
-typedef enum {
-	XBRW_READ = 1,			/* transfer into target memory */
-	XBRW_WRITE = 2,			/* transfer from target memory */
-	XBRW_ZERO = 3,			/* Zero target memory */
-} xfs_buf_rw_t;
-
 #define XBF_READ	 (1 << 0) /* buffer intended for reading from device */
 #define XBF_WRITE	 (1 << 1) /* buffer intended for writing to device */
 #define XBF_READ_AHEAD	 (1 << 2) /* asynchronous read-ahead */
@@ -305,10 +299,7 @@ static inline int xfs_buf_submit(struct xfs_buf *bp)
 	return __xfs_buf_submit(bp, wait);
 }
 
-extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, void *,
-				xfs_buf_rw_t);
-#define xfs_buf_zero(bp, off, len) \
-	    xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO)
+void xfs_buf_zero(struct xfs_buf *bp, size_t boff, size_t bsize);
 
 /* Buffer Utility Routines */
 extern void *xfs_buf_offset(struct xfs_buf *, size_t);