xfs: kill copy and paste segment checks in xfs_file_aio_read

The generic segment check code now returns a count of the number of
bytes in the iovec, so we don't need to roll our own anymore.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

fs/xfs/xfs_file.c

@@ -236,7 +236,6 @@ xfs_file_aio_read(
 	ssize_t			ret = 0;
 	int			ioflags = 0;
 	xfs_fsize_t		n;
-	unsigned long		seg;
 
 	XFS_STATS_INC(xs_read_calls);
 
@@ -247,19 +246,9 @@ xfs_file_aio_read(
 	if (file->f_mode & FMODE_NOCMTIME)
 		ioflags |= IO_INVIS;
 
-	/* START copy & waste from filemap.c */
-	for (seg = 0; seg < nr_segs; seg++) {
-		const struct iovec *iv = &iovp[seg];
-
-		/*
-		 * If any segment has a negative length, or the cumulative
-		 * length ever wraps negative then return -EINVAL.
-		 */
-		size += iv->iov_len;
-		if (unlikely((ssize_t)(size|iv->iov_len) < 0))
-			return XFS_ERROR(-EINVAL);
-	}
-	/* END copy & waste from filemap.c */
+	ret = generic_segment_checks(iovp, &nr_segs, &size, VERIFY_WRITE);
+	if (ret < 0)
+		return ret;
 
 	if (unlikely(ioflags & IO_ISDIRECT)) {
 		xfs_buftarg_t	*target =