xfs: simplify xfs_file_iomap_begin

We'll never get nimap == 0 for a successful return from xfs_bmapi_read,
so don't try to handle it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

fs/xfs/xfs_iomap.c

@@ -1037,20 +1037,14 @@ xfs_file_iomap_begin(
 			return error;
 
 		trace_xfs_iomap_alloc(ip, offset, length, 0, &imap);
-		xfs_bmbt_to_iomap(ip, iomap, &imap);
-	} else if (nimaps) {
-		xfs_iunlock(ip, XFS_ILOCK_EXCL);
-		trace_xfs_iomap_found(ip, offset, length, 0, &imap);
-		xfs_bmbt_to_iomap(ip, iomap, &imap);
 	} else {
+		ASSERT(nimaps);
+
 		xfs_iunlock(ip, XFS_ILOCK_EXCL);
-		trace_xfs_iomap_not_found(ip, offset, length, 0, &imap);
-		iomap->blkno = IOMAP_NULL_BLOCK;
-		iomap->type = IOMAP_HOLE;
-		iomap->offset = offset;
-		iomap->length = length;
+		trace_xfs_iomap_found(ip, offset, length, 0, &imap);
 	}
 
+	xfs_bmbt_to_iomap(ip, iomap, &imap);
 	return 0;
 }
 

fs/xfs/xfs_trace.h

@@ -1298,7 +1298,6 @@ DEFINE_IOMAP_EVENT(xfs_get_blocks_alloc);
 DEFINE_IOMAP_EVENT(xfs_get_blocks_map_direct);
 DEFINE_IOMAP_EVENT(xfs_iomap_alloc);
 DEFINE_IOMAP_EVENT(xfs_iomap_found);
-DEFINE_IOMAP_EVENT(xfs_iomap_not_found);
 
 DECLARE_EVENT_CLASS(xfs_simple_io_class,
 	TP_PROTO(struct xfs_inode *ip, xfs_off_t offset, ssize_t count),