pnfs: don't merge new ff lsegs with ones that have LAYOUTRETURN bit set

Otherwise, we'll end up returning layouts that we've just received if
the client issues a new LAYOUTGET prior to the LAYOUTRETURN.
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/flexfilelayout/flexfilelayout.c

@@ -299,6 +299,8 @@ ff_lseg_merge(struct pnfs_layout_segment *new,
 {
 	u64 new_end, old_end;
 
+	if (test_bit(NFS_LSEG_LAYOUTRETURN, &old->pls_flags))
+		return false;
 	if (new->pls_range.iomode != old->pls_range.iomode)
 		return false;
 	old_end = pnfs_calc_offset_end(old->pls_range.offset,
@@ -319,8 +321,6 @@ ff_lseg_merge(struct pnfs_layout_segment *new,
 			new_end);
 	if (test_bit(NFS_LSEG_ROC, &old->pls_flags))
 		set_bit(NFS_LSEG_ROC, &new->pls_flags);
-	if (test_bit(NFS_LSEG_LAYOUTRETURN, &old->pls_flags))
-		set_bit(NFS_LSEG_LAYOUTRETURN, &new->pls_flags);
 	return true;
 }