Allow verification of random overwrites w/ba < bs

When blockalign is less than blocksize, random overwrite
workloads may partially overwrite blocks.  This change
evicts partially-overwritten blocks from the iolog tree
so subsequent verification targets only intact blocks.

This change also allows verification with norandommap
and bsrange, though that is left disabled.
Signed-off-by: Justin Eno <jeno@micron.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/iolog.c b/iolog.c
index 99f8bc1..b867583 100644
--- a/iolog.c
+++ b/iolog.c
@@ -250,6 +250,7 @@
 	p = &td->io_hist_tree.rb_node;
 	parent = NULL;
 	while (*p) {
+		int overlap = 0;
 		parent = *p;
 
 		__ipo = rb_entry(parent, struct io_piece, rb_node);
@@ -257,11 +258,18 @@
 			p = &(*p)->rb_left;
 		else if (ipo->file > __ipo->file)
 			p = &(*p)->rb_right;
-		else if (ipo->offset < __ipo->offset)
+		else if (ipo->offset < __ipo->offset) {
 			p = &(*p)->rb_left;
-		else if (ipo->offset > __ipo->offset)
+			overlap = ipo->offset + ipo->len > __ipo->offset;
+		}
+		else if (ipo->offset > __ipo->offset) {
 			p = &(*p)->rb_right;
-		else {
+			overlap = __ipo->offset + __ipo->len > ipo->offset;
+		}
+		else
+			overlap = 1;
+
+		if (overlap) {
 			dprint(FD_IO, "iolog: overlap %llu/%lu, %llu/%lu",
 				__ipo->offset, __ipo->len,
 				ipo->offset, ipo->len);