qcow2: Improve check for overlapping allocations

The old code detected an overlapping allocation even when the
allocations didn't actually overlap, but were only adjacent.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

2 files changed, 6 insertions, 6 deletions

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 71e027a..7f4f73e 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -773,7 +773,7 @@ static int handle_dependencies(BlockDriverState *bs, uint64_t guest_offset,
         uint64_t old_start = old_alloc->offset >> s->cluster_bits;
         uint64_t old_end = old_start + old_alloc->nb_clusters;
 
-        if (end < old_start || start > old_end) {
+        if (end <= old_start || start >= old_end) {
             /* No intersection */
         } else {
             if (start < old_start) {
diff --git a/tests/qemu-iotests/038.out b/tests/qemu-iotests/038.out
index acc7629..9cd0cd8 100644
--- a/tests/qemu-iotests/038.out
+++ b/tests/qemu-iotests/038.out
@@ -517,9 +517,7 @@ qemu-io> wrote 65536/65536 bytes at offset 16711680
 qemu-io> Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=6442450944 backing_file='TEST_DIR/t.IMGFMT.base' 
 
 == Some concurrent requests touching the same cluster ==
-qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> wrote 81920/81920 bytes at offset XXX
-80 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-wrote 65536/65536 bytes at offset XXX
+qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> qemu-io> wrote 65536/65536 bytes at offset XXX
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 wrote 65536/65536 bytes at offset XXX
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
@@ -579,6 +577,8 @@ wrote 65536/65536 bytes at offset XXX
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 wrote 65536/65536 bytes at offset XXX
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 81920/81920 bytes at offset XXX
+80 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 wrote 65536/65536 bytes at offset XXX
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 wrote 65536/65536 bytes at offset XXX
@@ -645,6 +645,8 @@ wrote 65536/65536 bytes at offset XXX
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 wrote 65536/65536 bytes at offset XXX
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 81920/81920 bytes at offset XXX
+80 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 wrote 65536/65536 bytes at offset XXX
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 wrote 65536/65536 bytes at offset XXX
@@ -703,8 +705,6 @@ wrote 65536/65536 bytes at offset XXX
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 wrote 65536/65536 bytes at offset XXX
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-wrote 81920/81920 bytes at offset XXX
-80 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
 == Verify image content ==
 qemu-io> read 4096/4096 bytes at offset 2064384