On Mon, Aug 09, 2021 at 10:23:10AM +0200, Martin Kletzander wrote:
Signed-off-by: Martin Kletzander <mkletzan(a)redhat.com>
---
tests/test-cache-block-size.sh | 41 +++++++++++++++++++++-------------
1 file changed, 26 insertions(+), 15 deletions(-)
diff --git a/tests/test-cache-block-size.sh b/tests/test-cache-block-size.sh
index d20cc94002b6..403c295e57c9 100755
--- a/tests/test-cache-block-size.sh
+++ b/tests/test-cache-block-size.sh
@@ -43,28 +43,39 @@ rm -f $files
cleanup_fn rm -f $files
# Create an empty base image.
-truncate -s 128K cache-block-size.img
+truncate -s 256K cache-block-size.img
# Run nbdkit with the caching filter.
start_nbdkit -P cache-block-size.pid -U $sock --filter=cache \
- file cache-block-size.img cache-min-block-size=4K
+ file cache-block-size.img cache-min-block-size=128K \
+ cache-on-read=true
nbdsh --connect "nbd+unix://?socket=$sock" \
-c '
-# Write some pattern data to the overlay and check it reads back OK.
-buf = b"abcd" * 16384
-h.pwrite(buf, 32768)
-zero = h.pread(32768, 0)
-assert zero == bytearray(32768)
-buf2 = h.pread(65536, 32768)
-assert buf == buf2
+# Read half of cache-min-block-size
+
+zero = h.pread(64 * 1024, 0)
+assert zero == bytearray(64 * 1024)
+
+buf = b"abcd" * 16 * 1024
-# Flushing should write through to the underlying file.
-h.flush()
+# Write past the first read
+with open("cache-block-size.img", "wb") as file:
+ file.seek(64 * 1024)
+ file.write(buf * 2)
+ file.truncate(256 * 1024)
+# Check that it got written
with open("cache-block-size.img", "rb") as file:
- zero = file.read(32768)
- assert zero == bytearray(32768)
- buf2 = file.read(65536)
- assert buf == buf2
+ file.seek(64 * 1024)
+ buf2 = file.read(128 * 1024)
+ assert (buf * 2) == buf2
+
+# Now read the rest of the cache-min-block-size, it should stay empty
+zero = h.pread(64 * 1024, 64 * 1024)
+assert zero == bytearray(64 * 1024)
+
+# Read past that, the pattern should be visible there
+buf2 = h.pread(64 * 1024, 128 * 1024)
+assert buf == buf2
'
Seems reasonable, ACK.
Rich.
--
Richard Jones, Virtualization Group, Red Hat
http://people.redhat.com/~rjones
Read my programming and virtualization blog:
http://rwmj.wordpress.com
virt-top is 'top' for virtual machines. Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://people.redhat.com/~rjones/virt-top