[Libguestfs] [nbdkit PATCH 6/6] tests: Test retry after partial extents

[Eric Blake]

Add coverage for the previous patch.  Each retry of .extents must be
into a fresh extents object, to avoid mismatch between provided and
expected offsets.

Signed-off-by: Eric Blake <eblake at redhat.com>
---
 tests/Makefile.am           |   2 +
 tests/test-retry-extents.sh | 114 ++++++++++++++++++++++++++++++++++++
 2 files changed, 116 insertions(+)
 create mode 100755 tests/test-retry-extents.sh

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 4cf0325e..60cba6c5 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -120,6 +120,7 @@ EXTRA_DIST = \
 	test.rb \
 	test-readahead-copy.sh \
 	test-retry.sh \
+	test-retry-extents.sh \
 	test-retry-readonly.sh \
 	test-retry-reopen-fail.sh \
 	test-shutdown.sh \
@@ -1059,6 +1060,7 @@ test_readahead_LDADD = libtest.la $(LIBGUESTFS_LIBS)
 TESTS += \
 	test-retry.sh \
 	test-retry-readonly.sh \
+	test-retry-extents.sh \
 	test-retry-reopen-fail.sh \
 	$(NULL)

diff --git a/tests/test-retry-extents.sh b/tests/test-retry-extents.sh
new file mode 100755
index 00000000..ffcef311
--- /dev/null
+++ b/tests/test-retry-extents.sh
@@ -0,0 +1,114 @@
+#!/usr/bin/env bash
+# nbdkit
+# Copyright (C) 2018-2019 Red Hat Inc.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+# * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#
+# * Redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution.
+#
+# * Neither the name of Red Hat nor the names of its contributors may be
+# used to endorse or promote products derived from this software without
+# specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+
+source ./functions.sh
+set -e
+set -x
+
+requires nbdsh --base-allocation -c 'quit()'
+
+files="retry-extents-count retry-extents-open-count"
+rm -f $files
+cleanup_fn rm -f $files
+
+touch retry-extents-count retry-extents-open-count
+start_t=$SECONDS
+
+# Create a custom plugin which will test retrying.
+nbdkit -v -U - \
+       sh - \
+       --filter=retry retry-delay=1 \
+       --run 'nbdsh --base-allocation --uri $uri -c "
+entries = []
+def f (metacontext, offset, e, err):
+    global entries
+    assert err.value == 0
+    assert metacontext == nbd.CONTEXT_BASE_ALLOCATION
+    entries = e
+h.block_status (1024, 0, f)
+assert entries == [ 512, 0,
+                    512, 3]
+       "' <<'EOF'
+#!/usr/bin/env bash
+case "$1" in
+    open)
+        # Count how many times the connection is (re-)opened.
+        read i < retry-extents-open-count
+        echo $((i+1)) > retry-extents-open-count
+        ;;
+    extents)
+        # Fail in three different ways then succeed.
+        read i < retry-extents-count
+        ((i++))
+        echo $i > retry-extents-count
+        case $i in
+          1) echo "EIO pread failed" >&2; exit 1;;
+          2) echo "garbage"
+             exit 0;;
+          3) echo "0 512 0"
+             echo "garbage"
+             exit 0;;
+          *) echo "0 512 0"
+             echo "512 512 3"
+             exit 0;;
+        esac
+        ;;
+
+    can_extents) exit 0 ;;
+    get_size) echo 1024 ;;
+    *) exit 2 ;;
+esac
+EOF
+
+# In this test we should see 3 failures:
+# extents FAILS
+# retry and wait 1 seconds
+# extents FAILS
+# retry and wait 2 seconds
+# extents FAILS
+# retry and wait 4 seconds
+# extents succeeds
+
+# The minimum time for the test should be 1+2+4 = 7 seconds.
+end_t=$SECONDS
+if [ $((end_t - start_t)) -lt 7 ]; then
+    echo "$0: test ran too quickly"
+    exit 1
+fi
+
+# Check the handle was opened 4 times (first open + one reopen for
+# each retry).
+read open_count < retry-extents-open-count
+if [ $open_count -ne 4 ]; then
+    echo "$0: open-count ($open_count) != 4"
+    exit 1
+fi
-- 
2.21.0