Merge tag 'pull-block-2022-04-20' of https://gitlab.com/hreitz/qemu i…

…nto staging

Block patches:
- Some changes for qcow2's refcount repair algorithm to make it work for
  qcow2 images stored on block devices
- Skip test cases that require zstd when support for it is missing
- Some refactoring in the iotests' meson.build

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* tag 'pull-block-2022-04-20' of https://gitlab.com/hreitz/qemu:
  qcow2: Add errp to rebuild_refcount_structure()
  iotests/108: Test new refcount rebuild algorithm
  qcow2: Improve refcount structure rebuilding
  iotests/303: Check for zstd support
  iotests/065: Check for zstd support
  iotests.py: Add supports_qcow2_zstd_compression()
  tests/qemu-iotests: Move the bash and sanitizer checks to meson.build
  tests/qemu-iotests/meson.build: Improve the indentation

Signed-off-by: Richard Henderson <[email protected]>

tests/check-block.sh

@@ -18,36 +18,10 @@ skip() {
     exit 0
 }
 
-# Disable tests with any sanitizer except for specific ones
-SANITIZE_FLAGS=$( grep "CFLAGS.*-fsanitize" config-host.mak 2>/dev/null )
-ALLOWED_SANITIZE_FLAGS="safe-stack cfi-icall"
-#Remove all occurrencies of allowed Sanitize flags
-for j in ${ALLOWED_SANITIZE_FLAGS}; do
-    TMP_FLAGS=${SANITIZE_FLAGS}
-    SANITIZE_FLAGS=""
-    for i in ${TMP_FLAGS}; do
-        if ! echo ${i} | grep -q "${j}" 2>/dev/null; then
-            SANITIZE_FLAGS="${SANITIZE_FLAGS} ${i}"
-        fi
-    done
-done
-if echo ${SANITIZE_FLAGS} | grep -q "\-fsanitize" 2>/dev/null; then
-    # Have a sanitize flag that is not allowed, stop
-    skip "Sanitizers are enabled ==> Not running the qemu-iotests."
-fi
-
 if [ -z "$(find . -name 'qemu-system-*' -print)" ]; then
     skip "No qemu-system binary available ==> Not running the qemu-iotests."
 fi
 
-if ! command -v bash >/dev/null 2>&1 ; then
-    skip "bash not available ==> Not running the qemu-iotests."
-fi
-
-if LANG=C bash --version | grep -q 'GNU bash, version [123]' ; then
-    skip "bash version too old ==> Not running the qemu-iotests."
-fi
-
 cd tests/qemu-iotests
 
 # QEMU_CHECK_BLOCK_AUTO is used to disable some unstable sub-tests

tests/qemu-iotests/065

@@ -24,7 +24,7 @@ import os
 import re
 import json
 import iotests
-from iotests import qemu_img, qemu_img_info
+from iotests import qemu_img, qemu_img_info, supports_qcow2_zstd_compression
 import unittest
 
 test_img = os.path.join(iotests.test_dir, 'test.img')
@@ -95,11 +95,17 @@ class TestQCow2(TestQemuImgInfo):
 
 class TestQCow3NotLazy(TestQemuImgInfo):
     '''Testing a qcow2 version 3 image with lazy refcounts disabled'''
-    img_options = 'compat=1.1,lazy_refcounts=off,compression_type=zstd'
+    if supports_qcow2_zstd_compression():
+        compression_type = 'zstd'
+    else:
+        compression_type = 'zlib'
+
+    img_options = 'compat=1.1,lazy_refcounts=off'
+    img_options += f',compression_type={compression_type}'
     json_compare = { 'compat': '1.1', 'lazy-refcounts': False,
                      'refcount-bits': 16, 'corrupt': False,
-                     'compression-type': 'zstd', 'extended-l2': False }
-    human_compare = [ 'compat: 1.1', 'compression type: zstd',
+                     'compression-type': compression_type, 'extended-l2': False }
+    human_compare = [ 'compat: 1.1', f'compression type: {compression_type}',
                       'lazy refcounts: false', 'refcount bits: 16',
                       'corrupt: false', 'extended l2: false' ]
 
@@ -126,11 +132,17 @@ class TestQCow3NotLazyQMP(TestQMP):
 class TestQCow3LazyQMP(TestQMP):
     '''Testing a qcow2 version 3 image with lazy refcounts enabled, opening
        with lazy refcounts disabled'''
-    img_options = 'compat=1.1,lazy_refcounts=on,compression_type=zstd'
+    if supports_qcow2_zstd_compression():
+        compression_type = 'zstd'
+    else:
+        compression_type = 'zlib'
+
+    img_options = 'compat=1.1,lazy_refcounts=on'
+    img_options += f',compression_type={compression_type}'
     qemu_options = 'lazy-refcounts=off'
     compare = { 'compat': '1.1', 'lazy-refcounts': True,
                 'refcount-bits': 16, 'corrupt': False,
-                'compression-type': 'zstd', 'extended-l2': False }
+                'compression-type': compression_type, 'extended-l2': False }
 
 TestImageInfoSpecific = None
 TestQemuImgInfo = None

tests/qemu-iotests/108

@@ -30,13 +30,20 @@ status=1	# failure is the default!
 
 _cleanup()
 {
-	_cleanup_test_img
+    _cleanup_test_img
+    if [ -f "$TEST_DIR/qsd.pid" ]; then
+        qsd_pid=$(cat "$TEST_DIR/qsd.pid")
+        kill -KILL "$qsd_pid"
+        fusermount -u "$TEST_DIR/fuse-export" &>/dev/null
+    fi
+    rm -f "$TEST_DIR/fuse-export"
 }
 trap "_cleanup; exit \$status" 0 1 2 3 15
 
 # get standard environment, filters and checks
 . ./common.rc
 . ./common.filter
+. ./common.qemu
 
 # This tests qcow2-specific low-level functionality
 _supported_fmt qcow2
@@ -47,6 +54,22 @@ _supported_os Linux
 # files
 _unsupported_imgopts 'refcount_bits=\([^1]\|.\([^6]\|$\)\)' data_file
 
+# This test either needs sudo -n losetup or FUSE exports to work
+if sudo -n losetup &>/dev/null; then
+    loopdev=true
+else
+    loopdev=false
+
+    # QSD --export fuse will either yield "Parameter 'id' is missing"
+    # or "Invalid parameter 'fuse'", depending on whether there is
+    # FUSE support or not.
+    error=$($QSD --export fuse 2>&1)
+    if [[ $error = *"'fuse'"* ]]; then
+        _notrun 'Passwordless sudo for losetup or FUSE support required, but' \
+                'neither is available'
+    fi
+fi
+
 echo
 echo '=== Repairing an image without any refcount table ==='
 echo
@@ -138,6 +161,240 @@ _make_test_img 64M
 poke_file "$TEST_IMG" $((0x10008)) "\xff\xff\xff\xff\xff\xff\x00\x00"
 _check_test_img -r all
 
+echo
+echo '=== Check rebuilt reftable location ==='
+
+# In an earlier version of the refcount rebuild algorithm, the
+# reftable was generally placed at the image end (unless something was
+# allocated in the area covered by the refblock right before the image
+# file end, then we would try to place the reftable in that refblock).
+# This was later changed so the reftable would be placed in the
+# earliest possible location.  Test this.
+
+echo
+echo '--- Does the image size increase? ---'
+echo
+
+# First test: Just create some image, write some data to it, and
+# resize it so there is free space at the end of the image (enough
+# that it spans at least one full refblock, which for cluster_size=512
+# images, spans 128k).  With the old algorithm, the reftable would
+# have then been placed at the end of the image file, but with the new
+# one, it will be put in that free space.
+# We want to check whether the size of the image file increases due to
+# rebuilding the refcount structures (it should not).
+
+_make_test_img -o 'cluster_size=512' 1M
+# Write something
+$QEMU_IO -c 'write 0 64k' "$TEST_IMG" | _filter_qemu_io
+
+# Add free space
+file_len=$(stat -c '%s' "$TEST_IMG")
+truncate -s $((file_len + 256 * 1024)) "$TEST_IMG"
+
+# Corrupt the image by saying the image header was not allocated
+rt_offset=$(peek_file_be "$TEST_IMG" 48 8)
+rb_offset=$(peek_file_be "$TEST_IMG" $rt_offset 8)
+poke_file "$TEST_IMG" $rb_offset "\x00\x00"
+
+# Check whether rebuilding the refcount structures increases the image
+# file size
+file_len=$(stat -c '%s' "$TEST_IMG")
+echo
+# The only leaks there can be are the old refcount structures that are
+# leaked during rebuilding, no need to clutter the output with them
+_check_test_img -r all | grep -v '^Repairing cluster.*refcount=1 reference=0'
+echo
+post_repair_file_len=$(stat -c '%s' "$TEST_IMG")
+
+if [[ $file_len -eq $post_repair_file_len ]]; then
+    echo 'OK: Image size did not change'
+else
+    echo 'ERROR: Image size differs' \
+        "($file_len before, $post_repair_file_len after)"
+fi
+
+echo
+echo '--- Will the reftable occupy a hole specifically left for it?  ---'
+echo
+
+# Note: With cluster_size=512, every refblock covers 128k.
+# The reftable covers 8M per reftable cluster.
+
+# Create an image that requires two reftable clusters (just because
+# this is more interesting than a single-clustered reftable).
+_make_test_img -o 'cluster_size=512' 9M
+$QEMU_IO -c 'write 0 8M' "$TEST_IMG" | _filter_qemu_io
+
+# Writing 8M will have resized the reftable.  Unfortunately, doing so
+# will leave holes in the file, so we need to fill them up so we can
+# be sure the whole file is allocated.  Do that by writing
+# consecutively smaller chunks starting from 8 MB, until the file
+# length increases even with a chunk size of 512.  Then we must have
+# filled all holes.
+ofs=$((8 * 1024 * 1024))
+block_len=$((16 * 1024))
+while [[ $block_len -ge 512 ]]; do
+    file_len=$(stat -c '%s' "$TEST_IMG")
+    while [[ $(stat -c '%s' "$TEST_IMG") -eq $file_len ]]; do
+        # Do not include this in the reference output, it does not
+        # really matter which qemu-io calls we do here exactly
+        $QEMU_IO -c "write $ofs $block_len" "$TEST_IMG" >/dev/null
+        ofs=$((ofs + block_len))
+    done
+    block_len=$((block_len / 2))
+done
+
+# Fill up to 9M (do not include this in the reference output either,
+# $ofs is random for all we know)
+$QEMU_IO -c "write $ofs $((9 * 1024 * 1024 - ofs))" "$TEST_IMG" >/dev/null
+
+# Make space as follows:
+# - For the first refblock: Right at the beginning of the image (this
+#   refblock is placed in the first place possible),
+# - For the reftable somewhere soon afterwards, still near the
+#   beginning of the image (i.e. covered by the first refblock); the
+#   reftable too is placed in the first place possible, but only after
+#   all refblocks have been placed)
+# No space is needed for the other refblocks, because no refblock is
+# put before the space it covers.  In this test case, we do not mind
+# if they are placed at the image file's end.
+
+# Before we make that space, we have to find out the host offset of
+# the area that belonged to the two data clusters at guest offset 4k,
+# because we expect the reftable to be placed there, and we will have
+# to verify that it is.
+
+l1_offset=$(peek_file_be "$TEST_IMG" 40 8)
+l2_offset=$(peek_file_be "$TEST_IMG" $l1_offset 8)
+l2_offset=$((l2_offset & 0x00fffffffffffe00))
+data_4k_offset=$(peek_file_be "$TEST_IMG" \
+                 $((l2_offset + 4096 / 512 * 8)) 8)
+data_4k_offset=$((data_4k_offset & 0x00fffffffffffe00))
+
+$QEMU_IO -c "discard 0 512" -c "discard 4k 1k" "$TEST_IMG" | _filter_qemu_io
+
+# Corrupt the image by saying the image header was not allocated
+rt_offset=$(peek_file_be "$TEST_IMG" 48 8)
+rb_offset=$(peek_file_be "$TEST_IMG" $rt_offset 8)
+poke_file "$TEST_IMG" $rb_offset "\x00\x00"
+
+echo
+# The only leaks there can be are the old refcount structures that are
+# leaked during rebuilding, no need to clutter the output with them
+_check_test_img -r all | grep -v '^Repairing cluster.*refcount=1 reference=0'
+echo
+
+# Check whether the reftable was put where we expected
+rt_offset=$(peek_file_be "$TEST_IMG" 48 8)
+if [[ $rt_offset -eq $data_4k_offset ]]; then
+    echo 'OK: Reftable is where we expect it'
+else
+    echo "ERROR: Reftable is at $rt_offset, but was expected at $data_4k_offset"
+fi
+
+echo
+echo '--- Rebuilding refcount structures on block devices ---'
+echo
+
+# A block device cannot really grow, at least not during qemu-img
+# check.  As mentioned in the above cases, rebuilding the refcount
+# structure may lead to new refcount structures being written after
+# the end of the image, and in the past that happened even if there
+# was more than sufficient space in the image.  Such post-EOF writes
+# will not work on block devices, so test that the new algorithm
+# avoids it.
+
+# If we have passwordless sudo and losetup, we can use those to create
+# a block device.  Otherwise, we can resort to qemu's FUSE export to
+# create a file that isn't growable, which effectively tests the same
+# thing.
+
+_cleanup_test_img
+truncate -s $((64 * 1024 * 1024)) "$TEST_IMG"
+
+if $loopdev; then
+    export_mp=$(sudo -n losetup --show -f "$TEST_IMG")
+    export_mp_driver=host_device
+    sudo -n chmod go+rw "$export_mp"
+else
+    # Create non-growable FUSE export that is a bit like an empty
+    # block device
+    export_mp="$TEST_DIR/fuse-export"
+    export_mp_driver=file
+    touch "$export_mp"
+
+    $QSD \
+        --blockdev file,node-name=export-node,filename="$TEST_IMG" \
+        --export fuse,id=fuse-export,node-name=export-node,mountpoint="$export_mp",writable=on,growable=off \
+        --pidfile "$TEST_DIR/qsd.pid" \
+        --daemonize
+fi
+
+# Now create a qcow2 image on the device -- unfortunately, qemu-img
+# create force-creates the file, so we have to resort to the
+# blockdev-create job.
+_launch_qemu \
+    --blockdev $export_mp_driver,node-name=file,filename="$export_mp"
+
+_send_qemu_cmd \
+    $QEMU_HANDLE \
+    '{ "execute": "qmp_capabilities" }' \
+    'return'
+
+# Small cluster size again, so the image needs multiple refblocks
+_send_qemu_cmd \
+    $QEMU_HANDLE \
+    '{ "execute": "blockdev-create",
+       "arguments": {
+           "job-id": "create",
+           "options": {
+               "driver": "qcow2",
+               "file": "file",
+               "size": '$((64 * 1024 * 1024))',
+               "cluster-size": 512
+           } } }' \
+    '"concluded"'
+
+_send_qemu_cmd \
+    $QEMU_HANDLE \
+    '{ "execute": "job-dismiss", "arguments": { "id": "create" } }' \
+    'return'
+
+_send_qemu_cmd \
+    $QEMU_HANDLE \
+    '{ "execute": "quit" }' \
+    'return'
+
+wait=y _cleanup_qemu
+echo
+
+# Write some data
+$QEMU_IO -c 'write 0 64k' "$export_mp" | _filter_qemu_io
+
+# Corrupt the image by saying the image header was not allocated
+rt_offset=$(peek_file_be "$export_mp" 48 8)
+rb_offset=$(peek_file_be "$export_mp" $rt_offset 8)
+poke_file "$export_mp" $rb_offset "\x00\x00"
+
+# Repairing such a simple case should just work
+# (We used to put the reftable at the end of the image file, which can
+# never work for non-growable devices.)
+echo
+TEST_IMG="$export_mp" _check_test_img -r all \
+    | grep -v '^Repairing cluster.*refcount=1 reference=0'
+
+if $loopdev; then
+    sudo -n losetup -d "$export_mp"
+else
+    qsd_pid=$(cat "$TEST_DIR/qsd.pid")
+    kill -TERM "$qsd_pid"
+    # Wait for process to exit (cannot `wait` because the QSD is daemonized)
+    while [ -f "$TEST_DIR/qsd.pid" ]; do
+        true
+    done
+fi
+
 # success, all done
 echo '*** done'
 rm -f $seq.full