[PATCH 1/2] iotests: Make _filter_img_create more active

[Max Reitz]

Right now, _filter_img_create just filters out everything that looks
format-dependent, and applies some filename filters.  That means that we
have to add another filter line every time some format gets a new
creation option.  This can be avoided by instead discarding everything
and just keeping what we know is format-independent (format, size,
backing file, encryption information[1], preallocation) or just
interesting to have in the reference output (external data file path).

Furthermore, we probably want to sort these options.  Format drivers are
not required to define them in any specific order, so the output is
effectively random (although this has never bothered us until now).  We
need a specific order for our reference outputs, though.  Unfortunately,
just using a plain "sort" would change a lot of existing reference
outputs, so we have to pre-filter the option keys to keep our existing
order (fmt, size, backing*, data, encryption info, preallocation).

[1] Actually, the only thing that is really important is whether
    encryption is enabled or not.  A patch by Maxim thus removes all
    other "encrypt.*" options from the output:
    https://lists.nongnu.org/archive/html/qemu-block/2020-06/msg00339.html
    But that patch needs to come later so we can get away with changing
    as few reference outputs in this patch here as possible.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/qemu-iotests/112.out       |   2 +-
 tests/qemu-iotests/153           |   9 ++-
 tests/qemu-iotests/common.filter | 100 +++++++++++++++++++++++--------
 3 files changed, 81 insertions(+), 30 deletions(-)

diff --git a/tests/qemu-iotests/112.out b/tests/qemu-iotests/112.out
index ae0318cabe..182655dbf6 100644
--- a/tests/qemu-iotests/112.out
+++ b/tests/qemu-iotests/112.out
@@ -5,7 +5,7 @@ QA output created by 112
 qemu-img: TEST_DIR/t.IMGFMT: Refcount width must be a power of two and may not 
exceed 64 bits
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 qemu-img: TEST_DIR/t.IMGFMT: Refcount width must be a power of two and may not 
exceed 64 bits
-Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 refcount_bits=-1
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 qemu-img: TEST_DIR/t.IMGFMT: Refcount width must be a power of two and may not 
exceed 64 bits
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 qemu-img: TEST_DIR/t.IMGFMT: Refcount width must be a power of two and may not 
exceed 64 bits
diff --git a/tests/qemu-iotests/153 b/tests/qemu-iotests/153
index cf961d3609..11e3d28841 100755
--- a/tests/qemu-iotests/153
+++ b/tests/qemu-iotests/153
@@ -167,11 +167,10 @@ done
 
 echo
 echo "== Creating ${TEST_IMG}.[abc] ==" | _filter_testdir
-(
-    $QEMU_IMG create -f qcow2 "${TEST_IMG}.a" -b "${TEST_IMG}"
-    $QEMU_IMG create -f qcow2 "${TEST_IMG}.b" -b "${TEST_IMG}"
-    $QEMU_IMG create -f qcow2 "${TEST_IMG}.c" -b "${TEST_IMG}.b"
-) | _filter_img_create
+$QEMU_IMG create -f qcow2 "${TEST_IMG}.a" -b "${TEST_IMG}" | _filter_img_create
+$QEMU_IMG create -f qcow2 "${TEST_IMG}.b" -b "${TEST_IMG}" | _filter_img_create
+$QEMU_IMG create -f qcow2 "${TEST_IMG}.c" -b "${TEST_IMG}.b" \
+    | _filter_img_create
 
 echo
 echo "== Two devices sharing the same file in backing chain =="
diff --git a/tests/qemu-iotests/common.filter b/tests/qemu-iotests/common.filter
index 03e4f71808..f104ad7a9b 100644
--- a/tests/qemu-iotests/common.filter
+++ b/tests/qemu-iotests/common.filter
@@ -122,38 +122,90 @@ _filter_actual_image_size()
 # replace driver-specific options in the "Formatting..." line
 _filter_img_create()
 {
-    data_file_filter=()
-    if data_file=$(_get_data_file "$TEST_IMG"); then
-        data_file_filter=(-e "s# data_file=$data_file##")
+    # Keep QMP output unchanged
+    qmp_pre=''
+    qmp_post=''
+    to_filter=''
+
+    while read -r line; do
+        if echo "$line" | grep -q '^{.*}$'; then
+            if [ -z "$to_filter" ]; then
+                # Use $'\n' so the newline is not dropped on variable
+                # expansion
+                qmp_pre="$qmp_pre$line"$'\n'
+            else
+                qmp_post="$qmp_post$line"$'\n'
+            fi
+        else
+            to_filter="$to_filter$line"$'\n'
+        fi
+    done
+
+    readarray -td '' formatting_line < \
+        <(echo "$to_filter" | sed -e 's/, fmt=/\x0/')
+
+    filename_part=${formatting_line[0]}
+    if [ -n "${formatting_line[1]}" ]; then
+        options="fmt=${formatting_line[1]}"
+    else
+        options=''
     fi
 
-    $SED "${data_file_filter[@]}" \
+    # Set grep_data_file to '\|data_file' to keep it; make it empty
+    # to drop it.
+    # We want to drop it if it is part of the global $IMGOPTS, and we
+    # want to keep it otherwise (if the test specifically wants to
+    # test data files).
+    grep_data_file='\|data_file'
+    if _get_data_file "$TEST_IMG" > /dev/null; then
+        grep_data_file=''
+    fi
+
+    filename_filters=(
         -e "s#$REMOTE_TEST_DIR#TEST_DIR#g" \
         -e "s#$IMGPROTO:$TEST_DIR#TEST_DIR#g" \
         -e "s#$TEST_DIR#TEST_DIR#g" \
         -e "s#$SOCK_DIR#SOCK_DIR#g" \
         -e "s#$IMGFMT#IMGFMT#g" \
         -e 's#nbd:127.0.0.1:[0-9]\\+#TEST_DIR/t.IMGFMT#g' \
-        -e 's#nbd+unix:///\??socket=SOCK_DIR/nbd#TEST_DIR/t.IMGFMT#g' \
-        -e "s# encryption=off##g" \
-        -e "s# cluster_size=[0-9]\\+##g" \
-        -e "s# table_size=[0-9]\\+##g" \
-        -e "s# compat=[^ ]*##g" \
-        -e "s# compat6=\\(on\\|off\\)##g" \
-        -e "s# static=\\(on\\|off\\)##g" \
-        -e "s# zeroed_grain=\\(on\\|off\\)##g" \
-        -e "s# subformat=[^ ]*##g" \
-        -e "s# adapter_type=[^ ]*##g" \
-        -e "s# hwversion=[^ ]*##g" \
-        -e "s# lazy_refcounts=\\(on\\|off\\)##g" \
-        -e "s# block_size=[0-9]\\+##g" \
-        -e "s# block_state_zero=\\(on\\|off\\)##g" \
-        -e "s# log_size=[0-9]\\+##g" \
-        -e "s# refcount_bits=[0-9]\\+##g" \
-        -e "s# key-secret=[a-zA-Z0-9]\\+##g" \
-        -e "s# iter-time=[0-9]\\+##g" \
-        -e "s# force_size=\\(on\\|off\\)##g" \
-        -e "s# compression_type=[a-zA-Z0-9]\\+##g"
+        -e 's#nbd+unix:///\??socket=SOCK_DIR/nbd#TEST_DIR/t.IMGFMT#g'
+    )
+
+    filename_part=$(echo "$filename_part" | $SED "${filename_filters[@]}")
+
+    # Break the option line before each option (preserving pre-existing
+    # line breaks by replacing them by \0 and restoring them at the end),
+    # then filter out the options we want to keep and sort them according
+    # to some order that all block drivers used at the time of writing
+    # this function.
+    options=$(
+        echo "$options" \
+        | tr '\n' '\0' \
+        | sed -e 's/\x0$//' -e 's/ \([a-z0-9_.-]*\)=/\n\1=/g' \
+        | grep -ae 
"^\(fmt\\|size\\|backing\\|preallocation\\|encrypt$grep_data_file\\)" \
+        | $SED "${filename_filters[@]}" \
+            -e 's/^\(fmt\)/0-\1/' \
+            -e 's/^\(size\)/1-\1/' \
+            -e 's/^\(backing\)/2-\1/' \
+            -e 's/^\(data_file\)/3-\1/' \
+            -e 's/^\(encryption\)/4-\1/' \
+            -e 's/^\(encrypt\.format\)/5-\1/' \
+            -e 's/^\(encrypt\.key-secret\)/6-\1/' \
+            -e 's/^\(encrypt\.iter-time\)/7-\1/' \
+            -e 's/^\(preallocation\)/8-\1/' \
+        | sort \
+        | $SED -e 's/^[0-9]-//' \
+        | tr '\n\0' ' \n' \
+        | $SED -e 's/^ *$//' -e 's/ *$//'
+    )
+
+    echo -n "$qmp_pre"
+    if [ -n "$options" ]; then
+        echo "$filename_part, $options"
+    elif [ -n "$filename_part" ]; then
+        echo "$filename_part"
+    fi
+    echo -n "$qmp_post"
 }
 
 _filter_img_create_size()
-- 
2.26.2