Re: [PATCH v2 18/20] iotests: Allow testing FUSE exports

[Kevin Wolf]

Am 22.09.2020 um 12:49 hat Max Reitz geschrieben:
> This pretends FUSE exports are a kind of protocol.  As such, they are
> always tested under the format node.  This is probably the best way to
> test them, actually, because this will generate more I/O load and more
> varied patterns.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  tests/qemu-iotests/check         |   6 ++
>  tests/qemu-iotests/common.filter |   5 +-
>  tests/qemu-iotests/common.rc     | 124 +++++++++++++++++++++++++++++++
>  3 files changed, 134 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
> index 467a7cf1b7..07232138d7 100755
> --- a/tests/qemu-iotests/check
> +++ b/tests/qemu-iotests/check
> @@ -270,6 +270,7 @@ image protocol options
>      -rbd                test rbd
>      -sheepdog           test sheepdog
>      -nbd                test nbd
> +    -fuse               test fuse
>      -ssh                test ssh
>      -nfs                test nfs
>  
> @@ -382,6 +383,11 @@ testlist options
>              xpand=false
>              ;;
>  
> +        -fuse)
> +            IMGPROTO=fuse
> +            xpand=false
> +            ;;
> +
>          -ssh)
>              IMGPROTO=ssh
>              xpand=false
> diff --git a/tests/qemu-iotests/common.filter 
> b/tests/qemu-iotests/common.filter
> index 838ed15793..172ea5752e 100644
> --- a/tests/qemu-iotests/common.filter
> +++ b/tests/qemu-iotests/common.filter
> @@ -44,7 +44,8 @@ _filter_qom_path()
>  _filter_testdir()
>  {
>      $SED -e "s#$TEST_DIR/#TEST_DIR/#g" \
> -         -e "s#$SOCK_DIR/#SOCK_DIR/#g"
> +         -e "s#$SOCK_DIR/#SOCK_DIR/#g" \
> +         -e "s#SOCK_DIR/fuse-#TEST_DIR/#g"
>  }
>  
>  # replace occurrences of the actual IMGFMT value with IMGFMT
> @@ -127,6 +128,7 @@ _filter_img_create_filenames()
>          -e "s#$IMGPROTO:$TEST_DIR#TEST_DIR#g" \
>          -e "s#$TEST_DIR#TEST_DIR#g" \
>          -e "s#$SOCK_DIR#SOCK_DIR#g" \
> +        -e 's#SOCK_DIR/fuse-#TEST_DIR/#g' \
>          -e "s#$IMGFMT#IMGFMT#g" \
>          -e 's#nbd:127.0.0.1:[0-9]\\+#TEST_DIR/t.IMGFMT#g' \
>          -e 's#nbd+unix:///\??socket=SOCK_DIR/nbd#TEST_DIR/t.IMGFMT#g'
> @@ -227,6 +229,7 @@ _filter_img_info()
>          -e "s#$IMGFMT#IMGFMT#g" \
>          -e 's#nbd://127.0.0.1:[0-9]\\+$#TEST_DIR/t.IMGFMT#g' \
>          -e 's#nbd+unix:///\??socket=SOCK_DIR/nbd#TEST_DIR/t.IMGFMT#g' \
> +        -e 's#SOCK_DIR/fuse-#TEST_DIR/#g' \
>          -e "/encrypted: yes/d" \
>          -e "/cluster_size: [0-9]\\+/d" \
>          -e "/table_size: [0-9]\\+/d" \
> diff --git a/tests/qemu-iotests/common.rc b/tests/qemu-iotests/common.rc
> index e4751d4985..e17f813f06 100644
> --- a/tests/qemu-iotests/common.rc
> +++ b/tests/qemu-iotests/common.rc
> @@ -257,6 +257,9 @@ if [ "$IMGOPTSSYNTAX" = "true" ]; then
>          TEST_IMG_FILE=$TEST_DIR/t.$IMGFMT
>          TEST_IMG="$DRIVER,file.driver=nbd,file.type=unix"
>          TEST_IMG="$TEST_IMG,file.path=$SOCK_DIR/nbd"
> +    elif [ "$IMGPROTO" = "fuse" ]; then
> +        TEST_IMG_FILE=$TEST_DIR/t.$IMGFMT
> +        TEST_IMG="$DRIVER,file.filename=$SOCK_DIR/fuse-t.$IMGFMT"
>      elif [ "$IMGPROTO" = "ssh" ]; then
>          TEST_IMG_FILE=$TEST_DIR/t.$IMGFMT
>          
> TEST_IMG="$DRIVER,file.driver=ssh,file.host=127.0.0.1,file.path=$TEST_IMG_FILE"
> @@ -273,6 +276,9 @@ else
>      elif [ "$IMGPROTO" = "nbd" ]; then
>          TEST_IMG_FILE=$TEST_DIR/t.$IMGFMT
>          TEST_IMG="nbd+unix:///?socket=$SOCK_DIR/nbd"
> +    elif [ "$IMGPROTO" = "fuse" ]; then
> +        TEST_IMG_FILE=$TEST_DIR/t.$IMGFMT
> +        TEST_IMG="$SOCK_DIR/fuse-t.$IMGFMT"
>      elif [ "$IMGPROTO" = "ssh" ]; then
>          TEST_IMG_FILE=$TEST_DIR/t.$IMGFMT
>          
> REMOTE_TEST_DIR="ssh://\\($USER@\\)\\?127.0.0.1\\(:[0-9]\\+\\)\\?$TEST_DIR"
> @@ -288,6 +294,9 @@ fi
>  ORIG_TEST_IMG_FILE=$TEST_IMG_FILE
>  ORIG_TEST_IMG="$TEST_IMG"
>  
> +FUSE_PIDS=()
> +FUSE_EXPORTS=()
> +
>  if [ -z "$TEST_DIR" ]; then
>          TEST_DIR=$PWD/scratch
>  fi
> @@ -357,6 +366,10 @@ _test_img_to_test_img_file()
>              echo "$1"
>              ;;
>  
> +        fuse)
> +            echo "$1" | sed -e "s#$SOCK_DIR/fuse-#$TEST_DIR/#"
> +            ;;
> +
>          nfs)
>              echo "$1" | sed -e "s#nfs://127.0.0.1##"
>              ;;
> @@ -385,6 +398,11 @@ _make_test_img()
>      local opts_param=false
>      local misc_params=()
>  
> +    if [[ $IMGPROTO == fuse && $TEST_IMG == $SOCK_DIR/fuse-* ]]; then

Given that you sent this series, I assume the test cases pass, but I
don't understand how this works with more than one image. Shouldn't you
get an syntax error then because $SOCK_DIR/fuse-* will evaluate to
multiple words?

> +        # The caller may be trying to overwrite an existing image
> +        _rm_test_img "$TEST_IMG"
> +    fi
> +
>      if [ -z "$TEST_IMG_FILE" ]; then
>          img_name=$TEST_IMG
>      elif [ "$IMGOPTSSYNTAX" != "true" -a \
> @@ -469,11 +487,105 @@ _make_test_img()
>          eval "$QEMU_NBD -v -t -k '$SOCK_DIR/nbd' -f $IMGFMT -e 42 -x '' 
> $TEST_IMG_FILE >/dev/null &"
>          sleep 1 # FIXME: qemu-nbd needs to be listening before we continue
>      fi
> +
> +    if [ $IMGPROTO = "fuse" -a -f "$img_name" ]; then
> +        local export_mp
> +        local pid
> +        local pidfile
> +        local timeout
> +
> +        export_mp=$(echo "$img_name" | sed -e 
> "s#$TEST_DIR/#$SOCK_DIR/fuse-#")
> +        if ! echo "$export_mp" | grep -q "^$SOCK_DIR"; then
> +            echo 'Cannot use FUSE exports with images outside of TEST_DIR' 
> >&2
> +            return 1
> +        fi
> +
> +        touch "$export_mp"
> +        rm -f "$SOCK_DIR/fuse-output"
> +
> +        # Usually, users would export formatted nodes.  But we present fuse 
> as a
> +        # protocol-level driver here, so we have to leave the format to the
> +        # client.
> +        QEMU_STGD_NEED_PID=y $QEMU_STGD \
> +              --blockdev 
> file,node-name=export-node,filename=$img_name,discard=unmap \
> +              --export 
> fuse,id=fuse-export,node-name=export-node,mountpoint="$export_mp",writable=on,growable=on
>  \
> +              &
> +
> +        pidfile="$QEMU_TEST_DIR/qemu-storage-daemon.pid"
> +
> +        # Wait for the PID file
> +        while [ ! -f "$pidfile" ]; do
> +            sleep 0.5
> +        done
> +
> +        pid=$(cat "$pidfile")
> +        rm -f "$pidfile"
> +
> +        FUSE_PIDS+=($pid)
> +        FUSE_EXPORTS+=("$export_mp")
> +    fi
>  }
>  
>  _rm_test_img()
>  {
>      local img=$1
> +
> +    if [[ $IMGPROTO == fuse && $img == $SOCK_DIR/fuse-* ]]; then
> +        # Drop a FUSE export
> +        local df_output
> +        local i
> +        local image_file
> +        local index=''
> +        local timeout
> +
> +        for i in "${!FUSE_EXPORTS[@]}"; do
> +            if [ "${FUSE_EXPORTS[i]}" = "$img" ]; then
> +                index=$i
> +                break
> +            fi
> +        done
> +
> +        if [ -z "$index" ]; then
> +            # Probably gone already
> +            return 0
> +        fi
> +
> +        kill "${FUSE_PIDS[index]}"
> +
> +        # Wait until the mount is gone
> +        timeout=10 # *0.5 s
> +        while true; do
> +            # Will show the mount point; if the mount is still there,
> +            # it will be $img.
> +            df_output=$(df -T "$img" 2>/dev/null)

'df -T' doesn't seem to be portable.

Well, neither is FUSE, so I guess it doesn't matter?

> +
> +            # But df may also show an error ("Transpoint endpoint not
> +            # connected"), so retry in such cases
> +            if [ -n "$df_output" ]; then
> +                if ! echo "$df_output" | grep -q "$img"; then
> +                    break
> +                fi
> +            fi
> +
> +            sleep 0.5
> +
> +            timeout=$((timeout - 1))
> +            if [ "$timeout" = 0 ]; then
> +                echo 'Failed to take down FUSE export' >&2
> +                return 1
> +            fi
> +        done
> +
> +        rm -f "$img"
> +
> +        unset "FUSE_PIDS[$index]"
> +        unset "FUSE_EXPORTS[$index]"
> +
> +        image_file=$(echo "$img" | sed -e "s#$SOCK_DIR/fuse-#$TEST_DIR/#")
> +        _rm_test_img "$image_file"
> +        return
> +    fi
> +
>      if [ "$IMGFMT" = "vmdk" ]; then
>          # Remove all the extents for vmdk
>          "$QEMU_IMG" info "$img" 2>/dev/null | grep 'filename:' | cut -f 2 
> -d: \

Kevin