Re: [Libguestfs] [PATCH nbdinfo v2] info: Add a --map option for displaying allocation metadata.

On 9/26/20 11:36 AM, Richard W.M. Jones wrote: > --- > info/Makefile.am | 4 + > info/info-map-base-allocation-json.sh | 52 ++++++++++ > info/info-map-base-allocation.sh | 49 ++++++++++ > info/nbdinfo.c | 134 ++++++++++++++++++++++++-- > info/nbdinfo.pod | 39 +++++++- > 5 files changed, 271 insertions(+), 7 deletions(-) An interesting followup might be adding options for --start and --length to map out only a subset of the file. That was recently added to qemu-img map, because there are cases where a file is fragmented enough that getting the entire map can be time-consuming, in relation to mapping out just a subset of the image. > +++ b/info/info-map-base-allocation-json.sh > @@ -0,0 +1,52 @@ > +#!/usr/bin/env bash > +# nbd client library in userspace > +# Copyright (C) 2020 Red Hat Inc. > +# > +# This library is free software; you can redistribute it and/or > +# modify it under the terms of the GNU Lesser General Public > +# License as published by the Free Software Foundation; either > +# version 2 of the License, or (at your option) any later version. > +# > +# This library is distributed in the hope that it will be useful, > +# but WITHOUT ANY WARRANTY; without even the implied warranty of > +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > +# Lesser General Public License for more details. > +# > +# You should have received a copy of the GNU Lesser General Public > +# License along with this library; if not, write to the Free Software > +# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA > + > +. ../tests/functions.sh > + > +set -e > +set -x > + > +requires nbdkit --version > +requires nbdsh --version Why are we requiring nbdsh in the libnbd testsuite? :) Is there a configure option where you can have nbdinfo but not nbdsh?

On the other hand, we _do_ require URI support (libxml2); maybe it's worth porting 'requires_nbdsh_uri' from nbdkit back to libnbd's functions.sh, and using that...

> +requires jq --version > + > +out=info-base-allocation-json.out > +cleanup_fn rm -f $out > +rm -f $out > + > +# Note the memory plugin uses a 32K page size, and extents > +# are always aligned with this. > +nbdkit -U - memory 1M --run ' > + nbdsh -u "$uri" \ ...since you are depending on it. > +/* Callback handling --map. */ > +static const char * > +extent_description (const char *metacontext, uint32_t type) > +{ > + if (strcmp (metacontext, "base:allocation") == 0) { Should we favor the use of LIBNBD_CONTEXT_BASE_ALLOCATION instead of open-coding this?