On Mon, Feb 26, 2018 at 02:42:24PM -0800, Darrick J. Wong wrote: > Note that a libconfig file (Dave suggested libconfig ages ago) might > look more like this: No, Dave *only hinted* towards libconfig ;) I ran into grotesque issues with libconfig, and quickly moved to evaluate libini_config (used for SSSD) as an alternative. IMHO it had the best and up to date implementation, had great community traction, and I saw support for it on a slew of old older distros. I also evaluated Ted Tso's e2fprogs profile parser (based on MIT kerberos), and it turns out that its 14.86% the size of libini_config.so.5.2.0, which is an incredible bonus. It also supports to work with a slew of different OSes (which we probably don't care for), but the gains in size are perhaps worth considering. That and the fact that it will likely build on probably even more ancient distros. The e2fsprogs profile parser also lacks uint64_t support but adding support is very trivial. Another thing with e2fprogs's profile parser is we'd have to come to an agreement with Ted and the e2fsprogs community on sharing the library code. He seems to be open to that if we go this route. To help I already did a lot of the work of extracting what we'd need and also threw in a demo program: https://gitlab.com/mcgrof/libekprofile Similar review / demo is available with the other libraries: https://gitlab.com/mcgrof/libconfig-int64-issues https://gitlab.com/mcgrof/libini_config-demo For boring details on further evaluation with other filesystems and what they do and nitty gritty details of the above evaluation you can read my paper [0]. I even had evaluated NFS's configuration parser... at this point I was surprised everyone keeps re-inventing the wheel... One reason to consider sharing also is to help other filesystems as they likely will run into similar requirements. Why does everyone keep re-inventing this simple wheel on filesystem configuration parsers? Yes I suspect btrfs may want something similar. So in terms of bikeshedding -- its probably important also to at least zero down on a library we want to work with. The rest I suspect will actually be pretty trivial bikeshedding. FWIW both libini_config and the e2fsprogs profile parser could cope with namespaces on the configuration file as well. The syntax just varies slightly. IIRC with e2fsprogs profile parsers we could end up with something like: [defaults] foo=0 bar=0 [stuff] some_release = { foo=1 bar=2 } new_release = { foo=2 } Meanwhile I think with libini_config it was something like: [defaults] foo=0 bar=0 [stuff/some_release] foo=1 bar=2 [stuff/new_release] foo=2 [0] https://gitlab.com/mcgrof/filesystem-configuration-paper/blob/master/paper.pdf Luis -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
