On 2016-02-07 11:07, Qu Wenruo wrote: > +1 too. > > But first in C, then python wrapper. > > Not sure why there is no such libbtrfs for C wrapper of btrfs ioctls. > > Maybe just because current btrfs ioctl is too easy to use? Unfortunately no. I think the main problem of writing a libbtrfs, is the code changes needed. In fact in order to avoid code duplication (and to have more testing), the btrfs command has to be a client of libbtrfs. But it is not easy: you have to refactoring the error handling and the message printing... > AFAIK, systemd (container storage part) calls btrfs ioctl directly, especially for subvolume/snapshot creation mainly > because the design of them are quite easy. Also udev does the same (I don't remember if this happened before or after it went under the systemd umbrella). I remember a case where it was impossible to change the semantic of BTRFS_IOC_DEVICES_READY: on the basis of its name, it could be seems that this ioctl should _only_ check if a filesystem is ready. Unfortunately it register also the device [1]. It was discussed in the ML to change its semantic, but having already widespread client like udev it was impossible to do (even tough we could discuss to change their name) > Thanks, > Qu BR G.Baroncelli [1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=772744 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
