On Mon, Sep 18, 2017 at 10:56:51AM -0700, Christoph Hellwig wrote: > This seems to miss any explanation and 6 out of 7 patches. See linux-fsdevel for entire patch set. https://www.spinics.net/lists/linux-fsdevel/msg115740.html > > That being said, I really detest adding weird query modes to random > syscalls. We should expose capabilities through the interface that > was designed for such things: (f)pathconf, as there are a lot more > important parameters we currently fail to expose to userspace to > start with. (f)pathconf on it's own is useless because I need to get this information directly from the file system. Supported fallocate modes can differ with inode flags (encrypted files, extent/indirect based files on ext4). I also need in-kernel interface. That's why I though fallocate is the convenient place to put this. I have not looked to it, but other option might be to use fstat to get this. -Lukas
