> >There is no simple way to test if a filesystem supports hole punching or not so > >the check has to be done per fs. Thanks, > > Could put a flag word in superblock_operations. Filesystems which > support punching (or other features) can enable it there. No, it couldn't be in super_operations. It may vary on a per-inode basis for some file systems, such as ext4 (depending on whether the inode is extent-mapped or indirect-block mapped). So at least for ext4 we'd need to call into fallocate() function anyway, once we add support. I suppose if other file systems really want it, we could add a flag to the super block ops structure, so they don't have do the "do we support the punch" operation. I can go either way on that; although if we think the majority of file systems are going support punch in the long-term, then it might not be worth it to add such a flag. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
