> generic_listxattr() is different from generic_getxattr() / > generic_setxattr() / generic_removexattr. It makes sense only for > filesystems that support a fixed set of xattrs, which means that all > handlers will have handler->name set. > > If any of the handlers has handler->prefix set instead, that handler > matches a whole set of attributes. Generic_listxattr() would have to > fill in all of those names matching that handler, but it doesn't know > which those are. > > It is common for filesystems to have their own listxattr inode > operation and still use generic_{get,set,remove}xattr. That clears things up a bit. So that leaves a few questions. First question is looking at several of the file system's implementations I noticed it contains loops such as: list_for_each_xattr(entry, base_addr) { const struct xattr_handler *handler = blah_xattr_handler(entry->e_name_index); const char *prefix; size_t prefix_len; size_t size; if (!handler || (handler->list && !handler->list(dentry))) continue; ... } Is the handler->list() test needed for a private listxattr implementation? Also I don't see anyone using handler->list() which which brings up the next question. What is the purpose of list() function? -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html