From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8FDEBC433EF for ; Thu, 23 Dec 2021 10:24:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347688AbhLWKYs (ORCPT ); Thu, 23 Dec 2021 05:24:48 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:49688 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347664AbhLWKYr (ORCPT ); Thu, 23 Dec 2021 05:24:47 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 57FB161E1C; Thu, 23 Dec 2021 10:24:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38CFCC36AE9; Thu, 23 Dec 2021 10:24:44 +0000 (UTC) Date: Thu, 23 Dec 2021 11:24:40 +0100 From: Christian Brauner To: Stefan Roesch Cc: io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org, kernel-team@fb.com, torvalds@linux-foundation.org Subject: Re: [PATCH v6 2/5] fs: split off setxattr_setup function from setxattr Message-ID: <20211223102440.4bd5t25tojkhpbuy@wittgenstein> References: <20211222210127.958902-1-shr@fb.com> <20211222210127.958902-3-shr@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20211222210127.958902-3-shr@fb.com> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Dec 22, 2021 at 01:01:24PM -0800, Stefan Roesch wrote: > This splits of the setup part of the function > setxattr in its own dedicated function called > setxattr_setup. > > This makes it possible to call this function > from io_uring in the pre-processing of an > xattr request. > > Signed-off-by: Stefan Roesch > --- I like the introduction of struct xattr_ctx. But I would prefer if we called this setxattr_prepare() to mirror setattr_prepare() and change the signature to: int setxattr_setup(struct user_namespace *mnt_userns, const char __user *name, struct xattr_ctx *ctx, void **xattr_val); Since NULL is a success condition I think it makes more sense to have an error returned and the value be a return argument. So sm like (uncompiled and untested): int setxattr_prepare(struct user_namespace *mnt_userns, const char __user *name, struct xattr_ctx *ctx, void **xattr_val) { void *kvalue = NULL; int error; if (ctx->flags & ~(XATTR_CREATE | XATTR_REPLACE)) return -EINVAL; error = strncpy_from_user(ctx->kname, name, ctx->kname_sz); if (error == 0 || error == ctx->kname_sz) return -ERANGE; if (error < 0) return error; if (ctx->size) { if (ctx->size > XATTR_SIZE_MAX) return -E2BIG; kvalue = kvmalloc(ctx->size, GFP_KERNEL); if (!kvalue) return -ENOMEM; if (copy_from_user(kvalue, ctx->value, ctx->size)) { kvfree(kvalue); return -EFAULT; } if ((strcmp(ctx->kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) || (strcmp(ctx->kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0)) posix_acl_fix_xattr_from_user(mnt_userns, kvalue, ctx->size); } *xattr_val = kvalue; return 0; }