From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on gnuweeb.org X-Spam-Level: X-Spam-Status: No, score=-0.1 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_SOFTFAIL,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0E62C433EF for ; Wed, 23 Mar 2022 15:44:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239204AbiCWPqC (ORCPT ); Wed, 23 Mar 2022 11:46:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242398AbiCWPp7 (ORCPT ); Wed, 23 Mar 2022 11:45:59 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB7A33B028 for ; Wed, 23 Mar 2022 08:44:29 -0700 (PDT) Received: from pps.filterd (m0044010.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 22N6WTbj000755 for ; Wed, 23 Mar 2022 08:44:29 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=vOKmr/vrRfDGrDjMmzLYwzgJ+RL6bljKkS+ekZ0ooOk=; b=gbyKGICLJWHzXprGxN/3wk90qcvpa/vPYFtT1iXIvMoRTQazFaR4n6tcBEi52jv9nou7 LXHY/XgonnKIwwY1JSdx0dUPmZ/nhakNNQg7DacZQaRvjXzpR7OcjTjfuM/mHAZ1/xqI C3DXOVOQ4gcWur64uwG/DYCsA59RJLwGz/E= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3ey6ddmtxh-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 23 Mar 2022 08:44:29 -0700 Received: from twshared37304.07.ash9.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::c) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Wed, 23 Mar 2022 08:44:27 -0700 Received: by devvm225.atn0.facebook.com (Postfix, from userid 425415) id 7BC89CA024C5; Wed, 23 Mar 2022 08:44:22 -0700 (PDT) From: Stefan Roesch To: , , CC: , , Subject: [PATCH v13 1/4] fs: split off setxattr_copy and do_setxattr function from setxattr Date: Wed, 23 Mar 2022 08:44:17 -0700 Message-ID: <20220323154420.3301504-2-shr@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220323154420.3301504-1-shr@fb.com> References: <20220323154420.3301504-1-shr@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: HSy0r24TG-wwnN5tBnOaV93_sagSOxh3 X-Proofpoint-ORIG-GUID: HSy0r24TG-wwnN5tBnOaV93_sagSOxh3 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.850,Hydra:6.0.425,FMLib:17.11.64.514 definitions=2022-03-23_07,2022-03-23_01,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org This splits of the setup part of the function setxattr in its own dedicated function called setxattr_copy. In addition it also exposes a new function called do_setxattr for making the setxattr call. This makes it possible to call these two functions from io_uring in the processing of an xattr request. Signed-off-by: Stefan Roesch Acked-by: Christian Brauner --- fs/internal.h | 24 +++++++++++++++ fs/xattr.c | 82 ++++++++++++++++++++++++++++++++++++--------------- 2 files changed, 82 insertions(+), 24 deletions(-) diff --git a/fs/internal.h b/fs/internal.h index 56c0477f4215..96bbab6b58ba 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -196,3 +196,27 @@ long splice_file_to_pipe(struct file *in, struct pipe_inode_info *opipe, loff_t *offset, size_t len, unsigned int flags); + +/* + * fs/xattr.c: + */ +struct xattr_name { + char name[XATTR_NAME_MAX + 1]; +}; + +struct xattr_ctx { + /* Value of attribute */ + union { + const void __user *cvalue; + void __user *value; + }; + void *kvalue; + size_t size; + /* Attribute name */ + struct xattr_name *kname; + unsigned int flags; +}; + +int setxattr_copy(const char __user *name, struct xattr_ctx *ctx); +int do_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry= , + struct xattr_ctx *ctx); diff --git a/fs/xattr.c b/fs/xattr.c index 5c8c5175b385..717b3904c2e5 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -25,6 +25,8 @@ =20 #include =20 +#include "internal.h" + static const char * strcmp_prefix(const char *a, const char *a_prefix) { @@ -539,43 +541,75 @@ EXPORT_SYMBOL_GPL(vfs_removexattr); /* * Extended attribute SET operations */ -static long -setxattr(struct user_namespace *mnt_userns, struct dentry *d, - const char __user *name, const void __user *value, size_t size, - int flags) + +int setxattr_copy(const char __user *name, struct xattr_ctx *ctx) { int error; - void *kvalue =3D NULL; - char kname[XATTR_NAME_MAX + 1]; =20 - if (flags & ~(XATTR_CREATE|XATTR_REPLACE)) + if (ctx->flags & ~(XATTR_CREATE|XATTR_REPLACE)) return -EINVAL; =20 - error =3D strncpy_from_user(kname, name, sizeof(kname)); - if (error =3D=3D 0 || error =3D=3D sizeof(kname)) - error =3D -ERANGE; + error =3D strncpy_from_user(ctx->kname->name, name, + sizeof(ctx->kname->name)); + if (error =3D=3D 0 || error =3D=3D sizeof(ctx->kname->name)) + return -ERANGE; if (error < 0) return error; =20 - if (size) { - if (size > XATTR_SIZE_MAX) + error =3D 0; + if (ctx->size) { + if (ctx->size > XATTR_SIZE_MAX) return -E2BIG; - kvalue =3D kvmalloc(size, GFP_KERNEL); - if (!kvalue) - return -ENOMEM; - if (copy_from_user(kvalue, value, size)) { - error =3D -EFAULT; - goto out; + + ctx->kvalue =3D vmemdup_user(ctx->cvalue, ctx->size); + if (IS_ERR(ctx->kvalue)) { + error =3D PTR_ERR(ctx->kvalue); + ctx->kvalue =3D NULL; } - if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) =3D=3D 0) || - (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) =3D=3D 0)) - posix_acl_fix_xattr_from_user(mnt_userns, kvalue, size); } =20 - error =3D vfs_setxattr(mnt_userns, d, kname, kvalue, size, flags); -out: - kvfree(kvalue); + return error; +} + +static void setxattr_convert(struct user_namespace *mnt_userns, + struct xattr_ctx *ctx) +{ + if (ctx->size && + ((strcmp(ctx->kname->name, XATTR_NAME_POSIX_ACL_ACCESS) =3D=3D 0) || + (strcmp(ctx->kname->name, XATTR_NAME_POSIX_ACL_DEFAULT) =3D=3D 0))) + posix_acl_fix_xattr_from_user(mnt_userns, ctx->kvalue, ctx->size); +} + +int do_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry= , + struct xattr_ctx *ctx) +{ + setxattr_convert(mnt_userns, ctx); + return vfs_setxattr(mnt_userns, dentry, ctx->kname->name, + ctx->kvalue, ctx->size, ctx->flags); +} + +static long +setxattr(struct user_namespace *mnt_userns, struct dentry *d, + const char __user *name, const void __user *value, size_t size, + int flags) +{ + struct xattr_name kname; + struct xattr_ctx ctx =3D { + .cvalue =3D value, + .kvalue =3D NULL, + .size =3D size, + .kname =3D &kname, + .flags =3D flags, + }; + int error; + + error =3D setxattr_copy(name, &ctx); + if (error) + return error; + + error =3D do_setxattr(mnt_userns, d, &ctx); =20 + kvfree(ctx.kvalue); return error; } =20 --=20 2.30.2