From patchwork Tue Dec 21 16:49:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 12690091 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 85356C433FE for ; Tue, 21 Dec 2021 16:50:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240027AbhLUQuZ (ORCPT ); Tue, 21 Dec 2021 11:50:25 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:13912 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240016AbhLUQuY (ORCPT ); Tue, 21 Dec 2021 11:50:24 -0500 Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 1BLFvKuZ011958 for ; Tue, 21 Dec 2021 08:50:24 -0800 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=Y4xClo+bOKLBLadjxOpi5LCV+79V1c88iLat2gQz4Jk=; b=B3mvrqpgYA+TU1st8kL/WvP0MUxeS46Hb17miNU4mc1GqtGxbw3GhliJLZdElEG6FG5F MuJfEq1BLkdqpxAZmcpgMW5g5vjrfHhYo0Ei2gdELUxbrOB7rH7+rPU+CJsy4xvnToAH xpTwRUHZ1pgcryOp/kZP+zSDe7tv0Iavtz8= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3d35kcvxt9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 21 Dec 2021 08:50:24 -0800 Received: from twshared3205.02.ash9.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:21d::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Tue, 21 Dec 2021 08:50:08 -0800 Received: by devvm225.atn0.facebook.com (Postfix, from userid 425415) id ABD8885C07D8; Tue, 21 Dec 2021 08:50:01 -0800 (PST) From: Stefan Roesch To: , , CC: , Subject: [PATCH v5 2/5] fs: split off setxattr_setup function from setxattr Date: Tue, 21 Dec 2021 08:49:56 -0800 Message-ID: <20211221164959.174480-3-shr@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211221164959.174480-1-shr@fb.com> References: <20211221164959.174480-1-shr@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: UOBsaT_npJEEuNzqyzOCPAvU6lp8SxJp X-Proofpoint-ORIG-GUID: UOBsaT_npJEEuNzqyzOCPAvU6lp8SxJp X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.790,Hydra:6.0.425,FMLib:17.11.62.513 definitions=2021-12-21_04,2021-12-21_01,2021-12-02_01 X-Proofpoint-Spam-Details: rule=fb_outbound_notspam policy=fb_outbound score=0 mlxlogscore=999 bulkscore=0 mlxscore=0 priorityscore=1501 impostorscore=0 malwarescore=0 phishscore=0 adultscore=0 lowpriorityscore=0 spamscore=0 clxscore=1015 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2110150000 definitions=main-2112210083 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org 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 --- fs/internal.h | 16 +++++++++++ fs/xattr.c | 74 +++++++++++++++++++++++++++++++++------------------ 2 files changed, 64 insertions(+), 26 deletions(-) diff --git a/fs/internal.h b/fs/internal.h index 7979ff8d168c..d13b9f13df09 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -194,3 +194,19 @@ 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_ctx { + /* Value of attribute */ + const void __user *value; + size_t size; + /* Attribute name */ + char kname[XATTR_NAME_MAX + 1]; + unsigned int flags; +}; + +void *setxattr_setup(struct user_namespace *mnt_userns, + const char __user *name, + struct xattr_ctx *data); diff --git a/fs/xattr.c b/fs/xattr.c index 5c8c5175b385..a4b59523bd0e 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -25,6 +25,8 @@ #include +#include "internal.h" + static const char * strcmp_prefix(const char *a, const char *a_prefix) { @@ -539,43 +541,63 @@ 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) + +void *setxattr_setup(struct user_namespace *mnt_userns, const char __user *name, + struct xattr_ctx *ctx) { - int error; void *kvalue = NULL; - char kname[XATTR_NAME_MAX + 1]; + int error; - if (flags & ~(XATTR_CREATE|XATTR_REPLACE)) - return -EINVAL; + if (ctx->flags & ~(XATTR_CREATE|XATTR_REPLACE)) + return ERR_PTR(-EINVAL); - error = strncpy_from_user(kname, name, sizeof(kname)); - if (error == 0 || error == sizeof(kname)) - error = -ERANGE; + error = strncpy_from_user(ctx->kname, name, sizeof(ctx->kname)); + if (error == 0 || error == sizeof(ctx->kname)) + return ERR_PTR(-ERANGE); if (error < 0) - return error; + return ERR_PTR(error); - if (size) { - if (size > XATTR_SIZE_MAX) - return -E2BIG; - kvalue = kvmalloc(size, GFP_KERNEL); + if (ctx->size) { + if (ctx->size > XATTR_SIZE_MAX) + return ERR_PTR(-E2BIG); + + kvalue = kvmalloc(ctx->size, GFP_KERNEL); if (!kvalue) - return -ENOMEM; - if (copy_from_user(kvalue, value, size)) { - error = -EFAULT; - goto out; + return ERR_PTR(-ENOMEM); + + if (copy_from_user(kvalue, ctx->value, ctx->size)) { + kvfree(kvalue); + return ERR_PTR(-EFAULT); } - if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) || - (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0)) - posix_acl_fix_xattr_from_user(mnt_userns, kvalue, size); + + 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); } - error = vfs_setxattr(mnt_userns, d, kname, kvalue, size, flags); -out: - kvfree(kvalue); + return kvalue; +} +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_ctx ctx = { + .value = value, + .size = size, + .flags = flags, + }; + void *kvalue; + int error; + + kvalue = setxattr_setup(mnt_userns, name, &ctx); + if (IS_ERR(kvalue)) + return PTR_ERR(kvalue); + + error = vfs_setxattr(mnt_userns, d, ctx.kname, kvalue, size, flags); + + kvfree(kvalue); return error; }