From patchwork Thu Sep 22 08:44:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miklos Szeredi X-Patchwork-Id: 12984743 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 9465CC6FA8B for ; Thu, 22 Sep 2022 08:45:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230417AbiIVIp2 (ORCPT ); Thu, 22 Sep 2022 04:45:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230409AbiIVIpA (ORCPT ); Thu, 22 Sep 2022 04:45:00 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ABCC1AB4E1 for ; Thu, 22 Sep 2022 01:44:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1663836296; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=q2MdUQ+cskiOFqdTJdIqCbmLrGfJwLVlFJJJyVKZST0=; b=hZpOg9vEhhkbF+Ha0X6v40b2VMAvHNhCNPtQkK7jUqzT+JhqnqmZCsY4/y8Sjb3OtwI4mr E7neGS2ehBfjCHwCfOEQ6GuJtxlSSnzxU3A2wfH8jR20U+NyUEBjOFGoI8oqRp3VgjvHOG XkFfDMMxe0JmRFmGroTJRfb5+2VBO1k= Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-260-e52gERjiP4muMjHPc2yPAQ-1; Thu, 22 Sep 2022 04:44:55 -0400 X-MC-Unique: e52gERjiP4muMjHPc2yPAQ-1 Received: by mail-ed1-f72.google.com with SMTP id y1-20020a056402358100b00451b144e23eso6139633edc.18 for ; Thu, 22 Sep 2022 01:44:55 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date; bh=q2MdUQ+cskiOFqdTJdIqCbmLrGfJwLVlFJJJyVKZST0=; b=MNBzO8E/yf9Vb1pM4KDiZrwbMRWyvBaUb6YCFr+kGh2U+/jsvggxO35VrOVQ0irq2f obOzjd8Atv3+obMnadU+9Vi0lSuEICoNe7SBeo+BgBOBfBng4LsVeDQTDaHJT3bl3niv SrGRDYSJzo97/p0CndzjCX+RSlszyOXxoPN1QCtS/IFfUwm1oimoYTPERpfcrGzSG415 IO6fBSWC+w5I0GezDR0gGAvJDwQ7Bibvj9dMmBSYTeacFpYKYf33NS+qJD/qTRoJPlgs 7R/2L5apkjV0MUMoRjqnfBnHPWHhejTWugwhlugh2j1Vk3CyEmWLo9A6QE93P7lgD0GQ FdKA== X-Gm-Message-State: ACrzQf154peDksInun0la7E7RqJNhdeAv7D/8/vmwxEY5XqxBAHlqB+C TCH5VSNuE12HJUsSfVYyBZ8MXZatr5fMfhRs1SKCfzAtL1zoHKc/KpSxsvc18VarddlWrLQcnWc cATb/WOIWEGY2QYXxYP/J8h+xGF8xx38UEjfK+Nu+Y1TbQj5ZOPLLOfSNZKvftuPHWxx2x60f7W nqbA== X-Received: by 2002:a17:907:a40c:b0:781:53dd:27fd with SMTP id sg12-20020a170907a40c00b0078153dd27fdmr1846871ejc.261.1663836293810; Thu, 22 Sep 2022 01:44:53 -0700 (PDT) X-Google-Smtp-Source: AMsMyM5EOsg89DoiZJRR0cGBkgX2BhdVx/pNpXNSIrV8Tyan5OQ91mNaU83SqMVwLrjojl/fTzkeWw== X-Received: by 2002:a17:907:a40c:b0:781:53dd:27fd with SMTP id sg12-20020a170907a40c00b0078153dd27fdmr1846854ejc.261.1663836293564; Thu, 22 Sep 2022 01:44:53 -0700 (PDT) Received: from miu.piliscsaba.redhat.com (193-226-214-223.pool.digikabel.hu. [193.226.214.223]) by smtp.gmail.com with ESMTPSA id h15-20020a170906718f00b00730b3bdd8d7sm2297942ejk.179.2022.09.22.01.44.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Sep 2022 01:44:52 -0700 (PDT) From: Miklos Szeredi To: linux-fsdevel@vger.kernel.org Cc: Al Viro , Christian Brauner , Amir Goldstein , David Howells , Yu-li Lin , Chirantan Ekbote Subject: [PATCH v4 08/10] vfs: move open right after ->tmpfile() Date: Thu, 22 Sep 2022 10:44:40 +0200 Message-Id: <20220922084442.2401223-9-mszeredi@redhat.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220922084442.2401223-1-mszeredi@redhat.com> References: <20220922084442.2401223-1-mszeredi@redhat.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Create a helper finish_open_simple() that opens the file with the original dentry. Handle the error case here as well to simplify callers. Call this helper right after ->tmpfile() is called. Next patch will change the tmpfile API and move this call into tmpfile instances. Signed-off-by: Miklos Szeredi --- fs/namei.c | 83 ++++++++++++++++++---------------------------- include/linux/fs.h | 9 +++++ 2 files changed, 42 insertions(+), 50 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 03ad4e55fb26..fea56fe9f306 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3583,44 +3583,44 @@ static int do_open(struct nameidata *nd, * On non-idmapped mounts or if permission checking is to be performed on the * raw inode simply passs init_user_ns. */ -static struct dentry *vfs_tmpfile(struct user_namespace *mnt_userns, - struct dentry *dentry, umode_t mode, int open_flag) +static int vfs_tmpfile(struct user_namespace *mnt_userns, + const struct path *parentpath, + struct file *file, umode_t mode) { - struct dentry *child = NULL; - struct inode *dir = dentry->d_inode; + struct dentry *child; + struct inode *dir = d_inode(parentpath->dentry); struct inode *inode; int error; /* we want directory to be writable */ error = inode_permission(mnt_userns, dir, MAY_WRITE | MAY_EXEC); if (error) - goto out_err; - error = -EOPNOTSUPP; + return error; if (!dir->i_op->tmpfile) - goto out_err; - error = -ENOMEM; - child = d_alloc(dentry, &slash_name); + return -EOPNOTSUPP; + child = d_alloc(parentpath->dentry, &slash_name); if (unlikely(!child)) - goto out_err; + return -ENOMEM; + file->f_path.mnt = parentpath->mnt; + file->f_path.dentry = child; mode = vfs_prepare_mode(mnt_userns, dir, mode, mode, mode); error = dir->i_op->tmpfile(mnt_userns, dir, child, mode); + error = finish_open_simple(file, error); + dput(child); if (error) - goto out_err; - error = -ENOENT; - inode = child->d_inode; - if (unlikely(!inode)) - goto out_err; - if (!(open_flag & O_EXCL)) { + return error; + /* Don't check for other permissions, the inode was just created */ + error = may_open(mnt_userns, &file->f_path, 0, file->f_flags); + if (error) + return error; + inode = file_inode(file); + if (!(file->f_flags & O_EXCL)) { spin_lock(&inode->i_lock); inode->i_state |= I_LINKABLE; spin_unlock(&inode->i_lock); } ima_post_create_tmpfile(mnt_userns, inode); - return child; - -out_err: - dput(child); - return ERR_PTR(error); + return 0; } /** @@ -3641,25 +3641,15 @@ struct file *vfs_tmpfile_open(struct user_namespace *mnt_userns, { struct file *file; int error; - struct path path = { .mnt = parentpath->mnt }; - - path.dentry = vfs_tmpfile(mnt_userns, parentpath->dentry, mode, open_flag); - if (IS_ERR(path.dentry)) - return ERR_CAST(path.dentry); - - error = may_open(mnt_userns, &path, 0, open_flag); - file = ERR_PTR(error); - if (error) - goto out_dput; - - /* - * This relies on the "noaccount" property of fake open, otherwise - * equivalent to dentry_open(). - */ - file = open_with_fake_path(&path, open_flag, d_inode(path.dentry), cred); -out_dput: - dput(path.dentry); + file = alloc_empty_file_noaccount(open_flag, cred); + if (!IS_ERR(file)) { + error = vfs_tmpfile(mnt_userns, parentpath, file, mode); + if (error) { + fput(file); + file = ERR_PTR(error); + } + } return file; } EXPORT_SYMBOL(vfs_tmpfile_open); @@ -3669,26 +3659,19 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags, struct file *file) { struct user_namespace *mnt_userns; - struct dentry *child; struct path path; int error = path_lookupat(nd, flags | LOOKUP_DIRECTORY, &path); + if (unlikely(error)) return error; error = mnt_want_write(path.mnt); if (unlikely(error)) goto out; mnt_userns = mnt_user_ns(path.mnt); - child = vfs_tmpfile(mnt_userns, path.dentry, op->mode, op->open_flag); - error = PTR_ERR(child); - if (IS_ERR(child)) + error = vfs_tmpfile(mnt_userns, &path, file, op->mode); + if (error) goto out2; - dput(path.dentry); - path.dentry = child; - audit_inode(nd->name, child, 0); - /* Don't check for other permissions, the inode was just created */ - error = may_open(mnt_userns, &path, 0, op->open_flag); - if (!error) - error = vfs_open(&path, file); + audit_inode(nd->name, file->f_path.dentry, 0); out2: mnt_drop_write(path.mnt); out: diff --git a/include/linux/fs.h b/include/linux/fs.h index 02646542f6bb..a3c50869e79b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2780,6 +2780,15 @@ extern int finish_open(struct file *file, struct dentry *dentry, int (*open)(struct inode *, struct file *)); extern int finish_no_open(struct file *file, struct dentry *dentry); +/* Helper for the simple case when original dentry is used */ +static inline int finish_open_simple(struct file *file, int error) +{ + if (error) + return error; + + return finish_open(file, file->f_path.dentry, NULL); +} + /* fs/dcache.c */ extern void __init vfs_caches_init_early(void); extern void __init vfs_caches_init(void);