{"id":816600,"url":"http://patchwork.ozlabs.org/api/patches/816600/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-mtd/patch/20170920224605.22030-11-ebiggers3@gmail.com/","project":{"id":3,"url":"http://patchwork.ozlabs.org/api/projects/3/?format=json","name":"Linux MTD development","link_name":"linux-mtd","list_id":"linux-mtd.lists.infradead.org","list_email":"linux-mtd@lists.infradead.org","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20170920224605.22030-11-ebiggers3@gmail.com>","list_archive_url":null,"date":"2017-09-20T22:45:50","name":"[10/25] fscrypt: new helper function - fscrypt_prepare_setattr()","commit_ref":null,"pull_url":null,"state":"not-applicable","archived":false,"hash":"144c4b019d578b82ebd336e99e69983ad9a785f8","submitter":{"id":65202,"url":"http://patchwork.ozlabs.org/api/people/65202/?format=json","name":"Eric Biggers","email":"ebiggers3@gmail.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linux-mtd/patch/20170920224605.22030-11-ebiggers3@gmail.com/mbox/","series":[{"id":4250,"url":"http://patchwork.ozlabs.org/api/series/4250/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-mtd/list/?series=4250","date":"2017-09-20T22:45:45","name":"fscrypt: add some higher-level helper functions","version":1,"mbox":"http://patchwork.ozlabs.org/series/4250/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/816600/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/816600/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org; spf=none (mailfrom)\n\tsmtp.mailfrom=lists.infradead.org (client-ip=65.50.211.133;\n\thelo=bombadil.infradead.org;\n\tenvelope-from=linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org;\n\treceiver=)","ozlabs.org; dkim=pass (2048-bit key;\n\tunprotected) header.d=lists.infradead.org\n\theader.i=@lists.infradead.org header.b=\"KWB1+OIf\"; \n\tdkim=fail reason=\"signature verification failed\" (2048-bit key;\n\tunprotected) header.d=infradead.org header.i=@infradead.org\n\theader.b=\"rnHWdruK\"; \n\tdkim=fail reason=\"signature verification failed\" (2048-bit key;\n\tunprotected) header.d=gmail.com header.i=@gmail.com\n\theader.b=\"GLyIydD1\"; dkim-atps=neutral"],"Received":["from bombadil.infradead.org (bombadil.infradead.org\n\t[65.50.211.133])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256\n\tbits)) (No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xyFxJ4n8Rz9s7m\n\tfor ;\n\tThu, 21 Sep 2017 09:16:36 +1000 (AEST)","from localhost ([127.0.0.1] helo=bombadil.infradead.org)\n\tby bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux))\n\tid 1duoEG-00037i-Sx; Wed, 20 Sep 2017 23:16:28 +0000","from casper.infradead.org ([2001:8b0:10b:1236::1])\n\tby bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux))\n\tid 1duoAs-0006j8-HI\n\tfor linux-mtd@bombadil.infradead.org; Wed, 20 Sep 2017 23:12:58 +0000","from mail-pg0-x242.google.com ([2607:f8b0:400e:c05::242])\n\tby casper.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux))\n\tid 1dunm8-0004se-C7\n\tfor linux-mtd@lists.infradead.org; Wed, 20 Sep 2017 22:47:25 +0000","by mail-pg0-x242.google.com with SMTP id i130so2381408pgc.0\n\tfor ;\n\tWed, 20 Sep 2017 15:47:03 -0700 (PDT)","from ebiggers-linuxstation.kir.corp.google.com ([100.66.174.81])\n\tby smtp.gmail.com with ESMTPSA id j2sm6249pgn.26.2017.09.20.15.47.01\n\t(version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128);\n\tWed, 20 Sep 2017 15:47:01 -0700 (PDT)"],"DKIM-Signature":["v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;\n\td=lists.infradead.org; s=bombadil.20170209; h=Sender:\n\tContent-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe:\n\tList-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References:\n\tIn-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID:\n\tContent-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc\n\t:Resent-Message-ID:List-Owner;\n\tbh=xEwzjuRRucmk19CNuOrjZ1kRSSMMwEs2HQrKZiU4gLg=;\n\tb=KWB1+OIfs7rWJFq4lzpK/KQPGg\n\t8pPkRGW3Eo2cYYaFQliq7XQUEwJcAeHQ5rojegznCA53nR41vIIOZy2cYtvOxEmhbiho8m2W0Hmhr\n\ty2RplhtKUK3h+3CZK9B7LPGZgFsNUsKMcVar3JFtAGRpfezicCnaopFvcRF2a6se8gjzXXdIDkb0P\n\tQOyIo1nlUtOjbk92YzWjY0OyN6/8Wt07enNfRbR2Rq293LM+45EODqLrsPg+f9h8CCNq1mQ9w9wxi\n\t4bmtbohdgUbKFpACN4gvAKCoY6DhgIHg60nP2pxEljkPPQ3AMliT9WKkys3qJ63OiOaontkM2oKW7\n\tYzOIqU7A==;","v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;\n\td=infradead.org; s=casper.20170209;\n\th=References:In-Reply-To:Message-Id:Date:\n\tSubject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type:\n\tContent-Transfer-Encoding:Content-ID:Content-Description:Resent-Date:\n\tResent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:\n\tList-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive;\n\tbh=CXOIAKtWON/V/TY53npXTAfo3/xiUczbtICqD1BkKUE=;\n\tb=rnHWdruK7jnxjMj+zYS6dxBKy\n\ttSX632FSSaW+AYbXUzxeKZZSTjaFNK5BCCTnta1QyLZBiSo8KbcxUjCvFtvMkFGnkDJB6RdhpXLdb\n\tuKNWi+F1Mxihpg6v0ZM+gjI2NBCKlZLF+wHvdpgIKKjXmmvaLI4BvNBZIac93lNgy/wFYobzJfo0v\n\tTDQSKxDtSXp8FKzDWCiomAv2/1HuYYBhAWSygaw0YAKNIsJQuX1DffnVfvKpnXZpLDtVI293PP48S\n\t6lDteJ4GcGlK0tbytK7xFbjguIirfwNOj2yXxybbLYM9T2+wo9kEUO2RHipnwwgBQRzBUqm/5iX8m\n\to8v7azlpw==;","v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025;\n\th=from:to:cc:subject:date:message-id:in-reply-to:references;\n\tbh=CXOIAKtWON/V/TY53npXTAfo3/xiUczbtICqD1BkKUE=;\n\tb=GLyIydD1lNvj2+I4MU5s2IxOd+DPck3Z3BMuZ1tctVMoIFjOJeb3ZOn9YedrRFNA/D\n\tCwJoc4xiiRhoPdLX7TmZ9JLRPwDGzJg7xHhwJ96j34jchFA0JCmv8jRYSKq0YlmA0a0P\n\tpiQMi/2p+l59t/K38IFB/Yfn8Pqi43DY45cTnnZBuRfbJT15c7XYoN+xkT5UPPBD4tCt\n\tbDVBoqzZFdEBhZ3FK/koHWHpJjGMAjNtZqVbl3CTmXYHzZ+GxOf3dW5HKAb0bOrhSnu2\n\t6ascTFV7m3A/J3qusNd2sTmI8GUJk3v0EGRXB4CIePRaMAkJasFjsZ3qwonXa7YP9p3J\n\tQLTQ=="],"X-Google-DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=1e100.net; s=20161025;\n\th=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to\n\t:references;\n\tbh=CXOIAKtWON/V/TY53npXTAfo3/xiUczbtICqD1BkKUE=;\n\tb=Yd8EcFN0yBf/vjmCh0jc1jR+seotqX1JqZFCJhMtFS8kuYplKB1sET44p2CQB/TnTf\n\t8mjZlk+RXPMo6kr5M3thZ9h0olBbTWwO04QXvD7cKChkQge5J5z1Wt04iQPAIpXUs3gr\n\t8HXbF7KiRTiwkLKtikRCHONuPB1pmt/4kockWeXUHYewWphYQSWSa/6WCizeM702XLdX\n\tcxdIu7tABm7zmvRmxhAA/0+u28FI2J+Tl2M42BQBMDtJ6Dbb0guEjZyt4OPmwbGQ6bjA\n\t8fZ6TeZHx9LuX3LqV7XebL4Ziumh4WpNlaC0EnrEbgP5Fj4EuJKvnfGXYBYLR2ZJF2uL\n\td5ew==","X-Gm-Message-State":"AHPjjUh7zT2BhDwkF3JzivQgvyKEqhmGNnpeKve3GYz2eLNyaocvauZZ\n\tZvzj+bjB9DRkPwMWGwPzd0w=","X-Google-Smtp-Source":"AOwi7QB31rzc3THPqVCbTPvbx8PuoattTFuqT5wSpHHJSIzN6IiXU/Gmde6i6mqJHP5qBcsH6CgMDw==","X-Received":"by 10.99.53.206 with SMTP id c197mr3677053pga.440.1505947622479; \n\tWed, 20 Sep 2017 15:47:02 -0700 (PDT)","From":"Eric Biggers ","To":"linux-fscrypt@vger.kernel.org","Subject":"[PATCH 10/25] fscrypt: new helper function -\n\tfscrypt_prepare_setattr()","Date":"Wed, 20 Sep 2017 15:45:50 -0700","Message-Id":"<20170920224605.22030-11-ebiggers3@gmail.com>","X-Mailer":"git-send-email 2.14.1.821.g8fa685d3b7-goog","In-Reply-To":"<20170920224605.22030-1-ebiggers3@gmail.com>","References":"<20170920224605.22030-1-ebiggers3@gmail.com>","X-CRM114-Version":"20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 ","X-CRM114-CacheID":"sfid-20170920_234724_549570_D151D190 ","X-CRM114-Status":"GOOD ( 16.72 )","X-Spam-Score":"-1.8 (-)","X-Spam-Report":"SpamAssassin version 3.4.1 on casper.infradead.org summary:\n\tContent analysis details: (-1.8 points, 5.0 required)\n\tpts rule name description\n\t---- ----------------------\n\t--------------------------------------------------\n\t-0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/,\n\tno\n\ttrust [2607:f8b0:400e:c05:0:0:0:242 listed in] [list.dnswl.org]\n\t-0.0 SPF_PASS SPF: sender matches SPF record\n\t0.2 FREEMAIL_ENVFROM_END_DIGIT Envelope-from freemail username ends\n\tin digit (ebiggers3[at]gmail.com)\n\t0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail\n\tprovider (ebiggers3[at]gmail.com)\n\t-1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1%\n\t[score: 0.0000]\n\t-0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from\n\tauthor's domain\n\t0.1 DKIM_SIGNED Message has a DKIM or DK signature,\n\tnot necessarily valid\n\t-0.1 DKIM_VALID Message has at least one valid DKIM or DK signature","X-BeenThere":"linux-mtd@lists.infradead.org","X-Mailman-Version":"2.1.21","Precedence":"list","List-Id":"Linux MTD discussion mailing list ","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"\"Theodore Y . Ts'o\" , Eric Biggers , \n\tMichael Halcrow ,\n\tlinux-f2fs-devel@lists.sourceforge.net, \n\tlinux-mtd@lists.infradead.org, linux-fsdevel@vger.kernel.org,\n\tJaegeuk Kim , linux-ext4@vger.kernel.org","MIME-Version":"1.0","Content-Type":"text/plain; charset=\"us-ascii\"","Content-Transfer-Encoding":"7bit","Sender":"\"linux-mtd\" ","Errors-To":"linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org"},"content":"From: Eric Biggers \n\nIntroduce a helper function for filesystems to call when processing\n->setattr() on a possibly-encrypted inode. It handles enforcing that an\nencrypted file can only be truncated if its encryption key is available.\n\nSigned-off-by: Eric Biggers \n---\n include/linux/fscrypt_notsupp.h | 8 ++++++++\n include/linux/fscrypt_supp.h | 25 +++++++++++++++++++++++++\n 2 files changed, 33 insertions(+)","diff":"diff --git a/include/linux/fscrypt_notsupp.h b/include/linux/fscrypt_notsupp.h\nindex e9b437605f9c..b0dd2d1756b2 100644\n--- a/include/linux/fscrypt_notsupp.h\n+++ b/include/linux/fscrypt_notsupp.h\n@@ -218,4 +218,12 @@ static inline int fscrypt_prepare_lookup(struct inode *dir,\n \treturn 0;\n }\n \n+static inline int fscrypt_prepare_setattr(struct dentry *dentry,\n+\t\t\t\t\t struct iattr *attr)\n+{\n+\tif (IS_ENCRYPTED(d_inode(dentry)) && (attr->ia_valid & ATTR_SIZE))\n+\t\treturn -EOPNOTSUPP;\n+\treturn 0;\n+}\n+\n #endif\t/* _LINUX_FSCRYPT_NOTSUPP_H */\ndiff --git a/include/linux/fscrypt_supp.h b/include/linux/fscrypt_supp.h\nindex 2b99bc01c59b..bdd01e02435b 100644\n--- a/include/linux/fscrypt_supp.h\n+++ b/include/linux/fscrypt_supp.h\n@@ -270,4 +270,29 @@ static inline int fscrypt_prepare_lookup(struct inode *dir,\n \treturn 0;\n }\n \n+/**\n+ * fscrypt_prepare_setattr - prepare to change a possibly-encrypted inode's attributes\n+ * @dentry: dentry through which the inode is being changed\n+ * @attr: attributes to change\n+ *\n+ * Prepare for ->setattr() on a possibly-encrypted inode. On an encrypted file,\n+ * most attribute changes are allowed even without the encryption key. However,\n+ * without the encryption key we do have to forbid truncates. This is needed\n+ * because the size being truncated to may not be a multiple of the filesystem\n+ * block size, and in that case we'd have to decrypt the final block, zero the\n+ * portion past i_size, and re-encrypt it. (We *could* allow truncating to a\n+ * filesystem block boundary, but it's simpler to just forbid all truncates ---\n+ * and we already forbid all other contents modifications without the key.)\n+ *\n+ * Return: 0 on success, -ENOKEY if the key is missing, or another -errno code\n+ * if a problem occurred while setting up the encryption key.\n+ */\n+static inline int fscrypt_prepare_setattr(struct dentry *dentry,\n+\t\t\t\t\t struct iattr *attr)\n+{\n+\tif (IS_ENCRYPTED(d_inode(dentry)) && (attr->ia_valid & ATTR_SIZE))\n+\t\treturn fscrypt_require_key(d_inode(dentry));\n+\treturn 0;\n+}\n+\n #endif\t/* _LINUX_FSCRYPT_SUPP_H */\n","prefixes":["10/25"]}