From patchwork Tue Jun 23 22:39:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frank van der Linden X-Patchwork-Id: 11621951 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 89F0D1392 for ; Tue, 23 Jun 2020 22:44:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 72ABF20888 for ; Tue, 23 Jun 2020 22:44:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="p8xjcrzy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387818AbgFWWoP (ORCPT ); Tue, 23 Jun 2020 18:44:15 -0400 Received: from smtp-fw-6002.amazon.com ([52.95.49.90]:54771 "EHLO smtp-fw-6002.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387666AbgFWWoM (ORCPT ); Tue, 23 Jun 2020 18:44:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1592952251; x=1624488251; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=NLVN9Q2A0b00snDAE9ThJnTCcOLANkKYH+fT6qiOcKU=; b=p8xjcrzy8LkPN+nQ8P/ahevjbNUKWE43EOInXOspx+gl8WVfUNciGNQj g6gAJJMCx+E2OzK/JA6MvfvcfLcLqfBSm6gOIhu7g/sdh0E1IC3WN/FOo mIz59W/eSiUUX4gxD7kjMnuVKhFzn7CpqAXev6X0k8fJD44vC49QD+uLy M=; IronPort-SDR: REZWfGI3okiv3ZfNXBVjstILgGPtDTxHBi/xMy9BcJ8sRDsI/zrbyEwL5cJwDjL9lNjNvF47r1 k6c70RRnJd5Q== X-IronPort-AV: E=Sophos;i="5.75,272,1589241600"; d="scan'208";a="37982007" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-2a-119b4f96.us-west-2.amazon.com) ([10.43.8.6]) by smtp-border-fw-out-6002.iad6.amazon.com with ESMTP; 23 Jun 2020 22:39:38 +0000 Received: from EX13MTAUWB001.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan2.pdx.amazon.com [10.170.41.162]) by email-inbound-relay-2a-119b4f96.us-west-2.amazon.com (Postfix) with ESMTPS id 403441A0D62; Tue, 23 Jun 2020 22:39:37 +0000 (UTC) Received: from EX13D13UWB002.ant.amazon.com (10.43.161.21) by EX13MTAUWB001.ant.amazon.com (10.43.161.249) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 23 Jun 2020 22:39:29 +0000 Received: from EX13MTAUEA001.ant.amazon.com (10.43.61.82) by EX13D13UWB002.ant.amazon.com (10.43.161.21) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 23 Jun 2020 22:39:29 +0000 Received: from dev-dsk-fllinden-2c-c1893d73.us-west-2.amazon.com (172.23.141.97) by mail-relay.amazon.com (10.43.61.243) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 23 Jun 2020 22:39:28 +0000 Received: by dev-dsk-fllinden-2c-c1893d73.us-west-2.amazon.com (Postfix, from userid 6262777) id 096C1CD35B; Tue, 23 Jun 2020 22:39:28 +0000 (UTC) From: Frank van der Linden To: , , CC: Frank van der Linden , , Al Viro Subject: [PATCH v3 02/10] xattr: add a function to check if a namespace is supported Date: Tue, 23 Jun 2020 22:39:19 +0000 Message-ID: <20200623223927.31795-3-fllinden@amazon.com> X-Mailer: git-send-email 2.16.6 In-Reply-To: <20200623223927.31795-1-fllinden@amazon.com> References: <20200623223927.31795-1-fllinden@amazon.com> MIME-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Add a function that checks is an extended attribute namespace is supported for an inode, meaning that a handler must be present for either the whole namespace, or at least one synthetic xattr in the namespace. To be used by the nfs server code when being queried for extended attributes support. Cc: linux-fsdevel@vger.kernel.org Cc: Al Viro Signed-off-by: Frank van der Linden --- fs/xattr.c | 27 +++++++++++++++++++++++++++ include/linux/xattr.h | 2 ++ 2 files changed, 29 insertions(+) diff --git a/fs/xattr.c b/fs/xattr.c index 95f38f57347f..386b45676d7e 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -134,6 +134,33 @@ xattr_permission(struct inode *inode, const char *name, int mask) return inode_permission(inode, mask); } +/* + * Look for any handler that deals with the specified namespace. + */ +int +xattr_supported_namespace(struct inode *inode, const char *prefix) +{ + const struct xattr_handler **handlers = inode->i_sb->s_xattr; + const struct xattr_handler *handler; + size_t preflen; + + if (!(inode->i_opflags & IOP_XATTR)) { + if (unlikely(is_bad_inode(inode))) + return -EIO; + return -EOPNOTSUPP; + } + + preflen = strlen(prefix); + + for_each_xattr_handler(handlers, handler) { + if (!strncmp(xattr_prefix(handler), prefix, preflen)) + return 0; + } + + return -EOPNOTSUPP; +} +EXPORT_SYMBOL(xattr_supported_namespace); + int __vfs_setxattr(struct dentry *dentry, struct inode *inode, const char *name, const void *value, size_t size, int flags) diff --git a/include/linux/xattr.h b/include/linux/xattr.h index a2f3cd02653c..fac75810d9d3 100644 --- a/include/linux/xattr.h +++ b/include/linux/xattr.h @@ -61,6 +61,8 @@ ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_siz ssize_t vfs_getxattr_alloc(struct dentry *dentry, const char *name, char **xattr_value, size_t size, gfp_t flags); +int xattr_supported_namespace(struct inode *inode, const char *prefix); + static inline const char *xattr_prefix(const struct xattr_handler *handler) { return handler->prefix ?: handler->name;