From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CB2EC10F14 for ; Thu, 11 Apr 2019 23:18:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 52A9721872 for ; Thu, 11 Apr 2019 23:18:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555024714; bh=0niNzb1sDSGJbaGzN92vMkcz8ZPj+z+Fb8w8WF2/4so=; h=From:To:Subject:Date:In-Reply-To:References:List-ID:From; b=yQj3BU9/+mPTBXlRn9XXCXUUtPNHLr2gxBcua/ry9VygporBMPUzG5zPIBgLp/nOZ 2p5Yg5wV2FmKLfwNe8/eUEN76c96q4hBHDzYvjmMfogR4X9W7LxQgMUooX7AnFRGJw nQsdv8mvGbWchcIDnaASXN18ETtewiMJryPflyC0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726829AbfDKXSd (ORCPT ); Thu, 11 Apr 2019 19:18:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:32940 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726712AbfDKXSb (ORCPT ); Thu, 11 Apr 2019 19:18:31 -0400 Received: from ebiggers-linuxstation.mtv.corp.google.com (unknown [104.132.1.77]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3683F21850; Thu, 11 Apr 2019 23:18:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555024711; bh=0niNzb1sDSGJbaGzN92vMkcz8ZPj+z+Fb8w8WF2/4so=; h=From:To:Subject:Date:In-Reply-To:References:From; b=2ap3OOttRVzAWc6N8LuqynqzTWObEbZYeNtIYrsd5DStzV4L0NjsSrdZX6rkqakeJ 7NWWCVYZiAEWbbPNx9U13puCgdSqh7uRO/hg1oKKfRGGAL0mvrF/ghXtsHTMj+vO4Q rTErbtDnYDDnsNTrTK5ljQs1BLQUNajSoqsIi/zE= From: Eric Biggers To: linux-fsdevel@vger.kernel.org, Al Viro Subject: [PATCH 2/4] Documentation/filesystems/vfs.txt: document how ->i_link works Date: Thu, 11 Apr 2019 16:16:28 -0700 Message-Id: <20190411231630.50177-3-ebiggers@kernel.org> X-Mailer: git-send-email 2.21.0.392.gf8f6787159e-goog In-Reply-To: <20190411231630.50177-1-ebiggers@kernel.org> References: <20190411231630.50177-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Eric Biggers Signed-off-by: Eric Biggers --- Documentation/filesystems/vfs.txt | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 33120f220f86f..57fc576b1f3ea 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -463,6 +463,12 @@ otherwise noted. argument. If request can't be handled without leaving RCU mode, have it return ERR_PTR(-ECHILD). + If the filesystem stores the symlink target in ->i_link, the + VFS may use it directly without calling ->get_link(); however, + ->get_link() must still be provided. ->i_link must not be + freed until after an RCU grace period. Writing to ->i_link + post-iget() time requires a 'release' memory barrier. + readlink: this is now just an override for use by readlink(2) for the cases when ->get_link uses nd_jump_link() or object is not in fact a symlink. Normally filesystems should only implement -- 2.21.0.392.gf8f6787159e-goog