From patchwork Mon Aug 3 14:47:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kalesh Singh X-Patchwork-Id: 256287 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=-20.6 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=unavailable 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 66179C433E0 for ; Mon, 3 Aug 2020 14:50:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 429132076C for ; Mon, 3 Aug 2020 14:50:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="mGbuS+pG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726276AbgHCOrs (ORCPT ); Mon, 3 Aug 2020 10:47:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35844 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727863AbgHCOrq (ORCPT ); Mon, 3 Aug 2020 10:47:46 -0400 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 998B6C06179E for ; Mon, 3 Aug 2020 07:47:46 -0700 (PDT) Received: by mail-qt1-x84a.google.com with SMTP id m88so26885868qtd.15 for ; Mon, 03 Aug 2020 07:47:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=exegq5bRss6SDj4yQZt05Kc3+gr2w1N7iotmmiqvfaE=; b=mGbuS+pGC2mlZ1nnEmD1UyJJXrsA49ua7zPcaT6Pb99vdkfquF0DlxLELzi2UVFHnz UQUik19iARwlMzlIFxykMeRfQ6oge5n7bchL6BZu8lyh6evqernJZXAnv0/9WYrja5HD Q9W8tFLfkY4oPAcwJ4a0TnaLj217q3Daa7ocYAM6w+zVg8lJ9OjeITJ9jMx9RHiIcrB7 v5SJIb3A7rjAEpFPOqH6WpNaQLYoBGUgvH3dH8xM+4XSyt1OAM6VgEjlSccwOg8rJXEw qlBvT/iCSh0JFz0QGdWGzwIzM+bYQPBo/ooJ6ucHbeDPUskeVvdf+SxdjQ3AyeiIHfZk ZuQg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=exegq5bRss6SDj4yQZt05Kc3+gr2w1N7iotmmiqvfaE=; b=LlcVLDiQnHlbje7LE4KH8L4SdG+ViirBEEFi0xEYKc3C8UwyZEi6JJDA3vc55VU9AV ZIQPfBzWunWrg5fhfEajH4Q5V//brfTwZJpzuk6fVVktotocFeR5JHWpVxWg1lcaZppF dQhySdTNA8ra6FXX3kEBGANTnLfMh+8dy/aCg6t7D3gbxVhQdn3xgt1ejzfMOzz3HBJ2 mVH6FqAhJiezVB65cQurMztX/OLdAql5ND13E9wzzo2/hyY2TMrQLm79GOZdAUdFyCTa zejW8lZXwy/PNanVhotG6/+3GWK5c0KxmPvUl9K8Jl7TSeFCrJiA3w3IB19eSvJxbyc5 Kadw== X-Gm-Message-State: AOAM531RJjFpTBiNMMFVffIOghhloT4Z3uPoA/A8qs7tpFAwI3uJucao BlBHdSbZ+W+4KfKL+sJG23MRZMmpeMLE44IoUA== X-Google-Smtp-Source: ABdhPJzDwQ0aX/7NlvPVgwHIaoyHgpXGgCOEtbhY3RvNh0Xr+RtcQtfdf3+ncwToVPid9YW6tzvTvt4z+owCWodSjw== X-Received: by 2002:a0c:b743:: with SMTP id q3mr16777556qve.229.1596466065553; Mon, 03 Aug 2020 07:47:45 -0700 (PDT) Date: Mon, 3 Aug 2020 14:47:18 +0000 In-Reply-To: <20200803144719.3184138-1-kaleshsingh@google.com> Message-Id: <20200803144719.3184138-2-kaleshsingh@google.com> Mime-Version: 1.0 References: <20200803144719.3184138-1-kaleshsingh@google.com> X-Mailer: git-send-email 2.28.0.163.g6104cc2f0b6-goog Subject: [PATCH 1/2] fs: Add fd_install file operation From: Kalesh Singh To: Jonathan Corbet , Sumit Semwal , Alexander Viro , Steven Rostedt , Ingo Molnar Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-fsdevel@vger.kernel.org, Suren Baghdasaryan , Hridya Valsaraju , Ioannis Ilkos , John Stultz , kernel-team@android.com, Kalesh Singh Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Provides a per process hook for the acquisition of file descriptors, despite the method used to obtain the descriptor. Signed-off-by: Kalesh Singh --- Documentation/filesystems/vfs.rst | 5 +++++ fs/file.c | 3 +++ include/linux/fs.h | 1 + 3 files changed, 9 insertions(+) diff --git a/Documentation/filesystems/vfs.rst b/Documentation/filesystems/vfs.rst index ed17771c212b..95b30142c8d9 100644 --- a/Documentation/filesystems/vfs.rst +++ b/Documentation/filesystems/vfs.rst @@ -1123,6 +1123,11 @@ otherwise noted. ``fadvise`` possibly called by the fadvise64() system call. +``fd_install`` + called by the VFS when a file descriptor is installed in the + process's file descriptor table, regardless how the file descriptor + was acquired -- be it via the open syscall, received over IPC, etc. + Note that the file operations are implemented by the specific filesystem in which the inode resides. When opening a device node (character or block special) most filesystems will call special diff --git a/fs/file.c b/fs/file.c index abb8b7081d7a..f5db8622b851 100644 --- a/fs/file.c +++ b/fs/file.c @@ -616,6 +616,9 @@ void __fd_install(struct files_struct *files, unsigned int fd, void fd_install(unsigned int fd, struct file *file) { __fd_install(current->files, fd, file); + + if (file->f_op->fd_install) + file->f_op->fd_install(fd, file); } EXPORT_SYMBOL(fd_install); diff --git a/include/linux/fs.h b/include/linux/fs.h index f5abba86107d..b976fbe8c902 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1864,6 +1864,7 @@ struct file_operations { struct file *file_out, loff_t pos_out, loff_t len, unsigned int remap_flags); int (*fadvise)(struct file *, loff_t, loff_t, int); + void (*fd_install)(int, struct file *); } __randomize_layout; struct inode_operations {