From patchwork Mon Mar 8 17:06:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kalesh Singh X-Patchwork-Id: 12122981 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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 46A74C4332E for ; Mon, 8 Mar 2021 17:08:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 190B165247 for ; Mon, 8 Mar 2021 17:08:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230480AbhCHRHu (ORCPT ); Mon, 8 Mar 2021 12:07:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230144AbhCHRH3 (ORCPT ); Mon, 8 Mar 2021 12:07:29 -0500 Received: from mail-qk1-x74a.google.com (mail-qk1-x74a.google.com [IPv6:2607:f8b0:4864:20::74a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2B779C06174A for ; Mon, 8 Mar 2021 09:07:29 -0800 (PST) Received: by mail-qk1-x74a.google.com with SMTP id c7so7783580qka.6 for ; Mon, 08 Mar 2021 09:07:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:cc; bh=FELlWZu6ZUrIDop9zcwWE5SbsWsfE0sUJEQWoIVLbIQ=; b=hYb5lQauywPQTthGnoE4RKFrp2PzVO8/bodmVLivFY9uIrc0ODy++E4qhhdHSu4y6K dZHDkUAuYXDUShhlaRCWcxLaWDfF/E/pOwlJGCg4NTp/2bkHgnv9kIlt/QwIzwsE5+13 bgDJ9dc0jdtWU++uQxU2xlJepDCqEdZ71TCHIn16n1euTkiJZEAY6rIwyceGqTHQsJVo pxRnC1ywWFrv5F3pW+s5rgk/mFLVdoHDpXSD8SAz5w09ivsHTsnN0kxuv8aB5pKCci3l SerOLJs2MINBSIBq5mli51VnCPCCoUm4EeNUdfeNGEmq64axFUPUpl0bKjOp6hQfVfiN vcfw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:cc; bh=FELlWZu6ZUrIDop9zcwWE5SbsWsfE0sUJEQWoIVLbIQ=; b=M27UY/rz7J3jc3BnwD+5VXnzOwrjkTJ5pJZnjUX7w6p1Bp51b5fGBVRqeSKbwwHXxd 4JkdrID1qs43ny8377roY2ltYCmZwTxYYy4OeqFczQiYCgvkYvtw3KE7SGpyT4WVUOtl b6rvt0W5eJgL0s1vot2y339vBIfpI1NEjax/lkVzdBqJPTZdDwFesbhX2A66313Bz9Ht RMVCuBT1B8mSJyu0qnVdZn3UcVFWY1ey+l8Pa6M7pNgYzXq4soWw9seYGwa8TP9OEMM4 a7zEY7w9dZJ3CSbn/lmGbY8ym0Q6M/NoRjhgvB9Qk7u0tgzT8XO6d6ZCbYtmJRzZb5kj ZC0w== X-Gm-Message-State: AOAM532qMjJHi0lB6QOLe5/j/rNHxkxrz1ha6F2GhMYbUXJXv6i6Ww07 YAv7d0yVS5CwwbRX+meRYKZCGKSK9x37hATchg== X-Google-Smtp-Source: ABdhPJwQ1OG4X3NVtsMmrjf8jtl2/SSPlVWw8UmVa3aH/kv3pepByT4Cw0PoMXqlCni6TnfbCWlXnO3S2MqveaJ9Gw== Sender: "kaleshsingh via sendgmr" X-Received: from kaleshsingh.c.googlers.com ([fda3:e722:ac3:10:14:4d90:c0a8:2145]) (user=kaleshsingh job=sendgmr) by 2002:ad4:5144:: with SMTP id g4mr22172108qvq.26.1615223248223; Mon, 08 Mar 2021 09:07:28 -0800 (PST) Date: Mon, 8 Mar 2021 17:06:41 +0000 In-Reply-To: <20210308170651.919148-1-kaleshsingh@google.com> Message-Id: <20210308170651.919148-2-kaleshsingh@google.com> Mime-Version: 1.0 References: <20210308170651.919148-1-kaleshsingh@google.com> X-Mailer: git-send-email 2.30.1.766.gb4fecdf3b7-goog Subject: [RESEND PATCH v6 2/2] procfs/dmabuf: Add inode number to /proc/*/fdinfo From: Kalesh Singh Cc: jannh@google.com, jeffv@google.com, keescook@chromium.org, surenb@google.com, minchan@kernel.org, hridya@google.com, rdunlap@infradead.org, christian.koenig@amd.com, willy@infradead.org, viro@zeniv.linux.org.uk, kernel-team@android.com, Kalesh Singh , Alexey Dobriyan , Jonathan Corbet , Andrew Morton , Michal Hocko , Mauro Carvalho Chehab , Alexey Gladkov , "Eric W. Biederman" , Christian Brauner , Michel Lespinasse , Bernd Edlinger , Andrei Vagin , Helge Deller , James Morris , Serge Hallyn , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org And 'ino' field to /proc//fdinfo/ and /proc//task//fdinfo/. The inode numbers can be used to uniquely identify DMA buffers in user space and avoids a dependency on /proc//fd/* when accounting per-process DMA buffer sizes. Signed-off-by: Kalesh Singh Acked-by: Randy Dunlap Reviewed-by: Kees Cook --- Hi everyone, This a resend of the inital posting at [1]. There was no objections on the last threads, along with some positive feedback from Randy. If there is no other concern I would like to have this considered for mainline. Thanks, Kalesh [1] https://lore.kernel.org/linux-doc/20210208155315.1367371-2-kaleshsingh@google.com/ Changes in v5: - Fixed tab vs spaces, per Randy - Renamed inode_no to ino, per Matthew Changes in v4: - Add inode number as common field in fdinfo, per Christian Changes in v3: - Add documentation in proc.rst, per Randy Changes in v2: - Update patch description --- Documentation/filesystems/proc.rst | 37 +++++++++++++++++++++++++----- fs/proc/fd.c | 5 ++-- 2 files changed, 34 insertions(+), 8 deletions(-) diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst index 48fbfc336ebf..33d08fbb0022 100644 --- a/Documentation/filesystems/proc.rst +++ b/Documentation/filesystems/proc.rst @@ -1909,18 +1909,20 @@ if precise results are needed. 3.8 /proc//fdinfo/ - Information about opened file --------------------------------------------------------------- This file provides information associated with an opened file. The regular -files have at least three fields -- 'pos', 'flags' and 'mnt_id'. The 'pos' -represents the current offset of the opened file in decimal form [see lseek(2) -for details], 'flags' denotes the octal O_xxx mask the file has been -created with [see open(2) for details] and 'mnt_id' represents mount ID of -the file system containing the opened file [see 3.5 /proc//mountinfo -for details]. +files have at least four fields -- 'pos', 'flags', 'mnt_id' and 'ino'. +The 'pos' represents the current offset of the opened file in decimal +form [see lseek(2) for details], 'flags' denotes the octal O_xxx mask the +file has been created with [see open(2) for details] and 'mnt_id' represents +mount ID of the file system containing the opened file [see 3.5 +/proc//mountinfo for details]. 'ino' represents the inode number of +the file. A typical output is:: pos: 0 flags: 0100002 mnt_id: 19 + ino: 63107 All locks associated with a file descriptor are shown in its fdinfo too:: @@ -1937,6 +1939,7 @@ Eventfd files pos: 0 flags: 04002 mnt_id: 9 + ino: 63107 eventfd-count: 5a where 'eventfd-count' is hex value of a counter. @@ -1949,6 +1952,7 @@ Signalfd files pos: 0 flags: 04002 mnt_id: 9 + ino: 63107 sigmask: 0000000000000200 where 'sigmask' is hex value of the signal mask associated @@ -1962,6 +1966,7 @@ Epoll files pos: 0 flags: 02 mnt_id: 9 + ino: 63107 tfd: 5 events: 1d data: ffffffffffffffff pos:0 ino:61af sdev:7 where 'tfd' is a target file descriptor number in decimal form, @@ -1978,6 +1983,8 @@ For inotify files the format is the following:: pos: 0 flags: 02000000 + mnt_id: 9 + ino: 63107 inotify wd:3 ino:9e7e sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:7e9e0000640d1b6d where 'wd' is a watch descriptor in decimal form, i.e. a target file @@ -2000,6 +2007,7 @@ For fanotify files the format is:: pos: 0 flags: 02 mnt_id: 9 + ino: 63107 fanotify flags:10 event-flags:0 fanotify mnt_id:12 mflags:40 mask:38 ignored_mask:40000003 fanotify ino:4f969 sdev:800013 mflags:0 mask:3b ignored_mask:40000000 fhandle-bytes:8 fhandle-type:1 f_handle:69f90400c275b5b4 @@ -2024,6 +2032,7 @@ Timerfd files pos: 0 flags: 02 mnt_id: 9 + ino: 63107 clockid: 0 ticks: 0 settime flags: 01 @@ -2038,6 +2047,22 @@ details]. 'it_value' is remaining time until the timer expiration. with TIMER_ABSTIME option which will be shown in 'settime flags', but 'it_value' still exhibits timer's remaining time. +DMA Buffer files +~~~~~~~~~~~~~~~~ + +:: + + pos: 0 + flags: 04002 + mnt_id: 9 + ino: 63107 + size: 32768 + count: 2 + exp_name: system-heap + +where 'size' is the size of the DMA buffer in bytes. 'count' is the file count of +the DMA buffer file. 'exp_name' is the name of the DMA buffer exporter. + 3.9 /proc//map_files - Information about memory mapped files --------------------------------------------------------------------- This directory contains symbolic links which represent memory mapped files diff --git a/fs/proc/fd.c b/fs/proc/fd.c index 6a80b40fd2fe..172c86270b31 100644 --- a/fs/proc/fd.c +++ b/fs/proc/fd.c @@ -54,9 +54,10 @@ static int seq_show(struct seq_file *m, void *v) if (ret) return ret; - seq_printf(m, "pos:\t%lli\nflags:\t0%o\nmnt_id:\t%i\n", + seq_printf(m, "pos:\t%lli\nflags:\t0%o\nmnt_id:\t%i\nino:\t%lu\n", (long long)file->f_pos, f_flags, - real_mount(file->f_path.mnt)->mnt_id); + real_mount(file->f_path.mnt)->mnt_id, + file_inode(file)->i_ino); /* show_fd_locks() never deferences files so a stale value is safe */ show_fd_locks(m, file, files);