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=-10.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 82132C433E0 for ; Fri, 3 Jul 2020 06:54:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5160420771 for ; Fri, 3 Jul 2020 06:54:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="sCLm88+v" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726106AbgGCGy3 (ORCPT ); Fri, 3 Jul 2020 02:54:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725648AbgGCGy3 (ORCPT ); Fri, 3 Jul 2020 02:54:29 -0400 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2381AC08C5C1 for ; Thu, 2 Jul 2020 23:54:29 -0700 (PDT) Received: by mail-pj1-x1044.google.com with SMTP id b92so13598897pjc.4 for ; Thu, 02 Jul 2020 23:54:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=wrm96WwHAY7NcmiKOn3dljT8L1OhqnpuLxqvg48PumA=; b=sCLm88+vkuRQY6ys7VFVSVrDtAebX7oYvKYStBKqLq8LA5KxvoGDVYpPxCe6DAM2KK gVkbR/39VlRkxGe3FM2wbraa2c9DL3PhOF7wK4yJO8HLUX/Zd+la/1ZR9WDjfbF/r8nY KSiV6Sb2Aed1W4EdtxNjwhQrpgU6JNuUIOJ7pgpNrTO4LJG/XdlER0j4Bamrrqq80R9B S4rIwSUXSDqRheVC3LNh7h4qlZlqOmA7PejkOLL0DBvunpvdPOawNJD0QnT/Ai7h/ErG vOBBU5fnZMFJbeG683ybX6Rr8ewBx6FjQPc4AgCAWzShkoINhWPM8QfB7I05KoHY+Jek H4Rg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=wrm96WwHAY7NcmiKOn3dljT8L1OhqnpuLxqvg48PumA=; b=Yz1b1ttDcPu9MWwwCVbxnyYJU/K3c54EBGQ3+hDRscb735bsJjQPJ9u0loqFhH5R9Y V21j2J1XjxJ6rvLDwuCDDjMkckBsLLjUtuB97ap3pXQQSd/0CJMjX6kRz7DZwHdHehGT 5/z6J2R3pOvEUQQEd6ZZdPqc7MZL5eiuThp9iCs55GBs9D9FNo3Ba9Kz3VaOwoi1IHhe dpxnbqLPeaIU71qanRBPcr/5DVNSQuHXGcgCXZk6eIedZairb7kqKWPz+1NW+ZA8eYOp hXtbfnBeEQ1dv1KfJdbYsctTXOeOHV01ti5HZI6+rrwKPpZTgfoZn3QM2f5Evfig8A1O Gf4Q== X-Gm-Message-State: AOAM5327yml0Y0mpxop2LC5nuzY+VO25iOfJcN+tjowc140vetuKLrUP MQFJP+kLKMlu3Zxf0bnhML4prVvA4XU= X-Google-Smtp-Source: ABdhPJzaaweCWAO9H20DaJW4o6GMcuLpt1uhD39YL08FGVQMNekiW2THDFuGNU+a2KJ8950pygM/pw== X-Received: by 2002:a17:902:8a85:: with SMTP id p5mr2277820plo.308.1593759268136; Thu, 02 Jul 2020 23:54:28 -0700 (PDT) Received: from daehojeong1.seo.corp.google.com ([2401:fa00:d:1:a6ae:11ff:fe18:6ce2]) by smtp.gmail.com with ESMTPSA id s188sm10295612pfb.118.2020.07.02.23.54.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Jul 2020 23:54:27 -0700 (PDT) From: Daeho Jeong To: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com Cc: Daeho Jeong Subject: [PATCH v3] f2fs: add symbolic link to kobject in sysfs Date: Fri, 3 Jul 2020 15:54:20 +0900 Message-Id: <20200703065420.3544269-1-daeho43@gmail.com> X-Mailer: git-send-email 2.27.0.383.g050319c2ae-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Daeho Jeong Added a symbolic link to directory of sysfs. It will create a symbolic link such as "mount_0" and "mount_1" to each f2fs mount in the order of mounting filesystem. But once one mount point was umounted, that sequential number @x in "mount_@x" could be reused by later newly mounted point. It will provide easy access to sysfs node even if not knowing the specific device node name like sda19 and dm-3. Signed-off-by: Daeho Jeong --- Documentation/filesystems/f2fs.rst | 13 ++++++++++++- fs/f2fs/f2fs.h | 4 ++++ fs/f2fs/sysfs.c | 31 ++++++++++++++++++++++++++---- 3 files changed, 43 insertions(+), 5 deletions(-) diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst index 535021c46260..916956d433b2 100644 --- a/Documentation/filesystems/f2fs.rst +++ b/Documentation/filesystems/f2fs.rst @@ -279,7 +279,18 @@ Sysfs Entries Information about mounted f2fs file systems can be found in /sys/fs/f2fs. Each mounted filesystem will have a directory in -/sys/fs/f2fs based on its device name (i.e., /sys/fs/f2fs/sda). +/sys/fs/f2fs based on its device name (i.e., /sys/fs/f2fs/sda), +or mount_#x (#x is the number representing the order of mounting). +But once one mount point was umounted, that sequential number @x +in "mount_@x" could be reused by later newly mounted point. + +Here is an example of this. + +mount dev0 mount0 (mount_0 -> dev0) +mount dev1 mount1 (mount_1 -> dev1) +umount mount0 +mount dev2 (mount_0 -> dev2) + The files in each per-device directory are shown in table below. Files in /sys/fs/f2fs/ diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 4b28fd42fdbc..7d6c5f8ce16b 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1419,6 +1419,8 @@ struct decompress_io_ctx { #define MAX_COMPRESS_LOG_SIZE 8 #define MAX_COMPRESS_WINDOW_SIZE ((PAGE_SIZE) << MAX_COMPRESS_LOG_SIZE) +#define MOUNT_NAME_SIZE 20 + struct f2fs_sb_info { struct super_block *sb; /* pointer to VFS super block */ struct proc_dir_entry *s_proc; /* proc entry */ @@ -1599,6 +1601,8 @@ struct f2fs_sb_info { /* For sysfs suppport */ struct kobject s_kobj; struct completion s_kobj_unregister; + int s_mount_id; + char s_mount_name[MOUNT_NAME_SIZE]; /* For shrinker support */ struct list_head s_list; diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c index 2a140657fc4d..703d9f460d03 100644 --- a/fs/f2fs/sysfs.c +++ b/fs/f2fs/sysfs.c @@ -18,6 +18,7 @@ #include static struct proc_dir_entry *f2fs_proc_root; +static struct ida f2fs_mount_ida; /* Sysfs support for f2fs */ enum { @@ -908,6 +909,9 @@ int __init f2fs_init_sysfs(void) } else { f2fs_proc_root = proc_mkdir("fs/f2fs", NULL); } + + ida_init(&f2fs_mount_ida); + return ret; } @@ -917,6 +921,7 @@ void f2fs_exit_sysfs(void) kset_unregister(&f2fs_kset); remove_proc_entry("fs/f2fs", NULL); f2fs_proc_root = NULL; + ida_destroy(&f2fs_mount_ida); } int f2fs_register_sysfs(struct f2fs_sb_info *sbi) @@ -928,12 +933,22 @@ int f2fs_register_sysfs(struct f2fs_sb_info *sbi) init_completion(&sbi->s_kobj_unregister); err = kobject_init_and_add(&sbi->s_kobj, &f2fs_sb_ktype, NULL, "%s", sb->s_id); - if (err) { - kobject_put(&sbi->s_kobj); - wait_for_completion(&sbi->s_kobj_unregister); - return err; + if (err) + goto err1; + + sbi->s_mount_id = ida_simple_get(&f2fs_mount_ida, 0, 0, GFP_KERNEL); + if (sbi->s_mount_id < 0) { + err = sbi->s_mount_id; + goto err1; } + snprintf(sbi->s_mount_name, MOUNT_NAME_SIZE, "mount_%d", + sbi->s_mount_id); + err = sysfs_create_link(&f2fs_kset.kobj, &sbi->s_kobj, + sbi->s_mount_name); + if (err) + goto err2; + if (f2fs_proc_root) sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root); @@ -948,6 +963,12 @@ int f2fs_register_sysfs(struct f2fs_sb_info *sbi) victim_bits_seq_show, sb); } return 0; +err2: + ida_simple_remove(&f2fs_mount_ida, sbi->s_mount_id); +err1: + kobject_put(&sbi->s_kobj); + wait_for_completion(&sbi->s_kobj_unregister); + return err; } void f2fs_unregister_sysfs(struct f2fs_sb_info *sbi) @@ -959,6 +980,8 @@ void f2fs_unregister_sysfs(struct f2fs_sb_info *sbi) remove_proc_entry("victim_bits", sbi->s_proc); remove_proc_entry(sbi->sb->s_id, f2fs_proc_root); } + sysfs_remove_link(&f2fs_kset.kobj, sbi->s_mount_name); + ida_simple_remove(&f2fs_mount_ida, sbi->s_mount_id); kobject_del(&sbi->s_kobj); kobject_put(&sbi->s_kobj); } -- 2.27.0.383.g050319c2ae-goog