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=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 19C90C4708F for ; Fri, 4 Jun 2021 04:41:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F030861090 for ; Fri, 4 Jun 2021 04:41:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229921AbhFDEnY (ORCPT ); Fri, 4 Jun 2021 00:43:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:33226 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229882AbhFDEnY (ORCPT ); Fri, 4 Jun 2021 00:43:24 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 55D30613D8; Fri, 4 Jun 2021 04:41:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622781698; bh=EA8m/h6ZeO+GWthj96A3zUYlh51ysfiRNwAyTmIX7l8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=P7sqf64bVucUL2q7sGo9fbSOqUKogUkgrcoggDWwuEAgaIAtV/xR9NZL0XjbVZdru d0Yx1yIDNuKqxKvLuBUDC5lH9moaVfyG2K4IP3Gq3foPA5LbFAB4k7sgJmLRnoRa3m yEQYKtDYCNAr6tok/i6l0BdB/vzRONugSOhEnfEk/QIB/jjW3whSFMxrBksJsu2mUi k7LMgriMrize7VxYh/BpaG+WLdNzdtn60yry1wnMOJRUMMdAmKJqxnc9DwCD20cBr0 JLjMO3EGoGps7kjXD3u1MCe7WDrSPK8HgH70XGwHhPs30478EiO3Fw1BGQa4rmJ5DI /A9SnJWI13Rhw== Date: Thu, 3 Jun 2021 21:41:36 -0700 From: Jaegeuk Kim To: Eric Biggers Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [f2fs-dev] [PATCH] f2fs: clean up /sys/fs/f2fs//features Message-ID: References: <20210603220834.1949988-1-jaegeuk@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/03, Eric Biggers wrote: > On Thu, Jun 03, 2021 at 03:08:34PM -0700, Jaegeuk Kim wrote: > > Let's create /sys/fs/f2fs//feature_list/ to meet sysfs rule. > > > > Signed-off-by: Jaegeuk Kim > > --- > > Documentation/ABI/testing/sysfs-fs-f2fs | 18 ++- > > fs/f2fs/f2fs.h | 3 + > > fs/f2fs/sysfs.c | 152 +++++++++++++++++++++++- > > 3 files changed, 168 insertions(+), 5 deletions(-) > > > > diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs > > index 5088281e312e..43b2cde80b70 100644 > > --- a/Documentation/ABI/testing/sysfs-fs-f2fs > > +++ b/Documentation/ABI/testing/sysfs-fs-f2fs > > @@ -203,7 +203,23 @@ Description: Shows total written kbytes issued to disk. > > What: /sys/fs/f2fs//features > > Date: July 2017 > > Contact: "Jaegeuk Kim" > > -Description: Shows all enabled features in current device. > > +Description: /feature_list/ > > + Shows all enabled features in current device. > > + Supported features: > > + encryption, blkzoned, extra_attr, projquota, inode_checksum, > > + flexible_inline_xattr, quota_ino, inode_crtime, lost_found, > > + verity, sb_checksum, casefold, readonly, compression, > > + encrypted_casefold, pin_file. > > Isn't pin_file a feature of the implementation, not of a particular filesystem > instance? I.e. something that should go in /sys/fs/f2fs/features/, not here. Done. > > Likewise for encrypted_casefold, as it is implied by encryption && casefold. I think encrypted_casefold needs to be in both places: 1) kernel support by kconfig, 2) on-disk support by feature support. > > > + > > +What: /sys/fs/f2fs//feature_list/ > > +Date: June 2021 > > +Contact: "Jaegeuk Kim" > > +Description: Expand /sys/fs/f2fs//features to meet sysfs rule. > > + Supported features: > > + encryption, block_zoned, extra_attr, projquota, inode_checksum, > > + flexible_inline_xattr, quota_ino, inode_crtime, lost_found, > > + verity, sb_checksum, casefold, readonly, compression, > > + encrypted_casefold, pin_file. > > Is it intentional that the file has "blkzoned" but the directory has > "blk_zoned"? I tried to sync this with /sys/fs/f2fs/features/block_zoned. Let me add a comment in the doc. > > Also, your code has another difference -- "project_quota" is used instead of > "projquota". But that's not mentioned above. Ditto. > > And encrypted_casefold and pin_file don't seem appropriate to include here, as > mentioned above. Done. > > > @@ -1665,6 +1665,9 @@ struct f2fs_sb_info { > > struct kobject s_stat_kobj; /* /sys/fs/f2fs//stat */ > > struct completion s_stat_kobj_unregister; > > > > + struct kobject s_disk_feat_kobj; /* /sys/fs/f2fs//feature_list */ > > + struct completion s_disk_feat_kobj_unregister; > > This is for a particular filesystem instance, not a disk per se. (A f2fs > filesystem can use multiple disks.) So having "disk" in the name doesn't make > sense. > > Please use more logical names like s_feature_list_kobj, > f2fs_sb_feature_list_ktype, f2fs_sb_feat_attrs, etc. Done. > > > static ssize_t f2fs_feature_show(struct f2fs_attr *a, > > struct f2fs_sb_info *sbi, char *buf) > > { > > + unsigned long feat_supp = 0; > > + > > switch (a->id) { > > case FEAT_CRYPTO: > > + feat_supp |= f2fs_sb_has_encrypt(sbi) ? > > + (1 << FEAT_CRYPTO) : 0; > > + fallthrough; > > case FEAT_BLKZONED: > > - case FEAT_ATOMIC_WRITE: > > + feat_supp |= f2fs_sb_has_blkzoned(sbi) ? > > + (1 << FEAT_BLKZONED) : 0; > > + fallthrough; > > case FEAT_EXTRA_ATTR: > > + feat_supp |= f2fs_sb_has_extra_attr(sbi) ? > > + (1 << FEAT_EXTRA_ATTR) : 0; > > + fallthrough; > > case FEAT_PROJECT_QUOTA: > > + feat_supp |= f2fs_sb_has_project_quota(sbi) ? > > + (1 << FEAT_PROJECT_QUOTA) : 0; > > + fallthrough; > > case FEAT_INODE_CHECKSUM: > > + feat_supp |= f2fs_sb_has_inode_chksum(sbi) ? > > + (1 << FEAT_INODE_CHECKSUM) : 0; > > + fallthrough; > > case FEAT_FLEXIBLE_INLINE_XATTR: > > + feat_supp |= f2fs_sb_has_flexible_inline_xattr(sbi) ? > > + (1 << FEAT_FLEXIBLE_INLINE_XATTR) : 0; > > + fallthrough; > > case FEAT_QUOTA_INO: > > + feat_supp |= f2fs_sb_has_quota_ino(sbi) ? > > + (1 << FEAT_QUOTA_INO) : 0; > > + fallthrough; > > case FEAT_INODE_CRTIME: > > + feat_supp |= f2fs_sb_has_inode_crtime(sbi) ? > > + (1 << FEAT_INODE_CRTIME) : 0; > > + fallthrough; > > case FEAT_LOST_FOUND: > > + feat_supp |= f2fs_sb_has_lost_found(sbi) ? > > + (1 << FEAT_LOST_FOUND) : 0; > > + fallthrough; > > case FEAT_VERITY: > > + feat_supp |= f2fs_sb_has_verity(sbi) ? > > + (1 << FEAT_VERITY) : 0; > > + fallthrough; > > case FEAT_SB_CHECKSUM: > > + feat_supp |= f2fs_sb_has_sb_chksum(sbi) ? > > + (1 << FEAT_SB_CHECKSUM) : 0; > > + fallthrough; > > case FEAT_CASEFOLD: > > + feat_supp |= f2fs_sb_has_casefold(sbi) ? > > + (1 << FEAT_CASEFOLD) : 0; > > + fallthrough; > > case FEAT_COMPRESSION: > > + feat_supp |= f2fs_sb_has_compression(sbi) ? > > + (1 << FEAT_COMPRESSION) : 0; > > + fallthrough; > > case FEAT_RO: > > - case FEAT_TEST_DUMMY_ENCRYPTION_V2: > > + feat_supp |= f2fs_sb_has_readonly(sbi) ? > > + (1 << FEAT_RO) : 0; > > + fallthrough; > > case FEAT_ENCRYPTED_CASEFOLD: > > - return sprintf(buf, "supported\n"); > > + feat_supp |= (f2fs_sb_has_casefold(sbi) && > > + f2fs_sb_has_encrypt(sbi)) ? > > + (1 << FEAT_ENCRYPTED_CASEFOLD) : 0; > > + fallthrough; > > + case FEAT_PIN_FILE: > > + feat_supp |= (1 << FEAT_PIN_FILE); > > + fallthrough; > > + case FEAT_TEST_DUMMY_ENCRYPTION_V2: > > + case FEAT_ATOMIC_WRITE: > > + if (!a->offset || feat_supp & (1 << a->id)) > > + return sprintf(buf, "supported\n"); > > } > > - return 0; > > + return sprintf(buf, "not supported\n"); > > } > > This function doesn't make much sense. > > Part of the problem is that the same function is handling both > /sys/fs/f2fs/features/ and /sys/fs/f2fs/$s_id/feature_list/. > > All the former needs is to print "supported", since unsupported is indicated by > the file not being there at all. So it should simply have its own ->show > function separate from the one for feature_list/. > > And the feature_list/ ones could just store the F2FS_FEATURE_* bit in > f2fs_attr::id and check for it using F2FS_HAS_FEATURE(). That would be much > simpler -- no need for the feat_id enum or the long switch statement. > > Also for feature_list/ it might be better to use "unsupported" than > "not supported", so that \ doesn't match... Done. > > > static struct f2fs_attr f2fs_attr_##_name = { \ > > .attr = {.name = __stringify(_name), .mode = 0444 }, \ > > .show = f2fs_feature_show, \ > > + .offset = 0, \ > > .id = _id, \ > > } > > There's no need to use the .offset argument if features/ and $s_id/feature_list/ > just used different ->show functions. > > > +#define F2FS_DISK_FEATURE_RO_ATTR(_name, _id) \ > > F2FS_SB_FEATURE_ATTR would be a much better name, since these pertain to a > filesystem instance (not necessarily a disk), and all the feature attributes are > read-only. Used F2FS_SB_FEATURE_RO_ATTR. > > > static int __maybe_unused segment_info_seq_show(struct seq_file *seq, > > void *offset) > > { > > @@ -1149,6 +1279,15 @@ int f2fs_register_sysfs(struct f2fs_sb_info *sbi) > > if (err) > > goto put_stat_kobj; > > > > + sbi->s_disk_feat_kobj.kset = &f2fs_kset; > > + init_completion(&sbi->s_disk_feat_kobj_unregister); > > + err = kobject_init_and_add(&sbi->s_disk_feat_kobj, > > + &f2fs_disk_feat_ktype, > > + &sbi->s_kobj, "feature_list"); > > + if (err) > > + goto put_stat_kobj; > > + > > + > > if (f2fs_proc_root) > > sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root); > > > > @@ -1166,6 +1305,8 @@ int f2fs_register_sysfs(struct f2fs_sb_info *sbi) > > put_stat_kobj: > > kobject_put(&sbi->s_stat_kobj); > > wait_for_completion(&sbi->s_stat_kobj_unregister); > > + kobject_put(&sbi->s_disk_feat_kobj); > > + wait_for_completion(&sbi->s_disk_feat_kobj_unregister); > > It seems this should go to its own label. > > Also, please note that it's very easy to get confused between > /sys/fs/f2fs/features/, /sys/fs/f2fs/$s_id/features, and > /sys/fs/f2fs/$s_id/feature_list/. Adding some comments could clarify things a > lot. Done. > > - Eric