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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A2254CD98F8 for ; Fri, 19 Jun 2026 08:37:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Cc:To:In-Reply-To:References :Message-Id:Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date: From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=jbUuCX3vx9aLYGBX988mlwiGk5Wln7VCA85d3B3BDv0=; b=OmsrzPman8CJDVHO2nw1RrDVQT kL8AM77gr4nf9bsUrGgnAIoa7PCMh5avoKntJ397IW1fffxv5pbJEtTQlqdwsOP+cC675KrPmMK+a nuMAreiufUVyWw1cthdKKaxg7YUHEgkM8Iut1zV8MdU/We0+1M0WL4xJsi/LIxJAi8HIJ4nGMHsBf GpxmX1ISlRRSo5uOAz7gmpghjPxkqLJsllVgusQcmLTNCeH/8iLsFFIdLMwzYSs9418cn7qZkjpUD Oxm/lGphOYGTCpYlX3MzogNLSCCHMb6zNNFZeHWkD6/0vtqeRzz9YXNoeOb4n76/cfho81tTEMWmk SABwaYBg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1waUit-00000002Ab2-0wjM; Fri, 19 Jun 2026 08:37:11 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1waUis-00000002AaC-1rM8 for linux-nvme@lists.infradead.org; Fri, 19 Jun 2026 08:37:10 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id DCF5F601F3; Fri, 19 Jun 2026 08:37:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 26ABD1F00A3D; Fri, 19 Jun 2026 08:37:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781858229; bh=jbUuCX3vx9aLYGBX988mlwiGk5Wln7VCA85d3B3BDv0=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=LdYL9o7PUfBJgqpLUvabvIn8e1uS0Wi4qxLsFzreV0SljqTPwrBl7CfNC8XjN576b xrIm+AqQIffdOVmr3JXo4+1P+FHy/hM2BzFmrJulgkmZD/IbGy4tW6otsGiDbZNDs5 F3v5HxK2FM9RJXQFtHilZQpuh8xNygSP0k6JRQjL/OiK2lLrYlmISBBC0AaX68AnXY 20wEJnPmPAxms9jIxtwfVVXxz1sA1F+uaIbHyrtd3U9pFlRET2yfQi/jzmwtD8Ul9T Sp6CKpPAFk1dcEfGI2OZOK8UoIf8xmCE2I+Hyl5NvcbyV7miRRjBXdvCsNxYplXW0j akqzvHGf6ezxQ== From: Hannes Reinecke Date: Fri, 19 Jun 2026 10:36:45 +0200 Subject: [PATCH RFC v2 05/12] fs/configfs: add 'fill_subsystem' and 'clear_subsystem' callbacks MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260619-configfs-ns-v2-5-82fd7094b8dc@kernel.org> References: <20260619-configfs-ns-v2-0-82fd7094b8dc@kernel.org> In-Reply-To: <20260619-configfs-ns-v2-0-82fd7094b8dc@kernel.org> To: Andreas Hindborg , Breno Leitao , Alexander Viro , Christian Brauner , Jan Kara , Christoph Hellwig , Sagi Grimberg , Chaitanya Kulkarni Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nvme@lists.infradead.org, Hannes Reinecke X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1781858211; l=6940; i=hare@kernel.org; s=20260619; h=from:subject:message-id; bh=b0JLZ6RASLDI+YIWaCBzx3Uelur6q/zuN25Ek3VaKn4=; b=TG4JLWpL1thcAmUkgEmD8d2P8v9mRqXmfImmO08BUimzqyTdWMXgdOPs63pAejfF8pet96OfO QjO1Ug39zyrDngFahxGJCRfzILX9BPUVxNRghlI/iS323RIDmrEyhTy X-Developer-Key: i=hare@kernel.org; a=ed25519; pk=iekPF4ZZFva3sutm7d1ryPNR1G/WFfUgHaDB423JXho= X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org When creating a new per-namespace filesystem static initialisation doesn't work, so implement a 'fill_subsystem' and 'clear_subsystem' callbacks to 'struct configfs_subsystem' to allow for every driver to populate the subsystem structure dynamicall. Signed-off-by: Hannes Reinecke --- fs/configfs/configfs_internal.h | 4 ++ fs/configfs/dir.c | 101 +++++++++++++++++++++++++++++++++++++++- fs/configfs/mount.c | 4 ++ include/linux/configfs.h | 5 ++ 4 files changed, 113 insertions(+), 1 deletion(-) diff --git a/fs/configfs/configfs_internal.h b/fs/configfs/configfs_internal.h index a4f10dd8ce0f46873d2053860a9fd25f3ee4c809..35eddc274b88796442c080fe4fe8a6ea68762185 100644 --- a/fs/configfs/configfs_internal.h +++ b/fs/configfs/configfs_internal.h @@ -94,6 +94,10 @@ extern struct dentry *configfs_pin_fs(struct super_block *sb); extern void configfs_release_fs(struct super_block *sb); extern struct configfs_super_info *configfs_get_super_info(struct net *net_ns); extern void configfs_put_super_info(struct configfs_super_info *info); +extern void configfs_link_subsystems(struct super_block *sb, + struct configfs_super_info *info); +extern void configfs_unlink_subsystems(struct super_block *sb, + struct configfs_super_info *info); extern const struct file_operations configfs_dir_operations; extern const struct file_operations configfs_file_operations; diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c index 9b3738f58ccb891a8269708f0e875b0a75c1ab8e..891238ef0088a98467d6d63a10d633a40fc19c8b 100644 --- a/fs/configfs/dir.c +++ b/fs/configfs/dir.c @@ -1931,15 +1931,92 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys) goto out_put; } + if (subsys->fill_subsystem) { + INIT_LIST_HEAD(&subsys->su_link); + mutex_init(&subsys->su_mutex); + config_group_init(&subsys->su_group); + err = subsys->fill_subsystem(subsys, info->ns_id); + if (err) + goto out_release; + } + err = configfs_link_root(info, subsys, root); + if (err) { + if (subsys->clear_subsystem) + subsys->clear_subsystem(subsys, info->ns_id); + goto out_release; + } + + mutex_lock(&info->subsys_mutex); + list_add(&subsys->su_link, &info->subsys_list); + mutex_unlock(&info->subsys_mutex); + +out_release: if (err) configfs_release_fs(NULL); - out_put: configfs_put_super_info(info); return err; } +void configfs_link_subsystems(struct super_block *sb, + struct configfs_super_info *info) +{ + struct configfs_subsystem *s; + struct configfs_super_info *parent = configfs_get_super_info(0); + LIST_HEAD(subsys_list); + + if (WARN_ON(IS_ERR(parent))) + return; + if ((info->ns_id == 0) || WARN_ON(parent == info)) + return; + mutex_lock(&parent->subsys_mutex); + list_splice_init(&parent->subsys_list, &subsys_list); + mutex_unlock(&parent->subsys_mutex); + list_for_each_entry(s, &subsys_list, su_link) { + struct configfs_subsystem *subsys; + struct dentry *root; + int err; + + if (!s->fill_subsystem) + continue; + subsys = kzalloc_obj(*subsys); + if (!subsys) + continue; + subsys->fill_subsystem = s->fill_subsystem; + subsys->clear_subsystem = s->clear_subsystem; + INIT_LIST_HEAD(&subsys->su_link); + mutex_init(&subsys->su_mutex); + err = subsys->fill_subsystem(subsys, info->ns_id); + if (err) { + kfree(subsys); + continue; + } + root = configfs_pin_fs(sb); + if (IS_ERR(root)) { + if (subsys->clear_subsystem) + subsys->clear_subsystem(subsys, info->ns_id); + kfree(subsys); + continue; + } + err = configfs_link_root(info, subsys, root); + if (err) { + configfs_release_fs(sb); + if (subsys->clear_subsystem) + subsys->clear_subsystem(subsys, info->ns_id); + kfree(subsys); + continue; + } + mutex_lock(&info->subsys_mutex); + list_add(&subsys->su_link, &info->subsys_list); + mutex_unlock(&info->subsys_mutex); + } + mutex_lock(&parent->subsys_mutex); + list_splice(&subsys_list, &parent->subsys_list); + mutex_unlock(&parent->subsys_mutex); + configfs_put_super_info(parent); +} + static bool configfs_unlink_root(struct configfs_subsystem *subsys) { struct config_group *group = &subsys->su_group; @@ -1982,6 +2059,25 @@ static bool configfs_unlink_root(struct configfs_subsystem *subsys) return true; } +void configfs_unlink_subsystems(struct super_block *sb, + struct configfs_super_info *info) +{ + struct configfs_subsystem *subsys, *s; + + mutex_lock(&info->subsys_mutex); + list_for_each_entry_safe(subsys, s, &info->subsys_list, su_link) { + list_del_init(&subsys->su_link); + if (!configfs_unlink_root(subsys)) + continue; + if (subsys->clear_subsystem) + subsys->clear_subsystem(subsys, info->ns_id); + unlink_group(&subsys->su_group); + configfs_release_fs(sb); + kfree(subsys); + } + mutex_unlock(&info->subsys_mutex); +} + void configfs_unregister_subsystem(struct configfs_subsystem *subsys) { struct configfs_super_info *info = configfs_get_super_info(0); @@ -1994,6 +2090,9 @@ void configfs_unregister_subsystem(struct configfs_subsystem *subsys) return; mutex_lock(&info->subsys_mutex); + list_del_init(&subsys->su_link); + if (subsys->clear_subsystem) + subsys->clear_subsystem(subsys, info->ns_id); unlink_group(group); mutex_unlock(&info->subsys_mutex); configfs_release_fs(NULL); diff --git a/fs/configfs/mount.c b/fs/configfs/mount.c index 8b26ceb7b0d4a03a17c251de42902aaabef5a652..d36fc4a6f6439bea645e62b8423b518a5d7d51c1 100644 --- a/fs/configfs/mount.c +++ b/fs/configfs/mount.c @@ -157,6 +157,9 @@ static int configfs_fill_super(struct super_block *sb, struct fs_context *fc) sb->s_root = root; set_default_d_op(sb, &configfs_dentry_ops); /* the rest get that */ sb->s_d_flags |= DCACHE_DONTCACHE; + + configfs_link_subsystems(sb, info); + return 0; } @@ -179,6 +182,7 @@ static void configfs_kill_sb(struct super_block *sb) { struct configfs_super_info *info = sb->s_fs_info; + configfs_unlink_subsystems(sb, info); kill_anon_super(sb); configfs_put_super_info(info); sb->s_fs_info = NULL; diff --git a/include/linux/configfs.h b/include/linux/configfs.h index 19165e36da810c75500bb584702ae3a594c3510d..c1cdadba0a48f0abea30da5ee324807b9ac4ff8f 100644 --- a/include/linux/configfs.h +++ b/include/linux/configfs.h @@ -227,8 +227,13 @@ struct configfs_group_operations { }; struct configfs_subsystem { + struct list_head su_link; struct config_group su_group; struct mutex su_mutex; + int (*fill_subsystem)(struct configfs_subsystem *subsys, + u64 ns_id); + void (*clear_subsystem)(struct configfs_subsystem *subsys, + u64 ns_id); }; static inline struct configfs_subsystem *to_configfs_subsystem(struct config_group *group) -- 2.51.0