From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [62.89.141.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4B52A248F47; Sun, 21 Sep 2025 22:26:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.89.141.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758493587; cv=none; b=EdMkwmdZuH2aujFHy4cYr9I/gzqeA99AXEZ6WsIiFsDv2ZSWX7JBOBIa05ZxKCmKFfUIYgoaKjqh1tPauQdgJH9fHdrRAn5VjREaa41AeSadaVjZnWIBSqFN1F/7pDpbynKYqEeNAmBFzlcg97uBhbyS1jQE3cM24sbD4tO2b2s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758493587; c=relaxed/simple; bh=Ao7FRcIHDja1QeoCgIQG3DXJaBHIl03/IoyecYtegWA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cKP7jQ7RR+McKcBtosHxYAKxZSblP7steKk6Nv2BO/mHYzP1QM9jmkB0KnlkGqzLvpe/PZmlRxXR2M0daBaPGVbOdJTvDzzQmPd0DlNxjyoeHZE/eemxDMh1jfkC7/eVVyEZA2hpHFXAVyZyIpwqupfFBdgVJyHqmXbjXEd0HUQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk; spf=none smtp.mailfrom=ftp.linux.org.uk; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b=usSSiHDQ; arc=none smtp.client-ip=62.89.141.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=ftp.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b="usSSiHDQ" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description; bh=vlILJqwe+hl8iDH5chyH6rCDu8EauUbPjDhI89Nes6o=; b=usSSiHDQ2Qbq/moPc13PFOUsWD OZvJvj3RMtsst8Itt4LV6ByI/pzdDEGYN59hMSjI9D0WKjMpT8umQJlX0udr+u4Z6EjToaCR2MjnL JebpsLsLxysXhYvgIRefuiFMxaAfazcku591eCGxw6/Bs7jzvr5ECie8rG4QZaTP+dCdYplQgGebB YeDuAM/mp6sz+txh4iD92ykjvSJ0E6qNuH5HhVaoO7funuh+WDy1Dw1yHMep3uwkJGBdVEjnzoTwA wjFjO1cvVgjL6w9gvL00vzdQ4iPjYVLDWXrxzvViNv4wuO++/Zm/0MKeyjfWXJDfNuQ+w27Vk9XKP fM2DzG5w==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1v0SVf-00000003poQ-2RiS; Sun, 21 Sep 2025 22:26:19 +0000 Date: Sun, 21 Sep 2025 23:26:19 +0100 From: Al Viro To: Paul Moore Cc: linux-fsdevel@vger.kernel.org, torvalds@linux-foundation.org, brauner@kernel.org, jack@suse.cz, raven@themaw.net, miklos@szeredi.hu, a.hindborg@kernel.org, linux-mm@kvack.org, linux-efi@vger.kernel.org, ocfs2-devel@lists.linux.dev, kees@kernel.org, rostedt@goodmis.org, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, casey@schaufler-ca.com, linuxppc-dev@lists.ozlabs.org, borntraeger@linux.ibm.com Subject: Re: [PATCH 31/39] convert selinuxfs Message-ID: <20250921222619.GO39973@ZenIV> References: <20250920074156.GK39973@ZenIV> <20250920074759.3564072-1-viro@zeniv.linux.org.uk> <20250920074759.3564072-31-viro@zeniv.linux.org.uk> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: Al Viro On Sun, Sep 21, 2025 at 04:44:28PM -0400, Paul Moore wrote: > On Sat, Sep 20, 2025 at 3:48 AM Al Viro wrote: > > > > Tree has invariant part + two subtrees that get replaced upon each > > policy load. Invariant parts stay for the lifetime of filesystem, > > these two subdirs - from policy load to policy load (serialized > > on lock_rename(root, ...)). > > > > All object creations are via d_alloc_name()+d_add() inside selinuxfs, > > all removals are via simple_recursive_removal(). > > > > Turn those d_add() into d_make_persistent()+dput() and that's mostly it. > > Don't bother to store the dentry of /policy_capabilities - it belongs > > to invariant part of tree and we only use it to populate that directory, > > so there's no reason to keep it around afterwards. > > Minor comment on that below, as well as a comment style nitpick, but > overall no major concerns from me. FWIW, how's this for the preparatory part? commit 17f3b70a28233078dd3dae3cf773b68fcd899950 Author: Al Viro Date: Sun Sep 21 18:09:48 2025 -0400 selinuxfs: don't stash the dentry of /policy_capabilities Don't bother to store the dentry of /policy_capabilities - it belongs to invariant part of tree and we only use it to populate that directory, so there's no reason to keep it around afterwards. Same situation as with /avc, /ss, etc. There are two directories that get replaced on policy load - /class and /booleans. These we need to stash (and update the pointers on policy reload); /policy_capabilities is not in the same boat. Signed-off-by: Al Viro diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index 9aa1d03ab612..482a2cac9640 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -75,7 +75,6 @@ struct selinux_fs_info { struct dentry *class_dir; unsigned long last_class_ino; bool policy_opened; - struct dentry *policycap_dir; unsigned long last_ino; struct super_block *sb; }; @@ -117,7 +116,6 @@ static void selinux_fs_info_free(struct super_block *sb) #define BOOL_DIR_NAME "booleans" #define CLASS_DIR_NAME "class" -#define POLICYCAP_DIR_NAME "policy_capabilities" #define TMPBUFLEN 12 static ssize_t sel_read_enforce(struct file *filp, char __user *buf, @@ -1879,23 +1877,24 @@ static int sel_make_classes(struct selinux_policy *newpolicy, return rc; } -static int sel_make_policycap(struct selinux_fs_info *fsi) +static int sel_make_policycap(struct dentry *dir) { + struct super_block *sb = dir->d_sb; unsigned int iter; struct dentry *dentry = NULL; struct inode *inode = NULL; for (iter = 0; iter <= POLICYDB_CAP_MAX; iter++) { if (iter < ARRAY_SIZE(selinux_policycap_names)) - dentry = d_alloc_name(fsi->policycap_dir, + dentry = d_alloc_name(dir, selinux_policycap_names[iter]); else - dentry = d_alloc_name(fsi->policycap_dir, "unknown"); + dentry = d_alloc_name(dir, "unknown"); if (dentry == NULL) return -ENOMEM; - inode = sel_make_inode(fsi->sb, S_IFREG | 0444); + inode = sel_make_inode(sb, S_IFREG | 0444); if (inode == NULL) { dput(dentry); return -ENOMEM; @@ -2079,15 +2078,13 @@ static int sel_fill_super(struct super_block *sb, struct fs_context *fc) goto err; } - fsi->policycap_dir = sel_make_dir(sb->s_root, POLICYCAP_DIR_NAME, - &fsi->last_ino); - if (IS_ERR(fsi->policycap_dir)) { - ret = PTR_ERR(fsi->policycap_dir); - fsi->policycap_dir = NULL; + dentry = sel_make_dir(sb->s_root, "policy_capabilities", &fsi->last_ino); + if (IS_ERR(dentry)) { + ret = PTR_ERR(dentry); goto err; } - ret = sel_make_policycap(fsi); + ret = sel_make_policycap(dentry); if (ret) { pr_err("SELinux: failed to load policy capabilities\n"); goto err;