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 A217434402B; Tue, 11 Nov 2025 06:55:27 +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=1762844132; cv=none; b=doYmHcOaxT2InUQG0sjqhMCrSskfRgf3nUYXlGljSvjDOrw17j6qoIiCb69I5EeAmgz32MIr8WjdhXD2URczRHOQluKQhf4bv0RZJVdc9d6zJzs1b3zoSvD1MPwV4s0Md+GV3/4bOMZWR8rnMIcv3BTBMp9BdjQgivxXII1P5gU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762844132; c=relaxed/simple; bh=jGXLbtBoU52kB5fq2se2ip0WlsiUE6GUM8W8byZni/8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=px/SPc6Jqb556BYShkwCPl84q32GUQq9i1G2S4GPvs1E8YgVKZVUOKo+5CRhjB4+LQqXKMQ2ECyWMY3lYF861CnoMjbHD57WKnjjDlDLLpSdfde2ykKg5vbKnSxfGuz7dO9xpAR2ZOTUMDWHgE+szf1wtQrdo5i104/KtCe6+go= 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=HiKTZzZ/; 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="HiKTZzZ/" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=XM4FZa0do0+xkZhNaAyLfkF8FdfO7rZo+6nC0ji7Cc4=; b=HiKTZzZ/q4UOe5+JDM6CDFXNw+ HyDR5VqKNtpjR2amfKboMkRHLZr4PaGe7CCAYJP+76LUWUXz8vpbtEKAIPStBmmhP8Sjxzs+thRRb rJWYPOUAtvnPrutA0+F0/TY1GdkWOThpY2oCwiyCD0KsJ/zHRyjJ4bPea0L/z8x5fffm3GVWTUX/F C1klgokjca5tCzuxZN45ZPaBHqDRnIqHcrhKNk50YL8SEnnGxVsxtfM/mF0CaVVxuNE6g5P/XIX9V OIeVgxtX/90DlBBBiZxd8xJJxrKK6b8c92oeeg8BBKwc8nngThjXp3MfbnCwxU5TS6sArZUNYqKB0 MGm2kVNA==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vIiHj-0000000BwyW-3XSb; Tue, 11 Nov 2025 06:55:23 +0000 From: Al Viro To: linux-fsdevel@vger.kernel.org Cc: torvalds@linux-foundation.org, brauner@kernel.org, jack@suse.cz, raven@themaw.net, miklos@szeredi.hu, neil@brown.name, 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, paul@paul-moore.com, casey@schaufler-ca.com, linuxppc-dev@lists.ozlabs.org, john.johansen@canonical.com, selinux@vger.kernel.org, borntraeger@linux.ibm.com, bpf@vger.kernel.org Subject: [PATCH v3 17/50] convert fuse_ctl Date: Tue, 11 Nov 2025 06:54:46 +0000 Message-ID: <20251111065520.2847791-18-viro@zeniv.linux.org.uk> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20251111065520.2847791-1-viro@zeniv.linux.org.uk> References: <20251111065520.2847791-1-viro@zeniv.linux.org.uk> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: Al Viro objects are created in fuse_ctl_add_dentry() by d_alloc_name()+d_add(), removed by simple_remove_by_name(). What we return is a borrowed reference - it is valid until the call of fuse_ctl_remove_conn() and we depend upon the exclusion (on fuse_mutex) for safety. Return value is used only within the caller (fuse_ctl_add_conn()). Replace d_add() with d_make_persistent() + dput(). dput() is paired with d_alloc_name() and return value is the result of d_make_persistent(). Signed-off-by: Al Viro --- fs/fuse/control.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/fs/fuse/control.c b/fs/fuse/control.c index 3dca752127ff..140bd5730d99 100644 --- a/fs/fuse/control.c +++ b/fs/fuse/control.c @@ -236,8 +236,14 @@ static struct dentry *fuse_ctl_add_dentry(struct dentry *parent, inc_nlink(inode); } inode->i_private = fc; - d_add(dentry, inode); - + d_make_persistent(dentry, inode); + dput(dentry); + + /* + * We are returning a borrowed reference here - it's only good while + * fuse_mutex is held. Actually it's d_make_persistent() return + * value... + */ return dentry; } @@ -346,7 +352,7 @@ static void fuse_ctl_kill_sb(struct super_block *sb) fuse_control_sb = NULL; mutex_unlock(&fuse_mutex); - kill_litter_super(sb); + kill_anon_super(sb); } static struct file_system_type fuse_ctl_fs_type = { -- 2.47.3