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 8A7522D837B for ; Wed, 3 Sep 2025 04:55:50 +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=1756875352; cv=none; b=qydHa/VOi3udyA75UwqBZOCyY/XuRc3IZJAU1RwHny0c0+UyEmEhECrv/fGeQ2lYs93TvDSbL6WlB/+X3J3ldQL/oPG8GAyKC2VXa/Tl+ygXxdEG6xpb1/YubdhfEO3vCe7n6PZS54MOR1ljrHtoT9tHpXghlTbPkR2yC8H0dzk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756875352; c=relaxed/simple; bh=FewYrgDSdQa2CbmZic8njTGOtCjeOs0M4QcJIk7Z0eg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Zc01DAR3DFbpOMXcMnBi7eUdcLfs/PFCchAHRYW5pIwm8MC1/IbiCTWGAfINtd6gt2PzZk/RfxXLfg++2nLdbKQBJ9rvYlDAZUhLMUV6blh9fOeHJkd0CUYoGviXTqVWl6YavkQ+ivwp3O4hB6pdQP4OW+jGtYDnVoYCNc4WeZY= 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=UyqEyfyo; 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="UyqEyfyo" 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=QItb5Ml6CFjhjPOZFdS8F9jBR12A3+kVWEwlb0Bt/Ts=; b=UyqEyfyoYG2e/t8H5U9ZQV9oVn LaOEG5qfEtMjbaSAY21Znkd6Uyjqm2McQM6tK22rSlX7dXssOIimkmQqTdh4lEzfnadEbVpWkLCJc G5Xdvb6Ipl+JmdplPvBwFs3DXscUMqtkpBjfJ4XX+kCyzAek5uUDUnQTvbv7UYyS1QFPIeF3Ne7PN kQSM550Chi2sf5ERNmNj65rqT/oxgTnxbbnzl00mX5rW/b4ag8BXdlYDMuus0G/9EH9Ja1zZcKSyz BiWQOJCj7OzGP8hrKvhDKSnox11+BfU1KVZeTUsrCeiRAadOjlRp43oaktS5xTckv/DyGue4dZjh+ 2gnEm8UQ==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1utfXA-0000000ApGO-3pj6; Wed, 03 Sep 2025 04:55:49 +0000 From: Al Viro To: linux-fsdevel@vger.kernel.org Cc: brauner@kernel.org, jack@suse.cz, torvalds@linux-foundation.org Subject: [PATCH v3 54/65] path_has_submounts(): use guard(mount_locked_reader) Date: Wed, 3 Sep 2025 05:55:17 +0100 Message-ID: <20250903045537.2579614-56-viro@zeniv.linux.org.uk> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250903045537.2579614-1-viro@zeniv.linux.org.uk> References: <20250903045432.GH39973@ZenIV> <20250903045537.2579614-1-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-Transfer-Encoding: 8bit Sender: Al Viro Needed there since the callback passed to d_walk() (path_check_mount()) is using __path_is_mountpoint(), which uses __lookup_mnt(). Has to be taken in the caller - d_walk() might take rename_lock spinlock component and that nests inside mount_lock. Signed-off-by: Al Viro --- fs/dcache.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/dcache.c b/fs/dcache.c index 60046ae23d51..ab21a8402db0 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1390,6 +1390,7 @@ struct check_mount { unsigned int mounted; }; +/* locks: mount_locked_reader && dentry->d_lock */ static enum d_walk_ret path_check_mount(void *data, struct dentry *dentry) { struct check_mount *info = data; @@ -1416,9 +1417,8 @@ int path_has_submounts(const struct path *parent) { struct check_mount data = { .mnt = parent->mnt, .mounted = 0 }; - read_seqlock_excl(&mount_lock); + guard(mount_locked_reader)(); d_walk(parent->dentry, &data, path_check_mount); - read_sequnlock_excl(&mount_lock); return data.mounted; } -- 2.47.2