From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DE757606A326 for ; Wed, 11 Nov 2026 21:17:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=jsbu+4am; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=B3k5bbEA 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-Unsubscribe-Post: List-Owner; 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Tue, 10 Nov 2026 09:16:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794302171; bh=48wS641dZNlMgTbgKHYJJRZjCIIpBYSCk6vN7nPVst0=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=B3k5bbEAWfpJtZp1vzeXux0KzrY0ieZxwUJi/83P+f7eKHCKBYc9mkYVfNK2b/51Z IE7odp0lQqQ7mwusK6pgB1WlHVkO/UlsckyLpTfE8Yp89sMOk+QjYT1he8sjTHJobl zbSxv5PQZ8XY+Ts/6iaugpn66hCj3rJCosVRpDg0+EuqU7+TpcsCN1TcwITx1L6QCL 1C6NNljvCVnJ+dNekIZ/1LCG3UXVW6y81kv+eHD0umTjqyrBp3lV94BaeU5UIyHZKc zDKybfsspnrP1qhiqd+dsnxznVfYXFvZSeoRYSBElTyxocH2QJC3b5d8zXbtpIhziF ygU0pzxGVue5w== From: Christian Brauner Date: Tue, 10 Nov 2026 10:14:18 +0100 Subject: [PATCH RFC 02/41] nvmet: check that the file backend supports ->{read,write}_iter X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261110-work-loop-pseudo-v1-2-4c998976c6c7@kernel.org> References: <20261110-work-loop-pseudo-v1-0-4c998976c6c7@kernel.org> In-Reply-To: <20261110-work-loop-pseudo-v1-0-4c998976c6c7@kernel.org> To: linux-fsdevel@vger.kernel.org Cc: Jann Horn , Chris Mason , Josef Bacik , Christoph Hellwig , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, Alexander Viro , Jan Kara , linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, driver-core@lists.linux.dev, linux-mm@kvack.org, bpf@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, apparmor@lists.ubuntu.com, linux-nfs@vger.kernel.org, netdev@vger.kernel.org, fuse-devel@lists.linux.dev, linux-efi@vger.kernel.org, xen-devel@lists.xenproject.org, ocfs2-devel@lists.linux.dev, linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-usb@vger.kernel.org, Amir Goldstein , linux-erofs@lists.ozlabs.org, linux-kselftest@vger.kernel.org, "Christian Brauner (Amutable)" X-Mailer: b4 0.17-dev-ce4c1 X-Developer-Signature: v=1; a=openpgp-sha256; l=1206; i=brauner@kernel.org; h=from:subject:message-id; bh=9rTO3vQgbbKMLgtf9DhInii/7oHGTrugRkWUh4dwMMs=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWR9ejBtltmGmxnek3mf9QvZzp8xjWWx5Y+Awzls7lyHP /4+2Dk3oqOUhUGMi0FWTJHFod0kXG45T8Vmo0wNmDmsTCBDGLg4BWAivzwZGU4478oq2RB1Nuut 48Jj7Tu4n8+545UyJdpwumO4VdS2g7kM/9TW5p9ep3/AsD+mInRXw3I+rR/SC0xnPXVmN7wifGZ vBB8A X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 X-Mailman-Approved-At: Wed, 11 Nov 2026 13:17:02 -0800 X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" X-Spam-Status: No, score=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 The file backend calls ->read_iter() and ->write_iter() of the backing file directly but never checks that they exist. Everything that isn't a block device ends up in the file backend. So a namespace pointing to a file without them calls a NULL pointer on its first I/O. Only buffered_io=1 gets that far as the O_DIRECT open fails for such files. Refuse them when the namespace is enabled the same way zloop does since commit 0c10f8a1a7ae ("zloop: check that the zone backing file support ->{read,write}_iter"). Fixes: d5eff33ee6f8 ("nvmet: add simple file backed ns support") Signed-off-by: Christian Brauner (Amutable) --- drivers/nvme/target/io-cmd-file.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c index 695963dd932e..dfa8aa46188c 100644 --- a/drivers/nvme/target/io-cmd-file.c +++ b/drivers/nvme/target/io-cmd-file.c @@ -47,6 +47,11 @@ int nvmet_file_ns_enable(struct nvmet_ns *ns) return ret; } + if (!ns->file->f_op->read_iter || !ns->file->f_op->write_iter) { + ret = -EINVAL; + goto err; + } + nvmet_file_ns_revalidate(ns); /* -- 2.53.0