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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; 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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