On Tue 10-11-26 10:14:18, Christian Brauner wrote:
> 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) <[email protected]>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <[email protected]>
Honza
> ---
> 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
>
--
Jan Kara <[email protected]>
SUSE Labs, CR
