[dm-devel] [PATCH] multipath: return failure on an invalid remove command

[Martin Wilck]

On Tue, 2022-03-29 at 22:21 -0500, Benjamin Marzinski wrote:
> When "multipath -f" is run on a device that doesn't exist or isn't a
> multipath device, the command will not remove any device, but it will
> still return success.  Multiple functions rely on _dm_flush_map()
> returning success when called with name that doesn't match any
> multipath device. So before calling _dm_flush_map(), call
> dm_is_mpath(),
> to check if the device exists and is a multipath device, and return
> failure if it's not.
> 
> Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
> ---
>  multipath/main.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/multipath/main.c b/multipath/main.c
> index d09f62db..e865309d 100644
> --- a/multipath/main.c
> +++ b/multipath/main.c
> @@ -1060,6 +1060,11 @@ main (int argc, char *argv[])
>         if (retries < 0)
>                 retries = conf->remove_retries;
>         if (cmd == CMD_FLUSH_ONE) {
> +               if (dm_is_mpath(dev) != 1) {
> +                       condlog(0, "failed removing \"%s\"", dev);

Could we provide a more meaningful error message here?
(As you're the native speaker - shouldn't it rather be "failed to
remove"?)

Otherwise, ack.

Martin


> +                       r = RTVL_FAIL;
> +                       goto out;
> +               }
>                 r = dm_suspend_and_flush_map(dev, retries) ?
>                     RTVL_FAIL : RTVL_OK;
>                 goto out;