On Tue, 2025-09-30 at 23:35 -0400, Benjamin Marzinski wrote:
> When libmpathpersist is in the process of changing a registered key,
> multipathd needs to remember both the old and new values of the key
> to
> deal with a race between limpathpersist updating the key and
> multipathd
> restoring a failed path. It was supposed to stop remembering the old
> value when libmpathpersist was done changing the key and issued a
> "setprstatus" command. However, clearing the old key was done in
> set_pr(), which only gets called by cli_setprstatus() when
> registering a
> new device, not when changing the key on a registered device. Also,
> set_pr() is called by update_map_pr(). This means that multipathd
> was
> forgetting the key when it shouldn't and not when it should. Fix this
> to only forget the key when cli_setprstatus() is called, and always
> then.
>
> Fixes: 1aeffa9e ("libmpathpersist: handle updating key race
> condition")
> Signed-off-by: Benjamin Marzinski <[email protected]>
Reviewed-by: Martin Wilck <[email protected]>
> ---
> multipathd/cli_handlers.c | 1 +
> multipathd/main.c | 1 -
> 2 files changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/multipathd/cli_handlers.c b/multipathd/cli_handlers.c
> index 0c65e7d2..7f572fb4 100644
> --- a/multipathd/cli_handlers.c
> +++ b/multipathd/cli_handlers.c
> @@ -1293,6 +1293,7 @@ cli_setprstatus(void * v, struct strbuf *reply,
> void * data)
> set_pr(mpp);
> condlog(2, "%s: prflag set", param);
> }
> + memset(&mpp->old_pr_key, 0, 8);
>
> return 0;
> }
> diff --git a/multipathd/main.c b/multipathd/main.c
> index d7642a0b..d11a8576 100644
> --- a/multipathd/main.c
> +++ b/multipathd/main.c
> @@ -4250,7 +4250,6 @@ void set_pr(struct multipath *mpp)
> {
> mpp->ever_registered_pr = true;
> mpp->prflag = PR_SET;
> - memset(&mpp->old_pr_key, 0, 8);
> }
>
> void unset_pr(struct multipath *mpp)
