On Fri, 2024-11-22 at 16:11 -0500, Benjamin Marzinski wrote:
> If dm_get_opencount() fails, open_count will be negative, which means
> mpath_in_use() will never fail. However, dm_flush_map__() will
> eventually fail. There are multiple callers of dm_get_opencount()
> that
> run when trying to remove a device. All the others treat a failed
> call
> as if the device was in use, including one that will later be called
> directly on this device. So save ourselves the work, and exit early
>
> Signed-off-by: Benjamin Marzinski <bmarzins@xxxxxxxxxx>
Side note: I realize that there are other callers of dm_get_opencount()
that take a negative return value for a "yes". That happens to be
correct for the respective callers, but it's quite unclean.
Your patch is fine though.
Martin
> ---
> libmultipath/devmapper.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c
> index 751b45d8..3667c51b 100644
> --- a/libmultipath/devmapper.c
> +++ b/libmultipath/devmapper.c
> @@ -961,6 +961,11 @@ int mpath_in_use(const char *name)
> {
> int open_count = dm_get_opencount(name);
>
> + if (open_count < 0) {
> + condlog(0, "%s: %s: failed to get open count,
> assuming in use",
> + __func__, name);
> + return 1;
> + }
> if (open_count) {
> int part_count = 0;
>
