On Fri, Oct 16, 2020 at 12:44:46PM +0200, mwilck@xxxxxxxx wrote:
> From: Martin Wilck <mwilck@xxxxxxxx>
>
> This function prepares for calling dm_lib_exit() on program exit.
> It undoes changes to libdm internals done by libmultipath.
> It doesn't call dm_lib_exit(), as the caller may want to keep
> libdm active.
>
Reviewed-by: Benjamin Marzinski <bmarzins@xxxxxxxxxx>
> Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
> ---
> libmultipath/config.c | 1 +
> libmultipath/config.h | 2 ++
> libmultipath/devmapper.c | 15 +++++++++++++++
> libmultipath/devmapper.h | 1 +
> 4 files changed, 19 insertions(+)
>
> diff --git a/libmultipath/config.c b/libmultipath/config.c
> index f74417c..b9cb413 100644
> --- a/libmultipath/config.c
> +++ b/libmultipath/config.c
> @@ -60,6 +60,7 @@ int libmultipath_init(void)
> static void _libmultipath_exit(void)
> {
> libmultipath_exit_called = true;
> + libmp_dm_exit();
> udev_unref(udev);
> }
>
> diff --git a/libmultipath/config.h b/libmultipath/config.h
> index f478df7..5d46035 100644
> --- a/libmultipath/config.h
> +++ b/libmultipath/config.h
> @@ -271,6 +271,8 @@ int libmultipath_init(void);
> *
> * This function un-initializes libmultipath data structures.
> * It is recommended to call this function at program exit.
> + * If the application also calls dm_lib_exit(), it should do so
> + * after libmultipath_exit().
> *
> * Calls to libmultipath_init() after libmultipath_exit() will fail
> * (in other words, libmultipath can't be re-initialized).
> diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c
> index 2e3ae8a..a8e0611 100644
> --- a/libmultipath/devmapper.c
> +++ b/libmultipath/devmapper.c
> @@ -333,6 +333,20 @@ void libmp_udev_set_sync_support(int on)
> libmp_dm_udev_sync = !!on;
> }
>
> +static bool libmp_dm_init_called;
> +void libmp_dm_exit(void)
> +{
> + if (!libmp_dm_init_called)
> + return;
> +
> + /* switch back to default libdm logging */
> + dm_log_init(NULL);
> +#ifdef LIBDM_API_HOLD_CONTROL
> + /* make sure control fd is closed in dm_lib_release() */
> + dm_hold_control_dev(0);
> +#endif
> +}
> +
> static void libmp_dm_init(void)
> {
> struct config *conf;
> @@ -349,6 +363,7 @@ static void libmp_dm_init(void)
> dm_hold_control_dev(1);
> #endif
> dm_udev_set_sync_support(libmp_dm_udev_sync);
> + libmp_dm_init_called = true;
> }
>
> static void _do_skip_libmp_dm_init(void)
> diff --git a/libmultipath/devmapper.h b/libmultipath/devmapper.h
> index 158057e..ecf2e66 100644
> --- a/libmultipath/devmapper.h
> +++ b/libmultipath/devmapper.h
> @@ -35,6 +35,7 @@ enum {
>
> int dm_prereq(unsigned int *v);
> void skip_libmp_dm_init(void);
> +void libmp_dm_exit(void);
> void libmp_udev_set_sync_support(int on);
> struct dm_task *libmp_dm_task_create(int task);
> int dm_simplecmd_flush (int, const char *, uint16_t);
> --
> 2.28.0
--
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