[dm-devel] [RFC PATCH 4/5] libmultipath: add helper functions

[Martin Wilck]

On Fri, 2018-02-09 at 23:07 -0600, Benjamin Marzinski wrote:
> Add the ability to reset a vector without completely freeing it, and
> to
> check the version of the device-mapper module.  The existing version
> checking code checks the version of a specific device mapper target,
> and
> has been renamed for clarity's sake. These functions will be used in
> a
> later patch.
> 
> Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
> ---
Reviewed-by: Martin Wilck <mwilck at suse.com>


>  libmultipath/devmapper.c | 28 ++++++++++++++++++++++++----
>  libmultipath/devmapper.h |  3 ++-
>  libmultipath/vector.c    | 16 ++++++++++++----
>  libmultipath/vector.h    |  1 +
>  multipathd/main.c        |  2 +-
>  5 files changed, 40 insertions(+), 10 deletions(-)
> 
> diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c
> index 573fc75..2960bf5 100644
> --- a/libmultipath/devmapper.c
> +++ b/libmultipath/devmapper.c
> @@ -132,7 +132,27 @@ dm_lib_prereq (void)
>  }
>  
>  int
> -dm_drv_version (unsigned int * version, char * str)
> +dm_drv_version(unsigned int *v)
> +{
> +	char buff[64];
> +
> +	v[0] = 0;
> +	v[1] = 0;
> +	v[2] = 0;
> +
> +	if (!dm_driver_version(buff, sizeof(buff))) {
> +		condlog(0, "cannot get kernel dm version");
> +		return 1;
> +	}
> +	if (sscanf(buff, "%u.%u.%u ", &v[0], &v[1], &v[2]) != 3) {
> +		condlog(0, "invalid kernel dm version '%s'", buff);
> +		return 1;
> +	}
> +	return 0;
> +}
> +
> +int
> +dm_tgt_version (unsigned int * version, char * str)
>  {
>  	int r = 2;
>  	struct dm_task *dmt;
> @@ -179,13 +199,13 @@ out:
>  }
>  
>  static int
> -dm_drv_prereq (unsigned int *ver)
> +dm_tgt_prereq (unsigned int *ver)
>  {
>  	unsigned int minv[3] = {1, 0, 3};
>  	unsigned int version[3] = {0, 0, 0};
>  	unsigned int * v = version;
>  
> -	if (dm_drv_version(v, TGT_MPATH)) {
> +	if (dm_tgt_version(v, TGT_MPATH)) {
>  		/* in doubt return not capable */
>  		return 1;
>  	}
> @@ -210,7 +230,7 @@ static int dm_prereq(unsigned int *v)
>  {
>  	if (dm_lib_prereq())
>  		return 1;
> -	return dm_drv_prereq(v);
> +	return dm_tgt_prereq(v);
>  }
>  
>  static int libmp_dm_udev_sync = 0;
> diff --git a/libmultipath/devmapper.h b/libmultipath/devmapper.h
> index 62e14d1..52d4af8 100644
> --- a/libmultipath/devmapper.h
> +++ b/libmultipath/devmapper.h
> @@ -28,7 +28,8 @@ void dm_init(int verbosity);
>  void libmp_dm_init(void);
>  void libmp_udev_set_sync_support(int on);
>  struct dm_task *libmp_dm_task_create(int task);
> -int dm_drv_version (unsigned int * version, char * str);
> +int dm_drv_version (unsigned int * version);
> +int dm_tgt_version (unsigned int * version, char * str);
>  int dm_simplecmd_flush (int, const char *, uint16_t);
>  int dm_simplecmd_noflush (int, const char *, uint16_t);
>  int dm_addmap_create (struct multipath *mpp, char *params);
> diff --git a/libmultipath/vector.c b/libmultipath/vector.c
> index 6266e0a..f741ae0 100644
> --- a/libmultipath/vector.c
> +++ b/libmultipath/vector.c
> @@ -145,18 +145,26 @@ vector_repack(vector v)
>  			vector_del_slot(v, i--);
>  }
>  
> -/* Free memory vector allocation */
> -void
> -vector_free(vector v)
> +vector
> +vector_reset(vector v)
>  {
>  	if (!v)
> -		return;
> +		return NULL;
>  
>  	if (v->slot)
>  		FREE(v->slot);
>  
>  	v->allocated = 0;
>  	v->slot = NULL;
> +	return v;
> +}
> +
> +/* Free memory vector allocation */
> +void
> +vector_free(vector v)
> +{
> +	if (!vector_reset(v))
> +		return;
>  	FREE(v);
>  }
>  
> diff --git a/libmultipath/vector.h b/libmultipath/vector.h
> index 5cfd4d0..d69cd0b 100644
> --- a/libmultipath/vector.h
> +++ b/libmultipath/vector.h
> @@ -45,6 +45,7 @@ typedef struct _vector *vector;
>  /* Prototypes */
>  extern vector vector_alloc(void);
>  extern void *vector_alloc_slot(vector v);
> +vector vector_reset(vector v);
>  extern void vector_free(vector v);
>  extern void free_strvec(vector strvec);
>  extern void vector_set_slot(vector v, void *value);
> diff --git a/multipathd/main.c b/multipathd/main.c
> index efc39d7..2963bde 100644
> --- a/multipathd/main.c
> +++ b/multipathd/main.c
> @@ -2228,7 +2228,7 @@ reconfigure (struct vectors * vecs)
>  	/* Re-read any timezone changes */
>  	tzset();
>  
> -	dm_drv_version(conf->version, TGT_MPATH);
> +	dm_tgt_version(conf->version, TGT_MPATH);
>  	if (verbosity)
>  		conf->verbosity = verbosity;
>  	if (bindings_read_only)

-- 
Dr. Martin Wilck <mwilck at suse.com>, Tel. +49 (0)911 74053 2107
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)