[lvm-devel] [PATCH 1/2] Use vg->vgmem to allocate vg/lv/pv string properties instead of dm_malloc/free.

[Zdenek Kabelac]

On 14.4.2010 17:14, Dave Wysochanski wrote:
> Everywhere else in the API the caller can rely on lvm2app taking care of
> memory allocation and free, so make the 'name' and 'uuid' properties of a
> vg/lv/pv use the vg handle to allocate memory.
> 
> Signed-off-by: Dave Wysochanski <dwysocha at redhat.com>
> ---
>  liblvm/lvm2app.h |   24 ++++++++++++------------
>  liblvm/lvm_lv.c  |   10 +++-------
>  liblvm/lvm_pv.c  |   10 +++-------
>  liblvm/lvm_vg.c  |    9 ++-------
>  4 files changed, 20 insertions(+), 33 deletions(-)
> 
> diff --git a/liblvm/lvm2app.h b/liblvm/lvm2app.h
> index 61ffd87..dad92c0 100644
> --- a/liblvm/lvm2app.h
> +++ b/liblvm/lvm2app.h
> @@ -642,12 +642,12 @@ uint64_t lvm_vg_is_partial(vg_t vg);
>  uint64_t lvm_vg_get_seqno(const vg_t vg);
>  
>  /**
> - * Get the current name of a volume group.
> + * Get the current uuid of a volume group.
>   *
>   * \memberof vg_t
>   *
> - * Memory is allocated using dm_malloc() and caller must free the memory
> - * using dm_free().
> + * The memory allocated for the uuid is tied to the vg_t handle and will be
> + * released when lvm_vg_close() is called.
>   *
>   * \param   vg
>   * VG handle obtained from lvm_vg_create or lvm_vg_open().
> @@ -658,12 +658,12 @@ uint64_t lvm_vg_get_seqno(const vg_t vg);
>  char *lvm_vg_get_uuid(const vg_t vg);
>  
>  /**
> - * Get the current uuid of a volume group.
> + * Get the current name of a volume group.
>   *
>   * \memberof vg_t
>   *
> - * Memory is allocated using dm_malloc() and caller must free the memory
> - * using dm_free().
> + * The memory allocated for the name is tied to the vg_t handle and will be
> + * released when lvm_vg_close() is called.
>   *
>   * \param   vg
>   * VG handle obtained from lvm_vg_create or lvm_vg_open().
> @@ -783,7 +783,7 @@ uint64_t lvm_vg_get_max_lv(const vg_t vg);
>   * \memberof vg_t
>   *
>   * The memory allocated for the list is tied to the vg_t handle and will be
> - * released when lvm_vg_close is called.
> + * released when lvm_vg_close() is called.
>   *
>   * To process the list, use the dm_list iterator functions.  For example:
>   *      vg_t vg;
> @@ -1001,7 +1001,7 @@ int lvm_lv_remove_tag(lv_t lv, const char *tag);
>   * \memberof lv_t
>   *
>   * The memory allocated for the list is tied to the vg_t handle and will be
> - * released when lvm_vg_close is called.
> + * released when lvm_vg_close() is called.
>   *
>   * To process the list, use the dm_list iterator functions.  For example:
>   *      lv_t lv;
> @@ -1057,8 +1057,8 @@ int lvm_lv_resize(const lv_t lv, uint64_t new_size);
>   *
>   * \memberof pv_t
>   *
> - * Memory is allocated using dm_malloc() and caller must free the memory
> - * using dm_free().
> + * The memory allocated for the uuid is tied to the vg_t handle and will be
> + * released when lvm_vg_close() is called.
>   *
>   * \param   pv
>   * Physical volume handle.
> @@ -1073,8 +1073,8 @@ char *lvm_pv_get_uuid(const pv_t pv);
>   *
>   * \memberof pv_t
>   *
> - * Memory is allocated using dm_malloc() and caller must free the memory
> - * using dm_free().
> + * The memory allocated for the uuid is tied to the vg_t handle and will be
> + * released when lvm_vg_close() is called.
>   *
>   * \param   pv
>   * Physical volume handle.
> diff --git a/liblvm/lvm_lv.c b/liblvm/lvm_lv.c
> index d3bb6b8..1a6c6ce 100644
> --- a/liblvm/lvm_lv.c
> +++ b/liblvm/lvm_lv.c
> @@ -47,17 +47,13 @@ char *lvm_lv_get_uuid(const lv_t lv)
>  		log_error(INTERNAL_ERROR "unable to convert uuid");
>  		return NULL;
>  	}
> -	return strndup((const char *)uuid, 64);
> +	return dm_pool_strndup(lv->vg->vgmem, (const char *)uuid, 64);
>  }
>  
>  char *lvm_lv_get_name(const lv_t lv)
>  {
> -	char *name;
> -
> -	name = dm_malloc(NAME_LEN + 1);
> -	strncpy(name, (const char *)lv->name, NAME_LEN);
> -	name[NAME_LEN] = '\0';
> -	return name;
> +	return dm_pool_strndup(lv->vg->vgmem, (const char *)lv->name,
> +			       NAME_LEN+1);
>  }
>  
>  uint64_t lvm_lv_is_active(const lv_t lv)
> diff --git a/liblvm/lvm_pv.c b/liblvm/lvm_pv.c
> index 894aa4b..033bc88 100644
> --- a/liblvm/lvm_pv.c
> +++ b/liblvm/lvm_pv.c
> @@ -25,17 +25,13 @@ char *lvm_pv_get_uuid(const pv_t pv)
>  		log_error(INTERNAL_ERROR "Unable to convert uuid");
>  		return NULL;
>  	}
> -	return strndup((const char *)uuid, 64);
> +	return dm_pool_strndup(pv->vg->vgmem, (const char *)uuid, 64);
>  }
>  
>  char *lvm_pv_get_name(const pv_t pv)
>  {
> -	char *name;
> -
> -	name = dm_malloc(NAME_LEN + 1);
> -	strncpy(name, (const char *)pv_dev_name(pv), NAME_LEN);
> -	name[NAME_LEN] = '\0';
> -	return name;
> +	return dm_pool_strndup(pv->vg->vgmem,
> +			       (const char *)pv_dev_name(pv), NAME_LEN + 1);
>  }

Why not return const char* for given PV - if user needs local copy,
he may do a local copy himself calling strdup - doing this all the time is not
really effective.

Zdenek