[Kimchi-devel] [PATCH] Logical Storage Pool: Detect and Enumerate Multipath Block Devices

[Mark Wu]

On 03/25/2014 11:52 AM, zhshzhou at linux.vnet.ibm.com wrote:
> From: Zhou Zheng Sheng <zhshzhou at linux.vnet.ibm.com>
>
> When creating a logical storage pool Kimci ignores multipath block
> devices. This is on purpose because at the time the kimchi.disks was
> implemented, there was not enough time to test every kind of devices.
>
> This patch adds the missing support for multipath block devices. After
> this patch, the kimchi.disks will include multipath devices in the
> available partition list. The front-end code is also changed
> accordingly.
>
> Signed-off-by: Zhou Zheng Sheng <zhshzhou at linux.vnet.ibm.com>
> ---
>   src/kimchi/disks.py                      | 20 +++++++++++++++++++-
>   ui/js/src/kimchi.storagepool_add_main.js |  3 ++-
>   2 files changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/src/kimchi/disks.py b/src/kimchi/disks.py
> index ce0c5bb..6817ab4 100644
> --- a/src/kimchi/disks.py
> +++ b/src/kimchi/disks.py
> @@ -17,6 +17,7 @@
>   # License along with this library; if not, write to the Free Software
>   # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
>
> +import errno
>   import re
>   import subprocess
>
> @@ -27,8 +28,25 @@ from kimchi.exception import OperationFailed
>   from kimchi.utils import kimchi_log
>
>
> +def _get_friendly_dm_path(maj_min):
> +    """ Returns user friendly dm path given the device number 'major:min' """
> +    dm_name = "/sys/dev/block/%s/dm/name" % maj_min
> +    try:
> +        with open(dm_name) as dm_f:
> +            content = dm_f.read().rstrip('\n')
> +    except IOError as e:
> +        if not e.errno == errno.ENOENT:
why not "!="
> +            raise
> +        return None
> +    return "/dev/mapper/" + content
> +
> +
>   def _get_dev_node_path(maj_min):
>       """ Returns device node path given the device number 'major:min' ""
> +    dm_path = _get_friendly_dm_path(maj_min)
check if string starts with "253:"  could avoid reading the dm name file 
for non device mapper file.
The major device number 253 is reserved for device mapper device in 
kernel.  It's reliable.
> +    if dm_path is not None:
> +        return dm_path
> +
>       uevent = "/sys/dev/block/%s/uevent" % maj_min
>       with open(uevent) as ueventf:
>           content = ueventf.read()
> @@ -137,7 +155,7 @@ def get_partitions_names():
>           # leaf means a partition, a disk has no partition, or a disk not held
>           # by any multipath device. Physical volume belongs to no volume group
>           # is also listed. Extended partitions should not be listed.
> -        if not (dev['type'] in ['part', 'disk'] and
> +        if not (dev['type'] in ['part', 'disk', 'mpath'] and
>                   dev['fstype'] in ['', 'LVM2_member'] and
>                   dev['mountpoint'] == "" and
>                   _get_vgname(devNodePath) == "" and
> diff --git a/ui/js/src/kimchi.storagepool_add_main.js b/ui/js/src/kimchi.storagepool_add_main.js
> index 10833be..f3b85d2 100644
> --- a/ui/js/src/kimchi.storagepool_add_main.js
> +++ b/ui/js/src/kimchi.storagepool_add_main.js
> @@ -28,7 +28,8 @@ kimchi.initStorageAddPage = function() {
>               var deviceHtml = $('#partitionTmpl').html();
>               var listHtml = '';
>               $.each(data, function(index, value) {
> -                if (value.type === 'part' || value.type === 'disk') {
> +                valid_types = {part: 'part', disk: 'disk', mpath: 'mpath'};
what we need is just a list,  not sure if we can have a 'in' operation 
for list in js.   Maybe Hongliang can help here.
> +                if (value.type in valid_types) {
>                       listHtml += kimchi.template(deviceHtml, value);
>                   }
>               });