src/patches/suse-2.6.27.31/patches.suse/dm-mpath-no-partitions-feature

   1 From: Hannes Reinecke <hare@suse.de>
   2 Subject: Disable partitions scan for multipathed devices
   3 References: bnc#402922,bnc#514767
   4
   5 When multipath devices are being used as disks for VM Guests
   6 any partition scanning / setup should be done within the VM Guest,
   7 not from host. So we need to switch off partitions scanning via
   8 kpartx there.
   9 For this I've implemented a new feature 'no_partitions' which
  10 just serves as a notifier to kpartx to _not_ create partitions
  11 on these devices.
  12
  13 Patch ported to SLES11.
  14
  15 Signed-off-by: Hannes Reinecke <hare@suse.de>
  16
  17 ---
  18  drivers/md/dm-mpath.c |   12 +++++++++++-
  19  1 file changed, 11 insertions(+), 1 deletion(-)
  20
  21 --- a/drivers/md/dm-mpath.c
  22 +++ b/drivers/md/dm-mpath.c
  23 @@ -55,6 +55,8 @@ struct priority_group {
  24         struct list_head pgpaths;
  25  };
  26
  27 +#define FEATURE_NO_PARTITIONS 1
  28 +
  29  /* Multipath context */
  30  struct multipath {
  31         struct list_head list;
  32 @@ -79,6 +81,7 @@ struct multipath {
  33         unsigned saved_queue_if_no_path;/* Saved state during suspension */
  34         unsigned pg_init_retries;       /* Number of times to retry pg_init */
  35         unsigned pg_init_count;         /* Number of times pg_init called */
  36 +       unsigned features;              /* Additional selected features */
  37
  38         struct work_struct process_queued_ios;
  39         struct list_head queued_ios;
  40 @@ -802,6 +805,10 @@ static int parse_features(struct arg_set
  41                         continue;
  42                 }
  43
  44 +               if (!strnicmp(param_name, MESG_STR("no_partitions"))) {
  45 +                       m->features |= FEATURE_NO_PARTITIONS;
  46 +                       continue;
  47 +               }
  48                 if (!strnicmp(param_name, MESG_STR("pg_init_retries")) &&
  49                     (argc >= 1)) {
  50                         r = read_param(_params + 1, shift(as),
  51 @@ -1321,11 +1328,14 @@ static int multipath_status(struct dm_ta
  52                 DMEMIT("2 %u %u ", m->queue_size, m->pg_init_count);
  53         else {
  54                 DMEMIT("%u ", m->queue_if_no_path +
  55 -                             (m->pg_init_retries > 0) * 2);
  56 +                             (m->pg_init_retries > 0) * 2 +
  57 +                             (m->features & FEATURE_NO_PARTITIONS));
  58                 if (m->queue_if_no_path)
  59                         DMEMIT("queue_if_no_path ");
  60                 if (m->pg_init_retries)
  61                         DMEMIT("pg_init_retries %u ", m->pg_init_retries);
  62 +               if (m->features & FEATURE_NO_PARTITIONS)
  63 +                       DMEMIT("no_partitions ");
  64         }
  65
  66         if (!m->hw_handler_name || type == STATUSTYPE_INFO)