src/patches/suse-2.6.27.25/patches.suse/dm-table-change-mode-to-ro

   1 From: Hannes Reinecke <hare@suse.de>
   2 Subject: Switch device-mapper tables to READ-WRITE
   3 References: bnc#440959
   4
   5 Switching a device-mapper table to READ-ONLY works quite well, but
   6 we can't switch back to READ-WRITE as this change will be masked out.
   7 So get rid of this masking and use the flags directly.
   8 And implement a fallback to automatically switch to read-only.
   9
  10 Signed-off-by: Hannes Reinecke <hare@suse.de>
  11
  12 --- linux-2.6.27/drivers/md/dm-table.c.orig     2009-02-02 13:09:06.000000000 +0100
  13 +++ linux-2.6.27/drivers/md/dm-table.c  2009-02-02 14:03:03.000000000 +0100
  14 @@ -423,9 +423,13 @@ static int upgrade_mode(struct dm_dev *d
  15
  16         dd_copy = *dd;
  17
  18 -       dd->mode |= new_mode;
  19 +       dd->mode = new_mode;
  20         dd->bdev = NULL;
  21         r = open_dev(dd, dev, md);
  22 +       if (r == -EROFS) {
  23 +               dd->mode &= ~FMODE_WRITE;
  24 +               r = open_dev(dd, dev, md);
  25 +       }
  26         if (!r)
  27                 close_dev(&dd_copy, md);
  28         else
  29 @@ -487,7 +491,7 @@ static int __table_get_device(struct dm_
  30                 atomic_set(&dd->count, 0);
  31                 list_add(&dd->list, &t->devices);
  32
  33 -       } else if (dd->mode != (mode | dd->mode)) {
  34 +       } else if (dd->mode != mode) {
  35                 r = upgrade_mode(dd, mode, t->md);
  36                 if (r)
  37                         return r;