src/patches/suse-2.6.27.25/patches.fixes/dm-table-switch-to-readonly

   1 From: Hannes Reinecke <hare@suse.de>
   2 Subject: dm multipath devices are not getting created for readonly devices
   3 References: bnc#382705
   4
   5 Currently we cannot create device-mapper tables for multipath devices
   6 whenever they are read-only.
   7 This patch modifies the device-mapper to set the 'READ-ONLY' flag
   8 automatically whenever a read-only is added to the table.
   9
  10 Signed-off-by: Hannes Reinecke <hare@suse.de>
  11
  12 ---
  13  drivers/md/dm-table.c |   10 +++++++++-
  14  drivers/md/dm.c       |   18 ++++++++++++++++--
  15  2 files changed, 25 insertions(+), 3 deletions(-)
  16
  17 --- a/drivers/md/dm.c
  18 +++ b/drivers/md/dm.c
  19 @@ -310,16 +310,25 @@ static void __exit dm_exit(void)
  20  static int dm_blk_open(struct inode *inode, struct file *file)
  21  {
  22         struct mapped_device *md;
  23 +       int retval = 0;
  24
  25         spin_lock(&_minor_lock);
  26
  27         md = inode->i_bdev->bd_disk->private_data;
  28 -       if (!md)
  29 +       if (!md) {
  30 +               retval = -ENXIO;
  31                 goto out;
  32 +       }
  33
  34         if (test_bit(DMF_FREEING, &md->flags) ||
  35             test_bit(DMF_DELETING, &md->flags)) {
  36                 md = NULL;
  37 +               retval = -ENXIO;
  38 +               goto out;
  39 +       }
  40 +       if (md->disk->policy && (file->f_mode & FMODE_WRITE)) {
  41 +               md = NULL;
  42 +               retval = -EROFS;
  43                 goto out;
  44         }
  45
  46 @@ -329,7 +338,7 @@ static int dm_blk_open(struct inode *ino
  47  out:
  48         spin_unlock(&_minor_lock);
  49
  50 -       return md ? 0 : -ENXIO;
  51 +       return retval;
  52  }
  53
  54  static int dm_blk_close(struct inode *inode, struct file *file)
  55 @@ -1901,6 +1910,11 @@ static int __bind(struct mapped_device *
  56         write_lock(&md->map_lock);
  57         md->map = t;
  58         dm_table_set_restrictions(t, q);
  59 +       if (!(dm_table_get_mode(t) & FMODE_WRITE)) {
  60 +               set_disk_ro(md->disk, 1);
  61 +       } else {
  62 +               set_disk_ro(md->disk, 0);
  63 +       }
  64         write_unlock(&md->map_lock);
  65
  66         return 0;
  67 --- a/drivers/md/dm-table.c
  68 +++ b/drivers/md/dm-table.c
  69 @@ -451,11 +451,19 @@ static int __table_get_device(struct dm_
  70                 dd->mode = mode;
  71                 dd->bdev = NULL;
  72
  73 -               if ((r = open_dev(dd, dev, t->md))) {
  74 +               r = open_dev(dd, dev, t->md);
  75 +               if (r == -EROFS) {
  76 +                       dd->mode &= ~FMODE_WRITE;
  77 +                       r = open_dev(dd, dev, t->md);
  78 +               }
  79 +               if (r) {
  80                         kfree(dd);
  81                         return r;
  82                 }
  83
  84 +               if (dd->mode != mode)
  85 +                       t->mode = dd->mode;
  86 +
  87                 format_dev_t(dd->name, dev);
  88
  89                 atomic_set(&dd->count, 0);