git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From 2c43fd26e46734430122b8d2ad3024bb532df3ef Mon Sep 17 00:00:00 2001
   2 From: Joe Thornber <ejt@redhat.com>
   3 Date: Thu, 11 Dec 2014 11:12:19 +0000
   4 Subject: dm thin: fix missing out-of-data-space to write mode transition if blocks are released
   5
   6 From: Joe Thornber <ejt@redhat.com>
   7
   8 commit 2c43fd26e46734430122b8d2ad3024bb532df3ef upstream.
   9
  10 Discard bios and thin device deletion have the potential to release data
  11 blocks.  If the thin-pool is in out-of-data-space mode, and blocks were
  12 released, transition the thin-pool back to full write mode.
  13
  14 The correct time to do this is just after the thin-pool metadata commit.
  15 It cannot be done before the commit because the space maps will not
  16 allow immediate reuse of the data blocks in case there's a rollback
  17 following power failure.
  18
  19 Signed-off-by: Joe Thornber <ejt@redhat.com>
  20 Signed-off-by: Mike Snitzer <snitzer@redhat.com>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22
  23 ---
  24  drivers/md/dm-thin.c |   22 ++++++++++++++++++++--
  25  1 file changed, 20 insertions(+), 2 deletions(-)
  26
  27 --- a/drivers/md/dm-thin.c
  28 +++ b/drivers/md/dm-thin.c
  29 @@ -990,6 +990,24 @@ static void schedule_external_copy(struc
  30                 schedule_zero(tc, virt_block, data_dest, cell, bio);
  31  }
  32
  33 +static void set_pool_mode(struct pool *pool, enum pool_mode new_mode);
  34 +
  35 +static void check_for_space(struct pool *pool)
  36 +{
  37 +       int r;
  38 +       dm_block_t nr_free;
  39 +
  40 +       if (get_pool_mode(pool) != PM_OUT_OF_DATA_SPACE)
  41 +               return;
  42 +
  43 +       r = dm_pool_get_free_block_count(pool->pmd, &nr_free);
  44 +       if (r)
  45 +               return;
  46 +
  47 +       if (nr_free)
  48 +               set_pool_mode(pool, PM_WRITE);
  49 +}
  50 +
  51  /*
  52   * A non-zero return indicates read_only or fail_io mode.
  53   * Many callers don't care about the return value.
  54 @@ -1004,6 +1022,8 @@ static int commit(struct pool *pool)
  55         r = dm_pool_commit_metadata(pool->pmd);
  56         if (r)
  57                 metadata_operation_failed(pool, "dm_pool_commit_metadata", r);
  58 +       else
  59 +               check_for_space(pool);
  60
  61         return r;
  62  }
  63 @@ -1022,8 +1042,6 @@ static void check_low_water_mark(struct
  64         }
  65  }
  66
  67 -static void set_pool_mode(struct pool *pool, enum pool_mode new_mode);
  68 -
  69  static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
  70  {
  71         int r;