releases/2.6.25.1/dm-snapshot-fix-chunksize-sector-conversion.patch

   1 From stable-bounces@linux.kernel.org Fri Apr 25 13:47:58 2008
   2 From: Mikulas Patocka <mpatocka@redhat.com>
   3 Date: Fri, 25 Apr 2008 20:05:39 GMT
   4 Subject: dm snapshot: fix chunksize sector conversion
   5 To: jejb@kernel.org, stable@kernel.org
   6 Message-ID: <200804252005.m3PK5dXs013576@hera.kernel.org>
   7
   8 From: Mikulas Patocka <mpatocka@redhat.com>
   9
  10 commit: 924362629bf5645aee5f49f8a0d0d5b193e65997
  11
  12 If a snapshot has a smaller chunksize than the page size the
  13 conversion to pages currently returns 0 instead of 1, causing:
  14 kernel BUG in mempool_resize.
  15
  16 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
  17 Signed-off-by: Milan Broz <mbroz@redhat.com>
  18 Signed-off-by: Alasdair G Kergon <agk@redhat.com>
  19 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  20
  21 ---
  22  drivers/md/dm-exception-store.c |    2 +-
  23  1 file changed, 1 insertion(+), 1 deletion(-)
  24
  25 --- a/drivers/md/dm-exception-store.c
  26 +++ b/drivers/md/dm-exception-store.c
  27 @@ -131,7 +131,7 @@ struct pstore {
  28
  29  static unsigned sectors_to_pages(unsigned sectors)
  30  {
  31 -       return sectors / (PAGE_SIZE >> 9);
  32 +       return DIV_ROUND_UP(sectors, PAGE_SIZE >> 9);
  33  }
  34
  35  static int alloc_area(struct pstore *ps)