jbd2-blocks-reservation-fix-for-large-blk.patch

   1 jbd2: blocks reservation fix for large block support
   2
   3 From: Mingming Cao <cmm@us.ibm.com>
   4
   5 The blocks per page could be less or quals to 1 with the large
   6 block support in VM. The patch fixed the way to calculate the
   7 number of blocks to reserve in journal in the case blocksize > pagesize.
   8
   9 Signed-off-by: Mingming Cao <cmm@us.ibm.com>
  10 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
  11
  12 ---
  13
  14  fs/jbd2/journal.c |    7 ++++++-
  15  1 file changed, 6 insertions(+), 1 deletion(-)
  16
  17
  18 Index: linux-2.6.26-rc4/fs/jbd2/journal.c
  19 ===================================================================
  20 --- linux-2.6.26-rc4.orig/fs/jbd2/journal.c     2008-05-29 10:52:27.000000000 -0700
  21 +++ linux-2.6.26-rc4/fs/jbd2/journal.c  2008-05-29 10:52:41.000000000 -0700
  22 @@ -1935,7 +1935,12 @@ void jbd2_journal_ack_err(journal_t *jou
  23
  24  int jbd2_journal_blocks_per_page(struct inode *inode)
  25  {
  26 -       return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
  27 +       int bits = PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits;
  28 +
  29 +       if (bits > 0)
  30 +               return 1 << bits;
  31 +       else
  32 +               return 1;
  33  }
  34
  35  /*