add-ext4_should_use_dax

   1 ext4: add ext4_should_use_dax()
   2
   3 From: Ross Zwisler <ross.zwisler@linux.intel.com>
   4
   5 This helper, in the spirit of ext4_should_dioread_nolock() et al., replaces
   6 the complex conditional in ext4_set_inode_flags().
   7
   8 Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
   9 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  10 Reviewed-by: Jan Kara <jack@suse.cz>
  11 ---
  12  fs/ext4/inode.c | 19 ++++++++++++++++---
  13  1 file changed, 16 insertions(+), 3 deletions(-)
  14
  15 diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
  16 index 3207333..525dd63 100644
  17 --- a/fs/ext4/inode.c
  18 +++ b/fs/ext4/inode.c
  19 @@ -4577,6 +4577,21 @@ int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
  20                 !ext4_test_inode_state(inode, EXT4_STATE_XATTR));
  21  }
  22
  23 +static bool ext4_should_use_dax(struct inode *inode)
  24 +{
  25 +       if (!test_opt(inode->i_sb, DAX))
  26 +               return false;
  27 +       if (!S_ISREG(inode->i_mode))
  28 +               return false;
  29 +       if (ext4_should_journal_data(inode))
  30 +               return false;
  31 +       if (ext4_has_inline_data(inode))
  32 +               return false;
  33 +       if (ext4_encrypted_inode(inode))
  34 +               return false;
  35 +       return true;
  36 +}
  37 +
  38  void ext4_set_inode_flags(struct inode *inode)
  39  {
  40         unsigned int flags = EXT4_I(inode)->i_flags;
  41 @@ -4592,9 +4607,7 @@ void ext4_set_inode_flags(struct inode *inode)
  42                 new_fl |= S_NOATIME;
  43         if (flags & EXT4_DIRSYNC_FL)
  44                 new_fl |= S_DIRSYNC;
  45 -       if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode) &&
  46 -           !ext4_should_journal_data(inode) && !ext4_has_inline_data(inode) &&
  47 -           !ext4_encrypted_inode(inode))
  48 +       if (ext4_should_use_dax(inode))
  49                 new_fl |= S_DAX;
  50         inode_set_flags(inode, new_fl,
  51                         S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX);
  52 --
  53 2.9.5
  54
  55