freezer: unexport refrigerator() and update try_to_freeze() slightly

There is no reason to export two functions for entering the
refrigerator.  Calling refrigerator() instead of try_to_freeze()
doesn't save anything noticeable or removes any race condition.

* Rename refrigerator() to __refrigerator() and make it return bool
  indicating whether it scheduled out for freezing.

* Update try_to_freeze() to return bool and relay the return value of
  __refrigerator() if freezing().

* Convert all refrigerator() users to try_to_freeze().

* Update documentation accordingly.

* While at it, add might_sleep() to try_to_freeze().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Samuel Ortiz <samuel@sortiz.org>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: Christoph Hellwig <hch@infradead.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index bb24ab6c282f..0e72ad6f22aa 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -2470,7 +2470,7 @@ static int nilfs_segctor_thread(void *arg)
 
         if (freezing(current)) {
                 spin_unlock(&sci->sc_state_lock);
-                refrigerator();
+                try_to_freeze();
                 spin_lock(&sci->sc_state_lock);
         } else {
                 DEFINE_WAIT(wait);