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/jbd2/journal.c b/fs/jbd2/journal.c
index 0fa0123151d3..c0a5f9f1b127 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -173,7 +173,7 @@ loop:
                  */
                 jbd_debug(1, "Now suspending kjournald2\n");
                 write_unlock(&journal->j_state_lock);
-                refrigerator();
+                try_to_freeze();
                 write_lock(&journal->j_state_lock);
         } else {
                 /*