fix-checkpoint-list-cleanup

   1 jbd2: fix checkpoint list cleanup
   2
   3 From: Jan Kara <jack@suse.com>
   4
   5 Unlike comments and expectation of callers journal_clean_one_cp_list()
   6 returned 1 not only if it freed the transaction but also if it freed
   7 some buffers in the transaction. That could make
   8 __jbd2_journal_clean_checkpoint_list() skip processing
   9 t_checkpoint_io_list and continue with processing the next transaction.
  10 This is mostly a cosmetic issue since the only result is we can
  11 sometimes free less memory than we could. But it's still worth fixing.
  12 Fix journal_clean_one_cp_list() to return 1 only if the transaction was
  13 really freed.
  14
  15 Fixes: 50849db32a9f529235a84bcc84a6b8e631b1d0ec
  16 Signed-off-by: Jan Kara <jack@suse.com>
  17 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  18 Cc: stable@vger.kernel.org
  19 ---
  20  fs/jbd2/checkpoint.c | 8 +++-----
  21  1 file changed, 3 insertions(+), 5 deletions(-)
  22
  23 diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
  24 index 8c44654ce274..684996c8a3a4 100644
  25 --- a/fs/jbd2/checkpoint.c
  26 +++ b/fs/jbd2/checkpoint.c
  27 @@ -427,7 +427,6 @@ static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy)
  28         struct journal_head *last_jh;
  29         struct journal_head *next_jh = jh;
  30         int ret;
  31 -       int freed = 0;
  32
  33         if (!jh)
  34                 return 0;
  35 @@ -441,10 +440,9 @@ static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy)
  36                 else
  37                         ret = __jbd2_journal_remove_checkpoint(jh) + 1;
  38                 if (!ret)
  39 -                       return freed;
  40 +                       return 0;
  41                 if (ret == 2)
  42                         return 1;
  43 -               freed = 1;
  44                 /*
  45                  * This function only frees up some memory
  46                  * if possible so we dont have an obligation
  47 @@ -452,10 +450,10 @@ static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy)
  48                  * requested:
  49                  */
  50                 if (need_resched())
  51 -                       return freed;
  52 +                       return 0;
  53         } while (jh != last_jh);
  54
  55 -       return freed;
  56 +       return 0;
  57  }
  58
  59  /*
  60 --
  61 2.1.4
  62
  63