jbd2: fix checkpoint list cleanup

Unlike comments and expectation of callers journal_clean_one_cp_list()
returned 1 not only if it freed the transaction but also if it freed
some buffers in the transaction. That could make
__jbd2_journal_clean_checkpoint_list() skip processing
t_checkpoint_io_list and continue with processing the next transaction.
This is mostly a cosmetic issue since the only result is we can
sometimes free less memory than we could. But it's still worth fixing.
Fix journal_clean_one_cp_list() to return 1 only if the transaction was
really freed.

Fixes: 50849db32a9f529235a84bcc84a6b8e631b1d0ec
Signed-off-by: Jan Kara <jack@suse.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index 8c44654..684996c 100644 (file)
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -427,7 +427,6 @@ static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy)
        struct journal_head *last_jh;
        struct journal_head *next_jh = jh;
        int ret;
-       int freed = 0;
 
        if (!jh)
                return 0;
@@ -441,10 +440,9 @@ static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy)
                else
                        ret = __jbd2_journal_remove_checkpoint(jh) + 1;
                if (!ret)
-                       return freed;
+                       return 0;
                if (ret == 2)
                        return 1;
-               freed = 1;
                /*
                 * This function only frees up some memory
                 * if possible so we dont have an obligation
@@ -452,10 +450,10 @@ static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy)
                 * requested:
                 */
                if (need_resched())
-                       return freed;
+                       return 0;
        } while (jh != last_jh);
 
-       return freed;
+       return 0;
 }
 
 /*