f2fs: clarify and enhance the f2fs_gc flow

This patch makes clearer the ambiguous f2fs_gc flow as follows.

1. Remove intermediate checkpoint condition during f2fs_gc
 (i.e., should_do_checkpoint() and GC_BLOCKED)

2. Remove unnecessary return values of f2fs_gc because of #1.
 (i.e., GC_NODE, GC_OK, etc)

3. Simplify write_checkpoint() because of #2.

4. Clarify the main f2fs_gc flow.
 o monitor how many freed sections during one iteration of do_garbage_collect().
 o do GC more without checkpoints if we can't get enough free sections.
 o do checkpoint once we've got enough free sections through forground GCs.

5. Adopt thread-logging (Slack-Space-Recycle) scheme more aggressively on data
  log types. See. get_ssr_segement()

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index ddb665f54d17..8c117649a035 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -112,7 +112,7 @@ static void f2fs_put_super(struct super_block *sb)
         f2fs_destroy_stats(sbi);
         stop_gc_thread(sbi);
 
-        write_checkpoint(sbi, false, true);
+        write_checkpoint(sbi, true);
 
         iput(sbi->node_inode);
         iput(sbi->meta_inode);
@@ -136,7 +136,7 @@ int f2fs_sync_fs(struct super_block *sb, int sync)
                 return 0;
 
         if (sync)
-                write_checkpoint(sbi, false, false);
+                write_checkpoint(sbi, false);
         else
                 f2fs_balance_fs(sbi);