[PATCH 1/2] f2fs: pass down write hints to block layer for bufferd write

[Hyunchul Lee]

From: Hyunchul Lee <cheol....@lge.com>

This implements which hint is passed down to block layer
for datas from the specific segment type.

segment type                     hints
------------                     -----
COLD_NODE & COLD_DATA            WRITE_LIFE_EXTREME
WARM_DATA                        WRITE_LIFE_NONE
HOT_NODE & WARM_NODE             WRITE_LIFE_LONG
HOT_DATA                         WRITE_LIFE_MEDIUM
META_DATA                        WRITE_LIFE_SHORT

Many thanks to Chao Yu and Jaegeuk Kim for comments to
implement this patch.

Signed-off-by: Hyunchul Lee <cheol....@lge.com>
---
 fs/f2fs/data.c    |  1 +
 fs/f2fs/f2fs.h    |  2 ++
 fs/f2fs/segment.c | 29 +++++++++++++++++++++++++++++
 fs/f2fs/super.c   |  2 ++
 4 files changed, 34 insertions(+)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index a7ae418..0919a43 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -437,6 +437,7 @@ int f2fs_submit_page_write(struct f2fs_io_info *fio)
                }
                io->bio = __bio_alloc(sbi, fio->new_blkaddr,
                                                BIO_MAX_PAGES, false);
+               io->bio->bi_write_hint = io->write_hint;
                io->fio = *fio;
        }
 
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 7bcd148..be3cb0c 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -969,6 +969,7 @@ struct f2fs_bio_info {
        struct rw_semaphore io_rwsem;   /* blocking op for bio */
        spinlock_t io_lock;             /* serialize DATA/NODE IOs */
        struct list_head io_list;       /* track fios */
+       enum rw_hint write_hint;
 };
 
 #define FDEV(i)                                (sbi->devs[i])
@@ -2674,6 +2675,7 @@ int lookup_journal_in_cursum(struct f2fs_journal 
*journal, int type,
 int __init create_segment_manager_caches(void);
 void destroy_segment_manager_caches(void);
 int rw_hint_to_seg_type(enum rw_hint hint);
+enum rw_hint io_type_to_rw_hint(enum page_type page, enum temp_type temp);
 
 /*
  * checkpoint.c
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index c117e09..0570db7 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2446,6 +2446,35 @@ int rw_hint_to_seg_type(enum rw_hint hint)
        }
 }
 
+enum rw_hint io_type_to_rw_hint(enum page_type page, enum temp_type temp)
+{
+       if (page == DATA) {
+               switch (temp) {
+               case WARM:
+                       return WRITE_LIFE_NONE;
+               case COLD:
+                       return WRITE_LIFE_EXTREME;
+               case HOT:
+                       return WRITE_LIFE_MEDIUM;
+               default:
+                       return WRITE_LIFE_NOT_SET;
+               }
+       } else if (page == NODE) {
+               switch (temp) {
+               case WARM:
+               case HOT:
+                       return WRITE_LIFE_LONG;
+               case COLD:
+                       return WRITE_LIFE_EXTREME;
+               default:
+                       return WRITE_LIFE_NOT_SET;
+               }
+
+       } else {
+               return WRITE_LIFE_SHORT;
+       }
+}
+
 static int __get_segment_type_2(struct f2fs_io_info *fio)
 {
        if (fio->type == DATA)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index a6c5dd4..51c19a0 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2508,6 +2508,8 @@ static int f2fs_fill_super(struct super_block *sb, void 
*data, int silent)
                        sbi->write_io[i][j].bio = NULL;
                        spin_lock_init(&sbi->write_io[i][j].io_lock);
                        INIT_LIST_HEAD(&sbi->write_io[i][j].io_list);
+                       sbi->write_io[i][j].write_hint =
+                                               io_type_to_rw_hint(i, j);
                }
        }
 
-- 
1.9.1