f2fs: improve searching speed of __next_free_blkoff

To find a zero bit using the result of OR operation between ckpt_valid_map
and cur_valid_map is more fast than find a zero bit in each bitmap.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
[Jaegeuk Kim: adjust changed function name]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 12 insertions, 7 deletions

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index aa1d30d76719..67f1e5bbdac9 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -607,13 +607,18 @@ static void __next_free_blkoff(struct f2fs_sb_info *sbi,
                         struct curseg_info *seg, block_t start)
 {
         struct seg_entry *se = get_seg_entry(sbi, seg->segno);
-        block_t ofs;
-        for (ofs = start; ofs < sbi->blocks_per_seg; ofs++) {
-                if (!f2fs_test_bit(ofs, se->ckpt_valid_map)
-                        && !f2fs_test_bit(ofs, se->cur_valid_map))
-                        break;
-        }
-        seg->next_blkoff = ofs;
+        int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
+        unsigned long target_map[entries];
+        unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
+        unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
+        int i, pos;
+
+        for (i = 0; i < entries; i++)
+                target_map[i] = ckpt_map[i] | cur_map[i];
+
+        pos = __find_rev_next_zero_bit(target_map, sbi->blocks_per_seg, start);
+
+        seg->next_blkoff = pos;
 }
 
 /*