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>

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index aa1d30d76719ca11a79ad2f56a07e7d71cea45ef..67f1e5bbdac9d60a18ff86a5984ecc8820c3a1d3 100644 (file)
--- 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;
 }
 
 /*