f2fs: change reclaim rate in percentage

It is more reasonable to determine the reclaiming rate of prefree segments
according to the volume size, which is set to 5% by default.
For example, if the volume is 128GB, the prefree segments are reclaimed
when the number reaches to 6.4GB.

Signed-off-by: Jaegeuk Kim <[email protected]>
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 6c5a4f021..e7ff23a5 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1758,7 +1758,8 @@
 	sm_info->ovp_segments = le32_to_cpu(ckpt->overprov_segment_count);
 	sm_info->main_segments = le32_to_cpu(raw_super->segment_count_main);
 	sm_info->ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
-	sm_info->rec_prefree_segments = DEF_RECLAIM_PREFREE_SEGMENTS;
+	sm_info->rec_prefree_segments = sm_info->main_segments *
+					DEF_RECLAIM_PREFREE_SEGMENTS / 100;
 	sm_info->ipu_policy = F2FS_IPU_DISABLE;
 	sm_info->min_ipu_util = DEF_MIN_IPU_UTIL;