[PATCH 4/5] f2fs: add maximum prefree segments

[Jaegeuk Kim <jaegeuk@kernel.org>]

In 1TB storage, we need to admit 22841 prefree segments, which can consume
too much segments.
This patch sets 8GB in max. prefree segments in that case.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/segment.c | 3 +++
 fs/f2fs/segment.h | 1 +
 2 files changed, 4 insertions(+)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 08f6c0b..e87aa05 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2409,6 +2409,9 @@ int build_segment_manager(struct f2fs_sb_info *sbi)
 	sm_info->ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
 	sm_info->rec_prefree_segments = sm_info->main_segments *
 					DEF_RECLAIM_PREFREE_SEGMENTS / 100;
+	if (sm_info->rec_prefree_segments > DEF_MAX_RECLAIM_PREFREE_SEGMENTS)
+		sm_info->rec_prefree_segments = DEF_MAX_RECLAIM_PREFREE_SEGMENTS;
+
 	if (!test_opt(sbi, LFS))
 		sm_info->ipu_policy = 1 << F2FS_IPU_FSYNC;
 	sm_info->min_ipu_util = DEF_MIN_IPU_UTIL;
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 57d450f..b33f73e 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -16,6 +16,7 @@
 #define NULL_SECNO			((unsigned int)(~0))
 
 #define DEF_RECLAIM_PREFREE_SEGMENTS	5	/* 5% over total segments */
+#define DEF_MAX_RECLAIM_PREFREE_SEGMENTS	4096	/* 8GB in maximum */
 
 /* L: Logical segment # in volume, R: Relative segment # in main area */
 #define GET_L2R_SEGNO(free_i, segno)	(segno - free_i->start_segno)
-- 
2.8.3