From c7b41e161368388487238d71986a65290f83d74a Mon Sep 17 00:00:00 2001
From: Yunlei He <heyunlei@huawei.com>
Date: Thu, 7 Jul 2016 12:13:33 +0800
Subject: [PATCH] f2fs: avoid mismatching block range for discard

This patch skip discard block range smaller than trim_minlen,
and can not be merged by neighbour

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/segment.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 6d16ecf9d29e..9e13db05e3f0 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -672,6 +672,10 @@ static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 			break;
 
 		end = __find_rev_next_zero_bit(dmap, max_blocks, start + 1);
+		if (force && start && end != max_blocks
+					&& (end - start) < cpc->trim_minlen)
+			continue;
+
 		__add_discard_entry(sbi, cpc, se, start, end);
 	}
 }