Commit 7e515b31 authored Oct 18, 2017 by Chao Yu Committed by Jaegeuk Kim Oct 26, 2017

f2fs: fix to correct no_fggc_candidate



There may be extreme case as below:

For one section contains one segment, and there are total 100 segments
with 10% over-privision ratio in f2fs partition, fggc_threshold will
be rounded down to 460 instead of 460.8 as below caclulation:

sbi->fggc_threshold = div_u64((u64)(main_count - ovp_count) *
			BLKS_PER_SEC(sbi), (main_count - resv_count));

If section usage is as:
60 segments which contain 460 valid blocks
40 segments which contain 462 valid blocks

As valid block number in all sections is large than fggc_threshold, so
none of them will be chosen as candidate due to incorrect fggc_threshold.

Let's just soften the term of choosing foreground GC candidates.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

parent 6e5b5d41

fs/f2fs/segment.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -731,7 +731,7 @@ static inline block_t sum_blk_addr(struct f2fs_sb_info *sbi, int base, int type)
		static inline bool no_fggc_candidate(struct f2fs_sb_info *sbi,
		unsigned int secno)
		{
		if (get_valid_blocks(sbi, GET_SEG_FROM_SEC(sbi, secno), true) >=
		if (get_valid_blocks(sbi, GET_SEG_FROM_SEC(sbi, secno), true) >
		sbi->fggc_threshold)
		return true;
		return false;

Admin message