f2fs: add ovp valid_blocks check for bg gc victim to fg_gc
commit e93b9865251a0503d83fd570e7d5a7c8bc351715 upstream.
For foreground gc, greedy algorithm should be adapted, which makes
this formula work well:
(2 * (100 / config.overprovision + 1) + 6)
But currently, we fg_gc have a prior to select bg_gc victim segments to gc
first, these victims are selected by cost-benefit algorithm, we can't guarantee
such segments have the small valid blocks, which may destroy the f2fs rule, on
the worstest case, would consume all the free segments.
This patch fix this by add a filter in check_bg_victims, if segment's has # of
valid blocks over overprovision ratio, skip such segments.
Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index ecc3fd0..3a1640b 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -834,6 +834,9 @@
struct f2fs_gc_kthread *gc_thread; /* GC thread */
unsigned int cur_victim_sec; /* current victim section num */
+ /* threshold for converting bg victims for fg */
+ u64 fggc_threshold;
+
/* maximum # of trials to find a victim segment for SSR and GC */
unsigned int max_victim_search;
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 6f14ee9..34a69e7 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -166,7 +166,8 @@
p->ofs_unit = sbi->segs_per_sec;
}
- if (p->max_search > sbi->max_victim_search)
+ /* we need to check every dirty segments in the FG_GC case */
+ if (gc_type != FG_GC && p->max_search > sbi->max_victim_search)
p->max_search = sbi->max_victim_search;
p->offset = sbi->last_victim[p->gc_mode];
@@ -199,6 +200,10 @@
for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
if (sec_usage_check(sbi, secno))
continue;
+
+ if (no_fggc_candidate(sbi, secno))
+ continue;
+
clear_bit(secno, dirty_i->victim_secmap);
return secno * sbi->segs_per_sec;
}
@@ -322,13 +327,15 @@
nsearched++;
}
-
secno = GET_SECNO(sbi, segno);
if (sec_usage_check(sbi, secno))
goto next;
if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
goto next;
+ if (gc_type == FG_GC && p.alloc_mode == LFS &&
+ no_fggc_candidate(sbi, secno))
+ goto next;
cost = get_gc_cost(sbi, segno, &p);
@@ -972,5 +979,16 @@
void build_gc_manager(struct f2fs_sb_info *sbi)
{
+ u64 main_count, resv_count, ovp_count, blocks_per_sec;
+
DIRTY_I(sbi)->v_ops = &default_v_ops;
+
+ /* threshold of # of valid blocks in a section for victims of FG_GC */
+ main_count = SM_I(sbi)->main_segments << sbi->log_blocks_per_seg;
+ resv_count = SM_I(sbi)->reserved_segments << sbi->log_blocks_per_seg;
+ ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
+ blocks_per_sec = sbi->blocks_per_seg * sbi->segs_per_sec;
+
+ sbi->fggc_threshold = div_u64((main_count - ovp_count) * blocks_per_sec,
+ (main_count - resv_count));
}
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index fecb856..b164f83 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -688,6 +688,15 @@
- (base + 1) + type;
}
+static inline bool no_fggc_candidate(struct f2fs_sb_info *sbi,
+ unsigned int secno)
+{
+ if (get_valid_blocks(sbi, secno, sbi->segs_per_sec) >=
+ sbi->fggc_threshold)
+ return true;
+ return false;
+}
+
static inline bool sec_usage_check(struct f2fs_sb_info *sbi, unsigned int secno)
{
if (IS_CURSEC(sbi, secno) || (sbi->cur_victim_sec == secno))