f2fs: do FG_GC when GC boosting is required for zoned devices

Under low free section count, we need to use FG_GC instead of BG_GC to
recover free sections.
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/f2fs.h

@@ -1300,6 +1300,7 @@ struct f2fs_gc_control {
 	bool no_bg_gc;			/* check the space and stop bg_gc */
 	bool should_migrate_blocks;	/* should migrate blocks */
 	bool err_gc_skipped;		/* return EAGAIN if GC skipped */
+	bool one_time;			/* require one time GC in one migration unit */
 	unsigned int nr_free_secs;	/* # of free sections to do GC */
 };
 

fs/f2fs/gc.c

@@ -81,6 +81,8 @@ static int gc_thread_func(void *data)
 			continue;
 		}
 
+		gc_control.one_time = false;
+
 		/*
 		 * [GC triggering condition]
 		 * 0. GC is not conducted currently.
@@ -126,15 +128,19 @@ static int gc_thread_func(void *data)
 				wait_ms = gc_th->max_sleep_time;
 		}
 
-		if (need_to_boost_gc(sbi))
+		if (need_to_boost_gc(sbi)) {
 			decrease_sleep_time(gc_th, &wait_ms);
-		else
+			if (f2fs_sb_has_blkzoned(sbi))
+				gc_control.one_time = true;
+		} else {
 			increase_sleep_time(gc_th, &wait_ms);
+		}
 do_gc:
 		stat_inc_gc_call_count(sbi, foreground ?
 					FOREGROUND : BACKGROUND);
 
-		sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC;
+		sync_mode = (F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC) ||
+				gc_control.one_time;
 
 		/* foreground GC was been triggered via f2fs_balance_fs() */
 		if (foreground)
@@ -1701,7 +1707,7 @@ static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
 static int do_garbage_collect(struct f2fs_sb_info *sbi,
 				unsigned int start_segno,
 				struct gc_inode_list *gc_list, int gc_type,
-				bool force_migrate)
+				bool force_migrate, bool one_time)
 {
 	struct page *sum_page;
 	struct f2fs_summary_block *sum;
@@ -1728,7 +1734,7 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
 			sec_end_segno -= SEGS_PER_SEC(sbi) -
 					f2fs_usable_segs_in_sec(sbi, segno);
 
-		if (gc_type == BG_GC) {
+		if (gc_type == BG_GC || one_time) {
 			unsigned int window_granularity =
 				sbi->migration_window_granularity;
 
@@ -1911,7 +1917,8 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
 	}
 
 	seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type,
-				gc_control->should_migrate_blocks);
+				gc_control->should_migrate_blocks,
+				gc_control->one_time);
 	if (seg_freed < 0)
 		goto stop;
 
@@ -1922,6 +1929,9 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
 		total_sec_freed++;
 	}
 
+	if (gc_control->one_time)
+		goto stop;
+
 	if (gc_type == FG_GC) {
 		sbi->cur_victim_sec = NULL_SEGNO;
 
@@ -2047,7 +2057,7 @@ int f2fs_gc_range(struct f2fs_sb_info *sbi,
 		};
 
 		do_garbage_collect(sbi, segno, &gc_list, FG_GC,
-						dry_run_sections == 0);
+						dry_run_sections == 0, false);
 		put_gc_inode(&gc_list);
 
 		if (!dry_run && get_valid_blocks(sbi, segno, true))