f2fs: show # of on-going flush and discard bios

This patch adds stat information for flush and discard commands.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/debug.c

@@ -54,6 +54,12 @@ static void update_general_status(struct f2fs_sb_info *sbi)
 	si->max_aw_cnt = atomic_read(&sbi->max_aw_cnt);
 	si->nr_wb_cp_data = get_pages(sbi, F2FS_WB_CP_DATA);
 	si->nr_wb_data = get_pages(sbi, F2FS_WB_DATA);
+	if (SM_I(sbi) && SM_I(sbi)->fcc_info)
+		si->nr_flush =
+			atomic_read(&SM_I(sbi)->fcc_info->submit_flush);
+	if (SM_I(sbi) && SM_I(sbi)->dcc_info)
+		si->nr_discard =
+			atomic_read(&SM_I(sbi)->dcc_info->submit_discard);
 	si->total_count = (int)sbi->user_block_count / sbi->blocks_per_seg;
 	si->rsvd_segs = reserved_segments(sbi);
 	si->overp_segs = overprovision_segments(sbi);
@@ -318,8 +324,9 @@ static int stat_show(struct seq_file *s, void *v)
 		seq_printf(s, "  - Inner Struct Count: tree: %d(%d), node: %d\n",
 				si->ext_tree, si->zombie_tree, si->ext_node);
 		seq_puts(s, "\nBalancing F2FS Async:\n");
-		seq_printf(s, "  - IO (CP: %4d, Data: %4d)\n",
-			   si->nr_wb_cp_data, si->nr_wb_data);
+		seq_printf(s, "  - IO (CP: %4d, Data: %4d, Flush: %4d, Discard: %4d)\n",
+			   si->nr_wb_cp_data, si->nr_wb_data,
+			   si->nr_flush, si->nr_discard);
 		seq_printf(s, "  - inmem: %4d, atomic IO: %4d (Max. %4d)\n",
 			   si->inmem_pages, si->aw_cnt, si->max_aw_cnt);
 		seq_printf(s, "  - nodes: %4d in %4d\n",

fs/f2fs/f2fs.h

@@ -206,6 +206,7 @@ struct discard_cmd_control {
 	wait_queue_head_t discard_wait_queue;	/* waiting queue for wake-up */
 	struct mutex cmd_lock;
 	int max_discards;			/* max. discards to be issued */
+	atomic_t submit_discard;		/* # of issued discard */
 };
 
 /* for the list of fsync inodes, used only during recovery */
@@ -2262,7 +2263,7 @@ struct f2fs_stat_info {
 	unsigned int ndirty_dirs, ndirty_files, ndirty_all;
 	int nats, dirty_nats, sits, dirty_sits, free_nids, alloc_nids;
 	int total_count, utilization;
-	int bg_gc, nr_wb_cp_data, nr_wb_data;
+	int bg_gc, nr_wb_cp_data, nr_wb_data, nr_flush, nr_discard;
 	int inline_xattr, inline_inode, inline_dir, orphans;
 	int aw_cnt, max_aw_cnt;
 	unsigned int valid_count, valid_node_count, valid_inode_count, discard_blks;

fs/f2fs/segment.c

@@ -653,6 +653,9 @@ static void __remove_discard_cmd(struct f2fs_sb_info *sbi, struct discard_cmd *d
 {
 	int err = dc->bio->bi_error;
 
+	if (dc->state == D_DONE)
+		atomic_dec(&(SM_I(sbi)->dcc_info->submit_discard));
+
 	if (err == -EOPNOTSUPP)
 		err = 0;
 
@@ -678,6 +681,7 @@ void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
 			if (dc->state == D_PREP) {
 				dc->state = D_SUBMIT;
 				submit_bio(dc->bio);
+				atomic_inc(&dcc->submit_discard);
 			}
 			wait_for_completion_io(&dc->wait);
 
@@ -723,6 +727,7 @@ static int issue_discard_thread(void *data)
 		if (dc->state == D_PREP) {
 			dc->state = D_SUBMIT;
 			submit_bio(dc->bio);
+			atomic_inc(&dcc->submit_discard);
 			if (iter++ > DISCARD_ISSUE_RATE)
 				break;
 		} else if (dc->state == D_DONE) {
@@ -1049,6 +1054,7 @@ int create_discard_cmd_control(struct f2fs_sb_info *sbi)
 	INIT_LIST_HEAD(&dcc->discard_entry_list);
 	INIT_LIST_HEAD(&dcc->discard_cmd_list);
 	mutex_init(&dcc->cmd_lock);
+	atomic_set(&dcc->submit_discard, 0);
 	dcc->nr_discards = 0;
 	dcc->max_discards = 0;