f2fs: add discard info to sys entry of f2fs status

This patch add discard block count to sys entry of f2fs status
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/debug.c

@@ -54,6 +54,7 @@ static void update_general_status(struct f2fs_sb_info *sbi)
 	si->rsvd_segs = reserved_segments(sbi);
 	si->overp_segs = overprovision_segments(sbi);
 	si->valid_count = valid_user_blocks(sbi);
+	si->discard_blks = discard_blocks(sbi);
 	si->valid_node_count = valid_node_count(sbi);
 	si->valid_inode_count = valid_inode_count(sbi);
 	si->inline_xattr = atomic_read(&sbi->inline_xattr);
@@ -230,8 +231,13 @@ static int stat_show(struct seq_file *s, void *v)
 			   si->ssa_area_segs, si->main_area_segs);
 		seq_printf(s, "(OverProv:%d Resv:%d)]\n\n",
 			   si->overp_segs, si->rsvd_segs);
-		seq_printf(s, "Utilization: %d%% (%d valid blocks)\n",
+		if (test_opt(si->sbi, DISCARD))
+			seq_printf(s, "Utilization: %u%% (%u valid blocks, %u discard blocks)\n",
+				si->utilization, si->valid_count, si->discard_blks);
+		else
+			seq_printf(s, "Utilization: %u%% (%u valid blocks)\n",
 				si->utilization, si->valid_count);
+
 		seq_printf(s, "  - Node: %u (Inode: %u, ",
 			   si->valid_node_count, si->valid_inode_count);
 		seq_printf(s, "Other: %u)\n  - Data: %u\n",

fs/f2fs/f2fs.h

@@ -1250,6 +1250,11 @@ static inline block_t valid_user_blocks(struct f2fs_sb_info *sbi)
 	return sbi->total_valid_block_count;
 }
 
+static inline block_t discard_blocks(struct f2fs_sb_info *sbi)
+{
+	return sbi->discard_blks;
+}
+
 static inline unsigned long __bitmap_size(struct f2fs_sb_info *sbi, int flag)
 {
 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
@@ -2136,7 +2141,7 @@ struct f2fs_stat_info {
 	int total_count, utilization;
 	int bg_gc, wb_bios;
 	int inline_xattr, inline_inode, inline_dir, orphans;
-	unsigned int valid_count, valid_node_count, valid_inode_count;
+	unsigned int valid_count, valid_node_count, valid_inode_count, discard_blks;
 	unsigned int bimodal, avg_vblocks;
 	int util_free, util_valid, util_invalid;
 	int rsvd_segs, overp_segs;