[PATCH] f2fs: including waf data in f2fs status information

[beomsu kim]

When evaluating in f2fs, it takes much time to obtain waf data.
This patch helps to obtain waf data without calcluation.

Signed-off-by: Beomsu Kim <beomsu7.kim@xxxxxxxxxxx>
---
 fs/f2fs/iostat.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/fs/f2fs/iostat.c b/fs/f2fs/iostat.c
index 3d5bfb1ad585..6eab11b0610d 100644
--- a/fs/f2fs/iostat.c
+++ b/fs/f2fs/iostat.c
@@ -34,10 +34,22 @@ int __maybe_unused iostat_info_seq_show(struct seq_file *seq, void *offset)
 {
        struct super_block *sb = seq->private;
        struct f2fs_sb_info *sbi = F2FS_SB(sb);
+       int j;
+       unsigned long long waf = 0;
+       unsigned long long data_written_to_storage = 0;
+       unsigned long long data_written_by_user = 0;
 
        if (!sbi->iostat_enable)
                return 0;
 
+       for (j = FS_DATA_IO; j <= FS_CP_META_IO; j++)
+               data_written_to_storage += sbi->iostat_bytes[j];
+       for (j = FS_DATA_IO; j <= FS_CDATA_IO; j++)
+               data_written_by_user += sbi->iostat_bytes[j];
+
+       if (data_written_by_user > 0)
+               waf = data_written_to_storage * 100 / data_written_by_user;
+
        seq_printf(seq, "time:          %-16llu\n", ktime_get_real_seconds());
        seq_printf(seq, "\t\t\t%-16s %-16s %-16s\n",
                                "io_bytes", "count", "avg_bytes");
@@ -81,6 +93,10 @@ int __maybe_unused iostat_info_seq_show(struct seq_file *seq, void *offset)
        IOSTAT_INFO_SHOW("fs discard", FS_DISCARD_IO);
        IOSTAT_INFO_SHOW("fs flush", FS_FLUSH_IO);
 
+       /* print waf */
+       seq_puts(seq, "[WAF]\n");
+       seq_printf(seq, "fs waf:                %llu.%02llu\n", waf / 100, waf % 100);
+
        return 0;
 }
 
-- 
2.17.1