f2fs: Add f2fs stats to sysfs

Currently f2fs stats are only available from /d/f2fs/status. This patch
adds some of the f2fs stats to sysfs so that they are accessible even
when debugfs is not mounted.

The following sysfs nodes are added:
-/sys/fs/f2fs/<disk>/free_segments
-/sys/fs/f2fs/<disk>/cp_foreground_calls
-/sys/fs/f2fs/<disk>/cp_background_calls
-/sys/fs/f2fs/<disk>/gc_foreground_calls
-/sys/fs/f2fs/<disk>/gc_background_calls
-/sys/fs/f2fs/<disk>/moved_blocks_foreground
-/sys/fs/f2fs/<disk>/moved_blocks_background
-/sys/fs/f2fs/<disk>/avg_vblocks

Signed-off-by: Hridya Valsaraju <hridya@google.com>
[Jaegeuk Kim: allow STAT_FS without DEBUG_FS]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 43 insertions, 36 deletions

diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index ce2936554ef8..6b89eae5e4ca 100644
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -21,9 +21,45 @@
 #include "gc.h"
 
 static LIST_HEAD(f2fs_stat_list);
-static struct dentry *f2fs_debugfs_root;
 static DEFINE_MUTEX(f2fs_stat_mutex);
+#ifdef CONFIG_DEBUG_FS
+static struct dentry *f2fs_debugfs_root;
+#endif
+
+/*
+ * This function calculates BDF of every segments
+ */
+void f2fs_update_sit_info(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
+	unsigned long long blks_per_sec, hblks_per_sec, total_vblocks;
+	unsigned long long bimodal, dist;
+	unsigned int segno, vblocks;
+	int ndirty = 0;
+
+	bimodal = 0;
+	total_vblocks = 0;
+	blks_per_sec = BLKS_PER_SEC(sbi);
+	hblks_per_sec = blks_per_sec / 2;
+	for (segno = 0; segno < MAIN_SEGS(sbi); segno += sbi->segs_per_sec) {
+		vblocks = get_valid_blocks(sbi, segno, true);
+		dist = abs(vblocks - hblks_per_sec);
+		bimodal += dist * dist;
+
+		if (vblocks > 0 && vblocks < blks_per_sec) {
+			total_vblocks += vblocks;
+			ndirty++;
+		}
+	}
+	dist = div_u64(MAIN_SECS(sbi) * hblks_per_sec * hblks_per_sec, 100);
+	si->bimodal = div64_u64(bimodal, dist);
+	if (si->dirty_count)
+		si->avg_vblocks = div_u64(total_vblocks, ndirty);
+	else
+		si->avg_vblocks = 0;
+}
 
+#ifdef CONFIG_DEBUG_FS
 static void update_general_status(struct f2fs_sb_info *sbi)
 {
 	struct f2fs_stat_info *si = F2FS_STAT(sbi);
@@ -116,7 +152,6 @@ static void update_general_status(struct f2fs_sb_info *sbi)
 	si->free_nids = NM_I(sbi)->nid_cnt[FREE_NID];
 	si->avail_nids = NM_I(sbi)->available_nids;
 	si->alloc_nids = NM_I(sbi)->nid_cnt[PREALLOC_NID];
-	si->bg_gc = sbi->bg_gc;
 	si->io_skip_bggc = sbi->io_skip_bggc;
 	si->other_skip_bggc = sbi->other_skip_bggc;
 	si->skipped_atomic_files[BG_GC] = sbi->skipped_atomic_files[BG_GC];
@@ -148,39 +183,6 @@ static void update_general_status(struct f2fs_sb_info *sbi)
 }
 
 /*
- * This function calculates BDF of every segments
- */
-static void update_sit_info(struct f2fs_sb_info *sbi)
-{
-	struct f2fs_stat_info *si = F2FS_STAT(sbi);
-	unsigned long long blks_per_sec, hblks_per_sec, total_vblocks;
-	unsigned long long bimodal, dist;
-	unsigned int segno, vblocks;
-	int ndirty = 0;
-
-	bimodal = 0;
-	total_vblocks = 0;
-	blks_per_sec = BLKS_PER_SEC(sbi);
-	hblks_per_sec = blks_per_sec / 2;
-	for (segno = 0; segno < MAIN_SEGS(sbi); segno += sbi->segs_per_sec) {
-		vblocks = get_valid_blocks(sbi, segno, true);
-		dist = abs(vblocks - hblks_per_sec);
-		bimodal += dist * dist;
-
-		if (vblocks > 0 && vblocks < blks_per_sec) {
-			total_vblocks += vblocks;
-			ndirty++;
-		}
-	}
-	dist = div_u64(MAIN_SECS(sbi) * hblks_per_sec * hblks_per_sec, 100);
-	si->bimodal = div64_u64(bimodal, dist);
-	if (si->dirty_count)
-		si->avg_vblocks = div_u64(total_vblocks, ndirty);
-	else
-		si->avg_vblocks = 0;
-}
-
-/*
  * This function calculates memory footprint.
  */
 static void update_mem_info(struct f2fs_sb_info *sbi)
@@ -445,7 +447,7 @@ static int stat_show(struct seq_file *s, void *v)
 			   si->block_count[LFS], si->segment_count[LFS]);
 
 		/* segment usage info */
-		update_sit_info(si->sbi);
+		f2fs_update_sit_info(si->sbi);
 		seq_printf(s, "\nBDF: %u, avg. vblocks: %u\n",
 			   si->bimodal, si->avg_vblocks);
 
@@ -465,6 +467,7 @@ static int stat_show(struct seq_file *s, void *v)
 }
 
 DEFINE_SHOW_ATTRIBUTE(stat);
+#endif
 
 int f2fs_build_stats(struct f2fs_sb_info *sbi)
 {
@@ -525,14 +528,18 @@ void f2fs_destroy_stats(struct f2fs_sb_info *sbi)
 
 void __init f2fs_create_root_stats(void)
 {
+#ifdef CONFIG_DEBUG_FS
 	f2fs_debugfs_root = debugfs_create_dir("f2fs", NULL);
 
 	debugfs_create_file("status", S_IRUGO, f2fs_debugfs_root, NULL,
 			    &stat_fops);
+#endif
 }
 
 void f2fs_destroy_root_stats(void)
 {
+#ifdef CONFIG_DEBUG_FS
 	debugfs_remove_recursive(f2fs_debugfs_root);
 	f2fs_debugfs_root = NULL;
+#endif
 }