f2fs: separate out iostat feature

Added F2FS_IOSTAT config option to support getting IO statistics through
sysfs and printing out periodic IO statistics tracepoint events and
moved I/O statistics related codes into separate files for better
maintenance.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
[Jaegeuk Kim: set default=y]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 154 insertions, 0 deletions

diff --git a/fs/f2fs/iostat.c b/fs/f2fs/iostat.c
new file mode 100644
index 000000000000..21c29e121a86
--- /dev/null
+++ b/fs/f2fs/iostat.c
@@ -0,0 +1,154 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * f2fs iostat support
+ *
+ * Copyright 2021 Google LLC
+ * Author: Daeho Jeong <daehojeong@google.com>
+ */
+
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/seq_file.h>
+
+#include "f2fs.h"
+#include "iostat.h"
+#include <trace/events/f2fs.h>
+
+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);
+	time64_t now = ktime_get_real_seconds();
+
+	if (!sbi->iostat_enable)
+		return 0;
+
+	seq_printf(seq, "time:		%-16llu\n", now);
+
+	/* print app write IOs */
+	seq_puts(seq, "[WRITE]\n");
+	seq_printf(seq, "app buffered:	%-16llu\n",
+				sbi->rw_iostat[APP_BUFFERED_IO]);
+	seq_printf(seq, "app direct:	%-16llu\n",
+				sbi->rw_iostat[APP_DIRECT_IO]);
+	seq_printf(seq, "app mapped:	%-16llu\n",
+				sbi->rw_iostat[APP_MAPPED_IO]);
+
+	/* print fs write IOs */
+	seq_printf(seq, "fs data:	%-16llu\n",
+				sbi->rw_iostat[FS_DATA_IO]);
+	seq_printf(seq, "fs node:	%-16llu\n",
+				sbi->rw_iostat[FS_NODE_IO]);
+	seq_printf(seq, "fs meta:	%-16llu\n",
+				sbi->rw_iostat[FS_META_IO]);
+	seq_printf(seq, "fs gc data:	%-16llu\n",
+				sbi->rw_iostat[FS_GC_DATA_IO]);
+	seq_printf(seq, "fs gc node:	%-16llu\n",
+				sbi->rw_iostat[FS_GC_NODE_IO]);
+	seq_printf(seq, "fs cp data:	%-16llu\n",
+				sbi->rw_iostat[FS_CP_DATA_IO]);
+	seq_printf(seq, "fs cp node:	%-16llu\n",
+				sbi->rw_iostat[FS_CP_NODE_IO]);
+	seq_printf(seq, "fs cp meta:	%-16llu\n",
+				sbi->rw_iostat[FS_CP_META_IO]);
+
+	/* print app read IOs */
+	seq_puts(seq, "[READ]\n");
+	seq_printf(seq, "app buffered:	%-16llu\n",
+				sbi->rw_iostat[APP_BUFFERED_READ_IO]);
+	seq_printf(seq, "app direct:	%-16llu\n",
+				sbi->rw_iostat[APP_DIRECT_READ_IO]);
+	seq_printf(seq, "app mapped:	%-16llu\n",
+				sbi->rw_iostat[APP_MAPPED_READ_IO]);
+
+	/* print fs read IOs */
+	seq_printf(seq, "fs data:	%-16llu\n",
+				sbi->rw_iostat[FS_DATA_READ_IO]);
+	seq_printf(seq, "fs gc data:	%-16llu\n",
+				sbi->rw_iostat[FS_GDATA_READ_IO]);
+	seq_printf(seq, "fs compr_data:	%-16llu\n",
+				sbi->rw_iostat[FS_CDATA_READ_IO]);
+	seq_printf(seq, "fs node:	%-16llu\n",
+				sbi->rw_iostat[FS_NODE_READ_IO]);
+	seq_printf(seq, "fs meta:	%-16llu\n",
+				sbi->rw_iostat[FS_META_READ_IO]);
+
+	/* print other IOs */
+	seq_puts(seq, "[OTHER]\n");
+	seq_printf(seq, "fs discard:	%-16llu\n",
+				sbi->rw_iostat[FS_DISCARD]);
+
+	return 0;
+}
+
+static inline void f2fs_record_iostat(struct f2fs_sb_info *sbi)
+{
+	unsigned long long iostat_diff[NR_IO_TYPE];
+	int i;
+
+	if (time_is_after_jiffies(sbi->iostat_next_period))
+		return;
+
+	/* Need double check under the lock */
+	spin_lock(&sbi->iostat_lock);
+	if (time_is_after_jiffies(sbi->iostat_next_period)) {
+		spin_unlock(&sbi->iostat_lock);
+		return;
+	}
+	sbi->iostat_next_period = jiffies +
+				msecs_to_jiffies(sbi->iostat_period_ms);
+
+	for (i = 0; i < NR_IO_TYPE; i++) {
+		iostat_diff[i] = sbi->rw_iostat[i] -
+				sbi->prev_rw_iostat[i];
+		sbi->prev_rw_iostat[i] = sbi->rw_iostat[i];
+	}
+	spin_unlock(&sbi->iostat_lock);
+
+	trace_f2fs_iostat(sbi, iostat_diff);
+}
+
+void f2fs_reset_iostat(struct f2fs_sb_info *sbi)
+{
+	int i;
+
+	spin_lock(&sbi->iostat_lock);
+	for (i = 0; i < NR_IO_TYPE; i++) {
+		sbi->rw_iostat[i] = 0;
+		sbi->prev_rw_iostat[i] = 0;
+	}
+	spin_unlock(&sbi->iostat_lock);
+}
+
+void f2fs_update_iostat(struct f2fs_sb_info *sbi,
+			enum iostat_type type, unsigned long long io_bytes)
+{
+	if (!sbi->iostat_enable)
+		return;
+
+	spin_lock(&sbi->iostat_lock);
+	sbi->rw_iostat[type] += io_bytes;
+
+	if (type == APP_WRITE_IO || type == APP_DIRECT_IO)
+		sbi->rw_iostat[APP_BUFFERED_IO] =
+			sbi->rw_iostat[APP_WRITE_IO] -
+			sbi->rw_iostat[APP_DIRECT_IO];
+
+	if (type == APP_READ_IO || type == APP_DIRECT_READ_IO)
+		sbi->rw_iostat[APP_BUFFERED_READ_IO] =
+			sbi->rw_iostat[APP_READ_IO] -
+			sbi->rw_iostat[APP_DIRECT_READ_IO];
+	spin_unlock(&sbi->iostat_lock);
+
+	f2fs_record_iostat(sbi);
+}
+
+int f2fs_init_iostat(struct f2fs_sb_info *sbi)
+{
+	/* init iostat info */
+	spin_lock_init(&sbi->iostat_lock);
+	sbi->iostat_enable = false;
+	sbi->iostat_period_ms = DEFAULT_IOSTAT_PERIOD_MS;
+
+	return 0;
+}