1 files changed, 287 insertions, 0 deletions
diff --git a/fs/f2fs/iostat.c b/fs/f2fs/iostat.c
new file mode 100644
index 000000000000..cdcf54ae0db8
--- /dev/null
+++ b/fs/f2fs/iostat.c
@@ -0,0 +1,287 @@
+// 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>
+
+#define NUM_PREALLOC_IOSTAT_CTXS	128
+static struct kmem_cache *bio_iostat_ctx_cache;
+static mempool_t *bio_iostat_ctx_pool;
+
+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 __record_iostat_latency(struct f2fs_sb_info *sbi)
+{
+	int io, idx = 0;
+	unsigned int cnt;
+	struct f2fs_iostat_latency iostat_lat[MAX_IO_TYPE][NR_PAGE_TYPE];
+	struct iostat_lat_info *io_lat = sbi->iostat_io_lat;
+
+	spin_lock_irq(&sbi->iostat_lat_lock);
+	for (idx = 0; idx < MAX_IO_TYPE; idx++) {
+		for (io = 0; io < NR_PAGE_TYPE; io++) {
+			cnt = io_lat->bio_cnt[idx][io];
+			iostat_lat[idx][io].peak_lat =
+			   jiffies_to_msecs(io_lat->peak_lat[idx][io]);
+			iostat_lat[idx][io].cnt = cnt;
+			iostat_lat[idx][io].avg_lat = cnt ?
+			   jiffies_to_msecs(io_lat->sum_lat[idx][io]) / cnt : 0;
+			io_lat->sum_lat[idx][io] = 0;
+			io_lat->peak_lat[idx][io] = 0;
+			io_lat->bio_cnt[idx][io] = 0;
+		}
+	}
+	spin_unlock_irq(&sbi->iostat_lat_lock);
+
+	trace_f2fs_iostat_latency(sbi, iostat_lat);
+}
+
+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);
+
+	__record_iostat_latency(sbi);
+}
+
+void f2fs_reset_iostat(struct f2fs_sb_info *sbi)
+{
+	struct iostat_lat_info *io_lat = sbi->iostat_io_lat;
+	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);
+
+	spin_lock_irq(&sbi->iostat_lat_lock);
+	memset(io_lat, 0, sizeof(struct iostat_lat_info));
+	spin_unlock_irq(&sbi->iostat_lat_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);
+}
+
+static inline void __update_iostat_latency(struct bio_iostat_ctx *iostat_ctx,
+				int rw, bool is_sync)
+{
+	unsigned long ts_diff;
+	unsigned int iotype = iostat_ctx->type;
+	unsigned long flags;
+	struct f2fs_sb_info *sbi = iostat_ctx->sbi;
+	struct iostat_lat_info *io_lat = sbi->iostat_io_lat;
+	int idx;
+
+	if (!sbi->iostat_enable)
+		return;
+
+	ts_diff = jiffies - iostat_ctx->submit_ts;
+	if (iotype >= META_FLUSH)
+		iotype = META;
+
+	if (rw == 0) {
+		idx = READ_IO;
+	} else {
+		if (is_sync)
+			idx = WRITE_SYNC_IO;
+		else
+			idx = WRITE_ASYNC_IO;
+	}
+
+	spin_lock_irqsave(&sbi->iostat_lat_lock, flags);
+	io_lat->sum_lat[idx][iotype] += ts_diff;
+	io_lat->bio_cnt[idx][iotype]++;
+	if (ts_diff > io_lat->peak_lat[idx][iotype])
+		io_lat->peak_lat[idx][iotype] = ts_diff;
+	spin_unlock_irqrestore(&sbi->iostat_lat_lock, flags);
+}
+
+void iostat_update_and_unbind_ctx(struct bio *bio, int rw)
+{
+	struct bio_iostat_ctx *iostat_ctx = bio->bi_private;
+	bool is_sync = bio->bi_opf & REQ_SYNC;
+
+	if (rw == 0)
+		bio->bi_private = iostat_ctx->post_read_ctx;
+	else
+		bio->bi_private = iostat_ctx->sbi;
+	__update_iostat_latency(iostat_ctx, rw, is_sync);
+	mempool_free(iostat_ctx, bio_iostat_ctx_pool);
+}
+
+void iostat_alloc_and_bind_ctx(struct f2fs_sb_info *sbi,
+		struct bio *bio, struct bio_post_read_ctx *ctx)
+{
+	struct bio_iostat_ctx *iostat_ctx;
+	/* Due to the mempool, this never fails. */
+	iostat_ctx = mempool_alloc(bio_iostat_ctx_pool, GFP_NOFS);
+	iostat_ctx->sbi = sbi;
+	iostat_ctx->submit_ts = 0;
+	iostat_ctx->type = 0;
+	iostat_ctx->post_read_ctx = ctx;
+	bio->bi_private = iostat_ctx;
+}
+
+int __init f2fs_init_iostat_processing(void)
+{
+	bio_iostat_ctx_cache =
+		kmem_cache_create("f2fs_bio_iostat_ctx",
+				  sizeof(struct bio_iostat_ctx), 0, 0, NULL);
+	if (!bio_iostat_ctx_cache)
+		goto fail;
+	bio_iostat_ctx_pool =
+		mempool_create_slab_pool(NUM_PREALLOC_IOSTAT_CTXS,
+					 bio_iostat_ctx_cache);
+	if (!bio_iostat_ctx_pool)
+		goto fail_free_cache;
+	return 0;
+
+fail_free_cache:
+	kmem_cache_destroy(bio_iostat_ctx_cache);
+fail:
+	return -ENOMEM;
+}
+
+void f2fs_destroy_iostat_processing(void)
+{
+	mempool_destroy(bio_iostat_ctx_pool);
+	kmem_cache_destroy(bio_iostat_ctx_cache);
+}
+
+int f2fs_init_iostat(struct f2fs_sb_info *sbi)
+{
+	/* init iostat info */
+	spin_lock_init(&sbi->iostat_lock);
+	spin_lock_init(&sbi->iostat_lat_lock);
+	sbi->iostat_enable = false;
+	sbi->iostat_period_ms = DEFAULT_IOSTAT_PERIOD_MS;
+	sbi->iostat_io_lat = f2fs_kzalloc(sbi, sizeof(struct iostat_lat_info),
+					GFP_KERNEL);
+	if (!sbi->iostat_io_lat)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void f2fs_destroy_iostat(struct f2fs_sb_info *sbi)
+{
+	kfree(sbi->iostat_io_lat);
+}