linux/fs/f2fs/iostat.c
Eric Biggers a1e09b03e6 f2fs: use iomap for direct I/O
Make f2fs_file_read_iter() and f2fs_file_write_iter() use the iomap
direct I/O implementation instead of the fs/direct-io.c one.

The iomap implementation is more efficient, and it also avoids the need
to add new features and optimizations to the old implementation.

This new implementation also eliminates the need for f2fs to hook bio
submission and completion and to allocate memory per-bio.  This is
because it's possible to correctly update f2fs's in-flight DIO counters
using __iomap_dio_rw() in combination with an implementation of
iomap_dio_ops::end_io() (as suggested by Christoph Hellwig).

When possible, this new implementation preserves existing f2fs behavior
such as the conditions for falling back to buffered I/O.

This patch has been tested with xfstests by running 'gce-xfstests -c
f2fs -g auto -X generic/017' with and without this patch; no regressions
were seen.  (Some tests fail both before and after.  generic/017 hangs
both before and after, so it had to be excluded.)

Signed-off-by: Eric Biggers <ebiggers@google.com>
[Jaegeuk Kim: use spin_lock_bh for f2fs_update_iostat in softirq]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-12-10 15:48:30 -08:00

284 lines
7.3 KiB
C

// 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_bh(&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_bh(&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_bh(&sbi->iostat_lock);
if (time_is_after_jiffies(sbi->iostat_next_period)) {
spin_unlock_bh(&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_bh(&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_bh(&sbi->iostat_lock);
for (i = 0; i < NR_IO_TYPE; i++) {
sbi->rw_iostat[i] = 0;
sbi->prev_rw_iostat[i] = 0;
}
spin_unlock_bh(&sbi->iostat_lock);
spin_lock_bh(&sbi->iostat_lat_lock);
memset(io_lat, 0, sizeof(struct iostat_lat_info));
spin_unlock_bh(&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_bh(&sbi->iostat_lock);
sbi->rw_iostat[type] += io_bytes;
if (type == APP_BUFFERED_IO || type == APP_DIRECT_IO)
sbi->rw_iostat[APP_WRITE_IO] += io_bytes;
if (type == APP_BUFFERED_READ_IO || type == APP_DIRECT_READ_IO)
sbi->rw_iostat[APP_READ_IO] += io_bytes;
spin_unlock_bh(&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;
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_bh(&sbi->iostat_lat_lock);
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_bh(&sbi->iostat_lat_lock);
}
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);
}