Re: [PATCH v6] f2fs: add async reset zone command support

From: Jaegeuk Kim
Date: Tue May 09 2023 - 14:53:44 EST


On 05/08, Daejun Park wrote:
> v5 -> v6
> Added trace_f2fs_iostat support for zone reset command.
>
> v4 -> v5
> Added f2fs iostat for zone reset command.
>
> v3 -> v4
> Fixed build error caused by unused function.
>
> v2 -> v3
> Modified arguments to be correct for ftrace parameter.
> Changed __submit_zone_reset_cmd to void return.
> Refactored the f2fs_wait_discard_bio function.
> Fixed code that was previously incorrectly merged.
>
> v1 -> v2
> Changed to apply the optional async reset write pointer by default.

Don't add the history in the patch description.

>
> This patch enables submit reset zone command asynchornously. It helps
> decrease average latency of write IOs in high utilization scenario by
> faster checkpointing.
>
> Signed-off-by: Daejun Park <daejun7.park@xxxxxxxxxxx>
> ---
> fs/f2fs/f2fs.h | 1 +
> fs/f2fs/iostat.c | 1 +
> fs/f2fs/segment.c | 84 +++++++++++++++++++++++++++++++++++--
> include/trace/events/f2fs.h | 24 +++++++++--
> 4 files changed, 104 insertions(+), 6 deletions(-)
>
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index d211ee89c158..51b68a629814 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -1175,6 +1175,7 @@ enum iostat_type {
> /* other */
> FS_DISCARD_IO, /* discard */
> FS_FLUSH_IO, /* flush */
> + FS_ZONE_RESET_IO, /* zone reset */
> NR_IO_TYPE,
> };
>
> diff --git a/fs/f2fs/iostat.c b/fs/f2fs/iostat.c
> index 3d5bfb1ad585..f8703038e1d8 100644
> --- a/fs/f2fs/iostat.c
> +++ b/fs/f2fs/iostat.c
> @@ -80,6 +80,7 @@ int __maybe_unused iostat_info_seq_show(struct seq_file *seq, void *offset)
> seq_puts(seq, "[OTHER]\n");
> IOSTAT_INFO_SHOW("fs discard", FS_DISCARD_IO);
> IOSTAT_INFO_SHOW("fs flush", FS_FLUSH_IO);
> + IOSTAT_INFO_SHOW("fs zone reset", FS_ZONE_RESET_IO);
>
> return 0;
> }
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 6db410f1bb8c..4802b05a795b 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -1196,6 +1196,45 @@ static void __init_discard_policy(struct f2fs_sb_info *sbi,
> static void __update_discard_tree_range(struct f2fs_sb_info *sbi,
> struct block_device *bdev, block_t lstart,
> block_t start, block_t len);
> +
> +#ifdef CONFIG_BLK_DEV_ZONED
> +static void __submit_zone_reset_cmd(struct f2fs_sb_info *sbi,

Why can't we use __f2fs_issue_discard_zone()?

> + struct discard_cmd *dc, blk_opf_t flag,
> + struct list_head *wait_list,
> + unsigned int *issued)
> +{
> + struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
> + struct block_device *bdev = dc->bdev;
> + struct bio *bio = bio_alloc(bdev, 0, REQ_OP_ZONE_RESET | flag, GFP_NOFS);
> + unsigned long flags;
> +
> + trace_f2fs_issue_reset_zone(bdev, dc->di.start);
> +
> + spin_lock_irqsave(&dc->lock, flags);
> + dc->state = D_SUBMIT;
> + dc->bio_ref++;
> + spin_unlock_irqrestore(&dc->lock, flags);
> +
> + if (issued)
> + (*issued)++;
> +
> + atomic_inc(&dcc->queued_discard);
> + dc->queued++;
> + list_move_tail(&dc->list, wait_list);
> +
> + /* sanity check on discard range */
> + __check_sit_bitmap(sbi, dc->di.lstart, dc->di.lstart + dc->di.len);
> +
> + bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(dc->di.start);
> + bio->bi_private = dc;
> + bio->bi_end_io = f2fs_submit_discard_endio;
> + submit_bio(bio);
> +
> + atomic_inc(&dcc->issued_discard);
> + f2fs_update_iostat(sbi, NULL, FS_ZONE_RESET_IO, dc->di.len * F2FS_BLKSIZE);
> +}
> +#endif
> +
> /* this function is copied from blkdev_issue_discard from block/blk-lib.c */
> static int __submit_discard_cmd(struct f2fs_sb_info *sbi,
> struct discard_policy *dpolicy,
> @@ -1217,6 +1256,13 @@ static int __submit_discard_cmd(struct f2fs_sb_info *sbi,
> if (is_sbi_flag_set(sbi, SBI_NEED_FSCK))
> return 0;
>
> +#ifdef CONFIG_BLK_DEV_ZONED
> + if (f2fs_sb_has_blkzoned(sbi) && bdev_is_zoned(bdev)) {
> + __submit_zone_reset_cmd(sbi, dc, flag, wait_list, issued);
> + return 0;
> + }
> +#endif
> +
> trace_f2fs_issue_discard(bdev, dc->di.start, dc->di.len);
>
> lstart = dc->di.lstart;
> @@ -1461,6 +1507,19 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi,
> }
> }
>
> +#ifdef CONFIG_BLK_DEV_ZONED
> +static void __queue_zone_reset_cmd(struct f2fs_sb_info *sbi,
> + struct block_device *bdev, block_t blkstart, block_t lblkstart,
> + block_t blklen)
> +{
> + trace_f2fs_queue_reset_zone(bdev, blkstart);
> +
> + mutex_lock(&SM_I(sbi)->dcc_info->cmd_lock);
> + __insert_discard_cmd(sbi, bdev, lblkstart, blkstart, blklen);
> + mutex_unlock(&SM_I(sbi)->dcc_info->cmd_lock);
> +}
> +#endif
> +
> static void __queue_discard_cmd(struct f2fs_sb_info *sbi,
> struct block_device *bdev, block_t blkstart, block_t blklen)
> {
> @@ -1724,6 +1783,19 @@ static void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
>
> mutex_lock(&dcc->cmd_lock);
> dc = __lookup_discard_cmd(sbi, blkaddr);
> +#ifdef CONFIG_BLK_DEV_ZONED
> + if (dc && f2fs_sb_has_blkzoned(sbi) && bdev_is_zoned(dc->bdev)) {
> + /* force submit zone reset */
> + if (dc->state == D_PREP)
> + __submit_zone_reset_cmd(sbi, dc, REQ_SYNC,
> + &dcc->wait_list, NULL);
> + dc->ref++;
> + mutex_unlock(&dcc->cmd_lock);
> + /* wait zone reset */
> + __wait_one_discard_bio(sbi, dc);
> + return;
> + }
> +#endif
> if (dc) {
> if (dc->state == D_PREP) {
> __punch_discard_cmd(sbi, dc, blkaddr);
> @@ -1876,9 +1948,15 @@ static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
> blkstart, blklen);
> return -EIO;
> }
> - trace_f2fs_issue_reset_zone(bdev, blkstart);
> - return blkdev_zone_mgmt(bdev, REQ_OP_ZONE_RESET,
> - sector, nr_sects, GFP_NOFS);
> +
> + if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING))) {
> + trace_f2fs_issue_reset_zone(bdev, blkstart);
> + return blkdev_zone_mgmt(bdev, REQ_OP_ZONE_RESET,
> + sector, nr_sects, GFP_NOFS);
> + }
> +
> + __queue_zone_reset_cmd(sbi, bdev, blkstart, lblkstart, blklen);
> + return 0;
> }
>
> /* For conventional zones, use regular discard if supported */
> diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
> index 99cbc5949e3c..793f82cc1515 100644
> --- a/include/trace/events/f2fs.h
> +++ b/include/trace/events/f2fs.h
> @@ -1512,7 +1512,7 @@ DEFINE_EVENT(f2fs_discard, f2fs_remove_discard,
> TP_ARGS(dev, blkstart, blklen)
> );
>
> -TRACE_EVENT(f2fs_issue_reset_zone,
> +DECLARE_EVENT_CLASS(f2fs_reset_zone,
>
> TP_PROTO(struct block_device *dev, block_t blkstart),
>
> @@ -1528,11 +1528,25 @@ TRACE_EVENT(f2fs_issue_reset_zone,
> __entry->blkstart = blkstart;
> ),
>
> - TP_printk("dev = (%d,%d), reset zone at block = 0x%llx",
> + TP_printk("dev = (%d,%d), zone at block = 0x%llx",
> show_dev(__entry->dev),
> (unsigned long long)__entry->blkstart)
> );
>
> +DEFINE_EVENT(f2fs_reset_zone, f2fs_queue_reset_zone,
> +
> + TP_PROTO(struct block_device *dev, block_t blkstart),
> +
> + TP_ARGS(dev, blkstart)
> +);
> +
> +DEFINE_EVENT(f2fs_reset_zone, f2fs_issue_reset_zone,
> +
> + TP_PROTO(struct block_device *dev, block_t blkstart),
> +
> + TP_ARGS(dev, blkstart)
> +);
> +
> TRACE_EVENT(f2fs_issue_flush,
>
> TP_PROTO(struct block_device *dev, unsigned int nobarrier,
> @@ -1979,6 +1993,7 @@ TRACE_EVENT(f2fs_iostat,
> __field(unsigned long long, fs_nrio)
> __field(unsigned long long, fs_mrio)
> __field(unsigned long long, fs_discard)
> + __field(unsigned long long, fs_reset_zone)
> ),
>
> TP_fast_assign(
> @@ -2010,12 +2025,14 @@ TRACE_EVENT(f2fs_iostat,
> __entry->fs_nrio = iostat[FS_NODE_READ_IO];
> __entry->fs_mrio = iostat[FS_META_READ_IO];
> __entry->fs_discard = iostat[FS_DISCARD_IO];
> + __entry->fs_reset_zone = iostat[FS_ZONE_RESET_IO];
> ),
>
> TP_printk("dev = (%d,%d), "
> "app [write=%llu (direct=%llu, buffered=%llu), mapped=%llu, "
> "compr(buffered=%llu, mapped=%llu)], "
> - "fs [data=%llu, cdata=%llu, node=%llu, meta=%llu, discard=%llu], "
> + "fs [data=%llu, cdata=%llu, node=%llu, meta=%llu, discard=%llu, "
> + "reset_zone=%llu], "
> "gc [data=%llu, node=%llu], "
> "cp [data=%llu, node=%llu, meta=%llu], "
> "app [read=%llu (direct=%llu, buffered=%llu), mapped=%llu], "
> @@ -2026,6 +2043,7 @@ TRACE_EVENT(f2fs_iostat,
> __entry->app_bio, __entry->app_mio, __entry->app_bcdio,
> __entry->app_mcdio, __entry->fs_dio, __entry->fs_cdio,
> __entry->fs_nio, __entry->fs_mio, __entry->fs_discard,
> + __entry->fs_reset_zone,
> __entry->fs_gc_dio, __entry->fs_gc_nio, __entry->fs_cp_dio,
> __entry->fs_cp_nio, __entry->fs_cp_mio,
> __entry->app_rio, __entry->app_drio, __entry->app_brio,
> --
> 2.25.1