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Message-ID: <85723a69-0b8c-020c-11f9-3beb9ed54e0d@kernel.org>
Date:   Sun, 8 May 2022 22:27:51 +0800
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Subject: Re: [f2fs-dev] [PATCH 2/5] f2fs: introduce f2fs_gc_control to
 consolidate f2fs_gc parameters
Content-Language: en-US
To:     Jaegeuk Kim <jaegeuk@kernel.org>, linux-kernel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net
References: <20220506232032.1264078-1-jaegeuk@kernel.org>
 <20220506232032.1264078-2-jaegeuk@kernel.org>
From:   Chao Yu <chao@kernel.org>
In-Reply-To: <20220506232032.1264078-2-jaegeuk@kernel.org>
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On 2022/5/7 7:20, Jaegeuk Kim wrote:
> No functional change.
> 
> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> ---
>   fs/f2fs/f2fs.h              | 11 +++++++++--
>   fs/f2fs/file.c              | 30 +++++++++++++++++++++++++-----
>   fs/f2fs/gc.c                | 29 ++++++++++++++++++-----------
>   fs/f2fs/segment.c           |  8 +++++++-
>   fs/f2fs/super.c             |  8 +++++++-
>   include/trace/events/f2fs.h | 18 +++++++++---------
>   6 files changed, 75 insertions(+), 29 deletions(-)
> 
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index efe5e80163a8..d49b9b476592 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -1276,6 +1276,14 @@ struct atgc_management {
>   	unsigned long long age_threshold;	/* age threshold */
>   };
>   
> +struct f2fs_gc_control {
> +	unsigned int victim_segno;	/* target victim segment number */
> +	int init_gc_type;		/* FG_GC or BG_GC */
> +	bool no_bg_gc;			/* check the space and stop bg_gc */
> +	bool should_migrate_blocks;	/* should migrate blocks */
> +	bool err_gc_skipped;		/* return EAGAIN if GC skipped */
> +};
> +
>   /* For s_flag in struct f2fs_sb_info */
>   enum {
>   	SBI_IS_DIRTY,				/* dirty flag for checkpoint */
> @@ -3786,8 +3794,7 @@ extern const struct iomap_ops f2fs_iomap_ops;
>   int f2fs_start_gc_thread(struct f2fs_sb_info *sbi);
>   void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi);
>   block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode);
> -int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, bool background, bool force,
> -			unsigned int segno);
> +int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control);
>   void f2fs_build_gc_manager(struct f2fs_sb_info *sbi);
>   int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count);
>   int __init f2fs_create_garbage_collection_cache(void);
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index b307d96a0a7c..0e7d101c3e65 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -1647,6 +1647,10 @@ static int expand_inode_data(struct inode *inode, loff_t offset,
>   	struct f2fs_map_blocks map = { .m_next_pgofs = NULL,
>   			.m_next_extent = NULL, .m_seg_type = NO_CHECK_TYPE,
>   			.m_may_create = true };
> +	struct f2fs_gc_control gc_control = { .victim_segno = NULL_SEGNO,
> +			.init_gc_type = FG_GC,

.no_bg_gc will be printed by tracepoint, let's initialize it as well...

.no_bg_gc = false,

> +			.should_migrate_blocks = false,
> +			.err_gc_skipped = true };
>   	pgoff_t pg_start, pg_end;
>   	loff_t new_size = i_size_read(inode);
>   	loff_t off_end;
> @@ -1684,7 +1688,7 @@ static int expand_inode_data(struct inode *inode, loff_t offset,
>   		if (has_not_enough_free_secs(sbi, 0,
>   			GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi)))) {
>   			f2fs_down_write(&sbi->gc_lock);
> -			err = f2fs_gc(sbi, true, false, false, NULL_SEGNO);
> +			err = f2fs_gc(sbi, &gc_control);
>   			if (err && err != -ENODATA)
>   				goto out_err;
>   		}
> @@ -2447,6 +2451,9 @@ static int f2fs_ioc_gc(struct file *filp, unsigned long arg)
>   {
>   	struct inode *inode = file_inode(filp);
>   	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> +	struct f2fs_gc_control gc_control = { .victim_segno = NULL_SEGNO,
> +			.no_bg_gc = false,
> +			.should_migrate_blocks = false };
>   	__u32 sync;
>   	int ret;
>   
> @@ -2472,7 +2479,9 @@ static int f2fs_ioc_gc(struct file *filp, unsigned long arg)
>   		f2fs_down_write(&sbi->gc_lock);
>   	}
>   
> -	ret = f2fs_gc(sbi, sync, true, false, NULL_SEGNO);
> +	gc_control.init_gc_type = sync ? FG_GC : BG_GC;
> +	gc_control.err_gc_skipped = sync;
> +	ret = f2fs_gc(sbi, &gc_control);
>   out:
>   	mnt_drop_write_file(filp);
>   	return ret;
> @@ -2481,6 +2490,11 @@ static int f2fs_ioc_gc(struct file *filp, unsigned long arg)
>   static int __f2fs_ioc_gc_range(struct file *filp, struct f2fs_gc_range *range)
>   {
>   	struct f2fs_sb_info *sbi = F2FS_I_SB(file_inode(filp));
> +	struct f2fs_gc_control gc_control = {
> +			.init_gc_type = range->sync ? FG_GC : BG_GC,
> +			.no_bg_gc = false,
> +			.should_migrate_blocks = false,
> +			.err_gc_skipped = range->sync };
>   	u64 end;
>   	int ret;
>   
> @@ -2508,8 +2522,8 @@ static int __f2fs_ioc_gc_range(struct file *filp, struct f2fs_gc_range *range)
>   		f2fs_down_write(&sbi->gc_lock);
>   	}
>   
> -	ret = f2fs_gc(sbi, range->sync, true, false,
> -				GET_SEGNO(sbi, range->start));
> +	gc_control.victim_segno = GET_SEGNO(sbi, range->start);
> +	ret = f2fs_gc(sbi, &gc_control);
>   	if (ret) {
>   		if (ret == -EBUSY)
>   			ret = -EAGAIN;
> @@ -2923,6 +2937,10 @@ static int f2fs_ioc_flush_device(struct file *filp, unsigned long arg)
>   	unsigned int start_segno = 0, end_segno = 0;
>   	unsigned int dev_start_segno = 0, dev_end_segno = 0;
>   	struct f2fs_flush_device range;
> +	struct f2fs_gc_control gc_control = {
> +			.init_gc_type = FG_GC,

.no_bg_gc = false,

> +			.should_migrate_blocks = true,
> +			.err_gc_skipped = true };
>   	int ret;
>   
>   	if (!capable(CAP_SYS_ADMIN))
> @@ -2966,7 +2984,9 @@ static int f2fs_ioc_flush_device(struct file *filp, unsigned long arg)
>   		sm->last_victim[GC_CB] = end_segno + 1;
>   		sm->last_victim[GC_GREEDY] = end_segno + 1;
>   		sm->last_victim[ALLOC_NEXT] = end_segno + 1;
> -		ret = f2fs_gc(sbi, true, true, true, start_segno);
> +
> +		gc_control.victim_segno = start_segno;
> +		ret = f2fs_gc(sbi, &gc_control);
>   		if (ret == -EAGAIN)
>   			ret = 0;
>   		else if (ret < 0)
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index 3009c0a97ab4..aeffcc1d5c02 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -35,6 +35,9 @@ static int gc_thread_func(void *data)
>   	wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
>   	wait_queue_head_t *fggc_wq = &sbi->gc_thread->fggc_wq;
>   	unsigned int wait_ms;
> +	struct f2fs_gc_control gc_control = {
> +		.victim_segno = NULL_SEGNO,
> +		.should_migrate_blocks = false };
>   
>   	wait_ms = gc_th->min_sleep_time;
>   
> @@ -141,8 +144,12 @@ static int gc_thread_func(void *data)
>   		if (foreground)
>   			sync_mode = false;
>   
> +		gc_control.init_gc_type = sync_mode ? FG_GC : BG_GC;
> +		gc_control.no_bg_gc = foreground;
> +		gc_control.err_gc_skipped = sync_mode;
> +
>   		/* if return value is not zero, no victim was selected */
> -		if (f2fs_gc(sbi, sync_mode, !foreground, false, NULL_SEGNO))
> +		if (f2fs_gc(sbi, &gc_control))
>   			wait_ms = gc_th->no_gc_sleep_time;
>   
>   		if (foreground)
> @@ -1753,14 +1760,13 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
>   	return seg_freed;
>   }
>   
> -int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
> -			bool background, bool force, unsigned int segno)
> +int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
>   {
> -	int gc_type = sync ? FG_GC : BG_GC;
> +	int gc_type = gc_control->init_gc_type;
> +	unsigned int segno = gc_control->victim_segno;
>   	int sec_freed = 0, seg_freed = 0, total_freed = 0;
>   	int ret = 0;
>   	struct cp_control cpc;
> -	unsigned int init_segno = segno;
>   	struct gc_inode_list gc_list = {
>   		.ilist = LIST_HEAD_INIT(gc_list.ilist),
>   		.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
> @@ -1769,7 +1775,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
>   	unsigned long long first_skipped;
>   	unsigned int skipped_round = 0, round = 0;
>   
> -	trace_f2fs_gc_begin(sbi->sb, sync, background,
> +	trace_f2fs_gc_begin(sbi->sb, gc_type, gc_control->no_bg_gc,
>   				get_pages(sbi, F2FS_DIRTY_NODES),
>   				get_pages(sbi, F2FS_DIRTY_DENTS),
>   				get_pages(sbi, F2FS_DIRTY_IMETA),
> @@ -1808,7 +1814,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
>   	}
>   
>   	/* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
> -	if (gc_type == BG_GC && !background) {
> +	if (gc_type == BG_GC && gc_control->no_bg_gc) {
>   		ret = -EINVAL;
>   		goto stop;
>   	}
> @@ -1824,7 +1830,8 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
>   		goto stop;
>   	}
>   
> -	seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type, force);
> +	seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type,
> +				gc_control->should_migrate_blocks);
>   	if (gc_type == FG_GC &&
>   		seg_freed == f2fs_usable_segs_in_sec(sbi, segno))
>   		sec_freed++;
> @@ -1841,7 +1848,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
>   	if (gc_type == FG_GC)
>   		sbi->cur_victim_sec = NULL_SEGNO;
>   
> -	if (sync)
> +	if (gc_control->init_gc_type == FG_GC)
>   		goto stop;
>   
>   	if (!has_not_enough_free_secs(sbi, sec_freed, 0))
> @@ -1871,7 +1878,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
>   		ret = f2fs_write_checkpoint(sbi, &cpc);
>   stop:
>   	SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
> -	SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
> +	SIT_I(sbi)->last_victim[FLUSH_DEVICE] = gc_control->victim_segno;
>   
>   	if (gc_type == FG_GC)
>   		f2fs_unpin_all_sections(sbi, true);
> @@ -1889,7 +1896,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
>   
>   	put_gc_inode(&gc_list);
>   
> -	if (sync && !ret)
> +	if (gc_control->err_gc_skipped && !ret)
>   		ret = sec_freed ? 0 : -EAGAIN;
>   	return ret;
>   }
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 87ff2b3cdf94..bc63f0572c64 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -523,8 +523,14 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need)
>   			io_schedule();
>   			finish_wait(&sbi->gc_thread->fggc_wq, &wait);
>   		} else {
> +			struct f2fs_gc_control gc_control = {
> +				.victim_segno = NULL_SEGNO,
> +				.init_gc_type = BG_GC,
> +				.no_bg_gc = true,
> +				.should_migrate_blocks = false,
> +				.err_gc_skipped = false };
>   			f2fs_down_write(&sbi->gc_lock);
> -			f2fs_gc(sbi, false, false, false, NULL_SEGNO);
> +			f2fs_gc(sbi, &gc_control);
>   		}
>   	}
>   }
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 7edb018a60a6..8b23fa6fc6b7 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -2080,8 +2080,14 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi)
>   	sbi->gc_mode = GC_URGENT_HIGH;
>   
>   	while (!f2fs_time_over(sbi, DISABLE_TIME)) {
> +		struct f2fs_gc_control gc_control = {
> +			.victim_segno = NULL_SEGNO,
> +			.init_gc_type = FG_GC,

.no_bg_gc = false,

Thanks,

> +			.should_migrate_blocks = false,
> +			.err_gc_skipped = true };
> +
>   		f2fs_down_write(&sbi->gc_lock);
> -		err = f2fs_gc(sbi, true, false, false, NULL_SEGNO);
> +		err = f2fs_gc(sbi, &gc_control);
>   		if (err == -ENODATA) {
>   			err = 0;
>   			break;
> diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
> index 4d1ad64d4cab..6699174977a3 100644
> --- a/include/trace/events/f2fs.h
> +++ b/include/trace/events/f2fs.h
> @@ -652,19 +652,19 @@ TRACE_EVENT(f2fs_background_gc,
>   
>   TRACE_EVENT(f2fs_gc_begin,
>   
> -	TP_PROTO(struct super_block *sb, bool sync, bool background,
> +	TP_PROTO(struct super_block *sb, int gc_type, bool no_bg_gc,
>   			long long dirty_nodes, long long dirty_dents,
>   			long long dirty_imeta, unsigned int free_sec,
>   			unsigned int free_seg, int reserved_seg,
>   			unsigned int prefree_seg),
>   
> -	TP_ARGS(sb, sync, background, dirty_nodes, dirty_dents, dirty_imeta,
> +	TP_ARGS(sb, gc_type, no_bg_gc, dirty_nodes, dirty_dents, dirty_imeta,
>   		free_sec, free_seg, reserved_seg, prefree_seg),
>   
>   	TP_STRUCT__entry(
>   		__field(dev_t,		dev)
> -		__field(bool,		sync)
> -		__field(bool,		background)
> +		__field(int,		gc_type)
> +		__field(bool,		no_bg_gc)
>   		__field(long long,	dirty_nodes)
>   		__field(long long,	dirty_dents)
>   		__field(long long,	dirty_imeta)
> @@ -676,8 +676,8 @@ TRACE_EVENT(f2fs_gc_begin,
>   
>   	TP_fast_assign(
>   		__entry->dev		= sb->s_dev;
> -		__entry->sync		= sync;
> -		__entry->background	= background;
> +		__entry->gc_type	= gc_type;
> +		__entry->no_bg_gc	= no_bg_gc;
>   		__entry->dirty_nodes	= dirty_nodes;
>   		__entry->dirty_dents	= dirty_dents;
>   		__entry->dirty_imeta	= dirty_imeta;
> @@ -687,12 +687,12 @@ TRACE_EVENT(f2fs_gc_begin,
>   		__entry->prefree_seg	= prefree_seg;
>   	),
>   
> -	TP_printk("dev = (%d,%d), sync = %d, background = %d, nodes = %lld, "
> +	TP_printk("dev = (%d,%d), gc_type = %s, no_background_GC = %d, nodes = %lld, "
>   		"dents = %lld, imeta = %lld, free_sec:%u, free_seg:%u, "
>   		"rsv_seg:%d, prefree_seg:%u",
>   		show_dev(__entry->dev),
> -		__entry->sync,
> -		__entry->background,
> +		show_gc_type(__entry->gc_type),
> +		__entry->no_bg_gc,
>   		__entry->dirty_nodes,
>   		__entry->dirty_dents,
>   		__entry->dirty_imeta,