Re: [f2fs-dev] [PATCH v4] f2fs: add f2fs_gc exception handle in f2fs_ioc_gc_range

["yuchangchun (C)" <yuchangchun1@huawei.com>]

在 2020/6/28 14:39, Qilong Zhang 写道:
> When f2fs_ioc_gc_range performs multiple segments gc ops, the return
> value of f2fs_ioc_gc_range is determined by the last segment gc ops.
> If its ops failed, the f2fs_ioc_gc_range will be considered to be failed
> despite some of previous segments gc ops succeeded. Therefore, so we
> fix: Redefine the return value of getting victim ops and add exception
> handle for f2fs_gc. In particular, 1).if target has no valid block, it
> will go on. 2).if target sectoion has valid block(s), but it is current
> section, we will reminder the caller.
>
> Signed-off-by: Qilong Zhang <zhangqilong3@huawei.com>
> Reviewed-by: Chao Yu <yuchao0@huawei.com>
> ---
>   fs/f2fs/file.c    |  5 +++++
>   fs/f2fs/gc.c      | 19 +++++++++++++------
>   fs/f2fs/segment.c |  4 ++--
>   3 files changed, 20 insertions(+), 8 deletions(-)
>
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 3268f8dd59bb..fe006477a4e4 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -2527,6 +2527,11 @@ static int f2fs_ioc_gc_range(struct file *filp, unsigned long arg)
>   	}
>   
>   	ret = f2fs_gc(sbi, range.sync, true, GET_SEGNO(sbi, range.start));
> +	if (ret) {
> +		if (ret == -EBUSY)
> +			ret = -EAGAIN;
> +		goto out;
> +	}
>   	range.start += BLKS_PER_SEC(sbi);
>   	if (range.start <= end)
>   		goto do_more;
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index 5b95d5a146eb..71cb4a02aeee 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -321,6 +321,7 @@ static int get_victim_by_default(struct f2fs_sb_info *sbi,
>   	unsigned int secno, last_victim;
>   	unsigned int last_segment;
>   	unsigned int nsearched = 0;
> +	int ret;
>   
>   	mutex_lock(&dirty_i->seglist_lock);
>   	last_segment = MAIN_SECS(sbi) * sbi->segs_per_sec;
> @@ -332,12 +333,18 @@ static int get_victim_by_default(struct f2fs_sb_info *sbi,
>   	p.min_cost = get_max_cost(sbi, &p);
>   
>   	if (*result != NULL_SEGNO) {
> -		if (get_valid_blocks(sbi, *result, false) &&
> -			!sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
> +		ret = 0;
> +		if (!get_valid_blocks(sbi, *result, false))
> +			goto out;
Should it return specific errno to stop GC if this victim segment has no 
valid blocks  in accordance with original code.

Thanks,

> +
> +		if (sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
> +			ret = -EBUSY;
> +		else
>   			p.min_segno = *result;
>   		goto out;
>   	}
>   
> +	ret = -ENODATA;
>   	if (p.max_search == 0)
>   		goto out;
>   
> @@ -440,6 +447,7 @@ static int get_victim_by_default(struct f2fs_sb_info *sbi,
>   			else
>   				set_bit(secno, dirty_i->victim_secmap);
>   		}
> +		ret = 0;
>   
>   	}
>   out:
> @@ -449,7 +457,7 @@ static int get_victim_by_default(struct f2fs_sb_info *sbi,
>   				prefree_segments(sbi), free_segments(sbi));
>   	mutex_unlock(&dirty_i->seglist_lock);
>   
> -	return (p.min_segno == NULL_SEGNO) ? 0 : 1;
> +	return ret;
>   }
>   
>   static const struct victim_selection default_v_ops = {
> @@ -1333,10 +1341,9 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
>   		ret = -EINVAL;
>   		goto stop;
>   	}
> -	if (!__get_victim(sbi, &segno, gc_type)) {
> -		ret = -ENODATA;
> +	ret = __get_victim(sbi, &segno, gc_type);
> +	if (ret)
>   		goto stop;
> -	}
>   
>   	seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type);
>   	if (gc_type == FG_GC && seg_freed == sbi->segs_per_sec)
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 196f31503511..b9fd93761b0a 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -2605,7 +2605,7 @@ static int get_ssr_segment(struct f2fs_sb_info *sbi, int type)
>   	bool reversed = false;
>   
>   	/* f2fs_need_SSR() already forces to do this */
> -	if (v_ops->get_victim(sbi, &segno, BG_GC, type, SSR)) {
> +	if (!v_ops->get_victim(sbi, &segno, BG_GC, type, SSR)) {
>   		curseg->next_segno = segno;
>   		return 1;
>   	}
> @@ -2632,7 +2632,7 @@ static int get_ssr_segment(struct f2fs_sb_info *sbi, int type)
>   	for (; cnt-- > 0; reversed ? i-- : i++) {
>   		if (i == type)
>   			continue;
> -		if (v_ops->get_victim(sbi, &segno, BG_GC, i, SSR)) {
> +		if (!v_ops->get_victim(sbi, &segno, BG_GC, i, SSR)) {
>   			curseg->next_segno = segno;
>   			return 1;
>   		}





_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel