Re: [PATCH v2] f2fs: add bug_on when f2fs_gc even fails to get one victim

[Yunlong Song]

Agree.

On 2017/11/3 11:44, Jaegeuk Kim wrote:
> On 10/13, Yunlong Song wrote:
> > This can help us to debug on some corner case.
> >
> > Signed-off-by: Yunlong Song <yunlong.song@xxxxxxxxxx>
> > Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
> > ---
> >   fs/f2fs/gc.c | 6 +++++-
> >   1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> > index 197ebf4..2b03202 100644
> > --- a/fs/f2fs/gc.c
> > +++ b/fs/f2fs/gc.c
> > @@ -986,6 +986,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
> >   		.ilist = LIST_HEAD_INIT(gc_list.ilist),
> >   		.iroot = RADIX_TREE_INIT(GFP_NOFS),
> >   	};
> > +	bool need_fggc = false;
> >   
> >   	trace_f2fs_gc_begin(sbi->sb, sync, background,
> >   				get_pages(sbi, F2FS_DIRTY_NODES),
> > @@ -1018,8 +1019,10 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
> >   			if (ret)
> >   				goto stop;
> >   		}
> > -		if (has_not_enough_free_secs(sbi, 0, 0))
> > +		if (has_not_enough_free_secs(sbi, 0, 0)) {
> >   			gc_type = FG_GC;
> > +			need_fggc = true;
> > +		}
> >   	}
> >   
> >   	/* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
> > @@ -1028,6 +1031,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
> >   		goto stop;
> >   	}
> >   	if (!__get_victim(sbi, &segno, gc_type)) {
> > +		f2fs_bug_on(sbi, !total_freed && need_fggc);
> Just like this?
That's OK.

> 		f2fs_bug_on(sbi, !total_freed && !sync && gc_type == FG_GC);
>
> >   		ret = -ENODATA;
> >   		goto stop;
> >   	}
> > --
> > 1.8.5.2
> .

--
Thanks,
Yunlong Song