On 11/08, Yunlong Song wrote: > So we should use f2fs_bug_on(sbi, !total_freed && !sync && gc_type == > FG_GC); f2fs_bug_on(sbi, !total_freed && has_not_enough_free_secs(sbi, 0, 0)); ? > > On 2017/11/7 14:56, Chao Yu wrote: > > On 2017/11/7 12:01, Yunlong Song wrote: > > > Sorry, misunderstanding, because I think when sync == true, FG_GC does not > > > check has_not_enough_free_secs, so maybe it does not have to do any gc > > > at all. > > > For example, if there are 100 segments for f2fs, and 20 segments are full or > > > valid blocks over fggc_threshold, then it is correct to fail in get victim. > > > > > > > > > On 2017/11/7 11:26, Jaegeuk Kim wrote: > > > > On 11/07, Yunlong Song wrote: > > > > > Because I find that some out-of-free problem is caused by the failure > > > > > of get victim target. For example, chao has pointed out that he has > > > > > found out a bug when adding this bug_on last week. > > > > That's NOT what I asked. Why not checking FG_GC all the time like this? > > > > > > > > f2fs_bug_on(sbi, !total_freed && gc_type == FG_GC); > > ioctl(F2FS_IOC_GARBAGE_COLLECT, &1) will simply trigger this bug_on, so we > > have to check the conditon only when we run out-of-free-space? > > > > Thanks, > > > > > > > On 2017/11/7 10:40, Jaegeuk Kim wrote: > > > > > > On 11/06, Jaegeuk Kim wrote: > > > > > > > On 11/06, Yunlong Song wrote: > > > > > > > > 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. > > > > > > > I'm not quite sure whether this is really a bug_on case. > > > > > > > Let me make it WARN_ON() for debugging purpose first. > > > > > > BTW, why is this the special case where BG_GC detects FG_GC? > > > > > > > > > > > > > Thanks, > > > > > > > > > > > > > > > > f2fs_bug_on(sbi, !total_freed && !sync && gc_type == FG_GC); > > > > > > > > > > > > > > > > > > > ret = -ENODATA; > > > > > > > > > > goto stop; > > > > > > > > > > } > > > > > > > > > > -- > > > > > > > > > > 1.8.5.2 > > > > > > > > > . > > > > > > > > > > > > > > > > > -- > > > > > > > > Thanks, > > > > > > > > Yunlong Song > > > > > > > > > > > > > > . > > > > > > > > > > > -- > > > > > Thanks, > > > > > Yunlong Song > > > > > > > > > . > > > > > > > > . > > > > -- > Thanks, > Yunlong Song >