Messages in this thread | | | Date | Mon, 2 Feb 2015 15:37:34 -0800 | From | Jaegeuk Kim <> | Subject | Re: [PATCH 2/2] f2fs: don't discard next free dnode page for an umount checkpoint |
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Hi Chao,
On Sat, Jan 31, 2015 at 05:06:59PM +0800, Chao Yu wrote: > Previously, discard_next_dnode is added before a checkpoint to prevent that we > may meet a garbage dnode page readed from next free blkaddr in recover flow. > > Since f2fs will skip recovery flow for a clean umount image, this condition will > never happen. > > So it's safe for us to leave next free dnode as it is in an umount checkpoint. > > Signed-off-by: Chao Yu <chao2.yu@samsung.com> > --- > fs/f2fs/checkpoint.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c > index f7cdcad..991fd0a 100644 > --- a/fs/f2fs/checkpoint.c > +++ b/fs/f2fs/checkpoint.c > @@ -905,8 +905,12 @@ static void do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) > /* > * This avoids to conduct wrong roll-forward operations and uses > * metapages, so should be called prior to sync_meta_pages below. > + * But if we are in an umount checkpoint, we'd better skip this > + * because we will not enter recovery flow to use the next free > + * blkaddr when mounting it. > */ > - discard_next_dnode(sbi, NEXT_FREE_BLKADDR(sbi, curseg)); > + if (cpc->reason != CP_UMOUNT) > + discard_next_dnode(sbi, NEXT_FREE_BLKADDR(sbi, curseg));
The reason for discard_next_dnode is to avoid wrong execution due to old mkfs.f2fs which remains gabage data. It needs to do all the time.
Thanks,
> > /* Flush all the NAT/SIT pages */ > while (get_pages(sbi, F2FS_DIRTY_META)) { > -- > 2.2.1
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