Re: [f2fs-dev] [PATCH] f2fs-tools: allocate logs after conventional area for HM zoned devices

[Daeho Jeong]

On Sun, Jan 28, 2024 at 5:27 PM Chao Yu <chao@xxxxxxxxxx> wrote:
>
> On 2024/1/27 2:17, Daeho Jeong wrote:
> > On Thu, Jan 25, 2024 at 5:27 PM Chao Yu <chao@xxxxxxxxxx> wrote:
> >>
> >> On 2024/1/26 0:25, Daeho Jeong wrote:
> >>> On Wed, Jan 24, 2024 at 7:34 PM Chao Yu <chao@xxxxxxxxxx> wrote:
> >>>>
> >>>> +Cc Yongpeng Yang
> >>>>
> >>>> Daeho,
> >>>>
> >>>> Yongpeng reports a potential issue: if c.devices[0].total_segments is
> >>>> larger than segments of mainarea, c.cur_seg[CURSEG_HOT_NODE] will exceed
> >>>> end boundary of mainarea. Could you please check that? though it's a corner
> >>>> case.
> >>>
> >>> Can you elaborate more?
> >>
> >> Since c.cur_seg[CURSEG_HOT_NODE] is an offset started from main_blkaddr.
> >
> > Oh, Got it.
> > Then, how about this?
> >
> >           c.cur_seg[CURSEG_HOT_NODE] = c.zoned_model == F2FS_ZONED_HM ?
> >                           (c.devices[1].start_blkaddr -
> > get_sb(main_blkaddr)) / c.blks_per_seg : 0;
>
> Better, but log header should align to start blkaddr of zone?

It's already aligned here.

        if (c.zoned_mode && c.ndevs > 1)
                zone_align_start_offset +=
                        (c.devices[0].total_sectors * c.sector_size) %
zone_size_bytes;

..

        for (i = 0; i < c.ndevs; i++) {
                if (i == 0) {
                        c.devices[i].total_segments =
                                (c.devices[i].total_sectors *
                                c.sector_size - zone_align_start_offset) /
                                segment_size_bytes;
                        c.devices[i].start_blkaddr = 0;
                        c.devices[i].end_blkaddr = c.devices[i].total_segments *
                                                c.blks_per_seg - 1 +
                                                sb->segment0_blkaddr;
                } else {
                        c.devices[i].total_segments =
                                c.devices[i].total_sectors /
                                (c.sectors_per_blk * c.blks_per_seg);
                        c.devices[i].start_blkaddr =
                                        c.devices[i - 1].end_blkaddr + 1;

..

        total_meta_zones = ZONE_ALIGN(total_meta_segments *
                                                c.blks_per_seg);

        set_sb(main_blkaddr, get_sb(segment0_blkaddr) + total_meta_zones *
                                c.segs_per_zone * c.blks_per_seg);

>
> Thanks,
>
> >
> >> If c.cur_seg[CURSEG_HOT_NODE] was assigned w/ c.devices[0].total_segments,
> >> and c.devices[0].total_segments is larger than segments of mainare,
> >> c.cur_seg[CURSEG_HOT_NODE] will exceed the end boundary of mainarea.
> >>
> >>          c.cur_seg[CURSEG_HOT_NODE] = c.zoned_model == F2FS_ZONED_HM ?
> >>                          c.devices[0].total_segments : 0;
> >>
> >>> In the case of F2FS_ZONED_HM, we have the devices[1].
> >>> Do you mean the case we format the filesystem intentionally smaller
> >>> than what devices have?
> >>
> >> I mean blew case:
> >> device[0]: conventional device size = 10240 MB
> >> device[1]: zone device size = 2 MB
> >>
> >> Thanks,
> >>
> >>>
> >>>>
> >>>> On 2024/1/18 7:00, Daeho Jeong wrote:
> >>>>> From: Daeho Jeong <daehojeong@xxxxxxxxxx>
> >>>>>
> >>>>> Make to allocate logs after conventional area for HM zoned devices to
> >>>>> spare them for file pinning support.
> >>>>>
> >>>>> Signed-off-by: Daeho Jeong <daehojeong@xxxxxxxxxx>
> >>>>> ---
> >>>>>     mkfs/f2fs_format.c | 3 ++-
> >>>>>     1 file changed, 2 insertions(+), 1 deletion(-)
> >>>>>
> >>>>> diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
> >>>>> index f2840c8..91a7f4b 100644
> >>>>> --- a/mkfs/f2fs_format.c
> >>>>> +++ b/mkfs/f2fs_format.c
> >>>>> @@ -557,7 +557,8 @@ static int f2fs_prepare_super_block(void)
> >>>>>                 c.cur_seg[CURSEG_COLD_DATA] = 0;
> >>>>>                 c.cur_seg[CURSEG_WARM_DATA] = next_zone(CURSEG_COLD_DATA);
> >>>>>         } else if (c.zoned_mode) {
> >>>>> -             c.cur_seg[CURSEG_HOT_NODE] = 0;
> >>>>> +             c.cur_seg[CURSEG_HOT_NODE] = c.zoned_model == F2FS_ZONED_HM ?
> >>>>> +                     c.devices[0].total_segments : 0;
> >>>>>                 c.cur_seg[CURSEG_WARM_NODE] = next_zone(CURSEG_HOT_NODE);
> >>>>>                 c.cur_seg[CURSEG_COLD_NODE] = next_zone(CURSEG_WARM_NODE);
> >>>>>                 c.cur_seg[CURSEG_HOT_DATA] = next_zone(CURSEG_COLD_NODE);