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

From: Yongpeng Yang
Date: Mon Jan 29 2024 - 21:17:58 EST


cur_seg[CURSEG_COLD_DATA] will exceed end boundary of main area when:
device[1]: zone device size = [2 MB ~ 10MB]

So, if there are not enough seq zones for six cursegs, we should still assign 0 to c.cur_seg[CURSEG_HOT_NODE] or reserve several conv zones for cursegs.

On 1/29/2024 11:47 PM, Daeho Jeong wrote:
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);