Re: [f2fs-dev] [PATCH] mkfs.f2fs: update allocation policy for ro feature

[Jaegeuk Kim <jaegeuk@kernel.org>]

On 10/01, Chao Yu wrote:
> On 2022/10/1 6:33, Jaegeuk Kim wrote:
> > On 09/30, Chao Yu wrote:
> > > On 2022/9/30 2:27, Jaegeuk Kim wrote:
> > > > On 09/28, Chao Yu wrote:
> > > > > On 2022/9/28 11:15, Jaegeuk Kim wrote:
> > > > > > On 09/28, Chao Yu wrote:
> > > > > > > On 2022/9/28 0:40, Jaegeuk Kim wrote:
> > > > > > > > On 09/25, Chao Yu wrote:
> > > > > > > > > Update allocation policy for ro feature:
> > > > > > > > > - hot_data: allocating blocks by LBA ascending order
> > > > > > > > > - hot_node: allocating blocks by LBA descending order
> > > > > > > > 
> > > > > > > > This will increase the RO image size.
> > > > > > > 
> > > > > > > Shouldn't RO image has fixed-size during mkfs?
> > > > > > 
> > > > > > First run gives the reduced size information, and second round makes the image
> > > > > > with the required size.
> > > > > 
> > > > > I didn't get it, in which step it may increase the RO image size?
> > > > > 
> > > > > IIUC, after we apply this patch, reduced size information won't change due
> > > > > to that after sload in first run, total used block count should be fixed?
> > > > 
> > > > First run fills the data and leaves the maximum LBA touched in the image. Then,
> > > 
> > > How about caclulating required size w/ total used blocks rather than maximum LBA?
> > 
> > Do you think that can give the smallest size for the image?
> 
> I guess so, but let me do some tests to check that.
> 
> Segments for data block and node block should be calculated separately:
> required_blks = roundup(data_blks, blks_per_seg) + roundup(node_blks, blks_per_seg)
> 
> Am I missing something?

I think that'd be fine tho, please test first.

> 
> Thanks,
> 
> > 
> > > 
> > > Thanks,
> > > 
> > > > it'll resize the image file and run again with the smallest image.
> > > > 
> > > > > 
> > > > > Thanks,
> > > > > 
> > > > > > 
> > > > > > > 
> > > > > > > > 
> > > > > > > > > 
> > > > > > > > > Signed-off-by: Chao Yu <chao@kernel.org>
> > > > > > > > > ---
> > > > > > > > >      mkfs/f2fs_format.c | 4 ++--
> > > > > > > > >      1 file changed, 2 insertions(+), 2 deletions(-)
> > > > > > > > > 
> > > > > > > > > diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
> > > > > > > > > index 40ac589..8d0f410 100644
> > > > > > > > > --- a/mkfs/f2fs_format.c
> > > > > > > > > +++ b/mkfs/f2fs_format.c
> > > > > > > > > @@ -544,10 +544,10 @@ static int f2fs_prepare_super_block(void)
> > > > > > > > >      	}
> > > > > > > > >      	if (c.feature & cpu_to_le32(F2FS_FEATURE_RO)) {
> > > > > > > > > -		c.cur_seg[CURSEG_HOT_NODE] = 0;
> > > > > > > > > +		c.cur_seg[CURSEG_HOT_NODE] = last_section(last_zone(total_zones));
> > > > > > > > >      		c.cur_seg[CURSEG_WARM_NODE] = 0;
> > > > > > > > >      		c.cur_seg[CURSEG_COLD_NODE] = 0;
> > > > > > > > > -		c.cur_seg[CURSEG_HOT_DATA] = 1;
> > > > > > > > > +		c.cur_seg[CURSEG_HOT_DATA] = 0;
> > > > > > > > >      		c.cur_seg[CURSEG_COLD_DATA] = 0;
> > > > > > > > >      		c.cur_seg[CURSEG_WARM_DATA] = 0;
> > > > > > > > >      	} else if (c.heap) {
> > > > > > > > > -- 
> > > > > > > > > 2.36.1


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