1. Patchew
  2. linux
  3. View series

[PATCH v2] libf2fs: Fix calculation of usable segments for single

Yonggil Song posted 1 patch 1 month, 2 weeks ago 
lib/libf2fs_zoned.c | 5 +++++
1 file changed, 5 insertions(+)
[PATCH v2] libf2fs: Fix calculation of usable segments for single
Posted by Yonggil Song 1 month, 2 weeks ago 
There was a problem that did not subtract the super block area when calculating
the usable segments for a single zoned device with a conventional zone.
This resulted in incorrect the overprovision and reserved area.

	<256MiB legacy block + zoned block w/ 32MiB zone size>
	Info: Overprovision ratio = 3.570%
	Info: Overprovision segments = 656 (GC reserved = 560)

	<8 conventional zone + 1016 sequential zone w/ 32MiB zone size>
	Info: Overprovision ratio = 3.700%
	Info: Overprovision segments = 676 (GC reserved = 578)

This patch addresses the problem by subtracting the super block area when
there is only one zoned device.

Signed-off-by: Yonggil Song <yonggil.song@samsung.com>
---
 lib/libf2fs_zoned.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/libf2fs_zoned.c b/lib/libf2fs_zoned.c
index 89ba5ad73a76..1a0985378789 100644
--- a/lib/libf2fs_zoned.c
+++ b/lib/libf2fs_zoned.c
@@ -555,6 +555,11 @@ uint32_t f2fs_get_usable_segments(struct f2fs_super_block *sb)
 	}
 	usable_segs -= (get_sb(main_blkaddr) - get_sb(segment0_blkaddr)) >>
 						get_sb(log_blocks_per_seg);
+
+	/* single zoned device needs to remove a super block area */
+	if (c.ndevs == 1 && c.devices[0].zoned_model == F2FS_ZONED_HM)
+		usable_segs -= (get_sb(segment0_blkaddr) >> get_sb(log_blocks_per_seg));
+
 	return usable_segs;
 #endif
 	return get_sb(segment_count_main);
-- 
2.43.0
Re: [PATCH v2] libf2fs: Fix calculation of usable segments for single
Posted by Jaegeuk Kim 1 month, 2 weeks ago 
On 10/10, Yonggil Song wrote:
> There was a problem that did not subtract the super block area when calculating
> the usable segments for a single zoned device with a conventional zone.
> This resulted in incorrect the overprovision and reserved area.
> 
> 	<256MiB legacy block + zoned block w/ 32MiB zone size>
> 	Info: Overprovision ratio = 3.570%
> 	Info: Overprovision segments = 656 (GC reserved = 560)
> 
> 	<8 conventional zone + 1016 sequential zone w/ 32MiB zone size>
> 	Info: Overprovision ratio = 3.700%
> 	Info: Overprovision segments = 676 (GC reserved = 578)
> 
> This patch addresses the problem by subtracting the super block area when
> there is only one zoned device.
> 
> Signed-off-by: Yonggil Song <yonggil.song@samsung.com>
> ---
>  lib/libf2fs_zoned.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/lib/libf2fs_zoned.c b/lib/libf2fs_zoned.c
> index 89ba5ad73a76..1a0985378789 100644
> --- a/lib/libf2fs_zoned.c
> +++ b/lib/libf2fs_zoned.c
> @@ -555,6 +555,11 @@ uint32_t f2fs_get_usable_segments(struct f2fs_super_block *sb)
>  	}
>  	usable_segs -= (get_sb(main_blkaddr) - get_sb(segment0_blkaddr)) >>
>  						get_sb(log_blocks_per_seg);
> +
> +	/* single zoned device needs to remove a super block area */
> +	if (c.ndevs == 1 && c.devices[0].zoned_model == F2FS_ZONED_HM)

Does this work?

> +		usable_segs -= (get_sb(segment0_blkaddr) >> get_sb(log_blocks_per_seg));
> +
>  	return usable_segs;
>  #endif
>  	return get_sb(segment_count_main);
> -- 
> 2.43.0
RE:(2) [PATCH v2] libf2fs: Fix calculation of usable segments for single
Posted by Yonggil Song 1 month, 2 weeks ago 
> On 10/10, Yonggil Song wrote:
> > There was a problem that did not subtract the super block area when calculating
> > the usable segments for a single zoned device with a conventional zone.
> > This resulted in incorrect the overprovision and reserved area.
> > 
> > 	<256MiB legacy block + zoned block w/ 32MiB zone size>
> > 	Info: Overprovision ratio = 3.570%
> > 	Info: Overprovision segments = 656 (GC reserved = 560)
> > 
> > 	<8 conventional zone + 1016 sequential zone w/ 32MiB zone size>
> > 	Info: Overprovision ratio = 3.700%
> > 	Info: Overprovision segments = 676 (GC reserved = 578)
> > 
> > This patch addresses the problem by subtracting the super block area when
> > there is only one zoned device.
> > 
> > Signed-off-by: Yonggil Song <yonggil.song@samsung.com>
> > ---
> >  lib/libf2fs_zoned.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> > 
> > diff --git a/lib/libf2fs_zoned.c b/lib/libf2fs_zoned.c
> > index 89ba5ad73a76..1a0985378789 100644
> > --- a/lib/libf2fs_zoned.c
> > +++ b/lib/libf2fs_zoned.c
> > @@ -555,6 +555,11 @@ uint32_t f2fs_get_usable_segments(struct f2fs_super_block *sb)
> >  	}
> >  	usable_segs -= (get_sb(main_blkaddr) - get_sb(segment0_blkaddr)) >>
> >  						get_sb(log_blocks_per_seg);
> > +
> > +	/* single zoned device needs to remove a super block area */
> > +	if (c.ndevs == 1 && c.devices[0].zoned_model == F2FS_ZONED_HM)
> 
> Does this work?
> 
Yes, it works.

I have attached the results of test on null_blk below.
If you have any concerns, please feedback.

						before				after
legacy block (32GB)				136 (GC reserved = 130)		136 (GC reserved = 130)
single zoned block				676 (GC reserved = 578)		656 (GC reserved = 560)
(32GB, 32MB zone, 8 conv, 1016 seq)
legacy + zoned multi				656 (GC reserved = 560)		656 (GC reserved = 560)
(32GB, 256MB legacy block + 32MB zone, 1016 seq)

Thanks.
> > +		usable_segs -= (get_sb(segment0_blkaddr) >> get_sb(log_blocks_per_seg));
> > +
> >  	return usable_segs;
> >  #endif
> >  	return get_sb(segment_count_main);
> > -- 
> > 2.43.0
[RESEND][PATCH v2] libf2fs: Fix calculation of usable segments for single zoned device
Posted by Yonggil Song 1 month, 2 weeks ago 
There was a problem that did not subtract the super block area when calculating
the usable segments for a single zoned device with a conventional zone.
This resulted in incorrect the overprovision and reserved area.

	<256MiB legacy block + zoned block w/ 32MiB zone size>
	Info: Overprovision ratio = 3.570%
	Info: Overprovision segments = 656 (GC reserved = 560)

	<8 conventional zone + 1016 sequential zone w/ 32MiB zone size>
	Info: Overprovision ratio = 3.700%
	Info: Overprovision segments = 676 (GC reserved = 578)

This patch addresses the problem by subtracting the super block area when
there is only one zoned device.

Signed-off-by: Yonggil Song <yonggil.song@samsung.com>
---
 lib/libf2fs_zoned.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/libf2fs_zoned.c b/lib/libf2fs_zoned.c
index 89ba5ad73a76..1a0985378789 100644
--- a/lib/libf2fs_zoned.c
+++ b/lib/libf2fs_zoned.c
@@ -555,6 +555,11 @@ uint32_t f2fs_get_usable_segments(struct f2fs_super_block *sb)
 	}
 	usable_segs -= (get_sb(main_blkaddr) - get_sb(segment0_blkaddr)) >>
 						get_sb(log_blocks_per_seg);
+
+	/* single zoned device needs to remove a super block area */
+	if (c.ndevs == 1 && c.devices[0].zoned_model == F2FS_ZONED_HM)
+		usable_segs -= (get_sb(segment0_blkaddr) >> get_sb(log_blocks_per_seg));
+
 	return usable_segs;
 #endif
 	return get_sb(segment_count_main);
-- 
2.43.0

Patchew 2.1-devel-b67e4c2

© 2016 - 2024 Red Hat, Inc.