2017-08-14 09:22:53

by Yunlong Song

Subject: [PATCH] f2fs: free_user_blocks should use reserved_segments instead

The part (overprovision_segments - reserved_segments) can still be used for LFS,
so free_use_blocks should use reserved_segments instead, rather than use
overprovision_segments.

Signed-off-by: Yunlong Song <[email protected]>
---
fs/f2fs/gc.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
index 9325191..6258305 100644
--- a/fs/f2fs/gc.h
+++ b/fs/f2fs/gc.h
@@ -49,10 +49,10 @@ struct gc_inode_list {
*/
static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
{
- if (free_segments(sbi) < overprovision_segments(sbi))
+ if (free_segments(sbi) < reserved_segments(sbi))
return 0;
else
- return (free_segments(sbi) - overprovision_segments(sbi))
+ return (free_segments(sbi) - reserved_segments(sbi))
<< sbi->log_blocks_per_seg;
}

--
1.8.5.2

2017-08-15 03:33:01

by Jaegeuk Kim

Subject: Re: [PATCH] f2fs: free_user_blocks should use reserved_segments instead

On 08/14, Yunlong Song wrote:
> The part (overprovision_segments - reserved_segments) can still be used for LFS,
> so free_use_blocks should use reserved_segments instead, rather than use
> overprovision_segments.
>
> Signed-off-by: Yunlong Song <[email protected]>
> ---
> fs/f2fs/gc.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
> index 9325191..6258305 100644
> --- a/fs/f2fs/gc.h
> +++ b/fs/f2fs/gc.h
> @@ -49,10 +49,10 @@ struct gc_inode_list {
> */
> static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)

NAK. This gives user-visible block count.

> {
> - if (free_segments(sbi) < overprovision_segments(sbi))
> + if (free_segments(sbi) < reserved_segments(sbi))
> return 0;
> else
> - return (free_segments(sbi) - overprovision_segments(sbi))
> + return (free_segments(sbi) - reserved_segments(sbi))
> << sbi->log_blocks_per_seg;
> }
>
> --
> 1.8.5.2

2017-08-15 07:14:50

by Yunlong Song

Subject: [PATCH v2] f2fs: free_user_blocks should use reserved_segments instead

The part (overprovision_segments - reserved_segments) can still be used for LFS
in some case, e.g., there are lots of invalid block from dirty segments, then
the part (overprovision_segments - reserved_segments) can be safely used. So
free_use_blocks should use reserved_segments instead, rather than directly use
overprovision_segments. BTW, we also add the constraint of sbi->reserved_blocks.

Signed-off-by: Yunlong Song <[email protected]>
---
fs/f2fs/gc.h | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
index 9325191..542612a 100644
--- a/fs/f2fs/gc.h
+++ b/fs/f2fs/gc.h
@@ -49,11 +49,23 @@ struct gc_inode_list {
*/
static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
{
- if (free_segments(sbi) < overprovision_segments(sbi))
+ block_t avail_user_block_count, free_blocks, avail_free_blocks;
+ block_t reserved_blocks;
+
+ avail_user_block_count = sbi->user_block_count - sbi->reserved_blocks;
+
+ if (unlikely(sbi->total_valid_block_count > avail_user_block_count))
+ return 0;
+
+ free_blocks = free_segments(sbi) << sbi->log_blocks_per_seg;
+ avail_free_blocks = min(free_blocks, avail_user_block_count -
+ sbi->total_valid_block_count);
+ reserved_blocks = reserved_segments(sbi) << sbi->log_blocks_per_seg;
+
+ if (avail_free_blocks < reserved_blocks)
return 0;
else
- return (free_segments(sbi) - overprovision_segments(sbi))
- << sbi->log_blocks_per_seg;
+ return avail_free_blocks - reserved_blocks;
}

static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)
--
1.8.5.2

2017-08-15 07:18:33

by Yunlong Song

Subject: Re: [PATCH] f2fs: free_user_blocks should use reserved_segments instead

Consider this, I have sent another patch v2, please review.

The part (overprovision_segments - reserved_segments) can still be used for LFS
in some case, e.g., there are lots of invalid block from dirty segments, then
the part (overprovision_segments - reserved_segments) can be safely used. So
free_use_blocks should use reserved_segments instead, rather than directly use
overprovision_segments. BTW, we also add the constraint of sbi->reserved_blocks.


On 2017/8/15 11:32, Jaegeuk Kim wrote:
> On 08/14, Yunlong Song wrote:
>> The part (overprovision_segments - reserved_segments) can still be used for LFS,
>> so free_use_blocks should use reserved_segments instead, rather than use
>> overprovision_segments.
>>
>> Signed-off-by: Yunlong Song <[email protected]>
>> ---
>> fs/f2fs/gc.h | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
>> index 9325191..6258305 100644
>> --- a/fs/f2fs/gc.h
>> +++ b/fs/f2fs/gc.h
>> @@ -49,10 +49,10 @@ struct gc_inode_list {
>> */
>> static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
> NAK. This gives user-visible block count.
>
>> {
>> - if (free_segments(sbi) < overprovision_segments(sbi))
>> + if (free_segments(sbi) < reserved_segments(sbi))
>> return 0;
>> else
>> - return (free_segments(sbi) - overprovision_segments(sbi))
>> + return (free_segments(sbi) - reserved_segments(sbi))
>> << sbi->log_blocks_per_seg;
>> }
>>
>> --
>> 1.8.5.2
> .
>

--
Thanks,
Yunlong Song

2017-08-18 10:03:03

by Yunlong Song

Subject: Re: [PATCH v2] f2fs: free_user_blocks should use reserved_segments instead

ping...

On 2017/8/15 15:14, Yunlong Song wrote:
> The part (overprovision_segments - reserved_segments) can still be used for LFS
> in some case, e.g., there are lots of invalid block from dirty segments, then
> the part (overprovision_segments - reserved_segments) can be safely used. So
> free_use_blocks should use reserved_segments instead, rather than directly use
> overprovision_segments. BTW, we also add the constraint of sbi->reserved_blocks.
>
> Signed-off-by: Yunlong Song <[email protected]>
> ---
> fs/f2fs/gc.h | 18 +++++++++++++++---
> 1 file changed, 15 insertions(+), 3 deletions(-)
>
> diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
> index 9325191..542612a 100644
> --- a/fs/f2fs/gc.h
> +++ b/fs/f2fs/gc.h
> @@ -49,11 +49,23 @@ struct gc_inode_list {
> */
> static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
> {
> - if (free_segments(sbi) < overprovision_segments(sbi))
> + block_t avail_user_block_count, free_blocks, avail_free_blocks;
> + block_t reserved_blocks;
> +
> + avail_user_block_count = sbi->user_block_count - sbi->reserved_blocks;
> +
> + if (unlikely(sbi->total_valid_block_count > avail_user_block_count))
> + return 0;
> +
> + free_blocks = free_segments(sbi) << sbi->log_blocks_per_seg;
> + avail_free_blocks = min(free_blocks, avail_user_block_count -
> + sbi->total_valid_block_count);
> + reserved_blocks = reserved_segments(sbi) << sbi->log_blocks_per_seg;
> +
> + if (avail_free_blocks < reserved_blocks)
> return 0;
> else
> - return (free_segments(sbi) - overprovision_segments(sbi))
> - << sbi->log_blocks_per_seg;
> + return avail_free_blocks - reserved_blocks;
> }
>
> static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)

--
Thanks,
Yunlong Song

2017-08-18 15:20:23

by Chao Yu

Subject: Re: [PATCH v2] f2fs: free_user_blocks should use reserved_segments instead

Hi Yunlong,

I think you have changed original implication of the function, IMO, it would be
more accurate to use user_free_segment_blocks instead of free_user_blocks.

Thanks,

On 2017/8/18 18:02, Yunlong Song wrote:
> ping...
>
> On 2017/8/15 15:14, Yunlong Song wrote:
>> The part (overprovision_segments - reserved_segments) can still be used for LFS
>> in some case, e.g., there are lots of invalid block from dirty segments, then
>> the part (overprovision_segments - reserved_segments) can be safely used. So
>> free_use_blocks should use reserved_segments instead, rather than directly use
>> overprovision_segments. BTW, we also add the constraint of sbi->reserved_blocks.
>>
>> Signed-off-by: Yunlong Song <[email protected]>
>> ---
>> fs/f2fs/gc.h | 18 +++++++++++++++---
>> 1 file changed, 15 insertions(+), 3 deletions(-)
>>
>> diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
>> index 9325191..542612a 100644
>> --- a/fs/f2fs/gc.h
>> +++ b/fs/f2fs/gc.h
>> @@ -49,11 +49,23 @@ struct gc_inode_list {
>> */
>> static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
>> {
>> - if (free_segments(sbi) < overprovision_segments(sbi))
>> + block_t avail_user_block_count, free_blocks, avail_free_blocks;
>> + block_t reserved_blocks;
>> +
>> + avail_user_block_count = sbi->user_block_count - sbi->reserved_blocks;
>> +
>> + if (unlikely(sbi->total_valid_block_count > avail_user_block_count))
>> + return 0;
>> +
>> + free_blocks = free_segments(sbi) << sbi->log_blocks_per_seg;
>> + avail_free_blocks = min(free_blocks, avail_user_block_count -
>> + sbi->total_valid_block_count);
>> + reserved_blocks = reserved_segments(sbi) << sbi->log_blocks_per_seg;
>> +
>> + if (avail_free_blocks < reserved_blocks)
>> return 0;
>> else
>> - return (free_segments(sbi) - overprovision_segments(sbi))
>> - << sbi->log_blocks_per_seg;
>> + return avail_free_blocks - reserved_blocks;
>> }
>> static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)
>