2017-08-08 04:12:44

by Yunlong Song

[permalink] [raw]
Subject: [PATCH] f2fs: fix some cases with reserved_blocks

Signed-off-by: Yunlong Song <[email protected]>
---
fs/f2fs/recovery.c | 3 ++-
fs/f2fs/super.c | 9 +++++----
2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index a3d0261..e288319 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -51,7 +51,8 @@ bool space_for_roll_forward(struct f2fs_sb_info *sbi)
{
s64 nalloc = percpu_counter_sum_positive(&sbi->alloc_valid_block_count);

- if (sbi->last_valid_block_count + nalloc > sbi->user_block_count)
+ if (sbi->last_valid_block_count + nalloc +
+ sbi->reserved_blocks > sbi->user_block_count)
return false;
return true;
}
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 4c1bdcb..c644bf5 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -946,6 +946,7 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
block_t total_count, user_block_count, start_count, ovp_count;
u64 avail_node_count;
+ block_t avail_user_block_count;

total_count = le64_to_cpu(sbi->raw_super->block_count);
user_block_count = sbi->user_block_count;
@@ -953,16 +954,16 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
buf->f_type = F2FS_SUPER_MAGIC;
buf->f_bsize = sbi->blocksize;
+ avail_user_block_count = user_block_count - sbi->reserved_blocks;

buf->f_blocks = total_count - start_count;
buf->f_bfree = user_block_count - valid_user_blocks(sbi) + ovp_count;
- buf->f_bavail = user_block_count - valid_user_blocks(sbi) -
- sbi->reserved_blocks;
+ buf->f_bavail = avail_user_block_count - valid_user_blocks(sbi);

avail_node_count = sbi->total_node_count - F2FS_RESERVED_NODE_NUM;

- if (avail_node_count > user_block_count) {
- buf->f_files = user_block_count;
+ if (avail_node_count > avail_user_block_count) {
+ buf->f_files = avail_user_block_count;
buf->f_ffree = buf->f_bavail;
} else {
buf->f_files = avail_node_count;
--
1.8.5.2


2017-08-08 06:08:51

by Chao Yu

[permalink] [raw]
Subject: Re: [PATCH] f2fs: fix some cases with reserved_blocks

On 2017/8/8 12:12, Yunlong Song wrote:
> Signed-off-by: Yunlong Song <[email protected]>
> ---
> fs/f2fs/recovery.c | 3 ++-
> fs/f2fs/super.c | 9 +++++----
> 2 files changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
> index a3d0261..e288319 100644
> --- a/fs/f2fs/recovery.c
> +++ b/fs/f2fs/recovery.c
> @@ -51,7 +51,8 @@ bool space_for_roll_forward(struct f2fs_sb_info *sbi)
> {
> s64 nalloc = percpu_counter_sum_positive(&sbi->alloc_valid_block_count);
>
> - if (sbi->last_valid_block_count + nalloc > sbi->user_block_count)
> + if (sbi->last_valid_block_count + nalloc +
> + sbi->reserved_blocks > sbi->user_block_count)

I think we can treat reserved blocks as over-provision space in f2fs, so it
would be safe to store invalid data (may become valid during recovery) there.
Anyway, it OK to remain old condition judgment.

> return false;
> return true;
> }
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 4c1bdcb..c644bf5 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -946,6 +946,7 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
> u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
> block_t total_count, user_block_count, start_count, ovp_count;
> u64 avail_node_count;
> + block_t avail_user_block_count;
>
> total_count = le64_to_cpu(sbi->raw_super->block_count);
> user_block_count = sbi->user_block_count;
> @@ -953,16 +954,16 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
> ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
> buf->f_type = F2FS_SUPER_MAGIC;
> buf->f_bsize = sbi->blocksize;
> + avail_user_block_count = user_block_count - sbi->reserved_blocks;
>
> buf->f_blocks = total_count - start_count;
> buf->f_bfree = user_block_count - valid_user_blocks(sbi) + ovp_count;
> - buf->f_bavail = user_block_count - valid_user_blocks(sbi) -
> - sbi->reserved_blocks;
> + buf->f_bavail = avail_user_block_count - valid_user_blocks(sbi);
>
> avail_node_count = sbi->total_node_count - F2FS_RESERVED_NODE_NUM;
>
> - if (avail_node_count > user_block_count) {
> - buf->f_files = user_block_count;
> + if (avail_node_count > avail_user_block_count) {

Likewise f_blocks calculation, the f_files one doesn't need to consider
reserved_blocks.

Thanks,

> + buf->f_files = avail_user_block_count;
> buf->f_ffree = buf->f_bavail;
> } else {
> buf->f_files = avail_node_count;
>

2017-08-08 06:35:12

by Yunlong Song

[permalink] [raw]
Subject: Re: [PATCH] f2fs: fix some cases with reserved_blocks

Does this means the reserved_blocks cannot be used by users by can be
used by filesystem?
If it can be used by filesystem, then this cannot ensure the flash
device really reserve the
reserved_blocks space, right? The reserved_blocks is just for users?

On 2017/8/8 14:08, Chao Yu wrote:
> On 2017/8/8 12:12, Yunlong Song wrote:
>> Signed-off-by: Yunlong Song <[email protected]>
>> ---
>> fs/f2fs/recovery.c | 3 ++-
>> fs/f2fs/super.c | 9 +++++----
>> 2 files changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
>> index a3d0261..e288319 100644
>> --- a/fs/f2fs/recovery.c
>> +++ b/fs/f2fs/recovery.c
>> @@ -51,7 +51,8 @@ bool space_for_roll_forward(struct f2fs_sb_info *sbi)
>> {
>> s64 nalloc = percpu_counter_sum_positive(&sbi->alloc_valid_block_count);
>>
>> - if (sbi->last_valid_block_count + nalloc > sbi->user_block_count)
>> + if (sbi->last_valid_block_count + nalloc +
>> + sbi->reserved_blocks > sbi->user_block_count)
> I think we can treat reserved blocks as over-provision space in f2fs, so it
> would be safe to store invalid data (may become valid during recovery) there.
> Anyway, it OK to remain old condition judgment.
>
>> return false;
>> return true;
>> }
>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>> index 4c1bdcb..c644bf5 100644
>> --- a/fs/f2fs/super.c
>> +++ b/fs/f2fs/super.c
>> @@ -946,6 +946,7 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
>> u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
>> block_t total_count, user_block_count, start_count, ovp_count;
>> u64 avail_node_count;
>> + block_t avail_user_block_count;
>>
>> total_count = le64_to_cpu(sbi->raw_super->block_count);
>> user_block_count = sbi->user_block_count;
>> @@ -953,16 +954,16 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
>> ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
>> buf->f_type = F2FS_SUPER_MAGIC;
>> buf->f_bsize = sbi->blocksize;
>> + avail_user_block_count = user_block_count - sbi->reserved_blocks;
>>
>> buf->f_blocks = total_count - start_count;
>> buf->f_bfree = user_block_count - valid_user_blocks(sbi) + ovp_count;
>> - buf->f_bavail = user_block_count - valid_user_blocks(sbi) -
>> - sbi->reserved_blocks;
>> + buf->f_bavail = avail_user_block_count - valid_user_blocks(sbi);
>>
>> avail_node_count = sbi->total_node_count - F2FS_RESERVED_NODE_NUM;
>>
>> - if (avail_node_count > user_block_count) {
>> - buf->f_files = user_block_count;
>> + if (avail_node_count > avail_user_block_count) {
> Likewise f_blocks calculation, the f_files one doesn't need to consider
> reserved_blocks.
>
> Thanks,
>
>> + buf->f_files = avail_user_block_count;
>> buf->f_ffree = buf->f_bavail;
>> } else {
>> buf->f_files = avail_node_count;
>>
>
> .
>

--
Thanks,
Yunlong Song


2017-08-08 08:13:30

by Chao Yu

[permalink] [raw]
Subject: Re: [PATCH] f2fs: fix some cases with reserved_blocks

On 2017/8/8 14:33, Yunlong Song wrote:
> Does this means the reserved_blocks cannot be used by users by can be
> used by filesystem?

Yup.

> If it can be used by filesystem, then this cannot ensure the flash
> device really reserve the
> reserved_blocks space, right? The reserved_blocks is just for users?

No, only if we didn't issue any discards, otherwise we can benefit from less GC
overhead in device due to higher over-provision rate.

Thanks,

>
> On 2017/8/8 14:08, Chao Yu wrote:
>> On 2017/8/8 12:12, Yunlong Song wrote:
>>> Signed-off-by: Yunlong Song <[email protected]>
>>> ---
>>> fs/f2fs/recovery.c | 3 ++-
>>> fs/f2fs/super.c | 9 +++++----
>>> 2 files changed, 7 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
>>> index a3d0261..e288319 100644
>>> --- a/fs/f2fs/recovery.c
>>> +++ b/fs/f2fs/recovery.c
>>> @@ -51,7 +51,8 @@ bool space_for_roll_forward(struct f2fs_sb_info *sbi)
>>> {
>>> s64 nalloc = percpu_counter_sum_positive(&sbi->alloc_valid_block_count);
>>>
>>> - if (sbi->last_valid_block_count + nalloc > sbi->user_block_count)
>>> + if (sbi->last_valid_block_count + nalloc +
>>> + sbi->reserved_blocks > sbi->user_block_count)
>> I think we can treat reserved blocks as over-provision space in f2fs, so it
>> would be safe to store invalid data (may become valid during recovery) there.
>> Anyway, it OK to remain old condition judgment.
>>
>>> return false;
>>> return true;
>>> }
>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>>> index 4c1bdcb..c644bf5 100644
>>> --- a/fs/f2fs/super.c
>>> +++ b/fs/f2fs/super.c
>>> @@ -946,6 +946,7 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
>>> u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
>>> block_t total_count, user_block_count, start_count, ovp_count;
>>> u64 avail_node_count;
>>> + block_t avail_user_block_count;
>>>
>>> total_count = le64_to_cpu(sbi->raw_super->block_count);
>>> user_block_count = sbi->user_block_count;
>>> @@ -953,16 +954,16 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf)
>>> ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
>>> buf->f_type = F2FS_SUPER_MAGIC;
>>> buf->f_bsize = sbi->blocksize;
>>> + avail_user_block_count = user_block_count - sbi->reserved_blocks;
>>>
>>> buf->f_blocks = total_count - start_count;
>>> buf->f_bfree = user_block_count - valid_user_blocks(sbi) + ovp_count;
>>> - buf->f_bavail = user_block_count - valid_user_blocks(sbi) -
>>> - sbi->reserved_blocks;
>>> + buf->f_bavail = avail_user_block_count - valid_user_blocks(sbi);
>>>
>>> avail_node_count = sbi->total_node_count - F2FS_RESERVED_NODE_NUM;
>>>
>>> - if (avail_node_count > user_block_count) {
>>> - buf->f_files = user_block_count;
>>> + if (avail_node_count > avail_user_block_count) {
>> Likewise f_blocks calculation, the f_files one doesn't need to consider
>> reserved_blocks.
>>
>> Thanks,
>>
>>> + buf->f_files = avail_user_block_count;
>>> buf->f_ffree = buf->f_bavail;
>>> } else {
>>> buf->f_files = avail_node_count;
>>>
>>
>> .
>>
>