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 <yunlong.song@xxxxxxxxxx>
>>> ---
>>> 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;
>>>
>>
>> .
>>
>
