Re: [PATCH v2 6/6] f2fs: give up CP_TRIMMED_FLAG if it drops discards

[Chao Yu]

On 2017/10/24 20:46, Jaegeuk Kim wrote:
> On 10/24, Chao Yu wrote:
>> Hi Jaegeuk,
>>
>> On 2017/10/4 9:08, Chao Yu wrote:
>>> From: Chao Yu <yuchao0@xxxxxxxxxx>
>>>
>>> In ->umount, once we drop remained discard entries, we should not
>>> set CP_TRIMMED_FLAG with another checkpoint.
>>>
>>> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
>>> ---
>>> v2:
>>> - rebase on last codes of Jaegeuk's dev-test branch.
>>>  fs/f2fs/f2fs.h    |  2 +-
>>>  fs/f2fs/segment.c | 15 +++++++++++----
>>>  fs/f2fs/super.c   |  5 +++--
>>>  3 files changed, 15 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>> index f274805e231d..c85f49c41003 100644
>>> --- a/fs/f2fs/f2fs.h
>>> +++ b/fs/f2fs/f2fs.h
>>> @@ -2565,7 +2565,7 @@ void init_discard_policy(struct discard_policy *dpolicy, int discard_type,
>>>  						unsigned int granularity);
>>>  void refresh_sit_entry(struct f2fs_sb_info *sbi, block_t old, block_t new);
>>>  void stop_discard_thread(struct f2fs_sb_info *sbi);
>>> -void f2fs_wait_discard_bios(struct f2fs_sb_info *sbi);
>>> +bool f2fs_wait_discard_bios(struct f2fs_sb_info *sbi);
>>>  void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc);
>>>  void release_discard_addrs(struct f2fs_sb_info *sbi);
>>>  int npages_for_summary_flush(struct f2fs_sb_info *sbi, bool for_ra);
>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>>> index 4a108321233d..bfbcff8339c5 100644
>>> --- a/fs/f2fs/segment.c
>>> +++ b/fs/f2fs/segment.c
>>> @@ -1196,12 +1196,13 @@ static int __issue_discard_cmd(struct f2fs_sb_info *sbi,
>>>  	return issued;
>>>  }
>>>  
>>> -static void __drop_discard_cmd(struct f2fs_sb_info *sbi)
>>> +static bool __drop_discard_cmd(struct f2fs_sb_info *sbi)
>>>  {
>>>  	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
>>>  	struct list_head *pend_list;
>>>  	struct discard_cmd *dc, *tmp;
>>>  	int i;
>>> +	bool dropped = false;
>>>  
>>>  	mutex_lock(&dcc->cmd_lock);
>>>  	for (i = MAX_PLIST_NUM - 1; i >= 0; i--) {
>>> @@ -1209,9 +1210,12 @@ static void __drop_discard_cmd(struct f2fs_sb_info *sbi)
>>>  		list_for_each_entry_safe(dc, tmp, pend_list, list) {
>>>  			f2fs_bug_on(sbi, dc->state != D_PREP);
>>>  			__remove_discard_cmd(sbi, dc);
>>> +			dropped = true;
>>>  		}
>>>  	}
>>>  	mutex_unlock(&dcc->cmd_lock);
>>> +
>>> +	return dropped;
>>>  }
>>>  
>>>  static void __wait_one_discard_bio(struct f2fs_sb_info *sbi,
>>> @@ -1306,15 +1310,18 @@ void stop_discard_thread(struct f2fs_sb_info *sbi)
>>>  }
>>>  
>>>  /* This comes from f2fs_put_super */
>>> -void f2fs_wait_discard_bios(struct f2fs_sb_info *sbi)
>>> +bool f2fs_wait_discard_bios(struct f2fs_sb_info *sbi)
>>>  {
>>>  	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
>>>  	struct discard_policy dpolicy;
>>> +	bool dropped;
>>>  
>>>  	init_discard_policy(&dpolicy, DPOLICY_UMOUNT, dcc->discard_granularity);
>>>  	__issue_discard_cmd(sbi, &dpolicy);
>>> -	__drop_discard_cmd(sbi);
>>> +	dropped = __drop_discard_cmd(sbi);
>>>  	__wait_all_discard_cmd(sbi, &dpolicy);
>>> +
>>> +	return dropped;
>>>  }
>>>  
>>>  static int issue_discard_thread(void *data)
>>> @@ -1659,7 +1666,7 @@ void init_discard_policy(struct discard_policy *dpolicy,
>>>  		dpolicy->max_interval = DEF_MAX_DISCARD_ISSUE_TIME;
>>>  		dpolicy->max_requests = DEF_MAX_DISCARD_REQUEST;
>>>  		dpolicy->io_aware_gran = MAX_PLIST_NUM;
>>> -		dpolicy->io_aware = false;
>>> +		dpolicy->io_aware = true;
>>
>> I notice this change should not belong to this patch, could you please help to
>> move this into "f2fs: split discard policy" in your branch?
> 
> Yup, done. Could you check it in dev-test?

I didn't find it, did you forget to push to that branch?

Thanks,

> 
> Thanks,
> 
>>
>> Thanks,
>>
>>>  	} else if (discard_type == DPOLICY_FSTRIM) {
>>>  		dpolicy->max_requests = DEF_MAX_DISCARD_REQUEST;
>>>  		dpolicy->io_aware_gran = MAX_PLIST_NUM;
>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>>> index a13269d1a1f0..1d68c18a487b 100644
>>> --- a/fs/f2fs/super.c
>>> +++ b/fs/f2fs/super.c
>>> @@ -807,6 +807,7 @@ static void f2fs_put_super(struct super_block *sb)
>>>  {
>>>  	struct f2fs_sb_info *sbi = F2FS_SB(sb);
>>>  	int i;
>>> +	bool dropped;
>>>  
>>>  	f2fs_quota_off_umount(sb);
>>>  
>>> @@ -827,9 +828,9 @@ static void f2fs_put_super(struct super_block *sb)
>>>  	}
>>>  
>>>  	/* be sure to wait for any on-going discard commands */
>>> -	f2fs_wait_discard_bios(sbi, true);
>>> +	dropped = f2fs_wait_discard_bios(sbi);
>>>  
>>> -	if (f2fs_discard_en(sbi) && !sbi->discard_blks) {
>>> +	if (f2fs_discard_en(sbi) && !sbi->discard_blks && !dropped) {
>>>  		struct cp_control cpc = {
>>>  			.reason = CP_UMOUNT | CP_TRIMMED,
>>>  		};
>>>