Re: [f2fs-dev] [PATCH] f2fs: cover update_free_nid_bitmap with free_list_lock

[Chao Yu]

On 2017/3/14 3:57, Jaegeuk Kim wrote:
> On 03/13, Kinglong Mee wrote:
>> On 3/13/2017 20:10, Chao Yu wrote:
>>> free_nid_bitmap and free_nid_count in update_free_nid_bitmap should be
>>> updated atomically, use free_list_lock cover them to avoid race in
>>
>> nid_list_lock?
> 
> Think so.
> I merged a modified one in dev-test and started to test it.

Thanks for fixing.

> 
> Thanks,
> 
>>
>> Reviewed-by: Kinglong Mee <kinglongmee@xxxxxxxxx>

Thanks for the review.

Thanks,

>>
>>> concurrent scenario.
>>>
>>> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
>>> ---
>>>  fs/f2fs/f2fs.h |  1 -
>>>  fs/f2fs/node.c | 27 +++++++++++----------------
>>>  2 files changed, 11 insertions(+), 17 deletions(-)
>>>
>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>> index 843ce39502bc..d905e53ba524 100644
>>> --- a/fs/f2fs/f2fs.h
>>> +++ b/fs/f2fs/f2fs.h
>>> @@ -561,7 +561,6 @@ struct f2fs_nm_info {
>>>  	unsigned char (*free_nid_bitmap)[NAT_ENTRY_BITMAP_SIZE];
>>>  	unsigned char *nat_block_bitmap;
>>>  	unsigned short *free_nid_count;	/* free nid count of NAT block */
>>> -	spinlock_t free_nid_lock;	/* protect updating of nid count */
>>>  
>>>  	/* for checkpoint */
>>>  	char *nat_bitmap;		/* NAT bitmap pointer */
>>> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
>>> index 11df8ab32478..3bfffd744f87 100644
>>> --- a/fs/f2fs/node.c
>>> +++ b/fs/f2fs/node.c
>>> @@ -1815,7 +1815,7 @@ static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid)
>>>  }
>>>  
>>>  static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid,
>>> -			bool set, bool build, bool locked)
>>> +							bool set, bool build)
>>>  {
>>>  	struct f2fs_nm_info *nm_i = NM_I(sbi);
>>>  	unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid);
>>> @@ -1829,14 +1829,10 @@ static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid,
>>>  	else
>>>  		__clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
>>>  
>>> -	if (!locked)
>>> -		spin_lock(&nm_i->free_nid_lock);
>>>  	if (set)
>>>  		nm_i->free_nid_count[nat_ofs]++;
>>>  	else if (!build)
>>>  		nm_i->free_nid_count[nat_ofs]--;
>>> -	if (!locked)
>>> -		spin_unlock(&nm_i->free_nid_lock);
>>>  }
>>>  
>>>  static void scan_nat_page(struct f2fs_sb_info *sbi,
>>> @@ -1865,7 +1861,9 @@ static void scan_nat_page(struct f2fs_sb_info *sbi,
>>>  		f2fs_bug_on(sbi, blk_addr == NEW_ADDR);
>>>  		if (blk_addr == NULL_ADDR)
>>>  			freed = add_free_nid(sbi, start_nid, true);
>>> -		update_free_nid_bitmap(sbi, start_nid, freed, true, false);
>>> +		spin_lock(&NM_I(sbi)->nid_list_lock);
>>> +		update_free_nid_bitmap(sbi, start_nid, freed, true);
>>> +		spin_unlock(&NM_I(sbi)->nid_list_lock);
>>>  	}
>>>  }
>>>  
>>> @@ -2020,7 +2018,7 @@ bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
>>>  		__insert_nid_to_list(sbi, i, ALLOC_NID_LIST, false);
>>>  		nm_i->available_nids--;
>>>  
>>> -		update_free_nid_bitmap(sbi, *nid, false, false, false);
>>> +		update_free_nid_bitmap(sbi, *nid, false, false);
>>>  
>>>  		spin_unlock(&nm_i->nid_list_lock);
>>>  		return true;
>>> @@ -2076,7 +2074,7 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
>>>  
>>>  	nm_i->available_nids++;
>>>  
>>> -	update_free_nid_bitmap(sbi, nid, true, false, false);
>>> +	update_free_nid_bitmap(sbi, nid, true, false);
>>>  
>>>  	spin_unlock(&nm_i->nid_list_lock);
>>>  
>>> @@ -2406,11 +2404,11 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi,
>>>  			add_free_nid(sbi, nid, false);
>>>  			spin_lock(&NM_I(sbi)->nid_list_lock);
>>>  			NM_I(sbi)->available_nids++;
>>> -			update_free_nid_bitmap(sbi, nid, true, false, false);
>>> +			update_free_nid_bitmap(sbi, nid, true, false);
>>>  			spin_unlock(&NM_I(sbi)->nid_list_lock);
>>>  		} else {
>>>  			spin_lock(&NM_I(sbi)->nid_list_lock);
>>> -			update_free_nid_bitmap(sbi, nid, false, false, false);
>>> +			update_free_nid_bitmap(sbi, nid, false, false);
>>>  			spin_unlock(&NM_I(sbi)->nid_list_lock);
>>>  		}
>>>  	}
>>> @@ -2535,10 +2533,10 @@ inline void load_free_nid_bitmap(struct f2fs_sb_info *sbi)
>>>  		nid = i * NAT_ENTRY_PER_BLOCK;
>>>  		last_nid = (i + 1) * NAT_ENTRY_PER_BLOCK;
>>>  
>>> -		spin_lock(&nm_i->free_nid_lock);
>>> +		spin_lock(&NM_I(sbi)->nid_list_lock);
>>>  		for (; nid < last_nid; nid++)
>>> -			update_free_nid_bitmap(sbi, nid, true, true, true);
>>> -		spin_unlock(&nm_i->free_nid_lock);
>>> +			update_free_nid_bitmap(sbi, nid, true, true);
>>> +		spin_unlock(&NM_I(sbi)->nid_list_lock);
>>>  	}
>>>  
>>>  	for (i = 0; i < nm_i->nat_blocks; i++) {
>>> @@ -2629,9 +2627,6 @@ static int init_free_nid_cache(struct f2fs_sb_info *sbi)
>>>  					sizeof(unsigned short), GFP_KERNEL);
>>>  	if (!nm_i->free_nid_count)
>>>  		return -ENOMEM;
>>> -
>>> -	spin_lock_init(&nm_i->free_nid_lock);
>>> -
>>>  	return 0;
>>>  }
>>>  
>>>
> 
> .
>