Re: [PATCH 1/2] f2fs: split f2fs_allocate_new_segments()

[Chao Yu]

On 2020/6/30 4:19, Jaegeuk Kim wrote:
> On 06/22, Chao Yu wrote:
>> to two independent functions:
>> - f2fs_allocate_new_segment() for specified type segment allocation
>> - f2fs_allocate_new_segments() for all data type segments allocation
>>
>> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
>> ---
>>  fs/f2fs/f2fs.h     |  3 ++-
>>  fs/f2fs/file.c     |  2 +-
>>  fs/f2fs/recovery.c |  2 +-
>>  fs/f2fs/segment.c  | 39 +++++++++++++++++++++++----------------
>>  4 files changed, 27 insertions(+), 19 deletions(-)
>>
>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>> index 70565d81320b..07290943e91d 100644
>> --- a/fs/f2fs/f2fs.h
>> +++ b/fs/f2fs/f2fs.h
>> @@ -3327,7 +3327,8 @@ void f2fs_release_discard_addrs(struct f2fs_sb_info *sbi);
>>  int f2fs_npages_for_summary_flush(struct f2fs_sb_info *sbi, bool for_ra);
>>  void f2fs_allocate_segment_for_resize(struct f2fs_sb_info *sbi, int type,
>>  					unsigned int start, unsigned int end);
>> -void f2fs_allocate_new_segments(struct f2fs_sb_info *sbi, int type);
>> +void f2fs_allocate_new_segment(struct f2fs_sb_info *sbi, int type);
>> +void f2fs_allocate_new_segments(struct f2fs_sb_info *sbi);
>>  int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range);
>>  bool f2fs_exist_trim_candidates(struct f2fs_sb_info *sbi,
>>  					struct cp_control *cpc);
>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>> index f196187159e9..67c65e40b22b 100644
>> --- a/fs/f2fs/file.c
>> +++ b/fs/f2fs/file.c
>> @@ -1659,7 +1659,7 @@ static int expand_inode_data(struct inode *inode, loff_t offset,
>>  		map.m_seg_type = CURSEG_COLD_DATA_PINNED;
>>  
>>  		f2fs_lock_op(sbi);
>> -		f2fs_allocate_new_segments(sbi, CURSEG_COLD_DATA);
>> +		f2fs_allocate_new_segment(sbi, CURSEG_COLD_DATA_PINNED);
> 
> This should be CURSEG_COLD_DATA. Otherwise it causes the below kernel panic.
> I fixed this in the -dev, so let me know, if you have other concern.

It looks I made a mistake when spliting this cleanup patch from
"f2fs: introduce inmem curseg", thanks for fixing this.

Thanks,

> 
>   259 Unable to handle kernel NULL pointer dereference at virtual address 00000008
>   259 task: 0000000082b4de99 task.stack: 00000000c6b39dbf
>   259 pc : f2fs_do_write_data_page+0x2b4/0x794
>   259 lr : f2fs_do_write_data_page+0x290/0x794
>   259 sp : ffffff800c83b5a0 pstate : 60c00145
>   259 Call trace:
>   259  f2fs_do_write_data_page+0x2b4/0x794
>   259  f2fs_write_single_data_page+0x4a4/0x764
>   259  f2fs_write_data_pages+0x4dc/0x968
>   259  do_writepages+0x60/0x124
>   259  __writeback_single_inode+0xd8/0x490
>   259  writeback_sb_inodes+0x3a8/0x6e4
>   259  __writeback_inodes_wb+0xa4/0x14c
>   259  wb_writeback+0x218/0x434
>   259  wb_workfn+0x2bc/0x57c
>   259  process_one_work+0x25c/0x440
>   259  worker_thread+0x24c/0x480
>   259  kthread+0x11c/0x12c
>   259  ret_from_fork+0x10/0x18
> 
>>  		f2fs_unlock_op(sbi);
>>  
>>  		err = f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_DIO);
>> diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
>> index ae5310f02e7f..af974ba273b3 100644
>> --- a/fs/f2fs/recovery.c
>> +++ b/fs/f2fs/recovery.c
>> @@ -742,7 +742,7 @@ static int recover_data(struct f2fs_sb_info *sbi, struct list_head *inode_list,
>>  		f2fs_put_page(page, 1);
>>  	}
>>  	if (!err)
>> -		f2fs_allocate_new_segments(sbi, NO_CHECK_TYPE);
>> +		f2fs_allocate_new_segments(sbi);
>>  	return err;
>>  }
>>  
>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>> index 113114f98087..f15711e8ee5b 100644
>> --- a/fs/f2fs/segment.c
>> +++ b/fs/f2fs/segment.c
>> @@ -2707,28 +2707,35 @@ void f2fs_allocate_segment_for_resize(struct f2fs_sb_info *sbi, int type,
>>  	up_read(&SM_I(sbi)->curseg_lock);
>>  }
>>  
>> -void f2fs_allocate_new_segments(struct f2fs_sb_info *sbi, int type)
>> +void __allocate_new_segment(struct f2fs_sb_info *sbi, int type)
>>  {
>> -	struct curseg_info *curseg;
>> +	struct curseg_info *curseg = CURSEG_I(sbi, type);
>>  	unsigned int old_segno;
>> -	int i;
>>  
>> -	down_write(&SIT_I(sbi)->sentry_lock);
>> +	if (!curseg->next_blkoff &&
>> +		!get_valid_blocks(sbi, curseg->segno, false) &&
>> +		!get_ckpt_valid_blocks(sbi, curseg->segno))
>> +		return;
>>  
>> -	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
>> -		if (type != NO_CHECK_TYPE && i != type)
>> -			continue;
>> +	old_segno = curseg->segno;
>> +	SIT_I(sbi)->s_ops->allocate_segment(sbi, type, true);
>> +	locate_dirty_segment(sbi, old_segno);
>> +}
>>  
>> -		curseg = CURSEG_I(sbi, i);
>> -		if (type == NO_CHECK_TYPE || curseg->next_blkoff ||
>> -				get_valid_blocks(sbi, curseg->segno, false) ||
>> -				get_ckpt_valid_blocks(sbi, curseg->segno)) {
>> -			old_segno = curseg->segno;
>> -			SIT_I(sbi)->s_ops->allocate_segment(sbi, i, true);
>> -			locate_dirty_segment(sbi, old_segno);
>> -		}
>> -	}
>> +void f2fs_allocate_new_segment(struct f2fs_sb_info *sbi, int type)
>> +{
>> +	down_write(&SIT_I(sbi)->sentry_lock);
>> +	__allocate_new_segment(sbi, type);
>> +	up_write(&SIT_I(sbi)->sentry_lock);
>> +}
>>  
>> +void f2fs_allocate_new_segments(struct f2fs_sb_info *sbi)
>> +{
>> +	int i;
>> +
>> +	down_write(&SIT_I(sbi)->sentry_lock);
>> +	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++)
>> +		__allocate_new_segment(sbi, i);
>>  	up_write(&SIT_I(sbi)->sentry_lock);
>>  }
>>  
>> -- 
>> 2.26.2
> .
>