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

From: Chao Yu
Date: Mon Jun 29 2020 - 21:21:40 EST


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
> .
>