Re: [PATCH] f2fs: allow write page cache when writting cp

[heyunlei <heyunlei@huawei.com>]

Hi, Jaegeuk

On 2017/3/10 5:28, Jaegeuk Kim wrote:
> Hi Yunlei,
>
> On 03/07, Yunlei He wrote:
>> This patch allow write data to normal file when writting
>> new checkpoint.
>>
>> Signed-off-by: Yunlei He <heyunlei@huawei.com>
>> ---
>>  fs/f2fs/checkpoint.c |  4 +++-
>>  fs/f2fs/data.c       | 23 ++++++++++++++++-------
>>  fs/f2fs/f2fs.h       |  1 +
>>  fs/f2fs/super.c      |  1 +
>>  4 files changed, 21 insertions(+), 8 deletions(-)
>>
>> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
>> index 0339daf..1d86171 100644
>> --- a/fs/f2fs/checkpoint.c
>> +++ b/fs/f2fs/checkpoint.c
>> @@ -979,9 +979,10 @@ static int block_operations(struct f2fs_sb_info *sbi)
>>  	 * POR: we should ensure that there are no dirty node pages
>>  	 * until finishing nat/sit flush.
>>  	 */
>> +
>> +	down_write(&sbi->node_change);
>>  retry_flush_nodes:
>>  	down_write(&sbi->node_write);
>> -
>>  	if (get_pages(sbi, F2FS_DIRTY_NODES)) {
>>  		up_write(&sbi->node_write);
>>  		err = sync_node_pages(sbi, &wbc);
>> @@ -992,6 +993,7 @@ static int block_operations(struct f2fs_sb_info *sbi)
>>  		goto retry_flush_nodes;
>>  	}
>>  out:
>> +	up_write(&sbi->node_change);
>
> After block_operation, block allocator updates some block counters in terms of
> node or data blocks which will be written in checkpoint.

Yes, you are right! Can we prepare the checkpoint pack before we allow write
page cache?

Thanks

>
> Thanks,
>
>>  	blk_finish_plug(&plug);
>>  	return err;
>>  }
>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>> index 1375fef..c7eccb0 100644
>> --- a/fs/f2fs/data.c
>> +++ b/fs/f2fs/data.c
>> @@ -827,7 +827,9 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
>>  	}
>>
>>  next_dnode:
>> -	if (create)
>> +	if (create && flag == F2FS_GET_BLOCK_PRE_AIO)
>> +		down_read(&sbi->node_change);
>> +	else if (create)
>>  		f2fs_lock_op(sbi);
>>
>>  	/* When reading holes, we need its node page */
>> @@ -936,17 +938,23 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
>>  		goto next_block;
>>
>>  	f2fs_put_dnode(&dn);
>> -
>> -	if (create) {
>> +	if (create && flag == F2FS_GET_BLOCK_PRE_AIO) {
>> +		up_read(&sbi->node_change);
>> +		f2fs_balance_fs(sbi, dn.node_changed);
>> +	} else if (create) {
>>  		f2fs_unlock_op(sbi);
>>  		f2fs_balance_fs(sbi, dn.node_changed);
>>  	}
>> +
>>  	goto next_dnode;
>>
>>  sync_out:
>>  	f2fs_put_dnode(&dn);
>>  unlock_out:
>> -	if (create) {
>> +	if (create && flag == F2FS_GET_BLOCK_PRE_AIO) {
>> +		up_read(&sbi->node_change);
>> +		f2fs_balance_fs(sbi, dn.node_changed);
>> +	} else if (create) {
>>  		f2fs_unlock_op(sbi);
>>  		f2fs_balance_fs(sbi, dn.node_changed);
>>  	}
>> @@ -1686,7 +1694,7 @@ static int prepare_write_begin(struct f2fs_sb_info *sbi,
>>
>>  	if (f2fs_has_inline_data(inode) ||
>>  			(pos & PAGE_MASK) >= i_size_read(inode)) {
>> -		f2fs_lock_op(sbi);
>> +		down_read(&sbi->node_change);
>>  		locked = true;
>>  	}
>>  restart:
>> @@ -1703,6 +1711,7 @@ static int prepare_write_begin(struct f2fs_sb_info *sbi,
>>  		if (pos + len <= MAX_INLINE_DATA) {
>>  			read_inline_data(page, ipage);
>>  			set_inode_flag(inode, FI_DATA_EXIST);
>> +			dn.node_changed = true;
>>  			if (inode->i_nlink)
>>  				set_inline_node(ipage);
>>  		} else {
>> @@ -1722,7 +1731,7 @@ static int prepare_write_begin(struct f2fs_sb_info *sbi,
>>  			err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
>>  			if (err || dn.data_blkaddr == NULL_ADDR) {
>>  				f2fs_put_dnode(&dn);
>> -				f2fs_lock_op(sbi);
>> +				down_read(&sbi->node_change);
>>  				locked = true;
>>  				goto restart;
>>  			}
>> @@ -1736,7 +1745,7 @@ static int prepare_write_begin(struct f2fs_sb_info *sbi,
>>  	f2fs_put_dnode(&dn);
>>  unlock_out:
>>  	if (locked)
>> -		f2fs_unlock_op(sbi);
>> +		up_read(&sbi->node_change);
>>  	return err;
>>  }
>>
>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>> index 7e29249..0568f78 100644
>> --- a/fs/f2fs/f2fs.h
>> +++ b/fs/f2fs/f2fs.h
>> @@ -830,6 +830,7 @@ struct f2fs_sb_info {
>>  	struct mutex cp_mutex;			/* checkpoint procedure lock */
>>  	struct rw_semaphore cp_rwsem;		/* blocking FS operations */
>>  	struct rw_semaphore node_write;		/* locking node writes */
>> +	struct rw_semaphore node_change;		/* locking node change */
>>  	wait_queue_head_t cp_wait;
>>  	unsigned long last_time[MAX_TIME];	/* to store time in jiffies */
>>  	long interval_time[MAX_TIME];		/* to store thresholds */
>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>> index 2d494d5..d217114 100644
>> --- a/fs/f2fs/super.c
>> +++ b/fs/f2fs/super.c
>> @@ -1929,6 +1929,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
>>  	mutex_init(&sbi->gc_mutex);
>>  	mutex_init(&sbi->cp_mutex);
>>  	init_rwsem(&sbi->node_write);
>> +	init_rwsem(&sbi->node_change);
>>
>>  	/* disallow all the data/node/meta page writes */
>>  	set_sbi_flag(sbi, SBI_POR_DOING);
>> --
>> 2.10.1
>>
>>
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>
> .
>


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