Re: [PATCH v4] f2fs: add bio cache for IPU

[Chao Yu <yuchao0@huawei.com>]

On 2019/3/2 1:55, Jaegeuk Kim wrote:
> On 02/28, Chao Yu wrote:
>> Ping,
> 
> Ditto.

Copied.

Thanks,

> 
>>
>> On 2019/2/19 16:15, Chao Yu wrote:
>>> SQLite in Wal mode may trigger sequential IPU write in db-wal file, after
>>> commit d1b3e72d5490 ("f2fs: submit bio of in-place-update pages"), we
>>> lost the chance of merging page in inner managed bio cache, result in
>>> submitting more small-sized IO.
>>>
>>> So let's add temporary bio in writepages() to cache mergeable write IO as
>>> much as possible.
>>>
>>> Test case:
>>> 1. xfs_io -f /mnt/f2fs/file -c "pwrite 0 65536" -c "fsync"
>>> 2. xfs_io -f /mnt/f2fs/file -c "pwrite 0 65536" -c "fsync"
>>>
>>> Before:
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65544, size = 4096
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65552, size = 4096
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65560, size = 4096
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65568, size = 4096
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65576, size = 4096
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65584, size = 4096
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65592, size = 4096
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65600, size = 4096
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65608, size = 4096
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65616, size = 4096
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65624, size = 4096
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65632, size = 4096
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65640, size = 4096
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65648, size = 4096
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65656, size = 4096
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65664, size = 4096
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), NODE, sector = 57352, size = 4096
>>>
>>> After:
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65544, size = 65536
>>> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), NODE, sector = 57368, size = 4096
>>>
>>> Signed-off-by: Chao Yu <yuchao0@huawei.com>
>>> ---
>>> v4:
>>> - fix to set *bio to NULL in f2fs_submit_ipu_bio()
>>> - spread f2fs_submit_ipu_bio()
>>> - fix to count dirty encrypted page correctly in f2fs_merge_page_bio()
>>> - remove redundant assignment of fio->last_block
>>>  fs/f2fs/data.c    | 88 ++++++++++++++++++++++++++++++++++++++++++-----
>>>  fs/f2fs/f2fs.h    |  3 ++
>>>  fs/f2fs/segment.c |  5 ++-
>>>  3 files changed, 86 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>>> index 35910ff23582..e4c183e85de8 100644
>>> --- a/fs/f2fs/data.c
>>> +++ b/fs/f2fs/data.c
>>> @@ -296,20 +296,20 @@ static void __submit_merged_bio(struct f2fs_bio_info *io)
>>>  	io->bio = NULL;
>>>  }
>>>  
>>> -static bool __has_merged_page(struct f2fs_bio_info *io, struct inode *inode,
>>> +static bool __has_merged_page(struct bio *bio, struct inode *inode,
>>>  						struct page *page, nid_t ino)
>>>  {
>>>  	struct bio_vec *bvec;
>>>  	struct page *target;
>>>  	int i;
>>>  
>>> -	if (!io->bio)
>>> +	if (!bio)
>>>  		return false;
>>>  
>>>  	if (!inode && !page && !ino)
>>>  		return true;
>>>  
>>> -	bio_for_each_segment_all(bvec, io->bio, i) {
>>> +	bio_for_each_segment_all(bvec, bio, i) {
>>>  
>>>  		if (bvec->bv_page->mapping)
>>>  			target = bvec->bv_page;
>>> @@ -360,7 +360,7 @@ static void __submit_merged_write_cond(struct f2fs_sb_info *sbi,
>>>  			struct f2fs_bio_info *io = sbi->write_io[btype] + temp;
>>>  
>>>  			down_read(&io->io_rwsem);
>>> -			ret = __has_merged_page(io, inode, page, ino);
>>> +			ret = __has_merged_page(io->bio, inode, page, ino);
>>>  			up_read(&io->io_rwsem);
>>>  		}
>>>  		if (ret)
>>> @@ -429,6 +429,61 @@ int f2fs_submit_page_bio(struct f2fs_io_info *fio)
>>>  	return 0;
>>>  }
>>>  
>>> +int f2fs_merge_page_bio(struct f2fs_io_info *fio)
>>> +{
>>> +	struct bio *bio = *fio->bio;
>>> +	struct page *page = fio->encrypted_page ?
>>> +			fio->encrypted_page : fio->page;
>>> +
>>> +	if (!f2fs_is_valid_blkaddr(fio->sbi, fio->new_blkaddr,
>>> +			__is_meta_io(fio) ? META_GENERIC : DATA_GENERIC))
>>> +		return -EFAULT;
>>> +
>>> +	trace_f2fs_submit_page_bio(page, fio);
>>> +	f2fs_trace_ios(fio, 0);
>>> +
>>> +	if (bio && (*fio->last_block + 1 != fio->new_blkaddr ||
>>> +			!__same_bdev(fio->sbi, fio->new_blkaddr, bio))) {
>>> +		__submit_bio(fio->sbi, bio, fio->type);
>>> +		bio = NULL;
>>> +	}
>>> +alloc_new:
>>> +	if (!bio) {
>>> +		bio = __bio_alloc(fio->sbi, fio->new_blkaddr, fio->io_wbc,
>>> +				BIO_MAX_PAGES, false, fio->type, fio->temp);
>>> +		bio_set_op_attrs(bio, fio->op, fio->op_flags);
>>> +	}
>>> +
>>> +	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
>>> +		__submit_bio(fio->sbi, bio, fio->type);
>>> +		bio = NULL;
>>> +		goto alloc_new;
>>> +	}
>>> +
>>> +	if (fio->io_wbc)
>>> +		wbc_account_io(fio->io_wbc, page, PAGE_SIZE);
>>> +
>>> +	inc_page_count(fio->sbi, WB_DATA_TYPE(page));
>>> +
>>> +	*fio->last_block = fio->new_blkaddr;
>>> +	*fio->bio = bio;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +void f2fs_submit_ipu_bio(struct f2fs_sb_info *sbi, struct bio **bio,
>>> +							struct page *page)
>>> +{
>>> +	if (!bio)
>>> +		return;
>>> +
>>> +	if (!__has_merged_page(*bio, NULL, page, 0))
>>> +		return;
>>> +
>>> +	__submit_bio(sbi, *bio, DATA);
>>> +	*bio = NULL;
>>> +}
>>> +
>>>  void f2fs_submit_page_write(struct f2fs_io_info *fio)
>>>  {
>>>  	struct f2fs_sb_info *sbi = fio->sbi;
>>> @@ -1854,6 +1909,8 @@ int f2fs_do_write_data_page(struct f2fs_io_info *fio)
>>>  }
>>>  
>>>  static int __write_data_page(struct page *page, bool *submitted,
>>> +				struct bio **bio,
>>> +				sector_t *last_block,
>>>  				struct writeback_control *wbc,
>>>  				enum iostat_type io_type)
>>>  {
>>> @@ -1879,6 +1936,8 @@ static int __write_data_page(struct page *page, bool *submitted,
>>>  		.need_lock = LOCK_RETRY,
>>>  		.io_type = io_type,
>>>  		.io_wbc = wbc,
>>> +		.bio = bio,
>>> +		.last_block = last_block,
>>>  	};
>>>  
>>>  	trace_f2fs_writepage(page, DATA);
>>> @@ -1976,10 +2035,13 @@ static int __write_data_page(struct page *page, bool *submitted,
>>>  	}
>>>  
>>>  	unlock_page(page);
>>> -	if (!S_ISDIR(inode->i_mode) && !IS_NOQUOTA(inode))
>>> +	if (!S_ISDIR(inode->i_mode) && !IS_NOQUOTA(inode)) {
>>> +		f2fs_submit_ipu_bio(sbi, bio, page);
>>>  		f2fs_balance_fs(sbi, need_balance_fs);
>>> +	}
>>>  
>>>  	if (unlikely(f2fs_cp_error(sbi))) {
>>> +		f2fs_submit_ipu_bio(sbi, bio, page);
>>>  		f2fs_submit_merged_write(sbi, DATA);
>>>  		submitted = NULL;
>>>  	}
>>> @@ -2006,7 +2068,7 @@ static int __write_data_page(struct page *page, bool *submitted,
>>>  static int f2fs_write_data_page(struct page *page,
>>>  					struct writeback_control *wbc)
>>>  {
>>> -	return __write_data_page(page, NULL, wbc, FS_DATA_IO);
>>> +	return __write_data_page(page, NULL, NULL, NULL, wbc, FS_DATA_IO);
>>>  }
>>>  
>>>  /*
>>> @@ -2022,6 +2084,8 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
>>>  	int done = 0;
>>>  	struct pagevec pvec;
>>>  	struct f2fs_sb_info *sbi = F2FS_M_SB(mapping);
>>> +	struct bio *bio = NULL;
>>> +	sector_t last_block;
>>>  	int nr_pages;
>>>  	pgoff_t uninitialized_var(writeback_index);
>>>  	pgoff_t index;
>>> @@ -2098,17 +2162,20 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
>>>  			}
>>>  
>>>  			if (PageWriteback(page)) {
>>> -				if (wbc->sync_mode != WB_SYNC_NONE)
>>> +				if (wbc->sync_mode != WB_SYNC_NONE) {
>>>  					f2fs_wait_on_page_writeback(page,
>>>  							DATA, true, true);
>>> -				else
>>> +					f2fs_submit_ipu_bio(sbi, &bio, page);
>>> +				} else {
>>>  					goto continue_unlock;
>>> +				}
>>>  			}
>>>  
>>>  			if (!clear_page_dirty_for_io(page))
>>>  				goto continue_unlock;
>>>  
>>> -			ret = __write_data_page(page, &submitted, wbc, io_type);
>>> +			ret = __write_data_page(page, &submitted, &bio,
>>> +					&last_block, wbc, io_type);
>>>  			if (unlikely(ret)) {
>>>  				/*
>>>  				 * keep nr_to_write, since vfs uses this to
>>> @@ -2157,6 +2224,9 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
>>>  	if (nwritten)
>>>  		f2fs_submit_merged_write_cond(F2FS_M_SB(mapping), mapping->host,
>>>  								NULL, 0, DATA);
>>> +	/* submit cached bio of IPU write */
>>> +	if (bio)
>>> +		__submit_bio(sbi, bio, DATA);
>>>  
>>>  	return ret;
>>>  }
>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>> index 46db3ed87c84..7c4355927d28 100644
>>> --- a/fs/f2fs/f2fs.h
>>> +++ b/fs/f2fs/f2fs.h
>>> @@ -1048,6 +1048,8 @@ struct f2fs_io_info {
>>>  	bool retry;		/* need to reallocate block address */
>>>  	enum iostat_type io_type;	/* io type */
>>>  	struct writeback_control *io_wbc; /* writeback control */
>>> +	struct bio **bio;		/* bio for ipu */
>>> +	sector_t *last_block;		/* last block number in bio */
>>>  	unsigned char version;		/* version of the node */
>>>  };
>>>  
>>> @@ -3105,6 +3107,7 @@ void f2fs_submit_merged_write_cond(struct f2fs_sb_info *sbi,
>>>  				nid_t ino, enum page_type type);
>>>  void f2fs_flush_merged_writes(struct f2fs_sb_info *sbi);
>>>  int f2fs_submit_page_bio(struct f2fs_io_info *fio);
>>> +int f2fs_merge_page_bio(struct f2fs_io_info *fio);
>>>  void f2fs_submit_page_write(struct f2fs_io_info *fio);
>>>  struct block_device *f2fs_target_device(struct f2fs_sb_info *sbi,
>>>  			block_t blk_addr, struct bio *bio);
>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>>> index b2167d53fb9d..66838ab2f21e 100644
>>> --- a/fs/f2fs/segment.c
>>> +++ b/fs/f2fs/segment.c
>>> @@ -3196,7 +3196,10 @@ int f2fs_inplace_write_data(struct f2fs_io_info *fio)
>>>  
>>>  	stat_inc_inplace_blocks(fio->sbi);
>>>  
>>> -	err = f2fs_submit_page_bio(fio);
>>> +	if (fio->bio)
>>> +		err = f2fs_merge_page_bio(fio);
>>> +	else
>>> +		err = f2fs_submit_page_bio(fio);
>>>  	if (!err)
>>>  		update_device_state(fio);
>>>  
>>>
> 
> .
>