Re: [PATCH] f2fs: refactor bio-related operations

[Chao Yu <chao2.yu@samsung.com>]

Hi,

Some comments as following.

> -----Original Message-----
> From: Jaegeuk Kim [mailto:jaegeuk.kim@samsung.com]
> Sent: Saturday, November 30, 2013 2:26 PM
> Cc: linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.org; linux-f2fs-devel@lists.sourceforge.net
> Subject: [f2fs-dev] [PATCH] f2fs: refactor bio-related operations
> 

[snip]

> +void f2fs_submit_page_mbio(struct f2fs_sb_info *sbi, struct page *page,
> +			block_t blk_addr, enum page_type type, int rw)
> +{
> +	enum page_type btype = PAGE_TYPE_OF_BIO(type);
> +	struct block_device *bdev = sbi->sb->s_bdev;
> +	struct f2fs_bio_info *io;
> +	int bio_blocks;
> +
> +	io = is_read_io(rw) ? &sbi->read_io : &sbi->write_io[btype];
> +
> +	verify_block_addr(sbi, blk_addr);
> +
> +	mutex_lock(&io->io_mutex);
> +
> +	if (!is_read_io(rw))
> +		inc_page_count(sbi, F2FS_WRITEBACK);
> +
> +	if (io->bio && io->last_block_in_bio != blk_addr - 1)
> +		__submit_merged_bio(sbi, io, type, true, rw);
> +alloc_new:
> +	if (io->bio == NULL) {
> +		bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
> +		io->bio = __bio_alloc(bdev, bio_blocks);
> +		io->bio->bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr);
> +		io->bio->bi_end_io = is_read_io(rw) ? f2fs_read_end_io :
> +							f2fs_write_end_io;
> +		/*
> +		 * The end_io will be assigned at the sumbission phase.
> +		 * Until then, let bio_add_page() merge consecutive IOs as much
> +		 * as possible.
> +		 */
> +	}
> +
> +	if (bio_add_page(io->bio, page, PAGE_CACHE_SIZE, 0) <
> +							PAGE_CACHE_SIZE) {
> +		__submit_merged_bio(sbi, io, type, true, rw);
> +		io->bio = NULL;

We should remove the redundant code " io->bio = NULL;" here,
because __submit_merged_bio does the same job.

[snip]

>  /*
>   * data.c
>   */
> +void f2fs_submit_merged_bio(struct f2fs_sb_info *, enum page_type, bool, int);
> +int f2fs_submit_page_bio(struct f2fs_sb_info *, struct page *, block_t, int);

Redundant to the following code.

> +void f2fs_submit_page_mbio(struct f2fs_sb_info *, struct page *, block_t,
> +							enum page_type, int);
>  int reserve_new_block(struct dnode_of_data *);
>  int f2fs_reserve_block(struct dnode_of_data *, pgoff_t);
>  void update_extent_cache(block_t, struct dnode_of_data *);
>  struct page *find_data_page(struct inode *, pgoff_t, bool);
>  struct page *get_lock_data_page(struct inode *, pgoff_t);
>  struct page *get_new_data_page(struct inode *, struct page *, pgoff_t, bool);
> -int f2fs_readpage(struct f2fs_sb_info *, struct page *, block_t, int);
> -void f2fs_submit_read_bio(struct f2fs_sb_info *, int);
> -void submit_read_page(struct f2fs_sb_info *, struct page *, block_t, int);
> +int f2fs_submit_page_bio(struct f2fs_sb_info *, struct page *, block_t, int);

Here.

[snip]


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