Re: [PATCH 2/4] f2fs: lookup extent cache first under IPU scenario

[Jaegeuk Kim <jaegeuk@kernel.org>]

Hi Pengyang,

On 04/25, Hou Pengyang wrote:
> If a page is cold, NOT atomit written and need_ipu now, there is
> a high probability that IPU should be adapted. For IPU, we try to
> check extent tree to get the block index first, instead of reading
> the dnode page, where may lead to an useless dnode IO, since no need to
> update the dnode index for IPU.
> 
> Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
> Signed-off-by: Chao Yu <yuchao0@huawei.com>
> ---
>  fs/f2fs/data.c    | 11 ++++++++++-
>  fs/f2fs/gc.c      |  1 +
>  fs/f2fs/segment.c |  1 +
>  3 files changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 02400b0..183a426 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -1346,21 +1346,29 @@ int do_write_data_page(struct f2fs_io_info *fio)
>  	struct page *page = fio->page;
>  	struct inode *inode = page->mapping->host;
>  	struct dnode_of_data dn;
> +	struct extent_info ei = {0,0,0};
>  	int err = 0;
>  
>  	set_new_dnode(&dn, inode, NULL, NULL, 0);
> +	if (need_inplace_update(fio) &&
> +			f2fs_lookup_extent_cache(inode, page->index, &ei)) {
> +		fio->old_blkaddr = ei.blk + page->index - ei.fofs;
> +		if (fio->old_blkaddr != NULL_ADDR &&
> +				fio->old_blkaddr != NEW_ADDR)

			ipu_force = true;

I added one variable to do below ipu explicitly.

Thanks,

> +			goto got_it;
> +	}
>  	err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
>  	if (err)
>  		return err;
>  
>  	fio->old_blkaddr = dn.data_blkaddr;
> -
>  	/* This page is already truncated */
>  	if (fio->old_blkaddr == NULL_ADDR) {
>  		ClearPageUptodate(page);
>  		goto out_writepage;
>  	}
>  
> +got_it:
>  	err = encrypt_one_page(fio);
>  	if (err)
>  		goto out_writepage;
> @@ -1408,6 +1416,7 @@ static int __write_data_page(struct page *page, bool *submitted,
>  		.type = DATA,
>  		.op = REQ_OP_WRITE,
>  		.op_flags = wbc_to_write_flags(wbc),
> +		.old_blkaddr = NULL_ADDR,
>  		.page = page,
>  		.encrypted_page = NULL,
>  		.submitted = false,
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index 499a43f..e034857 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -712,6 +712,7 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
>  			.type = DATA,
>  			.op = REQ_OP_WRITE,
>  			.op_flags = REQ_SYNC,
> +			.old_blkaddr = NULL_ADDR,
>  			.page = page,
>  			.encrypted_page = NULL,
>  		};
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 2a95535..9f86b98 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -291,6 +291,7 @@ static int __commit_inmem_pages(struct inode *inode,
>  		.type = DATA,
>  		.op = REQ_OP_WRITE,
>  		.op_flags = REQ_SYNC | REQ_PRIO,
> +		.old_blkaddr = NULL_ADDR,
>  		.encrypted_page = NULL,
>  	};
>  	pgoff_t last_idx = ULONG_MAX;
> -- 
> 2.10.1
> 
> 
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