linux-kernel - RE: [PATCH] f2fs: add new wraper function for reading inline data

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Date:	Fri, 19 Feb 2016 15:35:18 +0800
From:	Chao Yu <chao2.yu@...sung.com>
To:	'Shawn Lin' <shawn.lin@...k-chips.com>,
	'Jaegeuk Kim' <jaegeuk@...nel.org>,
	'Changman Lee' <cm224.lee@...sung.com>
Cc:	linux-f2fs-devel@...ts.sourceforge.net,
	linux-kernel@...r.kernel.org
Subject: RE: [PATCH] f2fs: add new wraper function for reading inline data

Hi Shawn,

> -----Original Message-----
> From: Shawn Lin [mailto:shawn.lin@...k-chips.com]
> Sent: Friday, February 19, 2016 10:50 AM
> To: Jaegeuk Kim; Changman Lee
> Cc: Chao Yu; linux-f2fs-devel@...ts.sourceforge.net; linux-kernel@...r.kernel.org; Shawn Lin
> Subject: [PATCH] f2fs: add new wraper function for reading inline data
> 
> This patch add __read_inline_data which will no check
> PageUptodate and page->index. This can be reused by
> f2fs_convert_inline_page to reduce the redundant code
> copied from read_inline_data.
> 
> Signed-off-by: Shawn Lin <shawn.lin@...k-chips.com>
> ---
> 
>  fs/f2fs/inline.c | 26 ++++++++++++--------------
>  1 file changed, 12 insertions(+), 14 deletions(-)
> 
> diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
> index d27347e..39eeff1 100644
> --- a/fs/f2fs/inline.c
> +++ b/fs/f2fs/inline.c
> @@ -42,15 +42,11 @@ bool f2fs_may_inline_dentry(struct inode *inode)
>  	return true;
>  }
> 
> -void read_inline_data(struct page *page, struct page *ipage)
> +static inline void __read_inline_data(struct page *page,
> +				      struct page *ipage)
>  {
>  	void *src_addr, *dst_addr;
> 
> -	if (PageUptodate(page))
> -		return;
> -
> -	f2fs_bug_on(F2FS_P_SB(page), page->index);
> -
>  	zero_user_segment(page, MAX_INLINE_DATA, PAGE_CACHE_SIZE);
> 
>  	/* Copy the whole inline data block */
> @@ -61,6 +57,15 @@ void read_inline_data(struct page *page, struct page *ipage)
>  	kunmap_atomic(dst_addr);
>  	SetPageUptodate(page);
>  }
> +void read_inline_data(struct page *page, struct page *ipage)
> +{
> +	if (PageUptodate(page))
> +		return;
> +
> +	f2fs_bug_on(F2FS_P_SB(page), page->index);
> +
> +	__read_inline_data(page, ipage);
> +}
> 
>  bool truncate_inline_inode(struct page *ipage, u64 from)
>  {
> @@ -128,15 +133,8 @@ int f2fs_convert_inline_page(struct dnode_of_data *dn, struct page *page)
>  	if (PageUptodate(page))
>  		goto no_update;

Seems we can remove above check and below 'no_update' tag completely
if we use read_inline_data here.

So what about using read_inline_data to clean up codes in
f2fs_convert_inline_page?

Thanks,

> 
> -	zero_user_segment(page, MAX_INLINE_DATA, PAGE_CACHE_SIZE);
> +	__read_inline_data(page, dn->inode_page);
> 
> -	/* Copy the whole inline data block */
> -	src_addr = inline_data_addr(dn->inode_page);
> -	dst_addr = kmap_atomic(page);
> -	memcpy(dst_addr, src_addr, MAX_INLINE_DATA);
> -	flush_dcache_page(page);
> -	kunmap_atomic(dst_addr);
> -	SetPageUptodate(page);
>  no_update:
>  	set_page_dirty(page);
> 
> --
> 2.3.7
>