Re: [PATCH v2] f2fs: use memcpy_{to,from}_page() where possible

["Fabio M. De Francesco" <fmdefrancesco@gmail.com>]

On sabato 20 agosto 2022 00:33:00 CEST Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> This is simpler, and as a side effect it replaces several uses of
> kmap_atomic() with its recommended replacement kmap_local_page().
> 
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> ---
> 
> v2: remove unneeded calls to flush_dcache_page(),
>     and convert the kmap_atomic() in f2fs_write_inline_data().
> 
>  fs/f2fs/inline.c | 15 ++++-----------
>  fs/f2fs/super.c  | 11 ++---------
>  fs/f2fs/verity.c | 10 ++--------
>  3 files changed, 8 insertions(+), 28 deletions(-)

It looks good to me...

Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>

Thanks,

Fabio

> diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
> index bf46a7dfbea2fc..73da9331803696 100644
> --- a/fs/f2fs/inline.c
> +++ b/fs/f2fs/inline.c
> @@ -64,7 +64,6 @@ bool f2fs_may_inline_dentry(struct inode *inode)
>  void f2fs_do_read_inline_data(struct page *page, struct page *ipage)
>  {
>  	struct inode *inode = page->mapping->host;
> -	void *src_addr, *dst_addr;
> 
>  	if (PageUptodate(page))
>  		return;
> @@ -74,11 +73,8 @@ void f2fs_do_read_inline_data(struct page *page, struct
> page *ipage) zero_user_segment(page, MAX_INLINE_DATA(inode), PAGE_SIZE);
> 
>  	/* Copy the whole inline data block */
> -	src_addr = inline_data_addr(inode, ipage);
> -	dst_addr = kmap_atomic(page);
> -	memcpy(dst_addr, src_addr, MAX_INLINE_DATA(inode));
> -	flush_dcache_page(page);
> -	kunmap_atomic(dst_addr);
> +	memcpy_to_page(page, 0, inline_data_addr(inode, ipage),
> +		       MAX_INLINE_DATA(inode));
>  	if (!PageUptodate(page))
>  		SetPageUptodate(page);
>  }
> @@ -246,7 +242,6 @@ int f2fs_convert_inline_inode(struct inode *inode)
> 
>  int f2fs_write_inline_data(struct inode *inode, struct page *page)
>  {
> -	void *src_addr, *dst_addr;
>  	struct dnode_of_data dn;
>  	int err;
> 
> @@ -263,10 +258,8 @@ int f2fs_write_inline_data(struct inode *inode, struct
> page *page) f2fs_bug_on(F2FS_I_SB(inode), page->index);
> 
>  	f2fs_wait_on_page_writeback(dn.inode_page, NODE, true, true);
> -	src_addr = kmap_atomic(page);
> -	dst_addr = inline_data_addr(inode, dn.inode_page);
> -	memcpy(dst_addr, src_addr, MAX_INLINE_DATA(inode));
> -	kunmap_atomic(src_addr);
> +	memcpy_from_page(inline_data_addr(inode, dn.inode_page),
> +			 page, 0, MAX_INLINE_DATA(inode));
>  	set_page_dirty(dn.inode_page);
> 
>  	f2fs_clear_page_cache_dirty_tag(page);
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 2451623c05a7a8..3e5743b2538240 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -2465,7 +2465,6 @@ static ssize_t f2fs_quota_read(struct super_block *sb,
> int type, char *data, size_t toread;
>  	loff_t i_size = i_size_read(inode);
>  	struct page *page;
> -	char *kaddr;
> 
>  	if (off > i_size)
>  		return 0;
> @@ -2498,9 +2497,7 @@ static ssize_t f2fs_quota_read(struct super_block *sb,
> int type, char *data, return -EIO;
>  		}
> 
> -		kaddr = kmap_atomic(page);
> -		memcpy(data, kaddr + offset, tocopy);
> -		kunmap_atomic(kaddr);
> +		memcpy_from_page(data, page, offset, tocopy);
>  		f2fs_put_page(page, 1);
> 
>  		offset = 0;
> @@ -2522,7 +2519,6 @@ static ssize_t f2fs_quota_write(struct super_block 
*sb,
> int type, size_t towrite = len;
>  	struct page *page;
>  	void *fsdata = NULL;
> -	char *kaddr;
>  	int err = 0;
>  	int tocopy;
> 
> @@ -2541,10 +2537,7 @@ static ssize_t f2fs_quota_write(struct super_block 
*sb,
> int type, break;
>  		}
> 
> -		kaddr = kmap_atomic(page);
> -		memcpy(kaddr + offset, data, tocopy);
> -		kunmap_atomic(kaddr);
> -		flush_dcache_page(page);
> +		memcpy_to_page(page, offset, data, tocopy);
> 
>  		a_ops->write_end(NULL, mapping, off, tocopy, tocopy,
>  						page, fsdata);
> diff --git a/fs/f2fs/verity.c b/fs/f2fs/verity.c
> index 7b8f2b41c29b12..97ec60f39d6960 100644
> --- a/fs/f2fs/verity.c
> +++ b/fs/f2fs/verity.c
> @@ -47,16 +47,13 @@ static int pagecache_read(struct inode *inode, void 
*buf,
> size_t count, size_t n = min_t(size_t, count,
>  				 PAGE_SIZE - offset_in_page(pos));
>  		struct page *page;
> -		void *addr;
> 
>  		page = read_mapping_page(inode->i_mapping, pos >> 
PAGE_SHIFT,
>  					 NULL);
>  		if (IS_ERR(page))
>  			return PTR_ERR(page);
> 
> -		addr = kmap_atomic(page);
> -		memcpy(buf, addr + offset_in_page(pos), n);
> -		kunmap_atomic(addr);
> +		memcpy_from_page(buf, page, offset_in_page(pos), n);
> 
>  		put_page(page);
> 
> @@ -85,16 +82,13 @@ static int pagecache_write(struct inode *inode, const 
void
> *buf, size_t count, PAGE_SIZE - offset_in_page(pos));
>  		struct page *page;
>  		void *fsdata;
> -		void *addr;
>  		int res;
> 
>  		res = aops->write_begin(NULL, mapping, pos, n, &page, 
&fsdata);
>  		if (res)
>  			return res;
> 
> -		addr = kmap_atomic(page);
> -		memcpy(addr + offset_in_page(pos), buf, n);
> -		kunmap_atomic(addr);
> +		memcpy_to_page(page, offset_in_page(pos), buf, n);
> 
>  		res = aops->write_end(NULL, mapping, pos, n, n, page, 
fsdata);
>  		if (res < 0)
> 
> base-commit: 568035b01cfb107af8d2e4bd2fb9aea22cf5b868
> --
> 2.37.1