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From: David Sterba <dsterba@suse.cz>
To: ira.weiny@intel.com
Cc: Chris Mason <clm@fb.com>, Josef Bacik <josef@toxicpanda.com>,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 1/4] fs/btrfs: Convert kmap to kmap_local_page() using coccinelle
Date: Fri, 12 Mar 2021 19:58:39 +0100	[thread overview]
Message-ID: <20210312185839.GR7604@suse.cz> (raw)
In-Reply-To: <20210217024826.3466046-2-ira.weiny@intel.com>

On Tue, Feb 16, 2021 at 06:48:23PM -0800, ira.weiny@intel.com wrote:
> --- a/fs/btrfs/lzo.c
> +++ b/fs/btrfs/lzo.c
> @@ -118,7 +118,7 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
>  	struct workspace *workspace = list_entry(ws, struct workspace, list);
>  	int ret = 0;
>  	char *data_in;
> -	char *cpage_out;
> +	char *cpage_out, *sizes_ptr;
>  	int nr_pages = 0;
>  	struct page *in_page = NULL;
>  	struct page *out_page = NULL;
> @@ -258,10 +258,9 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
>  	}
>  
>  	/* store the size of all chunks of compressed data */
> -	cpage_out = kmap(pages[0]);
> -	write_compress_length(cpage_out, tot_out);
> -
> -	kunmap(pages[0]);
> +	sizes_ptr = kmap_local_page(pages[0]);
> +	write_compress_length(sizes_ptr, tot_out);
> +	kunmap_local(sizes_ptr);

Why is not cpage_out reused for this mapping? I don't see any reason for
another temporary variable, cpage_out is not used at this point.

  reply	other threads:[~2021-03-12 19:01 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-17  2:48 [PATCH 0/4] btrfs: Convert more kmaps to kmap_local_page() ira.weiny
2021-02-17  2:48 ` [PATCH 1/4] fs/btrfs: Convert kmap to kmap_local_page() using coccinelle ira.weiny
2021-03-12 18:58   ` David Sterba [this message]
2021-03-12 20:03     ` Ira Weiny
2021-03-16 11:04       ` David Sterba
2021-02-17  2:48 ` [PATCH 2/4] fs/btrfs: Convert raid5/6 kmaps to kmap_local_page() ira.weiny
2021-03-12 19:26   ` David Sterba
2021-02-17  2:48 ` [PATCH 3/4] fs/btrfs: Use kmap_local_page() in __btrfsic_submit_bio() ira.weiny
2021-02-17  2:48 ` [PATCH 4/4] fs/btrfs: Convert block context kmap's to kmap_local_page() ira.weiny
2021-03-11 21:30 ` [PATCH 0/4] btrfs: Convert more kmaps " Ira Weiny
2021-03-12 19:41 ` David Sterba
2021-03-12 20:05   ` Ira Weiny
2021-03-16 11:07     ` David Sterba
2021-03-16 16:56       ` Ira Weiny

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