linux-ext4 - Re: [PATCH,RFC 6/7] ext4: move setup of the mpd structure to write_cache_pages

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20110213014000.GI19533@dhcp231-156.rdu.redhat.com>
Date:	Sat, 12 Feb 2011 20:40:01 -0500
From:	Josef Bacik <josef@...hat.com>
To:	"Theodore Ts'o" <tytso@....edu>
Cc:	Ext4 Developers List <linux-ext4@...r.kernel.org>
Subject: Re: [PATCH,RFC 6/7] ext4: move setup of the mpd structure to
	write_cache_pages_da()

On Sat, Feb 12, 2011 at 07:15:56PM -0500, Theodore Ts'o wrote:
> Move the initialization of all of the fields of the mpd structure to
> write_cache_pages_da().  This simplifies the code considerably.
> 
> Signed-off-by: "Theodore Ts'o" <tytso@....edu>
> ---
>  fs/ext4/inode.c |   29 +++++++----------------------
>  1 files changed, 7 insertions(+), 22 deletions(-)
> 
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 2ac64e3..235a90e 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -2714,7 +2714,8 @@ static int ext4_da_writepages_trans_blocks(struct inode *inode)
>  /*
>   * write_cache_pages_da - walk the list of dirty pages of the given
>   * address space and accumulate pages that need writing, and call
> - * mpage_da_map_and_submit to map the pages and then write them.
> + * mpage_da_map_and_submit to map a single contiguous memory region
> + * and then write them.
>   */
>  static int write_cache_pages_da(struct address_space *mapping,
>  				struct writeback_control *wbc,
> @@ -2722,7 +2723,7 @@ static int write_cache_pages_da(struct address_space *mapping,
>  				pgoff_t *done_index)
>  {
>  	struct buffer_head	*bh, *head;
> -	struct inode		*inode = mpd->inode;
> +	struct inode		*inode = mapping->host;
>  	struct pagevec		pvec;
>  	unsigned int		nr_pages;
>  	sector_t		logical;
> @@ -2730,6 +2731,9 @@ static int write_cache_pages_da(struct address_space *mapping,
>  	long			nr_to_write = wbc->nr_to_write;
>  	int			i, tag, ret = 0;
>  
> +	memset(mpd, 0, sizeof(struct mpage_da_data));
> +	mpd->wbc = wbc;
> +	mpd->inode = inode;
>  	pagevec_init(&pvec, 0);
>  	index = wbc->range_start >> PAGE_CACHE_SHIFT;
>  	end = wbc->range_end >> PAGE_CACHE_SHIFT;
> @@ -2794,16 +2798,8 @@ static int write_cache_pages_da(struct address_space *mapping,
>  
>  			BUG_ON(PageWriteback(page));
>  
> -			if (mpd->next_page != page->index) {
> -				/*
> -				 * Start next extent of pages and blocks
> -				 */
> +			if (mpd->next_page != page->index)
>  				mpd->first_page = page->index;
> -				mpd->b_size = 0;
> -				mpd->b_state = 0;
> -				mpd->b_blocknr = 0;
> -			}
> -
>  			mpd->next_page = page->index + 1;
>  			logical = (sector_t) page->index <<
>  				(PAGE_CACHE_SHIFT - inode->i_blkbits);
> @@ -2975,9 +2971,6 @@ static int ext4_da_writepages(struct address_space *mapping,
>  		wbc->nr_to_write = desired_nr_to_write;
>  	}
>  
> -	mpd.wbc = wbc;
> -	mpd.inode = mapping->host;
> -
>  retry:
>  	if (wbc->sync_mode == WB_SYNC_ALL)
>  		tag_pages_for_writeback(mapping, index, end);
> @@ -3008,14 +3001,6 @@ retry:
>  		 * contiguous region of logical blocks that need
>  		 * blocks to be allocated by ext4 and submit them.
>  		 */
> -		mpd.b_size = 0;
> -		mpd.b_state = 0;
> -		mpd.b_blocknr = 0;
> -		mpd.first_page = 0;
> -		mpd.next_page = 0;
> -		mpd.io_done = 0;
> -		mpd.pages_written = 0;
> -		mpd.retval = 0;
>  		ret = write_cache_pages_da(mapping, wbc, &mpd, &done_index);
>  		/*
>  		 * If we have a contiguous extent of pages and we

Looks good,

Josef
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html