Re: [Patch 1/4] fs.h: b_journal_head

Nathan Scott
2003-12-09T23:47:41Z

Hi Joe,

On Tue, Dec 09, 2003 at 12:24:18PM +0000, Joe Thornber wrote:
> Add a new member to struct buffer_head called b_journal_head. This is
> for jbd to use, rather than have it peeking at b_private for in flight
> ios.
> ...
> --- diff/include/linux/fs.h 2003-12-09 10:25:27.000000000 +0000
> +++ source/include/linux/fs.h 2003-12-09 10:32:41.000000000 +0000
> @@ -265,7 +265,7 @@
> struct page *b_page; /* the page this bh is mapped to */
> void (*b_end_io)(struct buffer_head *bh, int uptodate); /* I/O completion */
> void *b_private; /* reserved for b_end_io */
> -
> + void *b_journal_head; /* ext3 journal_heads */
> unsigned long b_rsector; /* Real buffer location on disk */
> wait_queue_head_t b_wait;
>

Could you explain a bit more about when b_private should and
shouldn't be used with this change? We make use of b_private
within XFS, I'm just wondering if we will be stepping on each
others toes here? And if XFS does need to use b_journal_head
instead of b_private with DM, maybe a more generic name like
"b_fsprivate" or something would be clearer?

thanks.

--
Nathan