Re: [PATCH] ide barrier support, #2

[Jens Axboe <axboe@suse.de>]

On Tue, Oct 14 2003, Andi Kleen wrote:
> Jens Axboe <axboe@suse.de> writes:
> 
> This adds support for XFS for log writes (not for fsync).
> Based on the 2.4 XFS patch for write barriers I did some time ago.
> 
> It just does a flush, not a barrier. I think that's enough for
> log writes because XFS waits until the log write has hit disk.
> 
> It doesn't do anything special when the flush fails - just
> shuts down the file system as usual. 
> 
> diff -u linux/fs/xfs/pagebuf/page_buf.c-o linux-2.6.0test6-work/fs/xfs/pagebuf/page_buf.c
> --- linux/fs/xfs/pagebuf/page_buf.c-o	2003-09-28 10:52:55.000000000 +0200
> +++ linux/fs/xfs/pagebuf/page_buf.c	2003-10-14 14:48:44.000000000 +0200
> @@ -1403,12 +1403,12 @@
>  
>  submit_io:
>  	if (likely(bio->bi_size)) {
> -		if (pb->pb_flags & PBF_READ) {
> -			submit_bio(READ, bio);
> -		} else {
> -			submit_bio(WRITE, bio);
> -		}
> -
> +		int cmd = WRITE; 
> +		if (pb->pb_flags & PBF_READ)
> +			cmd = READ;
> +		else if (pb->pb_flags & PBF_FLUSH)
> +			cmd = WRITESYNC;

Uh be careful! It must be WRITEBARRIER, not WRITESYNC. I think I'll kill
WRITEBARRIER and just call it WRITESYNC, it's more logical. I've added
the modified variant, thanks.

-- 
Jens Axboe