2007-05-29 09:11:38

by Geert Uytterhoeven

Subject: [PATCH] Update Documentation/block/barrier.txt

Documentation/block/barrier.txt is not in sync with the actual code:
- blk_queue_ordered() no longer has a gfp_mask parameter
- blk_queue_ordered_locked() no longer exists
- sd_prepare_flush() looks slightly different

Signed-off-by: Geert Uytterhoeven <[email protected]>
---
Documentation/block/barrier.txt | 16 +++-------------
1 files changed, 3 insertions(+), 13 deletions(-)

--- a/Documentation/block/barrier.txt
+++ b/Documentation/block/barrier.txt
@@ -82,23 +82,12 @@ including draining and flushing.
typedef void (prepare_flush_fn)(request_queue_t *q, struct request *rq);

int blk_queue_ordered(request_queue_t *q, unsigned ordered,
- prepare_flush_fn *prepare_flush_fn,
- unsigned gfp_mask);
-
-int blk_queue_ordered_locked(request_queue_t *q, unsigned ordered,
- prepare_flush_fn *prepare_flush_fn,
- unsigned gfp_mask);
-
-The only difference between the two functions is whether or not the
-caller is holding q->queue_lock on entry. The latter expects the
-caller is holding the lock.
+ prepare_flush_fn *prepare_flush_fn);

@q : the queue in question
@ordered : the ordered mode the driver/device supports
@prepare_flush_fn : this function should prepare @rq such that it
flushes cache to physical medium when executed
-@gfp_mask : gfp_mask used when allocating data structures
- for ordered processing

For example, SCSI disk driver's prepare_flush_fn looks like the
following.
@@ -106,9 +95,10 @@ following.
static void sd_prepare_flush(request_queue_t *q, struct request *rq)
{
memset(rq->cmd, 0, sizeof(rq->cmd));
- rq->flags |= REQ_BLOCK_PC;
+ rq->cmd_type = REQ_TYPE_BLOCK_PC;
rq->timeout = SD_TIMEOUT;
rq->cmd[0] = SYNCHRONIZE_CACHE;
+ rq->cmd_len = 10;
}

The following seven ordered modes are supported. The following table

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- Sony Network and Software Technology Center Europe (NSCE)
[email protected] ------- The Corporate Village, Da Vincilaan 7-D1
Voice +32-2-7008453 Fax +32-2-7008622 ---------------- B-1935 Zaventem, Belgium

2007-05-29 12:23:40

by Tejun Heo

Subject: Re: [PATCH] Update Documentation/block/barrier.txt

Geert Uytterhoeven wrote:
> Documentation/block/barrier.txt is not in sync with the actual code:
> - blk_queue_ordered() no longer has a gfp_mask parameter
> - blk_queue_ordered_locked() no longer exists
> - sd_prepare_flush() looks slightly different
>
> Signed-off-by: Geert Uytterhoeven <[email protected]>

Acked-by: Tejun Heo <[email protected]>

Thanks.

--
tejun