block: add blk_queue_update_dma_pad

This adds blk_queue_update_dma_pad to prevent LLDs from overwriting
the dma pad mask wrongly (we added blk_queue_update_dma_alignment due
to the same reason).

This also converts libata to use blk_queue_update_dma_pad instead of
blk_queue_dma_pad.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
FUJITA Tomonori 2008-07-04 09:30:03 +02:00 committed by Jens Axboe
parent 2610324fca
commit 27f8221af4
3 changed files with 23 additions and 5 deletions

View file

@ -302,11 +302,10 @@ EXPORT_SYMBOL(blk_queue_stack_limits);
* @q: the request queue for the device
* @mask: pad mask
*
* Set pad mask. Direct IO requests are padded to the mask specified.
* Set dma pad mask.
*
* Appending pad buffer to a request modifies ->data_len such that it
* includes the pad buffer. The original requested data length can be
* obtained using blk_rq_raw_data_len().
* Appending pad buffer to a request modifies the last entry of a
* scatter list such that it includes the pad buffer.
**/
void blk_queue_dma_pad(struct request_queue *q, unsigned int mask)
{
@ -314,6 +313,23 @@ void blk_queue_dma_pad(struct request_queue *q, unsigned int mask)
}
EXPORT_SYMBOL(blk_queue_dma_pad);
/**
* blk_queue_update_dma_pad - update pad mask
* @q: the request queue for the device
* @mask: pad mask
*
* Update dma pad mask.
*
* Appending pad buffer to a request modifies the last entry of a
* scatter list such that it includes the pad buffer.
**/
void blk_queue_update_dma_pad(struct request_queue *q, unsigned int mask)
{
if (mask > q->dma_pad_mask)
q->dma_pad_mask = mask;
}
EXPORT_SYMBOL(blk_queue_update_dma_pad);
/**
* blk_queue_dma_drain - Set up a drain buffer for excess dma.
* @q: the request queue for the device

View file

@ -885,7 +885,8 @@ static int ata_scsi_dev_config(struct scsi_device *sdev,
/* set the min alignment and padding */
blk_queue_update_dma_alignment(sdev->request_queue,
ATA_DMA_PAD_SZ - 1);
blk_queue_dma_pad(sdev->request_queue, ATA_DMA_PAD_SZ - 1);
blk_queue_update_dma_pad(sdev->request_queue,
ATA_DMA_PAD_SZ - 1);
/* configure draining */
buf = kmalloc(ATAPI_MAX_DRAIN, q->bounce_gfp | GFP_KERNEL);

View file

@ -776,6 +776,7 @@ extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
extern void blk_queue_hardsect_size(struct request_queue *, unsigned short);
extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
extern int blk_queue_dma_drain(struct request_queue *q,
dma_drain_needed_fn *dma_drain_needed,
void *buf, unsigned int size);