From fd5d806266935179deda1502101624832eacd01f Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 16 Oct 2007 11:05:02 +0200 Subject: block: convert blkdev_issue_flush() to use empty barriers Then we can get rid of ->issue_flush_fn() and all the driver private implementations of that. Signed-off-by: Jens Axboe --- block/ll_rw_blk.c | 56 +++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 36 insertions(+), 20 deletions(-) (limited to 'block') diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index 4fde3a3c92d..4df7d027eb0 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -304,23 +304,6 @@ int blk_queue_ordered(struct request_queue *q, unsigned ordered, EXPORT_SYMBOL(blk_queue_ordered); -/** - * blk_queue_issue_flush_fn - set function for issuing a flush - * @q: the request queue - * @iff: the function to be called issuing the flush - * - * Description: - * If a driver supports issuing a flush command, the support is notified - * to the block layer by defining it through this call. - * - **/ -void blk_queue_issue_flush_fn(struct request_queue *q, issue_flush_fn *iff) -{ - q->issue_flush_fn = iff; -} - -EXPORT_SYMBOL(blk_queue_issue_flush_fn); - /* * Cache flushing for ordered writes handling */ @@ -2666,6 +2649,14 @@ int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk, EXPORT_SYMBOL(blk_execute_rq); +static void bio_end_empty_barrier(struct bio *bio, int err) +{ + if (err) + clear_bit(BIO_UPTODATE, &bio->bi_flags); + + complete(bio->bi_private); +} + /** * blkdev_issue_flush - queue a flush * @bdev: blockdev to issue flush for @@ -2678,7 +2669,10 @@ EXPORT_SYMBOL(blk_execute_rq); */ int blkdev_issue_flush(struct block_device *bdev, sector_t *error_sector) { + DECLARE_COMPLETION_ONSTACK(wait); struct request_queue *q; + struct bio *bio; + int ret; if (bdev->bd_disk == NULL) return -ENXIO; @@ -2686,10 +2680,32 @@ int blkdev_issue_flush(struct block_device *bdev, sector_t *error_sector) q = bdev_get_queue(bdev); if (!q) return -ENXIO; - if (!q->issue_flush_fn) - return -EOPNOTSUPP; - return q->issue_flush_fn(q, bdev->bd_disk, error_sector); + bio = bio_alloc(GFP_KERNEL, 0); + if (!bio) + return -ENOMEM; + + bio->bi_end_io = bio_end_empty_barrier; + bio->bi_private = &wait; + bio->bi_bdev = bdev; + submit_bio(1 << BIO_RW_BARRIER, bio); + + wait_for_completion(&wait); + + /* + * The driver must store the error location in ->bi_sector, if + * it supports it. For non-stacked drivers, this should be copied + * from rq->sector. + */ + if (error_sector) + *error_sector = bio->bi_sector; + + ret = 0; + if (!bio_flagged(bio, BIO_UPTODATE)) + ret = -EIO; + + bio_put(bio); + return ret; } EXPORT_SYMBOL(blkdev_issue_flush); -- cgit v1.2.3