diff options
Diffstat (limited to 'Documentation/block/barrier.txt')
| -rw-r--r-- | Documentation/block/barrier.txt | 16 |
1 files changed, 3 insertions, 13 deletions
diff --git a/Documentation/block/barrier.txt b/Documentation/block/barrier.txt index a272c3d..7d279f2 100644 --- 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 |
