block: kill blk_queue_flush()
We don't have any drivers left using it, so kill it off. Update
documentation to use the newer blk_queue_write_cache().
Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/Documentation/block/writeback_cache_control.txt b/Documentation/block/writeback_cache_control.txt
index 83407d3..59e0516 100644
--- a/Documentation/block/writeback_cache_control.txt
+++ b/Documentation/block/writeback_cache_control.txt
@@ -71,7 +71,7 @@
driver needs to tell the block layer that it supports flushing caches by
doing:
- blk_queue_flush(sdkp->disk->queue, REQ_FLUSH);
+ blk_queue_write_cache(sdkp->disk->queue, true, false);
and handle empty REQ_FLUSH requests in its prep_fn/request_fn. Note that
REQ_FLUSH requests with a payload are automatically turned into a sequence
@@ -79,7 +79,7 @@
layer. For devices that also support the FUA bit the block layer needs
to be told to pass through the REQ_FUA bit using:
- blk_queue_flush(sdkp->disk->queue, REQ_FLUSH | REQ_FUA);
+ blk_queue_write_cache(sdkp->disk->queue, true, true);
and the driver must handle write requests that have the REQ_FUA bit set
in prep_fn/request_fn. If the FUA bit is not natively supported the block