aboutsummaryrefslogtreecommitdiff
path: root/block/blk-settings.c
diff options
context:
space:
mode:
authorTejun Heo <tj@kernel.org>2010-09-03 11:56:16 +0200
committerJens Axboe <jaxboe@fusionio.com>2010-09-10 12:35:36 +0200
commit4913efe456c987057e5d36a3f0a55422a9072cae (patch)
tree295f04a7214e1933df3301dd42c12ff3f282a22c /block/blk-settings.c
parent6958f145459ca7ad9715024de97445addacb8510 (diff)
downloadlinux-linaro-stable-4913efe456c987057e5d36a3f0a55422a9072cae.tar.gz
block: deprecate barrier and replace blk_queue_ordered() with blk_queue_flush()
Barrier is deemed too heavy and will soon be replaced by FLUSH/FUA requests. Deprecate barrier. All REQ_HARDBARRIERs are failed with -EOPNOTSUPP and blk_queue_ordered() is replaced with simpler blk_queue_flush(). blk_queue_flush() takes combinations of REQ_FLUSH and FUA. If a device has write cache and can flush it, it should set REQ_FLUSH. If the device can handle FUA writes, it should also set REQ_FUA. All blk_queue_ordered() users are converted. * ORDERED_DRAIN is mapped to 0 which is the default value. * ORDERED_DRAIN_FLUSH is mapped to REQ_FLUSH. * ORDERED_DRAIN_FLUSH_FUA is mapped to REQ_FLUSH | REQ_FUA. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Boaz Harrosh <bharrosh@panasas.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Cc: David S. Miller <davem@davemloft.net> Cc: Alasdair G Kergon <agk@redhat.com> Cc: Pierre Ossman <drzeus@drzeus.cx> Cc: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'block/blk-settings.c')
-rw-r--r--block/blk-settings.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c
index a234f4bf1d6f..9b18afcfe925 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -794,6 +794,26 @@ void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
}
EXPORT_SYMBOL(blk_queue_update_dma_alignment);
+/**
+ * blk_queue_flush - configure queue's cache flush capability
+ * @q: the request queue for the device
+ * @flush: 0, REQ_FLUSH or REQ_FLUSH | REQ_FUA
+ *
+ * Tell block layer cache flush capability of @q. If it supports
+ * flushing, REQ_FLUSH should be set. If it supports bypassing
+ * write cache for individual writes, REQ_FUA should be set.
+ */
+void blk_queue_flush(struct request_queue *q, unsigned int flush)
+{
+ WARN_ON_ONCE(flush & ~(REQ_FLUSH | REQ_FUA));
+
+ if (WARN_ON_ONCE(!(flush & REQ_FLUSH) && (flush & REQ_FUA)))
+ flush &= ~REQ_FUA;
+
+ q->flush_flags = flush & (REQ_FLUSH | REQ_FUA);
+}
+EXPORT_SYMBOL_GPL(blk_queue_flush);
+
static int __init blk_settings_init(void)
{
blk_max_low_pfn = max_low_pfn - 1;