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author | Tejun Heo <tj@kernel.org> | 2010-09-03 11:56:16 +0200 |
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committer | Jens Axboe <jaxboe@fusionio.com> | 2010-09-10 12:35:36 +0200 |
commit | 4913efe456c987057e5d36a3f0a55422a9072cae (patch) | |
tree | 295f04a7214e1933df3301dd42c12ff3f282a22c /block/blk-settings.c | |
parent | block: kill QUEUE_ORDERED_BY_TAG (diff) | |
download | linux-4913efe456c987057e5d36a3f0a55422a9072cae.tar.xz linux-4913efe456c987057e5d36a3f0a55422a9072cae.zip |
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.c | 20 |
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; |