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authorLinus Torvalds <torvalds@linux-foundation.org>2010-10-22 17:07:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-22 17:07:18 -0700
commita2887097f25cd38cadfc11d10769e2b349fb5eca (patch)
treecd4adcb305365d6ba9acd2c02d4eb9d0125c6f8d /block/blk-settings.c
parent8abfc6e7a45eb74e51904bbae676fae008b11366 (diff)
parent005a1d15f5a6b2bb4ada80349513effbf22b4588 (diff)
downloadlinux-linaro-stable-a2887097f25cd38cadfc11d10769e2b349fb5eca.tar.gz
Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block: (46 commits) xen-blkfront: disable barrier/flush write support Added blk-lib.c and blk-barrier.c was renamed to blk-flush.c block: remove BLKDEV_IFL_WAIT aic7xxx_old: removed unused 'req' variable block: remove the BH_Eopnotsupp flag block: remove the BLKDEV_IFL_BARRIER flag block: remove the WRITE_BARRIER flag swap: do not send discards as barriers fat: do not send discards as barriers ext4: do not send discards as barriers jbd2: replace barriers with explicit flush / FUA usage jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier jbd: replace barriers with explicit flush / FUA usage nilfs2: replace barriers with explicit flush / FUA usage reiserfs: replace barriers with explicit flush / FUA usage gfs2: replace barriers with explicit flush / FUA usage btrfs: replace barriers with explicit flush / FUA usage xfs: replace barriers with explicit flush / FUA usage block: pass gfp_mask and flags to sb_issue_discard dm: convey that all flushes are processed as empty ...
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 315b88c8cbbb..701859fb9647 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -792,6 +792,26 @@ 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;