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authorLinus Torvalds <torvalds@linux-foundation.org>2011-05-25 09:15:35 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-05-25 09:15:35 -0700
commit929cfdd5d3bdc772aff32e5a3fb4e3894394aa75 (patch)
treef67202d079eaf1f8d65b2e1bfac70b768ae34bc4 /include/xen
parent798ce8f1cca29dcc3f4b55947f611f4ffb32ac2b (diff)
parenta1c15c59feee36267c43142a41152fbf7402afb6 (diff)
Merge branch 'for-2.6.40/drivers' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.40/drivers' of git://git.kernel.dk/linux-2.6-block: (110 commits) loop: handle on-demand devices correctly loop: limit 'max_part' module param to DISK_MAX_PARTS drbd: fix warning drbd: fix warning drbd: Fix spelling drbd: fix schedule in atomic drbd: Take a more conservative approach when deciding max_bio_size drbd: Fixed state transitions after async outdate-peer-handler returned drbd: Disallow the peer_disk_state to be D_OUTDATED while connected drbd: Fix for the connection problems on high latency links drbd: fix potential activity log refcount imbalance in error path drbd: Only downgrade the disk state in case of disk failures drbd: fix disconnect/reconnect loop, if ping-timeout == ping-int drbd: fix potential distributed deadlock lru_cache.h: fix comments referring to ts_ instead of lc_ drbd: Fix for application IO with the on-io-error=pass-on policy xen/p2m: Add EXPORT_SYMBOL_GPL to the M2P override functions. xen/p2m/m2p/gnttab: Support GNTMAP_host_map in the M2P override. xen/blkback: don't fail empty barrier requests xen/blkback: fix xenbus_transaction_start() hang caused by double xenbus_transaction_end() ...
Diffstat (limited to 'include/xen')
-rw-r--r--include/xen/interface/io/blkif.h13
1 files changed, 13 insertions, 0 deletions
diff --git a/include/xen/interface/io/blkif.h b/include/xen/interface/io/blkif.h
index 61e523af3c46..3d5d6db864fe 100644
--- a/include/xen/interface/io/blkif.h
+++ b/include/xen/interface/io/blkif.h
@@ -45,6 +45,19 @@ typedef uint64_t blkif_sector_t;
#define BLKIF_OP_WRITE_BARRIER 2
/*
+ * Recognised if "feature-flush-cache" is present in backend xenbus
+ * info. A flush will ask the underlying storage hardware to flush its
+ * non-volatile caches as appropriate. The "feature-flush-cache" node
+ * contains a boolean indicating whether flush requests are likely to
+ * succeed or fail. Either way, a flush request may fail at any time
+ * with BLKIF_RSP_EOPNOTSUPP if it is unsupported by the underlying
+ * block-device hardware. The boolean simply indicates whether or not it
+ * is worthwhile for the frontend to attempt flushes. If a backend does
+ * not recognise BLKIF_OP_WRITE_FLUSH_CACHE, it should *not* create the
+ * "feature-flush-cache" node!
+ */
+#define BLKIF_OP_FLUSH_DISKCACHE 3
+/*
* Maximum scatter/gather segments per request.
* This is carefully chosen so that sizeof(struct blkif_ring) <= PAGE_SIZE.
* NB. This could be 12 if the ring indexes weren't stored in the same page.