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| author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2011-05-05 18:41:03 +0200 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2011-05-12 14:55:56 +0200 |
| commit | 6dcfb751c927879399e404b3885cbdef7d8d368b (patch) | |
| tree | a8c23cddfb6af14684e472725137f7c70f065c74 /include/xen | |
| parent | xen-blkfront: fix data size for xenbus_gather in blkfront_connect (diff) | |
| download | linux-6dcfb751c927879399e404b3885cbdef7d8d368b.tar.xz linux-6dcfb751c927879399e404b3885cbdef7d8d368b.zip | |
xen-blkfront: Provide for 'feature-flush-cache' the BLKIF_OP_WRITE_FLUSH_CACHE operation.
The operation BLKIF_OP_WRITE_FLUSH_CACHE has existed in the Xen
tree header file for years but it was never present in the Linux tree
because the frontend (nor the backend) supported this interface.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'include/xen')
| -rw-r--r-- | include/xen/interface/io/blkif.h | 13 |
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. |