From bc37b06a5cde24fb24c2a2cc44dd86756034ba9d Mon Sep 17 00:00:00 2001 From: Vladimir Sementsov-Ogievskiy Date: Fri, 13 Apr 2018 17:31:56 +0300 Subject: nbd/server: introduce NBD_CMD_CACHE Handle nbd CACHE command. Just do read, without sending read data back. Cache mechanism should be done by exported node driver chain. Signed-off-by: Vladimir Sementsov-Ogievskiy Message-Id: <20180413143156.11409-1-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake [eblake: fix two missing case labels in switch statements] Signed-off-by: Eric Blake --- include/block/nbd.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/block/nbd.h b/include/block/nbd.h index 8bb9606c39..daaeae61bf 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -135,6 +135,7 @@ typedef struct NBDExtent { #define NBD_FLAG_SEND_TRIM (1 << 5) /* Send TRIM (discard) */ #define NBD_FLAG_SEND_WRITE_ZEROES (1 << 6) /* Send WRITE_ZEROES */ #define NBD_FLAG_SEND_DF (1 << 7) /* Send DF (Do not Fragment) */ +#define NBD_FLAG_SEND_CACHE (1 << 8) /* Send CACHE (prefetch) */ /* New-style handshake (global) flags, sent from server to client, and control what will happen during handshake phase. */ @@ -195,7 +196,7 @@ enum { NBD_CMD_DISC = 2, NBD_CMD_FLUSH = 3, NBD_CMD_TRIM = 4, - /* 5 reserved for failed experiment NBD_CMD_CACHE */ + NBD_CMD_CACHE = 5, NBD_CMD_WRITE_ZEROES = 6, NBD_CMD_BLOCK_STATUS = 7, }; -- cgit v1.2.3