Note for the brace police: the style in this commit and the following
is consistent with the rest of the file. It is then fixed together with
the introduction of coroutines.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
block/nbd.c | 31 +++++++++++++++++++++++++++++++
nbd.c | 15 ++++++++++++++-
2 files changed, 45 insertions(+), 1 deletions(-)
diff --git a/block/nbd.c b/block/nbd.c
index 76f04d8..b6b2f2d 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -238,6 +238,36 @@ static int nbd_write(BlockDriverState *bs, int64_t
sector_num,
return 0;
}
+static int nbd_flush(BlockDriverState *bs)
+{
+ BDRVNBDState *s = bs->opaque;
+ struct nbd_request request;
+ struct nbd_reply reply;
+
+ if (!(s->nbdflags & NBD_FLAG_SEND_FLUSH)) {
+ return 0;
+ }
+
+ request.type = NBD_CMD_FLUSH;
+ request.handle = (uint64_t)(intptr_t)bs;
+ request.from = 0;
+ request.len = 0;
+
+ if (nbd_send_request(s->sock, &request) == -1)
+ return -errno;
+
+ if (nbd_receive_reply(s->sock, &reply) == -1)
+ return -errno;
+
+ if (reply.error != 0)
+ return -reply.error;
+
+ if (reply.handle != request.handle)
+ return -EIO;
+
+ return 0;
+}
+
static void nbd_close(BlockDriverState *bs)
{
BDRVNBDState *s = bs->opaque;
@@ -261,6 +291,7 @@ static BlockDriver bdrv_nbd = {
.bdrv_read = nbd_read,
.bdrv_write = nbd_write,
.bdrv_close = nbd_close,
+ .bdrv_flush = nbd_flush,
.bdrv_getlength = nbd_getlength,
.protocol_name = "nbd",
};
diff --git a/nbd.c b/nbd.c
index 5df9745..f06090b 100644
--- a/nbd.c
+++ b/nbd.c
@@ -194,7 +194,8 @@ int nbd_negotiate(int csock, off_t size, uint32_t flags)
memcpy(buf, "NBDMAGIC", 8);
cpu_to_be64w((uint64_t*)(buf + 8), 0x00420281861253LL);
cpu_to_be64w((uint64_t*)(buf + 16), size);
- cpu_to_be32w((uint32_t*)(buf + 24), flags | NBD_FLAG_HAS_FLAGS);
+ cpu_to_be32w((uint32_t*)(buf + 24),
+ flags | NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_FLUSH);
memset(buf + 28, 0, 124);
if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
@@ -686,6 +687,18 @@ int nbd_trip(BlockDriverState *bs, int csock, off_t size,
uint64_t dev_offset,
TRACE("Request type is DISCONNECT");
errno = 0;
return 1;
+ case NBD_CMD_FLUSH:
+ TRACE("Request type is FLUSH");
+
+ ret = bdrv_flush(bs);
+ if (ret < 0) {
+ LOG("flush failed");
+ reply.error = -ret;
+ }
+
+ if (nbd_send_reply(csock, &reply) == -1)
+ return -1;
+ break;
default:
LOG("invalid request type (%u) received", request.type);
errno = EINVAL;
--
1.7.6
