nbd: add support for NBD_CMD_FLUSH

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2011-10-21 13:17:14 +02:00
parent 2c7989a9b1
commit 1486d04a1b
2 changed files with 51 additions and 9 deletions

View File

@ -407,6 +407,34 @@ static int nbd_co_writev(BlockDriverState *bs, int64_t sector_num,
return nbd_co_writev_1(bs, sector_num, nb_sectors, qiov, offset);
}
static int nbd_co_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;
if (s->nbdflags & NBD_FLAG_SEND_FUA) {
request.type |= NBD_CMD_FLAG_FUA;
}
request.from = 0;
request.len = 0;
nbd_coroutine_start(s, &request);
if (nbd_co_send_request(s, &request, NULL, 0) == -1) {
reply.error = errno;
} else {
nbd_co_receive_reply(s, &request, &reply, NULL, 0);
}
nbd_coroutine_end(s, &request);
return -reply.error;
}
static void nbd_close(BlockDriverState *bs)
{
BDRVNBDState *s = bs->opaque;
@ -424,14 +452,15 @@ static int64_t nbd_getlength(BlockDriverState *bs)
}
static BlockDriver bdrv_nbd = {
.format_name = "nbd",
.instance_size = sizeof(BDRVNBDState),
.bdrv_file_open = nbd_open,
.bdrv_co_readv = nbd_co_readv,
.bdrv_co_writev = nbd_co_writev,
.bdrv_close = nbd_close,
.bdrv_getlength = nbd_getlength,
.protocol_name = "nbd",
.format_name = "nbd",
.instance_size = sizeof(BDRVNBDState),
.bdrv_file_open = nbd_open,
.bdrv_co_readv = nbd_co_readv,
.bdrv_co_writev = nbd_co_writev,
.bdrv_close = nbd_close,
.bdrv_co_flush_to_os = nbd_co_flush,
.bdrv_getlength = nbd_getlength,
.protocol_name = "nbd",
};
static void bdrv_nbd_init(void)

15
nbd.c
View File

@ -203,7 +203,8 @@ int nbd_negotiate(int csock, off_t size, uint32_t flags)
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 | NBD_FLAG_SEND_FUA);
flags | NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_FLUSH |
NBD_FLAG_SEND_FUA);
memset(buf + 28, 0, 124);
if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
@ -710,6 +711,18 @@ 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;