@@ -276,6 +276,36 @@ static int nbd_flush(BlockDriverState *bs)
return 0;
}
+static int nbd_discard(BlockDriverState *bs, int64_t sector_num,
+ int nb_sectors)
+{
+ BDRVNBDState *s = bs->opaque;
+ struct nbd_request request;
+ struct nbd_reply reply;
+
+ if (!(s->nbdflags & NBD_FLAG_SEND_TRIM)) {
+ return 0;
+ }
+ request.type = NBD_CMD_TRIM;
+ request.handle = (uint64_t)(intptr_t)bs;
+ request.from = sector_num * 512;;
+ request.len = nb_sectors * 512;
+
+ 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;
@@ -300,6 +330,7 @@ static BlockDriver bdrv_nbd = {
.bdrv_write = nbd_write,
.bdrv_close = nbd_close,
.bdrv_flush = nbd_flush,
+ .bdrv_discard = nbd_discard,
.bdrv_getlength = nbd_getlength,
.protocol_name = "nbd",
};
@@ -195,7 +195,7 @@ 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 |
+ flags | NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM |
NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA);
memset(buf + 28, 0, 124);
@@ -708,6 +708,17 @@ int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
if (nbd_send_reply(csock, &reply) == -1)
return -1;
break;
+ case NBD_CMD_TRIM:
+ TRACE("Request type is TRIM");
+ ret = bdrv_discard(bs, (request.from + dev_offset) / 512,
+ request.len / 512);
+ if (ret < 0) {
+ LOG("discard 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;
Map it to bdrv_discard. The server can also expose NBD_FLAG_SEND_TRIM. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- block/nbd.c | 31 +++++++++++++++++++++++++++++++ nbd.c | 13 ++++++++++++- 2 files changed, 43 insertions(+), 1 deletions(-)