NBD client has not implemented callback for .bdrv_has_zero_init. So
bdrv_has_zero_init always returns 0 when doing non-shared storage
migration.
This patch implemented NBD_CMD_HAS_ZERO_INIT and will avoid unnecessary
set-dirty.
Signed-off-by: Yi Fang <eric.fan...@huawei.com>
---
block/block-backend.c | 5 +++++
block/nbd-client.c | 28 ++++++++++++++++++++++++++++
block/nbd-client.h | 1 +
block/nbd.c | 8 ++++++++
include/block/nbd.h | 3 +++
include/sysemu/block-backend.h | 1 +
nbd/server.c | 10 +++++++++-
7 files changed, 55 insertions(+), 1 deletion(-)
diff --git a/block/block-backend.c b/block/block-backend.c
index efbf398..4369c85 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1239,6 +1239,11 @@ void blk_drain_all(void)
bdrv_drain_all();
}
+int blk_has_zero_init(BlockBackend *blk)
+{
+ return bdrv_has_zero_init(blk_bs(blk));
+}
+
void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error,
BlockdevOnError on_write_error)
{
diff --git a/block/nbd-client.c b/block/nbd-client.c
index 3779c6c..8b1d98d 100644
--- a/block/nbd-client.c
+++ b/block/nbd-client.c
@@ -376,6 +376,34 @@ void nbd_client_attach_aio_context(BlockDriverState *bs,
false, nbd_reply_ready, NULL, bs);
}
+int nbd_client_co_has_zero_init(BlockDriverState *bs)
+{
+ NBDClientSession *client = nbd_get_client_session(bs);
+ NBDRequest request = { .type = NBD_CMD_HAS_ZERO_INIT };
+ NBDReply reply;
+ ssize_t ret;
+
+ if (!(client->nbdflags & NBD_FLAG_HAS_ZERO_INIT)) {
+ return 0;
+ }
+
+ request.from = 0;
+ request.len = 0;
+
+ nbd_coroutine_start(client, &request);
+ ret = nbd_co_send_request(bs, &request, NULL);
+ if (ret < 0) {
+ reply.error = -ret;
+ } else {
+ nbd_co_receive_reply(client, &request, &reply, NULL);
+ }
+ nbd_coroutine_end(client, &request);
+ if (reply.error == 0) {
+ return 1;
+ }
+ return 0;
+}
+
void nbd_client_close(BlockDriverState *bs)
{
NBDClientSession *client = nbd_get_client_session(bs);
diff --git a/block/nbd-client.h b/block/nbd-client.h
index f8d6006..ec01938 100644
--- a/block/nbd-client.h
+++ b/block/nbd-client.h
@@ -56,5 +56,6 @@ int nbd_client_co_preadv(BlockDriverState *bs, uint64_t
offset,
void nbd_client_detach_aio_context(BlockDriverState *bs);
void nbd_client_attach_aio_context(BlockDriverState *bs,
AioContext *new_context);
+int nbd_client_co_has_zero_init(BlockDriverState *bs);
#endif /* NBD_CLIENT_H */
diff --git a/block/nbd.c b/block/nbd.c
index 35f24be..40dd9a2 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -552,6 +552,11 @@ static void nbd_refresh_filename(BlockDriverState *bs,
QDict *options)
bs->full_open_options = opts;
}
+static int nbd_co_has_zero_init(BlockDriverState *bs)
+{
+ return nbd_client_co_has_zero_init(bs);
+}
+
static BlockDriver bdrv_nbd = {
.format_name = "nbd",
.protocol_name = "nbd",
@@ -569,6 +574,7 @@ static BlockDriver bdrv_nbd = {
.bdrv_detach_aio_context = nbd_detach_aio_context,
.bdrv_attach_aio_context = nbd_attach_aio_context,
.bdrv_refresh_filename = nbd_refresh_filename,
+ .bdrv_has_zero_init = nbd_co_has_zero_init,
};
static BlockDriver bdrv_nbd_tcp = {
@@ -588,6 +594,7 @@ static BlockDriver bdrv_nbd_tcp = {
.bdrv_detach_aio_context = nbd_detach_aio_context,
.bdrv_attach_aio_context = nbd_attach_aio_context,
.bdrv_refresh_filename = nbd_refresh_filename,
+ .bdrv_has_zero_init = nbd_co_has_zero_init,
};
static BlockDriver bdrv_nbd_unix = {
@@ -607,6 +614,7 @@ static BlockDriver bdrv_nbd_unix = {
.bdrv_detach_aio_context = nbd_detach_aio_context,
.bdrv_attach_aio_context = nbd_attach_aio_context,
.bdrv_refresh_filename = nbd_refresh_filename,
+ .bdrv_has_zero_init = nbd_co_has_zero_init,
};
static void bdrv_nbd_init(void)
diff --git a/include/block/nbd.h b/include/block/nbd.h
index 3e373f0..9aa9265 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -72,6 +72,7 @@ typedef struct NBDReply NBDReply;
#define NBD_FLAG_ROTATIONAL (1 << 4) /* Use elevator algorithm -
rotational media */
#define NBD_FLAG_SEND_TRIM (1 << 5) /* Send TRIM (discard) */
#define NBD_FLAG_SEND_WRITE_ZEROES (1 << 6) /* Send WRITE_ZEROES */
+#define NBD_FLAG_HAS_ZERO_INIT (1 << 8) /* Send HAS_ZERO_INIT */
/* New-style handshake (global) flags, sent from server to client, and
control what will happen during handshake phase. */
@@ -109,6 +110,8 @@ enum {
NBD_CMD_TRIM = 4,
/* 5 reserved for failed experiment NBD_CMD_CACHE */
NBD_CMD_WRITE_ZEROES = 6,
+ /* 7 reserved for STRUCTURED_REPLY */
+ NBD_CMD_HAS_ZERO_INIT = 8,
};
#define NBD_DEFAULT_PORT 10809
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 6444e41..9bd0822 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -156,6 +156,7 @@ int blk_flush(BlockBackend *blk);
int blk_commit_all(void);
void blk_drain(BlockBackend *blk);
void blk_drain_all(void);
+int blk_has_zero_init(BlockBackend *blk);
void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error,
BlockdevOnError on_write_error);
BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read);
diff --git a/nbd/server.c b/nbd/server.c
index 5b76261..7ae91b7 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -617,7 +617,8 @@ static coroutine_fn int nbd_negotiate(NBDClientNewData
*data)
int rc;
const uint16_t myflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM |
NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA |
- NBD_FLAG_SEND_WRITE_ZEROES);
+ NBD_FLAG_SEND_WRITE_ZEROES |
+ NBD_FLAG_HAS_ZERO_INIT);
bool oldStyle;
size_t len;
@@ -1321,6 +1322,13 @@ static void nbd_trip(void *opaque)
goto out;
}
break;
+ case NBD_CMD_HAS_ZERO_INIT:
+ TRACE("Request type is HAS_ZERO_INIT");
+ reply.error = !blk_has_zero_init(exp->blk);
+ if (nbd_co_send_reply(req, &reply, 0) < 0) {
+ goto out;
+ }
+ break;
default:
LOG("invalid request type (%" PRIu32 ") received", request.type);
reply.error = EINVAL;
--
1.8.5
