From: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Minimal realization: only one extent in server answer is supported.
Flag NBD_CMD_FLAG_REQ_ONE is used to force this behavior.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Message-Id: <20180312152126.286890-6-vsement...@virtuozzo.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
[eblake: grammar tweaks, fix min_block check and 32-bit cap, use -1
instead of errno on failure in nbd_negotiate_simple_meta_context,
ensure that block status makes progress on success]
Signed-off-by: Eric Blake <ebl...@redhat.com>
---
block/nbd-client.h | 6 +++
include/block/nbd.h | 3 ++
block/nbd-client.c | 150 ++++++++++++++++++++++++++++++++++++++++++++++++++++
block/nbd.c | 3 ++
nbd/client.c | 117 ++++++++++++++++++++++++++++++++++++++++
5 files changed, 279 insertions(+)
diff --git a/block/nbd-client.h b/block/nbd-client.h
index 612c4c21a0c..0ece76e5aff 100644
--- a/block/nbd-client.h
+++ b/block/nbd-client.h
@@ -61,4 +61,10 @@ void nbd_client_detach_aio_context(BlockDriverState *bs);
void nbd_client_attach_aio_context(BlockDriverState *bs,
AioContext *new_context);
+int coroutine_fn nbd_client_co_block_status(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset, int64_t bytes,
+ int64_t *pnum, int64_t *map,
+ BlockDriverState **file);
+
#endif /* NBD_CLIENT_H */
diff --git a/include/block/nbd.h b/include/block/nbd.h
index 2285637e673..fcdcd545023 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -260,6 +260,7 @@ struct NBDExportInfo {
/* In-out fields, set by client before nbd_receive_negotiate() and
* updated by server results during nbd_receive_negotiate() */
bool structured_reply;
+ bool base_allocation; /* base:allocation context for NBD_CMD_BLOCK_STATUS
*/
/* Set by server results during nbd_receive_negotiate() */
uint64_t size;
@@ -267,6 +268,8 @@ struct NBDExportInfo {
uint32_t min_block;
uint32_t opt_block;
uint32_t max_block;
+
+ uint32_t meta_base_allocation_id;
};
typedef struct NBDExportInfo NBDExportInfo;
diff --git a/block/nbd-client.c b/block/nbd-client.c
index 0d9f73a137f..e64e346d690 100644
--- a/block/nbd-client.c
+++ b/block/nbd-client.c
@@ -228,6 +228,48 @@ static int
nbd_parse_offset_hole_payload(NBDStructuredReplyChunk *chunk,
return 0;
}
+/* nbd_parse_blockstatus_payload
+ * support only one extent in reply and only for
+ * base:allocation context
+ */
+static int nbd_parse_blockstatus_payload(NBDClientSession *client,
+ NBDStructuredReplyChunk *chunk,
+ uint8_t *payload, uint64_t
orig_length,
+ NBDExtent *extent, Error **errp)
+{
+ uint32_t context_id;
+
+ if (chunk->length != sizeof(context_id) + sizeof(extent)) {
+ error_setg(errp, "Protocol error: invalid payload for "
+ "NBD_REPLY_TYPE_BLOCK_STATUS");
+ return -EINVAL;
+ }
+
+ context_id = payload_advance32(&payload);
+ if (client->info.meta_base_allocation_id != context_id) {
+ error_setg(errp, "Protocol error: unexpected context id %d for "
+ "NBD_REPLY_TYPE_BLOCK_STATUS, when negotiated context
"
+ "id is %d", context_id,
+ client->info.meta_base_allocation_id);
+ return -EINVAL;
+ }
+
+ extent->length = payload_advance32(&payload);
+ extent->flags = payload_advance32(&payload);
+
+ if (extent->length == 0 ||
+ (client->info.min_block && !QEMU_IS_ALIGNED(extent->length,
+ client->info.min_block)) ||
+ extent->length > orig_length)
+ {
+ error_setg(errp, "Protocol error: server sent status chunk with "
+ "invalid length");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
/* nbd_parse_error_payload
* on success @errp contains message describing nbd error reply
*/
@@ -642,6 +684,68 @@ static int nbd_co_receive_cmdread_reply(NBDClientSession
*s, uint64_t handle,
return iter.ret;
}
+static int nbd_co_receive_blockstatus_reply(NBDClientSession *s,
+ uint64_t handle, uint64_t length,
+ NBDExtent *extent, Error **errp)
+{
+ NBDReplyChunkIter iter;
+ NBDReply reply;
+ void *payload = NULL;
+ Error *local_err = NULL;
+ bool received = false;
+
+ assert(!extent->length);
+ NBD_FOREACH_REPLY_CHUNK(s, iter, handle, s->info.structured_reply,
+ NULL, &reply, &payload)
+ {
+ int ret;
+ NBDStructuredReplyChunk *chunk = &reply.structured;
+
+ assert(nbd_reply_is_structured(&reply));
+
+ switch (chunk->type) {
+ case NBD_REPLY_TYPE_BLOCK_STATUS:
+ if (received) {
+ s->quit = true;
+ error_setg(&local_err, "Several BLOCK_STATUS chunks in reply");
+ nbd_iter_error(&iter, true, -EINVAL, &local_err);
+ }
+ received = true;
+
+ ret = nbd_parse_blockstatus_payload(s, &reply.structured,
+ payload, length, extent,
+ &local_err);
+ if (ret < 0) {
+ s->quit = true;
+ nbd_iter_error(&iter, true, ret, &local_err);
+ }
+ break;
+ default:
+ if (!nbd_reply_type_is_error(chunk->type)) {
+ s->quit = true;
+ error_setg(&local_err,
+ "Unexpected reply type: %d (%s) "
+ "for CMD_BLOCK_STATUS",
+ chunk->type, nbd_reply_type_lookup(chunk->type));
+ nbd_iter_error(&iter, true, -EINVAL, &local_err);
+ }
+ }
+
+ g_free(payload);
+ payload = NULL;
+ }
+
+ if (!extent->length && !iter.err) {
+ error_setg(&iter.err,
+ "Server did not reply with any status extents");
+ if (!iter.ret) {
+ iter.ret = -EIO;
+ }
+ }
+ error_propagate(errp, iter.err);
+ return iter.ret;
+}
+
static int nbd_co_request(BlockDriverState *bs, NBDRequest *request,
QEMUIOVector *write_qiov)
{
@@ -784,6 +888,51 @@ int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t
offset, int bytes)
return nbd_co_request(bs, &request, NULL);
}
+int coroutine_fn nbd_client_co_block_status(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset, int64_t bytes,
+ int64_t *pnum, int64_t *map,
+ BlockDriverState **file)
+{
+ int64_t ret;
+ NBDExtent extent = { 0 };
+ NBDClientSession *client = nbd_get_client_session(bs);
+ Error *local_err = NULL;
+
+ NBDRequest request = {
+ .type = NBD_CMD_BLOCK_STATUS,
+ .from = offset,
+ .len = MIN(MIN_NON_ZERO(QEMU_ALIGN_DOWN(INT_MAX,
+ bs->bl.request_alignment),
+ client->info.max_block), bytes),
+ .flags = NBD_CMD_FLAG_REQ_ONE,
+ };
+
+ if (!client->info.base_allocation) {
+ *pnum = bytes;
+ return BDRV_BLOCK_DATA;
+ }
+
+ ret = nbd_co_send_request(bs, &request, NULL);
+ if (ret < 0) {
+ return ret;
+ }
+
+ ret = nbd_co_receive_blockstatus_reply(client, request.handle, bytes,
+ &extent, &local_err);
+ if (local_err) {
+ error_report_err(local_err);
+ }
+ if (ret < 0) {
+ return ret;
+ }
+
+ assert(extent.length);
+ *pnum = extent.length;
+ return (extent.flags & NBD_STATE_HOLE ? 0 : BDRV_BLOCK_DATA) |
+ (extent.flags & NBD_STATE_ZERO ? BDRV_BLOCK_ZERO : 0);
+}
+
void nbd_client_detach_aio_context(BlockDriverState *bs)
{
NBDClientSession *client = nbd_get_client_session(bs);
@@ -828,6 +977,7 @@ int nbd_client_init(BlockDriverState *bs,
client->info.request_sizes = true;
client->info.structured_reply = true;
+ client->info.base_allocation = true;
ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), export,
tlscreds, hostname,
&client->ioc, &client->info, errp);
diff --git a/block/nbd.c b/block/nbd.c
index d4e4172c08c..1e2b3ba2d3b 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -585,6 +585,7 @@ 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_co_block_status = nbd_client_co_block_status,
};
static BlockDriver bdrv_nbd_tcp = {
@@ -604,6 +605,7 @@ 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_co_block_status = nbd_client_co_block_status,
};
static BlockDriver bdrv_nbd_unix = {
@@ -623,6 +625,7 @@ 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_co_block_status = nbd_client_co_block_status,
};
static void bdrv_nbd_init(void)
diff --git a/nbd/client.c b/nbd/client.c
index dcad23a0531..9b9b7f0ea29 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -595,6 +595,111 @@ static QIOChannel *nbd_receive_starttls(QIOChannel *ioc,
return QIO_CHANNEL(tioc);
}
+/* nbd_negotiate_simple_meta_context:
+ * Set one meta context. Simple means that reply must contain zero (not
+ * negotiated) or one (negotiated) contexts. More contexts would be considered
+ * as a protocol error. It's also implied that meta-data query equals queried
+ * context name, so, if server replies with something different then @context,
+ * it considered as error too.
+ * return 1 for successful negotiation, context_id is set
+ * 0 if operation is unsupported,
+ * -1 with errp set for any other error
+ */
+static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
+ const char *export,
+ const char *context,
+ uint32_t *context_id,
+ Error **errp)
+{
+ int ret;
+ NBDOptionReply reply;
+ uint32_t received_id;
+ bool received;
+ uint32_t export_len = strlen(export);
+ uint32_t context_len = strlen(context);
+ uint32_t data_len = sizeof(export_len) + export_len +
+ sizeof(uint32_t) + /* number of queries */
+ sizeof(context_len) + context_len;
+ char *data = g_malloc(data_len);
+ char *p = data;
+
+ stl_be_p(p, export_len);
+ memcpy(p += sizeof(export_len), export, export_len);
+ stl_be_p(p += export_len, 1);
+ stl_be_p(p += sizeof(uint32_t), context_len);
+ memcpy(p += sizeof(context_len), context, context_len);
+
+ ret = nbd_send_option_request(ioc, NBD_OPT_SET_META_CONTEXT, data_len,
data,
+ errp);
+ g_free(data);
+ if (ret < 0) {
+ return ret;
+ }
+
+ if (nbd_receive_option_reply(ioc, NBD_OPT_SET_META_CONTEXT, &reply,
+ errp) < 0)
+ {
+ return -1;
+ }
+
+ ret = nbd_handle_reply_err(ioc, &reply, errp);
+ if (ret <= 0) {
+ return ret;
+ }
+
+ if (reply.type == NBD_REP_META_CONTEXT) {
+ char *name;
+ size_t len;
+
+ if (nbd_read(ioc, &received_id, sizeof(received_id), errp) < 0) {
+ return -1;
+ }
+ be32_to_cpus(&received_id);
+
+ len = reply.length - sizeof(received_id);
+ name = g_malloc(len + 1);
+ if (nbd_read(ioc, name, len, errp) < 0) {
+ g_free(name);
+ return -1;
+ }
+ name[len] = '\0';
+ if (strcmp(context, name)) {
+ error_setg(errp, "Failed to negotiate meta context '%s', server "
+ "answered with different context '%s'", context,
+ name);
+ g_free(name);
+ return -1;
+ }
+ g_free(name);
+
+ received = true;
+
+ /* receive NBD_REP_ACK */
+ if (nbd_receive_option_reply(ioc, NBD_OPT_SET_META_CONTEXT, &reply,
+ errp) < 0)
+ {
+ return -1;
+ }
+
+ ret = nbd_handle_reply_err(ioc, &reply, errp);
+ if (ret <= 0) {
+ return ret;
+ }
+ }
+
+ if (reply.type != NBD_REP_ACK) {
+ error_setg(errp, "Unexpected reply type %" PRIx32 " expected %x",
+ reply.type, NBD_REP_ACK);
+ return -1;
+ }
+
+ if (received) {
+ *context_id = received_id;
+ return 1;
+ }
+
+ return 0;
+}
int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
QCryptoTLSCreds *tlscreds, const char *hostname,
@@ -606,10 +711,12 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char
*name,
int rc;
bool zeroes = true;
bool structured_reply = info->structured_reply;
+ bool base_allocation = info->base_allocation;
trace_nbd_receive_negotiate(tlscreds, hostname ? hostname : "<null>");
info->structured_reply = false;
+ info->base_allocation = false;
rc = -EINVAL;
if (outioc) {
@@ -700,6 +807,16 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char
*name,
info->structured_reply = result == 1;
}
+ if (info->structured_reply && base_allocation) {
+ result = nbd_negotiate_simple_meta_context(
+ ioc, name, "base:allocation",
+ &info->meta_base_allocation_id, errp);
+ if (result < 0) {
+ goto fail;
+ }
+ info->base_allocation = result == 1;
+ }
+
/* Try NBD_OPT_GO first - if it works, we are done (it
* also gives us a good message if the server requires
* TLS). If it is not available, fall back to
--
2.14.3
