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author | Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> | 2018-03-12 18:21:23 +0300 |
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committer | Eric Blake <eblake@redhat.com> | 2018-03-13 15:43:48 -0500 |
commit | 78a33ab58782efdb206de14fa44ea626e2360bfc (patch) | |
tree | fa7858141d63f531161b407db2f55e5cee44f065 /nbd | |
parent | 1e98efc0299977a4b0815c2d0a216ae19881e389 (diff) | |
download | qemu-78a33ab58782efdb206de14fa44ea626e2360bfc.zip qemu-78a33ab58782efdb206de14fa44ea626e2360bfc.tar.gz qemu-78a33ab58782efdb206de14fa44ea626e2360bfc.tar.bz2 |
nbd: BLOCK_STATUS for standard get_block_status function: client part
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 <vsementsov@virtuozzo.com>
Message-Id: <20180312152126.286890-6-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@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 <eblake@redhat.com>
Diffstat (limited to 'nbd')
-rw-r--r-- | nbd/client.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/nbd/client.c b/nbd/client.c index dcad23a..9b9b7f0 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 |