---
name: "nbd_set_request_meta_context"
section: "3"
platform: "linux"
package: "libnbd"
version: "1.24.4-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/nbd_set_request_meta_context"
---

# nbd\_set\_request\_meta\_context(3)

control whether connect automatically requests meta contexts

## NAME

nbd\_set\_request\_meta\_context - control whether connect automatically requests meta contexts

## SYNOPSIS

```
 #include <libnbd.h>
 int nbd_set_request_meta_context (
       struct nbd_handle *h, bool request
     );
```

## DESCRIPTION

This function controls whether the act of connecting to an export (all `"nbd_connect_*"` calls when [**nbd\_set\_opt\_mode**(3)](/nbd_set_opt_mode/3.md) is false, or [**nbd\_opt\_go**(3)](/nbd_opt_go/3.md) and [**nbd\_opt\_info**(3)](/nbd_opt_info/3.md) when option mode is enabled) will also try to issue NBD\_OPT\_SET\_META\_CONTEXT when the server supports structured replies or extended headers and any contexts were registered by [**nbd\_add\_meta\_context**(3)](/nbd_add_meta_context/3.md).  The default setting is true; however the extra step of negotiating meta contexts is not always desirable: performing both info and go on the same export works without needing to re-negotiate contexts on the second call; integration testing of other servers may benefit from manual invocation of [**nbd\_opt\_set\_meta\_context**(3)](/nbd_opt_set_meta_context/3.md) at other times in the negotiation sequence; and even when using just [**nbd\_opt\_info**(3)](/nbd_opt_info/3.md), it can be faster to collect the server's results by relying on the callback function passed to [**nbd\_opt\_list\_meta\_context**(3)](/nbd_opt_list_meta_context/3.md) than a series of post-process calls to [**nbd\_can\_meta\_context**(3)](/nbd_can_meta_context/3.md).

Note that this control has no effect if the server does not negotiate structured replies or extended headers, or if the client did not request any contexts via [**nbd\_add\_meta\_context**(3)](/nbd_add_meta_context/3.md). Setting this control to false may cause [**nbd\_block\_status**(3)](/nbd_block_status/3.md) to fail.

## RETURN VALUE

If the call is successful the function returns `0`.

## ERRORS

On error `-1` is returned.

Refer to "ERROR HANDLING" in [**libnbd**(3)](/libnbd/3.md) for how to get further details of the error.

The following parameters must not be NULL: `"h"`. For more information see "Non-NULL parameters" in [**libnbd**(3)](/libnbd/3.md).

## HANDLE STATE

nbd\_set\_request\_meta\_context can be called when the handle is in the following states:

```
 ┌─────────────────────────────────────┬─────────────────────────┐
 │ Handle created, before connecting   │ ✅ allowed              │
 │ Connecting                          │ ❌ error                │
 │ Connecting & handshaking (opt_mode) │ ✅ allowed              │
 │ Connected to the server             │ ❌ error                │
 │ Connection shut down                │ ❌ error                │
 │ Handle dead                         │ ❌ error                │
 └─────────────────────────────────────┴─────────────────────────┘
```

## VERSION

This function first appeared in libnbd 1.16.

If you need to test if this function is available at compile time check if the following macro is defined:

```
 #define LIBNBD_HAVE_NBD_SET_REQUEST_META_CONTEXT 1
```

## SEE ALSO

[**nbd\_add\_meta\_context**(3)](/nbd_add_meta_context/3.md), [**nbd\_block\_status**(3)](/nbd_block_status/3.md), [**nbd\_can\_meta\_context**(3)](/nbd_can_meta_context/3.md), [**nbd\_create**(3)](/nbd_create/3.md), [**nbd\_get\_request\_meta\_context**(3)](/nbd_get_request_meta_context/3.md), [**nbd\_get\_structured\_replies\_negotiated**(3)](/nbd_get_structured_replies_negotiated/3.md), [**nbd\_opt\_go**(3)](/nbd_opt_go/3.md), [**nbd\_opt\_info**(3)](/nbd_opt_info/3.md), [**nbd\_opt\_list\_meta\_context**(3)](/nbd_opt_list_meta_context/3.md), [**nbd\_opt\_set\_meta\_context**(3)](/nbd_opt_set_meta_context/3.md), [**nbd\_set\_opt\_mode**(3)](/nbd_set_opt_mode/3.md), [**libnbd**(3)](/libnbd/3.md).

## AUTHORS

Eric Blake

Richard W.M. Jones

## COPYRIGHT

Copyright Red Hat

## LICENSE

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA