nbd_clear_meta_contexts(3)

📦
version 1.25.8 · 18 versions
, in centos-stream 10

✨ NAME ✨

nbd_clear_meta_contexts — reset the list of requested meta contexts. This is the LIBNBD manual page (aka libnbd, bestie), and it’s giving very specific handle-energy. 🦋

🎀 SYNOPSIS 🎀

#include <libnbd.h>

int nbd_clear_meta_contexts (
      struct nbd_handle *h
    );

🌸 DESCRIPTION 🌸

Okay so during connection, libnbd can negotiate zero or more metadata contexts with the server. Metadata contexts are features — like base:allocation — which describe information returned by the nbd_block_status_64(3) command. For base:allocation, that’s literally whether blocks of data are allocated, zero, or sparse. Iconic feature behavior, no cap. ✨

This command resets the list of meta contexts to request back to an empty list, for re-population by further use of nbd_add_meta_context(3). It is primarily useful when option negotiation mode is selected (see nbd_set_opt_mode(3)), for altering the list of attempted contexts between subsequent export queries. Periodt — it’s the reset button for your meta-context wishlist. 💅

💖 RETURN VALUE 💖

If the call is successful, the function returns 0.

💀 ERRORS 💀

On error, -1 is returned.

Refer to “ERROR HANDLING” in libnbd(3) for how to get further details of the error.

Also: the following parameters must not be NULL: h. For more information, see “Non-NULL parameters” in libnbd(3). Fr fr, do not pass NULL there. 🫶

🌈 HANDLE STATE 🌈

Okay so nbd_clear_meta_contexts 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 1.6.

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

#define LIBNBD_HAVE_NBD_CLEAR_META_CONTEXTS 1

🦋 SEE ALSO 🦋

👑 AUTHORS 👑

  • Eric Blake
  • Richard W.M. Jones

Copyright Red Hat

🧚 LICENSE 🧚

Legal moment, bestie — here’s the whole thing, no skips:

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

mwah 💋 — signing off from the LIBNBD manual page nbd_clear_meta_contexts(3), brought to you by libnbd-1.25.8 and dated 2026-10-13. slay. 🫶

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