vdo_enter_read_only_mode(9)

✨💅 vdo_enter_read_only_mode(9) 💅✨

okay so this page is from the Kernel API Manual, section 9, and it's all about putting a VDO into read-only mode and saving that read-only state in the super block. bestie, it's giving “emergency brake but make it kernel.” 🫶

🌸 NAME 🌸

vdo_enter_read_only_mode — Put a VDO into read-only mode and save the read-only state in the super block. 💖

✨ SYNOPSIS ✨

void vdo_enter_read_only_mode (struct vdo *vdo , int error_code );

🎀 ARGUMENTS 🎀

• vdo — the VDO itself, the main character here. 👑
• error_code — the error which caused the VDO to enter read-only mode 😭 that's the reason, no cap.

🦋 DESCRIPTION 🦋

This method is a no-op if the VDO is already read-only. literally nothing happens, bestie — it is already read-only, so it stays unbothered 💅✨

🌈 SEE ALSO 🌈

okay the friend group is huge, but we do not skip anyone:

• Kernel file ./drivers/md/dm-vdo/vdo.c — Introduction(9)
• vdo_initialize_device_registry_once(9)
• filter_vdos_locked(9)
• vdo_find_matching(9)
• initialize_thread_config(9)
• get_thread_name(9)
• vdo_make_thread(9)
• register_vdo(9)
• vdo_format(9)
• initialize_vdo(9)
• vdo_make(9)
• free_listeners(9)
• unregister_vdo(9)
• vdo_destroy(9)
• finish_reading_super_block(9)
• handle_super_block_read_error(9)
• vdo_load_super_block(9)
• vdo_get_backing_device(9)
• vdo_get_device_name(9)
• vdo_synchronous_flush(9)
• vdo_get_state(9)
• vdo_set_state(9)
• vdo_get_admin_state(9)
• record_vdo(9)
• continue_parent(9)
• handle_geometry_block_save_error(9)
• vdo_save_geometry_block(9)
• handle_super_block_save_error(9)
• vdo_save_super_block(9)
• vdo_save_components(9)
• vdo_register_read_only_listener(9)
• notify_vdo_of_read_only_mode(9)
• vdo_enable_read_only_entry(9)
• vdo_wait_until_not_entering_read_only_mode(9)
• as_notifier(9)
• finish_entering_read_only_mode(9)
• make_thread_read_only(9)
• vdo_allow_read_only_mode_entry(9)
• vdo_is_read_only(9)
• vdo_in_read_only_mode(9)
• vdo_in_recovery_mode(9)
• vdo_enter_recovery_mode(9)
• complete_synchronous_action(9)
• perform_synchronous_action(9)
• set_compression_callback(9)
• vdo_set_compressing(9)
• vdo_get_compressing(9)
• vdo_get_physical_blocks_allocated(9)
• vdo_get_physical_blocks_overhead(9)
• get_vdo_statistics(9)
• vdo_fetch_statistics_callback(9)
• vdo_fetch_statistics(9)
• vdo_get_callback_thread_id(9)
• vdo_dump_status(9)
• vdo_assert_on_admin_thread(9)
• vdo_assert_on_logical_zone_thread(9)
• vdo_assert_on_physical_zone_thread(9)
• vdo_get_physical_zone(9)

mwah 💋 this little page comes from the ./drivers/md/dm-vdo source/version, stamped October 2026, and it's literally vdo_enter_read_only_mode(9). bye bestie, slay your kernel debugging! 🫶💖