parse_optional_arguments(9)

💅 parse_optional_arguments(9)

okay so this is a page from the Kernel API Manual — yes, the kernel, yes, it's a whole vibe 🐧✨

✨ NAME ✨

parse_optional_arguments — literally the function that parses the configuration string you passed in for optional arguments. that's it, that's the whole job 🎀

🌸 SYNOPSIS 🌸

int parse_optional_arguments (struct dm_arg_set *arg_set , char
**error_ptr , struct device_config *config );

bestie it returns an int, it takes three things, and we're gonna go through all of them one by one 🫶

🦋 ARGUMENTS 🦋

• arg_set — the structure holding the arguments we're about to parse. it's giving "the container of the thing" 💅
• error_ptr — pointer to a buffer that's gonna hold the error string. if something goes sideways, this is where the receipts live 😭
• config — pointer to the device configuration data that gets updated. main character energy, honestly 👑

💖 DESCRIPTION 💖

okay so here's the situation, and it's actually two situations depending on your version, periodt.

For V0/V1 configurations, there will only be one optional parameter; the thread configuration. the configuration string should contain one or more comma-separated specs of the form "typename=number", and the supported type names are "cpu", "ack", "bio", "bioRotationInterval", "logical", "physical", and "hash". so like, exactly those seven, no inventing your own ✨

For V2 configurations and beyond, there could be any number of arguments. they should contain one or more key/value pairs separated by a space. so it's giving "glow up, we're flexible now" 🦋

ngl the two formats are different and that is not a typo — commas and = for the old ones, spaces and key/value pairs for the new ones. read the version, bestie 🔥

🌈 RETURN 🌈

VDO_SUCCESS or error. that's the whole range of outcomes, no surprises, no cap 💀

🎀 SEE ALSO 🎀

• Kernel file ./drivers/md/dm-vdo/dm-vdo-target.c
• free_device_config(9)
• get_version_number(9)
• parse_bool(9)
• parse_memory(9)
• parse_slab_size(9)
• process_one_thread_config_spec(9)
• parse_one_thread_config_spec(9)
• parse_thread_config_string(9)
• process_one_key_value_pair(9)
• parse_one_key_value_pair(9)
• parse_key_value_pairs(9)
• handle_parse_error(9)
• parse_device_config(9)
• get_thread_id_for_phase(9)
• advance_phase(9)
• finish_operation_callback(9)
• decode_from_super_block(9)
• decode_vdo(9)
• pre_load_callback(9)
• get_bit_array_size(9)
• grow_bit_array(9)
• allocate_instance(9)
• check_may_grow_physical(9)
• grow_layout(9)
• validate_new_device_config(9)
• write_super_block_for_suspend(9)
• suspend_callback(9)
• was_new(9)
• requires_repair(9)
• get_load_type(9)
• load_callback(9)
• handle_load_error(9)
• write_super_block_for_resume(9)
• resume_callback(9)
• grow_logical_callback(9)
• handle_logical_growth_error(9)
• perform_grow_logical(9)
• copy_partition(9)
• grow_physical_callback(9)
• handle_physical_growth_error(9)
• perform_grow_physical(9)
• apply_new_vdo_configuration(9)

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and that's the page!! 💜 this icon came out of ./drivers/md/dm-vdo and it's dated October 2026 — go off, future kernel docs, we love to see it 🧚⭐🍓