vdo_validat...onent_states(9)

💅 vdo_validate_component_states(9) — like, the whole entire vibe check for your super block config

okay so bestie, grab a snack 🍓 because we're in the Kernel API Manual, section 9, and the star of the show is vdo_validate_component_states — yes that's the full name, the page header truncates it to vdo_validat...onent_states(9) because terminal width is a hater, but we know her full government name 💖

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✨ NAME ✨

vdo_validate_component_states — the function that goes "hmm, let me look at this decoded super block configuration real quick" and then validates it. no cap, that's literally her whole job 🫶

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🌸 SYNOPSIS 🌸

int vdo_validate_component_states (struct vdo_component_states *states ,
nonce_t geometry_nonce , block_count_t physical_size , block_count_t
logical_size );

she returns an int, she takes four things, and she is thriving ✨

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🎀 ARGUMENTS 🎀

okay so here's who's invited to the function call:

• states — the state that got decoded from the super block. this is the main character of the whole operation 👑 she's the thing being validated, everyone else is just here to check her vibe.
• geometry_nonce — the nonce from the geometry block. type nonce_t. she's the reference point, the receipts, the "ma'am can I see some ID" 😭
• physical_size — the minimum block count of the underlying storage. type block_count_t. lowkey the floor, the bare minimum, the you must be at least this tall to ride energy 🎢
• logical_size — the expected logical size of the VDO, or 0 if the logical size may be unspecified. yes, 0 is a real and valid value here, it means "we're not checking that, leave her be" 🙈 that 0 is doing so much work fr fr.

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🔥 RETURN 🔥

VDO_SUCCESS — slay, everything checks out, we're so back 💖

or, an error if the configuration is invalid. 💀 that's it, that's the return. either iconic success or an error, no in-between, no notes.

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🌈 SEE ALSO 🌈

bestie these all live in the Kernel file ./drivers/md/dm-vdo/encodings.c and honestly the guest list is long, but nobody gets left out of the group chat 🫶 :

• validate_version(9)
• vdo_validate_header(9)
• decode_volume_geometry(9)
• vdo_encode_volume_geometry(9)
• vdo_parse_geometry_block(9)
• vdo_compute_new_forest_pages(9)
• encode_recovery_journal_state_7_0(9)
• decode_recovery_journal_state_7_0(9)
• vdo_get_journal_operation_name(9)
• encode_slab_depot_state_2_0(9)
• decode_slab_depot_state_2_0(9)
• vdo_configure_slab_depot(9)
• vdo_configure_slab(9)
• vdo_decode_slab_journal_entry(9)
• allocate_partition(9)
• make_partition(9)
• vdo_initialize_layout(9)
• vdo_uninitialize_layout(9)
• vdo_get_partition(9)
• vdo_get_known_partition(9)
• pack_vdo_config(9)
• pack_vdo_component(9)
• unpack_vdo_config(9)
• unpack_vdo_component_41_0(9)
• decode_vdo_component(9)
• vdo_validate_config(9)
• vdo_destroy_component_states(9)
• decode_components(9)
• vdo_decode_component_states(9)
• vdo_encode_component_states(9)
• vdo_encode_super_block(9)
• vdo_decode_super_block(9)
• vdo_initialize_component_states(9)
• vdo_compute_index_blocks(9)
• vdo_initialize_volume_geometry(9)

like, thirty-five of them. thirty-five!! the encodings file really said "everyone's invited" 🎉

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heads up bestie: the 0 in logical_size isn't a typo and isn't a bug — the manpage says the logical size may be unspecified, and 0 is how you say that. don't "fix" it 💅

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and that's the page!! 🦋 brought to you by the source at ./drivers/md/dm-vdo, dated October 2026, filed under vdo_validat...onent_states(9) in the Kernel API Manual. go validate those component states, you absolute icon ⭐ 💜