vdo_compute_slab_count(9)

💅 vdo_compute_slab_count(9) — like, the Kernel API Manual era 🎀

okay so bestie, welcome to vdo_compute_slab_count from the Kernel API Manual, and honestly? this one is a little math gremlin and I'm obsessed 🧚✨

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✨ NAME ✨

vdo_compute_slab_count — literally computes the number of slabs that a depot would have, given its parameters. that's it. that's the whole vibe check 💅

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🌸 SYNOPSIS 🌸

slab_count_t vdo_compute_slab_count (physical_block_number_t first_block
, physical_block_number_t last_block , unsigned int slab_size_shift );

look at her go 👑 no cap, that's the entire signature, copy it exactly, don't @ me.

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🦋 ARGUMENTS 🦋

• first_block — the PBN of the first data block. like, where the data party starts 🎉
• last_block — the PBN of the last data block. where it wraps up, periodt 💀
• slab_size_shift — the exponent for the number of blocks per slab. it's giving "shift me, I'm a power of two" 🌈

ngl if you're wondering what PBN means, it's physical block number, and yes you should absolutely treat these as exact values, not vibes 🙈

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💜 RETURN 💜

returns the number of slabs. that's the answer, main character energy, no extra lore needed ✨

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🫶 SEE ALSO 🫶

okay this is the part where the group chat gets LONG, but every single one of these is invited to the party, so:

• the Kernel file ./drivers/md/dm-vdo/encodings.h, and also Block map entries(9) 🗺️
• vdo_are_same_version(9)
• vdo_pack_version_number(9)
• vdo_unpack_version_number(9)
• vdo_pack_header(9)
• vdo_unpack_header(9)
• vdo_get_index_region_start(9)
• vdo_get_data_region_start(9)
• vdo_get_index_region_size(9)
• vdo_pack_recovery_journal_entry(9)
• vdo_unpack_recovery_journal_entry(9)
• vdo_is_valid_recovery_journal_sector(9)
• vdo_compute_recovery_journal_block_number(9)
• vdo_get_journal_block_sector(9)
• vdo_pack_recovery_block_header(9)
• vdo_unpack_recovery_block_header(9)
• vdo_get_saved_reference_count_size(9)
• vdo_get_slab_journal_start_block(9)
• vdo_advance_journal_point(9)
• vdo_before_journal_point(9)
• vdo_pack_journal_point(9)
• vdo_unpack_journal_point(9)
• vdo_pack_slab_journal_block_header(9)
• vdo_unpack_slab_journal_block_header(9)
• vdo_pack_slab_journal_entry(9)
• vdo_unpack_slab_journal_entry(9)
• vdo_get_slab_summary_hint_shift(9)

like I said. the whole friend group. iykyk 💖

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and that's the page, bestie — brought to you by the fine people at ./drivers/md/dm-vdo, dated October 2026, filed under vdo_compute_slab_count(9) in the Kernel API Manual. slay, go count some slabs, you got this 🎀💜🔥