vdo_downgrad...n_write_lock(9)

💅 vdo_downgrade_pbn_write_lock — the Kernel API Manual glow-up ✨

okay bestie, welcome to the Kernel API Manual entry for vdo_downgrade_pbn_write_lock(9) — yes the title gets abbreviated all cute as vdo_downgrad...n_write_lock(9), that's just how the man page wears its name 🎀

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🌸 NAME 🌸

vdo_downgrade_pbn_write_lock — it literally downgrades a PBN write lock into a PBN read lock. that's the whole vibe. no cap. 🔥

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✨ SYNOPSIS ✨

void vdo_downgrade_pbn_write_lock (struct pbn_lock *lock , bool compressed_write );

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🦋 ARGUMENTS 🦋

• lock — the PBN write lock you're downgrading, bestie. that's the one. the main character of this operation 👑
• compressed_write — a bool. it's True if the block that got written was a compressed block. literally just tells you whether compression was involved 🫶

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💖 DESCRIPTION 💖

so here's the tea ☕ — the lock holder count gets cleared. that's it, that's the move. and then? the caller is responsible for setting the new count. not the function, not the kernel, you. the caller. that's on you, babe 😭💅

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🌈 SEE ALSO 🌈

the whole friend group, fr fr — and heads up, these all live in the kernel file ./drivers/md/dm-vdo/physical-zone.c 🧚

• vdo_is_pbn_read_lock(9)
• vdo_claim_pbn_lock_increment(9)
• vdo_assign_pbn_lock_provisional_reference(9)
• vdo_unassign_pbn_lock_provisional_reference(9)
• release_pbn_lock_provisional_reference(9)
• union idle_pbn_lock(9)
• struct pbn_lock_pool(9)
• return_pbn_lock_to_pool(9)
• make_pbn_lock_pool(9)
• free_pbn_lock_pool(9)
• borrow_pbn_lock_from_pool(9)
• initialize_zone(9)
• vdo_make_physical_zones(9)
• vdo_free_physical_zones(9)
• vdo_get_physical_zone_pbn_lock(9)
• vdo_attempt_physical_zone_pbn_lock(9)
• allocate_and_lock_block(9)
• retry_allocation(9)
• continue_allocating(9)
• vdo_allocate_block_in_zone(9)
• vdo_release_physical_zone_pbn_lock(9)
• vdo_dump_physical_zone(9)

like, that's the entire group chat and they ALL ate 💀🔥

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🎀 the sign-off 🎀

this lil beauty comes to you from ./drivers/md/dm-vdo, dated October 2026 — and the page answers to vdo_downgrad...n_write_lock(9) if you ever need to find it again. go off, king. periodt. 💜⭐🍓