shrink_liability(9)

💅 shrink_liability(9) — a Kernel API Manual moment

okay so you found the shrink_liability page in the Kernel API Manual, and honestly? iconic. it's a tiny little function that does one very specific vibe: it writes back dirty stuff so UBIFS stops being so stressed. let's get into it 🫶

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✨ NAME ✨

shrink_liability — write-back some dirty pages/inodes.

like, that's it. that's the whole job. she writes stuff back. 💅

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🌸 SYNOPSIS 🌸

void shrink_liability (struct ubifs_info *c , int nr_to_write );

literally returns nothing (void), takes two things, and yes bestie the spacing is exactly like that, don't @ me 😭

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🎀 ARGUMENTS 🎀

• c — the UBIFS file-system description object. it's the whole file system's little info blob, she needs it to know what she's working with 🦋
• nr_to_write — how many dirty pages to write-back. that's the number, that's the budget of pages, go off 👑

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🔥 DESCRIPTION 🔥

so. this function shrinks UBIFS liability by means of writing back some amount of dirty inodes and their pages. that's the whole slay. less liability, more written-back content, everyone breathes easier ✨

⚠️ important note, no cap: this function synchronizes even VFS inodes which are locked (i_mutex) by the caller of the budgeting function. why is that allowed? because write-back does not touch i_mutex. so she's out here casually handling locked inodes and it's fine. it's fine!! 😭💖

like yes, that sounds slightly cursed, but that's genuinely the documented behaviour, so we're not gonna pretend otherwise 🙈

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🌈 SEE ALSO 🌈

kernel file ./fs/ubifs/budget.c — and here's the whole friend group, all 17 of them, in order, because I would never do them dirty by skipping anyone 💜

• run_gc(9)
• get_liability(9)
• make_free_space(9)
• ubifs_calc_min_idx_lebs(9)
• ubifs_calc_available(9)
• can_use_rp(9)
• do_budget_space(9)
• calc_idx_growth(9)
• calc_data_growth(9)
• calc_dd_growth(9)
• ubifs_budget_space(9)
• ubifs_release_budget(9)
• ubifs_convert_page_budget(9)
• ubifs_release_dirty_inode_budget(9)
• ubifs_reported_space(9)
• ubifs_get_free_space_nolock(9)
• ubifs_get_free_space(9)

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aaaand that's the page 🎀 she lives in ./fs/ubifs, the source/version is ./fs/ubifs, and this cutie is dated October 2026. mwah, go read the other budget functions bestie, they're all in the same friend group 💖✨