allocate_budget(9)

💖 allocate_budget(9) — the ubifs_write_begin() budget bestie 💖

okay so this is a page from the Kernel API Manual, and today we are learning about allocate_budget 🎀 stay with me, it's actually not scary, i promise 🫶

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✨ NAME ✨

allocate_budget — allocate budget for ubifs_write_begin() 💅

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🌸 SYNOPSIS 🌸

int allocate_budget (struct ubifs_info *c , struct folio *folio , struct
ubifs_inode *ui , int appending );

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🦋 ARGUMENTS 🦋

• c — the UBIFS file-system description object, literally the whole filesystem's vibe in one struct 👑
• folio — the folio we're allocating budget for, the actual main character here 🍓
• ui — the UBIFS inode object that the page belongs to, ikyk what a page belongs to and all that 🧚
• appending — non-zero if the page is appended, zero if it's not, no cap 💀

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💜 DESCRIPTION 💜

so this is a helper function for ubifs_write_begin, and its whole job is allocating budget for the operation ✨

here's the thing bestie — the budget is allocated differently depending on whether this is appending, whether the page is dirty or not, and so on 🔥 like, it's not one-size-fits-all, the function is reading the room, highkey 💅

and the detail you cannot miss: this function leaves ui->ui_mutex locked in case of appending 🔒 periodt. so do not go unlocking it yourself thinking you're being helpful, that's not the move 🙈

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⭐ RETURN ⭐

• 0 — success, we ate, everything's fine 🌈
• -ENOSPC — failure, the budget situation is giving no space 😭

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💖 SEE ALSO 💖

peep the kernel file ./fs/ubifs/file.c and go meet the whole friend group:

• release_new_page_budget(9)
• release_existing_page_budget(9)
• cancel_budget(9)
• populate_page(9)
• ubifs_do_bulk_read(9)
• ubifs_bulk_read(9)
• do_attr_changes(9)
• do_truncation(9)
• do_setattr(9)
• mctime_update_needed(9)
• update_mctime(9)

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and that's the whole page, bestie 🫶 this one lives in ./fs/ubifs and it's dated October 2026 — so like, mark your calendar, iconic behavior honestly 👑✨