folio_redirty_for_writepage(9)

💅 folio_redirty_for_writepage(9) — the kernel API manual, bestie edition

okay so you found folio_redirty_for_writepage in the Kernel API Manual and you're like "what is this, why is it here, do I need it" — don't worry, I got you 🫶 this is literally the "jk, never mind, keep it dirty" function and honestly it's giving main character energy for anyone writing a writepage implementation ✨

---

🌸 NAME 🌸

folio_redirty_for_writepage — Decline to write a dirty folio.

like, you're saying "no thanks bestie, I'm not writing this one" 💅

---

🎀 SYNOPSIS 🎀

bool folio_redirty_for_writepage (struct writeback_control *wbc , struct
folio *folio );

so it hands you back a bool, and you feed it a wbc and a folio. that's the whole vibe check 😌

---

✨ ARGUMENTS ✨

• wbc — The writeback control. yes, the actual writeback control struct, she's the boss of this whole operation 👑
• folio — The folio. the folio in question. the one we're talking about. the star of the show 🌟

---

💖 DESCRIPTION 💖

okay so here's the tea ☕ when a writepage implementation decides that it doesn't want to write folio for some reason — and honestly valid, we've all been there — it should call this function, unlock folio, and return 0.

that's it. that's the whole thing. call it, unlock the folio, return 0, move on with your life. no cap 🧚

---

🔥 RETURN 🔥

• True if we redirtied the folio. slay, mission accomplished 💅
• False if someone else dirtied it first. awkward but okay, they beat you to it 😭

ngl, that True/False distinction is lowkey important — it's literally telling you whether you were the one who re-dirtied it or whether another thread got there first. iykyk 👀

---

🦋 SEE ALSO 🦋

Kernel file ./mm/page-writeback.c and honestly the whole friend group:

• node_dirtyable_memory(9)
• global_dirtyable_memory(9)
• domain_dirty_limits(9)
• global_dirty_limits(9)
• node_dirty_limit(9)
• node_dirty_ok(9)
• __wb_calc_thresh(9)
• balance_dirty_pages_ratelimited_flags(9)
• balance_dirty_pages_ratelimited(9)
• wb_over_bg_thresh(9)
• tag_pages_for_writeback(9)
• writeback_iter(9)
• filemap_dirty_folio(9)
• folio_mark_dirty(9)
• folio_wait_writeback(9)
• folio_wait_writeback_killable(9)
• folio_wait_stable(9)

like a whole squad of dirty-page besties, go say hi 🌈

---

and that's the page bestie!! 🎀 this one lives in ./mm, dated October 2026, and it's filed under folio_redirty_for_writepage(9) — periodt. go forth and decline to write that folio 💜✨