ubifs_calc_dark(9)

📦 version 7.3.1, in nixpkgs unstable

💅 ubifs_calc_dark(9) — the Kernel API Manual, bestie edition ✨

okay so before we even start, you should know this page lives in the Kernel API Manual, and it's all about our girl ubifs_calc_dark. she's doing one job and doing it cute. let's get into it 🫶

🌸 SYNOPSIS 🌸

int ubifs_calc_dark (const struct ubifs_info *c , int spc );

literally that's the whole thing. short, sweet, iconic 👑

🎀 ARGUMENTS 🎀

  • c — the UBIFS file-system description object. yes bestie, the whole file system, all up in one struct. she's the main character, everything else is a supporting role 💖
  • spc — the amount of free and dirty space in the LEB. both. at once. she contains multitudes 🦋

✨ DESCRIPTION ✨

so this function calculates and returns the amount of dark space in an LEB that has spc bytes of free and dirty space. that's the whole vibe check 🔥

now, what even is dark space? glad you asked, because it's giving "space that might not be usable." UBIFS is out here trying to account for all of it — like, it's keeping track of the square footage that just isn't gonna work out for anybody. and that space? we call it "dark space." spooky name, very practical concept 💀

the example i need you to internalize: if an LEB has only 512 free bytes, that's dark space, because it cannot fit a large data node. like, sweetie, there's just not enough room 😭 the space is there but it's not useful space, and that's the whole point — she's counting the space that's technically free but functionally pointless. no cap 🎯

👀 SEE ALSO 👀

okay this list is long, so buckle up, we're doing the whole squad, all from the Kernel file ./fs/ubifs/lprops.c:

like i said. the whole squad. go read them, they're all obsessed with property accounting too 🧚💜

lowkey if you only remember one thing: spc goes in, dark space comes out, and small leftover free bytes are still "dark" because nothing big fits in them. periodt 💅

and that's the page, bestie!! 🌈 this one's from ./fs/ubifs, dated October 2026, and it's filed under ubifs_calc_dark(9) — mwah, go be great, and remember: dark space is real and it's coming for your free bytes 🍓⭐

📦 where this page comes from