dbg_check_key_order(9)

📦 version 7.3.1, in nixpkgs unstable

💅 dbg_check_key_order(9)

okay so real talk, this one lives in the Kernel API Manual and bestie, it's lowkey a vibe-checker for your B-tree keys. Let's get into it ✨

🌸 NAME 🌸

dbg_check_key_order — literally makes sure that those colliding keys are properly ordered. no cap, that's the whole job 🎀

🦋 SYNOPSIS 🦋

int dbg_check_key_order (struct ubifs_info *c , struct ubifs_zbranch
*zbr1 , struct ubifs_zbranch *zbr2 );

look at that signature, it's giving "three arguments and a dream" 💖

✨ ARGUMENTS ✨

  • c — the UBIFS file-system description object. iconic. she holds everything together 👑
  • zbr1 — the first zbranch, aka the one that's supposed to come first 🥇
  • zbr2 — the following zbranch, aka the one that's supposed to come after 🥈

💜 DESCRIPTION 💜

okay so here's the tea ☕ — in UBIFS indexing B-tree, colliding keys have to be sorted in binary order of the names of the direntries/xentries that those keys refer to. that's the rule, periodt.

so what does this function do? she reads the direntries/xentries referred to by zbr1 and zbr2 and makes sure the name of the direntry/xentry referred to by zbr1 is less than the direntry/xentry referred to by zbr2. that's it. that's the whole assignment 💅

and the returns, bestie, pay attention:

  • returns zero if that's true (slay ✅)
  • returns 1 if it's not true (uh oh 🙈)
  • returns a negative error code in case of failure (and we don't talk about that 💀)

🌈 SEE ALSO 🌈

the whole friend group 🫶 she's in the kernel file ./fs/ubifs/debug.c, and here's everybody else:

and that's the page, bestie 🧚💖 this lore drop came from ./fs/ubifs, dated October 2026, filed under dbg_check_key_order(9) — mwah, go check those key orders, ily, bye 🍓

📦 where this page comes from