jbd2_journal...sed_features(9)

📦 version 7.3.1, in nixpkgs unstable

💅 jbd2_journal...sed_features(9) — Kernel API Manual 🎀

okay bestie, welcome to the kernel API manual, this one's the jbd2_journal...sed_features(9) page and honestly it's a lil cutie — one function, checks some bits, slays, goes home. no cap. let's get into it ✨

✨ NAME ✨

jbd2_journal_check_used_features — check if features specified are used. literally that's the whole gig 🫶

🌸 SYNOPSIS 🌸

int jbd2_journal_check_used_features (journal_t *journal , unsigned long
compat , unsigned long ro , unsigned long incompat );

she takes a journal and three bitmasks and returns an int, periodt 💅

🦋 ARGUMENTS 🦋

  • journal — the journal to check. the main character of this whole operation 👑
  • compat — bitmask of compatible features. the chill ones 💖
  • ro — bitmask of features that force read-only mount. the ones that make everything go read-only, so, important 😭
  • incompat — bitmask of incompatible features. the spicy ones 🔥

🧚 DESCRIPTION 🧚

so here's the vibe: you hand her a set of features, and she checks whether the journal uses all of them. all. every single one. no partial credit, bestie 🙈

if it does use all of them, she returns true (non-zero). that's it, that's the function. iconic behavior honestly ⭐

ngl it's giving "quick bitmask check" energy and we love that for her. tiny function, big purpose. 🔥

🌈 SEE ALSO 🌈

kernel file ./fs/jbd2/journal.c — and yes, the whole friend group is here, look at this roster 🫶:

so yeah, that's the page 💜 sourced from ./fs/jbd2, dated October 2026, and filed under jbd2_journal...sed_features(9). go read the whole jbd2 saga, it's lowkey a whole universe 🌌 mwah, ily, bye 🎀✨

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