__jbd2_journal_erase(9)

📦 version 7.3.1, in nixpkgs unstable

💅 __jbd2_journal_erase — the kernel API manual, bestie edition ✨

Okay so welcome to __jbd2_journal_erase(9), the page where we literally wipe journal blocks clean. Grab a snack, this one's short and cute 🍓

🌸 NAME 🌸

__jbd2_journal_erase — the function that discards or zeroouts journal blocks (and like, not the superblock, she's exempt, she's booked and busy, main character energy 👑)

✨ SYNOPSIS ✨

int __jbd2_journal_erase (journal_t *journal , unsigned int flags );

That's the whole vibe. An int comes back, you hand her a journal_t *journal and an unsigned int flags, and she handles it 🫶

🎀 ARGUMENTS 🎀

  • journal — the journal to erase. That's the one. The target. The moment 💅
  • flags — okay so a discard/zeroout request gets sent for each physically contigous region of the journal. (yes, that's how the original spells "contiguous" — we do not fix, we respect ⭐) Either JBD2_JOURNAL_FLUSH_DISCARD or JBD2_JOURNAL_FLUSH_ZEROOUT must be set, because that's literally how she knows which operation to perform. No flag, no vibe check passed, bestie 🙈

🔥 NOTE 🔥

JBD2_JOURNAL_FLUSH_ZEROOUT attempts to use hardware offload. But if there's no hardware offload available, the zeroes get explicitly written anyway — so it still slays, just manually. See blkdev_issue_zeroout for more details 💖

Fr fr though: no hardware offload ≠ no zeros. She writes them herself. Iconic behaviour, no cap.

🌈 SEE ALSO 🌈

Kernel file ./fs/jbd2/journal.c — and here's the whole friend group, all of them listed, all of them linked, all of them invited to the group chat 😭💀

That's the page, bestie, you ate 🍓🦋

Source: ./fs/jbd2 · Date: October 2026 · Doc name: __jbd2_journal_erase(9) — mwah, kiss kiss, go erase some blocks 💜✨

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