offset_readdir(9)

📦 version 7.3.1, in nixpkgs unstable

💖 offset_readdir(9) 💖

okay bestie, welcome to offset_readdir — straight out of the Kernel API Manual, and yes it's a section 9 page so it's ~kernel internals~ core, we're in the big leagues now 🫶

✨ NAME ✨

offset_readdir — emit entries starting at offset @ctx->pos 💅

✨ SYNOPSIS ✨

int offset_readdir (struct file *file , struct dir_context *ctx );

✨ ARGUMENTS ✨

  • file — an open directory that we're gonna iterate over 📂
  • ctx — the directory iteration context, aka the vibe tracker for where we're at 👑

✨ DESCRIPTION ✨

so the caller must hold the file's i_rwsem — like, non-negotiable — because that's literally what stops entries from being inserted or removed while this call is running 😤 no cap, that's the whole point.

On entry, ctx->pos holds an offset that represents the first entry to be read from the directory ✨

Then the operation just keeps going — until there are no more entries to read, or until the ctx->actor says there's no more space in the caller's output buffer, whichever hits first 🫠

On return, ctx->pos contains an offset that will read the next entry in this directory when offset_readdir gets called again with ctx 🔁 the caller then places this value in the d_off field of the last entry in the user's buffer. yeah. that's the ritual. 🕯️

Return values: 0 - Complete ✅

✨ SEE ALSO ✨

Kernel file ./fs/libfs.c has the whole friend group, and honestly they all ate:

okay that's the page!! 💖 this one came from ./fs, dated October 2026, and it's filed under offset_readdir(9) — slay, go read some directories babes 🌸🦋

📦 where this page comes from