fscache_update_cookie(9)

📦 version 7.3.1, in nixpkgs unstable

okay so real talk, bestie — this one is a kernel API page, which sounds scary but it's literally just "hey cache, pls refresh ur notes about this object." No cap. Let's get into it 💅

🌸 NAME 🌸

fscache_update_cookie — request that a cache object be updated ✨

🎀 SYNOPSIS 🎀

void fscache_update_cookie (struct fscache_cookie *cookie , const void
*aux_data , const loff_t *object_size );

like, that's the whole signature. she's serving void — she returns nothing, she just does the thing. main character energy fr fr 💜

🦋 ARGUMENTS 🦋

  • cookie — the cookie representing the cache object 🍪 like yes bestie, the actual handle for the thing in the cache
  • aux_data — the updated auxiliary data for the cookie (may be NULL) — so it's optional, she can be null, she's allowed 🙈
  • object_size — the current size of the object (may be NULL) — also optional, also allowed to be null, we love a flexible parameter ✨

💖 DESCRIPTION 💖

so what she does: she requests an update of the index data for the cache object associated with the cookie. that's the vibe. 🫶

the way the order works — and this is important, iykyk — the auxiliary data on the cookie gets updated first if aux_data is set, and then the object size gets updated, and the object possibly gets trimmed, if object_size is set. so like, aux data first, then size + possible trim. periodt. 👑

and if you want the complete description (the full lore, the director's cut), go read Documentation/filesystems/caching/netfs-api.rst. it's all there, bestie, i promise 📖💫

🌈 SEE ALSO 🌈

kernel file ./include/linux/fscache.h — that's where she lives, that's her home 🏠💜

and the whole friend group, the entire fscache squad, no one left out:

like?? the whole roster. ate. 🔥

lowkey a reminder that aux_data and object_size are both allowed to be NULL — that's not a bug, that's the API being chill. check before you assume, bestie 💀

okay that's the page!! 🎀 this one's from ./include/linux, dated October 2026, and it's the fscache_update_cookie(9) page from the Kernel API Manual. slay, go update ur cookies 💅✨🦋

📦 where this page comes from