nilfs_ioctl_do_get_suinfo(9)

📦 version 7.3.1, in nixpkgs unstable

💅 nilfs_ioctl_do_get_suinfo — the kernel API manual, but make it make sense

okay so bestie, this is a page from the Kernel API Manual (section 9, kernel-land, not your regular man 1 situation) and the star of the show is nilfs_ioctl_do_get_suinfo. it's literally the callback method that gets segment usage info. that's the whole vibe. let's get into it 🎀

✨ NAME ✨

nilfs_ioctl_do_get_suinfo — the callback method that goes and gets segment usage info. yep, that's her job description. 💅

🌸 SYNOPSIS 🌸

ssize_t nilfs_ioctl_do_get_suinfo (struct the_nilfs *nilfs , __u64 *posp
, int flags , void *buf , size_t size , size_t nmembs );

like, look at that signature. so many parameters. she's got range. 🦋

🫶 ARGUMENTS 🫶

  • nilfs — the nilfs object. the main character, honestly.
  • posp — a pointer on an array of segment numbers. it's giving "here's the list, go off" ✨
  • flags — not used. literally ignored. she said "no thoughts, head empty" 🙈
  • buf — the buffer for storing the suinfo array. this is where the goods land.
  • size — the size in bytes of one suinfo item in the array. one (1) single item. measure twice.
  • nmembs — the count of segment numbers and suinfos in the array. yes, both. they're matching. 👑

💖 DESCRIPTION 💖

so the nilfs_ioctl_do_get_suinfo function returns segment usage info about the requested segments. like, you ask about segments, it hands you the tea about those segments. periodt.

the NILFS_IOCTL_GET_SUINFO ioctl is what's used in lssu, nilfs_resize utilities and by the nilfs_cleanerd daemon. so yeah, she's booked and busy — multiple clients, one icon. 🔥

⭐ RETURN ⭐

on success? it returns the count of nilfs_suinfo structures in the output buffer. slay.

on failure? a negative error code. 😭 not the negative energy. handle your errors, bestie.

🦋 SEE ALSO 🦋

the whole friend group, no cap:

ok that's the whole page, go read the source, ily 💜

and that's a wrap, bestie 🎀 this one lives in ./fs/nilfs2, it's dated October 2026, and you can find her under nilfs_ioctl_do_get_suinfo(9) in the Kernel API Manual. mwah. 💋✨

📦 where this page comes from