nilfs_cpfile_is_snapshot(9)

📦 version 7.3.1, in nixpkgs unstable

💖 nilfs_cpfile_is_snapshot(9) 💖

okay so bestie, welcome to the Kernel API Manual, section 9 — this one's a lil function from the NILFS2 world and honestly it's giving "tiny detective" energy. It's asking one very simple question: is this checkpoint a snapshot or not?? 🕵️‍♀️✨

🌸 NAME 🌸

nilfs_cpfile_is_snapshot — literally just determine if a checkpoint is a snapshot. that's it. that's the whole vibe check 🎀

🦋 SYNOPSIS 🦋

int nilfs_cpfile_is_snapshot (struct inode *cpfile , __u64 cno );

✨ ARGUMENTS ✨

  • cpfile — the inode of the checkpoint file. yep, the whole checkpoint file, that's your starting point bestie 💅
  • cno — the checkpoint number. the specific one you're asking about 👑 no cap

🔥 RETURN 🔥

so here's what comes back at you:

  • 1 — if the checkpoint specified by cno is a snapshot 🎉 slay, it's a snapshot
  • 0 — if it's not a snapshot. not today 🫶

and if things go sideways, you get one of these negative error codes instead 😭:

  • -EIO — I/O error (including metadata corruption). this one's the "something's lowkey broken in the data itself" situation, not just a lil network blip 💀
  • -ENOENT — No such checkpoint. the checkpoint you're looking for? it's not there. ghosted fr fr 🙈
  • -ENOMEM — Insufficient memory available. not enough memory to do the thing, tragic 😔

💜 SEE ALSO 💜

Kernel file ./fs/nilfs2/cpfile.c — that's the whole neighbourhood these functions live in, iykyk 🏡

the full squad of related functions, all in section 9, go like this:

and that's the whole page bestie, go check those snapshots 💖✨

lowkey reminder: 1 and 0 are your answers, and the negative codes are your "something went wrong" flags — don't get it twisted 🎀

this lil page comes straight out of ./fs/nilfs2 and is dated October 2026 — mwah, drink water, and may all your checkpoints be exactly what you expected 🧚‍♀️💜🌷

📦 where this page comes from