nilfs_sufile_set_suinfo(9)

💖 nilfs_sufile_set_suinfo(9) 💖

ok so this is a page from the Kernel API Manual — yes bestie, we're in kernel land today, put your hair up, we're going in 🧚✨

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✨ NAME ✨

nilfs_sufile_set_suinfo — sets segment usage info 🎀

like, it literally updates the segment usage info. that's the whole vibe. no cap.

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🌸 SYNOPSIS 🌸

ssize_t nilfs_sufile_set_suinfo (struct inode *sufile , void *buf ,
       unsigned int supsz , size_t nsup );

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🦋 ARGUMENTS 🦋

• sufile — the inode of the segment usage file 💅 that's your main character right there.
• buf — an array of suinfo_update 👑 yes, an array, plural energy.
• supsz — the byte size of a suinfo_update 📏 (one of them, not the whole pile)
• nsup — the size of the suinfo_update array 🌈 i.e. how many of them you're handing over.

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💜 DESCRIPTION 💜

okay so picture this: you hand it an array of nilfs_suinfo_update structs, and it updates the segment usage accordingly. that's it. that's the function. ate and left no crumbs 🔥

but here's the important part, bestie — only the fields indicated by the sup_flags get updated. the way that it's selective?? iconic. it will not touch what you didn't ask it to touch 🙈

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⭐ RETURN ⭐

0 on success 🎉 or one of these negative error codes when it's not giving:

• -EINVAL — invalid values in the input 💀 specifically the segment number, flags or nblocks. check your inputs before you come at it like that.
• -EIO — I/O error 😭 and yes, that includes metadata corruption, so like… be aware.
• -ENOMEM — not enough memory available 🫶 the classic. insufficient memory, insufficient vibes.

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🍓 SEE ALSO 🍓

• Kernel file ./fs/nilfs2/sufile.c 📁 (the source, the origin story)
• struct nilfs_sufile_info(9)
• nilfs_sufile_segment_usage_offset(9)
• nilfs_sufile_get_ncleansegs(9)
• nilfs_sufile_updatev(9)
• nilfs_sufile_set_alloc_range(9)
• nilfs_sufile_alloc(9)
• nilfs_sufile_mark_dirty(9)
• nilfs_sufile_set_segment_usage(9)
• nilfs_sufile_get_stat(9)
• nilfs_sufile_truncate_range(9)
• nilfs_sufile_resize(9)
• nilfs_sufile_get_suinfo(9)
• nilfs_sufile_trim_fs(9)
• nilfs_sufile_read(9)

like, the whole sufile friend group 🫶 go read all of them, iykyk 💅

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and that's the page!! mwah 💋 sourced straight from ./fs/nilfs2, dated October 2026 — so like, freshly stamped, go forth and set that suinfo bestie 🌟🦋💖