update_mctime(9)

💅 update_mctime(9) — like, the kernel API manual bestie 🎀

okay so real talk, this is a page from the Kernel API Manual and it's about one (1) little function that keeps your inode's timestamps looking fresh. not me being obsessed with file metadata but here we are ✨

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🌸 NAME 🌸

update_mctime — updates the mtime and the ctime of an inode. both of them. at once. slay 💅

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✨ SYNOPSIS ✨

int update_mctime (struct inode *inode );

that's it, that's the whole signature, no cap 🫶

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🦋 ARGUMENTS 🦋

• inode — the inode you wanna update, bestie. that's the one. 👑

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💖 DESCRIPTION 💖

so here's the vibe: this function updates the mtime and ctime of the inode — but only if it's not equivalent to the current time. like, if it's already giving current-time energy, it just doesn't bother. lowkey respectful of its own time ngl 😭✨

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🔥 RETURN 🔥

• 0 — success!! we ate, we left no crumbs 🎀
• a negative error code — failure, and it's giving 💀 (still negative tho, so you know something went sideways)

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👑 SEE ALSO 👑

the kernel file ./fs/ubifs/file.c and its whole friend group, fr fr:

• release_new_page_budget(9)
• release_existing_page_budget(9)
• allocate_budget(9)
• cancel_budget(9)
• populate_page(9)
• ubifs_do_bulk_read(9)
• ubifs_bulk_read(9)
• do_attr_changes(9)
• do_truncation(9)
• do_setattr(9)
• mctime_update_needed(9)

like, the whole ubifs squad is in the group chat, iykyk 🌈🫶

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and that's the page!! this lil icon lives in ./fs/ubifs, dated October 2026, and yes it's still update_mctime(9) — periodt 💜🧚⭐