vfs_ioctl(9)

💅 vfs_ioctl(9) — Kernel API Manual

okay so bestie, welcome to the vfs_ioctl(9) page 💖 this one lives in the Kernel API Manual and honestly? it's a little one-trick pony but it ate. let's get into it.

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✨ NAME ✨

vfs_ioctl — call filesystem specific ioctl methods 🎀

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🌸 SYNOPSIS 🌸

int vfs_ioctl (struct file *filp , unsigned int cmd , unsigned long arg );

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🦋 ARGUMENTS 🦋

• filp — the open file you're gonna invoke the ioctl method on, like the main character of this whole operation 👑
• cmd — the ioctl command to execute, i.e. which thing you want done ✨
• arg — the command-specific argument for the ioctl, so like, the lil extra detail your command needs 🫶

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💜 DESCRIPTION 💜

okay so what it does: it invokes the filesystem specific ->unlocked_ioctl, if one exists. that's the whole vibe. 🧚

but if there's no ->unlocked_ioctl? it does not improvise, bestie — it just returns -ENOTTY. no method, no service. 💀

Returns 0 on success, -errno on error. that's it, that's the tea ☕

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🌈 SEE ALSO 🌈

• Kernel file ./fs/ioctl.c
• fiemap_fill_next_extent(9)
• fiemap_prep(9)
• compat_ptr_ioctl(9)

go read those next, iykyk 📚✨

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and that's the page!! 🎀 tysm for reading, this came from the source ./fs, dated October 2026, and it's your girl vfs_ioctl(9) signing off — mwah 💋✨