bpf_real_data_inode(9)

💅 bpf_real_data_inode(9) — the Kernel API Manual, bestie edition 🎀

okay so real talk, this is a page out of the Kernel API Manual and it's about bpf_real_data_inode(9) — the little kfunc that tells you which inode actually holds a file's data. it's giving "who is she really" energy and honestly? obsessed. ✨

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🌸 NAME 🌸

bpf_real_data_inode — get the real inode hosting a file's data. that's it, that's the whole vibe. no cap. 💖

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🦋 SYNOPSIS 🦋

__bpf_kfunc struct inode * bpf_real_data_inode (struct file *file );

look at that signature, so clean, so iconic. 👑

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🎀 ARGUMENTS 🎀

• file — the file to resolve. literally just hand it the file and let it do its thing. that's the whole ask. 🫶

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💜 DESCRIPTION 💜

okay so here's the tea. 🍵

bpf_real_data_inode resolves file to the inode that hosts its data.

for a regular file sitting on a union/overlay filesystem, what you get back is the underlying inode — upper or lower — that actually stores the data, not the overlay inode. like, the real one. the one doing the work. main character inode energy fr fr. 💅

but here's the caveat bestie, listen up: data resolution only applies to regular files. so:

• for a non-regular file (think a device node, a fifo or a socket — the weird kids 😭) on a union/overlay filesystem, you just get the overlay inode itself returned. no digging, no peeling back the layers.
• for any file on a non-union filesystem, you get the inode that's attached to file. simple, straightforward, slay.

like, it's a vibe check for inodes and the answer depends entirely on what kind of file you're dealing with. iykyk. ✨

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⭐ RETURN ⭐

the inode hosting file's data. or NULL. that's the whole range, king. 👑 (NULL absolutely counts as an answer, don't come for her 🙈)

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🌈 SEE ALSO 🌈

kernel file ./fs/bpf_fs_kfuncs.c — go read it, it's right there, it's giving source material. 📖

and the whole friend group, because nobody does it alone:

• bpf_get_task_exe_file(9)
• bpf_put_file(9)
• bpf_path_d_path(9)
• bpf_get_dentry_xattr(9)
• bpf_get_file_xattr(9)
• bpf_set_dentry_xattr_locked(9)
• bpf_remove_dentry_xattr_locked(9)
• bpf_set_dentry_xattr(9)
• bpf_remove_dentry_xattr(9)
• bpf_cgroup_read_xattr(9)
• bpf_sock_read_xattr(9)

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✨ friendly reminder that this page lives under ./fs and it's dated October 2026 — so if you're reading this and the year is wrong for you, that's a you problem, not a her problem. 💀

okay bye bestie, go resolve some inodes, drink some water, and remember: the overlay inode is not the real one and you deserve the truth. 💖🦋🌸💅🫶🎀⭐