securityfs_create_file(9)

💖 securityfs_create_file 💖

okay so this whole page is from the Kernel API Manual, section 9, and it's literally all about one function: securityfs_create_file. bestie, it makes a file in securityfs. that's the vibe. ✨

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🌸 NAME 🌸

securityfs_create_file — create a file in the securityfs filesystem 🎀

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🦋 SYNOPSIS 🦋

struct dentry * securityfs_create_file (const char *name , umode_t mode
, struct dentry *parent , void *data , const struct file_operations
*fops );

like, five arguments, one dentry pointer out. it's giving "small function, big responsibilities" ngl 💅

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✨ ARGUMENTS ✨

• name — a pointer to a string with the name of the file you wanna create. that's its whole thing. name it something cute 💖
• mode — the permission the file should have. yes, the permissions. you know the ones 🫶
• parent — a pointer to the parent dentry for this file. if it's set, it should be a directory dentry (obvi). and if this parameter is NULL, then the file gets created in the root of the securityfs filesystem. no parent, no problem ✨
• data — a pointer to something the caller is gonna want to get back to later on. fr fr. the inode.i_private pointer will point to this value on the open call 👀
• fops — a pointer to a struct file_operations that should be used for this file. that's the personality of the file basically 🎀

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💅 DESCRIPTION 💅

so this function creates a file in securityfs with the given name. periodt. 🦋

when it works, this function returns a pointer to a dentry. and here's the thing — you MUST pass that pointer to the securityfs_remove function when the file is to be removed. no automatic cleanup happens if your module is unloaded. none. zero. you are responsible here, bestie 💀

like literally, you're the main character of cleanup. own it 🙈

if an error occurs, the function will return the error value (via ERR_PTR). yup, error value tucked inside the pointer. iykyk 🌸

and if securityfs isn't enabled in the kernel, the value -ENODEV is returned. so if you see -ENODEV, check your kernel config before you spiral 😭

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🌈 SEE ALSO 🌈

• Kernel file ./security/inode.c — like, the source of truth 💜
• securityfs_create_dentry(9)
• securityfs_create_dir(9)
• securityfs_create_symlink(9)
• securityfs_remove(9) — the one you have to call, remember? 👑

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and that's the page!! 🎀 source & version vibes: ./security, dated October 2026, from the Kernel API Manual, section 9. slay, go write your securityfs files responsibly. mwah 💋✨