vfs_posix_acl_to_xattr(9)

🌸 NAME 🌸

Okay bestie, you're on the vfs_posix_acl_to_xattr(9) page in the Kernel API Manual, and the function is literally vfs_posix_acl_to_xattr — convert from kernel to userspace representation. No cap, that's the whole name vibe. 💅

---

✨ SYNOPSIS ✨

ssize_t vfs_posix_acl_to_xattr (struct mnt_idmap *idmap , struct inode
*inode , const struct posix_acl *acl , void *buffer , size_t size );

---

🎀 ARGUMENTS 🎀

• idmap — idmap of the mount. It's a struct mnt_idmap *, iconic.
• inode — inode the posix acls are set on. Type check: struct inode *.
• acl — the posix acls as represented by the vfs. Yes, const struct posix_acl *.
• buffer — the buffer into which to convert acl. It's void *, mysterious but valid.
• size — size of buffer. size_t behavior, fr fr.

---

🦋 DESCRIPTION 🦋

So what it actually does: this converts acl from the VFS representation in the filesystem idmapping to the uapi form reportable to userspace. And mount and caller idmappings are handled appropriately. Periodt. ✨

---

🔥 RETURN 🔥

On success, it gives you the size of the stored uapi posix acls. On error, it gives you a negative errno. That's the return vibe, no surprises. 💖

---

💜 SEE ALSO 💜

The see-also squad, no skips:

• Kernel file ./fs/posix_acl.c
• posix_acl_chmod(9)
• posix_acl_update_mode(9)
• posix_acl_from_xattr(9)
• vfs_set_acl(9)
• vfs_get_acl(9)
• vfs_remove_acl(9)

---

byeee 🫶 — source/version: ./fs, date: October 2026, page: vfs_posix_acl_to_xattr(9). Mwah! 💋