i_uid_into_vfsuid(9)

💅 i_uid_into_vfsuid — Kernel API Manual, bestie ✨

okay so picture this: you're deep in Kernel API Manual territory and you need to take an inode's i_uid and map it down according to an idmapping. that's the whole gig. that's the function. let me break it down 🫶

---

✨ NAME ✨

i_uid_into_vfsuid — map an inode's i_uid down according to an idmapping 💖

---

🌸 SYNOPSIS 🌸

vfsuid_t i_uid_into_vfsuid (struct mnt_idmap *idmap , const struct inode
       *inode );

---

🎀 ARGUMENTS 🎀

• idmap — the idmap of the mount that the inode was found from. like, which mount are we even talking about, yknow? that one. 💫
• inode — the inode we're mapping. the little guy in question. 🌟

---

🦋 RETURN 🦋

you get back the inode's i_uid mapped down according to idmap. slay. 💅

but listen — if the inode's i_uid has no mapping, you get INVALID_VFSUID back instead. no cap, that's the failure mode, so handle it bestie 😭

---

🌈 SEE ALSO 🌈

all of these live in the kernel file ./include/linux/fs.h, and honestly it's giving main character energy, so here's the whole squad in order 👑:

• enum positive_aop_returns(9)
• struct address_space(9)
• struct file_ra_state(9)
• struct file(9)
• i_uid_needs_update(9)
• i_uid_update(9)
• i_gid_into_vfsgid(9)
• i_gid_needs_update(9)
• i_gid_update(9)
• inode_fsuid_set(9)
• inode_fsgid_set(9)
• fsuidgid_has_mapping(9)
• inode_set_ctime(9)
• file_write_started(9)
• file_write_not_started(9)
• struct renamedata(9)
• is_mgtime(9)
• iput_if_not_last(9)
• is_idmapped_mnt(9)
• file_start_write(9)
• file_end_write(9)
• kiocb_start_write(9)
• kiocb_end_write(9)
• name_is_dot_dotdot(9)
• name_contains_dotdot(9)
• inode_dio_begin(9)
• inode_dio_end(9)
• generic_ci_validate_strict_name(9)

---

okay that's the whole page, you ate that 🍓 this one comes to you straight from ./include/linux, dated October 2026, and it's filed under i_uid_into_vfsuid(9) — go forth and map responsibly, ily 💜✨