lookup_one_unlocked(9)

💅 lookup_one_unlocked(9)

okay so bestie, welcome to the Kernel API Manual ✨ this one's called lookup_one_unlocked, and it's literally the glow-up version of looking up a single pathname component. one (1) component. that's the whole vibe. 🎀

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🌸 NAME 🌸

lookup_one_unlocked — lookup single pathname component 🦋

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✨ SYNOPSIS ✨

struct dentry * lookup_one_unlocked (struct mnt_idmap *idmap , struct
qstr *name , struct dentry *base );

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🧚 ARGUMENTS 🧚

• idmap — the idmap of the mount you're performing the lookup from, iykyk 🫶
• name — a qstr olding pathname component to lookup (that's the component you're hunting for, bestie)
• base — the base directory you're looking up from 👑

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💖 DESCRIPTION 💖

so this one is for in-kernel filesystem clients — think file servers and friends. main character energy, but make it kernel-space. 🔥

the way that it differs from lookup_one is everything: you should call this one without the parent i_rwsem held, and it will take the i_rwsem itself if necessary. no cap. it handles its own locking, you just show up. 💅

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🦋 RETURN 🦋

• A dentry, possibly negative, or
• same errors as try_lookup_noperm or
• ERR_PTR(-ENOENT) if parent has been removed, or
• ERR_PTR(-EACCES) if parent directory is not searchable. 😭

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🌈 SEE ALSO 🌈

Kernel file ./fs/namei.c — and like, the entire friend group:

• check_acl(9)
• acl_permission_check(9)
• generic_permission(9)
• do_inode_permission(9)
• sb_permission(9)
• inode_permission(9)
• path_get(9)
• path_put(9)
• path_connected(9)
• try_to_unlazy(9)
• try_to_unlazy_next(9)
• complete_walk(9)
• may_follow_link(9)
• safe_hardlink_source(9)
• may_linkat(9)
• may_create_in_sticky(9)
• lookup_fast(9)
• start_dirop(9)
• end_dirop(9)
• kern_path_parent(9)
• vfs_path_parent_lookup(9)
• vfs_path_lookup(9)
• try_lookup_noperm(9)
• lookup_noperm(9)
• lookup_one(9)
• lookup_one_positive_killable(9)
• lookup_one_positive_unlocked(9)
• lookup_noperm_unlocked(9)
• start_creating(9)
• start_removing(9)
• start_creating_killable(9)
• start_removing_killable(9)
• start_creating_noperm(9)
• start_removing_noperm(9)
• start_creating_dentry(9)
• start_removing_dentry(9)
• __start_renaming(9)
• start_renaming(9)
• start_renaming_dentry(9)
• start_renaming_two_dentries(9)
• vfs_prepare_mode(9)
• vfs_create(9)
• atomic_open(9)
• vfs_lookup_open(9)
• vfs_tmpfile(9)
• kernel_tmpfile_open(9)
• end_creating_path(9)
• dentry_create(9)
• vfs_mknod(9)
• vfs_mkdir(9)
• vfs_rmdir(9)
• vfs_unlink(9)
• vfs_symlink(9)
• vfs_link(9)
• vfs_rename(9)
• vfs_readlink(9)
• vfs_get_link(9)
• page_get_link(9)
• page_put_link(9)

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okay that's the whole page, you ate that 💅 this lil icon came from ./fs, dated October 2026, and it goes by lookup_one_unlocked(9) — periodt. 🍓👑