ilookup5_nowait(9)

💅 ilookup5_nowait(9) — like, the inode-cache search girlie

okay so this is a page from the Kernel API Manual (9 section, kernel girlies know) and it's all about ilookup5_nowait — searching for an inode in the inode cache, but make it unbothered ✨

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🎀 NAME 🎀

ilookup5_nowait — search for an inode in the inode cache. that's it, that's the vibe 🦋

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✨ SYNOPSIS ✨

struct inode * ilookup5_nowait (struct super_block *sb , u64 hashval ,
int (*test)(struct inode *, void *) , void *data , bool *isnew );

like, look at her. five args, no waiting, main character energy 👑

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🌸 ARGUMENTS 🌸

• sb — the super block of the file system you're searching, bestie. that's your whole search domain 💖
• hashval — the hash value (usually the inode number) you're looking for ✨
• test — the callback used for comparisons between inodes. it's the little matchmaker doing the "are you the one" check 🫶
• data — an opaque data pointer you pass along to test. it's giving wingman 🌈
• isnew — return argument telling whether I_NEW was set when the inode was found in hash — and heads up, the caller needs to wait for I_NEW to clear 😭

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💜 DESCRIPTION 💜

So you search for the inode specified by hashval and data in the inode cache. literally that's the job 💅

and if the inode is in the cache? it gets returned with an incremented reference count 🔥 iconic behaviour, no notes.

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💀 NOTE 💀

okay this is the part where I need you to focus bestie:

I_NEW is not waited upon, so you have to be very careful what you do with the returned inode. you probably should be using ilookup5 instead 👀

like—the function just hands you the inode and dips. no gatekeeping, no waiting. so be careful, fr fr 🙈

Note2: test is called with the inode_hash_lock held, so it can't sleep 😴🚫 — do not try it, do not pass go, do not collect a hundred dollars.

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🦋 SEE ALSO 🦋

Kernel file ./fs/inode.c and honestly the whole inode friend group came through:

• inode_init_always_gfp(9)
• alloc_inode(9)
• drop_nlink(9)
• clear_nlink(9)
• set_nlink(9)
• inc_nlink(9)
• inode_sb_list_add(9)
• __insert_inode_hash(9)
• __remove_inode_hash(9)
• evict_inodes(9)
• new_inode(9)
• unlock_new_inode(9)
• lock_two_nondirectories(9)
• unlock_two_nondirectories(9)
• inode_insert5(9)
• iget5_locked(9)
• iget5_locked_rcu(9)
• iget_locked(9)
• iunique(9)
• ihold(9)
• ilookup5(9)
• ilookup(9)
• find_inode_nowait(9)
• find_inode_rcu(9)
• find_inode_by_ino_rcu(9)
• iput(9)
• iput_not_last(9)
• bmap(9)
• inode_update_time(9)
• generic_update_time(9)
• atime_needs_update(9)
• file_remove_privs(9)
• current_time(9)
• file_update_time(9)
• file_modified_flags(9)
• file_modified(9)
• kiocb_modified(9)
• inode_init_owner(9)
• inode_owner_or_capable(9)
• inode_dio_wait(9)
• timestamp_truncate(9)
• inode_set_ctime_current(9)
• inode_set_ctime_deleg(9)
• in_group_or_capable(9)
• mode_strip_sgid(9)
• dump_inode(9)

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and that's the whole page, bestie 💖 mwah. this one lives in ./fs, stamped October 2026, and it's ilookup5_nowait(9) — go be careful with your reference counts, ily 🎀🫶