ceph_cls_lock(9)

💅 ceph_cls_lock(9) — the Kernel API Manual, bestie edition 🎀

okay so this is page ceph_cls_lock(9) from the Kernel API Manual, and it's literally about grabbing a rados lock for an object. yes bestie, we're doing kernel locking today, put your hair up 💖

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✨ NAME ✨

ceph_cls_lock — grab rados lock for object 🔒

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✨ SYNOPSIS ✨

int ceph_cls_lock (struct ceph_osd_client *osdc , struct ceph_object_id
*oid , struct ceph_object_locator *oloc , char *lock_name , u8 type ,
char *cookie , char *tag , char *desc , u8 flags );

it returns an int, and the way that this signature is LONG — nine whole parameters, she's highkey doing the most 😭 but we love her for it 🫶

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✨ ARGUMENTS ✨

• osdc — the OSD client instance, aka your main character struct 💅
• oid — the object you wanna lock 👑
• oloc — the object you wanna lock (yes, same description as oid, no bestie I'm not messing with you, that's literally what it says 🙈)
• lock_name — the name of the lock, give her a name, she deserves one 🎀
• type — the lock type, and it's either CEPH_CLS_LOCK_EXCLUSIVE or CEPH_CLS_LOCK_SHARED — pick one, queen 🌈
• cookie — a user-defined identifier for this instance of the lock 🍓
• tag — a user-defined tag, remember this one, she comes back in the description 👀
• desc — a user-defined lock description ✨
• flags — lock flags, that's it, that's the vibe 🦋

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✨ DESCRIPTION ✨

okay so here's the one (1) actual rule and it's important, no cap:

all operations on the same lock should use the same <italic>tag</italic> 💀

like literally, if you're touching the same lock from different places, keep the tag consistent. consistency is iconic, inconsistency is giving chaos 😭

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✨ SEE ALSO ✨

• the Kernel file ./net/ceph/cls_lock_client.c — that's where the real lore lives 📖
• ceph_cls_unlock(9) — for when you're done holding the lock, let her go 🕊️
• ceph_cls_break_lock(9) — for when you gotta be dramatic about it 💅

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that's the whole page bestie, short and sweet, hope you slayed ✨

mwah 💖 — this has been ./net/ceph, October 2026, from the Kernel API Manual. catch you in the next ceph_cls_lock(9), ily 🫶