xenbus_watch_path(9)

💅 xenbus_watch_path(9) — like, the kernel API manual edition 🎀

okay bestie, welcome to the xenbus_watch_path page, straight out of the Kernel API Manual. this one's a little function that registers a watch, and honestly? she's giving "small but mighty." let's get into it ✨

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✨ NAME ✨

xenbus_watch_path — register a watch 🫶

✨ SYNOPSIS ✨

int xenbus_watch_path (struct xenbus_device *dev , const char *path ,
struct xenbus_watch *watch , bool (*will_handle)(struct xenbus_watch *,
const char *, const char *) , void (*callback)(struct xenbus_watch *,
const char *, const char *) );

✨ ARGUMENTS ✨

• dev — the xenbus device, your main character for this call 👑
• path — the path to watch, like literally the thing you're keeping eyes on 🌸
• watch — the watch to register, this is the storage bestie 💖
• will_handle — events queuing determine callback, i.e. the function that decides whether each event needs to be queued 🤔
• callback — callback to register, the one that actually gets called 🎀

✨ DESCRIPTION ✨

so what she does is: register a watch on the given path, using the given xenbus_watch structure for storage, with will_handle function as the callback to determine if each event need to be queued, and the given callback function as the callback. periodt 💅

On success, the given path will be saved as watch->node, and remains the caller's to free — yes bestie, yours to free, don't forget 😭

On error, watch->node will be NULL, the device will switch to XenbusStateClosing, and the error will be saved in the store. so like... not the vibe, but at least it's documented 💀

✨ RETURN ✨

0 on success or -errno on error. slay when it's zero, sad girl hours when it's not 🥲

✨ SEE ALSO ✨

• Kernel file ./drivers/xen/xenbus/xenbus_client.c
• xenbus_watch_pathfmt(9)
• xenbus_switch_state(9)
• xenbus_dev_error(9)
• xenbus_dev_fatal(9)
• xenbus_map_ring_valloc(9)
• xenbus_unmap_ring(9)
• xenbus_unmap_ring_vfree(9)
• xenbus_read_driver_state(9)

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and that's the page!! 🦋 mwah, go read the neighbours too, they're all icons fr fr 💜

that's a wrap from ./drivers/xen/xenbus, dated October 2026, xenbus_watch_path(9) — catch you in the next manpage bestie 🌈⭐