submit_cache_miss_req(9)

💅 submit_cache_miss_req(9) — Kernel API Manual 🦋

🌸 NAME 🌸

submit_cache_miss_req — submit a backing request when cache data is missing. literally the “bestie, the cache missed” rescue mission 💖

✨ SYNOPSIS ✨

void submit_cache_miss_req (struct pcache_cache *cache , struct
       pcache_backing_dev_req *backing_req );

🎀 ARGUMENTS 🎀

• cache — the cache context that manages cache operations. It’s the main-character cache brain running the show 👑.
• backing_req — the cache request containing information about the read request. read-request receipt vibes 🧾.

💖 DESCRIPTION 💖

okay so picture this, bestie: a cache read request shows up and it cannot locate the required data in the cache. That’s the miss. 😭 When this kind of miss happens during cache_subtree_walk, it triggers a backing read request to fetch data from the backing storage. No cap, that’s the whole rescue arc 🌈.

If pcache_req->priv_data is set, it points to a pcache_cache_key, representing a new cache key to be inserted into the cache. The function calls cache_key_insert to attempt adding the key. On insertion failure, it releases the key reference and clears priv_data to avoid further processing. Important caveat: that failure path is real, bestie — on insertion failure the key reference gets released and priv_data gets cleared, periodt 💅.

🔥 SEE ALSO 🔥

Kernel file ./drivers/md/dm-pcache/cache_req.c: cache_data_alloc(9), miss_read_end_req(9), read_walk_finally(9), cache_read(9), pcache_cache_flush(9). Go give these icons a look 👀✨

mwah 🫶 this page is from the ./drivers/md/dm-pcache source, version date October 2026, and it’s all about submit_cache_miss_req(9) 💖