fixup_overlap_contained(9)

NAME 💖

okay bestie, welcome to the Kernel API Manual page for fixup_overlap_contained(9) — this one handles overlap when a new key is contained in an existing key. that's the name, that's the vibe, periodt. ✨

SYNOPSIS 🌸

int fixup_overlap_contained (struct pcache_cache_key *key , struct pcache_cache_key *key_tmp , struct pcache_cache_subtree_walk_ctx *ctx );

ARGUMENTS 🎀

• key — the new cache key being inserted. main character key, freshly arriving on the scene 💅
• key_tmp — the existing cache key that overlaps with the new key. the one we're checking against, iykyk.
• ctx — context for the cache tree walk. literally the walk context, no cap.

DESCRIPTION 🦋

okay so here's the tea: this function adjusts the existing key if the new key is contained within it. simple enough, right? 🫶

if the existing key is empty, that indicates a placeholder key that was inserted during a miss read. this placeholder will later be updated with real data from backing_dev, making it no longer an empty key. so it's not forever-empty, it's just waiting for its glow-up 🌈

⚠️ caveat time, bestie: if we delete key or insert a key, the structure of the entire cache tree may change, requiring a full research of the tree to find a new insertion point. yes, the tree can rearrange itself, so this is a whole situation 😭

SEE ALSO 🌟

the squad, in order:

• Kernel file: ./drivers/md/dm-pcache/cache_key.c
• cache_key_get(9)
• cache_key_destroy(9)
• cache_key_append(9)
• cache_subtree_walk(9)
• cache_subtree_search(9)
• fixup_overlap_tail(9)
• fixup_overlap_contain(9)
• fixup_overlap_head(9)
• cache_key_insert(9)
• clean_fn(9)

mwah 💋 that's the whole page, bestie — fixup_overlap_contained(9) from the ./drivers/md/dm-pcache source/version, dated October 2026, now go walk that cache tree and slay 🫶✨