mtree_insert_range(9)

💖 NAME 💖

mtree_insert_range — bestie, this is the one that drops an entry into a range [first, last] only if there's no value there already. Like, it's not gonna fight something that's already occupying the spot. No cap. ✨

(Oh and hey, we're in the Kernel API Manual today — kernel girlies rise up 🫶)

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✨ SYNOPSIS ✨

int mtree_insert_range (struct maple_tree *mt , unsigned long first ,
unsigned long last , void *entry , gfp_t gfp );

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🎀 ARGUMENTS 🎀

• mt — the maple tree itself, the main character we're all here for 🌳👑
• first — where the range starts
• last — where the range ends, and yes it's inclusive 💅
• entry — the thing you want to store, your precious little payload 🎁
• gfp — the GFP_FLAGS used for allocations ✨

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🦋 DESCRIPTION 🦋

Okay so real talk: last is inclusive. Not "inclusive-ish", not "kinda", literally inclusive. So this is the math you want, iykyk:

last = first + length - 1

Write that down, bestie, because off-by-one errors are not the vibe 😭

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🌸 RETURN 🌸

• 0 — slayed, it worked ✨
• -EEXISTS — nope, the range is already occupied, someone got there first 💀
• -EINVAL — invalid request, like... what were you even trying to do 🙈
• -ENOMEM — couldn't allocate memory, the allocations said "not today" 😭

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💜 SEE ALSO 💜

Kernel file ./lib/maple_tree.c — and the whole friend group, fr fr:

• mas_prealloc_calc(9), mas_wr_preallocate(9), mas_insert(9), mas_alloc_cyclic(9), mas_walk(9), mte_dead_walk(9), mt_free_walk(9), mas_store(9), mas_store_gfp(9), mas_store_prealloc(9), mas_preallocate(9), mas_next(9), mas_next_range(9), mt_next(9), mas_prev(9), mas_prev_range(9), mt_prev(9), mas_pause(9), mas_find_setup(9), mas_find(9), mas_find_range(9), mas_find_rev_setup(9), mas_find_rev(9), mas_find_range_rev(9), mas_erase(9), mas_nomem(9), mas_nomem_nofail(9), mtree_load(9), mtree_store_range(9), mtree_store(9), mtree_insert(9), mtree_alloc_cyclic(9), mtree_erase(9), __mt_dup(9), mtree_dup(9), __mt_destroy(9), mtree_destroy(9), mt_find(9), mt_find_after(9)

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Reminder bestie: last = inclusive. Do NOT come crying to me when you forget. 🫶

Okay that's the whole page — from ./lib, the October 2026 edition, mwah 💋 go forth and insert those ranges responsibly 🔥