get_mergeable_locked(9)

🌸 get_mergeable_locked(9) 🌸

okay bestie, welcome to the Kernel API Manual — yes, that's the whole manual name, we're fancy here 💅. This page is all about get_mergeable_locked, which is genuinely such a vibe: it's the function that goes "hmm, has somebody already queued up a bio that my bio could smoosh into?" 🫶

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✨ NAME ✨

get_mergeable_locked — literally goes looking for an already queued bio that the current bio can be merged with. that's it. that's the whole job. icon behaviour honestly 👑

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🦋 SYNOPSIS 🦋

struct vio * get_mergeable_locked (struct int_map *map , struct vio *vio
, bool back_merge );

like yes she takes three args and returns a struct vio *, we been knew 💖 (the spacing in there is exactly how the original has it, do not come for me 🙈)

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🎀 ARGUMENTS 🎀

• map — the bio map to use for merging. your lookup zone, your little matchmaking directory 🗂️
• vio — the vio we want to merge. this is the main character of the operation, the one we're trying to pair up 💫
• back_merge — set to true for a back merge, false for a front merge. yes it's a boolean, yes you have to pick a side 🎯

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💀 DESCRIPTION 💀

so there are two types of merging possible: forward and backward 🌈. the way you tell them apart is a flag — and that flag uses kernel elevator terminology, which is such a specific little detail but okay go off, storage stack 🛗✨

like that's genuinely the whole scope of this function's documentation and tbh? respect. no fluff, no filler, just merging facts 🔥

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⭐ RETURN ⭐

returns the vio to merge to 🫶 — and if no merging is possible, you get NULL. that's your "no match found, bestie, better luck next bio" moment 😭

ngl, always check for the NULL. it's giving "left on read" energy and you do not want to dereference that 💀

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🌸 SEE ALSO 🌸

• kernel file ./drivers/md/dm-vdo/io-submitter.c — the source, the origin, the mothership 🧚
• count_all_bios(9)
• assert_in_bio_zone(9)
• send_bio_to_device(9)
• vdo_submit_vio(9)
• get_bio_list(9)
• submit_data_vio(9)
• try_bio_map_merge(9)
• vdo_submit_data_vio(9)
• __submit_metadata_vio(9)
• vdo_submit_metadata_vio_wait(9)
• vdo_make_io_submitter(9)
• vdo_cleanup_io_submitter(9)
• vdo_free_io_submitter(9)

all of these are your little friends, read them too iykyk 🦋

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💜 that's the whole page! this one lives in ./drivers/md/dm-vdo, dated October 2026, and its man page name is get_mergeable_locked(9) — go forth and merge responsibly, bestie, you've got this 🎀✨🌸