bio_add_page(9)

💫 bio_add_page(9) 💫

okay so this is a page straight out of the Kernel API Manual, and it's literally all about bio_add_page — the little function that tries to shove page(s) into a bio 🫶

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✨ NAME ✨

bio_add_page — attempt to add page(s) to bio

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🎀 SYNOPSIS 🎀

int bio_add_page (struct bio *bio , struct page *page , unsigned int len
, unsigned int offset );

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🌸 ARGUMENTS 🌸

• bio — the destination bio, aka where the pages are headed 💌
• page — the start page you're adding
• len — the vec entry length, and ngl it may cross pages
• offset — the vec entry offset relative to the page, which, bestie, may also cross pages

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🦋 DESCRIPTION 🦋

So the whole vibe here is: attempt to add page(s) to the bio_vec maplist ✨

And it will only fail in two situations, no cap:

1. bio->bi_vcnt == bio->bi_max_vecs
2. it's a cloned bio

like... that's it. that's the whole failure criteria. if neither of those is true, it slays 💅

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🔥 SEE ALSO 🔥

Kernel file ./block/bio.c, plus the whole friend group:

• bio_reset(9)
• bio_reuse(9)
• bio_chain(9)
• bio_chain_and_submit(9)
• bio_alloc_bioset(9)
• bio_kmalloc(9)
• bio_truncate(9)
• guard_bio_eod(9)
• bio_put(9)
• bio_alloc_clone(9)
• bio_init_clone(9)
• bio_full(9)
• __bio_add_page(9)
• bio_add_virt_nofail(9)
• bio_add_folio(9)
• bio_add_vmalloc_chunk(9)
• bio_add_vmalloc(9)
• bio_iov_iter_get_pages(9)
• bio_iov_iter_bounce(9)
• bio_iov_iter_unbounce(9)
• bio_await(9)
• submit_bio_wait(9)
• bdev_rw_virt(9)
• bio_copy_data(9)
• bio_endio(9)
• bio_split(9)
• bio_trim(9)
• bioset_init(9)

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okay that's the whole page!! 🎀 this came from the ./block corner of the kernel and it's dated October 2026 — mwah, iconic, no notes 💖✨🌷