hfsplus_submit_bio(9)

💅 NAME 💅

hfsplus_submit_bio — bestie, this is literally the block I/O function, no cap ✨

---

🎀 SYNOPSIS 🎀

int hfsplus_submit_bio (struct super_block *sb , sector_t sector ,
                        void *buf , void **data , blk_opf_t opf );

---

🌸 ARGUMENTS 🌸

• sb — the super block of the volume you're doing I/O on 💖 like, this is the whole vibe of which filesystem we're talking to.
• sector — the block to read or write, measured in blocks of HFSPLUS_SECTOR_SIZE bytes. yes queen, that's the unit 🫶
• buf — the buffer for the I/O. where the data lives, basically ✨
• data — an output pointer that tells you where the requested data actually ended up. it's giving "surprise location reveal" 💅
• opf — the I/O operation type and flags. read? write? the whole little outfit 🔥

---

🦋 DESCRIPTION 🦋

okay so the unit of I/O here is hfsplus_min_io_size(sb) — and ngl, that can be bigger than HFSPLUS_SECTOR_SIZE, so buf has to be sized accordingly. don't skimp on the buffer, bestie, it will not slay 😭

On reads, data returns a pointer to the start of the requested sector, which may not be the same location as buf. so like… don't assume they're matching, because they're literally not 🙈

If sector isn't aligned to the bdev logical block size, it gets rounded down. for writes, that means buf should contain data that starts at the rounded-down address. and here's the iconic part: as long as the data was read using hfsplus_submit_bio and the same buffer is used, things will work correctly. periodt 💯

lowkey important: the alignment rounding-down is not a suggestion, it's what happens. for writes you must match your buffer to the rounded-down address or the whole thing gets weird 🫠

---

⭐ RETURN ⭐

0 on success — slay 💖 — otherwise a -errno code, which is the kernel's way of saying "not today" 💀

---

🌈 SEE ALSO 🌈

• Kernel file ./fs/hfsplus/wrapper.c — go read it, iykyk 👑

---

and that's the whole page, bestie! mwah 💋

this absolute icon of a manpage comes to you from ./fs/hfsplus, dated October 2026, and it's filed under hfsplus_submit_bio(9) — go off, kernel docs ✨🫶