PROBE::IOBLOCK.END(3stap)

💅 PROBE::IOBLOCK.END — from the IO Scheduler and block IO Taps manual, bestie

okay so welcome to the 3stap girlies, this is probe::ioblock.end and she is THAT probe ✨

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✨ NAME ✨

probe::ioblock.end — fires whenever a block I/O transfer is complete. like, the moment it's DONE done. no cap 🎀

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🦋 SYNOPSIS 🦋

probe ioblock.end {}

that's it. that's the whole vibe. she takes no arguments, she's just there, serving 🌸

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💖 VALUES 💖

these are all the lil variables you get handed when this probe goes off. read them like a group chat, bestie 💅

• vcnt — the bio vector count, which is how many array elements (page, offset, length) go into making up this I/O request.
• ino — i-node number of the mapped file 👑
• bytes_done — number of bytes transferred. literally the receipts.
• name — name of the probe point.
• size — total size in bytes.
• phys_segments — number of segments in this bio after physical address coalescing has been performed.
• hw_segments — number of segments after physical and DMA remapping hardware coalescing has been performed.
• opf — operations and flags.
• rw — binary trace for read/write request.
• flags — see below, it's giving bitfield energy:
  • BIO_UPTODATE 0 — ok after I/O completion
  • BIO_RW_BLOCK 1 — RW_AHEAD set, and read/write would block
  • BIO_EOF 2 — out-out-bounds error
  • BIO_SEG_VALID 3 — nr_hw_seg valid
  • BIO_CLONED 4 — doesn't own data
  • BIO_BOUNCED 5 — bio is a bounce bio
  • BIO_USER_MAPPED 6 — contains user pages
  • BIO_EOPNOTSUPP 7 — not supported
• error — 0 on success 🫶
• sector — beginning sector for the entire bio.
• idx — offset into the bio vector array.
• devname — block device name.

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🌈 CONTEXT 🌈

The process signals the transfer is done. so when this probe fires, that's the energy you're in. periodt 💀

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🌸 SEE ALSO 🌸

• tapset::ioblock(3stap) — go read her sister page, iykyk

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and that's the whole page, bestie!! every flag, every value, every byte accounted for, we ate and left zero crumbs 👑

mwah 💖 this was the SystemTap Tapset Reference, version info stamped Ver September 2026, and the page signs off as PROBE::...OCK.END(3stap) — catch you on the next manpage, love u, bye 🎀✨🦋