---
name: "probe::ioblock.request"
section: "3stap"
platform: "linux"
package: "systemtap-doc"
version: "5.1-5"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/probe::ioblock.request"
---

# probe::ioblock.request(3stap)

Fires whenever making a generic block I/O request.

## NAME

probe::ioblock.request - Fires whenever making a generic block I/O request.

## SYNOPSIS

```
ioblock.request
```

## VALUES

*flags*

see below 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

*name*

name of the probe point

*vcnt*

bio vector count which represents number of array element (page, offset, length) which make up this I/O request

*size*

total size in bytes

*sector*

beginning sector for the entire bio

*bdev\_contains*

points to the device object which contains the partition (when bio structure represents a partition)

*idx*

offset into the bio vector array

*phys\_segments*

number of segments in this bio after physical address coalescing is performed

*opf*

operations and flags

*hw\_segments*

number of segments after physical and DMA remapping hardware coalescing is performed

*rw*

binary trace for read/write request

*ino*

i-node number of the mapped file

*p\_start\_sect*

points to the start sector of the partition structure of the device

*bdev*

target block device

*devname*

block device name

## CONTEXT

The process makes block I/O request

## SEE ALSO0

[*tapset::ioblock*(3stap)](/tapset::ioblock/3stap.md)