Provided by: systemtap-doc_4.2-3ubuntu0.1_all 

NAME
probe::ioblock_trace.request - Fires just as a generic block I/O request is created for a bio.
SYNOPSIS
ioblock_trace.request
VALUES
devname
block device name
ino
i-node number of the mapped file
idx
offset into the bio vector array phys_segments - number of segments in this bio after physical
address coalescing is performed.
bytes_done
number of bytes transferred
size
total size in bytes
bdev
target block device
vcnt
bio vector count which represents number of array element (page, offset, length) which make up this
I/O request
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
p_start_sect
points to the start sector of the partition structure of the device
bdev_contains
points to the device object which contains the partition (when bio structure represents a partition)
q
request queue on which this bio was queued.
rw
binary trace for read/write request
sector
beginning sector for the entire bio
name
name of the probe point
opf
operations and flags
CONTEXT
The process makes block I/O request
SEE ALSO
tapset::ioblock(3stap)
SystemTap Tapset Reference November 2019 PROBE::IOBLOCK_TRACE(3stap)