NAME

       probe::ioblock_trace.request - Fires just as a generic block I/O request is created for a bio.

SYNOPSIS

       ioblock_trace.request

VALUES

       bdev
           target block device

       bytes_done
           number of bytes transferred

       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.

       rw
           binary trace for read/write request

       q
           request queue on which this bio was queued.

       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

       size
           total size in bytes

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

       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

       sector
           beginning sector for the entire bio

       devname
           block device name

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

CONTEXT

       The process makes block I/O request

SEE ALSO

       tapset::ioblock(3stap)

SystemTap Tapset Reference                         March 2016                        PROBE::IOBLOCK_TRACE(3stap)