probe::ioblock_trace.request.3stap man page
probe::ioblock_trace.request — Fires just as a generic block I/O request is created for a bio.
target block device
number of bytes transferred
i-node number of the mapped file
offset into the bio vector array phys_segments - number of segments in this bio after physical address coalescing is performed.
binary trace for read/write request
request queue on which this bio was queued.
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
total size in bytes
points to the start sector of the partition structure of the device
name of the probe point
bio vector count which represents number of array element (page, offset, length) which make up this I/O request
beginning sector for the entire bio
block device name
points to the device object which contains the partition (when bio structure represents a partition)
The process makes block I/O request