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